[merged] mm-memcg-slab-fix-return-child-memcg-objcg-for-root-memcg.patch removed from -mm tree

[merged] mm-memcg-slab-fix-return-child-memcg-objcg-for-root-memcg.patch removed from -mm tree

[akpm]

The patch titled
     Subject: mm: memcg/slab: fix return of child memcg objcg for root memcg
has been removed from the -mm tree.  Its filename was
     mm-memcg-slab-fix-return-child-memcg-objcg-for-root-memcg.patch

This patch was dropped because it was merged into mainline or a subsystem tree

------------------------------------------------------
From: Muchun Song <songmuchun@bytedance.com>
Subject: mm: memcg/slab: fix return of child memcg objcg for root memcg

Consider the following memcg hierarchy.

                    root
                   /    \
                  A      B

If we failed to get the reference on objcg of memcg A, the
get_obj_cgroup_from_current can return the wrong objcg for the root
memcg.

Link: https://lkml.kernel.org/r/20201029164429.58703-1-songmuchun@bytedance.com
Fixes: bf4f059954dc ("mm: memcg/slab: obj_cgroup API")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Roman Gushchin <guro@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Yafang Shao <laoar.shao@gmail.com>
Cc: Chris Down <chris@chrisdown.name>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Eugene Syromiatnikov <esyr@redhat.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Adrian Reber <areber@redhat.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/memcontrol.c |    1 +
 1 file changed, 1 insertion(+)

--- a/mm/memcontrol.c~mm-memcg-slab-fix-return-child-memcg-objcg-for-root-memcg
+++ a/mm/memcontrol.c
@@ -2975,6 +2975,7 @@ __always_inline struct obj_cgroup *get_o
 		objcg = rcu_dereference(memcg->objcg);
 		if (objcg && obj_cgroup_tryget(objcg))
 			break;
+		objcg = NULL;
 	}
 	rcu_read_unlock();
 
_

Patches currently in -mm which might be from songmuchun@bytedance.com are