--- zzzz-none-000/linux-4.4.60/kernel/trace/trace_event_perf.c	2017-04-08 07:53:53.000000000 +0000
+++ wasp-540e-714/linux-4.4.60/kernel/trace/trace_event_perf.c	2019-07-03 09:21:34.000000000 +0000
@@ -256,7 +256,8 @@
 void perf_trace_del(struct perf_event *p_event, int flags)
 {
 	struct trace_event_call *tp_event = p_event->tp_event;
-	hlist_del_rcu(&p_event->hlist_entry);
+	if (!hlist_unhashed(&p_event->hlist_entry))
+		hlist_del_rcu(&p_event->hlist_entry);
 	tp_event->class->reg(tp_event, TRACE_REG_PERF_DEL, p_event);
 }