From: Eric Dumazet <eric.dumazet@gmail.com>
To: Patrick McHardy <kaber@trash.net>
Cc: Ingo Molnar <mingo@elte.hu>, David Miller <davem@davemloft.net>,
Thomas Gleixner <tglx@linutronix.de>,
torvalds@linux-foundation.org, akpm@linux-foundation.org,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [bug] __nf_ct_refresh_acct(): WARNING: at lib/list_debug.c:30 __list_add+0x7d/0xad()
Date: Wed, 17 Jun 2009 17:29:11 +0200 [thread overview]
Message-ID: <4A390BC7.3030901@gmail.com> (raw)
In-Reply-To: <4A38FC5A.70500@trash.net>
Patrick McHardy a écrit :
> Patrick McHardy wrote:
>> Eric Dumazet wrote:
>>> Patrick McHardy a écrit :
>>>> No, before it is confirmed, its only visible to the CPU handling
>>>> the initial packet of a connection. Confirmation is the step that
>>>> makes it visible to other CPUs.
>>>
>>> Thanks Patrick, I missed this, and your patch seems fine now :)
>>
>> Thanks for your help, I'll send it to Dave later today.
>
> I'm having some trouble figuring out the exact events that would
> lead to the timer base corruption. Ingo, could you please test
> this patch to make sure it also fixes the problem?
>
>
;)
Event can be described as following :
CPU1 CPU2
/* __nf_conntrack_confirm() */
__nf_conntrack_hash_insert(ct, hash, repl_hash);
// now 'ct' is visible by other cpus
// search conntrack and find ct
// timeout.expires becomes absolute here
ct->timeout.expires += jiffies;
add_timer(&ct->timeout);
/* __nf_ct_refresh_acct() */
if (!nf_ct_is_confirmed(ct)) {
// we *believe* timeout.expires
// is not yet in use by timer code
// and is still a relative quantity.
// We want to 'update' it but we should not !
ct->timeout.expires = extra_jiffies; << CORRUPTION >>
} else {
// too late :(
set_bit(IPS_CONFIRMED_BIT, &ct->status);
This is how I understood the problem, but I may be wrong ?
next prev parent reply other threads:[~2009-06-17 15:29 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-06-15 12:04 [GIT]: Networking David Miller
2009-06-16 9:15 ` Ingo Molnar
2009-06-16 9:19 ` David Miller
2009-06-16 9:33 ` Ingo Molnar
2009-06-16 9:44 ` Ingo Molnar
2009-06-16 9:44 ` Alan Cox
2009-06-16 9:48 ` Ingo Molnar
2009-06-16 9:56 ` David Miller
2009-06-16 10:11 ` Ingo Molnar
2009-06-16 10:35 ` David Miller
2009-06-16 13:38 ` Eric Dumazet
2009-06-16 14:19 ` Eric Dumazet
2009-06-16 18:59 ` Linus Torvalds
2009-06-16 19:08 ` David Miller
2009-06-16 19:37 ` Eric Dumazet
2009-06-16 20:12 ` Eric Dumazet
2009-06-17 6:41 ` [PATCH] net: correct off-by-one write allocations reports Eric Dumazet
2009-06-17 11:31 ` [PATCH] atm: sk_wmem_alloc initial value is one Eric Dumazet
2009-06-18 2:06 ` David Miller
2009-06-18 2:05 ` [PATCH] net: correct off-by-one write allocations reports David Miller
2009-06-17 11:32 ` [GIT]: Networking David Miller
2009-06-16 9:21 ` David Miller
2009-06-16 9:26 ` Ingo Molnar
2009-06-16 10:47 ` David Miller
2009-06-16 10:53 ` Ingo Molnar
2009-06-16 12:24 ` Ingo Molnar
2009-06-16 12:39 ` David Miller
2009-06-17 9:21 ` [bug] __nf_ct_refresh_acct(): WARNING: at lib/list_debug.c:30 __list_add+0x7d/0xad() Ingo Molnar
2009-06-17 10:18 ` Eric Dumazet
2009-06-17 11:08 ` Ingo Molnar
2009-06-17 11:35 ` David Miller
2009-06-18 5:23 ` Ingo Molnar
2009-06-18 5:58 ` Eric Dumazet
2009-06-18 9:47 ` Patrick McHardy
2009-06-18 14:56 ` Patrick McHardy
2009-06-18 15:46 ` Eric Dumazet
2009-06-18 16:09 ` Patrick McHardy
2009-06-18 16:13 ` Pablo Neira Ayuso
2009-06-18 22:46 ` [PATCH] netfilter: conntrack: death_by_timeout() fix Eric Dumazet
2009-06-19 11:15 ` Patrick McHardy
2009-06-20 15:47 ` [bug] __nf_ct_refresh_acct(): WARNING: at lib/list_debug.c:30 __list_add+0x7d/0xad() Ingo Molnar
2009-06-20 15:56 ` Patrick McHardy
2009-06-17 11:38 ` Patrick McHardy
2009-06-17 11:51 ` Patrick McHardy
2009-06-17 11:55 ` Eric Dumazet
2009-06-17 12:00 ` Patrick McHardy
2009-06-17 12:33 ` Eric Dumazet
2009-06-17 12:36 ` Patrick McHardy
2009-06-17 13:27 ` Eric Dumazet
2009-06-17 13:29 ` Patrick McHardy
2009-06-17 14:23 ` Patrick McHardy
2009-06-17 15:29 ` Eric Dumazet [this message]
2009-06-17 15:34 ` Patrick McHardy
2009-06-18 23:18 ` [GIT]: Networking Tilman Schmidt
2009-06-19 3:36 ` David Miller
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