[PATCH] futex: fix requeue_pi key imbalance

[Darren Hart]

futex: fix requeue_pi key imbalance

From: Darren Hart <dvhltc@xxxxxxxxxx>

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@xxxxxxxxxxxxxxx>
Signed-off-by: Darren Hart <dvhltc@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
CC: Eric Dumazet <eric.dumazet@xxxxxxxxx>
CC: Dinakar Guniguntala <dino@xxxxxxxxxx>
CC: John Stultz <johnstul@xxxxxxxxxx>
---

kernel/futex.c |    1 -
1 files changed, 0 insertions(+), 1 deletions(-)


Index: linux-2.6.git/kernel/futex.c
===================================================================
--- linux-2.6.git.orig/kernel/futex.c
+++ linux-2.6.git/kernel/futex.c
@@ -2117,7 +2117,6 @@ int handle_early_requeue_pi_wakeup(struc
		 * 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;
--
Darren Hart
IBM Linux Technology Center
Real-Time Linux Team
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