All of lore.kernel.org
 help / color / mirror / Atom feed
From: Dmitry Vyukov <dvyukov@google.com>
To: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: syzbot <syzbot+ea7d9cb314b4ab49a18a@syzkaller.appspotmail.com>,
	David Miller <davem@davemloft.net>,
	Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>,
	LKML <linux-kernel@vger.kernel.org>,
	netdev <netdev@vger.kernel.org>,
	syzkaller-bugs <syzkaller-bugs@googlegroups.com>,
	Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
	Linux-MM <linux-mm@kvack.org>
Subject: Re: INFO: rcu detected stall in ndisc_alloc_skb
Date: Sun, 6 Jan 2019 14:24:23 +0100	[thread overview]
Message-ID: <CACT4Y+Y5cdD=optF2k4a0W7vriVnzmzLU0SPGEJoOHRMi_bsZA@mail.gmail.com> (raw)
In-Reply-To: <8cdbcb63-d2f7-cace-0eda-d73255fd47e7@i-love.sakura.ne.jp>

On Sat, Jan 5, 2019 at 11:49 AM Tetsuo Handa
<penguin-kernel@i-love.sakura.ne.jp> wrote:
>
> On 2019/01/03 2:06, Tetsuo Handa wrote:
> > On 2018/12/31 17:24, Dmitry Vyukov wrote:
> >>>> Since this involves OOMs and looks like a one-off induced memory corruption:
> >>>>
> >>>> #syz dup: kernel panic: corrupted stack end in wb_workfn
> >>>>
> >>>
> >>> Why?
> >>>
> >>> RCU stall in this case is likely to be latency caused by flooding of printk().
> >>
> >> Just a hypothesis. OOMs lead to arbitrary memory corruptions, so can
> >> cause stalls as well. But can be what you said too. I just thought
> >> that cleaner dashboard is more useful than a large assorted pile of
> >> crashes. If you think it's actionable in some way, feel free to undup.
> >>
> >
> > We don't know why bpf tree is hitting this problem.
> > Let's continue monitoring this problem.
> >
> > #syz undup
> >
>
> A report at 2019/01/05 10:08 from "no output from test machine (2)"
> ( https://syzkaller.appspot.com/text?tag=CrashLog&x=1700726f400000 )
> says that there are flood of memory allocation failure messages.
> Since continuous memory allocation failure messages itself is not
> recognized as a crash, we might be misunderstanding that this problem
> is not occurring recently. It will be nice if we can run testcases
> which are executed on bpf-next tree.

What exactly do you mean by running test cases on bpf-next tree?
syzbot tests bpf-next, so it executes lots of test cases on that tree.
One can also ask for patch testing on bpf-next tree to test a specific
test case.

  reply	other threads:[~2019-01-06 13:24 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-12-31  7:42 INFO: rcu detected stall in ndisc_alloc_skb syzbot
2018-12-31  7:49 ` Dmitry Vyukov
2018-12-31  7:49   ` Dmitry Vyukov
2018-12-31  8:17   ` Tetsuo Handa
2018-12-31  8:24     ` Dmitry Vyukov
2018-12-31  8:24       ` Dmitry Vyukov
2019-01-02 17:06       ` Tetsuo Handa
2019-01-05 10:49         ` Tetsuo Handa
2019-01-06 13:24           ` Dmitry Vyukov [this message]
2019-01-06 13:24             ` Dmitry Vyukov
2019-01-06 13:47             ` Tetsuo Handa
2019-01-07 11:12               ` Dmitry Vyukov
2019-01-07 11:12                 ` Dmitry Vyukov
2019-01-18  5:20                 ` Tetsuo Handa
2019-01-19 12:16                   ` Dmitry Vyukov
2019-01-19 12:16                     ` Dmitry Vyukov
2019-01-19 13:10                     ` Tetsuo Handa
2019-01-20 13:30                       ` Dmitry Vyukov
2019-01-20 13:30                         ` Dmitry Vyukov
2019-01-20 14:24                         ` Tetsuo Handa

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='CACT4Y+Y5cdD=optF2k4a0W7vriVnzmzLU0SPGEJoOHRMi_bsZA@mail.gmail.com' \
    --to=dvyukov@google.com \
    --cc=davem@davemloft.net \
    --cc=kuznet@ms2.inr.ac.ru \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=netdev@vger.kernel.org \
    --cc=penguin-kernel@i-love.sakura.ne.jp \
    --cc=syzbot+ea7d9cb314b4ab49a18a@syzkaller.appspotmail.com \
    --cc=syzkaller-bugs@googlegroups.com \
    --cc=yoshfuji@linux-ipv6.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.