From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755872Ab3LVUlt (ORCPT ); Sun, 22 Dec 2013 15:41:49 -0500 Received: from aserp1040.oracle.com ([141.146.126.69]:39442 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753296Ab3LVUlr (ORCPT ); Sun, 22 Dec 2013 15:41:47 -0500 Message-ID: <52B74E81.4000305@oracle.com> Date: Sun, 22 Dec 2013 15:41:37 -0500 From: Sasha Levin User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.1.0 MIME-Version: 1.0 To: Greg KH , Tejun Heo CC: LKML Subject: kernfs: gpf when offlining cpus Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Source-IP: ucsinet21.oracle.com [156.151.31.93] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi all, While fuzzing with trinity inside a KVM tools guest running latest -next kernel, I've stumbled on the following spew. Beyond regular trinity fuzzing, the machine was in the middle of attempting to offline all of it's cpus (64 of them). [ 696.029538] general protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC [ 696.030042] Dumping ftrace buffer: [ 696.030042] (ftrace buffer empty) [ 696.030042] Modules linked in: [ 696.030042] CPU: 49 PID: 18975 Comm: trinity-c574 Tainted: G W 3.13.0-rc4- next-20131220-sasha-00013-gf9a57f1-dirty #6 [ 696.030042] task: ffff8801ced5b000 ti: ffff8801d384e000 task.ti: ffff8801d384e000 [ 696.030042] RIP: 0010:[] [] sysfs_file_ops+0x5b /0x70 [ 696.030042] RSP: 0018:ffff8801d384f858 EFLAGS: 00010202 [ 696.030042] RAX: 0000000000000000 RBX: ffff88010bd938e0 RCX: 0000000000000001 [ 696.030042] RDX: 6b6b6b6b6b6b6b6b RSI: ffff88007de8e6c8 RDI: 0000000000000286 [ 696.030042] RBP: ffff8801d384f868 R08: 0000000000000000 R09: 0000000000000003 [ 696.030042] R10: 0000000000000001 R11: 0000000000000000 R12: ffff88012c1537c8 [ 696.030042] R13: ffff88010bd938e0 R14: ffff88001b8ecb48 R15: ffff8801d384f8f0 [ 696.030042] FS: 00007f63221d6700(0000) GS:ffff88003f400000(0000) knlGS:000000000000 0000 [ 696.030042] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 696.030042] CR2: 000000000068c000 CR3: 00000001e8d66000 CR4: 00000000000006e0 [ 696.030042] DR0: 0000000000697000 DR1: 0000000000000000 DR2: 0000000000000000 [ 696.030042] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000010602 [ 696.030042] Stack: [ 696.030042] ffff8801d384f878 ffff88012c1537c8 ffff8801d384f898 ffffffff8135d68d [ 696.030042] ffff88001a21f900 ffff88012c1537c8 0000000000000001 ffff8801d384f978 [ 696.030042] ffff8801d384f8a8 ffffffff813608b9 ffff8801d384f928 ffffffff812fdfba [ 696.030042] Call Trace: [ 696.030042] [] sysfs_kf_seq_show+0x3d/0x130 [ 696.030042] [] kernfs_seq_show+0x29/0x30 [ 696.030042] [] seq_read+0x1ba/0x430 [ 696.030042] [] kernfs_fop_read+0x29/0x40 [ 696.030042] [] do_readv_writev+0x18c/0x2e0 [ 696.030042] [] ? kernfs_file_direct_read+0x130/0x130 [ 696.030042] [] ? alloc_pages_current+0x1f4/0x230 [ 696.030042] [] ? default_file_splice_read+0x12c/0x330 [ 696.030042] [] ? sched_clock_local+0x25/0x90 [ 696.030042] [] vfs_readv+0x43/0x50 [ 696.030042] [] default_file_splice_read+0x1f1/0x330 [ 696.030042] [] ? put_lock_stats+0xe/0x30 [ 696.030042] [] ? deactivate_slab+0x8cf/0x920 [ 696.030042] [] ? _raw_spin_unlock+0x35/0x60 [ 696.030042] [] ? deactivate_slab+0x8cf/0x920 [ 696.030042] [] ? dump_trace+0x2c1/0x2f0 [ 696.030042] [] ? get_partial_node+0x471/0x4b0 [ 696.030042] [] ? alloc_pipe_info+0x46/0xd0 [ 696.030042] [] ? set_track+0xab/0x100 [ 696.030042] [] ? __slab_alloc+0x677/0x6c0 [ 696.030042] [] ? trace_hardirqs_on+0xd/0x10 [ 696.030042] [] ? __lock_release+0x1da/0x1f0 [ 696.030042] [] ? __do_page_fault+0x530/0x5a0 [ 696.030042] [] ? alloc_pipe_info+0x46/0xd0 [ 696.030042] [] ? page_cache_pipe_buf_release+0x30/0x30 [ 696.030042] [] do_splice_to+0x8a/0xa0 [ 696.030042] [] splice_direct_to_actor+0xd3/0x1e0 [ 696.030042] [] ? splice_from_pipe_begin+0x20/0x20 [ 696.030042] [] do_splice_direct+0xa6/0xc0 [ 696.030042] [] ? rw_verify_area+0xcc/0x100 [ 696.030042] [] do_sendfile+0x1d7/0x3a0 [ 696.030042] [] SyS_sendfile64+0x61/0xc0 [ 696.030042] [] tracesys+0xdd/0xe2 [ 696.030042] Code: e8 eb 12 e3 ff 85 c0 75 17 be 21 00 00 00 48 c7 c7 1b 0d 7c 85 e8 b6 23 dd ff 66 0f 1f 44 00 00 48 8b 53 28 31 c0 48 85 d2 74 04 <48> 8b 42 08 48 83 c4 0 8 5b c9 c3 66 2e 0f 1f 84 00 00 00 00 00 [ 696.030042] RIP [] sysfs_file_ops+0x5b/0x70 [ 696.030042] RSP Thanks, Sasha