diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 421557f..c6bd67b 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -2825,6 +2825,7 @@
 }
 
 void cgroup_iter_start(struct cgroup *cgrp, struct cgroup_iter *it)
+	__acquires(css_set_lock)
 {
 	/*
 	 * The first time anyone tries to iterate across a cgroup,
@@ -2864,6 +2865,7 @@
 }
 
 void cgroup_iter_end(struct cgroup *cgrp, struct cgroup_iter *it)
+	__releases(css_set_lock)
 {
 	read_unlock(&css_set_lock);
 }