1 files changed, 3 insertions, 3 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index ac35bccadb7b..f72b5e52451a 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1148,7 +1148,7 @@ bool __mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg,
 {
         if (root_memcg == memcg)
                 return true;
-        if (!root_memcg->use_hierarchy)
+        if (!root_memcg->use_hierarchy || !memcg)
                 return false;
         return css_is_ancestor(&memcg->css, &root_memcg->css);
 }
@@ -1234,7 +1234,7 @@ int mem_cgroup_inactive_file_is_low(struct lruvec *lruvec)
 
 /**
  * mem_cgroup_margin - calculate chargeable space of a memory cgroup
- * @mem: the memory cgroup
+ * @memcg: the memory cgroup
  *
  * Returns the maximum amount of memory @mem can be charged with, in
  * pages.
@@ -1508,7 +1508,7 @@ static unsigned long mem_cgroup_reclaim(struct mem_cgroup *memcg,
 
 /**
  * test_mem_cgroup_node_reclaimable
- * @mem: the target memcg
+ * @memcg: the target memcg
  * @nid: the node ID to be checked.
  * @noswap : specify true here if the user wants flle only information.
  *