author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> 2021-08-13 12:40:49 +0200
committer: Minda Chen <minda.chen@starfivetech.com> 2023-11-06 19:24:44 +0800
commit: eb893f04744a485ef1a9e6c69f872a48e4932657
parent: 27b073576dcb1cac6c2855aa6688156903d4740e
Commit Summary:
Diffstat:
1 file changed, 17 insertions, 1 deletion
diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
index 6bb116c559b4..3665583361c0 100644
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -1097,8 +1097,26 @@ static int __sched task_blocks_on_rt_mutex(struct rt_mutex_base *lock,
* which is wrong, as the other waiter is not in a deadlock
* situation.
*/
- if (owner == task)
+ if (owner == task) {
+#if defined(DEBUG_WW_MUTEXES) && defined(CONFIG_DEBUG_LOCKING_API_SELFTESTS)
+ /*
+ * The lockdep selftest for ww-mutex assumes in a few cases
+ * the ww_ctx->contending_lock assignment via
+ * __ww_mutex_check_kill() which does not happen if the rtmutex
+ * detects the deadlock early.
+ */
+ if (build_ww_mutex() && ww_ctx) {
+ struct rt_mutex *rtm;
+
+ /* Check whether the waiter should backout immediately */
+ rtm = container_of(lock, struct rt_mutex, rtmutex);
+
+ __ww_mutex_add_waiter(waiter, rtm, ww_ctx);
+ __ww_mutex_check_kill(rtm, waiter, ww_ctx);
+ }
+#endif
return -EDEADLK;
+ }
raw_spin_lock(&task->pi_lock);
waiter->task = task;