Messages in this thread Patch in this message | | | Date | Mon, 12 Mar 2007 10:13:42 +0100 | From | Ingo Molnar <> | Subject | [patch] futex: PI state locking fix |
| |
Subject: [patch] futex: PI state locking fix From: Ingo Molnar <mingo@elte.hu>
testing of -rt by IBM uncovered a locking bug in wake_futex_pi(): the PI state needs to be locked before we access it.
this patch has been tested in -rt. Must-have for v2.6.21.
Signed-off-by: Ingo Molnar <mingo@elte.hu> -- kernel/futex.c | 2 ++ 1 file changed, 2 insertions(+)
Index: linux/kernel/futex.c =================================================================== --- linux.orig/kernel/futex.c +++ linux/kernel/futex.c @@ -566,6 +566,7 @@ static int wake_futex_pi(u32 __user *uad if (!pi_state) return -EINVAL; + spin_lock(&pi_state->pi_mutex.wait_lock); new_owner = rt_mutex_next_owner(&pi_state->pi_mutex); /* @@ -605,6 +606,7 @@ static int wake_futex_pi(u32 __user *uad pi_state->owner = new_owner; spin_unlock_irq(&new_owner->pi_lock); + spin_unlock(&pi_state->pi_mutex.wait_lock); rt_mutex_unlock(&pi_state->pi_mutex); return 0; - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |