From: Oleg Nesterov <oleg@redhat.com>
To: Dmitry Vyukov <dvyukov@google.com>
Cc: Roland McGrath <roland@hack.frob.com>,
Andrew Morton <akpm@linux-foundation.org>,
amanieu@gmail.com, pmoore@redhat.com,
Ingo Molnar <mingo@kernel.org>,
vdavydov@parallels.com, qiaowei.ren@intel.com, dave@stgolabs.net,
palmer@dabbelt.com, LKML <linux-kernel@vger.kernel.org>,
syzkaller <syzkaller@googlegroups.com>,
Kostya Serebryany <kcc@google.com>,
Alexander Potapenko <glider@google.com>,
Sasha Levin <sasha.levin@oracle.com>
Subject: Re: WARNING in task_participate_group_stop
Date: Mon, 2 Nov 2015 19:06:24 +0100 [thread overview]
Message-ID: <20151102180624.GA24361@redhat.com> (raw)
In-Reply-To: <20151102163654.GA18804@redhat.com>
On 11/02, Oleg Nesterov wrote:
>
> On 11/02, Oleg Nesterov wrote:
> >
> > On 11/02, Dmitry Vyukov wrote:
> > >
> > > But I wasn't able
> > > to figure out what's the root cause (why task does not have
> > > JOBCTL_STOP_PENDING) and maybe the same WARNING can be triggered
> > > without root and/or with other than init process. So still posting it
> > > here.
> >
> > Yes I think you are right. SIGSTOP can race with SIGKILL which (unlike SIGCONT)
> > doesn't clear JOBCTL_STOP_DEQUEUED/PENDING/etc.
>
> I was wrong... I forgot that complete_signal(SIGKILL) sets SIGNAL_GROUP_EXIT.
> Unless SIGNAL_UNKILLABLE is set, and this is what makes init "special".
and I think this should be fixed anyway, if nothing else to make this logic more
correct. I'll try to recheck this all later.
> So it seems that everything is clear. Except I can't understand why your
> test-case doesn't work for me ;) It should.
Damn. Sorry Dmitry it actually works. Just I didn't see the output from
pr_warn()'s on the serial console due to the wrong console_loglevel.
Oleg.
next prev parent reply other threads:[~2015-11-02 17:10 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-02 13:25 WARNING in task_participate_group_stop Dmitry Vyukov
2015-11-02 15:13 ` Oleg Nesterov
2015-11-02 14:21 ` Dmitry Vyukov
2015-11-02 15:33 ` Oleg Nesterov
2015-11-02 16:36 ` Oleg Nesterov
2015-11-02 18:06 ` Oleg Nesterov [this message]
2015-11-04 19:18 ` [PATCH 0/1] (Was: WARNING in task_participate_group_stop) Oleg Nesterov
2015-11-04 19:19 ` [PATCH 1/1] signal: kill the obsolete SIGNAL_UNKILLABLE check in complete_signal() Oleg Nesterov
2015-11-05 1:21 ` Andrew Morton
2015-11-05 16:08 ` Oleg Nesterov
2015-11-05 18:02 ` Oleg Nesterov
2017-10-30 19:12 WARNING in task_participate_group_stop syzbot
2017-10-30 19:20 ` Dmitry Vyukov
2017-10-31 16:34 ` Oleg Nesterov
2017-11-01 5:55 ` Dmitry Vyukov
2017-11-02 17:01 ` Oleg Nesterov
2017-11-06 11:02 ` Dmitry Vyukov
2017-11-06 11:25 ` Jamie Iles
2017-11-06 11:56 ` Dmitry Vyukov
2017-11-06 12:26 ` Jamie Iles
2017-11-06 14:31 ` Oleg Nesterov
2017-11-07 17:31 ` Dmitry Vyukov
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