diff options
| author | Mike Galbraith <efault@gmx.de> | 2017-04-05 10:08:27 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2017-04-05 16:59:37 +0200 |
| commit | def34eaae5ce04b324e48e1bfac873091d945213 (patch) | |
| tree | d262afbd2361a24be327fa101c445c427c3d480d /kernel/locking | |
| parent | 19830e55247cddb3f46f1bf60b8e245593491bea (diff) | |
| download | linux-def34eaae5ce04b324e48e1bfac873091d945213.tar.bz2 | |
rtmutex: Plug preempt count leak in rt_mutex_futex_unlock()
mark_wakeup_next_waiter() already disables preemption, doing so again
leaves us with an unpaired preempt_disable().
Fixes: 2a1c60299406 ("rtmutex: Deboost before waking up the top waiter")
Signed-off-by: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: xlpang@redhat.com
Cc: rostedt@goodmis.org
Link: http://lkml.kernel.org/r/1491379707.6538.2.camel@gmx.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/locking')
| -rw-r--r-- | kernel/locking/rtmutex.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c index 0e641eb473de..b95509416909 100644 --- a/kernel/locking/rtmutex.c +++ b/kernel/locking/rtmutex.c @@ -1581,13 +1581,13 @@ bool __sched __rt_mutex_futex_unlock(struct rt_mutex *lock, return false; /* done */ } - mark_wakeup_next_waiter(wake_q, lock); /* - * We've already deboosted, retain preempt_disabled when dropping - * the wait_lock to avoid inversion until the wakeup. Matched - * by rt_mutex_postunlock(); + * We've already deboosted, mark_wakeup_next_waiter() will + * retain preempt_disabled when we drop the wait_lock, to + * avoid inversion prior to the wakeup. preempt_disable() + * therein pairs with rt_mutex_postunlock(). */ - preempt_disable(); + mark_wakeup_next_waiter(wake_q, lock); return true; /* call postunlock() */ } |