Commit-ID: 3d7bdf7880ea243f25cddd847ca65475ed627e5f Gitweb: http://git.kernel.org/tip/3d7bdf7880ea243f25cddd847ca65475ed627e5f Author: Darren Hart <dvhltc@xxxxxxxxxx> AuthorDate: Thu, 12 Mar 2009 00:56:06 -0700 Commit: Ingo Molnar <mingo@xxxxxxx> CommitDate: Fri, 13 Mar 2009 01:21:00 +0100 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@xxxxxxxxxx> Acked-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Rusty Russell <rusty@xxxxxxxxxxxxxxx> LKML-Reference: <20090312075606.9856.88729.stgit@Aeon> Signed-off-by: Ingo Molnar <mingo@xxxxxxx> --- kernel/futex.c | 7 +++++++ 1 files changed, 7 insertions(+), 0 deletions(-) diff --git a/kernel/futex.c b/kernel/futex.c index a66cd2d..7e0a916 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -1570,6 +1570,13 @@ 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); -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
|