From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King - ARM Linux Subject: Re: [BUG 4.4-rc4]: oops around sock_recvmsg Date: Thu, 7 Jan 2016 09:42:50 +0000 Message-ID: <20160107094249.GD19062@n2100.arm.linux.org.uk> References: <87d1td6a1l.fsf@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-arm-kernel@lists.infradead.org, netdev@vger.kernel.org To: Holger Schurig Return-path: Received: from pandora.arm.linux.org.uk ([78.32.30.218]:46136 "EHLO pandora.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751121AbcAGJm4 (ORCPT ); Thu, 7 Jan 2016 04:42:56 -0500 Content-Disposition: inline In-Reply-To: <87d1td6a1l.fsf@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, Jan 07, 2016 at 09:58:14AM +0100, Holger Schurig wrote: > This oops with sock_recvmsg() inside it now happened 3 times, just not > at my test box, only at one very remote from me. That's also the reason > why the log is truncated, the people that grabbed it from Windows with > Putty over the serial line just did give this to me ... :-( It's a little incomplete, but luckily we have some useful information buried in it. > BTW, are several places with "???" below. Is this just a "grabbing from > Windows" artifact? Or an indication that the processor/memory of the > system got completely insane? No idea, sorry. ... > [] (do_page_fault) from [] (do_PrefetchAbort+0x3c/0xa0) > r10:c0037790 r9:00000001 r8:00000001 r7:ed9a9bf8 r6:fffffffe r5:c055fbc4 > r4:00000007 > [] (do_PrefetchAbort) from [] (__pabt_svc+0x4c/0x80) > Exception stack(0xed9a9bf8 to 0xed9a9c40) > 9be0:?????????????????????????????????????????????????????? ebaa3d18 00000001 > 9c00: 00000001 00000304 ee1c2c04 fffffff3 00000001 00000304 00000001 00000001 > 9c20: c0037790 ed9a9c74 ffffffff ed9a9c48 c004febc fffffffe 800100b3 ffffffff These are the registers - r0 to pc, cpsr and "orig_r0". The PC value triggering the prefetch abort was 0xfffffffe, and the link register was 0xc004febc - this should be the instruction after the call. To do any diagnosis, I'd need the disassembly around the link register - it may be best if you can send me the vmlinux file itself by private mail in case I need to reference other functions too. I've left the remainder of the trace in place - please retain it when you reply with the disassembly so I can refer directly to it in my next reply without having to find the previous email. Thanks. > r7:ed9a9c2c r6:ffffffff r5:800100b3 r4:fffffffe > [] (__wake_up_common) from [] (__wake_up_sync_key+0x4c/0x60) > r10:00000000 r9:00000010 r8:00000304 r7:00000001 r6:00000001 r5:a0010013 > r4:ee1c2c00 r3:00000001 > [] (__wake_up_sync_key) from [] (unix_write_space+0x60/0x90) > r8:ed9a9df4 r7:eb9decc0 r6:ed95d5e4 r5:ed95f02c r4:ed95ef80 > [] (unix_write_space) from [] (sock_wfree+0x4c/0x84) > r4:ed95ef80 r3:c03cf970 > [] (sock_wfree) from [] (unix_destruct_scm+0x6c/0x74) > r5:00000000 r4:eb9decc0 > [] (unix_destruct_scm) from [] (skb_release_head_state+0x70/0xb0) > r4:eb9decc0 > [] (skb_release_head_state) from [] (skb_release_all+0x14/0x2c) > r4:eb9decc0 r3:00000001 > [] (skb_release_all) from [] (__kfree_skb+0x14/0x94) > r4:eb9decc0 r3:00000001 > [] (__kfree_skb) from [] (consume_skb+0x58/0x5c) > r4:ed95d400 r3:00000001 > [] (consume_skb) from [] (unix_stream_read_generic+0x5ec/0x750) > [] (unix_stream_read_generic) from [] (unix_stream_recvmsg+0x50/0x5c) > r10:ecc13800 r9:ed9a9e88 r8:bee12988 r7:00000040 r6:ecc13800 r5:ed9a9f4c > r4:00001000 > [] (unix_stream_recvmsg) from [] (sock_recvmsg+0x18/0x1c) > r7:bee1296c r6:00000040 r5:00000000 r4:ed9a9f4c > [] (sock_recvmsg) from [] (___sys_recvmsg+0x98/0x170) > [] (___sys_recvmsg) from [] (__sys_recvmsg+0x44/0x68) > r10:00000000 r9:ed9a8000 r8:c000f1e4 r7:00000129 r6:bee1296c r5:00000000 > r4:ecc13800 > [] (__sys_recvmsg) from [] (SyS_recvmsg+0x10/0x14) > r6:b6f7df10 r5:81196c08 r4:bee12988 > [] (SyS_recvmsg) from [] (ret_fast_syscall+0x0/0x3c) -- RMK's Patch system: http://www.arm.linux.org.uk/developer/patches/ FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up according to speedtest.net.