From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,UNPARSEABLE_RELAY,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3482DC2D0E4 for ; Tue, 24 Nov 2020 13:55:12 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 95F3F20782 for ; Tue, 24 Nov 2020 13:55:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 95F3F20782 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 9C1226B0142; Tue, 24 Nov 2020 08:55:10 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 9957E6B0144; Tue, 24 Nov 2020 08:55:10 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8D34C6B0145; Tue, 24 Nov 2020 08:55:10 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0062.hostedemail.com [216.40.44.62]) by kanga.kvack.org (Postfix) with ESMTP id 771FB6B0142 for ; Tue, 24 Nov 2020 08:55:10 -0500 (EST) Received: from smtpin27.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 3A2843637 for ; Tue, 24 Nov 2020 13:55:10 +0000 (UTC) X-FDA: 77519458380.27.food89_400cf632736e Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin27.hostedemail.com (Postfix) with ESMTP id E4DB23D663 for ; Tue, 24 Nov 2020 13:55:09 +0000 (UTC) X-HE-Tag: food89_400cf632736e X-Filterd-Recvd-Size: 4736 Received: from out4436.biz.mail.alibaba.com (out4436.biz.mail.alibaba.com [47.88.44.36]) by imf16.hostedemail.com (Postfix) with ESMTP for ; Tue, 24 Nov 2020 13:55:08 +0000 (UTC) X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R271e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=alimailimapcm10staff010182156082;MF=alex.shi@linux.alibaba.com;NM=1;PH=DS;RN=8;SR=0;TI=SMTPD_---0UGQEzw8_1606226103; Received: from IT-FVFX43SYHV2H.lan(mailfrom:alex.shi@linux.alibaba.com fp:SMTPD_---0UGQEzw8_1606226103) by smtp.aliyun-inc.com(127.0.0.1); Tue, 24 Nov 2020 21:55:04 +0800 Subject: Re: INFO: task can't die in shrink_inactive_list (2) From: Alex Shi To: Andrew Morton , syzbot Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, syzkaller-bugs@googlegroups.com, Hugh Dickins , Johannes Weiner , peterz@infradead.org References: <0000000000000340a105b49441d3@google.com> <20201123195452.8ecd01b1fc2ce287dfd6a0d5@linux-foundation.org> <97ca8171-c3eb-6462-fcb6-fee53287868a@linux.alibaba.com> Message-ID: <4ff2d017-c9c3-e4fa-2d71-5f000188d3a4@linux.alibaba.com> Date: Tue, 24 Nov 2020 21:53:04 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: <97ca8171-c3eb-6462-fcb6-fee53287868a@linux.alibaba.com> Content-Type: text/plain; charset=gbk Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: =D4=DA 2020/11/24 =CF=C2=CE=E78:00, Alex Shi =D0=B4=B5=C0: >>> >>> syzbot found the following issue on: >>> >>> HEAD commit: 03430750 Add linux-next specific files for 20201116 >>> git tree: linux-next >>> console output: https://syzkaller.appspot.com/x/log.txt?x=3D13f80e5e5= 00000 >>> kernel config: https://syzkaller.appspot.com/x/.config?x=3Da1c4c3f27= 041fdb8 >>> dashboard link: https://syzkaller.appspot.com/bug?extid=3De5a33e700b1= dd0da20a2 >>> compiler: gcc (GCC) 10.1.0-syz 20200507 >>> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=3D12f7bc5= a500000 >>> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=3D10934cf25= 00000 > CC Peter Zijlstra. >=20 > I found next-20200821 had a very very similar ops as this. > https://groups.google.com/g/syzkaller-upstream-moderation/c/S0pyqK1dZv8= /m/dxMoEhGdAQAJ > So does this means the bug exist for long time from 5.9-rc1? 5.8 kernel sometime also failed on this test on my 2 cpus vm guest with 2= g memory: Thanks Alex [ 5875.750929][ T946] INFO: task repro:31866 blocked for more than 143 s= econds. [ 5875.751618][ T946] Not tainted 5.8.0 #6 [ 5875.752046][ T946] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"= disables th. [ 5875.752845][ T946] repro D12088 31866 1 0x80004086 [ 5875.753436][ T946] Call Trace: [ 5875.753747][ T946] __schedule+0x394/0x950 [ 5875.774033][ T946] ? __mutex_lock+0x46f/0x9c0 [ 5875.774481][ T946] ? blkdev_put+0x18/0x120 [ 5875.774894][ T946] schedule+0x37/0xe0 [ 5875.775260][ T946] schedule_preempt_disabled+0xf/0x20 [ 5875.775753][ T946] __mutex_lock+0x474/0x9c0 [ 5875.776174][ T946] ? lock_acquire+0xa7/0x390 [ 5875.776602][ T946] ? locks_remove_file+0x1e7/0x2d0 [ 5875.777079][ T946] ? blkdev_put+0x18/0x120 [ 5875.777485][ T946] blkdev_put+0x18/0x120 [ 5875.777880][ T946] blkdev_close+0x1f/0x30 [ 5875.778281][ T946] __fput+0xf0/0x260 [ 5875.778639][ T946] task_work_run+0x68/0xb0 [ 5875.779054][ T946] do_exit+0x3df/0xce0 [ 5875.779430][ T946] ? get_signal+0x11d/0xca0 [ 5875.779846][ T946] do_group_exit+0x42/0xb0 [ 5875.780261][ T946] get_signal+0x16a/0xca0 [ 5875.780662][ T946] ? handle_mm_fault+0xc8f/0x19c0 [ 5875.781134][ T946] do_signal+0x2b/0x8e0 [ 5875.781521][ T946] ? trace_hardirqs_off+0xe/0xf0 [ 5875.781989][ T946] __prepare_exit_to_usermode+0xef/0x1f0 [ 5875.782512][ T946] ? asm_exc_page_fault+0x8/0x30 [ 5875.782979][ T946] prepare_exit_to_usermode+0x5/0x30 [ 5875.783461][ T946] asm_exc_page_fault+0x1e/0x30 [ 5875.783909][ T946] RIP: 0033:0x428dd7 [ 5875.794899][ T946] Code: Bad RIP value. [ 5875.795290][ T946] RSP: 002b:00007f37c99e0d78 EFLAGS: 00010202 [ 5875.795858][ T946] RAX: 0000000020000080 RBX: 0000000000000000 RCX: 0= 000000076656f [ 5875.796588][ T946] RDX: 000000000000000c RSI: 00000000004b2370 RDI: 0= 0000000200000 [ 5875.797326][ T946] RBP: 00007f37c99e0da0 R08: 00007f37c99e1700 R09: 0= 0007f37c99e10 [ 5875.798063][ T946] R10: 00007f37c99e19d0 R11: 0000000000000202 R12: 0= 0000000000000 [ 5875.798802][ T946] R13: 0000000000021000 R14: 0000000000000000 R15: 0= 0007f37c99e10