Commit Graph

26483 Commits

Author SHA1 Message Date
Linus Torvalds
8b335c7d22 Merge branch 'for-4.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fix from Tejun Heo:
 "cgroup.threads should be delegatable (ie. a container should be able
  to write to it from inside) but was missing the flag.

  The change is very low risk"

* 'for-4.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: make cgroup.threads delegatable
2018-01-19 11:25:17 -08:00
Linus Torvalds
a2c9c1c035 Merge branch 'for-4.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue fixlet from Tejun Heo:
 "One patch to add touch_nmi_watchdog() while dumping workqueue debug
  messages to avoid triggering the lockup detector spuriously.

  The change is very low risk"

* 'for-4.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: avoid hard lockups in show_workqueue_state()
2018-01-19 11:23:39 -08:00
Linus Torvalds
726ba84b50 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:

 1) Fix BPF divides by zero, from Eric Dumazet and Alexei Starovoitov.

 2) Reject stores into bpf context via st and xadd, from Daniel
    Borkmann.

 3) Fix a memory leak in TUN, from Cong Wang.

 4) Disable RX aggregation on a specific troublesome configuration of
    r8152 in a Dell TB16b dock.

 5) Fix sw_ctx leak in tls, from Sabrina Dubroca.

 6) Fix program replacement in cls_bpf, from Daniel Borkmann.

 7) Fix uninitialized station_info structures in cfg80211, from Johannes
    Berg.

 8) Fix miscalculation of transport header offset field in flow
    dissector, from Eric Dumazet.

 9) Fix LPM tree leak on failure in mlxsw driver, from Ido Schimmel.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (29 commits)
  ibmvnic: Fix IPv6 packet descriptors
  ibmvnic: Fix IP offload control buffer
  ipv6: don't let tb6_root node share routes with other node
  ip6_gre: init dev->mtu and dev->hard_header_len correctly
  mlxsw: spectrum_router: Free LPM tree upon failure
  flow_dissector: properly cap thoff field
  fm10k: mark PM functions as __maybe_unused
  cfg80211: fix station info handling bugs
  netlink: reset extack earlier in netlink_rcv_skb
  can: af_can: canfd_rcv(): replace WARN_ONCE by pr_warn_once
  can: af_can: can_rcv(): replace WARN_ONCE by pr_warn_once
  bpf: mark dst unknown on inconsistent {s, u}bounds adjustments
  bpf: fix cls_bpf on filter replace
  Net: ethernet: ti: netcp: Fix inbound ping crash if MTU size is greater than 1500
  tls: reset crypto_info when do_tls_setsockopt_tx fails
  tls: return -EBUSY if crypto_info is already set
  tls: fix sw_ctx leak
  net/tls: Only attach to sockets in ESTABLISHED state
  net: fs_enet: do not call phy_stop() in interrupts
  r8152: disable RX aggregation on Dell TB16 dock
  ...
2018-01-19 09:30:33 -08:00
David S. Miller
7155f8f391 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says:

====================
pull-request: bpf 2018-01-18

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

The main changes are:

1) Fix a divide by zero due to wrong if (src_reg == 0) check in
   64-bit mode. Properly handle this in interpreter and mask it
   also generically in verifier to guard against similar checks
   in JITs, from Eric and Alexei.

2) Fix a bug in arm64 JIT when tail calls are involved and progs
   have different stack sizes, from Daniel.

3) Reject stores into BPF context that are not expected BPF_STX |
   BPF_MEM variant, from Daniel.

4) Mark dst reg as unknown on {s,u}bounds adjustments when the
   src reg has derived bounds from dead branches, from Daniel.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-18 09:17:04 -05:00
Daniel Borkmann
6f16101e6a bpf: mark dst unknown on inconsistent {s, u}bounds adjustments
syzkaller generated a BPF proglet and triggered a warning with
the following:

  0: (b7) r0 = 0
  1: (d5) if r0 s<= 0x0 goto pc+0
   R0=inv0 R1=ctx(id=0,off=0,imm=0) R10=fp0
  2: (1f) r0 -= r1
   R0=inv0 R1=ctx(id=0,off=0,imm=0) R10=fp0
  verifier internal error: known but bad sbounds

What happens is that in the first insn, r0's min/max value
are both 0 due to the immediate assignment, later in the jsle
test the bounds are updated for the min value in the false
path, meaning, they yield smin_val = 1, smax_val = 0, and when
ctx pointer is subtracted from r0, verifier bails out with the
internal error and throwing a WARN since smin_val != smax_val
for the known constant.

For min_val > max_val scenario it means that reg_set_min_max()
and reg_set_min_max_inv() (which both refine existing bounds)
demonstrated that such branch cannot be taken at runtime.

In above scenario for the case where it will be taken, the
existing [0, 0] bounds are kept intact. Meaning, the rejection
is not due to a verifier internal error, and therefore the
WARN() is not necessary either.

We could just reject such cases in adjust_{ptr,scalar}_min_max_vals()
when either known scalars have smin_val != smax_val or
umin_val != umax_val or any scalar reg with bounds
smin_val > smax_val or umin_val > umax_val. However, there
may be a small risk of breakage of buggy programs, so handle
this more gracefully and in adjust_{ptr,scalar}_min_max_vals()
just taint the dst reg as unknown scalar when we see ops with
such kind of src reg.

Reported-by: syzbot+6d362cadd45dc0a12ba4@syzkaller.appspotmail.com
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-17 16:23:17 -08:00
Linus Torvalds
9a4ba2ab08 Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fix from Ingo Molnar:
 "A delayacct statistics correctness fix"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  delayacct: Account blkio completion on the correct task
2018-01-17 12:28:22 -08:00
Linus Torvalds
b8c22594b1 Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixes from Ingo Molnar:
 "Two futex fixes: a input parameters robustness fix, and futex race
  fixes"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  futex: Prevent overflow by strengthen input validation
  futex: Avoid violating the 10th rule of futex
2018-01-17 12:24:42 -08:00
Linus Torvalds
dd43f3465d Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fix from Thomas Gleixner:
 "A one-liner fix which prevents deferrable timers becoming stale when
  the system does not switch into NOHZ mode"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timers: Unconditionally check deferrable base
2018-01-17 11:43:42 -08:00
Daniel Borkmann
f37a8cb84c bpf: reject stores into ctx via st and xadd
Alexei found that verifier does not reject stores into context
via BPF_ST instead of BPF_STX. And while looking at it, we
also should not allow XADD variant of BPF_STX.

The context rewriter is only assuming either BPF_LDX_MEM- or
BPF_STX_MEM-type operations, thus reject anything other than
that so that assumptions in the rewriter properly hold. Add
test cases as well for BPF selftests.

Fixes: d691f9e8d4 ("bpf: allow programs to write to certain skb fields")
Reported-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-16 15:04:58 -08:00
Linus Torvalds
b45a53be53 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:

 1) Two read past end of buffer fixes in AF_KEY, from Eric Biggers.

 2) Memory leak in key_notify_policy(), from Steffen Klassert.

 3) Fix overflow with bpf arrays, from Daniel Borkmann.

 4) Fix RDMA regression with mlx5 due to mlx5 no longer using
    pci_irq_get_affinity(), from Saeed Mahameed.

 5) Missing RCU read locking in nl80211_send_iface() when it calls
    ieee80211_bss_get_ie(), from Dominik Brodowski.

 6) cfg80211 should check dev_set_name()'s return value, from Johannes
    Berg.

 7) Missing module license tag in 9p protocol, from Stephen Hemminger.

 8) Fix crash due to too small MTU in udp ipv6 sendmsg, from Mike
    Maloney.

 9) Fix endless loop in netlink extack code, from David Ahern.

10) TLS socket layer sets inverted error codes, resulting in an endless
    loop. From Robert Hering.

11) Revert openvswitch erspan tunnel support, it's mis-designed and we
    need to kill it before it goes into a real release. From William Tu.

12) Fix lan78xx failures in full speed USB mode, from Yuiko Oshino.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (54 commits)
  net, sched: fix panic when updating miniq {b,q}stats
  qed: Fix potential use-after-free in qed_spq_post()
  nfp: use the correct index for link speed table
  lan78xx: Fix failure in USB Full Speed
  sctp: do not allow the v4 socket to bind a v4mapped v6 address
  sctp: return error if the asoc has been peeled off in sctp_wait_for_sndbuf
  sctp: reinit stream if stream outcnt has been change by sinit in sendmsg
  ibmvnic: Fix pending MAC address changes
  netlink: extack: avoid parenthesized string constant warning
  ipv4: Make neigh lookup keys for loopback/point-to-point devices be INADDR_ANY
  net: Allow neigh contructor functions ability to modify the primary_key
  sh_eth: fix dumping ARSTR
  Revert "openvswitch: Add erspan tunnel support."
  net/tls: Fix inverted error codes to avoid endless loop
  ipv6: ip6_make_skb() needs to clear cork.base.dst
  sctp: avoid compiler warning on implicit fallthru
  net: ipv4: Make "ip route get" match iif lo rules again.
  netlink: extack needs to be reset each time through loop
  tipc: fix a memory leak in tipc_nl_node_get_link()
  ipv6: fix udpv6 sendmsg crash caused by too small MTU
  ...
2018-01-16 12:45:30 -08:00
Linus Torvalds
921d4f67bf This includes two fixes
- Bring back context level recursive protection in ring buffer.
    The simpler counter protection failed, due to a path when
    tracing with trace_clock_global() as it could not be reentrant
    and depended on the ring buffer recursive protection to keep that
    from happening.
 
  - Prevent branch profiling when FORTIFY_SOURCE is enabled. It causes
    50 - 60 MB in warning messages. Branch profiling should never be
    run on production systems, so there's no reason that it needs to
    be enabled with FORTIFY_SOURCE.
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Merge tag 'trace-v4.15-rc4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Bring back context level recursive protection in ring buffer.

   The simpler counter protection failed, due to a path when tracing
   with trace_clock_global() as it could not be reentrant and depended
   on the ring buffer recursive protection to keep that from happening.

 - Prevent branch profiling when FORTIFY_SOURCE is enabled.

   It causes 50 - 60 MB in warning messages. Branch profiling should
   never be run on production systems, so there's no reason that it
   needs to be enabled with FORTIFY_SOURCE.

* tag 'trace-v4.15-rc4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Prevent PROFILE_ALL_BRANCHES when FORTIFY_SOURCE=y
  ring-buffer: Bring back context level recursive checks
2018-01-16 12:09:36 -08:00
Josh Snyder
c96f5471ce delayacct: Account blkio completion on the correct task
Before commit:

  e33a9bba85 ("sched/core: move IO scheduling accounting from io_schedule_timeout() into scheduler")

delayacct_blkio_end() was called after context-switching into the task which
completed I/O.

This resulted in double counting: the task would account a delay both waiting
for I/O and for time spent in the runqueue.

With e33a9bba85, delayacct_blkio_end() is called by try_to_wake_up().
In ttwu, we have not yet context-switched. This is more correct, in that
the delay accounting ends when the I/O is complete.

But delayacct_blkio_end() relies on 'get_current()', and we have not yet
context-switched into the task whose I/O completed. This results in the
wrong task having its delay accounting statistics updated.

Instead of doing that, pass the task_struct being woken to delayacct_blkio_end(),
so that it can update the statistics of the correct task.

Signed-off-by: Josh Snyder <joshs@netflix.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Cc: <stable@vger.kernel.org>
Cc: Brendan Gregg <bgregg@netflix.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-block@vger.kernel.org
Fixes: e33a9bba85 ("sched/core: move IO scheduling accounting from io_schedule_timeout() into scheduler")
Link: http://lkml.kernel.org/r/1513613712-571-1-git-send-email-joshs@netflix.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-01-16 03:29:36 +01:00
Randy Dunlap
68e76e034b tracing: Prevent PROFILE_ALL_BRANCHES when FORTIFY_SOURCE=y
I regularly get 50 MB - 60 MB files during kernel randconfig builds.
These large files mostly contain (many repeats of; e.g., 124,594):

In file included from ../include/linux/string.h:6:0,
                 from ../include/linux/uuid.h:20,
                 from ../include/linux/mod_devicetable.h:13,
                 from ../scripts/mod/devicetable-offsets.c:3:
../include/linux/compiler.h:64:4: warning: '______f' is static but declared in inline function 'strcpy' which is not static [enabled by default]
    ______f = {     \
    ^
../include/linux/compiler.h:56:23: note: in expansion of macro '__trace_if'
                       ^
../include/linux/string.h:425:2: note: in expansion of macro 'if'
  if (p_size == (size_t)-1 && q_size == (size_t)-1)
  ^

This only happens when CONFIG_FORTIFY_SOURCE=y and
CONFIG_PROFILE_ALL_BRANCHES=y, so prevent PROFILE_ALL_BRANCHES if
FORTIFY_SOURCE=y.

Link: http://lkml.kernel.org/r/9199446b-a141-c0c3-9678-a3f9107f2750@infradead.org

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-15 14:15:31 -05:00
Steven Rostedt (VMware)
a0e3a18f4b ring-buffer: Bring back context level recursive checks
Commit 1a149d7d3f ("ring-buffer: Rewrite trace_recursive_(un)lock() to be
simpler") replaced the context level recursion checks with a simple counter.
This would prevent the ring buffer code from recursively calling itself more
than the max number of contexts that exist (Normal, softirq, irq, nmi). But
this change caused a lockup in a specific case, which was during suspend and
resume using a global clock. Adding a stack dump to see where this occurred,
the issue was in the trace global clock itself:

  trace_buffer_lock_reserve+0x1c/0x50
  __trace_graph_entry+0x2d/0x90
  trace_graph_entry+0xe8/0x200
  prepare_ftrace_return+0x69/0xc0
  ftrace_graph_caller+0x78/0xa8
  queued_spin_lock_slowpath+0x5/0x1d0
  trace_clock_global+0xb0/0xc0
  ring_buffer_lock_reserve+0xf9/0x390

The function graph tracer traced queued_spin_lock_slowpath that was called
by trace_clock_global. This pointed out that the trace_clock_global() is not
reentrant, as it takes a spin lock. It depended on the ring buffer recursive
lock from letting that happen.

By removing the context detection and adding just a max number of allowable
recursions, it allowed the trace_clock_global() to be entered again and try
to retake the spinlock it already held, causing a deadlock.

Fixes: 1a149d7d3f ("ring-buffer: Rewrite trace_recursive_(un)lock() to be simpler")
Reported-by: David Weinehall <david.weinehall@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-15 12:28:06 -05:00
Thomas Gleixner
ed4bbf7910 timers: Unconditionally check deferrable base
When the timer base is checked for expired timers then the deferrable base
must be checked as well. This was missed when making the deferrable base
independent of base::nohz_active.

Fixes: ced6d5c11d ("timers: Use deferrable base independent of base::nohz_active")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Anna-Maria Gleixner <anna-maria@linutronix.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Cc: rt@linutronix.de
2018-01-14 23:25:33 +01:00
Alexei Starovoitov
68fda450a7 bpf: fix 32-bit divide by zero
due to some JITs doing if (src_reg == 0) check in 64-bit mode
for div/mod operations mask upper 32-bits of src register
before doing the check

Fixes: 622582786c ("net: filter: x86: internal BPF JIT")
Fixes: 7a12b5031c ("sparc64: Add eBPF JIT.")
Reported-by: syzbot+48340bb518e88849e2e3@syzkaller.appspotmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-01-14 23:05:33 +01:00
Li Jinyue
fbe0e839d1 futex: Prevent overflow by strengthen input validation
UBSAN reports signed integer overflow in kernel/futex.c:

 UBSAN: Undefined behaviour in kernel/futex.c:2041:18
 signed integer overflow:
 0 - -2147483648 cannot be represented in type 'int'

Add a sanity check to catch negative values of nr_wake and nr_requeue.

Signed-off-by: Li Jinyue <lijinyue@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: peterz@infradead.org
Cc: dvhart@infradead.org
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1513242294-31786-1-git-send-email-lijinyue@huawei.com
2018-01-14 18:55:03 +01:00
Peter Zijlstra
c1e2f0eaf0 futex: Avoid violating the 10th rule of futex
Julia reported futex state corruption in the following scenario:

   waiter                                  waker                                            stealer (prio > waiter)

   futex(WAIT_REQUEUE_PI, uaddr, uaddr2,
         timeout=[N ms])
      futex_wait_requeue_pi()
         futex_wait_queue_me()
            freezable_schedule()
            <scheduled out>
                                           futex(LOCK_PI, uaddr2)
                                           futex(CMP_REQUEUE_PI, uaddr,
                                                 uaddr2, 1, 0)
                                              /* requeues waiter to uaddr2 */
                                           futex(UNLOCK_PI, uaddr2)
                                                 wake_futex_pi()
                                                    cmp_futex_value_locked(uaddr2, waiter)
                                                    wake_up_q()
           <woken by waker>
           <hrtimer_wakeup() fires,
            clears sleeper->task>
                                                                                           futex(LOCK_PI, uaddr2)
                                                                                              __rt_mutex_start_proxy_lock()
                                                                                                 try_to_take_rt_mutex() /* steals lock */
                                                                                                    rt_mutex_set_owner(lock, stealer)
                                                                                              <preempted>
         <scheduled in>
         rt_mutex_wait_proxy_lock()
            __rt_mutex_slowlock()
               try_to_take_rt_mutex() /* fails, lock held by stealer */
               if (timeout && !timeout->task)
                  return -ETIMEDOUT;
            fixup_owner()
               /* lock wasn't acquired, so,
                  fixup_pi_state_owner skipped */

   return -ETIMEDOUT;

   /* At this point, we've returned -ETIMEDOUT to userspace, but the
    * futex word shows waiter to be the owner, and the pi_mutex has
    * stealer as the owner */

   futex_lock(LOCK_PI, uaddr2)
     -> bails with EDEADLK, futex word says we're owner.

And suggested that what commit:

  73d786bd04 ("futex: Rework inconsistent rt_mutex/futex_q state")

removes from fixup_owner() looks to be just what is needed. And indeed
it is -- I completely missed that requeue_pi could also result in this
case. So we need to restore that, except that subsequent patches, like
commit:

  16ffa12d74 ("futex: Pull rt_mutex_futex_unlock() out from under hb->lock")

changed all the locking rules. Even without that, the sequence:

-               if (rt_mutex_futex_trylock(&q->pi_state->pi_mutex)) {
-                       locked = 1;
-                       goto out;
-               }

-               raw_spin_lock_irq(&q->pi_state->pi_mutex.wait_lock);
-               owner = rt_mutex_owner(&q->pi_state->pi_mutex);
-               if (!owner)
-                       owner = rt_mutex_next_owner(&q->pi_state->pi_mutex);
-               raw_spin_unlock_irq(&q->pi_state->pi_mutex.wait_lock);
-               ret = fixup_pi_state_owner(uaddr, q, owner);

already suggests there were races; otherwise we'd never have to look
at next_owner.

So instead of doing 3 consecutive wait_lock sections with who knows
what races, we do it all in a single section. Additionally, the usage
of pi_state->owner in fixup_owner() was only safe because only the
rt_mutex owner would modify it, which this additional case wrecks.

Luckily the values can only change away and not to the value we're
testing, this means we can do a speculative test and double check once
we have the wait_lock.

Fixes: 73d786bd04 ("futex: Rework inconsistent rt_mutex/futex_q state")
Reported-by: Julia Cartwright <julia@ni.com>
Reported-by: Gratian Crisan <gratian.crisan@ni.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Julia Cartwright <julia@ni.com>
Tested-by: Gratian Crisan <gratian.crisan@ni.com>
Cc: Darren Hart <dvhart@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20171208124939.7livp7no2ov65rrc@hirez.programming.kicks-ass.net
2018-01-14 18:49:16 +01:00
Eric Dumazet
c366287ebd bpf: fix divides by zero
Divides by zero are not nice, lets avoid them if possible.

Also do_div() seems not needed when dealing with 32bit operands,
but this seems a minor detail.

Fixes: bd4cf0ed33 ("net: filter: rework/optimize internal BPF interpreter's instruction set")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-14 09:03:43 -08:00
Linus Torvalds
ed93de8420 Merge branch 'akpm' (patches from Andrew)
Merge misc fixlets from Andrew Morton:
 "4 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  tools/objtool/Makefile: don't assume sync-check.sh is executable
  kdump: write correct address of mem_section into vmcoreinfo
  kmemleak: allow to coexist with fault injection
  MAINTAINERS, nilfs2: change project home URLs
2018-01-13 11:07:55 -08:00
Kirill A. Shutemov
a0b1280368 kdump: write correct address of mem_section into vmcoreinfo
Depending on configuration mem_section can now be an array or a pointer
to an array allocated dynamically.  In most cases, we can continue to
refer to it as 'mem_section' regardless of what it is.

But there's one exception: '&mem_section' means "address of the array"
if mem_section is an array, but if mem_section is a pointer, it would
mean "address of the pointer".

We've stepped onto this in kdump code.  VMCOREINFO_SYMBOL(mem_section)
writes down address of pointer into vmcoreinfo, not array as we wanted.

Let's introduce VMCOREINFO_SYMBOL_ARRAY() that would handle the
situation correctly for both cases.

Link: http://lkml.kernel.org/r/20180112162532.35896-1-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Fixes: 83e3c48729 ("mm/sparsemem: Allocate mem_section at runtime for CONFIG_SPARSEMEM_EXTREME=y")
Acked-by: Baoquan He <bhe@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Dave Young <dyoung@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-01-13 10:42:48 -08:00
Sergey Senozhatsky
62635ea8c1 workqueue: avoid hard lockups in show_workqueue_state()
show_workqueue_state() can print out a lot of messages while being in
atomic context, e.g. sysrq-t -> show_workqueue_state(). If the console
device is slow it may end up triggering NMI hard lockup watchdog.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org # v4.5+
2018-01-12 11:39:49 -08:00
Linus Torvalds
67549d46d4 Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar:
 "A Kconfig fix, a build fix and a membarrier bug fix"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  membarrier: Disable preemption when calling smp_call_function_many()
  sched/isolation: Make CONFIG_CPU_ISOLATION=y depend on SMP or COMPILE_TEST
  ia64, sched/cputime: Fix build error if CONFIG_VIRT_CPU_ACCOUNTING_NATIVE=y
2018-01-12 10:23:59 -08:00
Linus Torvalds
02776b9b53 Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixes from Ingo Molnar:
 "No functional effects intended: removes leftovers from recent lockdep
  and refcounts work"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/refcounts: Remove stale comment from the ARCH_HAS_REFCOUNT Kconfig entry
  locking/lockdep: Remove cross-release leftovers
  locking/Documentation: Remove stale crossrelease_fullstack parameter
2018-01-12 10:14:09 -08:00
Daniel Borkmann
bbeb6e4323 bpf, array: fix overflow in max_entries and undefined behavior in index_mask
syzkaller tried to alloc a map with 0xfffffffd entries out of a userns,
and thus unprivileged. With the recently added logic in b2157399cc
("bpf: prevent out-of-bounds speculation") we round this up to the next
power of two value for max_entries for unprivileged such that we can
apply proper masking into potentially zeroed out map slots.

However, this will generate an index_mask of 0xffffffff, and therefore
a + 1 will let this overflow into new max_entries of 0. This will pass
allocation, etc, and later on map access we still enforce on the original
attr->max_entries value which was 0xfffffffd, therefore triggering GPF
all over the place. Thus bail out on overflow in such case.

Moreover, on 32 bit archs roundup_pow_of_two() can also not be used,
since fls_long(max_entries - 1) can result in 32 and 1UL << 32 in 32 bit
space is undefined. Therefore, do this by hand in a 64 bit variable.

This fixes all the issues triggered by syzkaller's reproducers.

Fixes: b2157399cc ("bpf: prevent out-of-bounds speculation")
Reported-by: syzbot+b0efb8e572d01bce1ae0@syzkaller.appspotmail.com
Reported-by: syzbot+6c15e9744f75f2364773@syzkaller.appspotmail.com
Reported-by: syzbot+d2f5524fb46fd3b312ee@syzkaller.appspotmail.com
Reported-by: syzbot+61d23c95395cc90dbc2b@syzkaller.appspotmail.com
Reported-by: syzbot+0d363c942452cca68c01@syzkaller.appspotmail.com
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-10 14:46:39 -08:00
Daniel Borkmann
7891a87efc bpf: arsh is not supported in 32 bit alu thus reject it
The following snippet was throwing an 'unknown opcode cc' warning
in BPF interpreter:

  0: (18) r0 = 0x0
  2: (7b) *(u64 *)(r10 -16) = r0
  3: (cc) (u32) r0 s>>= (u32) r0
  4: (95) exit

Although a number of JITs do support BPF_ALU | BPF_ARSH | BPF_{K,X}
generation, not all of them do and interpreter does neither. We can
leave existing ones and implement it later in bpf-next for the
remaining ones, but reject this properly in verifier for the time
being.

Fixes: 17a5267067 ("bpf: verifier (add verifier core)")
Reported-by: syzbot+93c4904c5c70348a6890@syzkaller.appspotmail.com
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-10 14:42:22 -08:00
Colin Ian King
4095034393 bpf: fix spelling mistake: "obusing" -> "abusing"
Trivial fix to spelling mistake in error message text.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-10 14:32:59 -08:00
Roman Gushchin
4f58424da3 cgroup: make cgroup.threads delegatable
Make cgroup.threads file delegatable.
The behavior of cgroup.threads should follow the behavior of cgroup.procs.

Signed-off-by: Roman Gushchin <guro@fb.com>
Discovered-by: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2018-01-10 09:42:32 -08:00
David S. Miller
661e4e33a9 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says:

====================
pull-request: bpf 2018-01-09

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

The main changes are:

1) Prevent out-of-bounds speculation in BPF maps by masking the
   index after bounds checks in order to fix spectre v1, and
   add an option BPF_JIT_ALWAYS_ON into Kconfig that allows for
   removing the BPF interpreter from the kernel in favor of
   JIT-only mode to make spectre v2 harder, from Alexei.

2) Remove false sharing of map refcount with max_entries which
   was used in spectre v1, from Daniel.

3) Add a missing NULL psock check in sockmap in order to fix
   a race, from John.

4) Fix test_align BPF selftest case since a recent change in
   verifier rejects the bit-wise arithmetic on pointers
   earlier but test_align update was missing, from Alexei.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-10 11:17:21 -05:00
Mathieu Desnoyers
541676078b membarrier: Disable preemption when calling smp_call_function_many()
smp_call_function_many() requires disabling preemption around the call.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: <stable@vger.kernel.org> # v4.14+
Cc: Andrea Parri <parri.andrea@gmail.com>
Cc: Andrew Hunter <ahh@google.com>
Cc: Avi Kivity <avi@scylladb.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Dave Watson <davejwatson@fb.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Maged Michael <maged.michael@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul E . McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20171215192310.25293-1-mathieu.desnoyers@efficios.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-01-10 08:50:31 +01:00
Alexei Starovoitov
290af86629 bpf: introduce BPF_JIT_ALWAYS_ON config
The BPF interpreter has been used as part of the spectre 2 attack CVE-2017-5715.

A quote from goolge project zero blog:
"At this point, it would normally be necessary to locate gadgets in
the host kernel code that can be used to actually leak data by reading
from an attacker-controlled location, shifting and masking the result
appropriately and then using the result of that as offset to an
attacker-controlled address for a load. But piecing gadgets together
and figuring out which ones work in a speculation context seems annoying.
So instead, we decided to use the eBPF interpreter, which is built into
the host kernel - while there is no legitimate way to invoke it from inside
a VM, the presence of the code in the host kernel's text section is sufficient
to make it usable for the attack, just like with ordinary ROP gadgets."

To make attacker job harder introduce BPF_JIT_ALWAYS_ON config
option that removes interpreter from the kernel in favor of JIT-only mode.
So far eBPF JIT is supported by:
x64, arm64, arm32, sparc64, s390, powerpc64, mips64

The start of JITed program is randomized and code page is marked as read-only.
In addition "constant blinding" can be turned on with net.core.bpf_jit_harden

v2->v3:
- move __bpf_prog_ret0 under ifdef (Daniel)

v1->v2:
- fix init order, test_bpf and cBPF (Daniel's feedback)
- fix offloaded bpf (Jakub's feedback)
- add 'return 0' dummy in case something can invoke prog->bpf_func
- retarget bpf tree. For bpf-next the patch would need one extra hunk.
  It will be sent when the trees are merged back to net-next

Considered doing:
  int bpf_jit_enable __read_mostly = BPF_EBPF_JIT_DEFAULT;
but it seems better to land the patch as-is and in bpf-next remove
bpf_jit_enable global variable from all JITs, consolidate in one place
and remove this jit_init() function.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-01-09 22:25:26 +01:00
Alexei Starovoitov
b2157399cc bpf: prevent out-of-bounds speculation
Under speculation, CPUs may mis-predict branches in bounds checks. Thus,
memory accesses under a bounds check may be speculated even if the
bounds check fails, providing a primitive for building a side channel.

To avoid leaking kernel data round up array-based maps and mask the index
after bounds check, so speculated load with out of bounds index will load
either valid value from the array or zero from the padded area.

Unconditionally mask index for all array types even when max_entries
are not rounded to power of 2 for root user.
When map is created by unpriv user generate a sequence of bpf insns
that includes AND operation to make sure that JITed code includes
the same 'index & index_mask' operation.

If prog_array map is created by unpriv user replace
  bpf_tail_call(ctx, map, index);
with
  if (index >= max_entries) {
    index &= map->index_mask;
    bpf_tail_call(ctx, map, index);
  }
(along with roundup to power 2) to prevent out-of-bounds speculation.
There is secondary redundant 'if (index >= max_entries)' in the interpreter
and in all JITs, but they can be optimized later if necessary.

Other array-like maps (cpumap, devmap, sockmap, perf_event_array, cgroup_array)
cannot be used by unpriv, so no changes there.

That fixes bpf side of "Variant 1: bounds check bypass (CVE-2017-5753)" on
all architectures with and without JIT.

v2->v3:
Daniel noticed that attack potentially can be crafted via syscall commands
without loading the program, so add masking to those paths as well.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-01-09 00:53:49 +01:00
Linus Torvalds
29f7e49941 Merge branch 'for-4.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo:
 "This contains fixes for the following two non-trivial issues:

   - The task iterator got broken while adding thread mode support for
     v4.14. It was less visible because it only triggers when both
     cgroup1 and cgroup2 hierarchies are in use. The recent versions of
     systemd uses cgroup2 for process management even when cgroup1 is
     used for resource control exposing this issue.

   - cpuset CPU hotplug path could deadlock when racing against exits.

  There also are two patches to replace unlimited strcpy() usages with
  strlcpy()"

* 'for-4.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: fix css_task_iter crash on CSS_TASK_ITER_PROC
  cgroup: Fix deadlock in cpu hotplug path
  cgroup: use strlcpy() instead of strscpy() to avoid spurious warning
  cgroup: avoid copying strings longer than the buffers
2018-01-08 11:13:08 -08:00
Ingo Molnar
527187d285 locking/lockdep: Remove cross-release leftovers
There's two cross-release leftover facilities:

 - the crossrelease_hist_*() irq-tracing callbacks (NOPs currently)
 - the complete_release_commit() callback (NOP as well)

Remove them.

Cc: David Sterba <dsterba@suse.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-01-08 17:30:45 +01:00
Linus Torvalds
75d4276e83 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs fixes from Al Viro:

 - untangle sys_close() abuses in xt_bpf

 - deal with register_shrinker() failures in sget()

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fix "netfilter: xt_bpf: Fix XT_BPF_MODE_FD_PINNED mode of 'xt_bpf_info_v1'"
  sget(): handle failures of register_shrinker()
  mm,vmscan: Make unregister_shrinker() no-op if register_shrinker() failed.
2018-01-06 17:13:21 -08:00
John Fastabend
5731a879d0 bpf: sockmap missing NULL psock check
Add psock NULL check to handle a racing sock event that can get the
sk_callback_lock before this case but after xchg happens causing the
refcnt to hit zero and sock user data (psock) to be null and queued
for garbage collection.

Also add a comment in the code because this is a bit subtle and
not obvious in my opinion.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-01-07 00:01:46 +01:00
Al Viro
040ee69226 fix "netfilter: xt_bpf: Fix XT_BPF_MODE_FD_PINNED mode of 'xt_bpf_info_v1'"
Descriptor table is a shared object; it's not a place where you can
stick temporary references to files, especially when we don't need
an opened file at all.

Cc: stable@vger.kernel.org # v4.14
Fixes: 98589a0998 ("netfilter: xt_bpf: Fix XT_BPF_MODE_FD_PINNED mode of 'xt_bpf_info_v1'")
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-01-05 11:43:39 -05:00
Andrew Morton
dc8635b78c kernel/exit.c: export abort() to modules
gcc -fisolate-erroneous-paths-dereference can generate calls to abort()
from modular code too.

[arnd@arndb.de: drop duplicate exports of abort()]
  Link: http://lkml.kernel.org/r/20180102103311.706364-1-arnd@arndb.de
Reported-by: Vineet Gupta <Vineet.Gupta1@synopsys.com>
Cc: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Alexey Brodkin <Alexey.Brodkin@synopsys.com>
Cc: Russell King <rmk+kernel@armlinux.org.uk>
Cc: Jose Abreu <Jose.Abreu@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-01-04 16:45:09 -08:00
Oleg Nesterov
4d9570158b kernel/acct.c: fix the acct->needcheck check in check_free_space()
As Tsukada explains, the time_is_before_jiffies(acct->needcheck) check
is very wrong, we need time_is_after_jiffies() to make sys_acct() work.

Ignoring the overflows, the code should "goto out" if needcheck >
jiffies, while currently it checks "needcheck < jiffies" and thus in the
likely case check_free_space() does nothing until jiffies overflow.

In particular this means that sys_acct() is simply broken, acct_on()
sets acct->needcheck = jiffies and expects that check_free_space()
should set acct->active = 1 after the free-space check, but this won't
happen if jiffies increments in between.

This was broken by commit 32dc730860 ("get rid of timer in
kern/acct.c") in 2011, then another (correct) commit 795a2f22a8
("acct() should honour the limits from the very beginning") made the
problem more visible.

Link: http://lkml.kernel.org/r/20171213133940.GA6554@redhat.com
Fixes: 32dc730860 ("get rid of timer in kern/acct.c")
Reported-by: TSUKADA Koutaro <tsukada@ascade.co.jp>
Suggested-by: TSUKADA Koutaro <tsukada@ascade.co.jp>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-01-04 16:45:09 -08:00
Linus Torvalds
d6bbd51587 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull pid allocation bug fix from Eric Biederman:
 "The replacement of the pid hash table and the pid bitmap with an idr
  resulted in an implementation that now fails more often in low memory
  situations. Allowing fuzzers to observe bad behavior from a memory
  allocation failure during pid allocation.

  This is a small change to fix this by making the kernel more robust in
  the case of error. The non-error paths are left alone so the only
  danger is to the already broken error path. I have manually injected
  errors and verified that this new error handling works"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  pid: Handle failure to allocate the first pid in a pid namespace
2018-01-03 11:03:07 -08:00
Linus Torvalds
cea92e843e Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Thomas Gleixner:
 "A pile of fixes for long standing issues with the timer wheel and the
  NOHZ code:

   - Prevent timer base confusion accross the nohz switch, which can
     cause unlocked access and data corruption

   - Reinitialize the stale base clock on cpu hotplug to prevent subtle
     side effects including rollovers on 32bit

   - Prevent an interrupt storm when the timer softirq is already
     pending caused by tick_nohz_stop_sched_tick()

   - Move the timer start tracepoint to a place where it actually makes
     sense

   - Add documentation to timerqueue functions as they caused confusion
     several times now"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timerqueue: Document return values of timerqueue_add/del()
  timers: Invoke timer_start_debug() where it makes sense
  nohz: Prevent a timer interrupt storm in tick_nohz_stop_sched_tick()
  timers: Reinitialize per cpu bases on hotplug
  timers: Use deferrable base independent of base::nohz_active
2017-12-31 12:30:34 -08:00
Linus Torvalds
8d517bdfb5 Merge branch 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull smp fixlet from Thomas Gleixner:
 "A trivial build warning fix for newer compilers"

* 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  cpu/hotplug: Move inline keyword at the beginning of declaration
2017-12-31 12:29:02 -08:00
Linus Torvalds
4c470317f9 Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Thomas Gleixner:
 "Three patches addressing the fallout of the CPU_ISOLATION changes
  especially with NO_HZ_FULL plus documentation of boot parameter
  dependency"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/isolation: Document boot parameters dependency on CONFIG_CPU_ISOLATION=y
  sched/isolation: Enable CONFIG_CPU_ISOLATION=y by default
  sched/isolation: Make CONFIG_NO_HZ_FULL select CONFIG_CPU_ISOLATION
2017-12-31 12:27:19 -08:00
Linus Torvalds
88fa025d30 Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fixes from Thomas Gleixner:
 "A rather large update after the kaisered maintainer finally found time
  to handle regression reports.

   - The larger part addresses a regression caused by the x86 vector
     management rework.

     The reservation based model does not work reliably for MSI
     interrupts, if they cannot be masked (yes, yet another hw
     engineering trainwreck). The reason is that the reservation mode
     assigns a dummy vector when the interrupt is allocated and switches
     to a real vector when the interrupt is requested.

     If the MSI entry cannot be masked then the initialization might
     raise an interrupt before the interrupt is requested, which ends up
     as spurious interrupt and causes device malfunction and worse. The
     fix is to exclude MSI interrupts which do not support masking from
     reservation mode and assign a real vector right away.

   - Extend the extra lockdep class setup for nested interrupts with a
     class for the recently added irq_desc::request_mutex so lockdep can
     differeniate and does not emit false positive warnings.

   - A ratelimit guard for the bad irq printout so in case a bad irq
     comes back immediately the system does not drown in dmesg spam"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq/msi, x86/vector: Prevent reservation mode for non maskable MSI
  genirq/irqdomain: Rename early argument of irq_domain_activate_irq()
  x86/vector: Use IRQD_CAN_RESERVE flag
  genirq: Introduce IRQD_CAN_RESERVE flag
  genirq/msi: Handle reactivation only on success
  gpio: brcmstb: Make really use of the new lockdep class
  genirq: Guard handle_bad_irq log messages
  kernel/irq: Extend lockdep class for request mutex
2017-12-31 11:23:11 -08:00
Thomas Gleixner
fd45bb77ad timers: Invoke timer_start_debug() where it makes sense
The timer start debug function is called before the proper timer base is
set. As a consequence the trace data contains the stale CPU and flags
values.

Call the debug function after setting the new base and flags.

Fixes: 500462a9de ("timers: Switch to a non-cascading wheel")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: stable@vger.kernel.org
Cc: rt@linutronix.de
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Anna-Maria Gleixner <anna-maria@linutronix.de>
Link: https://lkml.kernel.org/r/20171222145337.792907137@linutronix.de
2017-12-29 23:13:10 +01:00
Thomas Gleixner
5d62c183f9 nohz: Prevent a timer interrupt storm in tick_nohz_stop_sched_tick()
The conditions in irq_exit() to invoke tick_nohz_irq_exit() which
subsequently invokes tick_nohz_stop_sched_tick() are:

  if ((idle_cpu(cpu) && !need_resched()) || tick_nohz_full_cpu(cpu))

If need_resched() is not set, but a timer softirq is pending then this is
an indication that the softirq code punted and delegated the execution to
softirqd. need_resched() is not true because the current interrupted task
takes precedence over softirqd.

Invoking tick_nohz_irq_exit() in this case can cause an endless loop of
timer interrupts because the timer wheel contains an expired timer, but
softirqs are not yet executed. So it returns an immediate expiry request,
which causes the timer to fire immediately again. Lather, rinse and
repeat....

Prevent that by adding a check for a pending timer soft interrupt to the
conditions in tick_nohz_stop_sched_tick() which avoid calling
get_next_timer_interrupt(). That keeps the tick sched timer on the tick and
prevents a repetitive programming of an already expired timer.

Reported-by: Sebastian Siewior <bigeasy@linutronix.d>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Anna-Maria Gleixner <anna-maria@linutronix.de>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1712272156050.2431@nanos
2017-12-29 23:13:10 +01:00
Thomas Gleixner
26456f87ac timers: Reinitialize per cpu bases on hotplug
The timer wheel bases are not (re)initialized on CPU hotplug. That leaves
them with a potentially stale clk and next_expiry valuem, which can cause
trouble then the CPU is plugged.

Add a prepare callback which forwards the clock, sets next_expiry to far in
the future and reset the control flags to a known state.

Set base->must_forward_clk so the first timer which is queued will try to
forward the clock to current jiffies.

Fixes: 500462a9de ("timers: Switch to a non-cascading wheel")
Reported-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Anna-Maria Gleixner <anna-maria@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1712272152200.2431@nanos
2017-12-29 23:13:09 +01:00
Anna-Maria Gleixner
ced6d5c11d timers: Use deferrable base independent of base::nohz_active
During boot and before base::nohz_active is set in the timer bases, deferrable
timers are enqueued into the standard timer base. This works correctly as
long as base::nohz_active is false.

Once it base::nohz_active is set and a timer which was enqueued before that
is accessed the lock selector code choses the lock of the deferred
base. This causes unlocked access to the standard base and in case the
timer is removed it does not clear the pending flag in the standard base
bitmap which causes get_next_timer_interrupt() to return bogus values.

To prevent that, the deferrable timers must be enqueued in the deferrable
base, even when base::nohz_active is not set. Those deferrable timers also
need to be expired unconditional.

Fixes: 500462a9de ("timers: Switch to a non-cascading wheel")
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: stable@vger.kernel.org
Cc: rt@linutronix.de
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Link: https://lkml.kernel.org/r/20171222145337.633328378@linutronix.de
2017-12-29 23:13:09 +01:00
Thomas Gleixner
bc976233a8 genirq/msi, x86/vector: Prevent reservation mode for non maskable MSI
The new reservation mode for interrupts assigns a dummy vector when the
interrupt is allocated and assigns a real vector when the interrupt is
requested. The reservation mode prevents vector pressure when devices with
a large amount of queues/interrupts are initialized, but only a minimal
subset of those queues/interrupts is actually used.

This mode has an issue with MSI interrupts which cannot be masked. If the
driver is not careful or the hardware emits an interrupt before the device
irq is requestd by the driver then the interrupt ends up on the dummy
vector as a spurious interrupt which can cause malfunction of the device or
in the worst case a lockup of the machine.

Change the logic for the reservation mode so that the early activation of
MSI interrupts checks whether:

 - the device is a PCI/MSI device
 - the reservation mode of the underlying irqdomain is activated
 - PCI/MSI masking is globally enabled
 - the PCI/MSI device uses either MSI-X, which supports masking, or
   MSI with the maskbit supported.

If one of those conditions is false, then clear the reservation mode flag
in the irq data of the interrupt and invoke irq_domain_activate_irq() with
the reserve argument cleared. In the x86 vector code, clear the can_reserve
flag in the vector allocation data so a subsequent free_irq() won't create
the same situation again. The interrupt stays assigned to a real vector
until pci_disable_msi() is invoked and all allocations are undone.

Fixes: 4900be8360 ("x86/vector/msi: Switch to global reservation mode")
Reported-by: Alexandru Chirvasitu <achirvasub@gmail.com>
Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexandru Chirvasitu <achirvasub@gmail.com>
Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Dou Liyang <douly.fnst@cn.fujitsu.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Mikael Pettersson <mikpelinux@gmail.com>
Cc: Josh Poulson <jopoulso@microsoft.com>
Cc: Mihai Costache <v-micos@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: linux-pci@vger.kernel.org
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Simon Xiao <sixiao@microsoft.com>
Cc: Saeed Mahameed <saeedm@mellanox.com>
Cc: Jork Loeser <Jork.Loeser@microsoft.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: devel@linuxdriverproject.org
Cc: KY Srinivasan <kys@microsoft.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Sakari Ailus <sakari.ailus@intel.com>,
Cc: linux-media@vger.kernel.org
Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1712291406420.1899@nanos
Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1712291409460.1899@nanos
2017-12-29 21:13:05 +01:00
Thomas Gleixner
702cb0a028 genirq/irqdomain: Rename early argument of irq_domain_activate_irq()
The 'early' argument of irq_domain_activate_irq() is actually used to
denote reservation mode. To avoid confusion, rename it before abuse
happens.

No functional change.

Fixes: 7249164346 ("genirq/irqdomain: Update irq_domain_ops.activate() signature")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Alexandru Chirvasitu <achirvasub@gmail.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Dou Liyang <douly.fnst@cn.fujitsu.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Mikael Pettersson <mikpelinux@gmail.com>
Cc: Josh Poulson <jopoulso@microsoft.com>
Cc: Mihai Costache <v-micos@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: linux-pci@vger.kernel.org
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Simon Xiao <sixiao@microsoft.com>
Cc: Saeed Mahameed <saeedm@mellanox.com>
Cc: Jork Loeser <Jork.Loeser@microsoft.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: devel@linuxdriverproject.org
Cc: KY Srinivasan <kys@microsoft.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Sakari Ailus <sakari.ailus@intel.com>,
Cc: linux-media@vger.kernel.org
2017-12-29 21:13:04 +01:00