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| author | Michal Hocko <mhocko@suse.cz> | 2015-09-08 15:01:13 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-09-08 15:35:28 -0700 |
| commit | a03f1f058969ec350fb7451a6fbca23096ee5727 (patch) | |
| tree | b6745897f8969fe99a4a514b9d76eaaa167ff84d | |
| parent | 9f2115f93b88e5e8d48b87b153e36a537afb58cb (diff) | |
| download | x86-pkeys-a03f1f058969ec350fb7451a6fbca23096ee5727.tar.gz | |
memcg, tcp_kmem: check for cg_proto in sock_update_memcg
sk_prot->proto_cgroup is allowed to return NULL but sock_update_memcg
doesn't check for NULL. The function relies on the mem_cgroup_is_root
check because we shouldn't get NULL otherwise because mem_cgroup_from_task
will always return !NULL.
All other callers are checking for NULL and we can safely replace
mem_cgroup_is_root() check by cg_proto != NULL which will be more
straightforward (proto_cgroup returns NULL for the root memcg already).
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/memcontrol.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 191d8aa5da713e..3033e6c4222952 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -315,8 +315,7 @@ void sock_update_memcg(struct sock *sk) rcu_read_lock(); memcg = mem_cgroup_from_task(current); cg_proto = sk->sk_prot->proto_cgroup(memcg); - if (!mem_cgroup_is_root(memcg) && - memcg_proto_active(cg_proto) && + if (cg_proto && memcg_proto_active(cg_proto) && css_tryget_online(&memcg->css)) { sk->sk_cgrp = cg_proto; } |