From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ding Tianhong Subject: Re: [PATCH net] net: neighbour: make sure the handler has finished before kfree neighbour Date: Sun, 01 Dec 2013 10:43:10 +0800 Message-ID: <529AA23E.8040306@gmail.com> References: <52973704.1030202@huawei.com> <20131130.162733.145727596946626316.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: dingtianhong@huawei.com, gaofeng@cn.fujitsu.com, yoshfuji@linux-ipv6.org, joe@perches.com, vfalico@redhat.com, netdev@vger.kernel.org To: David Miller Return-path: Received: from mail-pb0-f48.google.com ([209.85.160.48]:53831 "EHLO mail-pb0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751412Ab3LACyT (ORCPT ); Sat, 30 Nov 2013 21:54:19 -0500 Received: by mail-pb0-f48.google.com with SMTP id md12so16416530pbc.7 for ; Sat, 30 Nov 2013 18:54:18 -0800 (PST) In-Reply-To: <20131130.162733.145727596946626316.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: =E4=BA=8E 2013/12/1 5:27, David Miller =E5=86=99=E9=81=93: > From: Ding Tianhong > Date: Thu, 28 Nov 2013 20:28:52 +0800 >=20 >> I have met the oops in Suse11 SP2, the kernel is 2.6.32.59-0.7-defau= lt: >=20 > This doesn't make any sense. >=20 > If this actually was the reason, then del_timer() would have returned= true, > and thus neigh_del_timer() would have returned "1" and you would have > seen the "Impossible event" log message that neigh_destroy() prints o= ut. >=20 > You may think the cause is a pending timer, but the data you've provi= ded > does not support this at all. >=20 > And if it isn't happening, your patch removing that warning is wrong. >=20 > Furthermore, if this change to use del_timer_sync() is correct, it > probably belongs in neigh_del_timer() because all of it's other calle= rs > expect the timer to not be running and that all references to the obj= ect > are stable after such calls. >=20 > I'm not applying this, you really need to pursue this bug fix more > cleanly and more thoroughly because it's a non-trivial issue. >=20 > Thanks. ok=EF=BC=8Cthanks for the advice, I would like to think it over and mak= e it better. Regards Ding > -- > To unsubscribe from this list: send the line "unsubscribe netdev" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >=20