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From: Gao feng <gaofeng@cn.fujitsu.com>
To: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: netfilter-devel@vger.kernel.org
Subject: Re: [PATCH] ulog: add protection when remove ipt_ULOG
Date: Mon, 18 Feb 2013 11:57:36 +0800	[thread overview]
Message-ID: <5121A6B0.9090809@cn.fujitsu.com> (raw)
In-Reply-To: <20130207182708.GA18328@localhost>

Hi Pablo,

On 2013/02/08 02:27, Pablo Neira Ayuso wrote:
> Hi Gao,
> 
> On Tue, Feb 05, 2013 at 09:57:30AM +0800, Gao feng wrote:
>> We should add a lock protection when we free the skb,
>> because it maybe used by ipt_ulog_packet right now.
> 
> Did you hit a reproducible crash?
> 

I didn't.
I looked at the ebt_ulog.c and found ebt_ulog_fini
uses the spin lock to protect the ulog_buff's skb.


> I think this is very unlikely to happen. The removal of the module
> happens in user-context and the entire path to build and deliver the
> skb to user-space is protected is under spin_lock_bh, so scheduling
> is not possible.
>

Doesn't spin_lock_bh only disable local cpu's bottom-half?
the task that remove the modules can run on other cpus at the same time.
I'm wrong?

  reply	other threads:[~2013-02-18  4:12 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-02-05  1:57 [PATCH] ulog: add protection when remove ipt_ULOG Gao feng
2013-02-05  2:48 ` [PATCH 2/2] netfilter: ipt_ULOG: make spinlock per nlgroup Gao feng
2013-03-15 11:51   ` Pablo Neira Ayuso
2013-03-18  9:11     ` Gao feng
2013-02-07 18:27 ` [PATCH] ulog: add protection when remove ipt_ULOG Pablo Neira Ayuso
2013-02-18  3:57   ` Gao feng [this message]
2013-02-18 16:52     ` Pablo Neira Ayuso
2013-02-19  1:09       ` Gao feng
2013-03-15 11:49 ` Pablo Neira Ayuso

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