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From: Eric Dumazet <eric.dumazet@gmail.com>
To: "Bruno Prémont" <bonbons@linux-vserver.org>
Cc: "David S. Miller" <davem@davemloft.net>,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [2.6.33-rc5 regression] NULL pointer dereference in vlan_skb_recv - probably introduced by commit 9793241fe92f7d9303fb221e43fc598eb065f267
Date: Sun, 24 Jan 2010 14:42:54 +0100	[thread overview]
Message-ID: <4B5C4E5E.2010507@gmail.com> (raw)
In-Reply-To: <20100123223132.0e62d8cb@neptune.home>

Le 23/01/2010 22:31, Bruno Prémont a écrit :
>> Above part of code did change between 2.6.32 and 2.6.33-rc5 with
>> commit 9793241fe92f7d9303fb221e43fc598eb065f267 (vlan: Precise RX
>> stats accounting)
>> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=9793241fe92f7d9303fb221e43fc598eb065f267
> 
> Reverting just that commit gets the system running correctly.
> 
> Bruno

I have no idea how this patch can break vlan networking.

Your disassembly and .config seems to show your machine is not SMP

Maybe something is broken on UP and alloc_percpu() ?

Could you add a debug in vlan_dev_init()


 	vlan_dev_info(dev)->vlan_rx_stats = alloc_percpu(struct vlan_rx_stats);
	if (!vlan_dev_info(dev)->vlan_rx_stats)
 	return -ENOMEM;
+	pr_err("vlan_dev_init() rx_stats=%p\n", vlan_dev_info(dev)->vlan_rx_stats);


This make sure vlan_dev_init() is called and percpu allocation is properly done.

Thanks

  reply	other threads:[~2010-01-24 13:43 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-01-23 15:56 [2.6.33-rc5 regression] NULL pointer dereference in vlan_skb_recv - probably introduced by commit 9793241fe92f7d9303fb221e43fc598eb065f267 Bruno Prémont
2010-01-23 21:31 ` Bruno Prémont
2010-01-24 13:42   ` Eric Dumazet [this message]
2010-01-24 15:02     ` Bruno Prémont
2010-01-24 15:25       ` Bruno Prémont
2010-01-24 16:25         ` Américo Wang
2010-01-24 16:27           ` Eric Dumazet
2010-01-24 16:26         ` Eric Dumazet
2010-01-24 19:18           ` Bruno Prémont
2010-01-24 19:43             ` [PATCH] vlan: fix vlan_skb_recv() Eric Dumazet
2010-01-25  3:52               ` David Miller
2010-01-24  7:12 ` [2.6.33-rc5 regression] NULL pointer dereference in vlan_skb_recv - probably introduced by commit 9793241fe92f7d9303fb221e43fc598eb065f267 Américo Wang
2010-01-24  7:17   ` Alexey Dobriyan
2010-01-24  7:30     ` Américo Wang

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