Commit Graph

805 Commits

Author SHA1 Message Date
Linus Torvalds
f7458a5d63 Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU updates from Ingo Molnar:
 "The RCU changes in this cycle are:

   - Dynticks updates, consolidating open-coded counter accesses into a
     well-defined API

   - SRCU updates: Simplify algorithm, add formal verification

   - Documentation updates

   - Miscellaneous fixes

   - Torture-test updates

  Most of the diffstat comes from the relatively large documentation
  update"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (42 commits)
  srcu: Reduce probability of SRCU ->unlock_count[] counter overflow
  rcutorture: Add CBMC-based formal verification for SRCU
  srcu: Force full grace-period ordering
  srcu: Implement more-efficient reader counts
  rcu: Adjust FQS offline checks for exact online-CPU detection
  rcu: Check cond_resched_rcu_qs() state less often to reduce GP overhead
  rcu: Abstract extended quiescent state determination
  rcu: Abstract dynticks extended quiescent state enter/exit operations
  rcu: Add lockdep checks to synchronous expedited primitives
  rcu: Eliminate unused expedited_normal counter
  llist: Clarify comments about when locking is needed
  rcu: Fix comment in rcu_organize_nocb_kthreads()
  rcu: Enable RCU tracepoints by default to aid in debugging
  rcu: Make rcu_cpu_starting() use its "cpu" argument
  rcu: Add comment headers to expedited-grace-period counter functions
  rcu: Don't wake rcuc/X kthreads on NOCB CPUs
  rcu: Re-enable TASKS_RCU for User Mode Linux
  rcu: Once again use NMI-based stack traces in stall warnings
  rcu: Remove short-term CPU kicking
  rcu: Add long-term CPU kicking
  ...
2017-02-20 11:21:17 -08:00
Ard Biesheuvel
56067812d5 kbuild: modversions: add infrastructure for emitting relative CRCs
This add the kbuild infrastructure that will allow architectures to emit
vmlinux symbol CRCs as 32-bit offsets to another location in the kernel
where the actual value is stored. This works around problems with CRCs
being mistaken for relocatable symbols on kernels that self relocate at
runtime (i.e., powerpc with CONFIG_RELOCATABLE=y)

For the kbuild side of things, this comes down to the following:

 - introducing a Kconfig symbol MODULE_REL_CRCS

 - adding a -R switch to genksyms to instruct it to emit the CRC symbols
   as references into the .rodata section

 - making modpost distinguish such references from absolute CRC symbols
   by the section index (SHN_ABS)

 - making kallsyms disregard non-absolute symbols with a __crc_ prefix

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-03 08:28:25 -08:00
Ingo Molnar
a8709fa4a0 Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
Pull RCU changes from Paul E. McKenney:

 - Dynticks updates, consolidating open-coded counter accesses into a well-defined API

 - SRCU updates: Simplify algorithm, add formal verification

 - Documentation updates

 - Miscellaneous fixes

 - Torture-test updates

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-31 07:45:42 +01:00
Paul E. McKenney
1626c365f8 rcu: Re-enable TASKS_RCU for User Mode Linux
Now that User Mode Linux supports arch_irqs_disabled_flags(), this
commit re-enables TASKS_RCU for User Mode Linux.

Reported-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2017-01-23 11:37:12 -08:00
Sebastian Andrzej Siewior
7c6094db59 rcu: update: Make RCU_EXPEDITE_BOOT be the default
RCU_EXPEDITE_BOOT should speed up the boot process by enforcing
synchronize_rcu_expedited() instead of synchronize_rcu() during the boot
process. There should be no reason why one does not want this and there
is no need worry about real time latency at this point.
Therefore make it default.

Note that users wishing to avoid expediting entirely, for example when
bringing up new hardware possibly having flaky IPIs, can use the
rcu_normal boot parameter to override boot-time expediting.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
[ paulmck: Reworded commit log. ]
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2017-01-16 16:56:39 -08:00
Arnd Bergmann
73b3514735 cgroup: move CONFIG_SOCK_CGROUP_DATA to init/Kconfig
We now 'select SOCK_CGROUP_DATA' but Kconfig complains that this is
not right when CONFIG_NET is disabled and there is no socket interface:

warning: (CGROUP_BPF) selects SOCK_CGROUP_DATA which has unmet direct dependencies (NET)

I don't know what the correct solution for this is, but simply removing
the dependency on NET from SOCK_CGROUP_DATA by moving it out of the
'if NET' section avoids the warning and does not produce other build
errors.

Fixes: 483c4933ea ("cgroup: Fix CGROUP_BPF config")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-11 09:47:10 -05:00
Linus Torvalds
52f40e9d65 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes and cleanups from David Miller:

 1) Revert bogus nla_ok() change, from Alexey Dobriyan.

 2) Various bpf validator fixes from Daniel Borkmann.

 3) Add some necessary SET_NETDEV_DEV() calls to hsis_femac and hip04
    drivers, from Dongpo Li.

 4) Several ethtool ksettings conversions from Philippe Reynes.

 5) Fix bugs in inet port management wrt. soreuseport, from Tom Herbert.

 6) XDP support for virtio_net, from John Fastabend.

 7) Fix NAT handling within a vrf, from David Ahern.

 8) Endianness fixes in dpaa_eth driver, from Claudiu Manoil

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (63 commits)
  net: mv643xx_eth: fix build failure
  isdn: Constify some function parameters
  mlxsw: spectrum: Mark split ports as such
  cgroup: Fix CGROUP_BPF config
  qed: fix old-style function definition
  net: ipv6: check route protocol when deleting routes
  r6040: move spinlock in r6040_close as SOFTIRQ-unsafe lock order detected
  irda: w83977af_ir: cleanup an indent issue
  net: sfc: use new api ethtool_{get|set}_link_ksettings
  net: davicom: dm9000: use new api ethtool_{get|set}_link_ksettings
  net: cirrus: ep93xx: use new api ethtool_{get|set}_link_ksettings
  net: chelsio: cxgb3: use new api ethtool_{get|set}_link_ksettings
  net: chelsio: cxgb2: use new api ethtool_{get|set}_link_ksettings
  bpf: fix mark_reg_unknown_value for spilled regs on map value marking
  bpf: fix overflow in prog accounting
  bpf: dynamically allocate digest scratch buffer
  gtp: Fix initialization of Flags octet in GTPv1 header
  gtp: gtp_check_src_ms_ipv4() always return success
  net/x25: use designated initializers
  isdn: use designated initializers
  ...
2016-12-17 20:17:04 -08:00
Andy Lutomirski
483c4933ea cgroup: Fix CGROUP_BPF config
CGROUP_BPF depended on SOCK_CGROUP_DATA which can't be manually
enabled, making it rather challenging to turn CGROUP_BPF on.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-17 21:42:45 -05:00
Linus Torvalds
e7aa8c2eb1 These are the documentation changes for 4.10.
It's another busy cycle for the docs tree, as the sphinx conversion
 continues.  Highlights include:
 
  - Further work on PDF output, which remains a bit of a pain but should be
    more solid now.
 
  - Five more DocBook template files converted to Sphinx.  Only 27 to go...
    Lots of plain-text files have also been converted and integrated.
 
  - Images in binary formats have been replaced with more source-friendly
    versions.
 
  - Various bits of organizational work, including the renaming of various
    files discussed at the kernel summit.
 
  - New documentation for the device_link mechanism.
 
 ...and, of course, lots of typo fixes and small updates.
 -----BEGIN PGP SIGNATURE-----
 
 iQIcBAABAgAGBQJYTbl7AAoJEI3ONVYwIuV63NIP/REwzThnGWFJMRSuq8Ieq2r9
 sFSQsaGTGlhyKiDoEooo+SO/Za3uTonjK+e7WZg8mhdiEdamta5aociU/71C1Yy/
 T9ur0FhcGblrvZ1NidSDvCLwuECZOMMei7mgLZ9a+KCpc4ANqqTVZSUm1blKcqhF
 XelhVXxBa0ar35l/pVzyCxkdNXRWXv+MJZE8hp5XAdTdr11DS7UY9zrZdH31axtf
 BZlbYJrvB8WPydU6myTjRpirA17Hu7uU64MsL3bNIEiRQ+nVghEzQC8uxeUCvfVx
 r0H5AgGGQeir+e8GEv2T20SPZ+dumXs+y/HehKNb3jS3gV0mo+pKPeUhwLIxr+Zh
 QY64gf+jYf5ISHwAJRnU0Ima72ehObzSbx9Dko10nhq2OvbR5f83gjz9t9jKYFU7
 RDowICA8lwqyRbHRoVfyoW8CpVhWFpMFu3yNeJMckeTish3m7ANqzaWslbsqIP5G
 zxgFMIrVVSbeae+sUeygtEJAnWI09aZ4tuaUXYtGWwu6ikC/3aV6DryP4bthG2LF
 A19uV4nMrLuuh8g2wiTHHjMfjYRwvSn+f9yaolwJhwyNDXQzRPy+ZJ3W/6olOkXC
 bAxTmVRCW5GA/fmSrfXmW1KbnxlWfP2C62hzZQ09UHxzTHdR97oFLDQdZhKo1uwf
 pmSJR0hVeRUmA4uw6+Su
 =A0EV
 -----END PGP SIGNATURE-----

Merge tag 'docs-4.10' of git://git.lwn.net/linux

Pull documentation update from Jonathan Corbet:
 "These are the documentation changes for 4.10.

  It's another busy cycle for the docs tree, as the sphinx conversion
  continues. Highlights include:

   - Further work on PDF output, which remains a bit of a pain but
     should be more solid now.

   - Five more DocBook template files converted to Sphinx. Only 27 to
     go... Lots of plain-text files have also been converted and
     integrated.

   - Images in binary formats have been replaced with more
     source-friendly versions.

   - Various bits of organizational work, including the renaming of
     various files discussed at the kernel summit.

   - New documentation for the device_link mechanism.

  ... and, of course, lots of typo fixes and small updates"

* tag 'docs-4.10' of git://git.lwn.net/linux: (193 commits)
  dma-buf: Extract dma-buf.rst
  Update Documentation/00-INDEX
  docs: 00-INDEX: document directories/files with no docs
  docs: 00-INDEX: remove non-existing entries
  docs: 00-INDEX: add missing entries for documentation files/dirs
  docs: 00-INDEX: consolidate process/ and admin-guide/ description
  scripts: add a script to check if Documentation/00-INDEX is sane
  Docs: change sh -> awk in REPORTING-BUGS
  Documentation/core-api/device_link: Add initial documentation
  core-api: remove an unexpected unident
  ppc/idle: Add documentation for powersave=off
  Doc: Correct typo, "Introdution" => "Introduction"
  Documentation/atomic_ops.txt: convert to ReST markup
  Documentation/local_ops.txt: convert to ReST markup
  Documentation/assoc_array.txt: convert to ReST markup
  docs-rst: parse-headers.pl: cleanup the documentation
  docs-rst: fix media cleandocs target
  docs-rst: media/Makefile: reorganize the rules
  docs-rst: media: build SVG from graphviz files
  docs-rst: replace bayer.png by a SVG image
  ...
2016-12-12 21:58:13 -08:00
Linus Torvalds
9465d9cc31 Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer updates from Thomas Gleixner:
 "The time/timekeeping/timer folks deliver with this update:

   - Fix a reintroduced signed/unsigned issue and cleanup the whole
     signed/unsigned mess in the timekeeping core so this wont happen
     accidentaly again.

   - Add a new trace clock based on boot time

   - Prevent injection of random sleep times when PM tracing abuses the
     RTC for storage

   - Make posix timers configurable for real tiny systems

   - Add tracepoints for the alarm timer subsystem so timer based
     suspend wakeups can be instrumented

   - The usual pile of fixes and updates to core and drivers"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
  timekeeping: Use mul_u64_u32_shr() instead of open coding it
  timekeeping: Get rid of pointless typecasts
  timekeeping: Make the conversion call chain consistently unsigned
  timekeeping_Force_unsigned_clocksource_to_nanoseconds_conversion
  alarmtimer: Add tracepoints for alarm timers
  trace: Update documentation for mono, mono_raw and boot clock
  trace: Add an option for boot clock as trace clock
  timekeeping: Add a fast and NMI safe boot clock
  timekeeping/clocksource_cyc2ns: Document intended range limitation
  timekeeping: Ignore the bogus sleep time if pm_trace is enabled
  selftests/timers: Fix spelling mistake "Asyncrhonous" -> "Asynchronous"
  clocksource/drivers/bcm2835_timer: Unmap region obtained by of_iomap
  clocksource/drivers/arm_arch_timer: Map frame with of_io_request_and_map()
  arm64: dts: rockchip: Arch counter doesn't tick in system suspend
  clocksource/drivers/arm_arch_timer: Don't assume clock runs in suspend
  posix-timers: Make them configurable
  posix_cpu_timers: Move the add_device_randomness() call to a proper place
  timer: Move sys_alarm from timer.c to itimer.c
  ptp_clock: Allow for it to be optional
  Kconfig: Regenerate *.c_shipped files after previous changes
  ...
2016-12-12 19:56:15 -08:00
David S. Miller
2745529ac7 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Couple conflicts resolved here:

1) In the MACB driver, a bug fix to properly initialize the
   RX tail pointer properly overlapped with some changes
   to support variable sized rings.

2) In XGBE we had a "CONFIG_PM" --> "CONFIG_PM_SLEEP" fix
   overlapping with a reorganization of the driver to support
   ACPI, OF, as well as PCI variants of the chip.

3) In 'net' we had several probe error path bug fixes to the
   stmmac driver, meanwhile a lot of this code was cleaned up
   and reorganized in 'net-next'.

4) The cls_flower classifier obtained a helper function in
   'net-next' called __fl_delete() and this overlapped with
   Daniel Borkamann's bug fix to use RCU for object destruction
   in 'net'.  It also overlapped with Jiri's change to guard
   the rhashtable_remove_fast() call with a check against
   tc_skip_sw().

5) In mlx4, a revert bug fix in 'net' overlapped with some
   unrelated changes in 'net-next'.

6) In geneve, a stale header pointer after pskb_expand_head()
   bug fix in 'net' overlapped with a large reorganization of
   the same code in 'net-next'.  Since the 'net-next' code no
   longer had the bug in question, there was nothing to do
   other than to simply take the 'net-next' hunks.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-03 12:29:53 -05:00
Linus Torvalds
faaae2a581 Re-enable CONFIG_MODVERSIONS in a slightly weaker form
This enables CONFIG_MODVERSIONS again, but allows for missing symbol CRC
information in order to work around the issue that newer binutils
versions seem to occasionally drop the CRC on the floor.  binutils 2.26
seems to work fine, while binutils 2.27 seems to break MODVERSIONS of
symbols that have been defined in assembler files.

[ We've had random missing CRC's before - it may be an old problem that
  just is now reliably triggered with the weak asm symbols and a new
  version of binutils ]

Some day I really do want to remove MODVERSIONS entirely.  Sadly, today
does not appear to be that day: Debian people apparently do want the
option to enable MODVERSIONS to make it easier to have external modules
across kernel versions, and this seems to be a fairly minimal fix for
the annoying problem.

Cc: Ben Hutchings <ben@decadent.org.uk>
Acked-by: Michal Marek <mmarek@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-11-29 16:01:30 -08:00
David S. Miller
0b42f25d2f Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
udplite conflict is resolved by taking what 'net-next' did
which removed the backlog receive method assignment, since
it is no longer necessary.

Two entries were added to the non-priv ethtool operations
switch statement, one in 'net' and one in 'net-next, so
simple overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-26 23:42:21 -05:00
Linus Torvalds
cd3caefb46 Fix subtle CONFIG_MODVERSIONS problems
CONFIG_MODVERSIONS has been broken for pretty much the whole 4.9 series,
and quite frankly, nobody has cared very deeply.  We absolutely know how
to fix it, and it's not _complicated_, but it's not exactly pretty
either.

This oneliner fixes it without the ugliness, and allows for further
future cleanups.

  "We've secretly replaced their regular MODVERSIONS with nothing at
   all, let's see if they notice"

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-11-25 15:44:47 -08:00
Daniel Mack
3007098494 cgroup: add support for eBPF programs
This patch adds two sets of eBPF program pointers to struct cgroup.
One for such that are directly pinned to a cgroup, and one for such
that are effective for it.

To illustrate the logic behind that, assume the following example
cgroup hierarchy.

  A - B - C
        \ D - E

If only B has a program attached, it will be effective for B, C, D
and E. If D then attaches a program itself, that will be effective for
both D and E, and the program in B will only affect B and C. Only one
program of a given type is effective for a cgroup.

Attaching and detaching programs will be done through the bpf(2)
syscall. For now, ingress and egress inet socket filtering are the
only supported use-cases.

Signed-off-by: Daniel Mack <daniel@zonque.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-25 16:25:52 -05:00
Nicolas Pitre
baa73d9e47 posix-timers: Make them configurable
Some embedded systems have no use for them.  This removes about
25KB from the kernel binary size when configured out.

Corresponding syscalls are routed to a stub logging the attempt to
use those syscalls which should be enough of a clue if they were
disabled without proper consideration. They are: timer_create,
timer_gettime: timer_getoverrun, timer_settime, timer_delete,
clock_adjtime, setitimer, getitimer, alarm.

The clock_settime, clock_gettime, clock_getres and clock_nanosleep
syscalls are replaced by simple wrappers compatible with CLOCK_REALTIME,
CLOCK_MONOTONIC and CLOCK_BOOTTIME only which should cover the vast
majority of use cases with very little code.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <john.stultz@linaro.org>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Cc: Paul Bolle <pebolle@tiscali.nl>
Cc: linux-kbuild@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: Michal Marek <mmarek@suse.com>
Cc: Edward Cree <ecree@solarflare.com>
Link: http://lkml.kernel.org/r/1478841010-28605-7-git-send-email-nicolas.pitre@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-11-16 09:26:35 +01:00
Mauro Carvalho Chehab
8c27ceff36 docs: fix locations of several documents that got moved
The previous patch renamed several files that are cross-referenced
along the Kernel documentation. Adjust the links to point to
the right places.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-10-24 08:12:35 -02:00
Peter Zijlstra
26b5679e43 relay: Use irq_work instead of plain timer for deferred wakeup
Relay avoids calling wake_up_interruptible() for doing the wakeup of
readers/consumers, waiting for the generation of new data, from the
context of a process which produced the data.  This is apparently done to
prevent the possibility of a deadlock in case Scheduler itself is is
generating data for the relay, after acquiring rq->lock.

The following patch used a timer (to be scheduled at next jiffy), for
delegating the wakeup to another context.
	commit 7c9cb38302
	Author: Tom Zanussi <zanussi@comcast.net>
	Date:   Wed May 9 02:34:01 2007 -0700

	relay: use plain timer instead of delayed work

	relay doesn't need to use schedule_delayed_work() for waking readers
	when a simple timer will do.

Scheduling a plain timer, at next jiffies boundary, to do the wakeup
causes a significant wakeup latency for the Userspace client, which makes
relay less suitable for the high-frequency low-payload use cases where the
data gets generated at a very high rate, like multiple sub buffers getting
filled within a milli second.  Moreover the timer is re-scheduled on every
newly produced sub buffer so the timer keeps getting pushed out if sub
buffers are filled in a very quick succession (less than a jiffy gap
between filling of 2 sub buffers).  As a result relay runs out of sub
buffers to store the new data.

By using irq_work it is ensured that wakeup of userspace client, blocked
in the poll call, is done at earliest (through self IPI or next timer
tick) enabling it to always consume the data in time.  Also this makes
relay consistent with printk & ring buffers (trace), as they too use
irq_work for deferred wake up of readers.

[arnd@arndb.de: select CONFIG_IRQ_WORK]
 Link: http://lkml.kernel.org/r/20160912154035.3222156-1-arnd@arndb.de
[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/1472906487-1559-1-git-send-email-akash.goel@intel.com
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Akash Goel <akash.goel@intel.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11 15:06:32 -07:00
Linus Torvalds
997b611baf Merge branch 'parisc-4.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux
Pull parisc updates from Helge Deller:
 "Changes include:

   - Fix boot of 32bit SMP kernel (initial kernel mapping was too small)

   - Added hardened usercopy checks

   - Drop bootmem and switch to memblock and NO_BOOTMEM implementation

   - Drop the BROKEN_RODATA config option (and thus remove the relevant
     code from the generic headers and files because parisc was the last
     architecture which used this config option)

   - Improve segfault reporting by printing human readable error strings

   - Various smaller changes, e.g. dwarf debug support for assembly
     code, update comments regarding copy_user_page_asm, switch to
     kmalloc_array()"

* 'parisc-4.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Increase KERNEL_INITIAL_SIZE for 32-bit SMP kernels
  parisc: Drop bootmem and switch to memblock
  parisc: Add hardened usercopy feature
  parisc: Add cfi_startproc and cfi_endproc to assembly code
  parisc: Move hpmc stack into page aligned bss section
  parisc: Fix self-detected CPU stall warnings on Mako machines
  parisc: Report trap type as human readable string
  parisc: Update comment regarding implementation of copy_user_page_asm
  parisc: Use kmalloc_array() in add_system_map_addresses()
  parisc: Check return value of smp_boot_one_cpu()
  parisc: Drop BROKEN_RODATA config option
2016-10-07 20:50:37 -07:00
Helge Deller
b5d5cf2b8a parisc: Drop BROKEN_RODATA config option
PARISC was the only architecture which selected the BROKEN_RODATA config
option. Drop it and remove the special handling from init.h as well.

Signed-off-by: Helge Deller <deller@gmx.de>
2016-09-20 18:02:35 +02:00
Andy Lutomirski
c6c314a613 sched/core: Add try_get_task_stack() and put_task_stack()
There are a few places in the kernel that access stack memory
belonging to a different task.  Before we can start freeing task
stacks before the task_struct is freed, we need a way for those code
paths to pin the stack.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jann Horn <jann@thejh.net>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/17a434f50ad3d77000104f21666575e10a9c1fbd.1474003868.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-16 09:18:53 +02:00
Andy Lutomirski
c65eacbe29 sched/core: Allow putting thread_info into task_struct
If an arch opts in by setting CONFIG_THREAD_INFO_IN_TASK_STRUCT,
then thread_info is defined as a single 'u32 flags' and is the first
entry of task_struct.  thread_info::task is removed (it serves no
purpose if thread_info is embedded in task_struct), and
thread_info::cpu gets its own slot in task_struct.

This is heavily based on a patch written by Linus.

Originally-from: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jann Horn <jann@thejh.net>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/a0898196f0476195ca02713691a5037a14f2aac5.1473801993.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-15 08:25:13 +02:00
Linus Torvalds
1eccfa090e Implements HARDENED_USERCOPY verification of copy_to_user/copy_from_user
bounds checking for most architectures on SLAB and SLUB.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 Comment: Kees Cook <kees@outflux.net>
 
 iQIcBAABCgAGBQJXl9tlAAoJEIly9N/cbcAm5BoP/ikTtDp2bFw1sn92yHTnIWzl
 O+dcKVAeRgjfnSvPfb1JITpaM58exQSaDsPBeR0DbVzU1zDdhLcwHHiQupFh98Ka
 vBZthbrlL/u4NB26enEEW0iyA32BsxYBMnIu0z5ux9RbZflmQwGQ0c0rvy3dJ7/b
 FzB5ayVST5y/a0m6/sImeeExh78GU9rsMb1XmJRMwlJAy6miDz/F9TP0LnuW6PhG
 J5XC99ygNJS1pQBLACRsrZw6ImgBxXnWCok6tWPMxFfD+rJBU2//wqS+HozyMWHL
 iYP7+ytVo/ZVok4114X/V4Oof3a6wqgpBuYrivJ228QO+UsLYbYLo6sZ8kRK7VFm
 9GgHo/8rWB1T9lBbSaa7UL5r0dVNNLjFGS42vwV+YlgUMQ1A35VRojO0jUnJSIQU
 Ug1IxKmylLd0nEcwD8/l3DXeQABsfL8GsoKW0OtdTZtW4RND4gzq34LK6t7hvayF
 kUkLg1OLNdUJwOi16M/rhugwYFZIMfoxQtjkRXKWN4RZ2QgSHnx2lhqNmRGPAXBG
 uy21wlzUTfLTqTpoeOyHzJwyF2qf2y4nsziBMhvmlrUvIzW1LIrYUKCNT4HR8Sh5
 lC2WMGYuIqaiu+NOF3v6CgvKd9UW+mxMRyPEybH8mEgfm+FLZlWABiBjIUpSEZuB
 JFfuMv1zlljj/okIQRg8
 =USIR
 -----END PGP SIGNATURE-----

Merge tag 'usercopy-v4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull usercopy protection from Kees Cook:
 "Tbhis implements HARDENED_USERCOPY verification of copy_to_user and
  copy_from_user bounds checking for most architectures on SLAB and
  SLUB"

* tag 'usercopy-v4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  mm: SLUB hardened usercopy support
  mm: SLAB hardened usercopy support
  s390/uaccess: Enable hardened usercopy
  sparc/uaccess: Enable hardened usercopy
  powerpc/uaccess: Enable hardened usercopy
  ia64/uaccess: Enable hardened usercopy
  arm64/uaccess: Enable hardened usercopy
  ARM: uaccess: Enable hardened usercopy
  x86/uaccess: Enable hardened usercopy
  mm: Hardened usercopy
  mm: Implement stack frame object validation
  mm: Add is_migrate_cma_page
2016-08-08 14:48:14 -07:00
Valdis Kletnieks
f1cb637e75 init/Kconfig: add clarification for out-of-tree modules
It doesn't trim just symbols that are totally unused in-tree - it trims
the symbols unused by any in-tree modules actually built.  If you've
done a 'make localmodconfig' and only build a hundred or so modules,
it's pretty likely that your out-of-tree module will come up lacking
something...

Hopefully this will save the next guy from a Homer Simpson "D'oh!"
moment.

Link: http://lkml.kernel.org/r/10177.1469787292@turing-police.cc.vt.edu
Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 19:35:43 -04:00
Alexey Dobriyan
ac3339baff init/Kconfig: ban CONFIG_LOCALVERSION_AUTO with allmodconfig
Doing patches with allmodconfig kernel compiled and committing stuff
into local tree have unfortunate consequence: kernel version changes (as
it should) leading to recompiling and relinking of several files even if
they weren't touched (or interesting at all).  This and "git-whatever"
figuring out current version slow down compilation for no good reason.

But lets face it, "allmodconfig" kernels don't care about kernel
version, they are simply compile check guinea pigs.

Make LOCALVERSION_AUTO depend on !COMPILE_TEST, so it doesn't sneak into
allmodconfig .config.

Link: http://lkml.kernel.org/r/20160707214954.GC31678@p183.telecom.by
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 19:35:41 -04:00
Richard Weinberger
bc083a64b6 init/Kconfig: make COMPILE_TEST depend on !UML
UML is a bit special since it does not have iomem nor dma.  That means a
lot of drivers will not build if they miss a dependency on HAS_IOMEM.
s390 used to have the same issues but since it gained PCI support UML is
the only stranger.

We are tired of patching dozens of new drivers after every merge window
just to un-break allmod/yesconfig UML builds.  One could argue that a
decent driver has to know on what it depends and therefore a missing
HAS_IOMEM dependency is a clear driver bug.  But the dependency not
obvious and not everyone does UML builds with COMPILE_TEST enabled when
developing a device driver.

A possible solution to make these builds succeed on UML would be
providing stub functions for ioremap() and friends which fail upon
runtime.  Another one is simply disabling COMPILE_TEST for UML.  Since
it is the least hassle and does not force use to fake iomem support
let's do the latter.

Link: http://lkml.kernel.org/r/1466152995-28367-1-git-send-email-richard@nod.at
Signed-off-by: Richard Weinberger <richard@nod.at>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
seokhoon.yoon
9991a9c8db cgroup: update cgroup's document path
cgroup's document path is changed to "cgroup-v1".  update it.

Link: http://lkml.kernel.org/r/1470148443-6509-1-git-send-email-iamyooon@gmail.com
Signed-off-by: seokhoon.yoon <iamyooon@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
Linus Torvalds
69c4289449 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial tree updates from Jiri Kosina.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial:
  fat: fix error message for bogus number of directory entries
  fat: fix typo s/supeblock/superblock/
  ASoC: max9877: Remove unused function declaration
  dw2102: don't output spurious blank lines to the kernel log
  init: fix Kconfig text
  ARM: io: fix comment grammar
  ocfs: fix ocfs2_xattr_user_get() argument name
  scsi/qla2xxx: Remove erroneous unused macro qla82xx_get_temp_val1()
2016-07-28 14:22:25 -07:00
Thomas Garnier
210e7a43fa mm: SLUB freelist randomization
Implements freelist randomization for the SLUB allocator.  It was
previous implemented for the SLAB allocator.  Both use the same
configuration option (CONFIG_SLAB_FREELIST_RANDOM).

The list is randomized during initialization of a new set of pages.  The
order on different freelist sizes is pre-computed at boot for
performance.  Each kmem_cache has its own randomized freelist.

This security feature reduces the predictability of the kernel SLUB
allocator against heap overflows rendering attacks much less stable.

For example these attacks exploit the predictability of the heap:
 - Linux Kernel CAN SLUB overflow (https://goo.gl/oMNWkU)
 - Exploiting Linux Kernel Heap corruptions (http://goo.gl/EXLn95)

Performance results:

slab_test impact is between 3% to 4% on average for 100000 attempts
without smp.  It is a very focused testing, kernbench show the overall
impact on the system is way lower.

Before:

  Single thread testing
  =====================
  1. Kmalloc: Repeatedly allocate then free test
  100000 times kmalloc(8) -> 49 cycles kfree -> 77 cycles
  100000 times kmalloc(16) -> 51 cycles kfree -> 79 cycles
  100000 times kmalloc(32) -> 53 cycles kfree -> 83 cycles
  100000 times kmalloc(64) -> 62 cycles kfree -> 90 cycles
  100000 times kmalloc(128) -> 81 cycles kfree -> 97 cycles
  100000 times kmalloc(256) -> 98 cycles kfree -> 121 cycles
  100000 times kmalloc(512) -> 95 cycles kfree -> 122 cycles
  100000 times kmalloc(1024) -> 96 cycles kfree -> 126 cycles
  100000 times kmalloc(2048) -> 115 cycles kfree -> 140 cycles
  100000 times kmalloc(4096) -> 149 cycles kfree -> 171 cycles
  2. Kmalloc: alloc/free test
  100000 times kmalloc(8)/kfree -> 70 cycles
  100000 times kmalloc(16)/kfree -> 70 cycles
  100000 times kmalloc(32)/kfree -> 70 cycles
  100000 times kmalloc(64)/kfree -> 70 cycles
  100000 times kmalloc(128)/kfree -> 70 cycles
  100000 times kmalloc(256)/kfree -> 69 cycles
  100000 times kmalloc(512)/kfree -> 70 cycles
  100000 times kmalloc(1024)/kfree -> 73 cycles
  100000 times kmalloc(2048)/kfree -> 72 cycles
  100000 times kmalloc(4096)/kfree -> 71 cycles

After:

  Single thread testing
  =====================
  1. Kmalloc: Repeatedly allocate then free test
  100000 times kmalloc(8) -> 57 cycles kfree -> 78 cycles
  100000 times kmalloc(16) -> 61 cycles kfree -> 81 cycles
  100000 times kmalloc(32) -> 76 cycles kfree -> 93 cycles
  100000 times kmalloc(64) -> 83 cycles kfree -> 94 cycles
  100000 times kmalloc(128) -> 106 cycles kfree -> 107 cycles
  100000 times kmalloc(256) -> 118 cycles kfree -> 117 cycles
  100000 times kmalloc(512) -> 114 cycles kfree -> 116 cycles
  100000 times kmalloc(1024) -> 115 cycles kfree -> 118 cycles
  100000 times kmalloc(2048) -> 147 cycles kfree -> 131 cycles
  100000 times kmalloc(4096) -> 214 cycles kfree -> 161 cycles
  2. Kmalloc: alloc/free test
  100000 times kmalloc(8)/kfree -> 66 cycles
  100000 times kmalloc(16)/kfree -> 66 cycles
  100000 times kmalloc(32)/kfree -> 66 cycles
  100000 times kmalloc(64)/kfree -> 66 cycles
  100000 times kmalloc(128)/kfree -> 65 cycles
  100000 times kmalloc(256)/kfree -> 67 cycles
  100000 times kmalloc(512)/kfree -> 67 cycles
  100000 times kmalloc(1024)/kfree -> 64 cycles
  100000 times kmalloc(2048)/kfree -> 67 cycles
  100000 times kmalloc(4096)/kfree -> 67 cycles

Kernbench, before:

  Average Optimal load -j 12 Run (std deviation):
  Elapsed Time 101.873 (1.16069)
  User Time 1045.22 (1.60447)
  System Time 88.969 (0.559195)
  Percent CPU 1112.9 (13.8279)
  Context Switches 189140 (2282.15)
  Sleeps 99008.6 (768.091)

After:

  Average Optimal load -j 12 Run (std deviation):
  Elapsed Time 102.47 (0.562732)
  User Time 1045.3 (1.34263)
  System Time 88.311 (0.342554)
  Percent CPU 1105.8 (6.49444)
  Context Switches 189081 (2355.78)
  Sleeps 99231.5 (800.358)

Link: http://lkml.kernel.org/r/1464295031-26375-3-git-send-email-thgarnie@google.com
Signed-off-by: Thomas Garnier <thgarnie@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-26 16:19:19 -07:00
Kees Cook
ed18adc1cd mm: SLUB hardened usercopy support
Under CONFIG_HARDENED_USERCOPY, this adds object size checking to the
SLUB allocator to catch any copies that may span objects. Includes a
redzone handling fix discovered by Michael Ellerman.

Based on code from PaX and grsecurity.

Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Reviwed-by: Laura Abbott <labbott@redhat.com>
2016-07-26 14:43:54 -07:00
Kees Cook
04385fc5e8 mm: SLAB hardened usercopy support
Under CONFIG_HARDENED_USERCOPY, this adds object size checking to the
SLAB allocator to catch any copies that may span objects.

Based on code from PaX and grsecurity.

Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
2016-07-26 14:41:53 -07:00
Linus Torvalds
766fd5f6cd Merge branch 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull NOHZ updates from Ingo Molnar:

 - fix system/idle cputime leaked on cputime accounting (all nohz
   configs) (Rik van Riel)

 - remove the messy, ad-hoc irqtime account on nohz-full and make it
   compatible with CONFIG_IRQ_TIME_ACCOUNTING=y instead (Rik van Riel)

 - cleanups (Frederic Weisbecker)

 - remove unecessary irq disablement in the irqtime code (Rik van Riel)

* 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/cputime: Drop local_irq_save/restore from irqtime_account_irq()
  sched/cputime: Reorganize vtime native irqtime accounting headers
  sched/cputime: Clean up the old vtime gen irqtime accounting completely
  sched/cputime: Replace VTIME_GEN irq time code with IRQ_TIME_ACCOUNTING code
  sched/cputime: Count actually elapsed irq & softirq time
2016-07-25 14:43:00 -07:00
Linus Torvalds
df00ccca72 Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU updates from Ingo Molnar:
 "The main changes in this cycle were:

   - documentation updates

   - miscellaneous fixes

   - minor reorganization of code

   - torture-test updates"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (30 commits)
  rcu: Correctly handle sparse possible cpus
  rcu: sysctl: Panic on RCU Stall
  rcu: Fix a typo in a comment
  rcu: Make call_rcu_tasks() tolerate first call with irqs disabled
  rcu: Disable TASKS_RCU for usermode Linux
  rcu: No ordering for rcu_assign_pointer() of NULL
  rcutorture: Fix error return code in rcu_perf_init()
  torture: Inflict default jitter
  rcuperf: Don't treat gp_exp mis-setting as a WARN
  rcutorture: Drop "-soundhw pcspkr" from x86 boot arguments
  rcutorture: Don't specify the cpu type of QEMU on PPC
  rcutorture: Make -soundhw a x86 specific option
  rcutorture: Use vmlinux as the fallback kernel image
  rcutorture/doc: Create initrd using dracut
  torture: Stop onoff task if there is only one cpu
  torture: Add starvation events to error summary
  torture:  Break online and offline functions out of torture_onoff()
  torture: Forgive lengthy trace dumps and preemption
  torture: Remove CONFIG_RCU_TORTURE_TEST_RUNNABLE, simplify code
  torture: Simplify code, eliminate RCU_PERF_TEST_RUNNABLE
  ...
2016-07-25 12:04:11 -07:00
Rik van Riel
b58c358405 sched/cputime: Replace VTIME_GEN irq time code with IRQ_TIME_ACCOUNTING code
The CONFIG_VIRT_CPU_ACCOUNTING_GEN irq time tracking code does not
appear to currently work right.

On CPUs without nohz_full=, only tick based irq time sampling is
done, which breaks down when dealing with a nohz_idle CPU.

On firewalls and similar systems, no ticks may happen on a CPU for a
while, and the irq time spent may never get accounted properly. This
can cause issues with capacity planning and power saving, which use
the CPU statistics as inputs in decision making.

Remove the VTIME_GEN vtime irq time code, and replace it with the
IRQ_TIME_ACCOUNTING code, when selected as a config option by the user.

Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krcmar <rkrcmar@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wanpeng Li <wanpeng.li@hotmail.com>
Link: http://lkml.kernel.org/r/1468421405-20056-3-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-14 10:42:34 +02:00
Randy Dunlap
076501ff6b init/Kconfig: keep Expert users menu together
The "expert" menu was broken (split) such that all entries in it after
KALLSYMS were displayed in the "General setup" area instead of in the
"Expert users" area.  Fix this by adding one kconfig dependency.

Yes, the Expert users menu is fragile.  Problems like this have happened
several times in the past.  I will attempt to isolate the Expert users
menu if there is interest in that.

Fixes: 4d5d5664c9 ("x86: kallsyms: disable absolute percpu symbols on !SMP")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: stable@vger.kernel.org  # 4.6
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-06 16:27:20 -07:00
Geert Uytterhoeven
5e0d8d59a5 init: fix Kconfig text
[jkosina@suse.cz: folded another fix on top on the same line as spotted by
 Randy Dunlap]
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2016-06-21 13:25:13 +02:00
Paul E. McKenney
570dd3c742 rcu: Disable TASKS_RCU for usermode Linux
Usermode Linux currently does not implement arch_irqs_disabled_flags(),
which results in a build failure in TASKS_RCU.  Therefore, this commit
disables the TASKS_RCU Kconfig option in usermode Linux builds.  The
usermode Linux maintainers expect to merge arch_irqs_disabled_flags()
into 4.8, at which point this commit may be reverted.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Jeff Dike <jdike@addtoit.com>
Acked-by: Richard Weinberger <richard@nod.at>
2016-06-15 15:32:01 -07:00
Linus Torvalds
5b26fc8824 Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
Pull kbuild updates from Michal Marek:

 - new option CONFIG_TRIM_UNUSED_KSYMS which does a two-pass build and
   unexports symbols which are not used in the current config [Nicolas
   Pitre]

 - several kbuild rule cleanups [Masahiro Yamada]

 - warning option adjustments for gcov etc [Arnd Bergmann]

 - a few more small fixes

* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: (31 commits)
  kbuild: move -Wunused-const-variable to W=1 warning level
  kbuild: fix if_change and friends to consider argument order
  kbuild: fix adjust_autoksyms.sh for modules that need only one symbol
  kbuild: fix ksym_dep_filter when multiple EXPORT_SYMBOL() on the same line
  gcov: disable -Wmaybe-uninitialized warning
  gcov: disable tree-loop-im to reduce stack usage
  gcov: disable for COMPILE_TEST
  Kbuild: disable 'maybe-uninitialized' warning for CONFIG_PROFILE_ALL_BRANCHES
  Kbuild: change CC_OPTIMIZE_FOR_SIZE definition
  kbuild: forbid kernel directory to contain spaces and colons
  kbuild: adjust ksym_dep_filter for some cmd_* renames
  kbuild: Fix dependencies for final vmlinux link
  kbuild: better abstract vmlinux sequential prerequisites
  kbuild: fix call to adjust_autoksyms.sh when output directory specified
  kbuild: Get rid of KBUILD_STR
  kbuild: rename cmd_as_s_S to cmd_cpp_s_S
  kbuild: rename cmd_cc_i_c to cmd_cpp_i_c
  kbuild: drop redundant "PHONY += FORCE"
  kbuild: delete unnecessary "@:"
  kbuild: mark help target as PHONY
  ...
2016-05-26 22:01:22 -07:00
Petr Mladek
427934b871 printk/nmi: increase the size of NMI buffer and make it configurable
Testing has shown that the backtrace sometimes does not fit into the 4kB
temporary buffer that is used in NMI context.  The warnings are gone
when I double the temporary buffer size.

This patch doubles the buffer size and makes it configurable.

Note that this problem existed even in the x86-specific implementation
that was added by the commit a9edc88093 ("x86/nmi: Perform a safe NMI
stack trace on all CPUs").  Nobody noticed it because it did not print
any warnings.

Signed-off-by: Petr Mladek <pmladek@suse.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Jiri Kosina <jkosina@suse.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: David Miller <davem@davemloft.net>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-20 17:58:30 -07:00
Petr Mladek
42a0bb3f71 printk/nmi: generic solution for safe printk in NMI
printk() takes some locks and could not be used a safe way in NMI
context.

The chance of a deadlock is real especially when printing stacks from
all CPUs.  This particular problem has been addressed on x86 by the
commit a9edc88093 ("x86/nmi: Perform a safe NMI stack trace on all
CPUs").

The patchset brings two big advantages.  First, it makes the NMI
backtraces safe on all architectures for free.  Second, it makes all NMI
messages almost safe on all architectures (the temporary buffer is
limited.  We still should keep the number of messages in NMI context at
minimum).

Note that there already are several messages printed in NMI context:
WARN_ON(in_nmi()), BUG_ON(in_nmi()), anything being printed out from MCE
handlers.  These are not easy to avoid.

This patch reuses most of the code and makes it generic.  It is useful
for all messages and architectures that support NMI.

The alternative printk_func is set when entering and is reseted when
leaving NMI context.  It queues IRQ work to copy the messages into the
main ring buffer in a safe context.

__printk_nmi_flush() copies all available messages and reset the buffer.
Then we could use a simple cmpxchg operations to get synchronized with
writers.  There is also used a spinlock to get synchronized with other
flushers.

We do not longer use seq_buf because it depends on external lock.  It
would be hard to make all supported operations safe for a lockless use.
It would be confusing and error prone to make only some operations safe.

The code is put into separate printk/nmi.c as suggested by Steven
Rostedt.  It needs a per-CPU buffer and is compiled only on
architectures that call nmi_enter().  This is achieved by the new
HAVE_NMI Kconfig flag.

The are MN10300 and Xtensa architectures.  We need to clean up NMI
handling there first.  Let's do it separately.

The patch is heavily based on the draft from Peter Zijlstra, see

  https://lkml.org/lkml/2015/6/10/327

[arnd@arndb.de: printk-nmi: use %zu format string for size_t]
[akpm@linux-foundation.org: min_t->min - all types are size_t here]
Signed-off-by: Petr Mladek <pmladek@suse.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Jan Kara <jack@suse.cz>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>	[arm part]
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Jiri Kosina <jkosina@suse.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: David Miller <davem@davemloft.net>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-20 17:58:30 -07:00
Thomas Garnier
c7ce4f60ac mm: SLAB freelist randomization
Provides an optional config (CONFIG_SLAB_FREELIST_RANDOM) to randomize
the SLAB freelist.  The list is randomized during initialization of a
new set of pages.  The order on different freelist sizes is pre-computed
at boot for performance.  Each kmem_cache has its own randomized
freelist.  Before pre-computed lists are available freelists are
generated dynamically.  This security feature reduces the predictability
of the kernel SLAB allocator against heap overflows rendering attacks
much less stable.

For example this attack against SLUB (also applicable against SLAB)
would be affected:

  https://jon.oberheide.org/blog/2010/09/10/linux-kernel-can-slub-overflow/

Also, since v4.6 the freelist was moved at the end of the SLAB.  It
means a controllable heap is opened to new attacks not yet publicly
discussed.  A kernel heap overflow can be transformed to multiple
use-after-free.  This feature makes this type of attack harder too.

To generate entropy, we use get_random_bytes_arch because 0 bits of
entropy is available in the boot stage.  In the worse case this function
will fallback to the get_random_bytes sub API.  We also generate a shift
random number to shift pre-computed freelist for each new set of pages.

The config option name is not specific to the SLAB as this approach will
be extended to other allocators like SLUB.

Performance results highlighted no major changes:

Hackbench (running 90 10 times):

  Before average: 0.0698
  After average: 0.0663 (-5.01%)

slab_test 1 run on boot.  Difference only seen on the 2048 size test
being the worse case scenario covered by freelist randomization.  New
slab pages are constantly being created on the 10000 allocations.
Variance should be mainly due to getting new pages every few
allocations.

Before:

  Single thread testing
  =====================
  1. Kmalloc: Repeatedly allocate then free test
  10000 times kmalloc(8) -> 99 cycles kfree -> 112 cycles
  10000 times kmalloc(16) -> 109 cycles kfree -> 140 cycles
  10000 times kmalloc(32) -> 129 cycles kfree -> 137 cycles
  10000 times kmalloc(64) -> 141 cycles kfree -> 141 cycles
  10000 times kmalloc(128) -> 152 cycles kfree -> 148 cycles
  10000 times kmalloc(256) -> 195 cycles kfree -> 167 cycles
  10000 times kmalloc(512) -> 257 cycles kfree -> 199 cycles
  10000 times kmalloc(1024) -> 393 cycles kfree -> 251 cycles
  10000 times kmalloc(2048) -> 649 cycles kfree -> 228 cycles
  10000 times kmalloc(4096) -> 806 cycles kfree -> 370 cycles
  10000 times kmalloc(8192) -> 814 cycles kfree -> 411 cycles
  10000 times kmalloc(16384) -> 892 cycles kfree -> 455 cycles
  2. Kmalloc: alloc/free test
  10000 times kmalloc(8)/kfree -> 121 cycles
  10000 times kmalloc(16)/kfree -> 121 cycles
  10000 times kmalloc(32)/kfree -> 121 cycles
  10000 times kmalloc(64)/kfree -> 121 cycles
  10000 times kmalloc(128)/kfree -> 121 cycles
  10000 times kmalloc(256)/kfree -> 119 cycles
  10000 times kmalloc(512)/kfree -> 119 cycles
  10000 times kmalloc(1024)/kfree -> 119 cycles
  10000 times kmalloc(2048)/kfree -> 119 cycles
  10000 times kmalloc(4096)/kfree -> 121 cycles
  10000 times kmalloc(8192)/kfree -> 119 cycles
  10000 times kmalloc(16384)/kfree -> 119 cycles

After:

  Single thread testing
  =====================
  1. Kmalloc: Repeatedly allocate then free test
  10000 times kmalloc(8) -> 130 cycles kfree -> 86 cycles
  10000 times kmalloc(16) -> 118 cycles kfree -> 86 cycles
  10000 times kmalloc(32) -> 121 cycles kfree -> 85 cycles
  10000 times kmalloc(64) -> 176 cycles kfree -> 102 cycles
  10000 times kmalloc(128) -> 178 cycles kfree -> 100 cycles
  10000 times kmalloc(256) -> 205 cycles kfree -> 109 cycles
  10000 times kmalloc(512) -> 262 cycles kfree -> 136 cycles
  10000 times kmalloc(1024) -> 342 cycles kfree -> 157 cycles
  10000 times kmalloc(2048) -> 701 cycles kfree -> 238 cycles
  10000 times kmalloc(4096) -> 803 cycles kfree -> 364 cycles
  10000 times kmalloc(8192) -> 835 cycles kfree -> 404 cycles
  10000 times kmalloc(16384) -> 896 cycles kfree -> 441 cycles
  2. Kmalloc: alloc/free test
  10000 times kmalloc(8)/kfree -> 121 cycles
  10000 times kmalloc(16)/kfree -> 121 cycles
  10000 times kmalloc(32)/kfree -> 123 cycles
  10000 times kmalloc(64)/kfree -> 142 cycles
  10000 times kmalloc(128)/kfree -> 121 cycles
  10000 times kmalloc(256)/kfree -> 119 cycles
  10000 times kmalloc(512)/kfree -> 119 cycles
  10000 times kmalloc(1024)/kfree -> 119 cycles
  10000 times kmalloc(2048)/kfree -> 119 cycles
  10000 times kmalloc(4096)/kfree -> 119 cycles
  10000 times kmalloc(8192)/kfree -> 119 cycles
  10000 times kmalloc(16384)/kfree -> 119 cycles

[akpm@linux-foundation.org: propagate gfp_t into cache_random_seq_create()]
Signed-off-by: Thomas Garnier <thgarnie@google.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Greg Thelen <gthelen@google.com>
Cc: Laura Abbott <labbott@fedoraproject.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-19 19:12:14 -07:00
Arnd Bergmann
877417e6ff Kbuild: change CC_OPTIMIZE_FOR_SIZE definition
CC_OPTIMIZE_FOR_SIZE disables the often useful -Wmaybe-unused warning,
because that causes a ridiculous amount of false positives when combined
with -Os.

This means a lot of warnings don't show up in testing by the developers
that should see them with an 'allmodconfig' kernel that has
CC_OPTIMIZE_FOR_SIZE enabled, but only later in randconfig builds
that don't.

This changes the Kconfig logic around CC_OPTIMIZE_FOR_SIZE to make
it a 'choice' statement defaulting to CC_OPTIMIZE_FOR_PERFORMANCE
that gets added for this purpose. The allmodconfig and allyesconfig
kernels now default to -O2 with the maybe-unused warning enabled.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-05-10 17:12:48 +02:00
Andi Kleen
f76be61755 Make CONFIG_FHANDLE default y
Newer Fedora and OpenSUSE didn't boot with my standard configuration.
It took me some time to figure out why, in fact I had to write a script
to try different config options systematically.

The problem is that something (systemd) in dracut depends on
CONFIG_FHANDLE, which adds open by file handle syscalls.

While it is set in defconfigs it is very easy to miss when updating
older configs because it is not default y.

Make it default y and also depend on EXPERT, as dracut use is likely
widespread.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Richard Weinberger <richard.weinberger@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-01 17:03:37 -05:00
Nicolas Pitre
dbacb0ef67 kconfig option for TRIM_UNUSED_KSYMS
The config option to enable it all.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
2016-03-29 16:30:57 -04:00
Linus Torvalds
6b5f04b6cf Merge branch 'for-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:
 "cgroup changes for v4.6-rc1.  No userland visible behavior changes in
  this pull request.  I'll send out a separate pull request for the
  addition of cgroup namespace support.

   - The biggest change is the revamping of cgroup core task migration
     and controller handling logic.  There are quite a few places where
     controllers and tasks are manipulated.  Previously, many of those
     places implemented custom operations for each specific use case
     assuming specific starting conditions.  While this worked, it makes
     the code fragile and difficult to follow.

     The bulk of this pull request restructures these operations so that
     most related operations are performed through common helpers which
     implement recursive (subtrees are always processed consistently)
     and idempotent (they make cgroup hierarchy converge to the target
     state rather than performing operations assuming specific starting
     conditions).  This makes the code a lot easier to understand,
     verify and extend.

   - Implicit controller support is added.  This is primarily for using
     perf_event on the v2 hierarchy so that perf can match cgroup v2
     path without requiring the user to do anything special.  The kernel
     portion of perf_event changes is acked but userland changes are
     still pending review.

   - cgroup_no_v1= boot parameter added to ease testing cgroup v2 in
     certain environments.

   - There is a regression introduced during v4.4 devel cycle where
     attempts to migrate zombie tasks can mess up internal object
     management.  This was fixed earlier this week and included in this
     pull request w/ stable cc'd.

   - Misc non-critical fixes and improvements"

* 'for-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (44 commits)
  cgroup: avoid false positive gcc-6 warning
  cgroup: ignore css_sets associated with dead cgroups during migration
  Documentation: cgroup v2: Trivial heading correction.
  cgroup: implement cgroup_subsys->implicit_on_dfl
  cgroup: use css_set->mg_dst_cgrp for the migration target cgroup
  cgroup: make cgroup[_taskset]_migrate() take cgroup_root instead of cgroup
  cgroup: move migration destination verification out of cgroup_migrate_prepare_dst()
  cgroup: fix incorrect destination cgroup in cgroup_update_dfl_csses()
  cgroup: Trivial correction to reflect controller.
  cgroup: remove stale item in cgroup-v1 document INDEX file.
  cgroup: update css iteration in cgroup_update_dfl_csses()
  cgroup: allocate 2x cgrp_cset_links when setting up a new root
  cgroup: make cgroup_calc_subtree_ss_mask() take @this_ss_mask
  cgroup: reimplement rebind_subsystems() using cgroup_apply_control() and friends
  cgroup: use cgroup_apply_enable_control() in cgroup creation path
  cgroup: combine cgroup_mutex locking and offline css draining
  cgroup: factor out cgroup_{apply|finalize}_control() from cgroup_subtree_control_write()
  cgroup: introduce cgroup_{save|propagate|restore}_control()
  cgroup: make cgroup_drain_offline() and cgroup_apply_control_{disable|enable}() recursive
  cgroup: factor out cgroup_apply_control_enable() from cgroup_subtree_control_write()
  ...
2016-03-18 20:25:49 -07:00
Linus Torvalds
bb7aeae3d6 Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security layer updates from James Morris:
 "There are a bunch of fixes to the TPM, IMA, and Keys code, with minor
  fixes scattered across the subsystem.

  IMA now requires signed policy, and that policy is also now measured
  and appraised"

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (67 commits)
  X.509: Make algo identifiers text instead of enum
  akcipher: Move the RSA DER encoding check to the crypto layer
  crypto: Add hash param to pkcs1pad
  sign-file: fix build with CMS support disabled
  MAINTAINERS: update tpmdd urls
  MODSIGN: linux/string.h should be #included to get memcpy()
  certs: Fix misaligned data in extra certificate list
  X.509: Handle midnight alternative notation in GeneralizedTime
  X.509: Support leap seconds
  Handle ISO 8601 leap seconds and encodings of midnight in mktime64()
  X.509: Fix leap year handling again
  PKCS#7: fix unitialized boolean 'want'
  firmware: change kernel read fail to dev_dbg()
  KEYS: Use the symbol value for list size, updated by scripts/insert-sys-cert
  KEYS: Reserve an extra certificate symbol for inserting without recompiling
  modsign: hide openssl output in silent builds
  tpm_tis: fix build warning with tpm_tis_resume
  ima: require signed IMA policy
  ima: measure and appraise the IMA policy itself
  ima: load policy using path
  ...
2016-03-17 11:33:45 -07:00
Ard Biesheuvel
2213e9a66b kallsyms: add support for relative offsets in kallsyms address table
Similar to how relative extables are implemented, it is possible to emit
the kallsyms table in such a way that it contains offsets relative to
some anchor point in the kernel image rather than absolute addresses.

On 64-bit architectures, it cuts the size of the kallsyms address table
in half, since offsets between kernel symbols can typically be expressed
in 32 bits.  This saves several hundreds of kilobytes of permanent
.rodata on average.  In addition, the kallsyms address table is no
longer subject to dynamic relocation when CONFIG_RELOCATABLE is in
effect, so the relocation work done after decompression now doesn't have
to do relocation updates for all these values.  This saves up to 24
bytes (i.e., the size of a ELF64 RELA relocation table entry) per value,
which easily adds up to a couple of megabytes of uncompressed __init
data on ppc64 or arm64.  Even if these relocation entries typically
compress well, the combined size reduction of 2.8 MB uncompressed for a
ppc64_defconfig build (of which 2.4 MB is __init data) results in a ~500
KB space saving in the compressed image.

Since it is useful for some architectures (like x86) to retain the
ability to emit absolute values as well, this patch also adds support
for capturing both absolute and relative values when
KALLSYMS_ABSOLUTE_PERCPU is in effect, by emitting absolute per-cpu
addresses as positive 32-bit values, and addresses relative to the
lowest encountered relative symbol as negative values, which are
subtracted from the runtime address of this base symbol to produce the
actual address.

Support for the above is enabled by default for all architectures except
IA-64 and Tile-GX, whose symbols are too far apart to capture in this
manner.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Kees Cook <keescook@chromium.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Ard Biesheuvel
4d5d5664c9 x86: kallsyms: disable absolute percpu symbols on !SMP
scripts/kallsyms.c has a special --absolute-percpu command line option
which deals with the zero based per cpu offsets that are used when
building for SMP on x86_64.  This means that the option should only be
passed in that case, so add a Kconfig symbol with the correct predicate,
and use that instead.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Kees Cook <keescook@chromium.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Parav Pandit
6cc578df40 cgroup: Trivial correction to reflect controller.
Trivial correction in menuconfig help to reflect PIDs as
controller instead of subsystem to align to rest of the text
and documentation.

Signed-off-by: Parav Pandit <pandit.parav@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2016-03-05 07:48:01 -05:00
David Howells
d43de6c780 akcipher: Move the RSA DER encoding check to the crypto layer
Move the RSA EMSA-PKCS1-v1_5 encoding from the asymmetric-key public_key
subtype to the rsa crypto module's pkcs1pad template.  This means that the
public_key subtype no longer has any dependencies on public key type.

To make this work, the following changes have been made:

 (1) The rsa pkcs1pad template is now used for RSA keys.  This strips off the
     padding and returns just the message hash.

 (2) In a previous patch, the pkcs1pad template gained an optional second
     parameter that, if given, specifies the hash used.  We now give this,
     and pkcs1pad checks the encoded message E(M) for the EMSA-PKCS1-v1_5
     encoding and verifies that the correct digest OID is present.

 (3) The crypto driver in crypto/asymmetric_keys/rsa.c is now reduced to
     something that doesn't care about what the encryption actually does
     and and has been merged into public_key.c.

 (4) CONFIG_PUBLIC_KEY_ALGO_RSA is gone.  Module signing must set
     CONFIG_CRYPTO_RSA=y instead.

Thoughts:

 (*) Should the encoding style (eg. raw, EMSA-PKCS1-v1_5) also be passed to
     the padding template?  Should there be multiple padding templates
     registered that share most of the code?

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-03-03 21:49:27 +00:00