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From: Ross Zwisler <ross.zwisler@linux.intel.com>
To: Tejun Heo <tj@kernel.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Li Zefan <lizefan@huawei.com>,
	Daniel Wagner <daniel.wagner@bmw-carit.de>,
	Johannes Weiner <hannes@cmpxchg.org>,
	cgroups@vger.kernel.org, linux-kernel@vger.kernel.org,
	Dave Jones <davej@codemonkey.org.uk>,
	kernel-team@fb.com, Aleksa Sarai <cyphar@cyphar.com>,
	Michal Hocko <mhocko@kernel.org>, Ingo Molnar <mingo@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Neil Horman <nhorman@tuxdriver.com>
Subject: Re: [PATCH] cgroup: Fix uninitialized variable warning
Date: Wed, 23 Dec 2015 14:38:13 -0700	[thread overview]
Message-ID: <20151223213813.GA21287@linux.intel.com> (raw)
In-Reply-To: <20151223213519.GM5003@mtj.duckdns.org>

On Wed, Dec 23, 2015 at 04:35:19PM -0500, Tejun Heo wrote:
> Hello, Ross.
> 
> On Wed, Dec 23, 2015 at 02:30:40PM -0700, Ross Zwisler wrote:
> >  static int mem_cgroup_can_attach(struct cgroup_taskset *tset)
> >  {
> >  	struct cgroup_subsys_state *css;
> > -	struct mem_cgroup *memcg;
> > +	struct mem_cgroup *memcg = NULL;
> 
> It's one thing to add spurious init to shut up gcc
> 
> > @@ -4805,7 +4805,7 @@ static int mem_cgroup_can_attach(struct cgroup_taskset *tset)
> >  		p = leader;
> >  		memcg = mem_cgroup_from_css(css);
> >  	}
> > -	if (!p)
> > +	if (!p || !memcg)
> 
> and to another to add an additional processing on it.

Do you believe that the additional processing is incorrect?  If somehow we
*do* get through the above loop without setting memcg, the next deref will
OOPs the kernel...

  reply	other threads:[~2015-12-23 21:38 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-12-23 21:30 [PATCH] cgroup: Fix uninitialized variable warning Ross Zwisler
2015-12-23 21:35 ` Tejun Heo
2015-12-23 21:38   ` Ross Zwisler [this message]
2015-12-23 21:41     ` Tejun Heo
  -- strict thread matches above, loose matches on Subject: below --
2015-12-23 21:53 Ross Zwisler
2015-12-28 15:45 ` Tejun Heo

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