autoremove_wake_function uses list_del_init_careful, so should epoll's
more aggressive variant. It only doesn't because it was copied from an
older wait.c rather than the most recent.
Fixes: a16ceb139610 ("epoll: autoremove wakers even more aggressively")
Signed-off-by: Ben Segall <bsegall@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Change-Id: Icca05359250297f091779c9dcf4fefea92ee8c93
---
fs/eventpoll.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 980483455cc09..266d45c7685b4 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -1803,11 +1803,15 @@ static struct timespec64 *ep_timeout_to_timespec(struct timespec64 *to, long ms)
static int ep_autoremove_wake_function(struct wait_queue_entry *wq_entry,
unsigned int mode, int sync, void *key)
{
int ret = default_wake_function(wq_entry, mode, sync, key);
- list_del_init(&wq_entry->entry);
+ /*
+ * Pairs with list_empty_careful in ep_poll, and ensures future loop
+ * iterations see the cause of this wakeup.
+ */
+ list_del_init_careful(&wq_entry->entry);
return ret;
}
/**
* ep_poll - Retrieves ready events, and delivers them to the caller-supplied
--
2.41.0.rc0.172.g3f132b7071-goog
