From: Yosry Ahmed <yosryahmed@google.com>
To: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>,
Michal Hocko <mhocko@kernel.org>,
Roman Gushchin <roman.gushchin@linux.dev>,
Shakeel Butt <shakeelb@google.com>,
Muchun Song <songmuchun@bytedance.com>, Tejun Heo <tj@kernel.org>,
Zefan Li <lizefan.x@bytedance.com>, Shuah Khan <shuah@kernel.org>,
David Rientjes <rientjes@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
Cgroups <cgroups@vger.kernel.org>, Linux-MM <linux-mm@kvack.org>,
linux-kselftest@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: Re: [PATCH] selftests: memcg: uninitialized variable in test_memcg_reclaim()
Date: Wed, 20 Jul 2022 10:35:29 -0700 [thread overview]
Message-ID: <CAJD7tkYV60TkgfL2NF2HspJ_j+MB4CuqKNzugrAZ9jtfhicmog@mail.gmail.com> (raw)
In-Reply-To: <20220720092918.GD2316@kadam>
On Wed, Jul 20, 2022 at 2:29 AM Dan Carpenter <dan.carpenter@oracle.com> wrote:
>
> On Tue, Jul 19, 2022 at 10:27:36AM -0700, Yosry Ahmed wrote:
> >
> > Nit: keep the cleanup_* naming for labels to make it obvious and to be
> > consistent with the rest of the file (e.g. cleanup_free,
> > cleanup_memcg, cleanup_file/cleanup_all). See
> > test_memcg_subtree_control().
> >
> > I would honestly have one label to cleanup the memcg. Calling
> > cg_destroy() on a non-existent memcg should be fine. rmdir() will just
> > fail silently. All other tests do this and it's easier to read when we
> > have fewer return paths. My advice would be cleanup_file and
> > cleanup_memcg labels.
>
> One error label handling is very bug prone. You always end up freeing
> things which have not been initialized/allocated. Or dereferencing
> pointers which are NULL. Or, since most kernel functions clean up
> after themselves, you end up double freeing things.
I am not suggesting a single cleanup label, I said "one label to
cleanup the memcg", which is separate from cleaning up the file.
Basically just merging the destroy_memcg and free_memcg labels to be
consistent with other tests. I don't feel strongly about this anyway
:)
>
> regards,
> dan carpenter
prev parent reply other threads:[~2022-07-20 17:36 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-19 9:46 [PATCH] selftests: memcg: uninitialized variable in test_memcg_reclaim() Dan Carpenter
2022-07-19 17:27 ` Yosry Ahmed
2022-07-20 9:29 ` Dan Carpenter
2022-07-20 17:35 ` Yosry Ahmed [this message]
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