Commit 1bbf20835c4e088667a090ce6523a0f70b62dc76
Committed by
Ingo Molnar
Ingo Molnar
1 parent
90bc1a658a
Exists in
master
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20 other branches
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>
Showing 1 changed file with 1 additions and 3 deletions Side-by-side Diff
kernel/rtmutex.c
| ... | ... | @@ -1039,15 +1039,13 @@ |
| 1039 | 1039 | if (!rt_mutex_owner(lock) || try_to_steal_lock(lock, task)) { |
| 1040 | 1040 | /* We got the lock for task. */ |
| 1041 | 1041 | debug_rt_mutex_lock(lock); |
| 1042 | - | |
| 1043 | 1042 | rt_mutex_set_owner(lock, task, 0); |
| 1044 | - | |
| 1043 | + spin_unlock(&lock->wait_lock); | |
| 1045 | 1044 | rt_mutex_deadlock_account_lock(lock, task); |
| 1046 | 1045 | return 1; |
| 1047 | 1046 | } |
| 1048 | 1047 | |
| 1049 | 1048 | ret = task_blocks_on_rt_mutex(lock, waiter, task, detect_deadlock); |
| 1050 | - | |
| 1051 | 1049 | |
| 1052 | 1050 | if (ret && !waiter->task) { |
| 1053 | 1051 | /* |