diff options
| author | Darren Hart <dvhltc@us.ibm.com> | 2009-08-05 12:05:21 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-08-06 05:50:21 +0200 |
| commit | 1bbf20835c4e088667a090ce6523a0f70b62dc76 (patch) | |
| tree | 91fea2bd29abf6be58c55e259d2904de303fcf3e /kernel/rtmutex.c | |
| parent | 90bc1a658a53f8832ee799685703977a450e5af9 (diff) | |
| download | lwn-1bbf20835c4e088667a090ce6523a0f70b62dc76.tar.gz lwn-1bbf20835c4e088667a090ce6523a0f70b62dc76.zip | |
rtmutex: Avoid deadlock in rt_mutex_start_proxy_lock()
In the event of a lock steal or owner died,
rt_mutex_start_proxy_lock() will give the rt_mutex to the
waiting task, but it fails to release the wait_lock. This leads
to subsequent deadlocks when other tasks try to acquire the
rt_mutex.
I also removed a few extra blank lines that really spaced this
routine out. I must have been high on the \n when I wrote this
originally...
Signed-off-by: Darren Hart <dvhltc@us.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Dinakar Guniguntala <dino@in.ibm.com>
Cc: John Stultz <johnstul@linux.vnet.ibm.com>
LKML-Reference: <4A79D7F1.4000405@us.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/rtmutex.c')
| -rw-r--r-- | kernel/rtmutex.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/kernel/rtmutex.c b/kernel/rtmutex.c index fcd107a78c5a..29bd4baf9e75 100644 --- a/kernel/rtmutex.c +++ b/kernel/rtmutex.c @@ -1039,16 +1039,14 @@ int rt_mutex_start_proxy_lock(struct rt_mutex *lock, if (!rt_mutex_owner(lock) || try_to_steal_lock(lock, task)) { /* We got the lock for task. */ debug_rt_mutex_lock(lock); - rt_mutex_set_owner(lock, task, 0); - + spin_unlock(&lock->wait_lock); rt_mutex_deadlock_account_lock(lock, task); return 1; } ret = task_blocks_on_rt_mutex(lock, waiter, task, detect_deadlock); - if (ret && !waiter->task) { /* * Reset the return value. We might have |