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| author | Ingo Molnar <mingo@elte.hu> | 2007-03-16 13:38:31 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-03-16 19:25:06 -0700 |
| commit | 21778867b1c8e0feb567addb6dc0a7e2ca6ecdec (patch) | |
| tree | a88a1a8f9a469f0b9e94a2025a6d1990ee9fc407 /kernel/futex.c | |
| parent | d3a7b6df4951170079252402fd0c2dc70cb0ca2a (diff) | |
| download | blackbird-op-linux-21778867b1c8e0feb567addb6dc0a7e2ca6ecdec.tar.gz blackbird-op-linux-21778867b1c8e0feb567addb6dc0a7e2ca6ecdec.zip | |
[PATCH] futex: PI state locking fix
Testing of -rt by IBM uncovered a locking bug in wake_futex_pi(): the PI
state needs to be locked before we access it.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Chuck Ebbert <cebbert@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/futex.c')
| -rw-r--r-- | kernel/futex.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/futex.c b/kernel/futex.c index e749e7df14b1..5a270b5e3f95 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -565,6 +565,7 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *this) if (!pi_state) return -EINVAL; + spin_lock(&pi_state->pi_mutex.wait_lock); new_owner = rt_mutex_next_owner(&pi_state->pi_mutex); /* @@ -604,6 +605,7 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *this) 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; |
