From: Jiri Pirko <jpirko@redhat.com>
To: Patrick McHardy <kaber@trash.net>
Cc: Jan Engelhardt <jengelh@medozas.de>,
netfilter@vger.kernel.org, bart.de.schuymer@pandora.be,
davem@davemloft.net, shemminger@vyatta.com
Subject: Re: [Question] netfilter, xt_target->target and xt_target->checkentry locks
Date: Wed, 9 Jun 2010 15:13:11 +0200 [thread overview]
Message-ID: <20100609131310.GD2825@psychotron.lab.eng.brq.redhat.com> (raw)
In-Reply-To: <4C0F9117.9060801@trash.net>
Wed, Jun 09, 2010 at 03:03:19PM CEST, kaber@trash.net wrote:
>Jiri Pirko wrote:
>> Wed, Jun 09, 2010 at 02:37:51PM CEST, jengelh@medozas.de wrote:
>>
>>> On Wednesday 2010-06-09 14:21, Jiri Pirko wrote:
>>>
>>>
>>>> Hi Patrick.
>>>>
>>>> Once module registers it's struct xt_target by xt_register_target and
>>>> ->target and ->checkentry funtions are called later, is there any lock
>>>> guaranteed to be held?
>>>>
>>> >From what I see for ->target it looks like rcu_read_lock is held, but
>>>
>>>> I'm not sure for all paths. There would be nice to put a comment into
>>>> struct xt_target definition regarding locks.
>>>>
>>> Though nf_hook_slow invokes rcu_read_lock, that should not be a formal
>>> guarantee that Xtables extensions run with RCU. See xt_TCPMSS for
>>> example.
>>>
>>
>> A was afraid of it. Thanks.
>
>We actually assume this in all conntrack helpers, so I don't see anything
>wrong with making the same assumption in xtables modules, as long as
>its documented.
Where this is documented please?
next prev parent reply other threads:[~2010-06-09 13:13 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-06-09 12:21 [Question] netfilter, xt_target->target and xt_target->checkentry locks Jiri Pirko
2010-06-09 12:37 ` Jan Engelhardt
2010-06-09 13:00 ` Jiri Pirko
2010-06-09 13:03 ` Patrick McHardy
2010-06-09 13:13 ` Jiri Pirko [this message]
2010-06-09 13:26 ` Patrick McHardy
2010-06-09 14:06 ` Jiri Pirko
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