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 F31CEC3DA79 for ; Thu, 29 Dec 2022 12:34:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233301AbiL2MeR (ORCPT ); Thu, 29 Dec 2022 07:34:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33336 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230214AbiL2MeI (ORCPT ); Thu, 29 Dec 2022 07:34:08 -0500 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0A7B21054C; Thu, 29 Dec 2022 04:33:58 -0800 (PST) Received: from canpemm500002.china.huawei.com (unknown [172.30.72.53]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4NjSTY2XcQzJqRk; Thu, 29 Dec 2022 20:32:49 +0800 (CST) Received: from [10.174.151.185] (10.174.151.185) by canpemm500002.china.huawei.com (7.192.104.244) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.34; Thu, 29 Dec 2022 20:33:55 +0800 Subject: Re: [PATCH] mce: fix missing stack-dumping in mce_panic() To: Borislav Petkov CC: "Luck, Tony" , "x86@kernel.org" , "hpa@zytor.com" , "linux-edac@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "tglx@linutronix.de" , "mingo@redhat.com" , "dave.hansen@linux.intel.com" References: <20221202163728.392509-1-linmiaohe@huawei.com> <5cf492bf-9807-a091-6ac2-a953fce276da@huawei.com> From: Miaohe Lin Message-ID: <1e97c11d-99b6-c06f-b67f-c56ba6653d27@huawei.com> Date: Thu, 29 Dec 2022 20:33:55 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.151.185] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To canpemm500002.china.huawei.com (7.192.104.244) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022/12/29 19:54, Borislav Petkov wrote: > On Sat, Dec 03, 2022 at 10:19:32AM +0800, Miaohe Lin wrote: >> So I think it's better to have at least one stack dumps. Also what the commit >> 6e6f0a1f0fa6 ("panic: don't print redundant backtraces on oops") and commit >> 026ee1f66aaa ("panic: fix stack dump print on direct call to panic()") want >> to do is avoiding nested stack-dumping to have the original oops data being >> scrolled away on a 80x50 screen but to have *at least one backtraces*. So >> this patch acts more like a BUGFIX to ensure having at least one backtraces >> in mce_panic(). > Many thanks for your reply. :) > So which commit broke this? > I think it should be Fixes: 6e6f0a1f0fa6 ("panic: don't print redundant backtraces on oops") as there's missing stack-dumping in mce_panic() since then. Should I resend the patch with above Fixes tag attached? > One of the two above or > > 004429956b48 ("handle recursive calls to bust_spinlocks()") > > or > > d896a940ef4f ("x86, mce: remove oops_begin() use in 64bit machine check") > > or...? > > By looking at their dates, they're pretty much too old so that this can > go to *all* stable kernels. Yes, it should be a really old problem. And it seems it's unnoticed yet because mce should be a really rare event and corresponding dump-stacking might not be that attractive at that time. Thanks! Miaohe Lin