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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 91A13C4332D for ; Wed, 17 Feb 2021 22:30:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5508364DFF for ; Wed, 17 Feb 2021 22:30:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233881AbhBQW3n (ORCPT ); Wed, 17 Feb 2021 17:29:43 -0500 Received: from mga09.intel.com ([134.134.136.24]:13777 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233800AbhBQW3O (ORCPT ); Wed, 17 Feb 2021 17:29:14 -0500 IronPort-SDR: CK5RnHHDjpIkXTIQurkOVVO0FnZ5XHU9KNVow8A4FvuIX1p0mf+RPtjSvFBQNU+DucycuvVBtd 9Ozup4UXd+sA== X-IronPort-AV: E=McAfee;i="6000,8403,9898"; a="183461438" X-IronPort-AV: E=Sophos;i="5.81,185,1610438400"; d="scan'208";a="183461438" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Feb 2021 14:27:57 -0800 IronPort-SDR: 6Nkja6gk5lbsEGKXz5Gnbh7i0JRiXq3qyftHWyRwsRJhmqu5U6mDwdpnf71sUOY+B/hjESmx3P gIjxYJP90+wA== X-IronPort-AV: E=Sophos;i="5.81,185,1610438400"; d="scan'208";a="400172607" Received: from yyu32-desk.sc.intel.com ([143.183.136.146]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Feb 2021 14:27:56 -0800 From: Yu-cheng Yu To: 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 Cc: Yu-cheng Yu , Christoph Hellwig Subject: [PATCH v21 07/26] x86/mm: Remove _PAGE_DIRTY from kernel RO pages Date: Wed, 17 Feb 2021 14:27:11 -0800 Message-Id: <20210217222730.15819-8-yu-cheng.yu@intel.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20210217222730.15819-1-yu-cheng.yu@intel.com> References: <20210217222730.15819-1-yu-cheng.yu@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org 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 --- arch/x86/include/asm/pgtable_types.h | 6 +++--- arch/x86/mm/pat/set_memory.c | 2 +- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h index 394757ee030a..b8b79d618bbc 100644 --- a/arch/x86/include/asm/pgtable_types.h +++ b/arch/x86/include/asm/pgtable_types.h @@ -194,10 +194,10 @@ enum page_cache_mode { #define _KERNPG_TABLE (__PP|__RW| 0|___A| 0|___D| 0| 0| _ENC) #define _PAGE_TABLE_NOENC (__PP|__RW|_USR|___A| 0|___D| 0| 0) #define _PAGE_TABLE (__PP|__RW|_USR|___A| 0|___D| 0| 0| _ENC) -#define __PAGE_KERNEL_RO (__PP| 0| 0|___A|__NX|___D| 0|___G) -#define __PAGE_KERNEL_ROX (__PP| 0| 0|___A| 0|___D| 0|___G) +#define __PAGE_KERNEL_RO (__PP| 0| 0|___A|__NX| 0| 0|___G) +#define __PAGE_KERNEL_ROX (__PP| 0| 0|___A| 0| 0| 0|___G) #define __PAGE_KERNEL_NOCACHE (__PP|__RW| 0|___A|__NX|___D| 0|___G| __NC) -#define __PAGE_KERNEL_VVAR (__PP| 0|_USR|___A|__NX|___D| 0|___G) +#define __PAGE_KERNEL_VVAR (__PP| 0|_USR|___A|__NX| 0| 0|___G) #define __PAGE_KERNEL_LARGE (__PP|__RW| 0|___A|__NX|___D|_PSE|___G) #define __PAGE_KERNEL_LARGE_EXEC (__PP|__RW| 0|___A| 0|___D|_PSE|___G) #define __PAGE_KERNEL_WP (__PP|__RW| 0|___A|__NX|___D| 0|___G| __WP) diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c index 16f878c26667..6bebb95a6988 100644 --- a/arch/x86/mm/pat/set_memory.c +++ b/arch/x86/mm/pat/set_memory.c @@ -1932,7 +1932,7 @@ int set_memory_nx(unsigned long addr, int numpages) int set_memory_ro(unsigned long addr, int numpages) { - return change_page_attr_clear(&addr, numpages, __pgprot(_PAGE_RW), 0); + return change_page_attr_clear(&addr, numpages, __pgprot(_PAGE_RW | _PAGE_DIRTY), 0); } int set_memory_rw(unsigned long addr, int numpages) -- 2.21.0