diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2009-10-04 09:34:17 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2009-10-05 12:36:05 +0200 |
| commit | a374cc63356bdf15b2c350dfa3729de6717e8caf (patch) | |
| tree | c0a95b7bb91f8ef36ac4314b28c0c4dd20c7bd9b | |
| parent | f0f436465d7f6ff40694503d085d226159e93f5c (diff) | |
futex: Fix locking imbalance
Rich reported a lock imbalance in the futex code.
(http://bugzilla.kernel.org/show_bug.cgi?id=14288)
It's caused by the displacement of the retry_private label in
futex_wake_op(). The code unlocks the hash bucket locks in the error
handling path and retries without locking them again which makes the
next unlock fail.
Move retry_private so we lock the hash bucket locks when we retry.
Reported-by: Rich Ercolany <rercola@acm.jhu.edu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <new-submission>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Darren Hart <dvhltc@us.ibm.com>
Cc: stable-2.6.31 <stable@kernel.org>
| -rw-r--r-- | kernel/futex.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/futex.c b/kernel/futex.c index 4705d89205a1..4ac78d9da6fe 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -959,8 +959,8 @@ retry: hb1 = hash_futex(&key1); hb2 = hash_futex(&key2); - double_lock_hb(hb1, hb2); retry_private: + double_lock_hb(hb1, hb2); op_ret = futex_atomic_op_inuser(op, uaddr2); if (unlikely(op_ret < 0)) { |