[patch 07/20] posix-timers: Set k_itimer::it_signal to NULL on exit()

[Thomas Gleixner]

Technically it's not required to set k_itimer::it_signal to NULL on exit()
because there is no other thread anymore which could lookup the timer
concurrently.

Set it to NULL for consistency sake and add a comment to that effect.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
 kernel/time/posix-timers.c |    8 ++++++++
 1 file changed, 8 insertions(+)

--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -1107,6 +1107,14 @@ static void itimer_delete(struct k_itime
 	}
 	list_del(&timer->list);
 
+	/*
+	 * Setting timer::it_signal to NULL is technically not required
+	 * here as nothing can access the timer anymore legitimately via
+	 * the hash table. Set it to NULL nevertheless so that all deletion
+	 * paths are consistent.
+	 */
+	WRITE_ONCE(timer->it_signal, NULL);
+
 	spin_unlock_irqrestore(&timer->it_lock, flags);
 	release_posix_timer(timer, IT_ID_SET);
 }