[PATCH v2] locking/ww_mutex: Initialize waiter.ww_ctx properly

[Sebastian Andrzej Siewior]

The gathering of the debug code for the ww-mutex initialized moved the
POISON initialiation into one spot and only set waiter.ww_ctx if the
ww_ctx was non-NULL thus keeping the POISON value in ww-mutex case.

For ww-mutex without a context it is expected to set the context to
NULL, the poison value was intended only for the regular mutex.

Always initialized waiter.ww_ctx to ww_ctx in the ww-mutex case.

Fixes: c0afb0ffc06e6 ("locking/ww_mutex: Gather mutex_waiter initialization")
Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Suggested-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
---
v1…v2: Use PeterZ' approach.

 kernel/locking/mutex.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
index 05b68931622d1..2c70213934cd4 100644
--- a/kernel/locking/mutex.c
+++ b/kernel/locking/mutex.c
@@ -614,7 +614,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
 
 	debug_mutex_lock_common(lock, &waiter);
 	waiter.task = current;
-	if (ww_ctx)
+	if (use_ww_ctx)
 		waiter.ww_ctx = ww_ctx;
 
 	lock_contended(&lock->dep_map, ip);
-- 
2.33.0