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=-16.8 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=ham 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 ACFBDC4320E for ; Fri, 20 Aug 2021 18:19:31 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 608326121D for ; Fri, 20 Aug 2021 18:19:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 608326121D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 5852F8D000F; Fri, 20 Aug 2021 14:18:54 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 4BF7C8D0010; Fri, 20 Aug 2021 14:18:54 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 339348D000F; Fri, 20 Aug 2021 14:18:54 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0002.hostedemail.com [216.40.44.2]) by kanga.kvack.org (Postfix) with ESMTP id 0D7D58D0010 for ; Fri, 20 Aug 2021 14:18:54 -0400 (EDT) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id B94A218016835 for ; Fri, 20 Aug 2021 18:18:53 +0000 (UTC) X-FDA: 78496270146.16.0CBEDC3 Received: from mga18.intel.com (mga18.intel.com [134.134.136.126]) by imf24.hostedemail.com (Postfix) with ESMTP id 2075DB0000A8 for ; Fri, 20 Aug 2021 18:18:52 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10082"; a="203964251" X-IronPort-AV: E=Sophos;i="5.84,338,1620716400"; d="scan'208";a="203964251" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Aug 2021 11:18:50 -0700 X-IronPort-AV: E=Sophos;i="5.84,338,1620716400"; d="scan'208";a="533074752" Received: from yyu32-desk.sc.intel.com ([143.183.136.146]) by fmsmga002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Aug 2021 11:18:50 -0700 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" , Dave Martin , Weijiang Yang , Pengfei Xu , Haitao Huang , Rick P Edgecombe Cc: Yu-cheng Yu , "Kirill A . Shutemov" Subject: [PATCH v29 21/32] mm/mprotect: Exclude shadow stack from preserve_write Date: Fri, 20 Aug 2021 11:11:50 -0700 Message-Id: <20210820181201.31490-22-yu-cheng.yu@intel.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20210820181201.31490-1-yu-cheng.yu@intel.com> References: <20210820181201.31490-1-yu-cheng.yu@intel.com> MIME-Version: 1.0 X-Rspamd-Queue-Id: 2075DB0000A8 Authentication-Results: imf24.hostedemail.com; dkim=none; dmarc=fail reason="No valid SPF, No valid DKIM" header.from=intel.com (policy=none); spf=none (imf24.hostedemail.com: domain of yu-cheng.yu@intel.com has no SPF policy when checking 134.134.136.126) smtp.mailfrom=yu-cheng.yu@intel.com X-Rspamd-Server: rspam04 X-Stat-Signature: ucyq168hrrhogfoxseyu3mqc9upngsy1 X-HE-Tag: 1629483532-96085 Content-Transfer-Encoding: quoted-printable 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: In change_pte_range(), when a PTE is changed for prot_numa, _PAGE_RW is preserved to avoid the additional write fault after the NUMA hinting faul= t. However, pte_write() now includes both normal writable and shadow stack (RW=3D0, Dirty=3D1) PTEs, but the latter does not have _PAGE_RW and has n= o need to preserve it. Exclude shadow stack from preserve_write test, and apply the same change = to change_huge_pmd(). Signed-off-by: Yu-cheng Yu Reviewed-by: Kirill A. Shutemov --- v25: - Move is_shadow_stack_mapping() to a separate line. v24: - Change arch_shadow_stack_mapping() to is_shadow_stack_mapping(). --- mm/huge_memory.c | 7 +++++++ mm/mprotect.c | 7 +++++++ 2 files changed, 14 insertions(+) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index d35acb59dde9..bb38ecdf992f 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1776,6 +1776,13 @@ int change_huge_pmd(struct vm_area_struct *vma, pm= d_t *pmd, return 0; =20 preserve_write =3D prot_numa && pmd_write(*pmd); + + /* + * Preserve only normal writable huge PMD, but not shadow + * stack (RW=3D0, Dirty=3D1). + */ + if (is_shadow_stack_mapping(vma->vm_flags)) + preserve_write =3D false; ret =3D 1; =20 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION diff --git a/mm/mprotect.c b/mm/mprotect.c index 9b424f2fd3a9..94cb799216ec 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -77,6 +77,13 @@ static unsigned long change_pte_range(struct vm_area_s= truct *vma, pmd_t *pmd, pte_t ptent; bool preserve_write =3D prot_numa && pte_write(oldpte); =20 + /* + * Preserve only normal writable PTE, but not shadow + * stack (RW=3D0, Dirty=3D1). + */ + if (is_shadow_stack_mapping(vma->vm_flags)) + preserve_write =3D false; + /* * Avoid trapping faults against the zero or KSM * pages. See similar comment in change_huge_pmd. --=20 2.21.0