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=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 68F44C433E2 for ; Mon, 22 Mar 2021 14:54:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 459026192E for ; Mon, 22 Mar 2021 14:54:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230519AbhCVOyL (ORCPT ); Mon, 22 Mar 2021 10:54:11 -0400 Received: from mga04.intel.com ([192.55.52.120]:16678 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231394AbhCVOwz (ORCPT ); Mon, 22 Mar 2021 10:52:55 -0400 IronPort-SDR: PDZrzvMtyWpyPIHFH/Twk0eFOzWvkUpPcqhagvRHpupWi4PVRTdXsfeMImN3naPaAquc//CzEf an1nOr6NAE0A== X-IronPort-AV: E=McAfee;i="6000,8403,9931"; a="187962997" X-IronPort-AV: E=Sophos;i="5.81,269,1610438400"; d="scan'208";a="187962997" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Mar 2021 07:52:32 -0700 IronPort-SDR: AcDswo0o5vJUZRQnv7Qgq4FfRiJvce9xEXN0iZXavHHDTiu8NLkg8XL3qJb8K0JAMd3q/9W2Pq cGiyP/W0DPkQ== X-IronPort-AV: E=Sophos;i="5.81,269,1610438400"; d="scan'208";a="390502622" Received: from xzhan86-mobl.amr.corp.intel.com (HELO [10.209.39.64]) ([10.209.39.64]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Mar 2021 07:52:30 -0700 Subject: Re: [PATCH v23 07/28] x86/mm: Remove _PAGE_DIRTY from kernel RO pages To: "Kirill A. Shutemov" 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 , Borislav Petkov , 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 , Christoph Hellwig References: <20210316151054.5405-1-yu-cheng.yu@intel.com> <20210316151054.5405-8-yu-cheng.yu@intel.com> <20210322091351.ulemcluuhqkzuwkm@box> From: "Yu, Yu-cheng" Message-ID: <81fa71ee-3b0b-b959-b8c2-19e1a5adc4c4@intel.com> Date: Mon, 22 Mar 2021 07:52:31 -0700 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: <20210322091351.ulemcluuhqkzuwkm@box> 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 3/22/2021 2:13 AM, Kirill A. Shutemov wrote: > On Tue, Mar 16, 2021 at 08:10:33AM -0700, Yu-cheng Yu wrote: >> The x86 family of processors do not directly create read-only and Dirty >> PTEs. These PTEs are created by software. One such case is that kernel >> read-only pages are historically setup as Dirty. >> >> New processors that support Shadow Stack regard read-only and Dirty PTEs as >> shadow stack pages. This results in ambiguity between shadow stack and >> kernel read-only pages. To resolve this, removed Dirty from kernel read- >> only pages. >> >> Signed-off-by: Yu-cheng Yu >> Cc: "H. Peter Anvin" >> Cc: Kees Cook >> Cc: Thomas Gleixner >> Cc: Dave Hansen >> Cc: Christoph Hellwig >> Cc: Andy Lutomirski >> Cc: Ingo Molnar >> Cc: Borislav Petkov >> Cc: Peter Zijlstra > > Looks good to me. > > Reviewed-by: Kirill A. Shutemov > Thanks for reviewing. Yu-cheng