Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753964Ab3HEPuq (ORCPT ); Mon, 5 Aug 2013 11:50:46 -0400 Received: from icebox.esperi.org.uk ([81.187.191.129]:57935 "EHLO mail.esperi.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752941Ab3HEPuo (ORCPT ); Mon, 5 Aug 2013 11:50:44 -0400 From: Nix To: Jeff Layton Cc: NFS list , Linux Kernel Mailing List , dhowells@redhat.com Subject: Re: [3.10.4] NFS locking panic, plus persisting NFS shutdown panic from 3.9.* References: <8761vlv4z9.fsf@spindle.srvr.nix> <20130805084436.69ee4415@corrin.poochiereds.net> <87siyotcri.fsf@spindle.srvr.nix> <20130805110427.509db424@tlielax.poochiereds.net> <20130805111106.73d6ab90@tlielax.poochiereds.net> Emacs: there's a reason it comes with a built-in psychotherapist. Date: Mon, 05 Aug 2013 16:50:37 +0100 In-Reply-To: <20130805111106.73d6ab90@tlielax.poochiereds.net> (Jeff Layton's message of "Mon, 5 Aug 2013 11:11:06 -0400") Message-ID: <87zjswrvaq.fsf@spindle.srvr.nix> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3.50 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-DCC-wuwien-Metrics: spindle 1290; Body=4 Fuz1=4 Fuz2=4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6704 Lines: 119 On 5 Aug 2013, Jeff Layton said: > On Mon, 5 Aug 2013 11:04:27 -0400 > Jeff Layton wrote: > >> On Mon, 05 Aug 2013 15:48:01 +0100 >> Nix wrote: >> >> > On 5 Aug 2013, Jeff Layton stated: >> > >> > > On Sun, 04 Aug 2013 16:40:58 +0100 >> > > Nix wrote: >> > > >> > >> I just got this panic on 3.10.4, in the middle of a large parallel >> > >> compilation (of Chromium, as it happens) over NFSv3: >> > >> >> > >> [16364.527516] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 >> > >> [16364.527571] IP: [] nlmclnt_setlockargs+0x55/0xcf >> > >> [16364.527611] PGD 0 >> > >> [16364.527626] Oops: 0000 [#1] PREEMPT SMP >> > >> [16364.527656] Modules linked in: [last unloaded: microcode] >> > >> [16364.527690] CPU: 0 PID: 17034 Comm: flock Not tainted 3.10.4-05315-gf4ce424-dirty #1 >> > >> [16364.527730] Hardware name: System manufacturer System Product Name/P8H61-MX USB3, BIOS 0506 08/10/2012 >> > >> [16364.527775] task: ffff88041a97ad60 ti: ffff8803501d4000 task.ti: ffff8803501d4000 >> > >> [16364.527813] RIP: 0010:[] [] nlmclnt_setlockargs+0x55/0xcf >> > >> [16364.527860] RSP: 0018:ffff8803501d5c58 EFLAGS: 00010282 >> > >> [16364.527889] RAX: ffff88041a97ad60 RBX: ffff8803e49c8800 RCX: 0000000000000000 >> > >> [16364.527926] RDX: 0000000000000000 RSI: 000000000000004a RDI: ffff8803e49c8b54 >> > >> [16364.527962] RBP: ffff8803501d5c68 R08: 0000000000015720 R09: 0000000000000000 >> > >> [16364.527998] R10: 00007ffffffff000 R11: ffff8803501d5d58 R12: ffff8803501d5d58 >> > >> [16364.528034] R13: ffff88041bd2bc00 R14: 0000000000000000 R15: ffff8803fc9e2900 >> > >> [16364.528070] FS: 0000000000000000(0000) GS:ffff88042fa00000(0000) knlGS:0000000000000000 >> > >> [16364.528111] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >> > >> [16364.528142] CR2: 0000000000000008 CR3: 0000000001c0b000 CR4: 00000000001407f0 >> > >> [16364.528177] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 >> > >> [16364.528214] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 >> > >> [16364.528303] Stack: >> > >> [16364.528316] ffff8803501d5d58 ffff8803e49c8800 ffff8803501d5cd8 ffffffff81245418 >> > >> [16364.528369] 0000000000000000 ffff8803516f0bc0 ffff8803d7b7b6c0 ffffffff81215c81 >> > >> [16364.528418] ffff880300000007 ffff88041bd2bdc8 ffff8801aabe9650 ffff8803fc9e2900 >> > >> [16364.528467] Call Trace: >> > >> [16364.528485] [] nlmclnt_proc+0x148/0x5fb >> > >> [16364.528516] [] ? nfs_put_lock_context+0x69/0x6e >> > >> [16364.528550] [] nfs3_proc_lock+0x21/0x23 >> > >> [16364.528581] [] do_unlk+0x96/0xb2 >> > >> [16364.528608] [] nfs_flock+0x5a/0x71 >> > >> [16364.528637] [] locks_remove_flock+0x9e/0x113 >> > >> [16364.528668] [] __fput+0xb6/0x1e6 >> > >> [16364.528695] [] ____fput+0xe/0x10 >> > >> [16364.528724] [] task_work_run+0x7e/0x98 >> > >> [16364.528754] [] do_exit+0x3cc/0x8fa >> > >> [16364.528782] [] ? SyS_wait4+0xa5/0xc2 >> > >> [16364.528811] [] do_group_exit+0x6f/0xa2 >> > >> [16364.528843] [] SyS_exit_group+0x17/0x17 >> > >> [16364.528876] [] system_call_fastpath+0x16/0x1b >> > >> [16364.528907] Code: 00 00 65 48 8b 04 25 c0 b8 00 00 48 8b 72 20 48 81 ee c0 01 00 00 f3 a4 48 8d bb 54 03 00 00 be 4a 00 00 00 48 8b 90 68 05 00 00 <48> 8b 52 08 48 89 bb d0 00 00 00 48 83 c2 45 48 89 53 38 48 8b >> > >> [16364.529176] RIP [] nlmclnt_setlockargs+0x55/0xcf >> > >> [16364.529264] RSP >> > >> [16364.529283] CR2: 0000000000000008 >> > >> [16364.539039] ---[ end trace 5a73fddf23441377 ]--- [...] > The listing and disassembly from nlmclnt_proc is not terribly > interesting unfortunately. You really want to do the listing and > disassembly of the RIP at panic time (nlmclnt_setlockargs+0x55). Oh, sorry! Wrong end of the oops :) 0xffffffff81245157 is in nlmclnt_setlockargs (fs/lockd/clntproc.c:131). 126 struct nlm_args *argp = &req->a_args; 127 struct nlm_lock *lock = &argp->lock; 128 129 nlmclnt_next_cookie(&argp->cookie); 130 memcpy(&lock->fh, NFS_FH(file_inode(fl->fl_file)), sizeof(struct nfs_fh)); 131 lock->caller = utsname()->nodename; 132 lock->oh.data = req->a_owner; 133 lock->oh.len = snprintf(req->a_owner, sizeof(req->a_owner), "%u@%s", 134 (unsigned int)fl->fl_u.nfs_fl.owner->pid, 135 utsname()->nodename); 0xffffffff81245102 <+0>: callq 0xffffffff81613b00 <__fentry__> 0xffffffff81245107 <+5>: push %rbp 0xffffffff81245108 <+6>: mov %rsp,%rbp 0xffffffff8124510b <+9>: push %r12 0xffffffff8124510d <+11>: mov %rsi,%r12 0xffffffff81245110 <+14>: push %rbx 0xffffffff81245111 <+15>: mov %rdi,%rbx 0xffffffff81245114 <+18>: lea 0x10(%rdi),%rdi 0xffffffff81245118 <+22>: callq 0xffffffff812450df 0xffffffff8124511d <+27>: mov 0x60(%r12),%rdx 0xffffffff81245122 <+32>: lea 0x44(%rbx),%rax 0xffffffff81245126 <+36>: mov %rax,%rdi 0xffffffff81245129 <+39>: mov $0x82,%ecx 0xffffffff8124512e <+44>: mov %gs:0xb8c0,%rax 0xffffffff81245137 <+53>: mov 0x20(%rdx),%rsi 0xffffffff8124513b <+57>: sub $0x1c0,%rsi 0xffffffff81245142 <+64>: rep movsb %ds:(%rsi),%es:(%rdi) 0xffffffff81245144 <+66>: lea 0x354(%rbx),%rdi 0xffffffff8124514b <+73>: mov $0x4a,%esi 0xffffffff81245150 <+78>: mov 0x568(%rax),%rdx -> 0xffffffff81245157 <+85>: mov 0x8(%rdx),%rdx 0xffffffff8124515b <+89>: mov %rdi,0xd0(%rbx) 0xffffffff81245162 <+96>: add $0x45,%rdx (aside: wish GDB reported those offsets in hex, or the kernel reported them in decimal. Every time I look at these I forget to convert and get confused...) I wonder if req is NULL (possible if the assignment to argp at the top of the function's been pushed down by the optimizer). Time to stick a printk() in and find out (after work is over so I can reboot this box like billy-o). -- NULL && (void) -- 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/