linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
To: Dmitry Vyukov <dvyukov@google.com>,
	syzbot <syzbot+1505c80c74256c6118a5@syzkaller.appspotmail.com>,
	Ingo Molnar <mingo@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Amir Goldstein <amir73il@gmail.com>,
	"Darrick J. Wong" <darrick.wong@oracle.com>,
	Dave Chinner <david@fromorbit.com>,
	Johannes Weiner <hannes@cmpxchg.org>,
	Hugh Dickins <hughd@google.com>,
	Souptick Joarder <jrdr.linux@gmail.com>,
	LKML <linux-kernel@vger.kernel.org>,
	Linux-MM <linux-mm@kvack.org>,
	syzkaller-bugs <syzkaller-bugs@googlegroups.com>,
	Matthew Wilcox <willy@infradead.org>
Subject: Re: INFO: rcu detected stall in sys_sendfile64 (2)
Date: Sat, 19 Jan 2019 22:00:55 +0900	[thread overview]
Message-ID: <1737a5e1-f93a-e7ea-80d0-c244b22d0b61@I-love.SAKURA.ne.jp> (raw)
In-Reply-To: <CACT4Y+ZSK4DDhsz5gCAUnW49mCJPGcKECqC8yAn=PAA0Tx8D3w@mail.gmail.com>

On 2019/01/19 20:41, Dmitry Vyukov wrote:
> On Sat, Jan 19, 2019 at 12:32 PM syzbot
> <syzbot+1505c80c74256c6118a5@syzkaller.appspotmail.com> wrote:
>>
>> Hello,
>>
>> syzbot found the following crash on:
>>
>> HEAD commit:    2339e91d0e66 Merge tag 'media/v5.0-1' of git://git.kernel...
>> git tree:       upstream
>> console output: https://syzkaller.appspot.com/x/log.txt?x=175f2638c00000
>> kernel config:  https://syzkaller.appspot.com/x/.config?x=abc3dc9b7a900258
>> dashboard link: https://syzkaller.appspot.com/bug?extid=1505c80c74256c6118a5
>> compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
>> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=12c4dc28c00000
>> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=15df4108c00000
> 
> Looking at the reproducer it looks like something with scheduler as it
> involves perf_event_open and sched_setattr. So +Peter and Mingo.
> Is it the same root cause as the other stalls involving sched_setattr?

Yes. I think sched_setattr() involves this problem.

Reproducers from "BUG: workqueue lockup (4)" at
https://syzkaller.appspot.com/text?tag=ReproC&x=13ec31a5400000
involves sched_setattr(SCHED_DEADLINE) and
https://syzkaller.appspot.com/text?tag=ReproC&x=104da690c00000
also involves sched_setattr().


  reply	other threads:[~2019-01-19 13:01 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-19 11:32 INFO: rcu detected stall in sys_sendfile64 (2) syzbot
2019-01-19 11:41 ` Dmitry Vyukov
2019-01-19 13:00   ` Tetsuo Handa [this message]
2019-03-12  3:59 ` syzbot
2019-03-12  4:08   ` Al Viro
2019-03-12  8:00     ` Jani Nikula
2019-03-12 14:29     ` Tetsuo Handa
2019-03-12 17:15       ` Dmitry Vyukov
2019-03-12 21:11         ` Tetsuo Handa
2019-03-13  6:43           ` Dmitry Vyukov
2019-03-13 16:37             ` Theodore Ts'o
2019-03-13 16:56               ` Dmitry Vyukov
2019-03-13 23:40             ` Eric Biggers
2019-03-14 10:52               ` Tetsuo Handa
2019-03-20 12:49                 ` Dmitry Vyukov
2019-03-20 13:45                 ` Dmitry Vyukov
2019-03-12 17:10     ` Dmitry Vyukov

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1737a5e1-f93a-e7ea-80d0-c244b22d0b61@I-love.SAKURA.ne.jp \
    --to=penguin-kernel@i-love.sakura.ne.jp \
    --cc=akpm@linux-foundation.org \
    --cc=amir73il@gmail.com \
    --cc=darrick.wong@oracle.com \
    --cc=david@fromorbit.com \
    --cc=dvyukov@google.com \
    --cc=hannes@cmpxchg.org \
    --cc=hughd@google.com \
    --cc=jrdr.linux@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mingo@redhat.com \
    --cc=peterz@infradead.org \
    --cc=syzbot+1505c80c74256c6118a5@syzkaller.appspotmail.com \
    --cc=syzkaller-bugs@googlegroups.com \
    --cc=willy@infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).