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| author | Thomas Gleixner <tglx@linutronix.de> | 2017-04-10 18:03:36 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-04-14 10:29:53 +0200 |
| commit | 97181f9bd57405b879403763284537e27d46963d (patch) | |
| tree | a82fd592ce64cc25e7bd3b4a33740554c9ffcec1 | |
| parent | Merge branch 'linus' into locking/core, to pick up fixes (diff) | |
| download | linux-97181f9bd57405b879403763284537e27d46963d.tar.xz linux-97181f9bd57405b879403763284537e27d46963d.zip | |
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>
| -rw-r--r-- | kernel/futex.c | 4 |
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: |