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=-5.3 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 94BD3C0018C for ; Mon, 7 Dec 2020 17:12:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 52C122389B for ; Mon, 7 Dec 2020 17:12:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727498AbgLGRMY (ORCPT ); Mon, 7 Dec 2020 12:12:24 -0500 Received: from mga17.intel.com ([192.55.52.151]:53267 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725863AbgLGRMY (ORCPT ); Mon, 7 Dec 2020 12:12:24 -0500 IronPort-SDR: 4WedHcgKxXjpH7+vFiWLGLLHvQtdjRbFfq/ff0xfQJvwW9Li6MPS6UOARPI//UxeLXMA1zEYnH N/H9t/zY/2OQ== X-IronPort-AV: E=McAfee;i="6000,8403,9828"; a="153548837" X-IronPort-AV: E=Sophos;i="5.78,400,1599548400"; d="scan'208";a="153548837" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Dec 2020 09:11:41 -0800 IronPort-SDR: gU9g08IhB9QfbewodfyGKJL8AgbLIcT0M6qrKa1Z9jOWOFYTF2mvVDswR7gIVZyojuJ4MByAkr BeEAFFkD6PMQ== X-IronPort-AV: E=Sophos;i="5.78,400,1599548400"; d="scan'208";a="436903607" Received: from nkanakap-mobl1.amr.corp.intel.com (HELO [10.251.12.188]) ([10.251.12.188]) by fmsmga001-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Dec 2020 09:11:39 -0800 Subject: Re: [PATCH v15 07/26] x86/mm: Remove _PAGE_DIRTY_HW from kernel RO pages 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 , Christoph Hellwig References: <20201110162211.9207-1-yu-cheng.yu@intel.com> <20201110162211.9207-8-yu-cheng.yu@intel.com> <20201207163632.GE20489@zn.tnic> From: "Yu, Yu-cheng" Message-ID: Date: Mon, 7 Dec 2020 09:11:38 -0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.5.1 MIME-Version: 1.0 In-Reply-To: <20201207163632.GE20489@zn.tnic> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/7/2020 8:36 AM, Borislav Petkov wrote: > On Tue, Nov 10, 2020 at 08:21:52AM -0800, Yu-cheng Yu wrote: >> Kernel read-only PTEs are setup as _PAGE_DIRTY_HW. Since these become >> shadow stack PTEs, remove the dirty bit. > > This commit message is laconic to say the least. You need to start > explaining what you're doing because everytime I look at a patch of > yours, I'm always grepping the SDM and looking forward in the patchset, > trying to rhyme up what that is all about. > > Like for this one. I had to fast-forward to the next patch where all > that is explained. But this is not how review works - each patch's > commit message needs to be understandable on its own because when > they land upstream, they're not in a patchset like here. And review > should be done in the order the patches are numbered - not by jumping > back'n'forth. > > So please think of the readers of your patches when writing those commit > messages. Latter are *not* write-only and not unimportant. > > And those readers haven't spent copious amounts of time on the > technology so being more verbose and explaining things is a Good > Thing(tm). Don't worry about explaining too much - better too much than > too little. > > And last but not least, having understandable and properly written > commit messages increases the chances of your patches landing upstream > considerably. > > Thx. > Thanks for your feedback. I will improve the commit logs. -- Yu-cheng