From: Joe Buehler <aspam@cox•net>
To: Eric Dumazet <eric.dumazet@gmail•com>
Cc: netdev@vger•kernel.org
Subject: Re: kernel panic in fib_rules_lookup [2.6.27.7 vendor-patched]
Date: Fri, 22 Oct 2010 16:30:52 -0400 [thread overview]
Message-ID: <4CC1F47C.9020104@cox.net> (raw)
In-Reply-To: <1287612353.2545.11.camel@edumazet-laptop>
Eric Dumazet wrote:
> Could you provide a disassembly of function fib_rules_lookup ?
Try looking in http://68.100.141.95:3000/linux-crash/. There should be
the source file I am using (not current release if you recall), the .o,
the disassembly, and a -S compile that makes deducing the line numbers a
little easier.
I have tried adding a recursive spinlock as a quick fix without much
success. It looks like the code in net/core/fib_rules.c results in some
rather complex code paths through the kernel involving softirq handlers.
I get lockups though I took steps to make sure local interrupts were
off and preemption disabled when taking the spinlock.
I do not know the RCU API or the network code at all but some of the
code in fib_rules.c does not look right prima facie. For example,
dump_rules does not seem to bother about RCU when traversing rules_list.
Its caller, fib_nl_dumprule does, but only for one of two calls. The
fib_nl_newrule and fib_nl_delrule functions traverse rules_list without
any obvious RCU precautions.
Joe Buehler
next prev parent reply other threads:[~2010-10-22 20:31 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-10-12 17:14 kernel panic in fib_rules_lookup [2.6.27.7 vendor-patched] Joe Buehler
2010-10-12 17:40 ` Eric Dumazet
2010-10-13 11:18 ` Joe Buehler
2010-10-20 17:43 ` Joe Buehler
2010-10-20 22:05 ` Eric Dumazet
2010-10-22 20:30 ` Joe Buehler [this message]
2010-10-23 3:44 ` Eric Dumazet
2010-10-23 15:11 ` Eric Dumazet
2010-10-23 15:24 ` Eric Dumazet
2010-10-23 15:40 ` Joe Buehler
2010-10-23 16:07 ` Eric Dumazet
2010-10-23 15:33 ` Joe Buehler
2010-10-23 16:35 ` Eric Dumazet
2010-10-23 17:37 ` "Oleg A. Arkhangelsky"
2010-10-23 19:44 ` Eric Dumazet
2010-10-26 18:43 ` David Miller
2010-10-26 13:29 ` Joe Buehler
2010-10-26 13:36 ` Eric Dumazet
2010-10-26 13:53 ` Joe Buehler
2010-10-26 13:58 ` Eric Dumazet
2010-10-26 14:33 ` Eric Dumazet
2010-10-26 14:41 ` Joe Buehler
2010-10-27 21:01 ` Joe Buehler
2010-10-27 21:05 ` Eric Dumazet
2010-12-02 13:36 ` Joe Buehler
2010-12-02 14:04 ` Eric Dumazet
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