From: Miaohe Lin <linmiaohe@huawei.com>
To: Matthew Wilcox <willy@infradead.org>
Cc: <hannes@cmpxchg.org>, <mhocko@kernel.org>,
<vdavydov.dev@gmail.com>, <akpm@linux-foundation.org>,
<shakeelb@google.com>, <guro@fb.com>, <alexs@kernel.org>,
<richard.weiyang@gmail.com>, <songmuchun@bytedance.com>,
<linux-mm@kvack.org>, <linux-kernel@vger.kernel.org>,
<cgroups@vger.kernel.org>
Subject: Re: [PATCH 4/5] mm, memcg: avoid possible NULL pointer dereferencing in mem_cgroup_init()
Date: Fri, 30 Jul 2021 09:50:13 +0800 [thread overview]
Message-ID: <d174dcca-aad4-0534-4d6a-767e01dafd8b@huawei.com> (raw)
In-Reply-To: <YQKyn8bKRblCDuND@casper.infradead.org>
On 2021/7/29 21:52, Matthew Wilcox wrote:
> On Thu, Jul 29, 2021 at 08:57:54PM +0800, Miaohe Lin wrote:
>> rtpn might be NULL in very rare case. We have better to check it before
>> dereferencing it. Since memcg can live with NULL rb_tree_per_node in
>> soft_limit_tree, warn this case and continue.
>
> Why would we need to warn? the GFP flags don't contain NOWARN, so
> we already know an allocation failed.
I see. Will remove it. Many thanks!
> .
>
WARNING: multiple messages have this Message-ID (diff)
From: Miaohe Lin <linmiaohe-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
To: Matthew Wilcox <willy-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
Cc: hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org,
mhocko-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org,
vdavydov.dev-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org,
akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org,
shakeelb-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org,
guro-b10kYP2dOMg@public.gmane.org,
alexs-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org,
richard.weiyang-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org,
songmuchun-EC8Uxl6Npydl57MIdRCFDg@public.gmane.org,
linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [PATCH 4/5] mm, memcg: avoid possible NULL pointer dereferencing in mem_cgroup_init()
Date: Fri, 30 Jul 2021 09:50:13 +0800 [thread overview]
Message-ID: <d174dcca-aad4-0534-4d6a-767e01dafd8b@huawei.com> (raw)
In-Reply-To: <YQKyn8bKRblCDuND-FZi0V3Vbi30CUdFEqe4BF2D2FQJk+8+b@public.gmane.org>
On 2021/7/29 21:52, Matthew Wilcox wrote:
> On Thu, Jul 29, 2021 at 08:57:54PM +0800, Miaohe Lin wrote:
>> rtpn might be NULL in very rare case. We have better to check it before
>> dereferencing it. Since memcg can live with NULL rb_tree_per_node in
>> soft_limit_tree, warn this case and continue.
>
> Why would we need to warn? the GFP flags don't contain NOWARN, so
> we already know an allocation failed.
I see. Will remove it. Many thanks!
> .
>
next prev parent reply other threads:[~2021-07-30 1:50 UTC|newest]
Thread overview: 97+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-29 12:57 [PATCH 0/5] Cleanups and fixup for memcontrol Miaohe Lin
2021-07-29 12:57 ` Miaohe Lin
2021-07-29 12:57 ` [PATCH 1/5] mm, memcg: remove unused functions Miaohe Lin
2021-07-29 12:57 ` Miaohe Lin
2021-07-29 14:07 ` Shakeel Butt
2021-07-29 14:07 ` Shakeel Butt
2021-07-29 14:07 ` Shakeel Butt
2021-07-30 2:39 ` Muchun Song
2021-07-30 2:39 ` Muchun Song
2021-07-30 2:39 ` Muchun Song
2021-07-30 2:57 ` Roman Gushchin
2021-07-30 2:57 ` Roman Gushchin
2021-07-30 6:45 ` Michal Hocko
2021-07-30 6:45 ` Michal Hocko
2021-07-29 12:57 ` [PATCH 2/5] mm, memcg: narrow the scope of percpu_charge_mutex Miaohe Lin
2021-07-29 12:57 ` Miaohe Lin
2021-07-30 2:42 ` Muchun Song
2021-07-30 2:42 ` Muchun Song
2021-07-30 2:42 ` Muchun Song
2021-07-30 3:06 ` Roman Gushchin
2021-07-30 3:06 ` Roman Gushchin
2021-07-30 6:50 ` Michal Hocko
2021-07-30 6:50 ` Michal Hocko
2021-07-31 2:29 ` Miaohe Lin
2021-07-31 2:29 ` Miaohe Lin
2021-08-02 6:49 ` Michal Hocko
2021-08-02 6:49 ` Michal Hocko
2021-08-02 9:54 ` Miaohe Lin
2021-08-02 9:54 ` Miaohe Lin
2021-08-03 3:40 ` Roman Gushchin
2021-08-03 3:40 ` Roman Gushchin
2021-08-03 6:29 ` Miaohe Lin
2021-08-03 6:29 ` Miaohe Lin
2021-08-03 7:11 ` Michal Hocko
2021-08-03 7:11 ` Michal Hocko
2021-08-03 7:13 ` Roman Gushchin
2021-08-03 7:13 ` Roman Gushchin
2021-08-03 7:27 ` Michal Hocko
2021-08-03 7:27 ` Michal Hocko
2021-08-03 9:33 ` Muchun Song
2021-08-03 9:33 ` Muchun Song
2021-08-03 9:33 ` Muchun Song
2021-08-03 10:50 ` Miaohe Lin
2021-08-03 10:50 ` Miaohe Lin
2021-08-03 14:15 ` Johannes Weiner
2021-08-03 14:15 ` Johannes Weiner
2021-08-04 8:20 ` Michal Hocko
2021-08-04 8:20 ` Michal Hocko
2021-08-05 1:44 ` Miaohe Lin
2021-08-05 1:44 ` Miaohe Lin
2021-07-30 6:46 ` Michal Hocko
2021-07-29 12:57 ` [PATCH 3/5] mm, memcg: save some atomic ops when flush is already true Miaohe Lin
2021-07-29 12:57 ` Miaohe Lin
2021-07-29 14:40 ` Shakeel Butt
2021-07-29 14:40 ` Shakeel Butt
2021-07-29 14:40 ` Shakeel Butt
2021-07-30 2:37 ` Muchun Song
2021-07-30 2:37 ` Muchun Song
2021-07-30 2:37 ` Muchun Song
2021-07-30 3:07 ` Roman Gushchin
2021-07-30 3:07 ` Roman Gushchin
2021-07-30 6:51 ` Michal Hocko
2021-07-30 6:51 ` Michal Hocko
2021-07-29 12:57 ` [PATCH 4/5] mm, memcg: avoid possible NULL pointer dereferencing in mem_cgroup_init() Miaohe Lin
2021-07-29 12:57 ` Miaohe Lin
2021-07-29 13:52 ` Matthew Wilcox
2021-07-29 13:52 ` Matthew Wilcox
2021-07-30 1:50 ` Miaohe Lin [this message]
2021-07-30 1:50 ` Miaohe Lin
2021-07-30 3:12 ` Roman Gushchin
2021-07-30 3:12 ` Roman Gushchin
2021-07-30 6:29 ` Miaohe Lin
2021-07-30 6:29 ` Miaohe Lin
2021-07-30 6:44 ` Michal Hocko
2021-07-30 6:44 ` Michal Hocko
2021-07-31 2:05 ` Miaohe Lin
2021-07-31 2:05 ` Miaohe Lin
2021-08-02 6:43 ` Michal Hocko
2021-08-02 6:43 ` Michal Hocko
2021-08-02 10:00 ` Miaohe Lin
2021-08-02 10:00 ` Miaohe Lin
2021-08-02 10:42 ` Michal Hocko
2021-08-02 10:42 ` Michal Hocko
2021-08-02 11:18 ` Miaohe Lin
2021-08-02 11:18 ` Miaohe Lin
2021-07-29 12:57 ` [PATCH 5/5] mm, memcg: always call __mod_node_page_state() with preempt disabled Miaohe Lin
2021-07-29 12:57 ` Miaohe Lin
2021-07-29 14:39 ` Shakeel Butt
2021-07-29 14:39 ` Shakeel Butt
2021-07-29 14:39 ` Shakeel Butt
2021-07-30 1:52 ` Miaohe Lin
2021-07-30 1:52 ` Miaohe Lin
2021-07-30 2:33 ` [External] " Muchun Song
2021-07-30 2:33 ` Muchun Song
2021-07-30 2:33 ` Muchun Song
2021-07-30 2:46 ` Miaohe Lin
2021-07-30 2:46 ` Miaohe Lin
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