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authorThomas Gleixner <tglx@linutronix.de>2017-04-10 18:03:36 +0200
committerIngo Molnar <mingo@kernel.org>2017-04-14 10:29:53 +0200
commit97181f9bd57405b879403763284537e27d46963d (patch)
treea82fd592ce64cc25e7bd3b4a33740554c9ffcec1 /kernel/futex.c
parent0ba78a95a6629975ff16545ae868fa1bb38f786a (diff)
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futex: Avoid freeing an active timer
Alexander reported a hrtimer debug_object splat: ODEBUG: free active (active state 0) object type: hrtimer hint: hrtimer_wakeup (kernel/time/hrtimer.c:1423) debug_object_free (lib/debugobjects.c:603) destroy_hrtimer_on_stack (kernel/time/hrtimer.c:427) futex_lock_pi (kernel/futex.c:2740) do_futex (kernel/futex.c:3399) SyS_futex (kernel/futex.c:3447 kernel/futex.c:3415) do_syscall_64 (arch/x86/entry/common.c:284) entry_SYSCALL64_slow_path (arch/x86/entry/entry_64.S:249) Which was caused by commit: cfafcd117da0 ("futex: Rework futex_lock_pi() to use rt_mutex_*_proxy_lock()") ... losing the hrtimer_cancel() in the shuffle. Where previously the hrtimer_cancel() was done by rt_mutex_slowlock() we now need to do it manually. Reported-by: Alexander Levin <alexander.levin@verizon.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Fixes: cfafcd117da0 ("futex: Rework futex_lock_pi() to use rt_mutex_*_proxy_lock()") Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1704101802370.2906@nanos Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/futex.c')
-rw-r--r--kernel/futex.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/kernel/futex.c b/kernel/futex.c
index c3eebcdac206..7ac167683c9f 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -2736,8 +2736,10 @@ out_unlock_put_key:
out_put_key:
put_futex_key(&q.key);
out:
- if (to)
+ if (to) {
+ hrtimer_cancel(&to->timer);
destroy_hrtimer_on_stack(&to->timer);
+ }
return ret != -EINTR ? ret : -ERESTARTNOINTR;
uaddr_faulted: