From fc4db90fe71e640e3fe88df346f7cf653b75315d Mon Sep 17 00:00:00 2001
From: Roman Gushchin <roman.gushchin@linux.dev>
Date: Fri, 10 Jun 2022 11:03:10 -0700
Subject: mm: kmem: make mem_cgroup_from_obj() vmalloc()-safe
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Currently mem_cgroup_from_obj() is not working properly with objects
allocated using vmalloc().  It creates problems in some cases, when it's
called for static objects belonging to modules or generally allocated
using vmalloc().

This patch makes mem_cgroup_from_obj() safe to be called on objects
allocated using vmalloc().

It also introduces mem_cgroup_from_slab_obj(), which is a faster version
to use in places when we know the object is either a slab object or a
generic slab page (e.g.  when adding an object to a lru list).

Link: https://lkml.kernel.org/r/20220610180310.1725111-1-roman.gushchin@linux.dev
Suggested-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Acked-by: Shakeel Butt <shakeelb@google.com>
Tested-by: Vasily Averin <vvs@openvz.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Muchun Song <songmuchun@bytedance.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Naresh Kamboju <naresh.kamboju@linaro.org>
Cc: Qian Cai <quic_qiancai@quicinc.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
 include/linux/memcontrol.h | 6 ++++++
 1 file changed, 6 insertions(+)

(limited to 'include/linux')

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 9ecead1042b9..3ce96ce5fe3e 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -1740,6 +1740,7 @@ static inline int memcg_kmem_id(struct mem_cgroup *memcg)
 }
 
 struct mem_cgroup *mem_cgroup_from_obj(void *p);
+struct mem_cgroup *mem_cgroup_from_slab_obj(void *p);
 
 static inline void count_objcg_event(struct obj_cgroup *objcg,
 				     enum vm_event_item idx)
@@ -1801,6 +1802,11 @@ static inline struct mem_cgroup *mem_cgroup_from_obj(void *p)
        return NULL;
 }
 
+static inline struct mem_cgroup *mem_cgroup_from_slab_obj(void *p)
+{
+	return NULL;
+}
+
 static inline void count_objcg_event(struct obj_cgroup *objcg,
 				     enum vm_event_item idx)
 {
-- 
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