diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2009-10-04 09:34:17 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2009-10-12 12:40:11 -0700 |
| commit | 627376bd3503801263df2ac2df6d5685026bb231 (patch) | |
| tree | eb5d7ce260c01daf9e093d18c5812e0867cd60a7 /kernel | |
| parent | 1c4dacc248f10d641c9ea3a65a8d260d28732e6e (diff) | |
futex: Fix locking imbalance
commit eaaea8036d0261d87d7072c5bc88c7ea730c18ac upstream.
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>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Darren Hart <dvhltc@us.ibm.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'kernel')
| -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 7a2994d59e69..2362d06691ce 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -912,8 +912,8 @@ 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)) { |