From: Mike Galbraith <mgalbraith@suse.de>
To: Tejun Heo <tj@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>,
Li Zefan <lizf@cn.fujitsu.com>,
David Rientjes <rientjes@google.com>,
Paul Menage <paul@paulmenage.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [patch] cgroups: disallow attaching kthreadd
Date: Wed, 04 Apr 2012 04:34:38 +0200 [thread overview]
Message-ID: <1333506878.7433.2.camel@marge.simpson.net> (raw)
In-Reply-To: <20120403184901.GC27794@dhcp-172-17-108-109.mtv.corp.google.com>
On Tue, 2012-04-03 at 11:49 -0700, Tejun Heo wrote:
> On Tue, Apr 03, 2012 at 07:58:26PM +0200, Mike Galbraith wrote:
> > @@ -1894,6 +1895,14 @@ int cgroup_attach_task(struct cgroup *cg
> > if (tsk->flags & PF_EXITING)
> > return -ESRCH;
> >
> > + /*
> > + * Workqueue threads may acquire PF_THREAD_BOUND and become
> > + * trapped in a cpuset, or RT worker may be born in a cgroup
> > + * with no rt_runtime allocated. Just say no.
> > + */
> > + if (tsk == kthreadd_task)
> > + return -EINVAL;
> > +
> > /* Nothing to do if the task is already in that cgroup */
> > oldcgrp = task_cgroup_from_root(tsk, root);
> > if (cgrp == oldcgrp)
> > @@ -2172,6 +2181,17 @@ static int attach_task_by_pid(struct cgr
> >
> > if (threadgroup)
> > tsk = tsk->group_leader;
> > +
> > + /*
> > + * Workqueue threads may acquire PF_THREAD_BOUND and become
> > + * trapped in a cpuset, or RT worker may be born in a cgroup
> > + * with no rt_runtime allocated. Just say no.
> > + */
> > + if (tsk == kthreadd_task) {
> > + ret = -EINVAL;
> > + goto out_unlock_cgroup;
> > + }
>
> If we have this test here, do we need the same check in
> cgroup_attach_task()/
It looked to me like yes, because cgroup_attach_task() can be called
directly. For the problem at hand, user script doing bad things, no,
it's not needed.
-Mike
next prev parent reply other threads:[~2012-04-04 2:34 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-03 17:58 [patch] cgroups: disallow attaching kthreadd Mike Galbraith
2012-04-03 18:49 ` Tejun Heo
2012-04-04 2:34 ` Mike Galbraith [this message]
2012-04-04 23:06 ` Tejun Heo
2012-04-04 23:10 ` Tejun Heo
2012-04-04 7:15 ` David Rientjes
2012-04-04 10:38 ` Mike Galbraith
2012-04-04 11:29 ` David Rientjes
2012-04-04 12:30 ` Mike Galbraith
2012-04-04 21:17 ` David Rientjes
2012-04-04 23:09 ` Tejun Heo
2012-04-04 23:14 ` David Rientjes
2012-04-05 4:47 ` Mike Galbraith
2012-04-05 4:58 ` David Rientjes
2012-04-05 5:49 ` Mike Galbraith
2012-04-05 6:07 ` David Rientjes
2012-04-05 6:42 ` Mike Galbraith
2012-04-05 6:49 ` David Rientjes
2012-04-05 7:14 ` [patch 0/2] cpusets, cpu_cgroup: " David Rientjes
2012-04-05 7:14 ` [patch 1/2] cpusets: " David Rientjes
2012-04-05 7:14 ` [patch 2/2] cpu_cgroup: " David Rientjes
2012-04-05 16:08 ` [patch 0/2] cpusets, " Tejun Heo
2012-04-05 21:26 ` David Rientjes
2012-04-05 21:37 ` Tejun Heo
2012-04-05 21:46 ` Tejun Heo
2012-04-06 7:50 ` Li Zefan
2012-04-06 15:54 ` Tejun Heo
2012-04-05 22:03 ` David Rientjes
2012-04-05 22:24 ` Tejun Heo
2012-04-05 22:31 ` Tejun Heo
2012-04-05 22:55 ` David Rientjes
2012-04-05 22:58 ` Tejun Heo
2012-04-05 23:05 ` David Rientjes
2012-04-05 23:13 ` Tejun Heo
2012-04-05 23:40 ` David Rientjes
2012-04-06 15:52 ` Tejun Heo
2012-04-06 18:26 ` Peter Zijlstra
2012-04-06 20:49 ` David Rientjes
2012-04-07 15:02 ` Hiroyuki Kamezawa
2012-04-10 0:52 ` David Rientjes
2012-04-14 11:35 ` Peter Zijlstra
2012-04-20 17:55 ` Tejun Heo
2012-04-06 20:46 ` David Rientjes
2012-04-14 11:28 ` Peter Zijlstra
2012-04-05 7:36 ` [patch] cgroups: " Mike Galbraith
2012-04-05 8:00 ` David Rientjes
2012-04-14 11:17 ` Peter Zijlstra
2012-04-05 16:11 ` Tejun Heo
2012-04-20 17:57 ` Tejun Heo
2012-04-21 5:31 ` Mike Galbraith
2012-04-21 6:54 ` Li Zefan
2012-04-21 7:13 ` Mike Galbraith
2012-04-23 18:05 ` Tejun Heo
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