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=-5.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,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 1CCD0C433E6 for ; Mon, 8 Feb 2021 20:11:48 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A72A664E5D for ; Mon, 8 Feb 2021 20:11:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A72A664E5D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 156DC6B0005; Mon, 8 Feb 2021 15:11:47 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 108E56B006C; Mon, 8 Feb 2021 15:11:47 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id F38CD6B006E; Mon, 8 Feb 2021 15:11:46 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0212.hostedemail.com [216.40.44.212]) by kanga.kvack.org (Postfix) with ESMTP id DEBD56B0005 for ; Mon, 8 Feb 2021 15:11:46 -0500 (EST) Received: from smtpin18.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id A7774184FEC94 for ; Mon, 8 Feb 2021 20:11:46 +0000 (UTC) X-FDA: 77796196212.18.floor28_1a035e727601 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin18.hostedemail.com (Postfix) with ESMTP id 7A529100ED0C7 for ; Mon, 8 Feb 2021 20:11:46 +0000 (UTC) X-HE-Tag: floor28_1a035e727601 X-Filterd-Recvd-Size: 3865 Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by imf25.hostedemail.com (Postfix) with ESMTP for ; Mon, 8 Feb 2021 20:11:45 +0000 (UTC) IronPort-SDR: sPa1PTzpCIPsrakV9mTjRWjDaymIwTWaBNhf23pJyVkDKpHEmH6qcsY/gYxdgm1WsRu+TeussM oPLk1uwwgFSA== X-IronPort-AV: E=McAfee;i="6000,8403,9889"; a="180994923" X-IronPort-AV: E=Sophos;i="5.81,163,1610438400"; d="scan'208";a="180994923" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Feb 2021 12:11:35 -0800 IronPort-SDR: FvGwoSxWRzF4E22TLsPk5Oq5ub9aCuUNYVsQ16qDvTKMmDkANo5/BNExWtb6eKkve17QuOBXbk Inp+fnpUwetw== X-IronPort-AV: E=Sophos;i="5.81,163,1610438400"; d="scan'208";a="374625160" Received: from yyu32-mobl1.amr.corp.intel.com (HELO [10.251.11.33]) ([10.251.11.33]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Feb 2021 12:11:34 -0800 Subject: Re: [PATCH v19 06/25] x86/cet: Add control-protection fault handler To: Borislav Petkov Cc: x86@kernel.org, "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann , Andy Lutomirski , Balbir Singh , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H.J. Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Peter Zijlstra , Randy Dunlap , "Ravi V. Shankar" , Vedvyas Shanbhogue , Dave Martin , Weijiang Yang , Pengfei Xu , Michael Kerrisk References: <20210203225547.32221-1-yu-cheng.yu@intel.com> <20210203225547.32221-7-yu-cheng.yu@intel.com> <20210205135927.GH17488@zn.tnic> <2d829cba-784e-635a-e0c5-a7b334fa9b40@intel.com> <20210208182009.GE18227@zn.tnic> <690bc3b9-2890-e68d-5e4b-cda5c21b496b@intel.com> <20210208185341.GF18227@zn.tnic> <0e0c9e9d-aee1-ad1e-6c63-21b58a52163f@intel.com> <20210208194854.GI18227@zn.tnic> From: "Yu, Yu-cheng" Message-ID: Date: Mon, 8 Feb 2021 12:11:32 -0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.7.0 MIME-Version: 1.0 In-Reply-To: <20210208194854.GI18227@zn.tnic> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit 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: On 2/8/2021 11:48 AM, Borislav Petkov wrote: > On Mon, Feb 08, 2021 at 11:23:18AM -0800, Yu, Yu-cheng wrote: >> exc_general_protection() and do_trap() both call show_signal(), which >> then calls printk_ratelimit(). > > You could've done some git archeology and could've found > > abd4f7505baf ("x86: i386-show-unhandled-signals-v3") > > which explains why that ratelimiting is needed. > >> For example, if a shell script, in a loop re-starts an app when it >> exits, and the app is causing control-protection fault. The log >> messages should be rate limited. > > I think you should be able to get where I'm going with this, by now: > please put a comment over the ratelimiting to explain why it is there, > just like the above commit explains. I will add that. > > Thx. >