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-rw-r--r--kernel/locking/ww_mutex.h18
1 files changed, 16 insertions, 2 deletions
diff --git a/kernel/locking/ww_mutex.h b/kernel/locking/ww_mutex.h
index 37f025a096c9..45fe05e51db1 100644
--- a/kernel/locking/ww_mutex.h
+++ b/kernel/locking/ww_mutex.h
@@ -283,7 +283,15 @@ __ww_mutex_die(struct MUTEX *lock, struct MUTEX_WAITER *waiter,
if (waiter->ww_ctx->acquired > 0 && __ww_ctx_less(waiter->ww_ctx, ww_ctx)) {
#ifndef WW_RT
debug_mutex_wake_waiter(lock, waiter);
+ /*
+ * When waking up the task to die, be sure to clear the
+ * blocked_on pointer. Otherwise we can see circular
+ * blocked_on relationships that can't resolve.
+ */
+ WARN_ON(waiter->task->blocked_on &&
+ waiter->task->blocked_on != lock);
#endif
+ waiter->task->blocked_on = NULL;
wake_q_add(wake_q, waiter->task);
}
@@ -331,9 +339,15 @@ static bool __ww_mutex_wound(struct MUTEX *lock,
* it's wounded in __ww_mutex_check_kill() or has a
* wakeup pending to re-read the wounded state.
*/
- if (owner != current)
+ if (owner != current) {
+ /*
+ * When waking up the task to wound, be sure to clear the
+ * blocked_on pointer. Otherwise we can see circular
+ * blocked_on relationships that can't resolve.
+ */
+ owner->blocked_on = NULL;
wake_q_add(wake_q, owner);
-
+ }
return true;
}