From eaaea8036d0261d87d7072c5bc88c7ea730c18ac Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sun, 4 Oct 2009 09:34:17 +0200 Subject: 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 Signed-off-by: Thomas Gleixner Cc: Peter Zijlstra Cc: Darren Hart Cc: stable-2.6.31 LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/futex.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/futex.c b/kernel/futex.c index 463af2e..1e176f3 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -916,8 +916,8 @@ 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)) { -- cgit v1.1