From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lennart Schulte Subject: Re: oops in tcp_xmit_retransmit_queue() w/ v2.6.32.15 Date: Fri, 16 Jul 2010 14:25:41 +0200 Message-ID: <4C404FC5.6040107@nets.rwth-aachen.de> References: <4C358AAA.9080400@kernel.org> <4C3EF7EA.2040900@nets.rwth-aachen.de> <1279195528.2496.2.camel@edumazet-laptop> <4C3F053F.7090704@nets.rwth-aachen.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Eric Dumazet , Tejun Heo , "David S. Miller" , lkml , "netdev@vger.kernel.org" , "Fehrmann, Henning" , Carsten Aulbert To: =?ISO-8859-1?Q?Ilpo_J=E4rvinen?= Return-path: Received: from mail-i4.nets.RWTH-Aachen.DE ([137.226.12.21]:42378 "EHLO MAIL-i4.nets.rwth-aachen.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965280Ab0GPMZo (ORCPT ); Fri, 16 Jul 2010 08:25:44 -0400 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On 16.07.2010 14:02, Ilpo J=E4rvinen wrote: > >>>> [ 2754.413150] NULL head, pkts 0 >>>> [ 2754.413156] Errors caught so far 1 >>>> =20 > Thanks for reporting the results. > > Could you post the oops too or double check do the timestamps really = match > (and there wasn't more "Errors caught" prints in between)? Since this > condition doesn't seem to crash the kernel as also send_head should b= e > NULL, which saves the day here exiting the loop (unless send head wou= ld > too be corrupt). > =20 I can try to do some more testing, perhaps then I will get other=20 results. But until now I've always gotten something like above. With the debug patch the kernel doesn't crash, but I have an oops from = a=20 run before the patch: [ 3214.498061] BUG: unable to handle kernel NULL pointer dereference at= =20 (null) [ 3214.498085] IP: [] tcp_xmit_retransmit_queue+0x4c/0x2b0 [ 3214.498121] *pdpt =3D 00000002cf6fa001 [ 3214.498130] Thread overran stack, or stack corrupted [ 3214.498138] Oops: 0000 [#1] SMP [ 3214.498154] last sysfs file: /sys/kernel/uevent_seqnum [ 3214.498161] Modules linked in: tcp_ancr tcp_ncr [ 3214.498174] [ 3214.498180] Pid: 0, comm: swapper Not tainted (2.6.31.9-pae-um-wolff= =20 #79) [ 3214.498188] EIP: 0061:[] EFLAGS: 00010246 CPU: 0 [ 3214.498196] EIP is at tcp_xmit_retransmit_queue+0x4c/0x2b0 [ 3214.498203] EAX: c6da2900 EBX: c6da2880 ECX: 00000000 EDX: e50c512e [ 3214.498211] ESI: 00000000 EDI: 0000051b EBP: c6da2900 ESP: c13d5cf0 [ 3214.498219] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0069 [ 3214.498227] Process swapper (pid: 0, ti=3Dc13d4000 task=3Dc13e7a20=20 task.ti=3Dc13d4000) [ 3214.498236] Stack: [ 3214.498240] c1005a0b 00000001 00000000 e50c512e c7804300 00000013=20 c6da2880 0000051b [ 3214.498264] <0> e50c512e c1260709 c6cbf840 c6d42000 c1031826 c1288bb= d=20 c6da2900 c6e09320 [ 3214.498290] <0> c6e09300 00000000 00000000 00000001 e50c512d e521a34= 6=20 e50c512e 00000000 [ 3214.498318] Call Trace: [ 3214.498329] [] ? xen_restore_fl_direct_end+0x0/0x1 [ 3214.498339] [] ? tcp_ack+0x7f9/0x10d0 [ 3214.498350] [] ? local_bh_enable+0x56/0x80 [ 3214.498359] [] ? ipt_do_table+0x2dd/0x590 [ 3214.498369] [] ? tcp_rcv_state_process+0x41f/0x970 [ 3214.498378] [] ? tcp_v4_do_rcv+0x8f/0x1e0 [ 3214.498387] [] ? tcp_v4_rcv+0x68d/0x7d0 [ 3214.498397] [] ? ip_local_deliver_finish+0x0/0x1e0 [ 3214.498406] [] ? ip_local_deliver_finish+0x97/0x1e0 [ 3214.498416] [] ? ip_local_deliver_finish+0x0/0x1e0 [ 3214.498425] [] ? ip_rcv_finish+0x13b/0x340 [ 3214.498434] [] ? ip_rcv_finish+0x0/0x340 [ 3214.498442] [] ? ip_rcv+0x0/0x2e0 [ 3214.498452] [] ? netif_receive_skb+0x2f7/0x4c0 [ 3214.498468] [] ? process_backlog+0x70/0xb0 [ 3214.498476] [] ? net_rx_action+0xe8/0x1a0 [ 3214.498486] [] ? __do_softirq+0x8d/0x120 [ 3214.498494] [] ? xen_mc_flush+0xed/0x1a0 [ 3214.498504] [] ? move_native_irq+0x11/0x50 [ 3214.498513] [] ? do_softirq+0x38/0x40 [ 3214.498523] [] ? xen_evtchn_do_upcall+0x142/0x160 [ 3214.498534] [] ? xen_do_upcall+0x7/0xc [ 3214.498543] [] ? hypercall_page+0x3a7/0x1010 [ 3214.498552] [] ? xen_safe_halt+0xf/0x20 [ 3214.498560] [] ? xen_idle+0x1c/0x30 [ 3214.498569] [] ? cpu_idle+0x3a/0x60 [ 3214.498578] [] ? start_kernel+0x26a/0x300 [ 3214.498616] [] ? unknown_bootoption+0x0/0x1c0 [ 3214.498630] [] ? xen_start_kernel+0x3be/0x3e0 [ 3214.498637] Code: 00 00 8b b3 a0 03 00 00 85 f6 0f 84 53 02 00 00 8b= =20 46 3c 8d ab 80 00 00 00 8b 93 04 04 00 00 39 c2 89 54 24 0c 0f 89 1c 02= =20 00 00 <8b> 06 0f 18 00 90 39 ee 0f 84 30 01 00 00 39 b3 28 01 00 00 8d [ 3214.498820] EIP: [] tcp_xmit_retransmit_queue+0x4c/0x2b0=20 SS:ESP 0069:c13d5cf0 [ 3214.498836] CR2: 0000000000000000 [ 3214.498846] ---[ end trace 709a97adf87834a7 ]--- [ 3214.498852] Kernel panic - not syncing: Fatal exception in interrupt [ 3214.498862] Pid: 0, comm: swapper Tainted: G D =20 2.6.31.9-pae-um-wolff #79 [ 3214.498870] Call Trace: [ 3214.498878] [] ? panic+0x46/0x100 [ 3214.498904] [] ? oops_end+0x98/0xa0 [ 3214.498922] [] ? no_context+0x11f/0x1b0 [ 3214.498930] [] ? do_page_fault+0x66/0x240 [ 3214.498939] [] ? do_page_fault+0x0/0x240 [ 3214.498947] [] ? bad_area_nosemaphore+0xf/0x20 [ 3214.498955] [] ? error_code+0x66/0x6c [ 3214.498963] [] ? do_page_fault+0x0/0x240 [ 3214.498972] [] ? tcp_xmit_retransmit_queue+0x4c/0x2b0 [ 3214.498982] [] ? xen_restore_fl_direct_end+0x0/0x1 [ 3214.498991] [] ? tcp_ack+0x7f9/0x10d0 [ 3214.498999] [] ? local_bh_enable+0x56/0x80 [ 3214.499009] [] ? ipt_do_table+0x2dd/0x590 [ 3214.499017] [] ? tcp_rcv_state_process+0x41f/0x970 [ 3214.499025] [] ? tcp_v4_do_rcv+0x8f/0x1e0 [ 3214.499034] [] ? tcp_v4_rcv+0x68d/0x7d0 [ 3214.499044] [] ? ip_local_deliver_finish+0x0/0x1e0 [ 3214.499053] [] ? ip_local_deliver_finish+0x97/0x1e0 [ 3214.499063] [] ? ip_local_deliver_finish+0x0/0x1e0 [ 3214.499072] [] ? ip_rcv_finish+0x13b/0x340 [ 3214.499079] [] ? ip_rcv_finish+0x0/0x340 [ 3214.499087] [] ? ip_rcv+0x0/0x2e0 [ 3214.499101] [] ? netif_receive_skb+0x2f7/0x4c0 [ 3214.499115] [] ? process_backlog+0x70/0xb0 [ 3214.499123] [] ? net_rx_action+0xe8/0x1a0 [ 3214.499131] [] ? __do_softirq+0x8d/0x120 [ 3214.499143] [] ? xen_mc_flush+0xed/0x1a0 [ 3214.499152] [] ? move_native_irq+0x11/0x50 [ 3214.499160] [] ? do_softirq+0x38/0x40 [ 3214.499174] [] ? xen_evtchn_do_upcall+0x142/0x160 [ 3214.499188] [] ? xen_do_upcall+0x7/0xc [ 3214.499195] [] ? hypercall_page+0x3a7/0x1010 [ 3214.499203] [] ? xen_safe_halt+0xf/0x20 [ 3214.499214] [] ? xen_idle+0x1c/0x30 [ 3214.499223] [] ? cpu_idle+0x3a/0x60 [ 3214.499231] [] ? start_kernel+0x26a/0x300 [ 3214.499239] [] ? unknown_bootoption+0x0/0x1c0 [ 3214.499247] [] ? xen_start_kernel+0x3be/0x3e0