Commit-ID: def34eaae5ce04b324e48e1bfac873091d945213 Gitweb: http://git.kernel.org/tip/def34eaae5ce04b324e48e1bfac873091d945213 Author: Mike Galbraith <efault@xxxxxx> AuthorDate: Wed, 5 Apr 2017 10:08:27 +0200 Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx> CommitDate: Wed, 5 Apr 2017 16:59:37 +0200 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@xxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: xlpang@xxxxxxxxxx Cc: rostedt@xxxxxxxxxxx Link: http://lkml.kernel.org/r/1491379707.6538.2.camel@xxxxxx Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> --- kernel/locking/rtmutex.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c index 0e641eb..b955094 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() */ } -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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