From: Florian Westphal <fw@strlen.de>
To: Ani Sinha <ani@arista.com>
Cc: netdev@vger.kernel.org, ani@anirban.org, fruggeri@arista.com
Subject: Re: kernel BUG in ipmr_queue_xmit()
Date: Fri, 30 Oct 2015 01:15:10 +0100 [thread overview]
Message-ID: <20151030001510.GG18062@breakpoint.cc> (raw)
In-Reply-To: <alpine.OSX.2.00.1510291646320.59200@animac.local>
Ani Sinha <ani@arista.com> wrote:
[ trimmed CC list ]
> We are noticing the following kernel BUG in 3.18 kernel. The
> code path that leads to the crash is the following :
>
> ip_mroute_setsockopt()
> ->ipmr_mfc_add()
> ->ipmr_cache_resolve()
> ->ip_mr_forward()
> -> ipmr_queue_xmit()
> -> ipmr_forward_finish()
> ->IP_INC_STATS_BH()
> -> SNMP_INC_STATS64_BH()
> -> SNMP_INC_STATS_BH()
> -> __this_cpu_inc()
> -> __this_cpu_add()
> -> __this_cpu_preempt_check()
> -> check_preemption_disabled()
>
> I have verified that preempt_count() is 0 when the crash happens.
> Is anyone else seeing the same crash in the laetst upstream code? I dug
> around a little bit and it does not look like there were any fixes that
> went into post 3.18 kernel which could have disabled preemption in this
> code path but I could be wrong.
>
> thoughts?
Send a patch to preempt_disable before ip_mr_forward call in the affected
setsockopt path?
next prev parent reply other threads:[~2015-10-30 0:15 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-29 23:55 kernel BUG in ipmr_queue_xmit() Ani Sinha
2015-10-30 0:15 ` Florian Westphal [this message]
2015-10-30 1:41 ` Ani Sinha
2015-10-30 4:15 ` Eric Dumazet
2015-10-30 10:36 ` Florian Westphal
2015-10-30 10:40 ` Hannes Frederic Sowa
2015-10-30 10:48 ` Florian Westphal
2015-10-30 11:00 ` Eric Dumazet
2015-10-30 17:47 ` Ani Sinha
2015-10-30 19:12 ` Eric Dumazet
2015-10-30 21:10 ` Ani Sinha
2015-10-30 23:54 ` [PATCH 1/1] ipmr: fix possible race resulting from improper usage of IP_INC_STATS_BH() in preemptible context Ani Sinha
2015-11-01 22:35 ` Eric Dumazet
2015-11-02 20:57 ` David Miller
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=20151030001510.GG18062@breakpoint.cc \
--to=fw@strlen.de \
--cc=ani@anirban.org \
--cc=ani@arista.com \
--cc=fruggeri@arista.com \
--cc=netdev@vger.kernel.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.