From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f49.google.com (mail-wm0-f49.google.com [74.125.82.49]) by kanga.kvack.org (Postfix) with ESMTP id C35F46B0009 for ; Wed, 27 Jan 2016 13:07:33 -0500 (EST) Received: by mail-wm0-f49.google.com with SMTP id n5so39119034wmn.0 for ; Wed, 27 Jan 2016 10:07:33 -0800 (PST) Received: from mail-wm0-x236.google.com (mail-wm0-x236.google.com. [2a00:1450:400c:c09::236]) by mx.google.com with ESMTPS id y41si12446308wmh.107.2016.01.27.10.07.32 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 27 Jan 2016 10:07:32 -0800 (PST) Received: by mail-wm0-x236.google.com with SMTP id n5so39118458wmn.0 for ; Wed, 27 Jan 2016 10:07:32 -0800 (PST) MIME-Version: 1.0 In-Reply-To: References: From: Dmitry Vyukov Date: Wed, 27 Jan 2016 19:07:12 +0100 Message-ID: Subject: Re: mm: WARNING in __delete_from_page_cache Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: syzkaller Cc: Matthew Wilcox , Alexander Viro , "linux-fsdevel@vger.kernel.org" , LKML , Andrew Morton , Michal Hocko , Jan Kara , Vlastimil Babka , "Kirill A. Shutemov" , Matthew Wilcox , Junichi Nomura , Greg Thelen , Dave Hansen , "linux-mm@kvack.org" , Kostya Serebryany , Alexander Potapenko , Sasha Levin On Wed, Jan 27, 2016 at 7:02 PM, Ross Zwisler wrote: > On Sun, Jan 24, 2016 at 3:48 AM, Dmitry Vyukov wrote: >> Hello, >> >> The following program triggers WARNING in __delete_from_page_cache: >> >> ------------[ cut here ]------------ >> WARNING: CPU: 0 PID: 7676 at mm/filemap.c:217 >> __delete_from_page_cache+0x9f6/0xb60() >> Modules linked in: >> CPU: 0 PID: 7676 Comm: a.out Not tainted 4.4.0+ #276 >> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 >> 00000000ffffffff ffff88006d3f7738 ffffffff82999e2d 0000000000000000 >> ffff8800620a0000 ffffffff86473d20 ffff88006d3f7778 ffffffff81352089 >> ffffffff81658d36 ffffffff86473d20 00000000000000d9 ffffea0000009d60 >> Call Trace: >> [< inline >] __dump_stack lib/dump_stack.c:15 >> [] dump_stack+0x6f/0xa2 lib/dump_stack.c:50 >> [] warn_slowpath_common+0xd9/0x140 kernel/panic.c:482 >> [] warn_slowpath_null+0x29/0x30 kernel/panic.c:515 >> [] __delete_from_page_cache+0x9f6/0xb60 mm/filemap.c:217 >> [] delete_from_page_cache+0x112/0x200 mm/filemap.c:244 >> [] __dax_fault+0x859/0x1800 fs/dax.c:487 >> [] blkdev_dax_fault+0x26/0x30 fs/block_dev.c:1730 >> [< inline >] wp_pfn_shared mm/memory.c:2208 >> [] do_wp_page+0xc85/0x14f0 mm/memory.c:2307 >> [< inline >] handle_pte_fault mm/memory.c:3323 >> [< inline >] __handle_mm_fault mm/memory.c:3417 > > Having inline functions represented in the stack trace and having file > names with line numbers seems really useful - how did you get this > output? Is this a feature of some kernel patch applied for syzkaller? I pipe normal kernel output through this script: https://github.com/google/sanitizers/blob/master/address-sanitizer/tools/kasan_symbolize.py If you are in linux source dir with vmlinux and modules, then you just do: $ cat crash | kasan_symbolize.py -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org