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=-10.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 866CBC433B4 for ; Mon, 5 Apr 2021 11:45:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6474B6120E for ; Mon, 5 Apr 2021 11:45:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236957AbhDELpg (ORCPT ); Mon, 5 Apr 2021 07:45:36 -0400 Received: from www262.sakura.ne.jp ([202.181.97.72]:57371 "EHLO www262.sakura.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235438AbhDELpe (ORCPT ); Mon, 5 Apr 2021 07:45:34 -0400 Received: from fsav305.sakura.ne.jp (fsav305.sakura.ne.jp [153.120.85.136]) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTP id 135Bj15O094730; Mon, 5 Apr 2021 20:45:01 +0900 (JST) (envelope-from penguin-kernel@i-love.sakura.ne.jp) Received: from www262.sakura.ne.jp (202.181.97.72) by fsav305.sakura.ne.jp (F-Secure/fsigk_smtp/550/fsav305.sakura.ne.jp); Mon, 05 Apr 2021 20:45:01 +0900 (JST) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/fsav305.sakura.ne.jp) Received: from [192.168.1.9] (M106072142033.v4.enabler.ne.jp [106.72.142.33]) (authenticated bits=0) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTPSA id 135Bj0sU094716 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NO); Mon, 5 Apr 2021 20:45:01 +0900 (JST) (envelope-from penguin-kernel@i-love.sakura.ne.jp) Subject: Re: [PATCH v5] lockdep: Allow tuning tracing capacity constants. From: Tetsuo Handa To: Dmitry Vyukov Cc: Ingo Molnar , Will Deacon , Andrew Morton , LKML , Peter Zijlstra , Linus Torvalds References: <20210208102551.5256-1-penguin-kernel@I-love.SAKURA.ne.jp> <3d86eb9c-ab6f-c402-a326-a6376e9ea082@i-love.sakura.ne.jp> Message-ID: <968067e3-d87b-b04d-c2ba-fad04c439130@i-love.sakura.ne.jp> Date: Mon, 5 Apr 2021 20:44:58 +0900 User-Agent: Mozilla/5.0 (Windows NT 6.3; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.9.0 MIME-Version: 1.0 In-Reply-To: <3d86eb9c-ab6f-c402-a326-a6376e9ea082@i-love.sakura.ne.jp> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Dmitry, I've just sent this patch to tomoyo-test1.git tree, for finding bugs (which previously could not be found due to lack of this patch) in linux-next.git will be helpful anyway. Since this patch should appear in tomorrow's linux-next.git , please prepare syzkaller for tuning appropriate values (default value + 1 should be OK). On 2021/03/31 19:58, Tetsuo Handa wrote: > Peter, are you there? > > If you keep silence, we will assume that applying this patch is the way to go. > > On 2021/03/20 16:34, Dmitry Vyukov wrote: >> On Mon, Feb 8, 2021 at 11:29 AM Tetsuo Handa >> wrote: >>> >>> Since syzkaller continues various test cases until the kernel crashes, >>> syzkaller tends to examine more locking dependencies than normal systems. >>> As a result, syzbot is reporting that the fuzz testing was terminated >>> due to hitting upper limits lockdep can track [1] [2] [3]. Since analysis >>> via /proc/lockdep* did not show any obvious culprit [4] [5], we have no >>> choice but allow tuning tracing capacity constants. >>> >>> [1] https://syzkaller.appspot.com/bug?id=3d97ba93fb3566000c1c59691ea427370d33ea1b >>> [2] https://syzkaller.appspot.com/bug?id=381cb436fe60dc03d7fd2a092b46d7f09542a72a >>> [3] https://syzkaller.appspot.com/bug?id=a588183ac34c1437fc0785e8f220e88282e5a29f >>> [4] https://lkml.kernel.org/r/4b8f7a57-fa20-47bd-48a0-ae35d860f233@i-love.sakura.ne.jp >>> [5] https://lkml.kernel.org/r/1c351187-253b-2d49-acaf-4563c63ae7d2@i-love.sakura.ne.jp >>> >>> Reported-by: syzbot >>> Reported-by: syzbot >>> Reported-by: syzbot >>> References: https://lkml.kernel.org/r/1595640639-9310-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp >>> Signed-off-by: Tetsuo Handa >>> Acked-by: Dmitry Vyukov >> >> Peter, ping. >> Please at least provide some feedback. >> This is still the top crasher on syzbot and harms testing of the whole >> kernel. I am periodically thinking of disabling LOCKDEP on syzbot as >> harming more than helping, but so far talking myself out of it because >> it will likely be broken more when we try to re-enable it and I still >> hope for a timely resolution of this issue. >> >