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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 39327C54EE9 for ; Mon, 19 Sep 2022 13:44:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229844AbiISNoo (ORCPT ); Mon, 19 Sep 2022 09:44:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52406 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229581AbiISNok (ORCPT ); Mon, 19 Sep 2022 09:44:40 -0400 Received: from www262.sakura.ne.jp (www262.sakura.ne.jp [202.181.97.72]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0DFF15F61 for ; Mon, 19 Sep 2022 06:44:37 -0700 (PDT) Received: from fsav314.sakura.ne.jp (fsav314.sakura.ne.jp [153.120.85.145]) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTP id 28JDiI3U060788; Mon, 19 Sep 2022 22:44:19 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) Received: from www262.sakura.ne.jp (202.181.97.72) by fsav314.sakura.ne.jp (F-Secure/fsigk_smtp/550/fsav314.sakura.ne.jp); Mon, 19 Sep 2022 22:44:18 +0900 (JST) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/fsav314.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 28JDiIvT060785 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NO); Mon, 19 Sep 2022 22:44:18 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) Message-ID: <83fc4085-60cc-fdc6-43ba-ac701cfde80c@I-love.SAKURA.ne.jp> Date: Mon, 19 Sep 2022 22:44:16 +0900 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 6.3; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.2.2 Subject: Re: [PATCH v2] lockdep: report name and key when look_up_lock_class() got confused Content-Language: en-US To: Peter Zijlstra Cc: Boqun Feng , Ingo Molnar , Will Deacon , Waiman Long , LKML References: <55111c45-0f8f-c6f9-640c-6919939b77dd@I-love.SAKURA.ne.jp> From: Tetsuo Handa In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022/09/19 19:48, Peter Zijlstra wrote: > On Mon, Sep 19, 2022 at 09:52:13AM +0900, Tetsuo Handa wrote: >> Printing this information will be helpful. >> >> ------------[ cut here ]------------ >> Looking for class "l2tp_sock" with key l2tp_socket_class, but found a different class "slock-AF_INET6" with the same key >> WARNING: CPU: 1 PID: 14195 at kernel/locking/lockdep.c:940 look_up_lock_class+0xcc/0x140 >> Modules linked in: >> CPU: 1 PID: 14195 Comm: a.out Not tainted 6.0.0-rc6-dirty #863 >> Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 >> RIP: 0010:look_up_lock_class+0xcc/0x140 >> >> Signed-off-by: Tetsuo Handa > > Urgh, you hitting that WARN enough times to want to improve it seems to > suggest your machine is quite sick. My machine is not sick at all. I just wanted this hint for debugging https://syzkaller.appspot.com/bug?extid=94cc2a66fc228b23f360 . In a world of debugging without vmcore, printing as much hint as possible is important. Therefore, WARN_ONCE() is more appreciated than WARN_ON_ONCE(). > > Anyway, patch is ok I suppose. Thank you. Please send this patch and https://lkml.kernel.org/r/9f42e8a5-f809-3f2c-0fda-b7657bc94eb3@I-love.SAKURA.ne.jp via your tree.