1 files changed, 11 insertions, 4 deletions

diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c
index 59e9ef6aab40..e5c0244962b0 100644
--- a/kernel/cgroup_freezer.c
+++ b/kernel/cgroup_freezer.c
@@ -15,6 +15,7 @@
  */
 
 #include <linux/module.h>
+#include <linux/slab.h>
 #include <linux/cgroup.h>
 #include <linux/fs.h>
 #include <linux/uaccess.h>
@@ -47,17 +48,20 @@ static inline struct freezer *task_freezer(struct task_struct *task)
                             struct freezer, css);
 }
 
-int cgroup_frozen(struct task_struct *task)
+int cgroup_freezing_or_frozen(struct task_struct *task)
 {
         struct freezer *freezer;
         enum freezer_state state;
 
         task_lock(task);
         freezer = task_freezer(task);
-        state = freezer->state;
+        if (!freezer->css.cgroup->parent)
+                state = CGROUP_THAWED; /* root cgroup can't be frozen */
+        else
+                state = freezer->state;
         task_unlock(task);
 
-        return state == CGROUP_FROZEN;
+        return (state == CGROUP_FREEZING) || (state == CGROUP_FROZEN);
 }
 
 /*
@@ -201,9 +205,12 @@ static void freezer_fork(struct cgroup_subsys *ss, struct task_struct *task)
          * No lock is needed, since the task isn't on tasklist yet,
          * so it can't be moved to another cgroup, which means the
          * freezer won't be removed and will be valid during this
-         * function call.
+         * function call.  Nevertheless, apply RCU read-side critical
+         * section to suppress RCU lockdep false positives.
          */
+        rcu_read_lock();
         freezer = task_freezer(task);
+        rcu_read_unlock();
 
         /*
          * The root cgroup is non-freezable, so we can skip the