Commit Graph

22969 Commits

Author SHA1 Message Date
Joel Fernandes 7fa8b7171a tracing/function_graph: Fix filters for function_graph threshold
Function graph tracer currently ignores filters if tracing_thresh is set.
For example, even if set_ftrace_pid is set, then its ignored if tracing_thresh
set, resulting in all processes being traced.

To fix this, we reuse the same entry function as when tracing_thresh is not
set and do everything as in the regular case except for writing the function entry
to the ring buffer.

Link: http://lkml.kernel.org/r/1466228694-2677-1-git-send-email-agnel.joel@gmail.com

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Joel Fernandes <agnel.joel@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-06-27 13:29:24 -04:00
Richard Guy Briggs 86b2efbe3a audit: add fields to exclude filter by reusing user filter
RFE: add additional fields for use in audit filter exclude rules
https://github.com/linux-audit/audit-kernel/issues/5

Re-factor and combine audit_filter_type() with audit_filter_user() to
use audit_filter_user_rules() to enable the exclude filter to
additionally filter on PID, UID, GID, AUID, LOGINUID_SET, SUBJ_*.

The process of combining the similar audit_filter_user() and
audit_filter_type() functions, required inverting the meaning and
including the ALWAYS action of the latter.

Include audit_filter_user_rules() into audit_filter(), removing
unneeded logic in the process.

Keep the check to quit early if the list is empty.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: checkpatch.pl fixes - whitespace damage, wrapped description]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-06-27 11:01:00 -04:00
Peter Zijlstra 55e16d30bd sched/fair: Rework throttle_count sync
Since we already take rq->lock when creating a cgroup, use it to also
sync the throttle_count and avoid the extra state and enqueue path
branch.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
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: bsegall@google.com
Cc: linux-kernel@vger.kernel.org
[ Fixed build warning. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-27 12:53:19 +02:00
Zev Weiss 599b4840b0 sched/core: Fix sched_getaffinity() return value kerneldoc comment
Previous version was probably written referencing the man page for
glibc's wrapper, but the wrapper's behavior differs from that of the
syscall itself in this case.

Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.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
Link: http://lkml.kernel.org/r/1466975603-25408-1-git-send-email-zev@bewilderbeest.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-27 12:53:12 +02:00
Peter Zijlstra 8663e24d56 sched/fair: Reorder cgroup creation code
A future patch needs rq->lock held _after_ we link the task_group into
the hierarchy. In order to avoid taking every rq->lock twice, reorder
things a little and create online_fair_sched_group() to be called
after we link the task_group.

All this code is still ran from css_alloc() so css_online() isn't in
fact used for this.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
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: bsegall@google.com
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-27 12:17:55 +02:00
Peter Zijlstra 3d30544f02 sched/fair: Apply more PELT fixes
One additional 'rule' for using update_cfs_rq_load_avg() is that one
should call update_tg_load_avg() if it returns true.

Add a bunch of comments to hopefully clarify some of the rules:

 o  You need to update cfs_rq _before_ any entity attach/detach,
    this is important, because while for mathmatical consisency this
    isn't strictly needed, it is required for the physical
    interpretation of the model, you attach/detach _now_.

 o  When you modify the cfs_rq avg, you have to then call
    update_tg_load_avg() in order to propagate changes upwards.

 o  (Fair) entities are always attached, switched_{to,from}_fair()
    deal with !fair. This directly follows from the definition of the
    cfs_rq averages, namely that they are a direct sum of all
    (runnable or blocked) entities on that rq.

It is the second rule that this patch enforces, but it adds comments
pertaining to all of them.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.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
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-27 12:17:54 +02:00
Peter Zijlstra 7dc603c902 sched/fair: Fix PELT integrity for new tasks
Vincent and Yuyang found another few scenarios in which entity
tracking goes wobbly.

The scenarios are basically due to the fact that new tasks are not
immediately attached and thereby differ from the normal situation -- a
task is always attached to a cfs_rq load average (such that it
includes its blocked contribution) and are explicitly
detached/attached on migration to another cfs_rq.

Scenario 1: switch to fair class

  p->sched_class = fair_class;
  if (queued)
    enqueue_task(p);
      ...
        enqueue_entity()
	  enqueue_entity_load_avg()
	    migrated = !sa->last_update_time (true)
	    if (migrated)
	      attach_entity_load_avg()
  check_class_changed()
    switched_from() (!fair)
    switched_to()   (fair)
      switched_to_fair()
        attach_entity_load_avg()

If @p is a new task that hasn't been fair before, it will have
!last_update_time and, per the above, end up in
attach_entity_load_avg() _twice_.

Scenario 2: change between cgroups

  sched_move_group(p)
    if (queued)
      dequeue_task()
    task_move_group_fair()
      detach_task_cfs_rq()
        detach_entity_load_avg()
      set_task_rq()
      attach_task_cfs_rq()
        attach_entity_load_avg()
    if (queued)
      enqueue_task();
        ...
          enqueue_entity()
	    enqueue_entity_load_avg()
	      migrated = !sa->last_update_time (true)
	      if (migrated)
	        attach_entity_load_avg()

Similar as with scenario 1, if @p is a new task, it will have
!load_update_time and we'll end up in attach_entity_load_avg()
_twice_.

Furthermore, notice how we do a detach_entity_load_avg() on something
that wasn't attached to begin with.

As stated above; the problem is that the new task isn't yet attached
to the load tracking and thereby violates the invariant assumption.

This patch remedies this by ensuring a new task is indeed properly
attached to the load tracking on creation, through
post_init_entity_util_avg().

Of course, this isn't entirely as straightforward as one might think,
since the task is hashed before we call wake_up_new_task() and thus
can be poked at. We avoid this by adding TASK_NEW and teaching
cpu_cgroup_can_attach() to refuse such tasks.

Reported-by: Yuyang Du <yuyang.du@intel.com>
Reported-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.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
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-27 12:17:53 +02:00
Vincent Guittot ea86cb4b76 sched/cgroup: Fix cpu_cgroup_fork() handling
A new fair task is detached and attached from/to task_group with:

  cgroup_post_fork()
    ss->fork(child) := cpu_cgroup_fork()
      sched_move_task()
        task_move_group_fair()

Which is wrong, because at this point in fork() the task isn't fully
initialized and it cannot 'move' to another group, because its not
attached to any group as yet.

In fact, cpu_cgroup_fork() needs a small part of sched_move_task() so we
can just call this small part directly instead sched_move_task(). And
the task doesn't really migrate because it is not yet attached so we
need the following sequence:

  do_fork()
    sched_fork()
      __set_task_cpu()

    cgroup_post_fork()
      set_task_rq() # set task group and runqueue

    wake_up_new_task()
      select_task_rq() can select a new cpu
      __set_task_cpu
      post_init_entity_util_avg
        attach_task_cfs_rq()
      activate_task
        enqueue_task

This patch makes that happen.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
[ Added TASK_SET_GROUP to set depth properly. ]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.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
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-27 12:17:52 +02:00
Peter Zijlstra 010114739d sched/fair: Fix PELT integrity for new groups
Vincent reported that when a new task is moved into a new cgroup it
gets attached twice to the load tracking:

  sched_move_task()
    task_move_group_fair()
      detach_task_cfs_rq()
      set_task_rq()
      attach_task_cfs_rq()
        attach_entity_load_avg()
          se->avg.last_load_update = cfs_rq->avg.last_load_update // == 0

  enqueue_entity()
    enqueue_entity_load_avg()
      update_cfs_rq_load_avg()
        now = clock()
        __update_load_avg(&cfs_rq->avg)
          cfs_rq->avg.last_load_update = now
          // ages load/util for: now - 0, load/util -> 0
      if (migrated)
        attach_entity_load_avg()
          se->avg.last_load_update = cfs_rq->avg.last_load_update; // now != 0

The problem is that we don't update cfs_rq load_avg before all
entity attach/detach operations. Only enqueue_task() and migrate_task()
do this.

By fixing this, the above will not happen, because the
sched_move_task() attach will have updated cfs_rq's last_load_update
time before attach, and in turn the attach will have set the entity's
last_load_update stamp.

Note that there is a further problem with sched_move_task() calling
detach on a task that hasn't yet been attached; this will be taken
care of in a subsequent patch.

Reported-by: Vincent Guittot <vincent.guittot@linaro.org>
Tested-by:  Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.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: Yuyang Du <yuyang.du@intel.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-27 12:17:51 +02:00
Peter Zijlstra e210bffd39 sched/fair: Fix and optimize the fork() path
The task_fork_fair() callback already calls __set_task_cpu() and takes
rq->lock.

If we move the sched_class::task_fork callback in sched_fork() under
the existing p->pi_lock, right after its set_task_cpu() call, we can
avoid doing two such calls and omit the IRQ disabling on the rq->lock.

Change to __set_task_cpu() to skip the migration bits, this is a new
task, not a migration. Similarly, make wake_up_new_task() use
__set_task_cpu() for the same reason, the task hasn't actually
migrated as it hasn't ever ran.

This cures the problem of calling migrate_task_rq_fair(), which does
remove_entity_from_load_avg() on tasks that have never been added to
the load avg to begin with.

This bug would result in transiently messed up load_avg values, averaged
out after a few dozen milliseconds. This is probably the reason why
this bug was not found for such a long time.

Reported-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.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
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-27 12:17:50 +02:00
Pan Xinhui 0dceeaf599 locking/qspinlock: Use __this_cpu_dec() instead of full-blown this_cpu_dec()
queued_spin_lock_slowpath() should not worry about another
queued_spin_lock_slowpath() running in interrupt context and
changing node->count by accident, because node->count keeps
the same value every time we enter/leave queued_spin_lock_slowpath().

On some architectures this_cpu_dec() will save/restore irq flags,
which has high overhead. Use the much cheaper __this_cpu_dec() instead.

Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.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: Waiman.Long@hpe.com
Link: http://lkml.kernel.org/r/1465886247-3773-1-git-send-email-xinhui.pan@linux.vnet.ibm.com
[ Rewrote changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-27 11:37:41 +02:00
Ingo Molnar 630741fb60 Merge branch 'sched/urgent' into sched/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-27 11:35:02 +02:00
Ingo Molnar 8114e90ea4 Linux 4.7-rc5
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Merge tag 'v4.7-rc5' into perf/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-27 11:20:46 +02:00
Peter Zijlstra ea1dc6fc62 sched/fair: Fix calc_cfs_shares() fixed point arithmetics width confusion
Commit:

  fde7d22e01 ("sched/fair: Fix overly small weight for interactive group entities")

did something non-obvious but also did it buggy yet latent.

The problem was exposed for real by a later commit in the v4.7 merge window:

  2159197d66 ("sched/core: Enable increased load resolution on 64-bit kernels")

... after which tg->load_avg and cfs_rq->load.weight had different
units (10 bit fixed point and 20 bit fixed point resp.).

Add a comment to explain the use of cfs_rq->load.weight over the
'natural' cfs_rq->avg.load_avg and add scale_load_down() to correct
for the difference in unit.

Since this is (now, as per a previous commit) the only user of
calc_tg_weight(), collapse it.

The effects of this bug should be randomly inconsistent SMP-balancing
of cgroups workloads.

Reported-by: Jirka Hladky <jhladky@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 2159197d66 ("sched/core: Enable increased load resolution on 64-bit kernels")
Fixes: fde7d22e01 ("sched/fair: Fix overly small weight for interactive group entities")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-27 11:18:37 +02:00
Peter Zijlstra 7dd4912594 sched/fair: Fix effective_load() to consistently use smoothed load
Starting with the following commit:

  fde7d22e01 ("sched/fair: Fix overly small weight for interactive group entities")

calc_tg_weight() doesn't compute the right value as expected by effective_load().

The difference is in the 'correction' term. In order to ensure \Sum
rw_j >= rw_i we cannot use tg->load_avg directly, since that might be
lagging a correction on the current cfs_rq->avg.load_avg value.
Therefore we use tg->load_avg - cfs_rq->tg_load_avg_contrib +
cfs_rq->avg.load_avg.

Now, per the referenced commit, calc_tg_weight() doesn't use
cfs_rq->avg.load_avg, as is later used in @w, but uses
cfs_rq->load.weight instead.

So stop using calc_tg_weight() and do it explicitly.

The effects of this bug are wake_affine() making randomly
poor choices in cgroup-intense workloads.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org> # v4.3+
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: fde7d22e01 ("sched/fair: Fix overly small weight for interactive group entities")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-27 11:18:36 +02:00
Kees Cook 65fe935dd2 x86/KASLR, x86/power: Remove x86 hibernation restrictions
With the following fix:

  70595b479ce1 ("x86/power/64: Fix crash whan the hibernation code passes control to the image kernel")

... there is no longer a problem with hibernation resuming a
KASLR-booted kernel image, so remove the restriction.

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
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: Jonathan Corbet <corbet@lwn.net>
Cc: Len Brown <len.brown@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Linux PM list <linux-pm@vger.kernel.org>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: linux-doc@vger.kernel.org
Link: http://lkml.kernel.org/r/20160613221002.GA29719@www.outflux.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-26 12:32:03 +02:00
Linus Torvalds 57801c1b81 Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Thomas Gleixner:
 "A couple of scheduler fixes:

   - force watchdog reset while processing sysrq-w

   - fix a deadlock when enabling trace events in the scheduler

   - fixes to the throttled next buddy logic

   - fixes for the average accounting (missing serialization and
     underflow handling)

   - allow kernel threads for fallback to online but not active cpus"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/core: Allow kthreads to fall back to online && !active cpus
  sched/fair: Do not announce throttled next buddy in dequeue_task_fair()
  sched/fair: Initialize throttle_count for new task-groups lazily
  sched/fair: Fix cfs_rq avg tracking underflow
  kernel/sysrq, watchdog, sched/core: Reset watchdog on all CPUs while processing sysrq-w
  sched/debug: Fix deadlock when enabling sched events
  sched/fair: Fix post_init_entity_util_avg() serialization
2016-06-25 06:38:42 -07:00
Linus Torvalds e3b22bc3d7 Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fix from Thomas Gleixner:
 "A single fix to address a race in the static key logic"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/static_key: Fix concurrent static_key_slow_inc()
2016-06-25 06:14:44 -07:00
Michael Ellerman 9521d39976 Fix build break in fork.c when THREAD_SIZE < PAGE_SIZE
Commit b235beea9e ("Clarify naming of thread info/stack allocators")
breaks the build on some powerpc configs, where THREAD_SIZE < PAGE_SIZE:

  kernel/fork.c:235:2: error: implicit declaration of function 'free_thread_stack'
  kernel/fork.c:355:8: error: assignment from incompatible pointer type
    stack = alloc_thread_stack_node(tsk, node);
    ^

Fix it by renaming free_stack() to free_thread_stack(), and updating the
return type of alloc_thread_stack_node().

Fixes: b235beea9e ("Clarify naming of thread info/stack allocators")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-06-25 06:01:28 -07:00
Linus Torvalds 086e3eb65e Merge branch 'akpm' (patches from Andrew)
Merge misc fixes from Andrew Morton:
 "Two weeks worth of fixes here"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (41 commits)
  init/main.c: fix initcall_blacklisted on ia64, ppc64 and parisc64
  autofs: don't get stuck in a loop if vfs_write() returns an error
  mm/page_owner: avoid null pointer dereference
  tools/vm/slabinfo: fix spelling mistake: "Ocurrences" -> "Occurrences"
  fs/nilfs2: fix potential underflow in call to crc32_le
  oom, suspend: fix oom_reaper vs. oom_killer_disable race
  ocfs2: disable BUG assertions in reading blocks
  mm, compaction: abort free scanner if split fails
  mm: prevent KASAN false positives in kmemleak
  mm/hugetlb: clear compound_mapcount when freeing gigantic pages
  mm/swap.c: flush lru pvecs on compound page arrival
  memcg: css_alloc should return an ERR_PTR value on error
  memcg: mem_cgroup_migrate() may be called with irq disabled
  hugetlb: fix nr_pmds accounting with shared page tables
  Revert "mm: disable fault around on emulated access bit architecture"
  Revert "mm: make faultaround produce old ptes"
  mailmap: add Boris Brezillon's email
  mailmap: add Antoine Tenart's email
  mm, sl[au]b: add __GFP_ATOMIC to the GFP reclaim mask
  mm: mempool: kasan: don't poot mempool objects in quarantine
  ...
2016-06-24 19:08:33 -07:00
Michal Hocko 7407054209 oom, suspend: fix oom_reaper vs. oom_killer_disable race
Tetsuo has reported the following potential oom_killer_disable vs.
oom_reaper race:

 (1) freeze_processes() starts freezing user space threads.
 (2) Somebody (maybe a kenrel thread) calls out_of_memory().
 (3) The OOM killer calls mark_oom_victim() on a user space thread
     P1 which is already in __refrigerator().
 (4) oom_killer_disable() sets oom_killer_disabled = true.
 (5) P1 leaves __refrigerator() and enters do_exit().
 (6) The OOM reaper calls exit_oom_victim(P1) before P1 can call
     exit_oom_victim(P1).
 (7) oom_killer_disable() returns while P1 not yet finished
 (8) P1 perform IO/interfere with the freezer.

This situation is unfortunate.  We cannot move oom_killer_disable after
all the freezable kernel threads are frozen because the oom victim might
depend on some of those kthreads to make a forward progress to exit so
we could deadlock.  It is also far from trivial to teach the oom_reaper
to not call exit_oom_victim() because then we would lose a guarantee of
the OOM killer and oom_killer_disable forward progress because
exit_mm->mmput might block and never call exit_oom_victim.

It seems the easiest way forward is to workaround this race by calling
try_to_freeze_tasks again after oom_killer_disable.  This will make sure
that all the tasks are frozen or it bails out.

Fixes: 449d777d7a ("mm, oom_reaper: clear TIF_MEMDIE for all tasks queued for oom_reaper")
Link: http://lkml.kernel.org/r/1466597634-16199-1-git-send-email-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-06-24 17:23:52 -07:00
Linus Torvalds b235beea9e Clarify naming of thread info/stack allocators
We've had the thread info allocated together with the thread stack for
most architectures for a long time (since the thread_info was split off
from the task struct), but that is about to change.

But the patches that move the thread info to be off-stack (and a part of
the task struct instead) made it clear how confused the allocator and
freeing functions are.

Because the common case was that we share an allocation with the thread
stack and the thread_info, the two pointers were identical.  That
identity then meant that we would have things like

	ti = alloc_thread_info_node(tsk, node);
	...
	tsk->stack = ti;

which certainly _worked_ (since stack and thread_info have the same
value), but is rather confusing: why are we assigning a thread_info to
the stack? And if we move the thread_info away, the "confusing" code
just gets to be entirely bogus.

So remove all this confusion, and make it clear that we are doing the
stack allocation by renaming and clarifying the function names to be
about the stack.  The fact that the thread_info then shares the
allocation is an implementation detail, and not really about the
allocation itself.

This is a pure renaming and type fix: we pass in the same pointer, it's
just that we clarify what the pointer means.

The ia64 code that actually only has one single allocation (for all of
task_struct, thread_info and kernel thread stack) now looks a bit odd,
but since "tsk->stack" is actually not even used there, that oddity
doesn't matter.  It would be a separate thing to clean that up, I
intentionally left the ia64 changes as a pure brute-force renaming and
type change.

Acked-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-06-24 15:09:37 -07:00
Dan Williams f295e53b60 libnvdimm, pmem: allow nfit_test to override pmem_direct_access()
Currently phys_to_pfn_t() is an exported symbol to allow nfit_test to
override it and indicate that nfit_test-pmem is not device-mapped.  Now,
we want to enable nfit_test to operate without DMA_CMA and the pmem it
provides will no longer be physically contiguous, i.e. won't be capable
of supporting direct_access requests larger than a page.  Make
pmem_direct_access() a weak symbol so that it can be replaced by the
tools/testing/nvdimm/ version, and move phys_to_pfn_t() to a static
inline now that it no longer needs to be overridden.

Acked-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-06-24 11:39:29 -07:00
Seth Forshee d07b846f62 fs: Limit file caps to the user namespace of the super block
Capability sets attached to files must be ignored except in the
user namespaces where the mounter is privileged, i.e. s_user_ns
and its descendants. Otherwise a vector exists for gaining
privileges in namespaces where a user is not already privileged.

Add a new helper function, current_in_user_ns(), to test whether a user
namespace is the same as or a descendant of another namespace.
Use this helper to determine whether a file's capability set
should be applied to the caps constructed during exec.

--EWB Replaced in_userns with the simpler current_in_userns.

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2016-06-24 10:40:31 -05:00
Tejun Heo feb245e304 sched/core: Allow kthreads to fall back to online && !active cpus
During CPU hotplug, CPU_ONLINE callbacks are run while the CPU is
online but not active.  A CPU_ONLINE callback may create or bind a
kthread so that its cpus_allowed mask only allows the CPU which is
being brought online.  The kthread may start executing before the CPU
is made active and can end up in select_fallback_rq().

In such cases, the expected behavior is selecting the CPU which is
coming online; however, because select_fallback_rq() only chooses from
active CPUs, it determines that the task doesn't have any viable CPU
in its allowed mask and ends up overriding it to cpu_possible_mask.

CPU_ONLINE callbacks should be able to put kthreads on the CPU which
is coming online.  Update select_fallback_rq() so that it follows
cpu_online() rather than cpu_active() for kthreads.

Reported-by: Gautham R Shenoy <ego@linux.vnet.ibm.com>
Tested-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel-team@fb.com
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/20160616193504.GB3262@mtj.duckdns.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-24 08:26:53 +02:00
Konstantin Khlebnikov 754bd598be sched/fair: Do not announce throttled next buddy in dequeue_task_fair()
Hierarchy could be already throttled at this point. Throttled next
buddy could trigger a NULL pointer dereference in pick_next_task_fair().

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ben Segall <bsegall@google.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/146608183552.21905.15924473394414832071.stgit@buzz
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-24 08:26:45 +02:00
Konstantin Khlebnikov 094f469172 sched/fair: Initialize throttle_count for new task-groups lazily
Cgroup created inside throttled group must inherit current throttle_count.
Broken throttle_count allows to nominate throttled entries as a next buddy,
later this leads to null pointer dereference in pick_next_task_fair().

This patch initialize cfs_rq->throttle_count at first enqueue: laziness
allows to skip locking all rq at group creation. Lazy approach also allows
to skip full sub-tree scan at throttling hierarchy (not in this patch).

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bsegall@google.com
Link: http://lkml.kernel.org/r/146608182119.21870.8439834428248129633.stgit@buzz
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-24 08:26:44 +02:00
Paolo Bonzini 4c5ea0a9cd locking/static_key: Fix concurrent static_key_slow_inc()
The following scenario is possible:

    CPU 1                                   CPU 2
    static_key_slow_inc()
     atomic_inc_not_zero()
      -> key.enabled == 0, no increment
     jump_label_lock()
     atomic_inc_return()
      -> key.enabled == 1 now
                                            static_key_slow_inc()
                                             atomic_inc_not_zero()
                                              -> key.enabled == 1, inc to 2
                                             return
                                            ** static key is wrong!
     jump_label_update()
     jump_label_unlock()

Testing the static key at the point marked by (**) will follow the
wrong path for jumps that have not been patched yet.  This can
actually happen when creating many KVM virtual machines with userspace
LAPIC emulation; just run several copies of the following program:

    #include <fcntl.h>
    #include <unistd.h>
    #include <sys/ioctl.h>
    #include <linux/kvm.h>

    int main(void)
    {
        for (;;) {
            int kvmfd = open("/dev/kvm", O_RDONLY);
            int vmfd = ioctl(kvmfd, KVM_CREATE_VM, 0);
            close(ioctl(vmfd, KVM_CREATE_VCPU, 1));
            close(vmfd);
            close(kvmfd);
        }
        return 0;
    }

Every KVM_CREATE_VCPU ioctl will attempt a static_key_slow_inc() call.
The static key's purpose is to skip NULL pointer checks and indeed one
of the processes eventually dereferences NULL.

As explained in the commit that introduced the bug:

  706249c222 ("locking/static_keys: Rework update logic")

jump_label_update() needs key.enabled to be true.  The solution adopted
here is to temporarily make key.enabled == -1, and use go down the
slow path when key.enabled <= 0.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org> # v4.3+
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 706249c222 ("locking/static_keys: Rework update logic")
Link: http://lkml.kernel.org/r/1466527937-69798-1-git-send-email-pbonzini@redhat.com
[ Small stylistic edits to the changelog and the code. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-24 08:23:16 +02:00
Steven Rostedt (Red Hat) be54f69c26 tracing: Skip more functions when doing stack tracing of events
# echo 1 > options/stacktrace
 # echo 1 > events/sched/sched_switch/enable
 # cat trace
          <idle>-0     [002] d..2  1982.525169: <stack trace>
 => save_stack_trace
 => __ftrace_trace_stack
 => trace_buffer_unlock_commit_regs
 => event_trigger_unlock_commit
 => trace_event_buffer_commit
 => trace_event_raw_event_sched_switch
 => __schedule
 => schedule
 => schedule_preempt_disabled
 => cpu_startup_entry
 => start_secondary

The above shows that we are seeing 6 functions before ever making it to the
caller of the sched_switch event.

 # echo stacktrace > events/sched/sched_switch/trigger
 # cat trace
          <idle>-0     [002] d..3  2146.335208: <stack trace>
 => trace_event_buffer_commit
 => trace_event_raw_event_sched_switch
 => __schedule
 => schedule
 => schedule_preempt_disabled
 => cpu_startup_entry
 => start_secondary

The stacktrace trigger isn't as bad, because it adds its own skip to the
stacktracing, but still has two events extra.

One issue is that if the stacktrace passes its own "regs" then there should
be no addition to the skip, as the regs will not include the functions being
called. This was an issue that was fixed by commit 7717c6be69 ("tracing:
Fix stacktrace skip depth in trace_buffer_unlock_commit_regs()" as adding
the skip number for kprobes made the probes not have any stack at all.

But since this is only an issue when regs is being used, a skip should be
added if regs is NULL. Now we have:

 # echo 1 > options/stacktrace
 # echo 1 > events/sched/sched_switch/enable
 # cat trace
          <idle>-0     [000] d..2  1297.676333: <stack trace>
 => __schedule
 => schedule
 => schedule_preempt_disabled
 => cpu_startup_entry
 => rest_init
 => start_kernel
 => x86_64_start_reservations
 => x86_64_start_kernel

 # echo stacktrace > events/sched/sched_switch/trigger
 # cat trace
          <idle>-0     [002] d..3  1370.759745: <stack trace>
 => __schedule
 => schedule
 => schedule_preempt_disabled
 => cpu_startup_entry
 => start_secondary

And kprobes are not touched.

Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-06-23 18:48:56 -04:00
Daniel Bristot de Oliveira 82d6489d0f cgroup: Disable IRQs while holding css_set_lock
While testing the deadline scheduler + cgroup setup I hit this
warning.

[  132.612935] ------------[ cut here ]------------
[  132.612951] WARNING: CPU: 5 PID: 0 at kernel/softirq.c:150 __local_bh_enable_ip+0x6b/0x80
[  132.612952] Modules linked in: (a ton of modules...)
[  132.612981] CPU: 5 PID: 0 Comm: swapper/5 Not tainted 4.7.0-rc2 #2
[  132.612981] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.2-20150714_191134- 04/01/2014
[  132.612982]  0000000000000086 45c8bb5effdd088b ffff88013fd43da0 ffffffff813d229e
[  132.612984]  0000000000000000 0000000000000000 ffff88013fd43de0 ffffffff810a652b
[  132.612985]  00000096811387b5 0000000000000200 ffff8800bab29d80 ffff880034c54c00
[  132.612986] Call Trace:
[  132.612987]  <IRQ>  [<ffffffff813d229e>] dump_stack+0x63/0x85
[  132.612994]  [<ffffffff810a652b>] __warn+0xcb/0xf0
[  132.612997]  [<ffffffff810e76a0>] ? push_dl_task.part.32+0x170/0x170
[  132.612999]  [<ffffffff810a665d>] warn_slowpath_null+0x1d/0x20
[  132.613000]  [<ffffffff810aba5b>] __local_bh_enable_ip+0x6b/0x80
[  132.613008]  [<ffffffff817d6c8a>] _raw_write_unlock_bh+0x1a/0x20
[  132.613010]  [<ffffffff817d6c9e>] _raw_spin_unlock_bh+0xe/0x10
[  132.613015]  [<ffffffff811388ac>] put_css_set+0x5c/0x60
[  132.613016]  [<ffffffff8113dc7f>] cgroup_free+0x7f/0xa0
[  132.613017]  [<ffffffff810a3912>] __put_task_struct+0x42/0x140
[  132.613018]  [<ffffffff810e776a>] dl_task_timer+0xca/0x250
[  132.613027]  [<ffffffff810e76a0>] ? push_dl_task.part.32+0x170/0x170
[  132.613030]  [<ffffffff8111371e>] __hrtimer_run_queues+0xee/0x270
[  132.613031]  [<ffffffff81113ec8>] hrtimer_interrupt+0xa8/0x190
[  132.613034]  [<ffffffff81051a58>] local_apic_timer_interrupt+0x38/0x60
[  132.613035]  [<ffffffff817d9b0d>] smp_apic_timer_interrupt+0x3d/0x50
[  132.613037]  [<ffffffff817d7c5c>] apic_timer_interrupt+0x8c/0xa0
[  132.613038]  <EOI>  [<ffffffff81063466>] ? native_safe_halt+0x6/0x10
[  132.613043]  [<ffffffff81037a4e>] default_idle+0x1e/0xd0
[  132.613044]  [<ffffffff810381cf>] arch_cpu_idle+0xf/0x20
[  132.613046]  [<ffffffff810e8fda>] default_idle_call+0x2a/0x40
[  132.613047]  [<ffffffff810e92d7>] cpu_startup_entry+0x2e7/0x340
[  132.613048]  [<ffffffff81050235>] start_secondary+0x155/0x190
[  132.613049] ---[ end trace f91934d162ce9977 ]---

The warn is the spin_(lock|unlock)_bh(&css_set_lock) in the interrupt
context. Converting the spin_lock_bh to spin_lock_irq(save) to avoid
this problem - and other problems of sharing a spinlock with an
interrupt.

Cc: Tejun Heo <tj@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Juri Lelli <juri.lelli@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: cgroups@vger.kernel.org
Cc: stable@vger.kernel.org # 4.5+
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: "Luis Claudio R. Goncalves" <lgoncalv@redhat.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Acked-by: Zefan Li <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2016-06-23 17:23:12 -04:00
Linus Torvalds 6720a305df locking: avoid passing around 'thread_info' in mutex debugging code
None of the code actually wants a thread_info, it all wants a
task_struct, and it's just converting back and forth between the two
("ti->task" to get the task_struct from the thread_info, and
"task_thread_info(task)" to go the other way).

No semantic change.

Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-06-23 12:11:17 -07:00
Jon Hunter d16dcd3d18 irqdomain: Fix disposal of mappings for interrupt hierarchies
The function irq_create_of_mapping() is used to create an interrupt
mapping. However, depending on whether the irqdomain, to which the
interrupt belongs, is part of a hierarchy, determines whether the
mapping is created via calling irq_domain_alloc_irqs() or
irq_create_mapping().

To dispose of the interrupt mapping, drivers call irq_dispose_mapping().
However, this function does not check to see if the irqdomain is part
of a hierarchy or not and simply assumes that it was mapped via calling
irq_create_mapping() so calls irq_domain_disassociate() to unmap the
interrupt.

Fix this by checking to see if the irqdomain is part of a hierarchy and
if so call irq_domain_free_irqs() to free/unmap the interrupt.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Link: http://lkml.kernel.org/r/1466501002-16368-1-git-send-email-jonathanh@nvidia.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-06-23 10:21:06 +02:00
Kenny Yu 9f6870dd97 cgroup: Use lld instead of ld when printing pids controller events_limit
The `events_limit` variable needs to be formatted with %lld and not %ld.
This fixes the following warning discovered by kbuild test robot:

   kernel/cgroup_pids.c: In function 'pids_events_show':
   kernel/cgroup_pids.c:313:24: warning: format '%ld' expects argument of type
   'long int', but argument 3 has type 'long long int' [-Wformat=]
        seq_printf(sf, "max %ld\n", atomic64_read(&pids->events_limit));
                                   ^

tj: Added explicit (s64) cast as atomic64 switches between long long
    and long depending on 32 or 64.

Signed-off-by: Kenny Yu <kennyyu@fb.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2016-06-21 15:03:36 -04:00
Kenny Yu 135b8b37bd cgroup: Add pids controller event when fork fails because of pid limit
This patch adds more visibility into the pids controller when the controller
rejects a fork request. Whenever fork fails because the limit on the number of
pids in the cgroup is reached, the controller will log this and also notify the
newly added cgroups events file. The `max` key in the events file represents
the number of times fork failed because of the pids controller.

This change also logs only the first time the `max` event counter is
incremented. This is to provide a hint to the user to understand why fork
failed, as users are not yet used to seeing fork failures because of the
pids controller.

Signed-off-by: Kenny Yu <kennyyu@fb.com>
Acked-by: Johannes Weiner <hannes <at> cmpxchg.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2016-06-21 14:04:36 -04:00
Tejun Heo e7e15b87f8 cgroup: allow NULL return from ss->css_alloc()
cgroup core expected css_alloc to return an ERR_PTR value on failure
and caused NULL deref if it returned NULL.  It's an easy mistake to
make from an alloc function and there's no ambiguity in what's being
indicated.  Update css_create() so that it interprets NULL return from
css_alloc as -ENOMEM.

Signed-off-by: Tejun Heo <tj@kernel.org>
2016-06-21 13:07:09 -04:00
Thomas Gleixner c7d6b5a22c Merge branch 'fortglx/4.8/time' of https://git.linaro.org/people/john.stultz/linux into timers/core
Pull time(keeping) updates from John Stultz:

 - Handle the 1ns issue with the old refusing to die vsyscall machinery
 - More y2038 updates
 - Documentation fixes
 - Simplify clocksource handling
2016-06-21 08:22:51 +02:00
Arnd Bergmann 7c71feb0a6 timer: Avoid using timespec
The tstats_show() function prints a ktime_t variable by converting
it to struct timespec first. The algorithm is ok, but we want to
stop using timespec in general because of the 32-bit time_t
overflow problem.

This changes the code to use struct timespec64, without any
functional change.

Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2016-06-20 12:47:33 -07:00
Arnd Bergmann 4a19bd3d22 time: Avoid timespec in udelay_test
udelay_test_single() uses ktime_get_ts() to get two timespec values
and calculate the difference between them, while udelay_test_show()
uses the same to printk() the current monotonic time.

Both of these are y2038 safe on all machines, but we want to
get rid of struct timespec anyway, so this converts the code to
use ktime_get_ns() and ktime_get_ts64() respectively.

Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2016-06-20 12:47:26 -07:00
Deepa Dinamani e6c2682a1d time: Add time64_to_tm()
time_to_tm() takes time_t as an argument.
time_t is not y2038 safe.
Add time64_to_tm() that takes time64_t as an argument
which is y2038 safe.
The plan is to eventually replace all calls to time_to_tm()
by time64_to_tm().

Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2016-06-20 12:47:15 -07:00
Pratyush Patel af4afb4008 alarmtimer: Fix comments describing structure fields
Updated struct alarm and struct alarm_timer descriptions.

Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Pratyush Patel <pratyushpatel.1995@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2016-06-20 12:47:09 -07:00
Thomas Graziadei 0209b93756 timekeeping: Fix 1ns/tick drift with GENERIC_TIME_VSYSCALL_OLD
The user notices the problem in a raw and real time drift, calling
clock_gettime with CLOCK_REALTIME / CLOCK_MONOTONIC_RAW on a system
with no ntp correction taking place (no ntpd or ptp stuff running).

The problem is, that old_vsyscall_fixup adds an extra 1ns even though
xtime_nsec is already held in full nsecs and the remainder in this
case is 0. Do the rounding up buisness only if needed.

Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Thomas Graziadei <thomas.graziadei@omicronenergy.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2016-06-20 12:46:45 -07:00
Minfei Huang 0fb71d340d clocksource: Make clocksource insert entry more efficient
In clocksource_enqueue(), it is unnecessary to continue looping
the list, if we find there is an entry that the value of rating
is smaller than the new one. It is safe to be out the loop,
because all of entry are inserted in descending order.

Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Minfei Huang <mnghuan@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2016-06-20 12:46:34 -07:00
Linus Torvalds f780f00d72 Two fixes for the tracing system.
o When trace_printk() is used with a non constant format descriptor,
    it adds a NULL pointer into the trace format section, and the code
    isn't prepared to deal with it. This bug appeared by a change that
    was added in v3.5.
 
  o The ftracetest (selftests section) can't handle testing histograms
    when histograms are not configured. Currently it shows that they
    fail the test, when they should state that they are unsupported.
    This bug was added in the 4.7 merge window with the addition of
    the historgram code.
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Merge tag 'trace-v4.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Two fixes for the tracing system:

   - When trace_printk() is used with a non constant format descriptor,
     it adds a NULL pointer into the trace format section, and the code
     isn't prepared to deal with it.  This bug appeared by a change that
     was added in v3.5.

   - The ftracetest (selftests section) can't handle testing histograms
     when histograms are not configured.  Currently it shows that they
     fail the test, when they should state that they are unsupported.
     This bug was added in the 4.7 merge window with the addition of the
     historgram code"

* tag 'trace-v4.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftracetest: Fix hist unsupported result in hist selftests
  tracing: Handle NULL formats in hold_module_trace_bprintk_format()
2016-06-20 10:35:48 -07:00
Bjorn Helgaas 9a51933e36 tracing: Expose CPU physical addresses (resource values) for PCI devices
Previously, mmio_print_pcidev() put "user" addresses in the trace buffer.
On most architectures, these are the same as CPU physical addresses, but on
microblaze, mips, powerpc, and sparc, they may be something else, typically
a raw BAR value (a bus address as opposed to a CPU address).

Always expose the CPU physical address to avoid this arch-dependent
behavior.

This change should have no user-visible effect because this file currently
depends on CONFIG_HAVE_MMIOTRACE_SUPPORT, which is only defined for x86,
and pci_resource_to_user() is a no-op on x86.

Link: http://lkml.kernel.org/r/20160511190657.5898.4248.stgit@bhelgaas-glaptop2.roam.corp.google.com

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-06-20 09:54:22 -04:00
Steven Rostedt (Red Hat) e947841c0d tracing: Show the preempt count of when the event was called
Because tracepoint callbacks are done with preemption enabled, the trace
events are always called with preempt disable due to the
rcu_read_lock_sched_notrace() in __DO_TRACE(). This causes the preempt count
shown in the recorded trace event to be inaccurate. It is always one more
that what the preempt_count was when the tracepoint was called.

If CONFIG_PREEMPT is enabled, subtract 1 from the preempt_count before
recording it in the trace buffer.

Link: http://lkml.kernel.org/r/20160525132537.GA10808@linutronix.de

Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-06-20 09:54:21 -04:00
Andy Lutomirski e2ace00117 tracing: Choose static tp_printk buffer by explicit nesting count
Currently, the trace_printk code chooses which static buffer to use based
on what type of atomic context (NMI, IRQ, etc) it's in.  Simplify the
code and make it more robust: simply count the nesting depth and choose
a buffer based on the current nesting depth.

The new code will only drop an event if we nest more than 4 deep,
and the old code was guaranteed to malfunction if that happened.

Link: http://lkml.kernel.org/r/07ab03aecfba25fcce8f9a211b14c9c5e2865c58.1464289095.git.luto@kernel.org

Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-06-20 09:54:20 -04:00
Omar Sandoval 35abb67de7 tracing: expose current->comm to [ku]probe events
ftrace is very quick to give up on saving the task command line (see
`trace_save_cmdline()`). The workaround for events which really care
about the command line is to explicitly assign it as part of the entry.
However, this doesn't work for kprobe events, as there's no
straightforward way to get access to current->comm. Add a kprobe/uprobe
event variable $comm which provides exactly that.

Link: http://lkml.kernel.org/r/f59b472033b943a370f5f48d0af37698f409108f.1465435894.git.osandov@fb.com

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-06-20 09:54:19 -04:00
Steven Rostedt (Red Hat) 345ddcc882 ftrace: Have set_ftrace_pid use the bitmap like events do
Convert set_ftrace_pid to use the bitmap like set_event_pid does. This
allows for instances to use the pid filtering as well, and will allow for
function-fork option to set if the children of a traced function should be
traced or not.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-06-20 09:54:19 -04:00
Steven Rostedt (Red Hat) 76c813e266 tracing: Move pid_list write processing into its own function
The addition of PIDs into a pid_list via the write operation of
set_event_pid is a bit complex. The same operation will be needed for
function tracing pids. Move the code into its own generic function in
trace.c, so that we can avoid duplication of this code.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-06-20 09:54:18 -04:00
Steven Rostedt (Red Hat) 5cc8976bd5 tracing: Move the pid_list seq_file functions to be global
To allow other aspects of ftrace to use the pid_list logic, we need to reuse
the seq_file functions. Making the generic part into functions that can be
called by other files will help in this regard.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-06-20 09:54:17 -04:00
Steven Rostedt d8275c454d tracing: Move filtered_pid helper functions into trace.c
As the filtered_pid functions are going to be used by function tracer as
well as trace_events, move the code into the generic trace.c file.

The functions moved are:

 trace_find_filtered_pid()
 trace_ignore_this_task()
 trace_filter_add_remove_task()

Kernel Doc text was also added.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-06-20 09:54:17 -04:00
Steven Rostedt 4e267db135 tracing: Make the pid filtering helper functions global
Make the functions used for pid filtering global for tracing, such that the
function tracer can use the pid code as well.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-06-20 09:54:16 -04:00
Steven Rostedt (Red Hat) 70c8217acd tracing: Handle NULL formats in hold_module_trace_bprintk_format()
If a task uses a non constant string for the format parameter in
trace_printk(), then the trace_printk_fmt variable is set to NULL. This
variable is then saved in the __trace_printk_fmt section.

The function hold_module_trace_bprintk_format() checks to see if duplicate
formats are used by modules, and reuses them if so (saves them to the list
if it is new). But this function calls lookup_format() that does a strcmp()
to the value (which is now NULL) and can cause a kernel oops.

This wasn't an issue till 3debb0a9dd ("tracing: Fix trace_printk() to print
when not using bprintk()") which added "__used" to the trace_printk_fmt
variable, and before that, the kernel simply optimized it out (no NULL value
was saved).

The fix is simply to handle the NULL pointer in lookup_format() and have the
caller ignore the value if it was NULL.

Link: http://lkml.kernel.org/r/1464769870-18344-1-git-send-email-zhengjun.xing@intel.com

Reported-by: xingzhen <zhengjun.xing@intel.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Fixes: 3debb0a9dd ("tracing: Fix trace_printk() to print when not using bprintk()")
Cc: stable@vger.kernel.org # v3.5+
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-06-20 09:46:12 -04:00
Peter Zijlstra 8974189222 sched/fair: Fix cfs_rq avg tracking underflow
As per commit:

  b7fa30c9cc ("sched/fair: Fix post_init_entity_util_avg() serialization")

> the code generated from update_cfs_rq_load_avg():
>
> 	if (atomic_long_read(&cfs_rq->removed_load_avg)) {
> 		s64 r = atomic_long_xchg(&cfs_rq->removed_load_avg, 0);
> 		sa->load_avg = max_t(long, sa->load_avg - r, 0);
> 		sa->load_sum = max_t(s64, sa->load_sum - r * LOAD_AVG_MAX, 0);
> 		removed_load = 1;
> 	}
>
> turns into:
>
> ffffffff81087064:       49 8b 85 98 00 00 00    mov    0x98(%r13),%rax
> ffffffff8108706b:       48 85 c0                test   %rax,%rax
> ffffffff8108706e:       74 40                   je     ffffffff810870b0 <update_blocked_averages+0xc0>
> ffffffff81087070:       4c 89 f8                mov    %r15,%rax
> ffffffff81087073:       49 87 85 98 00 00 00    xchg   %rax,0x98(%r13)
> ffffffff8108707a:       49 29 45 70             sub    %rax,0x70(%r13)
> ffffffff8108707e:       4c 89 f9                mov    %r15,%rcx
> ffffffff81087081:       bb 01 00 00 00          mov    $0x1,%ebx
> ffffffff81087086:       49 83 7d 70 00          cmpq   $0x0,0x70(%r13)
> ffffffff8108708b:       49 0f 49 4d 70          cmovns 0x70(%r13),%rcx
>
> Which you'll note ends up with sa->load_avg -= r in memory at
> ffffffff8108707a.

So I _should_ have looked at other unserialized users of ->load_avg,
but alas. Luckily nikbor reported a similar /0 from task_h_load() which
instantly triggered recollection of this here problem.

Aside from the intermediate value hitting memory and causing problems,
there's another problem: the underflow detection relies on the signed
bit. This reduces the effective width of the variables, IOW its
effectively the same as having these variables be of signed type.

This patch changes to a different means of unsigned underflow
detection to not rely on the signed bit. This allows the variables to
use the 'full' unsigned range. And it does so with explicit LOAD -
STORE to ensure any intermediate value will never be visible in
memory, allowing these unserialized loads.

Note: GCC generates crap code for this, might warrant a look later.

Note2: I say 'full' above, if we end up at U*_MAX we'll still explode;
       maybe we should do clamping on add too.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
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: Yuyang Du <yuyang.du@intel.com>
Cc: bsegall@google.com
Cc: kernel@kyup.com
Cc: morten.rasmussen@arm.com
Cc: pjt@google.com
Cc: steve.muckle@linaro.org
Fixes: 9d89c257df ("sched/fair: Rewrite runnable load and utilization average tracking")
Link: http://lkml.kernel.org/r/20160617091948.GJ30927@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-20 11:29:09 +02:00
Keith Busch edd14cfebc genirq: Add untracked irq handler
This adds a software irq handler for controllers that multiplex
interrupts from multiple devices, but don't know which device generated
the interrupt. For these devices, the irq handler that demuxes must
check every action for every software irq using the same h/w irq in order
to find out which device generated the interrupt. This will inevitably
trigger spurious interrupt detection if we are noting the irq.

The new irq handler does not track the handling for spurious interrupt
detection. An irq that uses this also won't get stats tracked since it
didn't generate the interrupt, nor added to randomness since they are
not random.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org
Cc: Jon Derrick <jonathan.derrick@intel.com>
Link: http://lkml.kernel.org/r/1466200821-29159-1-git-send-email-keith.busch@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-06-18 10:00:55 +02:00
Arnd Bergmann 59a37f8bae blktrace: avoid using timespec
The blktrace code stores the current time in a 32-bit word in its
user interface. This is a bad idea because 32-bit seconds overflow
at some point.

We probably have until 2106 before this one overflows, as it seems
to use an 'unsigned' variable, but we should confirm that user
space treats it the same way.

Aside from this, we want to stop using 'struct timespec' here,
so I'm adding a comment about the overflow and change the code
to use timespec64 instead to make the loss of range more obvious.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-17 23:39:58 +02:00
Johannes Weiner d6ccc55e66 cgroup: remove unnecessary 0 check from css_from_id()
css_idr allocation starts at 1, so index 0 will never point to an
item. css_from_id() currently filters that before asking idr_find(),
but idr_find() would also just return NULL, so this is not needed.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2016-06-17 14:16:32 -04:00
Johannes Weiner 8c8a550218 cgroup: fix idr leak for the first cgroup root
The valid cgroup hierarchy ID range includes 0, so we can't filter for
positive numbers when freeing it, or it'll leak the first ID. No big
deal, just disruptive when reading the code.

The ID is freed during error handling and when the reference count
hits zero, so the double-free test is not necessary; remove it.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2016-06-17 14:16:28 -04:00
Tejun Heo 8fa3b8d689 cgroup: set css->id to -1 during init
If percpu_ref initialization fails during css_create(), the free path
can end up trying to free css->id of zero.  As ID 0 is unused, it
doesn't cause a critical breakage but it does trigger a warning
message.  Fix it by setting css->id to -1 from init_and_link_css().

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Wenwei Tao <ww.tao0320@gmail.com>
Fixes: 01e586598b ("cgroup: release css->id after css_free")
Cc: stable@vger.kernel.org # v4.0+
Signed-off-by: Tejun Heo <tj@kernel.org>
2016-06-16 17:59:35 -04:00
Paul Moore 66b12abc84 audit: fix some horrible switch statement style crimes
Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-06-16 17:08:19 -04:00
Peter Zijlstra d945b5e9f0 workqueue: Fix setting affinity of unbound worker threads
With commit e9d867a67f ("sched: Allow per-cpu kernel threads to
run on online && !active"), __set_cpus_allowed_ptr() expects that only
strict per-cpu kernel threads can have affinity to an online CPU which
is not yet active.

This assumption is currently broken in the CPU_ONLINE notification
handler for the workqueues where restore_unbound_workers_cpumask()
calls set_cpus_allowed_ptr() when the first cpu in the unbound
worker's pool->attr->cpumask comes online. Since
set_cpus_allowed_ptr() is called with pool->attr->cpumask in which
only one CPU is online which is not yet active, we get the following
WARN_ON during an CPU online operation.

------------[ cut here ]------------
WARNING: CPU: 40 PID: 248 at kernel/sched/core.c:1166
__set_cpus_allowed_ptr+0x228/0x2e0
Modules linked in:
CPU: 40 PID: 248 Comm: cpuhp/40 Not tainted 4.6.0-autotest+ #4
<..snip..>
Call Trace:
[c000000f273ff920] [c00000000010493c] __set_cpus_allowed_ptr+0x2cc/0x2e0 (unreliable)
[c000000f273ffac0] [c0000000000ed4b0] workqueue_cpu_up_callback+0x2c0/0x470
[c000000f273ffb70] [c0000000000f5c58] notifier_call_chain+0x98/0x100
[c000000f273ffbc0] [c0000000000c5ed0] __cpu_notify+0x70/0xe0
[c000000f273ffc00] [c0000000000c6028] notify_online+0x38/0x50
[c000000f273ffc30] [c0000000000c5214] cpuhp_invoke_callback+0x84/0x250
[c000000f273ffc90] [c0000000000c562c] cpuhp_up_callbacks+0x5c/0x120
[c000000f273ffce0] [c0000000000c64d4] cpuhp_thread_fun+0x184/0x1c0
[c000000f273ffd20] [c0000000000fa050] smpboot_thread_fn+0x290/0x2a0
[c000000f273ffd80] [c0000000000f45b0] kthread+0x110/0x130
[c000000f273ffe30] [c000000000009570] ret_from_kernel_thread+0x5c/0x6c
---[ end trace 00f1456578b2a3b2 ]---

This patch fixes this by limiting the mask to the intersection of
the pool affinity and online CPUs.

Changelog-cribbed-from: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Reported-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2016-06-16 15:37:05 -04:00
Peter Zijlstra 86a3b5f34f locking/atomic, arch/rwsem: Employ atomic_long_fetch_add()
Now that we have fetch_add() we can stop using add_return() - val.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jason Low <jason.low2@hpe.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <waiman.long@hpe.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-16 10:48:35 +02:00
Peter Zijlstra f9852b74be locking/atomic, arch/qrwlock: Employ atomic_fetch_add_acquire()
The only reason for the current code is to make GCC emit only the
"LOCK XADD" instruction on x86 (and not do a pointless extra ADD on
the result), do so nicer.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Waiman Long <waiman.long@hpe.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-16 10:48:34 +02:00
Peter Zijlstra e37837fb62 locking/atomic: Remove the deprecated atomic_{set,clear}_mask() functions
These functions have been deprecated for a while and there is only the
one user left, convert and kill.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-16 10:48:33 +02:00
Daniel Borkmann 3b1efb196e bpf, maps: flush own entries on perf map release
The behavior of perf event arrays are quite different from all
others as they are tightly coupled to perf event fds, f.e. shown
recently by commit e03e7ee34f ("perf/bpf: Convert perf_event_array
to use struct file") to make refcounting on perf event more robust.
A remaining issue that the current code still has is that since
additions to the perf event array take a reference on the struct
file via perf_event_get() and are only released via fput() (that
cleans up the perf event eventually via perf_event_release_kernel())
when the element is either manually removed from the map from user
space or automatically when the last reference on the perf event
map is dropped. However, this leads us to dangling struct file's
when the map gets pinned after the application owning the perf
event descriptor exits, and since the struct file reference will
in such case only be manually dropped or via pinned file removal,
it leads to the perf event living longer than necessary, consuming
needlessly resources for that time.

Relations between perf event fds and bpf perf event map fds can be
rather complex. F.e. maps can act as demuxers among different perf
event fds that can possibly be owned by different threads and based
on the index selection from the program, events get dispatched to
one of the per-cpu fd endpoints. One perf event fd (or, rather a
per-cpu set of them) can also live in multiple perf event maps at
the same time, listening for events. Also, another requirement is
that perf event fds can get closed from application side after they
have been attached to the perf event map, so that on exit perf event
map will take care of dropping their references eventually. Likewise,
when such maps are pinned, the intended behavior is that a user
application does bpf_obj_get(), puts its fds in there and on exit
when fd is released, they are dropped from the map again, so the map
acts rather as connector endpoint. This also makes perf event maps
inherently different from program arrays as described in more detail
in commit c9da161c65 ("bpf: fix clearing on persistent program
array maps").

To tackle this, map entries are marked by the map struct file that
added the element to the map. And when the last reference to that map
struct file is released from user space, then the tracked entries
are purged from the map. This is okay, because new map struct files
instances resp. frontends to the anon inode are provided via
bpf_map_new_fd() that is called when we invoke bpf_obj_get_user()
for retrieving a pinned map, but also when an initial instance is
created via map_create(). The rest is resolved by the vfs layer
automatically for us by keeping reference count on the map's struct
file. Any concurrent updates on the map slot are fine as well, it
just means that perf_event_fd_array_release() needs to delete less
of its own entires.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-15 23:42:57 -07:00
Daniel Borkmann d056a78876 bpf, maps: extend map_fd_get_ptr arguments
This patch extends map_fd_get_ptr() callback that is used by fd array
maps, so that struct file pointer from the related map can be passed
in. It's safe to remove map_update_elem() callback for the two maps since
this is only allowed from syscall side, but not from eBPF programs for these
two map types. Like in per-cpu map case, bpf_fd_array_map_update_elem()
needs to be called directly here due to the extra argument.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-15 23:42:57 -07:00
Daniel Borkmann 61d1b6a42f bpf, maps: add release callback
Add a release callback for maps that is invoked when the last
reference to its struct file is gone and the struct file about
to be released by vfs. The handler will be used by fd array maps.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-15 23:42:57 -07:00
Alexei Starovoitov ad572d1747 bpf, trace: check event type in bpf_perf_event_read
similar to bpf_perf_event_output() the bpf_perf_event_read() helper
needs to check the type of the perf_event before reading the counter.

Fixes: a43eec3042 ("bpf: introduce bpf_perf_event_output() helper")
Reported-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-15 23:37:54 -07:00
Alexei Starovoitov 19de99f70b bpf: fix matching of data/data_end in verifier
The ctx structure passed into bpf programs is different depending on bpf
program type. The verifier incorrectly marked ctx->data and ctx->data_end
access based on ctx offset only. That caused loads in tracing programs
int bpf_prog(struct pt_regs *ctx) { .. ctx->ax .. }
to be incorrectly marked as PTR_TO_PACKET which later caused verifier
to reject the program that was actually valid in tracing context.
Fix this by doing program type specific matching of ctx offsets.

Fixes: 969bf05eb3 ("bpf: direct packet access")
Reported-by: Sasha Goldshtein <goldshtn@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-15 23:37:54 -07:00
Paul E. McKenney 4d03754f04 Merge branches 'doc.2016.06.15a', 'fixes.2016.06.15b' and 'torture.2016.06.14a' into HEAD
doc.2016.06.15a: Documentation updates
fixes.2016.06.15b: Documentation updates
torture.2016.06.14a: Documentation updates
2016-06-15 16:58:03 -07:00
Mark Rutland bc75e99983 rcu: Correctly handle sparse possible cpus
In many cases in the RCU tree code, we iterate over the set of cpus for
a leaf node described by rcu_node::grplo and rcu_node::grphi, checking
per-cpu data for each cpu in this range. However, if the set of possible
cpus is sparse, some cpus described in this range are not possible, and
thus no per-cpu region will have been allocated (or initialised) for
them by the generic percpu code.

Erroneous accesses to a per-cpu area for these !possible cpus may fault
or may hit other data depending on the addressed generated when the
erroneous per cpu offset is applied. In practice, both cases have been
observed on arm64 hardware (the former being silent, but detectable with
additional patches).

To avoid issues resulting from this, we must iterate over the set of
*possible* cpus for a given leaf node. This patch add a new helper,
for_each_leaf_node_possible_cpu, to enable this. As iteration is often
intertwined with rcu_node local bitmask manipulation, a new
leaf_node_cpu_bit helper is added to make this simpler and more
consistent. The RCU tree code is made to use both of these where
appropriate.

Without this patch, running reboot at a shell can result in an oops
like:

[ 3369.075979] Unable to handle kernel paging request at virtual address ffffff8008b21b4c
[ 3369.083881] pgd = ffffffc3ecdda000
[ 3369.087270] [ffffff8008b21b4c] *pgd=00000083eca48003, *pud=00000083eca48003, *pmd=0000000000000000
[ 3369.096222] Internal error: Oops: 96000007 [#1] PREEMPT SMP
[ 3369.101781] Modules linked in:
[ 3369.104825] CPU: 2 PID: 1817 Comm: NetworkManager Tainted: G        W       4.6.0+ #3
[ 3369.121239] task: ffffffc0fa13e000 ti: ffffffc3eb940000 task.ti: ffffffc3eb940000
[ 3369.128708] PC is at sync_rcu_exp_select_cpus+0x188/0x510
[ 3369.134094] LR is at sync_rcu_exp_select_cpus+0x104/0x510
[ 3369.139479] pc : [<ffffff80081109a8>] lr : [<ffffff8008110924>] pstate: 200001c5
[ 3369.146860] sp : ffffffc3eb9435a0
[ 3369.150162] x29: ffffffc3eb9435a0 x28: ffffff8008be4f88
[ 3369.155465] x27: ffffff8008b66c80 x26: ffffffc3eceb2600
[ 3369.160767] x25: 0000000000000001 x24: ffffff8008be4f88
[ 3369.166070] x23: ffffff8008b51c3c x22: ffffff8008b66c80
[ 3369.171371] x21: 0000000000000001 x20: ffffff8008b21b40
[ 3369.176673] x19: ffffff8008b66c80 x18: 0000000000000000
[ 3369.181975] x17: 0000007fa951a010 x16: ffffff80086a30f0
[ 3369.187278] x15: 0000007fa9505590 x14: 0000000000000000
[ 3369.192580] x13: ffffff8008b51000 x12: ffffffc3eb940000
[ 3369.197882] x11: 0000000000000006 x10: ffffff8008b51b78
[ 3369.203184] x9 : 0000000000000001 x8 : ffffff8008be4000
[ 3369.208486] x7 : ffffff8008b21b40 x6 : 0000000000001003
[ 3369.213788] x5 : 0000000000000000 x4 : ffffff8008b27280
[ 3369.219090] x3 : ffffff8008b21b4c x2 : 0000000000000001
[ 3369.224406] x1 : 0000000000000001 x0 : 0000000000000140
...
[ 3369.972257] [<ffffff80081109a8>] sync_rcu_exp_select_cpus+0x188/0x510
[ 3369.978685] [<ffffff80081128b4>] synchronize_rcu_expedited+0x64/0xa8
[ 3369.985026] [<ffffff80086b987c>] synchronize_net+0x24/0x30
[ 3369.990499] [<ffffff80086ddb54>] dev_deactivate_many+0x28c/0x298
[ 3369.996493] [<ffffff80086b6bb8>] __dev_close_many+0x60/0xd0
[ 3370.002052] [<ffffff80086b6d48>] __dev_close+0x28/0x40
[ 3370.007178] [<ffffff80086bf62c>] __dev_change_flags+0x8c/0x158
[ 3370.012999] [<ffffff80086bf718>] dev_change_flags+0x20/0x60
[ 3370.018558] [<ffffff80086cf7f0>] do_setlink+0x288/0x918
[ 3370.023771] [<ffffff80086d0798>] rtnl_newlink+0x398/0x6a8
[ 3370.029158] [<ffffff80086cee84>] rtnetlink_rcv_msg+0xe4/0x220
[ 3370.034891] [<ffffff80086e274c>] netlink_rcv_skb+0xc4/0xf8
[ 3370.040364] [<ffffff80086ced8c>] rtnetlink_rcv+0x2c/0x40
[ 3370.045663] [<ffffff80086e1fe8>] netlink_unicast+0x160/0x238
[ 3370.051309] [<ffffff80086e24b8>] netlink_sendmsg+0x2f0/0x358
[ 3370.056956] [<ffffff80086a0070>] sock_sendmsg+0x18/0x30
[ 3370.062168] [<ffffff80086a21cc>] ___sys_sendmsg+0x26c/0x280
[ 3370.067728] [<ffffff80086a30ac>] __sys_sendmsg+0x44/0x88
[ 3370.073027] [<ffffff80086a3100>] SyS_sendmsg+0x10/0x20
[ 3370.078153] [<ffffff8008085e70>] el0_svc_naked+0x24/0x28

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reported-by: Dennis Chen <dennis.chen@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Steve Capper <steve.capper@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-06-15 16:00:05 -07:00
Daniel Bristot de Oliveira 088e9d253d rcu: sysctl: Panic on RCU Stall
It is not always easy to determine the cause of an RCU stall just by
analysing the RCU stall messages, mainly when the problem is caused
by the indirect starvation of rcu threads. For example, when preempt_rcu
is not awakened due to the starvation of a timer softirq.

We have been hard coding panic() in the RCU stall functions for
some time while testing the kernel-rt. But this is not possible in
some scenarios, like when supporting customers.

This patch implements the sysctl kernel.panic_on_rcu_stall. If
set to 1, the system will panic() when an RCU stall takes place,
enabling the capture of a vmcore. The vmcore provides a way to analyze
all kernel/tasks states, helping out to point to the culprit and the
solution for the stall.

The kernel.panic_on_rcu_stall sysctl is disabled by default.

Changes from v1:
- Fixed a typo in the git log
- The if(sysctl_panic_on_rcu_stall) panic() is in a static function
- Fixed the CONFIG_TINY_RCU compilation issue
- The var sysctl_panic_on_rcu_stall is now __read_mostly

Cc: Jonathan Corbet <corbet@lwn.net>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Reviewed-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Tested-by: "Luis Claudio R. Goncalves" <lgoncalv@redhat.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-06-15 16:00:05 -07:00
Paul E. McKenney aab057382c rcu: Fix a typo in a comment
In the area in hot pursuit of a bug, so might as well clean it up.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-06-15 15:59:10 -07:00
Paul E. McKenney 4929c913bd rcu: Make call_rcu_tasks() tolerate first call with irqs disabled
Currently, if the very first call to call_rcu_tasks() has irqs disabled,
it will create the rcu_tasks_kthread with irqs disabled, which will
result in a splat in the memory allocator, which kthread_run() invokes
with the expectation that irqs are enabled.

This commit fixes this problem by deferring kthread creation if called
with irqs disabled.  The first call to call_rcu_tasks() that has irqs
enabled will create the kthread.

This bug was detected by rcutorture changes that were motivated by
Iftekhar Ahmed's mutation-testing efforts.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-06-15 15:45:00 -07:00
Nicolai Stange df4565f9eb kernel/kcov: unproxify debugfs file's fops
Since commit 49d200deaa ("debugfs: prevent access to removed files'
private data"), a debugfs file's file_operations methods get proxied
through lifetime aware wrappers.

However, only a certain subset of the file_operations members is supported
by debugfs and ->mmap isn't among them -- it appears to be NULL from the
VFS layer's perspective.

This behaviour breaks the /sys/kernel/debug/kcov file introduced
concurrently with commit 5c9a8750a6 ("kernel: add kcov code coverage").

Since that file never gets removed, there is no file removal race and thus,
a lifetime checking proxy isn't needed.

Avoid the proxying for /sys/kernel/debug/kcov by creating it via
debugfs_create_file_unsafe() rather than debugfs_create_file().

Fixes: 49d200deaa ("debugfs: prevent access to removed files' private data")
Fixes: 5c9a8750a6 ("kernel: add kcov code coverage")
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-15 04:56:35 -07:00
Borislav Petkov ca5f2b4c4f PM / sleep: Make pm_prepare_console() return void
Nothing is using its return value so change it to return void.

No functionality change.

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-06-15 01:26:04 +02:00
Wei Yongjun 05dbbfe753 rcutorture: Fix error return code in rcu_perf_init()
Fix to return a negative error code -ENOMEM from kcalloc() error
handling case instead of 0, as done elsewhere in this function.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-06-14 16:03:32 -07:00
Boqun Feng af06d4f74a rcuperf: Don't treat gp_exp mis-setting as a WARN
0day found a boot warning triggered in rcu_perf_writer() on !SMP kernel:

	WARN_ON(rcu_gp_is_normal() && gp_exp);

, the root cause of which is trying to measure expedited grace
periods(by setting gp_exp to true by default) when all the grace periods
are normal(TINY RCU only has normal grace periods).

However, such a mis-setting would only result in failing to measure the
performance for a specific kind of grace periods, therefore using a
WARN_ON to check this is a little overkilling. We could handle this
inside rcuperf module via some error messages to tell users about the
mis-settings.

Therefore this patch removes the WARN_ON in rcu_perf_writer() and
handles those checkings in rcu_perf_init() with plain if() code.

Moreover, this patch changes the default value of gp_exp to 1) align
with rcutorture tests and 2) make the default setting work for all RCU
implementations by default.

Suggested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Fixes: http://lkml.kernel.org/r/57411b10.mFvG0+AgcrMXGtcj%fengguang.wu@intel.com
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-06-14 16:03:31 -07:00
Boqun Feng 750db0f5f7 torture: Stop onoff task if there is only one cpu
If the whole system has only one cpu, that cpu won't be able to be
offlined, so there is no need onoff task is stil running.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-06-14 16:03:28 -07:00
Paul E. McKenney d95f5ba90f torture: Break online and offline functions out of torture_onoff()
This commit breaks torture_online() and torture_offline() out of
torture_onoff() in preparation for allowing waketorture finer-grained
control of its CPU-hotplug workload.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-06-14 16:02:16 -07:00
Paul E. McKenney 4e9a073f60 torture: Remove CONFIG_RCU_TORTURE_TEST_RUNNABLE, simplify code
This commit removes CONFIG_RCU_TORTURE_TEST_RUNNABLE in favor of the
already-existing rcutorture.torture_runnable kernel boot parameter.
It also converts an #ifdef into IS_ENABLED(), saving a few lines of code.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-06-14 16:02:15 -07:00
Paul E. McKenney f8cbdee99b torture: Simplify code, eliminate RCU_PERF_TEST_RUNNABLE
This commit applies the infamous IS_ENABLED() macro to eliminate a #ifdef.
It also eliminates the RCU_PERF_TEST_RUNNABLE Kconfig option in favor
of the already-existing rcuperf.perf_runnable kernel boot parameter.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-06-14 16:02:15 -07:00
Paul E. McKenney 40e0a6cfd5 rcu: Move expedited code from tree_plugin.h to tree_exp.h
People have been having some difficulty finding their way around the
RCU code.  This commit therefore pulls some of the expedited grace-period
code from tree_plugin.h to a new tree_exp.h file.  This commit is strictly
code movement.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-06-14 16:01:42 -07:00
Paul E. McKenney 3549c2bc2c rcu: Move expedited code from tree.c to tree_exp.h
People have been having some difficulty finding their way around the
RCU code.  This commit therefore pulls some of the expedited grace-period
code from tree.c to a new tree_exp.h file.  This commit is strictly code
movement, with the exception of a forward declaration that was added
for the sync_sched_exp_online_cleanup() function.

A subsequent commit will move the remaining expedited grace-period code
from tree_plugin.h to tree_exp.h.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-06-14 16:01:41 -07:00
Peter Zijlstra d3acab65f2 rcu: Remove some superfluous lines
I think you'll find this condition is superfluous, as the whole function
is under #ifdef of that same.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-06-14 16:01:41 -07:00
Paul E. McKenney 590d1757b9 rcu: Fix outdated hotplug-exclusion comment in rcu_gp_init()
In the past, RCU grace-period initialization excluded CPU-hotplug
operations, but this is no longer the case.  This commit therefore
removed an outdated comment in rcu_gp_init() claiming that these
are excluded.

Reported-by: Lihao Liang <lihao.liang@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-06-14 16:01:40 -07:00
Paul E. McKenney 0d95092ccb rcu: Fix outdated rcu_scheduler_active comment
The comment header for rcu_scheduler_active states that it is used
to optimize synchronize_sched() at early boot.  This is incorrect.
The synchronize_sched() function instead checks the number of online
CPUs.  This commit therefore replaces the comment's synchronize_sched()
with synchronize_rcu(), which really does use rcu_scheduler_active for
this purpose.

Reported-by: Lihao Liang <lihao.liang@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-06-14 16:01:39 -07:00
Kees Cook ce6526e8af seccomp: recheck the syscall after RET_TRACE
When RET_TRACE triggers, a tracer may change a syscall into something that
should be filtered by seccomp. This re-runs seccomp after a trace event
to make sure things continue to pass.

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@kernel.org>
2016-06-14 10:54:41 -07:00
Kees Cook 8112c4f140 seccomp: remove 2-phase API
Since nothing is using the 2-phase API, and it adds more complexity than
benefit, remove it.

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@kernel.org>
2016-06-14 10:54:40 -07:00
Andy Lutomirski 2f275de5d1 seccomp: Add a seccomp_data parameter secure_computing()
Currently, if arch code wants to supply seccomp_data directly to
seccomp (which is generally much faster than having seccomp do it
using the syscall_get_xyz() API), it has to use the two-phase
seccomp hooks. Add it to the easy hooks, too.

Cc: linux-arch@vger.kernel.org
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
2016-06-14 10:54:39 -07:00
Andrey Ryabinin 57675cb976 kernel/sysrq, watchdog, sched/core: Reset watchdog on all CPUs while processing sysrq-w
Lengthy output of sysrq-w may take a lot of time on slow serial console.

Currently we reset NMI-watchdog on the current CPU to avoid spurious
lockup messages. Sometimes this doesn't work since softlockup watchdog
might trigger on another CPU which is waiting for an IPI to proceed.
We reset softlockup watchdogs on all CPUs, but we do this only after
listing all tasks, and this may be too late on a busy system.

So, reset watchdogs CPUs earlier, in for_each_process_thread() loop.

Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/1465474805-14641-1-git-send-email-aryabinin@virtuozzo.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-14 12:48:38 +02:00
Josh Poimboeuf eda8dca519 sched/debug: Fix deadlock when enabling sched events
I see a hang when enabling sched events:

  echo 1 > /sys/kernel/debug/tracing/events/sched/enable

The printk buffer shows:

  BUG: spinlock recursion on CPU#1, swapper/1/0
   lock: 0xffff88007d5d8c00, .magic: dead4ead, .owner: swapper/1/0, .owner_cpu: 1
  CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.7.0-rc2+ #1
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.1-20150318_183358- 04/01/2014
  ...
  Call Trace:
   <IRQ>  [<ffffffff8143d663>] dump_stack+0x85/0xc2
   [<ffffffff81115948>] spin_dump+0x78/0xc0
   [<ffffffff81115aea>] do_raw_spin_lock+0x11a/0x150
   [<ffffffff81891471>] _raw_spin_lock+0x61/0x80
   [<ffffffff810e5466>] ? try_to_wake_up+0x256/0x4e0
   [<ffffffff810e5466>] try_to_wake_up+0x256/0x4e0
   [<ffffffff81891a0a>] ? _raw_spin_unlock_irqrestore+0x4a/0x80
   [<ffffffff810e5705>] wake_up_process+0x15/0x20
   [<ffffffff810cebb4>] insert_work+0x84/0xc0
   [<ffffffff810ced7f>] __queue_work+0x18f/0x660
   [<ffffffff810cf9a6>] queue_work_on+0x46/0x90
   [<ffffffffa00cd95b>] drm_fb_helper_dirty.isra.11+0xcb/0xe0 [drm_kms_helper]
   [<ffffffffa00cdac0>] drm_fb_helper_sys_imageblit+0x30/0x40 [drm_kms_helper]
   [<ffffffff814babcd>] soft_cursor+0x1ad/0x230
   [<ffffffff814ba379>] bit_cursor+0x649/0x680
   [<ffffffff814b9d30>] ? update_attr.isra.2+0x90/0x90
   [<ffffffff814b5e6a>] fbcon_cursor+0x14a/0x1c0
   [<ffffffff81555ef8>] hide_cursor+0x28/0x90
   [<ffffffff81558b6f>] vt_console_print+0x3bf/0x3f0
   [<ffffffff81122c63>] call_console_drivers.constprop.24+0x183/0x200
   [<ffffffff811241f4>] console_unlock+0x3d4/0x610
   [<ffffffff811247f5>] vprintk_emit+0x3c5/0x610
   [<ffffffff81124bc9>] vprintk_default+0x29/0x40
   [<ffffffff811e965b>] printk+0x57/0x73
   [<ffffffff810f7a9e>] enqueue_entity+0xc2e/0xc70
   [<ffffffff810f7b39>] enqueue_task_fair+0x59/0xab0
   [<ffffffff8106dcd9>] ? kvm_sched_clock_read+0x9/0x20
   [<ffffffff8103fb39>] ? sched_clock+0x9/0x10
   [<ffffffff810e3fcc>] activate_task+0x5c/0xa0
   [<ffffffff810e4514>] ttwu_do_activate+0x54/0xb0
   [<ffffffff810e5cea>] sched_ttwu_pending+0x7a/0xb0
   [<ffffffff810e5e51>] scheduler_ipi+0x61/0x170
   [<ffffffff81059e7f>] smp_trace_reschedule_interrupt+0x4f/0x2a0
   [<ffffffff81893ba6>] trace_reschedule_interrupt+0x96/0xa0
   <EOI>  [<ffffffff8106e0d6>] ? native_safe_halt+0x6/0x10
   [<ffffffff8110fb1d>] ? trace_hardirqs_on+0xd/0x10
   [<ffffffff81040ac0>] default_idle+0x20/0x1a0
   [<ffffffff8104147f>] arch_cpu_idle+0xf/0x20
   [<ffffffff81102f8f>] default_idle_call+0x2f/0x50
   [<ffffffff8110332e>] cpu_startup_entry+0x37e/0x450
   [<ffffffff8105af70>] start_secondary+0x160/0x1a0

Note the hang only occurs when echoing the above from a physical serial
console, not from an ssh session.

The bug is caused by a deadlock where the task is trying to grab the rq
lock twice because printk()'s aren't safe in sched code.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Fixes: cb2517653f ("sched/debug: Make schedstats a runtime tunable that is disabled by default")
Link: http://lkml.kernel.org/r/20160613073209.gdvdybiruljbkn3p@treble
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-14 12:47:21 +02:00
Peter Zijlstra be3e784498 locking/spinlock: Update spin_unlock_wait() users
With the modified semantics of spin_unlock_wait() a number of
explicit barriers can be removed. Also update the comment for the
do_exit() usecase, as that was somewhat stale/obscure.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-14 11:55:15 +02:00
Peter Zijlstra 33ac279677 locking/barriers: Introduce smp_acquire__after_ctrl_dep()
Introduce smp_acquire__after_ctrl_dep(), this construct is not
uncommon, but the lack of this barrier is.

Use it to better express smp_rmb() uses in WRITE_ONCE(), the IPC
semaphore code and the qspinlock code.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-14 11:55:14 +02:00
Peter Zijlstra 1f03e8d291 locking/barriers: Replace smp_cond_acquire() with smp_cond_load_acquire()
This new form allows using hardware assisted waiting.

Some hardware (ARM64 and x86) allow monitoring an address for changes,
so by providing a pointer we can use this to replace the cpu_relax()
with hardware optimized methods in the future.

Requested-by: Will Deacon <will.deacon@arm.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-14 11:54:27 +02:00
Ingo Molnar 245050c287 Merge branch 'linus' into locking/core, to pick up fixes before merging new changes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-14 11:17:42 +02:00
Andi Kleen 2c95afc1e8 perf/x86/intel, watchdog: Switch NMI watchdog to ref cycles on x86
The NMI watchdog uses either the fixed cycles or a generic cycles
counter. This causes a lot of conflicts with users of the PMU who want
to run a full group including the cycles fixed counter, for example
the --topdown support recently added to perf stat. The code needs to
fall back to not use groups, which can cause measurement inaccuracy
due to multiplexing errors.

This patch switches the NMI watchdog to use reference cycles
on Intel systems.  This is actually more accurate than cycles,
because cycles can tick faster than the measured CPU Frequency
due to Turbo mode.

The ref cycles always tick at their frequency, or slower when
the system is idling. That means the NMI watchdog can never
expire too early, unlike with cycles.

The reference cycles tick roughly at the frequency of the TSC,
so the same period computation can be used.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Cc: jolsa@kernel.org
Link: http://lkml.kernel.org/r/1465478079-19993-1-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-14 11:16:59 +02:00
Ingo Molnar 3559ff9650 Merge branch 'linus' into perf/core, to pick up fixes before merging new changes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-14 11:14:34 +02:00
Wanpeng Li 807e5b8068 sched/cputime: Add steal time support to full dynticks CPU time accounting
This patch adds guest steal-time support to full dynticks CPU
time accounting. After the following commit:

ff9a9b4c43 ("sched, time: Switch VIRT_CPU_ACCOUNTING_GEN to jiffy granularity")

... time sampling became jiffy based, even if we do the sampling from the
context tracking code, so steal_account_process_tick() can be reused
to account how many 'ticks' are stolen-time, after the last accumulation.

Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1465813966-3116-4-git-send-email-wanpeng.li@hotmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-14 11:13:16 +02:00
Wanpeng Li 3d89e5478b sched/cputime: Fix prev steal time accouting during CPU hotplug
Commit:

  e9532e69b8 ("sched/cputime: Fix steal time accounting vs. CPU hotplug")

... set rq->prev_* to 0 after a CPU hotplug comes back, in order to
fix the case where (after CPU hotplug) steal time is smaller than
rq->prev_steal_time.

However, this should never happen. Steal time was only smaller because of the
KVM-specific bug fixed by the previous patch.  Worse, the previous patch
triggers a bug on CPU hot-unplug/plug operation: because
rq->prev_steal_time is cleared, all of the CPU's past steal time will be
accounted again on hot-plug.

Since the root cause has been fixed, we can just revert commit e9532e69b8.

Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 'commit e9532e69b8 ("sched/cputime: Fix steal time accounting vs. CPU hotplug")'
Link: http://lkml.kernel.org/r/1465813966-3116-3-git-send-email-wanpeng.li@hotmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-14 11:13:15 +02:00
Ingo Molnar 07f9f22087 Merge branch 'sched/urgent' into sched/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-14 11:04:13 +02:00
Peter Zijlstra b7fa30c9cc sched/fair: Fix post_init_entity_util_avg() serialization
Chris Wilson reported a divide by 0 at:

 post_init_entity_util_avg():

 >    725	if (cfs_rq->avg.util_avg != 0) {
 >    726		sa->util_avg  = cfs_rq->avg.util_avg * se->load.weight;
 > -> 727		sa->util_avg /= (cfs_rq->avg.load_avg + 1);
 >    728
 >    729		if (sa->util_avg > cap)
 >    730			sa->util_avg = cap;
 >    731	} else {

Which given the lack of serialization, and the code generated from
update_cfs_rq_load_avg() is entirely possible:

	if (atomic_long_read(&cfs_rq->removed_load_avg)) {
		s64 r = atomic_long_xchg(&cfs_rq->removed_load_avg, 0);
		sa->load_avg = max_t(long, sa->load_avg - r, 0);
		sa->load_sum = max_t(s64, sa->load_sum - r * LOAD_AVG_MAX, 0);
		removed_load = 1;
	}

turns into:

  ffffffff81087064:       49 8b 85 98 00 00 00    mov    0x98(%r13),%rax
  ffffffff8108706b:       48 85 c0                test   %rax,%rax
  ffffffff8108706e:       74 40                   je     ffffffff810870b0
  ffffffff81087070:       4c 89 f8                mov    %r15,%rax
  ffffffff81087073:       49 87 85 98 00 00 00    xchg   %rax,0x98(%r13)
  ffffffff8108707a:       49 29 45 70             sub    %rax,0x70(%r13)
  ffffffff8108707e:       4c 89 f9                mov    %r15,%rcx
  ffffffff81087081:       bb 01 00 00 00          mov    $0x1,%ebx
  ffffffff81087086:       49 83 7d 70 00          cmpq   $0x0,0x70(%r13)
  ffffffff8108708b:       49 0f 49 4d 70          cmovns 0x70(%r13),%rcx

Which you'll note ends up with 'sa->load_avg - r' in memory at
ffffffff8108707a.

By calling post_init_entity_util_avg() under rq->lock we're sure to be
fully serialized against PELT updates and cannot observe intermediate
state like this.

Reported-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
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: Yuyang Du <yuyang.du@intel.com>
Cc: bsegall@google.com
Cc: morten.rasmussen@arm.com
Cc: pjt@google.com
Cc: steve.muckle@linaro.org
Fixes: 2b8c41daba ("sched/fair: Initiate a new task's util avg to a bounded value")
Link: http://lkml.kernel.org/r/20160609130750.GQ30909@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-14 10:58:34 +02:00
James Morse 6783091177 PM / Hibernate: Don't let kasan instrument snapshot.c
Kasan causes the compiler to instrument C code and is used at runtime to
detect accesses to memory that has been freed, or not yet allocated.

The code in snapshot.c saves and restores memory when hibernating. This will
access whole pages in the slab cache that have both free and allocated
areas, resulting in a large number of false positives from Kasan.

Disable instrumentation of this file.

Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-06-14 00:38:56 +02:00
Rafael J. Wysocki bb4b9933e2 Merge back earlier cpufreq changes for v4.8. 2016-06-13 23:33:17 +02:00
Thomas Gleixner a5c8a01968 First drop of irqchip updates for 4.8:
- Fix a few bugs in configuring the default trigger from the irqdomain layer
 - Make the genirq layer PM aware
 - Add PM capability to the ARM GIC driver
 - Add support for 2-level translation tables to the GICv3 ITS driver
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Merge tag 'irqchip-for-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core

First drop of irqchip updates for 4.8 from Marc Zyngier:

 - Fix a few bugs in configuring the default trigger from the irqdomain layer
 - Make the genirq layer PM aware
 - Add PM capability to the ARM GIC driver
 - Add support for 2-level translation tables to the GICv3 ITS driver
2016-06-13 16:34:16 +02:00
Jon Hunter be45beb2df genirq: Add runtime power management support for IRQ chips
Some IRQ chips may be located in a power domain outside of the CPU
subsystem and hence will require device specific runtime power
management. In order to support such IRQ chips, add a pointer for a
device structure to the irq_chip structure, and if this pointer is
populated by the IRQ chip driver and CONFIG_PM is selected in the kernel
configuration, then the pm_runtime_get/put APIs for this chip will be
called when an IRQ is requested/freed, respectively.

Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-06-13 11:53:51 +01:00
Jon Hunter 1e2a7d7849 irqdomain: Don't set type when mapping an IRQ
Some IRQ chips, such as GPIO controllers or secondary level interrupt
controllers, may require require additional runtime power management
control to ensure they are accessible. For such IRQ chips, it makes sense
to enable the IRQ chip when interrupts are requested and disabled them
again once all interrupts have been freed.

When mapping an IRQ, the IRQ type settings are read and then programmed.
The mapping of the IRQ happens before the IRQ is requested and so the
programming of the type settings occurs before the IRQ is requested. This
is a problem for IRQ chips that require additional power management
control because they may not be accessible yet. Therefore, when mapping
the IRQ, don't program the type settings, just save them and then program
these saved settings when the IRQ is requested (so long as if they are not
overridden via the call to request the IRQ).

Add a stub function for irq_domain_free_irqs() to avoid any compilation
errors when CONFIG_IRQ_DOMAIN_HIERARCHY is not selected.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-06-13 11:53:51 +01:00
Marc Zyngier f35ad08378 genirq: Look-up percpu trigger type if not specified by caller
As we now do for non-percpu interrupt, perform a lookup of the
interrupt trigger if the user doesn't supply one. The difference
here is that we can only do it at enable time (trigger configuration
can be per-cpu as well).

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-06-13 11:53:51 +01:00
Jon Hunter 4b357daed6 genirq: Look-up trigger type if not specified by caller
For some devices the IRQ trigger type for a device is read from
firmware, such as device-tree. The IRQ trigger type is typically read
when the mapping for IRQ is created, which is before the IRQ is
requested. Hence, the IRQ trigger type is programmed when mapping the
IRQ and not when requesting the IRQ.

Although this works for most cases, in order to support IRQ chips which
require runtime power management, which may not be accessible prior
to requesting the IRQ, it is desirable to look-up the IRQ trigger type
when it is requested. Therefore, if the IRQ trigger type is not
specified when __setup_irq() is called, look-up the saved IRQ trigger
type. This will allow us to defer the programming of the trigger type
from when the IRQ is mapped to when it is actually requested.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-06-13 11:53:51 +01:00
Jon Hunter b62b2cf575 irqdomain: Fix handling of type settings for existing mappings
When mapping an IRQ, it is possible that a mapping for the IRQ already
exists. If mapping does exist then there are the following issues with
regard to the handling of the IRQ type settings ...
1. If the domain is part of a hierarchy, then:
   a. We do not check that the type settings for the existing mapping
      match those of the new mapping.
   b. We do not check to see if the type settings have been programmed
      yet (and they might not have been) and so we may never set the
      type.
2. If the domain is NOT part of a hierarchy, we will overwrite the
   current type settings programmed if they are different from the
   previous mapping. Please note that irq_create_mapping()
   calls irq_find_mapping() to check if a mapping already exists.

Although, it may be unlikely that the type settings for a shared
interrupt would not match, nonetheless we should check for this.
Therefore, to fix this check if a mapping exists (regardless of whether
the domain is part of a hierarchy or not) and if it does then:
1. Return the IRQ number if the type settings match or are not
   specified.
2. Program the type settings and return the IRQ number if the type
   settings have not been programmed yet.
3. Otherwise if the type setting do not match, then print a warning
   and don't return the IRQ number.

Furthermore, add a warning if the type return by irq_domain_translate()
has bits outside the sense mask set and then clear these bits. If these
bits are not cleared then this will cause the comparision of the type
settings for an existing mapping to fail with that of the new mapping
even if the sense bit themselves match. The reason being is that the
existing type settings are read by calling irq_get_trigger_type() which
will clear any bits outside the sense mask. This will allow us to detect
irqchips that are not correctly clearing these bits and fix them.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-06-13 11:53:50 +01:00
Linus Torvalds f5364c150a Merge branch 'stacking-fixes' (vfs stacking fixes from Jann)
Merge filesystem stacking fixes from Jann Horn.

* emailed patches from Jann Horn <jannh@google.com>:
  sched: panic on corrupted stack end
  ecryptfs: forbid opening files without mmap handler
  proc: prevent stacking filesystems on top
2016-06-10 12:10:02 -07:00
Jann Horn 29d6455178 sched: panic on corrupted stack end
Until now, hitting this BUG_ON caused a recursive oops (because oops
handling involves do_exit(), which calls into the scheduler, which in
turn raises an oops), which caused stuff below the stack to be
overwritten until a panic happened (e.g.  via an oops in interrupt
context, caused by the overwritten CPU index in the thread_info).

Just panic directly.

Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-06-10 12:09:43 -07:00
Linus Torvalds 60e383037b Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar:
 "Two scheduler debugging fixes"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/debug: Fix 'schedstats=enable' cmdline option
  sched/debug: Fix /proc/sched_debug regression
2016-06-10 11:24:39 -07:00
Linus Torvalds 7fcbc230c6 Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar:
 "A handful of tooling fixes, two PMU driver fixes and a cleanup of
  redundant code that addresses a security analyzer false positive"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Remove a redundant check
  perf/x86/intel/uncore: Remove SBOX support for Broadwell server
  perf ctf: Convert invalid chars in a string before set value
  perf record: Fix crash when kptr is restricted
  perf symbols: Check kptr_restrict for root
  perf/x86/intel/rapl: Fix pmus free during cleanup
2016-06-10 11:15:41 -07:00
Linus Torvalds 02b07bde61 Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixes from Ingo Molnar:
 "Misc fixes:

   - a file-based futex fix
   - one more spin_unlock_wait() fix
   - a ww-mutex deadlock detection improvement/fix
   - and a raw_read_seqcount_latch() barrier fix"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  futex: Calculate the futex key based on a tail page for file-based futexes
  locking/qspinlock: Fix spin_unlock_wait() some more
  locking/ww_mutex: Report recursive ww_mutex locking early
  locking/seqcount: Re-fix raw_read_seqcount_latch()
2016-06-10 10:53:46 -07:00
Linus Torvalds 698ea54dde Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:

 1) nfnetlink timestamp taken from wrong skb, fix from Florian Westphal.

 2) Revert some msleep conversions in rtlwifi as these spots are in
    atomic context, from Larry Finger.

 3) Validate that NFTA_SET_TABLE attribute is actually specified when we
    call nf_tables_getset().  From Phil Turnbull.

 4) Don't do mdio_reset in stmmac driver with spinlock held as that can
    sleep, from Vincent Palatin.

 5) sk_filter() does things other than run a BPF filter, so we should
    not elide it's call just because sk->sk_filter is NULL.  Fix from
    Eric Dumazet.

 6) Fix missing backlog updates in several packet schedulers, from Cong
    Wang.

 7) bnx2x driver should allow VLAN add/remove while the interface is
    down, from Michal Schmidt.

 8) Several RDS/TCP race fixes from Sowmini Varadhan.

 9) fq_codel scheduler doesn't return correct queue length in dumps,
    from Eric Dumazet.

10) Fix TCP stats for tail loss probe and early retransmit in ipv6, from
    Yuchung Cheng.

11) Properly initialize udp_tunnel_socket_cfg in l2tp_tunnel_create(),
    from Guillaume Nault.

12) qfq scheduler leaks SKBs if a kzalloc fails, fix from Florian
    Westphal.

13) sock_fprog passed into PACKET_FANOUT_DATA needs compat handling,
    from Willem de Bruijn.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (85 commits)
  vmxnet3: segCnt can be 1 for LRO packets
  packet: compat support for sock_fprog
  stmmac: fix parameter to dwmac4_set_umac_addr()
  net/mlx5e: Fix blue flame quota logic
  net/mlx5e: Use ndo_stop explicitly at shutdown flow
  net/mlx5: E-Switch, always set mc_promisc for allmulti vports
  net/mlx5: E-Switch, Modify node guid on vf set MAC
  net/mlx5: E-Switch, Fix vport enable flow
  net/mlx5: E-Switch, Use the correct error check on returned pointers
  net/mlx5: E-Switch, Use the correct free() function
  net/mlx5: Fix E-Switch flow steering capabilities check
  net/mlx5: Fix flow steering NIC capabilities check
  net/mlx5: Fix root flow table update
  net/mlx5: Fix MLX5_CMD_OP_MAX to be defined correctly
  net/mlx5: Fix masking of reserved bits in XRCD number
  net/mlx5: Fix the size of modify QP mailbox
  mlxsw: spectrum: Don't sleep during ndo_get_phys_port_name()
  mlxsw: spectrum: Make split flow match firmware requirements
  wext: Fix 32 bit iwpriv compatibility issue with 64 bit Kernel
  cfg80211: remove get/set antenna and tx power warnings
  ...
2016-06-10 08:32:24 -07:00
Linus Torvalds 524a3f2ca2 Power management fixes for v4.7-rc3
- Fix two intel_pstate initialization issues, one of which was
    introduced during the 4.4 cycle (Srinivas Pandruvada).
 
  - Fix kernel build with CONFIG_UBSAN set and CONFIG_CPU_IDLE
    unset (Catalin Marinas).
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Merge tag 'pm-4.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fixes from Rafael Wysocki:
 "Stable-candidate fixes for the intel_pstate driver and the cpuidle
  core.

  Specifics:

   - Fix two intel_pstate initialization issues, one of which was
     introduced during the 4.4 cycle (Srinivas Pandruvada)

   - Fix kernel build with CONFIG_UBSAN set and CONFIG_CPU_IDLE unset
     (Catalin Marinas)"

* tag 'pm-4.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: intel_pstate: Fix ->set_policy() interface for no_turbo
  cpufreq: intel_pstate: Fix code ordering in intel_pstate_set_policy()
  cpuidle: Do not access cpuidle_devices when !CONFIG_CPU_IDLE
2016-06-10 08:09:12 -07:00
Weongyo Jeong ff5b706f51 genirq: Remove unnecessary memset() calls
sprintf() and snprintf() implementation of kernel guarantees that
its result is terminated with null byte if size is larger than 0. So we
don't need to call memset() at all.

Signed-off-by: Weongyo Jeong <weongyo.linux@gmail.com>
Link: http://lkml.kernel.org/r/1459451703-5744-1-git-send-email-weongyo.linux@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-06-10 17:07:50 +02:00
Jianyu Zhan fe3464ca87 genirq: Remove redundant NULL check of irq_desc
for_each_irq_desc() macro has already skipped NULL irq_desc, don't
bother to check it again.

Signed-off-by: Jianyu Zhan <nasa4836@gmail.com>
Cc: mingo@kernel.org
Cc: yhlu.kernel@gmail.com
Link: http://lkml.kernel.org/r/1458395959-7046-1-git-send-email-nasa4836@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-06-10 17:07:49 +02:00
Pratyush Patel 86721ab63b hrtimer: Remove redundant #ifdef block
Only need CONFIG_NO_HZ_COMMON as this block is already in a
CONFIG_SMP block.

Signed-off-by: Pratyush Patel <pratyushpatel.1995@gmail.com>
Link: http://lkml.kernel.org/r/20160301172849.GA18152@cyborg
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-06-10 11:25:35 +02:00
Bjorn Helgaas b5227d03b7 timers: Clarify usleep_range() function comment
Update the usleep_range() function comment to make it clear that it can
only be used in non-atomic context.

Previously we claimed usleep_range() was a drop-in replacement for udelay()
where wakeup is flexible.  But that's only true in non-atomic contexts,
where it's possible to sleep instead of delay.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20160531212302.28502.44995.stgit@bhelgaas-glaptop2.roam.corp.google.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-06-10 00:59:14 +02:00
Rafael J. Wysocki 3681196ae5 Merge branches 'pm-cpufreq-fixes' and 'pm-cpuidle'
* pm-cpufreq-fixes:
  cpufreq: intel_pstate: Fix ->set_policy() interface for no_turbo
  cpufreq: intel_pstate: Fix code ordering in intel_pstate_set_policy()

* pm-cpuidle:
  cpuidle: Do not access cpuidle_devices when !CONFIG_CPU_IDLE
2016-06-09 23:49:16 +02:00
Zhouyi Zhou ba62bafe94 kernel/relay.c: fix potential memory leak
When relay_open_buf() fails in relay_open(), code will goto free_bufs,
but chan is nowhere freed.

Link: http://lkml.kernel.org/r/1464777927-19675-1-git-send-email-yizhouzhou@ict.ac.cn
Signed-off-by: Zhouyi Zhou <zhouzhouyi@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
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>
2016-06-09 14:23:11 -07:00
Christoph Hellwig 288dab8a35 block: add a separate operation type for secure erase
Instead of overloading the discard support with the REQ_SECURE flag.
Use the opportunity to rename the queue flag as well, and remove the
dead checks for this flag in the RAID 1 and RAID 10 drivers that don't
claim support for secure erase.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-09 09:52:25 -06:00
Mel Gorman 077fa7aed1 futex: Calculate the futex key based on a tail page for file-based futexes
Mike Galbraith reported that the LTP test case futex_wake04 was broken
by commit 65d8fc777f ("futex: Remove requirement for lock_page()
in get_futex_key()").

This test case uses futexes backed by hugetlbfs pages and so there is an
associated inode with a futex stored on such pages. The problem is that
the key is being calculated based on the head page index of the hugetlbfs
page and not the tail page.

Prior to the optimisation, the page lock was used to stabilise mappings and
pin the inode is file-backed which is overkill. If the page was a compound
page, the head page was automatically looked up as part of the page lock
operation but the tail page index was used to calculate the futex key.

After the optimisation, the compound head is looked up early and the page
lock is only relied upon to identify truncated pages, special pages or a
shmem page moving to swapcache. The head page is looked up because without
the page lock, special care has to be taken to pin the inode correctly.
However, the tail page is still required to calculate the futex key so
this patch records the tail page.

On vanilla 4.6, the output of the test case is;

futex_wake04    0  TINFO  :  Hugepagesize 2097152
futex_wake04    1  TFAIL  :  futex_wake04.c:126: Bug: wait_thread2 did not wake after 30 secs.

With the patch applied

futex_wake04    0  TINFO  :  Hugepagesize 2097152
futex_wake04    1  TPASS  :  Hi hydra, thread2 awake!

Fixes: 65d8fc777f "futex: Remove requirement for lock_page() in get_futex_key()"
Reported-and-tested-by: Mike Galbraith <umgwanakikbuti@gmail.com>
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20160608132522.GM2469@suse.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-06-08 19:23:54 +02:00
Peter Zijlstra 6428671bae locking/mutex: Optimize mutex_trylock() fast-path
A while back Viro posted a number of 'interesting' mutex_is_locked()
users on IRC, one of those was RCU.

RCU seems to use mutex_is_locked() to avoid doing mutex_trylock(), the
regular load before modify pattern.

While the use isn't wrong per se, its curious in that its needed at all,
mutex_trylock() should be good enough on its own to avoid the pointless
cacheline bounces.

So fix those and remove the mutex_is_locked() (ab)use from RCU.

Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Paul McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <Waiman.Long@hpe.com>
Link: http://lkml.kernel.org/r/20160601185815.GW3190@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-08 15:17:01 +02:00
Waiman Long ddd0fa73c2 locking/rwsem: Streamline the rwsem_optimistic_spin() code
This patch moves the owner loading and checking code entirely inside of
rwsem_spin_on_owner() to simplify the logic of rwsem_optimistic_spin()
loop.

Suggested-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Waiman Long <Waiman.Long@hpe.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Douglas Hatch <doug.hatch@hpe.com>
Cc: Jason Low <jason.low2@hp.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott J Norton <scott.norton@hpe.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1463534783-38814-6-git-send-email-Waiman.Long@hpe.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-08 15:17:00 +02:00
Waiman Long bf7b4c472d locking/rwsem: Improve reader wakeup code
In __rwsem_do_wake(), the reader wakeup code will assume a writer
has stolen the lock if the active reader/writer count is not 0.
However, this is not as reliable an indicator as the original
"< RWSEM_WAITING_BIAS" check. If another reader is present, the code
will still break out and exit even if the writer is gone. This patch
changes it to check the same "< RWSEM_WAITING_BIAS" condition to
reduce the chance of false positive.

Signed-off-by: Waiman Long <Waiman.Long@hpe.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Douglas Hatch <doug.hatch@hpe.com>
Cc: Jason Low <jason.low2@hp.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott J Norton <scott.norton@hpe.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1463534783-38814-5-git-send-email-Waiman.Long@hpe.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-08 15:17:00 +02:00
Waiman Long fb6a44f33b locking/rwsem: Protect all writes to owner by WRITE_ONCE()
Without using WRITE_ONCE(), the compiler can potentially break a
write into multiple smaller ones (store tearing). So a read from the
same data by another task concurrently may return a partial result.
This can result in a kernel crash if the data is a memory address
that is being dereferenced.

This patch changes all write to rwsem->owner to use WRITE_ONCE()
to make sure that store tearing will not happen. READ_ONCE() may
not be needed for rwsem->owner as long as the value is only used for
comparison and not dereferencing.

Signed-off-by: Waiman Long <Waiman.Long@hpe.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Douglas Hatch <doug.hatch@hpe.com>
Cc: Jason Low <jason.low2@hp.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott J Norton <scott.norton@hpe.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1463534783-38814-3-git-send-email-Waiman.Long@hpe.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-08 15:16:59 +02:00
Waiman Long 19c5d690e4 locking/rwsem: Add reader-owned state to the owner field
Currently, it is not possible to determine for sure if a reader
owns a rwsem by looking at the content of the rwsem data structure.
This patch adds a new state RWSEM_READER_OWNED to the owner field
to indicate that readers currently own the lock. This enables us to
address the following 2 issues in the rwsem optimistic spinning code:

 1) rwsem_can_spin_on_owner() will disallow optimistic spinning if
    the owner field is NULL which can mean either the readers own
    the lock or the owning writer hasn't set the owner field yet.
    In the latter case, we miss the chance to do optimistic spinning.

 2) While a writer is waiting in the OSQ and a reader takes the lock,
    the writer will continue to spin when out of the OSQ in the main
    rwsem_optimistic_spin() loop as the owner field is NULL wasting
    CPU cycles if some of readers are sleeping.

Adding the new state will allow optimistic spinning to go forward as
long as the owner field is not RWSEM_READER_OWNED and the owner is
running, if set, but stop immediately when that state has been reached.

On a 4-socket Haswell machine running on a 4.6-rc1 based kernel, the
fio test with multithreaded randrw and randwrite tests on the same
file on a XFS partition on top of a NVDIMM were run, the aggregated
bandwidths before and after the patch were as follows:

  Test      BW before patch     BW after patch  % change
  ----      ---------------     --------------  --------
  randrw         988 MB/s          1192 MB/s      +21%
  randwrite     1513 MB/s          1623 MB/s      +7.3%

The perf profile of the rwsem_down_write_failed() function in randrw
before and after the patch were:

   19.95%  5.88%  fio  [kernel.vmlinux]  [k] rwsem_down_write_failed
   14.20%  1.52%  fio  [kernel.vmlinux]  [k] rwsem_down_write_failed

The actual CPU cycles spend in rwsem_down_write_failed() dropped from
5.88% to 1.52% after the patch.

The xfstests was also run and no regression was observed.

Signed-off-by: Waiman Long <Waiman.Long@hpe.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Jason Low <jason.low2@hp.com>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Douglas Hatch <doug.hatch@hpe.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott J Norton <scott.norton@hpe.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1463534783-38814-2-git-send-email-Waiman.Long@hpe.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-08 15:16:59 +02:00
Jason Low 8ee62b1870 locking/rwsem: Convert sem->count to 'atomic_long_t'
Convert the rwsem count variable to an atomic_long_t since we use it
as an atomic variable. This also allows us to remove the
rwsem_atomic_{add,update}() "abstraction" which would now be an unnecesary
level of indirection. In follow up patches, we also remove the
rwsem_atomic_{add,update}() definitions across the various architectures.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Jason Low <jason.low2@hpe.com>
[ Build warning fixes on various architectures. ]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jason Low <jason.low2@hp.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Terry Rudd <terry.rudd@hpe.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Waiman Long <Waiman.Long@hpe.com>
Link: http://lkml.kernel.org/r/1465017963-4839-2-git-send-email-jason.low2@hpe.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-08 15:16:42 +02:00
Peter Zijlstra 055ce0fd1b locking/qspinlock: Add comments
I figured we need to document the spin_is_locked() and
spin_unlock_wait() constraints somwehere.

Ideally 'someone' would rewrite Documentation/atomic_ops.txt and we
could find a place in there. But currently that document is stale to
the point of hardly being useful.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <waiman.long@hpe.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-08 14:44:01 +02:00
Peter Zijlstra 8d53fa1904 locking/qspinlock: Clarify xchg_tail() ordering
While going over the code I noticed that xchg_tail() is a RELEASE but
had no obvious pairing commented.

It pairs with a somewhat unique address dependency through
decode_tail().

So the store-release of xchg_tail() is paired by the address
dependency of the load of xchg_tail followed by the dereference from
the pointer computed from that load.

The @old -> @prev transformation itself is pure, and therefore does
not depend on external state, so that is immaterial wrt. ordering.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <waiman.long@hpe.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-08 14:44:00 +02:00
Ingo Molnar ae0b5c2f03 Merge branch 'locking/urgent' into locking/core, to pick up dependency
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-08 14:35:29 +02:00
Josh Poimboeuf 03c041c5bf sched/debug: Always show 'nr_migrations'
The nr_migrations field is updated independently of CONFIG_SCHEDSTATS,
so it can be displayed regardless.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/5b1b04057ae2b14d73c2d03f56582c1d38cfe066.1464994423.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-08 14:34:49 +02:00
Ingo Molnar 067b4f9342 Merge branch 'sched/urgent' into sched/core, to pick up dependency
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-08 14:33:28 +02:00
Josh Poimboeuf 4698f88c06 sched/debug: Fix 'schedstats=enable' cmdline option
The 'schedstats=enable' option doesn't work, and also produces the
following warning during boot:

  WARNING: CPU: 0 PID: 0 at /home/jpoimboe/git/linux/kernel/jump_label.c:61 static_key_slow_inc+0x8c/0xa0
  static_key_slow_inc used before call to jump_label_init
  Modules linked in:
  CPU: 0 PID: 0 Comm: swapper Not tainted 4.7.0-rc1+ #25
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.1-20150318_183358- 04/01/2014
   0000000000000086 3ae3475a4bea95d4 ffffffff81e03da8 ffffffff8143fc83
   ffffffff81e03df8 0000000000000000 ffffffff81e03de8 ffffffff810b1ffb
   0000003d00000096 ffffffff823514d0 ffff88007ff197c8 0000000000000000
  Call Trace:
   [<ffffffff8143fc83>] dump_stack+0x85/0xc2
   [<ffffffff810b1ffb>] __warn+0xcb/0xf0
   [<ffffffff810b207f>] warn_slowpath_fmt+0x5f/0x80
   [<ffffffff811e9c0c>] static_key_slow_inc+0x8c/0xa0
   [<ffffffff810e07c6>] static_key_enable+0x16/0x40
   [<ffffffff8216d633>] setup_schedstats+0x29/0x94
   [<ffffffff82148a05>] unknown_bootoption+0x89/0x191
   [<ffffffff810d8617>] parse_args+0x297/0x4b0
   [<ffffffff82148d61>] start_kernel+0x1d8/0x4a9
   [<ffffffff8214897c>] ? set_init_arg+0x55/0x55
   [<ffffffff82148120>] ? early_idt_handler_array+0x120/0x120
   [<ffffffff821482db>] x86_64_start_reservations+0x2f/0x31
   [<ffffffff82148427>] x86_64_start_kernel+0x14a/0x16d

The problem is that it tries to update the 'sched_schedstats' static key
before jump labels have been initialized.

Changing jump_label_init() to be called earlier before
parse_early_param() wouldn't fix it: it would still fail trying to
poke_text() because mm isn't yet initialized.

Instead, just create a temporary '__sched_schedstats' variable which can
be copied to the static key later during sched_init() after jump labels
have been initialized.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: cb2517653f ("sched/debug: Make schedstats a runtime tunable that is disabled by default")
Link: http://lkml.kernel.org/r/453775fe3433bed65731a583e228ccea806d18cd.1465322027.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-08 14:33:05 +02:00
Josh Poimboeuf 9c57259117 sched/debug: Fix /proc/sched_debug regression
Commit:

  cb2517653f ("sched/debug: Make schedstats a runtime tunable that is disabled by default")

... introduced a bug when CONFIG_SCHEDSTATS is enabled and the
runtime tunable is disabled (which is the default).

The wait-time, sum-exec, and sum-sleep fields are missing from the
/proc/sched_debug file in the runnable_tasks section.

Fix it with a new schedstat_val() macro which returns the field value
when schedstats is enabled and zero otherwise.  The macro works with
both SCHEDSTATS and !SCHEDSTATS.  I put the macro in stats.h since it
might end up being useful in other places.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: cb2517653f ("sched/debug: Make schedstats a runtime tunable that is disabled by default")
Link: http://lkml.kernel.org/r/bcda7c2790cf2ccbe586a28c02dd7b6fe7749a2b.1464994423.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-08 14:31:58 +02:00
Alexander Shishkin 62a92c8f55 perf/core: Remove a redundant check
There is no way to end up in _free_event() with event::pmu being NULL.
The latter is initialized in event allocation path and remains set
forever. In case of allocation failure, the error path doesn't use
_free_event().

Having the check, however, suggests that it is possible to have a
event::pmu==NULL situation in _free_event() and confuses the robots.

This patch gets rid of the check.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: eranian@google.com
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/1465303455-26032-1-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-08 14:30:01 +02:00
Peter Zijlstra 2c61002271 locking/qspinlock: Fix spin_unlock_wait() some more
While this prior commit:

  54cf809b95 ("locking,qspinlock: Fix spin_is_locked() and spin_unlock_wait()")

... fixes spin_is_locked() and spin_unlock_wait() for the usage
in ipc/sem and netfilter, it does not in fact work right for the
usage in task_work and futex.

So while the 2 locks crossed problem:

	spin_lock(A)		spin_lock(B)
	if (!spin_is_locked(B)) spin_unlock_wait(A)
	  foo()			foo();

... works with the smp_mb() injected by both spin_is_locked() and
spin_unlock_wait(), this is not sufficient for:

	flag = 1;
	smp_mb();		spin_lock()
	spin_unlock_wait()	if (!flag)
				  // add to lockless list
	// iterate lockless list

... because in this scenario, the store from spin_lock() can be delayed
past the load of flag, uncrossing the variables and loosing the
guarantee.

This patch reworks spin_is_locked() and spin_unlock_wait() to work in
both cases by exploiting the observation that while the lock byte
store can be delayed, the contender must have registered itself
visibly in other state contained in the word.

It also allows for architectures to override both functions, as PPC
and ARM64 have an additional issue for which we currently have no
generic solution.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Giovanni Gherdovich <ggherdovich@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <waiman.long@hpe.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: stable@vger.kernel.org # v4.2 and later
Fixes: 54cf809b95 ("locking,qspinlock: Fix spin_is_locked() and spin_unlock_wait()")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-08 14:29:08 +02:00
Sebastian Andrzej Siewior a461d58792 locking/rtmutex: Only warn once on a trylock from bad context
One warning should be enough to get one motivated to fix this. It is
possible that this happens more than once and that starts flooding the
output. Later the prints will be suppressed so we only get half of it.
Depending on the console system used it might not be helpful.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1464356838-1755-1-git-send-email-bigeasy@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-08 14:22:00 +02:00
Peter Zijlstra dfaaf3fa01 locking/lockdep: Use __jhash_mix() for iterate_chain_key()
Use __jhash_mix() to mix the class_idx into the class_key. This
function provides better mixing than the previously used, home grown
mix function.

Leave hashing to the professionals :-)

Suggested-by: George Spelvin <linux@sciencehorizons.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-08 14:22:00 +02:00
Ingo Molnar 616d1c1b98 Merge branch 'linus' into perf/core, to refresh the branch
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-08 09:26:46 +02:00
David Carrillo-Cisneros a4f144ebbd perf/core: Fix crash due to account/unaccount_sb_event() inconsistency
unaccount_pmu_sb_event() did not check for attributes in event->attr
before calling detach_sb_event(), while account_pmu_event() did.

This caused NULL pointer reference in cgroup events that did not
have any of the attributes checked by account_pmu_event().

To trigger the bug just wait for a cgroup event to terminate, e.g.:

  $ mkdir /dev/cgroup/devices/test
  $ perf stat -e cycles -a -G test sleep 0

... see crash ...

Signed-off-by: David Carrillo-Cisneros <davidcc@google.com>
Reviewed-by: Stephane Eranian <eranian@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Zheng <zheng.z.yan@intel.com>
Link: http://lkml.kernel.org/r/1464809585-66072-1-git-send-email-davidcc@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-08 09:18:45 +02:00
Daniel Borkmann 5b6c1b4d46 bpf, trace: use READ_ONCE for retrieving file ptr
In bpf_perf_event_read() and bpf_perf_event_output(), we must use
READ_ONCE() for fetching the struct file pointer, which could get
updated concurrently, so we must prevent the compiler from potential
refetching.

We already do this with tail calls for fetching the related bpf_prog,
but not so on stored perf events. Semantics for both are the same
with regards to updates.

Fixes: a43eec3042 ("bpf: introduce bpf_perf_event_output() helper")
Fixes: 35578d7984 ("bpf: Implement function bpf_perf_event_read() that get the selected hardware PMU conuter")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-07 14:48:03 -07:00
Mike Christie 28a8f0d317 block, drivers, fs: rename REQ_FLUSH to REQ_PREFLUSH
To avoid confusion between REQ_OP_FLUSH, which is handled by
request_fn drivers, and upper layers requesting the block layer
perform a flush sequence along with possibly a WRITE, this patch
renames REQ_FLUSH to REQ_PREFLUSH.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07 13:41:38 -06:00
Mike Christie 3a5e02ced1 block, drivers: add REQ_OP_FLUSH operation
This adds a REQ_OP_FLUSH operation that is sent to request_fn
based drivers by the block layer's flush code, instead of
sending requests with the request->cmd_flags REQ_FLUSH bit set.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07 13:41:38 -06:00
Mike Christie 1b9a9ab78b blktrace: use op accessors
Have blktrace use the req/bio op accessor to get the REQ_OP.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07 13:41:38 -06:00
Mike Christie 162b99e311 pm: use bio op accessors
Separate the op from the rq_flag_bits and have the pm code
set/get the bio using bio_set_op_attrs/bio_op.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07 13:41:38 -06:00
Mike Christie 4e49ea4a3d block/fs/drivers: remove rw argument from submit_bio
This has callers of submit_bio/submit_bio_wait set the bio->bi_rw
instead of passing it in. This makes that use the same as
generic_make_request and how we set the other bio fields.

Signed-off-by: Mike Christie <mchristi@redhat.com>

Fixed up fs/ext4/crypto.c

Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07 13:41:38 -06:00
Tyler Hicks 98f368e9e2 kernel: Add noaudit variant of ns_capable()
When checking the current cred for a capability in a specific user
namespace, it isn't always desirable to have the LSMs audit the check.
This patch adds a noaudit variant of ns_capable() for when those
situations arise.

The common logic between ns_capable() and the new ns_capable_noaudit()
is moved into a single, shared function to keep duplicated code to a
minimum and ease maintainability.

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2016-06-06 20:16:18 +10:00
Linus Torvalds 8c52b6dcdd Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fixes from Thomas Gleixner:
 - a few simple fixes for fallout from the recent gic-v3 changes
 - a workaround for a Cavium thunderX erratum
 - a bugfix for the pic32 irqchip to make external interrupts work proper
 - a missing return value in the generic IPI management code

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/irq-pic32-evic: Fix bug with external interrupts.
  irqchip/gicv3-its: numa: Enable workaround for Cavium thunderx erratum 23144
  irqchip/gic-v3: Fix quiescence check in gic_enable_redist
  irqchip/gic-v3: Fix copy+paste mistakes in defines
  irqchip/gic-v3: Fix ICC_SGI1R_EL1.INTID decoding mask
  genirq: Fix missing return value in irq_destroy_ipi()
2016-06-03 16:12:35 -07:00
Thomas Gleixner 2eec3707a3 irqchip updates for 4.7-rc1:
- A number of embarassing buglets (GICv3, PIC32)
 - A more substential errata workaround for Cavium's GICv3 ITS
   (kept for post-rc1 due to its dependency on NUMA)
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Merge tag 'irqchip-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/urgent

Merge irqchip updates from Marc Zyngier:

- A number of embarassing buglets (GICv3, PIC32)
- A more substential errata workaround for Cavium's GICv3 ITS
  (kept for post-rc1 due to its dependency on NUMA)
2016-06-03 15:05:51 +02:00
Jason Low 6e2814745c locking/mutex: Set and clear owner using WRITE_ONCE()
The mutex owner can get read and written to locklessly.
Use WRITE_ONCE when setting and clearing the owner field
in order to avoid optimizations such as store tearing. This
avoids situations where the owner field gets written to with
multiple stores and another thread could concurrently read
and use a partially written owner value.

Signed-off-by: Jason Low <jason.low2@hpe.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Acked-by: Waiman Long <Waiman.Long@hpe.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott J Norton <scott.norton@hpe.com>
Cc: Terry Rudd <terry.rudd@hpe.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1463782776.2479.9.camel@j-VirtualBox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-03 12:06:10 +02:00
Jason Low c0fcb6c2d3 locking/rwsem: Optimize write lock by reducing operations in slowpath
When acquiring the rwsem write lock in the slowpath, we first try
to set count to RWSEM_WAITING_BIAS. When that is successful,
we then atomically add the RWSEM_WAITING_BIAS in cases where
there are other tasks on the wait list. This causes write lock
operations to often issue multiple atomic operations.

We can instead make the list_is_singular() check first, and then
set the count accordingly, so that we issue at most 1 atomic
operation when acquiring the write lock and reduce unnecessary
cacheline contention.

Signed-off-by: Jason Low <jason.low2@hpe.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Waiman Long<Waiman.Long@hpe.com>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Jason Low <jason.low2@hp.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Terry Rudd <terry.rudd@hpe.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/1463445486-16078-2-git-send-email-jason.low2@hpe.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-03 09:47:13 +02:00
Davidlohr Bueso e38513905e locking/rwsem: Rework zeroing reader waiter->task
Readers that are awoken will expect a nil ->task indicating
that a wakeup has occurred. Because of the way readers are
implemented, there's a small chance that the waiter will never
block in the slowpath (rwsem_down_read_failed), and therefore
requires some form of reference counting to avoid the following
scenario:

rwsem_down_read_failed()		rwsem_wake()
  get_task_struct();
  spin_lock_irq(&wait_lock);
  list_add_tail(&waiter.list)
  spin_unlock_irq(&wait_lock);
					  raw_spin_lock_irqsave(&wait_lock)
					  __rwsem_do_wake()
  while (1) {
    set_task_state(TASK_UNINTERRUPTIBLE);
					    waiter->task = NULL
    if (!waiter.task) // true
      break;
    schedule() // never reached

   __set_task_state(TASK_RUNNING);
 do_exit();
					    wake_up_process(tsk); // boom

... and therefore race with do_exit() when the caller returns.

There is also a mismatch between the smp_mb() and its documentation,
in that the serialization is done between reading the task and the
nil store. Furthermore, in addition to having the overlapping of
loads and stores to waiter->task guaranteed to be ordered within
that CPU, both wake_up_process() originally and now wake_q_add()
already imply barriers upon successful calls, which serves the
comment.

Now, as an alternative to perhaps inverting the checks in the blocker
side (which has its own penalty in that schedule is unavoidable),
with lockless wakeups this situation is naturally addressed and we
can just use the refcount held by wake_q_add(), instead doing so
explicitly. Of course, we must guarantee that the nil store is done
as the _last_ operation in that the task must already be marked for
deletion to not fall into the race above. Spurious wakeups are also
handled transparently in that the task's reference is only removed
when wake_up_q() is actually called _after_ the nil store.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman.Long@hpe.com
Cc: dave@stgolabs.net
Cc: jason.low2@hp.com
Cc: peter@hurleysoftware.com
Link: http://lkml.kernel.org/r/1463165787-25937-3-git-send-email-dave@stgolabs.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-03 09:47:12 +02:00
Davidlohr Bueso 133e89ef5e locking/rwsem: Enable lockless waiter wakeup(s)
As wake_qs gain users, we can teach rwsems about them such that
waiters can be awoken without the wait_lock. This is for both
readers and writer, the former being the most ideal candidate
as we can batch the wakeups shortening the critical region that
much more -- ie writer task blocking a bunch of tasks waiting to
service page-faults (mmap_sem readers).

In general applying wake_qs to rwsem (xadd) is not difficult as
the wait_lock is intended to be released soon _anyways_, with
the exception of when a writer slowpath will proactively wakeup
any queued readers if it sees that the lock is owned by a reader,
in which we simply do the wakeups with the lock held (see comment
in __rwsem_down_write_failed_common()).

Similar to other locking primitives, delaying the waiter being
awoken does allow, at least in theory, the lock to be stolen in
the case of writers, however no harm was seen in this (in fact
lock stealing tends to be a _good_ thing in most workloads), and
this is a tiny window anyways.

Some page-fault (pft) and mmap_sem intensive benchmarks show some
pretty constant reduction in systime (by up to ~8 and ~10%) on a
2-socket, 12 core AMD box. In addition, on an 8-core Westmere doing
page allocations (page_test)

aim9:
	 4.6-rc6				4.6-rc6
						rwsemv2
Min      page_test   378167.89 (  0.00%)   382613.33 (  1.18%)
Min      exec_test      499.00 (  0.00%)      502.67 (  0.74%)
Min      fork_test     3395.47 (  0.00%)     3537.64 (  4.19%)
Hmean    page_test   395433.06 (  0.00%)   414693.68 (  4.87%)
Hmean    exec_test      499.67 (  0.00%)      505.30 (  1.13%)
Hmean    fork_test     3504.22 (  0.00%)     3594.95 (  2.59%)
Stddev   page_test    17426.57 (  0.00%)    26649.92 (-52.93%)
Stddev   exec_test        0.47 (  0.00%)        1.41 (-199.05%)
Stddev   fork_test       63.74 (  0.00%)       32.59 ( 48.86%)
Max      page_test   429873.33 (  0.00%)   456960.00 (  6.30%)
Max      exec_test      500.33 (  0.00%)      507.66 (  1.47%)
Max      fork_test     3653.33 (  0.00%)     3650.90 ( -0.07%)

	     4.6-rc6     4.6-rc6
			 rwsemv2
User            1.12        0.04
System          0.23        0.04
Elapsed       727.27      721.98

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman.Long@hpe.com
Cc: dave@stgolabs.net
Cc: jason.low2@hp.com
Cc: peter@hurleysoftware.com
Link: http://lkml.kernel.org/r/1463165787-25937-2-git-send-email-dave@stgolabs.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-03 09:47:10 +02:00
Vineet Gupta a1396555ab perf/abi: Change the errno for sampling event not supported in hardware
Change the return code for sampling event not supported from -ENOTSUPP
to -EOPNOTSUPP.

This allows userspace to identify this case specifically, instead of
printing the catch-all error message it did previously.

Technically this is an ABI change, but we think we can get away
with it.

Old behavior:
 -------
 | # perf record ls
 | Error:
 | The sys_perf_event_open() syscall returned with 524 (Unknown error 524)
 | for event (cycles:ppp).
 | /bin/dmesg may provide additional information.
 | No CONFIG_PERF_EVENTS=y kernel support configured?

New behavior:
 -------
 | # perf record ls
 | Error:
 | PMU Hardware doesn't support sampling/overflow-interrupts.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <acme@redhat.com>
Cc: <linux-snps-arc@lists.infradead.org>
Cc: <vincent.weaver@maine.edu>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Vineet Gupta <Vineet.Gupta1@synopsys.com>
Link: http://lkml.kernel.org/r/1462786660-2900-3-git-send-email-vgupta@synopsys.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-03 09:40:42 +02:00
Kan Liang ab7fdefba6 perf/core: Fix implicitly enable dynamic interrupt throttle
This patch fixes an issue which was introduced by commit:

  91a612eea9 ("perf/core: Fix dynamic interrupt throttle")

... which commit unconditionally sets the perf_sample_allowed_ns value
to !0. But that could trigger a bug in the following corner case:

The user can disable the dynamic interrupt throttle mechanism by setting
perf_cpu_time_max_percent to 0. Then they change perf_event_max_sample_rate.
For this case, the mechanism will be enabled implicitly, because
perf_sample_allowed_ns becomes !0 - which is not what we want.

This patch only updates perf_sample_allowed_ns when the dynamic
interrupt throttle mechanism is enabled.

Signed-off-by: Kan Liang <kan.liang@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Link: http://lkml.kernel.org/r/1462260366-3160-1-git-send-email-kan.liang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-03 09:40:16 +02:00
Peter Zijlstra aab5b71ef2 perf/core: Rename the perf_event_aux*() APIs to perf_event_sb*(), to separate them from AUX ring-buffer records
There are now two different things called AUX in perf, the
infrastructure to deliver the mmap/comm/task records and the
AUX part in the mmap buffer (with associated AUX_RECORD).

Since the former is internal, rename it to side-band to reduce
the confusion factor.

No change in functionality.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-03 09:40:15 +02:00
Kan Liang f2fb6bef92 perf/core: Optimize side-band event delivery
The perf_event_aux() function iterates all PMUs and all events in
their respective per-CPU contexts to find the events to deliver
side-band records to.

For example, the brk test case in lkp triggers many mmap() operations,
which, if we're also running perf, results in many perf_event_aux()
invocations.

If we enable uncore PMU support (even when uncore events are not used),
dozens of uncore PMUs will be iterated, which can significantly
decrease brk_test's throughput.

For example, the brk throughput:

  without uncore PMUs: 2647573 ops_per_sec
  with    uncore PMUs: 1768444 ops_per_sec

... a 33% reduction.

To get at the per-CPU events that need side-band records, this patch
puts these events on a per-CPU list, this avoids iterating the PMUs
and any events that do not need side-band records.

Per task events are unchanged to avoid extra overhead on the context
switch paths.

Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reported-by: Huang, Ying <ying.huang@linux.intel.com>
Signed-off-by: Kan Liang <kan.liang@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1458757477-3781-1-git-send-email-kan.liang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-03 09:40:15 +02:00
Oleg Nesterov bac7857319 sched/fair: Use task_rcu_dereference()
Simplify task_numa_compare()'s task reference magic by using
task_rcu_dereference().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Kirill Tkhai <ktkhai@parallels.com>
Cc: Kirill Tkhai <tkhai@yandex.ru>
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: Vladimir Davydov <vdavydov@parallels.com>
Link: http://lkml.kernel.org/r/20160518195733.GA15914@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-03 09:18:58 +02:00
Oleg Nesterov 150593bf86 sched/api: Introduce task_rcu_dereference() and try_get_task_struct()
Generally task_struct is only protected by RCU if it was found on a
RCU protected list (say, for_each_process() or find_task_by_vpid()).

As Kirill pointed out rq->curr isn't protected by RCU, the scheduler
drops the (potentially) last reference without RCU gp, this means
that we need to fix the code which uses foreign_rq->curr under
rcu_read_lock().

Add a new helper which can be used to dereference rq->curr or any
other pointer to task_struct assuming that it should be cleared or
updated before the final put_task_struct(). It returns non-NULL
only if this task can't go away before rcu_read_unlock().

( Also add try_get_task_struct() to make it easier to use this API
  correctly. )

Suggested-by: Kirill Tkhai <ktkhai@parallels.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
[ Updated comments; added try_get_task_struct()]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Kirill Tkhai <tkhai@yandex.ru>
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: Vladimir Davydov <vdavydov@parallels.com>
Link: http://lkml.kernel.org/r/20160518170218.GY3192@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-03 09:18:57 +02:00
Gaurav Jindal (Gaurav Jindal) df55f462b9 sched/idle: Optimize the generic idle loop
Currently, smp_processor_id() is used to fetch the current CPU in
cpu_idle_loop(). Every time the idle thread runs, it fetches the
current CPU using smp_processor_id().

Since the idle thread is per CPU, the current CPU is constant, so we
can lift the load out of the loop, saving execution cycles/time in the
loop.

x86-64:

Before patch (execution in loop):
	148:    0f ae e8                lfence
	14b:    65 8b 04 25 00 00 00 00 mov %gs:0x0,%eax
	152:    00
	153:    89 c0                   mov %eax,%eax
	155:    49 0f a3 04 24          bt %rax,(%r12)

After patch (execution in loop):
	150:    0f ae e8                lfence
	153:    4d 0f a3 34 24          bt %r14,(%r12)

ARM64:

Before patch (execution in loop):
	168:    d5033d9f        dsb     ld
	16c:    b9405661        ldr     w1,[x19,#84]
	170:    1100fc20        add     w0,w1,#0x3f
	174:    6b1f003f        cmp     w1,wzr
	178:    1a81b000        csel    w0,w0,w1,lt
	17c:    130c7000        asr     w0,w0,#6
	180:    937d7c00        sbfiz   x0,x0,#3,#32
	184:    f8606aa0        ldr     x0,[x21,x0]
	188:    9ac12401        lsr     x1,x0,x1
	18c:    36000e61        tbz     w1,#0,358

After patch (execution in loop):
	1a8:    d50339df        dsb     ld
	1ac:    f8776ac0        ldr     x0,[x22,x23]
	ab0:    ea18001f        tst     x0,x24
	1b4:    54000ea0        b.eq    388

Further observance on ARM64 for 4 seconds shows that cpu_idle_loop is
called 8672 times. Shifting the code will save instructions executed
in loop and eventually time as well.

Signed-off-by: Gaurav Jindal <gaurav.jindal@spreadtrum.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Sanjeev Yadav <sanjeev.yadav@spreadtrum.com>
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>
Link: http://lkml.kernel.org/r/20160512101330.GA488@gauravjindalubtnb.del.spreadtrum.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-03 09:18:56 +02:00
Xunlei Pang 1a99ae3f00 sched/fair: Fix the wrong throttled clock time for cfs_rq_clock_task()
Two minor fixes for cfs_rq_clock_task():

 1) If cfs_rq is currently being throttled, we need to subtract the cfs
    throttled clock time.

 2) Make "throttled_clock_task_time" update SMP unrelated. Now UP cases
    need it as well.

Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1462885398-14724-1-git-send-email-xlpang@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-03 09:18:56 +02:00
Chris Wilson 0422e83d84 locking/ww_mutex: Report recursive ww_mutex locking early
Recursive locking for ww_mutexes was originally conceived as an
exception. However, it is heavily used by the DRM atomic modesetting
code. Currently, the recursive deadlock is checked after we have queued
up for a busy-spin and as we never release the lock, we spin until
kicked, whereupon the deadlock is discovered and reported.

A simple solution for the now common problem is to move the recursive
deadlock discovery to the first action when taking the ww_mutex.

Suggested-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1464293297-19777-1-git-send-email-chris@chris-wilson.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-03 08:37:26 +02:00
Viresh Kumar bf2be2de84 cpufreq: governor: Create cpufreq_policy_apply_limits()
Create a new helper to avoid code duplication across governors.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-06-02 23:24:39 +02:00
Rafael J. Wysocki e788892ba3 cpufreq: governor: Get rid of governor events
The design of the cpufreq governor API is not very straightforward,
as struct cpufreq_governor provides only one callback to be invoked
from different code paths for different purposes.  The purpose it is
invoked for is determined by its second "event" argument, causing it
to act as a "callback multiplexer" of sorts.

Unfortunately, that leads to extra complexity in governors, some of
which implement the ->governor() callback as a switch statement
that simply checks the event argument and invokes a separate function
to handle that specific event.

That extra complexity can be eliminated by replacing the all-purpose
->governor() callback with a family of callbacks to carry out specific
governor operations: initialization and exit, start and stop and policy
limits updates.  That also turns out to reduce the code size too, so
do it.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-06-02 23:24:15 +02:00
Catalin Marinas 9bd616e3db cpuidle: Do not access cpuidle_devices when !CONFIG_CPU_IDLE
The cpuidle_devices per-CPU variable is only defined when CPU_IDLE is
enabled. Commit c8cc7d4de7 ("sched/idle: Reorganize the idle loop")
removed the #ifdef CONFIG_CPU_IDLE around cpuidle_idle_call() with the
compiler optimising away __this_cpu_read(cpuidle_devices). However, with
CONFIG_UBSAN && !CONFIG_CPU_IDLE, this optimisation no longer happens
and the kernel fails to link since cpuidle_devices is not defined.

This patch introduces an accessor function for the current CPU cpuidle
device (returning NULL when !CONFIG_CPU_IDLE) and uses it in
cpuidle_idle_call().

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: 4.5+ <stable@vger.kernel.org> # 4.5+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-06-02 23:05:27 +02:00
Linus Torvalds 6b15d6650c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:

 1) Fix negative error code usage in ATM layer, from Stefan Hajnoczi.

 2) If CONFIG_SYSCTL is disabled, the default TTL is not initialized
    properly.  From Ezequiel Garcia.

 3) Missing spinlock init in mvneta driver, from Gregory CLEMENT.

 4) Missing unlocks in hwmb error paths, also from Gregory CLEMENT.

 5) Fix deadlock on team->lock when propagating features, from Ivan
    Vecera.

 6) Work around buffer offset hw bug in alx chips, from Feng Tang.

 7) Fix double listing of SCTP entries in sctp_diag dumps, from Xin
    Long.

 8) Various statistics bug fixes in mlx4 from Eric Dumazet.

 9) Fix some randconfig build errors wrt fou ipv6 from Arnd Bergmann.

10) All of l2tp was namespace aware, but the ipv6 support code was not
    doing so.  From Shmulik Ladkani.

11) Handle on-stack hrtimers properly in pktgen, from Guenter Roeck.

12) Propagate MAC changes properly through VLAN devices, from Mike
    Manning.

13) Fix memory leak in bnx2x_init_one(), from Vitaly Kuznetsov.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (62 commits)
  sfc: Track RPS flow IDs per channel instead of per function
  usbnet: smsc95xx: fix link detection for disabled autonegotiation
  virtio_net: fix virtnet_open and virtnet_probe competing for try_fill_recv
  bnx2x: avoid leaking memory on bnx2x_init_one() failures
  fou: fix IPv6 Kconfig options
  openvswitch: update checksum in {push,pop}_mpls
  sctp: sctp_diag should dump sctp socket type
  net: fec: update dirty_tx even if no skb
  vlan: Propagate MAC address to VLANs
  atm: iphase: off by one in rx_pkt()
  atm: firestream: add more reserved strings
  vxlan: Accept user specified MTU value when create new vxlan link
  net: pktgen: Call destroy_hrtimer_on_stack()
  timer: Export destroy_hrtimer_on_stack()
  net: l2tp: Make l2tp_ip6 namespace aware
  Documentation: ip-sysctl.txt: clarify secure_redirects
  sfc: use flow dissector helpers for aRFS
  ieee802154: fix logic error in ieee802154_llsec_parse_dev_addr
  net: nps_enet: Disable interrupts before napi reschedule
  net/lapb: tuse %*ph to dump buffers
  ...
2016-05-31 22:28:28 -07:00
Guenter Roeck c08376ac97 timer: Export destroy_hrtimer_on_stack()
hrtimer_init_on_stack() needs a matching call to
destroy_hrtimer_on_stack(), so both need to be exported.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-31 11:44:08 -07:00
Richard Guy Briggs 2b4c7afe79 audit: fixup: log on errors from filter user rules
In commit 724e4fcc the intention was to pass any errors back from
audit_filter_user_rules() to audit_filter_user().  Add that code.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-05-31 12:06:59 -04:00
Arnaldo Carvalho de Melo 97c79a38cd perf core: Per event callchain limit
Additionally to being able to control the system wide maximum depth via
/proc/sys/kernel/perf_event_max_stack, now we are able to ask for
different depths per event, using perf_event_attr.sample_max_stack for
that.

This uses an u16 hole at the end of perf_event_attr, that, when
perf_event_attr.sample_type has the PERF_SAMPLE_CALLCHAIN, if
sample_max_stack is zero, means use perf_event_max_stack, otherwise
it'll be bounds checked under callchain_mutex.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Zefan Li <lizefan@huawei.com>
Link: http://lkml.kernel.org/n/tip-kolmn1yo40p7jhswxwrc7rrd@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-05-30 12:41:44 -03:00
Linus Torvalds d102a56edb Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs fixes from Al Viro:
 "Followups to the parallel lookup work:

   - update docs

   - restore killability of the places that used to take ->i_mutex
     killably now that we have down_write_killable() merged

   - Additionally, it turns out that I missed a prerequisite for
     security_d_instantiate() stuff - ->getxattr() wasn't the only thing
     that could be called before dentry is attached to inode; with smack
     we needed the same treatment applied to ->setxattr() as well"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  switch ->setxattr() to passing dentry and inode separately
  switch xattr_handler->set() to passing dentry and inode separately
  restore killability of old mutex_lock_killable(&inode->i_mutex) users
  add down_write_killable_nested()
  update D/f/directory-locking
2016-05-27 17:14:05 -07:00
Arnd Bergmann 287980e49f remove lots of IS_ERR_VALUE abuses
Most users of IS_ERR_VALUE() in the kernel are wrong, as they
pass an 'int' into a function that takes an 'unsigned long'
argument. This happens to work because the type is sign-extended
on 64-bit architectures before it gets converted into an
unsigned type.

However, anything that passes an 'unsigned short' or 'unsigned int'
argument into IS_ERR_VALUE() is guaranteed to be broken, as are
8-bit integers and types that are wider than 'unsigned long'.

Andrzej Hajda has already fixed a lot of the worst abusers that
were causing actual bugs, but it would be nice to prevent any
users that are not passing 'unsigned long' arguments.

This patch changes all users of IS_ERR_VALUE() that I could find
on 32-bit ARM randconfig builds and x86 allmodconfig. For the
moment, this doesn't change the definition of IS_ERR_VALUE()
because there are probably still architecture specific users
elsewhere.

Almost all the warnings I got are for files that are better off
using 'if (err)' or 'if (err < 0)'.
The only legitimate user I could find that we get a warning for
is the (32-bit only) freescale fman driver, so I did not remove
the IS_ERR_VALUE() there but changed the type to 'unsigned long'.
For 9pfs, I just worked around one user whose calling conventions
are so obscure that I did not dare change the behavior.

I was using this definition for testing:

 #define IS_ERR_VALUE(x) ((unsigned long*)NULL == (typeof (x)*)NULL && \
       unlikely((unsigned long long)(x) >= (unsigned long long)(typeof(x))-MAX_ERRNO))

which ends up making all 16-bit or wider types work correctly with
the most plausible interpretation of what IS_ERR_VALUE() was supposed
to return according to its users, but also causes a compile-time
warning for any users that do not pass an 'unsigned long' argument.

I suggested this approach earlier this year, but back then we ended
up deciding to just fix the users that are obviously broken. After
the initial warning that caused me to get involved in the discussion
(fs/gfs2/dir.c) showed up again in the mainline kernel, Linus
asked me to send the whole thing again.

[ Updated the 9p parts as per Al Viro  - Linus ]

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.org/lkml/2016/1/7/363
Link: https://lkml.org/lkml/2016/5/27/486
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> # For nvmem part
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-27 15:26:11 -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
Michal Hocko 7ef949d77f mm: oom_reaper: remove some bloat
mmput_async is currently used only from the oom_reaper which is defined
only for CONFIG_MMU.  We can save work_struct in mm_struct for
!CONFIG_MMU.

[akpm@linux-foundation.org: fix typo, per Minchan]
Link: http://lkml.kernel.org/r/20160520061658.GB19172@dhcp22.suse.cz
Reported-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-26 15:35:44 -07:00
Wenwei Tao b00c52dae6 cgroup: remove redundant cleanup in css_create
When create css failed, before call css_free_rcu_fn, we remove the css
id and exit the percpu_ref, but we will do these again in
css_free_work_fn, so they are redundant.  Especially the css id, that
would cause problem if we remove it twice, since it may be assigned to
another css after the first remove.

tj: This was broken by two commits updating the free path without
    synchronizing the creation failure path.  This can be easily
    triggered by trying to create more than 64k memory cgroups.

Signed-off-by: Wenwei Tao <ww.tao0320@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Fixes: 9a1049da9b ("percpu-refcount: require percpu_ref to be exited explicitly")
Fixes: 01e586598b ("cgroup: release css->id after css_free")
Cc: stable@vger.kernel.org # v3.17+
2016-05-26 15:09:23 -04:00
Al Viro 887bddfa90 add down_write_killable_nested()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-26 00:04:58 -04:00
Linus Torvalds f89eae4ee7 Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar:
 "Two fixes: one for a lost wakeup, the other to fix the compiler
  optimizing out preempt operations on ARM64 (and possibly other non-x86
  architectures)"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/core: Fix remote wakeups
  sched/preempt: Fix preempt_count manipulations
2016-05-25 17:11:43 -07:00
Linus Torvalds bdc6b758e4 Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf updates from Ingo Molnar:
 "Mostly tooling and PMU driver fixes, but also a number of late updates
  such as the reworking of the call-chain size limiting logic to make
  call-graph recording more robust, plus tooling side changes for the
  new 'backwards ring-buffer' extension to the perf ring-buffer"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (34 commits)
  perf record: Read from backward ring buffer
  perf record: Rename variable to make code clear
  perf record: Prevent reading invalid data in record__mmap_read
  perf evlist: Add API to pause/resume
  perf trace: Use the ptr->name beautifier as default for "filename" args
  perf trace: Use the fd->name beautifier as default for "fd" args
  perf report: Add srcline_from/to branch sort keys
  perf evsel: Record fd into perf_mmap
  perf evsel: Add overwrite attribute and check write_backward
  perf tools: Set buildid dir under symfs when --symfs is provided
  perf trace: Only auto set call-graph to "dwarf" when syscalls are being traced
  perf annotate: Sort list of recognised instructions
  perf annotate: Fix identification of ARM blt and bls instructions
  perf tools: Fix usage of max_stack sysctl
  perf callchain: Stop validating callchains by the max_stack sysctl
  perf trace: Fix exit_group() formatting
  perf top: Use machine->kptr_restrict_warned
  perf trace: Warn when trying to resolve kernel addresses with kptr_restrict=1
  perf machine: Do not bail out if not managing to read ref reloc symbol
  perf/x86/intel/p4: Trival indentation fix, remove space
  ...
2016-05-25 17:05:40 -07:00
Linus Torvalds 877c057d2b More power management updates for v4.7-rc1
- Stable-candidate cpuidle fix to make it check the right variable
    when deciding whether or not to enable interrupts on the local CPU
    so as to avoid enabling iterrupts too early in some cases if the
    system has both coupled and per-core idle states (Daniel Lezcano).
 
  - Stable-candidate PM core fix to make it handle failures at the
    "late suspend" stage of device suspend consistently for all
    devices regardless of whether or not async suspend/resume is
    enabled for them (Rafael Wysocki).
 
  - Cleanups in the cpufreq core, the schedutil governor and the
    intel_pstate driver (Rafael Wysocki, Pankaj Gupta, Viresh Kumar).
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Merge tag 'pm-4.7-rc1-more' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull more power management updates from Rafael Wysocki:
 "These are two stable-candidate fixes (PM core, cpuidle) and a bunch of
  cpufreq cleanups.

  Specifics:

   - Stable-candidate cpuidle fix to make it check the right variable
     when deciding whether or not to enable interrupts on the local CPU
     so as to avoid enabling iterrupts too early in some cases if the
     system has both coupled and per-core idle states (Daniel Lezcano).

   - Stable-candidate PM core fix to make it handle failures at the
     "late suspend" stage of device suspend consistently for all devices
     regardless of whether or not async suspend/resume is enabled for
     them (Rafael Wysocki).

   - Cleanups in the cpufreq core, the schedutil governor and the
     intel_pstate driver (Rafael Wysocki, Pankaj Gupta, Viresh Kumar)"

* tag 'pm-4.7-rc1-more' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PM / sleep: Handle failures in device_suspend_late() consistently
  cpufreq: schedutil: Improve prints messages with pr_fmt
  cpuidle: Fix cpuidle_state_is_coupled() argument in cpuidle_enter()
  cpufreq: simplified goto out in cpufreq_register_driver()
  cpufreq: governor: CPUFREQ_GOV_STOP never fails
  cpufreq: governor: CPUFREQ_GOV_POLICY_EXIT never fails
  intel_pstate: Simplify conditional in intel_pstate_set_policy()
2016-05-25 15:29:21 -07:00
Rafael J. Wysocki 4c2628cd75 Merge branches 'pm-cpufreq', 'pm-cpuidle' and 'pm-core'
* pm-cpufreq:
  cpufreq: schedutil: Improve prints messages with pr_fmt
  cpufreq: simplified goto out in cpufreq_register_driver()
  cpufreq: governor: CPUFREQ_GOV_STOP never fails
  cpufreq: governor: CPUFREQ_GOV_POLICY_EXIT never fails
  intel_pstate: Simplify conditional in intel_pstate_set_policy()

* pm-cpuidle:
  cpuidle: Fix cpuidle_state_is_coupled() argument in cpuidle_enter()

* pm-core:
  PM / sleep: Handle failures in device_suspend_late() consistently
2016-05-25 21:54:45 +02:00
Peter Zijlstra b7e7ade34e sched/core: Fix remote wakeups
Commit:

  b5179ac70d ("sched/fair: Prepare to fix fairness problems on migration")

... introduced a bug: Mike Galbraith found that it introduced a
performance regression, while Paul E. McKenney reported lost
wakeups and bisected it to this commit.

The reason is that I mis-read ttwu_queue() such that I assumed any
wakeup that got a remote queue must have had the task migrated.

Since this is not so; we need to transfer this information between
queueing the wakeup and actually doing the wakeup. Use a new
task_struct::sched_flag for this, we already write to
sched_contributes_to_load in the wakeup path so this is a hot and
modified cacheline.

Reported-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reported-by: Mike Galbraith <umgwanakikbuti@gmail.com>
Tested-by: Mike Galbraith <umgwanakikbuti@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Hunter <ahh@google.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Ben Segall <bsegall@google.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Morten Rasmussen <morten.rasmussen@arm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul Turner <pjt@google.com>
Cc: Pavan Kondeti <pkondeti@codeaurora.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: byungchul.park@lge.com
Fixes: b5179ac70d ("sched/fair: Prepare to fix fairness problems on migration")
Link: http://lkml.kernel.org/r/20160523091907.GD15728@worktop.ger.corp.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-25 08:35:18 +02:00
Linus Torvalds 0e01df100b Fix a number of bugs, most notably a potential stale data exposure
after a crash and a potential BUG_ON crash if a file has the data
 journalling flag enabled while it has dirty delayed allocation blocks
 that haven't been written yet.  Also fix a potential crash in the new
 project quota code and a maliciously corrupted file system.
 
 In addition, fix some DAX-specific bugs, including when there is a
 transient ENOSPC situation and races between writes via direct I/O and
 an mmap'ed segment that could lead to lost I/O.
 
 Finally the usual set of miscellaneous cleanups.
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Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 updates from Ted Ts'o:
 "Fix a number of bugs, most notably a potential stale data exposure
  after a crash and a potential BUG_ON crash if a file has the data
  journalling flag enabled while it has dirty delayed allocation blocks
  that haven't been written yet.  Also fix a potential crash in the new
  project quota code and a maliciously corrupted file system.

  In addition, fix some DAX-specific bugs, including when there is a
  transient ENOSPC situation and races between writes via direct I/O and
  an mmap'ed segment that could lead to lost I/O.

  Finally the usual set of miscellaneous cleanups"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (23 commits)
  ext4: pre-zero allocated blocks for DAX IO
  ext4: refactor direct IO code
  ext4: fix race in transient ENOSPC detection
  ext4: handle transient ENOSPC properly for DAX
  dax: call get_blocks() with create == 1 for write faults to unwritten extents
  ext4: remove unmeetable inconsisteny check from ext4_find_extent()
  jbd2: remove excess descriptions for handle_s
  ext4: remove unnecessary bio get/put
  ext4: silence UBSAN in ext4_mb_init()
  ext4: address UBSAN warning in mb_find_order_for_block()
  ext4: fix oops on corrupted filesystem
  ext4: fix check of dqget() return value in ext4_ioctl_setproject()
  ext4: clean up error handling when orphan list is corrupted
  ext4: fix hang when processing corrupted orphaned inode list
  ext4: remove trailing \n from ext4_warning/ext4_error calls
  ext4: fix races between changing inode journal mode and ext4_writepages
  ext4: handle unwritten or delalloc buffers before enabling data journaling
  ext4: fix jbd2 handle extension in ext4_ext_truncate_extend_restart()
  ext4: do not ask jbd2 to write data for delalloc buffers
  jbd2: add support for avoiding data writes during transaction commits
  ...
2016-05-24 12:55:26 -07:00
Matt Redfearn 59fa586020 genirq: Fix missing return value in irq_destroy_ipi()
Commit 7cec18a390 changed the return type of irq_destroy_ipi to int, but
missed adding a value to one return statement. Fix this to silence the
resulting compiler warning:

kernel/irq/ipi.c In function ‘irq_destroy_ipi’:
kernel/irq/ipi.c:128:3: warning: ‘return’ with no value, in function returning non-void [-Wreturn-type]

Fixes: 7cec18a390 "genirq: Add error code reporting to irq_{reserve,destroy}_ipi"
Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: linux-mips@linux-mips.org
Link: http://lkml.kernel.org/r/1464086550-24734-1-git-send-email-matt.redfearn@imgtec.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-05-24 15:40:14 +02:00
Michal Hocko 598fdc1d66 uprobes: wait for mmap_sem for write killable
xol_add_vma needs mmap_sem for write.  If the waiting task gets killed
by the oom killer it would block oom_reaper from asynchronous address
space reclaim and reduce the chances of timely OOM resolving.  Wait for
the lock in the killable mode and return with EINTR if the task got
killed while waiting.

Do not warn in dup_xol_work if __create_xol_area failed due to fatal
signal pending because this is usually considered a kernel issue.

Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-23 17:04:14 -07:00
Michal Hocko 17b0573d77 prctl: make PR_SET_THP_DISABLE wait for mmap_sem killable
PR_SET_THP_DISABLE requires mmap_sem for write.  If the waiting task
gets killed by the oom killer it would block oom_reaper from
asynchronous address space reclaim and reduce the chances of timely OOM
resolving.  Wait for the lock in the killable mode and return with EINTR
if the task got killed while waiting.

Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Alex Thorlton <athorlton@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-23 17:04:14 -07:00
Michal Hocko 7c05126793 mm, fork: make dup_mmap wait for mmap_sem for write killable
dup_mmap needs to lock current's mm mmap_sem for write.  If the waiting
task gets killed by the oom killer it would block oom_reaper from
asynchronous address space reclaim and reduce the chances of timely OOM
resolving.  Wait for the lock in the killable mode and return with EINTR
if the task got killed while waiting.

Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-23 17:04:14 -07:00
Xunlei Pang 7a0058ec78 s390/kexec: consolidate crash_map/unmap_reserved_pages() and arch_kexec_protect(unprotect)_crashkres()
Commit 3f625002581b ("kexec: introduce a protection mechanism for the
crashkernel reserved memory") is a similar mechanism for protecting the
crash kernel reserved memory to previous crash_map/unmap_reserved_pages()
implementation, the new one is more generic in name and cleaner in code
(besides, some arch may not be allowed to unmap the pgtable).

Therefore, this patch consolidates them, and uses the new
arch_kexec_protect(unprotect)_crashkres() to replace former
crash_map/unmap_reserved_pages() which by now has been only used by
S390.

The consolidation work needs the crash memory to be mapped initially,
this is done in machine_kdump_pm_init() which is after
reserve_crashkernel().  Once kdump kernel is loaded, the new
arch_kexec_protect_crashkres() implemented for S390 will actually
unmap the pgtable like before.

Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Minfei Huang <mhuang@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-23 17:04:14 -07:00
Minfei Huang 0eea08678e kexec: do a cleanup for function kexec_load
There are a lof of work to be done in function kexec_load, not only for
allocating structs and loading initram, but also for some misc.

To make it more clear, wrap a new function do_kexec_load which is used
to allocate structs and load initram.  And the pre-work will be done in
kexec_load.

Signed-off-by: Minfei Huang <mnfhuang@gmail.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Xunlei Pang <xlpang@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-23 17:04:14 -07:00
Minfei Huang 917a35605f kexec: make a pair of map/unmap reserved pages in error path
For some arch, kexec shall map the reserved pages, then use them, when
we try to start the kdump service.

kexec may return directly, without unmaping the reserved pages, if it
fails during starting service.  To fix it, we make a pair of map/unmap
reserved pages both in generic path and error path.

This patch only affects s390.  Other architecturess don't implement the
interface of crash_unmap_reserved_pages and crash_map_reserved_pages.

It isn't a urgent patch.  Kernel can work well without any risk,
although the reserved pages are not unmapped before returning in error
path.

Signed-off-by: Minfei Huang <mnfhuang@gmail.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Xunlei Pang <xlpang@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-23 17:04:14 -07:00
Xunlei Pang 9b492cf580 kexec: introduce a protection mechanism for the crashkernel reserved memory
For the cases that some kernel (module) path stamps the crash reserved
memory(already mapped by the kernel) where has been loaded the second
kernel data, the kdump kernel will probably fail to boot when panic
happens (or even not happens) leaving the culprit at large, this is
unacceptable.

The patch introduces a mechanism for detecting such cases:

1) After each crash kexec loading, it simply marks the reserved memory
   regions readonly since we no longer access it after that.  When someone
   stamps the region, the first kernel will panic and trigger the kdump.
   The weak arch_kexec_protect_crashkres() is introduced to do the actual
   protection.

2) To allow multiple loading, once 1) was done we also need to remark
   the reserved memory to readwrite each time a system call related to
   kdump is made.  The weak arch_kexec_unprotect_crashkres() is introduced
   to do the actual protection.

The architecture can make its specific implementation by overriding
arch_kexec_protect_crashkres() and arch_kexec_unprotect_crashkres().

Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Minfei Huang <mhuang@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-23 17:04:14 -07:00
Andi Kleen 725fc629ff kernek/fork.c: allocate idle task for a CPU always on its local node
Linux preallocates the task structs of the idle tasks for all possible
CPUs.  This currently means they all end up on node 0.  This also
implies that the cache line of MWAIT, which is around the flags field in
the task struct, are all located in node 0.

We see a noticeable performance improvement on Knights Landing CPUs when
the cache lines used for MWAIT are located in the local nodes of the
CPUs using them.  I would expect this to give a (likely slight)
improvement on other systems too.

The patch implements placing the idle task in the node of its CPUs, by
passing the right target node to copy_process()

[akpm@linux-foundation.org: use NUMA_NO_NODE, not a bare -1]
Link: http://lkml.kernel.org/r/1463492694-15833-1-git-send-email-andi@firstfloor.org
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-23 17:04:14 -07:00
Wang Xiaoqiang 747800efbe kernel/signal.c: convert printk(KERN_<LEVEL> ...) to pr_<level>(...)
Use pr_<level> instead of printk(KERN_<LEVEL> ).

Signed-off-by: Wang Xiaoqiang <wangxq10@lzu.edu.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-23 17:04:14 -07:00
Oleg Nesterov 91c4e8ea8f wait: allow sys_waitid() to accept __WNOTHREAD/__WCLONE/__WALL
I see no reason why waitid() can't support other linux-specific flags
allowed in sys_wait4().

In particular this change can help if we reconsider the previous change
("wait/ptrace: assume __WALL if the child is traced") which adds the
"automagical" __WALL for debugger.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Jan Kratochvil <jan.kratochvil@redhat.com>
Cc: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>
Cc: Pedro Alves <palves@redhat.com>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: <syzkaller@googlegroups.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-23 17:04:14 -07:00
Oleg Nesterov bf959931dd wait/ptrace: assume __WALL if the child is traced
The following program (simplified version of generated by syzkaller)

	#include <pthread.h>
	#include <unistd.h>
	#include <sys/ptrace.h>
	#include <stdio.h>
	#include <signal.h>

	void *thread_func(void *arg)
	{
		ptrace(PTRACE_TRACEME, 0,0,0);
		return 0;
	}

	int main(void)
	{
		pthread_t thread;

		if (fork())
			return 0;

		while (getppid() != 1)
			;

		pthread_create(&thread, NULL, thread_func, NULL);
		pthread_join(thread, NULL);
		return 0;
	}

creates an unreapable zombie if /sbin/init doesn't use __WALL.

This is not a kernel bug, at least in a sense that everything works as
expected: debugger should reap a traced sub-thread before it can reap the
leader, but without __WALL/__WCLONE do_wait() ignores sub-threads.

Unfortunately, it seems that /sbin/init in most (all?) distributions
doesn't use it and we have to change the kernel to avoid the problem.
Note also that most init's use sys_waitid() which doesn't allow __WALL, so
the necessary user-space fix is not that trivial.

This patch just adds the "ptrace" check into eligible_child().  To some
degree this matches the "tsk->ptrace" in exit_notify(), ->exit_signal is
mostly ignored when the tracee reports to debugger.  Or WSTOPPED, the
tracer doesn't need to set this flag to wait for the stopped tracee.

This obviously means the user-visible change: __WCLONE and __WALL no
longer have any meaning for debugger.  And I can only hope that this won't
break something, but at least strace/gdb won't suffer.

We could make a more conservative change.  Say, we can take __WCLONE into
account, or !thread_group_leader().  But it would be nice to not
complicate these historical/confusing checks.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Jan Kratochvil <jan.kratochvil@redhat.com>
Cc: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>
Cc: Pedro Alves <palves@redhat.com>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: <syzkaller@googlegroups.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-23 17:04:14 -07:00
Ralf Baechle f43edca7ed ELF/MIPS build fix
CONFIG_MIPS32_N32=y but CONFIG_BINFMT_ELF disabled results in the
following linker errors:

  arch/mips/built-in.o: In function `elf_core_dump':
  binfmt_elfn32.c:(.text+0x23dbc): undefined reference to `elf_core_extra_phdrs'
  binfmt_elfn32.c:(.text+0x246e4): undefined reference to `elf_core_extra_data_size'
  binfmt_elfn32.c:(.text+0x248d0): undefined reference to `elf_core_write_extra_phdrs'
  binfmt_elfn32.c:(.text+0x24ac4): undefined reference to `elf_core_write_extra_data'

CONFIG_MIPS32_O32=y but CONFIG_BINFMT_ELF disabled results in the following
linker errors:

  arch/mips/built-in.o: In function `elf_core_dump':
  binfmt_elfo32.c:(.text+0x28a04): undefined reference to `elf_core_extra_phdrs'
  binfmt_elfo32.c:(.text+0x29330): undefined reference to `elf_core_extra_data_size'
  binfmt_elfo32.c:(.text+0x2951c): undefined reference to `elf_core_write_extra_phdrs'
  binfmt_elfo32.c:(.text+0x29710): undefined reference to `elf_core_write_extra_data'

This is because binfmt_elfn32 and binfmt_elfo32 are using symbols from
elfcore but for these configurations elfcore will not be built.

Fixed by making elfcore selectable by a separate config symbol which
unlike the current mechanism can also be used from other directories
than kernel/, then having each flavor of ELF that relies on elfcore.o,
select it in Kconfig, including CONFIG_MIPS32_N32 and CONFIG_MIPS32_O32
which fixes this issue.

Link: http://lkml.kernel.org/r/20160520141705.GA1913@linux-mips.org
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: "Maciej W. Rozycki" <macro@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-23 17:04:14 -07:00
Daniel Borkmann 612bacad78 bpf, inode: disallow userns mounts
Follow-up to commit e27f4a942a ("bpf: Use mount_nodev not mount_ns
to mount the bpf filesystem"), which removes the FS_USERNS_MOUNT flag.

The original idea was to have a per mountns instance instead of a
single global fs instance, but that didn't work out and we had to
switch to mount_nodev() model. The intent of that middle ground was
that we avoid users who don't play nice to create endless instances
of bpf fs which are difficult to control and discover from an admin
point of view, but at the same time it would have allowed us to be
more flexible with regard to namespaces.

Therefore, since we now did the switch to mount_nodev() as a fix
where individual instances are created, we also need to remove userns
mount flag along with it to avoid running into mentioned situation.
I don't expect any breakage at this early point in time with removing
the flag and we can revisit this later should the requirement for
this come up with future users. This and commit e27f4a942a have
been split to facilitate tracking should any of them run into the
unlikely case of causing a regression.

Fixes: b2197755b2 ("bpf: add support for persistent maps/progs")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-23 15:08:26 -07:00
Linus Torvalds 7639dad93a Three more changes.
1) I forgot that I had another selftest to stress test the ftrace
    instance creation. It was actually suppose to go into the 4.6
    merge window, but I never committed it. I almost forgot about it
    again, but noticed it was missing from your tree.
 
 2) Soumya PN sent me a clean up patch to not disable interrupts when
    taking the tasklist_lock for read, as it's unnecessary because
    that lock is never taken for write in irq context.
 
 3) Newer gcc's can cause the jump in the function_graph code to the
    global ftrace_stub label to be a short jump instead of a long one.
    As that jump is dynamically converted to jump to the trace code to
    do function graph tracing, and that conversion expects a long jump
    it can corrupt the ftrace_stub itself (it's directly after that call).
    One way to prevent gcc from using a short jump is to declare the
    ftrace_stub as a weak function, which we do here to keep gcc from
    optimizing too much.
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Merge tag 'trace-v4.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull motr tracing updates from Steven Rostedt:
 "Three more changes.

   - I forgot that I had another selftest to stress test the ftrace
     instance creation.  It was actually suppose to go into the 4.6
     merge window, but I never committed it.  I almost forgot about it
     again, but noticed it was missing from your tree.

   - Soumya PN sent me a clean up patch to not disable interrupts when
     taking the tasklist_lock for read, as it's unnecessary because that
     lock is never taken for write in irq context.

   - Newer gcc's can cause the jump in the function_graph code to the
     global ftrace_stub label to be a short jump instead of a long one.
     As that jump is dynamically converted to jump to the trace code to
     do function graph tracing, and that conversion expects a long jump
     it can corrupt the ftrace_stub itself (it's directly after that
     call).  One way to prevent gcc from using a short jump is to
     declare the ftrace_stub as a weak function, which we do here to
     keep gcc from optimizing too much"

* tag 'trace-v4.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace/x86: Set ftrace_stub to weak to prevent gcc from using short jumps to it
  ftrace: Don't disable irqs when taking the tasklist_lock read_lock
  ftracetest: Add instance created, delete, read and enable event test
2016-05-22 19:40:39 -07:00
Linus Torvalds bd28b14591 x86: remove more uaccess_32.h complexity
I'm looking at trying to possibly merge the 32-bit and 64-bit versions
of the x86 uaccess.h implementation, but first this needs to be cleaned
up.

For example, the 32-bit version of "__copy_from_user_inatomic()" is
mostly the special cases for the constant size, and it's actually almost
never relevant.  Most users aren't actually using a constant size
anyway, and the few cases that do small constant copies are better off
just using __get_user() instead.

So get rid of the unnecessary complexity.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-22 17:21:27 -07:00
Linus Torvalds 5469dc270c Merge branch 'akpm' (patches from Andrew)
Merge more updates from Andrew Morton:

 - the rest of MM

 - KASAN updates

 - procfs updates

 - exit, fork updates

 - printk updates

 - lib/ updates

 - radix-tree testsuite updates

 - checkpatch updates

 - kprobes updates

 - a few other misc bits

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (162 commits)
  samples/kprobes: print out the symbol name for the hooks
  samples/kprobes: add a new module parameter
  kprobes: add the "tls" argument for j_do_fork
  init/main.c: simplify initcall_blacklisted()
  fs/efs/super.c: fix return value
  checkpatch: improve --git <commit-count> shortcut
  checkpatch: reduce number of `git log` calls with --git
  checkpatch: add support to check already applied git commits
  checkpatch: add --list-types to show message types to show or ignore
  checkpatch: advertise the --fix and --fix-inplace options more
  checkpatch: whine about ACCESS_ONCE
  checkpatch: add test for keywords not starting on tabstops
  checkpatch: improve CONSTANT_COMPARISON test for structure members
  checkpatch: add PREFER_IS_ENABLED test
  lib/GCD.c: use binary GCD algorithm instead of Euclidean
  radix-tree: free up the bottom bit of exceptional entries for reuse
  dax: move RADIX_DAX_ definitions to dax.c
  radix-tree: make radix_tree_descend() more useful
  radix-tree: introduce radix_tree_replace_clear_tags()
  radix-tree: tidy up __radix_tree_create()
  ...
2016-05-20 22:31:33 -07:00
Linus Torvalds 087afe8aaf Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes and more updates from David Miller:

 1) Tunneling fixes from Tom Herbert and Alexander Duyck.

 2) AF_UNIX updates some struct sock bit fields with the socket lock,
    whereas setsockopt() sets overlapping ones with locking.  Seperate
    out the synchronized vs.  the AF_UNIX unsynchronized ones to avoid
    corruption.  From Andrey Ryabinin.

 3) Mount BPF filesystem with mount_nodev rather than mount_ns, from
    Eric Biederman.

 4) A couple kmemdup conversions, from Muhammad Falak R Wani.

 5) BPF verifier fixes from Alexei Starovoitov.

 6) Don't let tunneled UDP packets get stuck in socket queues, if
    something goes wrong during the encapsulation just drop the packet
    rather than signalling an error up the call stack.  From Hannes
    Frederic Sowa.

 7) SKB ref after free in batman-adv, from Florian Westphal.

 8) TCP iSCSI, ocfs2, rds, and tipc have to disable BH in it's TCP
    callbacks since the TCP stack runs pre-emptibly now.  From Eric
    Dumazet.

 9) Fix crash in fixed_phy_add, from Rabin Vincent.

10) Fix length checks in xen-netback, from Paul Durrant.

11) Fix mixup in KEY vs KEYID macsec attributes, from Sabrina Dubroca.

12) RDS connection spamming bug fixes from Sowmini Varadhan

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (152 commits)
  net: suppress warnings on dev_alloc_skb
  uapi glibc compat: fix compilation when !__USE_MISC in glibc
  udp: prevent skbs lingering in tunnel socket queues
  bpf: teach verifier to recognize imm += ptr pattern
  bpf: support decreasing order in direct packet access
  net: usb: ch9200: use kmemdup
  ps3_gelic: use kmemdup
  net:liquidio: use kmemdup
  bpf: Use mount_nodev not mount_ns to mount the bpf filesystem
  net: cdc_ncm: update datagram size after changing mtu
  tuntap: correctly wake up process during uninit
  intel: Add support for IPv6 IP-in-IP offload
  ip6_gre: Do not allow segmentation offloads GRE_CSUM is enabled with FOU/GUE
  RDS: TCP: Avoid rds connection churn from rogue SYNs
  RDS: TCP: rds_tcp_accept_worker() must exit gracefully when terminating rds-tcp
  net: sock: move ->sk_shutdown out of bitfields.
  ipv6: Don't reset inner headers in ip6_tnl_xmit
  ip4ip6: Support for GSO/GRO
  ip6ip6: Support for GSO/GRO
  ipv6: Set features for IPv6 tunnels
  ...
2016-05-20 20:01:26 -07:00
Matthew Wilcox e9256efcc8 radix-tree: introduce radix_tree_empty
Commit e614523653 ("radix_tree: add support for multi-order entries")
left the impression that the support for multiorder radix tree entries
was functional.  As soon as Ross tried to use it, it became apparent
that my testing was completely inadequate, and it didn't even work a
little bit for orders that were not a multiple of shift.

This series of patches is the result of about 6 weeks of redesign,
reimplementation, testing, arguing and hair-pulling.  The great news is
that the test-suite is now far better than it was.  That's reflected in
the diffstat for the test-suite alone:

 12 files changed, 436 insertions(+), 28 deletions(-)

The highlight for users of the tree is that the restriction on the order
of inserted entries being >= RADIX_TREE_MAP_SHIFT is now gone; the radix
tree now supports any order between 0 and 64.

For those who are interested in how the tree works, patch 9 is probably
the most interesting one as it introduces the new machinery for handling
sibling entries.

I've tried to be fair in attributing authorship to the person who
contributed the majority of the code in each patch; Ross has been an
invaluable partner in the development of this support and it's fair to
say that each of us has code in every commit.

I should also express my appreciation of the 0day testing.  It prompted
me that I was bloating the tinyconfig in an unacceptable way, and it
bisected to a commit which contained a rather nasty memory-corruption
bug.

This patch (of 29):

The irqdomain code was checking for 0 or 1 entries, not 0 entries like
the comment said they were.  Introduce a new helper that will actually
check for an empty tree.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com>
Cc: Neil Brown <neilb@suse.de>
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
Andy Shevchenko ede9c27749 kernel/sysctl_binary.c: use generic UUID library
UUID library provides uuid_be type and uuid_be_to_bin() function.  This
substitutes open coded variant by generic library calls.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Jens Axboe <axboe@kernel.dk>
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 cf9b1106c8 printk/nmi: flush NMI messages on the system panic
In NMI context, printk() messages are stored into per-CPU buffers to
avoid a possible deadlock.  They are normally flushed to the main ring
buffer via an IRQ work.  But the work is never called when the system
calls panic() in the very same NMI handler.

This patch tries to flush NMI buffers before the crash dump is
generated.  In this case it does not risk a double release and bails out
when the logbuf_lock is already taken.  The aim is to get the messages
into the main ring buffer when possible.  It makes them better
accessible in the vmcore.

Then the patch tries to flush the buffers second time when other CPUs
are down.  It might be more aggressive and reset logbuf_lock.  The aim
is to get the messages available for the consequent kmsg_dump() and
console_flush_on_panic() calls.

The patch causes vprintk_emit() to be called even in NMI context again.
But it is done via printk_deferred() so that the console handling is
skipped.  Consoles use internal locks and we could not prevent a
deadlock easily.  They are explicitly called later when the crash dump
is not generated, see console_flush_on_panic().

Signed-off-by: Petr Mladek <pmladek@suse.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: David Miller <davem@davemloft.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jiri Kosina <jkosina@suse.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-20 17:58:30 -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 b522deabc6 printk/nmi: warn when some message has been lost in NMI context
We could not resize the temporary buffer in NMI context.  Let's warn if
a message is lost.

This is rather theoretical.  printk() should not be used in NMI.  The
only sensible use is when we want to print backtrace from all CPUs.  The
current buffer should be enough for this purpose.

[akpm@linux-foundation.org: whitespace fixlet]
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
Jiri Slaby 0740aa5f63 fork: free thread in copy_process on failure
When using this program (as root):

	#include <err.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <unistd.h>

	#include <sys/io.h>
	#include <sys/types.h>
	#include <sys/wait.h>

	#define ITER 1000
	#define FORKERS 15
	#define THREADS (6000/FORKERS) // 1850 is proc max

	static void fork_100_wait()
	{
		unsigned a, to_wait = 0;

		printf("\t%d forking %d\n", THREADS, getpid());

		for (a = 0; a < THREADS; a++) {
			switch (fork()) {
			case 0:
				usleep(1000);
				exit(0);
				break;
			case -1:
				break;
			default:
				to_wait++;
				break;
			}
		}

		printf("\t%d forked from %d, waiting for %d\n", THREADS, getpid(),
				to_wait);

		for (a = 0; a < to_wait; a++)
			wait(NULL);

		printf("\t%d waited from %d\n", THREADS, getpid());
	}

	static void run_forkers()
	{
		pid_t forkers[FORKERS];
		unsigned a;

		for (a = 0; a < FORKERS; a++) {
			switch ((forkers[a] = fork())) {
			case 0:
				fork_100_wait();
				exit(0);
				break;
			case -1:
				err(1, "DIE fork of %d'th forker", a);
				break;
			default:
				break;
			}
		}

		for (a = 0; a < FORKERS; a++)
			waitpid(forkers[a], NULL, 0);
	}

	int main()
	{
		unsigned a;
		int ret;

		ret = ioperm(10, 20, 0);
		if (ret < 0)
			err(1, "ioperm");

		for (a = 0; a < ITER; a++)
			run_forkers();

		return 0;
	}

kmemleak reports many occurences of this leak:
unreferenced object 0xffff8805917c8000 (size 8192):
  comm "fork-leak", pid 2932, jiffies 4295354292 (age 1871.028s)
  hex dump (first 32 bytes):
    ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff  ................
    ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff  ................
  backtrace:
    [<ffffffff814cfbf5>] kmemdup+0x25/0x50
    [<ffffffff8103ab43>] copy_thread_tls+0x6c3/0x9a0
    [<ffffffff81150174>] copy_process+0x1a84/0x5790
    [<ffffffff811dc375>] wake_up_new_task+0x2d5/0x6f0
    [<ffffffff8115411d>] _do_fork+0x12d/0x820
...

Due to the leakage of the memory items which should have been freed in
arch/x86/kernel/process.c:exit_thread().

Make sure the memory is freed when fork fails later in copy_process.
This is done by calling exit_thread with the thread to kill.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen Liqin <liqin.linux@gmail.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: David Howells <dhowells@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
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
Jiri Slaby e64646946e exit_thread: accept a task parameter to be exited
We need to call exit_thread from copy_process in a fail path.  So make it
accept task_struct as a parameter.

[v2]
* s390: exit_thread_runtime_instr doesn't make sense to be called for
  non-current tasks.
* arm: fix the comment in vfp_thread_copy
* change 'me' to 'tsk' for task_struct
* now we can change only archs that actually have exit_thread

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen Liqin <liqin.linux@gmail.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: David Howells <dhowells@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
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
Michal Hocko ec8d7c14ea mm, oom_reaper: do not mmput synchronously from the oom reaper context
Tetsuo has properly noted that mmput slow path might get blocked waiting
for another party (e.g.  exit_aio waits for an IO).  If that happens the
oom_reaper would be put out of the way and will not be able to process
next oom victim.  We should strive for making this context as reliable
and independent on other subsystems as much as possible.

Introduce mmput_async which will perform the slow path from an async
(WQ) context.  This will delay the operation but that shouldn't be a
problem because the oom_reaper has reclaimed the victim's address space
for most cases as much as possible and the remaining context shouldn't
bind too much memory anymore.  The only exception is when mmap_sem
trylock has failed which shouldn't happen too often.

The issue is only theoretical but not impossible.

Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: David Rientjes <rientjes@google.com>
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
Alexei Starovoitov 1b9b69ecb3 bpf: teach verifier to recognize imm += ptr pattern
Humans don't write C code like:
  u8 *ptr = skb->data;
  int imm = 4;
  imm += ptr;
but from llvm backend point of view 'imm' and 'ptr' are registers and
imm += ptr may be preferred vs ptr += imm depending which register value
will be used further in the code, while verifier can only recognize ptr += imm.
That caused small unrelated changes in the C code of the bpf program to
trigger rejection by the verifier. Therefore teach the verifier to recognize
both ptr += imm and imm += ptr.
For example:
when R6=pkt(id=0,off=0,r=62) R7=imm22
after r7 += r6 instruction
will be R6=pkt(id=0,off=0,r=62) R7=pkt(id=0,off=22,r=62)

Fixes: 969bf05eb3 ("bpf: direct packet access")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-20 19:53:03 -04:00
Alexei Starovoitov d91b28ed42 bpf: support decreasing order in direct packet access
when packet headers are accessed in 'decreasing' order (like TCP port
may be fetched before the program reads IP src) the llvm may generate
the following code:
[...]                // R7=pkt(id=0,off=22,r=70)
r2 = *(u32 *)(r7 +0) // good access
[...]
r7 += 40             // R7=pkt(id=0,off=62,r=70)
r8 = *(u32 *)(r7 +0) // good access
[...]
r1 = *(u32 *)(r7 -20) // this one will fail though it's within a safe range
                      // it's doing *(u32*)(skb->data + 42)
Fix verifier to recognize such code pattern

Alos turned out that 'off > range' condition is not a verifier bug.
It's a buggy program that may do something like:
if (ptr + 50 > data_end)
  return 0;
ptr += 60;
*(u32*)ptr;
in such case emit
"invalid access to packet, off=0 size=4, R1(id=0,off=60,r=50)" error message,
so all information is available for the program author to fix the program.

Fixes: 969bf05eb3 ("bpf: direct packet access")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-20 19:53:03 -04:00
Eric W. Biederman e27f4a942a bpf: Use mount_nodev not mount_ns to mount the bpf filesystem
While reviewing the filesystems that set FS_USERNS_MOUNT I spotted the
bpf filesystem.  Looking at the code I saw a broken usage of mount_ns
with current->nsproxy->mnt_ns. As the code does not acquire a
reference to the mount namespace it can not possibly be correct to
store the mount namespace on the superblock as it does.

Replace mount_ns with mount_nodev so that each mount of the bpf
filesystem returns a distinct instance, and the code is not buggy.

In discussion with Hannes Frederic Sowa it was reported that the use
of mount_ns was an attempt to have one bpf instance per mount
namespace, in an attempt to keep resources that pin resources from
hiding.  That intent simply does not work, the vfs is not built to
allow that kind of behavior.  Which means that the bpf filesystem
really is buggy both semantically and in it's implemenation as it does
not nor can it implement the original intent.

This change is userspace visible, but my experience with similar
filesystems leads me to believe nothing will break with a model of each
mount of the bpf filesystem is distinct from all others.

Fixes: b2197755b2 ("bpf: add support for persistent maps/progs")
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-20 19:45:40 -04:00
Daniel Borkmann b7552e1bcc bpf: rather use get_random_int for randomizations
Start address randomization and blinding in BPF currently use
prandom_u32(). prandom_u32() values are not exposed to unpriviledged
user space to my knowledge, but given other kernel facilities such as
ASLR, stack canaries, etc make use of stronger get_random_int(), we
better make use of it here as well given blinding requests successively
new random values. get_random_int() has minimal entropy pool depletion,
is not cryptographically secure, but doesn't need to be for our use
cases here.

Suggested-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-20 11:18:21 -07:00
Soumya PN 6112a300c9 ftrace: Don't disable irqs when taking the tasklist_lock read_lock
In ftrace.c inside the function alloc_retstack_tasklist() (which will be
invoked when function_graph tracing is on) the tasklist_lock is being
held as reader while iterating through a list of threads. Here the lock
is being held as reader with irqs disabled. The tasklist_lock is never
write_locked in interrupt context so it is safe to not disable interrupts
for the duration of read_lock in this block which, can be significant,
given the block of code iterates through all threads. Hence changing the
code to call read_lock() and read_unlock() instead of read_lock_irqsave()
and read_unlock_irqrestore().

A similar change was made in commits: 8063e41d2f ("tracing: Change
syscall_*regfunc() to check PF_KTHREAD and use for_each_process_thread()")'
and 3472eaa1f1 ("sched: normalize_rt_tasks(): Don't use _irqsave for
tasklist_lock, use task_rq_lock()")'

Link: http://lkml.kernel.org/r/1463500874-77480-1-git-send-email-soumya.p.n@hpe.com

Signed-off-by: Soumya PN <soumya.p.n@hpe.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-05-20 13:19:37 -04:00
Linus Torvalds c04a588029 powerpc updates for 4.7
Highlights:
  - Support for Power ISA 3.0 (Power9) Radix Tree MMU from Aneesh Kumar K.V
  - Live patching support for ppc64le (also merged via livepatching.git)
 
 Various cleanups & minor fixes from:
  - Aaro Koskinen, Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V,
    Chris Smart, Daniel Axtens, Frederic Barrat, Gavin Shan, Ian Munsie, Lennart
    Sorensen, Madhavan Srinivasan, Mahesh Salgaonkar, Markus Elfring, Michael
    Ellerman, Oliver O'Halloran, Paul Gortmaker, Paul Mackerras, Rashmica Gupta,
    Russell Currey, Suraj Jitindar Singh, Thiago Jung Bauermann, Valentin
    Rothberg, Vipin K Parashar.
 
 General:
  - Update LMB associativity index during DLPAR add/remove from Nathan Fontenot
  - Fix branching to OOL handlers in relocatable kernel from Hari Bathini
  - Add support for userspace Power9 copy/paste from Chris Smart
  - Always use STRICT_MM_TYPECHECKS from Michael Ellerman
  - Add mask of possible MMU features from Michael Ellerman
 
 PCI:
  - Enable pass through of NVLink to guests from Alexey Kardashevskiy
  - Cleanups in preparation for powernv PCI hotplug from Gavin Shan
  - Don't report error in eeh_pe_reset_and_recover() from Gavin Shan
  - Restore initial state in eeh_pe_reset_and_recover() from Gavin Shan
  - Revert "powerpc/eeh: Fix crash in eeh_add_device_early() on Cell" from Guilherme G. Piccoli
  - Remove the dependency on EEH struct in DDW mechanism from Guilherme G. Piccoli
 
 selftests:
  - Test cp_abort during context switch from Chris Smart
  - Add several tests for transactional memory support from Rashmica Gupta
 
 perf:
  - Add support for sampling interrupt register state from Anju T
  - Add support for unwinding perf-stackdump from Chandan Kumar
 
 cxl:
  - Configure the PSL for two CAPI ports on POWER8NVL from Philippe Bergheaud
  - Allow initialization on timebase sync failures from Frederic Barrat
  - Increase timeout for detection of AFU mmio hang from Frederic Barrat
  - Handle num_of_processes larger than can fit in the SPA from Ian Munsie
  - Ensure PSL interrupt is configured for contexts with no AFU IRQs from Ian Munsie
  - Add kernel API to allow a context to operate with relocate disabled from Ian Munsie
  - Check periodically the coherent platform function's state from Christophe Lombard
 
 Freescale:
  - Updates from Scott: "Contains 86xx fixes, minor device tree fixes, an erratum
    workaround, and a kconfig dependency fix."
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Merge tag 'powerpc-4.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:
 "Highlights:
   - Support for Power ISA 3.0 (Power9) Radix Tree MMU from Aneesh Kumar K.V
   - Live patching support for ppc64le (also merged via livepatching.git)

  Various cleanups & minor fixes from:
   - Aaro Koskinen, Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V,
     Chris Smart, Daniel Axtens, Frederic Barrat, Gavin Shan, Ian Munsie,
     Lennart Sorensen, Madhavan Srinivasan, Mahesh Salgaonkar, Markus Elfring,
     Michael Ellerman, Oliver O'Halloran, Paul Gortmaker, Paul Mackerras,
     Rashmica Gupta, Russell Currey, Suraj Jitindar Singh, Thiago Jung
     Bauermann, Valentin Rothberg, Vipin K Parashar.

  General:
   - Update LMB associativity index during DLPAR add/remove from Nathan
     Fontenot
   - Fix branching to OOL handlers in relocatable kernel from Hari Bathini
   - Add support for userspace Power9 copy/paste from Chris Smart
   - Always use STRICT_MM_TYPECHECKS from Michael Ellerman
   - Add mask of possible MMU features from Michael Ellerman

  PCI:
   - Enable pass through of NVLink to guests from Alexey Kardashevskiy
   - Cleanups in preparation for powernv PCI hotplug from Gavin Shan
   - Don't report error in eeh_pe_reset_and_recover() from Gavin Shan
   - Restore initial state in eeh_pe_reset_and_recover() from Gavin Shan
   - Revert "powerpc/eeh: Fix crash in eeh_add_device_early() on Cell"
     from Guilherme G Piccoli
   - Remove the dependency on EEH struct in DDW mechanism from Guilherme
     G Piccoli

  selftests:
   - Test cp_abort during context switch from Chris Smart
   - Add several tests for transactional memory support from Rashmica
     Gupta

  perf:
   - Add support for sampling interrupt register state from Anju T
   - Add support for unwinding perf-stackdump from Chandan Kumar

  cxl:
   - Configure the PSL for two CAPI ports on POWER8NVL from Philippe
     Bergheaud
   - Allow initialization on timebase sync failures from Frederic Barrat
   - Increase timeout for detection of AFU mmio hang from Frederic
     Barrat
   - Handle num_of_processes larger than can fit in the SPA from Ian
     Munsie
   - Ensure PSL interrupt is configured for contexts with no AFU IRQs
     from Ian Munsie
   - Add kernel API to allow a context to operate with relocate disabled
     from Ian Munsie
   - Check periodically the coherent platform function's state from
     Christophe Lombard

  Freescale:
   - Updates from Scott: "Contains 86xx fixes, minor device tree fixes,
     an erratum workaround, and a kconfig dependency fix."

* tag 'powerpc-4.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (192 commits)
  powerpc/86xx: Fix PCI interrupt map definition
  powerpc/86xx: Move pci1 definition to the include file
  powerpc/fsl: Fix build of the dtb embedded kernel images
  powerpc/fsl: Fix rcpm compatible string
  powerpc/fsl: Remove FSL_SOC dependency from FSL_LBC
  powerpc/fsl-pci: Add a workaround for PCI 5 errata
  powerpc/fsl: Fix SPI compatible on t208xrdb and t1040rdb
  powerpc/powernv/npu: Add PE to PHB's list
  powerpc/powernv: Fix insufficient memory allocation
  powerpc/iommu: Remove the dependency on EEH struct in DDW mechanism
  Revert "powerpc/eeh: Fix crash in eeh_add_device_early() on Cell"
  powerpc/eeh: Drop unnecessary label in eeh_pe_change_owner()
  powerpc/eeh: Ignore handlers in eeh_pe_reset_and_recover()
  powerpc/eeh: Restore initial state in eeh_pe_reset_and_recover()
  powerpc/eeh: Don't report error in eeh_pe_reset_and_recover()
  Revert "powerpc/powernv: Exclude root bus in pnv_pci_reset_secondary_bus()"
  powerpc/powernv/npu: Enable NVLink pass through
  powerpc/powernv/npu: Rework TCE Kill handling
  powerpc/powernv/npu: Add set/unset window helpers
  powerpc/powernv/ioda2: Export debug helper pe_level_printk()
  ...
2016-05-20 10:12:41 -07:00
Linus Torvalds a1c28b75a9 Merge branch 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm
Pull ARM updates from Russell King:
 "Changes included in this pull request:

   - revert pxa2xx-flash back to using ioremap_cached() and switch
     memremap() to use arch_memremap_wb()

   - remove pci=firmware command line argument handling

   - remove unnecessary arm_dma_set_mask() implementation, the generic
     implementation will do for ARM

   - removal of the ARM kallsyms "hack" to work around mode switching
     veneers and vectors located below PAGE_OFFSET

   - tidy up build system output a little

   - add L2 cache power management DT bindings

   - remove duplicated local_irq_disable() in reboot paths

   - handle AMBA primecell devices better at registration time with PM
     domains (needed for Samsung SoCs)

   - ARM specific preparation to support Keystone II kexec"

* 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm:
  ARM: 8567/1: cache-uniphier: activate ways for secondary CPUs
  ARM: 8570/2: Documentation: devicetree: Add PL310 PM bindings
  ARM: 8569/1: pl2x0: Add OF control of cache power management
  ARM: 8568/1: reboot: remove duplicated local_irq_disable()
  ARM: 8566/1: drivers: amba: properly handle devices with power domains
  ARM: provide arm_has_idmap_alias() helper
  ARM: kexec: remove 512MB restriction on kexec crashdump
  ARM: provide improved virt_to_idmap() functionality
  ARM: kexec: fix crashkernel= handling
  ARM: 8557/1: specify install, zinstall, and uinstall as PHONY targets
  ARM: 8562/1: suppress "include/generated/mach-types.h is up to date."
  ARM: 8553/1: kallsyms: remove --page-offset command line option
  ARM: 8552/1: kallsyms: remove special lower address limit for CONFIG_ARM
  ARM: 8555/1: kallsyms: ignore ARM mode switching veneers
  ARM: 8548/1: dma-mapping: remove arm_dma_set_mask()
  ARM: 8554/1: kernel: pci: remove pci=firmware command line parameter handling
  ARM: memremap: implement arch_memremap_wb()
  memremap: add arch specific hook for MEMREMAP_WB mappings
  mtd: pxa2xx-flash: switch back from memremap to ioremap_cached
  ARM: reintroduce ioremap_cached() for creating cached I/O mappings
2016-05-20 10:01:38 -07:00
Ingo Molnar 21f77d231f perf/core improvements and fixes:
User visible:
 
 - Honour the kernel.perf_event_max_stack knob more precisely by not counting
   PERF_CONTEXT_{KERNEL,USER} when deciding when to stop adding entries to
   the perf_sample->ip_callchain[] array (Arnaldo Carvalho de Melo)
 
 - Fix identation of 'stalled-backend-cycles' in 'perf stat' (Namhyung Kim)
 
 - Update runtime using 'cpu-clock' event in 'perf stat' (Namhyung Kim)
 
 - Use 'cpu-clock' for cpu targets in 'perf stat' (Namhyung Kim)
 
 - Avoid fractional digits for integer scales in 'perf stat' (Andi Kleen)
 
 - Store vdso buildid unconditionally, as it appears in callchains and
   we're not checking those when creating the build-id table, so we
   end up not being able to resolve VDSO symbols when doing analysis
   on a different machine than the one where recording was done, possibly
   of a different arch even (arm -> x86_64) (He Kuang)
 
 Infrastructure:
 
 - Generalize max_stack sysctl handler, will be used for configuring
   multiple kernel knobs related to callchains (Arnaldo Carvalho de Melo)
 
 Cleanups:
 
 - Introduce DSO__NAME_KALLSYMS and DSO__NAME_KCORE, to stop using
   open coded strings (Masami Hiramatsu)
 
 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Merge tag 'perf-core-for-mingo-20160516' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:

User visible changes:

- Honour the kernel.perf_event_max_stack knob more precisely by not counting
  PERF_CONTEXT_{KERNEL,USER} when deciding when to stop adding entries to
  the perf_sample->ip_callchain[] array (Arnaldo Carvalho de Melo)

- Fix identation of 'stalled-backend-cycles' in 'perf stat' (Namhyung Kim)

- Update runtime using 'cpu-clock' event in 'perf stat' (Namhyung Kim)

- Use 'cpu-clock' for cpu targets in 'perf stat' (Namhyung Kim)

- Avoid fractional digits for integer scales in 'perf stat' (Andi Kleen)

- Store vdso buildid unconditionally, as it appears in callchains and
  we're not checking those when creating the build-id table, so we
  end up not being able to resolve VDSO symbols when doing analysis
  on a different machine than the one where recording was done, possibly
  of a different arch even (arm -> x86_64) (He Kuang)

Infrastructure changes:

- Generalize max_stack sysctl handler, will be used for configuring
  multiple kernel knobs related to callchains (Arnaldo Carvalho de Melo)

Cleanups:

- Introduce DSO__NAME_KALLSYMS and DSO__NAME_KCORE, to stop using
  open coded strings (Masami Hiramatsu)

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-20 08:20:14 +02:00
Linus Torvalds a05a70db34 Merge branch 'akpm' (patches from Andrew)
Merge updates from Andrew Morton:

 - fsnotify fix

 - poll() timeout fix

 - a few scripts/ tweaks

 - debugobjects updates

 - the (small) ocfs2 queue

 - Minor fixes to kernel/padata.c

 - Maybe half of the MM queue

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (117 commits)
  mm, page_alloc: restore the original nodemask if the fast path allocation failed
  mm, page_alloc: uninline the bad page part of check_new_page()
  mm, page_alloc: don't duplicate code in free_pcp_prepare
  mm, page_alloc: defer debugging checks of pages allocated from the PCP
  mm, page_alloc: defer debugging checks of freed pages until a PCP drain
  cpuset: use static key better and convert to new API
  mm, page_alloc: inline pageblock lookup in page free fast paths
  mm, page_alloc: remove unnecessary variable from free_pcppages_bulk
  mm, page_alloc: pull out side effects from free_pages_check
  mm, page_alloc: un-inline the bad part of free_pages_check
  mm, page_alloc: check multiple page fields with a single branch
  mm, page_alloc: remove field from alloc_context
  mm, page_alloc: avoid looking up the first zone in a zonelist twice
  mm, page_alloc: shortcut watermark checks for order-0 pages
  mm, page_alloc: reduce cost of fair zone allocation policy retry
  mm, page_alloc: shorten the page allocator fast path
  mm, page_alloc: check once if a zone has isolated pageblocks
  mm, page_alloc: move __GFP_HARDWALL modifications out of the fastpath
  mm, page_alloc: simplify last cpupid reset
  mm, page_alloc: remove unnecessary initialisation from __alloc_pages_nodemask()
  ...
2016-05-19 20:00:06 -07:00
Vlastimil Babka 002f290627 cpuset: use static key better and convert to new API
An important function for cpusets is cpuset_node_allowed(), which
optimizes on the fact if there's a single root CPU set, it must be
trivially allowed.  But the check "nr_cpusets() <= 1" doesn't use the
cpusets_enabled_key static key the right way where static keys eliminate
branching overhead with jump labels.

This patch converts it so that static key is used properly.  It's also
switched to the new static key API and the checking functions are
converted to return bool instead of int.  We also provide a new variant
__cpuset_zone_allowed() which expects that the static key check was
already done and they key was enabled.  This is needed for
get_page_from_freelist() where we want to also avoid the relatively
slower check when ALLOC_CPUSET is not set in alloc_flags.

The impact on the page allocator microbenchmark is less than expected
but the cleanup in itself is worthwhile.

                                             4.6.0-rc2                  4.6.0-rc2
                                       multcheck-v1r20               cpuset-v1r20
  Min      alloc-odr0-1               348.00 (  0.00%)           348.00 (  0.00%)
  Min      alloc-odr0-2               254.00 (  0.00%)           254.00 (  0.00%)
  Min      alloc-odr0-4               213.00 (  0.00%)           213.00 (  0.00%)
  Min      alloc-odr0-8               186.00 (  0.00%)           183.00 (  1.61%)
  Min      alloc-odr0-16              173.00 (  0.00%)           171.00 (  1.16%)
  Min      alloc-odr0-32              166.00 (  0.00%)           163.00 (  1.81%)
  Min      alloc-odr0-64              162.00 (  0.00%)           159.00 (  1.85%)
  Min      alloc-odr0-128             160.00 (  0.00%)           157.00 (  1.88%)
  Min      alloc-odr0-256             169.00 (  0.00%)           166.00 (  1.78%)
  Min      alloc-odr0-512             180.00 (  0.00%)           180.00 (  0.00%)
  Min      alloc-odr0-1024            188.00 (  0.00%)           187.00 (  0.53%)
  Min      alloc-odr0-2048            194.00 (  0.00%)           193.00 (  0.52%)
  Min      alloc-odr0-4096            199.00 (  0.00%)           198.00 (  0.50%)
  Min      alloc-odr0-8192            202.00 (  0.00%)           201.00 (  0.50%)
  Min      alloc-odr0-16384           203.00 (  0.00%)           202.00 (  0.49%)

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Zefan Li <lizefan@huawei.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
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
Hugh Dickins 52b6f46bc1 mm: /proc/sys/vm/stat_refresh to force vmstat update
Provide /proc/sys/vm/stat_refresh to force an immediate update of
per-cpu into global vmstats: useful to avoid a sleep(2) or whatever
before checking counts when testing.  Originally added to work around a
bug which left counts stranded indefinitely on a cpu going idle (an
inaccuracy magnified when small below-batch numbers represent "huge"
amounts of memory), but I believe that bug is now fixed: nonetheless,
this is still a useful knob.

Its schedule_on_each_cpu() is probably too expensive just to fold into
reading /proc/meminfo itself: give this mode 0600 to prevent abuse.
Allow a write or a read to do the same: nothing to read, but "grep -h
Shmem /proc/sys/vm/stat_refresh /proc/meminfo" is convenient.  Oh, and
since global_page_state() itself is careful to disguise any underflow as
0, hack in an "Invalid argument" and pr_warn() if a counter is negative
after the refresh - this helped to fix a misaccounting of
NR_ISOLATED_FILE in my migration code.

But on recent kernels, I find that NR_ALLOC_BATCH and NR_PAGES_SCANNED
often go negative some of the time.  I have not yet worked out why, but
have no evidence that it's actually harmful.  Punt for the moment by
just ignoring the anomaly on those.

Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Yang Shi <yang.shi@linaro.org>
Cc: Ning Qu <quning@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
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
Andrew Morton 0edaf86cf1 include/linux/nodemask.h: create next_node_in() helper
Lots of code does

	node = next_node(node, XXX);
	if (node == MAX_NUMNODES)
		node = first_node(XXX);

so create next_node_in() to do this and use it in various places.

[mhocko@suse.com: use next_node_in() helper]
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Hui Zhu <zhuhui@xiaomi.com>
Cc: Wang Xiaoqiang <wangxq10@lzu.edu.cn>
Cc: Johannes Weiner <hannes@cmpxchg.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
Joonsoo Kim 0139aa7b7f mm: rename _count, field of the struct page, to _refcount
Many developers already know that field for reference count of the
struct page is _count and atomic type.  They would try to handle it
directly and this could break the purpose of page reference count
tracepoint.  To prevent direct _count modification, this patch rename it
to _refcount and add warning message on the code.  After that, developer
who need to handle reference count will find that field should not be
accessed directly.

[akpm@linux-foundation.org: fix comments, per Vlastimil]
[akpm@linux-foundation.org: Documentation/vm/transhuge.txt too]
[sfr@canb.auug.org.au: sync ethernet driver changes]
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Sunil Goutham <sgoutham@cavium.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Manish Chopra <manish.chopra@qlogic.com>
Cc: Yuval Mintz <yuval.mintz@qlogic.com>
Cc: Tariq Toukan <tariqt@mellanox.com>
Cc: Saeed Mahameed <saeedm@mellanox.com>
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 19d795b677 kernel/padata.c: hide unused functions
A recent cleanup removed some exported functions that were not used
anywhere, which in turn exposed the fact that some other functions in
the same file are only used in some configurations.

We now get a warning about them when CONFIG_HOTPLUG_CPU is disabled:

  kernel/padata.c:670:12: error: '__padata_remove_cpu' defined but not used [-Werror=unused-function]
   static int __padata_remove_cpu(struct padata_instance *pinst, int cpu)
              ^~~~~~~~~~~~~~~~~~~
  kernel/padata.c:650:12: error: '__padata_add_cpu' defined but not used [-Werror=unused-function]
   static int __padata_add_cpu(struct padata_instance *pinst, int cpu)

This rearranges the code so the __padata_remove_cpu/__padata_add_cpu
functions are within the #ifdef that protects the code that calls them.

[akpm@linux-foundation.org: coding-style fixes]
Fixes: 4ba6d78c671e ("kernel/padata.c: removed unused code")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Richard Cochran <rcochran@linutronix.de>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
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
Richard Cochran 815613da6a kernel/padata.c: removed unused code
By accident I stumbled across code that has never been used.  This
driver has EXPORT_SYMBOL functions, and the only user of the code is
pcrypt.c, but this only uses a subset of the exported symbols.

According to 'git log -G', the functions, padata_set_cpumasks,
padata_add_cpu, and padata_remove_cpu have never been used since they
were first introduced.  This patch removes the unused code.

On one 64 bit build, with CRYPTO_PCRYPT built in, the text is more than
4k smaller.

  kbuild_hp> size $KBUILD_OUTPUT/vmlinux
      text    data     bss      dec hex    filename
  10566658 4678360 1122304 16367322 f9beda vmlinux
  10561984 4678360 1122304 16362648 f9ac98 vmlinux

On another config, 32 bit, the saving is about 0.5k bytes.

  kbuild_hp-x86> size $KBUILD_OUTPUT/vmlinux
  6012005 2409513 2785280 11206798 ab008e vmlinux
  6011491 2409513 2785280 11206284 aafe8c vmlinux

Signed-off-by: Richard Cochran <rcochran@linutronix.de>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
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
Du, Changbin b9fdac7f66 debugobjects: insulate non-fixup logic related to static obj from fixup callbacks
When activating a static object we need make sure that the object is
tracked in the object tracker.  If it is a non-static object then the
activation is illegal.

In previous implementation, each subsystem need take care of this in
their fixup callbacks.  Actually we can put it into debugobjects core.
Thus we can save duplicated code, and have *pure* fixup callbacks.

To achieve this, a new callback "is_static_object" is introduced to let
the type specific code decide whether a object is static or not.  If
yes, we take it into object tracker, otherwise give warning and invoke
fixup callback.

This change has paassed debugobjects selftest, and I also do some test
with all debugobjects supports enabled.

At last, I have a concern about the fixups that can it change the object
which is in incorrect state on fixup? Because the 'addr' may not point
to any valid object if a non-static object is not tracked.  Then Change
such object can overwrite someone's memory and cause unexpected
behaviour.  For example, the timer_fixup_activate bind timer to function
stub_timer.

Link: http://lkml.kernel.org/r/1462576157-14539-1-git-send-email-changbin.du@intel.com
[changbin.du@intel.com: improve code comments where invoke the new is_static_object callback]
  Link: http://lkml.kernel.org/r/1462777431-8171-1-git-send-email-changbin.du@intel.com
Signed-off-by: Du, Changbin <changbin.du@intel.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Josh Triplett <josh@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tejun Heo <tj@kernel.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
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
Du, Changbin 3263d28eb5 rcu: update debugobjects fixup callbacks return type
Update the return type to use bool instead of int, corresponding to
cheange (debugobjects: make fixup functions return bool instead of int).

Signed-off-by: Du, Changbin <changbin.du@intel.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Josh Triplett <josh@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tejun Heo <tj@kernel.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
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
Du, Changbin e3252464da timer: update debugobjects fixup callbacks return type
Update the return type to use bool instead of int, corresponding to
cheange (debugobjects: make fixup functions return bool instead of int).

Signed-off-by: Du, Changbin <changbin.du@intel.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Josh Triplett <josh@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tejun Heo <tj@kernel.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
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
Du, Changbin 02a982a6ec workqueue: update debugobjects fixup callbacks return type
Update the return type to use bool instead of int, corresponding to
change (debugobjects: make fixup functions return bool instead of int)

Signed-off-by: Du, Changbin <changbin.du@intel.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Josh Triplett <josh@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tejun Heo <tj@kernel.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
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
Deepa Dinamani 8e4f70e218 time: remove timespec_add_safe()
All references to timespec_add_safe() now use timespec64_add_safe().

The plan is to replace struct timespec references with struct timespec64
throughout the kernel as timespec is not y2038 safe.

Drop timespec_add_safe() and use timespec64_add_safe() for all
architectures.

Link: http://lkml.kernel.org/r/1461947989-21926-4-git-send-email-deepa.kernel@gmail.com
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Acked-by: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-19 19:12:14 -07:00
Deepa Dinamani bc2c53e5f1 time: add missing implementation for timespec64_add_safe()
timespec64_add_safe() has been defined in time64.h for 64 bit systems.
But, 32 bit systems only have an extern function prototype defined.
Provide a definition for the above function.

The function will be necessary as part of y2038 changes.  struct
timespec is not y2038 safe.  All references to timespec will be replaced
by struct timespec64.  The function is meant to be a replacement for
timespec_add_safe().

The implementation is similar to timespec_add_safe().

Link: http://lkml.kernel.org/r/1461947989-21926-2-git-send-email-deepa.kernel@gmail.com
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Acked-by: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-19 19:12:14 -07:00
Linus Torvalds 07b75260eb Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
Pull MIPS updates from Ralf Baechle:
 "This is the main pull request for MIPS for 4.7.  Here's the summary of
  the changes:

   - ATH79: Support for DTB passuing using the UHI boot protocol
   - ATH79: Remove support for builtin DTB.
   - ATH79: Add zboot debug serial support.
   - ATH79: Add initial support for Dragino MS14 (Dragine 2), Onion Omega
            and DPT-Module.
   - ATH79: Update devicetree clock support for AR9132 and AR9331.
   - ATH79: Cleanup the DT code.
   - ATH79: Support newer SOCs in ath79_ddr_ctrl_init.
   - ATH79: Fix regression in PCI window initialization.
   - BCM47xx: Move SPROM driver to drivers/firmware/
   - BCM63xx: Enable partition parser in defconfig.
   - BMIPS: BMIPS5000 has I cache filing from D cache
   - BMIPS: BMIPS: Add cpu-feature-overrides.h
   - BMIPS: Add Whirlwind support
   - BMIPS: Adjust mips-hpt-frequency for BCM7435
   - BMIPS: Remove maxcpus from BCM97435SVMB DTS
   - BMIPS: Add missing 7038 L1 register cells to BCM7435
   - BMIPS: Various tweaks to initialization code.
   - BMIPS: Enable partition parser in defconfig.
   - BMIPS: Cache tweaks.
   - BMIPS: Add UART, I2C and SATA devices to DT.
   - BMIPS: Add BCM6358 and BCM63268support
   - BMIPS: Add device tree example for BCM6358.
   - BMIPS: Improve Improve BCM6328 and BCM6368 device trees
   - Lantiq: Add support for device tree file from boot loader
   - Lantiq: Allow build with no built-in DT.
   - Loongson 3: Reserve 32MB for RS780E integrated GPU.
   - Loongson 3: Fix build error after ld-version.sh modification
   - Loongson 3: Move chipset ACPI code from drivers to arch.
   - Loongson 3: Speedup irq processing.
   - Loongson 3: Add basic Loongson 3A support.
   - Loongson 3: Set cache flush handlers to nop.
   - Loongson 3: Invalidate special TLBs when needed.
   - Loongson 3: Fast TLB refill handler.
   - MT7620: Fallback strategy for invalid syscfg0.
   - Netlogic: Fix CP0_EBASE redefinition warnings
   - Octeon: Initialization fixes
   - Octeon: Add DTS files for the D-Link DSR-1000N and EdgeRouter Lite
   - Octeon: Enable add Octeon-drivers in cavium_octeon_defconfig
   - Octeon: Correctly handle endian-swapped initramfs images.
   - Octeon: Support CN73xx, CN75xx and CN78xx.
   - Octeon: Remove dead code from cvmx-sysinfo.
   - Octeon: Extend number of supported CPUs past 32.
   - Octeon: Remove some code limiting NR_IRQS to 255.
   - Octeon: Simplify octeon_irq_ciu_gpio_set_type.
   - Octeon: Mark some functions __init in smp.c
   - Octeon: Octeon: Add Octeon III CN7xxx interface detection
   - PIC32: Add serial driver and bindings for it.
   - PIC32: Add PIC32 deadman timer driver and bindings.
   - PIC32: Add PIC32 clock timer driver and bindings.
   - Pistachio: Determine SoC revision during boot
   - Sibyte: Fix Kconfig dependencies of SIBYTE_BUS_WATCHER.
   - Sibyte: Strip redundant comments from bcm1480_regs.h.
   - Panic immediately if panic_on_oops is set.
   - module: fix incorrect IS_ERR_VALUE macro usage.
   - module: Make consistent use of pr_*
   - Remove no longer needed work_on_cpu() call.
   - Remove CONFIG_IPV6_PRIVACY from defconfigs.
   - Fix registers of non-crashing CPUs in dumps.
   - Handle MIPSisms in new vmcore_elf32_check_arch.
   - Select CONFIG_HANDLE_DOMAIN_IRQ and make it work.
   - Allow RIXI to be used on non-R2 or R6 cores.
   - Reserve nosave data for hibernation
   - Fix siginfo.h to use strict POSIX types.
   - Don't unwind user mode with EVA.
   - Fix watchpoint restoration
   - Ptrace watchpoints for R6.
   - Sync icache when it fills from dcache
   - I6400 I-cache fills from dcache.
   - Various MSA fixes.
   - Cleanup MIPS_CPU_* definitions.
   - Signal: Move generic copy_siginfo to signal.h
   - Signal: Fix uapi include in exported asm/siginfo.h
   - Timer fixes for sake of KVM.
   - XPA TLB refill fixes.
   - Treat perf counter feature
   - Update John Crispin's email address
   - Add PIC32 watchdog and bindings.
   - Handle R10000 LL/SC bug in set_pte()
   - cpufreq: Various fixes for Longson1.
   - R6: Fix R2 emulation.
   - mathemu: Cosmetic fix to ADDIUPC emulation, plenty of other small fixes
   - ELF: ABI and FP fixes.
   - Allow for relocatable kernel and use that to support KASLR.
   - Fix CPC_BASE_ADDR mask
   - Plenty fo smp-cps, CM, R6 and M6250 fixes.
   - Make reset_control_ops const.
   - Fix kernel command line handling of leading whitespace.
   - Cleanups to cache handling.
   - Add brcm, bcm6345-l1-intc device tree bindings.
   - Use generic clkdev.h header
   - Remove CLK_IS_ROOT usage.
   - Misc small cleanups.
   - CM: Fix compilation error when !MIPS_CM
   - oprofile: Fix a preemption issue
   - Detect DSP ASE v3 support:1"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (275 commits)
  MIPS: pic32mzda: fix getting timer clock rate.
  MIPS: ath79: fix regression in PCI window initialization
  MIPS: ath79: make ath79_ddr_ctrl_init() compatible for newer SoCs
  MIPS: Fix VZ probe gas errors with binutils <2.24
  MIPS: perf: Fix I6400 event numbers
  MIPS: DEC: Export `ioasic_ssr_lock' to modules
  MIPS: MSA: Fix a link error on `_init_msa_upper' with older GCC
  MIPS: CM: Fix compilation error when !MIPS_CM
  MIPS: Fix genvdso error on rebuild
  USB: ohci-jz4740: Remove obsolete driver
  MIPS: JZ4740: Probe OHCI platform device via DT
  MIPS: JZ4740: Qi LB60: Remove support for AVT2 variant
  MIPS: pistachio: Determine SoC revision during boot
  MIPS: BMIPS: Adjust mips-hpt-frequency for BCM7435
  mips: mt7620: fallback to SDRAM when syscfg0 does not have a valid value for the memory type
  MIPS: Prevent "restoration" of MSA context in non-MSA kernels
  MIPS: cevt-r4k: Dynamically calculate min_delta_ns
  MIPS: malta-time: Take seconds into account
  MIPS: malta-time: Start GIC count before syncing to RTC
  MIPS: Force CPUs to lose FP context during mode switches
  ...
2016-05-19 10:02:26 -07:00
Linus Torvalds f4f27d0028 Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security subsystem updates from James Morris:
 "Highlights:

   - A new LSM, "LoadPin", from Kees Cook is added, which allows forcing
     of modules and firmware to be loaded from a specific device (this
     is from ChromeOS, where the device as a whole is verified
     cryptographically via dm-verity).

     This is disabled by default but can be configured to be enabled by
     default (don't do this if you don't know what you're doing).

   - Keys: allow authentication data to be stored in an asymmetric key.
     Lots of general fixes and updates.

   - SELinux: add restrictions for loading of kernel modules via
     finit_module().  Distinguish non-init user namespace capability
     checks.  Apply execstack check on thread stacks"

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (48 commits)
  LSM: LoadPin: provide enablement CONFIG
  Yama: use atomic allocations when reporting
  seccomp: Fix comment typo
  ima: add support for creating files using the mknodat syscall
  ima: fix ima_inode_post_setattr
  vfs: forbid write access when reading a file into memory
  fs: fix over-zealous use of "const"
  selinux: apply execstack check on thread stacks
  selinux: distinguish non-init user namespace capability checks
  LSM: LoadPin for kernel file loading restrictions
  fs: define a string representation of the kernel_read_file_id enumeration
  Yama: consolidate error reporting
  string_helpers: add kstrdup_quotable_file
  string_helpers: add kstrdup_quotable_cmdline
  string_helpers: add kstrdup_quotable
  selinux: check ss_initialized before revalidating an inode label
  selinux: delay inode label lookup as long as possible
  selinux: don't revalidate an inode's label when explicitly setting it
  selinux: Change bool variable name to index.
  KEYS: Add KEYCTL_DH_COMPUTE command
  ...
2016-05-19 09:21:36 -07:00
Linus Torvalds 2600a46ee0 This includes two new updates for the ftrace infrastructure.
1) With the changing of the code for filtering events by pid, from
   a list of pids to a bitmask, we can now easily implement following
   forks. With a new tracing option "event-fork" which, when set, will
   have tasks with pids in set_event_pid, when they fork, to have their
   child pids added to set_event_pid and the child will be traced as well.
 
   Note, if "event-fork" is set and a task with its pid in set_event_pid
   exits, its pid will be removed from set_event_pid
 
 2) The addition of Tom Zanussi's hist triggers. This includes a very
    thorough documentatino on how to use the hist triggers with events.
    This introduces a quick and easy way to get histogram data from
    events and their fields.
 
 Some other cleanups and updates were added as well. Like Masami Hiramatsu
 added test cases for the event trigger and hist triggers. Also I added
 a speed up of filtering by using a temp buffer when filters are set.
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Merge tag 'trace-v4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "This includes two new updates for the ftrace infrastructure.

   - With the changing of the code for filtering events by pid, from a
     list of pids to a bitmask, we can now easily implement following
     forks.  With a new tracing option "event-fork" which, when set,
     will have tasks with pids in set_event_pid, when they fork, to have
     their child pids added to set_event_pid and the child will be
     traced as well.

     Note, if "event-fork" is set and a task with its pid in
     set_event_pid exits, its pid will be removed from set_event_pid

   - The addition of Tom Zanussi's hist triggers.  This includes a very
     thorough documentatino on how to use the hist triggers with events.
     This introduces a quick and easy way to get histogram data from
     events and their fields.

  Some other cleanups and updates were added as well.  Like Masami
  Hiramatsu added test cases for the event trigger and hist triggers.
  Also I added a speed up of filtering by using a temp buffer when
  filters are set"

* tag 'trace-v4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (45 commits)
  tracing: Use temp buffer when filtering events
  tracing: Remove TRACE_EVENT_FL_USE_CALL_FILTER logic
  tracing: Remove unused function trace_current_buffer_lock_reserve()
  tracing: Remove one use of trace_current_buffer_lock_reserve()
  tracing: Have trace_buffer_unlock_commit() call the _regs version with NULL
  tracing: Remove unused function trace_current_buffer_discard_commit()
  tracing: Move trace_buffer_unlock_commit{_regs}() to local header
  tracing: Fold filter_check_discard() into its only user
  tracing: Make filter_check_discard() local
  tracing: Move event_trigger_unlock_commit{_regs}() to local header
  tracing: Don't use the address of the buffer array name in copy_from_user
  tracing: Handle tracing_map_alloc_elts() error path correctly
  tracing: Add check for NULL event field when creating hist field
  tracing: checking for NULL instead of IS_ERR()
  tracing: Do not inherit event-fork option for instances
  tracing: Fix unsigned comparison to zero in hist trigger code
  kselftests/ftrace: Add a test for log2 modifier of hist trigger
  tracing: Add hist trigger 'log2' modifier
  kselftests/ftrace: Add hist trigger testcases
  kselftests/ftrace : Add event trigger testcases
  ...
2016-05-18 18:55:19 -07:00
Linus Torvalds 03e1aa1cbb Merge branch 'stable-4.7' of git://git.infradead.org/users/pcmoore/audit
Pull audit updates from Paul Moore:
 "Four small audit patches for 4.7.

  Two are simple cleanups around the audit thread management code, one
  adds a tty field to AUDIT_LOGIN events, and the final patch makes
  tty_name() usable regardless of CONFIG_TTY.

  Nothing controversial, and it all passes our regression test"

* 'stable-4.7' of git://git.infradead.org/users/pcmoore/audit:
  tty: provide tty_name() even without CONFIG_TTY
  audit: add tty field to LOGIN event
  audit: we don't need to __set_current_state(TASK_RUNNING)
  audit: cleanup prune_tree_thread
2016-05-18 18:46:55 -07:00
Viresh Kumar 60f05e86cf cpufreq: schedutil: Improve prints messages with pr_fmt
Prefix print messages with KBUILD_MODNAME, i.e 'cpufreq_schedutil: '.
This helps to keep similar formatting for all the print messages
particular to a file and identify those easily in kernel logs.

Its already done this way for rest of the governors.

Along with that, remove the (now) redundant bits from a print message.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-05-19 01:02:52 +02:00
Linus Torvalds 9e17632c0a Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc vfs cleanups from Al Viro:
 "Assorted cleanups and fixes all over the place"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  coredump: only charge written data against RLIMIT_CORE
  coredump: get rid of coredump_params->written
  ecryptfs_lookup(): try either only encrypted or plaintext name
  ecryptfs: avoid multiple aliases for directories
  bpf: reject invalid names right in ->lookup()
  __d_alloc(): treat NULL name as QSTR("/", 1)
  mtd: switch ubi_open_volume_path() to vfs_stat()
  mtd: switch open_mtd_by_chdev() to use of vfs_stat()
2016-05-18 11:51:59 -07:00
Linus Torvalds 1eccc6e152 This is the bulk of GPIO changes for kernel cycle v4.7:
Core infrastructural changes:
 
 - Support for natively single-ended GPIO driver stages. This
   means that if the hardware has registers to configure open
   drain or open source configuration, we use that rather than
   (as we did before) try to emulate it by switching the line
   to an input to get high impedance. This is also documented
   throughly in Documentation/gpio/driver.txt for those of you
   who did not understand one word of what I just wrote.
 
 - Start to do away with the unnecessarily complex and
   unitelligible ARCH_REQUIRE_GPIOLIB and
   ARCH_WANT_OPTIONAL_GPIOLIB, another evolutional artifact from
   the time when the GPIO subsystem was unmaintained. Archs can
   now just select GPIOLIB and be done with it, cleanups to
   arches will trickle in for the next kernel. Some minor archs
   ACKed the changes immediately so these are included in this
   pull request.
 
 - Advancing the use of the data pointer inside the GPIO device
   for storing driver data by switching the PowerPC, Super-H
   Unicore and a few other subarches or subsystem drivers in
   ALSA SoC, Input, serial, SSB, staging etc to use it.
 
 - The initialization now reads the input/output state of the
   GPIO lines, so that each GPIO descriptor knows - if this
   callback is implemented - whether the line is input or
   output. This also reflects nicely in userspace "lsgpio".
 
 - It is now possible to name GPIO producer names, line names,
   from the device tree. (Platform data has been supported for
   a while.) I bet we will get a similar mechanism for ACPI
   one of those days. This makes is possible to get sensible
   producer names for e.g. GPIO rails in "lsgpio" in userspace.
 
 New drivers:
 
 - New driver for the Loongson1.
 
 - The XLP driver now supports Broadcom Vulcan ARM64.
 
 - The IT87 driver now supports IT8620 and IT8628.
 
 - The PCA953X driver now supports Galileo Gen2.
 
 Driver improvements:
 
 - MCP23S08 was switched to use the gpiolib irqchip helpers and
   now also suppors level-triggered interrupts.
 
 - 74x164 and RCAR now supports the .set_multiple() callback
 
 - AMDPT was converted to use generic GPIO.
 
 - TC3589x, TPS65218, SX150X, F7188X, MENZ127, VX855, WM831X, WM8994
   support the new single ended callback for open drain
   and in some cases open source.
 
 - Implement the .get_direction() callback for a few more drivers
   like PL061, Xgene.
 
 Cleanups:
 
 - Paul Gortmaker combed through the drivers and de-modularized
   those who are not really modules.
 
 - Move the GPIO poweroff DT bindings to the power subdir where
   they belong.
 
 - Rename gpio-generic.c to gpio-mmio.c, which is much more to the
   point. That's what it is handling, nothing more, nothing less.
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Merge tag 'gpio-v4.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio

Pull GPIO updates from Linus Walleij:
 "This is the bulk of GPIO changes for kernel cycle v4.7:

  Core infrastructural changes:

   - Support for natively single-ended GPIO driver stages.

     This means that if the hardware has registers to configure open
     drain or open source configuration, we use that rather than (as we
     did before) try to emulate it by switching the line to an input to
     get high impedance.

     This is also documented throughly in Documentation/gpio/driver.txt
     for those of you who did not understand one word of what I just
     wrote.

   - Start to do away with the unnecessarily complex and unitelligible
     ARCH_REQUIRE_GPIOLIB and ARCH_WANT_OPTIONAL_GPIOLIB, another
     evolutional artifact from the time when the GPIO subsystem was
     unmaintained.

     Archs can now just select GPIOLIB and be done with it, cleanups to
     arches will trickle in for the next kernel.  Some minor archs ACKed
     the changes immediately so these are included in this pull request.

   - Advancing the use of the data pointer inside the GPIO device for
     storing driver data by switching the PowerPC, Super-H Unicore and
     a few other subarches or subsystem drivers in ALSA SoC, Input,
     serial, SSB, staging etc to use it.

   - The initialization now reads the input/output state of the GPIO
     lines, so that each GPIO descriptor knows - if this callback is
     implemented - whether the line is input or output.  This also
     reflects nicely in userspace "lsgpio".

   - It is now possible to name GPIO producer names, line names, from
     the device tree.  (Platform data has been supported for a while).
     I bet we will get a similar mechanism for ACPI one of those days.
     This makes is possible to get sensible producer names for e.g.
     GPIO rails in "lsgpio" in userspace.

  New drivers:

   - New driver for the Loongson1.

   - The XLP driver now supports Broadcom Vulcan ARM64.

   - The IT87 driver now supports IT8620 and IT8628.

   - The PCA953X driver now supports Galileo Gen2.

  Driver improvements:

   - MCP23S08 was switched to use the gpiolib irqchip helpers and now
     also suppors level-triggered interrupts.

   - 74x164 and RCAR now supports the .set_multiple() callback

   - AMDPT was converted to use generic GPIO.

   - TC3589x, TPS65218, SX150X, F7188X, MENZ127, VX855, WM831X, WM8994
     support the new single ended callback for open drain and in some
     cases open source.

   - Implement the .get_direction() callback for a few more drivers like
     PL061, Xgene.

  Cleanups:

   - Paul Gortmaker combed through the drivers and de-modularized those
     who are not really modules.

   - Move the GPIO poweroff DT bindings to the power subdir where they
     belong.

   - Rename gpio-generic.c to gpio-mmio.c, which is much more to the
     point.  That's what it is handling, nothing more, nothing less"

* tag 'gpio-v4.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (126 commits)
  MIPS: do away with ARCH_[WANT_OPTIONAL|REQUIRE]_GPIOLIB
  gpio: zevio: make it explicitly non-modular
  gpio: timberdale: make it explicitly non-modular
  gpio: stmpe: make it explicitly non-modular
  gpio: sodaville: make it explicitly non-modular
  pinctrl: sh-pfc: Let gpio_chip.to_irq() return zero on error
  gpio: dwapb: Add ACPI device ID for DWAPB GPIO controller on X-Gene platforms
  gpio: dt-bindings: add wd,mbl-gpio bindings
  gpio: of: make it possible to name GPIO lines
  gpio: make gpiod_to_irq() return negative for NO_IRQ
  gpio: xgene: implement .get_direction()
  gpio: xgene: Enable ACPI support for X-Gene GFC GPIO driver
  gpio: tegra: Implement gpio_get_direction callback
  gpio: set up initial state from .get_direction()
  gpio: rename gpio-generic.c into gpio-mmio.c
  gpio: generic: fix GPIO_GENERIC_PLATFORM is set to module case
  gpio: dwapb: add gpio-signaled acpi event support
  gpio: dwapb: convert device node to fwnode
  gpio: dwapb: remove name from dwapb_port_property
  gpio/qoriq: select IRQ_DOMAIN
  ...
2016-05-17 17:39:42 -07:00
Linus Torvalds 0b86c75db6 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching
Pull livepatching updates from Jiri Kosina:

 - remove of our own implementation of architecture-specific relocation
   code and leveraging existing code in the module loader to perform
   arch-dependent work, from Jessica Yu.

   The relevant patches have been acked by Rusty (for module.c) and
   Heiko (for s390).

 - live patching support for ppc64le, which is a joint work of Michael
   Ellerman and Torsten Duwe.  This is coming from topic branch that is
   share between livepatching.git and ppc tree.

 - addition of livepatching documentation from Petr Mladek

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching:
  livepatch: make object/func-walking helpers more robust
  livepatch: Add some basic livepatch documentation
  powerpc/livepatch: Add live patching support on ppc64le
  powerpc/livepatch: Add livepatch stack to struct thread_info
  powerpc/livepatch: Add livepatch header
  livepatch: Allow architectures to specify an alternate ftrace location
  ftrace: Make ftrace_location_range() global
  livepatch: robustify klp_register_patch() API error checking
  Documentation: livepatch: outline Elf format and requirements for patch modules
  livepatch: reuse module loader code to write relocations
  module: s390: keep mod_arch_specific for livepatch modules
  module: preserve Elf information for livepatch modules
  Elf: add livepatch-specific Elf constants
2016-05-17 17:11:27 -07:00
Linus Torvalds a7fd20d1c4 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller:
 "Highlights:

   1) Support SPI based w5100 devices, from Akinobu Mita.

   2) Partial Segmentation Offload, from Alexander Duyck.

   3) Add GMAC4 support to stmmac driver, from Alexandre TORGUE.

   4) Allow cls_flower stats offload, from Amir Vadai.

   5) Implement bpf blinding, from Daniel Borkmann.

   6) Optimize _ASYNC_ bit twiddling on sockets, unless the socket is
      actually using FASYNC these atomics are superfluous.  From Eric
      Dumazet.

   7) Run TCP more preemptibly, also from Eric Dumazet.

   8) Support LED blinking, EEPROM dumps, and rxvlan offloading in mlx5e
      driver, from Gal Pressman.

   9) Allow creating ppp devices via rtnetlink, from Guillaume Nault.

  10) Improve BPF usage documentation, from Jesper Dangaard Brouer.

  11) Support tunneling offloads in qed, from Manish Chopra.

  12) aRFS offloading in mlx5e, from Maor Gottlieb.

  13) Add RFS and RPS support to SCTP protocol, from Marcelo Ricardo
      Leitner.

  14) Add MSG_EOR support to TCP, this allows controlling packet
      coalescing on application record boundaries for more accurate
      socket timestamp sampling.  From Martin KaFai Lau.

  15) Fix alignment of 64-bit netlink attributes across the board, from
      Nicolas Dichtel.

  16) Per-vlan stats in bridging, from Nikolay Aleksandrov.

  17) Several conversions of drivers to ethtool ksettings, from Philippe
      Reynes.

  18) Checksum neutral ILA in ipv6, from Tom Herbert.

  19) Factorize all of the various marvell dsa drivers into one, from
      Vivien Didelot

  20) Add VF support to qed driver, from Yuval Mintz"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1649 commits)
  Revert "phy dp83867: Fix compilation with CONFIG_OF_MDIO=m"
  Revert "phy dp83867: Make rgmii parameters optional"
  r8169: default to 64-bit DMA on recent PCIe chips
  phy dp83867: Make rgmii parameters optional
  phy dp83867: Fix compilation with CONFIG_OF_MDIO=m
  bpf: arm64: remove callee-save registers use for tmp registers
  asix: Fix offset calculation in asix_rx_fixup() causing slow transmissions
  switchdev: pass pointer to fib_info instead of copy
  net_sched: close another race condition in tcf_mirred_release()
  tipc: fix nametable publication field in nl compat
  drivers: net: Don't print unpopulated net_device name
  qed: add support for dcbx.
  ravb: Add missing free_irq() calls to ravb_close()
  qed: Remove a stray tab
  net: ethernet: fec-mpc52xx: use phy_ethtool_{get|set}_link_ksettings
  net: ethernet: fec-mpc52xx: use phydev from struct net_device
  bpf, doc: fix typo on bpf_asm descriptions
  stmmac: hardware TX COE doesn't work when force_thresh_dma_mode is set
  net: ethernet: fs-enet: use phy_ethtool_{get|set}_link_ksettings
  net: ethernet: fs-enet: use phydev from struct net_device
  ...
2016-05-17 16:26:30 -07:00
Linus Torvalds a4d1dbed0e Merge branch 'for-4.7/core' of git://git.kernel.dk/linux-block
Pull core block layer updates from Jens Axboe:
 "This is the core block IO changes for this merge window.  Nothing
  earth shattering in here, it's mostly just fixes.  In detail:

   - Fix for a long standing issue where wrong ordering in blk-mq caused
     order_to_size() to spew a warning.  From Bart.

   - Async discard support from Christoph.  Basically just splitting our
     sync interface into a submit + wait part.

   - Add a cleaner interface for flagging whether a device has a write
     back cache or not.  We've previously overloaded blk_queue_flush()
     with this, but let's make it more explicit.  Drivers cleaned up and
     updated in the drivers pull request.  From me.

   - Fix for a double check for whether IO accounting is enabled or not.
     From Michael Callahan.

   - Fix for the async discard from Mike Snitzer, reinstating the early
     EOPNOTSUPP return if the device doesn't support discards.

   - Also from Mike, export bio_inc_remaining() so dm can drop it's
     private copy of it.

   - From Ming Lin, add support for passing in an offset for request
     payloads.

   - Tag function export from Sagi, which will be used in NVMe in the
     drivers pull.

   - Two blktrace related fixes from Shaohua.

   - Propagate NOMERGE flag when making a request from a bio, also from
     Shaohua.

   - An optimization to not parse cgroup paths in blk-throttle, if we
     don't need to.  From Shaohua"

* 'for-4.7/core' of git://git.kernel.dk/linux-block:
  blk-mq: fix undefined behaviour in order_to_size()
  blk-throttle: don't parse cgroup path if trace isn't enabled
  blktrace: add missed mask name
  blktrace: delete garbage for message trace
  block: make bio_inc_remaining() interface accessible again
  block: reinstate early return of -EOPNOTSUPP from blkdev_issue_discard
  block: Minor blk_account_io_start usage cleanup
  block: add __blkdev_issue_discard
  block: remove struct bio_batch
  block: copy NOMERGE flag from bio to request
  block: add ability to flag write back caching on a device
  blk-mq: Export tagset iter function
  block: add offset in blk_add_request_payload()
  writeback: Fix performance regression in wb_over_bg_thresh()
2016-05-17 15:29:49 -07:00
Linus Torvalds 7f427d3a60 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull parallel filesystem directory handling update from Al Viro.

This is the main parallel directory work by Al that makes the vfs layer
able to do lookup and readdir in parallel within a single directory.
That's a big change, since this used to be all protected by the
directory inode mutex.

The inode mutex is replaced by an rwsem, and serialization of lookups of
a single name is done by a "in-progress" dentry marker.

The series begins with xattr cleanups, and then ends with switching
filesystems over to actually doing the readdir in parallel (switching to
the "iterate_shared()" that only takes the read lock).

A more detailed explanation of the process from Al Viro:
 "The xattr work starts with some acl fixes, then switches ->getxattr to
  passing inode and dentry separately.  This is the point where the
  things start to get tricky - that got merged into the very beginning
  of the -rc3-based #work.lookups, to allow untangling the
  security_d_instantiate() mess.  The xattr work itself proceeds to
  switch a lot of filesystems to generic_...xattr(); no complications
  there.

  After that initial xattr work, the series then does the following:

   - untangle security_d_instantiate()

   - convert a bunch of open-coded lookup_one_len_unlocked() to calls of
     that thing; one such place (in overlayfs) actually yields a trivial
     conflict with overlayfs fixes later in the cycle - overlayfs ended
     up switching to a variant of lookup_one_len_unlocked() sans the
     permission checks.  I would've dropped that commit (it gets
     overridden on merge from #ovl-fixes in #for-next; proper resolution
     is to use the variant in mainline fs/overlayfs/super.c), but I
     didn't want to rebase the damn thing - it was fairly late in the
     cycle...

   - some filesystems had managed to depend on lookup/lookup exclusion
     for *fs-internal* data structures in a way that would break if we
     relaxed the VFS exclusion.  Fixing hadn't been hard, fortunately.

   - core of that series - parallel lookup machinery, replacing
     ->i_mutex with rwsem, making lookup_slow() take it only shared.  At
     that point lookups happen in parallel; lookups on the same name
     wait for the in-progress one to be done with that dentry.

     Surprisingly little code, at that - almost all of it is in
     fs/dcache.c, with fs/namei.c changes limited to lookup_slow() -
     making it use the new primitive and actually switching to locking
     shared.

   - parallel readdir stuff - first of all, we provide the exclusion on
     per-struct file basis, same as we do for read() vs lseek() for
     regular files.  That takes care of most of the needed exclusion in
     readdir/readdir; however, these guys are trickier than lookups, so
     I went for switching them one-by-one.  To do that, a new method
     '->iterate_shared()' is added and filesystems are switched to it
     as they are either confirmed to be OK with shared lock on directory
     or fixed to be OK with that.  I hope to kill the original method
     come next cycle (almost all in-tree filesystems are switched
     already), but it's still not quite finished.

   - several filesystems get switched to parallel readdir.  The
     interesting part here is dealing with dcache preseeding by readdir;
     that needs minor adjustment to be safe with directory locked only
     shared.

     Most of the filesystems doing that got switched to in those
     commits.  Important exception: NFS.  Turns out that NFS folks, with
     their, er, insistence on VFS getting the fuck out of the way of the
     Smart Filesystem Code That Knows How And What To Lock(tm) have
     grown the locking of their own.  They had their own homegrown
     rwsem, with lookup/readdir/atomic_open being *writers* (sillyunlink
     is the reader there).  Of course, with VFS getting the fuck out of
     the way, as requested, the actual smarts of the smart filesystem
     code etc. had become exposed...

   - do_last/lookup_open/atomic_open cleanups.  As the result, open()
     without O_CREAT locks the directory only shared.  Including the
     ->atomic_open() case.  Backmerge from #for-linus in the middle of
     that - atomic_open() fix got brought in.

   - then comes NFS switch to saner (VFS-based ;-) locking, killing the
     homegrown "lookup and readdir are writers" kinda-sorta rwsem.  All
     exclusion for sillyunlink/lookup is done by the parallel lookups
     mechanism.  Exclusion between sillyunlink and rmdir is a real rwsem
     now - rmdir being the writer.

     Result: NFS lookups/readdirs/O_CREAT-less opens happen in parallel
     now.

   - the rest of the series consists of switching a lot of filesystems
     to parallel readdir; in a lot of cases ->llseek() gets simplified
     as well.  One backmerge in there (again, #for-linus - rockridge
     fix)"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (74 commits)
  ext4: switch to ->iterate_shared()
  hfs: switch to ->iterate_shared()
  hfsplus: switch to ->iterate_shared()
  hostfs: switch to ->iterate_shared()
  hpfs: switch to ->iterate_shared()
  hpfs: handle allocation failures in hpfs_add_pos()
  gfs2: switch to ->iterate_shared()
  f2fs: switch to ->iterate_shared()
  afs: switch to ->iterate_shared()
  befs: switch to ->iterate_shared()
  befs: constify stuff a bit
  isofs: switch to ->iterate_shared()
  get_acorn_filename(): deobfuscate a bit
  btrfs: switch to ->iterate_shared()
  logfs: no need to lock directory in lseek
  switch ecryptfs to ->iterate_shared
  9p: switch to ->iterate_shared()
  fat: switch to ->iterate_shared()
  romfs, squashfs: switch to ->iterate_shared()
  more trivial ->iterate_shared conversions
  ...
2016-05-17 11:01:31 -07:00
Linus Torvalds ede40902cf Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq updates from Thomas Gleixner:
 "This update delivers:

   - Yet another interrupt chip diver (LPC32xx)
   - Core functions to handle partitioned per-cpu interrupts
   - Enhancements to the IPI core
   - Proper handling of irq type configuration
   - A large set of ARM GIC enhancements
   - The usual pile of small fixes, cleanups and enhancements"

* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (31 commits)
  irqchip/bcm2836: Use a more generic memory barrier call
  irqchip/bcm2836: Fix compiler warning on 64-bit build
  irqchip/bcm2836: Drop smp_set_ops on arm64 builds
  irqchip/gic: Add helper functions for GIC setup and teardown
  irqchip/gic: Store GIC configuration parameters
  irqchip/gic: Pass GIC pointer to save/restore functions
  irqchip/gic: Return an error if GIC initialisation fails
  irqchip/gic: Remove static irq_chip definition for eoimode1
  irqchip/gic: Don't initialise chip if mapping IO space fails
  irqchip/gic: WARN if setting the interrupt type for a PPI fails
  irqchip/gic: Don't unnecessarily write the IRQ configuration
  irqchip: Mask the non-type/sense bits when translating an IRQ
  genirq: Ensure IRQ descriptor is valid when setting-up the IRQ
  irqchip/gic-v3: Configure all interrupts as non-secure Group-1
  irqchip/gic-v2m: Add workaround for Broadcom NS2 GICv2m erratum
  irqchip/irq-alpine-msi: Don't use <asm-generic/msi.h>
  irqchip/mbigen: Checking for IS_ERR() instead of NULL
  irqchip/gic-v3: Remove inexistant register definition
  irqchip/gicv3-its: Don't allow devices whose ID is outside range
  irqchip: Add LPC32xx interrupt controller driver
  ...
2016-05-17 10:27:29 -07:00
Linus Torvalds 91e8d0cbc9 Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer updates from Thomas Gleixner:
 "A rather small set of patches from the timer departement:

   - Some more y2038 work
   - Yet another new clocksource driver
   - The usual set of small fixes, cleanups and enhancements"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource/drivers/tegra: Remove unused suspend/resume code
  clockevents/driversi/mps2: add MPS2 Timer driver
  dt-bindings: document the MPS2 timer bindings
  clocksource/drivers/mtk_timer: Add __init attribute
  clockevents/drivers/dw_apb_timer: Implement ->set_state_oneshot_stopped()
  time: Introduce do_sys_settimeofday64()
  security: Introduce security_settime64()
  clocksource: Add missing include of of.h.
2016-05-17 09:49:28 -07:00
Linus Torvalds 2fe2edf85f Hao Qin reported an integer overflow possibility with signed and
unsigned numbers in the ring-buffer code.
 
   https://bugzilla.kernel.org/show_bug.cgi?id=118001
 
 At first I did not think this was too much of an issue, because the
 overflow would be caught later when either too much data was allocated
 or it would trigger RB_WARN_ON() which shuts down the ring buffer.
 
 But looking closer into it, I found that the right settings could bypass
 the checks and crash the kernel. Luckily, this is only accessible
 by root.
 
 The first fix is to convert all the variables into long, such that
 we don't get into issues between 32 bit variables being assigned 64 bit
 ones. This fixes the RB_WARN_ON() triggering.
 
 The next fix is to get rid of a duplicate DIV_ROUND_UP() that when called
 twice with the right value, can cause a kernel crash.
 
 The first DIV_ROUND_UP() is to normalize the input and it is checked
 against the minimum allowable value. But then DIV_ROUND_UP() is called
 again, which can overflow due to the (a + b - 1)/b, logic. The first
 called upped the value, the second can overflow (with the +b part).
 
 The second call to DIV_ROUND_UP() came in via a second change a while ago
 and the code is cleaned up to remove it.
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Merge tag 'trace-fixes-v4.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing ring-buffer fixes from Steven Rostedt:
 "Hao Qin reported an integer overflow possibility with signed and
  unsigned numbers in the ring-buffer code.

    https://bugzilla.kernel.org/show_bug.cgi?id=118001

  At first I did not think this was too much of an issue, because the
  overflow would be caught later when either too much data was allocated
  or it would trigger RB_WARN_ON() which shuts down the ring buffer.

  But looking closer into it, I found that the right settings could
  bypass the checks and crash the kernel.  Luckily, this is only
  accessible by root.

  The first fix is to convert all the variables into long, such that we
  don't get into issues between 32 bit variables being assigned 64 bit
  ones.  This fixes the RB_WARN_ON() triggering.

  The next fix is to get rid of a duplicate DIV_ROUND_UP() that when
  called twice with the right value, can cause a kernel crash.

  The first DIV_ROUND_UP() is to normalize the input and it is checked
  against the minimum allowable value.  But then DIV_ROUND_UP() is
  called again, which can overflow due to the (a + b - 1)/b, logic.  The
  first called upped the value, the second can overflow (with the +b
  part).

  The second call to DIV_ROUND_UP() came in via a second change a while
  ago and the code is cleaned up to remove it"

* tag 'trace-fixes-v4.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ring-buffer: Prevent overflow of size in ring_buffer_resize()
  ring-buffer: Use long for nr_pages to avoid overflow failures
2016-05-17 09:42:58 -07:00
Jiri Kosina be69f70e63 Merge branches 'for-4.7/core', 'for-4.7/livepatching-doc' and 'for-4.7/livepatching-ppc64' into for-linus 2016-05-17 12:06:35 +02:00
Al Viro 0e0162bb8c Merge branch 'ovl-fixes' into for-linus
Backmerge to resolve a conflict in ovl_lookup_real();
"ovl_lookup_real(): use lookup_one_len_unlocked()" instead,
but it was too late in the cycle to rebase.
2016-05-17 02:17:59 -04:00
Linus Torvalds d57d394319 Power management material for v4.7-rc1
- New cpufreq "schedutil" governor (making decisions based on CPU
    utilization information provided by the scheduler and capable of
    switching CPU frequencies right away if the underlying driver
    supports that) and support for fast frequency switching in the
    acpi-cpufreq driver (Rafael Wysocki).
 
  - Consolidation of CPU frequency management on ARM platforms allowing
    them to get rid of some platform-specific boilerplate code if they
    are going to use the cpufreq-dt driver (Viresh Kumar, Finley Xiao,
    Marc Gonzalez).
 
  - Support for ACPI _PPC and CPU frequency limits in the intel_pstate
    driver (Srinivas Pandruvada).
 
  - Fixes and cleanups in the cpufreq core and generic governor code
    (Rafael Wysocki, Sai Gurrappadi).
 
  - intel_pstate driver optimizations and cleanups (Rafael Wysocki,
    Philippe Longepe, Chen Yu, Joe Perches).
 
  - cpufreq powernv driver fixes and cleanups (Akshay Adiga, Shilpasri
    Bhat).
 
  - cpufreq qoriq driver fixes and cleanups (Jia Hongtao).
 
  - ACPI cpufreq driver cleanups (Viresh Kumar).
 
  - Assorted cpufreq driver updates (Ashwin Chaugule, Geliang Tang,
    Javier Martinez Canillas, Paul Gortmaker, Sudeep Holla).
 
  - Assorted cpufreq fixes and cleanups (Joe Perches, Arnd Bergmann).
 
  - Fixes and cleanups in the OPP (Operating Performance Points)
    framework, mostly related to OPP sharing, and reorganization of
    OF-dependent code in it (Viresh Kumar, Arnd Bergmann, Sudeep Holla).
 
  - New "passive" governor for devfreq (for SoC subsystems that will
    rely on someone else for the management of their power resources)
    and consolidation of devfreq support for Exynos platforms, coding
    style and typo fixes for devfreq (Chanwoo Choi, MyungJoo Ham).
 
  - PM core fixes and cleanups, mostly to make it work better with the
    generic power domains (genpd) framework, and updates for that
    framework (Ulf Hansson, Thierry Reding, Colin Ian King).
 
  - Intel Broxton support for the intel_idle driver (Len Brown).
 
  - cpuidle core optimization and fix (Daniel Lezcano, Dave Gerlach).
 
  - ARM cpuidle cleanups (Jisheng Zhang).
 
  - Intel Kabylake support for the RAPL power capping driver (Jacob Pan).
 
  - AVS (Adaptive Voltage Switching) rockchip-io driver update (Heiko
    Stuebner).
 
  - Updates for the cpupower tool (Arjun Sreedharan, Colin Ian King,
    Mattia Dongili, Thomas Renninger).
 
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Merge tag 'pm-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management updates from Rafael Wysocki:
 "The majority of changes go into the cpufreq subsystem this time.

  To me, quite obviously, the biggest ticket item is the new "schedutil"
  governor.  Interestingly enough, it's the first new cpufreq governor
  since the beginning of the git era (except for some out-of-the-tree
  ones).

  There are two main differences between it and the existing governors.
  First, it uses the information provided by the scheduler directly for
  making its decisions, so it doesn't have to track anything by itself.
  Second, it can invoke drivers (supporting that feature) to adjust CPU
  performance right away without having to spawn work items to be
  executed in process context or similar.  Currently, the acpi-cpufreq
  driver is the only one supporting that mode of operation, but then it
  is used on a large number of systems.

  The "schedutil" governor as included here is very simple and mostly
  regarded as a foundation for future work on the integration of the
  scheduler with CPU power management (in fact, there is work in
  progress on top of it already).  Nevertheless it works and the
  preliminary results obtained with it are encouraging.

  There also is some consolidation of CPU frequency management for ARM
  platforms that can add their machine IDs the the new stub dt-platdev
  driver now and that will take care of creating the requisite platform
  device for cpufreq-dt, so it is not necessary to do that in platform
  code any more.  Several ARM platforms are switched over to using this
  generic mechanism.

  In addition to that, the intel_pstate driver is now going to respect
  CPU frequency limits set by the platform firmware (or a BMC) and
  provided via the ACPI _PPC object.

  The devfreq subsystem is getting a new "passive" governor for SoCs
  subsystems that will depend on somebody else to manage their voltage
  rails and its support for Samsung Exynos SoCs is consolidated.

  The rest is support for new hardware (Intel Broxton support in
  intel_idle for one example), bug fixes, optimizations and cleanups in
  a number of places.

  Specifics:

   - New cpufreq "schedutil" governor (making decisions based on CPU
     utilization information provided by the scheduler and capable of
     switching CPU frequencies right away if the underlying driver
     supports that) and support for fast frequency switching in the
     acpi-cpufreq driver (Rafael Wysocki)

   - Consolidation of CPU frequency management on ARM platforms allowing
     them to get rid of some platform-specific boilerplate code if they
     are going to use the cpufreq-dt driver (Viresh Kumar, Finley Xiao,
     Marc Gonzalez)

   - Support for ACPI _PPC and CPU frequency limits in the intel_pstate
     driver (Srinivas Pandruvada)

   - Fixes and cleanups in the cpufreq core and generic governor code
     (Rafael Wysocki, Sai Gurrappadi)

   - intel_pstate driver optimizations and cleanups (Rafael Wysocki,
     Philippe Longepe, Chen Yu, Joe Perches)

   - cpufreq powernv driver fixes and cleanups (Akshay Adiga, Shilpasri
     Bhat)

   - cpufreq qoriq driver fixes and cleanups (Jia Hongtao)

   - ACPI cpufreq driver cleanups (Viresh Kumar)

   - Assorted cpufreq driver updates (Ashwin Chaugule, Geliang Tang,
     Javier Martinez Canillas, Paul Gortmaker, Sudeep Holla)

   - Assorted cpufreq fixes and cleanups (Joe Perches, Arnd Bergmann)

   - Fixes and cleanups in the OPP (Operating Performance Points)
     framework, mostly related to OPP sharing, and reorganization of
     OF-dependent code in it (Viresh Kumar, Arnd Bergmann, Sudeep Holla)

   - New "passive" governor for devfreq (for SoC subsystems that will
     rely on someone else for the management of their power resources)
     and consolidation of devfreq support for Exynos platforms, coding
     style and typo fixes for devfreq (Chanwoo Choi, MyungJoo Ham)

   - PM core fixes and cleanups, mostly to make it work better with the
     generic power domains (genpd) framework, and updates for that
     framework (Ulf Hansson, Thierry Reding, Colin Ian King)

   - Intel Broxton support for the intel_idle driver (Len Brown)

   - cpuidle core optimization and fix (Daniel Lezcano, Dave Gerlach)

   - ARM cpuidle cleanups (Jisheng Zhang)

   - Intel Kabylake support for the RAPL power capping driver (Jacob
     Pan)

   - AVS (Adaptive Voltage Switching) rockchip-io driver update (Heiko
     Stuebner)

   - Updates for the cpupower tool (Arjun Sreedharan, Colin Ian King,
     Mattia Dongili, Thomas Renninger)"

* tag 'pm-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (112 commits)
  intel_pstate: Clean up get_target_pstate_use_performance()
  intel_pstate: Use sample.core_avg_perf in get_avg_pstate()
  intel_pstate: Clarify average performance computation
  intel_pstate: Avoid unnecessary synchronize_sched() during initialization
  cpufreq: schedutil: Make default depend on CONFIG_SMP
  cpufreq: powernv: del_timer_sync when global and local pstate are equal
  cpufreq: powernv: Move smp_call_function_any() out of irq safe block
  intel_pstate: Clean up intel_pstate_get()
  cpufreq: schedutil: Make it depend on CONFIG_SMP
  cpufreq: governor: Fix handling of special cases in dbs_update()
  PM / OPP: Move CONFIG_OF dependent code in a separate file
  cpufreq: intel_pstate: Ignore _PPC processing under HWP
  cpufreq: arm_big_little: use generic OPP functions for {init, free}_opp_table
  PM / OPP: add non-OF versions of dev_pm_opp_{cpumask_, }remove_table
  cpufreq: tango: Use generic platdev driver
  PM / OPP: pass cpumask by reference
  cpufreq: Fix GOV_LIMITS handling for the userspace governor
  cpupower: fix potential memory leak
  PM / devfreq: style/typo fixes
  PM / devfreq: exynos: Add the detailed correlation for Exynos5422 bus
  ..
2016-05-16 19:17:22 -07:00