Commit da085681 authored Oct 07, 2009 by Darren Hart Committed by Thomas Gleixner Oct 07, 2009

futex: fix requeue_pi key imbalance



If futex_wait_requeue_pi() wakes prior to requeue, we drop the
reference to the source futex_key twice, once in
handle_early_requeue_pi_wakeup() and once on our way out.

Remove the drop from the handle_early_requeue_pi_wakeup() and keep
the get/drops together in futex_wait_requeue_pi().

Reported-by: Helge Bahmann <hcb@chaoticmind.net>
Signed-off-by: Darren Hart <dvhltc@us.ibm.com>
Cc: Helge Bahmann <hcb@chaoticmind.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Dinakar Guniguntala <dino@in.ibm.com>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: stable-2.6.31 <stable@kernel.org>
LKML-Reference: <4ACCE21E.5030805@us.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

parent f8d1e548

kernel/futex.c

+0 −1

Original line number	Diff line number	Diff line
		@@ -2111,7 +2111,6 @@ int handle_early_requeue_pi_wakeup(struct futex_hash_bucket *hb,
		* Unqueue the futex_q and determine which it was.
		*/
		plist_del(&q->list, &q->list.plist);
		drop_futex_key_refs(&q->key);

		if (timeout && !timeout->task)
		ret = -ETIMEDOUT;

Admin message