From: Rainer Weikusat <rweikusat@mobileactivedefense•com>
To: Mathias Krause <minipli@googlemail•com>
Cc: Rainer Weikusat <rweikusat@mobileactivedefense•com>,
Jason Baron <jbaron@akamai•com>,
netdev@vger•kernel.org,
"linux-kernel\@vger.kernel.org" <linux-kernel@vger•kernel.org>,
Eric Wong <normalperson@yhbt•net>,
Eric Dumazet <eric.dumazet@gmail•com>,
Alexander Viro <viro@zeniv•linux.org.uk>,
Davide Libenzi <davidel@xmailserver•org>,
Davidlohr Bueso <dave@stgolabs•net>,
Olivier Mauras <olivier@mauras•ch>,
PaX Team <pageexec@freemail•hu>,
Linus Torvalds <torvalds@linux-foundation•org>,
"peterz\@infradead.org" <peterz@infradead•org>,
"davem\@davemloft.net" <davem@davemloft•net>
Subject: Re: List corruption on epoll_ctl(EPOLL_CTL_DEL) an AF_UNIX socket
Date: Wed, 30 Sep 2015 14:25:58 +0100 [thread overview]
Message-ID: <87pp10t4wp.fsf@doppelsaurus.mobileactivedefense.com> (raw)
In-Reply-To: <CA+rthh_LqYaOBBMmdCa=zo55ukVDTff-pKM8cw0HzJDapg5Vvg@mail.gmail.com> (Mathias Krause's message of "Wed, 30 Sep 2015 13:55:57 +0200")
Mathias Krause <minipli@googlemail•com> writes:
> On 30 September 2015 at 12:56, Rainer Weikusat <rweikusat@mobileactivedefense•com> wrote:
>> Mathias Krause <minipli@googlemail•com> writes:
>>> On 29 September 2015 at 21:09, Jason Baron <jbaron@akamai•com> wrote:
>>>> However, if we call connect on socket 's', to connect to a new socket 'o2', we
>>>> drop the reference on the original socket 'o'. Thus, we can now close socket
>>>> 'o' without unregistering from epoll. Then, when we either close the ep
>>>> or unregister 'o', we end up with this list corruption. Thus, this is not a
>>>> race per se, but can be triggered sequentially.
>>>
>>> Sounds profound, but the reproducers calls connect only once per
>>> socket. So there is no "connect to a new socket", no?
>>> But w/e, see below.
>>
>> In case you want some information on this: This is a kernel warning I
>> could trigger (more than once) on the single day I could so far spend
>> looking into this (3.2.54 kernel):
>>
>> Sep 15 19:37:19 doppelsaurus kernel: WARNING: at lib/list_debug.c:53 list_del+0x9/0x30()
>> Sep 15 19:37:19 doppelsaurus kernel: Hardware name: 500-330nam
>> Sep 15 19:37:19 doppelsaurus kernel: list_del corruption. prev->next should be ffff88022c38f078, but was dead000000100100
>> [snip]
>
> Is that with Jason's patch or a vanilla v3.2.54?
That's a kernel warning which occurred repeatedly (among other "link
pointer disorganization" warnings) when I tested the "program with
unknown behaviour" you wrote with the kernel I'm currently supporting a
while ago (as I already wrote in the original mail).
next prev parent reply other threads:[~2015-09-30 13:25 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-13 19:53 List corruption on epoll_ctl(EPOLL_CTL_DEL) an AF_UNIX socket Mathias Krause
2015-09-14 2:39 ` Eric Wong
2015-09-29 18:09 ` Mathias Krause
2015-09-29 19:09 ` Jason Baron
2015-09-30 5:54 ` Mathias Krause
2015-09-30 7:34 ` Michal Kubecek
2015-10-01 2:55 ` Jason Baron
2015-09-30 10:56 ` Rainer Weikusat
2015-09-30 11:55 ` Mathias Krause
2015-09-30 13:25 ` Rainer Weikusat [this message]
2015-09-30 13:38 ` Mathias Krause
2015-09-30 13:51 ` Rainer Weikusat
2015-10-01 2:39 ` Jason Baron
2015-10-01 10:33 ` Rainer Weikusat
2015-10-01 12:10 ` Rainer Weikusat
2015-10-01 12:58 ` Rainer Weikusat
2015-09-15 17:07 ` Rainer Weikusat
2015-09-15 18:15 ` Mathias Krause
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=87pp10t4wp.fsf@doppelsaurus.mobileactivedefense.com \
--to=rweikusat@mobileactivedefense$(echo .)com \
--cc=dave@stgolabs$(echo .)net \
--cc=davem@davemloft$(echo .)net \
--cc=davidel@xmailserver$(echo .)org \
--cc=eric.dumazet@gmail$(echo .)com \
--cc=jbaron@akamai$(echo .)com \
--cc=linux-kernel@vger$(echo .)kernel.org \
--cc=minipli@googlemail$(echo .)com \
--cc=netdev@vger$(echo .)kernel.org \
--cc=normalperson@yhbt$(echo .)net \
--cc=olivier@mauras$(echo .)ch \
--cc=pageexec@freemail$(echo .)hu \
--cc=peterz@infradead$(echo .)org \
--cc=torvalds@linux-foundation$(echo .)org \
--cc=viro@zeniv$(echo .)linux.org.uk \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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