1. 25 9月, 2017 1 次提交
  2. 21 9月, 2017 1 次提交
    • Y
      bpf: one perf event close won't free bpf program attached by another perf event · ec9dd352
      Yonghong Song 提交于
      This patch fixes a bug exhibited by the following scenario:
        1. fd1 = perf_event_open with attr.config = ID1
        2. attach bpf program prog1 to fd1
        3. fd2 = perf_event_open with attr.config = ID1
           <this will be successful>
        4. user program closes fd2 and prog1 is detached from the tracepoint.
        5. user program with fd1 does not work properly as tracepoint
           no output any more.
      
      The issue happens at step 4. Multiple perf_event_open can be called
      successfully, but only one bpf prog pointer in the tp_event. In the
      current logic, any fd release for the same tp_event will free
      the tp_event->prog.
      
      The fix is to free tp_event->prog only when the closing fd
      corresponds to the one which registered the program.
      Signed-off-by: NYonghong Song <yhs@fb.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      ec9dd352
  3. 20 9月, 2017 5 次提交
    • D
      bpf: fix ri->map_owner pointer on bpf_prog_realloc · 7c300131
      Daniel Borkmann 提交于
      Commit 109980b8 ("bpf: don't select potentially stale
      ri->map from buggy xdp progs") passed the pointer to the prog
      itself to be loaded into r4 prior on bpf_redirect_map() helper
      call, so that we can store the owner into ri->map_owner out of
      the helper.
      
      Issue with that is that the actual address of the prog is still
      subject to change when subsequent rewrites occur that require
      slow path in bpf_prog_realloc() to alloc more memory, e.g. from
      patching inlining helper functions or constant blinding. Thus,
      we really need to take prog->aux as the address we're holding,
      which also works with prog clones as they share the same aux
      object.
      
      Instead of then fetching aux->prog during runtime, which could
      potentially incur cache misses due to false sharing, we are
      going to just use aux for comparison on the map owner. This
      will also keep the patchlet of the same size, and later check
      in xdp_map_invalid() only accesses read-only aux pointer from
      the prog, it's also in the same cacheline already from prior
      access when calling bpf_func.
      
      Fixes: 109980b8 ("bpf: don't select potentially stale ri->map from buggy xdp progs")
      Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      Acked-by: NAlexei Starovoitov <ast@kernel.org>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      7c300131
    • E
      bpf: do not disable/enable BH in bpf_map_free_id() · 930651a7
      Eric Dumazet 提交于
      syzkaller reported following splat [1]
      
      Since hard irq are disabled by the caller, bpf_map_free_id()
      should not try to enable/disable BH.
      
      Another solution would be to change htab_map_delete_elem() to
      defer the free_htab_elem() call after
      raw_spin_unlock_irqrestore(&b->lock, flags), but this might be not
      enough to cover other code paths.
      
      [1]
      WARNING: CPU: 1 PID: 8052 at kernel/softirq.c:161 __local_bh_enable_ip
      +0x1e/0x160 kernel/softirq.c:161
      Kernel panic - not syncing: panic_on_warn set ...
      
      CPU: 1 PID: 8052 Comm: syz-executor1 Not tainted 4.13.0-next-20170915+
      #23
      Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
      Google 01/01/2011
      Call Trace:
       __dump_stack lib/dump_stack.c:16 [inline]
       dump_stack+0x194/0x257 lib/dump_stack.c:52
       panic+0x1e4/0x417 kernel/panic.c:181
       __warn+0x1c4/0x1d9 kernel/panic.c:542
       report_bug+0x211/0x2d0 lib/bug.c:183
       fixup_bug+0x40/0x90 arch/x86/kernel/traps.c:178
       do_trap_no_signal arch/x86/kernel/traps.c:212 [inline]
       do_trap+0x260/0x390 arch/x86/kernel/traps.c:261
       do_error_trap+0x120/0x390 arch/x86/kernel/traps.c:298
       do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:311
       invalid_op+0x18/0x20 arch/x86/entry/entry_64.S:905
      RIP: 0010:__local_bh_enable_ip+0x1e/0x160 kernel/softirq.c:161
      RSP: 0018:ffff8801cdcd7748 EFLAGS: 00010046
      RAX: 0000000000000082 RBX: 0000000000000201 RCX: 0000000000000000
      RDX: 1ffffffff0b5933c RSI: 0000000000000201 RDI: ffffffff85ac99e0
      RBP: ffff8801cdcd7758 R08: ffffffff85b87158 R09: 1ffff10039b9aec6
      R10: ffff8801c99f24c0 R11: 0000000000000002 R12: ffffffff817b0b47
      R13: dffffc0000000000 R14: ffff8801cdcd77e8 R15: 0000000000000001
       __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:176 [inline]
       _raw_spin_unlock_bh+0x30/0x40 kernel/locking/spinlock.c:207
       spin_unlock_bh include/linux/spinlock.h:361 [inline]
       bpf_map_free_id kernel/bpf/syscall.c:197 [inline]
       __bpf_map_put+0x267/0x320 kernel/bpf/syscall.c:227
       bpf_map_put+0x1a/0x20 kernel/bpf/syscall.c:235
       bpf_map_fd_put_ptr+0x15/0x20 kernel/bpf/map_in_map.c:96
       free_htab_elem+0xc3/0x1b0 kernel/bpf/hashtab.c:658
       htab_map_delete_elem+0x74d/0x970 kernel/bpf/hashtab.c:1063
       map_delete_elem kernel/bpf/syscall.c:633 [inline]
       SYSC_bpf kernel/bpf/syscall.c:1479 [inline]
       SyS_bpf+0x2188/0x46a0 kernel/bpf/syscall.c:1451
       entry_SYSCALL_64_fastpath+0x1f/0xbe
      
      Fixes: f3f1c054 ("bpf: Introduce bpf_map ID")
      Signed-off-by: NEric Dumazet <edumazet@google.com>
      Cc: Martin KaFai Lau <kafai@fb.com>
      Acked-by: NMartin KaFai Lau <kafai@fb.com>
      Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      930651a7
    • T
      tracing: Fix trace_pipe behavior for instance traces · 75df6e68
      Tahsin Erdogan 提交于
      When reading data from trace_pipe, tracing_wait_pipe() performs a
      check to see if tracing has been turned off after some data was read.
      Currently, this check always looks at global trace state, but it
      should be checking the trace instance where trace_pipe is located at.
      
      Because of this bug, cat instances/i1/trace_pipe in the following
      script will immediately exit instead of waiting for data:
      
      cd /sys/kernel/debug/tracing
      echo 0 > tracing_on
      mkdir -p instances/i1
      echo 1 > instances/i1/tracing_on
      echo 1 > instances/i1/events/sched/sched_process_exec/enable
      cat instances/i1/trace_pipe
      
      Link: http://lkml.kernel.org/r/20170917102348.1615-1-tahsin@google.com
      
      Cc: stable@vger.kernel.org
      Fixes: 10246fa3 ("tracing: give easy way to clear trace buffer")
      Signed-off-by: NTahsin Erdogan <tahsin@google.com>
      Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
      75df6e68
    • Z
      tracing: Ignore mmiotrace from kernel commandline · c7b3ae0b
      Ziqian SUN (Zamir) 提交于
      The mmiotrace tracer cannot be enabled with ftrace=mmiotrace in kernel
      commandline. With this patch, noboot is added to the tracer struct,
      and when system boot with a tracer that has noboot=true, it will print
      out a warning message and continue booting.
      
      Link: http://lkml.kernel.org/r/1505111195-31942-1-git-send-email-zsun@redhat.comSigned-off-by: NZiqian SUN (Zamir) <zsun@redhat.com>
      Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
      c7b3ae0b
    • B
      tracing: Erase irqsoff trace with empty write · 8dd33bcb
      Bo Yan 提交于
      One convenient way to erase trace is "echo > trace". However, this
      is currently broken if the current tracer is irqsoff tracer. This
      is because irqsoff tracer use max_buffer as the default trace
      buffer.
      
      Set the max_buffer as the one to be cleared when it's the trace
      buffer currently in use.
      
      Link: http://lkml.kernel.org/r/1505754215-29411-1-git-send-email-byan@nvidia.com
      
      Cc: <mingo@redhat.com>
      Cc: stable@vger.kernel.org
      Fixes: 4acd4d00 ("tracing: give easy way to clear trace buffer")
      Signed-off-by: NBo Yan <byan@nvidia.com>
      Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
      8dd33bcb
  4. 19 9月, 2017 1 次提交
  5. 17 9月, 2017 1 次提交
    • T
      genirq: Fix cpumask check in __irq_startup_managed() · 9cb067ef
      Thomas Gleixner 提交于
      The result of cpumask_any_and() is invalid when result greater or equal
      nr_cpu_ids. The current check is checking for greater only. Fix it.
      
      Fixes: 761ea388 ("genirq: Handle managed irqs gracefully in irq_startup()")
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Juergen Gross <jgross@suse.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Chen Yu <yu.c.chen@intel.com>
      Cc: Marc Zyngier <marc.zyngier@arm.com>
      Cc: Alok Kataria <akataria@vmware.com>
      Cc: Joerg Roedel <joro@8bytes.org>
      Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: stable@vger.kernel.org
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Rui Zhang <rui.zhang@intel.com>
      Cc: "K. Y. Srinivasan" <kys@microsoft.com>
      Cc: Arjan van de Ven <arjan@linux.intel.com>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Len Brown <lenb@kernel.org>
      Link: http://lkml.kernel.org/r/20170913213152.272283444@linutronix.de
      9cb067ef
  6. 16 9月, 2017 1 次提交
  7. 15 9月, 2017 2 次提交
    • T
      sched/wait: Introduce wakeup boomark in wake_up_page_bit · 11a19c7b
      Tim Chen 提交于
      Now that we have added breaks in the wait queue scan and allow bookmark
      on scan position, we put this logic in the wake_up_page_bit function.
      
      We can have very long page wait list in large system where multiple
      pages share the same wait list. We break the wake up walk here to allow
      other cpus a chance to access the list, and not to disable the interrupts
      when traversing the list for too long.  This reduces the interrupt and
      rescheduling latency, and excessive page wait queue lock hold time.
      
      [ v2: Remove bookmark_wake_function ]
      Signed-off-by: NTim Chen <tim.c.chen@linux.intel.com>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      11a19c7b
    • T
      sched/wait: Break up long wake list walk · 2554db91
      Tim Chen 提交于
      We encountered workloads that have very long wake up list on large
      systems. A waker takes a long time to traverse the entire wake list and
      execute all the wake functions.
      
      We saw page wait list that are up to 3700+ entries long in tests of
      large 4 and 8 socket systems. It took 0.8 sec to traverse such list
      during wake up. Any other CPU that contends for the list spin lock will
      spin for a long time. It is a result of the numa balancing migration of
      hot pages that are shared by many threads.
      
      Multiple CPUs waking are queued up behind the lock, and the last one
      queued has to wait until all CPUs did all the wakeups.
      
      The page wait list is traversed with interrupt disabled, which caused
      various problems. This was the original cause that triggered the NMI
      watch dog timer in: https://patchwork.kernel.org/patch/9800303/ . Only
      extending the NMI watch dog timer there helped.
      
      This patch bookmarks the waker's scan position in wake list and break
      the wake up walk, to allow access to the list before the waker resume
      its walk down the rest of the wait list. It lowers the interrupt and
      rescheduling latency.
      
      This patch also provides a performance boost when combined with the next
      patch to break up page wakeup list walk. We saw 22% improvement in the
      will-it-scale file pread2 test on a Xeon Phi system running 256 threads.
      
      [ v2: Merged in Linus' changes to remove the bookmark_wake_function, and
        simply access to flags. ]
      Reported-by: NKan Liang <kan.liang@intel.com>
      Tested-by: NKan Liang <kan.liang@intel.com>
      Signed-off-by: NTim Chen <tim.c.chen@linux.intel.com>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      2554db91
  8. 14 9月, 2017 1 次提交
    • M
      mm: treewide: remove GFP_TEMPORARY allocation flag · 0ee931c4
      Michal Hocko 提交于
      GFP_TEMPORARY was introduced by commit e12ba74d ("Group short-lived
      and reclaimable kernel allocations") along with __GFP_RECLAIMABLE.  It's
      primary motivation was to allow users to tell that an allocation is
      short lived and so the allocator can try to place such allocations close
      together and prevent long term fragmentation.  As much as this sounds
      like a reasonable semantic it becomes much less clear when to use the
      highlevel GFP_TEMPORARY allocation flag.  How long is temporary? Can the
      context holding that memory sleep? Can it take locks? It seems there is
      no good answer for those questions.
      
      The current implementation of GFP_TEMPORARY is basically GFP_KERNEL |
      __GFP_RECLAIMABLE which in itself is tricky because basically none of
      the existing caller provide a way to reclaim the allocated memory.  So
      this is rather misleading and hard to evaluate for any benefits.
      
      I have checked some random users and none of them has added the flag
      with a specific justification.  I suspect most of them just copied from
      other existing users and others just thought it might be a good idea to
      use without any measuring.  This suggests that GFP_TEMPORARY just
      motivates for cargo cult usage without any reasoning.
      
      I believe that our gfp flags are quite complex already and especially
      those with highlevel semantic should be clearly defined to prevent from
      confusion and abuse.  Therefore I propose dropping GFP_TEMPORARY and
      replace all existing users to simply use GFP_KERNEL.  Please note that
      SLAB users with shrinkers will still get __GFP_RECLAIMABLE heuristic and
      so they will be placed properly for memory fragmentation prevention.
      
      I can see reasons we might want some gfp flag to reflect shorterm
      allocations but I propose starting from a clear semantic definition and
      only then add users with proper justification.
      
      This was been brought up before LSF this year by Matthew [1] and it
      turned out that GFP_TEMPORARY really doesn't have a clear semantic.  It
      seems to be a heuristic without any measured advantage for most (if not
      all) its current users.  The follow up discussion has revealed that
      opinions on what might be temporary allocation differ a lot between
      developers.  So rather than trying to tweak existing users into a
      semantic which they haven't expected I propose to simply remove the flag
      and start from scratch if we really need a semantic for short term
      allocations.
      
      [1] http://lkml.kernel.org/r/20170118054945.GD18349@bombadil.infradead.org
      
      [akpm@linux-foundation.org: fix typo]
      [akpm@linux-foundation.org: coding-style fixes]
      [sfr@canb.auug.org.au: drm/i915: fix up]
        Link: http://lkml.kernel.org/r/20170816144703.378d4f4d@canb.auug.org.au
      Link: http://lkml.kernel.org/r/20170728091904.14627-1-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com>
      Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
      Acked-by: NMel Gorman <mgorman@suse.de>
      Acked-by: NVlastimil Babka <vbabka@suse.cz>
      Cc: Matthew Wilcox <willy@infradead.org>
      Cc: Neil Brown <neilb@suse.de>
      Cc: "Theodore Ts'o" <tytso@mit.edu>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      0ee931c4
  9. 12 9月, 2017 5 次提交
  10. 11 9月, 2017 1 次提交
  11. 09 9月, 2017 16 次提交
  12. 07 9月, 2017 5 次提交
    • P
      sched/cpuset/pm: Fix cpuset vs. suspend-resume bugs · 50e76632
      Peter Zijlstra 提交于
      Cpusets vs. suspend-resume is _completely_ broken. And it got noticed
      because it now resulted in non-cpuset usage breaking too.
      
      On suspend cpuset_cpu_inactive() doesn't call into
      cpuset_update_active_cpus() because it doesn't want to move tasks about,
      there is no need, all tasks are frozen and won't run again until after
      we've resumed everything.
      
      But this means that when we finally do call into
      cpuset_update_active_cpus() after resuming the last frozen cpu in
      cpuset_cpu_active(), the top_cpuset will not have any difference with
      the cpu_active_mask and this it will not in fact do _anything_.
      
      So the cpuset configuration will not be restored. This was largely
      hidden because we would unconditionally create identity domains and
      mobile users would not in fact use cpusets much. And servers what do use
      cpusets tend to not suspend-resume much.
      
      An addition problem is that we'd not in fact wait for the cpuset work to
      finish before resuming the tasks, allowing spurious migrations outside
      of the specified domains.
      
      Fix the rebuild by introducing cpuset_force_rebuild() and fix the
      ordering with cpuset_wait_for_hotplug().
      Reported-by: NAndy Lutomirski <luto@kernel.org>
      Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: <stable@vger.kernel.org>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Fixes: deb7aa30 ("cpuset: reorganize CPU / memory hotplug handling")
      Link: http://lkml.kernel.org/r/20170907091338.orwxrqkbfkki3c24@hirez.programming.kicks-ass.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
      50e76632
    • T
      genirq: Make sparse_irq_lock protect what it should protect · 12ac1d0f
      Thomas Gleixner 提交于
      for_each_active_irq() iterates the sparse irq allocation bitmap. The caller
      must hold sparse_irq_lock. Several code pathes expect that an active bit in
      the sparse bitmap also has a valid interrupt descriptor.
      
      Unfortunately that's not true. The (de)allocation is a two step process,
      which holds the sparse_irq_lock only across the queue/remove from the radix
      tree and the set/clear in the allocation bitmap.
      
      If a iteration locks sparse_irq_lock between the two steps, then it might
      see an active bit but the corresponding irq descriptor is NULL. If that is
      dereferenced unconditionally, then the kernel oopses. Of course, all
      iterator sites could be audited and fixed, but....
      
      There is no reason why the sparse_irq_lock needs to be dropped between the
      two steps, in fact the code becomes simpler when the mutex is held across
      both and the semantics become more straight forward, so future problems of
      missing NULL pointer checks in the iteration are avoided and all existing
      sites are fixed in one go.
      
      Expand the lock held sections so both operations are covered and the bitmap
      and the radixtree are in sync.
      
      Fixes: a05a900a ("genirq: Make sparse_lock a mutex")
      Reported-and-tested-by: NHuang Ying <ying.huang@intel.com>
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Cc: stable@vger.kernel.org
      12ac1d0f
    • P
      sched/fair: Fix wake_affine_llc() balancing rules · a731ebe6
      Peter Zijlstra 提交于
      Chris Wilson reported that the SMT balance rules got the +1 on the
      wrong side, resulting in a bias towards the current LLC; which the
      load-balancer would then try and undo.
      Reported-by: NChris Wilson <chris@chris-wilson.co.uk>
      Tested-by: NChris Wilson <chris@chris-wilson.co.uk>
      Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: linux-kernel@vger.kernel.org
      Fixes: 90001d67 ("sched/fair: Fix wake_affine() for !NUMA_BALANCING")
      Link: http://lkml.kernel.org/r/20170906105131.gqjmaextmn3u6tj2@hirez.programming.kicks-ass.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
      a731ebe6
    • B
      tracing: Apply trace_clock changes to instance max buffer · 170b3b10
      Baohong Liu 提交于
      Currently trace_clock timestamps are applied to both regular and max
      buffers only for global trace. For instance trace, trace_clock
      timestamps are applied only to regular buffer. But, regular and max
      buffers can be swapped, for example, following a snapshot. So, for
      instance trace, bad timestamps can be seen following a snapshot.
      Let's apply trace_clock timestamps to instance max buffer as well.
      
      Link: http://lkml.kernel.org/r/ebdb168d0be042dcdf51f81e696b17fabe3609c1.1504642143.git.tom.zanussi@linux.intel.com
      
      Cc: stable@vger.kernel.org
      Fixes: 277ba044 ("tracing: Add interface to allow multiple trace buffers")
      Signed-off-by: NBaohong Liu <baohong.liu@intel.com>
      Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
      170b3b10
    • R
      mm,fork: introduce MADV_WIPEONFORK · d2cd9ede
      Rik van Riel 提交于
      Introduce MADV_WIPEONFORK semantics, which result in a VMA being empty
      in the child process after fork.  This differs from MADV_DONTFORK in one
      important way.
      
      If a child process accesses memory that was MADV_WIPEONFORK, it will get
      zeroes.  The address ranges are still valid, they are just empty.
      
      If a child process accesses memory that was MADV_DONTFORK, it will get a
      segmentation fault, since those address ranges are no longer valid in
      the child after fork.
      
      Since MADV_DONTFORK also seems to be used to allow very large programs
      to fork in systems with strict memory overcommit restrictions, changing
      the semantics of MADV_DONTFORK might break existing programs.
      
      MADV_WIPEONFORK only works on private, anonymous VMAs.
      
      The use case is libraries that store or cache information, and want to
      know that they need to regenerate it in the child process after fork.
      
      Examples of this would be:
       - systemd/pulseaudio API checks (fail after fork) (replacing a getpid
         check, which is too slow without a PID cache)
       - PKCS#11 API reinitialization check (mandated by specification)
       - glibc's upcoming PRNG (reseed after fork)
       - OpenSSL PRNG (reseed after fork)
      
      The security benefits of a forking server having a re-inialized PRNG in
      every child process are pretty obvious.  However, due to libraries
      having all kinds of internal state, and programs getting compiled with
      many different versions of each library, it is unreasonable to expect
      calling programs to re-initialize everything manually after fork.
      
      A further complication is the proliferation of clone flags, programs
      bypassing glibc's functions to call clone directly, and programs calling
      unshare, causing the glibc pthread_atfork hook to not get called.
      
      It would be better to have the kernel take care of this automatically.
      
      The patch also adds MADV_KEEPONFORK, to undo the effects of a prior
      MADV_WIPEONFORK.
      
      This is similar to the OpenBSD minherit syscall with MAP_INHERIT_ZERO:
      
          https://man.openbsd.org/minherit.2
      
      [akpm@linux-foundation.org: numerically order arch/parisc/include/uapi/asm/mman.h #defines]
      Link: http://lkml.kernel.org/r/20170811212829.29186-3-riel@redhat.comSigned-off-by: NRik van Riel <riel@redhat.com>
      Reported-by: NFlorian Weimer <fweimer@redhat.com>
      Reported-by: NColm MacCártaigh <colm@allcosts.net>
      Reviewed-by: NMike Kravetz <mike.kravetz@oracle.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Helge Deller <deller@gmx.de>
      Cc: Kees Cook <keescook@chromium.org>
      Cc: Matthew Wilcox <willy@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Will Drewry <wad@chromium.org>
      Cc: <linux-api@vger.kernel.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      d2cd9ede