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Subject[PATCH 3/3] locking: rtmutex: set state back to running on error
Date
The "usual" path is:
- rt_mutex_slowlock()
- set_current_state()
- task_blocks_on_rt_mutex() (ret 0)
- __rt_mutex_slowlock()
- sleep or not but do return with __set_current_state(TASK_RUNNING)
- back to caller.

In the early error case where task_blocks_on_rt_mutex() return -EDEADLK
we never change the task's state back to RUNNING. I assume this is
intended. Without this change after ww_mutex using rt_mutex the selftest
passes but later I get plenty of
| bad: scheduling from the idle thread!
backtraces.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
kernel/locking/rtmutex.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
index 6d7d72ffa619..c4d07f254bb4 100644
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -1305,6 +1305,7 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state,
}

if (unlikely(ret)) {
+ set_current_state(TASK_RUNNING);
if (rt_mutex_has_waiters(lock))
remove_waiter(lock, &waiter);
/* ww_mutex need the error reported */
--
2.1.4


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