diff options
| author | Darren Hart <dvhltc@us.ibm.com> | 2009-03-12 08:56:06 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-03-12 11:20:57 +0100 |
| commit | e8f6386c01a5699c115bdad10271a24076364c97 (patch) | |
| tree | 7375a9b8961c0e0fd8e25176c7912375aaaa4d1e | |
| parent | futex: use current->time_slack_ns for rt tasks too (diff) | |
| download | linux-e8f6386c01a5699c115bdad10271a24076364c97.tar.xz linux-e8f6386c01a5699c115bdad10271a24076364c97.zip | |
futex: unlock before returning -EFAULT
Impact: rt-mutex failure case fix
futex_lock_pi can potentially return -EFAULT with the rt_mutex
held. This seems like the wrong thing to do as userspace should
assume -EFAULT means the lock was not taken. Even if it could
figure this out, we'd be leaving the pi_state->owner in an
inconsistent state. This patch unlocks the rt_mutex prior to
returning -EFAULT to userspace.
Build and boot tested on a 4 way Intel x86_64 workstation.
Passes basic pthread_mutex and PI tests out of
ltp/testcases/realtime.
Signed-off-by: Darren Hart <dvhltc@us.ibm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
LKML-Reference: <20090312075606.9856.88729.stgit@Aeon>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | kernel/futex.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/kernel/futex.c b/kernel/futex.c index 6579912ee70c..c980a556f82c 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -1567,6 +1567,13 @@ retry_locked: } } + /* + * If fixup_pi_state_owner() faulted and was unable to handle the + * fault, unlock it and return the fault to userspace. + */ + if (ret && (rt_mutex_owner(&q.pi_state->pi_mutex) == current)) + rt_mutex_unlock(&q.pi_state->pi_mutex); + /* Unqueue and drop the lock */ unqueue_me_pi(&q); |