diff --git a/kernel/cgroup/cgroup-internal.h b/kernel/cgroup/cgroup-internal.h
index 3f116765bb001ef612585f57584abccb3ed6e1b3..6fc71b98209e42eec0b75ba31f111e7a0e1404ea 100644
--- a/kernel/cgroup/cgroup-internal.h
+++ b/kernel/cgroup/cgroup-internal.h
@@ -250,6 +250,8 @@ int cgroup_migrate(struct task_struct *leader, bool threadgroup,
 
 int cgroup_attach_task(struct cgroup *dst_cgrp, struct task_struct *leader,
 		       bool threadgroup);
+void cgroup_attach_lock(bool lock_threadgroup);
+void cgroup_attach_unlock(bool lock_threadgroup);
 struct task_struct *cgroup_procs_write_start(char *buf, bool threadgroup,
 					     bool *locked)
 	__acquires(&cgroup_threadgroup_rwsem);
diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c
index 647d0891cff68c37a59703473da3336e8f661f7b..b913923497e9807d4ced2e6d371512b5dfcc1a4e 100644
--- a/kernel/cgroup/cgroup-v1.c
+++ b/kernel/cgroup/cgroup-v1.c
@@ -57,8 +57,7 @@ int cgroup_attach_task_all(struct task_struct *from, struct task_struct *tsk)
 	int retval = 0;
 
 	mutex_lock(&cgroup_mutex);
-	cpus_read_lock();
-	percpu_down_write(&cgroup_threadgroup_rwsem);
+	cgroup_attach_lock(true);
 	for_each_root(root) {
 		struct cgroup *from_cgrp;
 
@@ -73,8 +72,7 @@ int cgroup_attach_task_all(struct task_struct *from, struct task_struct *tsk)
 		if (retval)
 			break;
 	}
-	percpu_up_write(&cgroup_threadgroup_rwsem);
-	cpus_read_unlock();
+	cgroup_attach_unlock(true);
 	mutex_unlock(&cgroup_mutex);
 
 	return retval;
@@ -109,7 +107,7 @@ int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from)
 
 	mutex_lock(&cgroup_mutex);
 
-	percpu_down_write(&cgroup_threadgroup_rwsem);
+	cgroup_attach_lock(true);
 
 	/* all tasks in @from are being moved, all csets are source */
 	spin_lock_irq(&css_set_lock);
@@ -145,7 +143,7 @@ int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from)
 	} while (task && !ret);
 out_err:
 	cgroup_migrate_finish(&mgctx);
-	percpu_up_write(&cgroup_threadgroup_rwsem);
+	cgroup_attach_unlock(true);
 	mutex_unlock(&cgroup_mutex);
 	return ret;
 }
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index d0a4a1c4c38d2f9fe7879be2b32bba6e6f32b4d1..2bc5bae49d200635cfaff704df69894c176297f1 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -2367,7 +2367,7 @@ EXPORT_SYMBOL_GPL(task_cgroup_path);
  * write-locking cgroup_threadgroup_rwsem. This allows ->attach() to assume that
  * CPU hotplug is disabled on entry.
  */
-static void cgroup_attach_lock(bool lock_threadgroup)
+void cgroup_attach_lock(bool lock_threadgroup)
 {
 	cpus_read_lock();
 	if (lock_threadgroup)
@@ -2378,7 +2378,7 @@ static void cgroup_attach_lock(bool lock_threadgroup)
  * cgroup_attach_unlock - Undo cgroup_attach_lock()
  * @lock_threadgroup: whether to up_write cgroup_threadgroup_rwsem
  */
-static void cgroup_attach_unlock(bool lock_threadgroup)
+void cgroup_attach_unlock(bool lock_threadgroup)
 {
 	if (lock_threadgroup)
 		percpu_up_write(&cgroup_threadgroup_rwsem);