Commit Graph

35694 Commits

Author SHA1 Message Date
Linus Torvalds
d635a69dd4 Networking updates for 5.11
Core:
 
  - support "prefer busy polling" NAPI operation mode, where we defer softirq
    for some time expecting applications to periodically busy poll
 
  - AF_XDP: improve efficiency by more batching and hindering
            the adjacency cache prefetcher
 
  - af_packet: make packet_fanout.arr size configurable up to 64K
 
  - tcp: optimize TCP zero copy receive in presence of partial or unaligned
         reads making zero copy a performance win for much smaller messages
 
  - XDP: add bulk APIs for returning / freeing frames
 
  - sched: support fragmenting IP packets as they come out of conntrack
 
  - net: allow virtual netdevs to forward UDP L4 and fraglist GSO skbs
 
 BPF:
 
  - BPF switch from crude rlimit-based to memcg-based memory accounting
 
  - BPF type format information for kernel modules and related tracing
    enhancements
 
  - BPF implement task local storage for BPF LSM
 
  - allow the FENTRY/FEXIT/RAW_TP tracing programs to use bpf_sk_storage
 
 Protocols:
 
  - mptcp: improve multiple xmit streams support, memory accounting and
           many smaller improvements
 
  - TLS: support CHACHA20-POLY1305 cipher
 
  - seg6: add support for SRv6 End.DT4/DT6 behavior
 
  - sctp: Implement RFC 6951: UDP Encapsulation of SCTP
 
  - ppp_generic: add ability to bridge channels directly
 
  - bridge: Connectivity Fault Management (CFM) support as is defined in
            IEEE 802.1Q section 12.14.
 
 Drivers:
 
  - mlx5: make use of the new auxiliary bus to organize the driver internals
 
  - mlx5: more accurate port TX timestamping support
 
  - mlxsw:
    - improve the efficiency of offloaded next hop updates by using
      the new nexthop object API
    - support blackhole nexthops
    - support IEEE 802.1ad (Q-in-Q) bridging
 
  - rtw88: major bluetooth co-existance improvements
 
  - iwlwifi: support new 6 GHz frequency band
 
  - ath11k: Fast Initial Link Setup (FILS)
 
  - mt7915: dual band concurrent (DBDC) support
 
  - net: ipa: add basic support for IPA v4.5
 
 Refactor:
 
  - a few pieces of in_interrupt() cleanup work from Sebastian Andrzej Siewior
 
  - phy: add support for shared interrupts; get rid of multiple driver
         APIs and have the drivers write a full IRQ handler, slight growth
 	of driver code should be compensated by the simpler API which
 	also allows shared IRQs
 
  - add common code for handling netdev per-cpu counters
 
  - move TX packet re-allocation from Ethernet switch tag drivers to
    a central place
 
  - improve efficiency and rename nla_strlcpy
 
  - number of W=1 warning cleanups as we now catch those in a patchwork
    build bot
 
 Old code removal:
 
  - wan: delete the DLCI / SDLA drivers
 
  - wimax: move to staging
 
  - wifi: remove old WDS wifi bridging support
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEE6jPA+I1ugmIBA4hXMUZtbf5SIrsFAl/YXmUACgkQMUZtbf5S
 IrvSQBAAgOrt4EFopEvVqlTHZbqI45IEqgtXS+YWmlgnjZCgshyMj8q1yK1zzane
 qYxr/NNJ9kV3FdtaynmmHPgEEEfR5kJ/D3B2BsxYDkaDDrD0vbNsBGw+L+/Gbhxl
 N/5l/9FjLyLY1D+EErknuwR5XGuQ6BSDVaKQMhYOiK2hgdnAAI4hszo8Chf6wdD0
 XDBslQ7vpD/05r+eMj0IkS5dSAoGOIFXUxhJ5dqrDbRHiKsIyWqA3PLbYemfAhxI
 s2XckjfmSgGE3FKL8PSFu+EcfHbJQQjLcULJUnqgVcdwEEtRuE9ggEi52nZRXMWM
 4e8sQJAR9Fx7pZy0G1xfS149j6iPU5LjRlU9TNSpVABz14Vvvo3gEL6gyIdsz+xh
 hMN7UBdp0FEaP028CXoIYpaBesvQqj0BSndmee8qsYAtN6j+QKcM2AOSr7JN1uMH
 C/86EDoGAATiEQIVWJvnX5MPmlAoblyLA+RuVhmxkIBx2InGXkFmWqRkXT5l4jtk
 LVl8/TArR4alSQqLXictXCjYlCm9j5N4zFFtEVasSYi7/ZoPfgRNWT+lJ2R8Y+Zv
 +htzGaFuyj6RJTVeFQMrkl3whAtBamo2a0kwg45NnxmmXcspN6kJX1WOIy82+MhD
 Yht7uplSs7MGKA78q/CDU0XBeGjpABUvmplUQBIfrR/jKLW2730=
 =GXs1
 -----END PGP SIGNATURE-----

Merge tag 'net-next-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from Jakub Kicinski:
 "Core:

   - support "prefer busy polling" NAPI operation mode, where we defer
     softirq for some time expecting applications to periodically busy
     poll

   - AF_XDP: improve efficiency by more batching and hindering the
     adjacency cache prefetcher

   - af_packet: make packet_fanout.arr size configurable up to 64K

   - tcp: optimize TCP zero copy receive in presence of partial or
     unaligned reads making zero copy a performance win for much smaller
     messages

   - XDP: add bulk APIs for returning / freeing frames

   - sched: support fragmenting IP packets as they come out of conntrack

   - net: allow virtual netdevs to forward UDP L4 and fraglist GSO skbs

  BPF:

   - BPF switch from crude rlimit-based to memcg-based memory accounting

   - BPF type format information for kernel modules and related tracing
     enhancements

   - BPF implement task local storage for BPF LSM

   - allow the FENTRY/FEXIT/RAW_TP tracing programs to use
     bpf_sk_storage

  Protocols:

   - mptcp: improve multiple xmit streams support, memory accounting and
     many smaller improvements

   - TLS: support CHACHA20-POLY1305 cipher

   - seg6: add support for SRv6 End.DT4/DT6 behavior

   - sctp: Implement RFC 6951: UDP Encapsulation of SCTP

   - ppp_generic: add ability to bridge channels directly

   - bridge: Connectivity Fault Management (CFM) support as is defined
     in IEEE 802.1Q section 12.14.

  Drivers:

   - mlx5: make use of the new auxiliary bus to organize the driver
     internals

   - mlx5: more accurate port TX timestamping support

   - mlxsw:
      - improve the efficiency of offloaded next hop updates by using
        the new nexthop object API
      - support blackhole nexthops
      - support IEEE 802.1ad (Q-in-Q) bridging

   - rtw88: major bluetooth co-existance improvements

   - iwlwifi: support new 6 GHz frequency band

   - ath11k: Fast Initial Link Setup (FILS)

   - mt7915: dual band concurrent (DBDC) support

   - net: ipa: add basic support for IPA v4.5

  Refactor:

   - a few pieces of in_interrupt() cleanup work from Sebastian Andrzej
     Siewior

   - phy: add support for shared interrupts; get rid of multiple driver
     APIs and have the drivers write a full IRQ handler, slight growth
     of driver code should be compensated by the simpler API which also
     allows shared IRQs

   - add common code for handling netdev per-cpu counters

   - move TX packet re-allocation from Ethernet switch tag drivers to a
     central place

   - improve efficiency and rename nla_strlcpy

   - number of W=1 warning cleanups as we now catch those in a patchwork
     build bot

  Old code removal:

   - wan: delete the DLCI / SDLA drivers

   - wimax: move to staging

   - wifi: remove old WDS wifi bridging support"

* tag 'net-next-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1922 commits)
  net: hns3: fix expression that is currently always true
  net: fix proc_fs init handling in af_packet and tls
  nfc: pn533: convert comma to semicolon
  af_vsock: Assign the vsock transport considering the vsock address flags
  af_vsock: Set VMADDR_FLAG_TO_HOST flag on the receive path
  vsock_addr: Check for supported flag values
  vm_sockets: Add VMADDR_FLAG_TO_HOST vsock flag
  vm_sockets: Add flags field in the vsock address data structure
  net: Disable NETIF_F_HW_TLS_TX when HW_CSUM is disabled
  tcp: Add logic to check for SYN w/ data in tcp_simple_retransmit
  net: mscc: ocelot: install MAC addresses in .ndo_set_rx_mode from process context
  nfc: s3fwrn5: Release the nfc firmware
  net: vxget: clean up sparse warnings
  mlxsw: spectrum_router: Use eXtended mezzanine to offload IPv4 router
  mlxsw: spectrum: Set KVH XLT cache mode for Spectrum2/3
  mlxsw: spectrum_router_xm: Introduce basic XM cache flushing
  mlxsw: reg: Add Router LPM Cache Enable Register
  mlxsw: reg: Add Router LPM Cache ML Delete Register
  mlxsw: spectrum_router_xm: Implement L-value tracking for M-index
  mlxsw: reg: Add XM Router M Table Register
  ...
2020-12-15 13:22:29 -08:00
Linus Torvalds
ac73e3dc8a Merge branch 'akpm' (patches from Andrew)
Merge misc updates from Andrew Morton:

 - a few random little subsystems

 - almost all of the MM patches which are staged ahead of linux-next
   material. I'll trickle to post-linux-next work in as the dependents
   get merged up.

Subsystems affected by this patch series: kthread, kbuild, ide, ntfs,
ocfs2, arch, and mm (slab-generic, slab, slub, dax, debug, pagecache,
gup, swap, shmem, memcg, pagemap, mremap, hmm, vmalloc, documentation,
kasan, pagealloc, memory-failure, hugetlb, vmscan, z3fold, compaction,
oom-kill, migration, cma, page-poison, userfaultfd, zswap, zsmalloc,
uaccess, zram, and cleanups).

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (200 commits)
  mm: cleanup kstrto*() usage
  mm: fix fall-through warnings for Clang
  mm: slub: convert sysfs sprintf family to sysfs_emit/sysfs_emit_at
  mm: shmem: convert shmem_enabled_show to use sysfs_emit_at
  mm:backing-dev: use sysfs_emit in macro defining functions
  mm: huge_memory: convert remaining use of sprintf to sysfs_emit and neatening
  mm: use sysfs_emit for struct kobject * uses
  mm: fix kernel-doc markups
  zram: break the strict dependency from lzo
  zram: add stat to gather incompressible pages since zram set up
  zram: support page writeback
  mm/process_vm_access: remove redundant initialization of iov_r
  mm/zsmalloc.c: rework the list_add code in insert_zspage()
  mm/zswap: move to use crypto_acomp API for hardware acceleration
  mm/zswap: fix passing zero to 'PTR_ERR' warning
  mm/zswap: make struct kernel_param_ops definitions const
  userfaultfd/selftests: hint the test runner on required privilege
  userfaultfd/selftests: fix retval check for userfaultfd_open()
  userfaultfd/selftests: always dump something in modes
  userfaultfd: selftests: make __{s,u}64 format specifiers portable
  ...
2020-12-15 12:53:37 -08:00
Vlastimil Babka
03b6c9a3e8 kernel/power: allow hibernation with page_poison sanity checking
Page poisoning used to be incompatible with hibernation, as the state of
poisoned pages was lost after resume, thus enabling CONFIG_HIBERNATION
forces CONFIG_PAGE_POISONING_NO_SANITY.  For the same reason, the
poisoning with zeroes variant CONFIG_PAGE_POISONING_ZERO used to disable
hibernation.  The latter restriction was removed by commit 1ad1410f63
("PM / Hibernate: allow hibernation with PAGE_POISONING_ZERO") and
similarly for init_on_free by commit 18451f9f9e ("PM: hibernate: fix
crashes with init_on_free=1") by making sure free pages are cleared after
resume.

We can use the same mechanism to instead poison free pages with
PAGE_POISON after resume.  This covers both zero and 0xAA patterns.  Thus
we can remove the Kconfig restriction that disables page poison sanity
checking when hibernation is enabled.

Link: https://lkml.kernel.org/r/20201113104033.22907-4-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>	[hibernation]
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Laura Abbott <labbott@kernel.org>
Cc: Mateusz Nosek <mateusznosek0@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 12:13:46 -08:00
Mike Rapoport
2abf962a8d PM: hibernate: make direct map manipulations more explicit
When DEBUG_PAGEALLOC or ARCH_HAS_SET_DIRECT_MAP is enabled a page may be
not present in the direct map and has to be explicitly mapped before it
could be copied.

Introduce hibernate_map_page() and hibernation_unmap_page() that will
explicitly use set_direct_map_{default,invalid}_noflush() for
ARCH_HAS_SET_DIRECT_MAP case and debug_pagealloc_{map,unmap}_pages() for
DEBUG_PAGEALLOC case.

The remapping of the pages in safe_copy_page() presumes that it only
changes protection bits in an existing PTE and so it is safe to ignore
return value of set_direct_map_{default,invalid}_noflush().

Still, add a pr_warn() so that future changes in set_memory APIs will not
silently break hibernation.

Link: https://lkml.kernel.org/r/20201109192128.960-3-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 12:13:43 -08:00
Walter Wu
e89a85d63f workqueue: kasan: record workqueue stack
Patch series "kasan: add workqueue stack for generic KASAN", v5.

Syzbot reports many UAF issues for workqueue, see [1].

In some of these access/allocation happened in process_one_work(), we
see the free stack is useless in KASAN report, it doesn't help
programmers to solve UAF for workqueue issue.

This patchset improves KASAN reports by making them to have workqueue
queueing stack.  It is useful for programmers to solve use-after-free or
double-free memory issue.

Generic KASAN also records the last two workqueue stacks and prints them
in KASAN report.  It is only suitable for generic KASAN.

[1] https://groups.google.com/g/syzkaller-bugs/search?q=%22use-after-free%22+process_one_work
[2] https://bugzilla.kernel.org/show_bug.cgi?id=198437

This patch (of 4):

When analyzing use-after-free or double-free issue, recording the
enqueuing work stacks is helpful to preserve usage history which
potentially gives a hint about the affected code.

For workqueue it has turned out to be useful to record the enqueuing work
call stacks.  Because user can see KASAN report to determine whether it is
root cause.  They don't need to enable debugobjects, but they have a
chance to find out the root cause.

Link: https://lkml.kernel.org/r/20201203022148.29754-1-walter-zh.wu@mediatek.com
Link: https://lkml.kernel.org/r/20201203022442.30006-1-walter-zh.wu@mediatek.com
Signed-off-by: Walter Wu <walter-zh.wu@mediatek.com>
Suggested-by: Marco Elver <elver@google.com>
Acked-by: Marco Elver <elver@google.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Marco Elver <elver@google.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 12:13:42 -08:00
John Hubbard
d3f5ffcacd mm: cleanup: remove unused tsk arg from __access_remote_vm
Despite a comment that said that page fault accounting would be charged to
whatever task_struct* was passed into __access_remote_vm(), the tsk
argument was actually unused.

Making page fault accounting actually use this task struct is quite a
project, so there is no point in keeping the tsk argument.

Delete both the comment, and the argument.

[rppt@linux.ibm.com: changelog addition]

Link: https://lkml.kernel.org/r/20201026074137.4147787-1-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 12:13:40 -08:00
Muchun Song
da3ceeff92 mm: memcg/slab: rename *_lruvec_slab_state to *_lruvec_kmem_state
The *_lruvec_slab_state is also suitable for pages allocated from buddy,
not just for the slab objects.  But the function name seems to tell us
that only slab object is applicable.  So we can rename the keyword of slab
to kmem.

Link: https://lkml.kernel.org/r/20201117085249.24319-1-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 12:13:40 -08:00
Roman Gushchin
9d9d341df4 cgroup: remove obsoleted broken_hierarchy and warned_broken_hierarchy
With the deprecation of the non-hierarchical mode of the memory controller
there are no more examples of broken hierarchies left.

Let's remove the cgroup core code which was supposed to print warnings
about creating of broken hierarchies.

Link: https://lkml.kernel.org/r/20201110220800.929549-4-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 12:13:40 -08:00
Roman Gushchin
bef8620cd8 mm: memcg: deprecate the non-hierarchical mode
Patch series "mm: memcg: deprecate cgroup v1 non-hierarchical mode", v1.

The non-hierarchical cgroup v1 mode is a legacy of early days
of the memory controller and doesn't bring any value today.
However, it complicates the code and creates many edge cases
all over the memory controller code.

It's a good time to deprecate it completely. This patchset removes
the internal logic, adjusts the user interface and updates
the documentation. The alt patch removes some bits of the cgroup
core code, which become obsolete.

Michal Hocko said:
  "All that we know today is that we have a warning in place to complain
   loudly when somebody relies on use_hierarchy=0 with a deeper
   hierarchy. For all those years we have seen _zero_ reports that would
   describe a sensible usecase.

   Moreover we (SUSE) have backported this warning into old distribution
   kernels (since 3.0 based kernels) to extend the coverage and didn't
   hear even for users who adopt new kernels only very slowly. The only
   report we have seen so far was a LTP test suite which doesn't really
   reflect any real life usecase"

This patch (of 3):

The non-hierarchical cgroup v1 mode is a legacy of early days of the
memory controller and doesn't bring any value today.  However, it
complicates the code and creates many edge cases all over the memory
controller code.

It's a good time to deprecate it completely.

Functionally this patch enabled is by default for all cgroups and forbids
switching it off.  Nothing changes if cgroup v2 is used: hierarchical mode
was enforced from scratch.

To protect the ABI memory.use_hierarchy interface is preserved with a
limited functionality: reading always returns "1", writing of "1" passes
silently, writing of any other value fails with -EINVAL and a warning to
dmesg (on the first occasion).

Link: https://lkml.kernel.org/r/20201110220800.929549-1-guro@fb.com
Link: https://lkml.kernel.org/r/20201110220800.929549-2-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 12:13:40 -08:00
Jason Gunthorpe
57efa1fe59 mm/gup: prevent gup_fast from racing with COW during fork
Since commit 70e806e4e6 ("mm: Do early cow for pinned pages during
fork() for ptes") pages under a FOLL_PIN will not be write protected
during COW for fork.  This means that pages returned from
pin_user_pages(FOLL_WRITE) should not become write protected while the pin
is active.

However, there is a small race where get_user_pages_fast(FOLL_PIN) can
establish a FOLL_PIN at the same time copy_present_page() is write
protecting it:

        CPU 0                             CPU 1
   get_user_pages_fast()
    internal_get_user_pages_fast()
                                       copy_page_range()
                                         pte_alloc_map_lock()
                                           copy_present_page()
                                             atomic_read(has_pinned) == 0
					     page_maybe_dma_pinned() == false
     atomic_set(has_pinned, 1);
     gup_pgd_range()
      gup_pte_range()
       pte_t pte = gup_get_pte(ptep)
       pte_access_permitted(pte)
       try_grab_compound_head()
                                             pte = pte_wrprotect(pte)
	                                     set_pte_at();
                                         pte_unmap_unlock()
      // GUP now returns with a write protected page

The first attempt to resolve this by using the write protect caused
problems (and was missing a barrrier), see commit f3c64eda3e ("mm: avoid
early COW write protect games during fork()")

Instead wrap copy_p4d_range() with the write side of a seqcount and check
the read side around gup_pgd_range().  If there is a collision then
get_user_pages_fast() fails and falls back to slow GUP.

Slow GUP is safe against this race because copy_page_range() is only
called while holding the exclusive side of the mmap_lock on the src
mm_struct.

[akpm@linux-foundation.org: coding style fixes]
  Link: https://lore.kernel.org/r/CAHk-=wi=iCnYCARbPGjkVJu9eyYeZ13N64tZYLdOB8CP5Q_PLw@mail.gmail.com

Link: https://lkml.kernel.org/r/2-v4-908497cf359a+4782-gup_fork_jgg@nvidia.com
Fixes: f3c64eda3e ("mm: avoid early COW write protect games during fork()")
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Peter Xu <peterx@redhat.com>
Acked-by: "Ahmed S. Darwish" <a.darwish@linutronix.de>	[seqcount_t parts]
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Kirill Shutemov <kirill@shutemov.name>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Leon Romanovsky <leonro@nvidia.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 12:13:39 -08:00
Petr Mladek
ebb2bdcef8 kthread_worker: document CPU hotplug handling
The kthread worker API is simple.  In short, it allows to create, use, and
destroy workers.  kthread_create_worker_on_cpu() just allows to bind a
newly created worker to a given CPU.

It is up to the API user how to handle CPU hotplug.  They have to decide
how to handle pending work items, prevent queuing new ones, and restore
the functionality when the CPU goes off and on.  There are few catches:

   + The CPU affinity gets lost when it is scheduled on an offline CPU.

   + The worker might not exist when the CPU was off when the user
     created the workers.

A good practice is to implement two CPU hotplug callbacks and
destroy/create the worker when CPU goes down/up.

Mention this in the function description.

[akpm@linux-foundation.org: grammar tweaks]

Link: https://lore.kernel.org/r/20201028073031.4536-1-qiang.zhang@windriver.com
Link: https://lkml.kernel.org/r/20201102101039.19227-1-pmladek@suse.com
Reported-by: Zhang Qiang <Qiang.Zhang@windriver.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 12:13:36 -08:00
Rob Clark
f630c7c6f1 kthread: add kthread_work tracepoints
While migrating some code from wq to kthread_worker, I found that I missed
the execute_start/end tracepoints.  So add similar tracepoints for
kthread_work.  And for completeness, queue_work tracepoint (although this
one differs slightly from the matching workqueue tracepoint).

Link: https://lkml.kernel.org/r/20201010180323.126634-1-robdclark@gmail.com
Signed-off-by: Rob Clark <robdclark@chromium.org>
Cc: Rob Clark <robdclark@chromium.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Phil Auld <pauld@redhat.com>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: Thara Gopinath <thara.gopinath@linaro.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Vincent Donnefort <vincent.donnefort@arm.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Ilias Stamatis <stamatis.iliass@gmail.com>
Cc: Liang Chen <cl@rock-chips.com>
Cc: Ben Dooks <ben.dooks@codethink.co.uk>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: "J. Bruce Fields" <bfields@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 12:13:36 -08:00
Rafael J. Wysocki
ee2cc4276b cpufreq: Add special-purpose fast-switching callback for drivers
First off, some cpufreq drivers (eg. intel_pstate) can pass hints
beyond the current target frequency to the hardware and there are no
provisions for doing that in the cpufreq framework.  In particular,
today the driver has to assume that it should not allow the frequency
to fall below the one requested by the governor (or the required
capacity may not be provided) which may not be the case and which may
lead to excessive energy usage in some scenarios.

Second, the hints passed by these drivers to the hardware need not be
in terms of the frequency, so representing the utilization numbers
coming from the scheduler as frequency before passing them to those
drivers is not really useful.

Address the two points above by adding a special-purpose replacement
for the ->fast_switch callback, called ->adjust_perf, allowing the
governor to pass abstract performance level (rather than frequency)
values for the minimum (required) and target (desired) performance
along with the CPU capacity to compare them to.

Also update the schedutil governor to use the new callback instead
of ->fast_switch if present and if the utilization mertics are
frequency-invariant (that is requisite for the direct mapping
between the utilization and the CPU performance levels to be a
reasonable approximation).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-12-15 19:24:18 +01:00
Rafael J. Wysocki
ca6827de4b cpufreq: schedutil: Add util to struct sg_cpu
Instead of passing util and max between functions while computing the
utilization and capacity, store the former in struct sg_cpu (along
with the latter and bw_dl).

This will allow the current utilization value to be compared with the
one obtained previously (which is requisite for some code changes to
follow this one), but also it causes the code to look slightly more
consistent and cleaner.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-12-15 19:24:18 +01:00
Paolo Bonzini
722e039d9a KVM/arm64 updates for Linux 5.11
- PSCI relay at EL2 when "protected KVM" is enabled
 - New exception injection code
 - Simplification of AArch32 system register handling
 - Fix PMU accesses when no PMU is enabled
 - Expose CSV3 on non-Meltdown hosts
 - Cache hierarchy discovery fixes
 - PV steal-time cleanups
 - Allow function pointers at EL2
 - Various host EL2 entry cleanups
 - Simplification of the EL2 vector allocation
 -----BEGIN PGP SIGNATURE-----
 
 iQJDBAABCgAtFiEEn9UcU+C1Yxj9lZw9I9DQutE9ekMFAl/XoggPHG1hekBrZXJu
 ZWwub3JnAAoJECPQ0LrRPXpDsRYP/3ZtGWsyBc1sKdaTBIwQdnrPQHL+7o1Mmjnl
 b+YqRMWcJW4g3O81GW6IA+vM0A1UMJxVOjzkZd8KulGv3RCZiqQmWJClWFlYbwLj
 e+HHx+Zo/qsmDrwcVoFI8/n+iC/a5fIaCbSWMSPaKHrOMxBiHQk0qlaq4AZ8gb7a
 /eHYqI/hISJQb1ZVFHmwlp8FoMnB2M6/FDpCf8oeGKjpF2hjghIPugJ0oRlPLZjB
 o3Q6ELEScJV1wBy7d1+5rkm52t9j8gpGhXxja0QwypADNzk5KHEzghXq+rTWUh1S
 et9OfqkflMtKMsh0qNwe5ZFbqtsH69qtYMAj4ok7rZOwQcbJ97VSrP5ka7VVzSdC
 AgcQU9c9LoyQ7rk0dbs3t0cd8hMgVu50guZ/iHfW88CcdykN9M0nnSPRAYpNbW85
 xndBQ5k/a4FoufwoY4e0hS28HIiRfLoEA68mps+yoMiiKh27HO2v4GFRIJoCNxzp
 YQ01zOBp9FKYTsxj0h7mMf+5EEyo9E4X/kJOfZpOVVbVKy82wPAGLJpDEnbnoJUe
 j1jBmiV/trkn+nTnWmDoXcw2ljuIF9dBm2M8r8yGKdNEHptnN8tMVRlCRImVVWW0
 BbZGAzoK0tpKXPIlUh4aXS3mtV9qlohs9rzjVyKfGnaRRbRGANM8qrH5aKuDFinM
 RugpMWyk
 =hf4L
 -----END PGP SIGNATURE-----

Merge tag 'kvmarm-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 updates for Linux 5.11

- PSCI relay at EL2 when "protected KVM" is enabled
- New exception injection code
- Simplification of AArch32 system register handling
- Fix PMU accesses when no PMU is enabled
- Expose CSV3 on non-Meltdown hosts
- Cache hierarchy discovery fixes
- PV steal-time cleanups
- Allow function pointers at EL2
- Various host EL2 entry cleanups
- Simplification of the EL2 vector allocation
2020-12-15 12:48:24 -05:00
Thomas Gleixner
64a1b95bb9 genirq: Restrict export of irq_to_desc()
No more (ab)use in drivers finally. There is still the modular build of
PPC/KVM which needs it, so restrict it to this case which still makes it
unavailable for most drivers.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201210194045.551428291@linutronix.de
2020-12-15 16:19:38 +01:00
Thomas Gleixner
501e2db67f genirq: Provide kstat_irqdesc_cpu()
Most users of kstat_irqs_cpu() have the irq descriptor already. No point in
calling into the core code and looking it up once more.

Use it in per_cpu_count_show() to start with.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201210194043.362094758@linutronix.de
2020-12-15 16:19:31 +01:00
Thomas Gleixner
26c19d0a86 genirq: Make kstat_irqs() static
No more users outside the core code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201210194043.268774449@linutronix.de
2020-12-15 16:19:31 +01:00
Thomas Gleixner
9e42ad10ce genirq: Annotate irq stats data races
Both the per cpu stats and the accumulated count are accessed lockless and
can be concurrently modified. That's intentional and the stats are a rough
estimate anyway. Annotate them with data_race().

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201210194043.067097663@linutronix.de
2020-12-15 16:19:30 +01:00
Thomas Gleixner
f1c6306c0d genirq: Move irq_set_lockdep_class() to core
irq_set_lockdep_class() is used from modules and requires irq_to_desc() to
be exported. Move it into the core code which lifts another requirement for
the export.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201210194042.860029489@linutronix.de
2020-12-15 16:19:30 +01:00
Thomas Gleixner
fdd0296304 genirq: Move status flag checks to core
These checks are used by modules and prevent the removal of the export of
irq_to_desc(). Move the accessor into the core.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201210194042.703779349@linutronix.de
2020-12-15 16:19:30 +01:00
Thomas Gleixner
a313357e70 genirq: Move irq_has_action() into core code
This function uses irq_to_desc() and is going to be used by modules to
replace the open coded irq_to_desc() (ab)usage. The final goal is to remove
the export of irq_to_desc() so driver cannot fiddle with it anymore.

Move it into the core code and fixup the usage sites to include the proper
header.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201210194042.548936472@linutronix.de
2020-12-15 16:19:30 +01:00
Rafael J. Wysocki
5e2cde03da Merge branches 'acpi-resources' and 'acpi-docs'
* acpi-resources:
  Revert "ACPI / resources: Use AE_CTRL_TERMINATE to terminate resources walks"
  resource: provide meaningful MODULE_LICENSE() in test suite
  ASoC: Intel: catpt: Replace open coded variant of resource_intersection()
  ACPI: watchdog: Replace open coded variant of resource_union()
  PCI/ACPI: Replace open coded variant of resource_union()
  resource: Add test cases for new resource API
  resource: Introduce resource_intersection() for overlapping resources
  resource: Introduce resource_union() for overlapping resources
  resource: Group resource_overlaps() with other inline helpers
  resource: Simplify region_intersects() by reducing conditionals

* acpi-docs:
  Documentation: ACPI: enumeration: add PCI hierarchy representation
  Documentation: ACPI: _DSD: enable hyperlink in final references
  Documentation: ACPI: explain how to use gpio-line-names
2020-12-15 15:30:03 +01:00
Steven Rostedt (VMware)
f6a694665f tracing: Offload eval map updates to a work queue
In order for tracepoints to export their enums to user space, the use of the
TRACE_DEFINE_ENUM() macro is used. On boot up, the strings shown in the
tracefs "print fmt" lines are processed, and all the enums registered by
TRACE_DEFINE_ENUM are replaced with the interger value. This way, userspace
tools that read the raw binary data, knows how to evaluate the raw events.

This is currently done in an initcall, but it has been noticed that slow
embedded boards that have tracing may take a few seconds to process them
all, and a few seconds slow down on an embedded device is detrimental to the
system.

Instead, offload the work to a work queue and make sure that its finished by
destroying the work queue (which flushes all work) in a late initcall. This
will allow the system to continue to boot and run the updates in the
background, and this speeds up the boot time. Note, the strings being
updated are only used by user space, so finishing the process before the
system is fully booted will prevent any race issues.

Link: https://lore.kernel.org/r/68d7b3327052757d0cd6359a6c9015a85b437232.camel@pengutronix.de

Reported-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-12-15 09:29:14 -05:00
Rafael J. Wysocki
42b4ca04cb Merge branches 'pm-sleep', 'pm-acpi', 'pm-domains' and 'powercap'
* pm-sleep:
  PM: sleep: Add dev_wakeup_path() helper
  PM / suspend: fix kernel-doc markup
  PM: sleep: Print driver flags for all devices during suspend/resume

* pm-acpi:
  PM: ACPI: Refresh wakeup device power configuration every time
  PM: ACPI: PCI: Drop acpi_pm_set_bridge_wakeup()
  PM: ACPI: reboot: Use S5 for reboot

* pm-domains:
  PM: domains: create debugfs nodes when adding power domains
  PM: domains: replace -ENOTSUPP with -EOPNOTSUPP

* powercap:
  powercap: Adjust printing the constraint name with new line
  powercap: RAPL: Add AMD Fam19h RAPL support
  powercap: Add AMD Fam17h RAPL support
  powercap/intel_rapl_msr: Convert rapl_msr_priv into pointer
  x86/msr-index: sort AMD RAPL MSRs by address
2020-12-15 15:26:14 +01:00
Rafael J. Wysocki
4c5744a0c4 Merge branches 'pm-cpuidle' and 'pm-em'
* pm-cpuidle:
  cpuidle: Select polling interval based on a c-state with a longer target residency
  cpuidle: psci: Enable suspend-to-idle for PSCI OSI mode
  PM: domains: Enable dev_pm_genpd_suspend|resume() for suspend-to-idle
  PM: domains: Rename pm_genpd_syscore_poweroff|poweron()

* pm-em:
  PM / EM: Micro optimization in em_cpu_energy
  PM: EM: Update Energy Model with new flag indicating power scale
  PM: EM: update the comments related to power scale
  PM: EM: Clarify abstract scale usage for power values in Energy Model
2020-12-15 15:25:37 +01:00
Rafael J. Wysocki
e1f1320fc0 Merge branch 'pm-cpufreq'
* pm-cpufreq: (31 commits)
  cpufreq: Fix cpufreq_online() return value on errors
  cpufreq: Fix up several kerneldoc comments
  cpufreq: stats: Use local_clock() instead of jiffies
  cpufreq: schedutil: Simplify sugov_update_next_freq()
  cpufreq: intel_pstate: Simplify intel_cpufreq_update_pstate()
  cpufreq: arm_scmi: Discover the power scale in performance protocol
  firmware: arm_scmi: Add power_scale_mw_get() interface
  cpufreq: tegra194: Rename tegra194_get_speed_common function
  cpufreq: tegra194: Remove unnecessary frequency calculation
  cpufreq: tegra186: Simplify cluster information lookup
  cpufreq: tegra186: Fix sparse 'incorrect type in assignment' warning
  cpufreq: imx: fix NVMEM_IMX_OCOTP dependency
  cpufreq: vexpress-spc: Add missing MODULE_ALIAS
  cpufreq: scpi: Add missing MODULE_ALIAS
  cpufreq: loongson1: Add missing MODULE_ALIAS
  cpufreq: sun50i: Add missing MODULE_DEVICE_TABLE
  cpufreq: st: Add missing MODULE_DEVICE_TABLE
  cpufreq: qcom: Add missing MODULE_DEVICE_TABLE
  cpufreq: mediatek: Add missing MODULE_DEVICE_TABLE
  cpufreq: highbank: Add missing MODULE_DEVICE_TABLE
  ...
2020-12-15 15:24:52 +01:00
Peter Zijlstra
ae79270232 sched: Optimize finish_lock_switch()
The kernel test robot measured a -1.6% performance regression on
will-it-scale/sched_yield due to commit:

  2558aacff8 ("sched/hotplug: Ensure only per-cpu kthreads run during hotplug")

Even though we were careful to replace a single load with another
single load from the same cacheline.

Restore finish_lock_switch() to the exact state before the offending
patch and solve the problem differently.

Fixes: 2558aacff8 ("sched/hotplug: Ensure only per-cpu kthreads run during hotplug")
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201210161408.GX3021@hirez.programming.kicks-ass.net
2020-12-15 11:27:53 +01:00
Thomas Gleixner
3c41e57a1e irqchip updates for Linux 5.11
- Preliminary support for managed interrupts on platform devices
 - Correctly identify allocation of MSIs proxyied by another device
 - Remove the fasteoi IPI flow which has been proved useless
 - Generalise the Ocelot support to new SoCs
 - Improve GICv4.1 vcpu entry, matching the corresponding KVM optimisation
 - Work around spurious interrupts on Qualcomm PDC
 - Random fixes and cleanups
 -----BEGIN PGP SIGNATURE-----
 
 iQJDBAABCgAtFiEEn9UcU+C1Yxj9lZw9I9DQutE9ekMFAl/Uxq8PHG1hekBrZXJu
 ZWwub3JnAAoJECPQ0LrRPXpDoW0P/0ZMDvFPxrfnJD46exUgUOPuuFF8jZxAlxD8
 7UExqar7u6yX7bbq394jPgtOOxldDagfCx/jCXgb9ja7DK5EHKRcrfjaDT8knHi2
 Keg5RaRMRi9TVltvWQTxAkXwSv0Atl881qqsndPeZCez0GNZp+HB34s+rNkZwBOu
 MBrWihMQOSv5QE6milsNc7HXLSHM1eLZ7Y2XgumNtKrIGEX9yZI7qwdMofwP8Za3
 ayMOvc1WAWaTJI7Mg5ac1yTCVbqLmRHhCtws6c6DMgaRu6SI0itmbpQzkDuJJIe3
 k9h4KQPaKAFcQsoo3GV0MKTMm63eq82XT3CAdv+htYRY1z95D2+nzNK+mJtsGptX
 gJ2zeJkUb4u+yVtNguL9qjo5ssCXV/6IybJxv6baaEFnSwQMUwqa066NdxmtqfIe
 1BOWnc153a7SRbQ34M9/llje+v8YJbueGMS2RFR2LQ6IjjpaHsXh+YCZokfA/kdk
 zGbOUD5WWFtFD1T3UoaJ4gFt+pzHjNqym4CcEj4S1Vf5y+POUkNmC+GYK+xfm2Fp
 WJMbdIUxJhHFRD9L1ShtfAVUSbp712VOOdILp9rYAkOdqfb51BVUiMUP++s2dGp1
 ZIT78qt7kTKT1CxbDdFAjzsi7RoMqdSGYgKmG4sVprELeZnFwq47nBkBr8XEQ1TT
 0ccEUOY8
 =7Z24
 -----END PGP SIGNATURE-----

Merge tag 'irqchip-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core

Pull irqchip updates for 5.11 from Marc Zyngier:

  - Preliminary support for managed interrupts on platform devices
  - Correctly identify allocation of MSIs proxyied by another device
  - Remove the fasteoi IPI flow which has been proved useless
  - Generalise the Ocelot support to new SoCs
  - Improve GICv4.1 vcpu entry, matching the corresponding KVM optimisation
  - Work around spurious interrupts on Qualcomm PDC
  - Random fixes and cleanups

Link: https://lore.kernel.org/r/20201212135626.1479884-1-maz@kernel.org
2020-12-15 10:48:07 +01:00
Linus Torvalds
148842c98a Yet another large set of x86 interrupt management updates:
- Simplification and distangling of the MSI related functionality
 
    - Let IO/APIC construct the RTE entries from an MSI message instead of
      having IO/APIC specific code in the interrupt remapping drivers
 
    - Make the retrieval of the parent interrupt domain (vector or remap
      unit) less hardcoded and use the relevant irqdomain callbacks for
      selection.
 
    - Allow the handling of more than 255 CPUs without a virtualized IOMMU
      when the hypervisor supports it. This has made been possible by the
      above modifications and also simplifies the existing workaround in the
      HyperV specific virtual IOMMU.
 
    - Cleanup of the historical timer_works() irq flags related
      inconsistencies.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAl/Xxd8THHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYoYpOD/9C5TppNlPMUyx2SflH6bxt37pJEpln
 +hYTKsk+jSThntr5mfj+GifGvgmHOVBTGnlDUnUnrpN7TQmLFBzwTOtnBLW53AO2
 16/u0+Xci4LNCtEkaymf0Rq4MfsfriXHPJr0A/CnZ0tpHSf5QKHAiitSiGujdMlb
 gbq43+zXd+jNkH7vkOLPX/7dZVI1hNASQEevJu2tRR4xYTuXFdBxvLgYkHtYKKrK
 R1sbs6nI6yIzye2u4m4xGu29SxgUft+zdUf+UehJKM3yFmf51d9qpkX+kLaTWuaL
 VPsMItbn0kdvxwXQWO6DYnIAAnVKCklyHQJTZCoNq9Fe91OoByak1CEVspSOa1av
 JmycNSch4IYWasR4vVCB1gbb+V9SejcKu5SV3CDrEDqwkOIpfiqpriUXSCJTLlFd
 QOEDOLuuk/79Qs//J/tb/nJ4IuKv8WPudDfIlMro8wUsAr67DjD4mnXprZ+svwWx
 Ct/0/Memk+BSa0cw6pvg24BUZGN6zrufkBu2HKT9GOXRUdNkdLkiPhT8mK4T/O0l
 f90QCLjPSOJ/K/pLEWdUHEPmgC5Q9RsXOmwVGqX+RbjfP7mYTJXlmWnBb+cFNch0
 xFIH3SxVGylxxT06NX3SkvinrHj10CoAlmneefBlLtx6dF+2P84DAMZSF0OFToVI
 c2KMg5zoesI4bg==
 =8Gfs
 -----END PGP SIGNATURE-----

Merge tag 'x86-apic-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 apic updates from Thomas Gleixner:
 "Yet another large set of x86 interrupt management updates:

   - Simplification and distangling of the MSI related functionality

   - Let IO/APIC construct the RTE entries from an MSI message instead
     of having IO/APIC specific code in the interrupt remapping drivers

   - Make the retrieval of the parent interrupt domain (vector or remap
     unit) less hardcoded and use the relevant irqdomain callbacks for
     selection.

   - Allow the handling of more than 255 CPUs without a virtualized
     IOMMU when the hypervisor supports it. This has made been possible
     by the above modifications and also simplifies the existing
     workaround in the HyperV specific virtual IOMMU.

   - Cleanup of the historical timer_works() irq flags related
     inconsistencies"

* tag 'x86-apic-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (42 commits)
  x86/ioapic: Cleanup the timer_works() irqflags mess
  iommu/hyper-v: Remove I/O-APIC ID check from hyperv_irq_remapping_select()
  iommu/amd: Fix IOMMU interrupt generation in X2APIC mode
  iommu/amd: Don't register interrupt remapping irqdomain when IR is disabled
  iommu/amd: Fix union of bitfields in intcapxt support
  x86/ioapic: Correct the PCI/ISA trigger type selection
  x86/ioapic: Use I/O-APIC ID for finding irqdomain, not index
  x86/hyperv: Enable 15-bit APIC ID if the hypervisor supports it
  x86/kvm: Enable 15-bit extension when KVM_FEATURE_MSI_EXT_DEST_ID detected
  iommu/hyper-v: Disable IRQ pseudo-remapping if 15 bit APIC IDs are available
  x86/apic: Support 15 bits of APIC ID in MSI where available
  x86/ioapic: Handle Extended Destination ID field in RTE
  iommu/vt-d: Simplify intel_irq_remapping_select()
  x86: Kill all traces of irq_remapping_get_irq_domain()
  x86/ioapic: Use irq_find_matching_fwspec() to find remapping irqdomain
  x86/hpet: Use irq_find_matching_fwspec() to find remapping irqdomain
  iommu/hyper-v: Implement select() method on remapping irqdomain
  iommu/vt-d: Implement select() method on remapping irqdomain
  iommu/amd: Implement select() method on remapping irqdomain
  x86/apic: Add select() method on vector irqdomain
  ...
2020-12-14 18:59:53 -08:00
Linus Torvalds
edd7ab7684 The new preemtible kmap_local() implementation:
- Consolidate all kmap_atomic() internals into a generic implementation
     which builds the base for the kmap_local() API and make the
     kmap_atomic() interface wrappers which handle the disabling/enabling of
     preemption and pagefaults.
 
   - Switch the storage from per-CPU to per task and provide scheduler
     support for clearing mapping when scheduling out and restoring them
     when scheduling back in.
 
   - Merge the migrate_disable/enable() code, which is also part of the
     scheduler pull request. This was required to make the kmap_local()
     interface available which does not disable preemption when a mapping
     is established. It has to disable migration instead to guarantee that
     the virtual address of the mapped slot is the same accross preemption.
 
   - Provide better debug facilities: guard pages and enforced utilization
     of the mapping mechanics on 64bit systems when the architecture allows
     it.
 
   - Provide the new kmap_local() API which can now be used to cleanup the
     kmap_atomic() usage sites all over the place. Most of the usage sites
     do not require the implicit disabling of preemption and pagefaults so
     the penalty on 64bit and 32bit non-highmem systems is removed and quite
     some of the code can be simplified. A wholesale conversion is not
     possible because some usage depends on the implicit side effects and
     some need to be cleaned up because they work around these side effects.
 
     The migrate disable side effect is only effective on highmem systems
     and when enforced debugging is enabled. On 64bit and 32bit non-highmem
     systems the overhead is completely avoided.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAl/XyQwTHHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYoUolD/9+R+BX96fGir+I8rG9dc3cbLw5meSi
 0I/Nq3PToZMs2Iqv50DsoaPYHHz/M6fcAO9LRIgsE9jRbnY93GnsBM0wU9Y8yQaT
 4wUzOG5WHaLDfqIkx/CN9coUl458oEiwOEbn79A2FmPXFzr7IpkufnV3ybGDwzwP
 p73bjMJMPPFrsa9ig87YiYfV/5IAZHi82PN8Cq1v4yNzgXRP3Tg6QoAuCO84ZnWF
 RYlrfKjcJ2xPdn+RuYyXolPtxr1hJQ0bOUpe4xu/UfeZjxZ7i1wtwLN9kWZe8CKH
 +x4Lz8HZZ5QMTQ9sCHOLtKzu2MceMcpISzoQH4/aFQCNMgLn1zLbS790XkYiQCuR
 ne9Cua+IqgYfGMG8cq8+bkU9HCNKaXqIBgPEKE/iHYVmqzCOqhW5Cogu4KFekf6V
 Wi7pyyUdX2en8BAWpk5NHc8de9cGcc+HXMq2NIcgXjVWvPaqRP6DeITERTZLJOmz
 XPxq5oPLGl7wdm7z+ICIaNApy8zuxpzb6sPLNcn7l5OeorViORlUu08AN8587wAj
 FiVjp6ZYomg+gyMkiNkDqFOGDH5TMENpOFoB0hNNEyJwwS0xh6CgWuwZcv+N8aPO
 HuS/P+tNANbD8ggT4UparXYce7YCtgOf3IG4GA3JJYvYmJ6pU+AZOWRoDScWq4o+
 +jlfoJhMbtx5Gg==
 =n71I
 -----END PGP SIGNATURE-----

Merge tag 'core-mm-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull kmap updates from Thomas Gleixner:
 "The new preemtible kmap_local() implementation:

   - Consolidate all kmap_atomic() internals into a generic
     implementation which builds the base for the kmap_local() API and
     make the kmap_atomic() interface wrappers which handle the
     disabling/enabling of preemption and pagefaults.

   - Switch the storage from per-CPU to per task and provide scheduler
     support for clearing mapping when scheduling out and restoring them
     when scheduling back in.

   - Merge the migrate_disable/enable() code, which is also part of the
     scheduler pull request. This was required to make the kmap_local()
     interface available which does not disable preemption when a
     mapping is established. It has to disable migration instead to
     guarantee that the virtual address of the mapped slot is the same
     across preemption.

   - Provide better debug facilities: guard pages and enforced
     utilization of the mapping mechanics on 64bit systems when the
     architecture allows it.

   - Provide the new kmap_local() API which can now be used to cleanup
     the kmap_atomic() usage sites all over the place. Most of the usage
     sites do not require the implicit disabling of preemption and
     pagefaults so the penalty on 64bit and 32bit non-highmem systems is
     removed and quite some of the code can be simplified. A wholesale
     conversion is not possible because some usage depends on the
     implicit side effects and some need to be cleaned up because they
     work around these side effects.

     The migrate disable side effect is only effective on highmem
     systems and when enforced debugging is enabled. On 64bit and 32bit
     non-highmem systems the overhead is completely avoided"

* tag 'core-mm-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits)
  ARM: highmem: Fix cache_is_vivt() reference
  x86/crashdump/32: Simplify copy_oldmem_page()
  io-mapping: Provide iomap_local variant
  mm/highmem: Provide kmap_local*
  sched: highmem: Store local kmaps in task struct
  x86: Support kmap_local() forced debugging
  mm/highmem: Provide CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP
  mm/highmem: Provide and use CONFIG_DEBUG_KMAP_LOCAL
  microblaze/mm/highmem: Add dropped #ifdef back
  xtensa/mm/highmem: Make generic kmap_atomic() work correctly
  mm/highmem: Take kmap_high_get() properly into account
  highmem: High implementation details and document API
  Documentation/io-mapping: Remove outdated blurb
  io-mapping: Cleanup atomic iomap
  mm/highmem: Remove the old kmap_atomic cruft
  highmem: Get rid of kmap_types.h
  xtensa/mm/highmem: Switch to generic kmap atomic
  sparc/mm/highmem: Switch to generic kmap atomic
  powerpc/mm/highmem: Switch to generic kmap atomic
  nds32/mm/highmem: Switch to generic kmap atomic
  ...
2020-12-14 18:35:53 -08:00
Linus Torvalds
adb35e8dc9 Scheduler updates:
- migrate_disable/enable() support which originates from the RT tree and
    is now a prerequisite for the new preemptible kmap_local() API which aims
    to replace kmap_atomic().
 
  - A fair amount of topology and NUMA related improvements
 
  - Improvements for the frequency invariant calculations
 
  - Enhanced robustness for the global CPU priority tracking and decision
    making
 
  - The usual small fixes and enhancements all over the place
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAl/XwK4THHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYoX28D/9cVrvziSQGfBfuQWnUiw8iOIq1QBa2
 Me+Tvenhfrlt7xU6rbP9ciFu7eTN+fS06m5uQPGI+t22WuJmHzbmw1bJVXfkvYfI
 /QoU+Hg7DkDAn1p7ZKXh0dRkV0nI9ixxSHl0E+Zf1ATBxCUMV2SO85flg6z/4qJq
 3VWUye0dmR7/bhtkIjv5rwce9v2JB2g1AbgYXYTW9lHVoUdGoMSdiZAF4tGyHLnx
 sJ6DMqQ+k+dmPyYO0z5MTzjW/fXit4n9w2e3z9TvRH/uBu58WSW1RBmQYX6aHBAg
 dhT9F4lvTs6lJY23x5RSFWDOv6xAvKF5a0xfb8UZcyH5EoLYrPRvm42a0BbjdeRa
 u0z7LbwIlKA+RFdZzFZWz8UvvO0ljyMjmiuqZnZ5dY9Cd80LSBuxrWeQYG0qg6lR
 Y2povhhCepEG+q8AXIe2YjHKWKKC1s/l/VY3CNnCzcd21JPQjQ4Z5eWGmHif5IED
 CntaeFFhZadR3w02tkX35zFmY3w4soKKrbI4EKWrQwd+cIEQlOSY7dEPI/b5BbYj
 MWAb3P4EG9N77AWTNmbhK4nN0brEYb+rBbCA+5dtNBVhHTxAC7OTWElJOC2O66FI
 e06dREjvwYtOkRUkUguWwErbIai2gJ2MH0VILV3hHoh64oRk7jjM8PZYnjQkdptQ
 Gsq0rJW5iiu/OQ==
 =Oz1V
 -----END PGP SIGNATURE-----

Merge tag 'sched-core-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler updates from Thomas Gleixner:

 - migrate_disable/enable() support which originates from the RT tree
   and is now a prerequisite for the new preemptible kmap_local() API
   which aims to replace kmap_atomic().

 - A fair amount of topology and NUMA related improvements

 - Improvements for the frequency invariant calculations

 - Enhanced robustness for the global CPU priority tracking and decision
   making

 - The usual small fixes and enhancements all over the place

* tag 'sched-core-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (61 commits)
  sched/fair: Trivial correction of the newidle_balance() comment
  sched/fair: Clear SMT siblings after determining the core is not idle
  sched: Fix kernel-doc markup
  x86: Print ratio freq_max/freq_base used in frequency invariance calculations
  x86, sched: Use midpoint of max_boost and max_P for frequency invariance on AMD EPYC
  x86, sched: Calculate frequency invariance for AMD systems
  irq_work: Optimize irq_work_single()
  smp: Cleanup smp_call_function*()
  irq_work: Cleanup
  sched: Limit the amount of NUMA imbalance that can exist at fork time
  sched/numa: Allow a floating imbalance between NUMA nodes
  sched: Avoid unnecessary calculation of load imbalance at clone time
  sched/numa: Rename nr_running and break out the magic number
  sched: Make migrate_disable/enable() independent of RT
  sched/topology: Condition EAS enablement on FIE support
  arm64: Rebuild sched domains on invariance status changes
  sched/topology,schedutil: Wrap sched domains rebuild
  sched/uclamp: Allow to reset a task uclamp constraint value
  sched/core: Fix typos in comments
  Documentation: scheduler: fix information on arch SD flags, sched_domain and sched_debug
  ...
2020-12-14 18:29:11 -08:00
Linus Torvalds
533369b145 timers and timekeeping updates:
Core:
 
   - Robustness improvements for the NOHZ tick management
 
   - Fixes and consolidation of the NTP/RTC synchronization code
 
   - Small fixes and improvements in various places
 
   - A set of function documentation udpates and fixes
 
  Drivers:
 
   - Cleanups and improvements in various clocksoure/event drivers
 
   - Removal of the EZChip NPS clocksource driver as the platfrom support
     was removed from ARC
 
   - The usual set of new device tree binding and json conversions
 
   - The RTC driver which have been acked by the RTC maintainer:
 
     - Fix a long standing bug in the MC146818 library code which can cause
       reading garbage during the RTC internal update.
 
     - The changes related to the NTP/RTC consolidation work.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAl/Xw1wTHHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYof7SD/4iIjuP5HoY7ec0z9wSFQ5U5nUwJnpW
 Sre13SUXpW+wOa/RcjAaHiD2G4MGtQyUIBibuL18Q5GMtGOvlIueEniuYP57p1XU
 ipr1UMnFvRkAaFNOnySzLiQyuliteBcNSDHrLYsSWW2BwjLbNzX46zG5kILrt31i
 IsseHZdD9+7SXBLvCjO6FAYkVH8FeIaFKv+3ZmroWOxPBOXi4wn02K86HrXs/6Wu
 9SCUIMcewhvSx3xCURzyMv6S2hgKSzywRNc5WcYIE8OPlKbnAE0IC370r3o2uL1B
 4dZPv4H1y7F7M4G+/XlIv0l2DTp9RuiWut9QcYmHtlFCKkrEO3ZGlcgPU6y5+mNc
 AwwG0J51yJYqg42aifdDNJ18B9GUNVCfVAKZcOYHLXOBgSvshd2WkPJkXsGaHd3z
 KrK3kZUnx+/QUWZB7dMuq+HQG2PJTvKkEwu4VGReWPGmubXbsIqBZ0vH5jYHjuEo
 t4QCUc5BpNlXOUJxal5wzVmDWnoqfKqbmnPky/f/cmNEfQNY6nA9hC3vo781j532
 Z5snFXhbITqIkaHoN86wMuuDCjKBKBJGQvejZKgPvh3oIg9d5yaj9P0UAhoYtv+M
 jMus4QDb6eBirgnZIVpgBC3kVZOxNOEHNsPeCcVfvPa7QOQnY4Cmb0GWnpZ2SZOz
 KYSjTIXKgZnHiQ==
 =eWC0
 -----END PGP SIGNATURE-----

Merge tag 'timers-core-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timers and timekeeping updates from Thomas Gleixner:
 "Core:

   - Robustness improvements for the NOHZ tick management

   - Fixes and consolidation of the NTP/RTC synchronization code

   - Small fixes and improvements in various places

   - A set of function documentation udpates and fixes

   Drivers:

   - Cleanups and improvements in various clocksoure/event drivers

   - Removal of the EZChip NPS clocksource driver as the platfrom
     support was removed from ARC

   - The usual set of new device tree binding and json conversions

   - The RTC driver which have been acked by the RTC maintainer:

       * fix a long standing bug in the MC146818 library code which can
         cause reading garbage during the RTC internal update.

       * changes related to the NTP/RTC consolidation work"

* tag 'timers-core-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (46 commits)
  ntp: Fix prototype in the !CONFIG_GENERIC_CMOS_UPDATE case
  tick/sched: Make jiffies update quick check more robust
  ntp: Consolidate the RTC update implementation
  ntp: Make the RTC sync offset less obscure
  ntp, rtc: Move rtc_set_ntp_time() to ntp code
  ntp: Make the RTC synchronization more reliable
  rtc: core: Make the sync offset default more realistic
  rtc: cmos: Make rtc_cmos sync offset correct
  rtc: mc146818: Reduce spinlock section in mc146818_set_time()
  rtc: mc146818: Prevent reading garbage
  clocksource/drivers/sh_cmt: Fix potential deadlock when calling runtime PM
  clocksource/drivers/arm_arch_timer: Correct fault programming of CNTKCTL_EL1.EVNTI
  clocksource/drivers/arm_arch_timer: Use stable count reader in erratum sne
  clocksource/drivers/dw_apb_timer_of: Add error handling if no clock available
  clocksource/drivers/riscv: Make RISCV_TIMER depends on RISCV_SBI
  clocksource/drivers/ingenic: Fix section mismatch
  clocksource/drivers/cadence_ttc: Fix memory leak in ttc_setup_clockevent()
  dt-bindings: timer: renesas: tmu: Convert to json-schema
  dt-bindings: timer: renesas: tmu: Document r8a774e1 bindings
  clocksource/drivers/orion: Add missing clk_disable_unprepare() on error path
  ...
2020-12-14 18:21:14 -08:00
Linus Torvalds
76d4acf22b perf/kprobes updates:
- Make kretprobes lockless to avoid the rp->lock performance and potential
    lock ordering issues.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAl/XvuYTHHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYoV3XEADA3yp4ApabrdSMK+JpTM053mM3NCCk
 VLZEdh5+ydvPfgTWZcgLDfL4P4MVySDKf40pSVgZOA73uDWhdO4jcMoJgl9Du4Nq
 qfvz6Atj0a8XEgAFNh1IWGGAHydIwKOQZJyjFT5Kh94QNOErF2PJGAMnoMYpdJsj
 E7kgDM+vmWJk0GE+OYTzsAYQ99XhLfUAO9f8WoRirxyNgga6bu0arRYWZSX3Sg/h
 oDUHeizyrrURUBgxJBewCxvCsy4TTfefwZFUBLK5gm3zRJLKDT2O8wiy+KzlRQqA
 kYV3fSx8fYETlSOJWJC8S01MLpxslGdenIdRgNc63C021DtwMGM83FCl0DLnPMeg
 iX5u+0Qg77rnJ8zh0cgSxyP6EgZzrUW8+DjZagge3PAnTXwYRv95pOJahJifDVmF
 mo2RJ2Me+XbqeB4BYoLivvWpXdsWOvtXl3BTA6ZLV+K823lMPYcZO/cXHIUYHhtu
 ExrZ+aw3opt43KT5sNQmPll7d1UsMD4/761L7gysIYK0RthunmlWpAnnfLTbRdPe
 ELKIHcuSCGkGfRs07/oPbbOpMorhel+3alW0B6Vzar0/0nw3fPX/yPIkCh7s941o
 G0UIPquvBGk3u0bZKZZ7QJPjT0ktdQpQs69+J2ARXWvApAGKnkOlPsNSI9TbPE3D
 ZIguKqSyzqJwuA==
 =PDBa
 -----END PGP SIGNATURE-----

Merge tag 'perf-kprobes-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf/kprobes updates from Thomas Gleixner:
 "Make kretprobes lockless to avoid the rp->lock performance and
  potential lock ordering issues"

* tag 'perf-kprobes-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/atomics: Regenerate the atomics-check SHA1's
  kprobes: Replace rp->free_instance with freelist
  freelist: Implement lockless freelist
  asm-generic/atomic: Add try_cmpxchg() fallbacks
  kprobes: Remove kretprobe hash
  llist: Add nonatomic __llist_add() and __llist_dell_all()
2020-12-14 17:41:38 -08:00
Linus Torvalds
8a8ca83ec3 Perf updates:
Core:
 
    - Better handling of page table leaves on archictectures which have
      architectures have non-pagetable aligned huge/large pages.  For such
      architectures a leaf can actually be part of a larger entry.
 
    - Prevent a deadlock vs. exec_update_mutex
 
  Architectures:
 
    - The related updates for page size calculation of leaf entries
 
    - The usual churn to support new CPUs
 
    - Small fixes and improvements all over the place
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAl/XvgATHHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYoUrdEACatdr93wv75vnm5tCZM4EsFvB2PzVJ
 ck4K4+hHiMVV4802qf+kW5plF+rckAU4TAai/L7wkTntKHvjD/0/o1epoIStb+dS
 SCpVkQMCLT/8xT242iHPOfgsQpVpJnIiBwVRjn8HXu82nXdgMJhKnBjTe634UfxW
 o2OCFiyJzpRi5l86gVp67ueqgvl34NPI2JaSLc0g80QfZ8akzdePPpED35CzYjZh
 41k+7ssvt6qch3vMUySHAhkX4gQl0nc80YAaF/XZbCfvdyY7D03PtfBjfvphTSK0
 l54z9aWh0ciK9P1aPfvkHDXBJUR2VtUAx2GiURK+XU3jNk3KMrz9CcBl1D/exIAg
 07IsiYVoB38YAUOZoR9K8p+p+5EuwYRRUMAgfQfBALCuaLQV477Cne82b2KmNCus
 1izUQvcDDf0s74OyYTHWFXRGla95COJvNLzkrZ1oU3mX4HgdKdOAUbf/2XTLWeKO
 3HOIS+jsg5cp82tRe4X5r51h73pONYlo9lLo/CjQXz25vMcXKtE/MZGq2gkRff4p
 N4k88eQ5LOsRqUaU46GcHozXRCfcpW7SPI9AaN5I/fKGIZvHP7uMdMb+g5DV8yHI
 dNZ8u5uLPHwdg80C3fJ3Pnp7VsVNHliPXMwv0vib7BCp7aUVZWeFnOntw3PdYFRk
 XKEbfl36IuAadg==
 =rZ99
 -----END PGP SIGNATURE-----

Merge tag 'perf-core-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf updates from Thomas Gleixner:
 "Core:

   - Better handling of page table leaves on archictectures which have
     architectures have non-pagetable aligned huge/large pages. For such
     architectures a leaf can actually be part of a larger entry.

   - Prevent a deadlock vs exec_update_mutex

  Architectures:

   - The related updates for page size calculation of leaf entries

   - The usual churn to support new CPUs

   - Small fixes and improvements all over the place"

* tag 'perf-core-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
  perf/x86/intel: Add Tremont Topdown support
  uprobes/x86: Fix fall-through warnings for Clang
  perf/x86: Fix fall-through warnings for Clang
  kprobes/x86: Fix fall-through warnings for Clang
  perf/x86/intel/lbr: Fix the return type of get_lbr_cycles()
  perf/x86/intel: Fix rtm_abort_event encoding on Ice Lake
  x86/kprobes: Restore BTF if the single-stepping is cancelled
  perf: Break deadlock involving exec_update_mutex
  sparc64/mm: Implement pXX_leaf_size() support
  powerpc/8xx: Implement pXX_leaf_size() support
  arm64/mm: Implement pXX_leaf_size() support
  perf/core: Fix arch_perf_get_page_size()
  mm: Introduce pXX_leaf_size()
  mm/gup: Provide gup_get_pte() more generic
  perf/x86/intel: Add event constraint for CYCLE_ACTIVITY.STALLS_MEM_ANY
  perf/x86/intel/uncore: Add Rocket Lake support
  perf/x86/msr: Add Rocket Lake CPU support
  perf/x86/cstate: Add Rocket Lake CPU support
  perf/x86/intel: Add Rocket Lake CPU support
  perf,mm: Handle non-page-table-aligned hugetlbfs
  ...
2020-12-14 17:34:12 -08:00
Linus Torvalds
e857b6fcc5 A moderate set of locking updates:
- A few extensions to the rwsem API and support for opportunistic
     spinning and lock stealing
 
   - lockdep selftest improvements
 
   - Documentation updates
 
   - Cleanups and small fixes all over the place
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAl/XvCgTHHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYodbkD/9kmXCablxzCG+IGdRU0KfSvbalHkoS
 hUW7sJ8qYdoysOVMdvImPwqxLDy/P6D8Nk6z+hdaPmfWvIDQQECd7Mg/UhZLkRzI
 BGNgpatnzX4PK5sm/IFExCisPCkkbkjprocnk//TGjdwTiMMDxrndsEpwVwcucDp
 TwOjPPxoAbfWHUmnv2SUOD7mWMqMH/ISTQlKUaz+UCQicPNuHumdsQKvZx3eu7Cv
 KvucTso5Qjmyy0HwpmJO/IEyZs7Ibrb5Ocw5wds3yo2PFTjYTvo3JlJ16g8IvaZW
 ckk+o+3QKp29oFAPQ+dFGEG10w4JQI3AZkDVouFR4BDD0sbOm7BvWCsVq/J8vk3i
 xnmaHT3zB5F4T97O+osBj2KS4zLliOHohWzDNv1+JVBCfniYbPo5hqa/n7OO2oot
 M3xXY3ddgfTEUOtvOPPfZwfG5XmPrgwj8iiyywlTQU4BR5rWYj2ehvhWOwugQJ6x
 g56nQzuf3KmyoI2S+1GZoxtgWSLwoXbUAPL8p4lyvy6jKKFV84BOJeVac803BBUo
 yLFBSvTfZ95iNc84XHjJOJ/MGE8e2hOGa2KEdxuh1qE5FPazBg5e2cQh2j125PLz
 uyhelQn7SgAHSKSXSAOPq0JFsrmxRmkzIgG9zLSEqo+6g6uKdWgGYVCbEzOB+9gB
 2tNEgP6Mfh+ARg==
 =uqcN
 -----END PGP SIGNATURE-----

Merge tag 'locking-core-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking updates from Thomas Gleixner:
 "A moderate set of locking updates:

   - A few extensions to the rwsem API and support for opportunistic
     spinning and lock stealing

   - lockdep selftest improvements

   - Documentation updates

   - Cleanups and small fixes all over the place"

* tag 'locking-core-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits)
  seqlock: kernel-doc: Specify when preemption is automatically altered
  seqlock: Prefix internal seqcount_t-only macros with a "do_"
  Documentation: seqlock: s/LOCKTYPE/LOCKNAME/g
  locking/rwsem: Remove reader optimistic spinning
  locking/rwsem: Enable reader optimistic lock stealing
  locking/rwsem: Prevent potential lock starvation
  locking/rwsem: Pass the current atomic count to rwsem_down_read_slowpath()
  locking/rwsem: Fold __down_{read,write}*()
  locking/rwsem: Introduce rwsem_write_trylock()
  locking/rwsem: Better collate rwsem_read_trylock()
  rwsem: Implement down_read_interruptible
  rwsem: Implement down_read_killable_nested
  refcount: Fix a kernel-doc markup
  completion: Drop init_completion define
  atomic: Update MAINTAINERS
  atomic: Delete obsolete documentation
  seqlock: Rename __seqprop() users
  lockdep/selftest: Add spin_nest_lock test
  lockdep/selftests: Fix PROVE_RAW_LOCK_NESTING
  seqlock: avoid -Wshadow warnings
  ...
2020-12-14 17:27:47 -08:00
Linus Torvalds
8c1dccc803 RCU, LKMM and KCSAN updates collected by Paul McKenney:
RCU:
 
     - Avoid cpuinfo-induced IPI pileups and idle-CPU IPIs.
 
     - Lockdep-RCU updates reducing the need for __maybe_unused.
 
     - Tasks-RCU updates.
 
     - Miscellaneous fixes.
 
     - Documentation updates.
 
     - Torture-test updates.
 
   KCSAN:
 
     - updates for selftests, avoiding setting watchpoints on NULL pointers
 
     - fix to watchpoint encoding
 
   LKMM:
 
     - updates for documentation along with some updates to example-code
       litmus tests
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAl/Xon4THHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYobXUD/92LJTI/TMgK6Z6EEQBiJZO/2mNKjK8
 FEKc6AqTNMlZNsWCfQ5UgqtHpn+MkBZsX1x4u22gehE1qaCB8gnQ5wXgbXon8tQm
 exxVk6vvQZjseeqCMqrsUYQlD7dNgHnf1qAmWXJvji4sA/1Opo6n2M74tqfE2ueV
 S5hpQwSuK/6Zu2Hrr62HD8+Fx0in6ZuKRZxHGp1392l++DGbniJM3dzntRXB+JbZ
 w3PDHFCQuGzTytyeKuQV48ot9IK+2YzmjIp/+4tHL6mvU38xeSu6gcYtqKPcfYWw
 D6HXvDa965h5IrFdSA2JWSzjJ+VYgZVElk2HyXDNIae0fM/8GidgoIDQipT1WAur
 sxW/Ke4U6Jm5MMqXqV8iMNduktkGD1/h6G/iB1Yis29xFdthorNpbHVAP+8cKXgf
 1cR6RorOuBYv6XpyzygHtE7qfLY5ST352pJ4+UqNzboujOcuEnGaygttt0F/F8sA
 ZH8NT5dyUfbGeqepdZWkbj116Hjeg3fyV3CZeyBhDeqpjf1Nn3nbJ1xRksPLfa3i
 IKvN7HSzEg+vKnsJNnQeFlAmQ/W3n2bedzRqfaCg77pNhKI6jPuavY5f2YGFUj0y
 yx0UzOYoI1Cln0keBMmynbyUKgJ7zstLkrt/JenjhtD3B+0df5BmYjkL+nqkP6ax
 +XTCu7Xg+B061g==
 =N/iO
 -----END PGP SIGNATURE-----

Merge tag 'core-rcu-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull RCU updates from Thomas Gleixner:
 "RCU, LKMM and KCSAN updates collected by Paul McKenney.

  RCU:
   - Avoid cpuinfo-induced IPI pileups and idle-CPU IPIs

   - Lockdep-RCU updates reducing the need for __maybe_unused

   - Tasks-RCU updates

   - Miscellaneous fixes

   - Documentation updates

   - Torture-test updates

  KCSAN:
   - updates for selftests, avoiding setting watchpoints on NULL pointers

   - fix to watchpoint encoding

  LKMM:
   - updates for documentation along with some updates to example-code
     litmus tests"

* tag 'core-rcu-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (72 commits)
  srcu: Take early exit on memory-allocation failure
  rcu/tree: Defer kvfree_rcu() allocation to a clean context
  rcu: Do not report strict GPs for outgoing CPUs
  rcu: Fix a typo in rcu_blocking_is_gp() header comment
  rcu: Prevent lockdep-RCU splats on lock acquisition/release
  rcu/tree: nocb: Avoid raising softirq for offloaded ready-to-execute CBs
  rcu,ftrace: Fix ftrace recursion
  rcu/tree: Make struct kernel_param_ops definitions const
  rcu/tree: Add a warning if CPU being onlined did not report QS already
  rcu: Clarify nocb kthreads naming in RCU_NOCB_CPU config
  rcu: Fix single-CPU check in rcu_blocking_is_gp()
  rcu: Implement rcu_segcblist_is_offloaded() config dependent
  list.h: Update comment to explicitly note circular lists
  rcu: Panic after fixed number of stalls
  x86/smpboot:  Move rcu_cpu_starting() earlier
  rcu: Allow rcu_irq_enter_check_tick() from NMI
  tools/memory-model: Label MP tests' producers and consumers
  tools/memory-model: Use "buf" and "flag" for message-passing tests
  tools/memory-model: Add types to litmus tests
  tools/memory-model: Add a glossary of LKMM terms
  ...
2020-12-14 17:21:16 -08:00
Linus Torvalds
1ac0884d54 A set of updates for entry/exit handling:
- More generalization of entry/exit functionality
 
  - The consolidation work to reclaim TIF flags on x86 and also for non-x86
    specific TIF flags which are solely relevant for syscall related work
    and have been moved into their own storage space. The x86 specific part
    had to be merged in to avoid a major conflict.
 
  - The TIF_NOTIFY_SIGNAL work which replaces the inefficient signal
    delivery mode of task work and results in an impressive performance
    improvement for io_uring. The non-x86 consolidation of this is going to
    come seperate via Jens.
 
  - The selective syscall redirection facility which provides a clean and
    efficient way to support the non-Linux syscalls of WINE by catching them
    at syscall entry and redirecting them to the user space emulation. This
    can be utilized for other purposes as well and has been designed
    carefully to avoid overhead for the regular fastpath. This includes the
    core changes and the x86 support code.
 
  - Simplification of the context tracking entry/exit handling for the users
    of the generic entry code which guarantee the proper ordering and
    protection.
 
  - Preparatory changes to make the generic entry code accomodate S390
    specific requirements which are mostly related to their syscall restart
    mechanism.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAl/XoPoTHHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYoe0tD/4jSKHIogVM9kVpiYfwjDGS1NluaBXn
 71ZoASbX9GZebyGandMyF2QP1iJ24ZO0RztBwHEVH6fyomKB2iFNedssCpO9yfWV
 3eFRpOvMpbszY2W2bd0QG3GrqaTttjVfB4ahkGLzqeSbchdob6hZpNDYtBZnujA6
 GSnrrurfJkCGoQny+yJQYdQJXQU+BIX90B2a2Q+jW123Luy/iHXC1f/krZSA1m14
 fC9xYLSUjPphTzh2ZOW+C3DgdjOL5PfAm/6F+DArt4GtLgrEGD7R74aLSFhvetky
 dn5QtG+yAsz1i0cc5Wu/JBcT9tOkY92rPYSyLI9bYQUSQ/bMyuprz6oYKj3dubsu
 ZSsKPdkNFPIniL4fLdCMWZcIXX5xgnrxKjdgXZXW3gtrcxSns8w8uED3Sh7dgE08
 pgIeq67E5g/OB8kJXH1VxdewmeQb9cOmnzzHwNO7TrrGbBKjDTYHNdYOKf1dUTTK
 ZX1UjLfGwxTkMYAbQD1k0JGZ2OLRshzSaH5BW/ZKa3bvJW6yYOq+/YT8B8hbJ8U3
 vThlO75/55IJxS5r5Y3vZd/IHdsYbPuETD+TA8tNYtPqNZasW8nnk4TYctWqzDuO
 /Ka1wvWYid3c6ySznQn4zSyRjr968AfHeZ9YTUMhWufy5waXVmdBMG41u3IKfsVt
 osyzNc4EK19/Mg==
 =hsjV
 -----END PGP SIGNATURE-----

Merge tag 'core-entry-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull core entry/exit updates from Thomas Gleixner:
 "A set of updates for entry/exit handling:

   - More generalization of entry/exit functionality

   - The consolidation work to reclaim TIF flags on x86 and also for
     non-x86 specific TIF flags which are solely relevant for syscall
     related work and have been moved into their own storage space. The
     x86 specific part had to be merged in to avoid a major conflict.

   - The TIF_NOTIFY_SIGNAL work which replaces the inefficient signal
     delivery mode of task work and results in an impressive performance
     improvement for io_uring. The non-x86 consolidation of this is
     going to come seperate via Jens.

   - The selective syscall redirection facility which provides a clean
     and efficient way to support the non-Linux syscalls of WINE by
     catching them at syscall entry and redirecting them to the user
     space emulation. This can be utilized for other purposes as well
     and has been designed carefully to avoid overhead for the regular
     fastpath. This includes the core changes and the x86 support code.

   - Simplification of the context tracking entry/exit handling for the
     users of the generic entry code which guarantee the proper ordering
     and protection.

   - Preparatory changes to make the generic entry code accomodate S390
     specific requirements which are mostly related to their syscall
     restart mechanism"

* tag 'core-entry-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
  entry: Add syscall_exit_to_user_mode_work()
  entry: Add exit_to_user_mode() wrapper
  entry_Add_enter_from_user_mode_wrapper
  entry: Rename exit_to_user_mode()
  entry: Rename enter_from_user_mode()
  docs: Document Syscall User Dispatch
  selftests: Add benchmark for syscall user dispatch
  selftests: Add kselftest for syscall user dispatch
  entry: Support Syscall User Dispatch on common syscall entry
  kernel: Implement selective syscall userspace redirection
  signal: Expose SYS_USER_DISPATCH si_code type
  x86: vdso: Expose sigreturn address on vdso to the kernel
  MAINTAINERS: Add entry for common entry code
  entry: Fix boot for !CONFIG_GENERIC_ENTRY
  x86: Support HAVE_CONTEXT_TRACKING_OFFSTACK
  context_tracking: Only define schedule_user() on !HAVE_CONTEXT_TRACKING_OFFSTACK archs
  sched: Detect call to schedule from critical entry code
  context_tracking: Don't implement exception_enter/exit() on CONFIG_HAVE_CONTEXT_TRACKING_OFFSTACK
  context_tracking: Introduce HAVE_CONTEXT_TRACKING_OFFSTACK
  x86: Reclaim unused x86 TI flags
  ...
2020-12-14 17:13:53 -08:00
Linus Torvalds
f9b4240b07 fixes-v5.11
-----BEGIN PGP SIGNATURE-----
 
 iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCX9daOgAKCRCRxhvAZXjc
 ohPkAQChXUB2BAjtIzXlCkZoDBbzHHblm5DZ37oy/4xYFmAcEwEA5sw6dQqyGHnF
 GEP9def51HvXLpBV2BzNUGggo1SoGgQ=
 =w/cO
 -----END PGP SIGNATURE-----

Merge tag 'fixes-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux

Pull misc fixes from Christian Brauner:
 "This contains several fixes which felt worth being combined into a
  single branch:

   - Use put_nsproxy() instead of open-coding it switch_task_namespaces()

   - Kirill's work to unify lifecycle management for all namespaces. The
     lifetime counters are used identically for all namespaces types.
     Namespaces may of course have additional unrelated counters and
     these are not altered. This work allows us to unify the type of the
     counters and reduces maintenance cost by moving the counter in one
     place and indicating that basic lifetime management is identical
     for all namespaces.

   - Peilin's fix adding three byte padding to Dmitry's
     PTRACE_GET_SYSCALL_INFO uapi struct to prevent an info leak.

   - Two smal patches to convert from the /* fall through */ comment
     annotation to the fallthrough keyword annotation which I had taken
     into my branch and into -next before df561f6688 ("treewide: Use
     fallthrough pseudo-keyword") made it upstream which fixed this
     tree-wide.

     Since I didn't want to invalidate all testing for other commits I
     didn't rebase and kept them"

* tag 'fixes-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
  nsproxy: use put_nsproxy() in switch_task_namespaces()
  sys: Convert to the new fallthrough notation
  signal: Convert to the new fallthrough notation
  time: Use generic ns_common::count
  cgroup: Use generic ns_common::count
  mnt: Use generic ns_common::count
  user: Use generic ns_common::count
  pid: Use generic ns_common::count
  ipc: Use generic ns_common::count
  uts: Use generic ns_common::count
  net: Use generic ns_common::count
  ns: Add a common refcount into ns_common
  ptrace: Prevent kernel-infoleak in ptrace_get_syscall_info()
2020-12-14 16:40:27 -08:00
Linus Torvalds
6d93a1971a time-namespace-v5.11
-----BEGIN PGP SIGNATURE-----
 
 iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCX9cwgAAKCRCRxhvAZXjc
 onViAP9CDMQct0RfdpdKOrh4NkxWiheBp7CzVSP1Xfy8KHBslgD/X7kilcthT8PC
 JTJmngrVWoehX+s49kl2PSuuLsGElAo=
 =llnx
 -----END PGP SIGNATURE-----

Merge tag 'time-namespace-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux

Pull time namespace updates from Christian Brauner:
 "When time namespaces were introduced we missed to virtualize the
  'btime' field in /proc/stat. This confuses tasks which are in another
  time namespace with a virtualized boottime which is common in some
  container workloads. This contains Michael's series to fix 'btime'
  which Thomas asked me to take through my tree.

  To fix 'btime' virtualization we simply subtract the offset of the
  time namespace's boottime from btime before printing the stats. Note
  that since start_boottime of processes are seconds since boottime and
  the boottime stamp is now shifted according to the time namespace's
  offset, the offset of the time namespace also needs to be applied
  before the process stats are given to userspace. This avoids that
  processes shown by tools such as 'ps' appear as time travelers in the
  corresponding time namespace.

  Selftests are included to verify that btime virtualization in
  /proc/stat works as expected"

* tag 'time-namespace-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
  namespace: make timens_on_fork() return nothing
  selftests/timens: added selftest for /proc/stat btime
  fs/proc: apply the time namespace offset to /proc/stat btime
  timens: additional helper functions for boottime offset handling
2020-12-14 16:35:39 -08:00
Linus Torvalds
0ca2ce81eb arm64 updates for 5.11:
- Expose tag address bits in siginfo. The original arm64 ABI did not
   expose any of the bits 63:56 of a tagged address in siginfo. In the
   presence of user ASAN or MTE, this information may be useful. The
   implementation is generic to other architectures supporting tags (like
   SPARC ADI, subject to wiring up the arch code). The user will have to
   opt in via sigaction(SA_EXPOSE_TAGBITS) so that the extra bits, if
   available, become visible in si_addr.
 
 - Default to 32-bit wide ZONE_DMA. Previously, ZONE_DMA was set to the
   lowest 1GB to cope with the Raspberry Pi 4 limitations, to the
   detriment of other platforms. With these changes, the kernel scans the
   Device Tree dma-ranges and the ACPI IORT information before deciding
   on a smaller ZONE_DMA.
 
 - Strengthen READ_ONCE() to acquire when CONFIG_LTO=y. When building
   with LTO, there is an increased risk of the compiler converting an
   address dependency headed by a READ_ONCE() invocation into a control
   dependency and consequently allowing for harmful reordering by the
   CPU.
 
 - Add CPPC FFH support using arm64 AMU counters.
 
 - set_fs() removal on arm64. This renders the User Access Override (UAO)
   ARMv8 feature unnecessary.
 
 - Perf updates: PMU driver for the ARM DMC-620 memory controller, sysfs
   identifier file for SMMUv3, stop event counters support for i.MX8MP,
   enable the perf events-based hard lockup detector.
 
 - Reorganise the kernel VA space slightly so that 52-bit VA
   configurations can use more virtual address space.
 
 - Improve the robustness of the arm64 memory offline event notifier.
 
 - Pad the Image header to 64K following the EFI header definition
   updated recently to increase the section alignment to 64K.
 
 - Support CONFIG_CMDLINE_EXTEND on arm64.
 
 - Do not use tagged PC in the kernel (TCR_EL1.TBID1==1), freeing up 8
   bits for PtrAuth.
 
 - Switch to vmapped shadow call stacks.
 
 - Miscellaneous clean-ups.
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE5RElWfyWxS+3PLO2a9axLQDIXvEFAl/XcSgACgkQa9axLQDI
 XvGkwg//SLknimELD/cphf2UzZm5RFuCU0x1UnIXs9XYo5BrOpgVLLA//+XkCrKN
 0GLAdtBDfw1axWJudzgMBiHrv6wSGh4p3YWjLIW06u/PJu3m3U8oiiolvvF8d7Yq
 UKDseKGQnQkrl97J0SyA+Da/u8D11GEzp52SWL5iRxzt6vInEC27iTOp9n1yoaoP
 f3y7qdp9kv831ryUM3rXFYpc8YuMWXk+JpBSNaxqmjlvjMzipA5PhzBLmNzfc657
 XcrRX5qsgjEeJW8UUnWUVNB42j7tVzN77yraoUpoVVCzZZeWOQxqq5EscKPfIhRt
 AjtSIQNOs95ZVE0SFCTjXnUUb823coUs4dMCdftqlE62JNRwdR+3bkfa+QjPTg1F
 O9ohW1AzX0/JB19QBxMaOgbheB8GFXh3DVJ6pizTgxJgyPvQQtFuEhT1kq8Cst0U
 Pe+pEWsg9t41bUXNz+/l9tUWKWpeCfFNMTrBXLmXrNlTLeOvDh/0UiF0+2lYJYgf
 YAboibQ5eOv2wGCcSDEbNMJ6B2/6GtubDJxH4du680F6Emb6pCSw0ntPwB7mSGLG
 5dXz+9FJxDLjmxw7BXxQgc5MoYIrt5JQtaOQ6UxU8dPy53/+py4Ck6tXNkz0+Ap7
 gPPaGGy1GqobQFu3qlHtOK1VleQi/sWcrpmPHrpiiFUf6N7EmcY=
 =zXFk
 -----END PGP SIGNATURE-----

Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Catalin Marinas:

 - Expose tag address bits in siginfo. The original arm64 ABI did not
   expose any of the bits 63:56 of a tagged address in siginfo. In the
   presence of user ASAN or MTE, this information may be useful. The
   implementation is generic to other architectures supporting tags
   (like SPARC ADI, subject to wiring up the arch code). The user will
   have to opt in via sigaction(SA_EXPOSE_TAGBITS) so that the extra
   bits, if available, become visible in si_addr.

 - Default to 32-bit wide ZONE_DMA. Previously, ZONE_DMA was set to the
   lowest 1GB to cope with the Raspberry Pi 4 limitations, to the
   detriment of other platforms. With these changes, the kernel scans
   the Device Tree dma-ranges and the ACPI IORT information before
   deciding on a smaller ZONE_DMA.

 - Strengthen READ_ONCE() to acquire when CONFIG_LTO=y. When building
   with LTO, there is an increased risk of the compiler converting an
   address dependency headed by a READ_ONCE() invocation into a control
   dependency and consequently allowing for harmful reordering by the
   CPU.

 - Add CPPC FFH support using arm64 AMU counters.

 - set_fs() removal on arm64. This renders the User Access Override
   (UAO) ARMv8 feature unnecessary.

 - Perf updates: PMU driver for the ARM DMC-620 memory controller, sysfs
   identifier file for SMMUv3, stop event counters support for i.MX8MP,
   enable the perf events-based hard lockup detector.

 - Reorganise the kernel VA space slightly so that 52-bit VA
   configurations can use more virtual address space.

 - Improve the robustness of the arm64 memory offline event notifier.

 - Pad the Image header to 64K following the EFI header definition
   updated recently to increase the section alignment to 64K.

 - Support CONFIG_CMDLINE_EXTEND on arm64.

 - Do not use tagged PC in the kernel (TCR_EL1.TBID1==1), freeing up 8
   bits for PtrAuth.

 - Switch to vmapped shadow call stacks.

 - Miscellaneous clean-ups.

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (78 commits)
  perf/imx_ddr: Add system PMU identifier for userspace
  bindings: perf: imx-ddr: add compatible string
  arm64: Fix build failure when HARDLOCKUP_DETECTOR_PERF is enabled
  arm64: mte: fix prctl(PR_GET_TAGGED_ADDR_CTRL) if TCF0=NONE
  arm64: mark __system_matches_cap as __maybe_unused
  arm64: uaccess: remove vestigal UAO support
  arm64: uaccess: remove redundant PAN toggling
  arm64: uaccess: remove addr_limit_user_check()
  arm64: uaccess: remove set_fs()
  arm64: uaccess cleanup macro naming
  arm64: uaccess: split user/kernel routines
  arm64: uaccess: refactor __{get,put}_user
  arm64: uaccess: simplify __copy_user_flushcache()
  arm64: uaccess: rename privileged uaccess routines
  arm64: sdei: explicitly simulate PAN/UAO entry
  arm64: sdei: move uaccess logic to arch/arm64/
  arm64: head.S: always initialize PSTATE
  arm64: head.S: cleanup SCTLR_ELx initialization
  arm64: head.S: rename el2_setup -> init_kernel_el
  arm64: add C wrappers for SET_PSTATE_*()
  ...
2020-12-14 16:24:30 -08:00
Jakub Kicinski
a6b5e026e6 Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2020-12-14

1) Expose bpf_sk_storage_*() helpers to iterator programs, from Florent Revest.

2) Add AF_XDP selftests based on veth devs to BPF selftests, from Weqaar Janjua.

3) Support for finding BTF based kernel attach targets through libbpf's
   bpf_program__set_attach_target() API, from Andrii Nakryiko.

4) Permit pointers on stack for helper calls in the verifier, from Yonghong Song.

5) Fix overflows in hash map elem size after rlimit removal, from Eric Dumazet.

6) Get rid of direct invocation of llc in BPF selftests, from Andrew Delgadillo.

7) Fix xsk_recvmsg() to reorder socket state check before access, from Björn Töpel.

8) Add new libbpf API helper to retrieve ring buffer epoll fd, from Brendan Jackman.

9) Batch of minor BPF selftest improvements all over the place, from Florian Lehner,
   KP Singh, Jiri Olsa and various others.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (31 commits)
  selftests/bpf: Add a test for ptr_to_map_value on stack for helper access
  bpf: Permits pointers on stack for helper calls
  libbpf: Expose libbpf ring_buffer epoll_fd
  selftests/bpf: Add set_attach_target() API selftest for module target
  libbpf: Support modules in bpf_program__set_attach_target() API
  selftests/bpf: Silence ima_setup.sh when not running in verbose mode.
  selftests/bpf: Drop the need for LLVM's llc
  selftests/bpf: fix bpf_testmod.ko recompilation logic
  samples/bpf: Fix possible hang in xdpsock with multiple threads
  selftests/bpf: Make selftest compilation work on clang 11
  selftests/bpf: Xsk selftests - adding xdpxceiver to .gitignore
  selftests/bpf: Drop tcp-{client,server}.py from Makefile
  selftests/bpf: Xsk selftests - Bi-directional Sockets - SKB, DRV
  selftests/bpf: Xsk selftests - Socket Teardown - SKB, DRV
  selftests/bpf: Xsk selftests - DRV POLL, NOPOLL
  selftests/bpf: Xsk selftests - SKB POLL, NOPOLL
  selftests/bpf: Xsk selftests framework
  bpf: Only provide bpf_sock_from_file with CONFIG_NET
  bpf: Return -ENOTSUPP when attaching to non-kernel BTF
  xsk: Validate socket state in xsk_recvmsg, prior touching socket members
  ...
====================

Link: https://lore.kernel.org/r/20201214214316.20642-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-14 15:34:36 -08:00
Uladzislau Rezki (Sony)
1b04fa9900 rcu-tasks: Move RCU-tasks initialization to before early_initcall()
PowerPC testing encountered boot failures due to RCU Tasks not being
fully initialized until core_initcall() time.  This commit therefore
initializes RCU Tasks (along with Rude RCU and RCU Tasks Trace) just
before early_initcall() time, thus allowing waiting on RCU Tasks grace
periods from early_initcall() handlers.

Link: https://lore.kernel.org/rcu/87eekfh80a.fsf@dja-thinkpad.axtens.net/
Fixes: 36dadef23f ("kprobes: Init kprobes in early_initcall")
Tested-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-12-14 15:31:13 -08:00
Yonghong Song
cd17d38f8b bpf: Permits pointers on stack for helper calls
Currently, when checking stack memory accessed by helper calls,
for spills, only PTR_TO_BTF_ID and SCALAR_VALUE are
allowed.

Song discovered an issue where the below bpf program
  int dump_task(struct bpf_iter__task *ctx)
  {
    struct seq_file *seq = ctx->meta->seq;
    static char[] info = "abc";
    BPF_SEQ_PRINTF(seq, "%s\n", info);
    return 0;
  }
may cause a verifier failure.

The verifier output looks like:
  ; struct seq_file *seq = ctx->meta->seq;
  1: (79) r1 = *(u64 *)(r1 +0)
  ; BPF_SEQ_PRINTF(seq, "%s\n", info);
  2: (18) r2 = 0xffff9054400f6000
  4: (7b) *(u64 *)(r10 -8) = r2
  5: (bf) r4 = r10
  ;
  6: (07) r4 += -8
  ; BPF_SEQ_PRINTF(seq, "%s\n", info);
  7: (18) r2 = 0xffff9054400fe000
  9: (b4) w3 = 4
  10: (b4) w5 = 8
  11: (85) call bpf_seq_printf#126
   R1_w=ptr_seq_file(id=0,off=0,imm=0) R2_w=map_value(id=0,off=0,ks=4,vs=4,imm=0)
  R3_w=inv4 R4_w=fp-8 R5_w=inv8 R10=fp0 fp-8_w=map_value
  last_idx 11 first_idx 0
  regs=8 stack=0 before 10: (b4) w5 = 8
  regs=8 stack=0 before 9: (b4) w3 = 4
  invalid indirect read from stack off -8+0 size 8

Basically, the verifier complains the map_value pointer at "fp-8" location.
To fix the issue, if env->allow_ptr_leaks is true, let us also permit
pointers on the stack to be accessible by the helper.

Reported-by: Song Liu <songliubraving@fb.com>
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201210013349.943719-1-yhs@fb.com
2020-12-14 21:50:10 +01:00
Linus Torvalds
9e4b0d55d8 Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto updates from Herbert Xu:
 "API:
   - Add speed testing on 1420-byte blocks for networking

  Algorithms:
   - Improve performance of chacha on ARM for network packets
   - Improve performance of aegis128 on ARM for network packets

  Drivers:
   - Add support for Keem Bay OCS AES/SM4
   - Add support for QAT 4xxx devices
   - Enable crypto-engine retry mechanism in caam
   - Enable support for crypto engine on sdm845 in qce
   - Add HiSilicon PRNG driver support"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (161 commits)
  crypto: qat - add capability detection logic in qat_4xxx
  crypto: qat - add AES-XTS support for QAT GEN4 devices
  crypto: qat - add AES-CTR support for QAT GEN4 devices
  crypto: atmel-i2c - select CONFIG_BITREVERSE
  crypto: hisilicon/trng - replace atomic_add_return()
  crypto: keembay - Add support for Keem Bay OCS AES/SM4
  dt-bindings: Add Keem Bay OCS AES bindings
  crypto: aegis128 - avoid spurious references crypto_aegis128_update_simd
  crypto: seed - remove trailing semicolon in macro definition
  crypto: x86/poly1305 - Use TEST %reg,%reg instead of CMP $0,%reg
  crypto: x86/sha512 - Use TEST %reg,%reg instead of CMP $0,%reg
  crypto: aesni - Use TEST %reg,%reg instead of CMP $0,%reg
  crypto: cpt - Fix sparse warnings in cptpf
  hwrng: ks-sa - Add dependency on IOMEM and OF
  crypto: lib/blake2s - Move selftest prototype into header file
  crypto: arm/aes-ce - work around Cortex-A57/A72 silion errata
  crypto: ecdh - avoid unaligned accesses in ecdh_set_secret()
  crypto: ccree - rework cache parameters handling
  crypto: cavium - Use dma_set_mask_and_coherent to simplify code
  crypto: marvell/octeontx - Use dma_set_mask_and_coherent to simplify code
  ...
2020-12-14 12:18:19 -08:00
Rafael J. Wysocki
30c768829a Merge branch 'cpufreq/arm/linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm
Pull ARM cpufreq updates for 5.11-rc1 from Viresh Kumar:

"This contains the following updates:

 - Fix imx's NVMEM_IMX_OCOTP dependency (Arnd Bergmann).

 - Add support for mt8167 and blacklist mt8516 (Fabien Parent).

 - Some ->get() callback related cleanups to the tegra194 driver and
   some optimizations in tegra186 driver (Jon Hunter and Sumit Gupta).

 - Power scale improvements to arm_scmi driver (Lukasz Luba).

 - Add missing MODULE_DEVICE_TABLE and MODULE_ALIAS to several drivers
   (Pali Rohár).

 - Fix error path in mediatek driver (Qinglang Miao).

 - Fix memleak in ST's cpufreq driver (Yangtao Li)."

* 'cpufreq/arm/linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm: (22 commits)
  cpufreq: arm_scmi: Discover the power scale in performance protocol
  firmware: arm_scmi: Add power_scale_mw_get() interface
  cpufreq: tegra194: Rename tegra194_get_speed_common function
  cpufreq: tegra194: Remove unnecessary frequency calculation
  cpufreq: tegra186: Simplify cluster information lookup
  cpufreq: tegra186: Fix sparse 'incorrect type in assignment' warning
  cpufreq: imx: fix NVMEM_IMX_OCOTP dependency
  cpufreq: vexpress-spc: Add missing MODULE_ALIAS
  cpufreq: scpi: Add missing MODULE_ALIAS
  cpufreq: loongson1: Add missing MODULE_ALIAS
  cpufreq: sun50i: Add missing MODULE_DEVICE_TABLE
  cpufreq: st: Add missing MODULE_DEVICE_TABLE
  cpufreq: qcom: Add missing MODULE_DEVICE_TABLE
  cpufreq: mediatek: Add missing MODULE_DEVICE_TABLE
  cpufreq: highbank: Add missing MODULE_DEVICE_TABLE
  cpufreq: ap806: Add missing MODULE_DEVICE_TABLE
  cpufreq: mediatek: add missing platform_driver_unregister() on error in mtk_cpufreq_driver_init
  cpufreq: tegra194: get consistent cpuinfo_cur_freq
  cpufreq: blacklist mt8516 in cpufreq-dt-platdev
  cpufreq: mediatek: Add support for mt8167
  ...
2020-12-14 20:29:50 +01:00
Steven Rostedt (VMware)
adab66b71a Revert: "ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS"
It was believed that metag was the only architecture that required the ring
buffer to keep 8 byte words aligned on 8 byte architectures, and with its
removal, it was assumed that the ring buffer code did not need to handle
this case. It appears that sparc64 also requires this.

The following was reported on a sparc64 boot up:

   kernel: futex hash table entries: 65536 (order: 9, 4194304 bytes, linear)
   kernel: Running postponed tracer tests:
   kernel: Testing tracer function:
   kernel: Kernel unaligned access at TPC[552a20] trace_function+0x40/0x140
   kernel: Kernel unaligned access at TPC[552a24] trace_function+0x44/0x140
   kernel: Kernel unaligned access at TPC[552a20] trace_function+0x40/0x140
   kernel: Kernel unaligned access at TPC[552a24] trace_function+0x44/0x140
   kernel: Kernel unaligned access at TPC[552a20] trace_function+0x40/0x140
   kernel: PASSED

Need to put back the 64BIT aligned code for the ring buffer.

Link: https://lore.kernel.org/r/CADxRZqzXQRYgKc=y-KV=S_yHL+Y8Ay2mh5ezeZUnpRvg+syWKw@mail.gmail.com

Cc: stable@vger.kernel.org
Fixes: 86b3de60a0 ("ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS")
Reported-by: Anatoly Pugachev <matorola@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-12-14 12:33:51 -05:00
Qiujun Huang
74e2afc6df ring-buffer: Add rb_check_bpage in __rb_allocate_pages
It may be better to check each page is aligned by 4 bytes. The 2
least significant bits of the address will be used as flags.

Link: https://lkml.kernel.org/r/20201015113842.2921-1-hqjagain@gmail.com

Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-12-14 12:26:32 -05:00
Qiujun Huang
82db909e6b ring-buffer: Fix two typos in comments
s/inerrupting/interrupting/
s/beween/between/

Link: https://lkml.kernel.org/r/20201014152749.29986-1-hqjagain@gmail.com

Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-12-14 12:21:27 -05:00
Lukas Bulwahn
3b3493531c tracing: Drop unneeded assignment in ring_buffer_resize()
Since commit 0a1754b2a9 ("ring-buffer: Return 0 on success from
ring_buffer_resize()"), computing the size is not needed anymore.

Drop unneeded assignment in ring_buffer_resize().

Link: https://lkml.kernel.org/r/20201214084503.3079-1-lukas.bulwahn@gmail.com

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-12-14 12:09:54 -05:00
Masami Hiramatsu
60efe21e59 tracing: Disable ftrace selftests when any tracer is running
Disable ftrace selftests when any tracer (kernel command line options
like ftrace=, trace_events=, kprobe_events=, and boot-time tracing)
starts running because selftest can disturb it.

Currently ftrace= and trace_events= are checked, but kprobe_events
has a different flag, and boot-time tracing didn't checked. This unifies
the disabled flag and all of those boot-time tracing features sets
the flag.

This also fixes warnings on kprobe-event selftest
(CONFIG_FTRACE_STARTUP_TEST=y and CONFIG_KPROBE_EVENTS=y) with boot-time
tracing (ftrace.event.kprobes.EVENT.probes) like below;

[   59.803496] trace_kprobe: Testing kprobe tracing:
[   59.804258] ------------[ cut here ]------------
[   59.805682] WARNING: CPU: 3 PID: 1 at kernel/trace/trace_kprobe.c:1987 kprobe_trace_self_tests_ib
[   59.806944] Modules linked in:
[   59.807335] CPU: 3 PID: 1 Comm: swapper/0 Not tainted 5.10.0-rc7+ #172
[   59.808029] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1 04/01/204
[   59.808999] RIP: 0010:kprobe_trace_self_tests_init+0x5f/0x42b
[   59.809696] Code: e8 03 00 00 48 c7 c7 30 8e 07 82 e8 6d 3c 46 ff 48 c7 c6 00 b2 1a 81 48 c7 c7 7
[   59.812439] RSP: 0018:ffffc90000013e78 EFLAGS: 00010282
[   59.813038] RAX: 00000000ffffffef RBX: 0000000000000000 RCX: 0000000000049443
[   59.813780] RDX: 0000000000049403 RSI: 0000000000049403 RDI: 000000000002deb0
[   59.814589] RBP: ffffc90000013e90 R08: 0000000000000001 R09: 0000000000000001
[   59.815349] R10: 0000000000000001 R11: 0000000000000000 R12: 00000000ffffffef
[   59.816138] R13: ffff888004613d80 R14: ffffffff82696940 R15: ffff888004429138
[   59.816877] FS:  0000000000000000(0000) GS:ffff88807dcc0000(0000) knlGS:0000000000000000
[   59.817772] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   59.818395] CR2: 0000000001a8dd38 CR3: 0000000002222000 CR4: 00000000000006a0
[   59.819144] Call Trace:
[   59.819469]  ? init_kprobe_trace+0x6b/0x6b
[   59.819948]  do_one_initcall+0x5f/0x300
[   59.820392]  ? rcu_read_lock_sched_held+0x4f/0x80
[   59.820916]  kernel_init_freeable+0x22a/0x271
[   59.821416]  ? rest_init+0x241/0x241
[   59.821841]  kernel_init+0xe/0x10f
[   59.822251]  ret_from_fork+0x22/0x30
[   59.822683] irq event stamp: 16403349
[   59.823121] hardirqs last  enabled at (16403359): [<ffffffff810db81e>] console_unlock+0x48e/0x580
[   59.824074] hardirqs last disabled at (16403368): [<ffffffff810db786>] console_unlock+0x3f6/0x580
[   59.825036] softirqs last  enabled at (16403200): [<ffffffff81c0033a>] __do_softirq+0x33a/0x484
[   59.825982] softirqs last disabled at (16403087): [<ffffffff81a00f02>] asm_call_irq_on_stack+0x10
[   59.827034] ---[ end trace 200c544775cdfeb3 ]---
[   59.827635] trace_kprobe: error on probing function entry.

Link: https://lkml.kernel.org/r/160741764955.3448999.3347769358299456915.stgit@devnote2

Fixes: 4d655281eb ("tracing/boot Add kprobe event support")
Cc: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-12-14 12:05:03 -05:00
Petr Mladek
5ed37174e6 Merge branch 'for-5.11' into for-linus 2020-12-14 15:15:07 +01:00
Petr Mladek
5f3b8d3986 Merge branch 'for-5.11-null-console' into for-linus 2020-12-14 15:14:57 +01:00
Linus Torvalds
ec6f5e0e5c A set of x86 and membarrier fixes:
- Correct a few problems in the x86 and the generic membarrier
     implementation. Small corrections for assumptions about visibility
     which have turned out not to be true.
 
   - Make the PAT bits for memory encryption correct vs. 4K and 2M/1G page
     table entries as they are at a different location.
 
   - Fix a concurrency issue in the the local bandwidth readout of resource
     control leading to incorrect values
 
   - Fix the ordering of allocating a vector for an interrupt. The order
     missed to respect the provided cpumask when the first attempt of
     allocating node local in the mask fails. It then tries the node instead
     of trying the full provided mask first. This leads to erroneous error
     messages and breaking the (user) supplied affinity request. Reorder it.
 
   - Make the INT3 padding detection in optprobe work correctly.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAl/WOw0THHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYodUhEACW02Al+mlpZjOhzIGwNUALGX7YGEOi
 wJoiIDTV2vOtKhcJ/AOVn05CznoWXa6PN1+7pm0nR2M1XaiXZ3B6HMjy1+0rpSqK
 5dCCEqr+QowwMRsKd4hnuJowR/7Og66FiYIcknDJg/1egg+RXy7yKds577W6/KW0
 2VV/x35xDywERiQ28qIftQ4L7NREyiioomN/GFpeoQf8tQF06Rb4t12T5pdA6D8S
 /C1wj0IKVRMJo/7HbB/X6skxPOK0PWAEBpaT0+Q66VKSNnFVN5ap+rGTKdUoTmuM
 NdxHOukpHyFCQtbRPOjRUeeSZJLKSX5oXsBO1GUvyyxcT2XNlTOdNamYLWyO+RfV
 uP97qhzYDKL+cgDkwypJ0WOzOb9EIXOh4P9BTnJFBGhc4EQwen3cpb3CyWWftjnv
 /obXiRDnAOE6P6H2AGiwrK3Pny+SvgrFYKMe+iy+ntToz1yrDh7ZrZ0DQKVoFWEr
 n3qUnlPZmVvRzHIRVYoK69nS/UgmNN0LssavzRBzab3BcK93f23QkW86P42kNCLa
 9kL+ZgGwlpqUZZR/p3pHq9Mv2ZXGEdUYY99h2vy1fgMwOw/RQZnPDAj/131UXlsU
 4DL0mAlTK1/0/81H6/V1GDBkMkO+hN4x6Y3asi7bPHEKEzlLe+P1tUt3YELd3CEC
 dc8ebICG1InXsw==
 =t31y
 -----END PGP SIGNATURE-----

Merge tag 'x86-urgent-2020-12-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Thomas Gleixner:
 "A set of x86 and membarrier fixes:

   - Correct a few problems in the x86 and the generic membarrier
     implementation. Small corrections for assumptions about visibility
     which have turned out not to be true.

   - Make the PAT bits for memory encryption correct vs 4K and 2M/1G
     page table entries as they are at a different location.

   - Fix a concurrency issue in the the local bandwidth readout of
     resource control leading to incorrect values

   - Fix the ordering of allocating a vector for an interrupt. The order
     missed to respect the provided cpumask when the first attempt of
     allocating node local in the mask fails. It then tries the node
     instead of trying the full provided mask first. This leads to
     erroneous error messages and breaking the (user) supplied affinity
     request. Reorder it.

   - Make the INT3 padding detection in optprobe work correctly"

* tag 'x86-urgent-2020-12-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/kprobes: Fix optprobe to detect INT3 padding correctly
  x86/apic/vector: Fix ordering in vector assignment
  x86/resctrl: Fix incorrect local bandwidth when mba_sc is enabled
  x86/mm/mem_encrypt: Fix definition of PMD_FLAGS_DEC_WP
  membarrier: Execute SYNC_CORE on the calling thread
  membarrier: Explicitly sync remote cores when SYNC_CORE is requested
  membarrier: Add an actual barrier before rseq_preempt()
  x86/membarrier: Get rid of a dubious optimization
2020-12-13 11:31:19 -08:00
Jens Axboe
e296dc4996 kernel: remove checking for TIF_NOTIFY_SIGNAL
It's available everywhere now, no need to check or add dummy defines.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-12 09:17:38 -07:00
Jens Axboe
98b89b649f signal: kill JOBCTL_TASK_WORK
It's no longer used, get rid of it.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-12 09:17:38 -07:00
Jens Axboe
03941ccfda task_work: remove legacy TWA_SIGNAL path
All archs now support TIF_NOTIFY_SIGNAL.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-12 09:17:38 -07:00
Jakub Kicinski
46d5e62dd3 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
xdp_return_frame_bulk() needs to pass a xdp_buff
to __xdp_return().

strlcpy got converted to strscpy but here it makes no
functional difference, so just keep the right code.

Conflicts:
	net/netfilter/nf_tables_api.c

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-11 22:29:38 -08:00
Thomas Gleixner
aa3b66f401 tick/sched: Make jiffies update quick check more robust
The quick check in tick_do_update_jiffies64() whether jiffies need to be
updated is not really correct under all circumstances and on all
architectures, especially not on 32bit systems.

The quick check does:

    if (now < READ_ONCE(tick_next_period))
    	return;

and the counterpart in the update is:

    WRITE_ONCE(tick_next_period, next_update_time);

This has two problems:

  1) On weakly ordered architectures there is no guarantee that the stores
     before the WRITE_ONCE() are visible which means that other CPUs can
     operate on a stale jiffies value.

  2) On 32bit the store of tick_next_period which is an u64 is split into
     two 32bit stores. If the first 32bit store advances tick_next_period
     far out and the second 32bit store is delayed (virt, NMI ...) then
     jiffies will become stale until the second 32bit store happens.

Address this by seperating the handling for 32bit and 64bit.

On 64bit problem #1 is addressed by replacing READ_ONCE() / WRITE_ONCE()
with smp_load_acquire() / smp_store_release().

On 32bit problem #2 is addressed by protecting the quick check with the
jiffies sequence counter. The load and stores can be plain because the
sequence count mechanics provides the required barriers already.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/87czzpc02w.fsf@nanos.tec.linutronix.de
2020-12-11 23:19:10 +01:00
Andrii Nakryiko
b7906b70a2 bpf: Fix enum names for bpf_this_cpu_ptr() and bpf_per_cpu_ptr() helpers
Remove bpf_ prefix, which causes these helpers to be reported in verifier
dump as bpf_bpf_this_cpu_ptr() and bpf_bpf_per_cpu_ptr(), respectively. Lets
fix it as long as it is still possible before UAPI freezes on these helpers.

Fixes: eaa6bcb71e ("bpf: Introduce bpf_per_cpu_ptr()")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-11 14:19:07 -08:00
Arnd Bergmann
6e7b64b9dd elfcore: fix building with clang
kernel/elfcore.c only contains weak symbols, which triggers a bug with
clang in combination with recordmcount:

  Cannot find symbol for section 2: .text.
  kernel/elfcore.o: failed

Move the empty stubs into linux/elfcore.h as inline functions.  As only
two architectures use these, just use the architecture specific Kconfig
symbols to key off the declaration.

Link: https://lkml.kernel.org/r/20201204165742.3815221-2-arnd@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Barret Rhoden <brho@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-11 14:02:14 -08:00
Ashish Kalra
e998879d4f x86,swiotlb: Adjust SWIOTLB bounce buffer size for SEV guests
For SEV, all DMA to and from guest has to use shared (un-encrypted) pages.
SEV uses SWIOTLB to make this happen without requiring changes to device
drivers.  However, depending on the workload being run, the default 64MB
of it might not be enough and it may run out of buffers to use for DMA,
resulting in I/O errors and/or performance degradation for high
I/O workloads.

Adjust the default size of SWIOTLB for SEV guests using a
percentage of the total memory available to guest for the SWIOTLB buffers.

Adds a new sev_setup_arch() function which is invoked from setup_arch()
and it calls into a new swiotlb generic code function swiotlb_adjust_size()
to do the SWIOTLB buffer adjustment.

v5 fixed build errors and warnings as
Reported-by: kbuild test robot <lkp@intel.com>

Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
Co-developed-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2020-12-11 15:43:41 -05:00
Rafael J. Wysocki
90ac908a41 cpufreq: schedutil: Simplify sugov_update_next_freq()
Rearrange a conditional to make it more straightforward.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-12-11 19:53:58 +01:00
John Garry
1d3aec8928 genirq/affinity: Add irq_update_affinity_desc()
Add a function to allow the affinity of an interrupt be switched to
managed, such that interrupts allocated for platform devices may be
managed.

This new interface has certain limitations, and attempts to use it in the
following circumstances will fail:
- For when the kernel is configured for generic IRQ reservation mode (in
  config GENERIC_IRQ_RESERVATION_MODE). The reason being that it could
  conflict with managed vs. non-managed interrupt accounting.
- The interrupt is already started, which should not be the case during
  init
- The interrupt is already configured as managed, which means double init

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/1606905417-183214-2-git-send-email-john.garry@huawei.com
2020-12-11 14:47:50 +00:00
Valentin Schneider
b388fa5014 Revert "genirq: Add fasteoi IPI flow"
handle_percpu_devid_fasteoi_ipi() has no more users, and
handle_percpu_devid_irq() can do all that it was supposed to do. Get rid of
it.

This reverts commit c5e5ec033c.

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201109094121.29975-6-valentin.schneider@arm.com
2020-12-11 14:47:50 +00:00
Thomas Gleixner
76e87d96b3 ntp: Consolidate the RTC update implementation
The code for the legacy RTC and the RTC class based update are pretty much
the same. Consolidate the common parts into one function and just invoke
the actual setter functions.

For RTC class based devices the update code checks whether the offset is
valid for the device, which is usually not the case for the first
invocation. If it's not the same it stores the correct offset and lets the
caller try again. That's not much different from the previous approach
where the first invocation had a pretty low probability to actually hit the
allowed window.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201206220542.355743355@linutronix.de
2020-12-11 10:40:53 +01:00
Thomas Gleixner
69eca258c8 ntp: Make the RTC sync offset less obscure
The current RTC set_offset_nsec value is not really intuitive to
understand. 

  tsched       twrite(t2.tv_sec - 1) 	 t2 (seconds increment)

The offset is calculated from twrite based on the assumption that t2 -
twrite == 1s. That means for the MC146818 RTC the offset needs to be
negative so that the write happens 500ms before t2.

It's easier to understand when the whole calculation is based on t2. That
avoids negative offsets and the meaning is obvious:

 t2 - twrite:     The time defined by the chip when seconds increment
      		  after the write.

 twrite - tsched: The time for the transport to the point where the chip
 	  	  is updated. 

==> set_offset_nsec =  t2 - tsched
    ttransport      =  twrite - tsched
    tRTCinc         =  t2 - twrite
==> set_offset_nsec =  ttransport + tRTCinc

tRTCinc is a chip property and can be obtained from the data sheet.

ttransport depends on how the RTC is connected. It is close to 0 for
directly accessible RTCs. For RTCs behind a slow bus, e.g. i2c, it's the
time required to send the update over the bus. This can be estimated or
even calibrated, but that's a different problem.

Adjust the implementation and update comments accordingly.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201206220542.263204937@linutronix.de
2020-12-11 10:40:53 +01:00
Thomas Gleixner
33e62e8323 ntp, rtc: Move rtc_set_ntp_time() to ntp code
rtc_set_ntp_time() is not really RTC functionality as the code is just a
user of RTC. Move it into the NTP code which allows further cleanups.

Requested-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201206220542.166871172@linutronix.de
2020-12-11 10:40:52 +01:00
Thomas Gleixner
c9e6189fb0 ntp: Make the RTC synchronization more reliable
Miroslav reported that the periodic RTC synchronization in the NTP code
fails more often than not to hit the specified update window.

The reason is that the code uses delayed_work to schedule the update which
needs to be in thread context as the underlying RTC might be connected via
a slow bus, e.g. I2C. In the update function it verifies whether the
current time is correct vs. the requirements of the underlying RTC.

But delayed_work is using the timer wheel for scheduling which is
inaccurate by design. Depending on the distance to the expiry the wheel
gets less granular to allow batching and to avoid the cascading of the
original timer wheel. See 500462a9de ("timers: Switch to a non-cascading
wheel") and the code for further details.

The code already deals with this by splitting the 660 seconds period into a
long 659 seconds timer and then retrying with a smaller delta.

But looking at the actual granularities of the timer wheel (which depend on
the HZ configuration) the 659 seconds timer ends up in an outer wheel level
and is affected by a worst case granularity of:

HZ          Granularity
1000        32s
 250        16s
 100        40s

So the initial timer can be already off by max 12.5% which is not a big
issue as the period of the sync is defined as ~11 minutes.

The fine grained second attempt schedules to the desired update point with
a timer expiring less than a second from now. Depending on the actual delta
and the HZ setting even the second attempt can end up in outer wheel levels
which have a large enough granularity to make the correctness check fail.

As this is a fundamental property of the timer wheel there is no way to
make this more accurate short of iterating in one jiffies steps towards the
update point.

Switch it to an hrtimer instead which schedules the actual update work. The
hrtimer will expire precisely (max 1 jiffie delay when high resolution
timers are not available). The actual scheduling delay of the work is the
same as before.

The update is triggered from do_adjtimex() which is a bit racy but not much
more racy than it was before:

     if (ntp_synced())
     	queue_delayed_work(system_power_efficient_wq, &sync_work, 0);

which is racy when the work is currently executed and has not managed to
reschedule itself.

This becomes now:

     if (ntp_synced() && !hrtimer_is_queued(&sync_hrtimer))
     	queue_work(system_power_efficient_wq, &sync_work, 0);

which is racy when the hrtimer has expired and the work is currently
executed and has not yet managed to rearm the hrtimer.

Not a big problem as it just schedules work for nothing.

The new implementation has a safe guard in place to catch the case where
the hrtimer is queued on entry to the work function and avoids an extra
update attempt of the RTC that way.

Reported-by: Miroslav Lichvar <mlichvar@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Miroslav Lichvar <mlichvar@redhat.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201206220542.062910520@linutronix.de
2020-12-11 10:40:52 +01:00
Barry Song
5b78f2dc31 sched/fair: Trivial correction of the newidle_balance() comment
idle_balance() has been renamed to newidle_balance(). To differentiate
with nohz_idle_balance, it seems refining the comment will be helpful
for the readers of the code.

Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20201202220641.22752-1-song.bao.hua@hisilicon.com
2020-12-11 10:30:44 +01:00
Mel Gorman
13d5a5e9f9 sched/fair: Clear SMT siblings after determining the core is not idle
The clearing of SMT siblings from the SIS mask before checking for an idle
core is a small but unnecessary cost. Defer the clearing of the siblings
until the scan moves to the next potential target. The cost of this was
not measured as it is borderline noise but it should be self-evident.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/20201130144020.GS3371@techsingularity.net
2020-12-11 10:30:38 +01:00
Mauro Carvalho Chehab
59a74b1544 sched: Fix kernel-doc markup
Kernel-doc requires that a kernel-doc markup to be immediately
below the function prototype, as otherwise it will rename it.
So, move sys_sched_yield() markup to the right place.

Also fix the cpu_util() markup: Kernel-doc markups
should use this format:
        identifier - description

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/50cd6f460aeb872ebe518a8e9cfffda2df8bdb0a.1606823973.git.mchehab+huawei@kernel.org
2020-12-11 10:30:31 +01:00
Linus Torvalds
4d31058b82 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from David Miller:

 1) IPsec compat fixes, from Dmitry Safonov.

 2) Fix memory leak in xfrm_user_policy(). Fix from Yu Kuai.

 3) Fix polling in xsk sockets by using sk_poll_wait() instead of
    datagram_poll() which keys off of sk_wmem_alloc and such which xsk
    sockets do not update. From Xuan Zhuo.

 4) Missing init of rekey_data in cfgh80211, from Sara Sharon.

 5) Fix destroy of timer before init, from Davide Caratti.

 6) Missing CRYPTO_CRC32 selects in ethernet driver Kconfigs, from Arnd
    Bergmann.

 7) Missing error return in rtm_to_fib_config() switch case, from Zhang
    Changzhong.

 8) Fix some src/dest address handling in vrf and add a testcase. From
    Stephen Suryaputra.

 9) Fix multicast handling in Seville switches driven by mscc-ocelot
    driver. From Vladimir Oltean.

10) Fix proto value passed to skb delivery demux in udp, from Xin Long.

11) HW pkt counters not reported correctly in enetc driver, from Claudiu
    Manoil.

12) Fix deadlock in bridge, from Joseph Huang.

13) Missing of_node_pur() in dpaa2 driver, fromn Christophe JAILLET.

14) Fix pid fetching in bpftool when there are a lot of results, from
    Andrii Nakryiko.

15) Fix long timeouts in nft_dynset, from Pablo Neira Ayuso.

16) Various stymmac fixes, from Fugang Duan.

17) Fix null deref in tipc, from Cengiz Can.

18) When mss is biog, coose more resonable rcvq_space in tcp, fromn Eric
    Dumazet.

19) Revert a geneve change that likely isnt necessary, from Jakub
    Kicinski.

20) Avoid premature rx buffer reuse in various Intel driversm from Björn
    Töpel.

21) retain EcT bits during TIS reflection in tcp, from Wei Wang.

22) Fix Tso deferral wrt. cwnd limiting in tcp, from Neal Cardwell.

23) MPLS_OPT_LSE_LABEL attribute is 342 ot 8 bits, from Guillaume Nault

24) Fix propagation of 32-bit signed bounds in bpf verifier and add test
    cases, from Alexei Starovoitov.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (81 commits)
  selftests: fix poll error in udpgro.sh
  selftests/bpf: Fix "dubious pointer arithmetic" test
  selftests/bpf: Fix array access with signed variable test
  selftests/bpf: Add test for signed 32-bit bound check bug
  bpf: Fix propagation of 32-bit signed bounds from 64-bit bounds.
  MAINTAINERS: Add entry for Marvell Prestera Ethernet Switch driver
  net: sched: Fix dump of MPLS_OPT_LSE_LABEL attribute in cls_flower
  net/mlx4_en: Handle TX error CQE
  net/mlx4_en: Avoid scheduling restart task if it is already running
  tcp: fix cwnd-limited bug for TSO deferral where we send nothing
  net: flow_offload: Fix memory leak for indirect flow block
  tcp: Retain ECT bits for tos reflection
  ethtool: fix stack overflow in ethnl_parse_bitset()
  e1000e: fix S0ix flow to allow S0i3.2 subset entry
  ice: avoid premature Rx buffer reuse
  ixgbe: avoid premature Rx buffer reuse
  i40e: avoid premature Rx buffer reuse
  igb: avoid transmit queue timeout in xdp path
  igb: use xdp_do_flush
  igb: skb add metasize for xdp
  ...
2020-12-10 15:30:13 -08:00
David S. Miller
d9838b1d39 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Alexei Starovoitov says:

====================
pull-request: bpf 2020-12-10

The following pull-request contains BPF updates for your *net* tree.

We've added 21 non-merge commits during the last 12 day(s) which contain
a total of 21 files changed, 163 insertions(+), 88 deletions(-).

The main changes are:

1) Fix propagation of 32-bit signed bounds from 64-bit bounds, from Alexei.

2) Fix ring_buffer__poll() return value, from Andrii.

3) Fix race in lwt_bpf, from Cong.

4) Fix test_offload, from Toke.

5) Various xsk fixes.

Please consider pulling these changes from:

  git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git

Thanks a lot!

Also thanks to reporters, reviewers and testers of commits in this pull-request:

Cong Wang, Hulk Robot, Jakub Kicinski, Jean-Philippe Brucker, John
Fastabend, Magnus Karlsson, Maxim Mikityanskiy, Yonghong Song
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-12-10 14:29:30 -08:00
Alexei Starovoitov
b02709587e bpf: Fix propagation of 32-bit signed bounds from 64-bit bounds.
The 64-bit signed bounds should not affect 32-bit signed bounds unless the
verifier knows that upper 32-bits are either all 1s or all 0s. For example the
register with smin_value==1 doesn't mean that s32_min_value is also equal to 1,
since smax_value could be larger than 32-bit subregister can hold.
The verifier refines the smax/s32_max return value from certain helpers in
do_refine_retval_range(). Teach the verifier to recognize that smin/s32_min
value is also bounded. When both smin and smax bounds fit into 32-bit
subregister the verifier can propagate those bounds.

Fixes: 3f50f132d8 ("bpf: Verifier, do explicit ALU32 bounds tracking")
Reported-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2020-12-10 13:02:53 -08:00
Eric W. Biederman
f7cfd871ae exec: Transform exec_update_mutex into a rw_semaphore
Recently syzbot reported[0] that there is a deadlock amongst the users
of exec_update_mutex.  The problematic lock ordering found by lockdep
was:

   perf_event_open  (exec_update_mutex -> ovl_i_mutex)
   chown            (ovl_i_mutex       -> sb_writes)
   sendfile         (sb_writes         -> p->lock)
     by reading from a proc file and writing to overlayfs
   proc_pid_syscall (p->lock           -> exec_update_mutex)

While looking at possible solutions it occured to me that all of the
users and possible users involved only wanted to state of the given
process to remain the same.  They are all readers.  The only writer is
exec.

There is no reason for readers to block on each other.  So fix
this deadlock by transforming exec_update_mutex into a rw_semaphore
named exec_update_lock that only exec takes for writing.

Cc: Jann Horn <jannh@google.com>
Cc: Vasiliy Kulikov <segoon@openwall.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Bernd Edlinger <bernd.edlinger@hotmail.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Christopher Yeoh <cyeoh@au1.ibm.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Sargun Dhillon <sargun@sargun.me>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Fixes: eea9673250 ("exec: Add exec_update_mutex to replace cred_guard_mutex")
[0] https://lkml.kernel.org/r/00000000000063640c05ade8e3de@google.com
Reported-by: syzbot+db9cdf3dd1f64252c6ef@syzkaller.appspotmail.com
Link: https://lkml.kernel.org/r/87ft4mbqen.fsf@x220.int.ebiederm.org
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2020-12-10 13:13:32 -06:00
Eric W. Biederman
66ed594409 bpf/task_iter: In task_file_seq_get_next use task_lookup_next_fd_rcu
When discussing[1] exec and posix file locks it was realized that none
of the callers of get_files_struct fundamentally needed to call
get_files_struct, and that by switching them to helper functions
instead it will both simplify their code and remove unnecessary
increments of files_struct.count.  Those unnecessary increments can
result in exec unnecessarily unsharing files_struct which breaking
posix locks, and it can result in fget_light having to fallback to
fget reducing system performance.

Using task_lookup_next_fd_rcu simplifies task_file_seq_get_next, by
moving the checking for the maximum file descritor into the generic
code, and by remvoing the need for capturing and releasing a reference
on files_struct.  As the reference count of files_struct no longer
needs to be maintained bpf_iter_seq_task_file_info can have it's files
member removed and task_file_seq_get_next no longer needs it's fstruct
argument.

The curr_fd local variable does need to become unsigned to be used
with fnext_task.  As curr_fd is assigned from and assigned a u32
making curr_fd an unsigned int won't cause problems and might prevent
them.

[1] https://lkml.kernel.org/r/20180915160423.GA31461@redhat.com
Suggested-by: Oleg Nesterov <oleg@redhat.com>
v1: https://lkml.kernel.org/r/20200817220425.9389-11-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20201120231441.29911-16-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2020-12-10 12:42:58 -06:00
Eric W. Biederman
ed77e80e14 kcmp: In get_file_raw_ptr use task_lookup_fd_rcu
Modify get_file_raw_ptr to use task_lookup_fd_rcu.  The helper
task_lookup_fd_rcu does the work of taking the task lock and verifying
that task->files != NULL and then calls files_lookup_fd_rcu.  So let
use the helper to make a simpler implementation of get_file_raw_ptr.

Acked-by: Cyrill Gorcunov <gorcunov@gmail.com>
Link: https://lkml.kernel.org/r/20201120231441.29911-13-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2020-12-10 12:42:49 -06:00
Eric W. Biederman
f36c294327 file: Replace fcheck_files with files_lookup_fd_rcu
This change renames fcheck_files to files_lookup_fd_rcu.  All of the
remaining callers take the rcu_read_lock before calling this function
so the _rcu suffix is appropriate.  This change also tightens up the
debug check to verify that all callers hold the rcu_read_lock.

All callers that used to call files_check with the files->file_lock
held have now been changed to call files_lookup_fd_locked.

This change of name has helped remind me of which locks and which
guarantees are in place helping me to catch bugs later in the
patchset.

The need for better names became apparent in the last round of
discussion of this set of changes[1].

[1] https://lkml.kernel.org/r/CAHk-=wj8BQbgJFLa+J0e=iT-1qpmCRTbPAJ8gd6MJQ=kbRPqyQ@mail.gmail.com
Link: https://lkml.kernel.org/r/20201120231441.29911-9-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2020-12-10 12:40:03 -06:00
Eric W. Biederman
b48845af01 bpf: In bpf_task_fd_query use fget_task
Use the helper fget_task to simplify bpf_task_fd_query.

As well as simplifying the code this removes one unnecessary increment of
struct files_struct.  This unnecessary increment of files_struct.count can
result in exec unnecessarily unsharing files_struct and breaking posix
locks, and it can result in fget_light having to fallback to fget reducing
performance.

This simplification comes from the observation that none of the
callers of get_files_struct actually need to call get_files_struct
that was made when discussing[1] exec and posix file locks.

[1] https://lkml.kernel.org/r/20180915160423.GA31461@redhat.com
Suggested-by: Oleg Nesterov <oleg@redhat.com>
v1: https://lkml.kernel.org/r/20200817220425.9389-5-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20201120231441.29911-5-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2020-12-10 12:39:44 -06:00
Eric W. Biederman
f43c283a89 kcmp: In kcmp_epoll_target use fget_task
Use the helper fget_task and simplify the code.

As well as simplifying the code this removes one unnecessary increment of
struct files_struct.  This unnecessary increment of files_struct.count can
result in exec unnecessarily unsharing files_struct and breaking posix
locks, and it can result in fget_light having to fallback to fget reducing
performance.

Suggested-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Cyrill Gorcunov <gorcunov@gmail.com>
v1: https://lkml.kernel.org/r/20200817220425.9389-4-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20201120231441.29911-4-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2020-12-10 12:39:40 -06:00
Eric W. Biederman
1f702603e7 exec: Simplify unshare_files
Now that exec no longer needs to return the unshared files to their
previous value there is no reason to return displaced.

Instead when unshare_fd creates a copy of the file table, call
put_files_struct before returning from unshare_files.

Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
v1: https://lkml.kernel.org/r/20200817220425.9389-2-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20201120231441.29911-2-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2020-12-10 12:39:32 -06:00
Dmitry Torokhov
b2058cd93d Input: gtco - remove driver
The driver has its own HID descriptor parsing code, that had and still
has several issues discovered by syzbot and other tools. Ideally we
should move the driver over to the HID subsystem, so that it uses proven
parsing code.  However the devices in question are EOL, and GTCO is not
willing to extend resources for that, so let's simply remove the driver.

Note that our HID support has greatly improved over the last 10 years,
we may also consider reverting 6f8d9e26e7 ("hid-core.c: Adds all GTCO
CalComp Digitizers and InterWrite School Products to blacklist") and see
if GTCO devices actually work with normal HID drivers.

Link: https://lore.kernel.org/r/X8wbBtO5KidME17K@google.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2020-12-09 17:47:36 -08:00
Saravana Kannan
01bb86b380 driver core: Add fwnode_init()
There are multiple locations in the kernel where a struct fwnode_handle
is initialized. Add fwnode_init() so that we have one way of
initializing a fwnode_handle.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20201121020232.908850-8-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-09 19:10:20 +01:00
Catalin Marinas
d889797530 Merge remote-tracking branch 'arm64/for-next/fixes' into for-next/core
* arm64/for-next/fixes: (26 commits)
  arm64: mte: fix prctl(PR_GET_TAGGED_ADDR_CTRL) if TCF0=NONE
  arm64: mte: Fix typo in macro definition
  arm64: entry: fix EL1 debug transitions
  arm64: entry: fix NMI {user, kernel}->kernel transitions
  arm64: entry: fix non-NMI kernel<->kernel transitions
  arm64: ptrace: prepare for EL1 irq/rcu tracking
  arm64: entry: fix non-NMI user<->kernel transitions
  arm64: entry: move el1 irq/nmi logic to C
  arm64: entry: prepare ret_to_user for function call
  arm64: entry: move enter_from_user_mode to entry-common.c
  arm64: entry: mark entry code as noinstr
  arm64: mark idle code as noinstr
  arm64: syscall: exit userspace before unmasking exceptions
  arm64: pgtable: Ensure dirty bit is preserved across pte_wrprotect()
  arm64: pgtable: Fix pte_accessible()
  ACPI/IORT: Fix doc warnings in iort.c
  arm64/fpsimd: add <asm/insn.h> to <asm/kprobes.h> to fix fpsimd build
  arm64: cpu_errata: Apply Erratum 845719 to KRYO2XX Silver
  arm64: proton-pack: Add KRYO2XX silver CPUs to spectre-v2 safe-list
  arm64: kpti: Add KRYO2XX gold/silver CPU cores to kpti safelist
  ...

# Conflicts:
#	arch/arm64/include/asm/exception.h
#	arch/arm64/kernel/sdei.c
2020-12-09 18:04:55 +00:00
Catalin Marinas
d45056ad73 Merge remote-tracking branch 'arm64/for-next/scs' into for-next/core
* arm64/for-next/scs:
  arm64: sdei: Push IS_ENABLED() checks down to callee functions
  arm64: scs: use vmapped IRQ and SDEI shadow stacks
  scs: switch to vmapped shadow stacks
2020-12-09 18:04:48 +00:00
peterz@infradead.org
78af4dc949 perf: Break deadlock involving exec_update_mutex
Syzbot reported a lock inversion involving perf. The sore point being
perf holding exec_update_mutex() for a very long time, specifically
across a whole bunch of filesystem ops in pmu::event_init() (uprobes)
and anon_inode_getfile().

This then inverts against procfs code trying to take
exec_update_mutex.

Move the permission checks later, such that we need to hold the mutex
over less code.

Reported-by: syzbot+db9cdf3dd1f64252c6ef@syzkaller.appspotmail.com
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2020-12-09 17:08:57 +01:00
Waiman Long
617f3ef951 locking/rwsem: Remove reader optimistic spinning
Reader optimistic spinning is helpful when the reader critical section
is short and there aren't that many readers around. It also improves
the chance that a reader can get the lock as writer optimistic spinning
disproportionally favors writers much more than readers.

Since commit d3681e269f ("locking/rwsem: Wake up almost all readers
in wait queue"), all the waiting readers are woken up so that they can
all get the read lock and run in parallel. When the number of contending
readers is large, allowing reader optimistic spinning will likely cause
reader fragmentation where multiple smaller groups of readers can get
the read lock in a sequential manner separated by writers. That reduces
reader parallelism.

One possible way to address that drawback is to limit the number of
readers (preferably one) that can do optimistic spinning. These readers
act as representatives of all the waiting readers in the wait queue as
they will wake up all those waiting readers once they get the lock.

Alternatively, as reader optimistic lock stealing has already enhanced
fairness to readers, it may be easier to just remove reader optimistic
spinning and simplifying the optimistic spinning code as a result.

Performance measurements (locking throughput kops/s) using a locking
microbenchmark with 50/50 reader/writer distribution and turbo-boost
disabled was done on a 2-socket Cascade Lake system (48-core 96-thread)
to see the impacts of these changes:

  1) Vanilla     - 5.10-rc3 kernel
  2) Before      - 5.10-rc3 kernel with previous patches in this series
  2) limit-rspin - 5.10-rc3 kernel with limited reader spinning patch
  3) no-rspin    - 5.10-rc3 kernel with reader spinning disabled

  # of threads  CS Load   Vanilla  Before   limit-rspin   no-rspin
  ------------  -------   -------  ------   -----------   --------
       2            1      5,185    5,662      5,214       5,077
       4            1      5,107    4,983      5,188       4,760
       8            1      4,782    4,564      4,720       4,628
      16            1      4,680    4,053      4,567       3,402
      32            1      4,299    1,115      1,118       1,098
      64            1      3,218      983      1,001         957
      96            1      1,938      944        957         930

       2           20      2,008    2,128      2,264       1,665
       4           20      1,390    1,033      1,046       1,101
       8           20      1,472    1,155      1,098       1,213
      16           20      1,332    1,077      1,089       1,122
      32           20        967      914        917         980
      64           20        787      874        891         858
      96           20        730      836        847         844

       2          100        372      356        360         355
       4          100        492      425        434         392
       8          100        533      537        529         538
      16          100        548      572        568         598
      32          100        499      520        527         537
      64          100        466      517        526         512
      96          100        406      497        506         509

The column "CS Load" represents the number of pause instructions issued
in the locking critical section. A CS load of 1 is extremely short and
is not likey in real situations. A load of 20 (moderate) and 100 (long)
are more realistic.

It can be seen that the previous patches in this series have reduced
performance in general except in highly contended cases with moderate
or long critical sections that performance improves a bit. This change
is mostly caused by the "Prevent potential lock starvation" patch that
reduce reader optimistic spinning and hence reduce reader fragmentation.

The patch that further limit reader optimistic spinning doesn't seem to
have too much impact on overall performance as shown in the benchmark
data.

The patch that disables reader optimistic spinning shows reduced
performance at lightly loaded cases, but comparable or slightly better
performance on with heavier contention.

This patch just removes reader optimistic spinning for now. As readers
are not going to do optimistic spinning anymore, we don't need to
consider if the OSQ is empty or not when doing lock stealing.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Davidlohr Bueso <dbueso@suse.de>
Link: https://lkml.kernel.org/r/20201121041416.12285-6-longman@redhat.com
2020-12-09 17:08:48 +01:00
Waiman Long
1a728dff85 locking/rwsem: Enable reader optimistic lock stealing
If the optimistic spinning queue is empty and the rwsem does not have
the handoff or write-lock bits set, it is actually not necessary to
call rwsem_optimistic_spin() to spin on it. Instead, it can steal the
lock directly as its reader bias is in the count already.  If it is
the first reader in this state, it will try to wake up other readers
in the wait queue.

With this patch applied, the following were the lock event counts
after rebooting a 2-socket system and a "make -j96" kernel rebuild.

  rwsem_opt_rlock=4437
  rwsem_rlock=29
  rwsem_rlock_steal=19

So lock stealing represents about 0.4% of all the read locks acquired
in the slow path.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Davidlohr Bueso <dbueso@suse.de>
Link: https://lkml.kernel.org/r/20201121041416.12285-4-longman@redhat.com
2020-12-09 17:08:48 +01:00
Waiman Long
2f06f70292 locking/rwsem: Prevent potential lock starvation
The lock handoff bit is added in commit 4f23dbc1e6 ("locking/rwsem:
Implement lock handoff to prevent lock starvation") to avoid lock
starvation. However, allowing readers to do optimistic spinning does
introduce an unlikely scenario where lock starvation can happen.

The lock handoff bit may only be set when a waiter is being woken up.
In the case of reader unlock, wakeup happens only when the reader count
reaches 0. If there is a continuous stream of incoming readers acquiring
read lock via optimistic spinning, it is possible that the reader count
may never reach 0 and so the handoff bit will never be asserted.

One way to prevent this scenario from happening is to disallow optimistic
spinning if the rwsem is currently owned by readers. If the previous
or current owner is a writer, optimistic spinning will be allowed.

If the previous owner is a reader but the reader count has reached 0
before, a wakeup should have been issued. So the handoff mechanism
will be kicked in to prevent lock starvation. As a result, it should
be OK to do optimistic spinning in this case.

This patch may have some impact on reader performance as it reduces
reader optimistic spinning especially if the lock critical sections
are short the number of contending readers are small.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Davidlohr Bueso <dbueso@suse.de>
Link: https://lkml.kernel.org/r/20201121041416.12285-3-longman@redhat.com
2020-12-09 17:08:48 +01:00
Waiman Long
c8fe8b0564 locking/rwsem: Pass the current atomic count to rwsem_down_read_slowpath()
The atomic count value right after reader count increment can be useful
to determine the rwsem state at trylock time. So the count value is
passed down to rwsem_down_read_slowpath() to be used when appropriate.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Davidlohr Bueso <dbueso@suse.de>
Link: https://lkml.kernel.org/r/20201121041416.12285-2-longman@redhat.com
2020-12-09 17:08:47 +01:00
Peter Zijlstra
c995e638cc locking/rwsem: Fold __down_{read,write}*()
There's a lot needless duplication in __down_{read,write}*(), cure
that with a helper.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201207090243.GE3040@hirez.programming.kicks-ass.net
2020-12-09 17:08:47 +01:00
Peter Zijlstra
285c61aedf locking/rwsem: Introduce rwsem_write_trylock()
One copy of this logic is better than three.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201207090243.GE3040@hirez.programming.kicks-ass.net
2020-12-09 17:08:47 +01:00
Peter Zijlstra
3379116a0c locking/rwsem: Better collate rwsem_read_trylock()
All users of rwsem_read_trylock() do rwsem_set_reader_owned(sem) on
success, move it into rwsem_read_trylock() proper.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201207090243.GE3040@hirez.programming.kicks-ass.net
2020-12-09 17:08:47 +01:00
Peter Zijlstra
2b3c99ee63 Merge branch 'locking/rwsem' 2020-12-09 17:08:45 +01:00
Eric W. Biederman
31784cff7e rwsem: Implement down_read_interruptible
In preparation for converting exec_update_mutex to a rwsem so that
multiple readers can execute in parallel and not deadlock, add
down_read_interruptible.  This is needed for perf_event_open to be
converted (with no semantic changes) from working on a mutex to
wroking on a rwsem.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/87k0tybqfy.fsf@x220.int.ebiederm.org
2020-12-09 17:08:42 +01:00
Eric W. Biederman
0f9368b5bf rwsem: Implement down_read_killable_nested
In preparation for converting exec_update_mutex to a rwsem so that
multiple readers can execute in parallel and not deadlock, add
down_read_killable_nested.  This is needed so that kcmp_lock
can be converted from working on a mutexes to working on rw_semaphores.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/87o8jabqh3.fsf@x220.int.ebiederm.org
2020-12-09 17:08:41 +01:00
John Ogness
b031a684bf printk: remove logbuf_lock writer-protection of ringbuffer
Since the ringbuffer is lockless, there is no need for it to be
protected by @logbuf_lock. Remove @logbuf_lock writer-protection of
the ringbuffer. The reader-protection is not removed because some
variables, used by readers, are using @logbuf_lock for synchronization:
@syslog_seq, @syslog_time, @syslog_partial, @console_seq,
struct kmsg_dumper.

For PRINTK_NMI_DIRECT_CONTEXT_MASK, @logbuf_lock usage is not removed
because it may be used for dumper synchronization.

Without @logbuf_lock synchronization of vprintk_store() it is no
longer possible to use the single static buffer for temporarily
sprint'ing the message. Instead, use vsnprintf() to determine the
length and perform the real vscnprintf() using the area reserved from
the ringbuffer. This leads to suboptimal packing of the message data,
but will result in less wasted storage than multiple per-cpu buffers
to support lockless temporary sprint'ing.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20201209004453.17720-3-john.ogness@linutronix.de
2020-12-09 11:31:02 +01:00
John Ogness
6b916706f8 printk: inline log_output(),log_store() in vprintk_store()
In preparation for removing logbuf_lock, inline log_output()
and log_store() into vprintk_store(). This will simplify dealing
with the various code branches and fallbacks that are possible.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20201209004453.17720-2-john.ogness@linutronix.de
2020-12-09 11:30:53 +01:00
Jessica Yu
38dc717e97 module: delay kobject uevent until after module init call
Apparently there has been a longstanding race between udev/systemd and
the module loader. Currently, the module loader sends a uevent right
after sysfs initialization, but before the module calls its init
function. However, some udev rules expect that the module has
initialized already upon receiving the uevent.

This race has been triggered recently (see link in references) in some
systemd mount unit files. For instance, the configfs module creates the
/sys/kernel/config mount point in its init function, however the module
loader issues the uevent before this happens. sys-kernel-config.mount
expects to be able to mount /sys/kernel/config upon receipt of the
module loading uevent, but if the configfs module has not called its
init function yet, then this directory will not exist and the mount unit
fails. A similar situation exists for sys-fs-fuse-connections.mount, as
the fuse sysfs mount point is created during the fuse module's init
function. If udev is faster than module initialization then the mount
unit would fail in a similar fashion.

To fix this race, delay the module KOBJ_ADD uevent until after the
module has finished calling its init routine.

References: https://github.com/systemd/systemd/issues/17586
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-By: Nicolas Morey-Chaisemartin <nmoreychaisemartin@suse.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
2020-12-09 09:42:47 +01:00
Andy Lutomirski
e45cdc71d1 membarrier: Execute SYNC_CORE on the calling thread
membarrier()'s MEMBARRIER_CMD_PRIVATE_EXPEDITED_SYNC_CORE is documented as
syncing the core on all sibling threads but not necessarily the calling
thread.  This behavior is fundamentally buggy and cannot be used safely.

Suppose a user program has two threads.  Thread A is on CPU 0 and thread B
is on CPU 1.  Thread A modifies some text and calls
membarrier(MEMBARRIER_CMD_PRIVATE_EXPEDITED_SYNC_CORE).

Then thread B executes the modified code.  If, at any point after
membarrier() decides which CPUs to target, thread A could be preempted and
replaced by thread B on CPU 0.  This could even happen on exit from the
membarrier() syscall.  If this happens, thread B will end up running on CPU
0 without having synced.

In principle, this could be fixed by arranging for the scheduler to issue
sync_core_before_usermode() whenever switching between two threads in the
same mm if there is any possibility of a concurrent membarrier() call, but
this would have considerable overhead.  Instead, make membarrier() sync the
calling CPU as well.

As an optimization, this avoids an extra smp_mb() in the default
barrier-only mode and an extra rseq preempt on the caller.

Fixes: 70216e18e5 ("membarrier: Provide core serializing command, *_SYNC_CORE")
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/r/250ded637696d490c69bef1877148db86066881c.1607058304.git.luto@kernel.org
2020-12-09 09:37:43 +01:00
Andy Lutomirski
758c9373d8 membarrier: Explicitly sync remote cores when SYNC_CORE is requested
membarrier() does not explicitly sync_core() remote CPUs; instead, it
relies on the assumption that an IPI will result in a core sync.  On x86,
this may be true in practice, but it's not architecturally reliable.  In
particular, the SDM and APM do not appear to guarantee that interrupt
delivery is serializing.  While IRET does serialize, IPI return can
schedule, thereby switching to another task in the same mm that was
sleeping in a syscall.  The new task could then SYSRET back to usermode
without ever executing IRET.

Make this more robust by explicitly calling sync_core_before_usermode()
on remote cores.  (This also helps people who search the kernel tree for
instances of sync_core() and sync_core_before_usermode() -- one might be
surprised that the core membarrier code doesn't currently show up in a
such a search.)

Fixes: 70216e18e5 ("membarrier: Provide core serializing command, *_SYNC_CORE")
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/776b448d5f7bd6b12690707f5ed67bcda7f1d427.1607058304.git.luto@kernel.org
2020-12-09 09:37:43 +01:00
Andy Lutomirski
2ecedd7569 membarrier: Add an actual barrier before rseq_preempt()
It seems that most RSEQ membarrier users will expect any stores done before
the membarrier() syscall to be visible to the target task(s).  While this
is extremely likely to be true in practice, nothing actually guarantees it
by a strict reading of the x86 manuals.  Rather than providing this
guarantee by accident and potentially causing a problem down the road, just
add an explicit barrier.

Fixes: 70216e18e5 ("membarrier: Provide core serializing command, *_SYNC_CORE")
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/d3e7197e034fa4852afcf370ca49c30496e58e40.1607058304.git.luto@kernel.org
2020-12-09 09:37:43 +01:00
Florent Revest
b60da4955f bpf: Only provide bpf_sock_from_file with CONFIG_NET
This moves the bpf_sock_from_file definition into net/core/filter.c
which only gets compiled with CONFIG_NET and also moves the helper proto
usage next to other tracing helpers that are conditional on CONFIG_NET.

This avoids
  ld: kernel/trace/bpf_trace.o: in function `bpf_sock_from_file':
  bpf_trace.c:(.text+0xe23): undefined reference to `sock_from_file'
When compiling a kernel with BPF and without NET.

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Florent Revest <revest@chromium.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: KP Singh <kpsingh@kernel.org>
Link: https://lore.kernel.org/bpf/20201208173623.1136863-1-revest@chromium.org
2020-12-08 18:23:36 -08:00
Andrii Nakryiko
8bdd8e275e bpf: Return -ENOTSUPP when attaching to non-kernel BTF
Return -ENOTSUPP if tracing BPF program is attempted to be attached with
specified attach_btf_obj_fd pointing to non-kernel (neither vmlinux nor
module) BTF object. This scenario might be supported in the future and isn't
outright invalid, so -EINVAL isn't the most appropriate error code.

Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20201208064326.667389-1-andrii@kernel.org
2020-12-08 17:14:27 +01:00
Lukas Bulwahn
8d143c610b printk: remove obsolete dead assignment
Commit 849f3127bb ("switch /dev/kmsg to ->write_iter()") refactored
devkmsg_write() and left over a dead assignment on the variable 'len'.

Hence, make clang-analyzer warns:

  kernel/printk/printk.c:744:4: warning: Value stored to 'len' is never read
    [clang-analyzer-deadcode.DeadStores]
                          len -= endp - line;
                          ^

Simply remove this obsolete dead assignment here.

Link: https://lore.kernel.org/r/20201130124915.7573-1-lukas.bulwahn@gmail.com
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
2020-12-08 16:31:28 +01:00
Lukas Bulwahn
2f4b03195f bpf: Propagate __user annotations properly
__htab_map_lookup_and_delete_batch() stores a user pointer in the local
variable ubatch and uses that in copy_{from,to}_user(), but ubatch misses a
__user annotation.

So, sparse warns in the various assignments and uses of ubatch:

  kernel/bpf/hashtab.c:1415:24: warning: incorrect type in initializer
    (different address spaces)
  kernel/bpf/hashtab.c:1415:24:    expected void *ubatch
  kernel/bpf/hashtab.c:1415:24:    got void [noderef] __user *

  kernel/bpf/hashtab.c:1444:46: warning: incorrect type in argument 2
    (different address spaces)
  kernel/bpf/hashtab.c:1444:46:    expected void const [noderef] __user *from
  kernel/bpf/hashtab.c:1444:46:    got void *ubatch

  kernel/bpf/hashtab.c:1608:16: warning: incorrect type in assignment
    (different address spaces)
  kernel/bpf/hashtab.c:1608:16:    expected void *ubatch
  kernel/bpf/hashtab.c:1608:16:    got void [noderef] __user *

  kernel/bpf/hashtab.c:1609:26: warning: incorrect type in argument 1
    (different address spaces)
  kernel/bpf/hashtab.c:1609:26:    expected void [noderef] __user *to
  kernel/bpf/hashtab.c:1609:26:    got void *ubatch

Add the __user annotation to repair this chain of propagating __user
annotations in __htab_map_lookup_and_delete_batch().

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20201207123720.19111-1-lukas.bulwahn@gmail.com
2020-12-07 19:26:09 -08:00
Qiujun Huang
888834903d ring-buffer: Fix a typo in function description
s/ring_buffer_commit_discard/ring_buffer_discard_commit/

Link: https://lkml.kernel.org/r/20201112151800.14382-1-hqjagain@gmail.com

Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-12-07 18:14:53 -05:00
Lukas Bulwahn
a32ded3389 ring-buffer: Remove obsolete rb_event_is_commit()
Commit a389d86f7f ("ring-buffer: Have nested events still record running
time stamp") removed the only uses of rb_event_is_commit() in
rb_update_event() and rb_update_write_stamp().

Hence, since then, make CC=clang W=1 warns:

  kernel/trace/ring_buffer.c:2763:1:
    warning: unused function 'rb_event_is_commit' [-Wunused-function]

Remove this obsolete function.

Link: https://lkml.kernel.org/r/20201117053703.11275-1-lukas.bulwahn@gmail.com

Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-12-07 18:08:53 -05:00
Eric Dumazet
e1868b9e36 bpf: Avoid overflows involving hash elem_size
Use of bpf_map_charge_init() was making sure hash tables would not use more
than 4GB of memory.

Since the implicit check disappeared, we have to be more careful
about overflows, to support big hash tables.

syzbot triggers a panic using :

bpf(BPF_MAP_CREATE, {map_type=BPF_MAP_TYPE_LRU_HASH, key_size=16384, value_size=8,
                     max_entries=262200, map_flags=0, inner_map_fd=-1, map_name="",
                     map_ifindex=0, btf_fd=-1, btf_key_type_id=0, btf_value_type_id=0,
                     btf_vmlinux_value_type_id=0}, 64) = ...

BUG: KASAN: vmalloc-out-of-bounds in bpf_percpu_lru_populate kernel/bpf/bpf_lru_list.c:594 [inline]
BUG: KASAN: vmalloc-out-of-bounds in bpf_lru_populate+0x4ef/0x5e0 kernel/bpf/bpf_lru_list.c:611
Write of size 2 at addr ffffc90017e4a020 by task syz-executor.5/19786

CPU: 0 PID: 19786 Comm: syz-executor.5 Not tainted 5.10.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x107/0x163 lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0x5/0x4c8 mm/kasan/report.c:385
 __kasan_report mm/kasan/report.c:545 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:562
 bpf_percpu_lru_populate kernel/bpf/bpf_lru_list.c:594 [inline]
 bpf_lru_populate+0x4ef/0x5e0 kernel/bpf/bpf_lru_list.c:611
 prealloc_init kernel/bpf/hashtab.c:319 [inline]
 htab_map_alloc+0xf6e/0x1230 kernel/bpf/hashtab.c:507
 find_and_alloc_map kernel/bpf/syscall.c:123 [inline]
 map_create kernel/bpf/syscall.c:829 [inline]
 __do_sys_bpf+0xa81/0x5170 kernel/bpf/syscall.c:4336
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45deb9
Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fd93fbc0c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 0000000000001a40 RCX: 000000000045deb9
RDX: 0000000000000040 RSI: 0000000020000280 RDI: 0000000000000000
RBP: 000000000119bf60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119bf2c
R13: 00007ffc08a7be8f R14: 00007fd93fbc19c0 R15: 000000000119bf2c

Fixes: 755e5d5536 ("bpf: Eliminate rlimit-based memory accounting for hashtab maps")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Roman Gushchin <guro@fb.com>
Link: https://lore.kernel.org/bpf/20201207182821.3940306-1-eric.dumazet@gmail.com
2020-12-07 12:57:25 -08:00
Christoph Hellwig
45dc656aeb blktrace: fix up a kerneldoc comment
Fixes: a54895fa05 ("block: remove the request_queue to argument request based tracepoints")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-07 13:20:31 -07:00
Linus Torvalds
cd796ed334 Fix userstacktrace option for instances
While writing an application that requires user stack trace option
 to work in instances, I found that the instance option has a bug
 that makes it a nop. The check for performing the user stack trace
 in an instance, checks the top level options (not the instance options)
 to determine if a user stack trace should be performed or not.
 
 This is not only incorrect, but also confusing for users. It confused
 me for a bit!
 -----BEGIN PGP SIGNATURE-----
 
 iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCX85BzBQccm9zdGVkdEBn
 b29kbWlzLm9yZwAKCRAp5XQQmuv6qv7XAQCzfq6DpHUv1gVaBkGytOszLW4IuEtd
 /09jDPbVSG8T2QEA+e6fpBP1aIixgLN6+vFVl3wAK3SaIQeIA/blkbBNFQ0=
 =o1Ew
 -----END PGP SIGNATURE-----

Merge tag 'trace-v5.10-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fix from Steven Rostedt:
 "Fix userstacktrace option for instances

  While writing an application that requires user stack trace option to
  work in instances, I found that the instance option has a bug that
  makes it a nop. The check for performing the user stack trace in an
  instance, checks the top level options (not the instance options) to
  determine if a user stack trace should be performed or not.

  This is not only incorrect, but also confusing for users. It confused
  me for a bit!"

* tag 'trace-v5.10-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix userstacktrace option for instances
2020-12-07 11:20:26 -08:00
Linus Torvalds
592d9a0835 A set of updates for the interrupt subsystem:
- Make multiqueue devices which use the managed interrupt affinity
     infrastructure work on PowerPC/Pseries. PowerPC does not use the
     generic infrastructure for setting up PCI/MSI interrupts and the
     multiqueue changes failed to update the legacy PCI/MSI infrastructure.
     Make this work by passing the affinity setup information down to the
     mapping and allocation functions.
 
   - Move Jason Cooper from MAINTAINERS to CREDITS as his mail is bouncing
     and he's not reachable. We hope all is well with him and say thanks
     for his work over the years.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAl/M1GwTHHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYoW8xD/4uG/0ayYgSdRf4nXcyXu4JKoHV5oK5
 y7IWY9s04fqTFbVO2fRaD1hBYHavWfdV80obP8dJio1g6R1BqzZiEVUmCdWI0tHJ
 recAsGYxqPrNj9soHEZ7ZmuGX6VhuzQj57srU+lhzsqk+88uY/n1d/TlrHCH7miU
 0cfBSoolP2l2p6UYHvXfH2wk1hRHg8sySOfxGSp6KSrewoOwAOT2CCNX8gIcmy1n
 dUsJaHEFzU547p55zDs5DTHfM0yJdsqqUpdxvpiZWpZhsIzoQvd8taiH7/uaRGqd
 yJI4sMWudJUGGas2Vq0yjG6L0uAJ7M+kjqodJzn0hAKq6MhAIKaPMEbpPx9TuZYb
 zZg9ce5o4LwzTphNPmcEMCjpPKRGNiEbcl1XY4qhQWnBvuOb1mIBFV4+6srd+Lpg
 o7kEt+XyjKZARgw01yDf9tHSJYOcBQuHqGUdRZQAWSCThizpQsOZJaUWB8l4mLDy
 fScYx4cH12oPmCg3Fdd22oq7JN0ed9O3M7BLuzmI006uSWsB8fbfEcM+k+g+63Go
 xpHYKM6VOzLlspFPFvVo3nwzvc787he2I9tIOPtCU0Hl4BBjjfGyB9FcnhNShNoe
 dfVVzTaEWmHNGonTI61suwZJeyOTudzHqbgw5rAmqmJeV5R8gFSiGmzINlqoWZX6
 TWDVz4Y1ma8QwA==
 =/DKJ
 -----END PGP SIGNATURE-----

Merge tag 'irq-urgent-2020-12-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull irq fixes from Thomas Gleixner:
 "A set of updates for the interrupt subsystem:

   - Make multiqueue devices which use the managed interrupt affinity
     infrastructure work on PowerPC/Pseries. PowerPC does not use the
     generic infrastructure for setting up PCI/MSI interrupts and the
     multiqueue changes failed to update the legacy PCI/MSI
     infrastructure. Make this work by passing the affinity setup
     information down to the mapping and allocation functions.

   - Move Jason Cooper from MAINTAINERS to CREDITS as his mail is
     bouncing and he's not reachable. We hope all is well with him and
     say thanks for his work over the years"

* tag 'irq-urgent-2020-12-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  powerpc/pseries: Pass MSI affinity to irq_create_mapping()
  genirq/irqdomain: Add an irq_create_mapping_affinity() function
  MAINTAINERS: Move Jason Cooper to CREDITS
2020-12-06 11:15:55 -08:00
Linus Torvalds
32f741b02f powerpc fixes for 5.10 #5
Three commits fixing possible missed TLB invalidations for multi-threaded
 processes when CPUs are hotplugged in and out.
 
 A fix for a host crash triggerable by host userspace (qemu) in KVM on Power9.
 
 A fix for a host crash in machine check handling when running HPT guests on a
 HPT host.
 
 One commit fixing potential missed TLB invalidations when using the hash MMU on
 Power9 or later.
 
 A regression fix for machines with CPUs on node 0 but no memory.
 
 Thanks to:
   Aneesh Kumar K.V, Cédric Le Goater, Greg Kurz, Milan Mohanty, Milton Miller,
   Nicholas Piggin, Paul Mackerras, Srikar Dronamraju.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCAAxFiEEJFGtCPCthwEv2Y/bUevqPMjhpYAFAl/LcwsTHG1wZUBlbGxl
 cm1hbi5pZC5hdQAKCRBR6+o8yOGlgOeiD/wKGX8eE7AJ5ZxoFLwpGEJhp9QgMDhe
 nP82CkKobwMM3UCbde9MC8PqYGC7/7PhRPM0GI03uh6EfeHUtle7AZlBAlZoGaeJ
 MwdQBQrZSqf1QJOyhUEa6CI0XTfCEOrsw+AkZQKdsv9JLcFBz7IyfP61gf7MHfyo
 QKlfYYilXHbJ7M9oiM9gKUdtrpPfMGH0YnIp0FR+JowJAWUfFY626H9j7chNwWK+
 7nrphtLHwsBVNtIoKWvPocuLKPsziOqXWnOP/do/RuCoKXMbGjtOJHhUgEYC5PM7
 eQug43YDaws4K1fxaHvQto/u92nL2GFY6FfKNeJ5FcQYgCIvi/T8jzEsJyqGbpVz
 YihZj1MbhhGr/neVtJW4SbdCTCU7R7X9QBy4He6XoWHR0fNoQDQvjNT/ziiuHiN0
 tU+Y9aoHwI/0Pb44ceiQ/T10nxYtk+6Cj5Cm9Ll7MvfjUsE/BpxlYdi+KMqRSGOb
 itOwFLQpgy28feMRKGZNKFURwTophASFaKO88yhjeSnlcGqxvicSIUpz8UD1jxwt
 o/tsger09ZXqBYVdVKLpqbKsifVbzUfJmmycvuDF37B+VjwHACP+VZltwdOqnX13
 BM9ndcDW2p6UnNLfs47FWJM+czmShrgwqI/W7qcCFleYL3r5XOS8hJHfgvJEcE04
 n7A9cNvK5q6nvg==
 =tIAZ
 -----END PGP SIGNATURE-----

Merge tag 'powerpc-5.10-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:
 "Some more powerpc fixes for 5.10:

   - Three commits fixing possible missed TLB invalidations for
     multi-threaded processes when CPUs are hotplugged in and out.

   - A fix for a host crash triggerable by host userspace (qemu) in KVM
     on Power9.

   - A fix for a host crash in machine check handling when running HPT
     guests on a HPT host.

   - One commit fixing potential missed TLB invalidations when using the
     hash MMU on Power9 or later.

   - A regression fix for machines with CPUs on node 0 but no memory.

  Thanks to Aneesh Kumar K.V, Cédric Le Goater, Greg Kurz, Milan
  Mohanty, Milton Miller, Nicholas Piggin, Paul Mackerras, and Srikar
  Dronamraju"

* tag 'powerpc-5.10-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/64s/powernv: Fix memory corruption when saving SLB entries on MCE
  KVM: PPC: Book3S HV: XIVE: Fix vCPU id sanity check
  powerpc/numa: Fix a regression on memoryless node 0
  powerpc/64s: Trim offlined CPUs from mm_cpumasks
  kernel/cpu: add arch override for clear_tasks_mm_cpumask() mm handling
  powerpc/64s/pseries: Fix hash tlbiel_all_isa300 for guest kernels
  powerpc/64s: Fix hash ISA v3.0 TLBIEL instruction generation
2020-12-05 11:16:21 -08:00
Steven Rostedt (VMware)
bcee527895 tracing: Fix userstacktrace option for instances
When the instances were able to use their own options, the userstacktrace
option was left hardcoded for the top level. This made the instance
userstacktrace option bascially into a nop, and will confuse users that set
it, but nothing happens (I was confused when it happened to me!)

Cc: stable@vger.kernel.org
Fixes: 16270145ce ("tracing: Add trace options for core options to instances")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-12-04 16:36:16 -05:00
Florent Revest
4f19cab761 bpf: Add a bpf_sock_from_file helper
While eBPF programs can check whether a file is a socket by file->f_op
== &socket_file_ops, they cannot convert the void private_data pointer
to a struct socket BTF pointer. In order to do this a new helper
wrapping sock_from_file is added.

This is useful to tracing programs but also other program types
inheriting this set of helpers such as iterators or LSM programs.

Signed-off-by: Florent Revest <revest@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: KP Singh <kpsingh@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20201204113609.1850150-2-revest@google.com
2020-12-04 22:32:40 +01:00
Christoph Hellwig
a54895fa05 block: remove the request_queue to argument request based tracepoints
The request_queue can trivially be derived from the request.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-04 09:42:00 -07:00
Christoph Hellwig
1c02fca620 block: remove the request_queue argument to the block_bio_remap tracepoint
The request_queue can trivially be derived from the bio.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-04 09:42:00 -07:00
Christoph Hellwig
eb6f7f7cd3 block: remove the request_queue argument to the block_split tracepoint
The request_queue can trivially be derived from the bio.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-04 09:42:00 -07:00
Christoph Hellwig
e8a676d61c block: simplify and extend the block_bio_merge tracepoint class
The block_bio_merge tracepoint class can be reused for most bio-based
tracepoints.  For that it just needs to lose the superfluous q and rq
parameters.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-04 09:42:00 -07:00
Christoph Hellwig
b81b8f40c5 block: remove the unused block_sleeprq tracepoint
The block_sleeprq tracepoint was only used by the legacy request code.
Remove it now that the legacy request code is gone.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-04 09:42:00 -07:00
Jakub Kicinski
a1dd1d8697 Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Alexei Starovoitov says:

====================
pull-request: bpf-next 2020-12-03

The main changes are:

1) Support BTF in kernel modules, from Andrii.

2) Introduce preferred busy-polling, from Björn.

3) bpf_ima_inode_hash() and bpf_bprm_opts_set() helpers, from KP Singh.

4) Memcg-based memory accounting for bpf objects, from Roman.

5) Allow bpf_{s,g}etsockopt from cgroup bind{4,6} hooks, from Stanislav.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (118 commits)
  selftests/bpf: Fix invalid use of strncat in test_sockmap
  libbpf: Use memcpy instead of strncpy to please GCC
  selftests/bpf: Add fentry/fexit/fmod_ret selftest for kernel module
  selftests/bpf: Add tp_btf CO-RE reloc test for modules
  libbpf: Support attachment of BPF tracing programs to kernel modules
  libbpf: Factor out low-level BPF program loading helper
  bpf: Allow to specify kernel module BTFs when attaching BPF programs
  bpf: Remove hard-coded btf_vmlinux assumption from BPF verifier
  selftests/bpf: Add CO-RE relocs selftest relying on kernel module BTF
  selftests/bpf: Add support for marking sub-tests as skipped
  selftests/bpf: Add bpf_testmod kernel module for testing
  libbpf: Add kernel module BTF support for CO-RE relocations
  libbpf: Refactor CO-RE relocs to not assume a single BTF object
  libbpf: Add internal helper to load BTF data by FD
  bpf: Keep module's btf_data_size intact after load
  bpf: Fix bpf_put_raw_tracepoint()'s use of __module_address()
  selftests/bpf: Add Userspace tests for TCP_WINDOW_CLAMP
  bpf: Adds support for setting window clamp
  samples/bpf: Fix spelling mistake "recieving" -> "receiving"
  bpf: Fix cold build of test_progs-no_alu32
  ...
====================

Link: https://lore.kernel.org/r/20201204021936.85653-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-04 07:48:12 -08:00
Andrii Nakryiko
290248a5b7 bpf: Allow to specify kernel module BTFs when attaching BPF programs
Add ability for user-space programs to specify non-vmlinux BTF when attaching
BTF-powered BPF programs: raw_tp, fentry/fexit/fmod_ret, LSM, etc. For this,
attach_prog_fd (now with the alias name attach_btf_obj_fd) should specify FD
of a module or vmlinux BTF object. For backwards compatibility reasons,
0 denotes vmlinux BTF. Only kernel BTF (vmlinux or module) can be specified.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201203204634.1325171-11-andrii@kernel.org
2020-12-03 17:38:21 -08:00
Andrii Nakryiko
22dc4a0f5e bpf: Remove hard-coded btf_vmlinux assumption from BPF verifier
Remove a permeating assumption thoughout BPF verifier of vmlinux BTF. Instead,
wherever BTF type IDs are involved, also track the instance of struct btf that
goes along with the type ID. This allows to gradually add support for kernel
module BTFs and using/tracking module types across BPF helper calls and
registers.

This patch also renames btf_id() function to btf_obj_id() to minimize naming
clash with using btf_id to denote BTF *type* ID, rather than BTF *object*'s ID.

Also, altough btf_vmlinux can't get destructed and thus doesn't need
refcounting, module BTFs need that, so apply BTF refcounting universally when
BPF program is using BTF-powered attachment (tp_btf, fentry/fexit, etc). This
makes for simpler clean up code.

Now that BTF type ID is not enough to uniquely identify a BTF type, extend BPF
trampoline key to include BTF object ID. To differentiate that from target
program BPF ID, set 31st bit of type ID. BTF type IDs (at least currently) are
not allowed to take full 32 bits, so there is no danger of confusing that bit
with a valid BTF type ID.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201203204634.1325171-10-andrii@kernel.org
2020-12-03 17:38:21 -08:00
Andrii Nakryiko
2fe8890848 bpf: Keep module's btf_data_size intact after load
Having real btf_data_size stored in struct module is benefitial to quickly
determine which kernel modules have associated BTF object and which don't.
There is no harm in keeping this info, as opposed to keeping invalid pointer.

Fixes: 607c543f93 ("bpf: Sanitize BTF data pointer after module is loaded")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201203204634.1325171-3-andrii@kernel.org
2020-12-03 17:38:20 -08:00
Andrii Nakryiko
12cc126df8 bpf: Fix bpf_put_raw_tracepoint()'s use of __module_address()
__module_address() needs to be called with preemption disabled or with
module_mutex taken. preempt_disable() is enough for read-only uses, which is
what this fix does. Also, module_put() does internal check for NULL, so drop
it as well.

Fixes: a38d1107f9 ("bpf: support raw tracepoints in modules")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20201203204634.1325171-2-andrii@kernel.org
2020-12-03 17:38:20 -08:00
Jakub Kicinski
55fd59b003 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Conflicts:
	drivers/net/ethernet/ibm/ibmvnic.c

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-03 15:44:09 -08:00
Amir Goldstein
950cc0d2be fsnotify: generalize handle_inode_event()
The handle_inode_event() interface was added as (quoting comment):
"a simple variant of handle_event() for groups that only have inode
marks and don't have ignore mask".

In other words, all backends except fanotify.  The inotify backend
also falls under this category, but because it required extra arguments
it was left out of the initial pass of backends conversion to the
simple interface.

This results in code duplication between the generic helper
fsnotify_handle_event() and the inotify_handle_event() callback
which also happen to be buggy code.

Generalize the handle_inode_event() arguments and add the check for
FS_EXCL_UNLINK flag to the generic helper, so inotify backend could
be converted to use the simple interface.

Link: https://lore.kernel.org/r/20201202120713.702387-2-amir73il@gmail.com
CC: stable@vger.kernel.org
Fixes: b9a1b97725 ("fsnotify: create method handle_inode_event() in fsnotify_operations")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2020-12-03 14:58:35 +01:00
Peter Zijlstra
8af26be062 perf/core: Fix arch_perf_get_page_size()
The (new) page-table walker in arch_perf_get_page_size() is broken in
various ways. Specifically while it is used in a lockless manner, it
doesn't depend on CONFIG_HAVE_FAST_GUP nor uses the proper _lockless
offset methods, nor is careful to only read each entry only once.

Also the hugetlb support is broken due to calling pte_page() without
first checking pte_special().

Rewrite the whole thing to be a proper lockless page-table walker and
employ the new pXX_leaf_size() pgtable functions to determine the
pagetable size without looking at the page-frames.

Fixes: 51b646b2d9 ("perf,mm: Handle non-page-table-aligned hugetlbfs")
Fixes: 8d97e71811 ("perf/core: Add PERF_SAMPLE_DATA_PAGE_SIZE")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Kan Liang <kan.liang@linux.intel.com>
Link: https://lkml.kernel.org/r/20201126124207.GM3040@hirez.programming.kicks-ass.net
2020-12-03 10:14:51 +01:00
Yejune Deng
6b3211842a audit: replace atomic_add_return()
atomic_inc_return() is a little neater

Signed-off-by: Yejune Deng <yejune.deng@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-12-02 22:52:16 -05:00
Roman Gushchin
3ac1f01b43 bpf: Eliminate rlimit-based memory accounting for bpf progs
Do not use rlimit-based memory accounting for bpf progs. It has been
replaced with memcg-based memory accounting.

Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201201215900.3569844-34-guro@fb.com
2020-12-02 18:32:47 -08:00
Roman Gushchin
80ee81e040 bpf: Eliminate rlimit-based memory accounting infra for bpf maps
Remove rlimit-based accounting infrastructure code, which is not used
anymore.

To provide a backward compatibility, use an approximation of the
bpf map memory footprint as a "memlock" value, available to a user
via map info. The approximation is based on the maximal number of
elements and key and value sizes.

Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201201215900.3569844-33-guro@fb.com
2020-12-02 18:32:47 -08:00
Roman Gushchin
ab31be378a bpf: Eliminate rlimit-based memory accounting for bpf local storage maps
Do not use rlimit-based memory accounting for bpf local storage maps.
It has been replaced with the memcg-based memory accounting.

Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201201215900.3569844-32-guro@fb.com
2020-12-02 18:32:47 -08:00
Roman Gushchin
370868107b bpf: Eliminate rlimit-based memory accounting for stackmap maps
Do not use rlimit-based memory accounting for stackmap maps.
It has been replaced with the memcg-based memory accounting.

Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201201215900.3569844-30-guro@fb.com
2020-12-02 18:32:47 -08:00
Roman Gushchin
abbdd0813f bpf: Eliminate rlimit-based memory accounting for bpf ringbuffer
Do not use rlimit-based memory accounting for bpf ringbuffer.
It has been replaced with the memcg-based memory accounting.

bpf_ringbuf_alloc() can't return anything except ERR_PTR(-ENOMEM)
and a valid pointer, so to simplify the code make it return NULL
in the first case. This allows to drop a couple of lines in
ringbuf_map_alloc() and also makes it look similar to other memory
allocating function like kmalloc().

Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20201201215900.3569844-28-guro@fb.com
2020-12-02 18:32:47 -08:00
Roman Gushchin
db54330d3e bpf: Eliminate rlimit-based memory accounting for reuseport_array maps
Do not use rlimit-based memory accounting for reuseport_array maps.
It has been replaced with the memcg-based memory accounting.

Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201201215900.3569844-27-guro@fb.com
2020-12-02 18:32:47 -08:00
Roman Gushchin
a37fb7ef24 bpf: Eliminate rlimit-based memory accounting for queue_stack_maps maps
Do not use rlimit-based memory accounting for queue_stack maps.
It has been replaced with the memcg-based memory accounting.

Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201201215900.3569844-26-guro@fb.com
2020-12-02 18:32:46 -08:00
Roman Gushchin
cbddcb574d bpf: Eliminate rlimit-based memory accounting for lpm_trie maps
Do not use rlimit-based memory accounting for lpm_trie maps.
It has been replaced with the memcg-based memory accounting.

Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201201215900.3569844-25-guro@fb.com
2020-12-02 18:32:46 -08:00
Roman Gushchin
755e5d5536 bpf: Eliminate rlimit-based memory accounting for hashtab maps
Do not use rlimit-based memory accounting for hashtab maps.
It has been replaced with the memcg-based memory accounting.

Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201201215900.3569844-24-guro@fb.com
2020-12-02 18:32:46 -08:00
Roman Gushchin
844f157f6c bpf: Eliminate rlimit-based memory accounting for devmap maps
Do not use rlimit-based memory accounting for devmap maps.
It has been replaced with the memcg-based memory accounting.

Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201201215900.3569844-23-guro@fb.com
2020-12-02 18:32:46 -08:00
Roman Gushchin
087b0d39fe bpf: Eliminate rlimit-based memory accounting for cgroup storage maps
Do not use rlimit-based memory accounting for cgroup storage maps.
It has been replaced with the memcg-based memory accounting.

Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201201215900.3569844-22-guro@fb.com
2020-12-02 18:32:46 -08:00
Roman Gushchin
711cabaf14 bpf: Eliminate rlimit-based memory accounting for cpumap maps
Do not use rlimit-based memory accounting for cpumap maps.
It has been replaced with the memcg-based memory accounting.

Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201201215900.3569844-21-guro@fb.com
2020-12-02 18:32:46 -08:00
Roman Gushchin
f043733f31 bpf: Eliminate rlimit-based memory accounting for bpf_struct_ops maps
Do not use rlimit-based memory accounting for bpf_struct_ops maps.
It has been replaced with the memcg-based memory accounting.

Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201201215900.3569844-20-guro@fb.com
2020-12-02 18:32:46 -08:00
Roman Gushchin
1bc5975613 bpf: Eliminate rlimit-based memory accounting for arraymap maps
Do not use rlimit-based memory accounting for arraymap maps.
It has been replaced with the memcg-based memory accounting.

Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201201215900.3569844-19-guro@fb.com
2020-12-02 18:32:46 -08:00
Roman Gushchin
e9aae8beba bpf: Memcg-based memory accounting for bpf local storage maps
Account memory used by bpf local storage maps:
per-socket, per-inode and per-task storages.

Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201201215900.3569844-16-guro@fb.com
2020-12-02 18:32:45 -08:00
Roman Gushchin
be4035c734 bpf: Memcg-based memory accounting for bpf ringbuffer
Enable the memcg-based memory accounting for the memory used by
the bpf ringbuffer.

Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201201215900.3569844-15-guro@fb.com
2020-12-02 18:32:45 -08:00
Roman Gushchin
353e7af4bf bpf: Memcg-based memory accounting for lpm_trie maps
Include lpm trie and lpm trie node objects into the memcg-based memory
accounting.

Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201201215900.3569844-14-guro@fb.com
2020-12-02 18:32:45 -08:00
Roman Gushchin
881456811a bpf: Refine memcg-based memory accounting for hashtab maps
Include percpu objects and the size of map metadata into the
accounting.

Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201201215900.3569844-13-guro@fb.com
2020-12-02 18:32:45 -08:00
Roman Gushchin
1440290adf bpf: Refine memcg-based memory accounting for devmap maps
Include map metadata and the node size (struct bpf_dtab_netdev)
into the accounting.

Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201201215900.3569844-12-guro@fb.com
2020-12-02 18:32:45 -08:00
Roman Gushchin
3a61c7c58b bpf: Memcg-based memory accounting for cgroup storage maps
Account memory used by cgroup storage maps including metadata
structures.

Account the percpu memory for the percpu flavor of cgroup storage.

Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201201215900.3569844-11-guro@fb.com
2020-12-02 18:32:45 -08:00
Roman Gushchin
e88cc05b61 bpf: Refine memcg-based memory accounting for cpumap maps
Include metadata and percpu data into the memcg-based memory
accounting.

Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201201215900.3569844-10-guro@fb.com
2020-12-02 18:32:45 -08:00
Roman Gushchin
6d192c7938 bpf: Refine memcg-based memory accounting for arraymap maps
Include percpu arrays and auxiliary data into the memcg-based memory
accounting.

Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201201215900.3569844-9-guro@fb.com
2020-12-02 18:32:45 -08:00
Roman Gushchin
d5299b67dd bpf: Memcg-based memory accounting for bpf maps
This patch enables memcg-based memory accounting for memory allocated
by __bpf_map_area_alloc(), which is used by many types of bpf maps for
large initial memory allocations.

Please note, that __bpf_map_area_alloc() should not be used outside of
map creation paths without setting the active memory cgroup to the
map's memory cgroup.

Following patches in the series will refine the accounting for
some of the map types.

Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201201215900.3569844-8-guro@fb.com
2020-12-02 18:32:45 -08:00
Roman Gushchin
48edc1f78a bpf: Prepare for memcg-based memory accounting for bpf maps
Bpf maps can be updated from an interrupt context and in such
case there is no process which can be charged. It makes the memory
accounting of bpf maps non-trivial.

Fortunately, after commit 4127c6504f ("mm: kmem: enable kernel
memcg accounting from interrupt contexts") and commit b87d8cefe4
("mm, memcg: rework remote charging API to support nesting")
it's finally possible.

To make the ownership model simple and consistent, when the map
is created, the memory cgroup of the current process is recorded.
All subsequent allocations related to the bpf map are charged to
the same memory cgroup. It includes allocations made by any processes
(even if they do belong to a different cgroup) and from interrupts.

This commit introduces 3 new helpers, which will be used by following
commits to enable the accounting of bpf maps memory:
  - bpf_map_kmalloc_node()
  - bpf_map_kzalloc()
  - bpf_map_alloc_percpu()

They are wrapping popular memory allocation functions. They set
the active memory cgroup to the map's memory cgroup and add
__GFP_ACCOUNT to the passed gfp flags. Then they call into
the corresponding memory allocation function and restore
the original active memory cgroup.

These helpers are supposed to use everywhere except the map creation
path. During the map creation when the map structure is allocated by
itself, it cannot be passed to those helpers. In those cases default
memory allocation function will be used with the __GFP_ACCOUNT flag.

Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201201215900.3569844-7-guro@fb.com
2020-12-02 18:32:34 -08:00
Roman Gushchin
ddf8503c7c bpf: Memcg-based memory accounting for bpf progs
Include memory used by bpf programs into the memcg-based accounting.
This includes the memory used by programs itself, auxiliary data,
statistics and bpf line info. A memory cgroup containing the
process which loads the program is getting charged.

Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201201215900.3569844-6-guro@fb.com
2020-12-02 18:28:06 -08:00
Roman Gushchin
bcfe06bf26 mm: memcontrol: Use helpers to read page's memcg data
Patch series "mm: allow mapping accounted kernel pages to userspace", v6.

Currently a non-slab kernel page which has been charged to a memory cgroup
can't be mapped to userspace.  The underlying reason is simple: PageKmemcg
flag is defined as a page type (like buddy, offline, etc), so it takes a
bit from a page->mapped counter.  Pages with a type set can't be mapped to
userspace.

But in general the kmemcg flag has nothing to do with mapping to
userspace.  It only means that the page has been accounted by the page
allocator, so it has to be properly uncharged on release.

Some bpf maps are mapping the vmalloc-based memory to userspace, and their
memory can't be accounted because of this implementation detail.

This patchset removes this limitation by moving the PageKmemcg flag into
one of the free bits of the page->mem_cgroup pointer.  Also it formalizes
accesses to the page->mem_cgroup and page->obj_cgroups using new helpers,
adds several checks and removes a couple of obsolete functions.  As the
result the code became more robust with fewer open-coded bit tricks.

This patch (of 4):

Currently there are many open-coded reads of the page->mem_cgroup pointer,
as well as a couple of read helpers, which are barely used.

It creates an obstacle on a way to reuse some bits of the pointer for
storing additional bits of information.  In fact, we already do this for
slab pages, where the last bit indicates that a pointer has an attached
vector of objcg pointers instead of a regular memcg pointer.

This commits uses 2 existing helpers and introduces a new helper to
converts all read sides to calls of these helpers:
  struct mem_cgroup *page_memcg(struct page *page);
  struct mem_cgroup *page_memcg_rcu(struct page *page);
  struct mem_cgroup *page_memcg_check(struct page *page);

page_memcg_check() is intended to be used in cases when the page can be a
slab page and have a memcg pointer pointing at objcg vector.  It does
check the lowest bit, and if set, returns NULL.  page_memcg() contains a
VM_BUG_ON_PAGE() check for the page not being a slab page.

To make sure nobody uses a direct access, struct page's
mem_cgroup/obj_cgroups is converted to unsigned long memcg_data.

Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Link: https://lkml.kernel.org/r/20201027001657.3398190-1-guro@fb.com
Link: https://lkml.kernel.org/r/20201027001657.3398190-2-guro@fb.com
Link: https://lore.kernel.org/bpf/20201201215900.3569844-2-guro@fb.com
2020-12-02 18:28:05 -08:00
Frederic Weisbecker
d14ce74f1f irq: Call tick_irq_enter() inside HARDIRQ_OFFSET
Now that account_hardirq_enter() is called after HARDIRQ_OFFSET has
been incremented, there is nothing left that prevents us from also
moving tick_irq_enter() after HARDIRQ_OFFSET is incremented.

The desired outcome is to remove the nasty hack that prevents softirqs
from being raised through ksoftirqd instead of the hardirq bottom half.
Also tick_irq_enter() then becomes appropriately covered by lockdep.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201202115732.27827-6-frederic@kernel.org
2020-12-02 20:20:05 +01:00
Frederic Weisbecker
d3759e7184 irqtime: Move irqtime entry accounting after irq offset incrementation
IRQ time entry is currently accounted before HARDIRQ_OFFSET or
SOFTIRQ_OFFSET are incremented. This is convenient to decide to which
index the cputime to account is dispatched.

Unfortunately it prevents tick_irq_enter() from being called under
HARDIRQ_OFFSET because tick_irq_enter() has to be called before the IRQ
entry accounting due to the necessary clock catch up. As a result we
don't benefit from appropriate lockdep coverage on tick_irq_enter().

To prepare for fixing this, move the IRQ entry cputime accounting after
the preempt offset is incremented. This requires the cputime dispatch
code to handle the extra offset.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20201202115732.27827-5-frederic@kernel.org
2020-12-02 20:20:05 +01:00
Frederic Weisbecker
8a6a5920d3 sched/vtime: Consolidate IRQ time accounting
The 3 architectures implementing CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
all have their own version of irq time accounting that dispatch the
cputime to the appropriate index: hardirq, softirq, system, idle,
guest... from an all-in-one function.

Instead of having these ad-hoc versions, move the cputime destination
dispatch decision to the core code and leave only the actual per-index
cputime accounting to the architecture.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201202115732.27827-4-frederic@kernel.org
2020-12-02 20:20:05 +01:00
Frederic Weisbecker
2b91ec9f55 s390/vtime: Use the generic IRQ entry accounting
s390 has its own version of IRQ entry accounting because it doesn't
account the idle time the same way the other architectures do. Only
the actual idle sleep time is accounted as idle time, the rest of the
idle task execution is accounted as system time.

Make the generic IRQ entry accounting aware of architectures that have
their own way of accounting idle time and convert s390 to use it.

This prepares s390 to get involved in further consolidations of IRQ
time accounting.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201202115732.27827-3-frederic@kernel.org
2020-12-02 20:20:04 +01:00
Frederic Weisbecker
7197688b20 sched/cputime: Remove symbol exports from IRQ time accounting
account_irq_enter_time() and account_irq_exit_time() are not called
from modules. EXPORT_SYMBOL_GPL() can be safely removed from the IRQ
cputime accounting functions called from there.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201202115732.27827-2-frederic@kernel.org
2020-12-02 20:20:04 +01:00
Sven Schnelle
c6156e1da6 entry: Add syscall_exit_to_user_mode_work()
This is the same as syscall_exit_to_user_mode() but without calling
exit_to_user_mode(). This can be used if there is an architectural reason
to avoid the combo function, e.g. restarting a syscall without returning to
userspace. Before returning to user space the caller has to invoke
exit_to_user_mode().

[ tglx: Amended comments ]

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201201142755.31931-6-svens@linux.ibm.com
2020-12-02 15:07:58 +01:00
Sven Schnelle
310de1a678 entry: Add exit_to_user_mode() wrapper
Called from architecture specific code when syscall_exit_to_user_mode() is
not suitable. It simply calls __exit_to_user_mode().

This way __exit_to_user_mode() can still be inlined because it is declared
static __always_inline.

[ tglx: Amended comments and moved it to a different place in the header ]

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201201142755.31931-5-svens@linux.ibm.com
2020-12-02 15:07:57 +01:00
Sven Schnelle
96e2fbccd0 entry_Add_enter_from_user_mode_wrapper
To be called from architecture specific code if the combo interfaces are
not suitable. It simply calls __enter_from_user_mode(). This way
__enter_from_user_mode will still be inlined because it is declared static
__always_inline.

[ tglx: Amend comments and move it to a different location in the header ]

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201201142755.31931-4-svens@linux.ibm.com
2020-12-02 15:07:57 +01:00
Sven Schnelle
bb793562f0 entry: Rename exit_to_user_mode()
In order to make this function publicly available rename it so it can still
be inlined. An additional exit_to_user_mode() function will be added with
a later commit.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201201142755.31931-3-svens@linux.ibm.com
2020-12-02 15:07:57 +01:00
Sven Schnelle
6666bb714f entry: Rename enter_from_user_mode()
In order to make this function publicly available rename it so it can still
be inlined. An additional enter_from_user_mode() function will be added with
a later commit.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201201142755.31931-2-svens@linux.ibm.com
2020-12-02 15:07:57 +01:00
Gabriel Krisman Bertazi
11894468e3 entry: Support Syscall User Dispatch on common syscall entry
Syscall User Dispatch (SUD) must take precedence over seccomp and
ptrace, since the use case is emulation (it can be invoked with a
different ABI) such that seccomp filtering by syscall number doesn't
make sense in the first place.  In addition, either the syscall is
dispatched back to userspace, in which case there is no resource for to
trace, or the syscall will be executed, and seccomp/ptrace will execute
next.

Since SUD runs before tracepoints, it needs to be a SYSCALL_WORK_EXIT as
well, just to prevent a trace exit event when dispatch was triggered.
For that, the on_syscall_dispatch() examines context to skip the
tracepoint, audit and other work.

[ tglx: Add a comment on the exit side ]

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20201127193238.821364-5-krisman@collabora.com
2020-12-02 15:07:56 +01:00
Gabriel Krisman Bertazi
1446e1df9e kernel: Implement selective syscall userspace redirection
Introduce a mechanism to quickly disable/enable syscall handling for a
specific process and redirect to userspace via SIGSYS.  This is useful
for processes with parts that require syscall redirection and parts that
don't, but who need to perform this boundary crossing really fast,
without paying the cost of a system call to reconfigure syscall handling
on each boundary transition.  This is particularly important for Windows
games running over Wine.

The proposed interface looks like this:

  prctl(PR_SET_SYSCALL_USER_DISPATCH, <op>, <off>, <length>, [selector])

The range [<offset>,<offset>+<length>) is a part of the process memory
map that is allowed to by-pass the redirection code and dispatch
syscalls directly, such that in fast paths a process doesn't need to
disable the trap nor the kernel has to check the selector.  This is
essential to return from SIGSYS to a blocked area without triggering
another SIGSYS from rt_sigreturn.

selector is an optional pointer to a char-sized userspace memory region
that has a key switch for the mechanism. This key switch is set to
either PR_SYS_DISPATCH_ON, PR_SYS_DISPATCH_OFF to enable and disable the
redirection without calling the kernel.

The feature is meant to be set per-thread and it is disabled on
fork/clone/execv.

Internally, this doesn't add overhead to the syscall hot path, and it
requires very little per-architecture support.  I avoided using seccomp,
even though it duplicates some functionality, due to previous feedback
that maybe it shouldn't mix with seccomp since it is not a security
mechanism.  And obviously, this should never be considered a security
mechanism, since any part of the program can by-pass it by using the
syscall dispatcher.

For the sysinfo benchmark, which measures the overhead added to
executing a native syscall that doesn't require interception, the
overhead using only the direct dispatcher region to issue syscalls is
pretty much irrelevant.  The overhead of using the selector goes around
40ns for a native (unredirected) syscall in my system, and it is (as
expected) dominated by the supervisor-mode user-address access.  In
fact, with SMAP off, the overhead is consistently less than 5ns on my
test box.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20201127193238.821364-4-krisman@collabora.com
2020-12-02 15:07:56 +01:00
Steven Rostedt (VMware)
5b7be9c709 ring-buffer: Add test to validate the time stamp deltas
While debugging a situation where a delta for an event was calucalted wrong,
I realize there was nothing making sure that the delta of events are
correct. If a single event has an incorrect delta, then all events after it
will also have one. If the discrepency gets large enough, it could cause
the time stamps to go backwards when crossing sub buffers, that record a
full 64 bit time stamp, and the new deltas are added to that.

Add a way to validate the events at most events and when crossing a buffer
page. This will help make sure that the deltas are always correct. This test
will detect if they are ever corrupted.

The test adds a high overhead to the ring buffer recording, as it does the
audit for almost every event, and should only be used for testing the ring
buffer.

This will catch the bug that is fixed by commit 55ea4cf403 ("ring-buffer:
Update write stamp with the correct ts"), which is not applied when this
commit is applied.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-12-01 22:00:46 -05:00
Jason Gunthorpe
2b0a999ba0 Linux 5.10-rc6
-----BEGIN PGP SIGNATURE-----
 
 iQFSBAABCAA8FiEEq68RxlopcLEwq+PEeb4+QwBBGIYFAl/EM9oeHHRvcnZhbGRz
 QGxpbnV4LWZvdW5kYXRpb24ub3JnAAoJEHm+PkMAQRiG/3kH/RNkFyTlHlUkZpJx
 8Ks2yWgUln7YhZcmOaG/IcIyWnhCgo3l35kiaH7XxM+rPMZzidp51MHUllaTAQDc
 u+5EFHMJsmTWUfE8ocHPb1cPdYEDSoVr6QUsixbL9+uADpRz+VZVtWMb89EiyMrC
 wvLIzpnqY5UNriWWBxD0hrmSsT4g9XCsauer4k2KB+zvebwg6vFOMCFLFc2qz7fb
 ABsrPFqLZOMp+16chGxyHP7LJ6ygI/Hwf7tPW8ppv4c+hes4HZg7yqJxXhV02QbJ
 s10s6BTcEWMqKg/T6L/VoScsMHWUcNdvrr3uuPQhgup240XdmB1XO8rOKddw27e7
 VIjrjNw=
 =4ZaP
 -----END PGP SIGNATURE-----

Merge tag 'v5.10-rc6' into rdma.git for-next

For dependencies in following patches

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2020-12-01 20:40:50 -04:00
Linus Torvalds
ef6900acc8 Tracing fixes for 5.10-rc6
- Use correct timestamp variable for ring buffer write stamp update
  - Fix up before stamp and write stamp when crossing ring buffer sub
    buffers
  - Keep a zero delta in ring buffer in slow path if cmpxchg fails
  - Fix trace_printk static buffer for archs that care
  - Fix ftrace record accounting for ftrace ops with trampolines
  - Fix DYNAMIC_FTRACE_WITH_DIRECT_CALLS dependency
  - Remove WARN_ON in hwlat tracer that triggers on something that is OK
  - Make "my_tramp" trampoline in ftrace direct sample code global
  - Fixes in the bootconfig tool for better alignment management
 -----BEGIN PGP SIGNATURE-----
 
 iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCX8ZzghQccm9zdGVkdEBn
 b29kbWlzLm9yZwAKCRAp5XQQmuv6qg0JAQCII1bDQyF3APLlNFRqfHf3bTo7Zl5z
 WaUd1Cd7JkY+WAD/eF1dWjN0JRtfU+oRlk6UZ4oNmp8WMJvQ7oV26ub2egE=
 =lts8
 -----END PGP SIGNATURE-----

Merge tag 'trace-v5.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Use correct timestamp variable for ring buffer write stamp update

 - Fix up before stamp and write stamp when crossing ring buffer sub
   buffers

 - Keep a zero delta in ring buffer in slow path if cmpxchg fails

 - Fix trace_printk static buffer for archs that care

 - Fix ftrace record accounting for ftrace ops with trampolines

 - Fix DYNAMIC_FTRACE_WITH_DIRECT_CALLS dependency

 - Remove WARN_ON in hwlat tracer that triggers on something that is OK

 - Make "my_tramp" trampoline in ftrace direct sample code global

 - Fixes in the bootconfig tool for better alignment management

* tag 'trace-v5.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ring-buffer: Always check to put back before stamp when crossing pages
  ftrace: Fix DYNAMIC_FTRACE_WITH_DIRECT_CALLS dependency
  ftrace: Fix updating FTRACE_FL_TRAMP
  tracing: Fix alignment of static buffer
  tracing: Remove WARN_ON in start_thread()
  samples/ftrace: Mark my_tramp[12]? global
  ring-buffer: Set the right timestamp in the slow path of __rb_reserve_next()
  ring-buffer: Update write stamp with the correct ts
  docs: bootconfig: Update file format on initrd image
  tools/bootconfig: Align the bootconfig applied initrd image size to 4
  tools/bootconfig: Fix to check the write failure correctly
  tools/bootconfig: Fix errno reference after printf()
2020-12-01 15:30:18 -08:00
Christoph Hellwig
0d02129e76 block: merge struct block_device and struct hd_struct
Instead of having two structures that represent each block device with
different life time rules, merge them into a single one.  This also
greatly simplifies the reference counting rules, as we can use the inode
reference count as the main reference count for the new struct
block_device, with the device model reference front ending it for device
model interaction.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:40 -07:00
Christoph Hellwig
29ff57c610 block: move the start_sect field to struct block_device
Move the start_sect field to struct block_device in preparation
of killing struct hd_struct.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:40 -07:00
Christoph Hellwig
a782483cc1 block: remove the nr_sects field in struct hd_struct
Now that the hd_struct always has a block device attached to it, there is
no need for having two size field that just get out of sync.

Additionally the field in hd_struct did not use proper serialization,
possibly allowing for torn writes.  By only using the block_device field
this problem also gets fixed.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Coly Li <colyli@suse.de>			[bcache]
Acked-by: Chao Yu <yuchao0@huawei.com>			[f2fs]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:40 -07:00
Sami Tolvanen
a2abe7cbd8 scs: switch to vmapped shadow stacks
The kernel currently uses kmem_cache to allocate shadow call stacks,
which means an overflows may not be immediately detected and can
potentially result in another task's shadow stack to be overwritten.

This change switches SCS to use virtually mapped shadow stacks for
tasks, which increases shadow stack size to a full page and provides
more robust overflow detection, similarly to VMAP_STACK.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20201130233442.2562064-2-samitolvanen@google.com
Signed-off-by: Will Deacon <will@kernel.org>
2020-12-01 10:30:28 +00:00
Steven Rostedt (VMware)
68e10d5ff5 ring-buffer: Always check to put back before stamp when crossing pages
The current ring buffer logic checks to see if the updating of the event
buffer was interrupted, and if it is, it will try to fix up the before stamp
with the write stamp to make them equal again. This logic is flawed, because
if it is not interrupted, the two are guaranteed to be different, as the
current event just updated the before stamp before allocation. This
guarantees that the next event (this one or another interrupting one) will
think it interrupted the time updates of a previous event and inject an
absolute time stamp to compensate.

The correct logic is to always update the timestamps when traversing to a
new sub buffer.

Cc: stable@vger.kernel.org
Fixes: a389d86f7f ("ring-buffer: Have nested events still record running time stamp")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-30 23:21:51 -05:00
Naveen N. Rao
49a962c075 ftrace: Fix DYNAMIC_FTRACE_WITH_DIRECT_CALLS dependency
DYNAMIC_FTRACE_WITH_DIRECT_CALLS should depend on
DYNAMIC_FTRACE_WITH_REGS since we need ftrace_regs_caller().

Link: https://lkml.kernel.org/r/fc4b257ea8689a36f086d2389a9ed989496ca63a.1606412433.git.naveen.n.rao@linux.vnet.ibm.com

Cc: stable@vger.kernel.org
Fixes: 763e34e74b ("ftrace: Add register_ftrace_direct()")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-30 21:43:08 -05:00
Naveen N. Rao
4c75b0ff4e ftrace: Fix updating FTRACE_FL_TRAMP
On powerpc, kprobe-direct.tc triggered FTRACE_WARN_ON() in
ftrace_get_addr_new() followed by the below message:
  Bad trampoline accounting at: 000000004222522f (wake_up_process+0xc/0x20) (f0000001)

The set of steps leading to this involved:
- modprobe ftrace-direct-too
- enable_probe
- modprobe ftrace-direct
- rmmod ftrace-direct <-- trigger

The problem turned out to be that we were not updating flags in the
ftrace record properly. From the above message about the trampoline
accounting being bad, it can be seen that the ftrace record still has
FTRACE_FL_TRAMP set though ftrace-direct module is going away. This
happens because we are checking if any ftrace_ops has the
FTRACE_FL_TRAMP flag set _before_ updating the filter hash.

The fix for this is to look for any _other_ ftrace_ops that also needs
FTRACE_FL_TRAMP.

Link: https://lkml.kernel.org/r/56c113aa9c3e10c19144a36d9684c7882bf09af5.1606412433.git.naveen.n.rao@linux.vnet.ibm.com

Cc: stable@vger.kernel.org
Fixes: a124692b69 ("ftrace: Enable trampoline when rec count returns back to one")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-30 21:43:07 -05:00
Minchan Kim
8fa655a3a0 tracing: Fix alignment of static buffer
With 5.9 kernel on ARM64, I found ftrace_dump output was broken but
it had no problem with normal output "cat /sys/kernel/debug/tracing/trace".

With investigation, it seems coping the data into temporal buffer seems to
break the align binary printf expects if the static buffer is not aligned
with 4-byte. IIUC, get_arg in bstr_printf expects that args has already
right align to be decoded and seq_buf_bprintf says ``the arguments are saved
in a 32bit word array that is defined by the format string constraints``.
So if we don't keep the align under copy to temporal buffer, the output
will be broken by shifting some bytes.

This patch fixes it.

Link: https://lkml.kernel.org/r/20201125225654.1618966-1-minchan@kernel.org

Cc: <stable@vger.kernel.org>
Fixes: 8e99cf91b9 ("tracing: Do not allocate buffer in trace_find_next_entry() in atomic")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-30 21:43:07 -05:00
Vasily Averin
310e3a4b5a tracing: Remove WARN_ON in start_thread()
This patch reverts commit 978defee11 ("tracing: Do a WARN_ON()
 if start_thread() in hwlat is called when thread exists")

.start hook can be legally called several times if according
tracer is stopped

screen window 1
[root@localhost ~]# echo 1 > /sys/kernel/tracing/events/kmem/kfree/enable
[root@localhost ~]# echo 1 > /sys/kernel/tracing/options/pause-on-trace
[root@localhost ~]# less -F /sys/kernel/tracing/trace

screen window 2
[root@localhost ~]# cat /sys/kernel/debug/tracing/tracing_on
0
[root@localhost ~]# echo hwlat >  /sys/kernel/debug/tracing/current_tracer
[root@localhost ~]# echo 1 > /sys/kernel/debug/tracing/tracing_on
[root@localhost ~]# cat /sys/kernel/debug/tracing/tracing_on
0
[root@localhost ~]# echo 2 > /sys/kernel/debug/tracing/tracing_on

triggers warning in dmesg:
WARNING: CPU: 3 PID: 1403 at kernel/trace/trace_hwlat.c:371 hwlat_tracer_start+0xc9/0xd0

Link: https://lkml.kernel.org/r/bd4d3e70-400d-9c82-7b73-a2d695e86b58@virtuozzo.com

Cc: Ingo Molnar <mingo@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 978defee11 ("tracing: Do a WARN_ON() if start_thread() in hwlat is called when thread exists")
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-30 21:43:07 -05:00
Andrea Righi
8785f51a17 ring-buffer: Set the right timestamp in the slow path of __rb_reserve_next()
In the slow path of __rb_reserve_next() a nested event(s) can happen
between evaluating the timestamp delta of the current event and updating
write_stamp via local_cmpxchg(); in this case the delta is not valid
anymore and it should be set to 0 (same timestamp as the interrupting
event), since the event that we are currently processing is not the last
event in the buffer.

Link: https://lkml.kernel.org/r/X8IVJcp1gRE+FJCJ@xps-13-7390

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lwn.net/Articles/831207
Fixes: a389d86f7f ("ring-buffer: Have nested events still record running time stamp")
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-30 15:22:05 -05:00
Steven Rostedt (VMware)
55ea4cf403 ring-buffer: Update write stamp with the correct ts
The write stamp, used to calculate deltas between events, was updated with
the stale "ts" value in the "info" structure, and not with the updated "ts"
variable. This caused the deltas between events to be inaccurate, and when
crossing into a new sub buffer, had time go backwards.

Link: https://lkml.kernel.org/r/20201124223917.795844-1-elavila@google.com

Cc: stable@vger.kernel.org
Fixes: a389d86f7f ("ring-buffer: Have nested events still record running time stamp")
Reported-by: "J. Avila" <elavila@google.com>
Tested-by: Daniel Mentz <danielmentz@google.com>
Tested-by: Will McVicker <willmcvicker@google.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-30 15:21:31 -05:00
Marc Zyngier
4615fbc378 genirq/irqdomain: Don't try to free an interrupt that has no mapping
When an interrupt allocation fails for N interrupts, it is pretty
common for the error handling code to free the same number of interrupts,
no matter how many interrupts have actually been allocated.

This may result in the domain freeing code to be unexpectedly called
for interrupts that have no mapping in that domain. Things end pretty
badly.

Instead, add some checks to irq_domain_free_irqs_hierarchy() to make sure
that thiss does not follow the hierarchy if no mapping exists for a given
interrupt.

Fixes: 6a6544e520 ("genirq/irqdomain: Remove auto-recursive hierarchy support")
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201129135551.396777-1-maz@kernel.org
2020-11-30 14:50:21 +01:00
Laurent Vivier
bb4c6910c8 genirq/irqdomain: Add an irq_create_mapping_affinity() function
There is currently no way to convey the affinity of an interrupt
via irq_create_mapping(), which creates issues for devices that
expect that affinity to be managed by the kernel.

In order to sort this out, rename irq_create_mapping() to
irq_create_mapping_affinity() with an additional affinity parameter that
can be passed down to irq_domain_alloc_descs().

irq_create_mapping() is re-implemented as a wrapper around
irq_create_mapping_affinity().

No functional change.

Fixes: e75eafb9b0 ("genirq/msi: Switch to new irq spreading infrastructure")
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kurz <groug@kaod.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20201126082852.1178497-2-lvivier@redhat.com
2020-11-30 12:21:31 +01:00
Linus Torvalds
f91a3aa6bc Yet two more places which invoke tracing from RCU disabled regions in the
idle path. Similar to the entry path the low level idle functions have to
 be non-instrumentable.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAl/DpAUTHHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYoXSLD/9klc0YimnEnROW6Q5Svb2IcyIutmXF
 bOIY1bYYoKILOBj3wyvDUhmdMuq5zh7H9yG11hO8MaVVWVQcLcOMLdHTYm9dcdmF
 xQk33+xqjuhRShB+nEmC9ayYtWogtH6W6uZ6WDtF9ZltMKU85n5ddGJ/Fvo+HoCb
 NbOdHGJdJ3/3ZCeHnxOnxM+5/GwjkBuccTV/tXmb3yXrfU9DBySyQ4/UchcpF43w
 LcEb0kiQbpZsBTByKJOQV8+RR654S0sILlvRwVXpmj94vrgGwhlVk1/9rz7tkOhF
 ksoo1mTVu75LMt22G/hXxE63787yRvFdHjapf0+kCOAuhl992NK+xlGDH8o9DXcu
 9y73D4bI0HnDFs20w6vs20iLvxECJiYHJqlgR5ZwFUToceaNgtiYr8kzuD7Zbae1
 KG2E7BuNSwHWMtf97fGn44GZknPEOaKdDn4Wv6/bvKHxLm77qe11RKF70Stcz2AI
 am13KmQzzsHGF5qNWwpElRUxSdxfJMR66RnOdTQULGrRedaZTFol/y2pnVzTSe3k
 SZnlpL5kE7y92UYDogPb5wWA7b+YkJN0OdSkRFy1FH26ZG8E4M7ZJ2tql5Sw7pGM
 lsTjXpAUphnK5rz7QcYE8KAZWj//fIAcElIrvdklVcBnS3IqjfksYW27B64133vx
 cT1B/lA1PHXj6Q==
 =raED
 -----END PGP SIGNATURE-----

Merge tag 'locking-urgent-2020-11-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking fixes from Thomas Gleixner:
 "Two more places which invoke tracing from RCU disabled regions in the
  idle path.

  Similar to the entry path the low level idle functions have to be
  non-instrumentable"

* tag 'locking-urgent-2020-11-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  intel_idle: Fix intel_idle() vs tracing
  sched/idle: Fix arch_cpu_idle() vs tracing
2020-11-29 11:19:26 -08:00
Jakub Kicinski
5c39f26e67 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Trivial conflict in CAN, keep the net-next + the byteswap wrapper.

Conflicts:
	drivers/net/can/usb/gs_usb.c

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-27 18:25:27 -08:00
Arnd Bergmann
718e43b5f8 Linux 5.10-rc2
-----BEGIN PGP SIGNATURE-----
 
 iQFSBAABCAA8FiEEq68RxlopcLEwq+PEeb4+QwBBGIYFAl+fOigeHHRvcnZhbGRz
 QGxpbnV4LWZvdW5kYXRpb24ub3JnAAoJEHm+PkMAQRiGoQ0H/RLJU2FMIjO0mzLX
 9LqePQ9QmNWG4KeqxwWaKq90MinIbnSG3CDPKruu8RNh2Rr6nsEJmqg1DWyEiFRB
 8gzsBXMAC1i2aPfOrOnCJEfP+L+svKlbSii475tNdZw2DhP+/FBT0RVCt3rRhrRs
 atc8+dM7ViGLnlvRJ4LlVqA3d1kjOr5bsPYcIcnGIHY8mYWBLFzTSVgDdrcB9+3l
 7lZud/zMhJ3dS0bcnbIUS1YpBxHCsgEaMFQYmcv3RruIaaFbh5THkfQUSmbmrAru
 /EeVjwVMuvpvb2jxS1ofLx2in7t4tsNgItu4AfMmV0BurM5NhpqKo7mo/1nmR/X9
 Q4tjPRc=
 =cUbb
 -----END PGP SIGNATURE-----

Backmerge tag 'v5.10-rc2' into arm/drivers

The SCMI pull request for the arm/drivers branch requires v5.10-rc2
because of dependencies with other git trees, so merge that in here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2020-11-27 21:04:53 +01:00
Linus Torvalds
43d6ecd97c Urgent printk fix for 5.10
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEESH4wyp42V4tXvYsjUqAMR0iAlPIFAl/A+VEACgkQUqAMR0iA
 lPIwGw/9F/E2ZdX+Vgi3ZiR/5GdfVZeIW+QwhKXBQc8Jr9+p2JJ+UOPeeazKQA5l
 bFt6GR67yjqtFS5gO76EPCQ6/Uu3cPA+A3HQRQZuE6p0zM+mrMXc/upLMy5DKi4Z
 f4zkW8dYWSBpAWPvM9bb0gIKO9wVV6Aj1IyyZLfEghX/KrJPx0zutioO4ScYxhA9
 YVITmnUQ6YzHEVE8CwWGV4lArC50ILGdIqNlZrkjuG3CuGTdyB2OY60P8XCy8bzn
 W3WgRGI/bvfHwCPh8oYKm/5nM9JAVdhbEpoFQj8cMPKoH5DeSGNWfYXkali2gqhL
 1Y2SntTcR7zclMcN0/gIn9ViVsma/eayAyawSYgQjmAdl6H/vv9B7x9ZswmK/b38
 JzOzHwP+H3lXVg2yN4EbH3uDMTMjqflYuC7QiZ/HNa43KURXhoritw2hBRczhazp
 mdyRQf4iv8NoYSthggD6LolCs+ay5NZpCeB3YXgnlpxiYFGCE+ykSz41AGdTyYTl
 jOWVtK1VawFD0/FgpgF8XK7/gOXWeYb+4WeBYgGKgCJdneiB5eJt8eWT7zmpAPpG
 FECexdAd4TAjD+EEbidiFWpMjJcY2TnOJp76O3/Wlo1QLbEgRHOklM/Rrq0zGg5b
 vm3w0kobGZfpIJuzSOAHyErX0jGEVTq6yUi381jSQpf4bTttIpc=
 =7IkU
 -----END PGP SIGNATURE-----

Merge tag 'printk-for-5.10-rc6-fixup' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

Pull printk fixes from Petr Mladek:

 - do not lose trailing newline in pr_cont() calls

 - two trivial fixes for a dead store and a config description

* tag 'printk-for-5.10-rc6-fixup' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
  printk: finalize records with trailing newlines
  printk: remove unneeded dead-store assignment
  init/Kconfig: Fix CPU number in LOG_CPU_MAX_BUF_SHIFT description
2020-11-27 10:38:36 -08:00
Petr Mladek
739e7116b1 Merge branch 'for-5.10-pr_cont-fixup' into for-linus 2020-11-27 13:41:23 +01:00
John Ogness
4ad9921af4 printk: finalize records with trailing newlines
Any record with a trailing newline (LOG_NEWLINE flag) cannot
be continued because the newline has been stripped and will
not be visible if the message is appended. This was already
handled correctly when committing in log_output() but was
not handled correctly when committing in log_store().

Fixes: f5f022e53b ("printk: reimplement log_cont using record extension")
Link: https://lore.kernel.org/r/20201126114836.14750-1-john.ogness@linutronix.de
Reported-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Tested-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
2020-11-27 11:58:54 +01:00
Ingo Molnar
a787bdaff8 Merge branch 'linus' into sched/core, to resolve semantic conflict
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-11-27 11:10:50 +01:00
Barry Song
65789daa80 dma-mapping: add benchmark support for streaming DMA APIs
Nowadays, there are increasing requirements to benchmark the performance
of dma_map and dma_unmap particually while the device is attached to an
IOMMU.

This patch enables the support. Users can run specified number of threads
to do dma_map_page and dma_unmap_page on a specific NUMA node with the
specified duration. Then dma_map_benchmark will calculate the average
latency for map and unmap.

A difficulity for this benchmark is that dma_map/unmap APIs must run on
a particular device. Each device might have different backend of IOMMU or
non-IOMMU.

So we use the driver_override to bind dma_map_benchmark to a particual
device by:
For platform devices:
echo dma_map_benchmark > /sys/bus/platform/devices/xxx/driver_override
echo xxx > /sys/bus/platform/drivers/xxx/unbind
echo xxx > /sys/bus/platform/drivers/dma_map_benchmark/bind

For PCI devices:
echo dma_map_benchmark > /sys/bus/pci/devices/0000:00:01.0/driver_override
echo 0000:00:01.0 > /sys/bus/pci/drivers/xxx/unbind
echo 0000:00:01.0 > /sys/bus/pci/drivers/dma_map_benchmark/bind

Cc: Will Deacon <will@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
[hch: folded in two fixes from Colin Ian King <colin.king@canonical.com>]
Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-11-27 10:33:42 +01:00
tangjianqiang
819b70ad62 dma-contiguous: fix a typo error in a comment
Fix a typo error in cma description comment: "then" -> "than".

Signed-off-by: tangjianqiang <tangjianqiang@xiaomi.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-11-27 10:33:42 +01:00
Tiezhu Yang
94035edcb4 dma-pool: no need to check return value of debugfs_create functions
When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-11-27 10:33:42 +01:00
Alexey Kardashevskiy
8d8d53cf8f dma-mapping: Allow mixing bypass and mapped DMA operation
At the moment we allow bypassing DMA ops only when we can do this for
the entire RAM. However there are configs with mixed type memory
where we could still allow bypassing IOMMU in most cases;
POWERPC with persistent memory is one example.

This adds an arch hook to determine where bypass can still work and
we invoke direct DMA API. The following patch checks the bus limit
on POWERPC to allow or disallow direct mapping.

This adds a ARCH_HAS_DMA_MAP_DIRECT config option to make the arch_xxxx
hooks no-op by default.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-11-27 10:33:40 +01:00
Nicholas Piggin
8ff00399b1 kernel/cpu: add arch override for clear_tasks_mm_cpumask() mm handling
powerpc/64s keeps a counter in the mm which counts bits set in
mm_cpumask as well as other things. This means it can't use generic code
to clear bits out of the mask and doesn't adjust the arch specific
counter.

Add an arch override that allows powerpc/64s to use
clear_tasks_mm_cpumask().

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201126102530.691335-4-npiggin@gmail.com
2020-11-27 00:10:39 +11:00
Peter Zijlstra
20c7775aec Merge remote-tracking branch 'origin/master' into perf/core
Further perf/core patches will depend on:

  d3f7b1bb20 ("mm/gup: fix gup_fast with dynamic page table folding")

which is already in Linus' tree.
2020-11-26 13:16:55 +01:00
KP Singh
27672f0d28 bpf: Add a BPF helper for getting the IMA hash of an inode
Provide a wrapper function to get the IMA hash of an inode. This helper
is useful in fingerprinting files (e.g executables on execution) and
using these fingerprints in detections like an executable unlinking
itself.

Since the ima_inode_hash can sleep, it's only allowed for sleepable
LSM hooks.

Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20201124151210.1081188-3-kpsingh@chromium.org
2020-11-26 00:04:04 +01:00
Hui Su
5a7b5f32c5 cgroup/cgroup.c: replace 'of->kn->priv' with of_cft()
we have supplied the inline function: of_cft() in cgroup.h.

So replace the direct use 'of->kn->priv' with inline func
of_cft(), which is more readable.

Signed-off-by: Hui Su <sh_def@163.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2020-11-25 17:13:53 -05:00
Bhaskar Chowdhury
58315c9665 kernel: cgroup: Mundane spelling fixes throughout the file
Few spelling fixes throughout the file.

Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2020-11-25 17:13:43 -05:00
Yunfeng Ye
01341fbd0d workqueue: Kick a worker based on the actual activation of delayed works
In realtime scenario, We do not want to have interference on the
isolated cpu cores. but when invoking alloc_workqueue() for percpu wq
on the housekeeping cpu, it kick a kworker on the isolated cpu.

  alloc_workqueue
    pwq_adjust_max_active
      wake_up_worker

The comment in pwq_adjust_max_active() said:
  "Need to kick a worker after thawed or an unbound wq's
   max_active is bumped"

So it is unnecessary to kick a kworker for percpu's wq when invoking
alloc_workqueue(). this patch only kick a worker based on the actual
activation of delayed works.

Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com>
Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2020-11-25 17:10:28 -05:00
Andy Shevchenko
b87e745945 resource: provide meaningful MODULE_LICENSE() in test suite
modpost complains that module has no licence provided.
Provide it via meaningful MODULE_LICENSE().

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-11-25 18:52:35 +01:00
Johan Hovold
b112082c89 module: simplify version-attribute handling
Instead of using the array-of-pointers trick to avoid having gcc mess up
the built-in module-version array stride, specify type alignment when
declaring entries to prevent gcc from increasing alignment.

This is essentially an alternative (one-line) fix to the problem
addressed by commit b4bc842802 ("module: deal with alignment issues in
built-in module versions").

gcc can increase the alignment of larger objects with static extent as
an optimisation, but this can be suppressed by using the aligned
attribute when declaring variables.

Note that we have been relying on this behaviour for kernel parameters
for 16 years and it indeed hasn't changed since the introduction of the
aligned attribute in gcc-3.1.

Link: https://lore.kernel.org/lkml/20201103175711.10731-1-johan@kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
2020-11-25 15:44:46 +01:00
Wedson Almeida Filho
59e2e27d22 bpf: Refactor check_cfg to use a structured loop.
The current implementation uses a number of gotos to implement a loop
and different paths within the loop, which makes the code less readable
than it would be with an explicit while-loop. This patch also replaces a
chain of if/if-elses keyed on the same expression with a switch
statement.

No change in behaviour is intended.

Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201121015509.3594191-1-wedsonaf@google.com
2020-11-24 20:29:26 -08:00
Alex Shi
ba59eae723 audit: fix macros warnings
Some unused macros could cause gcc warning:
kernel/audit.c:68:0: warning: macro "AUDIT_UNINITIALIZED" is not used
[-Wunused-macros]
kernel/auditsc.c:104:0: warning: macro "AUDIT_AUX_IPCPERM" is not used
[-Wunused-macros]
kernel/auditsc.c:82:0: warning: macro "AUDITSC_INVALID" is not used
[-Wunused-macros]

AUDIT_UNINITIALIZED and AUDITSC_INVALID are still meaningful and should
be in incorporated.

Just remove AUDIT_AUX_IPCPERM.

Thanks comments from Richard Guy Briggs and Paul Moore.

Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Richard Guy Briggs <rgb@redhat.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: linux-audit@redhat.com
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-11-24 23:28:02 -05:00
Andrii Nakryiko
607c543f93 bpf: Sanitize BTF data pointer after module is loaded
Given .BTF section is not allocatable, it will get trimmed after module is
loaded. BPF system handles that properly by creating an independent copy of
data. But prevent any accidental misused by resetting the pointer to BTF data.

Fixes: 36e68442d1 ("bpf: Load and verify kernel module BTFs")
Suggested-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jessica Yu <jeyu@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/bpf/20201121070829.2612884-2-andrii@kernel.org
2020-11-25 00:05:21 +01:00
Peter Zijlstra
2914b0ba61 irq_work: Optimize irq_work_single()
Trade one atomic op for a full memory barrier.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
2020-11-24 16:47:49 +01:00
Peter Zijlstra
545b8c8df4 smp: Cleanup smp_call_function*()
Get rid of the __call_single_node union and cleanup the API a little
to avoid external code relying on the structure layout as much.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
2020-11-24 16:47:49 +01:00
Peter Zijlstra
7a9f50a058 irq_work: Cleanup
Get rid of the __call_single_node union and clean up the API a little
to avoid external code relying on the structure layout as much.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
2020-11-24 16:47:48 +01:00
Mel Gorman
23e6082a52 sched: Limit the amount of NUMA imbalance that can exist at fork time
At fork time currently, a local node can be allowed to fill completely
and allow the periodic load balancer to fix the problem. This can be
problematic in cases where a task creates lots of threads that idle until
woken as part of a worker poll causing a memory bandwidth problem.

However, a "real" workload suffers badly from this behaviour. The workload
in question is mostly NUMA aware but spawns large numbers of threads
that act as a worker pool that can be called from anywhere. These need
to spread early to get reasonable behaviour.

This patch limits how much a local node can fill before spilling over
to another node and it will not be a universal win. Specifically,
very short-lived workloads that fit within a NUMA node would prefer
the memory bandwidth.

As I cannot describe the "real" workload, the best proxy measure I found
for illustration was a page fault microbenchmark. It's not representative
of the workload but demonstrates the hazard of the current behaviour.

pft timings
                                 5.10.0-rc2             5.10.0-rc2
                          imbalancefloat-v2          forkspread-v2
Amean     elapsed-1        46.37 (   0.00%)       46.05 *   0.69%*
Amean     elapsed-4        12.43 (   0.00%)       12.49 *  -0.47%*
Amean     elapsed-7         7.61 (   0.00%)        7.55 *   0.81%*
Amean     elapsed-12        4.79 (   0.00%)        4.80 (  -0.17%)
Amean     elapsed-21        3.13 (   0.00%)        2.89 *   7.74%*
Amean     elapsed-30        3.65 (   0.00%)        2.27 *  37.62%*
Amean     elapsed-48        3.08 (   0.00%)        2.13 *  30.69%*
Amean     elapsed-79        2.00 (   0.00%)        1.90 *   4.95%*
Amean     elapsed-80        2.00 (   0.00%)        1.90 *   4.70%*

This is showing the time to fault regions belonging to threads. The target
machine has 80 logical CPUs and two nodes. Note the ~30% gain when the
machine is approximately the point where one node becomes fully utilised.
The slower results are borderline noise.

Kernel building shows similar benefits around the same balance point.
Generally performance was either neutral or better in the tests conducted.
The main consideration with this patch is the point where fork stops
spreading a task so some workloads may benefit from different balance
points but it would be a risky tuning parameter.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/20201120090630.3286-5-mgorman@techsingularity.net
2020-11-24 16:47:48 +01:00
Mel Gorman
7d2b5dd0bc sched/numa: Allow a floating imbalance between NUMA nodes
Currently, an imbalance is only allowed when a destination node
is almost completely idle. This solved one basic class of problems
and was the cautious approach.

This patch revisits the possibility that NUMA nodes can be imbalanced
until 25% of the CPUs are occupied. The reasoning behind 25% is somewhat
superficial -- it's half the cores when HT is enabled.  At higher
utilisations, balancing should continue as normal and keep things even
until scheduler domains are fully busy or over utilised.

Note that this is not expected to be a universal win. Any benchmark
that prefers spreading as wide as possible with limited communication
will favour the old behaviour as there is more memory bandwidth.
Workloads that communicate heavily in pairs such as netperf or tbench
benefit. For the tests I ran, the vast majority of workloads saw
a benefit so it seems to be a worthwhile trade-off.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/20201120090630.3286-4-mgorman@techsingularity.net
2020-11-24 16:47:47 +01:00
Mel Gorman
5c339005f8 sched: Avoid unnecessary calculation of load imbalance at clone time
In find_idlest_group(), the load imbalance is only relevant when the group
is either overloaded or fully busy but it is calculated unconditionally.
This patch moves the imbalance calculation to the context it is required.
Technically, it is a micro-optimisation but really the benefit is avoiding
confusing one type of imbalance with another depending on the group_type
in the next patch.

No functional change.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/20201120090630.3286-3-mgorman@techsingularity.net
2020-11-24 16:47:47 +01:00
Mel Gorman
abeae76a47 sched/numa: Rename nr_running and break out the magic number
This is simply a preparation patch to make the following patches easier
to read. No functional change.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/20201120090630.3286-2-mgorman@techsingularity.net
2020-11-24 16:47:47 +01:00
Peter Zijlstra
58c644ba51 sched/idle: Fix arch_cpu_idle() vs tracing
We call arch_cpu_idle() with RCU disabled, but then use
local_irq_{en,dis}able(), which invokes tracing, which relies on RCU.

Switch all arch_cpu_idle() implementations to use
raw_local_irq_{en,dis}able() and carefully manage the
lockdep,rcu,tracing state like we do in entry.

(XXX: we really should change arch_cpu_idle() to not return with
interrupts enabled)

Reported-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lkml.kernel.org/r/20201120114925.594122626@infradead.org
2020-11-24 16:47:35 +01:00
Thomas Gleixner
5fbda3ecd1 sched: highmem: Store local kmaps in task struct
Instead of storing the map per CPU provide and use per task storage. That
prepares for local kmaps which are preemptible.

The context switch code is preparatory and not yet in use because
kmap_atomic() runs with preemption disabled. Will be made usable in the
next step.

The context switch logic is safe even when an interrupt happens after
clearing or before restoring the kmaps. The kmap index in task struct is
not modified so any nesting kmap in an interrupt will use unused indices
and on return the counter is the same as before.

Also add an assert into the return to user space code. Going back to user
space with an active kmap local is a nono.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20201118204007.372935758@linutronix.de
2020-11-24 14:42:09 +01:00
Thomas Gleixner
13c8da5db4 Merge branch 'sched/core' into core/mm
Pull the migrate disable mechanics which is a prerequisite for preemptible
kmap_local().
2020-11-24 11:26:11 +01:00
Thomas Gleixner
74d862b682 sched: Make migrate_disable/enable() independent of RT
Now that the scheduler can deal with migrate disable properly, there is no
real compelling reason to make it only available for RT.

There are quite some code pathes which needlessly disable preemption in
order to prevent migration and some constructs like kmap_atomic() enforce
it implicitly.

Making it available independent of RT allows to provide a preemptible
variant of kmap_atomic() and makes the code more consistent in general.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Grudgingly-Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20201118204007.269943012@linutronix.de
2020-11-24 11:25:44 +01:00
Jason Gunthorpe
ed92f6a52b Linux 5.10-rc5
-----BEGIN PGP SIGNATURE-----
 
 iQFSBAABCAA8FiEEq68RxlopcLEwq+PEeb4+QwBBGIYFAl+69egeHHRvcnZhbGRz
 QGxpbnV4LWZvdW5kYXRpb24ub3JnAAoJEHm+PkMAQRiGTSYH/ifRBlaxy5UiHFc0
 2zdR7pkjWrYfDTTT3sazIAhdlzzcfnkUqgFxOP45F4ZIqeTzunH3sUY+5UlT9IX7
 liUgnLxQ/1R9Gx8kPGQfu+tLCey78xVFydGsqJoW9sPRw2R+apMdGGa/lOrk+OXz
 DXIN+dDnGFqwCCNJpK+rxQQhFf++IPpSI8z6Y23moOFhsDZrEziHuVFy2FGyRM6z
 prZ/us/tcobE8ptCk1RmOxLoJ1DR6UxpA2vLimTE+JD8siOsSWPbjE0KudnWCnd5
 BLqIjrsPJbSxyuzzK3v9dnO5wMv7tMDuMIuYM/MQTXDttNwtsqt/aP6gdnUCym7N
 5eHEj5g=
 =MuO1
 -----END PGP SIGNATURE-----

Merge tag 'v5.10-rc5' into rdma.git for-next

For dependencies in following patches

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2020-11-23 16:50:59 -04:00
Alex Shi
ab150c3f80 PM / suspend: fix kernel-doc markup
Add parameter explanation to fix kernel-doc marks:

kernel/power/suspend.c:233: warning: Function parameter or member
'state' not described in 'suspend_valid_only_mem'
kernel/power/suspend.c:344: warning: Function parameter or member
'state' not described in 'suspend_prepare'

Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
[ rjw: Change the proposed parameter descriptions. ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-11-23 18:24:53 +01:00
Peter Collingbourne
6ac05e832a signal: define the SA_EXPOSE_TAGBITS bit in sa_flags
Architectures that support address tagging, such as arm64, may want to
expose fault address tag bits to the signal handler to help diagnose
memory errors. However, these bits have not been previously set,
and their presence may confuse unaware user applications. Therefore,
introduce a SA_EXPOSE_TAGBITS flag bit in sa_flags that a signal
handler may use to explicitly request that the bits are set.

The generic signal handler APIs expect to receive tagged addresses.
Architectures may specify how to untag addresses in the case where
SA_EXPOSE_TAGBITS is clear by defining the arch_untagged_si_addr
function.

Signed-off-by: Peter Collingbourne <pcc@google.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Link: https://linux-review.googlesource.com/id/I16dd0ed2081f091fce97be0190cb8caa874c26cb
Link: https://lkml.kernel.org/r/13cf24d00ebdd8e1f55caf1821c7c29d54100191.1605904350.git.pcc@google.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2020-11-23 10:31:06 -06:00
Peter Collingbourne
a54f0dfda7 signal: define the SA_UNSUPPORTED bit in sa_flags
Define a sa_flags bit, SA_UNSUPPORTED, which will never be supported
in the uapi. The purpose of this flag bit is to allow userspace to
distinguish an old kernel that does not clear unknown sa_flags bits
from a kernel that supports every flag bit.

In other words, if userspace does something like:

  act.sa_flags |= SA_UNSUPPORTED;
  sigaction(SIGSEGV, &act, 0);
  sigaction(SIGSEGV, 0, &oldact);

and finds that SA_UNSUPPORTED remains set in oldact.sa_flags, it means
that the kernel cannot be trusted to have cleared unknown flag bits
from sa_flags, so no assumptions about flag bit support can be made.

Signed-off-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Link: https://linux-review.googlesource.com/id/Ic2501ad150a3a79c1cf27fb8c99be342e9dffbcb
Link: https://lkml.kernel.org/r/bda7ddff8895a9bc4ffc5f3cf3d4d37a32118077.1605582887.git.pcc@google.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2020-11-23 10:31:06 -06:00
Peter Collingbourne
23acdc76f1 signal: clear non-uapi flag bits when passing/returning sa_flags
Previously we were not clearing non-uapi flag bits in
sigaction.sa_flags when storing the userspace-provided sa_flags or
when returning them via oldact. Start doing so.

This allows userspace to detect missing support for flag bits and
allows the kernel to use non-uapi bits internally, as we are already
doing in arch/x86 for two flag bits. Now that this change is in
place, we no longer need the code in arch/x86 that was hiding these
bits from userspace, so remove it.

This is technically a userspace-visible behavior change for sigaction, as
the unknown bits returned via oldact.sa_flags are no longer set. However,
we are free to define the behavior for unknown bits exactly because
their behavior is currently undefined, so for now we can define the
meaning of each of them to be "clear the bit in oldact.sa_flags unless
the bit becomes known in the future". Furthermore, this behavior is
consistent with OpenBSD [1], illumos [2] and XNU [3] (FreeBSD [4] and
NetBSD [5] fail the syscall if unknown bits are set). So there is some
precedent for this behavior in other kernels, and in particular in XNU,
which is probably the most popular kernel among those that I looked at,
which means that this change is less likely to be a compatibility issue.

Link: [1] f634a6a4b5/sys/kern/kern_sig.c (L278)
Link: [2] 76f19f5fdc/usr/src/uts/common/syscall/sigaction.c (L86)
Link: [3] a449c6a3b8/bsd/kern/kern_sig.c (L480)
Link: [4] eded70c370/sys/kern/kern_sig.c (L699)
Link: [5] 3365779bec/sys/kern/sys_sig.c (L473)
Signed-off-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Link: https://linux-review.googlesource.com/id/I35aab6f5be932505d90f3b3450c083b4db1eca86
Link: https://lkml.kernel.org/r/878dbcb5f47bc9b11881c81f745c0bef5c23f97f.1605235762.git.pcc@google.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2020-11-23 10:31:05 -06:00
Thomas Gleixner
ae9ef58996 softirq: Move related code into one section
To prepare for adding a RT aware variant of softirq serialization and
processing move related code into one section so the necessary #ifdeffery
is reduced to one.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20201113141733.974214480@linutronix.de
2020-11-23 10:31:06 +01:00
Linus Torvalds
f4b936f5d6 A couple of scheduler fixes:
- Make the conditional update of the overutilized state work correctly by
    caching the relevant flags state before overwriting them and checking
    them afterwards.
 
  - Fix a data race in the wakeup path which caused loadavg on ARM64
    platforms to become a random number generator.
 
  - Fix the ordering of the iowaiter accounting operations so it can't be
    decremented before it is incremented.
 
  - Fix a bug in the deadline scheduler vs. priority inheritance when a
    non-deadline task A has inherited the parameters of a deadline task B
    and then blocks on a non-deadline task C.
 
    The second inheritance step used the static deadline parameters of task
    A, which are usually 0, instead of further propagating task B's
    parameters. The zero initialized parameters trigger a bug in the
    deadline scheduler.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAl+6edsTHHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYoaJCEAC7VGr9IlWRzCI/173tKAXkLRrGXHVb
 yOYc/YjLMCTcERNxqpf8uIURd/ATSHU/RMwfFcB558NedKZ/QKZDoKmLqeCXnVeM
 e20tXv/fmpqRS7lgtmbBfhQ8mSDhst960oD1mHifdEwEBCCm7mLEaipTuTWjnZ0x
 rOz70Hir1mSjsP0E7ZorsxCr1yExbrt+jZfKCe9D2kUSvlWHf1ipzAYNlqb/DsfG
 n81G7q9LYV8NUhX3lt8oSZDq0K44aO6G6fEaP4EkfwsIAOh37yPHwuEuqDZCBmXw
 rQ17XUU3jQ2MtubPvVEKG/6Z+hAUyOsAKynpq/RhzueXQm/9Ns6+qHX/xY8yh39y
 S5qPd5DLRlac8f7cFwz2zPxP5E+xTJLONgRkuN1XlitMJZBxru9AzDNa0/6on8TM
 OtvbvVR+bPUfHiHULk4fTz7fLcbgYgxbCgfGoFsVlfskOxnzgEG8WfuI2Up2rRJ0
 nr1MCER+5fprciqPPs+18rVEFiC4mQSrV01cnwrNbpW8pqibZSomMilQ0oQvcTGL
 VDEHkaDTa5YbR92Szq4rYbr7Sf0ihFU0EZUNVQnu7SujdVFxTdHb1yr8UYcYp09b
 LqGFhr1FHBNYKbw3rEPx2R/FGuCii21oQkhz94ujDo1Np8EGVZYwFGh+iwbsa2Xn
 K1u0HzqLTfTkMw==
 =HiGq
 -----END PGP SIGNATURE-----

Merge tag 'sched-urgent-2020-11-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fixes from Thomas Gleixner:
 "A couple of scheduler fixes:

   - Make the conditional update of the overutilized state work
     correctly by caching the relevant flags state before overwriting
     them and checking them afterwards.

   - Fix a data race in the wakeup path which caused loadavg on ARM64
     platforms to become a random number generator.

   - Fix the ordering of the iowaiter accounting operations so it can't
     be decremented before it is incremented.

   - Fix a bug in the deadline scheduler vs. priority inheritance when a
     non-deadline task A has inherited the parameters of a deadline task
     B and then blocks on a non-deadline task C.

     The second inheritance step used the static deadline parameters of
     task A, which are usually 0, instead of further propagating task
     B's parameters. The zero initialized parameters trigger a bug in
     the deadline scheduler"

* tag 'sched-urgent-2020-11-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/deadline: Fix priority inheritance with multiple scheduling classes
  sched: Fix rq->nr_iowait ordering
  sched: Fix data-race in wakeup
  sched/fair: Fix overutilized update in enqueue_task_fair()
2020-11-22 13:26:07 -08:00
Linus Torvalds
855cf1ee47 A single fix for lockdep which makes the recursion protection cover graph
lock/unlock.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAl+6dQ4THHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYoXLiD/91TaQTrgVht6NxF5CmvEpoYPzGg/TO
 MeU7GmgeXv7ciIIDaPONsCLOGjGx5dSxk1QJ5OH+GhJ/lIXbtvbVUgbs7Ezjkl4d
 SyjRHNv3wYV7VJySEgqxo+Rd6fCQN7rOf/J3ZbzPHtMl40qxSpz1FeXTRft7cn62
 pkunRKM+f/tE/Ue96tiHCQVbwRxG3LEPIuXtLJQqtPvgMzb9zhC9mZpUcr5ZJyVD
 BfX69iIs1W1XKql6yH/KuBUY9d3qRzzmhko6a2mMSL3+VX0j4o46LMlP4HRndKTT
 5fEsUC3UOItqn7X4f3HHeQhckEAKXNGEMR30th84CligiEanQuIIHNNKazsnp87A
 GT/XA8RO9+OAd5TRP4CEaFDUR0a0OOZjiw3vW6E77BObi31Se9/EO3Z7XpJC2BSl
 vTsukplOmeilyspQJT7inVgZrtUlF0lpVV5YbMLjtbn5kzLu/75GZN3JagwCmflN
 GKbix/8tnH0KrbizCE8ujUZl+aNjk2TM64mAzOXMlmg+yZ47af31hFs846tCMhv5
 JHXkiMaXpWx3PapgGHM+4PJ1WDGTxm6mUvgAcyCVWgT4gxVXsppnkn0RLdRTGQ50
 C9movzOn1K2fEe7Pp40arG0tm18l9Ukp7mqN1CL+givRKNb61Owybe6qh2qk0IWT
 DAcgdC9h2rdTqQ==
 =dsm4
 -----END PGP SIGNATURE-----

Merge tag 'locking-urgent-2020-11-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking fix from Thomas Gleixner:
 "A single fix for lockdep which makes the recursion protection cover
  graph lock/unlock"

* tag 'locking-urgent-2020-11-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  lockdep: Put graph lock/unlock under lock_recursion protection
2020-11-22 13:19:53 -08:00
Linus Torvalds
ea0ab64306 seccomp fixes for v5.10-rc5
- Fix typos in seccomp selftests on powerpc and sh (Kees Cook)
 
 - Fix PF_SUPERPRIV audit marking in seccomp and ptrace (Mickaël Salaün)
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEpcP2jyKd1g9yPm4TiXL039xtwCYFAl+4FQgACgkQiXL039xt
 wCYERA/8Cwb8p8PWbtOq6uUKsZ4kJQuMZee3crP+LM0B1a427hOCSuezoDtOY1wO
 N7IEOr3ipHxoxZ1Zf2Ln4lGyktxlwzA8pqlGZyqR5zFIl+0HArbXdAfcRMcaeqUp
 eSV30CNBD5XfGLc2R5s1qHnrshVBJFebCpgMfSCOQQWMpZ51nnaoFN8N8iSEx6PN
 kYHC1C1WX5g3vtKo29xS2Y7KCThMOXvcNI7eFpVD0C4ZwEr8lywbTTzBBhXUIGBX
 6NoNOV7kVxIjNLQ8x17F1OacrC6h4ZzNTl4MEYnMZ/Mw0NVB3MvoHQohwW+Y98Rf
 97sPQPZjYeJ6xURolRsWX+kvXC7PyLYvfldsQi00QDfdc6RGu0pnsG4UuivsldlY
 OhswE9Q/KKHmzXiHnZBmcw4NcSyhZiL3LYB1VZl3jDobeOhVKyHw72vo8Zrhhz8A
 ksCDg3vNvOo/x2iH9GSUG4Fjk8coXRif8P6lH5Btw6V+x9ZlFiaW5WbSbP0G3PzJ
 zS5nPu8PE6Sm70XlRn0BbRmIjV9AhEZqNNZoOsndrbR86klH6WolyCB4ifj2MKuR
 ZwbeDblUrYyRne/Ll9XGQVDSFv8J5phxtDQM0phiGK0jOsvXqbl8RvlckCKqBwm0
 7VgtEumU5vJTx01avrXw86Sj7B2IR4M1nTgpwWJ2EVs9U98Emew=
 =1Mse
 -----END PGP SIGNATURE-----

Merge tag 'seccomp-v5.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull seccomp fixes from Kees Cook:
 "This gets the seccomp selftests running again on powerpc and sh, and
  fixes an audit reporting oversight noticed in both seccomp and ptrace.

   - Fix typos in seccomp selftests on powerpc and sh (Kees Cook)

   - Fix PF_SUPERPRIV audit marking in seccomp and ptrace (Mickaël
     Salaün)"

* tag 'seccomp-v5.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  selftests/seccomp: sh: Fix register names
  selftests/seccomp: powerpc: Fix typo in macro variable name
  seccomp: Set PF_SUPERPRIV when checking capability
  ptrace: Set PF_SUPERPRIV when checking capability
2020-11-21 10:24:05 -08:00
Kees Cook
7ef95e3dbc Merge branch 'for-linus/seccomp' into for-next/seccomp 2020-11-20 11:39:39 -08:00
Jann Horn
fab686eb03 seccomp: Remove bogus __user annotations
Buffers that are passed to read_actions_logged() and write_actions_logged()
are in kernel memory; the sysctl core takes care of copying from/to
userspace.

Fixes: 32927393dc ("sysctl: pass kernel pointers to ->proc_handler")
Reviewed-by: Tyler Hicks <code@tyhicks.com>
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20201120170545.1419332-1-jannh@google.com
2020-11-20 11:39:21 -08:00
Song Liu
91b2db27d3 bpf: Simplify task_file_seq_get_next()
Simplify task_file_seq_get_next() by removing two in/out arguments: task
and fstruct. Use info->task and info->files instead.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20201120002833.2481110-1-songliubraving@fb.com
2020-11-20 20:36:34 +01:00
YiFei Zhu
0d8315dddd seccomp/cache: Report cache data through /proc/pid/seccomp_cache
Currently the kernel does not provide an infrastructure to translate
architecture numbers to a human-readable name. Translating syscall
numbers to syscall names is possible through FTRACE_SYSCALL
infrastructure but it does not provide support for compat syscalls.

This will create a file for each PID as /proc/pid/seccomp_cache.
The file will be empty when no seccomp filters are loaded, or be
in the format of:
<arch name> <decimal syscall number> <ALLOW | FILTER>
where ALLOW means the cache is guaranteed to allow the syscall,
and filter means the cache will pass the syscall to the BPF filter.

For the docker default profile on x86_64 it looks like:
x86_64 0 ALLOW
x86_64 1 ALLOW
x86_64 2 ALLOW
x86_64 3 ALLOW
[...]
x86_64 132 ALLOW
x86_64 133 ALLOW
x86_64 134 FILTER
x86_64 135 FILTER
x86_64 136 FILTER
x86_64 137 ALLOW
x86_64 138 ALLOW
x86_64 139 FILTER
x86_64 140 ALLOW
x86_64 141 ALLOW
[...]

This file is guarded by CONFIG_SECCOMP_CACHE_DEBUG with a default
of N because I think certain users of seccomp might not want the
application to know which syscalls are definitely usable. For
the same reason, it is also guarded by CAP_SYS_ADMIN.

Suggested-by: Jann Horn <jannh@google.com>
Link: https://lore.kernel.org/lkml/CAG48ez3Ofqp4crXGksLmZY6=fGrF_tWyUCg7PBkAetvbbOPeOA@mail.gmail.com/
Signed-off-by: YiFei Zhu <yifeifz2@illinois.edu>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/94e663fa53136f5a11f432c661794d1ee7060779.1605101222.git.yifeifz2@illinois.edu
2020-11-20 11:16:35 -08:00
YiFei Zhu
8e01b51a31 seccomp/cache: Add "emulator" to check if filter is constant allow
SECCOMP_CACHE will only operate on syscalls that do not access
any syscall arguments or instruction pointer. To facilitate
this we need a static analyser to know whether a filter will
return allow regardless of syscall arguments for a given
architecture number / syscall number pair. This is implemented
here with a pseudo-emulator, and stored in a per-filter bitmap.

In order to build this bitmap at filter attach time, each filter is
emulated for every syscall (under each possible architecture), and
checked for any accesses of struct seccomp_data that are not the "arch"
nor "nr" (syscall) members. If only "arch" and "nr" are examined, and
the program returns allow, then we can be sure that the filter must
return allow independent from syscall arguments.

Nearly all seccomp filters are built from these cBPF instructions:

BPF_LD  | BPF_W    | BPF_ABS
BPF_JMP | BPF_JEQ  | BPF_K
BPF_JMP | BPF_JGE  | BPF_K
BPF_JMP | BPF_JGT  | BPF_K
BPF_JMP | BPF_JSET | BPF_K
BPF_JMP | BPF_JA
BPF_RET | BPF_K
BPF_ALU | BPF_AND  | BPF_K

Each of these instructions are emulated. Any weirdness or loading
from a syscall argument will cause the emulator to bail.

The emulation is also halted if it reaches a return. In that case,
if it returns an SECCOMP_RET_ALLOW, the syscall is marked as good.

Emulator structure and comments are from Kees [1] and Jann [2].

Emulation is done at attach time. If a filter depends on more
filters, and if the dependee does not guarantee to allow the
syscall, then we skip the emulation of this syscall.

[1] https://lore.kernel.org/lkml/20200923232923.3142503-5-keescook@chromium.org/
[2] https://lore.kernel.org/lkml/CAG48ez1p=dR_2ikKq=xVxkoGg0fYpTBpkhJSv1w-6BG=76PAvw@mail.gmail.com/

Suggested-by: Jann Horn <jannh@google.com>
Signed-off-by: YiFei Zhu <yifeifz2@illinois.edu>
Reviewed-by: Jann Horn <jannh@google.com>
Co-developed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/71c7be2db5ee08905f41c3be5c1ad6e2601ce88f.1602431034.git.yifeifz2@illinois.edu
2020-11-20 11:16:34 -08:00
YiFei Zhu
f9d480b6ff seccomp/cache: Lookup syscall allowlist bitmap for fast path
The overhead of running Seccomp filters has been part of some past
discussions [1][2][3]. Oftentimes, the filters have a large number
of instructions that check syscall numbers one by one and jump based
on that. Some users chain BPF filters which further enlarge the
overhead. A recent work [6] comprehensively measures the Seccomp
overhead and shows that the overhead is non-negligible and has a
non-trivial impact on application performance.

We observed some common filters, such as docker's [4] or
systemd's [5], will make most decisions based only on the syscall
numbers, and as past discussions considered, a bitmap where each bit
represents a syscall makes most sense for these filters.

The fast (common) path for seccomp should be that the filter permits
the syscall to pass through, and failing seccomp is expected to be
an exceptional case; it is not expected for userspace to call a
denylisted syscall over and over.

When it can be concluded that an allow must occur for the given
architecture and syscall pair (this determination is introduced in
the next commit), seccomp will immediately allow the syscall,
bypassing further BPF execution.

Each architecture number has its own bitmap. The architecture
number in seccomp_data is checked against the defined architecture
number constant before proceeding to test the bit against the
bitmap with the syscall number as the index of the bit in the
bitmap, and if the bit is set, seccomp returns allow. The bitmaps
are all clear in this patch and will be initialized in the next
commit.

When only one architecture exists, the check against architecture
number is skipped, suggested by Kees Cook [7].

[1] https://lore.kernel.org/linux-security-module/c22a6c3cefc2412cad00ae14c1371711@huawei.com/T/
[2] https://lore.kernel.org/lkml/202005181120.971232B7B@keescook/T/
[3] https://github.com/seccomp/libseccomp/issues/116
[4] ae0ef82b90/profiles/seccomp/default.json
[5] 6743a1caf4/src/shared/seccomp-util.c (L270)
[6] Draco: Architectural and Operating System Support for System Call Security
    https://tianyin.github.io/pub/draco.pdf, MICRO-53, Oct. 2020
[7] https://lore.kernel.org/bpf/202010091614.8BB0EB64@keescook/

Co-developed-by: Dimitrios Skarlatos <dskarlat@cs.cmu.edu>
Signed-off-by: Dimitrios Skarlatos <dskarlat@cs.cmu.edu>
Signed-off-by: YiFei Zhu <yifeifz2@illinois.edu>
Reviewed-by: Jann Horn <jannh@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/10f91a367ec4fcdea7fc3f086de3f5f13a4a7436.1602431034.git.yifeifz2@illinois.edu
2020-11-20 11:16:34 -08:00
Petr Mladek
3cffa06aee printk/console: Allow to disable console output by using console="" or console=null
The commit 48021f9813 ("printk: handle blank console arguments
passed in.") prevented crash caused by empty console= parameter value.

Unfortunately, this value is widely used on Chromebooks to disable
the console output. The above commit caused performance regression
because the messages were pushed on slow console even though nobody
was watching it.

Use ttynull driver explicitly for console="" and console=null
parameters. It has been created for exactly this purpose.

It causes that preferred_console is set. As a result, ttySX and ttyX
are not used as a fallback. And only ttynull console gets registered by
default.

It still allows to register other consoles either by additional console=
parameters or SPCR. It prevents regression because it worked this way even
before. Also it is a sane semantic. Preventing output on all consoles
should be done another way, for example, by introducing mute_console
parameter.

Link: https://lore.kernel.org/r/20201006025935.GA597@jagdpanzerIV.localdomain
Suggested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20201111135450.11214-3-pmladek@suse.com
2020-11-20 12:29:05 +01:00
Eric Biggers
a24d22b225 crypto: sha - split sha.h into sha1.h and sha2.h
Currently <crypto/sha.h> contains declarations for both SHA-1 and SHA-2,
and <crypto/sha3.h> contains declarations for SHA-3.

This organization is inconsistent, but more importantly SHA-1 is no
longer considered to be cryptographically secure.  So to the extent
possible, SHA-1 shouldn't be grouped together with any of the other SHA
versions, and usage of it should be phased out.

Therefore, split <crypto/sha.h> into two headers <crypto/sha1.h> and
<crypto/sha2.h>, and make everyone explicitly specify whether they want
the declarations for SHA-1, SHA-2, or both.

This avoids making the SHA-1 declarations visible to files that don't
want anything to do with SHA-1.  It also prepares for potentially moving
sha1.h into a new insecure/ or dangerous/ directory.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-11-20 14:45:33 +11:00
Paul E. McKenney
c4638ff064 Merge branch 'kcsan.2020.11.06a' into HEAD
kcsan.2020.11.06a:  Kernel concurrency sanitizer (KCSAN) updates.
2020-11-19 19:38:25 -08:00
Paul E. McKenney
7fc91fc845 Merge branches 'cpuinfo.2020.11.06a', 'doc.2020.11.06a', 'fixes.2020.11.19b', 'lockdep.2020.11.02a', 'tasks.2020.11.06a' and 'torture.2020.11.06a' into HEAD
cpuinfo.2020.11.06a: Speedups for /proc/cpuinfo.
doc.2020.11.06a: Documentation updates.
fixes.2020.11.19b: Miscellaneous fixes.
lockdep.2020.11.02a: Lockdep-RCU updates to avoid "unused variable".
tasks.2020.11.06a: Tasks-RCU updates.
torture.2020.11.06a': Torture-test updates.
2020-11-19 19:37:47 -08:00
Paul E. McKenney
50edb98853 srcu: Take early exit on memory-allocation failure
It turns out that init_srcu_struct() can be invoked from usermode tasks,
and that fatal signals received by these tasks can cause memory-allocation
failures.  These failures are not handled well by init_srcu_struct(),
so much so that NULL pointer dereferences can result.  This commit
therefore causes init_srcu_struct() to take an early exit upon detection
of memory-allocation failure.

Link: https://lore.kernel.org/lkml/20200908144306.33355-1-aik@ozlabs.ru/
Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-19 19:37:17 -08:00
Uladzislau Rezki (Sony)
56292e8609 rcu/tree: Defer kvfree_rcu() allocation to a clean context
The current memmory-allocation interface causes the following difficulties
for kvfree_rcu():

a) If built with CONFIG_PROVE_RAW_LOCK_NESTING, the lockdep will
   complain about violation of the nesting rules, as in "BUG: Invalid
   wait context".  This Kconfig option checks for proper raw_spinlock
   vs. spinlock nesting, in particular, it is not legal to acquire a
   spinlock_t while holding a raw_spinlock_t.

   This is a problem because kfree_rcu() uses raw_spinlock_t whereas the
   "page allocator" internally deals with spinlock_t to access to its
   zones. The code also can be broken from higher level of view:
   <snip>
       raw_spin_lock(&some_lock);
       kfree_rcu(some_pointer, some_field_offset);
   <snip>

b) If built with CONFIG_PREEMPT_RT, spinlock_t is converted into
   sleeplock.  This means that invoking the page allocator from atomic
   contexts results in "BUG: scheduling while atomic".

c) Please note that call_rcu() is already invoked from raw atomic context,
   so it is only reasonable to expaect that kfree_rcu() and kvfree_rcu()
   will also be called from atomic raw context.

This commit therefore defers page allocation to a clean context using the
combination of an hrtimer and a workqueue.  The hrtimer stage is required
in order to avoid deadlocks with the scheduler.  This deferred allocation
is required only when kvfree_rcu()'s per-CPU page cache is empty.

Link: https://lore.kernel.org/lkml/20200630164543.4mdcf6zb4zfclhln@linutronix.de/
Fixes: 3042f83f19 ("rcu: Support reclaim for head-less object")
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-19 19:37:17 -08:00
Paul E. McKenney
bfb3aa735f rcu: Do not report strict GPs for outgoing CPUs
An outgoing CPU is marked offline in a stop-machine handler and most
of that CPU's services stop at that point, including IRQ work queues.
However, that CPU must take another pass through the scheduler and through
a number of CPU-hotplug notifiers, many of which contain RCU readers.
In the past, these readers were not a problem because the outgoing CPU
has interrupts disabled, so that rcu_read_unlock_special() would not
be invoked, and thus RCU would never attempt to queue IRQ work on the
outgoing CPU.

This changed with the advent of the CONFIG_RCU_STRICT_GRACE_PERIOD
Kconfig option, in which rcu_read_unlock_special() is invoked upon exit
from almost all RCU read-side critical sections.  Worse yet, because
interrupts are disabled, rcu_read_unlock_special() cannot immediately
report a quiescent state and will therefore attempt to defer this
reporting, for example, by queueing IRQ work.  Which fails with a splat
because the CPU is already marked as being offline.

But it turns out that there is no need to report this quiescent state
because rcu_report_dead() will do this job shortly after the outgoing
CPU makes its final dive into the idle loop.  This commit therefore
makes rcu_read_unlock_special() refrain from queuing IRQ work onto
outgoing CPUs.

Fixes: 44bad5b3cc ("rcu: Do full report for .need_qs for strict GPs")
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Jann Horn <jannh@google.com>
2020-11-19 19:37:17 -08:00
Zhouyi Zhou
354c3f0e22 rcu: Fix a typo in rcu_blocking_is_gp() header comment
This commit fixes a typo in the rcu_blocking_is_gp() function's header
comment.

Signed-off-by: Zhouyi Zhou <zhouzhouyi@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-19 19:37:17 -08:00
Paul E. McKenney
4d60b475f8 rcu: Prevent lockdep-RCU splats on lock acquisition/release
The rcu_cpu_starting() and rcu_report_dead() functions transition the
current CPU between online and offline state from an RCU perspective.
Unfortunately, this means that the rcu_cpu_starting() function's lock
acquisition and the rcu_report_dead() function's lock releases happen
while the CPU is offline from an RCU perspective, which can result
in lockdep-RCU splats about using RCU from an offline CPU.  And this
situation can also result in too-short grace periods, especially in
guest OSes that are subject to vCPU preemption.

This commit therefore uses sequence-count-like synchronization to forgive
use of RCU while RCU thinks a CPU is offline across the full extent of
the rcu_cpu_starting() and rcu_report_dead() function's lock acquisitions
and releases.

One approach would have been to use the actual sequence-count primitives
provided by the Linux kernel.  Unfortunately, the resulting code looks
completely broken and wrong, and is likely to result in patches that
break RCU in an attempt to address this appearance of broken wrongness.
Plus there is no net savings in lines of code, given the additional
explicit memory barriers required.

Therefore, this sequence count is instead implemented by a new ->ofl_seq
field in the rcu_node structure.  If this counter's value is an odd
number, RCU forgives RCU read-side critical sections on other CPUs covered
by the same rcu_node structure, even if those CPUs are offline from
an RCU perspective.  In addition, if a given leaf rcu_node structure's
->ofl_seq counter value is an odd number, rcu_gp_init() delays starting
the grace period until that counter value changes.

[ paulmck: Apply Peter Zijlstra feedback. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-19 19:37:17 -08:00
Joel Fernandes (Google)
bd56e0a4a2 rcu/tree: nocb: Avoid raising softirq for offloaded ready-to-execute CBs
Testing showed that rcu_pending() can return 1 when offloaded callbacks
are ready to execute.  This invokes RCU core processing, for example,
by raising RCU_SOFTIRQ, eventually resulting in a call to rcu_core().
However, rcu_core() explicitly avoids in any way manipulating offloaded
callbacks, which are instead handled by the rcuog and rcuoc kthreads,
which work independently of rcu_core().

One exception to this independence is that rcu_core() invokes
do_nocb_deferred_wakeup(), however, rcu_pending() also checks
rcu_nocb_need_deferred_wakeup() in order to correctly handle this case,
invoking rcu_core() when needed.

This commit therefore avoids needlessly invoking RCU core processing
by checking rcu_segcblist_ready_cbs() only on non-offloaded CPUs.
This reduces overhead, for example, by reducing softirq activity.

This change passed 30 minute tests of TREE01 through TREE09 each.

On TREE08, there is at most 150us from the time that rcu_pending() chose
not to invoke RCU core processing to the time when the ready callbacks
were invoked by the rcuoc kthread.  This provides further evidence that
there is no need to invoke rcu_core() for offloaded callbacks that are
ready to invoke.

Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Neeraj Upadhyay <neeraju@codeaurora.org>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-19 19:37:17 -08:00
Peter Zijlstra
d2098b4440 rcu,ftrace: Fix ftrace recursion
Kim reported that perf-ftrace made his box unhappy. It turns out that
commit:

  ff5c4f5cad ("rcu/tree: Mark the idle relevant functions noinstr")

removed one too many notrace qualifiers, probably due to there not being
a helpful comment.

This commit therefore reinstates the notrace and adds a comment to avoid
losing it again.

[ paulmck: Apply Steven Rostedt's feedback on the comment. ]
Fixes: ff5c4f5cad ("rcu/tree: Mark the idle relevant functions noinstr")
Reported-by: Kim Phillips <kim.phillips@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-19 19:37:17 -08:00
Joe Perches
7c47ee5aa0 rcu/tree: Make struct kernel_param_ops definitions const
These should be const, so make it so.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-19 19:37:17 -08:00
Joel Fernandes (Google)
9f866dac94 rcu/tree: Add a warning if CPU being onlined did not report QS already
Currently, rcu_cpu_starting() checks to see if the RCU core expects a
quiescent state from the incoming CPU.  However, the current interaction
between RCU quiescent-state reporting and CPU-hotplug operations should
mean that the incoming CPU never needs to report a quiescent state.
First, the outgoing CPU reports a quiescent state if needed.  Second,
the race where the CPU is leaving just as RCU is initializing a new
grace period is handled by an explicit check for this condition.  Third,
the CPU's leaf rcu_node structure's ->lock serializes these checks.

This means that if rcu_cpu_starting() ever feels the need to report
a quiescent state, then there is a bug somewhere in the CPU hotplug
code or the RCU grace-period handling code.  This commit therefore
adds a WARN_ON_ONCE() to bring that bug to everyone's attention.

Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Suggested-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-19 19:37:16 -08:00
Neeraj Upadhyay
a3941517fc rcu: Clarify nocb kthreads naming in RCU_NOCB_CPU config
This commit clarifies that the "p" and the "s" in the in the RCU_NOCB_CPU
config-option description refer to the "x" in the "rcuox/N" kthread name.

Signed-off-by: Neeraj Upadhyay <neeraju@codeaurora.org>
[ paulmck: While in the area, update description and advice. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-19 19:37:16 -08:00
Neeraj Upadhyay
ed73860cec rcu: Fix single-CPU check in rcu_blocking_is_gp()
Currently, for CONFIG_PREEMPTION=n kernels, rcu_blocking_is_gp() uses
num_online_cpus() to determine whether there is only one CPU online.  When
there is only a single CPU online, the simple fact that synchronize_rcu()
could be legally called implies that a full grace period has elapsed.
Therefore, in the single-CPU case, synchronize_rcu() simply returns
immediately.  Unfortunately, num_online_cpus() is unreliable while a
CPU-hotplug operation is transitioning to or from single-CPU operation
because:

1.	num_online_cpus() uses atomic_read(&__num_online_cpus) to
	locklessly sample the number of online CPUs.  The hotplug locks
	are not held, which means that an incoming CPU can concurrently
	update this count.  This in turn means that an RCU read-side
	critical section on the incoming CPU might observe updates
	prior to the grace period, but also that this critical section
	might extend beyond the end of the optimized synchronize_rcu().
	This breaks RCU's fundamental guarantee.

2.	In addition, num_online_cpus() does no ordering, thus providing
	another way that RCU's fundamental guarantee can be broken by
	the current code.

3.	The most probable failure mode happens on outgoing CPUs.
	The outgoing CPU updates the count of online CPUs in the
	CPUHP_TEARDOWN_CPU stop-machine handler, which is fine in
	and of itself due to preemption being disabled at the call
	to num_online_cpus().  Unfortunately, after that stop-machine
	handler returns, the CPU takes one last trip through the
	scheduler (which has RCU readers) and, after the resulting
	context switch, one final dive into the idle loop.  During this
	time, RCU needs to keep track of two CPUs, but num_online_cpus()
	will say that there is only one, which in turn means that the
	surviving CPU will incorrectly ignore the outgoing CPU's RCU
	read-side critical sections.

This problem is illustrated by the following litmus test in which P0()
corresponds to synchronize_rcu() and P1() corresponds to the incoming CPU.
The herd7 tool confirms that the "exists" clause can be satisfied,
thus demonstrating that this breakage can happen according to the Linux
kernel memory model.

   {
     int x = 0;
     atomic_t numonline = ATOMIC_INIT(1);
   }

   P0(int *x, atomic_t *numonline)
   {
     int r0;
     WRITE_ONCE(*x, 1);
     r0 = atomic_read(numonline);
     if (r0 == 1) {
       smp_mb();
     } else {
       synchronize_rcu();
     }
     WRITE_ONCE(*x, 2);
   }

   P1(int *x, atomic_t *numonline)
   {
     int r0; int r1;

     atomic_inc(numonline);
     smp_mb();
     rcu_read_lock();
     r0 = READ_ONCE(*x);
     smp_rmb();
     r1 = READ_ONCE(*x);
     rcu_read_unlock();
   }

   locations [x;numonline;]

   exists (1:r0=0 /\ 1:r1=2)

It is important to note that these problems arise only when the system
is transitioning to or from single-CPU operation.

One solution would be to hold the CPU-hotplug locks while sampling
num_online_cpus(), which was in fact the intent of the (redundant)
preempt_disable() and preempt_enable() surrounding this call to
num_online_cpus().  Actually blocking CPU hotplug would not only result
in excessive overhead, but would also unnecessarily impede CPU-hotplug
operations.

This commit therefore follows long-standing RCU tradition by maintaining
a separate RCU-specific set of CPU-hotplug books.

This separate set of books is implemented by a new ->n_online_cpus field
in the rcu_state structure that maintains RCU's count of the online CPUs.
This count is incremented early in the CPU-online process, so that
the critical transition away from single-CPU operation will occur when
there is only a single CPU.  Similarly for the critical transition to
single-CPU operation, the counter is decremented late in the CPU-offline
process, again while there is only a single CPU.  Because there is only
ever a single CPU when the ->n_online_cpus field undergoes the critical
1->2 and 2->1 transitions, full memory ordering and mutual exclusion is
provided implicitly and, better yet, for free.

In the case where the CPU is coming online, nothing will happen until
the current CPU helps it come online.  Therefore, the new CPU will see
all accesses prior to the optimized grace period, which means that RCU
does not need to further delay this new CPU.  In the case where the CPU
is going offline, the outgoing CPU is totally out of the picture before
the optimized grace period starts, which means that this outgoing CPU
cannot see any of the accesses following that grace period.  Again,
RCU needs no further interaction with the outgoing CPU.

This does mean that synchronize_rcu() will unnecessarily do a few grace
periods the hard way just before the second CPU comes online and just
after the second-to-last CPU goes offline, but it is not worth optimizing
this uncommon case.

Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Neeraj Upadhyay <neeraju@codeaurora.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-19 19:37:16 -08:00
Frederic Weisbecker
e3771c850d rcu: Implement rcu_segcblist_is_offloaded() config dependent
This commit simplifies the use of the rcu_segcblist_is_offloaded() API so
that its callers no longer need to check the RCU_NOCB_CPU Kconfig option.
Note that rcu_segcblist_is_offloaded() is defined in the header file,
which means that the generated code should be just as efficient as before.

Suggested-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-19 19:37:16 -08:00
chao
dfe564045c rcu: Panic after fixed number of stalls
Some stalls are transient, so that system fully recovers.  This commit
therefore allows users to configure the number of stalls that must happen
in order to trigger kernel panic.

Signed-off-by: chao <chao@eero.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-19 19:37:16 -08:00
Peter Zijlstra
6dbce04d84 rcu: Allow rcu_irq_enter_check_tick() from NMI
Eugenio managed to tickle #PF from NMI context which resulted in
hitting a WARN in RCU through irqentry_enter() ->
__rcu_irq_enter_check_tick().

However, this situation is perfectly sane and does not warrant an
WARN. The #PF will (necessarily) be atomic and not require messing
with the tick state, so early return is correct.  This commit
therefore removes the WARN.

Fixes: aaf2bc50df ("rcu: Abstract out rcu_irq_enter_check_tick() from rcu_nmi_enter()")
Reported-by: "Eugenio Pérez" <eupm90@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-19 19:34:17 -08:00
Jakub Kicinski
56495a2442 Merge https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-19 19:08:46 -08:00
Linus Torvalds
4d02da974e Networking fixes for 5.10-rc5, including fixes from the WiFi (mac80211),
can and bpf (including the strncpy_from_user fix).
 
 Current release - regressions:
 
  - mac80211: fix memory leak of filtered powersave frames
 
  - mac80211: free sta in sta_info_insert_finish() on errors to avoid
              sleeping in atomic context
 
  - netlabel: fix an uninitialized variable warning added in -rc4
 
 Previous release - regressions:
 
  - vsock: forward all packets to the host when no H2G is registered,
            un-breaking AWS Nitro Enclaves
 
  - net: Exempt multicast addresses from five-second neighbor lifetime
         requirement, decreasing the chances neighbor tables fill up
 
  - net/tls: fix corrupted data in recvmsg
 
  - qed: fix ILT configuration of SRC block
 
  - can: m_can: process interrupt only when not runtime suspended
 
 Previous release - always broken:
 
  - page_frag: Recover from memory pressure by not recycling pages
               allocating from the reserves
 
  - strncpy_from_user: Mask out bytes after NUL terminator
 
  - ip_tunnels: Set tunnel option flag only when tunnel metadata is
                present, always setting it confuses Open vSwitch
 
  - bpf, sockmap:
    - Fix partial copy_page_to_iter so progress can still be made
    - Fix socket memory accounting and obeying SO_RCVBUF
 
  - net: Have netpoll bring-up DSA management interface
 
  - net: bridge: add missing counters to ndo_get_stats64 callback
 
  - tcp: brr: only postpone PROBE_RTT if RTT is < current min_rtt
 
  - enetc: Workaround MDIO register access HW bug
 
  - net/ncsi: move netlink family registration to a subsystem init,
              instead of tying it to driver probe
 
  - net: ftgmac100: unregister NC-SI when removing driver to avoid crash
 
  - lan743x: prevent interrupt storm on open
 
  - lan743x: fix freeing skbs in the wrong context
 
  - net/mlx5e: Fix socket refcount leak on kTLS RX resync
 
  - net: dsa: mv88e6xxx: Avoid VLAN database corruption on 6097
 
  - fix 21 unset return codes and other mistakes on error paths,
    mostly detected by the Hulk Robot
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEE6jPA+I1ugmIBA4hXMUZtbf5SIrsFAl+226AACgkQMUZtbf5S
 IruE1w/+JX3CqJwGIqyzyhwVshNaKxmX9gAOMJzkckjEohn8932zPaNq7kbmNYqt
 5QsJoou3cXjFeoIEAkQA5fqR4stTZpZMnLO+7JnxxQ0vb2YBN+tIGQRNCnmd1Q0h
 u9gb5+5AdORdlmk3E7oC8v50dzQRfboJXLEEZTo2uGJwUgLlEAiqTSV2w4YDHMhL
 JtgtWA/fraL0CUc2WMoxuimg9NirbRuMijsU6+d/yExzznDpdoho/qsxL+Odu1NF
 hSdaKirA8B8ml0pOd/b4mj+fm4+lKyXZBfSyLx4Ki1TqluEMLzDp7gQPRnU6yyJm
 AOu4zsKxx6qitOX2qLQCNlEpkQp6LA2N2Zb1orliUV3Bsq2DJRhU35FgLcghtdRP
 GTRSdKHr2BvMScOZ7dQo8l4TqVc3e/khSZDRGdvpsM275Dt0JyS/l7yAWxunPqMb
 +/483/s75OuBRO57ULLJ/hR02TG37g/Jv5sI0sG/7oDpGfnulinQX+fxy9izyTEM
 KYl0mAPSqhb6RcjE0YXWG0rhJN6FSvc/lwPQHjq8wPSkwEdD/FTb6/eYqbXDi1ld
 UTYhFpkh1PQrwct14eSScMeJqTsNKvG0VV39/uZLZCzcqa3yOY5+oTzwaCFlMsy3
 a5yGGxqoh7/FTM8t1ml21is9uZ31LAQEnNTMPv69pZPwAv5G5yE=
 =SRwI
 -----END PGP SIGNATURE-----

Merge tag 'net-5.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Jakub Kicinski:
 "Networking fixes for 5.10-rc5, including fixes from the WiFi
  (mac80211), can and bpf (including the strncpy_from_user fix).

  Current release - regressions:

   - mac80211: fix memory leak of filtered powersave frames

   - mac80211: free sta in sta_info_insert_finish() on errors to avoid
     sleeping in atomic context

   - netlabel: fix an uninitialized variable warning added in -rc4

  Previous release - regressions:

   - vsock: forward all packets to the host when no H2G is registered,
     un-breaking AWS Nitro Enclaves

   - net: Exempt multicast addresses from five-second neighbor lifetime
     requirement, decreasing the chances neighbor tables fill up

   - net/tls: fix corrupted data in recvmsg

   - qed: fix ILT configuration of SRC block

   - can: m_can: process interrupt only when not runtime suspended

  Previous release - always broken:

   - page_frag: Recover from memory pressure by not recycling pages
     allocating from the reserves

   - strncpy_from_user: Mask out bytes after NUL terminator

   - ip_tunnels: Set tunnel option flag only when tunnel metadata is
     present, always setting it confuses Open vSwitch

   - bpf, sockmap:
      - Fix partial copy_page_to_iter so progress can still be made
      - Fix socket memory accounting and obeying SO_RCVBUF

   - net: Have netpoll bring-up DSA management interface

   - net: bridge: add missing counters to ndo_get_stats64 callback

   - tcp: brr: only postpone PROBE_RTT if RTT is < current min_rtt

   - enetc: Workaround MDIO register access HW bug

   - net/ncsi: move netlink family registration to a subsystem init,
     instead of tying it to driver probe

   - net: ftgmac100: unregister NC-SI when removing driver to avoid
     crash

   - lan743x:
      - prevent interrupt storm on open
      - fix freeing skbs in the wrong context

   - net/mlx5e: Fix socket refcount leak on kTLS RX resync

   - net: dsa: mv88e6xxx: Avoid VLAN database corruption on 6097

   - fix 21 unset return codes and other mistakes on error paths, mostly
     detected by the Hulk Robot"

* tag 'net-5.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (115 commits)
  fail_function: Remove a redundant mutex unlock
  selftest/bpf: Test bpf_probe_read_user_str() strips trailing bytes after NUL
  lib/strncpy_from_user.c: Mask out bytes after NUL terminator.
  net/smc: fix direct access to ib_gid_addr->ndev in smc_ib_determine_gid()
  net/smc: fix matching of existing link groups
  ipv6: Remove dependency of ipv6_frag_thdr_truncated on ipv6 module
  libbpf: Fix VERSIONED_SYM_COUNT number parsing
  net/mlx4_core: Fix init_hca fields offset
  atm: nicstar: Unmap DMA on send error
  page_frag: Recover from memory pressure
  net: dsa: mv88e6xxx: Wait for EEPROM done after HW reset
  mlxsw: core: Use variable timeout for EMAD retries
  mlxsw: Fix firmware flashing
  net: Have netpoll bring-up DSA management interface
  atl1e: fix error return code in atl1e_probe()
  atl1c: fix error return code in atl1c_probe()
  ah6: fix error return code in ah6_input()
  net: usb: qmi_wwan: Set DTR quirk for MR400
  can: m_can: process interrupt only when not runtime suspended
  can: flexcan: flexcan_chip_start(): fix erroneous flexcan_transceiver_enable() during bus-off recovery
  ...
2020-11-19 13:33:16 -08:00
Jakub Kicinski
e6ea60bac1 Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Alexei Starovoitov says:

====================
1) libbpf should not attempt to load unused subprogs, from Andrii.

2) Make strncpy_from_user() mask out bytes after NUL terminator, from Daniel.

3) Relax return code check for subprograms in the BPF verifier, from Dmitrii.

4) Fix several sockmap issues, from John.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  fail_function: Remove a redundant mutex unlock
  selftest/bpf: Test bpf_probe_read_user_str() strips trailing bytes after NUL
  lib/strncpy_from_user.c: Mask out bytes after NUL terminator.
  libbpf: Fix VERSIONED_SYM_COUNT number parsing
  bpf, sockmap: Avoid failures from skb_to_sgvec when skb has frag_list
  bpf, sockmap: Handle memory acct if skb_verdict prog redirects to self
  bpf, sockmap: Avoid returning unneeded EAGAIN when redirecting to self
  bpf, sockmap: Use truesize with sk_rmem_schedule()
  bpf, sockmap: Ensure SO_RCVBUF memory is observed on ingress redirect
  bpf, sockmap: Fix partial copy_page_to_iter so progress can still be made
  selftests/bpf: Fix error return code in run_getsockopt_test()
  bpf: Relax return code check for subprograms
  tools, bpftool: Add missing close before bpftool net attach exit
  MAINTAINERS/bpf: Update Andrii's entry.
  selftests/bpf: Fix unused attribute usage in subprogs_unused test
  bpf: Fix unsigned 'datasec_id' compared with zero in check_pseudo_btf_id
  bpf: Fix passing zero to PTR_ERR() in bpf_btf_printf_prepare
  libbpf: Don't attempt to load unused subprog as an entry-point BPF program
====================

Link: https://lore.kernel.org/r/20201119200721.288-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-19 12:26:10 -08:00
Luo Meng
2801a5da5b fail_function: Remove a redundant mutex unlock
Fix a mutex_unlock() issue where before copy_from_user() is
not called mutex_locked.

Fixes: 4b1a29a7f5 ("error-injection: Support fault injection framework")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Luo Meng <luomeng12@huawei.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/bpf/160570737118.263807.8358435412898356284.stgit@devnote2
2020-11-19 11:58:16 -08:00
Daniel Xu
6fa6d28051 lib/strncpy_from_user.c: Mask out bytes after NUL terminator.
do_strncpy_from_user() may copy some extra bytes after the NUL
terminator into the destination buffer. This usually does not matter for
normal string operations. However, when BPF programs key BPF maps with
strings, this matters a lot.

A BPF program may read strings from user memory by calling the
bpf_probe_read_user_str() helper which eventually calls
do_strncpy_from_user(). The program can then key a map with the
destination buffer. BPF map keys are fixed-width and string-agnostic,
meaning that map keys are treated as a set of bytes.

The issue is when do_strncpy_from_user() overcopies bytes after the NUL
terminator, it can result in seemingly identical strings occupying
multiple slots in a BPF map. This behavior is subtle and totally
unexpected by the user.

This commit masks out the bytes following the NUL while preserving
long-sized stride in the fast path.

Fixes: 6ae08ae3de ("bpf: Add probe_read_{user, kernel} and probe_read_{user, kernel}_str helpers")
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/21efc982b3e9f2f7b0379eed642294caaa0c27a7.1605642949.git.dxu@dxuuu.xyz
2020-11-19 11:56:16 -08:00
Ionela Voinescu
fa50e2b452 sched/topology: Condition EAS enablement on FIE support
In order to make accurate predictions across CPUs and for all performance
states, Energy Aware Scheduling (EAS) needs frequency-invariant load
tracking signals.

EAS task placement aims to minimize energy consumption, and does so in
part by limiting the search space to only CPUs with the highest spare
capacity (CPU capacity - CPU utilization) in their performance domain.
Those candidates are the placement choices that will keep frequency at
its lowest possible and therefore save the most energy.

But without frequency invariance, a CPU's utilization is relative to the
CPU's current performance level, and not relative to its maximum
performance level, which determines its capacity. As a result, it will
fail to correctly indicate any potential spare capacity obtained by an
increase in a CPU's performance level. Therefore, a non-invariant
utilization signal would render the EAS task placement logic invalid.

Now that we properly report support for the Frequency Invariance Engine
(FIE) through arch_scale_freq_invariant() for arm and arm64 systems,
while also ensuring a re-evaluation of the EAS use conditions for
possible invariance status change, we can assert this is the case when
initializing EAS. Warn and bail out otherwise.

Suggested-by: Quentin Perret <qperret@google.com>
Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201027180713.7642-4-ionela.voinescu@arm.com
2020-11-19 11:25:47 +01:00
Ionela Voinescu
31f6a8c0a4 sched/topology,schedutil: Wrap sched domains rebuild
Add the rebuild_sched_domains_energy() function to wrap the functionality
that rebuilds the scheduling domains if any of the Energy Aware Scheduling
(EAS) initialisation conditions change. This functionality is used when
schedutil is added or removed or when EAS is enabled or disabled
through the sched_energy_aware sysctl.

Therefore, create a single function that is used in both these cases and
that can be later reused.

Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Quentin Perret <qperret@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lkml.kernel.org/r/20201027180713.7642-2-ionela.voinescu@arm.com
2020-11-19 11:25:47 +01:00
Dietmar Eggemann
480a6ca2dc sched/uclamp: Allow to reset a task uclamp constraint value
In case the user wants to stop controlling a uclamp constraint value
for a task, use the magic value -1 in sched_util_{min,max} with the
appropriate sched_flags (SCHED_FLAG_UTIL_CLAMP_{MIN,MAX}) to indicate
the reset.

The advantage over the 'additional flag' approach (i.e. introducing
SCHED_FLAG_UTIL_CLAMP_RESET) is that no additional flag has to be
exported via uapi. This avoids the need to document how this new flag
has be used in conjunction with the existing uclamp related flags.

The following subtle issue is fixed as well. When a uclamp constraint
value is set on a !user_defined uclamp_se it is currently first reset
and then set.
Fix this by AND'ing !user_defined with !SCHED_FLAG_UTIL_CLAMP which
stands for the 'sched class change' case.
The related condition 'if (uc_se->user_defined)' moved from
__setscheduler_uclamp() into uclamp_reset().

Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Yun Hsiang <hsiang023167@gmail.com>
Link: https://lkml.kernel.org/r/20201113113454.25868-1-dietmar.eggemann@arm.com
2020-11-19 11:25:47 +01:00
Tal Zussman
b19a888c1e sched/core: Fix typos in comments
Signed-off-by: Tal Zussman <tz2294@columbia.edu>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201113005156.GA8408@charmander
2020-11-19 11:25:46 +01:00
Valentin Schneider
b5b217346d sched/topology: Warn when NUMA diameter > 2
NUMA topologies where the shortest path between some two nodes requires
three or more hops (i.e. diameter > 2) end up being misrepresented in the
scheduler topology structures.

This is currently detected when booting a kernel with CONFIG_SCHED_DEBUG=y
+ sched_debug on the cmdline, although this will only yield a warning about
sched_group spans not matching sched_domain spans:

  ERROR: groups don't span domain->span

Add an explicit warning for that case, triggered regardless of
CONFIG_SCHED_DEBUG, and decorate it with an appropriate comment.

The topology described in the comment can be booted up on QEMU by appending
the following to your usual QEMU incantation:

    -smp cores=4 \
    -numa node,cpus=0,nodeid=0 -numa node,cpus=1,nodeid=1, \
    -numa node,cpus=2,nodeid=2, -numa node,cpus=3,nodeid=3, \
    -numa dist,src=0,dst=1,val=20, -numa dist,src=0,dst=2,val=30, \
    -numa dist,src=0,dst=3,val=40, -numa dist,src=1,dst=2,val=20, \
    -numa dist,src=1,dst=3,val=30, -numa dist,src=2,dst=3,val=20

A somewhat more realistic topology (6-node mesh) with the same affliction
can be conjured with:

    -smp cores=6 \
    -numa node,cpus=0,nodeid=0 -numa node,cpus=1,nodeid=1, \
    -numa node,cpus=2,nodeid=2, -numa node,cpus=3,nodeid=3, \
    -numa node,cpus=4,nodeid=4, -numa node,cpus=5,nodeid=5, \
    -numa dist,src=0,dst=1,val=20, -numa dist,src=0,dst=2,val=30, \
    -numa dist,src=0,dst=3,val=40, -numa dist,src=0,dst=4,val=30, \
    -numa dist,src=0,dst=5,val=20, \
    -numa dist,src=1,dst=2,val=20, -numa dist,src=1,dst=3,val=30, \
    -numa dist,src=1,dst=4,val=20, -numa dist,src=1,dst=5,val=30, \
    -numa dist,src=2,dst=3,val=20, -numa dist,src=2,dst=4,val=30, \
    -numa dist,src=2,dst=5,val=40, \
    -numa dist,src=3,dst=4,val=20, -numa dist,src=3,dst=5,val=30, \
    -numa dist,src=4,dst=5,val=20

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Link: https://lore.kernel.org/lkml/jhjtux5edo2.mognet@arm.com
2020-11-19 11:25:46 +01:00
Daniel Jordan
406100f3da cpuset: fix race between hotplug work and later CPU offline
One of our machines keeled over trying to rebuild the scheduler domains.
Mainline produces the same splat:

  BUG: unable to handle page fault for address: 0000607f820054db
  CPU: 2 PID: 149 Comm: kworker/1:1 Not tainted 5.10.0-rc1-master+ #6
  Workqueue: events cpuset_hotplug_workfn
  RIP: build_sched_domains
  Call Trace:
   partition_sched_domains_locked
   rebuild_sched_domains_locked
   cpuset_hotplug_workfn

It happens with cgroup2 and exclusive cpusets only.  This reproducer
triggers it on an 8-cpu vm and works most effectively with no
preexisting child cgroups:

  cd $UNIFIED_ROOT
  mkdir cg1
  echo 4-7 > cg1/cpuset.cpus
  echo root > cg1/cpuset.cpus.partition

  # with smt/control reading 'on',
  echo off > /sys/devices/system/cpu/smt/control

RIP maps to

  sd->shared = *per_cpu_ptr(sdd->sds, sd_id);

from sd_init().  sd_id is calculated earlier in the same function:

  cpumask_and(sched_domain_span(sd), cpu_map, tl->mask(cpu));
  sd_id = cpumask_first(sched_domain_span(sd));

tl->mask(cpu), which reads cpu_sibling_map on x86, returns an empty mask
and so cpumask_first() returns >= nr_cpu_ids, which leads to the bogus
value from per_cpu_ptr() above.

The problem is a race between cpuset_hotplug_workfn() and a later
offline of CPU N.  cpuset_hotplug_workfn() updates the effective masks
when N is still online, the offline clears N from cpu_sibling_map, and
then the worker uses the stale effective masks that still have N to
generate the scheduling domains, leading the worker to read
N's empty cpu_sibling_map in sd_init().

rebuild_sched_domains_locked() prevented the race during the cgroup2
cpuset series up until the Fixes commit changed its check.  Make the
check more robust so that it can detect an offline CPU in any exclusive
cpuset's effective mask, not just the top one.

Fixes: 0ccea8feb9 ("cpuset: Make generate_sched_domains() work with partition")
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20201112171711.639541-1-daniel.m.jordan@oracle.com
2020-11-19 11:25:45 +01:00
Peter Zijlstra
1293771e43 sched: Fix migration_cpu_stop() WARN
Oleksandr reported hitting the WARN in the 'task_rq(p) != rq' branch
of migration_cpu_stop(). Valentin noted that using cpu_of(rq) in that
case is just plain wrong to begin with, since per the earlier branch
that isn't the actual CPU of the task.

Replace both instances of is_cpu_allowed() by a direct p->cpus_mask
test using task_cpu().

Reported-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Debugged-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2020-11-19 11:25:45 +01:00
Valentin Schneider
d707faa64d sched/core: Add missing completion for affine_move_task() waiters
Qian reported that some fuzzer issuing sched_setaffinity() ends up stuck on
a wait_for_completion(). The problematic pattern seems to be:

  affine_move_task()
      // task_running() case
      stop_one_cpu();
      wait_for_completion(&pending->done);

Combined with, on the stopper side:

  migration_cpu_stop()
    // Task moved between unlocks and scheduling the stopper
    task_rq(p) != rq &&
    // task_running() case
    dest_cpu >= 0

    => no complete_all()

This can happen with both PREEMPT and !PREEMPT, although !PREEMPT should
be more likely to see this given the targeted task has a much bigger window
to block and be woken up elsewhere before the stopper runs.

Make migration_cpu_stop() always look at pending affinity requests; signal
their completion if the stopper hits a rq mismatch but the task is
still within its allowed mask. When Migrate-Disable isn't involved, this
matches the previous set_cpus_allowed_ptr() vs migration_cpu_stop()
behaviour.

Fixes: 6d337eab04 ("sched: Fix migrate_disable() vs set_cpus_allowed_ptr()")
Reported-by: Qian Cai <cai@redhat.com>
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/lkml/8b62fd1ad1b18def27f18e2ee2df3ff5b36d0762.camel@redhat.com
2020-11-19 11:25:45 +01:00
Frederic Weisbecker
6775de4984 context_tracking: Only define schedule_user() on !HAVE_CONTEXT_TRACKING_OFFSTACK archs
schedule_user() was traditionally used by the entry code's tail to
preempt userspace after the call to user_enter(). Indeed the call to
user_enter() used to be performed upon syscall exit slow path which was
right before the last opportunity to schedule() while resuming to
userspace. The context tracking state had to be saved on the task stack
and set back to CONTEXT_KERNEL temporarily in order to safely switch to
another task.

Only a few archs use it now (namely sparc64 and powerpc64) and those
implementing HAVE_CONTEXT_TRACKING_OFFSTACK definetly can't rely on it.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201117151637.259084-5-frederic@kernel.org
2020-11-19 11:25:42 +01:00
Frederic Weisbecker
9f68b5b74c sched: Detect call to schedule from critical entry code
Detect calls to schedule() between user_enter() and user_exit(). Those
are symptoms of early entry code that either forgot to protect a call
to schedule() inside exception_enter()/exception_exit() or, in the case
of HAVE_CONTEXT_TRACKING_OFFSTACK, enabled interrupts or preemption in
a wrong spot.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201117151637.259084-4-frederic@kernel.org
2020-11-19 11:25:42 +01:00
Hui Su
aabe19b827
nsproxy: use put_nsproxy() in switch_task_namespaces()
We already have a dedicated helper that handles reference count
checking so stop open-coding the reference count check in
switch_task_namespaces() and use the dedicated put_nsproxy() helper
instead.
Take the change to fix a whitespace issue too.

Signed-off-by: Hui Su <sh_def@163.com>
[christian.brauner@ubuntu.com: expand commit message]
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20201115180054.GA371317@rlk
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-11-19 10:57:02 +01:00
Thomas Gleixner
b996544916 tick: Get rid of tick_period
The variable tick_period is initialized to NSEC_PER_TICK / HZ during boot
and never updated again.

If NSEC_PER_TICK is not an integer multiple of HZ this computation is less
accurate than TICK_NSEC which has proper rounding in place.

Aside of the inaccuracy there is no reason for having this variable at
all. It's just a pointless indirection and all usage sites can just use the
TICK_NSEC constant.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201117132006.766643526@linutronix.de
2020-11-19 10:48:29 +01:00
Yunfeng Ye
896b969e67 tick/sched: Release seqcount before invoking calc_load_global()
calc_load_global() does not need the sequence count protection.

[ tglx: Split it up properly and added comments ]

Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201117132006.660902274@linutronix.de
2020-11-19 10:48:29 +01:00
Thomas Gleixner
7a35bf2a6a tick/sched: Optimize tick_do_update_jiffies64() further
Now that it's clear that there is always one tick to account, simplify the
calculations some more.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201117132006.565663056@linutronix.de
2020-11-19 10:48:29 +01:00
Yunfeng Ye
94ad2e3ced tick/sched: Reduce seqcount held scope in tick_do_update_jiffies64()
If jiffies are up to date already (caller lost the race against another
CPU) there is no point to change the sequence count. Doing that just forces
other CPUs into the seqcount retry loop in tick_nohz_next_event() for
nothing.

Just bail out early.

[ tglx: Rewrote most of it ]

Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201117132006.462195901@linutronix.de
2020-11-19 10:48:29 +01:00
Thomas Gleixner
372acbbaa8 tick/sched: Use tick_next_period for lockless quick check
No point in doing calculations.

   tick_next_period = last_jiffies_update + tick_period

Just check whether now is before tick_next_period to figure out whether
jiffies need an update.

Add a comment why the intentional data race in the quick check is safe or
not so safe in a 32bit corner case and why we don't worry about it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201117132006.337366695@linutronix.de
2020-11-19 10:48:29 +01:00
Thomas Gleixner
c398960cd8 tick: Document protections for tick related data
The protection rules for tick_next_period and last_jiffies_update are blury
at best. Clarify this.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201117132006.197713794@linutronix.de
2020-11-19 10:48:28 +01:00
Thomas Gleixner
f73f64d568 tick/broadcast: Serialize access to tick_next_period
tick_broadcast_setup_oneshot() accesses tick_next_period twice without any
serialization. This is wrong in two aspects:

  - Reading it twice might make the broadcast data inconsistent if the
    variable is updated concurrently.

  - On 32bit systems the access might see an partial update

Protect it with jiffies_lock. That's safe as none of the callchains leading
up to this function can create a lock ordering violation:

timer interrupt
  run_local_timers()
    hrtimer_run_queues()
      hrtimer_switch_to_hres()
        tick_init_highres()
	  tick_switch_to_oneshot()
	    tick_broadcast_switch_to_oneshot()
or
     tick_check_oneshot_change()
       tick_nohz_switch_to_nohz()
         tick_switch_to_oneshot()
           tick_broadcast_switch_to_oneshot()

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201117132006.061341507@linutronix.de
2020-11-19 10:48:28 +01:00
Dmitrii Banshchikov
d055126180 bpf: Add bpf_ktime_get_coarse_ns helper
The helper uses CLOCK_MONOTONIC_COARSE source of time that is less
accurate but more performant.

We have a BPF CGROUP_SKB firewall that supports event logging through
bpf_perf_event_output(). Each event has a timestamp and currently we use
bpf_ktime_get_ns() for it. Use of bpf_ktime_get_coarse_ns() saves ~15-20
ns in time required for event logging.

bpf_ktime_get_ns():
EgressLogByRemoteEndpoint                              113.82ns    8.79M

bpf_ktime_get_coarse_ns():
EgressLogByRemoteEndpoint                               95.40ns   10.48M

Signed-off-by: Dmitrii Banshchikov <me@ubique.spb.ru>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20201117184549.257280-1-me@ubique.spb.ru
2020-11-18 23:25:32 +01:00
Hui Su
5c62634fc6 namespace: make timens_on_fork() return nothing
timens_on_fork() always return 0, and maybe not
need to judge the return value in copy_namespaces().

So make timens_on_fork() return nothing and do not
judge its return val in copy_namespaces().

Signed-off-by: Hui Su <sh_def@163.com>
Link: https://lore.kernel.org/r/20201117161750.GA45121@rlk
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-11-18 11:06:47 +01:00
Christoph Hellwig
16fee29b07
dma-mapping: remove the dma_direct_set_offset export
Drop the dma_direct_set_offset export and move the declaration to
dma-map-ops.h now that the Allwinner drivers have stopped calling it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
2020-11-18 09:11:38 +01:00
KP Singh
3f6719c7b6 bpf: Add bpf_bprm_opts_set helper
The helper allows modification of certain bits on the linux_binprm
struct starting with the secureexec bit which can be updated using the
BPF_F_BPRM_SECUREEXEC flag.

secureexec can be set by the LSM for privilege gaining executions to set
the AT_SECURE auxv for glibc.  When set, the dynamic linker disables the
use of certain environment variables (like LD_PRELOAD).

Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20201117232929.2156341-1-kpsingh@chromium.org
2020-11-18 01:36:27 +01:00
Mickaël Salaün
fb14528e44 seccomp: Set PF_SUPERPRIV when checking capability
Replace the use of security_capable(current_cred(), ...) with
ns_capable_noaudit() which set PF_SUPERPRIV.

Since commit 98f368e9e2 ("kernel: Add noaudit variant of
ns_capable()"), a new ns_capable_noaudit() helper is available.  Let's
use it!

Cc: Jann Horn <jannh@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tyler Hicks <tyhicks@linux.microsoft.com>
Cc: Will Drewry <wad@chromium.org>
Cc: stable@vger.kernel.org
Fixes: e2cfabdfd0 ("seccomp: add system call filtering using BPF")
Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com>
Reviewed-by: Jann Horn <jannh@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20201030123849.770769-3-mic@digikod.net
2020-11-17 12:53:22 -08:00
Mickaël Salaün
cf23705244 ptrace: Set PF_SUPERPRIV when checking capability
Commit 69f594a389 ("ptrace: do not audit capability check when outputing
/proc/pid/stat") replaced the use of ns_capable() with
has_ns_capability{,_noaudit}() which doesn't set PF_SUPERPRIV.

Commit 6b3ad6649a ("ptrace: reintroduce usage of subjective credentials in
ptrace_has_cap()") replaced has_ns_capability{,_noaudit}() with
security_capable(), which doesn't set PF_SUPERPRIV neither.

Since commit 98f368e9e2 ("kernel: Add noaudit variant of ns_capable()"), a
new ns_capable_noaudit() helper is available.  Let's use it!

As a result, the signature of ptrace_has_cap() is restored to its original one.

Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Serge E. Hallyn <serge@hallyn.com>
Cc: Tyler Hicks <tyhicks@linux.microsoft.com>
Cc: stable@vger.kernel.org
Fixes: 6b3ad6649a ("ptrace: reintroduce usage of subjective credentials in ptrace_has_cap()")
Fixes: 69f594a389 ("ptrace: do not audit capability check when outputing /proc/pid/stat")
Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com>
Reviewed-by: Jann Horn <jannh@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20201030123849.770769-2-mic@digikod.net
2020-11-17 12:53:22 -08:00
Christoph Hellwig
172292be01 dma-mapping: remove dma_virt_ops
Now that the RDMA core deals with devices that only do DMA mapping in
lower layers properly, there is no user for dma_virt_ops and it can be
removed.

Link: https://lore.kernel.org/r/20201106181941.1878556-11-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2020-11-17 15:22:07 -04:00
Linus Torvalds
9dacf44c38 Merge branch 'urgent-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu
Pull RCU fix from Paul McKenney:
 "A single commit that fixes a bug that was introduced a couple of merge
  windows ago, but which rather more recently converged to an
  agreed-upon fix. The bug is that interrupts can be incorrectly enabled
  while holding an irq-disabled spinlock. This can of course result in
  self-deadlocks.

  The bug is a bit difficult to trigger. It requires that a preempted
  task be blocking a preemptible-RCU grace period long enough to trigger
  an RCU CPU stall warning. In addition, an interrupt must occur at just
  the right time, and that interrupt's handler must acquire that same
  irq-disabled spinlock. Still, a deadlock is a deadlock.

  Furthermore, we do now have a fix, and that fix survives kernel test
  robot, -next, and rcutorture testing. It has also been verified by
  Sebastian as fixing the bug. Therefore..."

* 'urgent-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu:
  rcu: Don't invoke try_invoke_on_locked_down_task() with irqs disabled
2020-11-17 10:31:56 -08:00
Andy Shevchenko
5df38ca6af resource: Add test cases for new resource API
Add test cases for newly added resource APIs.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-11-17 18:06:28 +01:00
Andy Shevchenko
66f4fa32eb resource: Simplify region_intersects() by reducing conditionals
Now we have for 'other' and 'type' variables

other	type	return
  0	  0	REGION_DISJOINT
  0	  x	REGION_INTERSECTS
  x	  0	REGION_DISJOINT
  x	  x	REGION_MIXED

Obviously it's easier to check 'type' for 0 first instead of
currently checked 'other'.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
Tested-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-11-17 18:06:28 +01:00
Boqun Feng
43be4388e9 lockdep: Put graph lock/unlock under lock_recursion protection
A warning was hit when running xfstests/generic/068 in a Hyper-V guest:

[...] ------------[ cut here ]------------
[...] DEBUG_LOCKS_WARN_ON(lockdep_hardirqs_enabled())
[...] WARNING: CPU: 2 PID: 1350 at kernel/locking/lockdep.c:5280 check_flags.part.0+0x165/0x170
[...] ...
[...] Workqueue: events pwq_unbound_release_workfn
[...] RIP: 0010:check_flags.part.0+0x165/0x170
[...] ...
[...] Call Trace:
[...]  lock_is_held_type+0x72/0x150
[...]  ? lock_acquire+0x16e/0x4a0
[...]  rcu_read_lock_sched_held+0x3f/0x80
[...]  __send_ipi_one+0x14d/0x1b0
[...]  hv_send_ipi+0x12/0x30
[...]  __pv_queued_spin_unlock_slowpath+0xd1/0x110
[...]  __raw_callee_save___pv_queued_spin_unlock_slowpath+0x11/0x20
[...]  .slowpath+0x9/0xe
[...]  lockdep_unregister_key+0x128/0x180
[...]  pwq_unbound_release_workfn+0xbb/0xf0
[...]  process_one_work+0x227/0x5c0
[...]  worker_thread+0x55/0x3c0
[...]  ? process_one_work+0x5c0/0x5c0
[...]  kthread+0x153/0x170
[...]  ? __kthread_bind_mask+0x60/0x60
[...]  ret_from_fork+0x1f/0x30

The cause of the problem is we have call chain lockdep_unregister_key()
-> <irq disabled by raw_local_irq_save()> lockdep_unlock() ->
arch_spin_unlock() -> __pv_queued_spin_unlock_slowpath() -> pv_kick() ->
__send_ipi_one() -> trace_hyperv_send_ipi_one().

Although this particular warning is triggered because Hyper-V has a
trace point in ipi sending, but in general arch_spin_unlock() may call
another function having a trace point in it, so put the arch_spin_lock()
and arch_spin_unlock() after lock_recursion protection to fix this
problem and avoid similiar problems.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201113110512.1056501-1-boqun.feng@gmail.com
2020-11-17 13:15:35 +01:00
Juri Lelli
2279f540ea sched/deadline: Fix priority inheritance with multiple scheduling classes
Glenn reported that "an application [he developed produces] a BUG in
deadline.c when a SCHED_DEADLINE task contends with CFS tasks on nested
PTHREAD_PRIO_INHERIT mutexes.  I believe the bug is triggered when a CFS
task that was boosted by a SCHED_DEADLINE task boosts another CFS task
(nested priority inheritance).

 ------------[ cut here ]------------
 kernel BUG at kernel/sched/deadline.c:1462!
 invalid opcode: 0000 [#1] PREEMPT SMP
 CPU: 12 PID: 19171 Comm: dl_boost_bug Tainted: ...
 Hardware name: ...
 RIP: 0010:enqueue_task_dl+0x335/0x910
 Code: ...
 RSP: 0018:ffffc9000c2bbc68 EFLAGS: 00010002
 RAX: 0000000000000009 RBX: ffff888c0af94c00 RCX: ffffffff81e12500
 RDX: 000000000000002e RSI: ffff888c0af94c00 RDI: ffff888c10b22600
 RBP: ffffc9000c2bbd08 R08: 0000000000000009 R09: 0000000000000078
 R10: ffffffff81e12440 R11: ffffffff81e1236c R12: ffff888bc8932600
 R13: ffff888c0af94eb8 R14: ffff888c10b22600 R15: ffff888bc8932600
 FS:  00007fa58ac55700(0000) GS:ffff888c10b00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007fa58b523230 CR3: 0000000bf44ab003 CR4: 00000000007606e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 PKRU: 55555554
 Call Trace:
  ? intel_pstate_update_util_hwp+0x13/0x170
  rt_mutex_setprio+0x1cc/0x4b0
  task_blocks_on_rt_mutex+0x225/0x260
  rt_spin_lock_slowlock_locked+0xab/0x2d0
  rt_spin_lock_slowlock+0x50/0x80
  hrtimer_grab_expiry_lock+0x20/0x30
  hrtimer_cancel+0x13/0x30
  do_nanosleep+0xa0/0x150
  hrtimer_nanosleep+0xe1/0x230
  ? __hrtimer_init_sleeper+0x60/0x60
  __x64_sys_nanosleep+0x8d/0xa0
  do_syscall_64+0x4a/0x100
  entry_SYSCALL_64_after_hwframe+0x49/0xbe
 RIP: 0033:0x7fa58b52330d
 ...
 ---[ end trace 0000000000000002 ]—

He also provided a simple reproducer creating the situation below:

 So the execution order of locking steps are the following
 (N1 and N2 are non-deadline tasks. D1 is a deadline task. M1 and M2
 are mutexes that are enabled * with priority inheritance.)

 Time moves forward as this timeline goes down:

 N1              N2               D1
 |               |                |
 |               |                |
 Lock(M1)        |                |
 |               |                |
 |             Lock(M2)           |
 |               |                |
 |               |              Lock(M2)
 |               |                |
 |             Lock(M1)           |
 |             (!!bug triggered!) |

Daniel reported a similar situation as well, by just letting ksoftirqd
run with DEADLINE (and eventually block on a mutex).

Problem is that boosted entities (Priority Inheritance) use static
DEADLINE parameters of the top priority waiter. However, there might be
cases where top waiter could be a non-DEADLINE entity that is currently
boosted by a DEADLINE entity from a different lock chain (i.e., nested
priority chains involving entities of non-DEADLINE classes). In this
case, top waiter static DEADLINE parameters could be null (initialized
to 0 at fork()) and replenish_dl_entity() would hit a BUG().

Fix this by keeping track of the original donor and using its parameters
when a task is boosted.

Reported-by: Glenn Elliott <glenn@aurora.tech>
Reported-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Link: https://lkml.kernel.org/r/20201117061432.517340-1-juri.lelli@redhat.com
2020-11-17 13:15:28 +01:00
Peter Zijlstra
ec618b84f6 sched: Fix rq->nr_iowait ordering
schedule()				ttwu()
    deactivate_task();			  if (p->on_rq && ...) // false
					    atomic_dec(&task_rq(p)->nr_iowait);
    if (prev->in_iowait)
      atomic_inc(&rq->nr_iowait);

Allows nr_iowait to be decremented before it gets incremented,
resulting in more dodgy IO-wait numbers than usual.

Note that because we can now do ttwu_queue_wakelist() before
p->on_cpu==0, we lose the natural ordering and have to further delay
the decrement.

Fixes: c6e7bd7afa ("sched/core: Optimize ttwu() spinning on p->on_cpu")
Reported-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Link: https://lkml.kernel.org/r/20201117093829.GD3121429@hirez.programming.kicks-ass.net
2020-11-17 13:15:28 +01:00
Quentin Perret
8e1ac4299a sched/fair: Fix overutilized update in enqueue_task_fair()
enqueue_task_fair() attempts to skip the overutilized update for new
tasks as their util_avg is not accurate yet. However, the flag we check
to do so is overwritten earlier on in the function, which makes the
condition pretty much a nop.

Fix this by saving the flag early on.

Fixes: 2802bf3cd9 ("sched/fair: Add over-utilization/tipping point indicator")
Reported-by: Rick Yiu <rickyiu@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20201112111201.2081902-1-qperret@google.com
2020-11-17 13:15:27 +01:00
Gabriel Krisman Bertazi
2991552447 entry: Drop usage of TIF flags in the generic syscall code
Now that the flags migration in the common syscall entry code is complete
and the code relies exclusively on thread_info::syscall_work, clean up the
accesses to TI flags in that path.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20201116174206.2639648-10-krisman@collabora.com
2020-11-16 21:53:16 +01:00
Gabriel Krisman Bertazi
785dc4eb7f audit: Migrate to use SYSCALL_WORK flag
On architectures using the generic syscall entry code the architecture
independent syscall work is moved to flags in thread_info::syscall_work.
This removes architecture dependencies and frees up TIF bits.

Define SYSCALL_WORK_SYSCALL_AUDIT, use it in the generic entry code and
convert the code which uses the TIF specific helper functions to use the
new *_syscall_work() helpers which either resolve to the new mode for users
of the generic entry code or to the TIF based functions for the other
architectures.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20201116174206.2639648-9-krisman@collabora.com
2020-11-16 21:53:16 +01:00
Gabriel Krisman Bertazi
64eb35f701 ptrace: Migrate TIF_SYSCALL_EMU to use SYSCALL_WORK flag
On architectures using the generic syscall entry code the architecture
independent syscall work is moved to flags in thread_info::syscall_work.
This removes architecture dependencies and frees up TIF bits.

Define SYSCALL_WORK_SYSCALL_EMU, use it in the generic entry code and
convert the code which uses the TIF specific helper functions to use the
new *_syscall_work() helpers which either resolve to the new mode for users
of the generic entry code or to the TIF based functions for the other
architectures.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20201116174206.2639648-8-krisman@collabora.com
2020-11-16 21:53:16 +01:00
Gabriel Krisman Bertazi
64c19ba29b ptrace: Migrate to use SYSCALL_TRACE flag
On architectures using the generic syscall entry code the architecture
independent syscall work is moved to flags in thread_info::syscall_work.
This removes architecture dependencies and frees up TIF bits.

Define SYSCALL_WORK_SYSCALL_TRACE, use it in the generic entry code and
convert the code which uses the TIF specific helper functions to use the
new *_syscall_work() helpers which either resolve to the new mode for users
of the generic entry code or to the TIF based functions for the other
architectures.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20201116174206.2639648-7-krisman@collabora.com
2020-11-16 21:53:16 +01:00
Gabriel Krisman Bertazi
524666cb5d tracepoints: Migrate to use SYSCALL_WORK flag
On architectures using the generic syscall entry code the architecture
independent syscall work is moved to flags in thread_info::syscall_work.
This removes architecture dependencies and frees up TIF bits.

Define SYSCALL_WORK_SYSCALL_TRACEPOINT, use it in the generic entry code
and convert the code which uses the TIF specific helper functions to use
the new *_syscall_work() helpers which either resolve to the new mode for
users of the generic entry code or to the TIF based functions for the other
architectures.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20201116174206.2639648-6-krisman@collabora.com
2020-11-16 21:53:15 +01:00
Gabriel Krisman Bertazi
23d67a5485 seccomp: Migrate to use SYSCALL_WORK flag
On architectures using the generic syscall entry code the architecture
independent syscall work is moved to flags in thread_info::syscall_work.
This removes architecture dependencies and frees up TIF bits.

Define SYSCALL_WORK_SECCOMP, use it in the generic entry code and convert
the code which uses the TIF specific helper functions to use the new
*_syscall_work() helpers which either resolve to the new mode for users of
the generic entry code or to the TIF based functions for the other
architectures.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20201116174206.2639648-5-krisman@collabora.com
2020-11-16 21:53:15 +01:00
Gabriel Krisman Bertazi
b86678cf0f entry: Wire up syscall_work in common entry code
Prepare the common entry code to use the SYSCALL_WORK flags. They will
be defined in subsequent patches for each type of syscall
work. SYSCALL_WORK_ENTRY/EXIT are defined for the transition, as they
will replace the TIF_ equivalent defines.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20201116174206.2639648-4-krisman@collabora.com
2020-11-16 21:53:15 +01:00
Lukas Bulwahn
76980f5fa0 tracing: Clean up after filter logic rewriting
The functions event_{set,clear,}_no_set_filter_flag were only used in
replace_system_preds() [now, renamed to process_system_preds()].

Commit 80765597bc ("tracing: Rewrite filter logic to be simpler and
faster") removed the use of those functions in replace_system_preds().

Since then, the functions event_{set,clear,}_no_set_filter_flag were
unused. Fortunately, make CC=clang W=1 indicates this with
-Wunused-function warnings on those three functions.

So, clean up these obsolete unused functions.

Link: https://lkml.kernel.org/r/20201115155336.20248-1-lukas.bulwahn@gmail.com

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-16 12:32:34 -05:00
Francis Laniel
872f690341 treewide: rename nla_strlcpy to nla_strscpy.
Calls to nla_strlcpy are now replaced by calls to nla_strscpy which is the new
name of this function.

Signed-off-by: Francis Laniel <laniel_francis@privacyrequired.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-16 08:08:54 -08:00
Mauro Carvalho Chehab
8c67d247dc genirq: Fix kernel-doc markups
Some identifiers have different names between their prototypes
and the kernel-doc markup.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/13a44f4f0c3135e14b16ae8fcce4af1eab27cb5f.1605521731.git.mchehab+huawei@kernel.org
2020-11-16 15:20:54 +01:00
Mauro Carvalho Chehab
66981c37b3 hrtimer: Fix kernel-doc markups
The hrtimer_get_remaining() markup is documenting, instead,
__hrtimer_get_remaining(), as it is placed at the C file.

In order to properly document it, a kernel-doc markup is needed together
with the function prototype. So, add a new one, while preserving the
existing one, just fixing the function name.

The hrtimer_is_queued prototype has a typo: it is using
'=' instead of '-' to split: identifier - description
as required by kernel-doc markup.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/9dc87808c2fd07b7e050bafcd033c5ef05808fea.1605521731.git.mchehab+huawei@kernel.org
2020-11-16 15:20:01 +01:00
Thomas Gleixner
cc947f2b9c timers: Make run_local_timers() static
No users outside of the timer code. Move the caller below this function to
avoid a pointless forward declaration.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2020-11-16 15:20:01 +01:00
Ira Weiny
78a56e0494 entry: Fix spelling/typo errors in irq entry code
s/reguired/required/
s/Interupts/Interrupts/
s/quiescient/quiescent/
s/assemenbly/assembly/

Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201104230157.3378023-1-ira.weiny@intel.com
2020-11-15 23:54:00 +01:00
Alex Shi
6e5a91901c timekeeping: Address parameter documentation issues for various functions
The kernel-doc parser complains:

 kernel/time/timekeeping.c:1543: warning: Function parameter or member
 'ts' not described in 'read_persistent_clock64'

 kernel/time/timekeeping.c:764: warning: Function parameter or member
 'tk' not described in 'timekeeping_forward_now'

 kernel/time/timekeeping.c:1331: warning: Function parameter or member
 'ts' not described in 'timekeeping_inject_offset'

 kernel/time/timekeeping.c:1331: warning: Excess function parameter 'tv'
 description in 'timekeeping_inject_offset'

Add the missing parameter documentations and rename the 'tv' parameter of
timekeeping_inject_offset() to 'ts' so it matches the implemention.

[ tglx: Reworded a few docs and massaged changelog ]

Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/1605252275-63652-5-git-send-email-alex.shi@linux.alibaba.com
2020-11-15 23:47:24 +01:00
Alex Shi
29efc4612a timekeeping: Fix parameter docs of read_persistent_wall_and_boot_offset()
Address the following kernel-doc markup warnings:

 kernel/time/timekeeping.c:1563: warning: Function parameter or member
 'wall_time' not described in 'read_persistent_wall_and_boot_offset'
 kernel/time/timekeeping.c:1563: warning: Function parameter or member
 'boot_offset' not described in 'read_persistent_wall_and_boot_offset'

The parameters are described but miss the leading '@' and the colon after
the parameter names.

[ tglx: Massaged changelog ]

Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/1605252275-63652-6-git-send-email-alex.shi@linux.alibaba.com
2020-11-15 23:47:24 +01:00
Alex Shi
f27f7c3f10 timekeeping: Add missing parameter docs for pvclock_gtod_[un]register_notifier()
The kernel-doc parser complains about:
 kernel/time/timekeeping.c:651: warning: Function parameter or member
 'nb' not described in 'pvclock_gtod_register_notifier'
 kernel/time/timekeeping.c:670: warning: Function parameter or member
 'nb' not described in 'pvclock_gtod_unregister_notifier'

Add the missing parameter explanations.

[ tglx: Massaged changelog ]

Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/1605252275-63652-3-git-send-email-alex.shi@linux.alibaba.com
2020-11-15 23:47:24 +01:00
Thomas Gleixner
c1ce406e80 timekeeping: Fix up function documentation for the NMI safe accessors
Alex reported the following warning:

 kernel/time/timekeeping.c:464: warning: Function parameter or member
 'tkf' not described in '__ktime_get_fast_ns'

which is not entirely correct because the documented function is
ktime_get_mono_fast_ns() which does not have a parameter, but the
kernel-doc parser looks at the function declaration which follows the
comment and complains about the missing parameter documentation.

Aside of that the documentation for the rest of the NMI safe accessors is
either incomplete or missing.

  - Move the function documentation to the right place
  - Fixup the references and inconsistencies
  - Add the missing documentation for ktime_get_raw_fast_ns()

Reported-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2020-11-15 23:47:24 +01:00
Alex Shi
e025b03113 timekeeping: Add missing parameter documentation for update_fast_timekeeper()
Address the following warning:

 kernel/time/timekeeping.c:415: warning: Function parameter or member
 'tkf' not described in 'update_fast_timekeeper'

[ tglx: Remove the bogus ktime_get_mono_fast_ns() part ]

Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/1605252275-63652-2-git-send-email-alex.shi@linux.alibaba.com
2020-11-15 23:47:24 +01:00
Alex Shi
199d280c88 timekeeping: Remove static functions from kernel-doc markup
Various static functions in the timekeeping code have function comments
which pretend to be kernel-doc, but are incomplete and trigger parser
warnings.

As these functions are local to the timekeeping core code there is no need
to expose them via kernel-doc.

Remove the double star kernel-doc marker and remove excess newlines.

[ tglx: Massaged changelog and removed excess newlines ]

Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/1605252275-63652-4-git-send-email-alex.shi@linux.alibaba.com
2020-11-15 23:47:23 +01:00
Alex Shi
a0f5a65fa5 time: Add missing colons for parameter documentation of time64_to_tm()
Address these kernel-doc warnings:

 kernel/time/timeconv.c:79: warning: Function parameter or member
 'totalsecs' not described in 'time64_to_tm'
 kernel/time/timeconv.c:79: warning: Function parameter or member
 'offset' not described in 'time64_to_tm'
 kernel/time/timeconv.c:79: warning: Function parameter or member
 'result' not described in 'time64_to_tm'

The parameters are described but lack colons after the parameter name.

[ tglx: Massaged changelog ]

Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/1605252275-63652-1-git-send-email-alex.shi@linux.alibaba.com
2020-11-15 23:47:23 +01:00
Sebastian Andrzej Siewior
c725dafc95 timers: Don't block on ->expiry_lock for TIMER_IRQSAFE timers
PREEMPT_RT does not spin and wait until a running timer completes its
callback but instead it blocks on a sleeping lock to prevent a livelock in
the case that the task waiting for the callback completion preempted the
callback.

This cannot be done for timers flagged with TIMER_IRQSAFE. These timers can
be canceled from an interrupt disabled context even on RT kernels.

The expiry callback of such timers is invoked with interrupts disabled so
there is no need to use the expiry lock mechanism because obviously the
callback cannot be preempted even on RT kernels.

Do not use the timer_base::expiry_lock mechanism when waiting for a running
callback to complete if the timer is flagged with TIMER_IRQSAFE.

Also add a lockdep assertion for RT kernels to validate that the expiry
lock mechanism is always invoked in preemptible context.

Reported-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201103190937.hga67rqhvknki3tp@linutronix.de
2020-11-15 20:59:26 +01:00
Helge Deller
da88f9b311 timer_list: Use printk format instead of open-coded symbol lookup
Use the "%ps" printk format string to resolve symbol names.

This works on all platforms, including ia64, ppc64 and parisc64 on which
one needs to dereference pointers to function descriptors instead of
function pointers.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201104163401.GA3984@ls3530.fritz.box
2020-11-15 20:47:14 +01:00
Linus Torvalds
64b609d6a6 A set of fixes for perf:
- A set of commits which reduce the stack usage of various perf event
    handling functions which allocated large data structs on stack causing
    stack overflows in the worst case.
 
  - Use the proper mechanism for detecting soft interrupts in the recursion
    protection.
 
  - Make the resursion protection simpler and more robust.
 
  - Simplify the scheduling of event groups to make the code more robust and
    prepare for fixing the issues vs. scheduling of exclusive event groups.
 
  - Prevent event multiplexing and rotation for exclusive event groups
 
  - Correct the perf event attribute exclusive semantics to take pinned
    events, e.g. the PMU watchdog, into account
 
  - Make the anythread filtering conditional for Intel's generic PMU
    counters as it is not longer guaranteed to be supported on newer
    CPUs. Check the corresponding CPUID leaf to make sure.
 
  - Fixup a duplicate initialization in an array which was probably cause by
    the usual copy & paste - forgot to edit mishap.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAl+xIi0THHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYofixD/4+4gc8DhOmAkMrN0Z9tiW8ebgMKmb9
 wZRkMr5Osi0GzLJOPZ6SdY6jd0A3rMN/sW6P1DT6pDtcty4bKFoW5VZBuUDIAhel
 BC4C93L3y1En/GEZu1GTy3LvsBwLBQTOoY4goDjbdAbk60S/0RTHOGyQsRsOQFe6
 fVs3iXozAFuaR6I6N3dlxuJAE51zvr8MyBWaUoByNDB//1+lLNW+JfClaAOG1oXx
 qZIg/niatBVGzSGgKNRUyh3g8G1HJtabsA/NZ4PH8ZHuYABfmj4lmmUPR77ICLfV
 wMITEBG7eaktB8EqM9hvaoOZLA5kpXHO2JbCFSs4c4x11mlC8g7QMV3poCw33YoN
 a5TmT1A3muri1riy1/Ee9lXACOq7/tf2+Xfn9o6dvDdBwd6s5pzlhLGR8gILp2lF
 2bcg3IwYvHT/Kiurb/WGNpbCqQIPJpcUcfs3tNBCCtKegahUQNnGjxN3NVo9RCit
 zfL6xIJ8eZiYnsxXx4NKm744AukWiql3aRNgRkOdBP5WC68xt6VLcxG1YZKUoDhy
 jRSOCD/DuPSMSvAAgN7S8OWlPsKWBxVxxWYV+K8FpwhgzbQ3WbS3UDiYkhgjeOxu
 OlM692oWpllKvQWlvYthr2Be6oPCRRi1vvADNNbTKzgHk5i61bwympsGl1EZx3Pz
 2ROp7NJFRESnqw==
 =FzCf
 -----END PGP SIGNATURE-----

Merge tag 'perf-urgent-2020-11-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf fixes from Thomas Gleixner:
 "A set of fixes for perf:

    - A set of commits which reduce the stack usage of various perf
      event handling functions which allocated large data structs on
      stack causing stack overflows in the worst case

    - Use the proper mechanism for detecting soft interrupts in the
      recursion protection

    - Make the resursion protection simpler and more robust

    - Simplify the scheduling of event groups to make the code more
      robust and prepare for fixing the issues vs. scheduling of
      exclusive event groups

    - Prevent event multiplexing and rotation for exclusive event groups

    - Correct the perf event attribute exclusive semantics to take
      pinned events, e.g. the PMU watchdog, into account

    - Make the anythread filtering conditional for Intel's generic PMU
      counters as it is not longer guaranteed to be supported on newer
      CPUs. Check the corresponding CPUID leaf to make sure

    - Fixup a duplicate initialization in an array which was probably
      caused by the usual 'copy & paste - forgot to edit' mishap"

* tag 'perf-urgent-2020-11-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel/uncore: Fix Add BW copypasta
  perf/x86/intel: Make anythread filter support conditional
  perf: Tweak perf_event_attr::exclusive semantics
  perf: Fix event multiplexing for exclusive groups
  perf: Simplify group_sched_in()
  perf: Simplify group_sched_out()
  perf/x86: Make dummy_iregs static
  perf/arch: Remove perf_sample_data::regs_user_copy
  perf: Optimize get_recursion_context()
  perf: Fix get_recursion_context()
  perf/x86: Reduce stack usage for x86_pmu::drain_pebs()
  perf: Reduce stack usage of perf_output_begin()
2020-11-15 09:46:36 -08:00
Linus Torvalds
d0a37fd57f A set of scheduler fixes:
- Address a load balancer regression by making the load balancer use the
    same logic as the wakeup path to spread tasks in the LLC domain.
 
  - Prefer the CPU on which a task run last over the local CPU in the fast
    wakeup path for asymmetric CPU capacity systems to align with the
    symmetric case. This ensures more locality and prevents massive
    migration overhead on those asymetric systems
 
  - Fix a memory corruption bug in the scheduler debug code caused by
    handing a modified buffer pointer to kfree().
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAl+xJIoTHHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYofyGD/9rUnLlC1h7jEufVa4yPG94DcEqiXT7
 8B/zNRKnOmqQePCYUm+DS8njSFqpF9VjR+5zpos3bgYqwn7DyfV+hpxbbgS9NDh/
 qRg5gxhTrR4uMyZN62Fex5JS4bP8mKO7oc0usgV2Ytsg3e4H+9DqYhuaA5GrJAxC
 J3d1Hv/YBW2Uo+RZpB20aaJr0srN7bswTtPMxeeqo8q3Qh4pFcI+rmA4WphVAgHF
 jQWaNP4YVTgNjqxy7nBp7zFHlSdRbLohldZFtueYmRo1mjmkyQ34Cg7etfBvN1Uf
 iVYZLaInr0YPr0qR4FrQ3yI8ln/HESxshs0ARzMReYVT71mV//o5wftE18uCULQB
 rRu9vYz+LBVhkdgx118jJdNJqyqk6Ca6h9ZLqyBKuckj9a39289bwWiS6D/6W51p
 gurq58YTb2lRzyCnOVEULXehYRJkDI8EToiWppRVm9gy43OFPNox7n6TvNLW6BLS
 I8msTVdqDYXXj4U1o4Mf9K5LBKlda+ARuBu87r7kH1BJLxXHnOHcEkmeN8O9k7eu
 jdWfeDzDDjBjt/TU+X4f4RNjudUZrSPQrrESE5+XhfM4CwqcPXa2M/dGtPekW/ED
 9IqxPvwkau+0Ym6gkuanfnmda+JVR/nLvZV0uFuUGd+2xMcRemZbZE6hTUiYvYPY
 CAHpOhmeakbr6w==
 =wFcU
 -----END PGP SIGNATURE-----

Merge tag 'sched-urgent-2020-11-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fixes from Thomas Gleixner:
 "A set of scheduler fixes:

   - Address a load balancer regression by making the load balancer use
     the same logic as the wakeup path to spread tasks in the LLC domain

   - Prefer the CPU on which a task run last over the local CPU in the
     fast wakeup path for asymmetric CPU capacity systems to align with
     the symmetric case. This ensures more locality and prevents massive
     migration overhead on those asymetric systems

   - Fix a memory corruption bug in the scheduler debug code caused by
     handing a modified buffer pointer to kfree()"

* tag 'sched-urgent-2020-11-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/debug: Fix memory corruption caused by multiple small reads of flags
  sched/fair: Prefer prev cpu in asymmetric wakeup path
  sched/fair: Ensure tasks spreading in LLC during LB
2020-11-15 09:39:35 -08:00
Linus Torvalds
259c2fbef8 Two fixes for the locking subsystem:
- Prevent an unconditional interrupt enable in a futex helper function
     which can be called from contexts which expect interrupts to stay
     disabled across the call.
 
   - Don't modify lockdep chain keys in the validation process as that
     causes chain inconsistency.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAl+xF7cTHHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYoR9dD/0X7EmbGdTIL9ZgEQfch8fWY79uHqQ7
 EXgVQb26KuWDzRutgk0qeSixQTYfhzoT2nPRGNpAQtyYYir0p2fXG2kstJEQZQzq
 toK5VsL11NJKVhlO/1y5+RcufsgfjTqOpqygbMm1gz+7ejfe7kfJZUAEMwbWzZRn
 a8HZ/VTQb/Z/F1xv+PuACkCp79ezzosL4hiN5QG0FEyiX47Pf8HuXTHKAD3SJgnc
 6ZvCkDkCHOv3jGmQ68sXBQ2m/ciYnDs1D8J/SD9zmggLFs8+R0LKCNxI46HfgRDV
 3oqx7OivazDvBmNXlSCFQQG+saIgRlWuVPV8PVTD3Ihmx25DzXhreSyxjyRhl3uL
 WN7C3ztk6lJv0B/BbtpFceobXjE7IN71CjDIFCwii20dn5UTrgLaJwnW1YrX6qqb
 +iz3cJs4bNLD1brGAlx8lqZxZ2omyXcPNQOi+vSkdTy8C/OYmypC1xusWSBpBtkp
 1+V1uoYFtJWsBzKfmbXAPSSiw9ppIVe/w3J/LrCcFv3CAEaDlCkN0klOF3/ULsga
 d+hMEUKagIqRXNeBdoEfY78LzSfIqkovy3rLNnWATu8fS2IdoRiwhliRxMCU9Ceh
 4WU1F4QAqu42cd0zYVWnVIfDVP3Qx/ENl8/Jd0m7Z8jmmjhOQo5XO7o5PxP8uP3U
 NvnoT5d5D2KysA==
 =XuF7
 -----END PGP SIGNATURE-----

Merge tag 'locking-urgent-2020-11-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking fixes from Thomas Gleixner:
 "Two fixes for the locking subsystem:

   - Prevent an unconditional interrupt enable in a futex helper
     function which can be called from contexts which expect interrupts
     to stay disabled across the call

   - Don't modify lockdep chain keys in the validation process as that
     causes chain inconsistency"

* tag 'locking-urgent-2020-11-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  lockdep: Avoid to modify chain keys in validate_chain()
  futex: Don't enable IRQs unconditionally in put_pi_state()
2020-11-15 09:25:43 -08:00
David Woodhouse
c4d51a52c6 sched/wait: Add add_wait_queue_priority()
This allows an exclusive wait_queue_entry to be added at the head of the
queue, instead of the tail as normal. Thus, it gets to consume events
first without allowing non-exclusive waiters to be woken at all.

The (first) intended use is for KVM IRQFD, which currently has
inconsistent behaviour depending on whether posted interrupts are
available or not. If they are, KVM will bypass the eventfd completely
and deliver interrupts directly to the appropriate vCPU. If not, events
are delivered through the eventfd and userspace will receive them when
polling on the eventfd.

By using add_wait_queue_priority(), KVM will be able to consistently
consume events within the kernel without accidentally exposing them
to userspace when they're supposed to be bypassed. This, in turn, means
that userspace doesn't have to jump through hoops to avoid listening
on the erroneously noisy eventfd and injecting duplicate interrupts.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Message-Id: <20201027143944.648769-2-dwmw2@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-15 09:49:09 -05:00
Thomas Gleixner
e906a546bd genirq/irqdomain: Make irq_domain_disassociate() static
No users outside of the core code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/87a6vja7mb.fsf@nanos.tec.linutronix.de
2020-11-15 12:01:11 +01:00
Thomas Gleixner
f296dcd629 genirq: Remove GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
Commit bb9d812643 ("arch: remove tile port") removed the last user of
this cruft two years ago...

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/87eekvac06.fsf@nanos.tec.linutronix.de
2020-11-14 22:39:00 +01:00
Christophe Leroy
2f31ad64a9 panic: don't dump stack twice on warn
Before commit 3f388f2863 ("panic: dump registers on panic_on_warn"),
__warn() was calling show_regs() when regs was not NULL, and show_stack()
otherwise.

After that commit, show_stack() is called regardless of whether
show_regs() has been called or not, leading to duplicated Call Trace:

  ------------[ cut here ]------------
  WARNING: CPU: 0 PID: 1 at arch/powerpc/mm/nohash/8xx.c:186 mmu_mark_initmem_nx+0x24/0x94
  CPU: 0 PID: 1 Comm: swapper Not tainted 5.10.0-rc2-s3k-dev-01375-gf46ec0d3ecbd-dirty #4092
  NIP:  c00128b4 LR: c0010228 CTR: 00000000
  REGS: c9023e40 TRAP: 0700   Not tainted  (5.10.0-rc2-s3k-dev-01375-gf46ec0d3ecbd-dirty)
  MSR:  00029032 <EE,ME,IR,DR,RI>  CR: 24000424  XER: 00000000

  GPR00: c0010228 c9023ef8 c2100000 0074c000 ffffffff 00000000 c2151000 c07b3880
  GPR08: ff000900 0074c000 c8000000 c33b53a8 24000822 00000000 c0003a20 00000000
  GPR16: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
  GPR24: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00800000
  NIP [c00128b4] mmu_mark_initmem_nx+0x24/0x94
  LR [c0010228] free_initmem+0x20/0x58
  Call Trace:
    free_initmem+0x20/0x58
    kernel_init+0x1c/0x114
    ret_from_kernel_thread+0x14/0x1c
  Instruction dump:
  7d291850 7d234b78 4e800020 9421ffe0 7c0802a6 bfc10018 3fe0c060 3bff0000
  3fff4080 3bffffff 90010024 57ff0010 <0fe00000> 392001cd 7c3e0b78 953e0008
  CPU: 0 PID: 1 Comm: swapper Not tainted 5.10.0-rc2-s3k-dev-01375-gf46ec0d3ecbd-dirty #4092
  Call Trace:
    __warn+0x8c/0xd8 (unreliable)
    report_bug+0x11c/0x154
    program_check_exception+0x1dc/0x6e0
    ret_from_except_full+0x0/0x4
  --- interrupt: 700 at mmu_mark_initmem_nx+0x24/0x94
      LR = free_initmem+0x20/0x58
    free_initmem+0x20/0x58
    kernel_init+0x1c/0x114
    ret_from_kernel_thread+0x14/0x1c
  ---[ end trace 31702cd2a9570752 ]---

Only call show_stack() when regs is NULL.

Fixes: 3f388f2863 ("panic: dump registers on panic_on_warn")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexey Kardashevskiy <aik@ozlabs.ru>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Link: https://lkml.kernel.org/r/e8c055458b080707f1bc1a98ff8bea79d0cec445.1604748361.git.christophe.leroy@csgroup.eu
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-11-14 11:26:04 -08:00
Santosh Sivaraj
e7e046155a kernel/watchdog: fix watchdog_allowed_mask not used warning
Define watchdog_allowed_mask only when SOFTLOCKUP_DETECTOR is enabled.

Fixes: 7feeb9cd4f ("watchdog/sysctl: Clean up sysctl variable name space")
Signed-off-by: Santosh Sivaraj <santosh@fossix.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20201106015025.1281561-1-santosh@fossix.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-11-14 11:26:03 -08:00
Matteo Croce
df5b0ab3e0 reboot: fix overflow parsing reboot cpu number
Limit the CPU number to num_possible_cpus(), because setting it to a
value lower than INT_MAX but higher than NR_CPUS produces the following
error on reboot and shutdown:

    BUG: unable to handle page fault for address: ffffffff90ab1bb0
    #PF: supervisor read access in kernel mode
    #PF: error_code(0x0000) - not-present page
    PGD 1c09067 P4D 1c09067 PUD 1c0a063 PMD 0
    Oops: 0000 [#1] SMP
    CPU: 1 PID: 1 Comm: systemd-shutdow Not tainted 5.9.0-rc8-kvm #110
    Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
    RIP: 0010:migrate_to_reboot_cpu+0xe/0x60
    Code: ea ea 00 48 89 fa 48 c7 c7 30 57 f1 81 e9 fa ef ff ff 66 2e 0f 1f 84 00 00 00 00 00 53 8b 1d d5 ea ea 00 e8 14 33 fe ff 89 da <48> 0f a3 15 ea fc bd 00 48 89 d0 73 29 89 c2 c1 e8 06 65 48 8b 3c
    RSP: 0018:ffffc90000013e08 EFLAGS: 00010246
    RAX: ffff88801f0a0000 RBX: 0000000077359400 RCX: 0000000000000000
    RDX: 0000000077359400 RSI: 0000000000000002 RDI: ffffffff81c199e0
    RBP: ffffffff81c1e3c0 R08: ffff88801f41f000 R09: ffffffff81c1e348
    R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
    R13: 00007f32bedf8830 R14: 00000000fee1dead R15: 0000000000000000
    FS:  00007f32bedf8980(0000) GS:ffff88801f480000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: ffffffff90ab1bb0 CR3: 000000001d057000 CR4: 00000000000006a0
    DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
    DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
    Call Trace:
      __do_sys_reboot.cold+0x34/0x5b
      do_syscall_64+0x2d/0x40

Fixes: 1b3a5d02ee ("reboot: move arch/x86 reboot= handling to generic kernel")
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Fabian Frederick <fabf@skynet.be>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Robin Holt <robinmholt@gmail.com>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20201103214025.116799-3-mcroce@linux.microsoft.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-11-14 11:26:03 -08:00
Matteo Croce
8b92c4ff44 Revert "kernel/reboot.c: convert simple_strtoul to kstrtoint"
Patch series "fix parsing of reboot= cmdline", v3.

The parsing of the reboot= cmdline has two major errors:

 - a missing bound check can crash the system on reboot

 - parsing of the cpu number only works if specified last

Fix both.

This patch (of 2):

This reverts commit 616feab753.

kstrtoint() and simple_strtoul() have a subtle difference which makes
them non interchangeable: if a non digit character is found amid the
parsing, the former will return an error, while the latter will just
stop parsing, e.g.  simple_strtoul("123xyx") = 123.

The kernel cmdline reboot= argument allows to specify the CPU used for
rebooting, with the syntax `s####` among the other flags, e.g.
"reboot=warm,s31,force", so if this flag is not the last given, it's
silently ignored as well as the subsequent ones.

Fixes: 616feab753 ("kernel/reboot.c: convert simple_strtoul to kstrtoint")
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Robin Holt <robinmholt@gmail.com>
Cc: Fabian Frederick <fabf@skynet.be>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20201103214025.116799-2-mcroce@linux.microsoft.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-11-14 11:26:03 -08:00
Jakub Kicinski
07cbce2e46 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2020-11-14

1) Add BTF generation for kernel modules and extend BTF infra in kernel
   e.g. support for split BTF loading and validation, from Andrii Nakryiko.

2) Support for pointers beyond pkt_end to recognize LLVM generated patterns
   on inlined branch conditions, from Alexei Starovoitov.

3) Implements bpf_local_storage for task_struct for BPF LSM, from KP Singh.

4) Enable FENTRY/FEXIT/RAW_TP tracing program to use the bpf_sk_storage
   infra, from Martin KaFai Lau.

5) Add XDP bulk APIs that introduce a defer/flush mechanism to optimize the
   XDP_REDIRECT path, from Lorenzo Bianconi.

6) Fix a potential (although rather theoretical) deadlock of hashtab in NMI
   context, from Song Liu.

7) Fixes for cross and out-of-tree build of bpftool and runqslower allowing build
   for different target archs on same source tree, from Jean-Philippe Brucker.

8) Fix error path in htab_map_alloc() triggered from syzbot, from Eric Dumazet.

9) Move functionality from test_tcpbpf_user into the test_progs framework so it
   can run in BPF CI, from Alexander Duyck.

10) Lift hashtab key_size limit to be larger than MAX_BPF_STACK, from Florian Lehner.

Note that for the fix from Song we have seen a sparse report on context
imbalance which requires changes in sparse itself for proper annotation
detection where this is currently being discussed on linux-sparse among
developers [0]. Once we have more clarification/guidance after their fix,
Song will follow-up.

  [0] https://lore.kernel.org/linux-sparse/CAHk-=wh4bx8A8dHnX612MsDO13st6uzAz1mJ1PaHHVevJx_ZCw@mail.gmail.com/T/
      https://lore.kernel.org/linux-sparse/20201109221345.uklbp3lzgq6g42zb@ltop.local/T/

* git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (66 commits)
  net: mlx5: Add xdp tx return bulking support
  net: mvpp2: Add xdp tx return bulking support
  net: mvneta: Add xdp tx return bulking support
  net: page_pool: Add bulk support for ptr_ring
  net: xdp: Introduce bulking for xdp tx return path
  bpf: Expose bpf_d_path helper to sleepable LSM hooks
  bpf: Augment the set of sleepable LSM hooks
  bpf: selftest: Use bpf_sk_storage in FENTRY/FEXIT/RAW_TP
  bpf: Allow using bpf_sk_storage in FENTRY/FEXIT/RAW_TP
  bpf: Rename some functions in bpf_sk_storage
  bpf: Folding omem_charge() into sk_storage_charge()
  selftests/bpf: Add asm tests for pkt vs pkt_end comparison.
  selftests/bpf: Add skb_pkt_end test
  bpf: Support for pointers beyond pkt_end.
  tools/bpf: Always run the *-clean recipes
  tools/bpf: Add bootstrap/ to .gitignore
  bpf: Fix NULL dereference in bpf_task_storage
  tools/bpftool: Fix build slowdown
  tools/runqslower: Build bpftool using HOSTCC
  tools/runqslower: Enable out-of-tree build
  ...
====================

Link: https://lore.kernel.org/r/20201114020819.29584-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-14 09:13:41 -08:00
Dmitrii Banshchikov
f782e2c300 bpf: Relax return code check for subprograms
Currently verifier enforces return code checks for subprograms in the
same manner as it does for program entry points. This prevents returning
arbitrary scalar values from subprograms. Scalar type of returned values
is checked by btf_prepare_func_args() and hence it should be safe to
allow only scalars for now. Relax return code checks for subprograms and
allow any correct scalar values.

Fixes: 51c39bb1d5 (bpf: Introduce function-by-function verification)
Signed-off-by: Dmitrii Banshchikov <me@ubique.spb.ru>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201113171756.90594-1-me@ubique.spb.ru
2020-11-14 08:17:27 -08:00
Lukas Bulwahn
932f8c64d3 futex: Remove unused empty compat_exit_robust_list()
Commit ba31c1a485 ("futex: Move futex exit handling into futex code")
introduced compat_exit_robust_list() with a full-fledged implementation for
CONFIG_COMPAT, and an empty-body function for !CONFIG_COMPAT.

However, compat_exit_robust_list() is only used in futex_mm_release() under
#ifdef CONFIG_COMPAT.

Hence for !CONFIG_COMPAT, make CC=clang W=1 warns:

  kernel/futex.c:314:20:
    warning: unused function 'compat_exit_robust_list' [-Wunused-function]

There is no need to declare the unused empty function for !CONFIG_COMPAT.

Simply remove it.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Link: https://lore.kernel.org/r/20201113172012.27221-1-lukas.bulwahn@gmail.com
2020-11-14 01:15:35 +01:00
Linus Torvalds
88b31f07f3 arm64 fixes for -rc4
- Spectre/Meltdown safelisting for some Qualcomm KRYO cores
 
 - Fix RCU splat when failing to online a CPU due to a feature mismatch
 
 - Fix a recently introduced sparse warning in kexec()
 
 - Fix handling of CPU erratum 1418040 for late CPUs
 
 - Ensure hot-added memory falls within linear-mapped region
 -----BEGIN PGP SIGNATURE-----
 
 iQFEBAABCgAuFiEEPxTL6PPUbjXGY88ct6xw3ITBYzQFAl+ubogQHHdpbGxAa2Vy
 bmVsLm9yZwAKCRC3rHDchMFjNPD7B/9i5ao44AEJwjz0a68S/jD7kUD7i3xVkCNN
 Y8i/i9mx44IAcf8pmyQh3ngaFlJuF2C6oC/SQFiDbmVeGeZXLXvXV7uGAqXG5Xjm
 O2Svgr1ry176JWpsB7MNnZwzAatQffdkDjbjQCcUnUIKYcLvge8H2fICljujGcfQ
 094vNmT9VerTWRbWDti3Ck/ug+sanVHuzk5BWdKx3jamjeTqo+sBZK/wgBr6UoYQ
 mT3BFX42kLIGg+AzwXRDPlzkJymjYgQDbSwGsvny8qKdOEJbAUwWXYZ5sTs9J/gU
 E9PT3VJI7BYtTd1uPEWkD645U3arfx3Pf2JcJlbkEp86qx4CUF9s
 =T6k4
 -----END PGP SIGNATURE-----

Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fixes from Will Deacon:

 - Spectre/Meltdown safelisting for some Qualcomm KRYO cores

 - Fix RCU splat when failing to online a CPU due to a feature mismatch

 - Fix a recently introduced sparse warning in kexec()

 - Fix handling of CPU erratum 1418040 for late CPUs

 - Ensure hot-added memory falls within linear-mapped region

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: cpu_errata: Apply Erratum 845719 to KRYO2XX Silver
  arm64: proton-pack: Add KRYO2XX silver CPUs to spectre-v2 safe-list
  arm64: kpti: Add KRYO2XX gold/silver CPU cores to kpti safelist
  arm64: Add MIDR value for KRYO2XX gold/silver CPU cores
  arm64/mm: Validate hotplug range before creating linear mapping
  arm64: smp: Tell RCU about CPUs that fail to come online
  arm64: psci: Avoid printing in cpu_psci_cpu_die()
  arm64: kexec_file: Fix sparse warning
  arm64: errata: Fix handling of 1418040 with late CPU onlining
2020-11-13 09:23:10 -08:00
Kaixu Xia
b111545d26 tracing: Remove the useless value assignment in test_create_synth_event()
The value of variable ret is overwritten on the delete branch in the
test_create_synth_event() and we care more about the above error than
this delete portion. Remove it.

Link: https://lkml.kernel.org/r/1605283360-6804-1-git-send-email-kaixuxia@tencent.com

Reported-by: Tosk Robot <tencent_os_robot@tencent.com>
Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-13 12:19:52 -05:00
Steven Rostedt (VMware)
2860cd8a23 livepatch: Use the default ftrace_ops instead of REGS when ARGS is available
When CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS is available, the ftrace call
will be able to set the ip of the calling function. This will improve the
performance of live kernel patching where it does not need all the regs to
be stored just to change the instruction pointer.

If all archs that support live kernel patching also support
HAVE_DYNAMIC_FTRACE_WITH_ARGS, then the architecture specific function
klp_arch_set_pc() could be made generic.

It is possible that an arch can support HAVE_DYNAMIC_FTRACE_WITH_ARGS but
not HAVE_DYNAMIC_FTRACE_WITH_REGS and then have access to live patching.

Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: live-patching@vger.kernel.org
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-13 12:15:28 -05:00
Steven Rostedt (VMware)
02a474ca26 ftrace/x86: Allow for arguments to be passed in to ftrace_regs by default
Currently, the only way to get access to the registers of a function via a
ftrace callback is to set the "FL_SAVE_REGS" bit in the ftrace_ops. But as this
saves all regs as if a breakpoint were to trigger (for use with kprobes), it
is expensive.

The regs are already saved on the stack for the default ftrace callbacks, as
that is required otherwise a function being traced will get the wrong
arguments and possibly crash. And on x86, the arguments are already stored
where they would be on a pt_regs structure to use that code for both the
regs version of a callback, it makes sense to pass that information always
to all functions.

If an architecture does this (as x86_64 now does), it is to set
HAVE_DYNAMIC_FTRACE_WITH_ARGS, and this will let the generic code that it
could have access to arguments without having to set the flags.

This also includes having the stack pointer being saved, which could be used
for accessing arguments on the stack, as well as having the function graph
tracer not require its own trampoline!

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-13 12:14:59 -05:00
Steven Rostedt (VMware)
d19ad0775d ftrace: Have the callbacks receive a struct ftrace_regs instead of pt_regs
In preparation to have arguments of a function passed to callbacks attached
to functions as default, change the default callback prototype to receive a
struct ftrace_regs as the forth parameter instead of a pt_regs.

For callbacks that set the FL_SAVE_REGS flag in their ftrace_ops flags, they
will now need to get the pt_regs via a ftrace_get_regs() helper call. If
this is called by a callback that their ftrace_ops did not have a
FL_SAVE_REGS flag set, it that helper function will return NULL.

This will allow the ftrace_regs to hold enough just to get the parameters
and stack pointer, but without the worry that callbacks may have a pt_regs
that is not completely filled.

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-13 12:14:55 -05:00
KP Singh
6f100640ca bpf: Expose bpf_d_path helper to sleepable LSM hooks
Sleepable hooks are never called from an NMI/interrupt context, so it
is safe to use the bpf_d_path helper in LSM programs attaching to these
hooks.

The helper is not restricted to sleepable programs and merely uses the
list of sleepable hooks as the initial subset of LSM hooks where it can
be used.

Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20201113005930.541956-3-kpsingh@chromium.org
2020-11-13 15:47:21 +01:00
KP Singh
423f16108c bpf: Augment the set of sleepable LSM hooks
Update the set of sleepable hooks with the ones that do not trigger
a warning with might_fault() when exercised with the correct kernel
config options enabled, i.e.

	DEBUG_ATOMIC_SLEEP=y
	LOCKDEP=y
	PROVE_LOCKING=y

This means that a sleepable LSM eBPF program can be attached to these
LSM hooks. A new helper method bpf_lsm_is_sleepable_hook is added and
the set is maintained locally in bpf_lsm.c

Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20201113005930.541956-2-kpsingh@chromium.org
2020-11-13 15:45:54 +01:00
Martin KaFai Lau
8e4597c627 bpf: Allow using bpf_sk_storage in FENTRY/FEXIT/RAW_TP
This patch enables the FENTRY/FEXIT/RAW_TP tracing program to use
the bpf_sk_storage_(get|delete) helper, so those tracing programs
can access the sk's bpf_local_storage and the later selftest
will show some examples.

The bpf_sk_storage is currently used in bpf-tcp-cc, tc,
cg sockops...etc which is running either in softirq or
task context.

This patch adds bpf_sk_storage_get_tracing_proto and
bpf_sk_storage_delete_tracing_proto.  They will check
in runtime that the helpers can only be called when serving
softirq or running in a task context.  That should enable
most common tracing use cases on sk.

During the load time, the new tracing_allowed() function
will ensure the tracing prog using the bpf_sk_storage_(get|delete)
helper is not tracing any bpf_sk_storage*() function itself.
The sk is passed as "void *" when calling into bpf_local_storage.

This patch only allows tracing a kernel function.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201112211313.2587383-1-kafai@fb.com
2020-11-12 18:39:28 -08:00
Jakub Kicinski
e1d9d7b913 Merge https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-12 16:54:48 -08:00
Alexei Starovoitov
6d94e741a8 bpf: Support for pointers beyond pkt_end.
This patch adds the verifier support to recognize inlined branch conditions.
The LLVM knows that the branch evaluates to the same value, but the verifier
couldn't track it. Hence causing valid programs to be rejected.
The potential LLVM workaround: https://reviews.llvm.org/D87428
can have undesired side effects, since LLVM doesn't know that
skb->data/data_end are being compared. LLVM has to introduce extra boolean
variable and use inline_asm trick to force easier for the verifier assembly.

Instead teach the verifier to recognize that
r1 = skb->data;
r1 += 10;
r2 = skb->data_end;
if (r1 > r2) {
  here r1 points beyond packet_end and
  subsequent
  if (r1 > r2) // always evaluates to "true".
}

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20201111031213.25109-2-alexei.starovoitov@gmail.com
2020-11-13 01:42:11 +01:00
Linus Torvalds
db7c953555 Networking fixes for 5.10-rc4, including fixes from the bpf subtree.
Current release - regressions:
 
  - arm64: dts: fsl-ls1028a-kontron-sl28: specify in-band mode for ENETC
 
 Current release - bugs in new features:
 
  - mptcp: provide rmem[0] limit offset to fix oops
 
 Previous release - regressions:
 
  - IPv6: Set SIT tunnel hard_header_len to zero to fix path MTU
    calculations
 
  - lan743x: correctly handle chips with internal PHY
 
  - bpf: Don't rely on GCC __attribute__((optimize)) to disable GCSE
 
  - mlx5e: Fix VXLAN port table synchronization after function reload
 
 Previous release - always broken:
 
  - bpf: Zero-fill re-used per-cpu map element
 
  - net: udp: fix out-of-order packets when forwarding with UDP GSO
              fraglists turned on
    - fix UDP header access on Fast/frag0 UDP GRO
    - fix IP header access and skb lookup on Fast/frag0 UDP GRO
 
  - ethtool: netlink: add missing netdev_features_change() call
 
  - net: Update window_clamp if SOCK_RCVBUF is set
 
  - igc: Fix returning wrong statistics
 
  - ch_ktls: fix multiple leaks and corner cases in Chelsio TLS offload
 
  - tunnels: Fix off-by-one in lower MTU bounds for ICMP/ICMPv6 replies
 
  - r8169: disable hw csum for short packets on all chip versions
 
  - vrf: Fix fast path output packet handling with async Netfilter rules
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEE6jPA+I1ugmIBA4hXMUZtbf5SIrsFAl+thbIACgkQMUZtbf5S
 Irsy0RAAhYIYDNMSkQhcVcQPMxbtStwgTtKrWxg/D2zh3Kg+B4oRgoNZnt9kmlHX
 Su/aRWbTWBkDIMxIWBfRsO3z5zSQm4yLG1FTlfsOcWzOJcsntCO8SzikyxtnEZK8
 Bpi7dOoKB6KF0V2YjM9AHh5fbXvS7KJfp/PjZ7Kpn5BEbFV8rKtIyiJxwXXZUr6O
 ddM9Om4i0zf+dmsY1HVEyowPQMVB3vbn8F3dPk3ZrD8NVa53NtvMRxHKSsourRbZ
 yp4LKZV+POKHPFglO4jhLymhyeiwb1qgA8wssk7EKu0bwPeOcER4Tpewh1ib4C/C
 sRRzj0Wlw6dyPCkyNKx23D7dF/DrnLmXLUBhGS2mu2htSlWOH6w6rFQoVSNGGy9T
 DKUlUVUPG80mgYdME6NLJ27GOGQzxoAvzWgpcL6dJs9jz8nQqABJeXvdjw/vc/XH
 AOaKy4VwE3qf0W106JpUb+a/q0RJf7w3o4c1vLc/AZwpshNBOsrJBqrTk2E5Nrhd
 mcQykaF++DbLPIyTqhHl0GpKapohThESyMvfc4WRBFBaCwgFdOY/t0Gz3GA2N8Jc
 fuq9NOB1bfouaFGfzdkZ7RZJi3lFqZfv/XiJCh/knp1/lHAQPo4TuADcFDsjeEc9
 yr48SRDnCqahAQ7bUP0b5i31SZzwAYb/HnwYuvf4LWFvHl9XG5A=
 =AKM7
 -----END PGP SIGNATURE-----

Merge tag 'net-5.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Jakub Kicinski:
 "Current release - regressions:

   - arm64: dts: fsl-ls1028a-kontron-sl28: specify in-band mode for
     ENETC

  Current release - bugs in new features:

   - mptcp: provide rmem[0] limit offset to fix oops

  Previous release - regressions:

   - IPv6: Set SIT tunnel hard_header_len to zero to fix path MTU
     calculations

   - lan743x: correctly handle chips with internal PHY

   - bpf: Don't rely on GCC __attribute__((optimize)) to disable GCSE

   - mlx5e: Fix VXLAN port table synchronization after function reload

  Previous release - always broken:

   - bpf: Zero-fill re-used per-cpu map element

   - fix out-of-order UDP packets when forwarding with UDP GSO fraglists
     turned on:
       - fix UDP header access on Fast/frag0 UDP GRO
       - fix IP header access and skb lookup on Fast/frag0 UDP GRO

   - ethtool: netlink: add missing netdev_features_change() call

   - net: Update window_clamp if SOCK_RCVBUF is set

   - igc: Fix returning wrong statistics

   - ch_ktls: fix multiple leaks and corner cases in Chelsio TLS offload

   - tunnels: Fix off-by-one in lower MTU bounds for ICMP/ICMPv6 replies

   - r8169: disable hw csum for short packets on all chip versions

   - vrf: Fix fast path output packet handling with async Netfilter
     rules"

* tag 'net-5.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (65 commits)
  lan743x: fix use of uninitialized variable
  net: udp: fix IP header access and skb lookup on Fast/frag0 UDP GRO
  net: udp: fix UDP header access on Fast/frag0 UDP GRO
  devlink: Avoid overwriting port attributes of registered port
  vrf: Fix fast path output packet handling with async Netfilter rules
  cosa: Add missing kfree in error path of cosa_write
  net: switch to the kernel.org patchwork instance
  ch_ktls: stop the txq if reaches threshold
  ch_ktls: tcb update fails sometimes
  ch_ktls/cxgb4: handle partial tag alone SKBs
  ch_ktls: don't free skb before sending FIN
  ch_ktls: packet handling prior to start marker
  ch_ktls: Correction in middle record handling
  ch_ktls: missing handling of header alone
  ch_ktls: Correction in trimmed_len calculation
  cxgb4/ch_ktls: creating skbs causes panic
  ch_ktls: Update cheksum information
  ch_ktls: Correction in finding correct length
  cxgb4/ch_ktls: decrypted bit is not enough
  net/x25: Fix null-ptr-deref in x25_connect
  ...
2020-11-12 14:02:04 -08:00
Linus Torvalds
fcfb67918c Power management fixes for 5.10-rc4.
Make the intel_pstate driver behave as expected when it operates in
 the passive mode with HWP enabled and the "powersave" governor on
 top of it.
 -----BEGIN PGP SIGNATURE-----
 
 iQJGBAABCAAwFiEE4fcc61cGeeHD/fCwgsRv/nhiVHEFAl+tVWUSHHJqd0Byand5
 c29ja2kubmV0AAoJEILEb/54YlRxNIwQALNj2uV+CJL4DCvcMPFqvtB7bwwsk1mS
 fqRk/wEhz5noE/x3uhD1DKlL3VPj1sDUVRmHKSdIgqrwSFX2zbw+cf2y6E94WdDz
 /7x0Khj4mT5cfGHacItNBnkglCrxVXxSdU4DcPTgINlWM8iv6W8D3uK5OpFYDtKr
 5shqf45U8/+fh7hGCtNnofAZEVU+YTDzY0jHnnIxD8FKXFLaDFj6jVGjgdXgBD5s
 /XgsKz867SybzLuTW9O0SKDughMhmhaqXnHwtu9jvlw/3i1Wn16r2LeCWyIkoxWy
 MRNXg4rOerJvK084gxJW9BWmCuA6NnKBtKvXNlqHzl14ept3Cf3dYtaQ50x7eYQB
 osMWbBDdRjV1fo7SptMXQmn8sKxZgrjc0pSYicbiMOH3BkpIn5ed4+MPWfWN8pyb
 piRkx17sFwPE7jI5Rkuv+EucisG8tNvWImE9gFENxtelF1rj7njV1xMYlevrD/9u
 aYTNYUeRAc6DA2AF/mzXtqwXpDqoxa7X0UBl8JFmkLvcvORtR3XY6HlcYMgp820a
 /Sh0rZmuUlssUnrhd1Kr6QRiMIrCihTnbhTXsY0oZH4QSYYJCS89qijngAtqobEt
 K+eqsHHoGmVK3Ch+O+YpFo+GpH5Avk0b/DisX3Zu20hGEX4fvv4q7ZTuNSnHhgOL
 ERjLBUQZUFaf
 =zh3K
 -----END PGP SIGNATURE-----

Merge tag 'pm-5.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fixes from Rafael Wysocki:
 "Make the intel_pstate driver behave as expected when it operates in
  the passive mode with HWP enabled and the 'powersave' governor on top
  of it"

* tag 'pm-5.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: intel_pstate: Take CPUFREQ_GOV_STRICT_TARGET into account
  cpufreq: Add strict_target to struct cpufreq_policy
  cpufreq: Introduce CPUFREQ_GOV_STRICT_TARGET
  cpufreq: Introduce governor flags
2020-11-12 11:03:38 -08:00
Martin KaFai Lau
09a3dac7b5 bpf: Fix NULL dereference in bpf_task_storage
In bpf_pid_task_storage_update_elem(), it missed to
test the !task_storage_ptr(task) which then could trigger a NULL
pointer exception in bpf_local_storage_update().

Fixes: 4cf1bc1f10 ("bpf: Implement task local storage")
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Roman Gushchin <guro@fb.com>
Acked-by: KP Singh <kpsingh@google.com>
Link: https://lore.kernel.org/bpf/20201112001919.2028357-1-kafai@fb.com
2020-11-11 18:14:49 -08:00
Linus Torvalds
3d5e28bff7 Merge branch 'stable/for-linus-5.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb
Pull swiotlb fixes from Konrad Rzeszutek Wilk:
 "Two tiny fixes for issues that make drivers under Xen unhappy under
  certain conditions"

* 'stable/for-linus-5.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb:
  swiotlb: remove the tbl_dma_addr argument to swiotlb_tbl_map_single
  swiotlb: fix "x86: Don't panic if can not alloc buffer for swiotlb"
2020-11-11 14:15:06 -08:00
Nikolay Borisov
584da07686 printk: ringbuffer: Reference text_data_ring directly in callees.
A bunch of functions in the new ringbuffer code take both a
printk_ringbuffer struct and a separate prb_data_ring. This is a relic
from an earlier version of the code when a second data ring was present.
Since this is no longer the case remove the extra function argument
from:
 - data_make_reusable()
 - data_push_tail()
 - data_alloc()
 - data_realloc()

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
2020-11-11 16:55:39 +01:00
Kaixu Xia
f16e631333 bpf: Fix unsigned 'datasec_id' compared with zero in check_pseudo_btf_id
The unsigned variable datasec_id is assigned a return value from the call
to check_pseudo_btf_id(), which may return negative error code.

This fixes the following coccicheck warning:

  ./kernel/bpf/verifier.c:9616:5-15: WARNING: Unsigned expression compared with zero: datasec_id > 0

Fixes: eaa6bcb71e ("bpf: Introduce bpf_per_cpu_ptr()")
Reported-by: Tosk Robot <tencent_os_robot@tencent.com>
Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Cc: Hao Luo <haoluo@google.com>
Link: https://lore.kernel.org/bpf/1605071026-25906-1-git-send-email-kaixuxia@tencent.com
2020-11-11 10:50:22 +01:00
Andrii Nakryiko
7112d12798 bpf: Compile out btf_parse_module() if module BTF is not enabled
Make sure btf_parse_module() is compiled out if module BTFs are not enabled.

Fixes: 36e68442d1 ("bpf: Load and verify kernel module BTFs")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201111040645.903494-1-andrii@kernel.org
2020-11-10 20:15:07 -08:00
Qiujun Huang
2b5894cc33 tracing: Fix some typos in comments
s/detetector/detector/
s/enfoced/enforced/
s/writen/written/
s/actualy/actually/
s/bascially/basically/
s/Regarldess/Regardless/
s/zeroes/zeros/
s/followd/followed/
s/incrememented/incremented/
s/separatelly/separately/
s/accesible/accessible/
s/sythetic/synthetic/
s/enabed/enabled/
s/heurisitc/heuristic/
s/assocated/associated/
s/otherwides/otherwise/
s/specfied/specified/
s/seaching/searching/
s/hierachry/hierarchy/
s/internel/internal/
s/Thise/This/

Link: https://lkml.kernel.org/r/20201029150554.3354-1-hqjagain@gmail.com

Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-10 20:39:40 -05:00
Alex Shi
045e269c1e ftrace: Remove unused varible 'ret'
'ret' in 2 functions are not used. and one of them is a void function.
So remove them to avoid gcc warning:
kernel/trace/ftrace.c:4166:6: warning: variable ‘ret’ set but not used
[-Wunused-but-set-variable]
kernel/trace/ftrace.c:5571:6: warning: variable ‘ret’ set but not used
[-Wunused-but-set-variable]

Link: https://lkml.kernel.org/r/1604674486-52350-1-git-send-email-alex.shi@linux.alibaba.com

Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-10 20:39:40 -05:00
Steven Rostedt (VMware)
28575c61ea ring-buffer: Add recording of ring buffer recursion into recursed_functions
Add a new config RING_BUFFER_RECORD_RECURSION that will place functions that
recurse from the ring buffer into the ftrace recused_functions file.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-10 20:39:40 -05:00
Steven Rostedt (VMware)
60602cb549 fgraph: Make overruns 4 bytes in graph stack structure
Inspecting the data structures of the function graph tracer, I found that
the overrun value is unsigned long, which is 8 bytes on a 64 bit machine,
and not only that, the depth is an int (4 bytes). The overrun can be simply
an unsigned int (4 bytes) and pack the ftrace_graph_ret structure better.

The depth is moved up next to the func, as it is used more often with func,
and improves cache locality.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-10 20:39:36 -05:00
Paul E. McKenney
c583bcb8f5 rcu: Don't invoke try_invoke_on_locked_down_task() with irqs disabled
The try_invoke_on_locked_down_task() function requires that
interrupts be enabled, but it is called with interrupts disabled from
rcu_print_task_stall(), resulting in an "IRQs not enabled as expected"
diagnostic.  This commit therefore updates rcu_print_task_stall()
to accumulate a list of the first few tasks while holding the current
leaf rcu_node structure's ->lock, then releases that lock and only then
uses try_invoke_on_locked_down_task() to attempt to obtain per-task
detailed information.  Of course, as soon as ->lock is released, the
task might exit, so the get_task_struct() function is used to prevent
the task structure from going away in the meantime.

Link: https://lore.kernel.org/lkml/000000000000903d5805ab908fc4@google.com/
Fixes: 5bef8da66a ("rcu: Add per-task state to RCU CPU stall warnings")
Reported-by: syzbot+cb3b69ae80afd6535b0e@syzkaller.appspotmail.com
Reported-by: syzbot+f04854e1c5c9e913cc27@syzkaller.appspotmail.com
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-10 17:10:38 -08:00
Andrii Nakryiko
36e68442d1 bpf: Load and verify kernel module BTFs
Add kernel module listener that will load/validate and unload module BTF.
Module BTFs gets ID generated for them, which makes it possible to iterate
them with existing BTF iteration API. They are given their respective module's
names, which will get reported through GET_OBJ_INFO API. They are also marked
as in-kernel BTFs for tooling to distinguish them from user-provided BTFs.

Also, similarly to vmlinux BTF, kernel module BTFs are exposed through
sysfs as /sys/kernel/btf/<module-name>. This is convenient for user-space
tools to inspect module BTF contents and dump their types with existing tools:

[vmuser@archvm bpf]$ ls -la /sys/kernel/btf
total 0
drwxr-xr-x  2 root root       0 Nov  4 19:46 .
drwxr-xr-x 13 root root       0 Nov  4 19:46 ..

...

-r--r--r--  1 root root     888 Nov  4 19:46 irqbypass
-r--r--r--  1 root root  100225 Nov  4 19:46 kvm
-r--r--r--  1 root root   35401 Nov  4 19:46 kvm_intel
-r--r--r--  1 root root     120 Nov  4 19:46 pcspkr
-r--r--r--  1 root root     399 Nov  4 19:46 serio_raw
-r--r--r--  1 root root 4094095 Nov  4 19:46 vmlinux

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/bpf/20201110011932.3201430-5-andrii@kernel.org
2020-11-10 15:25:53 -08:00
Andrii Nakryiko
5329722057 bpf: Assign ID to vmlinux BTF and return extra info for BTF in GET_OBJ_INFO
Allocate ID for vmlinux BTF. This makes it visible when iterating over all BTF
objects in the system. To allow distinguishing vmlinux BTF (and later kernel
module BTF) from user-provided BTFs, expose extra kernel_btf flag, as well as
BTF name ("vmlinux" for vmlinux BTF, will equal to module's name for module
BTF).  We might want to later allow specifying BTF name for user-provided BTFs
as well, if that makes sense. But currently this is reserved only for
in-kernel BTFs.

Having in-kernel BTFs exposed IDs will allow to extend BPF APIs that require
in-kernel BTF type with ability to specify BTF types from kernel modules, not
just vmlinux BTF. This will be implemented in a follow up patch set for
fentry/fexit/fmod_ret/lsm/etc.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201110011932.3201430-3-andrii@kernel.org
2020-11-10 15:25:53 -08:00
Andrii Nakryiko
951bb64621 bpf: Add in-kernel split BTF support
Adjust in-kernel BTF implementation to support a split BTF mode of operation.
Changes are mostly mirroring libbpf split BTF changes, with the exception of
start_id being 0 for in-kernel implementation due to simpler read-only mode.

Otherwise, for split BTF logic, most of the logic of jumping to base BTF,
where necessary, is encapsulated in few helper functions. Type numbering and
string offset in a split BTF are logically continuing where base BTF ends, so
most of the high-level logic is kept without changes.

Type verification and size resolution is only doing an added resolution of new
split BTF types and relies on already cached size and type resolution results
in the base BTF.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201110011932.3201430-2-andrii@kernel.org
2020-11-10 15:25:53 -08:00
Lukasz Luba
f2c90b12e7 PM: EM: update the comments related to power scale
The Energy Model supports power values expressed in milli-Watts or in an
'abstract scale'. Update the related comments is the code to reflect that
state.

Reviewed-by: Quentin Perret <qperret@google.com>
Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-11-10 20:29:28 +01:00
Lukasz Luba
c250d50fe2 PM: EM: Add a flag indicating units of power values in Energy Model
There are different platforms and devices which might use different scale
for the power values. Kernel sub-systems might need to check if all
Energy Model (EM) devices are using the same scale. Address that issue and
store the information inside EM for each device. Thanks to that they can
be easily compared and proper action triggered.

Suggested-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Quentin Perret <qperret@google.com>
Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-11-10 20:22:00 +01:00
Linus Torvalds
eccc876724 Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull core dump fix from Al Viro:
 "Fix for multithreaded coredump playing fast and loose with getting
  registers of secondary threads; if a secondary gets caught in the
  middle of exit(2), the conditition it will be stopped in for dumper to
  examine might be unusual enough for things to go wrong.

  Quite a few architectures are fine with that, but some are not."

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  don't dump the threads that had been already exiting when zapped.
2020-11-10 10:33:55 -08:00
Kai-Heng Feng
d60cd06331 PM: ACPI: reboot: Use S5 for reboot
After reboot, it's not possible to use hotkeys to enter BIOS setup
and boot menu on some HP laptops.

BIOS folks identified the root cause is the missing _PTS call, and
BIOS is expecting _PTS to do proper reset.

Using S5 for reboot is default behavior under Windows, "A full
shutdown (S5) occurs when a system restart is requested" [1], so
let's do the same here.

[1] https://docs.microsoft.com/en-us/windows/win32/power/system-power-states

Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
[ rjw: Subject edit ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-11-10 19:00:44 +01:00
Valentin Schneider
dc824eb898 sched/fair: Dissociate wakeup decisions from SD flag value
The CFS wakeup code will only ever go through EAS / its fast path on
"regular" wakeups (i.e. not on forks or execs). These are currently gated
by a check against 'sd_flag', which would be SD_BALANCE_WAKE at wakeup.

However, we now have a flag that explicitly tells us whether a wakeup is a
"regular" one, so hinge those conditions on that flag instead.

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201102184514.2733-4-valentin.schneider@arm.com
2020-11-10 18:39:06 +01:00
Valentin Schneider
3aef1551e9 sched: Remove select_task_rq()'s sd_flag parameter
Only select_task_rq_fair() uses that parameter to do an actual domain
search, other classes only care about what kind of wakeup is happening
(fork, exec, or "regular") and thus just translate the flag into a wakeup
type.

WF_TTWU and WF_EXEC have just been added, use these along with WF_FORK to
encode the wakeup types we care about. For select_task_rq_fair(), we can
simply use the shiny new WF_flag : SD_flag mapping.

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201102184514.2733-3-valentin.schneider@arm.com
2020-11-10 18:39:06 +01:00
Valentin Schneider
1777057905 sched: Add WF_TTWU, WF_EXEC wakeup flags
To remove the sd_flag parameter of select_task_rq(), we need another way of
encoding wakeup types. There already is a WF_FORK flag, add the missing two.

With that said, we still need an easy way to turn WF_foo into
SD_bar (e.g. WF_TTWU into SD_BALANCE_WAKE). As suggested by Peter, let's
make our lives easier and make them match exactly, and throw in some
compile-time checks for good measure.

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201102184514.2733-2-valentin.schneider@arm.com
2020-11-10 18:39:06 +01:00
Hui Su
cdb310474d sched/fair: Remove superfluous lock section in do_sched_cfs_slack_timer()
Since ab93a4bc95 ("sched/fair: Remove distribute_running fromCFS
bandwidth"), there is nothing to protect between
raw_spin_lock_irqsave/store() in do_sched_cfs_slack_timer().

Signed-off-by: Hui Su <sh_def@163.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Phil Auld <pauld@redhat.com>
Reviewed-by: Ben Segall <bsegall@google.com>
Link: https://lkml.kernel.org/r/20201030144621.GA96974@rlk
2020-11-10 18:39:05 +01:00
Peter Zijlstra
12fa97c64d Merge branch 'sched/migrate-disable' 2020-11-10 18:39:04 +01:00
Valentin Schneider
c777d84710 sched: Comment affine_move_task()
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201013140116.26651-2-valentin.schneider@arm.com
2020-11-10 18:39:02 +01:00
Valentin Schneider
885b3ba47a sched: Deny self-issued __set_cpus_allowed_ptr() when migrate_disable()
migrate_disable();
  set_cpus_allowed_ptr(current, {something excluding task_cpu(current)});
  affine_move_task(); <-- never returns

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201013140116.26651-1-valentin.schneider@arm.com
2020-11-10 18:39:02 +01:00
Peter Zijlstra
a7c81556ec sched: Fix migrate_disable() vs rt/dl balancing
In order to minimize the interference of migrate_disable() on lower
priority tasks, which can be deprived of runtime due to being stuck
below a higher priority task. Teach the RT/DL balancers to push away
these higher priority tasks when a lower priority task gets selected
to run on a freshly demoted CPU (pull).

This adds migration interference to the higher priority task, but
restores bandwidth to system that would otherwise be irrevocably lost.
Without this it would be possible to have all tasks on the system
stuck on a single CPU, each task preempted in a migrate_disable()
section with a single high priority task running.

This way we can still approximate running the M highest priority tasks
on the system.

Migrating the top task away is (ofcourse) still subject to
migrate_disable() too, which means the lower task is subject to an
interference equivalent to the worst case migrate_disable() section.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Link: https://lkml.kernel.org/r/20201023102347.499155098@infradead.org
2020-11-10 18:39:01 +01:00
Peter Zijlstra
ded467dc83 sched, lockdep: Annotate ->pi_lock recursion
There's a valid ->pi_lock recursion issue where the actual PI code
tries to wake up the stop task. Make lockdep aware so it doesn't
complain about this.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Link: https://lkml.kernel.org/r/20201023102347.406912197@infradead.org
2020-11-10 18:39:01 +01:00
Peter Zijlstra
95158a89dd sched,rt: Use the full cpumask for balancing
We want migrate_disable() tasks to get PULLs in order for them to PUSH
away the higher priority task.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Link: https://lkml.kernel.org/r/20201023102347.310519774@infradead.org
2020-11-10 18:39:00 +01:00
Peter Zijlstra
14e292f8d4 sched,rt: Use cpumask_any*_distribute()
Replace a bunch of cpumask_any*() instances with
cpumask_any*_distribute(), by injecting this little bit of random in
cpu selection, we reduce the chance two competing balance operations
working off the same lowest_mask pick the same CPU.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Link: https://lkml.kernel.org/r/20201023102347.190759694@infradead.org
2020-11-10 18:39:00 +01:00
Thomas Gleixner
3015ef4b98 sched/core: Make migrate disable and CPU hotplug cooperative
On CPU unplug tasks which are in a migrate disabled region cannot be pushed
to a different CPU until they returned to migrateable state.

Account the number of tasks on a runqueue which are in a migrate disabled
section and make the hotplug wait mechanism respect that.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Link: https://lkml.kernel.org/r/20201023102347.067278757@infradead.org
2020-11-10 18:39:00 +01:00
Peter Zijlstra
6d337eab04 sched: Fix migrate_disable() vs set_cpus_allowed_ptr()
Concurrent migrate_disable() and set_cpus_allowed_ptr() has
interesting features. We rely on set_cpus_allowed_ptr() to not return
until the task runs inside the provided mask. This expectation is
exported to userspace.

This means that any set_cpus_allowed_ptr() caller must wait until
migrate_enable() allows migrations.

At the same time, we don't want migrate_enable() to schedule, due to
patterns like:

	preempt_disable();
	migrate_disable();
	...
	migrate_enable();
	preempt_enable();

And:

	raw_spin_lock(&B);
	spin_unlock(&A);

this means that when migrate_enable() must restore the affinity
mask, it cannot wait for completion thereof. Luck will have it that
that is exactly the case where there is a pending
set_cpus_allowed_ptr(), so let that provide storage for the async stop
machine.

Much thanks to Valentin who used TLA+ most effective and found lots of
'interesting' cases.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Link: https://lkml.kernel.org/r/20201023102346.921768277@infradead.org
2020-11-10 18:39:00 +01:00
Peter Zijlstra
af449901b8 sched: Add migrate_disable()
Add the base migrate_disable() support (under protest).

While migrate_disable() is (currently) required for PREEMPT_RT, it is
also one of the biggest flaws in the system.

Notably this is just the base implementation, it is broken vs
sched_setaffinity() and hotplug, both solved in additional patches for
ease of review.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Link: https://lkml.kernel.org/r/20201023102346.818170844@infradead.org
2020-11-10 18:38:59 +01:00
Peter Zijlstra
9cfc3e18ad sched: Massage set_cpus_allowed()
Thread a u32 flags word through the *set_cpus_allowed*() callchain.
This will allow adding behavioural tweaks for future users.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Link: https://lkml.kernel.org/r/20201023102346.729082820@infradead.org
2020-11-10 18:38:59 +01:00
Peter Zijlstra
120455c514 sched: Fix hotplug vs CPU bandwidth control
Since we now migrate tasks away before DYING, we should also move
bandwidth unthrottle, otherwise we can gain tasks from unthrottle
after we expect all tasks to be gone already.

Also; it looks like the RT balancers don't respect cpu_active() and
instead rely on rq->online in part, complete this. This too requires
we do set_rq_offline() earlier to match the cpu_active() semantics.
(The bigger patch is to convert RT to cpu_active() entirely)

Since set_rq_online() is called from sched_cpu_activate(), place
set_rq_offline() in sched_cpu_deactivate().

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Link: https://lkml.kernel.org/r/20201023102346.639538965@infradead.org
2020-11-10 18:38:59 +01:00
Thomas Gleixner
1cf12e08bc sched/hotplug: Consolidate task migration on CPU unplug
With the new mechanism which kicks tasks off the outgoing CPU at the end of
schedule() the situation on an outgoing CPU right before the stopper thread
brings it down completely is:

 - All user tasks and all unbound kernel threads have either been migrated
   away or are not running and the next wakeup will move them to a online CPU.

 - All per CPU kernel threads, except cpu hotplug thread and the stopper
   thread have either been unbound or parked by the responsible CPU hotplug
   callback.

That means that at the last step before the stopper thread is invoked the
cpu hotplug thread is the last legitimate running task on the outgoing
CPU.

Add a final wait step right before the stopper thread is kicked which
ensures that any still running tasks on the way to park or on the way to
kick themself of the CPU are either sleeping or gone.

This allows to remove the migrate_tasks() crutch in sched_cpu_dying(). If
sched_cpu_dying() detects that there is still another running task aside of
the stopper thread then it will explode with the appropriate fireworks.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Link: https://lkml.kernel.org/r/20201023102346.547163969@infradead.org
2020-11-10 18:38:58 +01:00
Peter Zijlstra
06249738a4 workqueue: Manually break affinity on hotplug
Don't rely on the scheduler to force break affinity for us -- it will
stop doing that for per-cpu-kthreads.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Link: https://lkml.kernel.org/r/20201023102346.464718669@infradead.org
2020-11-10 18:38:58 +01:00
Thomas Gleixner
f2469a1fb4 sched/core: Wait for tasks being pushed away on hotplug
RT kernels need to ensure that all tasks which are not per CPU kthreads
have left the outgoing CPU to guarantee that no tasks are force migrated
within a migrate disabled section.

There is also some desire to (ab)use fine grained CPU hotplug control to
clear a CPU from active state to force migrate tasks which are not per CPU
kthreads away for power control purposes.

Add a mechanism which waits until all tasks which should leave the CPU
after the CPU active flag is cleared have moved to a different online CPU.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Link: https://lkml.kernel.org/r/20201023102346.377836842@infradead.org
2020-11-10 18:38:58 +01:00
Peter Zijlstra
2558aacff8 sched/hotplug: Ensure only per-cpu kthreads run during hotplug
In preparation for migrate_disable(), make sure only per-cpu kthreads
are allowed to run on !active CPUs.

This is ran (as one of the very first steps) from the cpu-hotplug
task which is a per-cpu kthread and completion of the hotplug
operation only requires such tasks.

This constraint enables the migrate_disable() implementation to wait
for completion of all migrate_disable regions on this CPU at hotplug
time without fear of any new ones starting.

This replaces the unlikely(rq->balance_callbacks) test at the tail of
context_switch with an unlikely(rq->balance_work), the fast path is
not affected.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Link: https://lkml.kernel.org/r/20201023102346.292709163@infradead.org
2020-11-10 18:38:57 +01:00
Peter Zijlstra
565790d28b sched: Fix balance_callback()
The intent of balance_callback() has always been to delay executing
balancing operations until the end of the current rq->lock section.
This is because balance operations must often drop rq->lock, and that
isn't safe in general.

However, as noted by Scott, there were a few holes in that scheme;
balance_callback() was called after rq->lock was dropped, which means
another CPU can interleave and touch the callback list.

Rework code to call the balance callbacks before dropping rq->lock
where possible, and otherwise splice the balance list onto a local
stack.

This guarantees that the balance list must be empty when we take
rq->lock. IOW, we'll only ever run our own balance callbacks.

Reported-by: Scott Wood <swood@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Link: https://lkml.kernel.org/r/20201023102346.203901269@infradead.org
2020-11-10 18:38:57 +01:00
Peter Zijlstra
a8b62fd085 stop_machine: Add function and caller debug info
Crashes in stop-machine are hard to connect to the calling code, add a
little something to help with that.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Link: https://lkml.kernel.org/r/20201023102346.116513635@infradead.org
2020-11-10 18:38:57 +01:00
Colin Ian King
8d4d9c7b43 sched/debug: Fix memory corruption caused by multiple small reads of flags
Reading /proc/sys/kernel/sched_domain/cpu*/domain0/flags mutliple times
with small reads causes oopses with slub corruption issues because the kfree is
free'ing an offset from a previous allocation. Fix this by adding in a new
pointer 'buf' for the allocation and kfree and use the temporary pointer tmp
to handle memory copies of the buf offsets.

Fixes: 5b9f8ff7b3 ("sched/debug: Output SD flag names rather than their values")
Reported-by: Jeff Bastian <jbastian@redhat.com>
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20201029151103.373410-1-colin.king@canonical.com
2020-11-10 18:38:49 +01:00
Vincent Guittot
b4c9c9f156 sched/fair: Prefer prev cpu in asymmetric wakeup path
During fast wakeup path, scheduler always check whether local or prev
cpus are good candidates for the task before looking for other cpus in
the domain. With commit b7a331615d ("sched/fair: Add asymmetric CPU
capacity wakeup scan") the heterogenous system gains a dedicated path
but doesn't try to reuse prev cpu whenever possible. If the previous
cpu is idle and belong to the LLC domain, we should check it 1st
before looking for another cpu because it stays one of the best
candidate and this also stabilizes task placement on the system.

This change aligns asymmetric path behavior with symmetric one and reduces
cases where the task migrates across all cpus of the sd_asym_cpucapacity
domains at wakeup.

This change does not impact normal EAS mode but only the overloaded case or
when EAS is not used.

- On hikey960 with performance governor (EAS disable)

./perf bench sched pipe -T -l 50000
             mainline           w/ patch
# migrations   999364                  0
ops/sec        149313(+/-0.28%)   182587(+/- 0.40) +22%

- On hikey with performance governor

./perf bench sched pipe -T -l 50000
             mainline           w/ patch
# migrations        0                  0
ops/sec         47721(+/-0.76%)    47899(+/- 0.56) +0.4%

According to test on hikey, the patch doesn't impact symmetric system
compared to current implementation (only tested on arm64)

Also read the uclamped value of task's utilization at most twice instead
instead each time we compare task's utilization with cpu's capacity.

Fixes: b7a331615d ("sched/fair: Add asymmetric CPU capacity wakeup scan")
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20201029161824.26389-1-vincent.guittot@linaro.org
2020-11-10 18:38:48 +01:00
Vincent Guittot
16b0a7a1a0 sched/fair: Ensure tasks spreading in LLC during LB
schbench shows latency increase for 95 percentile above since:
  commit 0b0695f2b3 ("sched/fair: Rework load_balance()")

Align the behavior of the load balancer with the wake up path, which tries
to select an idle CPU which belongs to the LLC for a waking task.

calculate_imbalance() will use nr_running instead of the spare
capacity when CPUs share resources (ie cache) at the domain level. This
will ensure a better spread of tasks on idle CPUs.

Running schbench on a hikey (8cores arm64) shows the problem:

tip/sched/core :
schbench -m 2 -t 4 -s 10000 -c 1000000 -r 10
Latency percentiles (usec)
	50.0th: 33
	75.0th: 45
	90.0th: 51
	95.0th: 4152
	*99.0th: 14288
	99.5th: 14288
	99.9th: 14288
	min=0, max=14276

tip/sched/core + patch :
schbench -m 2 -t 4 -s 10000 -c 1000000 -r 10
Latency percentiles (usec)
	50.0th: 34
	75.0th: 47
	90.0th: 52
	95.0th: 78
	*99.0th: 94
	99.5th: 94
	99.9th: 94
	min=0, max=94

Fixes: 0b0695f2b3 ("sched/fair: Rework load_balance()")
Reported-by: Chris Mason <clm@fb.com>
Suggested-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Rik van Riel <riel@surriel.com>
Tested-by: Rik van Riel <riel@surriel.com>
Link: https://lkml.kernel.org/r/20201102102457.28808-1-vincent.guittot@linaro.org
2020-11-10 18:38:48 +01:00
Boqun Feng
d61fc96a37 lockdep: Avoid to modify chain keys in validate_chain()
Chris Wilson reported a problem spotted by check_chain_key(): a chain
key got changed in validate_chain() because we modify the ->read in
validate_chain() to skip checks for dependency adding, and ->read is
taken into calculation for chain key since commit f611e8cf98
("lockdep: Take read/write status in consideration when generate
chainkey").

Fix this by avoiding to modify ->read in validate_chain() based on two
facts: a) since we now support recursive read lock detection, there is
no need to skip checks for dependency adding for recursive readers, b)
since we have a), there is only one case left (nest_lock) where we want
to skip checks in validate_chain(), we simply remove the modification
for ->read and rely on the return value of check_deadlock() to skip the
dependency adding.

Reported-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201102053743.450459-1-boqun.feng@gmail.com
2020-11-10 18:38:38 +01:00
Rafael J. Wysocki
9a2a9ebc0a cpufreq: Introduce governor flags
A new cpufreq governor flag will be added subsequently, so replace
the bool dynamic_switching fleid in struct cpufreq_governor with a
flags field and introduce CPUFREQ_GOV_DYNAMIC_SWITCHING to set for
the "dynamic switching" governors instead of it.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-11-10 18:31:17 +01:00
Will Deacon
04e613ded8 arm64: smp: Tell RCU about CPUs that fail to come online
Commit ce3d31ad3c ("arm64/smp: Move rcu_cpu_starting() earlier") ensured
that RCU is informed early about incoming CPUs that might end up calling
into printk() before they are online. However, if such a CPU fails the
early CPU feature compatibility checks in check_local_cpu_capabilities(),
then it will be powered off or parked without informing RCU, leading to
an endless stream of stalls:

  | rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
  | rcu:	2-O...: (0 ticks this GP) idle=002/1/0x4000000000000000 softirq=0/0 fqs=2593
  | (detected by 0, t=5252 jiffies, g=9317, q=136)
  | Task dump for CPU 2:
  | task:swapper/2       state:R  running task     stack:    0 pid:    0 ppid:     1 flags:0x00000028
  | Call trace:
  | ret_from_fork+0x0/0x30

Ensure that the dying CPU invokes rcu_report_dead() prior to being powered
off or parked.

Cc: Qian Cai <cai@redhat.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Suggested-by: Qian Cai <cai@redhat.com>
Link: https://lore.kernel.org/r/20201105222242.GA8842@willie-the-truck
Link: https://lore.kernel.org/r/20201106103602.9849-3-will@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2020-11-10 13:11:44 +00:00
Peng Wang
b6d37a764a sched/fair: Reorder throttle_cfs_rq() path
As commit:

  39f23ce07b ("sched/fair: Fix unthrottle_cfs_rq() for leaf_cfs_rq list")

does in unthrottle_cfs_rq(), throttle_cfs_rq() can also use the same
pattern as dequeue_task_fair().

No functional changes.

Signed-off-by: Peng Wang <rocking@linux.alibaba.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Phil Auld <pauld@redhat.com>
Cc: Ben Segall <bsegall@google.com>
Link: https://lore.kernel.org/r/f11dd2e3ab35cc538e2eb57bf0c99b6eaffce127.1604973978.git.rocking@linux.alibaba.com
2020-11-10 12:20:12 +01:00
Wang Qing
666475ccbf bpf, btf: Remove the duplicate btf_ids.h include
Remove duplicate btf_ids.h header which is included twice.

Signed-off-by: Wang Qing <wangqing@vivo.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/1604736650-11197-1-git-send-email-wangqing@vivo.com
2020-11-10 00:05:18 +01:00
Wang Qing
abbaa433de bpf: Fix passing zero to PTR_ERR() in bpf_btf_printf_prepare
There is a bug when passing zero to PTR_ERR() and return.
Fix the smatch error.

Fixes: c4d0bfb450 ("bpf: Add bpf_snprintf_btf helper")
Signed-off-by: Wang Qing <wangqing@vivo.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/1604735144-686-1-git-send-email-wangqing@vivo.com
2020-11-09 22:37:19 +01:00
Peter Zijlstra
1908dc9117 perf: Tweak perf_event_attr::exclusive semantics
Currently perf_event_attr::exclusive can be used to ensure an
event(group) is the sole group scheduled on the PMU. One consequence
is that when you have a pinned event (say the watchdog) you can no
longer have regular exclusive event(group)s.

Inspired by the fact that !pinned events are considered less strict,
allow !pinned,exclusive events to share the PMU with pinned,!exclusive
events.

Pinned,exclusive is still fully exclusive.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201029162902.105962225@infradead.org
2020-11-09 18:12:36 +01:00
Peter Zijlstra
2714c3962f perf: Fix event multiplexing for exclusive groups
Commit 9e6302056f ("perf: Use hrtimers for event multiplexing")
placed the hrtimer (re)start call in the wrong place.  Instead of
capturing all scheduling failures, it only considered the PMU failure.

The result is that groups using perf_event_attr::exclusive are no
longer rotated.

Fixes: 9e6302056f ("perf: Use hrtimers for event multiplexing")
Reported-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201029162902.038667689@infradead.org
2020-11-09 18:12:36 +01:00
Peter Zijlstra
251ff2d493 perf: Simplify group_sched_in()
Collate the error paths. Code duplication only leads to divergence and
extra bugs.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201029162901.972161394@infradead.org
2020-11-09 18:12:35 +01:00
Peter Zijlstra
8c7855d829 perf: Simplify group_sched_out()
Since event_sched_out() clears cpuctx->exclusive upon removal of an
exclusive event (and only group leaders can be exclusive), there is no
point in group_sched_out() trying to do it too. It is impossible for
cpuctx->exclusive to still be set here.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201029162901.904060564@infradead.org
2020-11-09 18:12:35 +01:00
Peter Zijlstra
76a4efa809 perf/arch: Remove perf_sample_data::regs_user_copy
struct perf_sample_data lives on-stack, we should be careful about it's
size. Furthermore, the pt_regs copy in there is only because x86_64 is a
trainwreck, solve it differently.

Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Steven Rostedt <rostedt@goodmis.org>
Link: https://lkml.kernel.org/r/20201030151955.258178461@infradead.org
2020-11-09 18:12:34 +01:00
Peter Zijlstra
09da9c8125 perf: Optimize get_recursion_context()
"Look ma, no branches!"

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Link: https://lkml.kernel.org/r/20201030151955.187580298@infradead.org
2020-11-09 18:12:34 +01:00
Peter Zijlstra
ce0f17fc93 perf: Fix get_recursion_context()
One should use in_serving_softirq() to detect SoftIRQ context.

Fixes: 96f6d44443 ("perf_counter: avoid recursion")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201030151955.120572175@infradead.org
2020-11-09 18:12:34 +01:00
Peter Zijlstra
267fb27352 perf: Reduce stack usage of perf_output_begin()
__perf_output_begin() has an on-stack struct perf_sample_data in the
unlikely case it needs to generate a LOST record. However, every call
to perf_output_begin() must already have a perf_sample_data on-stack.

Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201030151954.985416146@infradead.org
2020-11-09 18:12:33 +01:00
Jens Axboe
29701d69b9 Core changes to support TASK_NOTIFY_SIGNAL
-----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAl+pR0MTHHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYoSWpD/93kyOy0L7NkIELgM6/OHipjsLC6K12
 jMXifA5DfmIIm31sLLzLk08YPz4TOJU+lZKn1DGdqYLioMvvsJe3uZP/WQVyV81z
 QnqdwOpdJVxq7JIjQW04eaVDWjXmxFGmbjKq/tbGexph0hckOtUq/7JOEukzgbLX
 q5iZqYgFouU/G5HIW5Um21WiEVmzzjTFMp13zbqo3rMrG9vXIb5JQxm+TkBbx2P7
 u2kS8R3OFScQcH6UyhaFBBmNFyUHtfbMKPESnhVSXUggQ0aVhNi6pjylE2ZaEIB+
 d7C/yNGNwlC7rGPlh49W5gH5rogrX2Ft2YVrHf645q3Sj/GhbXZ1NqT4f1DJt5uM
 tKjKFxJv6g1dT7ejlUQmseAtLI4ue2wj3C0qtPeHOnUlPHlaDlkTLE2oaCh97Mgn
 mDpAZVnMOcLMRuBFt1J+fnoYcBHwXlfT1rAj//U6m6Pi5BbwIVwTsok5Vsysms4L
 Tyx31zXee3XTp8FEWRL9gqH0b5zXxEUuHxZkqu4vdQDf+wkTi08Q4FpGnhaxGBrY
 CHTwm42hmOK80hdQ6Vv4O38LkQcaEpTztVRexP7a89Q3zxmGlL5BsWGqIIoai0Fg
 8UWmHvauG3kqAif6giWv3QNQ5v0rWksHNxU1yK0tRT6s03no3Kz1eoHHLar8+hoU
 8+/AY23fcJookg==
 =SPWC
 -----END PGP SIGNATURE-----

Merge tag 'core-entry-notify-signal' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into tif-task_work.arch

Core changes to support TASK_NOTIFY_SIGNAL

* tag 'core-entry-notify-signal' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  task_work: Use TIF_NOTIFY_SIGNAL if available
  entry: Add support for TIF_NOTIFY_SIGNAL
  signal: Add task_sigpending() helper
2020-11-09 07:19:32 -07:00
Dan Carpenter
1e106aa350 futex: Don't enable IRQs unconditionally in put_pi_state()
The exit_pi_state_list() function calls put_pi_state() with IRQs disabled
and is not expecting that IRQs will be enabled inside the function.

Use the _irqsave() variant so that IRQs are restored to the original state
instead of being enabled unconditionally.

Fixes: 153fbd1226 ("futex: Fix more put_pi_state() vs. exit_pi_state_list() races")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20201106085205.GA1159983@mwanda
2020-11-09 14:30:30 +01:00
Sergey Shtylyov
24b9f0d220 module: fix comment style
Many comments in this module do not comply with the preferred multi-line
comment style as reported by 'scripts/checkpatch.pl':

WARNING: Block comments use * on subsequent lines
WARNING: Block comments use a trailing */ on a separate line

Fix those comments, along with (unreported for some reason?) the starts
of the multi-line comments not being /* on their own line...

Signed-off-by: Sergey Shtylyov <s.shtylyov@omprussia.ru>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
2020-11-09 14:28:12 +01:00
Sergey Shtylyov
2541743e99 module: add more 'kernel-doc' comments
Some functions have the proper 'kernel-doc' comments but these don't start
with proper /** -- fix that, along with adding () to the function name on
the following lines to fully comply with the 'kernel-doc' format.

Signed-off-by: Sergey Shtylyov <s.shtylyov@omprussia.ru>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
2020-11-09 13:47:42 +01:00
Sergey Shtylyov
24389b610b module: fix up 'kernel-doc' comments
Some 'kernel-doc' function comments do not fully comply with the specified
format due to:

- missing () after the function name;

- "RETURNS:"/"Returns:" instead of "Return:" when documenting the function's
  result.

- empty line before describing the function's arguments.

Signed-off-by: Sergey Shtylyov <s.shtylyov@omprussia.ru>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
2020-11-09 13:46:58 +01:00
Eddy Wu
b4e00444ca fork: fix copy_process(CLONE_PARENT) race with the exiting ->real_parent
current->group_leader->exit_signal may change during copy_process() if
current->real_parent exits.

Move the assignment inside tasklist_lock to avoid the race.

Signed-off-by: Eddy Wu <eddy_wu@trendmicro.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-11-08 11:18:39 -08:00
Linus Torvalds
100e38914a A single fix for the perf core plugging a memory leak in the address filter
parser.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAl+oC4ATHHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYoXveD/4mIAq1umSj/YdThj65S6nAHjhW1MjO
 VxGRNSEiUxOld6OnxZlyup1q4NvyYB1cVk71jLjdBIvEK/ANdq3Cd+PVB5tAAoNK
 726zrPlOXx4NJulq2q17ygazZQgOtl/5QsYovS0PymCyyvwfz56yr/OfPRThCe+S
 gJZs+zt8uunhEKz1J7lki/vn7D6bHRdaL8yTLabsPIQ296WXrUd2NS4fuanFNyLO
 kxETMAECyy77q17dgClFFDheyLHAotoySLm6qSwNeWUPFwlCmoCbHgzSBoryIlH5
 DMlwA5iuA5qVv/4jlZ0+WvVWeSWOyF0boZ1cZI+r4nitVvdwnnxTgXcyuTxDSggu
 nygQqLlTIQ31dwQleAfKrooJfwk9nB5uLEQkTwdx0BQwdHhvb7usnNEcIMx8WVFf
 86LorPlfbKrUTD7PWj7zg3x32GNv/nWjuDnzD0NW6BPKqVy6XaRZtaG2WyYfB9YW
 9KXpfsxjDeTBrZK5b/YOna1ah00J+2hwIL7sUhVf24aOmmImy3+Yqe2bQOlR/JGs
 yIBFOAPCWrl7AJOwziMD2NQGCTzk9hqKRyhy1WtPC/L0uohf16/xbnViyL1Ijhud
 Hzu09qoo8EXYbSwRcHQ+qK39s9fwDK1yvPp+k4XGXS/v94YN0W5rd3o49bTMvhxE
 T8CKfwngsBzeYg==
 =r2wz
 -----END PGP SIGNATURE-----

Merge tag 'perf-urgent-2020-11-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf fix from Thomas Gleixner:
 "A single fix for the perf core plugging a memory leak in the address
  filter parser"

* tag 'perf-urgent-2020-11-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Fix a memory leak in perf_event_parse_addr_filter()
2020-11-08 10:05:10 -08:00
Linus Torvalds
aaaaa7ecdc A single fix for the futex code where an intermediate state in the
underlying RT mutex was not handled correctly and triggering a BUG()
 instead of treating it as another variant of retry condition.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAl+oCqcTHHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYoUSvD/kBBV+cSHoLZqWzoYCySxnIgTX5xLgH
 imdhBnGX4MZsHydD1zu9IKuHbOTdRdnf/aXk+6akqyRTqtAxqL3e1BW7zfX2aWo/
 EOk5P36ZLzdqqLrc4Z/FZOLaUAx95t2dse0PA3jXOUTHaxr/bwih+/f1vR84xFBG
 /Sv1TubPLU7koZI057SrZsHmhF7yc22BMvg30UFUgx8tZyXGBIUEYOYS6sgGBwQe
 qXIxTHkpiRwCHu+i44QJiBdhPg8gEb4tsJQLlnmhPYz4m5v/w4HGe7ixZlBQU7f1
 isY4GEuDHRRheOzvP0d5LgcRx6r1hNDDu8MWNjWp7N1sTTKMGnDnZ/a36TgBtlvc
 Go+HVNCapfhSeul8qjZuL022a9Yv2NcsouwdPWfZpMyWuhkXYWnaVHWvuEKsB4UZ
 z0b34q5pULwSz/R4BiqwoLZXdWNsN8x/C31F3v0jBNa/HwK5dTEAgeez0+HNJhDA
 Ci/+CgggLuch6V6JYwOT1AEB4ymEXTuRK/d8IwlVADA3fN0wulUUAnbgVYHRWD4y
 JaXJKWHnw/G8R7AI31aVHa70D64tAM+0UdsLM+4/idP2kc2Cv7EcCdIHz2OUfQBD
 I1/RmugdCPsF5Zutb0dQFNumzxRGk6l+woa7EFnzpkO96GBJDCQiUZKvTFINdCh0
 LoLv49vOBVDifQ==
 =PX5t
 -----END PGP SIGNATURE-----

Merge tag 'locking-urgent-2020-11-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull futex fix from Thomas Gleixner:
 "A single fix for the futex code where an intermediate state in the
  underlying RT mutex was not handled correctly and triggering a BUG()
  instead of treating it as another variant of retry condition"

* tag 'locking-urgent-2020-11-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  futex: Handle transient "ownerless" rtmutex state correctly
2020-11-08 09:56:37 -08:00
Linus Torvalds
15a9844458 A set of fixes for interrupt chip drivers:
- Fix the fallout of the IPI as interrupt conversion in Kconfig and the
    BCM2836 interrupt chip driver/
 
  - Fixes for interrupt affinity setting and the handling of hierarchical
    irq domains in the SiFive PLIC driver.
 
  - Make the unmapped event handling in the TI SCI driver work correctly.
 
  - A few minor fixes and cleanups in various chip drivers and Kconfig.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAl+oCiATHHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYoUIkEAC9wYn4x5fObSRpamwj0lagGkUsd0dB
 JmKW+u/oUkhM1ZosqPegslA6RDc7LitONFcnqBD348JBrxyP94OnskhBWITv9Nx1
 p4AkLS7HDs0pgOpam66qJdxAmLZ0F0vOPnEgr2VQWqaRV8qlTESNiCxT2wKF7mRd
 qJn5pW3kSJnyfA66cpFVC3Db64KmdWQvv0BCnc1Wqq3odXgOuTvOkqzVrlqJZQ59
 RrZudU0Lz9FtUujQ7AuP+RZY7Ti/AjmEaZDvcsnz3SR6vZGV8qG1f/88RP31d4qK
 62cIOfz/bsl1uxAwnKGM4U84tzYua6djhRZXInlzL4/iYKlm5qVR8Qpotl7IxT5n
 ntMJGhu/Evy987mq1maOR2rWyqVNU5BoVJUeHHibP8LANTKf7sdWOaNqieXQRKYS
 ZnTmoRImBOFhxi0BuqKwwHqJILC4yOZpOa+ARMPqns2KzA4jpAvN+MwPWwpsBVaD
 giVm8e8CQvFgMQjjRHcOkfernSsQs/fyQSYQY9qJI/IzVqTEFcYUONneelJGFB7R
 iDFMURx7aQUPNf8p9c7eEx0BSBUBan+Quul4HQ1I+SnmOZg3QgRvlMm/zPxhnfyU
 3NV4oi4c/fG+7ex+tR3igcfYPCK35BP+6iDG+GKTBjAHimQqk9XXsDYN/Wh3nW6f
 UnsJIs9zdhPJsA==
 =HUPi
 -----END PGP SIGNATURE-----

Merge tag 'irq-urgent-2020-11-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull irq fixes from Thomas Gleixner:
 "A set of fixes for interrupt chip drivers:

   - Fix the fallout of the IPI as interrupt conversion in Kconfig and
     the BCM2836 interrupt chip driver

   - Fixes for interrupt affinity setting and the handling of
     hierarchical irq domains in the SiFive PLIC driver

   - Make the unmapped event handling in the TI SCI driver work
     correctly

   - A few minor fixes and cleanups in various chip drivers and Kconfig"

* tag 'irq-urgent-2020-11-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  dt-bindings: irqchip: ti, sci-inta: Fix diagram indentation for unmapped events
  irqchip/ti-sci-inta: Add support for unmapped event handling
  dt-bindings: irqchip: ti, sci-inta: Update for unmapped event handling
  irqchip/renesas-intc-irqpin: Merge irlm_bit and needs_irlm
  irqchip/sifive-plic: Fix chip_data access within a hierarchy
  irqchip/sifive-plic: Fix broken irq_set_affinity() callback
  irqchip/stm32-exti: Add all LP timer exti direct events support
  irqchip/bcm2836: Fix missing __init annotation
  irqchip/mips: Drop selection of IRQ_DOMAIN_HIERARCHY
  irqchip/mst: Make mst_intc_of_init static
  irqchip/mst: MST_IRQ should depend on ARCH_MEDIATEK or ARCH_MSTARV7
  genirq: Let GENERIC_IRQ_IPI select IRQ_DOMAIN_HIERARCHY
2020-11-08 09:52:57 -08:00
Linus Torvalds
6a8d0d283d A single fix for the generic entry code to correct the wrong assumption
that the lockdep interrupt state needs not to be established before calling
 the RCU check.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAl+oCN8THHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYoYgDD/42A/CTltvs1meUm8gpCbACe/mwY4Ms
 4K35p9E/3ozyhjkXbP1odZ6I/rh1pKZYz+qxS7JYDEDgl+3ZfZCeb8WFNspBRvD1
 uURn3ou5aVFHGutjF/5yEzrHP+Vkw8ViOvIjhZ1zpPQ0kWyEP7P5K+0wPFV1BVda
 ugk6T0ouQo7Kl7c7g/EP9tr9UNorih9ZmkJcsZ7fkzDin+5Ine6v9J1VRumSkm11
 4OU7My/c/0EpTuslnW4w4kVYk90B+o6dJccG5SVJVrRHvziD3qhM3slI2UqnIIb+
 /8NTrUy79mikZQh6LG5QrPoX9/+tp68csoFwzE6MpVvV+GTlfnbX7xn2ZW0t7ZSA
 FVYUxYSO3kCzvU2VfqzLc8HtgK/esoMpcgloB0FM9XDw2khlgvnJyTCAnsn44QIP
 tIA+FHGv9oa+QW5NoiRpBtTAYImTfiwaTa5AXCBFijHXsJVMziWDqZ+AQwf58LP9
 RjItnOu0ZKzvLHRYDfqpusIUytFv04YuAn2kJ1vDWL4nXeo3vma2at+s/zbPHOjW
 LZDUeavv7e5pqMDFC1QDja4o5fSfK0Q7ddVP8Xm1yrnZz5jPmQNCGpLxZWx8wsjq
 qxPEUdfqTFvRJQhLHkVznuQUrOVYPVlZfoPro47HNHeHs+qLI1QxmsJHhRu2vd1M
 PwVVBz1vvk4Txg==
 =ZSdr
 -----END PGP SIGNATURE-----

Merge tag 'core-urgent-2020-11-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull entry code fix from Thomas Gleixner:
 "A single fix for the generic entry code to correct the wrong
  assumption that the lockdep interrupt state needs not to be
  established before calling the RCU check"

* tag 'core-urgent-2020-11-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  entry: Fix the incorrect ordering of lockdep and RCU check
2020-11-08 09:51:28 -08:00
Mike Galbraith
9f5d1c336a futex: Handle transient "ownerless" rtmutex state correctly
Gratian managed to trigger the BUG_ON(!newowner) in fixup_pi_state_owner().
This is one possible chain of events leading to this:

Task Prio       Operation
T1   120	lock(F)
T2   120	lock(F)   -> blocks (top waiter)
T3   50 (RT)	lock(F)   -> boosts T1 and blocks (new top waiter)
XX   		timeout/  -> wakes T2
		signal
T1   50		unlock(F) -> wakes T3 (rtmutex->owner == NULL, waiter bit is set)
T2   120	cleanup   -> try_to_take_mutex() fails because T3 is the top waiter
     			     and the lower priority T2 cannot steal the lock.
     			  -> fixup_pi_state_owner() sees newowner == NULL -> BUG_ON()

The comment states that this is invalid and rt_mutex_real_owner() must
return a non NULL owner when the trylock failed, but in case of a queued
and woken up waiter rt_mutex_real_owner() == NULL is a valid transient
state. The higher priority waiter has simply not yet managed to take over
the rtmutex.

The BUG_ON() is therefore wrong and this is just another retry condition in
fixup_pi_state_owner().

Drop the locks, so that T3 can make progress, and then try the fixup again.

Gratian provided a great analysis, traces and a reproducer. The analysis is
to the point, but it confused the hell out of that tglx dude who had to
page in all the futex horrors again. Condensed version is above.

[ tglx: Wrote comment and changelog ]

Fixes: c1e2f0eaf0 ("futex: Avoid violating the 10th rule of futex")
Reported-by: Gratian Crisan <gratian.crisan@ni.com>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/87a6w6x7bb.fsf@ni.com
Link: https://lore.kernel.org/r/87sg9pkvf7.fsf@nanos.tec.linutronix.de
2020-11-07 22:07:04 +01:00
Ingo Molnar
666fab4a3e Merge branch 'linus' into perf/kprobes
Conflicts:
	include/asm-generic/atomic-instrumented.h
	kernel/kprobes.c

Use the upstream atomic-instrumented.h checksum, and pick
the kprobes version of kernel/kprobes.c, which effectively
reverts this upstream workaround:

  645f224e7b: ("kprobes: Tell lockdep about kprobe nesting")

Since the new code *should* be fine without nesting.

Knock on wood ...

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-11-07 13:20:17 +01:00
Ingo Molnar
0a986ea81e Merge branch 'linus' into perf/kprobes
Merge recent kprobes updates into perf/kprobes that came from -mm.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-11-07 13:18:49 +01:00
kiyin(尹亮)
7bdb157cde perf/core: Fix a memory leak in perf_event_parse_addr_filter()
As shown through runtime testing, the "filename" allocation is not
always freed in perf_event_parse_addr_filter().

There are three possible ways that this could happen:

 - It could be allocated twice on subsequent iterations through the loop,
 - or leaked on the success path,
 - or on the failure path.

Clean up the code flow to make it obvious that 'filename' is always
freed in the reallocation path and in the two return paths as well.

We rely on the fact that kfree(NULL) is NOP and filename is initialized
with NULL.

This fixes the leak. No other side effects expected.

[ Dan Carpenter: cleaned up the code flow & added a changelog. ]
[ Ingo Molnar: updated the changelog some more. ]

Fixes: 375637bc52 ("perf/core: Introduce address range filtering")
Signed-off-by: "kiyin(尹亮)" <kiyin@tencent.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: "Srivatsa S. Bhat" <srivatsa@csail.mit.edu>
Cc: Anthony Liguori <aliguori@amazon.com>
--
 kernel/events/core.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)
2020-11-07 13:07:26 +01:00
Andy Shevchenko
b6e95788fd irqdomain: Introduce irq_domain_create_legacy() API
Introduce irq_domain_create_legacy() API which is functional equivalent
to the existing irq_domain_add_legacy(), but takes a pointer to the struct
fwnode_handle as a parameter.

This is useful for non OF systems.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20201030165919.86234-5-andriy.shevchenko@linux.intel.com
2020-11-07 11:33:46 +01:00
Andy Shevchenko
c3a877fea9 irqdomain: Replace open coded of_node_to_fwnode()
of_node_to_fwnode() should be used for conversion.  Replace the open coded
variant of it in of_phandle_args_to_fwspec().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20201030165919.86234-4-andriy.shevchenko@linux.intel.com
2020-11-07 11:33:45 +01:00
Jakub Kicinski
86bbf01977 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Alexei Starovoitov says:

====================
pull-request: bpf 2020-11-06

1) Pre-allocated per-cpu hashmap needs to zero-fill reused element, from David.

2) Tighten bpf_lsm function check, from KP.

3) Fix bpftool attaching to flow dissector, from Lorenz.

4) Use -fno-gcse for the whole kernel/bpf/core.c instead of function attribute, from Ard.

* git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  bpf: Update verification logic for LSM programs
  bpf: Zero-fill re-used per-cpu map element
  bpf: BPF_PRELOAD depends on BPF_SYSCALL
  tools/bpftool: Fix attaching flow dissector
  libbpf: Fix possible use after free in xsk_socket__delete
  libbpf: Fix null dereference in xsk_socket__delete
  libbpf, hashmap: Fix undefined behavior in hash_bits
  bpf: Don't rely on GCC __attribute__((optimize)) to disable GCSE
  tools, bpftool: Remove two unused variables.
  tools, bpftool: Avoid array index warnings.
  xsk: Fix possible memory leak at socket close
  bpf: Add struct bpf_redir_neigh forward declaration to BPF helper defs
  samples/bpf: Set rlimit for memlock to infinity in all samples
  bpf: Fix -Wshadow warnings
  selftest/bpf: Fix profiler test using CO-RE relocation for enums
====================

Link: https://lore.kernel.org/r/20201106221759.24143-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-06 17:49:34 -08:00
Jakub Kicinski
ae0d0bb29b Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-06 17:33:38 -08:00
Marco Elver
1d094cefc3 kcsan: Fix encoding masks and regain address bit
The watchpoint encoding masks for size and address were off-by-one bit
each, with the size mask using 1 unnecessary bit and the address mask
missing 1 bit. However, due to the way the size is shifted into the
encoded watchpoint, we were effectively wasting and never using the
extra bit.

For example, on x86 with PAGE_SIZE==4K, we have 1 bit for the is-write
bit, 14 bits for the size bits, and then 49 bits left for the address.
Prior to this fix we would end up with this usage:

	[ write<1> | size<14> | wasted<1> | address<48> ]

Fix it by subtracting 1 bit from the GENMASK() end and start ranges of
size and address respectively. The added static_assert()s verify that
the masks are as expected. With the fixed version, we get the expected
usage:

	[ write<1> | size<14> |             address<49> ]

Functionally no change is expected, since that extra address bit is
insignificant for enabled architectures.

Acked-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-06 17:19:26 -08:00
Paul E. McKenney
75dc2da5ec rcu-tasks: Make the units of ->init_fract be jiffies
Currently, the units of ->init_fract are milliseconds while those of
->gp_sleep are jiffies.  For consistency with each other and with the
argument of schedule_timeout_idle(), this commit changes the units of
->init_fract to jiffies.

This change does affect the backoff algorithm, but only on systems where
HZ is not 1000, and even there the change makes more sense, given that the
current setup would "back off" to the same number of jiffies repeatedly.
In contrast, with this change, the number of jiffies waited increases
on each pass through the loop in the rcu_tasks_wait_gp() function.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-06 17:17:59 -08:00
Paul E. McKenney
a7eb937b67 rcutorture: Don't do need_resched() testing if ->sync is NULL
If cur_ops->sync is NULL, rcu_torture_fwd_prog_nr() will nevertheless
attempt to call through it.  This commit therefore flags cases where
neither need_resched() nor call_rcu() forward-progress testing
can be performed due to NULL function pointers, and also causes
rcu_torture_fwd_prog_nr() to take an early exit if cur_ops->sync()
is NULL.

Reported-by: Tom Rix <trix@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-06 17:13:57 -08:00
Hou Tao
0d7202876b locktorture: Invoke percpu_free_rwsem() to do percpu-rwsem cleanup
When executing the LOCK06 locktorture scenario featuring percpu-rwsem,
the RCU callback rcu_sync_func() may still be pending after locktorture
module is removed.  This can in turn lead to the following Oops:

  BUG: unable to handle page fault for address: ffffffffc00eb920
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 6500a067 P4D 6500a067 PUD 6500c067 PMD 13a36c067 PTE 800000013691c163
  Oops: 0000 [#1] PREEMPT SMP
  CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.9.0-rc5+ #4
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
  RIP: 0010:rcu_cblist_dequeue+0x12/0x30
  Call Trace:
   <IRQ>
   rcu_core+0x1b1/0x860
   __do_softirq+0xfe/0x326
   asm_call_on_stack+0x12/0x20
   </IRQ>
   do_softirq_own_stack+0x5f/0x80
   irq_exit_rcu+0xaf/0xc0
   sysvec_apic_timer_interrupt+0x2e/0xb0
   asm_sysvec_apic_timer_interrupt+0x12/0x20

This commit avoids tis problem by adding an exit hook in lock_torture_ops
and using it to call percpu_free_rwsem() for percpu rwsem torture during
the module-cleanup function, thus ensuring that rcu_sync_func() completes
before module exits.

It is also necessary to call the exit hook if lock_torture_init()
fails half-way, so this commit also adds an ->init_called field in
lock_torture_cxt to indicate that exit hook, if present, must be called.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-06 17:13:56 -08:00
Paul E. McKenney
85558182d5 scftorture: Add full-test stutter capability
In virtual environments on systems with hardware assist, inter-processor
interrupts must do very different things based on whether the target
vCPU is running or not.  This commit therefore enables torture-test
stuttering to better test these running/not-running transitions.

Suggested-by: Chris Mason <clm@fb.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-06 17:13:56 -08:00
Paul E. McKenney
293b93d66f rcutorture: Small code cleanups
The rcu_torture_cleanup() function fails to NULL out the reader_tasks
pointer after freeing it and its fakewriter_tasks loop has redundant
braces.  This commit therefore cleans these up.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-06 17:13:55 -08:00
Paul E. McKenney
ab1b7880de rcutorture: Make stutter_wait() caller restore priority
Currently, stutter_wait() will happily spin waiting for the stutter
interval to end even if the caller is running at a real-time priority
level.  This could starve normal-priority tasks for no good reason.  This
commit therefore drops the calling task's priority to SCHED_OTHER MAX_NICE
if stutter_wait() needs to wait.  But when it waits, stutter_wait()
returns true, which allows the caller to restore the priority if needed.
Callers that were already running at SCHED_OTHER MAX_NICE obviously
do not need any changes, but this commit also restores priority for
higher-priority callers.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-06 17:13:54 -08:00
Paul E. McKenney
4994684ce1 rcutorture: Prevent hangs for invalid arguments
If an rcutorture torture-test run is given a bad kvm.sh argument, the
test will complain to the console, which is good.  What is bad is that
from the user's perspective, it will just hang for the time specified
by the --duration argument.  This commit therefore forces an immediate
kernel shutdown if a rcu_torture_init()-time error occurs, thus avoiding
the appearance of a hang.  It also forces a console splat in this case
to clearly indicate the presence of an error.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-06 17:13:53 -08:00
Paul E. McKenney
6b74fa0a77 locktorture: Prevent hangs for invalid arguments
If an locktorture torture-test run is given a bad kvm.sh argument, the
test will complain to the console, which is good.  What is bad is that
from the user's perspective, it will just hang for the time specified
by the --duration argument.  This commit therefore forces an immediate
kernel shutdown if a lock_torture_init()-time error occurs, thus avoiding
the appearance of a hang.  It also forces a console splat in this case
to clearly indicate the presence of an error.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-06 17:13:53 -08:00
Hou Tao
e5ace37d83 locktorture: Ignore nreaders_stress if no readlock support
Exclusive locks do not have readlock support, which means that a
locktorture run with the following module parameters will do nothing:

 torture_type=mutex_lock nwriters_stress=0 nreaders_stress=1

This commit therefore rejects this combination for exclusive locks by
returning -EINVAL during module init.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-06 17:13:52 -08:00
Paul E. McKenney
bc80d353b3 refscale: Prevent hangs for invalid arguments
If an refscale torture-test run is given a bad kvm.sh argument, the
test will complain to the console, which is good.  What is bad is that
from the user's perspective, it will just hang for the time specified
by the --duration argument.  This commit therefore forces an immediate
kernel shutdown if a ref_scale_init()-time error occurs, thus avoiding
the appearance of a hang.  It also forces a console splat in this case
to clearly indicate the presence of an error.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-06 17:13:51 -08:00
Paul E. McKenney
2f2214d43c rcuscale: Prevent hangs for invalid arguments
If an rcuscale torture-test run is given a bad kvm.sh argument, the
test will complain to the console, which is good.  What is bad is that
from the user's perspective, it will just hang for the time specified
by the --duration argument.  This commit therefore forces an immediate
kernel shutdown if a rcu_scale_init()-time error occurs, thus avoiding
the appearance of a hang.  It also forces a console splat in this case
to clearly indicate the presence of an error.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-06 17:13:51 -08:00
Paul E. McKenney
899f317e48 rcuscale: Add RCU Tasks Trace
This commit adds the ability to test performance and scalability of RCU
Tasks Trace updaters.

Reported-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-06 17:13:50 -08:00
Paul E. McKenney
1ac78b49d6 scftorture: Add an alternative IPI vector
The scftorture tests currently use only smp_call_function() and
friends, which means that these tests cannot locate bugs caused by
interactions between different IPI vectors.  This commit therefore adds
the rescheduling IPI to the mix.

Note that this commit permits resched_cpus() only when scftorture is
built in.  This is a workaround.  Longer term, this will use real wakeups
rather than resched_cpu().

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-06 17:13:49 -08:00
Paul E. McKenney
fda5ba9ed2 torture: Make torture_stutter() use hrtimer
The torture_stutter() function uses schedule_timeout_interruptible()
to time the stutter duration, but this can miss race conditions due to
its being time-synchronized with everything else that is based on the
timer wheels.  This commit therefore converts torture_stutter() to use
the high-resolution timers via schedule_hrtimeout(), and also to fuzz
the stutter interval.  While in the area, this commit also limits the
spin-loop portion of the stutter_wait() function's wait loop to two
jiffies, down from about one second.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-06 17:13:49 -08:00
Paul E. McKenney
19012b786e torture: Periodically pause in stutter_wait()
Running locktorture scenario LOCK05 results in hangs:

tools/testing/selftests/rcutorture/bin/kvm.sh --allcpus --torture lock --duration 3 --configs LOCK05

The lock_torture_writer() kthreads set themselves to MAX_NICE while
running SCHED_OTHER.  Other locktorture kthreads run at default niceness,
also SCHED_OTHER.  This results in these other locktorture kthreads
indefinitely preempting the lock_torture_writer() kthreads.  Note that
the cond_resched() in the stutter_wait() function's loop is ineffective
because this scenario is built with CONFIG_PREEMPT=y.

It is not clear that such indefinite preemption is supposed to happen, but
in the meantime this commit prevents kthreads running in stutter_wait()
from being completely CPU-bound, thus allowing the other threads to get
some CPU in a timely fashion.  This commit also uses hrtimers to provide
very short sleeps to avoid degrading the sudden-on testing that stutter
is supposed to provide.

Reviewed-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-06 17:13:48 -08:00
Paul E. McKenney
3480d6774f locktorture: Track time of last ->writeunlock()
This commit adds a last_lock_release variable that tracks the time of
the last ->writeunlock() call, which allows easier diagnosing of lock
hangs when using a kernel debugger.

Acked-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-06 17:13:29 -08:00
Paul E. McKenney
3fcd6a230f x86/cpu: Avoid cpuinfo-induced IPIing of idle CPUs
Currently, accessing /proc/cpuinfo sends IPIs to idle CPUs in order to
learn their clock frequency.  Which is a bit strange, given that waking
them from idle likely significantly changes their clock frequency.
This commit therefore avoids sending /proc/cpuinfo-induced IPIs to
idle CPUs.

[ paulmck: Also check for idle in arch_freq_prepare_all(). ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <x86@kernel.org>
2020-11-06 16:59:11 -08:00
KP Singh
6f64e47783 bpf: Update verification logic for LSM programs
The current logic checks if the name of the BTF type passed in
attach_btf_id starts with "bpf_lsm_", this is not sufficient as it also
allows attachment to non-LSM hooks like the very function that performs
this check, i.e. bpf_lsm_verify_prog.

In order to ensure that this verification logic allows attachment to
only LSM hooks, the LSM_HOOK definitions in lsm_hook_defs.h are used to
generate a BTF_ID set. Upon verification, the attach_btf_id of the
program being attached is checked for presence in this set.

Fixes: 9e4e01dfd3 ("bpf: lsm: Implement attach, detach and execution")
Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201105230651.2621917-1-kpsingh@chromium.org
2020-11-06 13:15:21 -08:00
KP Singh
3ca1032ab7 bpf: Implement get_current_task_btf and RET_PTR_TO_BTF_ID
The currently available bpf_get_current_task returns an unsigned integer
which can be used along with BPF_CORE_READ to read data from
the task_struct but still cannot be used as an input argument to a
helper that accepts an ARG_PTR_TO_BTF_ID of type task_struct.

In order to implement this helper a new return type, RET_PTR_TO_BTF_ID,
is added. This is similar to RET_PTR_TO_BTF_ID_OR_NULL but does not
require checking the nullness of returned pointer.

Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20201106103747.2780972-6-kpsingh@chromium.org
2020-11-06 08:08:37 -08:00
KP Singh
4cf1bc1f10 bpf: Implement task local storage
Similar to bpf_local_storage for sockets and inodes add local storage
for task_struct.

The life-cycle of storage is managed with the life-cycle of the
task_struct.  i.e. the storage is destroyed along with the owning task
with a callback to the bpf_task_storage_free from the task_free LSM
hook.

The BPF LSM allocates an __rcu pointer to the bpf_local_storage in
the security blob which are now stackable and can co-exist with other
LSMs.

The userspace map operations can be done by using a pid fd as a key
passed to the lookup, update and delete operations.

Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20201106103747.2780972-3-kpsingh@chromium.org
2020-11-06 08:08:37 -08:00
KP Singh
9e7a4d9831 bpf: Allow LSM programs to use bpf spin locks
Usage of spin locks was not allowed for tracing programs due to
insufficient preemption checks. The verifier does not currently prevent
LSM programs from using spin locks, but the helpers are not exposed
via bpf_lsm_func_proto.

Based on the discussion in [1], non-sleepable LSM programs should be
able to use bpf_spin_{lock, unlock}.

Sleepable LSM programs can be preempted which means that allowng spin
locks will need more work (disabling preemption and the verifier
ensuring that no sleepable helpers are called when a spin lock is held).

[1]: https://lore.kernel.org/bpf/20201103153132.2717326-1-kpsingh@chromium.org/T/#md601a053229287659071600d3483523f752cd2fb

Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20201106103747.2780972-2-kpsingh@chromium.org
2020-11-06 08:08:37 -08:00
Steven Rostedt (VMware)
773c167050 ftrace: Add recording of functions that caused recursion
This adds CONFIG_FTRACE_RECORD_RECURSION that will record to a file
"recursed_functions" all the functions that caused recursion while a
callback to the function tracer was running.

Link: https://lkml.kernel.org/r/20201106023548.102375687@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Guo Ren <guoren@kernel.org>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Joe Lawrence <joe.lawrence@redhat.com>
Cc: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-csky@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-s390@vger.kernel.org
Cc: live-patching@vger.kernel.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-06 08:42:26 -05:00
Steven Rostedt (VMware)
a25d036d93 ftrace: Reverse what the RECURSION flag means in the ftrace_ops
Now that all callbacks are recursion safe, reverse the meaning of the
RECURSION flag and rename it from RECURSION_SAFE to simply RECURSION.
Now only callbacks that request to have recursion protecting it will
have the added trampoline to do so.

Also remove the outdated comment about "PER_CPU" when determining to
use the ftrace_ops_assist_func.

Link: https://lkml.kernel.org/r/20201028115613.742454631@goodmis.org
Link: https://lkml.kernel.org/r/20201106023547.904270143@goodmis.org

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh  Poimboeuf <jpoimboe@redhat.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: linux-doc@vger.kernel.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-06 08:42:12 -05:00
Steven Rostedt (VMware)
5d029b035b perf/ftrace: Check for rcu_is_watching() in callback function
If a ftrace callback requires "rcu_is_watching", then it adds the
FTRACE_OPS_FL_RCU flag and it will not be called if RCU is not "watching".
But this means that it will use a trampoline when called, and this slows
down the function tracing a tad. By checking rcu_is_watching() from within
the callback, it no longer needs the RCU flag set in the ftrace_ops and it
can be safely called directly.

Link: https://lkml.kernel.org/r/20201028115613.591878956@goodmis.org
Link: https://lkml.kernel.org/r/20201106023547.711035826@goodmis.org

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh  Poimboeuf <jpoimboe@redhat.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-06 08:42:05 -05:00
Steven Rostedt (VMware)
5d15a624c3 perf/ftrace: Add recursion protection to the ftrace callback
If a ftrace callback does not supply its own recursion protection and
does not set the RECURSION_SAFE flag in its ftrace_ops, then ftrace will
make a helper trampoline to do so before calling the callback instead of
just calling the callback directly.

The default for ftrace_ops is going to change. It will expect that handlers
provide their own recursion protection, unless its ftrace_ops states
otherwise.

Link: https://lkml.kernel.org/r/20201028115613.444477858@goodmis.org
Link: https://lkml.kernel.org/r/20201106023547.466892083@goodmis.org

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh  Poimboeuf <jpoimboe@redhat.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-06 08:41:56 -05:00
Steven Rostedt (VMware)
4b750b573c livepatch: Trigger WARNING if livepatch function fails due to recursion
If for some reason a function is called that triggers the recursion
detection of live patching, trigger a warning. By not executing the live
patch code, it is possible that the old unpatched function will be called
placing the system into an unknown state.

Link: https://lore.kernel.org/r/20201029145709.GD16774@alley
Link: https://lkml.kernel.org/r/20201106023547.312639435@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Joe Lawrence <joe.lawrence@redhat.com>
Cc: live-patching@vger.kernel.org
Suggested-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-06 08:41:47 -05:00
Steven Rostedt (VMware)
13f3ea9a2c livepatch/ftrace: Add recursion protection to the ftrace callback
If a ftrace callback does not supply its own recursion protection and
does not set the RECURSION_SAFE flag in its ftrace_ops, then ftrace will
make a helper trampoline to do so before calling the callback instead of
just calling the callback directly.

The default for ftrace_ops is going to change. It will expect that handlers
provide their own recursion protection, unless its ftrace_ops states
otherwise.

Link: https://lkml.kernel.org/r/20201028115613.291169246@goodmis.org
Link: https://lkml.kernel.org/r/20201106023547.122802424@goodmis.org

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Joe Lawrence <joe.lawrence@redhat.com>
Cc: live-patching@vger.kernel.org
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-06 08:36:23 -05:00
Steven Rostedt (VMware)
6e4eb9cb22 ftrace: Add ftrace_test_recursion_trylock() helper function
To make it easier for ftrace callbacks to have recursion protection, provide
a ftrace_test_recursion_trylock() and ftrace_test_recursion_unlock() helper
that tests for recursion.

Link: https://lkml.kernel.org/r/20201028115612.634927593@goodmis.org
Link: https://lkml.kernel.org/r/20201106023546.378584067@goodmis.org

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-06 08:33:23 -05:00
Steven Rostedt (VMware)
0264c8c9e1 ftrace: Move the recursion testing into global headers
Currently, if a callback is registered to a ftrace function and its
ftrace_ops does not have the RECURSION flag set, it is encapsulated in a
helper function that does the recursion for it.

Really, all the callbacks should have their own recursion protection for
performance reasons. But they should not all implement their own. Move the
recursion helpers to global headers, so that all callbacks can use them.

Link: https://lkml.kernel.org/r/20201028115612.460535535@goodmis.org
Link: https://lkml.kernel.org/r/20201106023546.166456258@goodmis.org

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-06 08:33:23 -05:00
Lukas Bulwahn
90574a9c02 printk: remove unneeded dead-store assignment
make clang-analyzer on x86_64 defconfig caught my attention with:

  kernel/printk/printk_ringbuffer.c:885:3: warning:
  Value stored to 'desc' is never read [clang-analyzer-deadcode.DeadStores]

		desc = to_desc(desc_ring, head_id);
		^

Commit b6cf8b3f33 ("printk: add lockless ringbuffer") introduced
desc_reserve() with this unneeded dead-store assignment.

As discussed with John Ogness privately, this is probably just some minor
left-over from previous iterations of the ringbuffer implementation. So,
simply remove this unneeded dead assignment to make clang-analyzer happy.

As compilers will detect this unneeded assignment and optimize this anyway,
the resulting object code is identical before and after this change.

No functional change. No change to object code.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20201106034005.18822-1-lukas.bulwahn@gmail.com
2020-11-06 11:05:44 +01:00
Florian Lehner
c6bde958a6 bpf: Lift hashtab key_size limit
Currently key_size of hashtab is limited to MAX_BPF_STACK.
As the key of hashtab can also be a value from a per cpu map it can be
larger than MAX_BPF_STACK.

The use-case for this patch originates to implement allow/disallow
lists for files and file paths. The maximum length of file paths is
defined by PATH_MAX with 4096 chars including nul.
This limit exceeds MAX_BPF_STACK.

Changelog:

v5:
 - Fix cast overflow

v4:
 - Utilize BPF skeleton in tests
 - Rebase

v3:
 - Rebase

v2:
 - Add a test for bpf side

Signed-off-by: Florian Lehner <dev@der-flo.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201029201442.596690-1-dev@der-flo.net
2020-11-05 20:04:46 -08:00
David Verbeiren
d3bec0138b bpf: Zero-fill re-used per-cpu map element
Zero-fill element values for all other cpus than current, just as
when not using prealloc. This is the only way the bpf program can
ensure known initial values for all cpus ('onallcpus' cannot be
set when coming from the bpf program).

The scenario is: bpf program inserts some elements in a per-cpu
map, then deletes some (or userspace does). When later adding
new elements using bpf_map_update_elem(), the bpf program can
only set the value of the new elements for the current cpu.
When prealloc is enabled, previously deleted elements are re-used.
Without the fix, values for other cpus remain whatever they were
when the re-used entry was previously freed.

A selftest is added to validate correct operation in above
scenario as well as in case of LRU per-cpu map element re-use.

Fixes: 6c90598174 ("bpf: pre-allocate hash map elements")
Signed-off-by: David Verbeiren <david.verbeiren@tessares.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201104112332.15191-1-david.verbeiren@tessares.net
2020-11-05 19:55:57 -08:00
Randy Dunlap
7c0afcad75 bpf: BPF_PRELOAD depends on BPF_SYSCALL
Fix build error when BPF_SYSCALL is not set/enabled but BPF_PRELOAD is
by making BPF_PRELOAD depend on BPF_SYSCALL.

ERROR: modpost: "bpf_preload_ops" [kernel/bpf/preload/bpf_preload.ko] undefined!

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201105195109.26232-1-rdunlap@infradead.org
2020-11-05 18:49:29 -08:00
Linus Torvalds
3249fe4563 Tracing fixes:
- Fix off-by-one error in retrieving the context buffer for trace_printk()
 
 - Fix off-by-one error in stack nesting limit
 
 - Fix recursion to not make all NMI code false positive as recursing
 
 - Stop losing events in function tracing when transitioning between irq context
 
 - Stop losing events in ring buffer when transitioning between irq context
 
 - Fix return code of error pointer in parse_synth_field() to prevent
   NULL pointer dereference.
 
 - Fix false positive of NMI recursion in kprobe event handling
 -----BEGIN PGP SIGNATURE-----
 
 iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCX6QqmRQccm9zdGVkdEBn
 b29kbWlzLm9yZwAKCRAp5XQQmuv6qtWiAQCKf3xblmQDcge2BLQPy2H7ih5VCSSb
 vDPrQKgLa35pSgEAhGj7mgAKxb6kDbae1BqPorfa/qn9Bi13XfRNTxBK2Qw=
 =zKfd
 -----END PGP SIGNATURE-----

Merge tag 'trace-v5.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Fix off-by-one error in retrieving the context buffer for
   trace_printk()

 - Fix off-by-one error in stack nesting limit

 - Fix recursion to not make all NMI code false positive as recursing

 - Stop losing events in function tracing when transitioning between irq
   context

 - Stop losing events in ring buffer when transitioning between irq
   context

 - Fix return code of error pointer in parse_synth_field() to prevent
   NULL pointer dereference.

 - Fix false positive of NMI recursion in kprobe event handling

* tag 'trace-v5.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  kprobes: Tell lockdep about kprobe nesting
  tracing: Make -ENOMEM the default error for parse_synth_field()
  ring-buffer: Fix recursion protection transitions between interrupt context
  tracing: Fix the checking of stackidx in __ftrace_trace_stack
  ftrace: Handle tracing when switching between context
  ftrace: Fix recursion check for NMI test
  tracing: Fix out of bounds write in get_trace_buf
2020-11-05 11:41:38 -08:00
Linus Torvalds
f786dfa374 Power management fixes for 5.10-rc3.
- Unify the handling of managed and stateless device links in the
    runtime PM framework and prevent runtime PM references to devices
    from being leaked after device link removal (Rafael Wysocki).
 
  - Fix two mistakes in the cpuidle documentation (Julia Lawall).
 
  - Prevent the schedutil cpufreq governor from missing policy
    limits updates in some cases (Viresh Kumar).
 
  - Prevent static OPPs from being dropped by mistake (Viresh Kumar).
 
  - Prevent helper function in the OPP framework from returning
    prematurely (Viresh Kumar).
 
  - Prevent opp_table_lock from being held too long during removal
    of OPP tables with no more active references (Viresh Kumar).
 
  - Drop redundant semicolon from the Intel RAPL power capping
    driver (Tom Rix).
 -----BEGIN PGP SIGNATURE-----
 
 iQJGBAABCAAwFiEE4fcc61cGeeHD/fCwgsRv/nhiVHEFAl+kAnUSHHJqd0Byand5
 c29ja2kubmV0AAoJEILEb/54YlRxND0P/j5e/wqFZ/34XEaUa4PIs27TDoJHq1Jh
 PfUxqSBEVO6Xm8TMCtOIuS8gw4x7ehenXC8gFdivy+Fu+4QNkPKYggF5/LgWO8Gl
 cMNzYwJ8shIBQWQZftIx01Bn5tAvk1YhV1mnSNf580Iy7FhKqojMnrvzQnpGD4jR
 piBkvBcbIJWDk+T96RzbqnqmMD0euvlYfzg1KnsyqsOpoRl7kZoH4ahWYskdIxDY
 NtA4SqQ8dvxjTwI8+a+JBb//ua9jjjDyjd7FUV87HMdcVh9rZKbmHKkk4Yv/3C4C
 jZuCTV6zaWIHCbbkZwi+OTNE8q21GgWm1xqwnGWVTFSGrs8ZyfjLs73/g9S5zI3N
 C/n4YUJxiYDVcnrAVwR7kSTEouiQ6mTuChOt7T3r1Ilx67rw4TDsI59Fk1Xn07bZ
 1wfaPASUPsFAxF7vMhkdzsidhpR3BYNgMwmAWo9R4Yvw4evyRN4tywoUQJ1X27zg
 ERir6mFVz6XCnXPrJhyx0bWLo+VD8J/arhfIPSTqHR7wn0tgc23aVeYy7wvfYiiu
 QQJqQ58Aoa0Z7ZpeAv3xbSung+eqQ/dDC9FnXqxdZCI6brYUhrZ19OhsFnEyzGUR
 IDRzcP1/72AxhidpjO71txOJSJFTqKF2LzL/wuS6kMbYwmFjYfj18xX5GvOUuXmL
 hO+E+QdleQFo
 =lKQA
 -----END PGP SIGNATURE-----

Merge tag 'pm-5.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fixes from Rafael Wysocki:
 "These fix the device links support in runtime PM, correct mistakes in
  the cpuidle documentation, fix the handling of policy limits changes
  in the schedutil cpufreq governor, fix assorted issues in the OPP
  (operating performance points) framework and make one janitorial
  change.

  Specifics:

   - Unify the handling of managed and stateless device links in the
     runtime PM framework and prevent runtime PM references to devices
     from being leaked after device link removal (Rafael Wysocki).

   - Fix two mistakes in the cpuidle documentation (Julia Lawall).

   - Prevent the schedutil cpufreq governor from missing policy limits
     updates in some cases (Viresh Kumar).

   - Prevent static OPPs from being dropped by mistake (Viresh Kumar).

   - Prevent helper function in the OPP framework from returning
     prematurely (Viresh Kumar).

   - Prevent opp_table_lock from being held too long during removal of
     OPP tables with no more active references (Viresh Kumar).

   - Drop redundant semicolon from the Intel RAPL power capping driver
     (Tom Rix)"

* tag 'pm-5.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PM: runtime: Resume the device earlier in __device_release_driver()
  PM: runtime: Drop pm_runtime_clean_up_links()
  PM: runtime: Drop runtime PM references to supplier on link removal
  powercap/intel_rapl: remove unneeded semicolon
  Documentation: PM: cpuidle: correct path name
  Documentation: PM: cpuidle: correct typo
  cpufreq: schedutil: Don't skip freq update if need_freq_update is set
  opp: Reduce the size of critical section in _opp_table_kref_release()
  opp: Fix early exit from dev_pm_opp_register_set_opp_helper()
  opp: Don't always remove static OPPs in _of_add_opp_table_v1()
2020-11-05 11:04:29 -08:00
Thomas Gleixner
b6be002bcd x86/entry: Move nmi entry/exit into common code
Lockdep state handling on NMI enter and exit is nothing specific to X86. It's
not any different on other architectures. Also the extra state type is not
necessary, irqentry_state_t can carry the necessary information as well.

Move it to common code and extend irqentry_state_t to carry lockdep state.

[ Ira: Make exit_rcu and lockdep a union as they are mutually exclusive
  between the IRQ and NMI exceptions, and add kernel documentation for
  struct irqentry_state_t ]

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201102205320.1458656-7-ira.weiny@intel.com
2020-11-04 22:55:36 +01:00
Thomas Gleixner
01be83eea0 Merge branch 'core/urgent' into core/entry
Pick up the entry fix before further modifications.
2020-11-04 18:14:52 +01:00
Thomas Gleixner
9d820f68b2 entry: Fix the incorrect ordering of lockdep and RCU check
When an exception/interrupt hits kernel space and the kernel is not
currently in the idle task then RCU must be watching.

irqentry_enter() validates this via rcu_irq_enter_check_tick(), which in
turn invokes lockdep when taking a lock. But at that point lockdep does not
yet know about the fact that interrupts have been disabled by the CPU,
which triggers a lockdep splat complaining about inconsistent state.

Invoking trace_hardirqs_off() before rcu_irq_enter_check_tick() defeats the
point of rcu_irq_enter_check_tick() because trace_hardirqs_off() uses RCU.

So use the same sequence as for the idle case and tell lockdep about the
irq state change first, invoke the RCU check and then do the lockdep and
tracer update.

Fixes: a5497bab5f ("entry: Provide generic interrupt entry/exit code")
Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/87y2jhl19s.fsf@nanos.tec.linutronix.de
2020-11-04 18:06:14 +01:00
Steven Rostedt (VMware)
645f224e7b kprobes: Tell lockdep about kprobe nesting
Since the kprobe handlers have protection that prohibits other handlers from
executing in other contexts (like if an NMI comes in while processing a
kprobe, and executes the same kprobe, it will get fail with a "busy"
return). Lockdep is unaware of this protection. Use lockdep's nesting api to
differentiate between locks taken in INT3 context and other context to
suppress the false warnings.

Link: https://lore.kernel.org/r/20201102160234.fa0ae70915ad9e2b21c08b85@kernel.org

Cc: Peter Zijlstra <peterz@infradead.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-04 09:46:06 -05:00
Sergey Shtylyov
076aa52e40 module: only handle errors with the *switch* statement in module_sig_check()
Let's handle the successful call of mod_verify_sig() right after that call,
making the *switch* statement only handle the real errors, and then move
the comment from the first *case* before *switch* itself and the comment
before *default* after it.  Fix the comment style, add article/comma/dash,
spell out "nomem" as "lack of memory" in these comments, while at it...

Suggested-by: Joe Perches <joe@perches.com>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Sergey Shtylyov <s.shtylyov@omprussia.ru>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
2020-11-04 15:31:29 +01:00
Sergey Shtylyov
10ccd1abb8 module: avoid *goto*s in module_sig_check()
Let's move the common handling of the non-fatal errors after the *switch*
statement -- this avoids *goto*s inside that *switch*...

Suggested-by: Joe Perches <joe@perches.com>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Sergey Shtylyov <s.shtylyov@omprussia.ru>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
2020-11-04 15:31:28 +01:00
Sergey Shtylyov
705e919518 module: merge repetitive strings in module_sig_check()
The 'reason' variable in module_sig_check() points to 3 strings across
the *switch* statement, all needlessly starting with the same text.
Let's put the starting text into the pr_notice() call -- it saves 21
bytes of the object code (x86 gcc 10.2.1).

Suggested-by: Joe Perches <joe@perches.com>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Sergey Shtylyov <s.shtylyov@omprussia.ru>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
2020-11-04 15:31:19 +01:00
Aleksandr Nogikh
b08e84da20 kernel: make kcov_common_handle consider the current context
kcov_common_handle is a method that is used to obtain a "default" KCOV
remote handle of the current process. The handle can later be passed
to kcov_remote_start in order to collect coverage for the processing
that is initiated by one process, but done in another. For details see
Documentation/dev-tools/kcov.rst and comments in kernel/kcov.c.

Presently, if kcov_common_handle is called in an IRQ context, it will
return a handle for the interrupted process. This may lead to
unreliable and incorrect coverage collection.

Adjust the behavior of kcov_common_handle in the following way. If it
is called in a task context, return the common handle for the
currently running task. Otherwise, return 0.

Signed-off-by: Aleksandr Nogikh <nogikh@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-02 18:00:20 -08:00
Paul E. McKenney
0c6d18d84d refscale: Bounds-check module parameters
The default value for refscale.nreaders is -1, which results in the code
setting the value to three-quarters of the number of CPUs.  On single-CPU
systems, this results in three-quarters of the value one, which the C
language's integer arithmetic rounds to zero.  This in turn results in
a divide-by-zero error.

This commit therefore adds bounds checking to the refscale module
parameters, so that if they are less than one, they are set to the
value one.

Reported-by: kernel test robot <lkp@intel.com>
Tested-by "Chen, Rong A" <rong.a.chen@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-02 17:13:29 -08:00
Paul E. McKenney
27c0f14483 rcutorture: Make grace-period kthread report match RCU flavor being tested
At the end of the test and after rcu_torture_writer() stalls, rcutorture
invokes show_rcu_gp_kthreads() in order to dump out information on the
RCU grace-period kthread.  This makes a lot of sense when testing vanilla
RCU, but not so much for the other flavors.  This commit therefore allows
per-flavor kthread-dump functions to be specified.

[ paulmck: Apply feedback from kernel test robot <lkp@intel.com>. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-02 17:12:43 -08:00
Paul E. McKenney
77dc174103 rcu-tasks: Convert rcu_tasks_wait_gp() for-loop to while-loop
The infinite for-loop in rcu_tasks_wait_gp() has its only exit at the
top of the loop, so this commit does the straightforward conversion to
a while-loop, thus saving a few lines.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-02 17:12:42 -08:00
Jakub Kicinski
f505d4346f srcu: Use a more appropriate lockdep helper
The lockdep_is_held() macro is defined as:

 #define lockdep_is_held(lock)		lock_is_held(&(lock)->dep_map)

This hides away the dereference, so that builds with !LOCKDEP don't break.
This works in current kernels because the RCU_LOCKDEP_WARN() eliminates
its condition at preprocessor time in !LOCKDEP kernels.  However, later
patches in this series will cause the compiler to see this condition even
in !LOCKDEP kernels.  This commit prepares for this upcoming change by
switching from lock_is_held() to lockdep_is_held().

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
--
CC: jiangshanlai@gmail.com
CC: paulmck@kernel.org
CC: josh@joshtriplett.org
CC: rostedt@goodmis.org
CC: mathieu.desnoyers@efficios.com
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-02 17:10:00 -08:00
Marco Elver
55a2346c7a kcsan: Never set up watchpoints on NULL pointers
Avoid setting up watchpoints on NULL pointers, as otherwise we would
crash inside the KCSAN runtime (when checking for value changes) instead
of the instrumented code.

Because that may be confusing, skip any address less than PAGE_SIZE.

Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-02 17:08:51 -08:00
Marco Elver
4761612ffe kcsan: selftest: Ensure that address is at least PAGE_SIZE
In preparation of supporting only addresses not within the NULL page,
change the selftest to never use addresses that are less than PAGE_SIZE.

Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-02 17:08:50 -08:00
Steven Rostedt (VMware)
561ca66910 tracing: Make -ENOMEM the default error for parse_synth_field()
parse_synth_field() returns a pointer and requires that errors get
surrounded by ERR_PTR(). The ret variable is initialized to zero, but should
never be used as zero, and if it is, it could cause a false return code and
produce a NULL pointer dereference. It makes no sense to set ret to zero.

Set ret to -ENOMEM (the most common error case), and have any other errors
set it to something else. This removes the need to initialize ret on *every*
error branch.

Fixes: 761a8c58db ("tracing, synthetic events: Replace buggy strcat() with seq_buf operations")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-02 15:58:32 -05:00
Steven Rostedt (VMware)
b02414c8f0 ring-buffer: Fix recursion protection transitions between interrupt context
The recursion protection of the ring buffer depends on preempt_count() to be
correct. But it is possible that the ring buffer gets called after an
interrupt comes in but before it updates the preempt_count(). This will
trigger a false positive in the recursion code.

Use the same trick from the ftrace function callback recursion code which
uses a "transition" bit that gets set, to allow for a single recursion for
to handle transitions between contexts.

Cc: stable@vger.kernel.org
Fixes: 567cd4da54 ("ring-buffer: User context bit recursion checking")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-02 15:58:32 -05:00
Lukas Bulwahn
3b70ae4f5c kernel/hung_task.c: make type annotations consistent
Commit 32927393dc ("sysctl: pass kernel pointers to ->proc_handler")
removed various __user annotations from function signatures as part of
its refactoring.

It also removed the __user annotation for proc_dohung_task_timeout_secs()
at its declaration in sched/sysctl.h, but not at its definition in
kernel/hung_task.c.

Hence, sparse complains:

  kernel/hung_task.c:271:5: error: symbol 'proc_dohung_task_timeout_secs' redeclared with different type (incompatible argument 3 (different address spaces))

Adjust the annotation at the definition fitting to that refactoring to make
sparse happy again, which also resolves this warning from sparse:

  kernel/hung_task.c:277:52: warning: incorrect type in argument 3 (different address spaces)
  kernel/hung_task.c:277:52:    expected void *
  kernel/hung_task.c:277:52:    got void [noderef] __user *buffer

No functional change. No change in object code.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrey Ignatov <rdna@fb.com>
Link: https://lkml.kernel.org/r/20201028130541.20320-1-lukas.bulwahn@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-11-02 12:14:19 -08:00
Zqiang
6993d0fdbe kthread_worker: prevent queuing delayed work from timer_fn when it is being canceled
There is a small race window when a delayed work is being canceled and
the work still might be queued from the timer_fn:

	CPU0						CPU1
kthread_cancel_delayed_work_sync()
   __kthread_cancel_work_sync()
     __kthread_cancel_work()
        work->canceling++;
					      kthread_delayed_work_timer_fn()
						   kthread_insert_work();

BUG: kthread_insert_work() should not get called when work->canceling is
set.

Signed-off-by: Zqiang <qiang.zhang@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20201014083030.16895-1-qiang.zhang@windriver.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-11-02 12:14:19 -08:00
Oleg Nesterov
7b3c36fc4c ptrace: fix task_join_group_stop() for the case when current is traced
This testcase

	#include <stdio.h>
	#include <unistd.h>
	#include <signal.h>
	#include <sys/ptrace.h>
	#include <sys/wait.h>
	#include <pthread.h>
	#include <assert.h>

	void *tf(void *arg)
	{
		return NULL;
	}

	int main(void)
	{
		int pid = fork();
		if (!pid) {
			kill(getpid(), SIGSTOP);

			pthread_t th;
			pthread_create(&th, NULL, tf, NULL);

			return 0;
		}

		waitpid(pid, NULL, WSTOPPED);

		ptrace(PTRACE_SEIZE, pid, 0, PTRACE_O_TRACECLONE);
		waitpid(pid, NULL, 0);

		ptrace(PTRACE_CONT, pid, 0,0);
		waitpid(pid, NULL, 0);

		int status;
		int thread = waitpid(-1, &status, 0);
		assert(thread > 0 && thread != pid);
		assert(status == 0x80137f);

		return 0;
	}

fails and triggers WARN_ON_ONCE(!signr) in do_jobctl_trap().

This is because task_join_group_stop() has 2 problems when current is traced:

	1. We can't rely on the "JOBCTL_STOP_PENDING" check, a stopped tracee
	   can be woken up by debugger and it can clone another thread which
	   should join the group-stop.

	   We need to check group_stop_count || SIGNAL_STOP_STOPPED.

	2. If SIGNAL_STOP_STOPPED is already set, we should not increment
	   sig->group_stop_count and add JOBCTL_STOP_CONSUME. The new thread
	   should stop without another do_notify_parent_cldstop() report.

To clarify, the problem is very old and we should blame
ptrace_init_task().  But now that we have task_join_group_stop() it makes
more sense to fix this helper to avoid the code duplication.

Reported-by: syzbot+3485e3773f7da290eecc@syzkaller.appspotmail.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christian Brauner <christian@brauner.io>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: Zhiqiang Liu <liuzhiqiang26@huawei.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20201019134237.GA18810@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-11-02 12:14:19 -08:00
Viresh Kumar
23a881852f cpufreq: schedutil: Don't skip freq update if need_freq_update is set
The cpufreq policy's frequency limits (min/max) can get changed at any
point of time, while schedutil is trying to update the next frequency.
Though the schedutil governor has necessary locking and support in place
to make sure we don't miss any of those updates, there is a corner case
where the governor will find that the CPU is already running at the
desired frequency and so may skip an update.

For example, consider that the CPU can run at 1 GHz, 1.2 GHz and 1.4 GHz
and is running at 1 GHz currently. Schedutil tries to update the
frequency to 1.2 GHz, during this time the policy limits get changed as
policy->min = 1.4 GHz. As schedutil (and cpufreq core) does clamp the
frequency at various instances, we will eventually set the frequency to
1.4 GHz, while we will save 1.2 GHz in sg_policy->next_freq.

Now lets say the policy limits get changed back at this time with
policy->min as 1 GHz. The next time schedutil is invoked by the
scheduler, we will reevaluate the next frequency (because
need_freq_update will get set due to limits change event) and lets say
we want to set the frequency to 1.2 GHz again. At this point
sugov_update_next_freq() will find the next_freq == current_freq and
will abort the update, while the CPU actually runs at 1.4 GHz.

Until now need_freq_update was used as a flag to indicate that the
policy's frequency limits have changed, and that we should consider the
new limits while reevaluating the next frequency.

This patch fixes the above mentioned issue by extending the purpose of
the need_freq_update flag. If this flag is set now, the schedutil
governor will not try to abort a frequency change even if next_freq ==
current_freq.

As similar behavior is required in the case of
CPUFREQ_NEED_UPDATE_LIMITS flag as well, need_freq_update will never be
set to false if that flag is set for the driver.

We also don't need to consider the need_freq_update flag in
sugov_update_single() anymore to handle the special case of busy CPU, as
we won't abort a frequency update anymore.

Reported-by: zhuguangqing <zhuguangqing@xiaomi.com>
Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Rearrange code to avoid a branch ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-11-02 17:57:49 +01:00
Qiujun Huang
906695e593 tracing: Fix the checking of stackidx in __ftrace_trace_stack
The array size is FTRACE_KSTACK_NESTING, so the index FTRACE_KSTACK_NESTING
is illegal too. And fix two typos by the way.

Link: https://lkml.kernel.org/r/20201031085714.2147-1-hqjagain@gmail.com

Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-02 11:21:40 -05:00
Eric Dumazet
8aaeed81fc bpf: Fix error path in htab_map_alloc()
syzbot was able to trigger a use-after-free in htab_map_alloc() [1]

htab_map_alloc() lacks a call to lockdep_unregister_key() in its error path.

lockdep_register_key() and lockdep_unregister_key() can not fail,
it seems better to use them right after htab allocation and before
htab freeing, avoiding more goto/labels in htab_map_alloc()

[1]
BUG: KASAN: use-after-free in lockdep_register_key+0x356/0x3e0 kernel/locking/lockdep.c:1182
Read of size 8 at addr ffff88805fa67ad8 by task syz-executor.3/2356

CPU: 1 PID: 2356 Comm: syz-executor.3 Not tainted 5.9.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x107/0x163 lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xae/0x4c8 mm/kasan/report.c:385
 __kasan_report mm/kasan/report.c:545 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:562
 lockdep_register_key+0x356/0x3e0 kernel/locking/lockdep.c:1182
 htab_init_buckets kernel/bpf/hashtab.c:144 [inline]
 htab_map_alloc+0x6c5/0x14a0 kernel/bpf/hashtab.c:521
 find_and_alloc_map kernel/bpf/syscall.c:122 [inline]
 map_create kernel/bpf/syscall.c:825 [inline]
 __do_sys_bpf+0xa80/0x5180 kernel/bpf/syscall.c:4381
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45deb9
Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f0eafee1c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 0000000000001a00 RCX: 000000000045deb9
RDX: 0000000000000040 RSI: 0000000020000040 RDI: 405a020000000000
RBP: 000000000118bf60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c
R13: 00007ffd3cf9eabf R14: 00007f0eafee29c0 R15: 000000000118bf2c

Allocated by task 2053:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
 kasan_set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:461
 kmalloc include/linux/slab.h:554 [inline]
 kzalloc include/linux/slab.h:666 [inline]
 htab_map_alloc+0xdf/0x14a0 kernel/bpf/hashtab.c:454
 find_and_alloc_map kernel/bpf/syscall.c:122 [inline]
 map_create kernel/bpf/syscall.c:825 [inline]
 __do_sys_bpf+0xa80/0x5180 kernel/bpf/syscall.c:4381
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 2053:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
 kasan_set_track+0x1c/0x30 mm/kasan/common.c:56
 kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:355
 __kasan_slab_free+0x102/0x140 mm/kasan/common.c:422
 slab_free_hook mm/slub.c:1544 [inline]
 slab_free_freelist_hook+0x5d/0x150 mm/slub.c:1577
 slab_free mm/slub.c:3142 [inline]
 kfree+0xdb/0x360 mm/slub.c:4124
 htab_map_alloc+0x3f9/0x14a0 kernel/bpf/hashtab.c:549
 find_and_alloc_map kernel/bpf/syscall.c:122 [inline]
 map_create kernel/bpf/syscall.c:825 [inline]
 __do_sys_bpf+0xa80/0x5180 kernel/bpf/syscall.c:4381
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

The buggy address belongs to the object at ffff88805fa67800
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 728 bytes inside of
 1024-byte region [ffff88805fa67800, ffff88805fa67c00)
The buggy address belongs to the page:
page:000000003c5582c4 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5fa60
head:000000003c5582c4 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head)
raw: 00fff00000010200 ffffea0000bc1200 0000000200000002 ffff888010041140
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88805fa67980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88805fa67a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                    ^
 ffff88805fa67b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88805fa67b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb

Fixes: c50eb518e2 ("bpf: Use separate lockdep class for each hashtab")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20201102114100.3103180-1-eric.dumazet@gmail.com
2020-11-02 17:20:21 +01:00
Christoph Hellwig
fc0021aa34 swiotlb: remove the tbl_dma_addr argument to swiotlb_tbl_map_single
The tbl_dma_addr argument is used to check the DMA boundary for the
allocations, and thus needs to be a dma_addr_t.  swiotlb-xen instead
passed a physical address, which could lead to incorrect results for
strange offsets.  Fix this by removing the parameter entirely and hard
code the DMA address for io_tlb_start instead.

Fixes: 91ffe4ad53 ("swiotlb-xen: introduce phys_to_dma/dma_to_phys translations")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2020-11-02 10:10:39 -05:00
Stefano Stabellini
e9696d259d swiotlb: fix "x86: Don't panic if can not alloc buffer for swiotlb"
kernel/dma/swiotlb.c:swiotlb_init gets called first and tries to
allocate a buffer for the swiotlb. It does so by calling

  memblock_alloc_low(PAGE_ALIGN(bytes), PAGE_SIZE);

If the allocation must fail, no_iotlb_memory is set.

Later during initialization swiotlb-xen comes in
(drivers/xen/swiotlb-xen.c:xen_swiotlb_init) and given that io_tlb_start
is != 0, it thinks the memory is ready to use when actually it is not.

When the swiotlb is actually needed, swiotlb_tbl_map_single gets called
and since no_iotlb_memory is set the kernel panics.

Instead, if swiotlb-xen.c:xen_swiotlb_init knew the swiotlb hadn't been
initialized, it would do the initialization itself, which might still
succeed.

Fix the panic by setting io_tlb_start to 0 on swiotlb initialization
failure, and also by setting no_iotlb_memory to false on swiotlb
initialization success.

Fixes: ac2cbab21f ("x86: Don't panic if can not alloc buffer for swiotlb")

Reported-by: Elliott Mitchell <ehem+xen@m5p.com>
Tested-by: Elliott Mitchell <ehem+xen@m5p.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2020-11-02 10:10:37 -05:00
Steven Rostedt (VMware)
726b3d3f14 ftrace: Handle tracing when switching between context
When an interrupt or NMI comes in and switches the context, there's a delay
from when the preempt_count() shows the update. As the preempt_count() is
used to detect recursion having each context have its own bit get set when
tracing starts, and if that bit is already set, it is considered a recursion
and the function exits. But if this happens in that section where context
has changed but preempt_count() has not been updated, this will be
incorrectly flagged as a recursion.

To handle this case, create another bit call TRANSITION and test it if the
current context bit is already set. Flag the call as a recursion if the
TRANSITION bit is already set, and if not, set it and continue. The
TRANSITION bit will be cleared normally on the return of the function that
set it, or if the current context bit is clear, set it and clear the
TRANSITION bit to allow for another transition between the current context
and an even higher one.

Cc: stable@vger.kernel.org
Fixes: edc15cafcb ("tracing: Avoid unnecessary multiple recursion checks")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-02 08:52:18 -05:00
Steven Rostedt (VMware)
ee11b93f95 ftrace: Fix recursion check for NMI test
The code that checks recursion will work to only do the recursion check once
if there's nested checks. The top one will do the check, the other nested
checks will see recursion was already checked and return zero for its "bit".
On the return side, nothing will be done if the "bit" is zero.

The problem is that zero is returned for the "good" bit when in NMI context.
This will set the bit for NMIs making it look like *all* NMI tracing is
recursing, and prevent tracing of anything in NMI context!

The simple fix is to return "bit + 1" and subtract that bit on the end to
get the real bit.

Cc: stable@vger.kernel.org
Fixes: edc15cafcb ("tracing: Avoid unnecessary multiple recursion checks")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-02 08:52:18 -05:00
Qiujun Huang
c1acb4ac1a tracing: Fix out of bounds write in get_trace_buf
The nesting count of trace_printk allows for 4 levels of nesting. The
nesting counter starts at zero and is incremented before being used to
retrieve the current context's buffer. But the index to the buffer uses the
nesting counter after it was incremented, and not its original number,
which in needs to do.

Link: https://lkml.kernel.org/r/20201029161905.4269-1-hqjagain@gmail.com

Cc: stable@vger.kernel.org
Fixes: 3d9622c12c ("tracing: Add barrier to trace_printk() buffer nesting modification")
Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-02 08:52:18 -05:00
Linus Torvalds
4312e0e8d3 A few fixes for timers/timekeeping:
- Prevent undefined behaviour in the timespec64_to_ns() conversion which
     is used for converting user supplied time input to nanoseconds. It
     lacked overflow protection.
 
   - Mark sched_clock_read_begin/retry() to prevent recursion in the tracer
 
   - Remove unused debug functions in the hrtimer and timerlist code
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAl+evaETHHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYoT69D/0Z3ZGdNQu3mAPYdMSaW7R3MfXnLKno
 biRCwre/T88Exv+Yu612iLthTlfNlxZbofAgUc5BvCwjAjtt+uXlmS8mwXNsbGFd
 516hisUnjJkjbcHI6WxrQQ7+YsK2XLjOeV90TpLs9zMgI94kQ+uzEzqKc6ZaRQP4
 Zi/emqgHeO/RoObNBWjNh9McrHqXllXU/LeqD7y82JXdLPik78PniKFkh7B1d6u8
 RL7kW1TeblkNaHMVjO4/lM9zR1hkZr4GPYbEHIbVN8FMQ10BAD2iswUR72U2mqx7
 zf2Jt+09UEzPRu2gOr4Lrvo6bJQKClu4ZUnRt4apU4BeTgyG0gi7pgy0VZ3M1xtq
 KUnN8dNSMBwTurv9GuGTdiNpfFad2nsnSAra8r7GlZDHxNe1wWIPJmyu/FV1xohD
 yUgRq2s7rvCb894oz159hyIwkI/ZNbFr/AJTCvdzowgf9nf4WS5/Y2/JVLF28LRT
 4xPhvuVUfrhHJajoZayuVvxYSVEPZFek2SgUEIFi6b1+FiMFwV6guv/f31D5GQ+E
 NHgvDMbDsVmzGt++c4zFHoqWvBrgC8Os8AEP8s2oczfvwMt2A8g7nIrGieAux+Jm
 eLO1DfXaXpQi/MmTBf/WD1dKwjuoLV9dT0Fp2y2docu9SXm/bMgRhxX7fm3uDge7
 W87XWkfIxd5fzA==
 =Gdoq
 -----END PGP SIGNATURE-----

Merge tag 'timers-urgent-2020-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer fixes from Thomas Gleixner:
 "A few fixes for timers/timekeeping:

   - Prevent undefined behaviour in the timespec64_to_ns() conversion
     which is used for converting user supplied time input to
     nanoseconds. It lacked overflow protection.

   - Mark sched_clock_read_begin/retry() to prevent recursion in the
     tracer

   - Remove unused debug functions in the hrtimer and timerlist code"

* tag 'timers-urgent-2020-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  time: Prevent undefined behaviour in timespec64_to_ns()
  timers: Remove unused inline funtion debug_timer_free()
  hrtimer: Remove unused inline function debug_hrtimer_free()
  time/sched_clock: Mark sched_clock_read_begin/retry() as notrace
2020-11-01 11:13:45 -08:00
Linus Torvalds
82423b46fc A single fix for stop machine. Mark functions no trace to prevent a crash
caused by recursion when enabling or disabling a tracer on RISC-V (probably
 all architectures which patch through stop machine).
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAl+evLQTHHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYoQR6D/49PIepVEn63HmgsKdePUShUFzYb+v6
 mPV0iwaDCdW6BKXVEuHkzGdz3dB5ytdIZP6tJLV5a44tYxPhYESO+O4FwAJnqBxD
 JGWLUELxqeEESnjBHww26/YptxqRwcVir2G0WeRDIO0eV2JE424ptdRSisgRVC2s
 Kcu41D9Ry5SLayEKN29GyRXQPrMwLCUTAzeziN4TwJeRB2exSUMg6iDFiGC2uZy6
 IzSu9BXak5T61LL7q5urElkY8a+sGLx6N29QBtSNxazYeXCzCoEtX+1IQ2e9b3PO
 4abFsEtYJ9Mbw4R+iKm0lIpUMKmr/GOPWBs/PDTqK0aYhpc8UnKXTCr6hWLTvtkE
 Anb/08AqN7YtvgbBR+bEN4fPOP4jL5kQVjLbNlIKm5ktRjZ5Sfd9OKOc//c/Bs3e
 Auqe2u+UW2REDsB3lNiVFY+I/1nQUVwKLwfOsBHJW1KzH6O+BhJrJgigUERTeyTf
 B5eLsOIxKgP1vprA/qQgPc/VT25PFIMOtxr7KhH1qPBej9R/wGEOdeOGSdJoiNYM
 aH3kCTUMU0NP8IUSyVQFt4v2IhZ5aF+3rQmyVXifGRl54QCXKgb5gzqcQ/L2SFn+
 I4SkB35hAoEzJ9S4vtx5ZtWPXAO20V644qRMalYv5X739zMVZQ2AyHGB9rhhktmX
 a8ZDIVFCh0ssmw==
 =38RZ
 -----END PGP SIGNATURE-----

Merge tag 'smp-urgent-2020-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull smp fix from Thomas Gleixner:
 "A single fix for stop machine.

  Mark functions no trace to prevent a crash caused by recursion when
  enabling or disabling a tracer on RISC-V (probably all architectures
  which patch through stop machine)"

* tag 'smp-urgent-2020-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  stop_machine, rcu: Mark functions as notrace
2020-11-01 11:11:38 -08:00
Linus Torvalds
8d99084efc A couple of locking fixes:
- Fix incorrect failure injection handling on the fuxtex code
 
  - Prevent a preemption warning in lockdep when tracking local_irq_enable()
    and interrupts are already enabled
 
  - Remove more raw_cpu_read() usage from lockdep which causes state
    corruption on !X86 architectures.
 
  - Make the nr_unused_locks accounting in lockdep correct again.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAl+evEUTHHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYod93EADG90GmRBYQxn6y2eQUKE/9f5SMiMFJ
 KdvuqNBqHOhYm3iUPbZJcb0P/JZi1NHP0fBFMishdESGi96tD96K7T04WD0gmjtm
 ArWFroe8uzEYtY9atlEwM0Nrvq0w8ZBLv9x1adXzJ59vB8/8Uq+wzYioSWn9yMcv
 ye3jfVyAlM7ouFHDQAA36s/nhvZfxms4C0t+6S3gjVTIp/6riGuYh5t7dbXUMlnu
 nGLiIJFjU+ekurweVDGpqD/nAxYfqf3UxebWnrosf7iu6suwYwaPFZGZ/kxlbr5e
 qWx0B1RuhjAoefVJlPTkHmuhd0SnH/Gm/tTNkQ3LidJhPTIhLJlb7zffwyZlc510
 VdaUipfZ6bNqDD6/dK6fKJtdKSE4w/z3pT53954NUD5zw/jIcHlgnaQieh72DH+F
 1EKqmsNrwHAxYfMndQxLGdIoBScUAFzHzDnzsY9KKS2cfhChljzLa2nDIfMsDfKQ
 aROugzEbZPQEb1iWUEOF3XopcuZzZQCaPlLDLvAnsBeYEPm0gdmbKFPFsDjOyBVX
 /Qc41O7DyHKcoiLX2zM2c7CxnV5J6YEZz3jQSZLFlpH9Ih7jwAl9/6VirggNUNvV
 YVsgM/myhYQtJBqHHojNppZFFW3KdgfxWuY7+qt7Ox5w/ck5qYQwRnoB4FROwVHV
 pzcYTBE5qkQnIw==
 =S01o
 -----END PGP SIGNATURE-----

Merge tag 'locking-urgent-2020-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking fixes from Thomas Gleixner:
 "A couple of locking fixes:

   - Fix incorrect failure injection handling in the fuxtex code

   - Prevent a preemption warning in lockdep when tracking
     local_irq_enable() and interrupts are already enabled

   - Remove more raw_cpu_read() usage from lockdep which causes state
     corruption on !X86 architectures.

   - Make the nr_unused_locks accounting in lockdep correct again"

* tag 'locking-urgent-2020-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  lockdep: Fix nr_unused_locks accounting
  locking/lockdep: Remove more raw_cpu_read() usage
  futex: Fix incorrect should_fail_futex() handling
  lockdep: Fix preemption WARN for spurious IRQ-enable
2020-11-01 11:08:17 -08:00
Linus Torvalds
53760f9b74 flexible-array member conversion patches for 5.10-rc2
Hi Linus,
 
 Please, pull the following patches that replace zero-length arrays with
 flexible-array members.
 
 Thanks
 --
 Gustavo
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEEkmRahXBSurMIg1YvRwW0y0cG2zEFAl+cjRUACgkQRwW0y0cG
 2zGWAhAAjUfTsAmXWhKNaWFSCYR0Q822puTUWOKfiBd+jjGaO04luTtr2gjv2Dkb
 Vgad8H4N8oZU79xfh5JZ5PUyScaso8wE6ZJTh2PLKXpKmNd213f5x/pIt78CCDTa
 Y1L/eR41mmveTL3VNS3sf6WaZpT9owxJKGIY8JgdiOmSjxJQpX5zdaC1KYso4eXr
 lIXIRo9VLEmVLhhHhZi+QmX6+aQ05E1D9K0ENe4/uEnRsV525W78iwZ4fYeLzr+A
 krEOdgx6sPgzajPYnHoayrrcKNKxD5YY1SWuVSm2tqYYIhlRoK3f5xgLOd10RiHE
 YMgx8aWzGmGJwoUhgp1bo/l9EZ7O8OWRqM/GOP4x6Wgjdhqw2x5jgskmhsKNGEXu
 /BlbS+qL5aUrMCxhvNbApuZW6xBiBbva76MH3vU9vFhZbVz1CHLQdGI0tfxggYWS
 jc2UPgoxL9OQlf3jSc+gK7RMFhBGNWn2Aiy8GQas3BxPYXuYPvwOj+irDOG/qZ9D
 VZ5swUw4+th+DsF5K53mEFeLv0fONMgL9Ka5bNR6+k6HG0WNLYYVOiet3xYUDo1f
 eZbMZthfc+QW7R8cwG0WuFk6rC6mLqE+A9nQuLZoJD+VMuJd4pwW9+6EW8nDX08w
 FS4/o92xUFJfOCgaLRS61FSAuSmFENieN+yoKMK/Uf6PJVdNMb4=
 =vyu3
 -----END PGP SIGNATURE-----

Merge tag 'flexible-array-conversions-5.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux

Pull more flexible-array member conversions from Gustavo A. R. Silva:
 "Replace zero-length arrays with flexible-array members"

* tag 'flexible-array-conversions-5.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux:
  printk: ringbuffer: Replace zero-length array with flexible-array member
  net/smc: Replace zero-length array with flexible-array member
  net/mlx5: Replace zero-length array with flexible-array member
  mei: hw: Replace zero-length array with flexible-array member
  gve: Replace zero-length array with flexible-array member
  Bluetooth: btintel: Replace zero-length array with flexible-array member
  scsi: target: tcmu: Replace zero-length array with flexible-array member
  ima: Replace zero-length array with flexible-array member
  enetc: Replace zero-length array with flexible-array member
  fs: Replace zero-length array with flexible-array member
  Bluetooth: Replace zero-length array with flexible-array member
  params: Replace zero-length array with flexible-array member
  tracepoint: Replace zero-length array with flexible-array member
  platform/chrome: cros_ec_proto: Replace zero-length array with flexible-array member
  platform/chrome: cros_ec_commands: Replace zero-length array with flexible-array member
  mailbox: zynqmp-ipi-message: Replace zero-length array with flexible-array member
  dmaengine: ti-cppi5: Replace zero-length array with flexible-array member
2020-10-31 14:31:28 -07:00
Gustavo A. R. Silva
a38283da05 printk: ringbuffer: Replace zero-length array with flexible-array member
There is a regular need in the kernel to provide a way to declare having a
dynamically sized set of trailing elements in a structure. Kernel code should
always use “flexible array members”[1] for these cases. The older style of
one-element or zero-length arrays should no longer be used[2].

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.9/process/deprecated.html#zero-length-and-one-element-arrays

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-10-30 16:57:42 -05:00
Arnd Bergmann
0774a6ed29 timekeeping: default GENERIC_CLOCKEVENTS to enabled
Almost all machines use GENERIC_CLOCKEVENTS, so it feels wrong to
require each one to select that symbol manually.

Instead, enable it whenever CONFIG_LEGACY_TIMER_TICK is disabled as
a simplification. It should be possible to select both
GENERIC_CLOCKEVENTS and LEGACY_TIMER_TICK from an architecture now
and decide at runtime between the two.

For the clockevents arch-support.txt file, this means that additional
architectures are marked as TODO when they have at least one machine
that still uses LEGACY_TIMER_TICK, rather than being marked 'ok' when
at least one machine has been converted. This means that both m68k and
arm (for riscpc) revert to TODO.

At this point, we could just always enable CONFIG_GENERIC_CLOCKEVENTS
rather than leaving it off when not needed. I built an m68k
defconfig kernel (using gcc-10.1.0) and found that this would add
around 5.5KB in kernel image size:

   text	   data	    bss	    dec	    hex	filename
3861936	1092236	 196656	5150828	 4e986c	obj-m68k/vmlinux-no-clockevent
3866201	1093832	 196184	5156217	 4ead79	obj-m68k/vmlinux-clockevent

On Arm (MACH_RPC), that difference appears to be twice as large,
around 11KB on top of an 6MB vmlinux.

Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2020-10-30 21:57:07 +01:00
Arnd Bergmann
56cc7b8acf timekeeping: remove xtime_update
There are no more users of xtime_update aside from legacy_timer_tick(),
so fold it into that function and remove the declaration.

update_process_times() is now only called inside of the kernel/time/
code, so the declaration can be moved there.

Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2020-10-30 21:57:07 +01:00
Arnd Bergmann
b3550164a1 timekeeping: add CONFIG_LEGACY_TIMER_TICK
All platforms that currently do not use generic clockevents roughly call
the same set of functions in their timer interrupts: xtime_update(),
update_process_times() and profile_tick(), sometimes in a different
sequence.

Add a helper function that performs all three of them, to make the
callers more uniform and simplify the interface.

Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2020-10-30 21:57:04 +01:00
Arnd Bergmann
77f6c0b874 timekeeping: remove arch_gettimeoffset
With Arm EBSA110 gone, nothing uses it any more, so the corresponding
code and the Kconfig option can be removed.

Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2020-10-30 21:57:04 +01:00
Song Liu
20b6cc34ea bpf: Avoid hashtab deadlock with map_locked
If a hashtab is accessed in both non-NMI and NMI context, the system may
deadlock on bucket->lock. Fix this issue with percpu counter map_locked.
map_locked rejects concurrent access to the same bucket from the same CPU.
To reduce memory overhead, map_locked is not added per bucket. Instead,
8 percpu counters are added to each hashtab. buckets are assigned to these
counters based on the lower bits of its hash.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201029071925.3103400-3-songliubraving@fb.com
2020-10-30 13:03:29 -07:00
Song Liu
c50eb518e2 bpf: Use separate lockdep class for each hashtab
If a hashtab is accessed in both NMI and non-NMI contexts, it may cause
deadlock in bucket->lock. LOCKDEP NMI warning highlighted this issue:

./test_progs -t stacktrace

[   74.828970]
[   74.828971] ================================
[   74.828972] WARNING: inconsistent lock state
[   74.828973] 5.9.0-rc8+ #275 Not tainted
[   74.828974] --------------------------------
[   74.828975] inconsistent {INITIAL USE} -> {IN-NMI} usage.
[   74.828976] taskset/1174 [HC2[2]:SC0[0]:HE0:SE1] takes:
[   74.828977] ffffc90000ee96b0 (&htab->buckets[i].raw_lock){....}-{2:2}, at: htab_map_update_elem+0x271/0x5a0
[   74.828981] {INITIAL USE} state was registered at:
[   74.828982]   lock_acquire+0x137/0x510
[   74.828983]   _raw_spin_lock_irqsave+0x43/0x90
[   74.828984]   htab_map_update_elem+0x271/0x5a0
[   74.828984]   0xffffffffa0040b34
[   74.828985]   trace_call_bpf+0x159/0x310
[   74.828986]   perf_trace_run_bpf_submit+0x5f/0xd0
[   74.828987]   perf_trace_urandom_read+0x1be/0x220
[   74.828988]   urandom_read_nowarn.isra.0+0x26f/0x380
[   74.828989]   vfs_read+0xf8/0x280
[   74.828989]   ksys_read+0xc9/0x160
[   74.828990]   do_syscall_64+0x33/0x40
[   74.828991]   entry_SYSCALL_64_after_hwframe+0x44/0xa9
[   74.828992] irq event stamp: 1766
[   74.828993] hardirqs last  enabled at (1765): [<ffffffff82800ace>] asm_exc_page_fault+0x1e/0x30
[   74.828994] hardirqs last disabled at (1766): [<ffffffff8267df87>] irqentry_enter+0x37/0x60
[   74.828995] softirqs last  enabled at (856): [<ffffffff81043e7c>] fpu__clear+0xac/0x120
[   74.828996] softirqs last disabled at (854): [<ffffffff81043df0>] fpu__clear+0x20/0x120
[   74.828997]
[   74.828998] other info that might help us debug this:
[   74.828999]  Possible unsafe locking scenario:
[   74.828999]
[   74.829000]        CPU0
[   74.829001]        ----
[   74.829001]   lock(&htab->buckets[i].raw_lock);
[   74.829003]   <Interrupt>
[   74.829004]     lock(&htab->buckets[i].raw_lock);
[   74.829006]
[   74.829006]  *** DEADLOCK ***
[   74.829007]
[   74.829008] 1 lock held by taskset/1174:
[   74.829008]  #0: ffff8883ec3fd020 (&cpuctx_lock){-...}-{2:2}, at: perf_event_task_tick+0x101/0x650
[   74.829012]
[   74.829013] stack backtrace:
[   74.829014] CPU: 0 PID: 1174 Comm: taskset Not tainted 5.9.0-rc8+ #275
[   74.829015] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014
[   74.829016] Call Trace:
[   74.829016]  <NMI>
[   74.829017]  dump_stack+0x9a/0xd0
[   74.829018]  lock_acquire+0x461/0x510
[   74.829019]  ? lock_release+0x6b0/0x6b0
[   74.829020]  ? stack_map_get_build_id_offset+0x45e/0x800
[   74.829021]  ? htab_map_update_elem+0x271/0x5a0
[   74.829022]  ? rcu_read_lock_held_common+0x1a/0x50
[   74.829022]  ? rcu_read_lock_held+0x5f/0xb0
[   74.829023]  _raw_spin_lock_irqsave+0x43/0x90
[   74.829024]  ? htab_map_update_elem+0x271/0x5a0
[   74.829025]  htab_map_update_elem+0x271/0x5a0
[   74.829026]  bpf_prog_1fd9e30e1438d3c5_oncpu+0x9c/0xe88
[   74.829027]  bpf_overflow_handler+0x127/0x320
[   74.829028]  ? perf_event_text_poke_output+0x4d0/0x4d0
[   74.829029]  ? sched_clock_cpu+0x18/0x130
[   74.829030]  __perf_event_overflow+0xae/0x190
[   74.829030]  handle_pmi_common+0x34c/0x470
[   74.829031]  ? intel_pmu_save_and_restart+0x90/0x90
[   74.829032]  ? lock_acquire+0x3f8/0x510
[   74.829033]  ? lock_release+0x6b0/0x6b0
[   74.829034]  intel_pmu_handle_irq+0x11e/0x240
[   74.829034]  perf_event_nmi_handler+0x40/0x60
[   74.829035]  nmi_handle+0x110/0x360
[   74.829036]  ? __intel_pmu_enable_all.constprop.0+0x72/0xf0
[   74.829037]  default_do_nmi+0x6b/0x170
[   74.829038]  exc_nmi+0x106/0x130
[   74.829038]  end_repeat_nmi+0x16/0x55
[   74.829039] RIP: 0010:__intel_pmu_enable_all.constprop.0+0x72/0xf0
[   74.829042] Code: 2f 1f 03 48 8d bb b8 0c 00 00 e8 29 09 41 00 48 ...
[   74.829043] RSP: 0000:ffff8880a604fc90 EFLAGS: 00000002
[   74.829044] RAX: 000000070000000f RBX: ffff8883ec2195a0 RCX: 000000000000038f
[   74.829045] RDX: 0000000000000007 RSI: ffffffff82e72c20 RDI: ffff8883ec21a258
[   74.829046] RBP: 000000070000000f R08: ffffffff8101b013 R09: fffffbfff0a7982d
[   74.829047] R10: ffffffff853cc167 R11: fffffbfff0a7982c R12: 0000000000000000
[   74.829049] R13: ffff8883ec3f0af0 R14: ffff8883ec3fd120 R15: ffff8883e9c92098
[   74.829049]  ? intel_pmu_lbr_enable_all+0x43/0x240
[   74.829050]  ? __intel_pmu_enable_all.constprop.0+0x72/0xf0
[   74.829051]  ? __intel_pmu_enable_all.constprop.0+0x72/0xf0
[   74.829052]  </NMI>
[   74.829053]  perf_event_task_tick+0x48d/0x650
[   74.829054]  scheduler_tick+0x129/0x210
[   74.829054]  update_process_times+0x37/0x70
[   74.829055]  tick_sched_handle.isra.0+0x35/0x90
[   74.829056]  tick_sched_timer+0x8f/0xb0
[   74.829057]  __hrtimer_run_queues+0x364/0x7d0
[   74.829058]  ? tick_sched_do_timer+0xa0/0xa0
[   74.829058]  ? enqueue_hrtimer+0x1e0/0x1e0
[   74.829059]  ? recalibrate_cpu_khz+0x10/0x10
[   74.829060]  ? ktime_get_update_offsets_now+0x1a3/0x360
[   74.829061]  hrtimer_interrupt+0x1bb/0x360
[   74.829062]  ? rcu_read_lock_sched_held+0xa1/0xd0
[   74.829063]  __sysvec_apic_timer_interrupt+0xed/0x3d0
[   74.829064]  sysvec_apic_timer_interrupt+0x3f/0xd0
[   74.829064]  ? asm_sysvec_apic_timer_interrupt+0xa/0x20
[   74.829065]  asm_sysvec_apic_timer_interrupt+0x12/0x20
[   74.829066] RIP: 0033:0x7fba18d579b4
[   74.829068] Code: 74 54 44 0f b6 4a 04 41 83 e1 0f 41 80 f9 ...
[   74.829069] RSP: 002b:00007ffc9ba69570 EFLAGS: 00000206
[   74.829071] RAX: 00007fba192084c0 RBX: 00007fba18c24d28 RCX: 00000000000007a4
[   74.829072] RDX: 00007fba18c30488 RSI: 0000000000000000 RDI: 000000000000037b
[   74.829073] RBP: 00007fba18ca5760 R08: 00007fba18c248fc R09: 00007fba18c94c30
[   74.829074] R10: 000000000000002f R11: 0000000000073c30 R12: 00007ffc9ba695e0
[   74.829075] R13: 00000000000003f3 R14: 00007fba18c21ac8 R15: 00000000000058d6

However, such warning should not apply across multiple hashtabs. The
system will not deadlock if one hashtab is used in NMI, while another
hashtab is used in non-NMI.

Use separate lockdep class for each hashtab, so that we don't get this
false alert.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201029071925.3103400-2-songliubraving@fb.com
2020-10-30 13:03:29 -07:00
Linus Torvalds
8843f40550 Power management fixes for 5.10-rc2
- Modify Kconfig to prevent configuring either the "conservative"
    or the "ondemand" governor as the default cpufreq governor if
    intel_pstate is selected, in which case "schedutil" is the
    default choice for the default governor setting (Rafael Wysocki).
 
  - Modify the cpufreq core, intel_pstate and the schedutil governor
    to avoid missing updates of the HWP max limit when intel_pstate
    operates in the passive mode with HWP enabled (Rafael Wysocki).
 
  - Fix max_cstate module parameter handling in intel_idle for
    processor models with C-state tables coming from ACPI (Chen Yu).
 
  - Clean up assorted pieces of power management code (Jackie Zamow,
    Tom Rix, Zhang Qilong).
 -----BEGIN PGP SIGNATURE-----
 
 iQJGBAABCAAwFiEE4fcc61cGeeHD/fCwgsRv/nhiVHEFAl+cOyISHHJqd0Byand5
 c29ja2kubmV0AAoJEILEb/54YlRxxj0P/1qmvZeLR5ODvSKLURSlzQYPiF4Ud0uo
 7huByO3K63hJ9qpEQZVVzNl0Yuu5vCa7cliebnIRNDHMy4AVOVw5Qf9Uhz/tFlmZ
 ZBvSX1LGWdvMzUnx00AASdHbNOrFy+YyooQ5RfA8sFmtvAhRhPNRW9VCzc9Midoh
 cICSQ6fQDn+0wb+hv89HQlIRvbakM6a8QDL4xI6Y8aS/a5OwOHGJQnC7ZLPIoQLi
 BxD/IEDdNvDiLFPx8OpxJ93NtLaz1tyvWFJHvqSnOREDYB22YkG8WLZftY7h8pz6
 MMbXrZN11/Tex1H0KXDI4YscCBnwxNnFuBo1ur/FX6GvDm2Sm9ybpVHCXxYKux46
 ZFc8K2auqApt98xTlrqKru/rfCB2/fubypUustqpYeCjowBENPFbjyag8bRaKLh3
 awiDwwz1wZDd2mZfEl4iaxJI4gjUwRmPDC1UiT1dlc7nozaDzPxrGGiQghAshOnW
 JVQAiw+evERIFuH5YvJ+/si1sJYhreMjoQ7mICNMmpgJ2ElVvNufpW9aVRQiycp1
 9a0u1ZgGs9DI1580+YTl1nGvsRefdgvMDpozcESwxY8dmMm+027+lyLhwlrUTPfy
 gmakUcb4jbvIicG53huxus7teqBLwrX36HOHBb1l3tSJfOkcQieddGUZxuT8Q9xp
 rAY2mRMRr7SI
 =w+LI
 -----END PGP SIGNATURE-----

Merge tag 'pm-5.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fixes from Rafael Wysocki:
 "These fix a few issues related to running intel_pstate in the passive
  mode with HWP enabled, correct the handling of the max_cstate module
  parameter in intel_idle and make a few janitorial changes.

  Specifics:

   - Modify Kconfig to prevent configuring either the "conservative" or
     the "ondemand" governor as the default cpufreq governor if
     intel_pstate is selected, in which case "schedutil" is the default
     choice for the default governor setting (Rafael Wysocki).

   - Modify the cpufreq core, intel_pstate and the schedutil governor to
     avoid missing updates of the HWP max limit when intel_pstate
     operates in the passive mode with HWP enabled (Rafael Wysocki).

   - Fix max_cstate module parameter handling in intel_idle for
     processor models with C-state tables coming from ACPI (Chen Yu).

   - Clean up assorted pieces of power management code (Jackie Zamow,
     Tom Rix, Zhang Qilong)"

* tag 'pm-5.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: schedutil: Always call driver if CPUFREQ_NEED_UPDATE_LIMITS is set
  cpufreq: Introduce cpufreq_driver_test_flags()
  cpufreq: speedstep: remove unneeded semicolon
  PM: sleep: fix typo in kernel/power/process.c
  intel_idle: Fix max_cstate for processor models without C-state tables
  cpufreq: intel_pstate: Avoid missing HWP max updates in passive mode
  cpufreq: Introduce CPUFREQ_NEED_UPDATE_LIMITS driver flag
  cpufreq: Avoid configuring old governors as default with intel_pstate
  cpufreq: e_powersaver: remove unreachable break
2020-10-30 12:45:04 -07:00
Peter Zijlstra
1a39340865 lockdep: Fix nr_unused_locks accounting
Chris reported that commit 24d5a3bffef1 ("lockdep: Fix
usage_traceoverflow") breaks the nr_unused_locks validation code
triggered by /proc/lockdep_stats.

By fully splitting LOCK_USED and LOCK_USED_READ it becomes a bad
indicator for accounting nr_unused_locks; simplyfy by using any first
bit.

Fixes: 24d5a3bffef1 ("lockdep: Fix usage_traceoverflow")
Reported-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://lkml.kernel.org/r/20201027124834.GL2628@hirez.programming.kicks-ass.net
2020-10-30 17:07:18 +01:00
Peter Zijlstra
d48e385003 locking/lockdep: Remove more raw_cpu_read() usage
I initially thought raw_cpu_read() was OK, since if it is !0 we have
IRQs disabled and can't get migrated, so if we get migrated both CPUs
must have 0 and it doesn't matter which 0 we read.

And while that is true; it isn't the whole store, on pretty much all
architectures (except x86) this can result in computing the address for
one CPU, getting migrated, the old CPU continuing execution with another
task (possibly setting recursion) and then the new CPU reading the value
of the old CPU, which is no longer 0.

Similer to:

  baffd723e4 ("lockdep: Revert "lockdep: Use raw_cpu_*() for per-cpu variables"")

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201026152256.GB2651@hirez.programming.kicks-ass.net
2020-10-30 17:07:18 +01:00
Rafael J. Wysocki
dea47cf45a Merge branches 'pm-cpuidle' and 'pm-sleep'
* pm-cpuidle:
  intel_idle: Fix max_cstate for processor models without C-state tables

* pm-sleep:
  PM: sleep: fix typo in kernel/power/process.c
2020-10-30 16:30:14 +01:00
Ard Biesheuvel
080b6f4076 bpf: Don't rely on GCC __attribute__((optimize)) to disable GCSE
Commit 3193c0836 ("bpf: Disable GCC -fgcse optimization for
___bpf_prog_run()") introduced a __no_fgcse macro that expands to a
function scope __attribute__((optimize("-fno-gcse"))), to disable a
GCC specific optimization that was causing trouble on x86 builds, and
was not expected to have any positive effect in the first place.

However, as the GCC manual documents, __attribute__((optimize))
is not for production use, and results in all other optimization
options to be forgotten for the function in question. This can
cause all kinds of trouble, but in one particular reported case,
it causes -fno-asynchronous-unwind-tables to be disregarded,
resulting in .eh_frame info to be emitted for the function.

This reverts commit 3193c0836, and instead, it disables the -fgcse
optimization for the entire source file, but only when building for
X86 using GCC with CONFIG_BPF_JIT_ALWAYS_ON disabled. Note that the
original commit states that CONFIG_RETPOLINE=n triggers the issue,
whereas CONFIG_RETPOLINE=y performs better without the optimization,
so it is kept disabled in both cases.

Fixes: 3193c0836f ("bpf: Disable GCC -fgcse optimization for ___bpf_prog_run()")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/lkml/CAMuHMdUg0WJHEcq6to0-eODpXPOywLot6UD2=GFHpzoj_hCoBQ@mail.gmail.com/
Link: https://lore.kernel.org/bpf/20201028171506.15682-2-ardb@kernel.org
2020-10-29 20:01:46 -07:00
Gustavo A. R. Silva
fa29c9c11d params: Replace zero-length array with flexible-array member
There is a regular need in the kernel to provide a way to declare having a
dynamically sized set of trailing elements in a structure. Kernel code should
always use “flexible array members”[1] for these cases. The older style of
one-element or zero-length arrays should no longer be used[2].

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.9-rc1/process/deprecated.html#zero-length-and-one-element-arrays

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-10-29 17:22:59 -05:00
Gustavo A. R. Silva
9d0a49c702 tracepoint: Replace zero-length array with flexible-array member
There is a regular need in the kernel to provide a way to declare having a
dynamically sized set of trailing elements in a structure. Kernel code should
always use “flexible array members”[1] for these cases. The older style of
one-element or zero-length arrays should no longer be used[2].

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.9-rc1/process/deprecated.html#zero-length-and-one-element-arrays

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-10-29 17:22:59 -05:00
Rafael J. Wysocki
d1e7c2996e cpufreq: schedutil: Always call driver if CPUFREQ_NEED_UPDATE_LIMITS is set
Because sugov_update_next_freq() may skip a frequency update even if
the need_freq_update flag has been set for the policy at hand, policy
limits updates may not take effect as expected.

For example, if the intel_pstate driver operates in the passive mode
with HWP enabled, it needs to update the HWP min and max limits when
the policy min and max limits change, respectively, but that may not
happen if the target frequency does not change along with the limit
at hand.  In particular, if the policy min is changed first, causing
the target frequency to be adjusted to it, and the policy max limit
is changed later to the same value, the HWP max limit will not be
updated to follow it as expected, because the target frequency is
still equal to the policy min limit and it will not change until
that limit is updated.

To address this issue, modify get_next_freq() to let the driver
callback run if the CPUFREQ_NEED_UPDATE_LIMITS cpufreq driver flag
is set regardless of whether or not the new frequency to set is
equal to the previous one.

Fixes: f6ebbcf08f ("cpufreq: intel_pstate: Implement passive mode with HWP enabled")
Reported-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Cc: 5.9+ <stable@vger.kernel.org> # 5.9+: 1c534352f4 cpufreq: Introduce CPUFREQ_NEED_UPDATE_LIMITS ...
Cc: 5.9+ <stable@vger.kernel.org> # 5.9+: a62f68f5ca cpufreq: Introduce cpufreq_driver_test_flags()
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-10-29 14:12:18 +01:00
Miroslav Benes
5e8ed280da module: set MODULE_STATE_GOING state when a module fails to load
If a module fails to load due to an error in prepare_coming_module(),
the following error handling in load_module() runs with
MODULE_STATE_COMING in module's state. Fix it by correctly setting
MODULE_STATE_GOING under "bug_cleanup" label.

Signed-off-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
2020-10-29 12:29:16 +01:00
Ira Weiny
45ff510517 entry: Fixup irqentry_enter() comment
irq_enter_from_user_mode() was changed to irqentry_enter_from_user_mode().
Update the comment within irqentry_enter() to reflect this change.

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201028163632.965518-1-ira.weiny@intel.com
2020-10-29 11:31:29 +01:00
Peter Zijlstra
51b646b2d9 perf,mm: Handle non-page-table-aligned hugetlbfs
A limited nunmber of architectures support hugetlbfs sizes that do not
align with the page-tables (ARM64, Power, Sparc64). Add support for
this to the generic perf_get_page_size() implementation, and also
allow an architecture to override this implementation.

This latter is only needed when it uses non-page-table aligned huge
pages in its kernel map.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2020-10-29 11:00:39 +01:00
Stephane Eranian
995f088efe perf/core: Add support for PERF_SAMPLE_CODE_PAGE_SIZE
When studying code layout, it is useful to capture the page size of the
sampled code address.

Add a new sample type for code page size.
The new sample type requires collecting the ip. The code page size can
be calculated from the NMI-safe perf_get_page_size().

For large PEBS, it's very unlikely that the mapping is gone for the
earlier PEBS records. Enable the feature for the large PEBS. The worst
case is that page-size '0' is returned.

Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201001135749.2804-5-kan.liang@linux.intel.com
2020-10-29 11:00:39 +01:00
Kan Liang
8d97e71811 perf/core: Add PERF_SAMPLE_DATA_PAGE_SIZE
Current perf can report both virtual addresses and physical addresses,
but not the MMU page size. Without the MMU page size information of the
utilized page, users cannot decide whether to promote/demote large pages
to optimize memory usage.

Add a new sample type for the data MMU page size.

Current perf already has a facility to collect data virtual addresses.
A page walker is required to walk the pages tables and calculate the
MMU page size from a given virtual address.

On some platforms, e.g., X86, the page walker is invoked in an NMI
handler. So the page walker must be NMI-safe and low overhead. Besides,
the page walker should work for both user and kernel virtual address.
The existing generic page walker, e.g., walk_page_range_novma(), is a
little bit complex and doesn't guarantee the NMI-safe. The follow_page()
is only for user-virtual address.

Add a new function perf_get_page_size() to walk the page tables and
calculate the MMU page size. In the function:
- Interrupts have to be disabled to prevent any teardown of the page
  tables.
- For user space threads, the current->mm is used for the page walker.
  For kernel threads and the like, the current->mm is NULL. The init_mm
  is used for the page walker. The active_mm is not used here, because
  it can be NULL.
  Quote from Peter Zijlstra,
  "context_switch() can set prev->active_mm to NULL when it transfers it
   to @next. It does this before @current is updated. So an NMI that
   comes in between this active_mm swizzling and updating @current will
   see !active_mm."
- The MMU page size is calculated from the page table level.

The method should work for all architectures, but it has only been
verified on X86. Should there be some architectures, which support perf,
where the method doesn't work, it can be fixed later separately.
Reporting the wrong page size would not be fatal for the architecture.

Some under discussion features may impact the method in the future.
Quote from Dave Hansen,
  "There are lots of weird things folks are trying to do with the page
   tables, like Address Space Isolation.  For instance, if you get a
   perf NMI when running userspace, current->mm->pgd is *different* than
   the PGD that was in use when userspace was running. It's close enough
   today, but it might not stay that way."
If the case happens later, lots of consecutive page walk errors will
happen. The worst case is that lots of page-size '0' are returned, which
would not be fatal.
In the perf tool, a check is implemented to detect this case. Once it
happens, a kernel patch could be implemented accordingly then.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201001135749.2804-2-kan.liang@linux.intel.com
2020-10-29 11:00:38 +01:00
Julia Lawall
d8fcb81f1a sched/fair: Check for idle core in wake_affine
In the case of a thread wakeup, wake_affine determines whether a core
will be chosen for the thread on the socket where the thread ran
previously or on the socket of the waker.  This is done primarily by
comparing the load of the core where th thread ran previously (prev)
and the load of the waker (this).

commit 11f10e5420 ("sched/fair: Use load instead of runnable load
in wakeup path") changed the load computation from the runnable load
to the load average, where the latter includes the load of threads
that have already blocked on the core.

When a short-running daemon processes happens to run on prev, this
change raised the situation that prev could appear to have a greater
load than this, even when prev is actually idle.  When prev and this
are on the same socket, the idle prev is detected later, in
select_idle_sibling.  But if that does not hold, prev is completely
ignored, causing the waking thread to move to the socket of the waker.
In the case of N mostly active threads on N cores, this triggers other
migrations and hurts performance.

In contrast, before commit 11f10e5420, the load on an idle core
was 0, and in the case of a non-idle waker core, the effect of
wake_affine was to select prev as the target for searching for a core
for the waking thread.

To avoid unnecessary migrations, extend wake_affine_idle to check
whether the core where the thread previously ran is currently idle,
and if so simply return that core as the target.

[1] commit 11f10e5420 ("sched/fair: Use load instead of runnable
load in wakeup path")

This particularly has an impact when using the ondemand power manager,
where kworkers run every 0.004 seconds on all cores, increasing the
likelihood that an idle core will be considered to have a load.

The following numbers were obtained with the benchmarking tool
hyperfine (https://github.com/sharkdp/hyperfine) on the NAS parallel
benchmarks (https://www.nas.nasa.gov/publications/npb.html).  The
tests were run on an 80-core Intel(R) Xeon(R) CPU E7-8870 v4 @
2.10GHz.  Active (intel_pstate) and passive (intel_cpufreq) power
management were used.  Times are in seconds.  All experiments use all
160 hardware threads.

	v5.9/intel-pstate	v5.9+patch/intel-pstate
bt.C.c	24.725724+-0.962340	23.349608+-1.607214
lu.C.x	29.105952+-4.804203	25.249052+-5.561617
sp.C.x	31.220696+-1.831335	30.227760+-2.429792
ua.C.x	26.606118+-1.767384	25.778367+-1.263850

	v5.9/ondemand		v5.9+patch/ondemand
bt.C.c	25.330360+-1.028316	23.544036+-1.020189
lu.C.x	35.872659+-4.872090	23.719295+-3.883848
sp.C.x	32.141310+-2.289541	29.125363+-0.872300
ua.C.x	29.024597+-1.667049	25.728888+-1.539772

On the smaller data sets (A and B) and on the other NAS benchmarks
there is no impact on performance.

This also has a major impact on the splash2x.volrend benchmark of the
parsec benchmark suite that goes from 1m25 without this patch to 0m45,
in active (intel_pstate) mode.

Fixes: 11f10e5420 ("sched/fair: Use load instead of runnable load in wakeup path")
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by Vincent Guittot <vincent.guittot@linaro.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Link: https://lkml.kernel.org/r/1603372550-14680-1-git-send-email-Julia.Lawall@inria.fr
2020-10-29 11:00:32 +01:00
Peter Zijlstra
43c31ac0e6 sched: Remove relyance on STRUCT_ALIGNMENT
Florian reported that all of kernel/sched/ is rebuild when
CONFIG_BLK_DEV_INITRD is changed, which, while not a bug is
unexpected. This is due to us including vmlinux.lds.h.

Jakub explained that the problem is that we put the alignment
requirement on the type instead of on a variable. Type alignment is a
minimum, the compiler is free to pick any larger alignment for a
specific instance of the type (eg. the variable).

So force the type alignment on all individual variable definitions and
remove the undesired dependency on vmlinux.lds.h.

Fixes: 85c2ce9104 ("sched, vmlinux.lds: Increase STRUCT_ALIGNMENT to 64 bytes for GCC-4.9")
Reported-by: Florian Fainelli <f.fainelli@gmail.com>
Suggested-by: Jakub Jelinek <jakub@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2020-10-29 11:00:32 +01:00
Thomas Gleixner
345a957fcc sched: Reenable interrupts in do_sched_yield()
do_sched_yield() invokes schedule() with interrupts disabled which is
not allowed. This goes back to the pre git era to commit a6efb709806c
("[PATCH] irqlock patch 2.5.27-H6") in the history tree.

Reenable interrupts and remove the misleading comment which "explains" it.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/87r1pt7y5c.fsf@nanos.tec.linutronix.de
2020-10-29 11:00:31 +01:00
Mathieu Desnoyers
25595eb6aa sched: membarrier: document memory ordering scenarios
Document membarrier ordering scenarios in membarrier.c. Thanks to Alan
Stern for refreshing my memory. Now that I have those in mind, it seems
appropriate to serialize them to comments for posterity.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201020134715.13909-4-mathieu.desnoyers@efficios.com
2020-10-29 11:00:31 +01:00
Mathieu Desnoyers
618758ed3a sched: membarrier: cover kthread_use_mm (v4)
Add comments and memory barrier to kthread_use_mm and kthread_unuse_mm
to allow the effect of membarrier(2) to apply to kthreads accessing
user-space memory as well.

Given that no prior kthread use this guarantee and that it only affects
kthreads, adding this guarantee does not affect user-space ABI.

Refine the check in membarrier_global_expedited to exclude runqueues
running the idle thread rather than all kthreads from the IPI cpumask.

Now that membarrier_global_expedited can IPI kthreads, the scheduler
also needs to update the runqueue's membarrier_state when entering lazy
TLB state.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201020134715.13909-3-mathieu.desnoyers@efficios.com
2020-10-29 11:00:31 +01:00
Mathieu Desnoyers
5bc7850232 sched: fix exit_mm vs membarrier (v4)
exit_mm should issue memory barriers after user-space memory accesses,
before clearing current->mm, to order user-space memory accesses
performed prior to exit_mm before clearing tsk->mm, which has the
effect of skipping the membarrier private expedited IPIs.

exit_mm should also update the runqueue's membarrier_state so
membarrier global expedited IPIs are not sent when they are not
needed.

The membarrier system call can be issued concurrently with do_exit
if we have thread groups created with CLONE_VM but not CLONE_THREAD.

Here is the scenario I have in mind:

Two thread groups are created, A and B. Thread group B is created by
issuing clone from group A with flag CLONE_VM set, but not CLONE_THREAD.
Let's assume we have a single thread within each thread group (Thread A
and Thread B).

The AFAIU we can have:

Userspace variables:

int x = 0, y = 0;

CPU 0                   CPU 1
Thread A                Thread B
(in thread group A)     (in thread group B)

x = 1
barrier()
y = 1
exit()
exit_mm()
current->mm = NULL;
                        r1 = load y
                        membarrier()
                          skips CPU 0 (no IPI) because its current mm is NULL
                        r2 = load x
                        BUG_ON(r1 == 1 && r2 == 0)

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201020134715.13909-2-mathieu.desnoyers@efficios.com
2020-10-29 11:00:30 +01:00
Peter Zijlstra
45da7a2b0a sched/fair: Exclude the current CPU from find_new_ilb()
It is possible for find_new_ilb() to select the current CPU, however,
this only happens from newidle balancing, in which case need_resched()
will be true, and consequently nohz_csd_func() will not trigger the
softirq.

Exclude the current CPU from becoming an ILB target.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2020-10-29 11:00:30 +01:00
Peter Zijlstra
b13772f813 sched/cpupri: Add CPUPRI_HIGHER
Add CPUPRI_HIGHER above the RT99 priority to denote the CPU is in use
by higher priority tasks (specifically deadline).

XXX: we should probably drive PUSH-PULL from cpupri, that would
automagically result in an RT-PUSH when DL sets cpupri to CPUPRI_HIGHER.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
2020-10-29 11:00:30 +01:00
Peter Zijlstra
934fc3314b sched/cpupri: Remap CPUPRI_NORMAL to MAX_RT_PRIO-1
This makes the mapping continuous and frees up 100 for other usage.

Prev mapping:

p->rt_priority   p->prio   newpri   cpupri

                               -1       -1 (CPUPRI_INVALID)

                              100        0 (CPUPRI_NORMAL)

             1        98       98        1
           ...
            49        50       50       49
            50        49       49       50
           ...
            99         0        0       99

New mapping:

p->rt_priority   p->prio   newpri   cpupri

                               -1       -1 (CPUPRI_INVALID)

                               99        0 (CPUPRI_NORMAL)

             1        98       98        1
           ...
            49        50       50       49
            50        49       49       50
           ...
            99         0        0       99

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
2020-10-29 11:00:30 +01:00
Dietmar Eggemann
1b08782ce3 sched/cpupri: Remove pri_to_cpu[1]
pri_to_cpu[1] isn't used since cpupri_set(..., newpri) is
never called with newpri = 99.

The valid RT priorities RT1..RT99 (p->rt_priority = [1..99]) map into
cpupri (idx of pri_to_cpu[]) = [2..100]

Current mapping:

p->rt_priority   p->prio   newpri   cpupri

                               -1       -1 (CPUPRI_INVALID)

                              100        0 (CPUPRI_NORMAL)

             1        98       98        2
           ...
            49        50       50       50
            50        49       49       51
           ...
            99         0        0      100

So cpupri = 1 isn't used.

Reduce the size of pri_to_cpu[] by 1 and adapt the cpupri
implementation accordingly. This will save a useless for loop with an
atomic_read in cpupri_find_fitness() calling __cpupri_find().

New mapping:

p->rt_priority   p->prio   newpri   cpupri

                               -1       -1 (CPUPRI_INVALID)

                              100        0 (CPUPRI_NORMAL)

             1        98       98        1
           ...
            49        50       50       49
            50        49       49       50
           ...
            99         0        0       99

Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200922083934.19275-3-dietmar.eggemann@arm.com
2020-10-29 11:00:29 +01:00
Dietmar Eggemann
5e054bca44 sched/cpupri: Remove pri_to_cpu[CPUPRI_IDLE]
pri_to_cpu[CPUPRI_IDLE=0] isn't used since cpupri_set(..., newpri) is
never called with newpri = MAX_PRIO (140).

Current mapping:

p->rt_priority   p->prio   newpri   cpupri

                               -1       -1 (CPUPRI_INVALID)

                              140        0 (CPUPRI_IDLE)

                              100        1 (CPUPRI_NORMAL)

             1        98       98        3
           ...
            49        50       50       51
            50        49       49       52
           ...
            99         0        0      101

Even when cpupri was introduced with commit 6e0534f278 ("sched: use a
2-d bitmap for searching lowest-pri CPU") in v2.6.27, only

   (1) CPUPRI_INVALID (-1),
   (2) MAX_RT_PRIO (100),
   (3) an RT prio (RT1..RT99)

were used as newprio in cpupri_set(..., newpri) -> convert_prio(newpri).

MAX_RT_PRIO is used only in dec_rt_tasks() -> dec_rt_prio() ->
dec_rt_prio_smp() -> cpupri_set() in case of !rt_rq->rt_nr_running.
I.e. it stands for a non-rt task, including the IDLE task.

Commit 57785df5ac ("sched: Fix task priority bug") removed code in
v2.6.33 which did set the priority of the IDLE task to MAX_PRIO.
Although this happened after the introduction of cpupri, it didn't have
an effect on the values used for cpupri_set(..., newpri).

Remove CPUPRI_IDLE and adapt the cpupri implementation accordingly.
This will save a useless for loop with an atomic_read in
cpupri_find_fitness() calling __cpupri_find().

New mapping:

p->rt_priority   p->prio   newpri   cpupri

                               -1       -1 (CPUPRI_INVALID)

                              100        0 (CPUPRI_NORMAL)

             1        98       98        2
           ...
            49        50       50       50
            50        49       49       51
           ...
            99         0        0      100

Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200922083934.19275-2-dietmar.eggemann@arm.com
2020-10-29 11:00:29 +01:00
Peng Liu
a57415f5d1 sched/deadline: Fix sched_dl_global_validate()
When change sched_rt_{runtime, period}_us, we validate that the new
settings should at least accommodate the currently allocated -dl
bandwidth:

  sched_rt_handler()
    -->	sched_dl_bandwidth_validate()
	{
		new_bw = global_rt_runtime()/global_rt_period();

		for_each_possible_cpu(cpu) {
			dl_b = dl_bw_of(cpu);
			if (new_bw < dl_b->total_bw)    <-------
				ret = -EBUSY;
		}
	}

But under CONFIG_SMP, dl_bw is per root domain , but not per CPU,
dl_b->total_bw is the allocated bandwidth of the whole root domain.
Instead, we should compare dl_b->total_bw against "cpus*new_bw",
where 'cpus' is the number of CPUs of the root domain.

Also, below annotation(in kernel/sched/sched.h) implied implementation
only appeared in SCHED_DEADLINE v2[1], then deadline scheduler kept
evolving till got merged(v9), but the annotation remains unchanged,
meaningless and misleading, update it.

* With respect to SMP, the bandwidth is given on a per-CPU basis,
* meaning that:
*  - dl_bw (< 100%) is the bandwidth of the system (group) on each CPU;
*  - dl_total_bw array contains, in the i-eth element, the currently
*    allocated bandwidth on the i-eth CPU.

[1]: https://lore.kernel.org/lkml/1267385230.13676.101.camel@Palantir/

Fixes: 332ac17ef5 ("sched/deadline: Add bandwidth management for SCHED_DEADLINE tasks")
Signed-off-by: Peng Liu <iwtbavbm@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Acked-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://lkml.kernel.org/r/db6bbda316048cda7a1bbc9571defde193a8d67e.1602171061.git.iwtbavbm@gmail.com
2020-10-29 11:00:29 +01:00
Peng Liu
26762423a2 sched/deadline: Optimize sched_dl_global_validate()
Under CONFIG_SMP, dl_bw is per root domain, but not per CPU.
When checking or updating dl_bw, currently iterating every CPU is
overdoing, just need iterate each root domain once.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Peng Liu <iwtbavbm@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Acked-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://lkml.kernel.org/r/78d21ee792cc48ff79e8cd62a5f26208463684d6.1602171061.git.iwtbavbm@gmail.com
2020-10-29 11:00:28 +01:00
jun qian
b9c88f7522 sched/fair: Improve the accuracy of sched_stat_wait statistics
When the sched_schedstat changes from 0 to 1, some sched se maybe
already in the runqueue, the se->statistics.wait_start will be 0.
So it will let the (rq_of(cfs_rq)) - se->statistics.wait_start)
wrong. We need to avoid this scenario.

Signed-off-by: jun qian <qianjun.kernel@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lkml.kernel.org/r/20201015064846.19809-1-qianjun.kernel@gmail.com
2020-10-29 11:00:28 +01:00
Jens Axboe
114518eb64 task_work: Use TIF_NOTIFY_SIGNAL if available
If the arch supports TIF_NOTIFY_SIGNAL, then use that for TWA_SIGNAL as
it's more efficient than using the signal delivery method. This is
especially true on threaded applications, where ->sighand is shared across
threads, but it's also lighter weight on non-shared cases.

io_uring is a heavy consumer of TWA_SIGNAL based task_work. A test with
threads shows a nice improvement running an io_uring based echo server.

stock kernel:
0.01% <= 0.1 milliseconds
95.86% <= 0.2 milliseconds
98.27% <= 0.3 milliseconds
99.71% <= 0.4 milliseconds
100.00% <= 0.5 milliseconds
100.00% <= 0.6 milliseconds
100.00% <= 0.7 milliseconds
100.00% <= 0.8 milliseconds
100.00% <= 0.9 milliseconds
100.00% <= 1.0 milliseconds
100.00% <= 1.1 milliseconds
100.00% <= 2 milliseconds
100.00% <= 3 milliseconds
100.00% <= 3 milliseconds
1378930.00 requests per second
~1600% CPU

1.38M requests/second, and all 16 CPUs are maxed out.

patched kernel:
0.01% <= 0.1 milliseconds
98.24% <= 0.2 milliseconds
99.47% <= 0.3 milliseconds
99.99% <= 0.4 milliseconds
100.00% <= 0.5 milliseconds
100.00% <= 0.6 milliseconds
100.00% <= 0.7 milliseconds
100.00% <= 0.8 milliseconds
100.00% <= 0.9 milliseconds
100.00% <= 1.2 milliseconds
1666111.38 requests per second
~1450% CPU

1.67M requests/second, and we're no longer just hammering on the sighand
lock. The original reporter states:

"For 5.7.15 my benchmark achieves 1.6M qps and system cpu is at ~80%.
 for 5.7.16 or later it achieves only 1M qps and the system cpu is is
 at ~100%"

with the only difference there being that TWA_SIGNAL is used
unconditionally in 5.7.16, since it's required to be able to handle the
inability to run task_work if the application is waiting in the kernel
already on an event that needs task_work run to be satisfied. Also see
commit 0ba9c9edcd.

Reported-by: Roman Gershman <romger@amazon.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/r/20201026203230.386348-5-axboe@kernel.dk
2020-10-29 09:37:37 +01:00
Jens Axboe
12db8b6900 entry: Add support for TIF_NOTIFY_SIGNAL
Add TIF_NOTIFY_SIGNAL handling in the generic entry code, which if set,
will return true if signal_pending() is used in a wait loop. That causes an
exit of the loop so that notify_signal tracehooks can be run. If the wait
loop is currently inside a system call, the system call is restarted once
task_work has been processed.

In preparation for only having arch_do_signal() handle syscall restarts if
_TIF_SIGPENDING isn't set, rename it to arch_do_signal_or_restart().  Pass
in a boolean that tells the architecture specific signal handler if it
should attempt to get a signal, or just process a potential syscall
restart.

For !CONFIG_GENERIC_ENTRY archs, add the TIF_NOTIFY_SIGNAL handling to
get_signal(). This is done to minimize the needed architecture changes to
support this feature.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/r/20201026203230.386348-3-axboe@kernel.dk
2020-10-29 09:37:36 +01:00
Jens Axboe
5c251e9dc0 signal: Add task_sigpending() helper
This is in preparation for maintaining signal_pending() as the decider of
whether or not a schedule() loop should be broken, or continue sleeping.
This is different than the core signal use cases, which really need to know
whether an actual signal is pending or not. task_sigpending() returns
non-zero if TIF_SIGPENDING is set.

Only core kernel use cases should care about the distinction between
the two, make sure those use the task_sigpending() helper.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/r/20201026203230.386348-2-axboe@kernel.dk
2020-10-29 09:37:36 +01:00
Yonghong Song
cf83b2d2e2 bpf: Permit cond_resched for some iterators
Commit e679654a70 ("bpf: Fix a rcu_sched stall issue with
bpf task/task_file iterator") tries to fix rcu stalls warning
which is caused by bpf task_file iterator when running
"bpftool prog".

      rcu: INFO: rcu_sched self-detected stall on CPU
      rcu: \x097-....: (20999 ticks this GP) idle=302/1/0x4000000000000000 softirq=1508852/1508852 fqs=4913
      \x09(t=21031 jiffies g=2534773 q=179750)
      NMI backtrace for cpu 7
      CPU: 7 PID: 184195 Comm: bpftool Kdump: loaded Tainted: G        W         5.8.0-00004-g68bfc7f8c1b4 #6
      Hardware name: Quanta Twin Lakes MP/Twin Lakes Passive MP, BIOS F09_3A17 05/03/2019
      Call Trace:
      <IRQ>
      dump_stack+0x57/0x70
      nmi_cpu_backtrace.cold+0x14/0x53
      ? lapic_can_unplug_cpu.cold+0x39/0x39
      nmi_trigger_cpumask_backtrace+0xb7/0xc7
      rcu_dump_cpu_stacks+0xa2/0xd0
      rcu_sched_clock_irq.cold+0x1ff/0x3d9
      ? tick_nohz_handler+0x100/0x100
      update_process_times+0x5b/0x90
      tick_sched_timer+0x5e/0xf0
      __hrtimer_run_queues+0x12a/0x2a0
      hrtimer_interrupt+0x10e/0x280
      __sysvec_apic_timer_interrupt+0x51/0xe0
      asm_call_on_stack+0xf/0x20
      </IRQ>
      sysvec_apic_timer_interrupt+0x6f/0x80
      ...
      task_file_seq_next+0x52/0xa0
      bpf_seq_read+0xb9/0x320
      vfs_read+0x9d/0x180
      ksys_read+0x5f/0xe0
      do_syscall_64+0x38/0x60
      entry_SYSCALL_64_after_hwframe+0x44/0xa9

The fix is to limit the number of bpf program runs to be
one million. This fixed the program in most cases. But
we also found under heavy load, which can increase the wallclock
time for bpf_seq_read(), the warning may still be possible.

For example, calling bpf_delay() in the "while" loop of
bpf_seq_read(), which will introduce artificial delay,
the warning will show up in my qemu run.

  static unsigned q;
  volatile unsigned *p = &q;
  volatile unsigned long long ll;
  static void bpf_delay(void)
  {
         int i, j;

         for (i = 0; i < 10000; i++)
                 for (j = 0; j < 10000; j++)
                         ll += *p;
  }

There are two ways to fix this issue. One is to reduce the above
one million threshold to say 100,000 and hopefully rcu warning will
not show up any more. Another is to introduce a target feature
which enables bpf_seq_read() calling cond_resched().

This patch took second approach as the first approach may cause
more -EAGAIN failures for read() syscalls. Note that not all bpf_iter
targets can permit cond_resched() in bpf_seq_read() as some, e.g.,
netlink seq iterator, rcu read lock critical section spans through
seq_ops->next() -> seq_ops->show() -> seq_ops->next().

For the kernel code with the above hack, "bpftool p" roughly takes
38 seconds to finish on my VM with 184 bpf program runs.
Using the following command, I am able to collect the number of
context switches:
   perf stat -e context-switches -- ./bpftool p >& log
Without this patch,
   69      context-switches
With this patch,
   75      context-switches
This patch added additional 6 context switches, roughly every 6 seconds
to reschedule, to avoid lengthy no-rescheduling which may cause the
above RCU warnings.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201028061054.1411116-1-yhs@fb.com
2020-10-28 14:54:31 -07:00
Al Viro
77f6ab8b77 don't dump the threads that had been already exiting when zapped.
Coredump logics needs to report not only the registers of the dumping
thread, but (since 2.5.43) those of other threads getting killed.

Doing that might require extra state saved on the stack in asm glue at
kernel entry; signal delivery logics does that (we need to be able to
save sigcontext there, at the very least) and so does seccomp.

That covers all callers of do_coredump().  Secondary threads get hit with
SIGKILL and caught as soon as they reach exit_mm(), which normally happens
in signal delivery, so those are also fine most of the time.  Unfortunately,
it is possible to end up with secondary zapped when it has already entered
exit(2) (or, worse yet, is oopsing).  In those cases we reach exit_mm()
when mm->core_state is already set, but the stack contents is not what
we would have in signal delivery.

At least on two architectures (alpha and m68k) it leads to infoleaks - we
end up with a chunk of kernel stack written into coredump, with the contents
consisting of normal C stack frames of the call chain leading to exit_mm()
instead of the expected copy of userland registers.  In case of alpha we
leak 312 bytes of stack.  Other architectures (including the regset-using
ones) might have similar problems - the normal user of regsets is ptrace
and the state of tracee at the time of such calls is special in the same
way signal delivery is.

Note that had the zapper gotten to the exiting thread slightly later,
it wouldn't have been included into coredump anyway - we skip the threads
that have already cleared their ->mm.  So let's pretend that zapper always
loses the race.  IOW, have exit_mm() only insert into the dumper list if
we'd gotten there from handling a fatal signal[*]

As the result, the callers of do_exit() that have *not* gone through get_signal()
are not seen by coredump logics as secondary threads.  Which excludes voluntary
exit()/oopsen/traps/etc.  The dumper thread itself is unaffected by that,
so seccomp is fine.

[*] originally I intended to add a new flag in tsk->flags, but ebiederman pointed
out that PF_SIGNALED is already doing just what we need.

Cc: stable@vger.kernel.org
Fixes: d89f3847def4 ("[PATCH] thread-aware coredumps, 2.5.43-C3")
History-tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-10-28 16:39:49 -04:00
David Woodhouse
2cbd5a45e5 genirq/irqdomain: Implement get_name() method on irqchip fwnodes
Prerequisite to make x86 more irqdomain compliant.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201024213535.443185-23-dwmw2@infradead.org
2020-10-28 20:26:27 +01:00
Linus Torvalds
23859ae444 Fix synthetic event "strcat" overrun
New synthetic event code used strcat() and miscalculated the ending, causing
 the concatenation to write beyond the allocated memory.
 
 Instead of using strncat(), the code is switched over to seq_buf which has
 all the mechanisms in place to protect against writing more than what is
 allocated, and cleans up the code a bit.
 -----BEGIN PGP SIGNATURE-----
 
 iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCX5lZkBQccm9zdGVkdEBn
 b29kbWlzLm9yZwAKCRAp5XQQmuv6qu8+AQDfg1UM12HUIs1XRhbXBxf9g3kjwrJh
 nuoMilEZZstSCgD8DDQiPckOS9NfrdkyCPQ86tIKoOsGPowoA21sNOHPvQQ=
 =+V+S
 -----END PGP SIGNATURE-----

Merge tag 'trace-v5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fix from Steven Rostedt:
 "Fix synthetic event "strcat" overrun

  New synthetic event code used strcat() and miscalculated the ending,
  causing the concatenation to write beyond the allocated memory.

  Instead of using strncat(), the code is switched over to seq_buf which
  has all the mechanisms in place to protect against writing more than
  what is allocated, and cleans up the code a bit"

* tag 'trace-v5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing, synthetic events: Replace buggy strcat() with seq_buf operations
2020-10-28 12:05:14 -07:00
Mateusz Nosek
921c7ebd13 futex: Fix incorrect should_fail_futex() handling
If should_futex_fail() returns true in futex_wake_pi(), then the 'ret'
variable is set to -EFAULT and then immediately overwritten. So the failure
injection is non-functional.

Fix it by actually leaving the function and returning -EFAULT.

The Fixes tag is kinda blury because the initial commit which introduced
failure injection was already sloppy, but the below mentioned commit broke
it completely.

[ tglx: Massaged changelog ]

Fixes: 6b4f4bc9cb ("locking/futex: Allow low-level atomic operations to return -EAGAIN")
Signed-off-by: Mateusz Nosek <mateusznosek0@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20200927000858.24219-1-mateusznosek0@gmail.com
2020-10-28 15:48:51 +01:00
Richard Guy Briggs
6d915476e6 audit: trigger accompanying records when no rules present
When there are no audit rules registered, mandatory records (config,
etc.) are missing their accompanying records (syscall, proctitle, etc.).

This is due to audit context dummy set on syscall entry based on absence
of rules that signals that no other records are to be printed.  Clear the dummy
bit if any record is generated, open coding this in audit_log_start().

The proctitle context and dummy checks are pointless since the
proctitle record will not be printed if no syscall records are printed.

The fds array is reset to -1 after the first syscall to indicate it
isn't valid any more, but was never set to -1 when the context was
allocated to indicate it wasn't yet valid.

Check ctx->pwd in audit_log_name().

The audit_inode* functions can be called without going through
getname_flags() or getname_kernel() that sets audit_names and cwd, so
set the cwd in audit_alloc_name() if it has not already been done so due to
audit_names being valid and purge all other audit_getcwd() calls.

Revert the LSM dump_common_audit_data() LSM_AUDIT_DATA_* cases from the
ghak96 patch since they are no longer necessary due to cwd coverage in
audit_alloc_name().

Thanks to bauen1 <j2468h@googlemail.com> for reporting LSM situations in
which context->cwd is not valid, inadvertantly fixed by the ghak96 patch.

Please see upstream github issue
https://github.com/linux-audit/audit-kernel/issues/120
This is also related to upstream github issue
https://github.com/linux-audit/audit-kernel/issues/96

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-10-27 21:02:57 -04:00
Mauro Carvalho Chehab
cbb5262192 audit: fix a kernel-doc markup
typo:
	kauditd_print_skb -> kauditd_printk_skb

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-10-27 21:02:54 -04:00
Jackie Zamow
4d4ce8053b PM: sleep: fix typo in kernel/power/process.c
Fix a typo in a comment in freeze_processes().

Signed-off-by: Jackie Zamow <jackie.zamow@gmail.com>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-10-27 19:11:44 +01:00
Steven Rostedt (VMware)
761a8c58db tracing, synthetic events: Replace buggy strcat() with seq_buf operations
There was a memory corruption bug happening while running the synthetic
event selftests:

 kmemleak: Cannot insert 0xffff8c196fa2afe5 into the object search tree (overlaps existing)
 CPU: 5 PID: 6866 Comm: ftracetest Tainted: G        W         5.9.0-rc5-test+ #577
 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016
 Call Trace:
  dump_stack+0x8d/0xc0
  create_object.cold+0x3b/0x60
  slab_post_alloc_hook+0x57/0x510
  ? tracing_map_init+0x178/0x340
  __kmalloc+0x1b1/0x390
  tracing_map_init+0x178/0x340
  event_hist_trigger_func+0x523/0xa40
  trigger_process_regex+0xc5/0x110
  event_trigger_write+0x71/0xd0
  vfs_write+0xca/0x210
  ksys_write+0x70/0xf0
  do_syscall_64+0x33/0x40
  entry_SYSCALL_64_after_hwframe+0x44/0xa9
 RIP: 0033:0x7fef0a63a487
 Code: 64 89 02 48 c7 c0 ff ff ff ff eb bb 0f 1f 80 00 00 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
 RSP: 002b:00007fff76f18398 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
 RAX: ffffffffffffffda RBX: 0000000000000039 RCX: 00007fef0a63a487
 RDX: 0000000000000039 RSI: 000055eb3b26d690 RDI: 0000000000000001
 RBP: 000055eb3b26d690 R08: 000000000000000a R09: 0000000000000038
 R10: 000055eb3b2cdb80 R11: 0000000000000246 R12: 0000000000000039
 R13: 00007fef0a70b500 R14: 0000000000000039 R15: 00007fef0a70b700
 kmemleak: Kernel memory leak detector disabled
 kmemleak: Object 0xffff8c196fa2afe0 (size 8):
 kmemleak:   comm "ftracetest", pid 6866, jiffies 4295082531
 kmemleak:   min_count = 1
 kmemleak:   count = 0
 kmemleak:   flags = 0x1
 kmemleak:   checksum = 0
 kmemleak:   backtrace:
      __kmalloc+0x1b1/0x390
      tracing_map_init+0x1be/0x340
      event_hist_trigger_func+0x523/0xa40
      trigger_process_regex+0xc5/0x110
      event_trigger_write+0x71/0xd0
      vfs_write+0xca/0x210
      ksys_write+0x70/0xf0
      do_syscall_64+0x33/0x40
      entry_SYSCALL_64_after_hwframe+0x44/0xa9

The cause came down to a use of strcat() that was adding an string that was
shorten, but the strcat() did not take that into account.

strcat() is extremely dangerous as it does not care how big the buffer is.
Replace it with seq_buf operations that prevent the buffer from being
overwritten if what is being written is bigger than the buffer.

Fixes: 10819e2579 ("tracing: Handle synthetic event array field type checking correctly")
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Tested-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-27 09:25:36 -04:00
Zong Li
4230e2deaa stop_machine, rcu: Mark functions as notrace
Some architectures assume that the stopped CPUs don't make function calls
to traceable functions when they are in the stopped state. See also commit
cb9d7fd51d ("watchdog: Mark watchdog touch functions as notrace").

Violating this assumption causes kernel crashes when switching tracer on
RISC-V.

Mark rcu_momentary_dyntick_idle() and stop_machine_yield() notrace to
prevent this.

Fixes: 4ecf0a43e7 ("processor: get rid of cpu_relax_yield")
Fixes: 366237e7b0 ("stop_machine: Provide RCU quiescent state in multi_cpu_stop()")
Signed-off-by: Zong Li <zong.li@sifive.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Atish Patra <atish.patra@wdc.com>
Tested-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20201021073839.43935-1-zong.li@sifive.com
2020-10-26 12:12:27 +01:00
Zeng Tao
cb47755725 time: Prevent undefined behaviour in timespec64_to_ns()
UBSAN reports:

Undefined behaviour in ./include/linux/time64.h:127:27
signed integer overflow:
17179869187 * 1000000000 cannot be represented in type 'long long int'
Call Trace:
 timespec64_to_ns include/linux/time64.h:127 [inline]
 set_cpu_itimer+0x65c/0x880 kernel/time/itimer.c:180
 do_setitimer+0x8e/0x740 kernel/time/itimer.c:245
 __x64_sys_setitimer+0x14c/0x2c0 kernel/time/itimer.c:336
 do_syscall_64+0xa1/0x540 arch/x86/entry/common.c:295

Commit bd40a17576 ("y2038: itimer: change implementation to timespec64")
replaced the original conversion which handled time clamping correctly with
timespec64_to_ns() which has no overflow protection.

Fix it in timespec64_to_ns() as this is not necessarily limited to the
usage in itimers.

[ tglx: Added comment and adjusted the fixes tag ]

Fixes: 361a3bf005 ("time64: Add time64.h header and define struct timespec64")
Signed-off-by: Zeng Tao <prime.zeng@hisilicon.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/1598952616-6416-1-git-send-email-prime.zeng@hisilicon.com
2020-10-26 11:48:11 +01:00
YueHaibing
9010e3876e timers: Remove unused inline funtion debug_timer_free()
There is no caller in tree, remove it.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20200909134749.32300-1-yuehaibing@huawei.com
2020-10-26 11:39:21 +01:00
YueHaibing
5254cb87c0 hrtimer: Remove unused inline function debug_hrtimer_free()
There is no caller in tree, remove it.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20200909134850.21940-1-yuehaibing@huawei.com
2020-10-26 11:39:21 +01:00
Quanyang Wang
4cd2bb1298 time/sched_clock: Mark sched_clock_read_begin/retry() as notrace
Since sched_clock_read_begin() and sched_clock_read_retry() are called
by notrace function sched_clock(), they shouldn't be traceable either,
or else ftrace_graph_caller will run into a dead loop on the path
as below (arm for instance):

  ftrace_graph_caller()
    prepare_ftrace_return()
      function_graph_enter()
        ftrace_push_return_trace()
          trace_clock_local()
            sched_clock()
              sched_clock_read_begin/retry()

Fixes: 1b86abc1c6 ("sched_clock: Expose struct clock_read_data")
Signed-off-by: Quanyang Wang <quanyang.wang@windriver.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200929082027.16787-1-quanyang.wang@windriver.com
2020-10-26 11:34:31 +01:00
Davidlohr Bueso
1a2b85f1e2 timekeeping: Convert jiffies_seq to seqcount_raw_spinlock_t
Use the new api and associate the seqcounter to the jiffies_lock enabling
lockdep support - although for this particular case the write-side locking
and non-preemptibility are quite obvious.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201021190749.19363-1-dave@stgolabs.net
2020-10-26 11:04:14 +01:00
Joe Perches
33def8498f treewide: Convert macro and uses of __section(foo) to __section("foo")
Use a more generic form for __section that requires quotes to avoid
complications with clang and gcc differences.

Remove the quote operator # from compiler_attributes.h __section macro.

Convert all unquoted __section(foo) uses to quoted __section("foo").
Also convert __attribute__((section("foo"))) uses to __section("foo")
even if the __attribute__ has multiple list entry forms.

Conversion done using the script at:

    https://lore.kernel.org/lkml/75393e5ddc272dc7403de74d645e6c6e0f4e70eb.camel@perches.com/2-convert_section.pl

Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@gooogle.com>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-25 14:51:49 -07:00
Rasmus Villemoes
986b9eacb2 kernel/sys.c: fix prototype of prctl_get_tid_address()
tid_addr is not a "pointer to (pointer to int in userspace)"; it is in
fact a "pointer to (pointer to int in userspace) in userspace".  So
sparse rightfully complains about passing a kernel pointer to
put_user().

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-25 11:44:16 -07:00
Linus Torvalds
672f887126 A time namespace fix and a matching selftest. The futex absolute timeouts
which are based on CLOCK_MONOTONIC require time namespace corrected. This
 was missed in the original time namesapce support.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAl+VimUTHHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYoZKpEACuxPe0iHE5j2deQK7W6+bOSosh6tdI
 WlDoKoB+tfVqE+JLYNCk7hwKI4/mdgOIfzFbXQjUgfCsMFhJ5IOrKL+mmbqi0V02
 2Gy/9whww8kzhlk05/nbnKaK7LRVXhisWSbd9wZRrftIRwl2KKf64g9yWv90E3+j
 NNCTihRAyN0oXsg9nT2JnDTKSWvVGemlpW7ej0Yywh2WT/17p1ShKQXTBYXUJjvT
 3QC8Gfp7LJ2BSXuUzB2NwnjNxW7hVnwWSm+CKB0xtLGJ0KM/zLbJD9lFjqbEzlgs
 1yECw7PUQFFlhMubIOKJTP+kMvieRiQafi9v7iAh2UB1m3JyQO4daRPwxbDPhJKR
 3Hqln0Fl8i/Ge6XHTBWzo1SsRC5DdBxHxQVBNHsPI8hPCOlgKGgdYjNQC8V7AX0v
 bWrVSIFkVDreFOzOg4+LbGV/7HXdMSQCEb3XXCYtMPMMKOuxsLknHO884nqovM1E
 tL21Zw/TBHzBo4N4Kt7pNqmEKqmdcxl198aW3Lv+2UqWbVSo8UcYIlXq/jcPwXH+
 vnrsRBNaXZRBFUQYAmNsUbPjuIRJ6U9Ic0WxhbHrcTI2SyJXg/SjhCltoYEESJfT
 T2dyn2XEnysJ/RKZu3DHY81P6cn3NGSb/D/Po0faaACHgQu1InxR5BSABTuFWwAQ
 EXfTQfu0cDQ0wQ==
 =VFCv
 -----END PGP SIGNATURE-----

Merge tag 'timers-urgent-2020-10-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer fixes from Thomas Gleixner:
 "A time namespace fix and a matching selftest. The futex absolute
  timeouts which are based on CLOCK_MONOTONIC require time namespace
  corrected. This was missed in the original time namesapce support"

* tag 'timers-urgent-2020-10-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  selftests/timens: Add a test for futex()
  futex: Adjust absolute futex timeouts with per time namespace offset
2020-10-25 11:28:49 -07:00
Linus Torvalds
87702a337f Two scheduler fixes:
- A trivial build fix for sched_feat() to compile correctly with
     CONFIG_JUMP_LABEL=n
 
   - Replace a zero lenght array with a flexible array.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAl+VifUTHHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYoW2FD/9u7iQw1QvvK6li6nW3QWr1j3E8Z5E2
 7cPq02AKQZmfsacEgRVe68Bn9NidW7d3PNO+IsomZJyoiov27PfFKqjPmvcFVQBI
 NIHkCUEc41wF0ZkWA0Z1VqixkzBMQ9al+iTHp6W20MDqe7lQFVbLHiKghN9+o2uL
 1b2YxbvTy4NbgN40bd23l5P2zTTCW9hnaZX0rhj35PHKD069brcdy1bSfONXoq4e
 b1VxwBhFXMRbhaifMf1yy1WaYYc+9dEePF28otXZQ5EiOwmf7bnIIU7mEV7NotkN
 XWB4iy4EFt+NKxUB8tWB8duzJ2x5T6tB4bVQoBsh4/hE4n3vO+LjsUEAArIabzi+
 wIbrAtPeScD4M7gsxlVgc6q0vbBXuR0ymh+TrDZvsE3wIXABYxgajTg6nGRlB1S5
 ZfKuCTNWT4JBnCJHtMChwInJ5+y/GHHd92TvUIN8+5kHbkTlp5GNQtw+B5eTwY9P
 XtUTTiSh4z2T9wQiRq0fjbyTqkGNL8wbo2lXbtHf0hA/XFa0OY3Gx/vJ9w+74Sy+
 X60eS8Ew2XkkdWm+litDQ+f8ulZvYqg3ejitvteYlOORoryX3mpNUOCeNoDQzegj
 PDKBE7SJSI5aqtpkO+bQoic0eC4A4CpJYES2ZH8a4nCu1a74OF0fiFh91AHjwqCI
 yyeJzYsLbMo3PQ==
 =RNOk
 -----END PGP SIGNATURE-----

Merge tag 'sched-urgent-2020-10-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fixes from Thomas Gleixner:
 "Two scheduler fixes:

   - A trivial build fix for sched_feat() to compile correctly with
     CONFIG_JUMP_LABEL=n

   - Replace a zero lenght array with a flexible array"

* tag 'sched-urgent-2020-10-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/features: Fix !CONFIG_JUMP_LABEL case
  sched: Replace zero-length array with flexible-array
2020-10-25 11:25:16 -07:00
Linus Torvalds
81ecf91eab SafeSetID changes for v5.10
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEgvWslnM+qUy+sgVg5n2WYw6TPBAFAl+Ifu8ACgkQ5n2WYw6T
 PBCoxA/+Pn0XvwYa6V773lPNjon+Oa94Aq7Wl6YryDMJakiGDJFSJa0tEI8TmRkJ
 z21kjww2Us9gEvfmNoc0t4oDJ98UNAXERjc98fOZgxH1d1urpGUI7qdQ07YCo0xZ
 CDOvqXk/PobGF6p9BpF5QWqEJNq6G8xAKpA8nLa6OUPcjofHroWCgIs86Rl3CtTc
 DwjcOvCgUoTxFm9Vpvm04njFFkVuGUwmXuhyV3Xjh2vNhHvfpP/ibTPmmv1sx4dO
 9WE8BjW0HL5VMzms/BE/mnXmbu2BdPs+PW9/RjQfebbAH8DM3Noqr9f3Db8eqp7t
 TiqU8AO06TEVZa011+V3aywgz9rnH+XJ17TfutB28Z7lG3s4XPZYDgzubJxb1X8M
 4d2mCL3N/ao5otx6FqpgJ2oK0ZceB/voY9qyyfErEBhRumxifl7AQCHxt3LumH6m
 fvvNY+UcN/n7hZPJ7sgZVi/hnnwvO0e1eX0L9ZdNsDjR1bgzBQCdkY53XNxam+rM
 z7tmT3jlDpNtPzOzFCZeiJuTgWYMDdJFqekPLess/Vqaswzc4PPT2lyQ6N81NR5H
 +mzYf/PNIg5fqN8QlMQEkMTv2fnC19dHJT83NPgy4dQObpXzUqYGWAmdKcBxLpnG
 du8wDpPHusChRFMZKRMTXztdMvMAuNqY+KJ6bFojG0Z+qgR7oQk=
 =/anB
 -----END PGP SIGNATURE-----

Merge tag 'safesetid-5.10' of git://github.com/micah-morton/linux

Pull SafeSetID updates from Micah Morton:
 "The changes are mostly contained to within the SafeSetID LSM, with the
  exception of a few 1-line changes to change some ns_capable() calls to
  ns_capable_setid() -- causing a flag (CAP_OPT_INSETID) to be set that
  is examined by SafeSetID code and nothing else in the kernel.

  The changes to SafeSetID internally allow for setting up GID
  transition security policies, as already existed for UIDs"

* tag 'safesetid-5.10' of git://github.com/micah-morton/linux:
  LSM: SafeSetID: Fix warnings reported by test bot
  LSM: SafeSetID: Add GID security policy handling
  LSM: Signal to SafeSetID when setting group IDs
2020-10-25 10:45:26 -07:00
Linus Torvalds
91f28da8c9 random32: make prandom_u32() less predictable
This is the cleanup of the latest series of prandom_u32 experimentations
 consisting in using SipHash instead of Tausworthe to produce the randoms
 used by the network stack. The changes to the files were kept minimal,
 and the controversial commit that used to take noise from the fast_pool
 (f227e3ec3b) was reverted. Instead, a dedicated "net_rand_noise" per_cpu
 variable is fed from various sources of activities (networking, scheduling)
 to perturb the SipHash state using fast, non-trivially predictable data,
 instead of keeping it fully deterministic. The goal is essentially to make
 any occasional memory leakage or brute-force attempt useless.
 
 The resulting code was verified to be very slightly faster on x86_64 than
 what is was with the controversial commit above, though this remains barely
 above measurement noise. It was also tested on i386 and arm, and build-
 tested only on arm64.
 
 The whole discussion around this is archived here:
   https://lore.kernel.org/netdev/20200808152628.GA27941@SDF.ORG/
 -----BEGIN PGP SIGNATURE-----
 
 iQIcBAABAgAGBQJflHDtAAoJEE44bZycYXAvxXUP/A9aKCaSnJUgYi/0Fa507bi9
 yJkNs6cotQfzmG8GznQWdG2mdsviqI/d08UdIHD9JHKoin3wcT4+0So546pCw9BR
 tlrHnFcRnqEqXFLggnqkKnnIgGNNTppMDSi96BplNoXYXAMRjjvKW9Vl94lU2Abk
 a+aOOJRu4Vzj/5tRT3fkg/ldN6YGZ6nbqVkzd0WAwuYYIj1VSYUSkLgKc65n+4Xp
 ISnVWObeHJ+tnBRDVudTaUNYi7T3QvCF9glZZlFUVBDQbTRSqjMBSUmnBnOg1mhO
 Q5nY6xrfTi/0i39+/wOUUOTaxe7YggymibQfN+Y26w1rPO45RkvORiPKvXlfZWaI
 a3wh1TMoDAptrW9VXiO9pJv6a4xC16c7FyyTnGkP4jP+HTFdgmgixoNmPKrBxuEZ
 X8O+HOSf155j057aECMivk8bIj4FfLmYt2ciWqRZTVCwu9uK29AJSMx0SphTmYQ0
 p0HaJ8mHKnFVViX9n+YOPRfZDIRGH1zTOxzPhEkzuX8vx/4uiXsbp/ILxg0uZ913
 DgMk1rzzBlZsL7QqJQnf9JM810pFcU/PI7Y7PKaGKz3ntkJT2WV7gMeg+Wwv9254
 pPccvffYzdbtJAHgj+If8lHwixE33u5RscXqjpxIWLPcKTOLQNIf+6bRQ86sA+Kq
 Vbza8sDu6IWhvApCGLmB
 =KHhI
 -----END PGP SIGNATURE-----

Merge tag '20201024-v4-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/wtarreau/prandom

Pull random32 updates from Willy Tarreau:
 "Make prandom_u32() less predictable.

  This is the cleanup of the latest series of prandom_u32
  experimentations consisting in using SipHash instead of Tausworthe to
  produce the randoms used by the network stack.

  The changes to the files were kept minimal, and the controversial
  commit that used to take noise from the fast_pool (f227e3ec3b) was
  reverted. Instead, a dedicated "net_rand_noise" per_cpu variable is
  fed from various sources of activities (networking, scheduling) to
  perturb the SipHash state using fast, non-trivially predictable data,
  instead of keeping it fully deterministic. The goal is essentially to
  make any occasional memory leakage or brute-force attempt useless.

  The resulting code was verified to be very slightly faster on x86_64
  than what is was with the controversial commit above, though this
  remains barely above measurement noise. It was also tested on i386 and
  arm, and build- tested only on arm64"

Link: https://lore.kernel.org/netdev/20200808152628.GA27941@SDF.ORG/

* tag '20201024-v4-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/wtarreau/prandom:
  random32: add a selftest for the prandom32 code
  random32: add noise from network and scheduling activity
  random32: make prandom_u32() output unpredictable
2020-10-25 10:40:08 -07:00
Linus Torvalds
1b307ac870 dma-mapping fixes for 5.10:
- document the new document dma_{alloc,free}_pages API
  - two fixups for the dma-mapping.h split
 -----BEGIN PGP SIGNATURE-----
 
 iQI/BAABCgApFiEEgdbnc3r/njty3Iq9D55TZVIEUYMFAl+UN1ELHGhjaEBsc3Qu
 ZGUACgkQD55TZVIEUYPhkg//QLMwY4Lib1IPdeYR4k/UE2E4YtPjQghucNHXDkrd
 jjV5tvGPfNDOEKeCOamivTcOmc3E+jFhQFjpHplqd4OjsfZT3EyXaopdX/qN1Bbo
 JIib0WAAxO1N2MRhEPJzGAsCkMPT32Q52/ka1QUOmr1E8VPrKhU4T9+FnTbj1rgF
 HbMk+PdV4+HP53CvK+aaOfNHqJqQoTBeCx9xebybAjxIBCI+LedRwC7haV4Zz6tg
 xSp9cW0Ztdp9U7u1dOO4gEqnL/fNk3+RWF5iwtyCi96uYmguV+/vAqpWMyej97q5
 2Dx0jTQvj0FhnPug9asydadjtUqkzfRCSDGv4TybeHT/OZJEGAwkdJG7V/5PwGOg
 VCMpqi/WRIDPnUtN3OY4IZFigbyb4wJ6MOO/hvXagC7Lc2+z9ZhuUKUjSsV90LoT
 2a4xwm9M1JAglYbhGvLl5cjzmDSdCFXuGYlJ18lRZx7d4cGi34hAqq3WfqqteHm+
 IRfeAaWN7N+W8PgzGaDqfUVDrGNVZ7eo02kVicaJFCdJE5ecS3rUbyU8uVjhX7Sl
 h8zwBs8/5hFIKLCWUBiT+UBmvWXbG/a0plRh/vIvJ8lk4m4+kwdTRwgngpSkb3G/
 ytAJPZTeI7r75zkwxTHPE01Khf8/qWJ3cdv97PpQH+7mlo4J0XUr5ssmiQ7DAHuu
 jjo=
 =0N7Y
 -----END PGP SIGNATURE-----

Merge tag 'dma-mapping-5.10-1' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping fixes from Christoph Hellwig:

 - document the new dma_{alloc,free}_pages() API

 - two fixups for the dma-mapping.h split

* tag 'dma-mapping-5.10-1' of git://git.infradead.org/users/hch/dma-mapping:
  dma-mapping: document dma_{alloc,free}_pages
  dma-mapping: move more functions to dma-map-ops.h
  ARM/sa1111: add a missing include of dma-map-ops.h
2020-10-24 12:17:05 -07:00
Willy Tarreau
3744741ada random32: add noise from network and scheduling activity
With the removal of the interrupt perturbations in previous random32
change (random32: make prandom_u32() output unpredictable), the PRNG
has become 100% deterministic again. While SipHash is expected to be
way more robust against brute force than the previous Tausworthe LFSR,
there's still the risk that whoever has even one temporary access to
the PRNG's internal state is able to predict all subsequent draws till
the next reseed (roughly every minute). This may happen through a side
channel attack or any data leak.

This patch restores the spirit of commit f227e3ec3b ("random32: update
the net random state on interrupt and activity") in that it will perturb
the internal PRNG's statee using externally collected noise, except that
it will not pick that noise from the random pool's bits nor upon
interrupt, but will rather combine a few elements along the Tx path
that are collectively hard to predict, such as dev, skb and txq
pointers, packet length and jiffies values. These ones are combined
using a single round of SipHash into a single long variable that is
mixed with the net_rand_state upon each invocation.

The operation was inlined because it produces very small and efficient
code, typically 3 xor, 2 add and 2 rol. The performance was measured
to be the same (even very slightly better) than before the switch to
SipHash; on a 6-core 12-thread Core i7-8700k equipped with a 40G NIC
(i40e), the connection rate dropped from 556k/s to 555k/s while the
SYN cookie rate grew from 5.38 Mpps to 5.45 Mpps.

Link: https://lore.kernel.org/netdev/20200808152628.GA27941@SDF.ORG/
Cc: George Spelvin <lkml@sdf.org>
Cc: Amit Klein <aksecurity@gmail.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: tytso@mit.edu
Cc: Florian Westphal <fw@strlen.de>
Cc: Marc Plumb <lkml.mplumb@gmail.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
2020-10-24 20:21:57 +02:00
George Spelvin
c51f8f88d7 random32: make prandom_u32() output unpredictable
Non-cryptographic PRNGs may have great statistical properties, but
are usually trivially predictable to someone who knows the algorithm,
given a small sample of their output.  An LFSR like prandom_u32() is
particularly simple, even if the sample is widely scattered bits.

It turns out the network stack uses prandom_u32() for some things like
random port numbers which it would prefer are *not* trivially predictable.
Predictability led to a practical DNS spoofing attack.  Oops.

This patch replaces the LFSR with a homebrew cryptographic PRNG based
on the SipHash round function, which is in turn seeded with 128 bits
of strong random key.  (The authors of SipHash have *not* been consulted
about this abuse of their algorithm.)  Speed is prioritized over security;
attacks are rare, while performance is always wanted.

Replacing all callers of prandom_u32() is the quick fix.
Whether to reinstate a weaker PRNG for uses which can tolerate it
is an open question.

Commit f227e3ec3b ("random32: update the net random state on interrupt
and activity") was an earlier attempt at a solution.  This patch replaces
it.

Reported-by: Amit Klein <aksecurity@gmail.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Eric Dumazet <edumazet@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: tytso@mit.edu
Cc: Florian Westphal <fw@strlen.de>
Cc: Marc Plumb <lkml.mplumb@gmail.com>
Fixes: f227e3ec3b ("random32: update the net random state on interrupt and activity")
Signed-off-by: George Spelvin <lkml@sdf.org>
Link: https://lore.kernel.org/netdev/20200808152628.GA27941@SDF.ORG/
[ willy: partial reversal of f227e3ec3b5c; moved SIPROUND definitions
  to prandom.h for later use; merged George's prandom_seed() proposal;
  inlined siprand_u32(); replaced the net_rand_state[] array with 4
  members to fix a build issue; cosmetic cleanups to make checkpatch
  happy; fixed RANDOM32_SELFTEST build ]
Signed-off-by: Willy Tarreau <w@1wt.eu>
2020-10-24 20:21:57 +02:00
Linus Torvalds
a5e5c274c9 ring-buffer fix
The success return value of ring_buffer_resize() is stated to be zero,
 and checked that way. But it is incorrectly returning the size allocated.
 
 Also, a fix to a comment.
 -----BEGIN PGP SIGNATURE-----
 
 iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCX5LnlRQccm9zdGVkdEBn
 b29kbWlzLm9yZwAKCRAp5XQQmuv6qtPxAP439tmV1wWK4uBF6TLBahaPdj0tGe5b
 NT/ASnYjokZKWgEA//vmUBMMmNBohcd8DkkTu8Pp3tkc2b4RLR5WJIpXGwk=
 =1Og+
 -----END PGP SIGNATURE-----

Merge tag 'trace-v5.10-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing ring-buffer fix from Steven Rostedt:
 "The success return value of ring_buffer_resize() is stated to be
  zero and checked that way.

  But it was incorrectly returning the size allocated.

  Also, a fix to a comment"

* tag 'trace-v5.10-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ring-buffer: Update the description for ring_buffer_wait
  ring-buffer: Return 0 on success from ring_buffer_resize()
2020-10-23 17:09:38 -07:00
Linus Torvalds
41f762a15a More power management updates for 5.10-rc1
- Move the AVS drivers to new platform-specific locations and get
    rid of the drivers/power/avs directory (Ulf Hansson).
 
  - Add on/off notifiers and idle state accounting support to the
    generic power domains (genpd) framework (Ulf Hansson, Lina Iyer).
 
  - Ulf will maintain the PM domain part of cpuidle-psci (Ulf Hansson).
 
  - Make intel_idle disregard ACPI _CST if it cannot use the data
    returned by that method (Mel Gorman).
 
  - Modify intel_pstate to avoid leaving useless sysfs directory
    structure behind if it cannot be registered (Chen Yu).
 
  - Fix domain detection in the RAPL power capping driver and prevent
    it from failing to enumerate the Psys RAPL domain (Zhang Rui).
 
  - Allow acpi-cpufreq to use ACPI _PSD information with Family 19 and
    later AMD chips (Wei Huang).
 
  - Update the driver assumptions comment in intel_idle and fix a
    kerneldoc comment in the runtime PM framework (Alexander Monakov,
    Bean Huo).
 
  - Avoid unnecessary resets of the cached frequency in the schedutil
    cpufreq governor to reduce overhead (Wei Wang).
 
  - Clean up the cpufreq core a bit (Viresh Kumar).
 
  - Make assorted minor janitorial changes (Daniel Lezcano, Geert
    Uytterhoeven, Hubert Jasudowicz, Tom Rix).
 
  - Clean up and optimize the cpupower utility somewhat (Colin Ian
    King, Martin Kaistra).
 -----BEGIN PGP SIGNATURE-----
 
 iQJGBAABCAAwFiEE4fcc61cGeeHD/fCwgsRv/nhiVHEFAl+TD4gSHHJqd0Byand5
 c29ja2kubmV0AAoJEILEb/54YlRx3AgP/0Fpi50+Kggr7pIXKElwg7ECJA0nOLT6
 gp4Vc/J/3r6zqK0ANDgCRlEMckAT61ukll+eU+BlavBrI4ZYj/Homi0+u53t1GjM
 AOwj1SmQgSBcBavWsBOc8+12X6wYLzyQbyWc53oYH5os537n8s7zkSZuSBcGFUgb
 wWF4xOeuW/ETsxAzEYmY7LvtBeEmo3UjV0fZPPbo/ro5EHDaOpvO/4EUDjCQxR6b
 CvyjgLlxuAOFWG/B5lVTCx7S6MmBjHXUIFUizt+TA6YjyGd0mG0i0f7mgzs6hqUD
 gzERDSlehBC3zPh5O35HNGUG8ulvDi9+ugxuckFHu/j4wEeZswp8AuIpdLI6Mcnc
 LDb+LTeypAB5d1fzHeSziv8AL08cUAS6QT+q96whYibQs6WA1mE9yXECyg6ZGsLt
 1KPAc8KD4ojwjo9vtk9VU0ZaUcVBMnqyK+GK929l0nXohw2Fae6X/NlpQ0D7joZA
 NM+dWMXpHy6tuVOgdUmrmN+P6vWd8ApWBeufkUFsCzrh3zG57yVaLl2SAjEtpKh0
 Emr/kJ8Ox8cf++6mGKseR2ZbkGn0Tz2GD5l3hIAGnIv9Nda3YgCc6RyV7U9se7OW
 2xnQvrgXqQKyjjziptVFqDotcC/KXFACr3YZX6GlW675NOMXSGk1ZYI3FbrsM8yd
 0/zq7PyYmb0D
 =TFKg
 -----END PGP SIGNATURE-----

Merge tag 'pm-5.10-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull more power management updates from Rafael Wysocki:
 "First of all, the adaptive voltage scaling (AVS) drivers go to new
  platform-specific locations as planned (this part was reported to have
  merge conflicts against the new arm-soc updates in linux-next).

  In addition to that, there are some fixes (intel_idle, intel_pstate,
  RAPL, acpi_cpufreq), the addition of on/off notifiers and idle state
  accounting support to the generic power domains (genpd) code and some
  janitorial changes all over.

  Specifics:

   - Move the AVS drivers to new platform-specific locations and get rid
     of the drivers/power/avs directory (Ulf Hansson).

   - Add on/off notifiers and idle state accounting support to the
     generic power domains (genpd) framework (Ulf Hansson, Lina Iyer).

   - Ulf will maintain the PM domain part of cpuidle-psci (Ulf Hansson).

   - Make intel_idle disregard ACPI _CST if it cannot use the data
     returned by that method (Mel Gorman).

   - Modify intel_pstate to avoid leaving useless sysfs directory
     structure behind if it cannot be registered (Chen Yu).

   - Fix domain detection in the RAPL power capping driver and prevent
     it from failing to enumerate the Psys RAPL domain (Zhang Rui).

   - Allow acpi-cpufreq to use ACPI _PSD information with Family 19 and
     later AMD chips (Wei Huang).

   - Update the driver assumptions comment in intel_idle and fix a
     kerneldoc comment in the runtime PM framework (Alexander Monakov,
     Bean Huo).

   - Avoid unnecessary resets of the cached frequency in the schedutil
     cpufreq governor to reduce overhead (Wei Wang).

   - Clean up the cpufreq core a bit (Viresh Kumar).

   - Make assorted minor janitorial changes (Daniel Lezcano, Geert
     Uytterhoeven, Hubert Jasudowicz, Tom Rix).

   - Clean up and optimize the cpupower utility somewhat (Colin Ian
     King, Martin Kaistra)"

* tag 'pm-5.10-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (23 commits)
  PM: sleep: remove unreachable break
  PM: AVS: Drop the avs directory and the corresponding Kconfig
  PM: AVS: qcom-cpr: Move the driver to the qcom specific drivers
  PM: runtime: Fix typo in pm_runtime_set_active() helper comment
  PM: domains: Fix build error for genpd notifiers
  powercap: Fix typo in Kconfig "Plance" -> "Plane"
  cpufreq: schedutil: restore cached freq when next_f is not changed
  acpi-cpufreq: Honor _PSD table setting on new AMD CPUs
  PM: AVS: smartreflex Move driver to soc specific drivers
  PM: AVS: rockchip-io: Move the driver to the rockchip specific drivers
  PM: domains: enable domain idle state accounting
  PM: domains: Add curly braces to delimit comment + statement block
  PM: domains: Add support for PM domain on/off notifiers for genpd
  powercap/intel_rapl: enumerate Psys RAPL domain together with package RAPL domain
  powercap/intel_rapl: Fix domain detection
  intel_idle: Ignore _CST if control cannot be taken from the platform
  cpuidle: Remove pointless stub
  intel_idle: mention assumption that WBINVD is not needed
  MAINTAINERS: Add section for cpuidle-psci PM domain
  cpufreq: intel_pstate: Delete intel_pstate sysfs if failed to register the driver
  ...
2020-10-23 16:27:03 -07:00
Linus Torvalds
3cb12d27ff Fixes for 5.10-rc1 from the networking tree:
Cross-tree/merge window issues:
 
  - rtl8150: don't incorrectly assign random MAC addresses; fix late
    in the 5.9 cycle started depending on a return code from
    a function which changed with the 5.10 PR from the usb subsystem
 
 Current release - regressions:
 
  - Revert "virtio-net: ethtool configurable RXCSUM", it was causing
    crashes at probe when control vq was not negotiated/available
 
 Previous releases - regressions:
 
  - ixgbe: fix probing of multi-port 10 Gigabit Intel NICs with an MDIO
    bus, only first device would be probed correctly
 
  - nexthop: Fix performance regression in nexthop deletion by
    effectively switching from recently added synchronize_rcu()
    to synchronize_rcu_expedited()
 
  - netsec: ignore 'phy-mode' device property on ACPI systems;
    the property is not populated correctly by the firmware,
    but firmware configures the PHY so just keep boot settings
 
 Previous releases - always broken:
 
  - tcp: fix to update snd_wl1 in bulk receiver fast path, addressing
    bulk transfers getting "stuck"
 
  - icmp: randomize the global rate limiter to prevent attackers from
    getting useful signal
 
  - r8169: fix operation under forced interrupt threading, make the
    driver always use hard irqs, even on RT, given the handler is
    light and only wants to schedule napi (and do so through
    a _irqoff() variant, preferably)
 
  - bpf: Enforce pointer id generation for all may-be-null register
    type to avoid pointers erroneously getting marked as null-checked
 
  - tipc: re-configure queue limit for broadcast link
 
  - net/sched: act_tunnel_key: fix OOB write in case of IPv6 ERSPAN
    tunnels
 
  - fix various issues in chelsio inline tls driver
 
 Misc:
 
  - bpf: improve just-added bpf_redirect_neigh() helper api to support
    supplying nexthop by the caller - in case BPF program has already
    done a lookup we can avoid doing another one
 
  - remove unnecessary break statements
 
  - make MCTCP not select IPV6, but rather depend on it
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEE6jPA+I1ugmIBA4hXMUZtbf5SIrsFAl+R+5UACgkQMUZtbf5S
 Irt9KxAAiYme2aSvMOni0NQsOgQ5mVsy7tk0/4dyRqkAx0ggrfGcFuhgZYNm8ZKY
 KoQsQyn30Wb/2wAp1vX2I4Fod67rFyBfQg/8iWiEAu47X7Bj1lpPPJexSPKhF9/X
 e0TuGxZtoaDuV9C3Su/FOjRmnShGSFQu1SCyJThshwaGsFL3YQ0Ut07VRgRF8x05
 A5fy2SVVIw0JOQgV1oH0GP5oEK3c50oGnaXt8emm56PxVIfAYY0oq69hQUzrfMFP
 zV9R0XbnbCIibT8R3lEghjtXavtQTzK5rYDKazTeOyDU87M+yuykNYj7MhgDwl9Q
 UdJkH2OpMlJylEH3asUjz/+ObMhXfOuj/ZS3INtO5omBJx7x76egDZPMQe4wlpcC
 NT5EZMS7kBdQL8xXDob7hXsvFpuEErSUGruYTHp4H52A9ke1dRTH2kQszcKk87V3
 s+aVVPtJ5bHzF3oGEvfwP0DFLTF6WvjD0Ts0LmTY2DhpE//tFWV37j60Ni5XU21X
 fCPooihQbLOsq9D8zc0ydEvCg2LLWMXM5ovCkqfIAJzbGVYhnxJSryZwpOlKDS0y
 LiUmLcTZDoNR/szx0aJhVHdUUVgXDX/GsllHoc1w7ZvDRMJn40K+xnaF3dSMwtIl
 imhfc5pPi6fdBgjB0cFYRPfhwiwlPMQ4YFsOq9JvynJzmt6P5FQ=
 =ceke
 -----END PGP SIGNATURE-----

Merge tag 'net-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Jakub Kicinski:
 "Cross-tree/merge window issues:

   - rtl8150: don't incorrectly assign random MAC addresses; fix late in
     the 5.9 cycle started depending on a return code from a function
     which changed with the 5.10 PR from the usb subsystem

  Current release regressions:

   - Revert "virtio-net: ethtool configurable RXCSUM", it was causing
     crashes at probe when control vq was not negotiated/available

  Previous release regressions:

   - ixgbe: fix probing of multi-port 10 Gigabit Intel NICs with an MDIO
     bus, only first device would be probed correctly

   - nexthop: Fix performance regression in nexthop deletion by
     effectively switching from recently added synchronize_rcu() to
     synchronize_rcu_expedited()

   - netsec: ignore 'phy-mode' device property on ACPI systems; the
     property is not populated correctly by the firmware, but firmware
     configures the PHY so just keep boot settings

  Previous releases - always broken:

   - tcp: fix to update snd_wl1 in bulk receiver fast path, addressing
     bulk transfers getting "stuck"

   - icmp: randomize the global rate limiter to prevent attackers from
     getting useful signal

   - r8169: fix operation under forced interrupt threading, make the
     driver always use hard irqs, even on RT, given the handler is light
     and only wants to schedule napi (and do so through a _irqoff()
     variant, preferably)

   - bpf: Enforce pointer id generation for all may-be-null register
     type to avoid pointers erroneously getting marked as null-checked

   - tipc: re-configure queue limit for broadcast link

   - net/sched: act_tunnel_key: fix OOB write in case of IPv6 ERSPAN
     tunnels

   - fix various issues in chelsio inline tls driver

  Misc:

   - bpf: improve just-added bpf_redirect_neigh() helper api to support
     supplying nexthop by the caller - in case BPF program has already
     done a lookup we can avoid doing another one

   - remove unnecessary break statements

   - make MCTCP not select IPV6, but rather depend on it"

* tag 'net-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (62 commits)
  tcp: fix to update snd_wl1 in bulk receiver fast path
  net: Properly typecast int values to set sk_max_pacing_rate
  netfilter: nf_fwd_netdev: clear timestamp in forwarding path
  ibmvnic: save changed mac address to adapter->mac_addr
  selftests: mptcp: depends on built-in IPv6
  Revert "virtio-net: ethtool configurable RXCSUM"
  rtnetlink: fix data overflow in rtnl_calcit()
  net: ethernet: mtk-star-emac: select REGMAP_MMIO
  net: hdlc_raw_eth: Clear the IFF_TX_SKB_SHARING flag after calling ether_setup
  net: hdlc: In hdlc_rcv, check to make sure dev is an HDLC device
  bpf, libbpf: Guard bpf inline asm from bpf_tail_call_static
  bpf, selftests: Extend test_tc_redirect to use modified bpf_redirect_neigh()
  bpf: Fix bpf_redirect_neigh helper api to support supplying nexthop
  mptcp: depends on IPV6 but not as a module
  sfc: move initialisation of efx->filter_sem to efx_init_struct()
  mpls: load mpls_gso after mpls_iptunnel
  net/sched: act_tunnel_key: fix OOB write in case of IPv6 ERSPAN tunnels
  net/sched: act_gate: Unlock ->tcfa_lock in tc_setup_flow_action()
  net: dsa: bcm_sf2: make const array static, makes object smaller
  mptcp: MPTCP_IPV6 should depend on IPV6 instead of selecting it
  ...
2020-10-23 12:05:49 -07:00
Linus Torvalds
4a22709e21 arch-cleanup-2020-10-22
-----BEGIN PGP SIGNATURE-----
 
 iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAl+SOXIQHGF4Ym9lQGtl
 cm5lbC5kawAKCRD301j7KXHgptrcD/93VUDmRAn73ChKNd0TtXUicJlAlNLVjvfs
 VFTXWBDnlJnGkZT7ElkDD9b8dsz8l4xGf/QZ5dzhC/th2OsfObQkSTfe0lv5cCQO
 mX7CRSrDpjaHtW+WGPDa0oQsGgIfpqUz2IOg9NKbZZ1LJ2uzYfdOcf3oyRgwZJ9B
 I3sh1vP6OzjZVVCMmtMTM+sYZEsDoNwhZwpkpiwMmj8tYtOPgKCYKpqCiXrGU0x2
 ML5FtDIwiwU+O3zYYdCBWqvCb2Db0iA9Aov2whEBz/V2jnmrN5RMA/90UOh1E2zG
 br4wM1Wt3hNrtj5qSxZGlF/HEMYJVB8Z2SgMjYu4vQz09qRVVqpGdT/dNvLAHQWg
 w4xNCj071kVZDQdfwnqeWSKYUau9Xskvi8xhTT+WX8a5CsbVrM9vGslnS5XNeZ6p
 h2D3Q+TAYTvT756icTl0qsYVP7PrPY7DdmQYu0q+Lc3jdGI+jyxO2h9OFBRLZ3p6
 zFX2N8wkvvCCzP2DwVnnhIi/GovpSh7ksHnb039F36Y/IhZPqV1bGqdNQVdanv6I
 8fcIDM6ltRQ7dO2Br5f1tKUZE9Pm6x60b/uRVjhfVh65uTEKyGRhcm5j9ztzvQfI
 cCBg4rbVRNKolxuDEkjsAFXVoiiEEsb7pLf4pMO+Dr62wxFG589tQNySySneUIVZ
 J9ILnGAAeQ==
 =aVWo
 -----END PGP SIGNATURE-----

Merge tag 'arch-cleanup-2020-10-22' of git://git.kernel.dk/linux-block

Pull arch task_work cleanups from Jens Axboe:
 "Two cleanups that don't fit other categories:

   - Finally get the task_work_add() cleanup done properly, so we don't
     have random 0/1/false/true/TWA_SIGNAL confusing use cases. Updates
     all callers, and also fixes up the documentation for
     task_work_add().

   - While working on some TIF related changes for 5.11, this
     TIF_NOTIFY_RESUME cleanup fell out of that. Remove some arch
     duplication for how that is handled"

* tag 'arch-cleanup-2020-10-22' of git://git.kernel.dk/linux-block:
  task_work: cleanup notification modes
  tracehook: clear TIF_NOTIFY_RESUME in tracehook_notify_resume()
2020-10-23 10:06:38 -07:00
Linus Torvalds
746b25b1aa Kbuild updates for v5.10
- Support 'make compile_commands.json' to generate the compilation
    database more easily, avoiding stale entries
 
  - Support 'make clang-analyzer' and 'make clang-tidy' for static checks
    using clang-tidy
 
  - Preprocess scripts/modules.lds.S to allow CONFIG options in the module
    linker script
 
  - Drop cc-option tests from compiler flags supported by our minimal
    GCC/Clang versions
 
  - Use always 12-digits commit hash for CONFIG_LOCALVERSION_AUTO=y
 
  - Use sha1 build id for both BFD linker and LLD
 
  - Improve deb-pkg for reproducible builds and rootless builds
 
  - Remove stale, useless scripts/namespace.pl
 
  - Turn -Wreturn-type warning into error
 
  - Fix build error of deb-pkg when CONFIG_MODULES=n
 
  - Replace 'hostname' command with more portable 'uname -n'
 
  - Various Makefile cleanups
 -----BEGIN PGP SIGNATURE-----
 
 iQJJBAABCgAzFiEEbmPs18K1szRHjPqEPYsBB53g2wYFAl+RfS0VHG1hc2FoaXJv
 eUBrZXJuZWwub3JnAAoJED2LAQed4NsGG1QP/2hzoMzK1YXErPUhGrhYU1rxz7Nu
 HkLTIkyKF1HPwSJf5XyNW/FTBI4SDlkNoVg/weEDCS1yFxxpvQLIck8ChzA1kIIM
 P+1IfBWOTzqn91XsapU2zwSno3gylphVchVIvYAB3oLUotGeMSluy1cQtBRzyA5D
 rj2Q7H8fzkzk3YoBcBC/BOKDlfo/usqQ1X/gsfRFwN/BJxeZSYoujNBE7KtHaDsd
 8K/ggBIqmST4NBn+M8c11d8CxzvWbtG1gq3EkUL5nG8T13DsGn1EFC0SPt85bkvv
 f9YywfJi37HixhZzK6tXYjN/PWoiEY6z90mhd0NtZghQT7kQMiTQ3sWrM8dX3ssf
 phBzO94uFQDjhyxOaSSsCoI/TIciAPo4+G8PNjcaEtj63IEfhEz/dnlstYwY5Y9P
 Pp3aZtVjSGJwGW2u2EUYj6paFVqjf6DXQjQKPNHnsYCEidIvFTjjguRGvx9gl6mx
 yd8oseOsAtOEf0alRe9MMdvN17O3UrRAxgBdap7fktg02TLVRGxZIbuwKmBf29ho
 ORl9zeFkYBn6XQFyuItJoXy/kYFyHDaBEPYCRQcY4dwqcjZIiAc/FhYbqYthJ59L
 5vLN2etmDIVSuUv1J5nBqHHGCqJChykbqg7riQ651dCNKw4gZB8ctCay2lXhBXMg
 1mqOcoG5WWL7//F+
 =tZRN
 -----END PGP SIGNATURE-----

Merge tag 'kbuild-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Support 'make compile_commands.json' to generate the compilation
   database more easily, avoiding stale entries

 - Support 'make clang-analyzer' and 'make clang-tidy' for static checks
   using clang-tidy

 - Preprocess scripts/modules.lds.S to allow CONFIG options in the
   module linker script

 - Drop cc-option tests from compiler flags supported by our minimal
   GCC/Clang versions

 - Use always 12-digits commit hash for CONFIG_LOCALVERSION_AUTO=y

 - Use sha1 build id for both BFD linker and LLD

 - Improve deb-pkg for reproducible builds and rootless builds

 - Remove stale, useless scripts/namespace.pl

 - Turn -Wreturn-type warning into error

 - Fix build error of deb-pkg when CONFIG_MODULES=n

 - Replace 'hostname' command with more portable 'uname -n'

 - Various Makefile cleanups

* tag 'kbuild-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (34 commits)
  kbuild: Use uname for LINUX_COMPILE_HOST detection
  kbuild: Only add -fno-var-tracking-assignments for old GCC versions
  kbuild: remove leftover comment for filechk utility
  treewide: remove DISABLE_LTO
  kbuild: deb-pkg: clean up package name variables
  kbuild: deb-pkg: do not build linux-headers package if CONFIG_MODULES=n
  kbuild: enforce -Werror=return-type
  scripts: remove namespace.pl
  builddeb: Add support for all required debian/rules targets
  builddeb: Enable rootless builds
  builddeb: Pass -n to gzip for reproducible packages
  kbuild: split the build log of kallsyms
  kbuild: explicitly specify the build id style
  scripts/setlocalversion: make git describe output more reliable
  kbuild: remove cc-option test of -Werror=date-time
  kbuild: remove cc-option test of -fno-stack-check
  kbuild: remove cc-option test of -fno-strict-overflow
  kbuild: move CFLAGS_{KASAN,UBSAN,KCSAN} exports to relevant Makefiles
  kbuild: remove redundant CONFIG_KASAN check from scripts/Makefile.kasan
  kbuild: do not create built-in objects for external module builds
  ...
2020-10-22 13:13:57 -07:00
Linus Torvalds
2b71482060 Modules updates for v5.10
Summary of modules changes for the 5.10 merge window:
 
 - Code cleanups. More informative error messages and statically
   initialize init_free_wq to avoid a workqueue warning.
 
 Signed-off-by: Jessica Yu <jeyu@kernel.org>
 -----BEGIN PGP SIGNATURE-----
 
 iQJEBAABCAAuFiEEVrp26glSWYuDNrCUwEV+OM47wXIFAl+RbXUQHGpleXVAa2Vy
 bmVsLm9yZwAKCRDARX44zjvBcm/QD/42Nm/9UZB1DKL2vh/rWw3UJWN0BU05+1s9
 QvSVQxKEXgEA3tEE1HP7LL5g/6JVFqypghUsX69Uf79P0FlIjlvcCoOQPSaNLXyj
 Md90Jg26AQiI9CrtDCQx2uli8KVUCVAtzuKOqShjUwSiIvI8yBoQpjMMRdnmxNGT
 HTM0yEbdD4Nfa9F/v51J0Tnq3Czj8IlIEjCuHVpyNTbaRZVGfmIJygKDRWQWh4lU
 fnOWLzHeARsvW7T0VvpolenPhoLp+Z+mWKeNg2XJpXpMc9RtZk85DUPn0MDVbL+b
 sZhQXTTsdvF0GVCsdm06wyWLuFc9ti7Oy5Ca+aHdaYsWLoYpoGwW7F7EID4dHu0a
 Sj9cUIWz7ss+TA64Itd5PImaSQasdsU0mGn5PVZNxqnBjlaw6scMpc8AZVXJhqPR
 ihSQgNELTV62AtS4zmpu2K0uVMsjCHmpXMMVkpxZYUfFOoHV4kqFn1iMGPUe9ud3
 dLq3scH6GY0m2nLa0n/Qwk7GLA3X0WO49BDBY7Vwg2XbqY52i5GYiKWJux2wf5hM
 j4+F/iB3IVysocKpP3brGU7hjPKCjRy9KwJ7IHW7w08j/9Q0p/RNGLC+ZyP8op+i
 WgOjXyWiPpLr1XDS8NYVCVAEXiDBa87pKWhdkOahYLvbp24bVWlWRRFk0U8Nl06y
 rx6DGdGrLQ==
 =7nzH
 -----END PGP SIGNATURE-----

Merge tag 'modules-for-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux

Pull modules updates from Jessica Yu:
 "Code cleanups: more informative error messages and statically
  initialize init_free_wq to avoid a workqueue warning"

* tag 'modules-for-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
  module: statically initialize init section freeing data
  module: Add more error message for failed kernel module loading
2020-10-22 13:08:57 -07:00
Linus Torvalds
f56e65dff6 Merge branch 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull initial set_fs() removal from Al Viro:
 "Christoph's set_fs base series + fixups"

* 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs: Allow a NULL pos pointer to __kernel_read
  fs: Allow a NULL pos pointer to __kernel_write
  powerpc: remove address space overrides using set_fs()
  powerpc: use non-set_fs based maccess routines
  x86: remove address space overrides using set_fs()
  x86: make TASK_SIZE_MAX usable from assembly code
  x86: move PAGE_OFFSET, TASK_SIZE & friends to page_{32,64}_types.h
  lkdtm: remove set_fs-based tests
  test_bitmap: remove user bitmap tests
  uaccess: add infrastructure for kernel builds with set_fs()
  fs: don't allow splice read/write without explicit ops
  fs: don't allow kernel reads and writes without iter ops
  sysctl: Convert to iter interfaces
  proc: add a read_iter method to proc proc_ops
  proc: cleanup the compat vs no compat file ops
  proc: remove a level of indentation in proc_get_inode
2020-10-22 09:59:21 -07:00
Qiujun Huang
e1981f75d3 ring-buffer: Update the description for ring_buffer_wait
The function changed at some point, but the description was not
updated.

Link: https://lkml.kernel.org/r/20201017095246.5170-1-hqjagain@gmail.com

Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-22 11:26:26 -04:00
Qiujun Huang
0a1754b2a9 ring-buffer: Return 0 on success from ring_buffer_resize()
We don't need to check the new buffer size, and the return value
had confused resize_buffer_duplicate_size().
...
	ret = ring_buffer_resize(trace_buf->buffer,
		per_cpu_ptr(size_buf->data,cpu_id)->entries, cpu_id);
	if (ret == 0)
		per_cpu_ptr(trace_buf->data, cpu_id)->entries =
			per_cpu_ptr(size_buf->data, cpu_id)->entries;
...

Link: https://lkml.kernel.org/r/20201019142242.11560-1-hqjagain@gmail.com

Cc: stable@vger.kernel.org
Fixes: d60da506cb ("tracing: Add a resize function to make one buffer equivalent to another buffer")
Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-22 11:24:10 -04:00
Peter Zijlstra
f8e48a3dca lockdep: Fix preemption WARN for spurious IRQ-enable
It is valid (albeit uncommon) to call local_irq_enable() without first
having called local_irq_disable(). In this case we enter
lockdep_hardirqs_on*() with IRQs enabled and trip a preemption warning
for using __this_cpu_read().

Use this_cpu_read() instead to avoid the warning.

Fixes: 4d004099a6 ("lockdep: Fix lockdep recursion")
Reported-by: syzbot+53f8ce8bbc07924b6417@syzkaller.appspotmail.com
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2020-10-22 12:37:22 +02:00
Sami Tolvanen
0f6372e522 treewide: remove DISABLE_LTO
This change removes all instances of DISABLE_LTO from
Makefiles, as they are currently unused, and the preferred
method of disabling LTO is to filter out the flags instead.

Note added by Masahiro Yamada:
DISABLE_LTO was added as preparation for GCC LTO, but GCC LTO was
not pulled into the mainline. (https://lkml.org/lkml/2014/4/8/272)

Suggested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-10-21 00:28:53 +09:00
Andrei Vagin
c2f7d08ccc futex: Adjust absolute futex timeouts with per time namespace offset
For all commands except FUTEX_WAIT, the timeout is interpreted as an
absolute value. This absolute value is inside the task's time namespace and
has to be converted to the host's time.

Fixes: 5a590f35ad ("posix-clocks: Wire up clock_gettime() with timens offsets")
Reported-by: Hans van der Laan <j.h.vanderlaan@student.utwente.nl>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20201015160020.293748-1-avagin@gmail.com
2020-10-20 17:02:57 +02:00
Christoph Hellwig
695cebe58d dma-mapping: move more functions to dma-map-ops.h
Due to a mismerge a bunch of prototypes that should have moved to
dma-map-ops.h are still in dma-mapping.h, fix that up.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-10-20 10:41:07 +02:00
Martin KaFai Lau
93c230e3f5 bpf: Enforce id generation for all may-be-null register type
The commit af7ec13833 ("bpf: Add bpf_skc_to_tcp6_sock() helper")
introduces RET_PTR_TO_BTF_ID_OR_NULL and
the commit eaa6bcb71e ("bpf: Introduce bpf_per_cpu_ptr()")
introduces RET_PTR_TO_MEM_OR_BTF_ID_OR_NULL.
Note that for RET_PTR_TO_MEM_OR_BTF_ID_OR_NULL, the reg0->type
could become PTR_TO_MEM_OR_NULL which is not covered by
BPF_PROBE_MEM.

The BPF_REG_0 will then hold a _OR_NULL pointer type. This _OR_NULL
pointer type requires the bpf program to explicitly do a NULL check first.
After NULL check, the verifier will mark all registers having
the same reg->id as safe to use.  However, the reg->id
is not set for those new _OR_NULL return types.  One of the ways
that may be wrong is, checking NULL for one btf_id typed pointer will
end up validating all other btf_id typed pointers because
all of them have id == 0.  The later tests will exercise
this path.

To fix it and also avoid similar issue in the future, this patch
moves the id generation logic out of each individual RET type
test in check_helper_call().  Instead, it does one
reg_type_may_be_null() test and then do the id generation
if needed.

This patch also adds a WARN_ON_ONCE in mark_ptr_or_null_reg()
to catch future breakage.

The _OR_NULL pointer usage in the bpf_iter_reg.ctx_arg_info is
fine because it just happens that the existing id generation after
check_ctx_access() has covered it.  It is also using the
reg_type_may_be_null() to decide if id generation is needed or not.

Fixes: af7ec13833 ("bpf: Add bpf_skc_to_tcp6_sock() helper")
Fixes: eaa6bcb71e ("bpf: Introduce bpf_per_cpu_ptr()")
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201019194212.1050855-1-kafai@fb.com
2020-10-19 15:57:42 -07:00