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 676DEC433E0 for ; Tue, 16 Mar 2021 15:19:44 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 0ABDB650DB for ; Tue, 16 Mar 2021 15:19:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0ABDB650DB Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 8BB126B007B; Tue, 16 Mar 2021 11:19:43 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 86A998D0002; Tue, 16 Mar 2021 11:19:43 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6BD076B007E; Tue, 16 Mar 2021 11:19:43 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0163.hostedemail.com [216.40.44.163]) by kanga.kvack.org (Postfix) with ESMTP id 4FA836B007B for ; Tue, 16 Mar 2021 11:19:43 -0400 (EDT) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 0F1E51802E6CE for ; Tue, 16 Mar 2021 15:19:43 +0000 (UTC) X-FDA: 77926097046.16.1EBE1E8 Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by imf23.hostedemail.com (Postfix) with ESMTP id EEB8AA006BD5 for ; Tue, 16 Mar 2021 15:19:38 +0000 (UTC) IronPort-SDR: b1qXffcb8R6ERjDKX1Cg5pydapVdPveD/D45mW8aQs0vDDXABnc3QItWOh+p8JmGZ0Z/MB5/dp Bhxq2JS8xRxA== X-IronPort-AV: E=McAfee;i="6000,8403,9924"; a="169190323" X-IronPort-AV: E=Sophos;i="5.81,251,1610438400"; d="scan'208";a="169190323" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Mar 2021 08:11:31 -0700 IronPort-SDR: gj+WE5fkO/VYqGjB4KZ7jB9zpahFHSYquIF/cGoTfPLWwOpDzu1BVt93UiX5QEwwvpLMtM0Dl0 IpxWaBnFlPVQ== X-IronPort-AV: E=Sophos;i="5.81,251,1610438400"; d="scan'208";a="405570311" Received: from yyu32-desk.sc.intel.com ([143.183.136.146]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Mar 2021 08:11:31 -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" , Vedvyas Shanbhogue , Dave Martin , Weijiang Yang , Pengfei Xu , Haitao Huang Cc: Yu-cheng Yu Subject: [PATCH v23 20/28] mm/mprotect: Exclude shadow stack from preserve_write Date: Tue, 16 Mar 2021 08:10:46 -0700 Message-Id: <20210316151054.5405-21-yu-cheng.yu@intel.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20210316151054.5405-1-yu-cheng.yu@intel.com> References: <20210316151054.5405-1-yu-cheng.yu@intel.com> MIME-Version: 1.0 X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: EEB8AA006BD5 X-Stat-Signature: h1yix11pk6j1xjs44xdun7x78j44fo4f Received-SPF: none (intel.com>: No applicable sender policy available) receiver=imf23; identity=mailfrom; envelope-from=""; helo=mga17.intel.com; client-ip=192.55.52.151 X-HE-DKIM-Result: none/none X-HE-Tag: 1615907978-681273 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 --- mm/huge_memory.c | 7 ++++++- mm/mprotect.c | 9 ++++++++- 2 files changed, 14 insertions(+), 2 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 3ad7d521a7b5..107c2be2156d 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1812,12 +1812,17 @@ int change_huge_pmd(struct vm_area_struct *vma, p= md_t *pmd, bool prot_numa =3D cp_flags & MM_CP_PROT_NUMA; bool uffd_wp =3D cp_flags & MM_CP_UFFD_WP; bool uffd_wp_resolve =3D cp_flags & MM_CP_UFFD_WP_RESOLVE; + bool shstk =3D arch_shadow_stack_mapping(vma->vm_flags); =20 ptl =3D __pmd_trans_huge_lock(pmd, vma); if (!ptl) 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). + */ + preserve_write =3D prot_numa && pmd_write(*pmd) && !shstk; ret =3D 1; =20 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION diff --git a/mm/mprotect.c b/mm/mprotect.c index c1ce78d688b6..e69278b346a9 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -75,7 +75,14 @@ static unsigned long change_pte_range(struct vm_area_s= truct *vma, pmd_t *pmd, oldpte =3D *pte; if (pte_present(oldpte)) { pte_t ptent; - bool preserve_write =3D prot_numa && pte_write(oldpte); + bool shstk =3D arch_shadow_stack_mapping(vma->vm_flags); + bool preserve_write; + + /* + * Preserve only normal writable PTE, but not shadow + * stack (RW=3D0, Dirty=3D1). + */ + preserve_write =3D prot_numa && pte_write(oldpte) && !shstk; =20 /* * Avoid trapping faults against the zero or KSM --=20 2.21.0