io_uring: Use helper function hrtimer_update_function()

covanam · KAGA-KOKO · commit 3f8d93d1371f · 2025-02-18T17:41:35.000+01:00
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@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/9b33f490fb1d207d3918ef5e116dc3412ae35c1e.1738746927.git.namcao@linutronix.de
diff --git 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:

Original file line number	Diff line number	Diff line change
`@@ -2421,7 +2421,7 @@ static enum hrtimer_restart io_cqring_min_timer_wakeup(struct hrtimer *timer)`
`2421`	`2421`	`goto out_wake;`
`2422`	`2422`	`}`
`2423`	`2423`
`2424`		`- iowq->t.function = io_cqring_timer_wakeup;`
	`2424`	`+ hrtimer_update_function(&iowq->t, io_cqring_timer_wakeup);`
`2425`	`2425`	`hrtimer_set_expires(timer, iowq->timeout);`
`2426`	`2426`	`return HRTIMER_RESTART;`
`2427`	`2427`	`out_wake:`