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=-12.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 60925C6369E for ; Tue, 10 Nov 2020 16:24:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1C8F420870 for ; Tue, 10 Nov 2020 16:24:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730595AbgKJQY3 (ORCPT ); Tue, 10 Nov 2020 11:24:29 -0500 Received: from mga02.intel.com ([134.134.136.20]:25984 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730468AbgKJQWz (ORCPT ); Tue, 10 Nov 2020 11:22:55 -0500 IronPort-SDR: C7wXi6x4wSXy6KNIZHY9jOeqQemKBP+6v632RNrgpjcM+0wO1ZJn4bAMA3Wyi8a35Upy+Y9t1h O8O5JtLsW2Sw== X-IronPort-AV: E=McAfee;i="6000,8403,9801"; a="157008723" X-IronPort-AV: E=Sophos;i="5.77,466,1596524400"; d="scan'208";a="157008723" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Nov 2020 08:22:53 -0800 IronPort-SDR: Mi5hXwSV3BGmEBv/CJDdY3u7Z4kpDzp15me3v0NZxUtCxx7PgN9zZ8wTWTqz4n5gdlXaY6Tipd G0lfDFEV0ICQ== X-IronPort-AV: E=Sophos;i="5.77,466,1596524400"; d="scan'208";a="365572864" Received: from yyu32-desk.sc.intel.com ([143.183.136.146]) by fmsmga003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Nov 2020 08:22:52 -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 Cc: Yu-cheng Yu Subject: [PATCH v15 14/26] x86/mm: Update maybe_mkwrite() for shadow stack Date: Tue, 10 Nov 2020 08:21:59 -0800 Message-Id: <20201110162211.9207-15-yu-cheng.yu@intel.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20201110162211.9207-1-yu-cheng.yu@intel.com> References: <20201110162211.9207-1-yu-cheng.yu@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org Shadow stack memory is writable, but its VMA has VM_SHSTK instead of VM_WRITE. Update maybe_mkwrite() to include the shadow stack. Signed-off-by: Yu-cheng Yu --- arch/x86/Kconfig | 4 ++++ arch/x86/mm/pgtable.c | 18 ++++++++++++++++++ include/linux/mm.h | 2 ++ include/linux/pgtable.h | 24 ++++++++++++++++++++++++ mm/huge_memory.c | 2 ++ 5 files changed, 50 insertions(+) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index a51d2a3de166..960993862b96 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1938,6 +1938,9 @@ config AS_HAS_SHADOW_STACK config X86_CET def_bool n +config ARCH_MAYBE_MKWRITE + def_bool n + config ARCH_HAS_SHADOW_STACK def_bool n @@ -1948,6 +1951,7 @@ config X86_SHADOW_STACK_USER depends on AS_HAS_SHADOW_STACK select ARCH_USES_HIGH_VMA_FLAGS select X86_CET + select ARCH_MAYBE_MKWRITE select ARCH_HAS_SHADOW_STACK help Shadow Stacks provides protection against program stack diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c index dfd82f51ba66..a9666b64bc05 100644 --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -610,6 +610,24 @@ int pmdp_clear_flush_young(struct vm_area_struct *vma, } #endif +#ifdef CONFIG_ARCH_MAYBE_MKWRITE +pte_t arch_maybe_mkwrite(pte_t pte, struct vm_area_struct *vma) +{ + if (likely(vma->vm_flags & VM_SHSTK)) + pte = pte_mkwrite_shstk(pte); + return pte; +} + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +pmd_t arch_maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma) +{ + if (likely(vma->vm_flags & VM_SHSTK)) + pmd = pmd_mkwrite_shstk(pmd); + return pmd; +} +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ +#endif /* CONFIG_ARCH_MAYBE_MKWRITE */ + /** * reserve_top_address - reserves a hole in the top of kernel address space * @reserve - size of hole to reserve diff --git a/include/linux/mm.h b/include/linux/mm.h index c7f527bd21fb..09f07d07a8ff 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -977,6 +977,8 @@ static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma) { if (likely(vma->vm_flags & VM_WRITE)) pte = pte_mkwrite(pte); + else + pte = arch_maybe_mkwrite(pte, vma); return pte; } diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h index 71125a4676c4..ea66461610ae 100644 --- a/include/linux/pgtable.h +++ b/include/linux/pgtable.h @@ -1384,6 +1384,30 @@ static inline bool arch_has_pfn_modify_check(void) } #endif /* !_HAVE_ARCH_PFN_MODIFY_ALLOWED */ +#ifdef CONFIG_MMU +#ifdef CONFIG_ARCH_MAYBE_MKWRITE +pte_t arch_maybe_mkwrite(pte_t pte, struct vm_area_struct *vma); + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +pmd_t arch_maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma); +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ + +#else /* !CONFIG_ARCH_MAYBE_MKWRITE */ +static inline pte_t arch_maybe_mkwrite(pte_t pte, struct vm_area_struct *vma) +{ + return pte; +} + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +static inline pmd_t arch_maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma) +{ + return pmd; +} +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ + +#endif /* CONFIG_ARCH_MAYBE_MKWRITE */ +#endif /* CONFIG_MMU */ + /* * Architecture PAGE_KERNEL_* fallbacks * diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 9474dbc150ed..ecd23777b8bf 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -464,6 +464,8 @@ pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma) { if (likely(vma->vm_flags & VM_WRITE)) pmd = pmd_mkwrite(pmd); + else + pmd = arch_maybe_pmd_mkwrite(pmd, vma); return pmd; } -- 2.21.0