lib: add more strict sanity checks for del_timer()

Signed-off-by: Hajime Tazaki <[email protected]>
libos-nuse · Jul 17, 2015 · 9672e6d · 9672e6d
1 parent 4977649
commit 9672e6d
Showing 1 changed file with 6 additions and 4 deletions.
diff --git a/arch/lib/timer.c b/arch/lib/timer.c
@@ -185,22 +185,24 @@ int del_timer(struct timer_list *timer)
 	int retval;
 	struct lib_timer *l_timer;
 
-	if (timer->entry.pprev == 0)
+	if (timer->entry.pprev == NULL)
 		return 0;
 
 	l_timer = lib_timer_find(timer);
 	if (l_timer != NULL && l_timer->event != NULL) {
 		lib_event_cancel(l_timer->event);
 
-		if (l_timer->t_hash.next != LIST_POISON1)
+		if (l_timer->t_hash.next != LIST_POISON1) {
 			hlist_del(&l_timer->t_hash);
-		lib_free(l_timer);
+			lib_free(l_timer);
+		}
 		retval = 1;
 	} else {
 		retval = 0;
 	}
 
-	hlist_del(&timer->entry);
+	if (timer->entry.next != LIST_POISON1)
+		hlist_del(&timer->entry);
 	timer->entry.pprev = NULL;
 	return retval;
 }