From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michele Baldessari Subject: Re: IPv6 kernel warning Date: Fri, 20 Sep 2013 17:08:30 +0100 Message-ID: <20130920160830.GA4241@marquez.int.rhx> References: <20130920131153.GF12758@n2100.arm.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev@vger.kernel.org, ycheng@google.com To: Russell King - ARM Linux Return-path: Received: from palahniuk.acksyn.org ([5.9.7.26]:51340 "EHLO palahniuk.acksyn.org" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1752549Ab3ITQIe (ORCPT ); Fri, 20 Sep 2013 12:08:34 -0400 Content-Disposition: inline In-Reply-To: <20130920131153.GF12758@n2100.arm.linux.org.uk> Sender: netdev-owner@vger.kernel.org List-ID: Hi Russell, On Fri, Sep 20, 2013 at 02:11:53PM +0100, Russell King - ARM Linux wrote: > While running v3.11 on my firewall, I saw this warning. I'm not sure > what it means or what its implications are: > > ------------[ cut here ]------------ > WARNING: CPU: 0 PID: 0 at /home/rmk/git/linux-rmk/net/ipv4/tcp_input.c:2711 tcp_fastretrans_alert+0x178/0x840() > Modules linked in: ipt_REJECT xt_multiport iptable_filter ipt_MASQUERADE xt_nat > xt_mark iptable_nat nf_nat_ipv4 nf_nat ip6table_mangle xt_LOG xt_limit nf_conntrack_ipv6 nf_defrag_ipv6 xt_state ip6table_filter pata_pcmcia libata scsi_mod 3c589_cs ide_gd_mod ide_cs ide_core sa1111_cs sa1100_cs sa11xx_base soc_common sa11x0_dma virt_dma usbcore usb_common > CPU: 0 PID: 0 Comm: swapper Not tainted 3.11.0+ #15 > Backtrace: > [] (dump_backtrace+0x0/0x114) from [] (show_stack+0x18/0x1c) r6:c0520824 r5:00000009 r4:00000000 > [] (show_stack+0x0/0x1c) from [] (dump_stack+0x20/0x28) > [] (dump_stack+0x0/0x28) from [] (warn_slowpath_common+0x68/0x88) > [] (warn_slowpath_common+0x0/0x88) from [] (warn_slowpath_null+0x24/0x28) > r8:00000000 r7:00000001 r6:00000006 r5:00004320 r4:c11c6580 > [] (warn_slowpath_null+0x0/0x28) from [] (tcp_fastretrans_alert+0x178/0x840) > [] (tcp_fastretrans_alert+0x0/0x840) from [] (tcp_ack+0xa14/0xc18) > [] (tcp_ack+0x0/0xc18) from [] (tcp_rcv_established+0x494/0x594) > [] (tcp_rcv_established+0x0/0x594) from [] (tcp_v6_do_rcv+0xd0/0x428) > [] (tcp_v6_do_rcv+0x0/0x428) from [] (tcp_v6_rcv+0x340/0x63c) > [] (tcp_v6_rcv+0x0/0x63c) from [] (ip6_input_finish+0x214/0x3c4) > [] (ip6_input_finish+0x0/0x3c4) from [] (ip6_input+0x64/0x74) > [] (ip6_input+0x0/0x74) from [] (ip6_rcv_finish+0x80/0x8c) > r4:c1c9ee20 > [] (ip6_rcv_finish+0x0/0x8c) from [] (ipv6_rcv+0x424/0x48c) > r4:c1c9ee20 > [] (ipv6_rcv+0x0/0x48c) from [] (__netif_receive_skb_core+0x618/0x688) > r8:0000dd86 r7:00000000 r6:c11f6800 r5:c05ee6cc r4:c05f1b98 > [] (__netif_receive_skb_core+0x0/0x688) from [] (__netif_receive_skb+0x78/0x80) > [] (__netif_receive_skb+0x0/0x80) from [] (process_backlog+0x94/0x14c) > r5:c06091e0 r4:c0609220 > [] (process_backlog+0x0/0x14c) from [] (net_rx_action+0x78/0x1ac) > [] (net_rx_action+0x0/0x1ac) from [] (__do_softirq+0xb4/0x198) > [] (__do_softirq+0x0/0x198) from [] (irq_exit+0x74/0xc8) > [] (irq_exit+0x0/0xc8) from [] (handle_IRQ+0x68/0x88) > r4:0000000b > [] (handle_IRQ+0x0/0x88) from [] (asm_do_IRQ+0x10/0x14) > r5:60000013 r4:c0246818 > [] (asm_do_IRQ+0x0/0x14) from [] (__irq_svc+0x2c/0x98) > Exception stack(0xc05e7f54 to 0xc05e7f9c) > 7f40: 00000000 00000000 00000000 > 7f60: 60000013 c05e6000 c06092a4 c05ee080 00000001 c0204000 6901b115 c05e0800 > 7f80: c05e7fb8 c05e7f9c c05e7f9c c020f348 c0246818 60000013 ffffffff > [] (cpu_startup_entry+0x0/0xe8) from [] (rest_init+0x64/0x7c) > r7:c05f3940 r6:c0922200 r5:c0609340 r4:c05ee0c0 > [] (rest_init+0x0/0x7c) from [] (start_kernel+0x350/0x3ac) > [] (start_kernel+0x0/0x3ac) from [] (0xc0208040) > ---[ end trace ab55f0e3f592fa5e ]--- there's been multiple reports about this one: https://bugzilla.redhat.com/show_bug.cgi?id=989251 http://bugzilla.kernel.org/show_bug.cgi?id=60779 Could you try Yuchung's debug patch? http://www.spinics.net/lists/netdev/msg250193.html thanks, Michele -- Michele Baldessari C2A5 9DA3 9961 4FFB E01B D0BC DDD4 DCCB 7515 5C6D