Look for 'la57' in /proc/cpuinfo to see if your machine supports 5-level
paging.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull sched.h split-up fixes for MIPS from Ingo Molnar:
 "These are the fixes for MIPS build failures due to the sched.h
  split-up, from Arnd Bergmann"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  MIPS: Add missing include files

Commit 13ad59df ("mm, page_alloc: avoid page_to_pfn() when merging
buddies") moved the check for memory holes out of page_is_buddy() and
had the callers do the check.

But this wasn't done correctly in one place which caused ia64 to crash
very early in boot.

Update to fix that and make ia64 boot again.

[ v2: Vlastimil pointed out we don't need to call page_to_pfn()
      since we already have the result of that in "buddy_pfn" ]

Fixes: 13ad59df

 ("avoid page_to_pfn() when merging buddies")
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull ktest fixes from Steven Rostedt:
 "Greg Kroah-Hartman reported to me that the ktest of v4.11-rc1 locked
  up in an infinite loop while doing the make mrproper.

  Looking into the cause I noticed that a recent update to the function
  run_command (used for running all shell commands, including "make
  mrproper") changed the internal loop to use the function
  wait_for_input.

  The wait_for_input function uses select to look at two file
  descriptors. One is the file descriptor of the command it is running,
  the other is STDIN. The STDIN check was not checking the return status
  of the sysread call, and was also just writing a lot of data into
  syswrite without regard to the size of the data read.

  Changing the code to check the return status of sysread, and also to
  still process the passed in descriptor data without looping back to
  the select fixed Greg's problem.

  While looking at this code I also realized that the loop did not honor
  the timeout if STDIN always had input (or for some reason return
  error). this could prevent wait_for_input to timeout on the file
  descriptor it is suppose to be waiting for. That is fixed too"

* tag 'ktest-v4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-ktest:
  ktest: Make sure wait_for_input does honor the timeout
  ktest: Fix while loop in wait_for_input

This removes the extra include header file that was added in commit
e58bc927

 "Pull overlayfs updates from Miklos Szeredi" now that it
is no longer needed.

There are probably other such includes that got added during the
scheduler header splitup series, but this is the one that annoyed me
personally and I know about.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The scheduler header file split and cleanups ended up exposing a few
nasty header file dependencies, and in particular it showed how we in
<linux/wait.h> ended up depending on "signal_pending()", which now comes
from <linux/sched/signal.h>.

That's a very subtle and annoying dependency, which already caused a
semantic merge conflict (see commit e58bc927

 "Pull overlayfs updates
from Miklos Szeredi", which added that fixup in the merge commit).

It turns out that we can avoid this dependency _and_ improve code
generation by moving the guts of the fairly nasty helper #define
__wait_event_interruptible_locked() to out-of-line code.  The code that
includes the signal_pending() check is all in the slow-path where we
actually go to sleep waiting for the event anyway, so using a helper
function is the right thing to do.

Using a helper function is also what we already did for the non-locked
versions, see the "__wait_event*()" macros and the "prepare_to_wait*()"
set of helper functions.

We might want to try to unify all these macro games, we have a _lot_ of
subtly different wait-event loops.  But this is the minimal patch to fix
the annoying header dependency.

Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The function wait_for_input takes in a timeout, and even has a default
timeout. But if for some reason the STDIN descriptor keeps sending in data,
the function will never time out. The timout is to wait for the data from
the passed in file descriptor, not for STDIN. Adding a test in the case
where there's no data from the passed in file descriptor that checks to see
if the timeout passed, will ensure that it will timeout properly even if
there's input in STDIN.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

The run_command function was changed to use the wait_for_input function to
allow having a timeout if the command to run takes too much time. There was
a bug in the wait_for_input where it could end up going into an infinite
loop. There's two issues here. One is that the return value of the sysread
wasn't used for the write (to write a proper size), and that it should
continue processing the passed in file descriptor too even if there was
input. There was no check for error, if for some reason STDIN returned an
error, the function would go into an infinite loop and never exit.

Reported-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixes: 6e98d1b4

 ("ktest: Add timeout to ssh command")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

After the split of linux/sched.h, several platforms in arch/mips stopped building.

Add the respective additional #include statements to fix the problem I first
tried adding these into asm/processor.h, but ran into circular header
dependencies with that which I could not figure out.

The commit I listed as causing the problem is the branch merge, as there is
likely a combination of multiple patches in that branch.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mips@linux-mips.org
Cc: ralf@linux-mips.org
Fixes: 1827adb1

 ("Merge branch 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip")
Link: http://lkml.kernel.org/r/20170308072931.3836696-1-arnd@arndb.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Pull x86 fixes from Ingo Molnar:
 "Misc fixes and minor updates all over the place:

   - an SGI/UV fix
   - a defconfig update
   - a build warning fix
   - move the boot_params file to the arch location in debugfs
   - a pkeys fix
   - selftests fix
   - boot message fixes
   - sparse fixes
   - a resume warning fix
   - ioapic hotplug fixes
   - reboot quirks

  ... plus various minor cleanups"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/build/x86_64_defconfig: Enable CONFIG_R8169
  x86/reboot/quirks: Add ASUS EeeBook X205TA/W reboot quirk
  x86/hpet: Prevent might sleep splat on resume
  x86/boot: Correct setup_header.start_sys name
  x86/purgatory: Fix sparse warning, symbol not declared
  x86/purgatory: Make functions and variables static
  x86/events: Remove last remnants of old filenames
  x86/pkeys: Check against max pkey to avoid overflows
  x86/ioapic: Split IOAPIC hot-removal into two steps
  x86/PCI: Implement pcibios_release_device to release IRQ from IOAPIC
  x86/intel_rdt: Remove duplicate inclusion of linux/cpu.h
  x86/vmware: Remove duplicate inclusion of asm/timer.h
  x86/hyperv: Hide unused label
  x86/reboot/quirks: Add ASUS EeeBook X205TA reboot quirk
  x86/platform/uv/BAU: Fix HUB errors by remove initial write to sw-ack register
  x86/selftests: Add clobbers for int80 on x86_64
  x86/apic: Simplify enable_IR_x2apic(), remove try_to_enable_IR()
  x86/apic: Fix a warning message in logical CPU IDs allocation
  x86/kdebugfs: Move boot params hierarchy under (debugfs)/x86/

Pull timer fixes from Ingo Molnar:
 "This includes a fix for lockups caused by incorrect nsecs related
  cleanup, and a capabilities check fix for timerfd"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  jiffies: Revert bogus conversion of NSEC_PER_SEC to TICK_NSEC
  timerfd: Only check CAP_WAKE_ALARM when it is needed

Pull scheduler fixes from Ingo Molnar:
 "A fix for KVM's scheduler clock which (erroneously) was always marked
  unstable, a fix for RT/DL load balancing, plus latency fixes"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/clock, x86/tsc: Rework the x86 'unstable' sched_clock() interface
  sched/core: Fix pick_next_task() for RT,DL
  sched/fair: Make select_idle_cpu() more aggressive

Pull perf fixes from Ingo Molnar:
 "This includes a fix for a crash if certain special addresses are
  kprobed, plus does a rename of two Kconfig variables that were a minor
  misnomer"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Rename CONFIG_[UK]PROBE_EVENT to CONFIG_[UK]PROBE_EVENTS
  kprobes/x86: Fix kernel panic when certain exception-handling addresses are probed

Pull locking fixes from Ingo Molnar:

 - Change the new refcount_t warnings from WARN() to WARN_ONCE()

 - two ww_mutex fixes

 - plus a new lockdep self-consistency check for a bug that triggered in
   practice

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/ww_mutex: Adjust the lock number for stress test
  locking/lockdep: Add nest_lock integrity test
  locking/ww_mutex: Replace cpu_relax() with cond_resched() for tests
  locking/refcounts: Change WARN() to WARN_ONCE()

Pull IRQ fix from Ingo Molnar:
 "Fix an ARM TI DRA7XX SoC irqchip driver local variables type
  bug/warning"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/crossbar: Fix incorrect type of local variables

Pull EFI fixes from Ingo Molnar:
 "A boot crash fix, and a secure boot related boot messages fix"

* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi/arm: Fix boot crash with CONFIG_CPUMASK_OFFSTACK=y
  efi/libstub: Treat missing SecureBoot variable as Secure Boot disabled

Pull core fixes from Ingo Molnar:
 "A couple of sched.h splitup related build fixes, plus an objtool fix"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Fix another GCC jump table detection issue
  drivers/char/nwbutton: Fix build breakage caused by include file reshuffling
  h8300: Fix build breakage caused by header file changes
  avr32: Fix build error caused by include file reshuffling

Pull idr fix (and new tests) from Matthew Wilcox:
 "One urgent patch in here; freeing the correct IDA bitmap.

  Everything else is changes to the test suite"

* 'idr-4.11' of git://git.infradead.org/users/willy/linux-dax:
  radix tree test suite: Specify -m32 in LDFLAGS too
  ida: Free correct IDA bitmap
  radix tree test suite: Depend on Makefile and quieten grep
  radix tree test suite: Fix build with --as-needed
  radix tree test suite: Build 32 bit binaries
  radix tree test suite: Add performance test for radix_tree_join()
  radix tree test suite: Add performance test for radix_tree_split()
  radix tree test suite: Add performance benchmarks
  radix tree test suite: Add test for radix_tree_clear_tags()
  radix tree test suite: Add tests for ida_simple_get() and ida_simple_remove()
  radix tree test suite: Add test for idr_get_next()

Pull powerpc fixes from Michael Ellerman:
 "Five fairly small fixes for things that went in this cycle.

  A fairly large patch to rework the CAS logic on Power9, necessitated
  by a late change to the firmware API, and we can't boot without it.

  Three fixes going to stable, allowing more instructions to be emulated
  on LE, fixing a boot crash on 32-bit Freescale BookE machines, and the
  OPAL XICS workaround.

  And a patch from me to sort the selects under CONFIG PPC. Annoying
  churn, but worth it in the long run, and best for it to go in now to
  avoid conflicts.

  Thanks to:
    Alexey Kardashevskiy, Anton Blanchard, Balbir Singh, Gautham R.
    Shenoy, Laurentiu Tudor, Nicholas Piggin, Paul Mackerras, Ravi
    Bangoria, Sachin Sant, Shile Zhang, Suraj Jitindar Singh"

* tag 'powerpc-4.11-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc: Sort the selects under CONFIG_PPC
  powerpc/64: Fix L1D cache shape vector reporting L1I values
  powerpc/64: Avoid panic during boot due to divide by zero in init_cache_info()
  powerpc: Update to new option-vector-5 format for CAS
  powerpc: Parse the command line before calling CAS
  powerpc/xics: Work around limitations of OPAL XICS priority handling
  powerpc/64: Fix checksum folding in csum_add()
  powerpc/powernv: Fix opal tracepoints with JUMP_LABEL=n
  powerpc/booke: Fix boot crash due to null hugepd
  powerpc: Fix compiling a BE kernel with a powerpc64le toolchain
  selftest/powerpc: Fix false failures for skipped tests
  powerpc/powernv: Fix bug due to labeling ambiguity in power_enter_stop
  powerpc/64: Invalidate process table caching after setting process table
  powerpc: emulate_step() tests for load/store instructions
  powerpc: Emulation support for load/store instructions on LE

Merge branch 'stable/for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb

Pull swiotlb updates from Konrad Rzeszutek Wilk:
 "Two tiny implementations of the DMA API for callback in ARM (for Xen)"

* 'stable/for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb:
  swiotlb-xen: implement xen_swiotlb_get_sgtable callback
  swiotlb-xen: implement xen_swiotlb_dma_mmap callback

Michael's patch to use the default make rule for linking and the patch
from Rehas to use -m32 if building a 32-bit test-suite on a 64-bit
platform don't work well together.

Reported-by: Rehas Sachdeva <aquannie@gmail.com>
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>

There's a relatively rare race where we look at the per-cpu preallocated
IDA bitmap, see it's NULL, allocate a new one, and atomically update it.
If the kmalloc() happened to sleep and we were rescheduled to a different
CPU, or an interrupt came in at the exact right time, another task
might have successfully allocated a bitmap and already deposited it.
I forgot what the semantics of cmpxchg() were and ended up freeing the
wrong bitmap leading to KASAN reporting a use-after-free.

Dmitry found the bug with syzkaller & wrote the patch.  I wrote the test
case that will reproduce the bug without his patch being applied.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>

Changing the CFLAGS in the Makefile didn't always lead to a
recompilation because the OFILES didn't depend on the Makefile.
Also, after doing make clean, grep would still complain about
a missing map-shift.h; we need -s as well as -q.

Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>

Currently the radix tree test suite doesn't build with toolchains that
use --as-needed by default, for example Ubuntu's:

  cc -I. -I../../include -g -O2 -Wall -D_LGPL_SOURCE -fsanitize=address -lpthread -lurcu main.o ... -o main
  /usr/bin/ld: regression1.o: undefined reference to symbol 'pthread_join@@GLIBC_2.17'
  /lib/powerpc64le-linux-gnu/libpthread.so.0: error adding symbols: DSO missing from command line
  collect2: error: ld returned 1 exit status

This is caused by the custom makefile rules placing LDFLAGS before the
.o files that need the libraries.

We could fix it by using --no-as-needed, or rewriting the custom rules.
But we can also just drop the custom rules and move the libraries to
LDLIBS, and then the default rules work correctly - with the one caveat
that we need to add -fsanitize=address to LDFLAGS because that must be
passed to the linker as well as the compiler.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>

Add option 'make BUILD=32' for building 32-bit binaries.

Signed-off-by: Rehas Sachdeva <aquannie@gmail.com>
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>

Signed-off-by: Rehas Sachdeva <aquannie@gmail.com>
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>

Signed-off-by: Rehas Sachdeva <aquannie@gmail.com>
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>

Add performance benchmarks for radix tree insertion, tagging and deletion.

Signed-off-by: Rehas Sachdeva <aquannie@gmail.com>
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>

Assert that radix_tree_clear_tags() clears the tags on the passed node and
slot. Assert that the case where the radix tree has only one entry at index
zero and the node is NULL, is also handled.

Signed-off-by: Rehas Sachdeva <aquannie@gmail.com>
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>

Assert that ida_simple_get() allocates an id in the passed range or returns
error on failure, and ida_simple_remove() releases an allocated id.

Signed-off-by: Rehas Sachdeva <aquannie@gmail.com>
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>

Assert that idr_get_next() returns the next populated entry in the tree with
an ID greater than or equal to the value pointed to by @nextid argument.

Signed-off-by: Rehas Sachdeva <aquannie@gmail.com>
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>

Pull namespace fix from Eric Biederman:
 "This fixes a race between put_ucounts and get_ucounts that can cause a
  use after free. The fix works by simplifying the code and so there is
  not even a temptation to be clever and play spinlock vs atomic
  reference games"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  ucount: Remove the atomicity from ucount->count

Pull tracing fixes from Steven Rostedt:
 "There was some breakage with the changes for jump labels in the 4.11
  merge window:

   - powerpc broke as jump labels uses the two LSB bits as flags in
     initialization.

     A check was added to make sure that all jump label entries were 4
     bytes aligned, but powerpc didn't work that way for modules. Adding
     an alignment in the module linker script appeared to be the best
     solution.

   - Jump labels also added an anonymous union to access those LSB bits
     as a normal long. But because this structure had static
     initialization, it broke older compilers that could not statically
     initialize anonymous unions without brackets.

   - The command line parameter for setting function graph filter broke
     the "EMPTY_HASH" descriptor by modifying it instead of creating a
     new hash to hold the entries.

   - The command line parameter ftrace_graph_max_depth was added to
     allow its setting at boot time. It uses existing code and only the
     command line hook was added.

     This is not really a fix, but as it uses existing code without
     affecting anything else, I added it to this release. It was ready
     before the merge window closed, but I wanted to let it sit in
     linux-next for a couple of days first"

* tag 'trace-v4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace/graph: Add ftrace_graph_max_depth kernel parameter
  tracing: Add #undef to fix compile error
  jump_label: Add comment about initialization order for anonymous unions
  jump_label: Fix anonymous union initialization
  module: set __jump_table alignment to 8
  ftrace/graph: Do not modify the EMPTY_HASH for the function_graph filter
  tracing: Fix code comment for ftrace_ops_get_func()

commit 93825f2e converted NSEC_PER_SEC to TICK_NSEC because the author
confused NSEC_PER_JIFFY with NSEC_PER_SEC.

As a result, the calculation of refined jiffies got broken, triggering
lockups.

Fixes: 93825f2e

 ("jiffies: Reuse TICK_NSEC instead of NSEC_PER_JIFFY")
Reported-and-tested-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1488880534-3777-1-git-send-email-fweisbec@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Arnd Bergmann reported a (false positive) objtool warning:

  drivers/infiniband/sw/rxe/rxe_resp.o: warning: objtool: rxe_responder()+0xfe: sibling call from callable instruction with changed frame pointer

The issue is in find_switch_table().  It tries to find a switch
statement's jump table by walking backwards from an indirect jump
instruction, looking for a relocation to the .rodata section.  In this
case it stopped walking prematurely: the first .rodata relocation it
encountered was for a variable (resp_state_name) instead of a jump
table, so it just assumed there wasn't a jump table.

The fix is to ignore any .rodata relocation which refers to an ELF
object symbol.  This works because the jump tables are anonymous and
have no symbols associated with them.

Reported-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 3732710f

 ("objtool: Improve rare switch jump table pattern detection")
Link: http://lkml.kernel.org/r/20170302225723.3ndbsnl4hkqbne7a@treble
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Fix:

  drivers/char/nwbutton.c: In function 'button_sequence_finished':
  drivers/char/nwbutton.c:134:3: error: implicit declaration of function 'kill_cad_pid'

The declaration has been moved from one include file to another.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: c3edc401

 ("sched/headers: Move task_struct::signal and ...")
Link: http://lkml.kernel.org/r/1488762811-9022-1-git-send-email-linux@roeck-us.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Fix the following h8300 build failures:

  arch/h8300/kernel/ptrace_h.c: In function ‘trace_trap’:
  arch/h8300/kernel/ptrace_h.c:253:3: error: implicit declaration of function ‘force_sig’

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: uclinux-h8-devel@lists.sourceforge.jp
Fixes: c3edc401

 ("sched/headers: Move task_struct::signal and ...")
Link: http://lkml.kernel.org/r/1488738434-3504-1-git-send-email-linux@roeck-us.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Various avr32 builds fail:

  arch/avr32/oprofile/backtrace.c:58: error: dereferencing pointer to incomplete type
  arch/avr32/oprofile/backtrace.c:60: error: implicit declaration of function 'user_mode'

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Hans-Christian Noren Egtvedt <egtvedt@samfundet.no>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robert Richter <rric@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: oprofile-list@lists.sf.net
Fixes: f780d89a

 ("sched/headers: Remove <asm/ptrace.h> from ...")
Link: http://lkml.kernel.org/r/1488762357-4500-1-git-send-email-linux@roeck-us.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Always increment/decrement ucount->count under the ucounts_lock.  The
increments are there already and moving the decrements there means the
locking logic of the code is simpler.  This simplification in the
locking logic fixes a race between put_ucounts and get_ucounts that
could result in a use-after-free because the count could go zero then
be found by get_ucounts and then be freed by put_ucounts.

A bug presumably this one was found by a combination of syzkaller and
KASAN.  JongWhan Kim reported the syzkaller failure and Dmitry Vyukov
spotted the race in the code.

Cc: stable@vger.kernel.org
Fixes: f6b2db1a

 ("userns: Make the count of user namespaces per user")
Reported-by: JongHwan Kim <zzoru007@gmail.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

We have a big list of selects under CONFIG_PPC, and currently they're
completely unsorted. This means people tend to add new selects at the
bottom of the list, and so two commits which both add a new select will
often conflict.

Instead sort it alphabetically. This is nicer in and of itself, but also
means two commits that add a new select will have a greater chance of
not conflicting.

Add a note at the top and bottom asking people to keep it sorted.

And while we're here pad out the 'if' expressions to make them stand
out.

Suggested-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>