Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932290AbWEWVYM (ORCPT ); Tue, 23 May 2006 17:24:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932289AbWEWVYM (ORCPT ); Tue, 23 May 2006 17:24:12 -0400 Received: from mail.unixshell.com ([207.210.106.37]:37532 "EHLO mail.unixshell.com") by vger.kernel.org with ESMTP id S932288AbWEWVYK (ORCPT ); Tue, 23 May 2006 17:24:10 -0400 Message-ID: <44737D53.9050006@tektonic.net> Date: Tue, 23 May 2006 17:23:31 -0400 From: Matt Ayres Organization: TekTonic User-Agent: Thunderbird 1.5.0.2 (Windows/20060308) MIME-Version: 1.0 To: Keir Fraser CC: Patrick McHardy , "xen-devel@lists.xensource.com" , Netfilter Development Mailinglist , James Morris , Linux Kernel Mailing List Subject: Re: [Xen-devel] Re: Panic in ipt_do_table with 2.6.16.13-xen References: <4468BE70.7030802@tektonic.net> <4468D613.20309@trash.net> <44691669.4080903@tektonic.net> <4469D84F.8080709@tektonic.net> <446D0A0D.5090608@tektonic.net> <446D0E6D.2080600@tektonic.net> <446D151D.6030307@tektonic.net> <4470A6CD.5010501@trash.net> <4471CB54.401@tektonic.net> <4471CE19.5070802@trash.net> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1834 Lines: 43 Keir Fraser wrote: > > On 22 May 2006, at 15:43, Patrick McHardy wrote: > >> Maybe this helps: there is not too much the Xen code could be doing >> wrong here. If I read your crash correctly it happend in the FORWARD >> chain, which could mean that the outgoing device (probably the Xen >> virtual network driver) has some bugs, but iptables really only cares >> about the names at this point, which practically can't be bogus. >> The only other thing I can imagine is that something is wrong with >> the per-CPU copy of the ruleset, i.e. either smp_processor_id is >> returning garbage or for_each_possible_cpu misses a CPU during >> initialization. I have no idea if Xen really does touch this code, >> but other than that I don't really see what it could break. > > Having looked at disassembly, the fault happens when accessing > e->ip.invflags in ip_packet_match() inlined inside ipt_do_table(). > > e = private->entries[smp_processor_id()] + > private->hook_entry[NF_IP_FORWARD] > > smp_processor_id() should be 0 (since the oops appears to occur on cpu0) > and presumably all the ipt_entry structures are static once set up. > Since this crash happens on a common path in ipt_do_table(), and since > it happens only after the system has been up a while (I believe?), it > rather looks as though something has either corrupted a pointer or > unmapped memory from under iptables' feet. > As the concerned user, what does this mean to me? It will only affect SMP systems? It is a bug in Xen or netfilter? I'd just like to understand what is going on. Thanks, Matt - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/