From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexey Dobriyan Subject: Re: Broken "Make ip6_frags per namespace" patch Date: Thu, 17 Jan 2008 14:30:41 +0300 Message-ID: <20080117113041.GG6217@localhost.sw.ru> References: <20080117100524.GF6217@localhost.sw.ru> <478F30AA.7080704@fr.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: davem@davemloft.net, den@sw.ru, netdev@vger.kernel.org, devel@openvz.org To: Daniel Lezcano Return-path: Received: from mailhub.sw.ru ([195.214.232.25]:43659 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751315AbYAQLa7 (ORCPT ); Thu, 17 Jan 2008 06:30:59 -0500 Content-Disposition: inline In-Reply-To: <478F30AA.7080704@fr.ibm.com> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, Jan 17, 2008 at 11:40:42AM +0100, Daniel Lezcano wrote: > Alexey Dobriyan wrote: > >>commit c064c4811b3e87ff8202f5a966ff4eea0bc54575 > >>Author: Daniel Lezcano > >>Date: Thu Jan 10 02:56:03 2008 -0800 > >> > >> [NETNS][IPV6]: Make ip6_frags per namespace. > >> > >> The ip6_frags is moved to the network namespace structure. Because > >> there can be multiple instances of the network namespaces, and the > >> ip6_frags is no longer a global static variable, a helper function has > >> been added to facilitate the initialization of the variables. > >> > >> Until the ipv6 protocol is not per namespace, the variables are > >> accessed relatively from the initial network namespace. > > > >>--- a/include/net/netns/ipv6.h > >>+++ b/include/net/netns/ipv6.h > > > >>@@ -11,6 +13,7 @@ struct netns_sysctl_ipv6 { > >> #ifdef CONFIG_SYSCTL > >> struct ctl_table_header *table; > >> #endif > >>+ struct inet_frags_ctl frags; > > > >>--- a/net/ipv6/reassembly.c > >>+++ b/net/ipv6/reassembly.c > > > >>@@ -632,6 +625,11 @@ static struct inet6_protocol frag_protocol = > >> .flags = INET6_PROTO_NOPOLICY, > >> }; > >> > >>+void ipv6_frag_sysctl_init(struct net *net) > >>+{ > >>+ ip6_frags.ctl = &net->ipv6.sysctl.frags; > >>+} > > > >_This_ can't work. ip6frags is only one and ->ctl pointer is flipped > >onto per-netns data. Changelog is also misleading: ip6_frags_ctl is > >moved to netns not all ip6_frags. > > > >Oopsing place below -- f->ctl dereference in preparation of mod_timer() > >call. > > > > > > > >BUG: unable to handle kernel paging request at virtual address f5da8fc8 > >printing eip: c11d868a *pdpt = 0000000000003001 *pde = 0000000001728067 > >*pte = 0000000035da8000 Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC > >Modules linked in: ebt_ip ebt_dnat ebt_arpreply ebt_arp ebt_among > >ebtable_nat ip6t_REJECT ip6table_filter ip6_tables ebtable_filter > >ebtable_broute ebt_802_3 ebtables des_generic nf_conntrack_netbios_ns > >nf_conntrack_ipv4 xt_state nf_conntrack xt_tcpudp ipt_REJECT > >iptable_filter ip_tables deflate zlib_deflate zlib_inflate cryptomgr > >crypto_hash cpufreq_stats cpufreq_ondemand cdrom cbc bridge llc blkcipher > >crypto_algapi arpt_mangle arptable_filter arp_tables x_tables ah6 > >af_packet ipv6 > > > >Pid: 0, comm: swapper Not tainted (2.6.24-rc7-net-2.6.25-nf-sysfs-n #30) > >EIP: 0060:[] EFLAGS: 00010246 CPU: 1 > >EIP is at inet_frag_secret_rebuild+0xaa/0xd0 > >EAX: f5da8fbc EBX: 00000000 ECX: c1310000 EDX: 00000100 > >ESI: f7cba000 EDI: f898f7a0 EBP: 00000040 ESP: c1310f90 > > DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 > >Process swapper (pid: 0, ti=c1310000 task=f7c9a580 task.ti=f7c9b000) > >Stack: f898f7a8 f898f8a8 000ddcbd f898f7a0 f7cba000 c1310fc4 00000100 > >c1026d60 00000002 00000001 c1191183 c4779ddc c11d85e0 f898c860 > > f898c860 c12c4a88 00000001 c1308da0 0000000a c1023477 00000001 > > c130b640 c130b640 f7c9bf34 Call Trace: > > [] run_timer_softirq+0x120/0x190 > > [] net_rx_action+0x53/0x220 > > [] inet_frag_secret_rebuild+0x0/0xd0 > > [] __do_softirq+0x87/0x100 > > [] do_softirq+0xaf/0x110 > > [] irq_exit+0x83/0x90 > > [] smp_apic_timer_interrupt+0x57/0x90 > > [] apic_timer_interrupt+0x29/0x38 > > [] apic_timer_interrupt+0x33/0x38 > > [] default_idle+0x0/0x60 > > [] default_idle+0x40/0x60 > > [] cpu_idle+0x73/0xb0 > >======================= > >Code: 8b 10 85 d2 89 13 74 03 89 5a 04 89 18 89 43 04 85 f6 89 f3 75 bb 45 > >83 fd 40 75 a5 8b 44 24 04 e8 4c 3f 01 00 8b 87 50 01 00 00 <8b> 50 0c 01 > >54 24 08 8d 87 38 01 00 00 8b 54 24 08 83 c4 0c 5b EIP: [] > >inet_frag_secret_rebuild+0xaa/0xd0 SS:ESP 0068:c1310f90 > >Kernel panic - not syncing: Fatal exception in interrupt > > Hi Alexey, > > does it happen after unsharing the network ? Yep. clone(CLONE_NEWNET) in a loop and sooner or later you'll see this.