From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andrew Morton <akpm@osdl.org>
Subject: Re: 2.6.15-rc2-mm1
Date: Wed, 23 Nov 2005 11:22:18 -0800
Message-ID: <20051123112218.73f68926.akpm@osdl.org>
References: <20051123033550.00d6a6e8.akpm@osdl.org>
	<6bffcb0e0511230615y7531e268n@mail.gmail.com>
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Cc: linux-kernel@vger.kernel.org, Harald Welte <laforge@netfilter.org>,
	netdev@vger.kernel.org
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To: Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
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Michal Piotrowski <michal.k.k.piotrowski@gmail.com> wrote:
>
>  Debug: sleeping function called from invalid context at
>  include/asm/semaphore.h:123
>  in_atomic():1, irqs_disabled():0
>   [<c0103be6>] dump_stack+0x17/0x19
>   [<c011a0c3>] __might_sleep+0x9c/0xae
>   [<fd9a090d>] translate_table+0x147/0xc14 [ip_tables]
>   [<fd9a2b2a>] ipt_register_table+0x93/0x20d [ip_tables]
>   [<f98fe027>] init+0x27/0x9e [iptable_filter]
>   [<c01376d0>] sys_init_module+0xd7/0x26c
>   [<c0102cc7>] sysenter_past_esp+0x54/0x75
>  ---------------------------
>  | preempt count: 00000001 ]
>  | 1 level deep critical section nesting:
>  ----------------------------------------
>  .. [<fd9a2aca>] .... ipt_register_table+0x33/0x20d [ip_tables]
>  .....[<f98fe027>] ..   ( <= init+0x27/0x9e [iptable_filter])
> 

ipt_register_table() does get_cpu() then calls translate_table(), and
somewhere under translate_table() we do something which sleeps, only I'm not
sure what it is - netfilter likes to hide things in unexpected places.

check_entry() will do sleepy things under that get_cpu(), but that doesn't
seem to be in this particular call chain.

Anyway, the new get_cpu() in ipt_register_table() is the problem.