Commit Graph

22200 Commits

Author SHA1 Message Date
David Howells 89053aa9c7 MODSIGN: linux/string.h should be #included to get memcpy()
linux/string.h should be #included in module_signing.c to get memcpy(),
lest the following occur:

    kernel/module_signing.c: In function 'mod_verify_sig':
    kernel/module_signing.c:57:2: error: implicit declaration of function 'memcpy' [-Werror=implicit-function-declaration]
      memcpy(&ms, mod + (modlen - sizeof(ms)), sizeof(ms));
      ^

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2016-03-01 10:36:07 +00:00
Tejun Heo fa5ff8a1c4 cgroup: fix and restructure error handling in copy_cgroup_ns()
copy_cgroup_ns()'s error handling was broken and the attempt to fix it
d22025570e ("cgroup: fix alloc_cgroup_ns() error handling in
copy_cgroup_ns()") was broken too in that it ended up trying an
ERR_PTR() value.

There's only one place where copy_cgroup_ns() needs to perform cleanup
after failure.  Simplify and fix the error handling by removing the
goto's.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
2016-02-29 16:22:52 -05:00
Taeung Song 026842d148 tracing/syscalls: Rename "/format" tracepoint field name "nr" to "__syscall_nr:
Some tracepoint have multiple fields with the same name, "nr", the first
one is a unique syscall ID, the other is a syscall argument:

  # cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_io_getevents/format
  name: sys_enter_io_getevents
  ID: 747
  format:
 	field:unsigned short common_type;	offset:0;	size:2;	signed:0;
 	field:unsigned char common_flags;	offset:2;	size:1;	signed:0;
 	field:unsigned char common_preempt_count;	offset:3;	size:1;	signed:0;
 	field:int common_pid;	offset:4;	size:4;	signed:1;

 	field:int nr;	offset:8;	size:4;	signed:1;
 	field:aio_context_t ctx_id;	offset:16;	size:8;	signed:0;
 	field:long min_nr;	offset:24;	size:8;	signed:0;
 	field:long nr;	offset:32;	size:8;	signed:0;
 	field:struct io_event * events;	offset:40;	size:8;	signed:0;
 	field:struct timespec * timeout;	offset:48;	size:8;	signed:0;

  print fmt: "ctx_id: 0x%08lx, min_nr: 0x%08lx, nr: 0x%08lx, events: 0x%08lx, timeout: 0x%08lx", ((unsigned long)(REC->ctx_id)), ((unsigned long)(REC->min_nr)), ((unsigned long)(REC->nr)), ((unsigned long)(REC->events)), ((unsigned long)(REC->timeout))
  #

Fix it by renaming the "/format" common tracepoint field "nr" to "__syscall_nr".

Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
[ Do not rename the struct member, just the '/format' field name ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160226132301.3ae065a4@gandalf.local.home
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-02-29 11:34:53 -03:00
David Howells ede5147d51 Handle ISO 8601 leap seconds and encodings of midnight in mktime64()
Handle the following ISO 8601 features in mktime64():

 (1) Leap seconds.

     Leap seconds are indicated by the seconds parameter being the value
     60.  Handle this by treating it the same as 00 of the following
     minute.

     It has been pointed out that a minute may contain two leap seconds.
     However, pending discussion of what that looks like and how to handle
     it, I'm not going to concern myself with it.

 (2) Alternate encodings of midnight.

     Two different encodings of midnight are permitted - 00:00:00 and
     24:00:00 - the first is midnight today and the second is midnight
     tomorrow and is exactly equivalent to the first with tomorrow's date.

As it happens, we don't actually need to change mktime64() to handle either
of these - just comment them as valid parameters.

These facility will be used by the X.509 parser.  Doing it in mktime64()
makes the policy common to the whole kernel and easier to find.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
cc: John Stultz <john.stultz@linaro.org>
cc: Rudolf Polzer <rpolzer@google.com>
cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
2016-02-29 14:29:40 +00:00
Ingo Molnar 9e4e7554e7 locking/lockdep: Detect chain_key collisions
Add detection for chain_key collision under CONFIG_DEBUG_LOCKDEP.
When a collision is detected the problem is reported and all lock
debugging is turned off.

Tested using liblockdep and the added tests before and after
applying the fix, confirming both that the code added for the
detection correctly reports the problem and that the fix actually
fixes it.

Tested tweaking lockdep to generate false collisions and
verified that the problem is reported and that lock debugging is
turned off.

Also tested with lockdep's test suite after applying the patch:

    [    0.000000] Good, all 253 testcases passed! |

Signed-off-by: Alfredo Alvarez Fernandez <alfredoalvarezernandez@gmail.com>
Cc: Alfredo Alvarez Fernandez <alfredoalvarezfernandez@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: sasha.levin@oracle.com
Link: http://lkml.kernel.org/r/1455864533-7536-4-git-send-email-alfredoalvarezernandez@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29 10:32:29 +01:00
Alfredo Alvarez Fernandez 5f18ab5c6b locking/lockdep: Prevent chain_key collisions
The chain_key hashing macro iterate_chain_key(key1, key2) does not
generate a new different value if both key1 and key2 are 0. In that
case the generated value is again 0. This can lead to collisions which
can result in lockdep not detecting deadlocks or circular
dependencies.

Avoid the problem by using class_idx (1-based) instead of class id
(0-based) as an input for the hashing macro 'key2' in
iterate_chain_key(key1, key2).

The use of class id created collisions in cases like the following:

1.- Consider an initial state in which no class has been acquired yet.
Under these circumstances an AA deadlock will not be detected by
lockdep:

  lock  [key1,key2]->new key  (key1=old chain_key, key2=id)
  --------------------------
  A     [0,0]->0
  A     [0,0]->0 (collision)

  The newly generated chain_key collides with the one used before and as
  a result the check for a deadlock is skipped

  A simple test using liblockdep and a pthread mutex confirms the
  problem: (omitting stack traces)

    new class 0xe15038: 0x7ffc64950f20
    acquire class [0xe15038] 0x7ffc64950f20
    acquire class [0xe15038] 0x7ffc64950f20
    hash chain already cached, key: 0000000000000000 tail class:
    [0xe15038] 0x7ffc64950f20

2.- Consider an ABBA in 2 different tasks and no class yet acquired.

  T1 [key1,key2]->new key     T2[key1,key2]->new key
  --                          --
  A [0,0]->0

                              B [0,1]->1

  B [0,1]->1  (collision)

                              A

In this case the collision prevents lockdep from creating the new
dependency A->B. This in turn results in lockdep not detecting the
circular dependency when T2 acquires A.

Signed-off-by: Alfredo Alvarez Fernandez <alfredoalvarezernandez@gmail.com>
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: sasha.levin@oracle.com
Link: http://lkml.kernel.org/r/1455147212-2389-4-git-send-email-alfredoalvarezernandez@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29 10:32:29 +01:00
Davidlohr Bueso 1329ce6fbb locking/mutex: Allow next waiter lockless wakeup
Make use of wake-queues and enable the wakeup to occur after releasing the
wait_lock. This is similar to what we do with rtmutex top waiter,
slightly shortening the critical region and allow other waiters to
acquire the wait_lock sooner. In low contention cases it can also help
the recently woken waiter to find the wait_lock available (fastpath)
when it continues execution.

Reviewed-by: Waiman Long <Waiman.Long@hpe.com>
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: Ding Tianhong <dingtianhong@huawei.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: Paul E. McKenney <paulmck@us.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Waiman Long <waiman.long@hpe.com>
Cc: Will Deacon <Will.Deacon@arm.com>
Link: http://lkml.kernel.org/r/20160125022343.GA3322@linux-uzut.site
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29 10:02:42 +01:00
Waiman Long 32d62510f9 locking/pvqspinlock: Enable slowpath locking count tracking
This patch enables the tracking of the number of slowpath locking
operations performed. This can be used to compare against the number
of lock stealing operations to see what percentage of locks are stolen
versus acquired via the regular slowpath.

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: Douglas Hatch <doug.hatch@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: Scott J Norton <scott.norton@hpe.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1449778666-13593-2-git-send-email-Waiman.Long@hpe.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29 10:02:42 +01:00
Waiman Long cb037fdad6 locking/qspinlock: Use smp_cond_acquire() in pending code
The newly introduced smp_cond_acquire() was used to replace the
slowpath lock acquisition loop. Similarly, the new function can also
be applied to the pending bit locking loop. This patch uses the new
function in that loop.

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: Douglas Hatch <doug.hatch@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: Scott J Norton <scott.norton@hpe.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1449778666-13593-1-git-send-email-Waiman.Long@hpe.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29 10:02:42 +01:00
Waiman Long eaff0e7003 locking/pvqspinlock: Move lock stealing count tracking code into pv_queued_spin_steal_lock()
This patch moves the lock stealing count tracking code into
pv_queued_spin_steal_lock() instead of via a jacket function simplifying
the code.

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: Douglas Hatch <doug.hatch@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: Scott J Norton <scott.norton@hpe.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1449778666-13593-3-git-send-email-Waiman.Long@hpe.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29 10:02:41 +01:00
Peter Zijlstra 920c720aa5 locking/mcs: Fix mcs_spin_lock() ordering
Similar to commit b4b29f9485 ("locking/osq: Fix ordering of node
initialisation in osq_lock") the use of xchg_acquire() is
fundamentally broken with MCS like constructs.

Furthermore, it turns out we rely on the global transitivity of this
operation because the unlock path observes the pointer with a
READ_ONCE(), not an smp_load_acquire().

This is non-critical because the MCS code isn't actually used and
mostly serves as documentation, a stepping stone to the more complex
things we've build on top of the idea.

Reported-by: Andrea Parri <parri.andrea@gmail.com>
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: Will Deacon <will.deacon@arm.com>
Fixes: 3552a07a9c ("locking/mcs: Use acquire/release semantics")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29 10:02:41 +01:00
Ingo Molnar 39a1142dbb Linux 4.5-rc6
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Merge tag 'v4.5-rc6' into locking/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29 09:55:22 +01:00
Peter Zijlstra 801ccdbf01 sched/deadline: Remove superfluous call to switched_to_dl()
if (A || B) {

	} else if (A && !B) {

	}

If A we'll take the first branch, if !A we will not satisfy the second.
Therefore the second branch will never be taken.

Reported-by: luca abeni <luca.abeni@unitn.it>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: 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: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160225140149.GK6357@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29 09:53:11 +01:00
Sebastian Andrzej Siewior f904f58263 sched/debug: Fix preempt_disable_ip recording for preempt_disable()
The preempt_disable() invokes preempt_count_add() which saves the caller
in ->preempt_disable_ip. It uses CALLER_ADDR1 which does not look for
its caller but for the parent of the caller. Which means we get the correct
caller for something like spin_lock() unless the architectures inlines
those invocations. It is always wrong for preempt_disable() or
local_bh_disable().

This patch makes the function get_lock_parent_ip() which tries
CALLER_ADDR0,1,2 if the former is a locking function.
This seems to record the preempt_disable() caller properly for
preempt_disable() itself as well as for get_cpu_var() or
local_bh_disable().

Steven asked for the get_parent_ip() -> get_lock_parent_ip() rename.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160226135456.GB18244@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29 09:53:10 +01:00
Rik van Riel ff9a9b4c43 sched, time: Switch VIRT_CPU_ACCOUNTING_GEN to jiffy granularity
When profiling syscall overhead on nohz-full kernels,
after removing __acct_update_integrals() from the profile,
native_sched_clock() remains as the top CPU user. This can be
reduced by moving VIRT_CPU_ACCOUNTING_GEN to jiffy granularity.

This will reduce timing accuracy on nohz_full CPUs to jiffy
based sampling, just like on normal CPUs. It results in
totally removing native_sched_clock from the profile, and
significantly speeding up the syscall entry and exit path,
as well as irq entry and exit, and KVM guest entry & exit.

Additionally, only call the more expensive functions (and
advance the seqlock) when jiffies actually changed.

This code relies on another CPU advancing jiffies when the
system is busy. On a nohz_full system, this is done by a
housekeeping CPU.

A microbenchmark calling an invalid syscall number 10 million
times in a row speeds up an additional 30% over the numbers
with just the previous patches, for a total speedup of about
40% over 4.4 and 4.5-rc1.

Run times for the microbenchmark:

 4.4				3.8 seconds
 4.5-rc1			3.7 seconds
 4.5-rc1 + first patch		3.3 seconds
 4.5-rc1 + first 3 patches	3.1 seconds
 4.5-rc1 + all patches		2.3 seconds

A non-NOHZ_FULL cpu (not the housekeeping CPU):

 all kernels			1.86 seconds

Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: clark@redhat.com
Cc: eric.dumazet@gmail.com
Cc: fweisbec@gmail.com
Cc: luto@amacapital.net
Link: http://lkml.kernel.org/r/1455152907-18495-5-git-send-email-riel@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29 09:53:10 +01:00
Rik van Riel 9344c92c2e time, acct: Drop irq save & restore from __acct_update_integrals()
It looks like all the call paths that lead to __acct_update_integrals()
already have irqs disabled, and __acct_update_integrals() does not need
to disable irqs itself.

This is very convenient since about half the CPU time left in this
function was spent in local_irq_save alone.

Performance of a microbenchmark that calls an invalid syscall
ten million times in a row on a nohz_full CPU improves 21% vs.
4.5-rc1 with both the removal of divisions from __acct_update_integrals()
and this patch, with runtime dropping from 3.7 to 2.9 seconds.

With these patches applied, the highest remaining cpu user in
the trace is native_sched_clock, which is addressed in the next
patch.

For testing purposes I stuck a WARN_ON(!irqs_disabled()) test
in __acct_update_integrals(). It did not trigger.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: clark@redhat.com
Cc: eric.dumazet@gmail.com
Cc: fweisbec@gmail.com
Cc: luto@amacapital.net
Link: http://lkml.kernel.org/r/1455152907-18495-4-git-send-email-riel@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29 09:53:09 +01:00
Rik van Riel b2add86edd acct, time: Change indentation in __acct_update_integrals()
Change the indentation in __acct_update_integrals() to make the function
a little easier to read.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Frederic Weisbecker <fweisbec@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: clark@redhat.com
Cc: eric.dumazet@gmail.com
Cc: fweisbec@gmail.com
Cc: luto@amacapital.net
Link: http://lkml.kernel.org/r/1455152907-18495-3-git-send-email-riel@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29 09:53:09 +01:00
Rik van Riel 382c2fe994 sched, time: Remove non-power-of-two divides from __acct_update_integrals()
When running a microbenchmark calling an invalid syscall number
in a loop, on a nohz_full CPU, we spend a full 9% of our CPU
time in __acct_update_integrals().

This function converts cputime_t to jiffies, to a timeval, only to
convert the timeval back to microseconds before discarding it.

This patch leaves __acct_update_integrals() functionally equivalent,
but speeds things up by about 12%, with 10 million calls to an
invalid syscall number dropping from 3.7 to 3.25 seconds.

Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: clark@redhat.com
Cc: eric.dumazet@gmail.com
Cc: fweisbec@gmail.com
Cc: luto@amacapital.net
Link: http://lkml.kernel.org/r/1455152907-18495-2-git-send-email-riel@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29 09:53:08 +01:00
Steven Rostedt c3a990dc9f sched/rt: Kick RT bandwidth timer immediately on start up
I've been debugging why deadline tasks can cause the RT scheduler to
throttle, even when the deadline tasks are only taking up 50% of the
CPU and RT tasks are not even using 1% of the CPU. Here's what I found.

In order to keep a CPU from being hogged by RT tasks, the deadline
scheduler adds its run time (delta_exec) to the rt_time of the RT
bandwidth. That way, if the two use more than 95% of the CPU within one
second (default settings), the RT tasks are throttled to allow non RT
tasks to run.

Although the deadline tasks add their run time to the RT bandwidth, it
lets the RT tasks do the accounting. This is where the problem lies. If
a deadline task runs for a bit, and no RT tasks are running, then it
will continually add to the RT rt_time that is used to calculate how
much CPU the RT tasks use. But no RT period is in play, and this
accumulation of the runtime never gets reset.

When an RT task finally gets to run, and the watchdog goes off, it can
see that the RT task has used more than it should of, because the
deadline task added all this runtime to its rt_time. Then the RT task
that just woke up gets throttled for no good reason.

I also noticed that when an RT task is queued, it starts the timer to
account for overload and such. But that timer goes off one period
later, which may be too late and the extra rt_time will trigger a
throttle.

This is a quick work around to the problem. When a new RT task is
queued, the bandwidth timer is set to go off immediately. Then the
timer can clear out the extra time added to the rt_time while there was
no RT task running. This stops my tests from triggering the throttle,
and it will still throttle if an RT task runs too much, even while a
deadline task is running.

A better solution may be to subtract the bandwidth that the deadline
task uses from the rt_runtime, and add it back when its finished. Then
there wont be a need for runtime tracking of the time used by deadline
tasks.

I may play with that solution tomorrow.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <juri.lelli@gmail.com>
Cc: <williams@redhat.com>
Cc: Clark Williams
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Juri Lelli
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/20160216183746.349ec98b@gandalf.local.home
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29 09:53:07 +01:00
Steven Rostedt (Red Hat) ef477183d0 sched/debug: Add deadline scheduler bandwidth ratio to /proc/sched_debug
Playing with SCHED_DEADLINE and cpusets, I found that I was unable to create
new SCHED_DEADLINE tasks, with the error of EBUSY as if the bandwidth was
already used up. I then realized there wa no way to see what bandwidth is
used by the runqueues to debug the issue.

By adding the dl_bw->bw and dl_bw->total_bw to the output of the deadline
info in /proc/sched_debug, this allows us to see what bandwidth has been
reserved and where a problem may exist.

For example, before the issue we see the ratio of the bandwidth:

 # cat /proc/sys/kernel/sched_rt_runtime_us
 950000
 # cat /proc/sys/kernel/sched_rt_period_us
 1000000

  # grep dl /proc/sched_debug
  dl_rq[0]:
    .dl_nr_running                 : 0
    .dl_bw->bw                     : 996147
    .dl_bw->total_bw               : 0
  dl_rq[1]:
    .dl_nr_running                 : 0
    .dl_bw->bw                     : 996147
    .dl_bw->total_bw               : 0
  dl_rq[2]:
    .dl_nr_running                 : 0
    .dl_bw->bw                     : 996147
    .dl_bw->total_bw               : 0
  dl_rq[3]:
    .dl_nr_running                 : 0
    .dl_bw->bw                     : 996147
    .dl_bw->total_bw               : 0
  dl_rq[4]:
    .dl_nr_running                 : 0
    .dl_bw->bw                     : 996147
    .dl_bw->total_bw               : 0
  dl_rq[5]:
    .dl_nr_running                 : 0
    .dl_bw->bw                     : 996147
    .dl_bw->total_bw               : 0
  dl_rq[6]:
    .dl_nr_running                 : 0
    .dl_bw->bw                     : 996147
    .dl_bw->total_bw               : 0
  dl_rq[7]:
    .dl_nr_running                 : 0
    .dl_bw->bw                     : 996147
    .dl_bw->total_bw               : 0

Note: (950000 / 1000000) << 20 == 996147

After I played with cpusets and hit the issue, the result is now:

  # grep dl /proc/sched_debug
  dl_rq[0]:
    .dl_nr_running                 : 0
    .dl_bw->bw                     : 996147
    .dl_bw->total_bw               : -104857
  dl_rq[1]:
    .dl_nr_running                 : 0
    .dl_bw->bw                     : 996147
    .dl_bw->total_bw               : 104857
  dl_rq[2]:
    .dl_nr_running                 : 0
    .dl_bw->bw                     : 996147
    .dl_bw->total_bw               : 104857
  dl_rq[3]:
    .dl_nr_running                 : 0
    .dl_bw->bw                     : 996147
    .dl_bw->total_bw               : 104857
  dl_rq[4]:
    .dl_nr_running                 : 0
    .dl_bw->bw                     : 996147
    .dl_bw->total_bw               : -104857
  dl_rq[5]:
    .dl_nr_running                 : 0
    .dl_bw->bw                     : 996147
    .dl_bw->total_bw               : -104857
  dl_rq[6]:
    .dl_nr_running                 : 0
    .dl_bw->bw                     : 996147
    .dl_bw->total_bw               : -104857
  dl_rq[7]:
    .dl_nr_running                 : 0
    .dl_bw->bw                     : 996147
    .dl_bw->total_bw               : -104857

This shows that there is definitely a problem as we should never have a
negative total bandwidth.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Clark Williams <williams@redhat.com>
Cc: Juri Lelli <juri.lelli@gmail.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/20160222212825.756849091@goodmis.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29 09:53:07 +01:00
Steven Rostedt (Red Hat) 3866e845ed sched/debug: Move sched_domain_sysctl to debug.c
The sched_domain_sysctl setup is only enabled when SCHED_DEBUG is
configured. As debug.c is only compiled when SCHED_DEBUG is configured as
well, move the setup of sched_domain_sysctl into that file.

Note, the (un)register_sched_domain_sysctl() functions had to be changed
from static to allow access to them from core.c.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Clark Williams <williams@redhat.com>
Cc: Juri Lelli <juri.lelli@gmail.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/20160222212825.599278093@goodmis.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29 09:53:06 +01:00
Steven Rostedt (Red Hat) d6ca41d792 sched/debug: Move the /sys/kernel/debug/sched_features file setup into debug.c
As /sys/kernel/debug/sched_features is only created when SCHED_DEBUG is enabled, and the file
debug.c is only compiled when SCHED_DEBUG is enabled, it makes sense to move
sched_feature setup into that file and get rid of the #ifdef.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Clark Williams <williams@redhat.com>
Cc: Juri Lelli <juri.lelli@gmail.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/20160222212825.464193063@goodmis.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29 09:53:06 +01:00
Peter Zijlstra ff77e46853 sched/rt: Fix PI handling vs. sched_setscheduler()
Andrea Parri reported:

> I found that the following scenario (with CONFIG_RT_GROUP_SCHED=y) is not
> handled correctly:
>
>     T1 (prio = 20)
>        lock(rtmutex);
>
>     T2 (prio = 20)
>        blocks on rtmutex  (rt_nr_boosted = 0 on T1's rq)
>
>     T1 (prio = 20)
>        sys_set_scheduler(prio = 0)
>           [new_effective_prio == oldprio]
>           T1 prio = 20    (rt_nr_boosted = 0 on T1's rq)
>
> The last step is incorrect as T1 is now boosted (c.f., rt_se_boosted());
> in particular, if we continue with
>
>    T1 (prio = 20)
>       unlock(rtmutex)
>          wakeup(T2)
>          adjust_prio(T1)
>             [prio != rt_mutex_getprio(T1)]
>	    dequeue(T1)
>	       rt_nr_boosted = (unsigned long)(-1)
>	       ...
>             T1 prio = 0
>
> then we end up leaving rt_nr_boosted in an "inconsistent" state.
>
> The simple program attached could reproduce the previous scenario; note
> that, as a consequence of the presence of this state, the "assertion"
>
>     WARN_ON(!rt_nr_running && rt_nr_boosted)
>
> from dec_rt_group() may trigger.

So normally we dequeue/enqueue tasks in sched_setscheduler(), which
would ensure the accounting stays correct. However in the early PI path
we fail to do so.

So this was introduced at around v3.14, by:

  c365c292d0 ("sched: Consider pi boosting in setscheduler()")

which fixed another problem exactly because that dequeue/enqueue, joy.

Fix this by teaching rt about DEQUEUE_SAVE/ENQUEUE_RESTORE and have it
preserve runqueue location with that option. This requires decoupling
the on_rt_rq() state from being on the list.

In order to allow for explicit movement during the SAVE/RESTORE,
introduce {DE,EN}QUEUE_MOVE. We still must use SAVE/RESTORE in these
cases to preserve other invariants.

Respecting the SAVE/RESTORE flags also has the (nice) side-effect that
things like sys_nice()/sys_sched_setaffinity() also do not reorder
FIFO tasks (whereas they used to before this patch).

Reported-by: Andrea Parri <parri.andrea@gmail.com>
Tested-by: Andrea Parri <parri.andrea@gmail.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>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29 09:53:05 +01:00
Dongsheng Yang 41d9339733 sched/core: Remove duplicated sched_group_set_shares() prototype
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <lizefan@huawei.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/1452674558-31897-1-git-send-email-yangds.fnst@cn.fujitsu.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29 09:53:05 +01:00
Frederic Weisbecker be68a682c0 sched/fair: Consolidate nohz CPU load update code
Lets factorize a bit of code there. We'll even have a third user soon.
While at it, standardize the idle update function name against the
others.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Byungchul Park <byungchul.park@lge.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E . McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1452700891-21807-3-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29 09:53:04 +01:00
Byungchul Park 7400d3bbaa sched/fair: Avoid using decay_load_missed() with a negative value
decay_load_missed() cannot handle nagative values, so we need to prevent
using the function with a negative value.

Reported-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Byungchul Park <byungchul.park@lge.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E . McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: perterz@infradead.org
Fixes: 5954327548 ("sched/fair: Prepare __update_cpu_load() to handle active tickless")
Link: http://lkml.kernel.org/r/20160115070749.GA1914@X58A-UD3R
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29 09:53:03 +01:00
Ingo Molnar 6aa447bcbb Merge branch 'sched/urgent' into sched/core, to pick up fixes before applying new changes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29 09:42:07 +01:00
Peter Zijlstra 48be3a67da sched/deadline: Always calculate end of period on sched_yield()
Steven noticed that occasionally a sched_yield() call would not result
in a wait for the next period edge as expected.

It turns out that when we call update_curr_dl() and end up with
delta_exec <= 0, we will bail early and fail to throttle.

Further inspection of the yield code revealed that yield_task_dl()
clearing dl.runtime is wrong too, it will not account the last bit of
runtime which could result in dl.runtime < 0, which in turn means that
replenish would gift us with too much runtime.

Fix both issues by not relying on the dl.runtime value for yield.

Reported-by: Steven Rostedt <rostedt@goodmis.org>
Tested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Clark Williams <williams@redhat.com>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Juri Lelli <juri.lelli@gmail.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/20160223122822.GP6357@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29 09:41:51 +01:00
Peter Zijlstra 6fe1f348b3 sched/cgroup: Fix cgroup entity load tracking tear-down
When a cgroup's CPU runqueue is destroyed, it should remove its
remaining load accounting from its parent cgroup.

The current site for doing so it unsuited because its far too late and
unordered against other cgroup removal (->css_free() will be, but we're also
in an RCU callback).

Put it in the ->css_offline() callback, which is the start of cgroup
destruction, right after the group has been made unavailable to
userspace. The ->css_offline() callbacks are called in hierarchical order
after the following v4.4 commit:

  aa226ff4a1 ("cgroup: make sure a parent css isn't offlined before its children")

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160121212416.GL6357@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29 09:41:50 +01:00
Thomas Gleixner 675965b00d perf: Export perf_event_sysfs_show()
Required to use it in modular perf drivers.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andi Kleen <andi.kleen@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Harish Chegondi <harish.chegondi@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.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: Stephane Eranian <eranian@google.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/20160222221012.930735780@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29 09:35:27 +01:00
Ingo Molnar 0a7348925f Linux 4.5-rc6
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Merge tag 'v4.5-rc6' into perf/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29 09:04:01 +01:00
Oleg Nesterov 869ae76147 uprobes: __create_xol_area() must nullify xol_mapping.fault
As Jiri pointed out, this recent commit:

 f872f5400c ("mm: Add a vm_special_mapping.fault() method")

breaks uprobes: __create_xol_area() doesn't initialize the new ->fault()
method and this obviously leads to kernel crash when the application
tries to execute the probed insn after bp hit.

We probably want to add uprobes_special_mapping_fault(), this allows to
turn xol_area->xol_mapping into a single instance of vm_special_mapping.
But we need a simple fix, so lets change __create_xol() to nullify the
new member as Jiri suggests.

Suggested-by: Jiri Olsa <jolsa@redhat.com>
Reported-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andy Lutomirski <tipbot@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pratyush Anand <panand@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160227221128.GA29565@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29 08:47:51 +01:00
Josh Poimboeuf 049369487e sched: Always inline context_switch()
When CONFIG_GCOV is enabled, gcc decides to put context_switch()
out-of-line, which is inconsistent with its normal behavior.

It also causes an objtool warning because __schedule() no longer inlines
context_switch(), so the "STACK_FRAME_NON_STANDARD(__schedule)"
statement loses its effect.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris J Arges <chris.j.arges@canonical.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Pedro Alves <palves@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: live-patching@vger.kernel.org
Link: http://lkml.kernel.org/r/d62aee926b6e303394e34a06999a964dc2773cf6.1456719558.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29 08:35:11 +01:00
Josh Poimboeuf 8e05e96ac9 sched: Mark __schedule() stack frame as non-standard
objtool reports the following warnings for __schedule():

  kernel/sched/core.o: warning: objtool:__schedule()+0x3c0: duplicate frame pointer save
  kernel/sched/core.o: warning: objtool:__schedule()+0x3fd: sibling call from callable instruction with changed frame pointer
  kernel/sched/core.o: warning: objtool:__schedule()+0x40a: call without frame pointer save/setup
  kernel/sched/core.o: warning: objtool:__schedule()+0x7fd: frame pointer state mismatch
  kernel/sched/core.o: warning: objtool:__schedule()+0x421: frame pointer state mismatch

Basically it's confused by two unusual attributes of the switch_to()
macro:

1. It saves prev's frame pointer to the old stack and restores next's
   frame pointer from the new stack.

2. For new tasks it jumps directly to ret_from_fork.

Eventually it would probably be a good idea to clean up the
ret_from_fork hack so that new tasks are created with a valid initial
stack, as suggested by Andy:

  https://lkml.kernel.org/r/CALCETrWsqCw4L1qKO9j9L5F+4ED4viuLQTFc=n1pKBZfFPQUFg@mail.gmail.com

Then __schedule() could return normally into the new code and objtool
hopefully wouldn't have a problem anymore.

In the meantime, mark its stack frame as non-standard so we can have a
baseline with no objtool warnings.  The marker also serves as a reminder
that this code could be improved a bit.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris J Arges <chris.j.arges@canonical.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Pedro Alves <palves@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: live-patching@vger.kernel.org
Link: http://lkml.kernel.org/r/91190e324ebd7fcd01748d508d0dfd4693e84d91.1456719558.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29 08:35:11 +01:00
Josh Poimboeuf 39853cc0cd bpf: Mark __bpf_prog_run() stack frame as non-standard
objtool reports the following false positive warnings:

  kernel/bpf/core.o: warning: objtool: __bpf_prog_run()+0x5c: sibling call from callable instruction with changed frame pointer
  kernel/bpf/core.o: warning: objtool: __bpf_prog_run()+0x60: function has unreachable instruction
  kernel/bpf/core.o: warning: objtool: __bpf_prog_run()+0x64: function has unreachable instruction
  [...]

It's confused by the following dynamic jump instruction in
__bpf_prog_run()::

  jmp     *(%r12,%rax,8)

which corresponds to the following line in the C code:

  goto *jumptable[insn->code];

There's no way for objtool to deterministically find all possible
branch targets for a dynamic jump, so it can't verify this code.

In this case the jumps all stay within the function, and there's nothing
unusual going on related to the stack, so we can whitelist the function.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris J Arges <chris.j.arges@canonical.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Pedro Alves <palves@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: live-patching@vger.kernel.org
Cc: netdev@vger.kernel.org
Link: http://lkml.kernel.org/r/b90e6bf3fdbfb5c4cc1b164b965502e53cf48935.1456719558.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29 08:35:11 +01:00
Linus Torvalds 1b9540ce03 Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Thomas Gleixner:
 "A rather largish series of 12 patches addressing a maze of race
  conditions in the perf core code from Peter Zijlstra"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf: Robustify task_function_call()
  perf: Fix scaling vs. perf_install_in_context()
  perf: Fix scaling vs. perf_event_enable()
  perf: Fix scaling vs. perf_event_enable_on_exec()
  perf: Fix ctx time tracking by introducing EVENT_TIME
  perf: Cure event->pending_disable race
  perf: Fix race between event install and jump_labels
  perf: Fix cloning
  perf: Only update context time when active
  perf: Allow perf_release() with !event->ctx
  perf: Do not double free
  perf: Close install vs. exit race
2016-02-28 07:52:00 -08:00
Linus Torvalds 76c03f0f5d Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixlet from Thomas Gleixner:
 "A trivial printk typo fix"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/deadline: Fix trivial typo in printk() message
2016-02-28 07:48:01 -08:00
Xiubo Li 63253ad814 cgroup: fix a mistake in warning message
There is a mistake about the print format name:id <--> %d:%s, which
the name is 'char *' type and id is 'int' type.  Change "name:id" to
"id:name" instead to be consistent with "cgroup_subsys %d:%s".

Signed-off-by: Xiubo Li <lixiubo@cmss.chinamobile.com>
Acked-by: Zefan Li <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2016-02-27 06:33:37 -05:00
Alexander Kuleshov 232d26373d jiffies: Use CLOCKSOURCE_MASK instead of constant
The CLOCKSOURCE_MASK(32) macro expands to the same value, but
makes code more readable.

Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Link: http://lkml.kernel.org/r/1456542854-22104-3-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-02-27 08:55:31 +01:00
Linus Torvalds 5bb9871eb8 Another small bug reported to me by Chunyu Hu.
When perf added a "reg" function to the function tracing event (not a
 tracepoint), it caused that event to be displayed as a tracepoint and
 could cause errors in tracepoint handling. That was solved by adding a
 flag to ignore ftrace non-tracepoint events. But that flag was missed
 when displaying events in available_events, which should only contain
 tracepoint events.
 
 This broke a documented way to enable all events with:
 
   cat available_events > set_event
 
 As the function non-tracepoint event would cause that to error out.
 The commit here fixes that by having the available_events file not list
 events that have the ignore flag set.
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Merge tag 'trace-fixes-v4.5-rc5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fix from Steven Rostedt:
 "Another small bug reported to me by Chunyu Hu.

  When perf added a "reg" function to the function tracing event (not a
  tracepoint), it caused that event to be displayed as a tracepoint and
  could cause errors in tracepoint handling.  That was solved by adding
  a flag to ignore ftrace non-tracepoint events.  But that flag was
  missed when displaying events in available_events, which should only
  contain tracepoint events.

  This broke a documented way to enable all events with:

      cat available_events > set_event

  As the function non-tracepoint event would cause that to error out.
  The commit here fixes that by having the available_events file not
  list events that have the ignore flag set"

* tag 'trace-fixes-v4.5-rc5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix showing function event in available_events
2016-02-25 20:12:09 -08:00
Linus Torvalds 3d7b365490 Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm
Pull libnvdimm fixes from Dan Williams:

 - Two fixes for compatibility with the ACPI 6.1 specification.

   Without these fixes multi-interface DIMMs will fail to be probed, and
   address range scrub commands to find memory errors will give results
   that the kernel will mis-interpret.  For multi-interface DIMMs Linux
   will accept either the original 6.0 implementation or 6.1.

   For address range scrub we'll only support 6.1 since ACPI formalized
   this DSM differently than the original example [1] implemented in
   v4.2.  The expectation is that production systems will only ever ship
   the ACPI 6.1 address range scrub command definition.

 - The wider async address range scrub work targeting 4.6 discovered
   that the original synchronous implementation in 4.5 is not sizing its
   return buffer correctly.

 - Arnd caught that my recent fix to the size of the pfn_t flags missed
   updating the flags variable used in the pmem driver.

 - Toshi found that we mishandle the memremap() return value in
   devm_memremap().

* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  nvdimm: use 'u64' for pfn flags
  devm_memremap: Fix error value when memremap failed
  nfit: update address range scrub commands to the acpi 6.1 format
  libnvdimm, tools/testing/nvdimm: fix 'ars_status' output buffer sizing
  nfit: fix multi-interface dimm handling, acpi6.1 compatibility
2016-02-25 18:54:53 -08:00
Paul Gortmaker abedf8e241 rcu: Use simple wait queues where possible in rcutree
As of commit dae6e64d2b ("rcu: Introduce proper blocking to no-CBs kthreads
GP waits") the RCU subsystem started making use of wait queues.

Here we convert all additions of RCU wait queues to use simple wait queues,
since they don't need the extra overhead of the full wait queue features.

Originally this was done for RT kernels[1], since we would get things like...

  BUG: sleeping function called from invalid context at kernel/rtmutex.c:659
  in_atomic(): 1, irqs_disabled(): 1, pid: 8, name: rcu_preempt
  Pid: 8, comm: rcu_preempt Not tainted
  Call Trace:
   [<ffffffff8106c8d0>] __might_sleep+0xd0/0xf0
   [<ffffffff817d77b4>] rt_spin_lock+0x24/0x50
   [<ffffffff8106fcf6>] __wake_up+0x36/0x70
   [<ffffffff810c4542>] rcu_gp_kthread+0x4d2/0x680
   [<ffffffff8105f910>] ? __init_waitqueue_head+0x50/0x50
   [<ffffffff810c4070>] ? rcu_gp_fqs+0x80/0x80
   [<ffffffff8105eabb>] kthread+0xdb/0xe0
   [<ffffffff8106b912>] ? finish_task_switch+0x52/0x100
   [<ffffffff817e0754>] kernel_thread_helper+0x4/0x10
   [<ffffffff8105e9e0>] ? __init_kthread_worker+0x60/0x60
   [<ffffffff817e0750>] ? gs_change+0xb/0xb

...and hence simple wait queues were deployed on RT out of necessity
(as simple wait uses a raw lock), but mainline might as well take
advantage of the more streamline support as well.

[1] This is a carry forward of work from v3.10-rt; the original conversion
was by Thomas on an earlier -rt version, and Sebastian extended it to
additional post-3.10 added RCU waiters; here I've added a commit log and
unified the RCU changes into one, and uprev'd it to match mainline RCU.

Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: linux-rt-users@vger.kernel.org
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1455871601-27484-6-git-send-email-wagi@monom.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-02-25 11:27:16 +01:00
Daniel Wagner 065bb78c5b rcu: Do not call rcu_nocb_gp_cleanup() while holding rnp->lock
rcu_nocb_gp_cleanup() is called while holding rnp->lock. Currently,
this is okay because the wake_up_all() in rcu_nocb_gp_cleanup() will
not enable the IRQs. lockdep is happy.

By switching over using swait this is not true anymore. swake_up_all()
enables the IRQs while processing the waiters. __do_softirq() can now
run and will eventually call rcu_process_callbacks() which wants to
grap nrp->lock.

Let's move the rcu_nocb_gp_cleanup() call outside the lock before we
switch over to swait.

If we would hold the rnp->lock and use swait, lockdep reports
following:

 =================================
 [ INFO: inconsistent lock state ]
 4.2.0-rc5-00025-g9a73ba0 #136 Not tainted
 ---------------------------------
 inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
 rcu_preempt/8 [HC0[0]:SC0[0]:HE1:SE1] takes:
  (rcu_node_1){+.?...}, at: [<ffffffff811387c7>] rcu_gp_kthread+0xb97/0xeb0
 {IN-SOFTIRQ-W} state was registered at:
   [<ffffffff81109b9f>] __lock_acquire+0xd5f/0x21e0
   [<ffffffff8110be0f>] lock_acquire+0xdf/0x2b0
   [<ffffffff81841cc9>] _raw_spin_lock_irqsave+0x59/0xa0
   [<ffffffff81136991>] rcu_process_callbacks+0x141/0x3c0
   [<ffffffff810b1a9d>] __do_softirq+0x14d/0x670
   [<ffffffff810b2214>] irq_exit+0x104/0x110
   [<ffffffff81844e96>] smp_apic_timer_interrupt+0x46/0x60
   [<ffffffff81842e70>] apic_timer_interrupt+0x70/0x80
   [<ffffffff810dba66>] rq_attach_root+0xa6/0x100
   [<ffffffff810dbc2d>] cpu_attach_domain+0x16d/0x650
   [<ffffffff810e4b42>] build_sched_domains+0x942/0xb00
   [<ffffffff821777c2>] sched_init_smp+0x509/0x5c1
   [<ffffffff821551e3>] kernel_init_freeable+0x172/0x28f
   [<ffffffff8182cdce>] kernel_init+0xe/0xe0
   [<ffffffff8184231f>] ret_from_fork+0x3f/0x70
 irq event stamp: 76
 hardirqs last  enabled at (75): [<ffffffff81841330>] _raw_spin_unlock_irq+0x30/0x60
 hardirqs last disabled at (76): [<ffffffff8184116f>] _raw_spin_lock_irq+0x1f/0x90
 softirqs last  enabled at (0): [<ffffffff810a8df2>] copy_process.part.26+0x602/0x1cf0
 softirqs last disabled at (0): [<          (null)>]           (null)
 other info that might help us debug this:
  Possible unsafe locking scenario:
        CPU0
        ----
   lock(rcu_node_1);
   <Interrupt>
     lock(rcu_node_1);
  *** DEADLOCK ***
 1 lock held by rcu_preempt/8:
  #0:  (rcu_node_1){+.?...}, at: [<ffffffff811387c7>] rcu_gp_kthread+0xb97/0xeb0
 stack backtrace:
 CPU: 0 PID: 8 Comm: rcu_preempt Not tainted 4.2.0-rc5-00025-g9a73ba0 #136
 Hardware name: Dell Inc. PowerEdge R820/066N7P, BIOS 2.0.20 01/16/2014
  0000000000000000 000000006d7e67d8 ffff881fb081fbd8 ffffffff818379e0
  0000000000000000 ffff881fb0812a00 ffff881fb081fc38 ffffffff8110813b
  0000000000000000 0000000000000001 ffff881f00000001 ffffffff8102fa4f
 Call Trace:
  [<ffffffff818379e0>] dump_stack+0x4f/0x7b
  [<ffffffff8110813b>] print_usage_bug+0x1db/0x1e0
  [<ffffffff8102fa4f>] ? save_stack_trace+0x2f/0x50
  [<ffffffff811087ad>] mark_lock+0x66d/0x6e0
  [<ffffffff81107790>] ? check_usage_forwards+0x150/0x150
  [<ffffffff81108898>] mark_held_locks+0x78/0xa0
  [<ffffffff81841330>] ? _raw_spin_unlock_irq+0x30/0x60
  [<ffffffff81108a28>] trace_hardirqs_on_caller+0x168/0x220
  [<ffffffff81108aed>] trace_hardirqs_on+0xd/0x10
  [<ffffffff81841330>] _raw_spin_unlock_irq+0x30/0x60
  [<ffffffff810fd1c7>] swake_up_all+0xb7/0xe0
  [<ffffffff811386e1>] rcu_gp_kthread+0xab1/0xeb0
  [<ffffffff811089bf>] ? trace_hardirqs_on_caller+0xff/0x220
  [<ffffffff81841341>] ? _raw_spin_unlock_irq+0x41/0x60
  [<ffffffff81137c30>] ? rcu_barrier+0x20/0x20
  [<ffffffff810d2014>] kthread+0x104/0x120
  [<ffffffff81841330>] ? _raw_spin_unlock_irq+0x30/0x60
  [<ffffffff810d1f10>] ? kthread_create_on_node+0x260/0x260
  [<ffffffff8184231f>] ret_from_fork+0x3f/0x70
  [<ffffffff810d1f10>] ? kthread_create_on_node+0x260/0x260

Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: linux-rt-users@vger.kernel.org
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1455871601-27484-5-git-send-email-wagi@monom.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-02-25 11:27:16 +01:00
Peter Zijlstra (Intel) 13b35686e8 wait.[ch]: Introduce the simple waitqueue (swait) implementation
The existing wait queue support has support for custom wake up call
backs, wake flags, wake key (passed to call back) and exclusive
flags that allow wakers to be tagged as exclusive, for limiting
the number of wakers.

In a lot of cases, none of these features are used, and hence we
can benefit from a slimmed down version that lowers memory overhead
and reduces runtime overhead.

The concept originated from -rt, where waitqueues are a constant
source of trouble, as we can't convert the head lock to a raw
spinlock due to fancy and long lasting callbacks.

With the removal of custom callbacks, we can use a raw lock for
queue list manipulations, hence allowing the simple wait support
to be used in -rt.

[Patch is from PeterZ which is based on Thomas version. Commit message is
 written by Paul G.
 Daniel:  - Fixed some compile issues
 	  - Added non-lazy implementation of swake_up_locked as suggested
	     by Boqun Feng.]

Originally-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: linux-rt-users@vger.kernel.org
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1455871601-27484-2-git-send-email-wagi@monom.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-02-25 11:27:16 +01:00
Qais Yousef 3b8e29a82d genirq: Implement ipi_send_mask/single()
Add APIs to send IPIs from driver and arch code.

We have different functions because we allow architecture code to cache the
irq descriptor to avoid lookups. Driver code has to use the irq number and is
subject to more restrictive checks.

[ tglx: Polish the implementation ]

Signed-off-by: Qais Yousef <qais.yousef@imgtec.com>
Cc: <jason@lakedaemon.net>
Cc: <marc.zyngier@arm.com>
Cc: <jiang.liu@linux.intel.com>
Cc: <ralf@linux-mips.org>
Cc: <linux-mips@linux-mips.org>
Cc: <lisa.parratt@imgtec.com>
Cc: Qais Yousef <qsyousef@gmail.com>
Link: http://lkml.kernel.org/r/1449580830-23652-12-git-send-email-qais.yousef@imgtec.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-02-25 10:56:57 +01:00
Qais Yousef f9bce791ae genirq: Add a new function to get IPI reverse mapping
When dealing with coprocessors we need to find out the actual hwirqs values to
pass on to the firmware so that it knows what it needs to use to receive IPIs
from and send IPIs to Linux cpus.

[ tglx: Fixed the single hwirq IPI case. The hardware irq number does not
  	change due to the cpu number ]

Signed-off-by: Qais Yousef <qais.yousef@imgtec.com>
Cc: <jason@lakedaemon.net>
Cc: <marc.zyngier@arm.com>
Cc: <jiang.liu@linux.intel.com>
Cc: <ralf@linux-mips.org>
Cc: <linux-mips@linux-mips.org>
Cc: <lisa.parratt@imgtec.com>
Cc: Qais Yousef <qsyousef@gmail.com>
Link: http://lkml.kernel.org/r/1449580830-23652-10-git-send-email-qais.yousef@imgtec.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-02-25 10:56:56 +01:00
Qais Yousef d17bf24e69 genirq: Add a new generic IPI reservation code to irq core
Add a generic mechanism to dynamically allocate an IPI. Depending on the
underlying implementation this creates either a single Linux irq or a
consective range of Linux irqs. The Linux irq is used later to send IPIs to
other CPUs.

[ tglx: Massaged the code and removed the 'consecutive mask' restriction for
  	the single IRQ case ]

Signed-off-by: Qais Yousef <qais.yousef@imgtec.com>
Cc: <jason@lakedaemon.net>
Cc: <marc.zyngier@arm.com>
Cc: <jiang.liu@linux.intel.com>
Cc: <ralf@linux-mips.org>
Cc: <linux-mips@linux-mips.org>
Cc: <lisa.parratt@imgtec.com>
Cc: Qais Yousef <qsyousef@gmail.com>
Link: http://lkml.kernel.org/r/1449580830-23652-9-git-send-email-qais.yousef@imgtec.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-02-25 10:56:56 +01:00
Qais Yousef ac0a0cd266 genirq: Make irq_domain_alloc_descs() non static
We will need to use this function to implement irq_reserve_ipi() later. So
make it non static and move the prototype to irqdomain.h to allow using it
outside irqdomain.c

Signed-off-by: Qais Yousef <qais.yousef@imgtec.com>
Cc: <jason@lakedaemon.net>
Cc: <marc.zyngier@arm.com>
Cc: <jiang.liu@linux.intel.com>
Cc: <ralf@linux-mips.org>
Cc: <linux-mips@linux-mips.org>
Cc: <lisa.parratt@imgtec.com>
Cc: Qais Yousef <qsyousef@gmail.com>
Link: http://lkml.kernel.org/r/1449580830-23652-8-git-send-email-qais.yousef@imgtec.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-02-25 10:56:56 +01:00
Qais Yousef 379b656446 genirq: Add GENERIC_IRQ_IPI Kconfig symbol
Select this to enable the generic IPI domain support

Signed-off-by: Qais Yousef <qais.yousef@imgtec.com>
Cc: <jason@lakedaemon.net>
Cc: <marc.zyngier@arm.com>
Cc: <jiang.liu@linux.intel.com>
Cc: <ralf@linux-mips.org>
Cc: <linux-mips@linux-mips.org>
Cc: <lisa.parratt@imgtec.com>
Cc: Qais Yousef <qsyousef@gmail.com>
Link: http://lkml.kernel.org/r/1449580830-23652-4-git-send-email-qais.yousef@imgtec.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-02-25 10:56:55 +01:00
Peter Zijlstra 0da4cf3e0a perf: Robustify task_function_call()
Since there is no serialization between task_function_call() doing
task_curr() and the other CPU doing context switches, we could end
up not sending an IPI even if we had to.

And I'm not sure I still buy my own argument we're OK.

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: Thomas Gleixner <tglx@linutronix.de>
Cc: dvyukov@google.com
Cc: eranian@google.com
Cc: oleg@redhat.com
Cc: panand@redhat.com
Cc: sasha.levin@oracle.com
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/20160224174948.340031200@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-25 08:44:29 +01:00
Peter Zijlstra a096309bc4 perf: Fix scaling vs. perf_install_in_context()
Completely reworks perf_install_in_context() (again!) in order to
ensure that there will be no ctx time hole between add_event_to_ctx()
and any potential ctx_sched_in().

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: Thomas Gleixner <tglx@linutronix.de>
Cc: dvyukov@google.com
Cc: eranian@google.com
Cc: oleg@redhat.com
Cc: panand@redhat.com
Cc: sasha.levin@oracle.com
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/20160224174948.279399438@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-25 08:44:29 +01:00
Peter Zijlstra bd2afa49d1 perf: Fix scaling vs. perf_event_enable()
Similar to the perf_enable_on_exec(), ensure that event timings are
consistent across perf_event_enable().

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: Thomas Gleixner <tglx@linutronix.de>
Cc: dvyukov@google.com
Cc: eranian@google.com
Cc: oleg@redhat.com
Cc: panand@redhat.com
Cc: sasha.levin@oracle.com
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/20160224174948.218288698@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-25 08:44:19 +01:00
Peter Zijlstra 7fce250915 perf: Fix scaling vs. perf_event_enable_on_exec()
The recent commit 3e349507d1 ("perf: Fix perf_enable_on_exec() event
scheduling") caused this by moving task_ctx_sched_out() from before
__perf_event_mask_enable() to after it.

The overlooked consequence of that change is that task_ctx_sched_out()
would update the ctx time fields, and now __perf_event_mask_enable()
uses stale time.

In order to fix this, explicitly stop our context's time before
enabling the event(s).

Reported-by: Oleg Nesterov <oleg@redhat.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: Thomas Gleixner <tglx@linutronix.de>
Cc: dvyukov@google.com
Cc: eranian@google.com
Cc: panand@redhat.com
Cc: sasha.levin@oracle.com
Cc: vince@deater.net
Fixes: 3e349507d1 ("perf: Fix perf_enable_on_exec() event scheduling")
Link: http://lkml.kernel.org/r/20160224174948.159242158@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-25 08:43:34 +01:00
Peter Zijlstra 3cbaa59069 perf: Fix ctx time tracking by introducing EVENT_TIME
Currently any ctx_sched_in() call will re-start the ctx time tracking,
this means that calls like:

	ctx_sched_in(.event_type = EVENT_PINNED);
	ctx_sched_in(.event_type = EVENT_FLEXIBLE);

will have a hole in their ctx time tracking. This is likely harmless
but can confuse things a little. By adding EVENT_TIME, we can have the
first ctx_sched_in() (is_active: 0 -> !0) start the time and any
further ctx_sched_in() will leave the timestamps alone.

Secondly, this allows for an early disable like:

	ctx_sched_out(.event_type = EVENT_TIME);

which would update the ctx time (if the ctx is active) and any further
calls to ctx_sched_out() would not further modify the ctx time.

For ctx_sched_in() any 0 -> !0 transition will automatically include
EVENT_TIME.

For ctx_sched_out(), any transition that clears EVENT_ALL will
automatically clear EVENT_TIME.

These two rules ensure that under normal circumstances we need not
bother with EVENT_TIME and get natural ctx time behaviour.

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: Thomas Gleixner <tglx@linutronix.de>
Cc: dvyukov@google.com
Cc: eranian@google.com
Cc: oleg@redhat.com
Cc: panand@redhat.com
Cc: sasha.levin@oracle.com
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/20160224174948.100446561@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-25 08:42:34 +01:00
Peter Zijlstra 28a967c3a2 perf: Cure event->pending_disable race
Because event_sched_out() checks event->pending_disable _before_
actually disabling the event, it can happen that the event fires after
it checks but before it gets disabled.

This would leave event->pending_disable set and the queued irq_work
will try and process it.

However, if the event trigger was during schedule(), the event might
have been de-scheduled by the time the irq_work runs, and
perf_event_disable_local() will fail.

Fix this by checking event->pending_disable _after_ we call
event->pmu->del(). This depends on the latter being a compiler
barrier, such that the compiler does not lift the load and re-creates
the problem.

Tested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: 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: Thomas Gleixner <tglx@linutronix.de>
Cc: dvyukov@google.com
Cc: eranian@google.com
Cc: oleg@redhat.com
Cc: panand@redhat.com
Cc: sasha.levin@oracle.com
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/20160224174948.040469884@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-25 08:42:34 +01:00
Peter Zijlstra 9107c89e26 perf: Fix race between event install and jump_labels
perf_install_in_context() relies upon the context switch hooks to have
scheduled in events when the IPI misses its target -- after all, if
the task has moved from the CPU (or wasn't running at all), it will
have to context switch to run elsewhere.

This however doesn't appear to be happening.

It is possible for the IPI to not happen (task wasn't running) only to
later observe the task running with an inactive context.

The only possible explanation is that the context switch hooks are not
called. Therefore put in a sync_sched() after toggling the jump_label
to guarantee all CPUs will have them enabled before we install an
event.

A simple if (0->1) sync_sched() will not in fact work, because any
further increment can race and complete before the sync_sched().
Therefore we must jump through some hoops.

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: Thomas Gleixner <tglx@linutronix.de>
Cc: dvyukov@google.com
Cc: eranian@google.com
Cc: oleg@redhat.com
Cc: panand@redhat.com
Cc: sasha.levin@oracle.com
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/20160224174947.980211985@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-25 08:42:34 +01:00
Peter Zijlstra a69b0ca4ac perf: Fix cloning
Alexander reported that when the 'original' context gets destroyed, no
new clones happen.

This can happen irrespective of the ctx switch optimization, any task
can die, even the parent, and we want to continue monitoring the task
hierarchy until we either close the event or no tasks are left in the
hierarchy.

perf_event_init_context() will attempt to pin the 'parent' context
during clone(). At that point current is the parent, and since current
cannot have exited while executing clone(), its context cannot have
passed through perf_event_exit_task_context(). Therefore
perf_pin_task_context() cannot observe ctx->task == TASK_TOMBSTONE.

However, since inherit_event() does:

	if (parent_event->parent)
		parent_event = parent_event->parent;

it looks at the 'original' event when it does: is_orphaned_event().
This can return true if the context that contains the this event has
passed through perf_event_exit_task_context(). And thus we'll fail to
clone the perf context.

Fix this by adding a new state: STATE_DEAD, which is set by
perf_release() to indicate that the filedesc (or kernel reference) is
dead and there are no observers for our data left.

Only for STATE_DEAD will is_orphaned_event() be true and inhibit
cloning.

STATE_EXIT is otherwise preserved such that is_event_hup() remains
functional and will report when the observed task hierarchy becomes
empty.

Reported-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Tested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: 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: Thomas Gleixner <tglx@linutronix.de>
Cc: dvyukov@google.com
Cc: eranian@google.com
Cc: oleg@redhat.com
Cc: panand@redhat.com
Cc: sasha.levin@oracle.com
Cc: vince@deater.net
Fixes: c6e5b73242 ("perf: Synchronously clean up child events")
Link: http://lkml.kernel.org/r/20160224174947.919845295@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-25 08:42:33 +01:00
Peter Zijlstra 6f932e5be1 perf: Only update context time when active
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: Thomas Gleixner <tglx@linutronix.de>
Cc: dvyukov@google.com
Cc: eranian@google.com
Cc: oleg@redhat.com
Cc: panand@redhat.com
Cc: sasha.levin@oracle.com
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/20160224174947.860690919@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-25 08:42:33 +01:00
Peter Zijlstra a4f4bb6d0c perf: Allow perf_release() with !event->ctx
In the err_file: fput(event_file) case, the event will not yet have
been attached to a context. However perf_release() does assume it has
been. Cure this.

Tested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: 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: Thomas Gleixner <tglx@linutronix.de>
Cc: dvyukov@google.com
Cc: eranian@google.com
Cc: oleg@redhat.com
Cc: panand@redhat.com
Cc: sasha.levin@oracle.com
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/20160224174947.793996260@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-25 08:42:33 +01:00
Peter Zijlstra 130056275a perf: Do not double free
In case of: err_file: fput(event_file), we'll end up calling
perf_release() which in turn will free the event.

Do not then free the event _again_.

Tested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: 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: Thomas Gleixner <tglx@linutronix.de>
Cc: dvyukov@google.com
Cc: eranian@google.com
Cc: oleg@redhat.com
Cc: panand@redhat.com
Cc: sasha.levin@oracle.com
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/20160224174947.697350349@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-25 08:42:32 +01:00
Peter Zijlstra 84c4e620d3 perf: Close install vs. exit race
Consider the following scenario:

  CPU0					CPU1

  ctx = find_get_ctx();
					perf_event_exit_task_context()
  mutex_lock(&ctx->mutex);
  perf_install_in_context(ctx, ...);
    /* NO-OP */
  mutex_unlock(&ctx->mutex);

  ...

  perf_release()
    WARN_ON_ONCE(event->state != STATE_EXIT);

Since the event doesn't pass through perf_remove_from_context()
because perf_install_in_context() NO-OPs because the ctx is dead, and
perf_event_exit_task_context() will not observe the event because its
not attached yet, the event->state will not be set.

Solve this by revalidating ctx->task after we acquire ctx->mutex and
failing the event creation as a whole.

Tested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: 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: Thomas Gleixner <tglx@linutronix.de>
Cc: dvyukov@google.com
Cc: eranian@google.com
Cc: oleg@redhat.com
Cc: panand@redhat.com
Cc: sasha.levin@oracle.com
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/20160224174947.626853419@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-25 08:42:32 +01:00
Steven Rostedt (Red Hat) d045437a16 tracing: Fix showing function event in available_events
The ftrace:function event is only displayed for parsing the function tracer
data. It is not used to enable function tracing, and does not include an
"enable" file in its event directory.

Originally, this event was kept separate from other events because it did
not have a ->reg parameter. But perf added a "reg" parameter for its use
which caused issues, because it made the event available to functions where
it was not compatible for.

Commit 9b63776fa3 "tracing: Do not enable function event with enable"
added a TRACE_EVENT_FL_IGNORE_ENABLE flag that prevented the function event
from being enabled by normal trace events. But this commit missed keeping
the function event from being displayed by the "available_events" directory,
which is used to show what events can be enabled by set_event.

One documented way to enable all events is to:

 cat available_events > set_event

But because the function event is displayed in the available_events, this
now causes an INVALID error:

 cat: write error: Invalid argument

Reported-by: Chunyu Hu <chuhu@redhat.com>
Fixes: 9b63776fa3 "tracing: Do not enable function event with enable"
Cc: stable@vger.kernel.org # 3.4+
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-02-24 09:17:11 -05:00
Paul E. McKenney 4f2a848c56 rcu: Export rcu_gp_is_normal()
This commit exports rcu_gp_is_normal() in order to allow it to be used
by rcutorture and rcuperf.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-02-23 20:04:51 -08:00
Paul E. McKenney 4b455dc3e1 rcu: Catch up rcu_report_qs_rdp() comment with reality
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-02-23 19:59:56 -08:00
Paul Gortmaker 9fc9204ef9 rcu: Make rcu/tiny_plugin.h explicitly non-modular
The Kconfig currently controlling compilation of this code is:

init/Kconfig:config TINY_RCU
init/Kconfig:   bool

...meaning that it currently is not being built as a module by anyone.

Lets remove the modular code that is essentially orphaned, so that
when reading the code there is no doubt it is builtin-only.

Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.  We could
consider moving this to an earlier initcall (subsys?) if desired.

We also delete the MODULE_LICENSE tag etc. since all that information
is already contained at the top of the file in the comments.

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>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-02-23 19:59:55 -08:00
Boqun Feng b354286eff irq: Privatize irq_common_data::state_use_accessors
irq_common_data::state_use_accessors is not designed for public use.
Therefore make it private so that people who write code accessing it
directly will get blamed by sparse. Also #undef the macro
__irqd_to_state after used in header files, so that the macro can't be
misused.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-02-23 19:59:54 -08:00
Boqun Feng 67c583a7de RCU: Privatize rcu_node::lock
In patch:

"rcu: Add transitivity to remaining rcu_node ->lock acquisitions"

All locking operations on rcu_node::lock are replaced with the wrappers
because of the need of transitivity, which indicates we should never
write code using LOCK primitives alone(i.e. without a proper barrier
following) on rcu_node::lock outside those wrappers. We could detect
this kind of misuses on rcu_node::lock in the future by adding __private
modifier on rcu_node::lock.

To privatize rcu_node::lock, unlock wrappers are also needed. Replacing
spinlock unlocks with these wrappers not only privatizes rcu_node::lock
but also makes it easier to figure out critical sections of rcu_node.

This patch adds __private modifier to rcu_node::lock and makes every
access to it wrapped by ACCESS_PRIVATE(). Besides, unlock wrappers are
added and raw_spin_unlock(&rnp->lock) and its friends are replaced with
those wrappers.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-02-23 19:59:54 -08:00
Chen Gang 1914aab543 rcu: Remove useless rcu_data_p when !PREEMPT_RCU
The related warning from gcc 6.0:

  In file included from kernel/rcu/tree.c:4630:0:
  kernel/rcu/tree_plugin.h:810:40: warning: ‘rcu_data_p’ defined but not used [-Wunused-const-variable]
   static struct rcu_data __percpu *const rcu_data_p = &rcu_sched_data;
                                          ^~~~~~~~~~

Also remove always redundant rcu_data_p in tree.c.

Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-02-23 19:59:53 -08:00
Paul E. McKenney aa5a898876 rcutorture: Correct no-expedite console messages
The "Disabled dynamic grace-period expediting" console message is
currently printed unconditionally.  This commit causes it to be
output only when it is impossible to switch between normal and
expedited grace periods, which was the original intent.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-02-23 19:59:52 -08:00
Paul E. McKenney 23a9bacd35 rcu: Set rdp->gpwrap when CPU is idle
Commit #e3663b1024d1 ("rcu: Handle gpnum/completed wrap while dyntick
idle") sets rdp->gpwrap on the wrong side of the "if" statement in
dyntick_save_progress_counter(), that is, it sets it when the CPU is
not idle instead of when it is idle.  Of course, if the CPU is not idle,
its rdp->gpnum won't be lagging beind the global rsp->gpnum, which means
that rdp->gpwrap will never be set.

This commit therefore moves this code to the proper leg of that "if"
statement.  This change means that the "else" cause is just "return 0"
and the "then" clause ends with "return 1", so also move the "return 0"
to follow the "if", dropping the "else" clause.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-02-23 19:59:52 -08:00
Paul E. McKenney 4914950aaa rcu: Stop treating in-kernel CPU-bound workloads as errors
Commit 4a81e8328d ("Reduce overhead of cond_resched() checks for RCU")
handles the error case where a nohz_full loops indefinitely in the kernel
with the scheduling-clock interrupt disabled.  However, this handling
includes IPIing the CPU running the offending loop, which is not what
we want for real-time workloads.  And there are starting to be real-time
CPU-bound in-kernel workloads, and these must be handled without IPIing
the CPU, at least not in the common case.  Therefore, this situation can
no longer be dismissed as an error case.

This commit therefore splits the handling out, so that the setting of
bits in the per-CPU rcu_sched_qs_mask variable is done relatively early,
but if the problem persists, resched_cpu() is eventually used to IPI the
CPU containing the offending loop.  Assuming that in-kernel CPU-bound
loops used by real-time tasks contain frequent calls cond_resched_rcu_qs()
(as in more than once per few tens of milliseconds), the real-time tasks
will never be IPIed.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
2016-02-23 19:59:51 -08:00
Paul E. McKenney 8994515cf0 rcu: Update rcu_report_qs_rsp() comment
The header comment for rcu_report_qs_rsp() was obsolete, dating well
before the advent of RCU grace-period kthreads.  This commit therefore
brings this comment back into alignment with current reality.

Reported-by: Lihao Liang <lihao.liang@cs.ox.ac.uk>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-02-23 19:59:51 -08:00
Paul E. McKenney bb53e416e0 rcu: Assign false instead of 0 for ->core_needs_qs
A zero seems to have escaped earlier true/false substitution efforts,
so this commit changes 0 to false for the ->core_needs_qs boolean field.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-02-23 19:59:51 -08:00
Toshi Kani 93f834df9c devm_memremap: Fix error value when memremap failed
devm_memremap() returns an ERR_PTR() value in case of error.
However, it returns NULL when memremap() failed.  This causes
the caller, such as the pmem driver, to proceed and oops later.

Change devm_memremap() to return ERR_PTR(-ENXIO) when memremap()
failed.

Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: <stable@vger.kernel.org>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-02-23 17:17:20 -08:00
Tejun Heo 62716ea0f2 cgroup: use ->subtree_control when testing no internal process rule
No internal process rule is enforced by cgroup_migrate_prepare_dst()
during process migration.  It tests whether the target cgroup's
->child_subsys_mask is zero which is different from "subtree_control"
write path which tests ->subtree_control.  This hasn't mattered
because up until now, both ->child_subsys_mask and ->subtree_control
are zero or non-zero at the same time.  However, with the planned
addition of implicit controllers, this will no longer be true.

This patch prepares for the change by making
cgorup_migrate_prepare_dst() test ->subtree_control instead.

Signed-off-by: Tejun Heo <tj@kernel.org>
2016-02-23 10:00:51 -05:00
Tejun Heo f17fc25f2b cgroup: make css_tryget_online_from_dir() also recognize cgroup2 fs
The function currently returns -EBADF for a directory on the default
hierarchy.  Make it also recognize cgroup2_fs_type.  This will be used
for perf_event cgroup2 support.

Signed-off-by: Tejun Heo <tj@kernel.org>
2016-02-23 10:00:51 -05:00
Tejun Heo b38e42e962 cgroup: convert cgroup_subsys flag fields to bool bitfields
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
2016-02-23 10:00:50 -05:00
Tejun Heo a716526442 cgroup: s/cgrp_dfl_root_/cgrp_dfl_/
These var names are unnecessarily unwiedly and another similar
variable will be added.  Let's shorten them.

Signed-off-by: Tejun Heo <tj@kernel.org>
2016-02-23 10:00:50 -05:00
David S. Miller b633353115 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/phy/bcm7xxx.c
	drivers/net/phy/marvell.c
	drivers/net/vxlan.c

All three conflicts were cases of simple overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-23 00:09:14 -05:00
Tejun Heo 6e5c830770 cgroup: make cgroup subsystem masks u16
After the recent do_each_subsys_mask() conversion, there's no reason
to use ulong for subsystem masks.  We'll be adding more subsystem
masks to persistent data structures, let's reduce its size to u16
which should be enough for now and the foreseeable future.

This doesn't create any noticeable behavior differences.

v2: Johannes spotted that the initial patch missed cgroup_no_v1_mask.
    Converted.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
2016-02-22 22:25:47 -05:00
Tejun Heo 996cd1fb73 cgroup: use do_each_subsys_mask() where applicable
There are several places in cgroup_subtree_control_write() which can
use do_each_subsys_mask() instead of manual mask testing.  Use it.

No functional changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
2016-02-22 22:25:46 -05:00
Tejun Heo b4e0eeafba cgroup: convert for_each_subsys_which() to do-while style
for_each_subsys_which() allows iterating subsystems specified in a
subsystem bitmask; unfortunately, it requires the mask to be an
unsigned long l-value which can be inconvenient and makes it awkward
to use a smaller type for subsystem masks.

This patch converts for_each_subsy_which() to do-while style which
allows it to drop the l-value requirement.  The new iterator is named
do_each_subsys_mask() / while_each_subsys_mask().

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Aleksa Sarai <cyphar@cyphar.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
2016-02-22 22:25:46 -05:00
Tejun Heo 8699b7762a cgroup: s/child_subsys_mask/subtree_ss_mask/
For consistency with cgroup->subtree_control.

* cgroup->child_subsys_mask -> cgroup->subtree_ss_mask
* cgroup_calc_child_subsys_mask() -> cgroup_calc_subtree_ss_mask()
* cgroup_refresh_child_subsys_mask() -> cgroup_refresh_subtree_ss_mask()

No functional changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
2016-02-22 22:25:46 -05:00
Tejun Heo 5eb385cc5a Revert "cgroup: add cgroup_subsys->css_e_css_changed()"
This reverts commit 56c807ba4e.

cgroup_subsys->css_e_css_changed() was supposed to be used by cgroup
writeback support; however, the change to per-inode cgroup association
made it unnecessary and the callback doesn't have any user.  Remove
it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
2016-02-22 22:25:46 -05:00
Tejun Heo b598dde354 cgroup: fix error return value of cgroup_addrm_files()
cgroup_addrm_files() incorrectly returned 0 after add failure.  Fix
it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
2016-02-22 22:25:45 -05:00
Linus Torvalds 4de8ebeff8 Two more small fixes.
One is by Yang Shi who added a READ_ONCE_NOCHECK() to the scan of the
 stack made by the stack tracer. As the stack tracer scans the entire
 kernel stack, KASAN triggers seeing it as a "stack out of bounds" error.
 As the scan is looking at the contents of the stack from parent functions.
 The NOCHECK() tells KASAN that this is done on purpose, and is not some
 kind of stack overflow.
 
 The second fix is to the ftrace selftests, to retrieve the PID of executed
 commands from the shell with "$!" and not by parsing "jobs".
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Merge tag 'trace-fixes-v4.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Two more small fixes.

  One is by Yang Shi who added a READ_ONCE_NOCHECK() to the scan of the
  stack made by the stack tracer.  As the stack tracer scans the entire
  kernel stack, KASAN triggers seeing it as a "stack out of bounds"
  error.  As the scan is looking at the contents of the stack from
  parent functions.  The NOCHECK() tells KASAN that this is done on
  purpose, and is not some kind of stack overflow.

  The second fix is to the ftrace selftests, to retrieve the PID of
  executed commands from the shell with '$!' and not by parsing 'jobs'"

* tag 'trace-fixes-v4.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing, kasan: Silence Kasan warning in check_stack of stack_tracer
  ftracetest: Fix instance test to use proper shell command for pids
2016-02-22 14:09:18 -08:00
Kees Cook d2aa1acad2 mm/init: Add 'rodata=off' boot cmdline parameter to disable read-only kernel mappings
It may be useful to debug writes to the readonly sections of memory,
so provide a cmdline "rodata=off" to allow for this. This can be
expanded in the future to support "log" and "write" modes, but that
will need to be architecture-specific.

This also makes KDB software breakpoints more usable, as read-only
mappings can now be disabled on any kernel.

Suggested-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Brown <david.brown@linaro.org>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Emese Revfy <re.emese@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathias Krause <minipli@googlemail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: PaX Team <pageexec@freemail.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel-hardening@lists.openwall.com
Cc: linux-arch <linux-arch@vger.kernel.org>
Link: http://lkml.kernel.org/r/1455748879-21872-3-git-send-email-keescook@chromium.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-22 08:51:37 +01:00
Daniel Borkmann 8e2fe1d9f1 bpf: add new arg_type that allows for 0 sized stack buffer
Currently, when we pass a buffer from the eBPF stack into a helper
function, the function proto indicates argument types as ARG_PTR_TO_STACK
and ARG_CONST_STACK_SIZE pair. If R<X> contains the former, then R<X+1>
must be of the latter type. Then, verifier checks whether the buffer
points into eBPF stack, is initialized, etc. The verifier also guarantees
that the constant value passed in R<X+1> is greater than 0, so helper
functions don't need to test for it and can always assume a non-NULL
initialized buffer as well as non-0 buffer size.

This patch adds a new argument types ARG_CONST_STACK_SIZE_OR_ZERO that
allows to also pass NULL as R<X> and 0 as R<X+1> into the helper function.
Such helper functions, of course, need to be able to handle these cases
internally then. Verifier guarantees that either R<X> == NULL && R<X+1> == 0
or R<X> != NULL && R<X+1> != 0 (like the case of ARG_CONST_STACK_SIZE), any
other combinations are not possible to load.

I went through various options of extending the verifier, and introducing
the type ARG_CONST_STACK_SIZE_OR_ZERO seems to have most minimal changes
needed to the verifier.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-21 22:07:09 -05:00
Mimi Zohar b804defe42 kexec: replace call to copy_file_from_fd() with kernel version
Replace copy_file_from_fd() with kernel_read_file_from_fd().

Two new identifiers named READING_KEXEC_IMAGE and READING_KEXEC_INITRAMFS
are defined for measuring, appraising or auditing the kexec image and
initramfs.

Changelog v3:
- return -EBADF, not -ENOEXEC
- identifier change
- split patch, moving copy_file_from_fd() to a separate patch
- split patch, moving IMA changes to a separate patch
v0:
- use kstat file size type loff_t, not size_t
- Calculate the file hash from the in memory buffer - Dave Young

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Acked-by: Dave Young <dyoung@redhat.com>
2016-02-21 09:06:14 -05:00
Mimi Zohar a1db742094 module: replace copy_module_from_fd with kernel version
Replace copy_module_from_fd() with kernel_read_file_from_fd().

Although none of the upstreamed LSMs define a kernel_module_from_file
hook, IMA is called, based on policy, to prevent unsigned kernel modules
from being loaded by the original kernel module syscall and to
measure/appraise signed kernel modules.

The security function security_kernel_module_from_file() was called prior
to reading a kernel module.  Preventing unsigned kernel modules from being
loaded by the original kernel module syscall remains on the pre-read
kernel_read_file() security hook.  Instead of reading the kernel module
twice, once for measuring/appraising and again for loading the kernel
module, the signature validation is moved to the kernel_post_read_file()
security hook.

This patch removes the security_kernel_module_from_file() hook and security
call.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
2016-02-21 09:06:12 -05:00
Linus Torvalds 06b74c658c 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 CPU hotplug related fixes"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Plug potential memory leak in CPU_UP_PREPARE
  perf/core: Remove the bogus and dangerous CPU_DOWN_FAILED hotplug state
  perf/core: Remove bogus UP_CANCELED hotplug state
  perf/x86/amd/uncore: Plug reference leak
2016-02-20 09:30:42 -08:00
Simon Guinot 59ceeaaf35 kernel/resource.c: fix muxed resource handling in __request_region()
In __request_region, if a conflict with a BUSY and MUXED resource is
detected, then the caller goes to sleep and waits for the resource to be
released.  A pointer on the conflicting resource is kept.  At wake-up
this pointer is used as a parent to retry to request the region.

A first problem is that this pointer might well be invalid (if for
example the conflicting resource have already been freed).  Another
problem is that the next call to __request_region() fails to detect a
remaining conflict.  The previously conflicting resource is passed as a
parameter and __request_region() will look for a conflict among the
children of this resource and not at the resource itself.  It is likely
to succeed anyway, even if there is still a conflict.

Instead, the parent of the conflicting resource should be passed to
__request_region().

As a fix, this patch doesn't update the parent resource pointer in the
case we have to wait for a muxed region right after.

Reported-and-tested-by: Vincent Pelletier <plr.vincent@gmail.com>
Signed-off-by: Simon Guinot <simon.guinot@sequanux.org>
Tested-by: Vincent Donnefort <vdonnefort@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-20 08:57:52 -08:00
Alexei Starovoitov d5a3b1f691 bpf: introduce BPF_MAP_TYPE_STACK_TRACE
add new map type to store stack traces and corresponding helper
bpf_get_stackid(ctx, map, flags) - walk user or kernel stack and return id
@ctx: struct pt_regs*
@map: pointer to stack_trace map
@flags: bits 0-7 - numer of stack frames to skip
        bit 8 - collect user stack instead of kernel
        bit 9 - compare stacks by hash only
        bit 10 - if two different stacks hash into the same stackid
                 discard old
        other bits - reserved
Return: >= 0 stackid on success or negative error

stackid is a 32-bit integer handle that can be further combined with
other data (including other stackid) and used as a key into maps.

Userspace will access stackmap using standard lookup/delete syscall commands to
retrieve full stack trace for given stackid.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-20 00:21:44 -05:00
Alexei Starovoitov 568b329a02 perf: generalize perf_callchain
. avoid walking the stack when there is no room left in the buffer
. generalize get_perf_callchain() to be called from bpf helper

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-20 00:21:44 -05:00
Linus Torvalds 87d9ac712b Merge branch 'akpm' (patches from Andrew)
Merge fixes from Andrew Morton:
 "10 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm: slab: free kmem_cache_node after destroy sysfs file
  ipc/shm: handle removed segments gracefully in shm_mmap()
  MAINTAINERS: update Kselftest Framework mailing list
  devm_memremap_release(): fix memremap'd addr handling
  mm/hugetlb.c: fix incorrect proc nr_hugepages value
  mm, x86: fix pte_page() crash in gup_pte_range()
  fsnotify: turn fsnotify reaper thread into a workqueue job
  Revert "fsnotify: destroy marks with call_srcu instead of dedicated thread"
  mm: fix regression in remap_file_pages() emulation
  thp, dax: do not try to withdraw pgtable from non-anon VMA
2016-02-19 13:36:00 -08:00
Sasha Levin 6bbd9a05a1 bpf: grab rcu read lock for bpf_percpu_hash_update
bpf_percpu_hash_update() expects rcu lock to be held and warns if it's not,
which pointed out a missing rcu read lock.

Fixes: 15a07b338 ("bpf: add lookup/update support for per-cpu hash and array maps")
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-19 14:37:43 -05:00
Yang Shi 6e22c83664 tracing, kasan: Silence Kasan warning in check_stack of stack_tracer
When enabling stack trace via "echo 1 > /proc/sys/kernel/stack_tracer_enabled",
the below KASAN warning is triggered:

BUG: KASAN: stack-out-of-bounds in check_stack+0x344/0x848 at addr ffffffc0689ebab8
Read of size 8 by task ksoftirqd/4/29
page:ffffffbdc3a27ac0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x0()
page dumped because: kasan: bad access detected
CPU: 4 PID: 29 Comm: ksoftirqd/4 Not tainted 4.5.0-rc1 #129
Hardware name: Freescale Layerscape 2085a RDB Board (DT)
Call trace:
[<ffffffc000091300>] dump_backtrace+0x0/0x3a0
[<ffffffc0000916c4>] show_stack+0x24/0x30
[<ffffffc0009bbd78>] dump_stack+0xd8/0x168
[<ffffffc000420bb0>] kasan_report_error+0x6a0/0x920
[<ffffffc000421688>] kasan_report+0x70/0xb8
[<ffffffc00041f7f0>] __asan_load8+0x60/0x78
[<ffffffc0002e05c4>] check_stack+0x344/0x848
[<ffffffc0002e0c8c>] stack_trace_call+0x1c4/0x370
[<ffffffc0002af558>] ftrace_ops_no_ops+0x2c0/0x590
[<ffffffc00009f25c>] ftrace_graph_call+0x0/0x14
[<ffffffc0000881bc>] fpsimd_thread_switch+0x24/0x1e8
[<ffffffc000089864>] __switch_to+0x34/0x218
[<ffffffc0011e089c>] __schedule+0x3ac/0x15b8
[<ffffffc0011e1f6c>] schedule+0x5c/0x178
[<ffffffc0001632a8>] smpboot_thread_fn+0x350/0x960
[<ffffffc00015b518>] kthread+0x1d8/0x2b0
[<ffffffc0000874d0>] ret_from_fork+0x10/0x40
Memory state around the buggy address:
 ffffffc0689eb980: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 f4 f4 f4
 ffffffc0689eba00: f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00
>ffffffc0689eba80: 00 00 f1 f1 f1 f1 00 f4 f4 f4 f3 f3 f3 f3 00 00
                                        ^
 ffffffc0689ebb00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffffc0689ebb80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

The stacker tracer traverses the whole kernel stack when saving the max stack
trace. It may touch the stack red zones to cause the warning. So, just disable
the instrumentation to silence the warning.

Link: http://lkml.kernel.org/r/1455309960-18930-1-git-send-email-yang.shi@linaro.org

Signed-off-by: Yang Shi <yang.shi@linaro.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-02-19 12:36:44 -05:00
Linus Torvalds 705d43dbe1 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching
Pull livepatching fixes from Jiri Kosina:

 - regression (from 4.4) fix for ordering issue, introduced by an
   earlier ftrace change, that broke live patching of modules.

   The fix replaces the ftrace module notifier by direct call in order
   to make the ordering guaranteed and well-defined.  The patch, from
   Jessica Yu, has been acked both by Steven and Rusty

 - error message fix from Miroslav Benes

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching:
  ftrace/module: remove ftrace module notifier
  livepatch: change the error message in asm/livepatch.h header files
2016-02-18 16:34:15 -08:00
Toshi Kani 9273a8bbf5 devm_memremap_release(): fix memremap'd addr handling
The pmem driver calls devm_memremap() to map a persistent memory range.
When the pmem driver is unloaded, this memremap'd range is not released
so the kernel will leak a vma.

Fix devm_memremap_release() to handle a given memremap'd address
properly.

Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-18 16:23:24 -08:00
Tejun Heo d22025570e cgroup: fix alloc_cgroup_ns() error handling in copy_cgroup_ns()
alloc_cgroup_ns() returns an ERR_PTR value on error but
copy_cgroup_ns() was checking for NULL for error.  Fix it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
2016-02-18 11:44:24 -05:00
Dave Hansen cd0ea35ff5 signals, pkeys: Notify userspace about protection key faults
A protection key fault is very similar to any other access error.
There must be a VMA, etc...  We even want to take the same action
(SIGSEGV) that we do with a normal access fault.

However, we do need to let userspace know that something is
different.  We do this the same way what we did with SEGV_BNDERR
with Memory Protection eXtensions (MPX): define a new SEGV code:
SEGV_PKUERR.

We add a siginfo field: si_pkey that reveals to userspace which
protection key was set on the PTE that we faulted on.  There is
no other easy way for userspace to figure this out.  They could
parse smaps but that would be a bit cruel.

We share space with in siginfo with _addr_bnd.  #BR faults from
MPX are completely separate from page faults (#PF) that trigger
from protection key violations, so we never need both at the same
time.

Note that _pkey is a 64-bit value.  The current hardware only
supports 4-bit protection keys.  We do this because there is
_plenty_ of space in _sigfault and it is possible that future
processors would support more than 4 bits of protection keys.

The x86 code to actually fill in the siginfo is in the next
patch.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Amanieu d'Antras <amanieu@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rik van Riel <riel@redhat.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20160212210212.3A9B83AC@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-18 09:32:42 +01:00
Lars-Peter Clausen 23217b443b workqueue: Replace usage of init_name with dev_set_name()
The init_name property of the device struct is sort of a hack and should
only be used for statically allocated devices. Since the device is
dynamically allocated here it is safe to use the proper way to set a
devices name by calling dev_set_name().

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
2016-02-17 16:14:18 -05:00
Jessica Yu 7dcd182bec ftrace/module: remove ftrace module notifier
Remove the ftrace module notifier in favor of directly calling
ftrace_module_enable() and ftrace_release_mod() in the module loader.
Hard-coding the function calls directly in the module loader removes
dependence on the module notifier call chain and provides better
visibility and control over what gets called when, which is important
to kernel utilities such as livepatch.

This fixes a notifier ordering issue in which the ftrace module notifier
(and hence ftrace_module_enable()) for coming modules was being called
after klp_module_notify(), which caused livepatch modules to initialize
incorrectly. This patch removes dependence on the module notifier call
chain in favor of hard coding the corresponding function calls in the
module loader. This ensures that ftrace and livepatch code get called in
the correct order on patch module load and unload.

Fixes: 5156dca34a ("ftrace: Fix the race between ftrace and insmod")
Signed-off-by: Jessica Yu <jeyu@redhat.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Petr Mladek <pmladek@suse.cz>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2016-02-17 22:14:06 +01:00
Mel Gorman 65d8fc777f futex: Remove requirement for lock_page() in get_futex_key()
When dealing with key handling for shared futexes, we can drastically reduce
the usage/need of the page lock. 1) For anonymous pages, the associated futex
object is the mm_struct which does not require the page lock. 2) For inode
based, keys, we can check under RCU read lock if the page mapping is still
valid and take reference to the inode. This just leaves one rare race that
requires the page lock in the slow path when examining the swapcache.

Additionally realtime users currently have a problem with the page lock being
contended for unbounded periods of time during futex operations.

Task A
     get_futex_key()
     lock_page()
    ---> preempted

Now any other task trying to lock that page will have to wait until
task A gets scheduled back in, which is an unbound time.

With this patch, we pretty much have a lockless futex_get_key().

Experiments show that this patch can boost/speedup the hashing of shared
futexes with the perf futex benchmarks (which is good for measuring such
change) by up to 45% when there are high (> 100) thread counts on a 60 core
Westmere. Lower counts are pretty much in the noise range or less than 10%,
but mid range can be seen at over 30% overall throughput (hash ops/sec).
This makes anon-mem shared futexes much closer to its private counterpart.

Signed-off-by: Mel Gorman <mgorman@suse.de>
[ Ported on top of thp refcount rework, changelog, comments, fixes. ]
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Chris Mason <clm@fb.com>
Cc: Darren Hart <dvhart@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: dave@stgolabs.net
Link: http://lkml.kernel.org/r/1455045314-8305-3-git-send-email-dave@stgolabs.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-17 10:42:17 +01:00
Davidlohr Bueso 8ad7b378d0 futex: Rename barrier references in ordering guarantees
Ingo suggested we rename how we reference barriers A and B
regarding futex ordering guarantees. This patch replaces,
for both barriers, MB (A) with smp_mb(); (A), such that:

 - We explicitly state that the barriers are SMP, and

 - We standardize how we reference these across futex.c
   helping readers follow what barrier does what and where.

Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Chris Mason <clm@fb.com>
Cc: Darren Hart <dvhart@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: dave@stgolabs.net
Link: http://lkml.kernel.org/r/1455045314-8305-2-git-send-email-dave@stgolabs.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-17 10:42:17 +01:00
Thomas Gleixner 3b364d7b58 perf/core: Remove unused arguments from a bunch of functions
No functional change, just less confusing to read.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/20160209201007.921540566@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-17 10:37:48 +01:00
Ingo Molnar 9109dc97b0 Merge branch 'perf/urgent' into perf/core, to queue up dependent patch
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-17 10:37:36 +01:00
Thomas Gleixner 059fcd8cd1 perf/core: Plug potential memory leak in CPU_UP_PREPARE
If CPU_UP_PREPARE is called it is not guaranteed, that a previously allocated
and assigned hash has been freed already, but perf_event_init_cpu()
unconditionally allocates and assignes a new hash if the swhash is referenced.
By overwriting the pointer the existing hash is not longer accessible.

Verify that there is no hash assigned on this cpu before allocating and
assigning a new one.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/20160209201007.843269966@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-17 10:37:30 +01:00
Thomas Gleixner 27ca9236c9 perf/core: Remove the bogus and dangerous CPU_DOWN_FAILED hotplug state
If CPU_DOWN_PREPARE fails the perf hotplug notifier is called for
CPU_DOWN_FAILED and calls perf_event_init_cpu(), which checks whether the
swhash is referenced. If yes it allocates a new hash and stores the pointer in
the per cpu data structure.

But at this point the cpu is still online, so there must be a valid hash
already. By overwriting the pointer the existing hash is not longer
accessible.

Remove the CPU_DOWN_FAILED state, as there is nothing to (re)allocate.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/20160209201007.763417379@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-17 10:37:29 +01:00
Thomas Gleixner b4f75d44be perf/core: Remove bogus UP_CANCELED hotplug state
If CPU_UP_PREPARE fails the perf hotplug code calls perf_event_exit_cpu(),
which is a pointless exercise. The cpu is not online, so the smp function
calls return -ENXIO. So the result is a list walk to call noops.

Remove it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/20160209201007.682184765@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-17 10:37:28 +01:00
Steven Rostedt c219b7ddb6 sched/deadline: Fix trivial typo in printk() message
It's "too much" not "to much".

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Juri Lelli <juri.lelli@arm.com>
Cc: Jiri Kosina <trivial@kernel.org>
Cc: Juri Lelli <juri.lelli@gmail.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/20160210120422.4ca77e68@gandalf.local.home
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-17 10:02:00 +01:00
Byungchul Park 3223d052b7 sched/core: Remove dead statement in __schedule()
Remove an unnecessary assignment of variable not used any more.

( This has no runtime effects as GCC is smart enough to optimize
  this out. )

Signed-off-by: Byungchul Park <byungchul.park@lge.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1455159578-17256-1-git-send-email-byungchul.park@lge.com
[ Edited the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-17 09:32:03 +01:00
Serge Hallyn 1c53753e0d Add FS_USERNS_FLAG to cgroup fs
allowing root in a non-init user namespace to mount it.  This should
now be safe, because

1. non-init-root cannot mount a previously unbound subsystem
2. the task doing the mount must be privileged with respect to the
   user namespace owning the cgroup namespace
3. the mounted subsystem will have its current cgroup as the root dentry.
   the permissions will be unchanged, so tasks will receive no new
   privilege over the cgroups which they did not have on the original
   mounts.

Signed-off-by: Serge Hallyn <serge.hallyn@canonical.com>
2016-02-16 13:04:59 -05:00
Serge Hallyn ed82571b1a cgroup: mount cgroupns-root when inside non-init cgroupns
This patch enables cgroup mounting inside userns when a process
as appropriate privileges. The cgroup filesystem mounted is
rooted at the cgroupns-root. Thus, in a container-setup, only
the hierarchy under the cgroupns-root is exposed inside the container.
This allows container management tools to run inside the containers
without depending on any global state.

Signed-off-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2016-02-16 13:04:59 -05:00
Aditya Kali a0530e087e cgroup: cgroup namespace setns support
setns on a cgroup namespace is allowed only if
task has CAP_SYS_ADMIN in its current user-namespace and
over the user-namespace associated with target cgroupns.
No implicit cgroup changes happen with attaching to another
cgroupns. It is expected that the somone moves the attaching
process under the target cgroupns-root.

Signed-off-by: Aditya Kali <adityakali@google.com>
Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2016-02-16 13:04:58 -05:00
Aditya Kali a79a908fd2 cgroup: introduce cgroup namespaces
Introduce the ability to create new cgroup namespace. The newly created
cgroup namespace remembers the cgroup of the process at the point
of creation of the cgroup namespace (referred as cgroupns-root).
The main purpose of cgroup namespace is to virtualize the contents
of /proc/self/cgroup file. Processes inside a cgroup namespace
are only able to see paths relative to their namespace root
(unless they are moved outside of their cgroupns-root, at which point
 they will see a relative path from their cgroupns-root).
For a correctly setup container this enables container-tools
(like libcontainer, lxc, lmctfy, etc.) to create completely virtualized
containers without leaking system level cgroup hierarchy to the task.
This patch only implements the 'unshare' part of the cgroupns.

Signed-off-by: Aditya Kali <adityakali@google.com>
Signed-off-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2016-02-16 13:04:58 -05:00
Dave Hansen 1e9877902d mm/gup: Introduce get_user_pages_remote()
For protection keys, we need to understand whether protections
should be enforced in software or not.  In general, we enforce
protections when working on our own task, but not when on others.
We call these "current" and "remote" operations.

This patch introduces a new get_user_pages() variant:

        get_user_pages_remote()

Which is a replacement for when get_user_pages() is called on
non-current tsk/mm.

We also introduce a new gup flag: FOLL_REMOTE which can be used
for the "__" gup variants to get this new behavior.

The uprobes is_trap_at_addr() location holds mmap_sem and
calls get_user_pages(current->mm) on an instruction address.  This
makes it a pretty unique gup caller.  Being an instruction access
and also really originating from the kernel (vs. the app), I opted
to consider this a 'remote' access where protection keys will not
be enforced.

Without protection keys, this patch should not change any behavior.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: jack@suse.cz
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20160212210154.3F0E51EA@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-16 10:04:09 +01:00
Masanari Iida fc4fa6e112 treewide: Fix typo in printk
This patch fix spelling typos found in printk and Kconfig.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2016-02-15 11:18:22 +01:00
Daniel Lezcano f944b5a7af genirq: Use a common macro to go through the actions list
The irq code browses the list of actions differently to inspect the element
one by one. Even if it is not a problem, for the sake of consistent code,
provide a macro similar to for_each_irq_desc in order to have the same loop to
go through the actions list and use it in the code.

[ tglx: Renamed the macro ]

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: http://lkml.kernel.org/r/1452765253-31148-1-git-send-email-daniel.lezcano@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-02-15 00:07:34 +01:00
Greg Kroah-Hartman 249f3c4fe4 Merge 4.5-rc4 into tty-next
We want the fixes in here, and this resolves a merge error in tty_io.c

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-14 14:36:04 -08:00
Linus Torvalds cb490d632b Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull lockdep fix from Thomas Gleixner:
 "A single fix for the stack trace caching logic in lockdep, where the
  duplicate avoidance managed to store no back trace at all"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/lockdep: Fix stack trace caching logic
2016-02-14 12:02:05 -08:00
Frederic Weisbecker 8537bb95a6 nohz: Implement wide kick on top of irq work
It simplifies it and allows wide kick to be performed, even when IRQs
are disabled, without an asynchronous level in the middle.

This comes at a cost of some more overhead on features like perf and
posix cpu timers slow-paths, which is probably not much important
for nohz full users.

Requested-by: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2016-02-13 15:34:28 +01:00
Frederic Weisbecker 5fd7a09cfb atomic: Export fetch_or()
Export fetch_or() that's implemented and used internally by the
scheduler. We are going to use it for NO_HZ so make it generally
available.

Reviewed-by: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2016-02-13 15:34:28 +01:00
Ingo Molnar e2d6f8a5f5 Merge branch 'linus' into locking/core, to resolve conflicts
Conflicts:
	kernel/locking/lockdep.c

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-13 08:30:07 +01:00
Johannes Weiner 223ffb29f9 cgroup: provide cgroup_nov1= to disable controllers in v1 mounts
Testing cgroup2 can be painful with system software automatically
mounting and populating all cgroup controllers in v1 mode. Sometimes
they can be unmounted from rc.local, sometimes even that is too late.

Provide a commandline option to disable certain controllers in v1
mounts, so that they remain available for cgroup2 mounts.

Example use:

cgroup_no_v1=memory,cpu
cgroup_no_v1=all

Disabling will be confirmed at boot-time as such:

[    0.013770] Disabling cpu control group subsystem in v1 mounts
[    0.016004] Disabling memory control group subsystem in v1 mounts

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2016-02-12 15:01:45 -05:00
Dan Williams db78c22230 mm: fix pfn_t vs highmem
The pfn_t type uses an unsigned long to store a pfn + flags value.  On a
64-bit platform the upper 12 bits of an unsigned long are never used for
storing the value of a pfn.  However, this is not true on highmem
platforms, all 32-bits of a pfn value are used to address a 44-bit
physical address space.  A pfn_t needs to store a 64-bit value.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=112211
Fixes: 01c8f1c44b ("mm, dax, gpu: convert vm_insert_mixed to pfn_t")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reported-by: Stuart Foster <smf.linux@ntlworld.com>
Reported-by: Julian Margetson <runaway@candw.ms>
Tested-by: Julian Margetson <runaway@candw.ms>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-11 18:35:48 -08:00
Andrew Morton 4a389810bc kernel/locking/lockdep.c: convert hash tables to hlists
Mike said:

: CONFIG_UBSAN_ALIGNMENT breaks x86-64 kernel with lockdep enabled, i.  e
: kernel with CONFIG_UBSAN_ALIGNMENT fails to load without even any error
: message.
:
: The problem is that ubsan callbacks use spinlocks and might be called
: before lockdep is initialized.  Particularly this line in the
: reserve_ebda_region function causes problem:
:
: lowmem = *(unsigned short *)__va(BIOS_LOWMEM_KILOBYTES);
:
: If i put lockdep_init() before reserve_ebda_region call in
: x86_64_start_reservations kernel loads well.

Fix this ordering issue permanently: change lockdep so that it uses
hlists for the hash tables.  Unlike a list_head, an hlist_head is in its
initialized state when it is all-zeroes, so lockdep is ready for
operation immediately upon boot - lockdep_init() need not have run.

The patch will also save some memory.

lockdep_init() and lockdep_initialized can be done away with now - a 4.6
patch has been prepared to do this.

Reported-by: Mike Krinkin <krinkin.m.u@gmail.com>
Suggested-by: Mike Krinkin <krinkin.m.u@gmail.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-11 18:35:48 -08:00
Linus Torvalds 5de6ac75d9 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:

 1) Fix BPF handling of branch offset adjustmnets on backjumps, from
    Daniel Borkmann.

 2) Make sure selinux knows about SOCK_DESTROY netlink messages, from
    Lorenzo Colitti.

 3) Fix openvswitch tunnel mtu regression, from David Wragg.

 4) Fix ICMP handling of TCP sockets in syn_recv state, from Eric
    Dumazet.

 5) Fix SCTP user hmacid byte ordering bug, from Xin Long.

 6) Fix recursive locking in ipv6 addrconf, from Subash Abhinov
    Kasiviswanathan.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  bpf: fix branch offset adjustment on backjumps after patching ctx expansion
  vxlan, gre, geneve: Set a large MTU on ovs-created tunnel devices
  geneve: Relax MTU constraints
  vxlan: Relax MTU constraints
  flow_dissector: Fix unaligned access in __skb_flow_dissector when used by eth_get_headlen
  of: of_mdio: Add marvell, 88e1145 to whitelist of PHY compatibilities.
  selinux: nlmsgtab: add SOCK_DESTROY to the netlink mapping tables
  sctp: translate network order to host order when users get a hmacid
  enic: increment devcmd2 result ring in case of timeout
  tg3: Fix for tg3 transmit queue 0 timed out when too many gso_segs
  net:Add sysctl_max_skb_frags
  tcp: do not drop syn_recv on all icmp reports
  ipv6: fix a lockdep splat
  unix: correctly track in-flight fds in sending process user_struct
  update be2net maintainers' email addresses
  dwc_eth_qos: Reset hardware before PHY start
  ipv6: addrconf: Fix recursive spin lock call
2016-02-11 11:00:34 -08:00
saurabh 22e09b333f PM / suspend: replacing printk
replacing printk(s) with appropriate pr_info and pr_err
in order to fix checkpatch.pl warnings

Signed-off-by: Saurabh Sengar <saurabh.truth@gmail.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-02-11 11:12:55 +01:00
Abhilash Jindal f7b382b988 PM/freezer: y2038, use boottime to compare tstamps
Wall time obtained from do_gettimeofday gives 32 bit timeval which can only
represent time until January 2038. This patch moves to ktime_t, a 64-bit time.

Also, wall time is susceptible to sudden jumps due to user setting the time or
due to NTP.  Boot time is constantly increasing time better suited for
subtracting two timestamps.

Signed-off-by: Abhilash Jindal <klock.android@gmail.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-02-11 11:10:43 +01:00
Rafael J. Wysocki b2a3b193b7 Merge branch 'pm-opp' into pm-cpufreq 2016-02-11 00:24:00 +01:00
Daniel Borkmann a1b14d27ed bpf: fix branch offset adjustment on backjumps after patching ctx expansion
When ctx access is used, the kernel often needs to expand/rewrite
instructions, so after that patching, branch offsets have to be
adjusted for both forward and backward jumps in the new eBPF program,
but for backward jumps it fails to account the delta. Meaning, for
example, if the expansion happens exactly on the insn that sits at
the jump target, it doesn't fix up the back jump offset.

Analysis on what the check in adjust_branches() is currently doing:

  /* adjust offset of jmps if necessary */
  if (i < pos && i + insn->off + 1 > pos)
    insn->off += delta;
  else if (i > pos && i + insn->off + 1 < pos)
    insn->off -= delta;

First condition (forward jumps):

  Before:                         After:

  insns[0]                        insns[0]
  insns[1] <--- i/insn            insns[1] <--- i/insn
  insns[2] <--- pos               insns[P] <--- pos
  insns[3]                        insns[P]  `------| delta
  insns[4] <--- target_X          insns[P]   `-----|
  insns[5]                        insns[3]
                                  insns[4] <--- target_X
                                  insns[5]

First case is if we cross pos-boundary and the jump instruction was
before pos. This is handeled correctly. I.e. if i == pos, then this
would mean our jump that we currently check was the patchlet itself
that we just injected. Since such patchlets are self-contained and
have no awareness of any insns before or after the patched one, the
delta is correctly not adjusted. Also, for the second condition in
case of i + insn->off + 1 == pos, means we jump to that newly patched
instruction, so no offset adjustment are needed. That part is correct.

Second condition (backward jumps):

  Before:                         After:

  insns[0]                        insns[0]
  insns[1] <--- target_X          insns[1] <--- target_X
  insns[2] <--- pos <-- target_Y  insns[P] <--- pos <-- target_Y
  insns[3]                        insns[P]  `------| delta
  insns[4] <--- i/insn            insns[P]   `-----|
  insns[5]                        insns[3]
                                  insns[4] <--- i/insn
                                  insns[5]

Second interesting case is where we cross pos-boundary and the jump
instruction was after pos. Backward jump with i == pos would be
impossible and pose a bug somewhere in the patchlet, so the first
condition checking i > pos is okay only by itself. However, i +
insn->off + 1 < pos does not always work as intended to trigger the
adjustment. It works when jump targets would be far off where the
delta wouldn't matter. But, for example, where the fixed insn->off
before pointed to pos (target_Y), it now points to pos + delta, so
that additional room needs to be taken into account for the check.
This means that i) both tests here need to be adjusted into pos + delta,
and ii) for the second condition, the test needs to be <= as pos
itself can be a target in the backjump, too.

Fixes: 9bac3d6d54 ("bpf: allow extended BPF programs access skb fields")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-10 16:56:47 -05:00
Linus Torvalds fb0dc5f129 Merge branch 'for-4.5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo:

 - The destruction path of cgroup objects are asynchronous and
   multi-staged and some of them ended up destroying parents before
   children leading to failures in cpu and memory controllers.  Ensure
   that parents are always destroyed after children.

 - cpuset mm node migration was performed synchronously while holding
   threadgroup and cgroup mutexes and the recent threadgroup locking
   update resulted in a possible deadlock.  The migration is best effort
   and shouldn't have been performed under those locks to begin with.
   Made asynchronous.

 - Minor documentation fix.

* 'for-4.5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  Documentation: cgroup: Fix 'cgroup-legacy' -> 'cgroup-v1'
  cgroup: make sure a parent css isn't freed before its children
  cgroup: make sure a parent css isn't offlined before its children
  cpuset: make mm migration asynchronous
2016-02-10 11:36:19 -08:00
Linus Torvalds 9aece75c13 Merge branch 'for-4.5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue fixes from Tejun Heo:
 "Workqueue fixes for v4.5-rc3.

   - Remove a spurious triggering of flush dependency warning.

   - Officially break local execution guarantee of unbound work items
     and add a debug feature to flush out usages which depend on it.

   - Work around CPU -> NODE mapping becoming invalid on CPU offline.

  The branch is young but pushing out early as stable kernels are being
  affected"

* 'for-4.5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: handle NUMA_NO_NODE for unbound pool_workqueue lookup
  workqueue: implement "workqueue.debug_force_rr_cpu" debug feature
  workqueue: schedule WORK_CPU_UNBOUND work on wq_unbound_cpumask CPUs
  Revert "workqueue: make sure delayed work run in local cpu"
  workqueue: skip flush dependency checks for legacy workqueues
2016-02-10 11:04:05 -08:00
Tejun Heo d6e022f1d2 workqueue: handle NUMA_NO_NODE for unbound pool_workqueue lookup
When looking up the pool_workqueue to use for an unbound workqueue,
workqueue assumes that the target CPU is always bound to a valid NUMA
node.  However, currently, when a CPU goes offline, the mapping is
destroyed and cpu_to_node() returns NUMA_NO_NODE.

This has always been broken but hasn't triggered often enough before
874bbfe600 ("workqueue: make sure delayed work run in local cpu").
After the commit, workqueue forcifully assigns the local CPU for
delayed work items without explicit target CPU to fix a different
issue.  This widens the window where CPU can go offline while a
delayed work item is pending causing delayed work items dispatched
with target CPU set to an already offlined CPU.  The resulting
NUMA_NO_NODE mapping makes workqueue try to queue the work item on a
NULL pool_workqueue and thus crash.

While 874bbfe600 has been reverted for a different reason making the
bug less visible again, it can still happen.  Fix it by mapping
NUMA_NO_NODE to the default pool_workqueue from unbound_pwq_by_node().
This is a temporary workaround.  The long term solution is keeping CPU
-> NODE mapping stable across CPU off/online cycles which is being
worked on.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Len Brown <len.brown@intel.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/g/1454424264.11183.46.camel@gmail.com
Link: http://lkml.kernel.org/g/1453702100-2597-1-git-send-email-tangchen@cn.fujitsu.com
2016-02-10 12:13:05 -05:00
Linus Torvalds 2178cbc68f Fix for async_probe module param added in 4.3 (clearly not widely used yet),
and a much more interesting kallsyms race which has been around approximately
 forever.  This fix is more invasive, and will require some care in backporting,
 but I hated all the bandaids I could think of, so...
 
 There are some more coming, which are only for breakages introduced this
 cycle (livepatch), but wanted these in now.
 
 Thanks,
 Rusty.
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Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

Pull module fixes from Rusty Russell:
 "Fix for async_probe module param added in 4.3 (clearly not widely used
  yet), and a much more interesting kallsyms race which has been around
  approximately forever.  This fix is more invasive, and will require
  some care in backporting, but I hated all the bandaids I could think
  of, so...

  There are some more coming, which are only for breakages introduced
  this cycle (livepatch), but wanted these in now"

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  modules: fix longstanding /proc/kallsyms vs module insertion race.
  module: wrapper for symbol name.
  modules: fix modparam async_probe request
2016-02-09 16:40:59 -08:00
Tejun Heo f303fccb82 workqueue: implement "workqueue.debug_force_rr_cpu" debug feature
Workqueue used to guarantee local execution for work items queued
without explicit target CPU.  The guarantee is gone now which can
break some usages in subtle ways.  To flush out those cases, this
patch implements a debug feature which forces round-robin CPU
selection for all such work items.

The debug feature defaults to off and can be enabled with a kernel
parameter.  The default can be flipped with a debug config option.

If you hit this commit during bisection, please refer to 041bd12e27
("Revert "workqueue: make sure delayed work run in local cpu"") for
more information and ping me.

Signed-off-by: Tejun Heo <tj@kernel.org>
2016-02-09 17:59:38 -05:00
Mike Galbraith ef55718044 workqueue: schedule WORK_CPU_UNBOUND work on wq_unbound_cpumask CPUs
WORK_CPU_UNBOUND work items queued to a bound workqueue always run
locally.  This is a good thing normally, but not when the user has
asked us to keep unbound work away from certain CPUs.  Round robin
these to wq_unbound_cpumask CPUs instead, as perturbation avoidance
trumps performance.

tj: Cosmetic and comment changes.  WARN_ON_ONCE() dropped from empty
    (wq_unbound_cpumask AND cpu_online_mask).  If we want that, it
    should be done when config changes.

Signed-off-by: Mike Galbraith <umgwanakikbuti@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2016-02-09 17:59:38 -05:00
Tejun Heo 041bd12e27 Revert "workqueue: make sure delayed work run in local cpu"
This reverts commit 874bbfe600.

Workqueue used to implicity guarantee that work items queued without
explicit CPU specified are put on the local CPU.  Recent changes in
timer broke the guarantee and led to vmstat breakage which was fixed
by 176bed1de5 ("vmstat: explicitly schedule per-cpu work on the CPU
we need it to run on").

vmstat is the most likely to expose the issue and it's quite possible
that there are other similar problems which are a lot more difficult
to trigger.  As a preventive measure, 874bbfe600 ("workqueue: make
sure delayed work run in local cpu") was applied to restore the local
CPU guarnatee.  Unfortunately, the change exposed a bug in timer code
which got fixed by 22b886dd10 ("timers: Use proper base migration in
add_timer_on()").  Due to code restructuring, the commit couldn't be
backported beyond certain point and stable kernels which only had
874bbfe600 started crashing.

The local CPU guarantee was accidental more than anything else and we
want to get rid of it anyway.  As, with the vmstat case fixed,
874bbfe600 is causing more problems than it's fixing, it has been
decided to take the chance and officially break the guarantee by
reverting the commit.  A debug feature will be added to force foreign
CPU assignment to expose cases relying on the guarantee and fixes for
the individual cases will be backported to stable as necessary.

Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: 874bbfe600 ("workqueue: make sure delayed work run in local cpu")
Link: http://lkml.kernel.org/g/20160120211926.GJ10810@quack.suse.cz
Cc: stable@vger.kernel.org
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Daniel Bilik <daniel.bilik@neosystem.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Shaohua Li <shli@fb.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Daniel Bilik <daniel.bilik@neosystem.cz>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Michal Hocko <mhocko@kernel.org>
2016-02-09 16:11:26 -05:00
Rik van Riel 4142c3ebb6 sched/numa: Spread memory according to CPU and memory use
The pseudo-interleaving in NUMA placement has a fundamental problem:
using hard usage thresholds to spread memory equally between nodes
can prevent workloads from converging, or keep memory "trapped" on
nodes where the workload is barely running any more.

In order for workloads to properly converge, the memory migration
should not be stopped when nodes reach parity, but instead be
distributed according to how heavily memory is used from each node.
This way memory migration and task migration reinforce each other,
instead of one putting the brakes on the other.

Remove the hard thresholds from the pseudo-interleaving code, and
instead use a more gradual policy on memory placement. This also
seems to improve convergence of workloads that do not run flat out,
but sleep in between bursts of activity.

We still want to slow down NUMA scanning and migration once a workload
has settled on a few actively used nodes, so keep the 3/4 hysteresis
in place. Keep track of whether a workload is actively running on
multiple nodes, so task_numa_migrate does a full scan of the system
for better task placement.

In the case of running 3 SPECjbb2005 instances on a 4 node system,
this code seems to result in fairer distribution of memory between
nodes, with more memory bandwidth for each instance.

Signed-off-by: Rik van Riel <riel@redhat.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: mgorman@suse.de
Link: http://lkml.kernel.org/r/20160125170739.2fc9a641@annuminas.surriel.com
[ Minor readability tweaks. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-09 14:47:18 +01:00
Andrey Ryabinin 06bea3dbfe locking/lockdep: Eliminate lockdep_init()
Lockdep is initialized at compile time now.  Get rid of lockdep_init().

Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Krinkin <krinkin.m.u@gmail.com>
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
Cc: mm-commits@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-09 12:03:25 +01:00
Andrew Morton a63f38cc4c locking/lockdep: Convert hash tables to hlists
Mike said:

: CONFIG_UBSAN_ALIGNMENT breaks x86-64 kernel with lockdep enabled, i.e.
: kernel with CONFIG_UBSAN_ALIGNMENT=y fails to load without even any error
: message.
:
: The problem is that ubsan callbacks use spinlocks and might be called
: before lockdep is initialized.  Particularly this line in the
: reserve_ebda_region function causes problem:
:
: lowmem = *(unsigned short *)__va(BIOS_LOWMEM_KILOBYTES);
:
: If i put lockdep_init() before reserve_ebda_region call in
: x86_64_start_reservations kernel loads well.

Fix this ordering issue permanently: change lockdep so that it uses hlists
for the hash tables.  Unlike a list_head, an hlist_head is in its
initialized state when it is all-zeroes, so lockdep is ready for operation
immediately upon boot - lockdep_init() need not have run.

The patch will also save some memory.

Probably lockdep_init() and lockdep_initialized can be done away with now.

Suggested-by: Mike Krinkin <krinkin.m.u@gmail.com>
Reported-by: Mike Krinkin <krinkin.m.u@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.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: linux-kernel@vger.kernel.org
Cc: mm-commits@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-09 12:03:25 +01:00
Mel Gorman cb2517653f sched/debug: Make schedstats a runtime tunable that is disabled by default
schedstats is very useful during debugging and performance tuning but it
incurs overhead to calculate the stats. As such, even though it can be
disabled at build time, it is often enabled as the information is useful.

This patch adds a kernel command-line and sysctl tunable to enable or
disable schedstats on demand (when it's built in). It is disabled
by default as someone who knows they need it can also learn to enable
it when necessary.

The benefits are dependent on how scheduler-intensive the workload is.
If it is then the patch reduces the number of cycles spent calculating
the stats with a small benefit from reducing the cache footprint of the
scheduler.

These measurements were taken from a 48-core 2-socket
machine with Xeon(R) E5-2670 v3 cpus although they were also tested on a
single socket machine 8-core machine with Intel i7-3770 processors.

netperf-tcp
                           4.5.0-rc1             4.5.0-rc1
                             vanilla          nostats-v3r1
Hmean    64         560.45 (  0.00%)      575.98 (  2.77%)
Hmean    128        766.66 (  0.00%)      795.79 (  3.80%)
Hmean    256        950.51 (  0.00%)      981.50 (  3.26%)
Hmean    1024      1433.25 (  0.00%)     1466.51 (  2.32%)
Hmean    2048      2810.54 (  0.00%)     2879.75 (  2.46%)
Hmean    3312      4618.18 (  0.00%)     4682.09 (  1.38%)
Hmean    4096      5306.42 (  0.00%)     5346.39 (  0.75%)
Hmean    8192     10581.44 (  0.00%)    10698.15 (  1.10%)
Hmean    16384    18857.70 (  0.00%)    18937.61 (  0.42%)

Small gains here, UDP_STREAM showed nothing intresting and neither did
the TCP_RR tests. The gains on the 8-core machine were very similar.

tbench4
                                 4.5.0-rc1             4.5.0-rc1
                                   vanilla          nostats-v3r1
Hmean    mb/sec-1         500.85 (  0.00%)      522.43 (  4.31%)
Hmean    mb/sec-2         984.66 (  0.00%)     1018.19 (  3.41%)
Hmean    mb/sec-4        1827.91 (  0.00%)     1847.78 (  1.09%)
Hmean    mb/sec-8        3561.36 (  0.00%)     3611.28 (  1.40%)
Hmean    mb/sec-16       5824.52 (  0.00%)     5929.03 (  1.79%)
Hmean    mb/sec-32      10943.10 (  0.00%)    10802.83 ( -1.28%)
Hmean    mb/sec-64      15950.81 (  0.00%)    16211.31 (  1.63%)
Hmean    mb/sec-128     15302.17 (  0.00%)    15445.11 (  0.93%)
Hmean    mb/sec-256     14866.18 (  0.00%)    15088.73 (  1.50%)
Hmean    mb/sec-512     15223.31 (  0.00%)    15373.69 (  0.99%)
Hmean    mb/sec-1024    14574.25 (  0.00%)    14598.02 (  0.16%)
Hmean    mb/sec-2048    13569.02 (  0.00%)    13733.86 (  1.21%)
Hmean    mb/sec-3072    12865.98 (  0.00%)    13209.23 (  2.67%)

Small gains of 2-4% at low thread counts and otherwise flat.  The
gains on the 8-core machine were slightly different

tbench4 on 8-core i7-3770 single socket machine
Hmean    mb/sec-1        442.59 (  0.00%)      448.73 (  1.39%)
Hmean    mb/sec-2        796.68 (  0.00%)      794.39 ( -0.29%)
Hmean    mb/sec-4       1322.52 (  0.00%)     1343.66 (  1.60%)
Hmean    mb/sec-8       2611.65 (  0.00%)     2694.86 (  3.19%)
Hmean    mb/sec-16      2537.07 (  0.00%)     2609.34 (  2.85%)
Hmean    mb/sec-32      2506.02 (  0.00%)     2578.18 (  2.88%)
Hmean    mb/sec-64      2511.06 (  0.00%)     2569.16 (  2.31%)
Hmean    mb/sec-128     2313.38 (  0.00%)     2395.50 (  3.55%)
Hmean    mb/sec-256     2110.04 (  0.00%)     2177.45 (  3.19%)
Hmean    mb/sec-512     2072.51 (  0.00%)     2053.97 ( -0.89%)

In constract, this shows a relatively steady 2-3% gain at higher thread
counts. Due to the nature of the patch and the type of workload, it's
not a surprise that the result will depend on the CPU used.

hackbench-pipes
                         4.5.0-rc1             4.5.0-rc1
                           vanilla          nostats-v3r1
Amean    1        0.0637 (  0.00%)      0.0660 ( -3.59%)
Amean    4        0.1229 (  0.00%)      0.1181 (  3.84%)
Amean    7        0.1921 (  0.00%)      0.1911 (  0.52%)
Amean    12       0.3117 (  0.00%)      0.2923 (  6.23%)
Amean    21       0.4050 (  0.00%)      0.3899 (  3.74%)
Amean    30       0.4586 (  0.00%)      0.4433 (  3.33%)
Amean    48       0.5910 (  0.00%)      0.5694 (  3.65%)
Amean    79       0.8663 (  0.00%)      0.8626 (  0.43%)
Amean    110      1.1543 (  0.00%)      1.1517 (  0.22%)
Amean    141      1.4457 (  0.00%)      1.4290 (  1.16%)
Amean    172      1.7090 (  0.00%)      1.6924 (  0.97%)
Amean    192      1.9126 (  0.00%)      1.9089 (  0.19%)

Some small gains and losses and while the variance data is not included,
it's close to the noise. The UMA machine did not show anything particularly
different

pipetest
                             4.5.0-rc1             4.5.0-rc1
                               vanilla          nostats-v2r2
Min         Time        4.13 (  0.00%)        3.99 (  3.39%)
1st-qrtle   Time        4.38 (  0.00%)        4.27 (  2.51%)
2nd-qrtle   Time        4.46 (  0.00%)        4.39 (  1.57%)
3rd-qrtle   Time        4.56 (  0.00%)        4.51 (  1.10%)
Max-90%     Time        4.67 (  0.00%)        4.60 (  1.50%)
Max-93%     Time        4.71 (  0.00%)        4.65 (  1.27%)
Max-95%     Time        4.74 (  0.00%)        4.71 (  0.63%)
Max-99%     Time        4.88 (  0.00%)        4.79 (  1.84%)
Max         Time        4.93 (  0.00%)        4.83 (  2.03%)
Mean        Time        4.48 (  0.00%)        4.39 (  1.91%)
Best99%Mean Time        4.47 (  0.00%)        4.39 (  1.91%)
Best95%Mean Time        4.46 (  0.00%)        4.38 (  1.93%)
Best90%Mean Time        4.45 (  0.00%)        4.36 (  1.98%)
Best50%Mean Time        4.36 (  0.00%)        4.25 (  2.49%)
Best10%Mean Time        4.23 (  0.00%)        4.10 (  3.13%)
Best5%Mean  Time        4.19 (  0.00%)        4.06 (  3.20%)
Best1%Mean  Time        4.13 (  0.00%)        4.00 (  3.39%)

Small improvement and similar gains were seen on the UMA machine.

The gain is small but it stands to reason that doing less work in the
scheduler is a good thing. The downside is that the lack of schedstats and
tracepoints may be surprising to experts doing performance analysis until
they find the existence of the schedstats= parameter or schedstats sysctl.
It will be automatically activated for latencytop and sleep profiling to
alleviate the problem. For tracepoints, there is a simple warning as it's
not safe to activate schedstats in the context when it's known the tracepoint
may be wanted but is unavailable.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <mgalbraith@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1454663316-22048-1-git-send-email-mgorman@techsingularity.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-09 11:54:23 +01:00
Martin KaFai Lau a7636d9ecf kprobes: Optimize hot path by using percpu counter to collect 'nhit' statistics
When doing ebpf+kprobe on some hot TCP functions (e.g.
tcp_rcv_established), the kprobe_dispatcher() function
shows up in 'perf report'.

In kprobe_dispatcher(), there is a lot of cache bouncing
on 'tk->nhit++'.  'tk->nhit' and 'tk->tp.flags' also share
the same cacheline.

perf report (cycles:pp):

	8.30%  ipv4_dst_check
	4.74%  copy_user_enhanced_fast_string
	3.93%  dst_release
	2.80%  tcp_v4_rcv
	2.31%  queued_spin_lock_slowpath
	2.30%  _raw_spin_lock
	1.88%  mlx4_en_process_rx_cq
	1.84%  eth_get_headlen
	1.81%  ip_rcv_finish
	~~~~
	1.71%  kprobe_dispatcher
	~~~~
	1.55%  mlx4_en_xmit
	1.09%  __probe_kernel_read

perf report after patch:

	9.15%  ipv4_dst_check
	5.00%  copy_user_enhanced_fast_string
	4.12%  dst_release
	2.96%  tcp_v4_rcv
	2.50%  _raw_spin_lock
	2.39%  queued_spin_lock_slowpath
	2.11%  eth_get_headlen
	2.03%  mlx4_en_process_rx_cq
	1.69%  mlx4_en_xmit
	1.19%  ip_rcv_finish
	1.12%  __probe_kernel_read
	1.02%  ehci_hcd_cleanup

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Kernel Team <kernel-team@fb.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/1454531308-2441898-1-git-send-email-kafai@fb.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-09 11:08:58 +01:00
Dmitry Vyukov 8a5fd56431 locking/lockdep: Fix stack trace caching logic
check_prev_add() caches saved stack trace in static trace variable
to avoid duplicate save_trace() calls in dependencies involving trylocks.
But that caching logic contains a bug. We may not save trace on first
iteration due to early return from check_prev_add(). Then on the
second iteration when we actually need the trace we don't save it
because we think that we've already saved it.

Let check_prev_add() itself control when stack is saved.

There is another bug. Trace variable is protected by graph lock.
But we can temporary release graph lock during printing.

Fix this by invalidating cached stack trace when we release graph lock.

Signed-off-by: Dmitry Vyukov <dvyukov@google.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: glider@google.com
Cc: kcc@google.com
Cc: peter@hurleysoftware.com
Cc: sasha.levin@oracle.com
Link: http://lkml.kernel.org/r/1454593240-121647-1-git-send-email-dvyukov@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-09 11:06:08 +01:00
Wei Yuan fd97646b05 audit: Fix typo in comment
Signed-off-by: Weiyuan <weiyuan.wei@huawei.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-02-08 11:25:39 -05:00
Thomas Gleixner fbf198030e genirq: Add default affinity mask command line option
If we isolate CPUs, then we don't want random device interrupts on them. Even
w/o the user space irq balancer enabled we can end up with irqs on non boot
cpus and chasing newly requested interrupts is a tedious task.

Allow to restrict the default irq affinity mask.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1602031948190.25254@nanos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-02-08 15:03:42 +01:00
Alexei Starovoitov 15a07b3381 bpf: add lookup/update support for per-cpu hash and array maps
The functions bpf_map_lookup_elem(map, key, value) and
bpf_map_update_elem(map, key, value, flags) need to get/set
values from all-cpus for per-cpu hash and array maps,
so that user space can aggregate/update them as necessary.

Example of single counter aggregation in user space:
  unsigned int nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
  long values[nr_cpus];
  long value = 0;

  bpf_lookup_elem(fd, key, values);
  for (i = 0; i < nr_cpus; i++)
    value += values[i];

The user space must provide round_up(value_size, 8) * nr_cpus
array to get/set values, since kernel will use 'long' copy
of per-cpu values to try to copy good counters atomically.
It's a best-effort, since bpf programs and user space are racing
to access the same memory.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06 03:34:36 -05:00
Alexei Starovoitov a10423b87a bpf: introduce BPF_MAP_TYPE_PERCPU_ARRAY map
Primary use case is a histogram array of latency
where bpf program computes the latency of block requests or other
events and stores histogram of latency into array of 64 elements.
All cpus are constantly running, so normal increment is not accurate,
bpf_xadd causes cache ping-pong and this per-cpu approach allows
fastest collision-free counters.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06 03:34:36 -05:00
Alexei Starovoitov 824bd0ce6c bpf: introduce BPF_MAP_TYPE_PERCPU_HASH map
Introduce BPF_MAP_TYPE_PERCPU_HASH map type which is used to do
accurate counters without need to use BPF_XADD instruction which turned
out to be too costly for high-performance network monitoring.
In the typical use case the 'key' is the flow tuple or other long
living object that sees a lot of events per second.

bpf_map_lookup_elem() returns per-cpu area.
Example:
struct {
  u32 packets;
  u32 bytes;
} * ptr = bpf_map_lookup_elem(&map, &key);
/* ptr points to this_cpu area of the value, so the following
 * increments will not collide with other cpus
 */
ptr->packets ++;
ptr->bytes += skb->len;

bpf_update_elem() atomically creates a new element where all per-cpu
values are zero initialized and this_cpu value is populated with
given 'value'.
Note that non-per-cpu hash map always allocates new element
and then deletes old after rcu grace period to maintain atomicity
of update. Per-cpu hash map updates element values in-place.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06 03:34:35 -05:00
Sasha Levin 823dd3224a signals: avoid random wakeups in sigsuspend()
A random wakeup can get us out of sigsuspend() without TIF_SIGPENDING
being set.

Avoid that by making sure we were signaled, like sys_pause() does.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Dmitry Vyukov <dvyukov@google.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>
2016-02-05 18:10:40 -08:00
Prarit Bhargava a6e4491c68 sched/isolcpus: Output warning when the 'isolcpus=' kernel parameter is invalid
The isolcpus= kernel boot parameter restricts userspace from scheduling on
the specified CPUs.

If a CPU is specified that is outside the range of 0 to nr_cpu_ids,
cpulist_parse() will return -ERANGE, return an empty cpulist, and
fail silently.

This patch adds an error message to isolated_cpu_setup() to indicate to
the user that something has gone awry, and returns 0 on error.

Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1454596680-10367-1-git-send-email-prarit@redhat.com
[ Twiddled some details. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-05 08:46:38 +01:00
Shilpasri G Bhat 0306e481d4 cpufreq: powernv/tracing: Add powernv_throttle tracepoint
This patch adds the powernv_throttle tracepoint to trace the CPU
frequency throttling event, which is used by the powernv-cpufreq
driver in POWER8.

Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-02-05 02:38:02 +01:00
Linus Torvalds ef582d095d A cleanup to the stack tracer broke stack tracing on s390.
Here's a simple fix to correct that issue.
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Merge tag 'trace-v4.5-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fix from Steven Rostedt:
 "A cleanup to the stack tracer broke stack tracing on s390.  Here's a
  simple fix to correct that issue"

* tag 'trace-v4.5-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing/stacktrace: Show entire trace if passed in function not found
2016-02-03 09:31:34 -08:00
Rusty Russell 8244062ef1 modules: fix longstanding /proc/kallsyms vs module insertion race.
For CONFIG_KALLSYMS, we keep two symbol tables and two string tables.
There's one full copy, marked SHF_ALLOC and laid out at the end of the
module's init section.  There's also a cut-down version that only
contains core symbols and strings, and lives in the module's core
section.

After module init (and before we free the module memory), we switch
the mod->symtab, mod->num_symtab and mod->strtab to point to the core
versions.  We do this under the module_mutex.

However, kallsyms doesn't take the module_mutex: it uses
preempt_disable() and rcu tricks to walk through the modules, because
it's used in the oops path.  It's also used in /proc/kallsyms.
There's nothing atomic about the change of these variables, so we can
get the old (larger!) num_symtab and the new symtab pointer; in fact
this is what I saw when trying to reproduce.

By grouping these variables together, we can use a
carefully-dereferenced pointer to ensure we always get one or the
other (the free of the module init section is already done in an RCU
callback, so that's safe).  We allocate the init one at the end of the
module init section, and keep the core one inside the struct module
itself (it could also have been allocated at the end of the module
core, but that's probably overkill).

Reported-by: Weilong Chen <chenweilong@huawei.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111541
Cc: stable@kernel.org
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-02-03 16:58:15 +10:30
Rusty Russell 2e7bac5361 module: wrapper for symbol name.
This trivial wrapper adds clarity and makes the following patch
smaller.

Cc: stable@kernel.org
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-02-03 16:58:14 +10:30
Luis R. Rodriguez 4355efbd80 modules: fix modparam async_probe request
Commit f2411da746 ("driver-core: add driver module
asynchronous probe support") added async probe support,
in two forms:

  * in-kernel driver specification annotation
  * generic async_probe module parameter (modprobe foo async_probe)

To support the generic kernel parameter parse_args() was
extended via commit ecc8617053 ("module: add extra
argument for parse_params() callback") however commit
failed to f2411da746 failed to add the required argument.

This causes a crash then whenever async_probe generic
module parameter is used. This was overlooked when the
form in which in-kernel async probe support was reworked
a bit... Fix this as originally intended.

Cc: Hannes Reinecke <hare@suse.de>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: stable@vger.kernel.org (4.2+)
Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> [minimized]
2016-02-03 16:58:14 +10:30
Linus Torvalds 29a8ea4fbe Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm
Pull libnvdimm fixes from Dan Williams:
 "1/ Fixes to the libnvdimm 'pfn' device that establishes a reserved
     area for storing a struct page array.

  2/ Fixes for dax operations on a raw block device to prevent pagecache
     collisions with dax mappings.

  3/ A fix for pfn_t usage in vm_insert_mixed that lead to a null
     pointer de-reference.

  These have received build success notification from the kbuild robot
  across 153 configs and pass the latest ndctl tests"

* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  phys_to_pfn_t: use phys_addr_t
  mm: fix pfn_t to page conversion in vm_insert_mixed
  block: use DAX for partition table reads
  block: revert runtime dax control of the raw block device
  fs, block: force direct-I/O for dax-enabled block devices
  devm_memremap_pages: fix vmem_altmap lifetime + alignment handling
  libnvdimm, pfn: fix restoring memmap location
  libnvdimm: fix mode determination for e820 devices
2016-02-01 15:21:20 -08:00
Greg Kroah-Hartman 6e9131cc43 Merge 4.5-rc2 into tty-next
We want the tty/serial fixes in here as well to make merges easier.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-01 12:53:14 -08:00
Linus Torvalds dc799d0179 Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Thomas Gleixner:
 "The timer departement delivers:

   - a regression fix for the NTP code along with a proper selftest
   - prevent a spurious timer interrupt in the NOHZ lowres code
   - a fix for user space interfaces returning the remaining time on
     architectures with CONFIG_TIME_LOW_RES=y
   - a few patches to fix COMPILE_TEST fallout"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tick/nohz: Set the correct expiry when switching to nohz/lowres mode
  clocksource: Fix dependencies for archs w/o HAS_IOMEM
  clocksource: Select CLKSRC_MMIO where needed
  tick/sched: Hide unused oneshot timer code
  kselftests: timers: Add adjtimex SETOFFSET validity tests
  ntp: Fix ADJ_SETOFFSET being used w/ ADJ_NANO
  itimers: Handle relative timers with CONFIG_TIME_LOW_RES proper
  posix-timers: Handle relative timers with CONFIG_TIME_LOW_RES proper
  timerfd: Handle relative timers with CONFIG_TIME_LOW_RES proper
  hrtimer: Handle remaining time proper for TIME_LOW_RES
  clockevents/tcb_clksrc: Prevent disabling an already disabled clock
2016-01-31 15:49:06 -08:00
Linus Torvalds 7ab85d4a85 Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Thomas Gleixner:
 "Three small fixes in the scheduler/core:

   - use after free in the numa code
   - crash in the numa init code
   - a simple spelling fix"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  pid: Fix spelling in comments
  sched/numa: Fix use-after-free bug in the task_numa_compare
  sched: Fix crash in sched_init_numa()
2016-01-31 15:44:04 -08:00
Linus Torvalds 29d14f0835 Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Thomas Gleixner:
 "This is much bigger than typical fixes, but Peter found a category of
  races that spurred more fixes and more debugging enhancements.  Work
  started before the merge window, but got finished only now.

  Aside of that this contains the usual small fixes to perf and tools.
  Nothing particular exciting"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (43 commits)
  perf: Remove/simplify lockdep annotation
  perf: Synchronously clean up child events
  perf: Untangle 'owner' confusion
  perf: Add flags argument to perf_remove_from_context()
  perf: Clean up sync_child_event()
  perf: Robustify event->owner usage and SMP ordering
  perf: Fix STATE_EXIT usage
  perf: Update locking order
  perf: Remove __free_event()
  perf/bpf: Convert perf_event_array to use struct file
  perf: Fix NULL deref
  perf/x86: De-obfuscate code
  perf/x86: Fix uninitialized value usage
  perf: Fix race in perf_event_exit_task_context()
  perf: Fix orphan hole
  perf stat: Do not clean event's private stats
  perf hists: Fix HISTC_MEM_DCACHELINE width setting
  perf annotate browser: Fix behaviour of Shift-Tab with nothing focussed
  perf tests: Remove wrong semicolon in while loop in CQM test
  perf: Synchronously free aux pages in case of allocation failure
  ...
2016-01-31 15:38:27 -08:00
Linus Torvalds bbfb239a10 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 commit, which makes the rtmutex.wait_lock an irq safe lock.

  This prevents a potential deadlock which can be triggered by the rcu
  boosting code from rcu_read_unlock()"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  rtmutex: Make wait_lock irq safe
2016-01-31 15:29:37 -08:00
Linus Torvalds 30e4c9ad04 Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull IRQ fixes from Ingo Molnar:
 "Mostly irqchip driver fixes, but also an irq core crash fix and a
  build fix"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/mxs: Add missing set_handle_irq()
  irqchip/atmel-aic: Fix wrong bit operation for IRQ priority
  irqchip/gic-v3-its: Recompute the number of pages on page size change
  base: Export platform_msi_domain_[alloc,free]_irqs
  of: MSI: Simplify irqdomain lookup
  irqdomain: Allow domain lookup with DOMAIN_BUS_WIRED token
  irqchip: Fix dependencies for archs w/o HAS_IOMEM
  irqchip/s3c24xx: Mark init_eint as __maybe_unused
  genirq: Validate action before dereferencing it in handle_irq_event_percpu()
2016-01-31 14:48:58 -08:00
Dan Williams 76e9f0ee52 phys_to_pfn_t: use phys_addr_t
A dma_addr_t is potentially smaller than a phys_addr_t on some archs.
Don't truncate the address when doing the pfn conversion.

Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Reported-by: Matthew Wilcox <willy@linux.intel.com>
[willy: fix pfn_t_to_phys as well]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-31 09:10:19 -08:00
Li Bin e11b956e9e kernel/Makefile: remove the useless CFLAGS_REMOVE_cgroup-debug.o
The file cgroup-debug.c had been removed from commit fe6934354f
(cgroups: move the cgroup debug subsys into cgroup.c to access internal state).
Remain the CFLAGS_REMOVE_cgroup-debug.o = $(CC_FLAGS_FTRACE)
useless in kernel/Makefile.

Signed-off-by: Li Bin <huawei.libin@huawei.com>
Acked-by: Zefan Li <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2016-01-31 05:11:21 -05:00
Toshi Kani a8fc42530d resource: Kill walk_iomem_res()
walk_iomem_res_desc() replaced walk_iomem_res() and there is no
caller to walk_iomem_res() any more. Kill it. Also remove @name
from find_next_iomem_res() as it is no longer used.

Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Dave Young <dyoung@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Hanjun Guo <hanjun.guo@linaro.org>
Cc: Jakub Sitnicki <jsitnicki@gmail.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-mm <linux-mm@kvack.org>
Link: http://lkml.kernel.org/r/1453841853-11383-17-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-30 09:49:59 +01:00
Toshi Kani f0f4711aa1 x86, kexec, nvdimm: Use walk_iomem_res_desc() for iomem search
Change the callers of walk_iomem_res() scanning for the
following resources by name to use walk_iomem_res_desc()
instead.

 "ACPI Tables"
 "ACPI Non-volatile Storage"
 "Persistent Memory (legacy)"
 "Crash kernel"

Note, the caller of walk_iomem_res() with "GART" will be removed
in a later patch.

Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Young <dyoung@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Chun-Yi <joeyli.kernel@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Lee, Chun-Yi <joeyli.kernel@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Minfei Huang <mnfhuang@gmail.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Takao Indoh <indou.takao@jp.fujitsu.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: kexec@lists.infradead.org
Cc: linux-arch@vger.kernel.org
Cc: linux-mm <linux-mm@kvack.org>
Cc: linux-nvdimm@lists.01.org
Link: http://lkml.kernel.org/r/1453841853-11383-15-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-30 09:49:59 +01:00
Toshi Kani 3f33647c41 resource: Add walk_iomem_res_desc()
Add a new interface, walk_iomem_res_desc(), which walks through
the iomem table by identifying a target with @flags and @desc.
This interface provides the same functionality as
walk_iomem_res(), but does not use strcmp() to @name for better
efficiency.

walk_iomem_res() is deprecated and will be removed in a later
patch.

Requested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
[ Fixup comments. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Hanjun Guo <hanjun.guo@linaro.org>
Cc: Jakub Sitnicki <jsitnicki@gmail.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-mm <linux-mm@kvack.org>
Link: http://lkml.kernel.org/r/1453841853-11383-14-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-30 09:49:59 +01:00
Toshi Kani 1c29f25bf5 memremap: Change region_intersects() to take @flags and @desc
Change region_intersects() to identify a target with @flags and
@desc, instead of @name with strcmp().

Change the callers of region_intersects(), memremap() and
devm_memremap(), to set IORESOURCE_SYSTEM_RAM in @flags and
IORES_DESC_NONE in @desc when searching System RAM.

Also, export region_intersects() so that the ACPI EINJ error
injection driver can call this function in a later patch.

Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jakub Sitnicki <jsitnicki@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: linux-arch@vger.kernel.org
Cc: linux-mm <linux-mm@kvack.org>
Link: http://lkml.kernel.org/r/1453841853-11383-13-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-30 09:49:58 +01:00
Toshi Kani bd7e6cb30c resource: Change walk_system_ram() to use System RAM type
Now that all System RAM resource entries have been initialized
to IORESOURCE_SYSTEM_RAM type, change walk_system_ram_res() and
walk_system_ram_range() to call find_next_iomem_res() by setting
@res.flags to IORESOURCE_SYSTEM_RAM and @name to NULL. With this
change, they walk through the iomem table to find System RAM
ranges without the need to do strcmp() on the resource names.

No functional change is made to the interfaces.

Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
[ Boris: fixup comments. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jakub Sitnicki <jsitnicki@gmail.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-mm <linux-mm@kvack.org>
Link: http://lkml.kernel.org/r/1453841853-11383-11-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-30 09:49:58 +01:00
Toshi Kani 1a085d0727 kexec: Set IORESOURCE_SYSTEM_RAM for System RAM
Set proper ioresource flags and types for crash kernel
reservation areas.

Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Young <dyoung@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
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: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Minfei Huang <mnfhuang@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: kexec@lists.infradead.org
Cc: linux-arch@vger.kernel.org
Cc: linux-mm <linux-mm@kvack.org>
Link: http://lkml.kernel.org/r/1453841853-11383-8-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-30 09:49:57 +01:00
Toshi Kani 43ee493bde resource: Add I/O resource descriptor
walk_iomem_res() and region_intersects() still need to use
strcmp() for searching a resource entry by @name in the iomem
table.

This patch introduces I/O resource descriptor 'desc' in struct
resource for the iomem search interfaces. Drivers can assign
their unique descriptor to a range when they support the search
interfaces.

Otherwise, 'desc' is set to IORES_DESC_NONE (0). This avoids
changing most of the drivers as they typically allocate resource
entries statically, or by calling alloc_resource(), kzalloc(),
or alloc_bootmem_low(), which set the field to zero by default.
A later patch will address some drivers that use kmalloc()
without zero'ing the field.

Also change release_mem_region_adjustable() to set 'desc' when
its resource entry gets separated. Other resource interfaces are
also changed to initialize 'desc' explicitly although
alloc_resource() sets it to 0.

Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jakub Sitnicki <jsitnicki@gmail.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-mm <linux-mm@kvack.org>
Link: http://lkml.kernel.org/r/1453841853-11383-4-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-30 09:49:56 +01:00
Toshi Kani a3650d53ba resource: Handle resource flags properly
I/O resource flags consist of I/O resource types and modifier
bits. Therefore, checking an I/O resource type in 'flags' must
be performed with a bitwise operation.

Fix find_next_iomem_res() and region_intersects() that simply
compare 'flags' against a given value.

Also change __request_region() to set 'res->flags' from
resource_type() and resource_ext_type() of the parent, so that
children nodes will inherit the extended I/O resource type.

Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jakub Sitnicki <jsitnicki@gmail.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-mm <linux-mm@kvack.org>
Link: http://lkml.kernel.org/r/1453841853-11383-3-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-30 09:49:56 +01:00
Zhen Lei 840d6fe742 pid: Fix spelling in comments
Accidentally discovered this typo when I studied this module.

Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tianhong Ding <dingtianhong@huawei.com>
Cc: Xinwei Hu <huxinwei@huawei.com>
Cc: Zefan Li <lizefan@huawei.com>
Link: http://lkml.kernel.org/r/1454119457-11272-1-git-send-email-thunder.leizhen@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-30 09:28:18 +01:00
Dan Williams eb7d78c9e7 devm_memremap_pages: fix vmem_altmap lifetime + alignment handling
to_vmem_altmap() needs to return valid results until
arch_remove_memory() completes.  It also needs to be valid for any pfn
in a section regardless of whether that pfn maps to data.  This escape
was a result of a bug in the unit test.

The signature of this bug is that free_pagetable() fails to retrieve a
vmem_altmap and goes off into the weeds:

 BUG: unable to handle kernel NULL pointer dereference at           (null)
 IP: [<ffffffff811d2629>] get_pfnblock_flags_mask+0x49/0x60
 [..]
 Call Trace:
  [<ffffffff811d3477>] free_hot_cold_page+0x97/0x1d0
  [<ffffffff811d367a>] __free_pages+0x2a/0x40
  [<ffffffff8191e669>] free_pagetable+0x8c/0xd4
  [<ffffffff8191ef4e>] remove_pagetable+0x37a/0x808
  [<ffffffff8191b210>] vmemmap_free+0x10/0x20

Fixes: 4b94ffdc41 ("x86, mm: introduce vmem_altmap to augment vmemmap_populate()")
Cc: Andrew Morton <akpm@linux-foundation.org>
Reported-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-29 21:54:04 -08:00
Linus Torvalds 46552e68ac More power management and ACPI fixes for v4.5-rc2
- Fix a recent cpuidle core regression that broke suspend-to-idle
    on all systems where cpuidle drivers don't provide ->enter_freeze
    callbacks for any states (Sudeep Holla).
 
  - Drop an unnecessary symbol definition from the cpuidle core code
    handling coupled CPU cores (Anders Roxell).
 
  - Fix a race condition related to governor initialization and removal
    in the cpufreq core (Viresh Kumar).
 
  - Clean up the cpufreq core to use list_is_last() for checking if
    the given policy object is the last element of a list instead of
    open coding that in a clumsy way (Gautham R Shenoy).
 
  - Fix compiler warnings in the pxa2xx and cpufreq-dt cpufreq drivers
    (Arnd Bergmann).
 
  - Fix two locking issues and clean up a comment in the generic power
    domains framework (Ulf Hansson, Marek Szyprowski, Moritz Fischer).
 
  - Fix the error code path of one function in the ACPI-based PCI
    hotplug framework (ACPIPHP) that forgets to release a lock
    acquired previously (Insu Yun).
 
  - Drop the ACPI backlight blacklist entry for Dell Inspiron 5737
    that is not necessary any more (Hans de Goede).
 
  - Clean up the top-level PM Kconfig to stop requiring APM emulation
    to depend on PM which in fact isn't necessary (Arnd Bergmann).
 
 /
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Merge tag 'pm+acpi-4.5-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management and ACPI fixes from Rafael Wysocki:
 "These are: cpuidle fixes (including one fix for a recent regression),
  cpufreq fixes (including fixes for two issues introduced during the
  4.2 cycle), generic power domains framework fixes (two locking fixes
  and one cleanup), one locking fix in the ACPI-based PCI hotplug
  framework (ACPIPHP), removal of one ACPI backlight blacklist entry
  that isn't necessary any more and a PM Kconfig cleanup.

  Specifics:

   - Fix a recent cpuidle core regression that broke suspend-to-idle on
     all systems where cpuidle drivers don't provide ->enter_freeze
     callbacks for any states (Sudeep Holla).

   - Drop an unnecessary symbol definition from the cpuidle core code
     handling coupled CPU cores (Anders Roxell).

   - Fix a race condition related to governor initialization and removal
     in the cpufreq core (Viresh Kumar).

   - Clean up the cpufreq core to use list_is_last() for checking if the
     given policy object is the last element of a list instead of open
     coding that in a clumsy way (Gautham R Shenoy).

   - Fix compiler warnings in the pxa2xx and cpufreq-dt cpufreq drivers
     (Arnd Bergmann).

   - Fix two locking issues and clean up a comment in the generic power
     domains framework (Ulf Hansson, Marek Szyprowski, Moritz Fischer).

   - Fix the error code path of one function in the ACPI-based PCI
     hotplug framework (ACPIPHP) that forgets to release a lock acquired
     previously (Insu Yun).

   - Drop the ACPI backlight blacklist entry for Dell Inspiron 5737 that
     is not necessary any more (Hans de Goede).

   - Clean up the top-level PM Kconfig to stop requiring APM emulation
     to depend on PM which in fact isn't necessary (Arnd Bergmann)"

* tag 'pm+acpi-4.5-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: cpufreq-dt: avoid uninitialized variable warnings:
  cpufreq: pxa2xx: fix pxa_cpufreq_change_voltage prototype
  PM: APM_EMULATION does not depend on PM
  cpufreq: Use list_is_last() to check last entry of the policy list
  cpufreq: Fix NULL reference crash while accessing policy->governor_data
  cpuidle: coupled: remove unused define cpuidle_coupled_lock
  PM / Domains: Fix typo in comment
  PM / Domains: Fix potential deadlock while adding/removing subdomains
  ACPI / PCI / hotplug: unlock in error path in acpiphp_enable_slot()
  ACPI: Revert "ACPI / video: Add Dell Inspiron 5737 to the blacklist"
  cpuidle: fix fallback mechanism for suspend to idle in absence of enter_freeze
  PM / domains: fix lockdep issue for all subdomains
2016-01-29 15:40:59 -08:00
Rafael J. Wysocki ad1ac94767 Merge branches 'pm-cpuidle', 'pm-cpufreq', 'pm-domains' and 'pm-sleep'
* pm-cpuidle:
  cpuidle: coupled: remove unused define cpuidle_coupled_lock
  cpuidle: fix fallback mechanism for suspend to idle in absence of enter_freeze

* pm-cpufreq:
  cpufreq: cpufreq-dt: avoid uninitialized variable warnings:
  cpufreq: pxa2xx: fix pxa_cpufreq_change_voltage prototype
  cpufreq: Use list_is_last() to check last entry of the policy list
  cpufreq: Fix NULL reference crash while accessing policy->governor_data

* pm-domains:
  PM / Domains: Fix typo in comment
  PM / Domains: Fix potential deadlock while adding/removing subdomains
  PM / domains: fix lockdep issue for all subdomains

* pm-sleep:
  PM: APM_EMULATION does not depend on PM
2016-01-29 21:45:17 +01:00
Linus Torvalds 704bb813c2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security layer fixes from James Morris:
 "The keys patch fixes a bug which is breaking kerberos, and the seccomp
  fix addresses a no_new_privs bypass"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  KEYS: Only apply KEY_FLAG_KEEP to a key if a parent keyring has it set
  seccomp: always propagate NO_NEW_PRIVS on tsync
2016-01-29 12:24:05 -08:00
Tejun Heo 23d11a58a9 workqueue: skip flush dependency checks for legacy workqueues
fca839c00a ("workqueue: warn if memory reclaim tries to flush
!WQ_MEM_RECLAIM workqueue") implemented flush dependency warning which
triggers if a PF_MEMALLOC task or WQ_MEM_RECLAIM workqueue tries to
flush a !WQ_MEM_RECLAIM workquee.

This assumes that workqueues marked with WQ_MEM_RECLAIM sit in memory
reclaim path and making it depend on something which may need more
memory to make forward progress can lead to deadlocks.  Unfortunately,
workqueues created with the legacy create*_workqueue() interface
always have WQ_MEM_RECLAIM regardless of whether they are depended
upon memory reclaim or not.  These spurious WQ_MEM_RECLAIM markings
cause spurious triggering of the flush dependency checks.

  WARNING: CPU: 0 PID: 6 at kernel/workqueue.c:2361 check_flush_dependency+0x138/0x144()
  workqueue: WQ_MEM_RECLAIM deferwq:deferred_probe_work_func is flushing !WQ_MEM_RECLAIM events:lru_add_drain_per_cpu
  ...
  Workqueue: deferwq deferred_probe_work_func
  [<c0017acc>] (unwind_backtrace) from [<c0013134>] (show_stack+0x10/0x14)
  [<c0013134>] (show_stack) from [<c0245f18>] (dump_stack+0x94/0xd4)
  [<c0245f18>] (dump_stack) from [<c0026f9c>] (warn_slowpath_common+0x80/0xb0)
  [<c0026f9c>] (warn_slowpath_common) from [<c0026ffc>] (warn_slowpath_fmt+0x30/0x40)
  [<c0026ffc>] (warn_slowpath_fmt) from [<c00390b8>] (check_flush_dependency+0x138/0x144)
  [<c00390b8>] (check_flush_dependency) from [<c0039ca0>] (flush_work+0x50/0x15c)
  [<c0039ca0>] (flush_work) from [<c00c51b0>] (lru_add_drain_all+0x130/0x180)
  [<c00c51b0>] (lru_add_drain_all) from [<c00f728c>] (migrate_prep+0x8/0x10)
  [<c00f728c>] (migrate_prep) from [<c00bfbc4>] (alloc_contig_range+0xd8/0x338)
  [<c00bfbc4>] (alloc_contig_range) from [<c00f8f18>] (cma_alloc+0xe0/0x1ac)
  [<c00f8f18>] (cma_alloc) from [<c001cac4>] (__alloc_from_contiguous+0x38/0xd8)
  [<c001cac4>] (__alloc_from_contiguous) from [<c001ceb4>] (__dma_alloc+0x240/0x278)
  [<c001ceb4>] (__dma_alloc) from [<c001cf78>] (arm_dma_alloc+0x54/0x5c)
  [<c001cf78>] (arm_dma_alloc) from [<c0355ea4>] (dmam_alloc_coherent+0xc0/0xec)
  [<c0355ea4>] (dmam_alloc_coherent) from [<c039cc4c>] (ahci_port_start+0x150/0x1dc)
  [<c039cc4c>] (ahci_port_start) from [<c0384734>] (ata_host_start.part.3+0xc8/0x1c8)
  [<c0384734>] (ata_host_start.part.3) from [<c03898dc>] (ata_host_activate+0x50/0x148)
  [<c03898dc>] (ata_host_activate) from [<c039d558>] (ahci_host_activate+0x44/0x114)
  [<c039d558>] (ahci_host_activate) from [<c039f05c>] (ahci_platform_init_host+0x1d8/0x3c8)
  [<c039f05c>] (ahci_platform_init_host) from [<c039e6bc>] (tegra_ahci_probe+0x448/0x4e8)
  [<c039e6bc>] (tegra_ahci_probe) from [<c0347058>] (platform_drv_probe+0x50/0xac)
  [<c0347058>] (platform_drv_probe) from [<c03458cc>] (driver_probe_device+0x214/0x2c0)
  [<c03458cc>] (driver_probe_device) from [<c0343cc0>] (bus_for_each_drv+0x60/0x94)
  [<c0343cc0>] (bus_for_each_drv) from [<c03455d8>] (__device_attach+0xb0/0x114)
  [<c03455d8>] (__device_attach) from [<c0344ab8>] (bus_probe_device+0x84/0x8c)
  [<c0344ab8>] (bus_probe_device) from [<c0344f48>] (deferred_probe_work_func+0x68/0x98)
  [<c0344f48>] (deferred_probe_work_func) from [<c003b738>] (process_one_work+0x120/0x3f8)
  [<c003b738>] (process_one_work) from [<c003ba48>] (worker_thread+0x38/0x55c)
  [<c003ba48>] (worker_thread) from [<c0040f14>] (kthread+0xdc/0xf4)
  [<c0040f14>] (kthread) from [<c000f778>] (ret_from_fork+0x14/0x3c)

Fix it by marking workqueues created via create*_workqueue() with
__WQ_LEGACY and disabling flush dependency checks on them.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-and-tested-by: Thierry Reding <thierry.reding@gmail.com>
Link: http://lkml.kernel.org/g/20160126173843.GA11115@ulmo.nvidia.com
Fixes: fca839c00a ("workqueue: warn if memory reclaim tries to flush !WQ_MEM_RECLAIM workqueue")
2016-01-29 13:31:10 -05:00
Steven Rostedt 6ccd83714a tracing/stacktrace: Show entire trace if passed in function not found
When a max stack trace is discovered, the stack dump is saved. In order to
not record the overhead of the stack tracer, the ip of the traced function
is looked for within the dump. The trace is started from the location of
that function. But if for some reason the ip is not found, the entire stack
trace is then truncated. That's not very useful. Instead, print everything
if the ip of the traced function is not found within the trace.

This issue showed up on s390.

Link: http://lkml.kernel.org/r/20160129102241.1b3c9c04@gandalf.local.home

Fixes: 72ac426a5b ("tracing: Clean up stack tracing and fix fentry updates")
Cc: stable@vger.kernel.org # v4.3+
Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-01-29 12:19:10 -05:00
Peter Zijlstra 5fa7c8ec57 perf: Remove/simplify lockdep annotation
Now that the perf_event_ctx_lock_nested() call has moved from
put_event() into perf_event_release_kernel() the first reason is no
longer valid as that can no longer happen.

The second reason seems to have been invalidated when Al Viro made fput()
unconditionally async in the following commit:

  4a9d4b024a ("switch fput to task_work_add")

such that munmap()->fput()->release()->perf_release() would no longer happen.

Therefore, remove the annotation. This should increase the efficiency
of lockdep coverage of perf locking.

Suggested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
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>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-29 08:35:36 +01:00
Peter Zijlstra c6e5b73242 perf: Synchronously clean up child events
The orphan cleanup workqueue doesn't always catch orphans, for example,
if they never schedule after they are orphaned. IOW, the event leak is
still very real. It also wouldn't work for kernel counters.

Doing it synchonously is a little hairy due to lock inversion issues,
but is made to work.

Patch based on work by Alexander Shishkin.

Suggested-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: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
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: vince@deater.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-29 08:35:35 +01:00
Peter Zijlstra 60beda8493 perf: Untangle 'owner' confusion
There are two concepts of owner wrt an event and they are conflated:

 - event::owner / event::owner_list,
   used by prctl(.option = PR_TASK_PERF_EVENTS_{EN,DIS}ABLE).

 - the 'owner' of the event object, typically the file descriptor.

Currently these two concepts are conflated, which gives trouble with
scm_rights passing of file descriptors. Passing the event and then
closing the creating task would render the event 'orphan' and would
have it cleared out. Unlikely what is expectd.

This patch untangles these two concepts by using PERF_EVENT_STATE_EXIT
to denote the second type.

Reported-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
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>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-29 08:35:34 +01:00
Peter Zijlstra 45a0e07abf perf: Add flags argument to perf_remove_from_context()
In preparation to adding more options, convert the boolean argument
into a flags word.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
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>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-29 08:35:33 +01:00
Peter Zijlstra 8ba289b8d4 perf: Clean up sync_child_event()
sync_child_event() has outgrown its purpose, it does far too much.
Bring it back to its named purpose.

Rename __perf_event_exit_task() to perf_event_exit_event() to better
reflect what it does and move the event->state assignment under the
ctx->lock, like state changes ought to be.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
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>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-29 08:35:32 +01:00
Peter Zijlstra f47c02c0c8 perf: Robustify event->owner usage and SMP ordering
Use smp_store_release() to clear event->owner and
lockless_dereference() to observe it. Further use READ_ONCE() for all
lockless reads.

This changes perf_remove_from_owner() to leave event->owner cleared.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
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>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-29 08:35:31 +01:00
Peter Zijlstra 6e801e0169 perf: Fix STATE_EXIT usage
We should never attempt to enable a STATE_EXIT event.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
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>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-29 08:35:30 +01:00
Peter Zijlstra 07c4a77613 perf: Update locking order
Update the locking order to note that ctx::lock nests inside of
child_mutex, as per:

  perf_ioctl():                ctx::mutex
  -> perf_event_for_each():    event::child_mutex
    -> _perf_event_enable():   ctx::lock

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
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>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-29 08:35:29 +01:00
Peter Zijlstra a0733e695b perf: Remove __free_event()
There is but a single caller, remove the function - we already have
_free_event(), the extra indirection is nonsensical..

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
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>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-29 08:35:25 +01:00
Alexei Starovoitov e03e7ee34f perf/bpf: Convert perf_event_array to use struct file
Robustify refcounting.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
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: vince@deater.net
Link: http://lkml.kernel.org/r/20160126045947.GA40151@ast-mbp.thefacebook.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-29 08:35:25 +01:00
Peter Zijlstra 828b6f0e26 perf: Fix NULL deref
Dan reported:

  1229                  if (ctx->task == TASK_TOMBSTONE ||
  1230                      !atomic_inc_not_zero(&ctx->refcount)) {
  1231                          raw_spin_unlock(&ctx->lock);
  1232                          ctx = NULL;
                                ^^^^^^^^^^
ctx is NULL.

  1233                  }
  1234
  1235                  WARN_ON_ONCE(ctx->task != task);
                                     ^^^^^^^^^^^^^^^^^
The patch adds a NULL dereference.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
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>
Fixes: 63b6da39bb ("perf: Fix perf_event_exit_task() race")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-29 08:35:24 +01:00
Linus Torvalds 26cd83670f This includes three minor fixes, mostly due to cut-and-paste issues.
The first is a cut and paste issue that changed the amount of stack
 to skip when tracing a stack dump from 0 to 6, which basically made
 the stack disappear for small stack traces.
 
 The second fix is just removing an unused field in a struct that is no
 longer used, and currently just wastes space.
 
 The third is another cut-and-paste fix that had a tracepoint recording
 the wrong field (it was recording the previous field a second time).
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Merge tag 'trace-v4.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull minor tracing fixes from Steven Rostedt:
 "This includes three minor fixes, mostly due to cut-and-paste issues.

  The first is a cut and paste issue that changed the amount of stack to
  skip when tracing a stack dump from 0 to 6, which basically made the
  stack disappear for small stack traces.

  The second fix is just removing an unused field in a struct that is no
  longer used, and currently just wastes space.

  The third is another cut-and-paste fix that had a tracepoint recording
  the wrong field (it was recording the previous field a second time)"

* tag 'trace-v4.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing/dma-buf/fence: Fix timeline str value on fence_annotate_wait_on
  ftrace: Remove unused nr_trampolines var
  tracing: Fix stacktrace skip depth in trace_buffer_unlock_commit_regs()
2016-01-28 17:00:50 -08:00
Peter Zijlstra 6a3351b612 perf: Fix race in perf_event_exit_task_context()
There is a race between perf_event_exit_task_context() and
orphans_remove_work() which results in a use-after-free.

We mark ctx->task with TASK_TOMBSTONE to indicate a context is
'dead', under ctx->lock. After which point event_function_call()
on any event of that context will NOP

A concurrent orphans_remove_work() will only hold ctx->mutex for
the list iteration and not serialize against this. Therefore its
possible that orphans_remove_work()'s perf_remove_from_context()
call will fail, but we'll continue to free the event, with the
result of free'd memory still being on lists and everything.

Once perf_event_exit_task_context() gets around to acquiring
ctx->mutex it too will iterate the event list, encounter the
already free'd event and proceed to free it _again_. This fails
with the WARN in free_event().

Plug the race by having perf_event_exit_task_context() hold
ctx::mutex over the whole tear-down, thereby 'naturally'
serializing against all other sites, including the orphan work.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
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: alexander.shishkin@linux.intel.com
Cc: dsahern@gmail.com
Cc: namhyung@kernel.org
Link: http://lkml.kernel.org/r/20160125130954.GY6357@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-28 20:06:36 +01:00
Peter Zijlstra 78cd2c748f perf: Fix orphan hole
We should set event->owner before we install the event,
otherwise there is a hole where the target task can fork() and
we'll not inherit the event because it thinks the event is
orphaned.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-28 20:06:35 +01:00
Peter Hurley 2e28d38ae1 tty: audit: Handle tty audit enable atomically
The audit_tty and audit_tty_log_passwd fields are actually bool
values, so merge into single memory location to access atomically.

NB: audit log operations may still occur after tty audit is disabled
which is consistent with the existing functionality

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-27 16:41:04 -08:00
Peter Hurley 37282a7795 tty: audit: Combine push functions
tty_audit_push() and tty_audit_push_current() perform identical
tasks; eliminate the tty_audit_push() implementation and the
tty_audit_push_current() name.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-27 16:41:04 -08:00
James Morris 1c1ecf172a Merge tag 'seccomp-4.5-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux into for-linus 2016-01-28 10:53:54 +11:00
Arnd Bergmann 993e9fe1e7 PM: APM_EMULATION does not depend on PM
The APM emulation code does multiple things, and some of them depend on
PM_SLEEP, while the battery management does not. However, selecting
the symbol like SHARPSL_PM does causes a Kconfig warning:

warning: (SHARPSL_PM && PMAC_APM_EMU) selects APM_EMULATION which has unmet direct dependencies (PM && SYS_SUPPORTS_APM_EMULATION)

From all I can tell, this is completely harmless, and we can simply allow
APM_EMULATION to be enabled here, even if PM is not.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-01-27 23:20:14 +01:00
Jann Horn 103502a35c seccomp: always propagate NO_NEW_PRIVS on tsync
Before this patch, a process with some permissive seccomp filter
that was applied by root without NO_NEW_PRIVS was able to add
more filters to itself without setting NO_NEW_PRIVS by setting
the new filter from a throwaway thread with NO_NEW_PRIVS.

Signed-off-by: Jann Horn <jann@thejh.net>
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
2016-01-27 07:38:25 -08:00
Wanpeng Li 1ca8ec532f tick/nohz: Set the correct expiry when switching to nohz/lowres mode
commit 0ff53d0964 sets the next tick interrupt to the last jiffies update,
i.e. in the past, because the forward operation is invoked before the set
operation. There is no resulting damage (yet), but we get an extra pointless
tick interrupt.

Revert the order so we get the next tick interrupt in the future.

Fixes: commit 0ff53d0964 "tick: sched: Force tick interrupt and get rid of softirq magic"
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1453893967-3458-1-git-send-email-wanpeng.li@hotmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-01-27 12:45:57 +01:00
Vitaly Kuznetsov bbf66d897a clocksource: Allow unregistering the watchdog
Hyper-V vmbus module registers TSC page clocksource when loaded. This is
the clocksource with the highest rating and thus it becomes the watchdog
making unloading of the vmbus module impossible.
Separate clocksource_select_watchdog() from clocksource_enqueue_watchdog()
and use it on clocksource register/rating change/unregister.

After all, lobotomized monkeys may need some love too.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Link: http://lkml.kernel.org/r/1453483913-25672-1-git-send-email-vkuznets@redhat.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-01-27 12:38:05 +01:00
Marc Zyngier 9006a01829 hrtimer: Catch illegal clockids
It is way too easy to take any random clockid and feed it to
the hrtimer subsystem. At best, it gets mapped to a monotonic
base, but it would be better to just catch illegal values as
early as possible.

This patch does exactly that, mapping illegal clockids to an
illegal base index, and panicing when we detect the illegal
condition.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Tomasz Nowicki <tn@semihalf.com>
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Link: http://lkml.kernel.org/r/1452879670-16133-3-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-01-27 12:38:04 +01:00
Marc Zyngier 9c808765e8 hrtimer: Add support for CLOCK_MONOTONIC_RAW
The KVM/ARM timer implementation arms a hrtimer when a vcpu is
blocked (usually because it is waiting for an interrupt)
while its timer is going to kick in the future.

It is essential that this timer doesn't get adjusted, or the
guest will end up being woken-up at the wrong time (NTP running
on the host seems to confuse the hell out of some guests).

In order to allow this, let's add CLOCK_MONOTONIC_RAW support
to hrtimer (it is so far only supported for posix timers). It also
has the (limited) benefit of fixing de0421d53b ("mac80211_hwsim:
shuffle code to prepare for dynamic radios"), which already uses
this functionnality without realizing wasn't implemented (just being
lucky...).

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Tomasz Nowicki <tn@semihalf.com>
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Link: http://lkml.kernel.org/r/1452879670-16133-2-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-01-27 12:38:04 +01:00
Arnd Bergmann 7809998ab1 tick/sched: Hide unused oneshot timer code
A couple of functions in kernel/time/tick-sched.c are only
relevant for oneshot timer mode, i.e. when hires-timers or
nohz mode are enabled. If both are disabled, we get gcc warnings
about them:

kernel/time/tick-sched.c:98:16: warning: 'tick_init_jiffy_update' defined but not used [-Wunused-function]
 static ktime_t tick_init_jiffy_update(void)
                ^
kernel/time/tick-sched.c:112:13: warning: 'tick_sched_do_timer' defined but not used [-Wunused-function]
 static void tick_sched_do_timer(ktime_t now)
             ^
kernel/time/tick-sched.c:134:13: warning: 'tick_sched_handle' defined but not used [-Wunused-function]
 static void tick_sched_handle(struct tick_sched *ts, struct pt_regs *regs)
             ^

This encloses the whole set of functions in an appropriate ifdef
to avoid the warning and to make it clearer when they are used.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1453736525-1959191-1-git-send-email-arnd@arndb.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-01-26 16:26:06 +01:00
Marc Zyngier 530cbe100e irqdomain: Allow domain lookup with DOMAIN_BUS_WIRED token
Let's take the (outlandish) example of an interrupt controller
capable of handling both wired interrupts and PCI MSIs.

With the current code, the PCI MSI domain is going to be tagged
with DOMAIN_BUS_PCI_MSI, and the wired domain with DOMAIN_BUS_ANY.

Things get hairy when we start looking up the domain for a wired
interrupt (typically when creating it based on some firmware
information - DT or ACPI).

In irq_create_fwspec_mapping(), we perform the lookup using
DOMAIN_BUS_ANY, which is actually used as a wildcard. This gives
us one chance out of two to end up with the wrong domain, and
we try to configure a wired interrupt with the MSI domain.
Everything grinds to a halt pretty quickly.

What we really need to do is to start looking for a domain that
would uniquely identify a wired interrupt domain, and only use
DOMAIN_BUS_ANY as a fallback.

In order to solve this, let's introduce a new DOMAIN_BUS_WIRED
token, which is going to be used exactly as described above.
Of course, this depends on the irqchip to setup the domain
bus_token, and nobody had to implement this so far.

Only so far.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Link: http://lkml.kernel.org/r/1453816347-32720-2-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-01-26 16:00:14 +01:00
Thomas Gleixner b4abf91047 rtmutex: Make wait_lock irq safe
Sasha reported a lockdep splat about a potential deadlock between RCU boosting
rtmutex and the posix timer it_lock.

CPU0					CPU1

rtmutex_lock(&rcu->rt_mutex)
  spin_lock(&rcu->rt_mutex.wait_lock)
					local_irq_disable()
					spin_lock(&timer->it_lock)
					spin_lock(&rcu->mutex.wait_lock)
--> Interrupt
    spin_lock(&timer->it_lock)

This is caused by the following code sequence on CPU1

     rcu_read_lock()
     x = lookup();
     if (x)
     	spin_lock_irqsave(&x->it_lock);
     rcu_read_unlock();
     return x;

We could fix that in the posix timer code by keeping rcu read locked across
the spinlocked and irq disabled section, but the above sequence is common and
there is no reason not to support it.

Taking rt_mutex.wait_lock irq safe prevents the deadlock.

Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
2016-01-26 11:08:35 +01:00
Richard Guy Briggs 935c9e7ff0 audit: log failed attempts to change audit_pid configuration
Failed attempts to change the audit_pid configuration are not presently
logged.  One case is an attempt to starve an old auditd by starting up
a new auditd when the old one is still alive and active.  The other
case is an attempt to orphan a new auditd when an old auditd shuts
down.

Log both as AUDIT_CONFIG_CHANGE messages with failure result.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>
2016-01-25 18:04:15 -05:00
Richard Guy Briggs 133e1e5acd audit: stop an old auditd being starved out by a new auditd
Nothing prevents a new auditd starting up and replacing a valid
audit_pid when an old auditd is still running, effectively starving out
the old auditd since audit_pid no longer points to the old valid
auditd.

If no message to auditd has been attempted since auditd died
unnaturally or got killed, audit_pid will still indicate it is alive.
There isn't an easy way to detect if an old auditd is still running on
the existing audit_pid other than attempting to send a message to see
if it fails.  An -ECONNREFUSED almost certainly means it disappeared
and can be replaced.  Other errors are not so straightforward and may
indicate transient problems that will resolve themselves and the old
auditd will recover.  Yet others will likely need manual intervention
for which a new auditd will not solve the problem.

Send a new message type (AUDIT_REPLACE) to the old auditd containing a
u32 with the PID of the new auditd.  If the audit replace message
succeeds (or doesn't fail with certainty), fail to register the new
auditd and return an error (-EEXIST).

This is expected to make the patch preventing an old auditd orphaning a
new auditd redundant.

V3: Switch audit message type from 1000 to 1300 block.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>
2016-01-25 18:04:15 -05:00
Al Viro 5955102c99 wrappers for ->i_mutex access
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).

Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-22 18:04:28 -05:00
Linus Torvalds eadee0ce6f Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more vfs updates from Al Viro:
 "Embarrassing braino fix + pipe page accounting + fixing an eyesore in
  find_filesystem() (checking that s1 is equal to prefix of s2 of given
  length can be done in many ways, but "compare strlen(s1) with length
  and then do strncmp()" is not a good one...)"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  [regression] fix braino in fs/dlm/user.c
  pipe: limit the per-user amount of pages allocated in pipes
  find_filesystem(): simplify comparison
2016-01-22 10:24:03 -08:00
Tejun Heo 8bb5ef79bc cgroup: make sure a parent css isn't freed before its children
There are three subsystem callbacks in css shutdown path -
css_offline(), css_released() and css_free().  Except for
css_released(), cgroup core didn't guarantee the order of invocation.
css_offline() or css_free() could be called on a parent css before its
children.  This behavior is unexpected and led to bugs in cpu and
memory controller.

The previous patch updated ordering for css_offline() which fixes the
cpu controller issue.  While there currently isn't a known bug caused
by misordering of css_free() invocations, let's fix it too for
consistency.

css_free() ordering can be trivially fixed by moving putting of the
parent css below css_free() invocation.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
2016-01-22 10:42:58 -05:00
Tejun Heo aa226ff4a1 cgroup: make sure a parent css isn't offlined before its children
There are three subsystem callbacks in css shutdown path -
css_offline(), css_released() and css_free().  Except for
css_released(), cgroup core didn't guarantee the order of invocation.
css_offline() or css_free() could be called on a parent css before its
children.  This behavior is unexpected and led to bugs in cpu and
memory controller.

This patch updates offline path so that a parent css is never offlined
before its children.  Each css keeps online_cnt which reaches zero iff
itself and all its children are offline and offline_css() is invoked
only after online_cnt reaches zero.

This fixes the memory controller bug and allows the fix for cpu
controller.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-and-tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reported-by: Brian Christiansen <brian.o.christiansen@gmail.com>
Link: http://lkml.kernel.org/g/5698A023.9070703@de.ibm.com
Link: http://lkml.kernel.org/g/CAKB58ikDkzc8REt31WBkD99+hxNzjK4+FBmhkgS+NVrC9vjMSg@mail.gmail.com
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
2016-01-22 10:42:57 -05:00
Tejun Heo e93ad19d05 cpuset: make mm migration asynchronous
If "cpuset.memory_migrate" is set, when a process is moved from one
cpuset to another with a different memory node mask, pages in used by
the process are migrated to the new set of nodes.  This was performed
synchronously in the ->attach() callback, which is synchronized
against process management.  Recently, the synchronization was changed
from per-process rwsem to global percpu rwsem for simplicity and
optimization.

Combined with the synchronous mm migration, this led to deadlocks
because mm migration could schedule a work item which may in turn try
to create a new worker blocking on the process management lock held
from cgroup process migration path.

This heavy an operation shouldn't be performed synchronously from that
deep inside cgroup migration in the first place.  This patch punts the
actual migration to an ordered workqueue and updates cgroup process
migration and cpuset config update paths to flush the workqueue after
all locks are released.  This way, the operations still seem
synchronous to userland without entangling mm migration with process
management synchronization.  CPU hotplug can also invoke mm migration
but there's no reason for it to wait for mm migrations and thus
doesn't synchronize against their completions.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-and-tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: stable@vger.kernel.org # v4.4+
2016-01-22 10:22:46 -05:00
Gavin Guo 1dff76b92f sched/numa: Fix use-after-free bug in the task_numa_compare
The following message can be observed on the Ubuntu v3.13.0-65 with KASan
backported:

  ==================================================================
  BUG: KASan: use after free in task_numa_find_cpu+0x64c/0x890 at addr ffff880dd393ecd8
  Read of size 8 by task qemu-system-x86/3998900
  =============================================================================
  BUG kmalloc-128 (Tainted: G    B        ): kasan: bad access detected
  -----------------------------------------------------------------------------

  INFO: Allocated in task_numa_fault+0xc1b/0xed0 age=41980 cpu=18 pid=3998890
	__slab_alloc+0x4f8/0x560
	__kmalloc+0x1eb/0x280
	task_numa_fault+0xc1b/0xed0
	do_numa_page+0x192/0x200
	handle_mm_fault+0x808/0x1160
	__do_page_fault+0x218/0x750
	do_page_fault+0x1a/0x70
	page_fault+0x28/0x30
	SyS_poll+0x66/0x1a0
	system_call_fastpath+0x1a/0x1f
  INFO: Freed in task_numa_free+0x1d2/0x200 age=62 cpu=18 pid=0
	__slab_free+0x2ab/0x3f0
	kfree+0x161/0x170
	task_numa_free+0x1d2/0x200
	finish_task_switch+0x1d2/0x210
	__schedule+0x5d4/0xc60
	schedule_preempt_disabled+0x40/0xc0
	cpu_startup_entry+0x2da/0x340
	start_secondary+0x28f/0x360
  Call Trace:
   [<ffffffff81a6ce35>] dump_stack+0x45/0x56
   [<ffffffff81244aed>] print_trailer+0xfd/0x170
   [<ffffffff8124ac36>] object_err+0x36/0x40
   [<ffffffff8124cbf9>] kasan_report_error+0x1e9/0x3a0
   [<ffffffff8124d260>] kasan_report+0x40/0x50
   [<ffffffff810dda7c>] ? task_numa_find_cpu+0x64c/0x890
   [<ffffffff8124bee9>] __asan_load8+0x69/0xa0
   [<ffffffff814f5c38>] ? find_next_bit+0xd8/0x120
   [<ffffffff810dda7c>] task_numa_find_cpu+0x64c/0x890
   [<ffffffff810de16c>] task_numa_migrate+0x4ac/0x7b0
   [<ffffffff810de523>] numa_migrate_preferred+0xb3/0xc0
   [<ffffffff810e0b88>] task_numa_fault+0xb88/0xed0
   [<ffffffff8120ef02>] do_numa_page+0x192/0x200
   [<ffffffff81211038>] handle_mm_fault+0x808/0x1160
   [<ffffffff810d7dbd>] ? sched_clock_cpu+0x10d/0x160
   [<ffffffff81068c52>] ? native_load_tls+0x82/0xa0
   [<ffffffff81a7bd68>] __do_page_fault+0x218/0x750
   [<ffffffff810c2186>] ? hrtimer_try_to_cancel+0x76/0x160
   [<ffffffff81a6f5e7>] ? schedule_hrtimeout_range_clock.part.24+0xf7/0x1c0
   [<ffffffff81a7c2ba>] do_page_fault+0x1a/0x70
   [<ffffffff81a772e8>] page_fault+0x28/0x30
   [<ffffffff8128cbd4>] ? do_sys_poll+0x1c4/0x6d0
   [<ffffffff810e64f6>] ? enqueue_task_fair+0x4b6/0xaa0
   [<ffffffff810233c9>] ? sched_clock+0x9/0x10
   [<ffffffff810cf70a>] ? resched_task+0x7a/0xc0
   [<ffffffff810d0663>] ? check_preempt_curr+0xb3/0x130
   [<ffffffff8128b5c0>] ? poll_select_copy_remaining+0x170/0x170
   [<ffffffff810d3bc0>] ? wake_up_state+0x10/0x20
   [<ffffffff8112a28f>] ? drop_futex_key_refs.isra.14+0x1f/0x90
   [<ffffffff8112d40e>] ? futex_requeue+0x3de/0xba0
   [<ffffffff8112e49e>] ? do_futex+0xbe/0x8f0
   [<ffffffff81022c89>] ? read_tsc+0x9/0x20
   [<ffffffff8111bd9d>] ? ktime_get_ts+0x12d/0x170
   [<ffffffff8108f699>] ? timespec_add_safe+0x59/0xe0
   [<ffffffff8128d1f6>] SyS_poll+0x66/0x1a0
   [<ffffffff81a830dd>] system_call_fastpath+0x1a/0x1f

As commit 1effd9f193 ("sched/numa: Fix unsafe get_task_struct() in
task_numa_assign()") points out, the rcu_read_lock() cannot protect the
task_struct from being freed in the finish_task_switch(). And the bug
happens in the process of calculation of imp which requires the access of
p->numa_faults being freed in the following path:

do_exit()
        current->flags |= PF_EXITING;
    release_task()
        ~~delayed_put_task_struct()~~
    schedule()
    ...
    ...
rq->curr = next;
    context_switch()
        finish_task_switch()
            put_task_struct()
                __put_task_struct()
		    task_numa_free()

The fix here to get_task_struct() early before end of dst_rq->lock to
protect the calculation process and also put_task_struct() in the
corresponding point if finally the dst_rq->curr somehow cannot be
assigned.

Additional credit to Liang Chen who helped fix the error logic and add the
put_task_struct() to the place it missed.

Signed-off-by: Gavin Guo <gavin.guo@canonical.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: jay.vosburgh@canonical.com
Cc: liang.chen@canonical.com
Link: http://lkml.kernel.org/r/1453264618-17645-1-git-send-email-gavin.guo@canonical.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-22 13:51:04 +01:00
John Stultz dd4e17ab70 ntp: Fix ADJ_SETOFFSET being used w/ ADJ_NANO
Recently, in commit 37cf4dc337 I forgot to check if the timeval being passed
was actually a timespec (as is signaled with ADJ_NANO).

This resulted in that patch breaking ADJ_SETOFFSET users who set
ADJ_NANO, by rejecting valid timespecs that were compared with
valid timeval ranges.

This patch addresses this by checking for the ADJ_NANO flag and
using the timepsec check instead in that case.

Reported-by: Harald Hoyer <harald@redhat.com>
Reported-by: Kay Sievers <kay@vrfy.org>
Fixes: 37cf4dc337 "time: Verify time values in adjtimex ADJ_SETOFFSET to avoid overflow"
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: David Herrmann <dh.herrmann@gmail.com>
Link: http://lkml.kernel.org/r/1453417415-19110-2-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-01-22 12:01:42 +01:00
Sudeep Holla 6f16886b7c cpuidle: fix fallback mechanism for suspend to idle in absence of enter_freeze
Commit 51164251f5 "sched / idle: Drop default_idle_call() fallback
from call_cpuidle()" made find_deepest_state() return non-negative
value and check all the states with index > 0.  Also as a result,
find_deepest_state() returns 0 even when enter_freeze callbacks are not
implemented and enter_freeze_proper() is called which ends up crashing
the kernel.

This patch updates the check for index > 0 in cpuidle_enter_freeze and
cpuidle_idle_call(when idle_should_freeze is true) to restore the
suspend-to-idle functionality in absence of enter_freeze callback.

Fixes: 51164251f5 "sched / idle: Drop default_idle_call() fallback from call_cpuidle()"
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-01-22 02:35:49 +01:00
Linus Torvalds eae21770b4 Merge branch 'akpm' (patches from Andrew)
Merge third patch-bomb from Andrew Morton:
 "I'm pretty much done for -rc1 now:

   - the rest of MM, basically

   - lib/ updates

   - checkpatch, epoll, hfs, fatfs, ptrace, coredump, exit

   - cpu_mask simplifications

   - kexec, rapidio, MAINTAINERS etc, etc.

   - more dma-mapping cleanups/simplifications from hch"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (109 commits)
  MAINTAINERS: add/fix git URLs for various subsystems
  mm: memcontrol: add "sock" to cgroup2 memory.stat
  mm: memcontrol: basic memory statistics in cgroup2 memory controller
  mm: memcontrol: do not uncharge old page in page cache replacement
  Documentation: cgroup: add memory.swap.{current,max} description
  mm: free swap cache aggressively if memcg swap is full
  mm: vmscan: do not scan anon pages if memcg swap limit is hit
  swap.h: move memcg related stuff to the end of the file
  mm: memcontrol: replace mem_cgroup_lruvec_online with mem_cgroup_online
  mm: vmscan: pass memcg to get_scan_count()
  mm: memcontrol: charge swap to cgroup2
  mm: memcontrol: clean up alloc, online, offline, free functions
  mm: memcontrol: flatten struct cg_proto
  mm: memcontrol: rein in the CONFIG space madness
  net: drop tcp_memcontrol.c
  mm: memcontrol: introduce CONFIG_MEMCG_LEGACY_KMEM
  mm: memcontrol: allow to disable kmem accounting for cgroup2
  mm: memcontrol: account "kmem" consumers in cgroup2 memory controller
  mm: memcontrol: move kmem accounting code to CONFIG_MEMCG
  mm: memcontrol: separate kmem code from legacy tcp accounting code
  ...
2016-01-21 12:32:08 -08:00
Linus Torvalds d43421565b PCI changes for the v4.5 merge window:
Enumeration
     Simplify config space size computation (Bjorn Helgaas)
     Avoid iterating through ROM outside the resource window (Edward O'Callaghan)
     Support PCIe devices with short cfg_size (Jason S. McMullan)
     Add Netronome vendor and device IDs (Jason S. McMullan)
     Limit config space size for Netronome NFP6000 family (Jason S. McMullan)
     Add Netronome NFP4000 PF device ID (Simon Horman)
     Limit config space size for Netronome NFP4000 (Simon Horman)
     Print warnings for all invalid expansion ROM headers (Vladis Dronov)
 
   Resource management
     Fix minimum allocation address overwrite (Christoph Biedl)
 
   PCI device hotplug
     acpiphp_ibm: Fix null dereferences on null ibm_slot (Colin Ian King)
     pciehp: Always protect pciehp_disable_slot() with hotplug mutex (Guenter Roeck)
     shpchp: Constify hpc_ops structure (Julia Lawall)
     ibmphp: Remove unneeded NULL test (Julia Lawall)
 
   Power management
     Make ASPM sysfs link_state_store() consistent with link_state_show() (Andy Lutomirski)
 
   Virtualization
     Add function 1 DMA alias quirk for Lite-On/Plextor M6e/Marvell 88SS9183 (Tim Sander)
 
   MSI
     Remove empty pci_msi_init_pci_dev() (Bjorn Helgaas)
     Mark PCIe/PCI (MSI) IRQ cascade handlers as IRQF_NO_THREAD (Grygorii Strashko)
     Initialize MSI capability for all architectures (Guilherme G. Piccoli)
     Relax msi_domain_alloc() to support parentless MSI irqdomains (Liu Jiang)
 
   ARM Versatile host bridge driver
     Remove unused pci_sys_data structures (Lorenzo Pieralisi)
 
   Broadcom iProc host bridge driver
     Hide CONFIG_PCIE_IPROC (Arnd Bergmann)
     Do not use 0x in front of %pap (Dmitry V. Krivenok)
     Update iProc PCIe device tree binding (Ray Jui)
     Add PAXC interface support (Ray Jui)
     Add iProc PCIe MSI device tree binding (Ray Jui)
     Add iProc PCIe MSI support (Ray Jui)
 
   Freescale i.MX6 host bridge driver
     Use gpio_set_value_cansleep() (Fabio Estevam)
     Add support for active-low reset GPIO (Petr Štetiar)
 
   HiSilicon host bridge driver
     Add support for HiSilicon Hip06 PCIe host controllers (Gabriele Paoloni)
 
   Intel VMD host bridge driver
     Export irq_domain_set_info() for module use (Keith Busch)
     x86/PCI: Allow DMA ops specific to a PCI domain (Keith Busch)
     Use 32 bit PCI domain numbers (Keith Busch)
     Add driver for Intel Volume Management Device (VMD) (Keith Busch)
 
   Qualcomm host bridge driver
     Document PCIe devicetree bindings (Stanimir Varbanov)
     Add Qualcomm PCIe controller driver (Stanimir Varbanov)
     dts: apq8064: add PCIe devicetree node (Stanimir Varbanov)
     dts: ifc6410: enable PCIe DT node for this board (Stanimir Varbanov)
 
   Renesas R-Car host bridge driver
     Add support for R-Car H3 to pcie-rcar (Harunobu Kurokawa)
     Allow DT to override default window settings (Phil Edworthy)
     Convert to DT resource parsing API (Phil Edworthy)
     Revert "PCI: rcar: Build pcie-rcar.c only on ARM" (Phil Edworthy)
     Remove unused pci_sys_data struct from pcie-rcar (Phil Edworthy)
     Add runtime PM support to pcie-rcar (Phil Edworthy)
     Add Gen2 PHY setup to pcie-rcar (Phil Edworthy)
     Add gen2 fallback compatibility string for pci-rcar-gen2 (Simon Horman)
     Add gen2 fallback compatibility string for pcie-rcar (Simon Horman)
 
   Synopsys DesignWare host bridge driver
     Simplify control flow (Bjorn Helgaas)
     Make config accessor override checking symmetric (Bjorn Helgaas)
     Ensure ATU is enabled before IO/conf space accesses (Stanimir Varbanov)
 
   Miscellaneous
     Add of_pci_get_host_bridge_resources() stub (Arnd Bergmann)
     Check for PCI_HEADER_TYPE_BRIDGE equality, not bitmask (Bjorn Helgaas)
     Fix all whitespace issues (Bogicevic Sasa)
     x86/PCI: Simplify pci_bios_{read,write} (Geliang Tang)
     Use to_pci_dev() instead of open-coding it (Geliang Tang)
     Use kobj_to_dev() instead of open-coding it (Geliang Tang)
     Use list_for_each_entry() to simplify code (Geliang Tang)
     Fix typos in <linux/msi.h> (Thomas Petazzoni)
     x86/PCI: Clarify AMD Fam10h config access restrictions comment (Tomasz Nowicki)
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Merge tag 'pci-v4.5-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

Pull PCI updates from Bjorn Helgaas:
 "PCI changes for the v4.5 merge window:

  Enumeration:
   - Simplify config space size computation (Bjorn Helgaas)
   - Avoid iterating through ROM outside the resource window (Edward O'Callaghan)
   - Support PCIe devices with short cfg_size (Jason S. McMullan)
   - Add Netronome vendor and device IDs (Jason S. McMullan)
   - Limit config space size for Netronome NFP6000 family (Jason S. McMullan)
   - Add Netronome NFP4000 PF device ID (Simon Horman)
   - Limit config space size for Netronome NFP4000 (Simon Horman)
   - Print warnings for all invalid expansion ROM headers (Vladis Dronov)

  Resource management:
   - Fix minimum allocation address overwrite (Christoph Biedl)

  PCI device hotplug:
   - acpiphp_ibm: Fix null dereferences on null ibm_slot (Colin Ian King)
   - pciehp: Always protect pciehp_disable_slot() with hotplug mutex (Guenter Roeck)
   - shpchp: Constify hpc_ops structure (Julia Lawall)
   - ibmphp: Remove unneeded NULL test (Julia Lawall)

  Power management:
   - Make ASPM sysfs link_state_store() consistent with link_state_show() (Andy Lutomirski)

  Virtualization
   - Add function 1 DMA alias quirk for Lite-On/Plextor M6e/Marvell 88SS9183 (Tim Sander)

  MSI:
   - Remove empty pci_msi_init_pci_dev() (Bjorn Helgaas)
   - Mark PCIe/PCI (MSI) IRQ cascade handlers as IRQF_NO_THREAD (Grygorii Strashko)
   - Initialize MSI capability for all architectures (Guilherme G. Piccoli)
   - Relax msi_domain_alloc() to support parentless MSI irqdomains (Liu Jiang)

  ARM Versatile host bridge driver:
   - Remove unused pci_sys_data structures (Lorenzo Pieralisi)

  Broadcom iProc host bridge driver:
   - Hide CONFIG_PCIE_IPROC (Arnd Bergmann)
   - Do not use 0x in front of %pap (Dmitry V. Krivenok)
   - Update iProc PCIe device tree binding (Ray Jui)
   - Add PAXC interface support (Ray Jui)
   - Add iProc PCIe MSI device tree binding (Ray Jui)
   - Add iProc PCIe MSI support (Ray Jui)

  Freescale i.MX6 host bridge driver:
   - Use gpio_set_value_cansleep() (Fabio Estevam)
   - Add support for active-low reset GPIO (Petr Štetiar)

  HiSilicon host bridge driver:
   - Add support for HiSilicon Hip06 PCIe host controllers (Gabriele Paoloni)

  Intel VMD host bridge driver:
   - Export irq_domain_set_info() for module use (Keith Busch)
   - x86/PCI: Allow DMA ops specific to a PCI domain (Keith Busch)
   - Use 32 bit PCI domain numbers (Keith Busch)
   - Add driver for Intel Volume Management Device (VMD) (Keith Busch)

  Qualcomm host bridge driver:
   - Document PCIe devicetree bindings (Stanimir Varbanov)
   - Add Qualcomm PCIe controller driver (Stanimir Varbanov)
   - dts: apq8064: add PCIe devicetree node (Stanimir Varbanov)
   - dts: ifc6410: enable PCIe DT node for this board (Stanimir Varbanov)

  Renesas R-Car host bridge driver:
   - Add support for R-Car H3 to pcie-rcar (Harunobu Kurokawa)
   - Allow DT to override default window settings (Phil Edworthy)
   - Convert to DT resource parsing API (Phil Edworthy)
   - Revert "PCI: rcar: Build pcie-rcar.c only on ARM" (Phil Edworthy)
   - Remove unused pci_sys_data struct from pcie-rcar (Phil Edworthy)
   - Add runtime PM support to pcie-rcar (Phil Edworthy)
   - Add Gen2 PHY setup to pcie-rcar (Phil Edworthy)
   - Add gen2 fallback compatibility string for pci-rcar-gen2 (Simon Horman)
   - Add gen2 fallback compatibility string for pcie-rcar (Simon Horman)

  Synopsys DesignWare host bridge driver:
   - Simplify control flow (Bjorn Helgaas)
   - Make config accessor override checking symmetric (Bjorn Helgaas)
   - Ensure ATU is enabled before IO/conf space accesses (Stanimir Varbanov)

  Miscellaneous:
   - Add of_pci_get_host_bridge_resources() stub (Arnd Bergmann)
   - Check for PCI_HEADER_TYPE_BRIDGE equality, not bitmask (Bjorn Helgaas)
   - Fix all whitespace issues (Bogicevic Sasa)
   - x86/PCI: Simplify pci_bios_{read,write} (Geliang Tang)
   - Use to_pci_dev() instead of open-coding it (Geliang Tang)
   - Use kobj_to_dev() instead of open-coding it (Geliang Tang)
   - Use list_for_each_entry() to simplify code (Geliang Tang)
   - Fix typos in <linux/msi.h> (Thomas Petazzoni)
   - x86/PCI: Clarify AMD Fam10h config access restrictions comment (Tomasz Nowicki)"

* tag 'pci-v4.5-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (58 commits)
  PCI: Add function 1 DMA alias quirk for Lite-On/Plextor M6e/Marvell 88SS9183
  PCI: Limit config space size for Netronome NFP4000
  PCI: Add Netronome NFP4000 PF device ID
  x86/PCI: Add driver for Intel Volume Management Device (VMD)
  PCI/AER: Use 32 bit PCI domain numbers
  x86/PCI: Allow DMA ops specific to a PCI domain
  irqdomain: Export irq_domain_set_info() for module use
  PCI: host: Add of_pci_get_host_bridge_resources() stub
  genirq/MSI: Relax msi_domain_alloc() to support parentless MSI irqdomains
  PCI: rcar: Add Gen2 PHY setup to pcie-rcar
  PCI: rcar: Add runtime PM support to pcie-rcar
  PCI: designware: Make config accessor override checking symmetric
  PCI: ibmphp: Remove unneeded NULL test
  ARM: dts: ifc6410: enable PCIe DT node for this board
  ARM: dts: apq8064: add PCIe devicetree node
  PCI: hotplug: Use list_for_each_entry() to simplify code
  PCI: rcar: Remove unused pci_sys_data struct from pcie-rcar
  PCI: hisi: Add support for HiSilicon Hip06 PCIe host controllers
  PCI: Avoid iterating through memory outside the resource window
  PCI: acpiphp_ibm: Fix null dereferences on null ibm_slot
  ...
2016-01-21 11:52:16 -08:00
Alexander Shishkin 45c815f06b perf: Synchronously free aux pages in case of allocation failure
We are currently using asynchronous deallocation in the error path in
AUX mmap code, which is unnecessary and also presents a problem for users
that wish to probe for the biggest possible buffer size they can get:
they'll get -EINVAL on all subsequent attemts to allocate a smaller
buffer before the asynchronous deallocation callback frees up the pages
from the previous unsuccessful attempt.

Currently, gdb does that for allocating AUX buffers for Intel PT traces.
More specifically, overwrite mode of AUX pmus that don't support hardware
sg (some implementations of Intel PT, for instance) is limited to only
one contiguous high order allocation for its buffer and there is no way
of knowing its size without trying.

This patch changes error path freeing to be synchronous as there won't
be any contenders for the AUX pages at that point.

Reported-by: Markus Metzger <markus.t.metzger@intel.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: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
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: vince@deater.net
Link: http://lkml.kernel.org/r/1453216469-9509-1-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-21 18:54:27 +01:00
Peter Zijlstra 63b6da39bb perf: Fix perf_event_exit_task() race
There is a race against perf_event_exit_task() vs
event_function_call(),find_get_context(),perf_install_in_context()
(iow, everyone).

Since there is no permanent marker on a context that its dead, it is
quite possible that we access (and even modify) a context after its
passed through perf_event_exit_task().

For instance, find_get_context() might find the context still
installed, but by the time we get to perf_install_in_context() it
might already have passed through perf_event_exit_task() and be
considered dead, we will however still add the event to it.

Solve this by marking a ctx dead by setting its ctx->task value to -1,
it must be !0 so we still know its a (former) task context.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
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>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-21 18:54:25 +01:00
Peter Zijlstra c97f473643 perf: Add more assertions
Try to trigger warnings before races do damage.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
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>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-21 18:54:25 +01:00
Peter Zijlstra fae3fde651 perf: Collapse and fix event_function_call() users
There is one common bug left in all the event_function_call() users,
between loading ctx->task and getting to the remote_function(),
ctx->task can already have been changed.

Therefore we need to double check and retry if ctx->task != current.

Insert another trampoline specific to event_function_call() that
checks for this and further validates state. This also allows getting
rid of the active/inactive functions.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
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>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-21 18:54:24 +01:00
Peter Zijlstra 32132a3d0d perf: Specialize perf_event_exit_task()
The perf_remove_from_context() usage in __perf_event_exit_task() is
different from the other usages in that this site has already
detached and scheduled out the task context.

This will stand in the way of stronger assertions checking the (task)
context scheduling invariants.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
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>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-21 18:54:24 +01:00
Peter Zijlstra 39a4364076 perf: Fix task context scheduling
There is a very nasty problem wrt disabling the perf task scheduling
hooks.

Currently we {set,clear} ctx->is_active on every
__perf_event_task_sched_{in,out}, _however_ this means that if we
disable these calls we'll have task contexts with ->is_active set that
are not active and 'active' task contexts without ->is_active set.

This can result in event_function_call() looping on the ctx->is_active
condition basically indefinitely.

Resolve this by changing things such that contexts without events do
not set ->is_active like we used to. From this invariant it trivially
follows that if there are no (task) events, every task ctx is inactive
and disabling the context switch hooks is harmless.

This leaves two places that need attention (and already had
accumulated weird and wonderful hacks to work around, without
recognising this actual problem).

Namely:

 - perf_install_in_context() will need to deal with installing events
   in an inactive context, meaning it cannot rely on ctx-is_active for
   its IPIs.

 - perf_remove_from_context() will have to mark a context as inactive
   when it removes the last event.

For specific detail, see the patch/comments.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
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>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-21 18:54:23 +01:00
Peter Zijlstra 63e30d3e52 perf: Make ctx->is_active and cpuctx->task_ctx consistent
For no apparent reason and to great confusion the rules for
ctx->is_active and cpuctx->task_ctx are different. This means that its
not always possible to find all active (task) contexts.

Fix this such that if ctx->is_active gets set, we also set (or verify)
cpuctx->task_ctx.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
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>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-21 18:54:23 +01:00
Peter Zijlstra 25432ae96a perf: Optimize perf_sched_events() usage
It doesn't make sense to take up-to _4_ references on
perf_sched_events() per event, avoid doing this.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
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>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-21 18:54:22 +01:00
Peter Zijlstra aee7dbc45f perf: Simplify/fix perf_event_enable() event scheduling
Like perf_enable_on_exec(), perf_event_enable() event scheduling has problems
respecting the context hierarchy when trying to schedule events (for
example, it will try and add a pinned event without first removing
existing flexible events).

So simplify it by using the new ctx_resched() call which will DTRT.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
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>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-21 18:54:22 +01:00
Peter Zijlstra 8833d0e286 perf: Use task_ctx_sched_out()
We have a function that does exactly what we want here, use it. This
reduces the amount of cpuctx->task_ctx muckery.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
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>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-21 18:54:21 +01:00
Peter Zijlstra 3e349507d1 perf: Fix perf_enable_on_exec() event scheduling
There are two problems with the current perf_enable_on_exec() event
scheduling:

  - the newly enabled events will be immediately scheduled
    irrespective of their ctx event list order.

  - there's a hole in the ctx->lock between scheduling the events
    out and putting them back on.

Esp. the latter issue is a real problem because a hole in event
scheduling leaves the thing in an observable inconsistent state,
confusing things.

Fix both issues by first doing the enable iteration and at the end,
when there are newly enabled events, reschedule the ctx in one go.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
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>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-21 18:54:20 +01:00
Peter Zijlstra 5947f6576e perf: Remove stale comment
The comment here is horribly out of date, remove it.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
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>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-21 18:54:20 +01:00
Peter Zijlstra 70a0165752 perf: Fix cgroup scheduling in perf_enable_on_exec()
There is a comment that states that perf_event_context_sched_in() will
also switch in the cgroup events, I cannot find it does so. Therefore
all the resulting logic goes out the window too.

Clean that up.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
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>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-21 18:54:19 +01:00
Peter Zijlstra 7e41d17753 perf: Fix cgroup event scheduling
There appears to be a problem in __perf_event_task_sched_in() wrt
cgroup event scheduling.

The normal event scheduling order is:

	CPU pinned
	Task pinned
	CPU flexible
	Task flexible

And since perf_cgroup_sched*() only schedules the cpu context, we must
call this _before_ adding the task events.

Note: double check what happens on the ctx switch optimization where
the task ctx isn't scheduled.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
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>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-21 18:54:19 +01:00
Peter Zijlstra c994d61367 perf: Add lockdep assertions
Make various bugs easier to see.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
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>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-21 18:54:18 +01:00
Linus Torvalds 30f05309bd More power management and ACPI updates for v4.5-rc1
- Modify the driver core and the USB subsystem to allow USB devices
    to stay suspended over system suspend/resume cycles if they have
    been runtime-suspended already beforehand and fix some bugs on
    top of these changes (Tomeu Vizoso, Rafael Wysocki).
 
  - Update ACPICA to upstream revision 20160108, including updates
    of the ACPICA's copyright notices, a code fixup resulting from
    a regression fix that was necessary in the upstream code only
    (the regression fixed by it has never been present in Linux)
    and a compiler warning fix (Bob Moore, Lv Zheng).
 
  - Fix a recent regression in the cpuidle menu governor that broke
    it on practically all architectures other than x86 and make a
    couple of optimizations on top of that fix (Rafael Wysocki).
 
  - Clean up the selection of cpuidle governors depending on whether
    or not the kernel is configured for tickless systems (Jean Delvare).
 
  - Revert a recent commit that introduced a regression in the ACPI
    backlight driver, address the problem it attempted to fix in a
    different way and revert one more cosmetic change depending on
    the problematic commit (Hans de Goede).
 
  - Add two more ACPI backlight quirks (Hans de Goede).
 
  - Fix a few minor problems in the core devfreq code, clean it up
    a bit and update the MAINTAINERS information related to it
    (Chanwoo Choi, MyungJoo Ham).
 
  - Improve an error message in the ACPI fan driver (Andy Lutomirski).
 
  - Fix a recent build regression in the cpupower tool (Shreyas Prabhu).
 
 /
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Merge tag 'pm+acpi-4.5-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull more power management and ACPI updates from Rafael Wysocki:
 "This includes fixes on top of the previous batch of PM+ACPI updates
  and some new material as well.

  From the new material perspective the most significant are the driver
  core changes that should allow USB devices to stay suspended over
  system suspend/resume cycles if they have been runtime-suspended
  already beforehand.  Apart from that, ACPICA is updated to upstream
  revision 20160108 (cosmetic mostly, but including one fixup on top of
  the previous ACPICA update) and there are some devfreq updates the
  didn't make it before (due to timing).

  A few recent regressions are fixed, most importantly in the cpuidle
  menu governor and in the ACPI backlight driver and some x86 platform
  drivers depending on it.

  Some more bugs are fixed and cleanups are made on top of that.

  Specifics:

   - Modify the driver core and the USB subsystem to allow USB devices
     to stay suspended over system suspend/resume cycles if they have
     been runtime-suspended already beforehand and fix some bugs on top
     of these changes (Tomeu Vizoso, Rafael Wysocki).

   - Update ACPICA to upstream revision 20160108, including updates of
     the ACPICA's copyright notices, a code fixup resulting from a
     regression fix that was necessary in the upstream code only (the
     regression fixed by it has never been present in Linux) and a
     compiler warning fix (Bob Moore, Lv Zheng).

   - Fix a recent regression in the cpuidle menu governor that broke it
     on practically all architectures other than x86 and make a couple
     of optimizations on top of that fix (Rafael Wysocki).

   - Clean up the selection of cpuidle governors depending on whether or
     not the kernel is configured for tickless systems (Jean Delvare).

   - Revert a recent commit that introduced a regression in the ACPI
     backlight driver, address the problem it attempted to fix in a
     different way and revert one more cosmetic change depending on the
     problematic commit (Hans de Goede).

   - Add two more ACPI backlight quirks (Hans de Goede).

   - Fix a few minor problems in the core devfreq code, clean it up a
     bit and update the MAINTAINERS information related to it (Chanwoo
     Choi, MyungJoo Ham).

   - Improve an error message in the ACPI fan driver (Andy Lutomirski).

   - Fix a recent build regression in the cpupower tool (Shreyas
     Prabhu)"

* tag 'pm+acpi-4.5-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (32 commits)
  cpuidle: menu: Avoid pointless checks in menu_select()
  sched / idle: Drop default_idle_call() fallback from call_cpuidle()
  cpupower: Fix build error in cpufreq-info
  cpuidle: Don't enable all governors by default
  cpuidle: Default to ladder governor on ticking systems
  time: nohz: Expose tick_nohz_enabled
  ACPICA: Update version to 20160108
  ACPICA: Silence a -Wbad-function-cast warning when acpi_uintptr_t is 'uintptr_t'
  ACPICA: Additional 2016 copyright changes
  ACPICA: Reduce regression fix divergence from upstream ACPICA
  ACPI / video: Add disable_backlight_sysfs_if quirk for the Toshiba Satellite R830
  ACPI / video: Revert "thinkpad_acpi: Use acpi_video_handles_brightness_key_presses()"
  ACPI / video: Document acpi_video_handles_brightness_key_presses() a bit
  ACPI / video: Fix using an uninitialized mutex / list_head in acpi_video_handles_brightness_key_presses()
  ACPI / video: Revert "ACPI / video: driver must be registered before checking for keypresses"
  ACPI / fan: Improve acpi_device_update_power error message
  ACPI / video: Add disable_backlight_sysfs_if quirk for the Toshiba Portege R700
  cpuidle: menu: Fix menu_select() for CPUIDLE_DRIVER_STATE_START == 0
  MAINTAINERS: Add devfreq-event entry
  MAINTAINERS: Add missing git repository and directory for devfreq
  ...
2016-01-20 19:06:49 -08:00
Mateusz Guzik ddf1d398e5 prctl: take mmap sem for writing to protect against others
An unprivileged user can trigger an oops on a kernel with
CONFIG_CHECKPOINT_RESTORE.

proc_pid_cmdline_read takes mmap_sem for reading and obtains args + env
start/end values. These get sanity checked as follows:
        BUG_ON(arg_start > arg_end);
        BUG_ON(env_start > env_end);

These can be changed by prctl_set_mm. Turns out also takes the semaphore for
reading, effectively rendering it useless. This results in:

  kernel BUG at fs/proc/base.c:240!
  invalid opcode: 0000 [#1] SMP
  Modules linked in: virtio_net
  CPU: 0 PID: 925 Comm: a.out Not tainted 4.4.0-rc8-next-20160105dupa+ #71
  Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
  task: ffff880077a68000 ti: ffff8800784d0000 task.ti: ffff8800784d0000
  RIP: proc_pid_cmdline_read+0x520/0x530
  RSP: 0018:ffff8800784d3db8  EFLAGS: 00010206
  RAX: ffff880077c5b6b0 RBX: ffff8800784d3f18 RCX: 0000000000000000
  RDX: 0000000000000002 RSI: 00007f78e8857000 RDI: 0000000000000246
  RBP: ffff8800784d3e40 R08: 0000000000000008 R09: 0000000000000001
  R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000050
  R13: 00007f78e8857800 R14: ffff88006fcef000 R15: ffff880077c5b600
  FS:  00007f78e884a740(0000) GS:ffff88007b200000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
  CR2: 00007f78e8361770 CR3: 00000000790a5000 CR4: 00000000000006f0
  Call Trace:
    __vfs_read+0x37/0x100
    vfs_read+0x82/0x130
    SyS_read+0x58/0xd0
    entry_SYSCALL_64_fastpath+0x12/0x76
  Code: 4c 8b 7d a8 eb e9 48 8b 9d 78 ff ff ff 4c 8b 7d 90 48 8b 03 48 39 45 a8 0f 87 f0 fe ff ff e9 d1 fe ff ff 4c 8b 7d 90 eb c6 0f 0b <0f> 0b 0f 0b 66 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00
  RIP   proc_pid_cmdline_read+0x520/0x530
  ---[ end trace 97882617ae9c6818 ]---

Turns out there are instances where the code just reads aformentioned
values without locking whatsoever - namely environ_read and get_cmdline.

Interestingly these functions look quite resilient against bogus values,
but I don't believe this should be relied upon.

The first patch gets rid of the oops bug by grabbing mmap_sem for
writing.

The second patch is optional and puts locking around aformentioned
consumers for safety.  Consumers of other fields don't seem to benefit
from similar treatment and are left untouched.

This patch (of 2):

The code was taking the semaphore for reading, which does not protect
against readers nor concurrent modifications.

The problem could cause a sanity checks to fail in procfs's cmdline
reader, resulting in an OOPS.

Note that some functions perform an unlocked read of various mm fields,
but they seem to be fine despite possible modificaton.

Signed-off-by: Mateusz Guzik <mguzik@redhat.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Jarod Wilson <jarod@redhat.com>
Cc: Jan Stancek <jstancek@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Anshuman Khandual <anshuman.linux@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-20 17:09:18 -08:00
Andrey Ryabinin 5c9cf8af2e kernel: printk: specify alignment for struct printk_log
On architectures that have support for efficient unaligned access struct
printk_log has 4-byte alignment.  Specify alignment attribute in type
declaration.

The whole point of this patch is to fix deadlock which happening when
UBSAN detects unaligned access in printk() thus UBSAN recursively calls
printk() with logbuf_lock held by top printk() call.

Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Yury Gribov <y.gribov@samsung.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Kostya Serebryany <kcc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-20 17:09:18 -08:00
Kees Cook 41662f5cc5 sysctl: enable strict writes
SYSCTL_WRITES_WARN was added in commit f4aacea2f5 ("sysctl: allow for
strict write position handling"), and released in v3.16 in August of
2014.  Since then I can find only 1 instance of non-zero offset
writing[1], and it was fixed immediately in CRIU[2].  As such, it
appears safe to flip this to the strict state now.

[1] https://www.google.com/search?q="when%20file%20position%20was%20not%200"
[2] http://lists.openvz.org/pipermail/criu/2015-April/019819.html

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-20 17:09:18 -08:00
Xunlei Pang 978e30c9b4 kexec: move some memembers and definitions within the scope of CONFIG_KEXEC_FILE
Move the stuff currently only used by the kexec file code within
CONFIG_KEXEC_FILE (and CONFIG_KEXEC_VERIFY_SIG).

Also move internal "struct kexec_sha_region" and "struct kexec_buf" into
"kexec_internal.h".

Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Dave Young <dyoung@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-20 17:09:18 -08:00
Geliang Tang 2b24692b92 kernel/kexec_core.c: use list_for_each_entry_safe in kimage_free_page_list
Use list_for_each_entry_safe() instead of list_for_each_safe() to
simplify the code.

Signed-off-by: Geliang Tang <geliangtang@163.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-20 17:09:18 -08:00
Xunlei Pang cdf4b3fa03 kexec: set KEXEC_TYPE_CRASH before sanity_check_segment_list()
sanity_check_segment_list() checks KEXEC_TYPE_CRASH flag to ensure all the
segments of the loaded crash kernel are within the kernel crash resource
limits, so set the flag beforehand.

Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-20 17:09:18 -08:00
Rasmus Villemoes 9425676a36 kernel/cpu.c: make set_cpu_* static inlines
Almost all callers of the set_cpu_* functions pass an explicit true or
false.  Making them static inline thus replaces the function calls with a
simple set_bit/clear_bit, saving some .text.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-20 17:09:18 -08:00
Rasmus Villemoes 5aec01b834 kernel/cpu.c: eliminate cpu_*_mask
Replace the variables cpu_possible_mask, cpu_online_mask, cpu_present_mask
and cpu_active_mask with macros expanding to expressions of the same type
and value, eliminating some indirection.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-20 17:09:18 -08:00
Rasmus Villemoes 4b804c85dc kernel/cpu.c: export __cpu_*_mask
Exporting the cpumasks __cpu_possible_mask and friends will allow us to
remove the extra indirection through the cpu_*_mask variables.  It will
also allow the set_cpu_* functions to become static inlines, which will
give a .text reduction.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-20 17:09:18 -08:00
Rasmus Villemoes c4c54dd1ca kernel/cpu.c: change type of cpu_possible_bits and friends
Change cpu_possible_bits and friends (online, present, active) from being
bitmaps that happen to have the right size to actually being struct
cpumasks.  Also rename them to __cpu_xyz_mask.  This is mostly a small
cleanup in preparation for exporting them and, eventually, eliminating the
extra indirection through the cpu_xyz_mask variables.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-20 17:09:18 -08:00
Dmitry Safonov c428fbdbf3 exit: remove unneeded declaration of exit_mm()
Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-20 17:09:18 -08:00
Jann Horn caaee6234d ptrace: use fsuid, fsgid, effective creds for fs access checks
By checking the effective credentials instead of the real UID / permitted
capabilities, ensure that the calling process actually intended to use its
credentials.

To ensure that all ptrace checks use the correct caller credentials (e.g.
in case out-of-tree code or newly added code omits the PTRACE_MODE_*CREDS
flag), use two new flags and require one of them to be set.

The problem was that when a privileged task had temporarily dropped its
privileges, e.g.  by calling setreuid(0, user_uid), with the intent to
perform following syscalls with the credentials of a user, it still passed
ptrace access checks that the user would not be able to pass.

While an attacker should not be able to convince the privileged task to
perform a ptrace() syscall, this is a problem because the ptrace access
check is reused for things in procfs.

In particular, the following somewhat interesting procfs entries only rely
on ptrace access checks:

 /proc/$pid/stat - uses the check for determining whether pointers
     should be visible, useful for bypassing ASLR
 /proc/$pid/maps - also useful for bypassing ASLR
 /proc/$pid/cwd - useful for gaining access to restricted
     directories that contain files with lax permissions, e.g. in
     this scenario:
     lrwxrwxrwx root root /proc/13020/cwd -> /root/foobar
     drwx------ root root /root
     drwxr-xr-x root root /root/foobar
     -rw-r--r-- root root /root/foobar/secret

Therefore, on a system where a root-owned mode 6755 binary changes its
effective credentials as described and then dumps a user-specified file,
this could be used by an attacker to reveal the memory layout of root's
processes or reveal the contents of files he is not allowed to access
(through /proc/$pid/cwd).

[akpm@linux-foundation.org: fix warning]
Signed-off-by: Jann Horn <jann@thejh.net>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: "Serge E. Hallyn" <serge.hallyn@ubuntu.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-20 17:09:18 -08:00
Oleg Nesterov 570ac9337b ptrace: task_stopped_code(ptrace => true) can't see TASK_STOPPED task
task_stopped_code()->task_is_stopped_or_traced() doesn't look right, the
traced task must never be TASK_STOPPED.

We can not add WARN_ON(task_is_stopped(p)), but this is only because
do_wait() can race with PTRACE_ATTACH from another thread.

[akpm@linux-foundation.org: teeny cleanup]
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Roland McGrath <roland@hack.frob.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Pedro Alves <palves@redhat.com>
Cc: Jan Kratochvil <jan.kratochvil@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-20 17:09:18 -08:00
Oleg Nesterov 7c3b00e06d ptrace: make wait_on_bit(JOBCTL_TRAPPING_BIT) in ptrace_attach() killable
ptrace_attach() can hang waiting for STOPPED -> TRACED transition if the
tracee gets frozen in between, change wait_on_bit() to use TASK_KILLABLE.

This doesn't really solve the problem(s) and we probably need to fix the
freezer.  In particular, note that this means that pm freezer will fail if
it races attach-to-stopped-task.

And otoh perhaps we can just remove JOBCTL_TRAPPING_BIT altogether, it is
not clear if we really need to hide this transition from debugger, WNOHANG
after PTRACE_ATTACH can fail anyway if it races with SIGCONT.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Roland McGrath <roland@hack.frob.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Pedro Alves <palves@redhat.com>
Cc: Jan Kratochvil <jan.kratochvil@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-20 17:09:18 -08:00
Rafael J. Wysocki f11aef69b2 Merge branch 'pm-cpuidle'
* pm-cpuidle:
  cpuidle: menu: Avoid pointless checks in menu_select()
  sched / idle: Drop default_idle_call() fallback from call_cpuidle()
  cpuidle: Don't enable all governors by default
  cpuidle: Default to ladder governor on ticking systems
  time: nohz: Expose tick_nohz_enabled
  cpuidle: menu: Fix menu_select() for CPUIDLE_DRIVER_STATE_START == 0
2016-01-21 00:43:21 +01:00