[PATCH v2 05/12] io_uring: Use helper function hrtimer_update_function()

[Nam Cao]

The field 'function' of struct hrtimer should not be changed directly, as
the write is lockless and a concurrent timer expiry might end up using the
wrong function pointer.

Switch to use hrtimer_update_function() which also performs runtime checks
that it is safe to modify the callback.

Signed-off-by: Nam Cao <namcao@xxxxxxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
---
 io_uring/io_uring.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index ceacf6230e34..936f8b4106cf 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -2421,7 +2421,7 @@ static enum hrtimer_restart io_cqring_min_timer_wakeup(struct hrtimer *timer)
 			goto out_wake;
 	}
 
-	iowq->t.function = io_cqring_timer_wakeup;
+	hrtimer_update_function(&iowq->t, io_cqring_timer_wakeup);
 	hrtimer_set_expires(timer, iowq->timeout);
 	return HRTIMER_RESTART;
 out_wake:
-- 
2.39.5