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 D1B3DC433E6 for ; Wed, 3 Mar 2021 03:11:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 927F364EBB for ; Wed, 3 Mar 2021 03:11:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244336AbhCCDFT (ORCPT ); Tue, 2 Mar 2021 22:05:19 -0500 Received: from mga12.intel.com ([192.55.52.136]:4766 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232971AbhCBXve (ORCPT ); Tue, 2 Mar 2021 18:51:34 -0500 IronPort-SDR: cpvKoa2amG/VNtTsYZeuoTrtQbqRKEk5UWbojAfbEIGfxODZQkeeC34u0XQ+eWqi1OY78DX5kn JDeTt6hVbfag== X-IronPort-AV: E=McAfee;i="6000,8403,9911"; a="166281817" X-IronPort-AV: E=Sophos;i="5.81,218,1610438400"; d="scan'208";a="166281817" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Mar 2021 15:46:35 -0800 IronPort-SDR: hv/iD/ygCIE8H3t1ule/ZVIvikOyUAjmtov+tEKECJNvBd4KKG97ozZ+KyDdeZWNtPmhqWwCMy sPoFp9TN6UxQ== X-IronPort-AV: E=Sophos;i="5.81,218,1610438400"; d="scan'208";a="406967876" Received: from yyu32-mobl1.amr.corp.intel.com (HELO [10.212.177.76]) ([10.212.177.76]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Mar 2021 15:46:32 -0800 Subject: Re: [PATCH v21 08/26] x86/mm: Introduce _PAGE_COW 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 , Haitao Huang References: <20210217222730.15819-1-yu-cheng.yu@intel.com> <20210217222730.15819-9-yu-cheng.yu@intel.com> <20210301155234.GF6699@zn.tnic> From: "Yu, Yu-cheng" Message-ID: <167f58a3-20ef-7210-1d66-cf25f4a9bbef@intel.com> Date: Tue, 2 Mar 2021 15:46:31 -0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.8.0 MIME-Version: 1.0 In-Reply-To: <20210301155234.GF6699@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-api@vger.kernel.org On 3/1/2021 7:52 AM, Borislav Petkov wrote: > On Wed, Feb 17, 2021 at 02:27:12PM -0800, Yu-cheng Yu wrote: [...] >> static inline pmd_t pmd_mkdirty(pmd_t pmd) >> { >> - return pmd_set_flags(pmd, _PAGE_DIRTY | _PAGE_SOFT_DIRTY); >> + pmdval_t dirty = _PAGE_DIRTY; >> + >> + /* Avoid creating (HW)Dirty=1, Write=0 PMDs */ >> + if (cpu_feature_enabled(X86_FEATURE_SHSTK) && !(pmd_flags(pmd) & _PAGE_RW)) > > !(pmd_write(pmd)) > There is a problem of doing that: pmd_write() is defined after this function. Maybe we can declare it first, or leave this as-is? -- Yu-cheng