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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 8FA36C83014 for ; Wed, 29 Apr 2020 22:09:06 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A5A57214AF for ; Wed, 29 Apr 2020 22:09:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A5A57214AF 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 34CC98E0011; Wed, 29 Apr 2020 18:08:48 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2FDA88E000E; Wed, 29 Apr 2020 18:08:48 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1013C8E0011; Wed, 29 Apr 2020 18:08:48 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0151.hostedemail.com [216.40.44.151]) by kanga.kvack.org (Postfix) with ESMTP id DE8D38E000E for ; Wed, 29 Apr 2020 18:08:47 -0400 (EDT) Received: from smtpin27.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 9B655181AC9CB for ; Wed, 29 Apr 2020 22:08:47 +0000 (UTC) X-FDA: 76762283094.27.song50_127a7a9b5a90d X-HE-Tag: song50_127a7a9b5a90d X-Filterd-Recvd-Size: 5050 Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) by imf31.hostedemail.com (Postfix) with ESMTP for ; Wed, 29 Apr 2020 22:08:46 +0000 (UTC) IronPort-SDR: t6wu35CdZrO7959k590TDo51/ADeIqeMBoXNtJZ4TqPJXjGvHs4f1v+3YjNCXtecwiOhvE8bpp L8Shp2W7AlMQ== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Apr 2020 15:08:46 -0700 IronPort-SDR: 2vxAJGg8O3iygJAHmEigMgsjXjgcykqGrkKoYfSXckrD2HdLJpx0LY/BIdbkyFACvdbjlmETut WX0gWiw++O2A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,333,1583222400"; d="scan'208";a="276308890" Received: from yyu32-desk.sc.intel.com ([143.183.136.146]) by orsmga002.jf.intel.com with ESMTP; 29 Apr 2020 15:08:45 -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 Cc: Yu-cheng Yu Subject: [PATCH v10 12/26] mm: Introduce VM_SHSTK for shadow stack memory Date: Wed, 29 Apr 2020 15:07:18 -0700 Message-Id: <20200429220732.31602-13-yu-cheng.yu@intel.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20200429220732.31602-1-yu-cheng.yu@intel.com> References: <20200429220732.31602-1-yu-cheng.yu@intel.com> MIME-Version: 1.0 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: A Shadow Stack PTE must be read-only and have _PAGE_DIRTY set. However, read-only and Dirty PTEs also exist for copy-on-write (COW) pages. These two cases are handled differently for page faults. Introduce VM_SHSTK to track shadow stack VMAs. Signed-off-by: Yu-cheng Yu Reviewed-by: Kees Cook --- v9: - Add VM_SHSTK case to arch_vma_name(). - Revise the commit log to explain why adding a new VM flag. arch/x86/mm/mmap.c | 2 ++ fs/proc/task_mmu.c | 3 +++ include/linux/mm.h | 8 ++++++++ 3 files changed, 13 insertions(+) diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c index cb91eccc4960..fe77fd6debf1 100644 --- a/arch/x86/mm/mmap.c +++ b/arch/x86/mm/mmap.c @@ -163,6 +163,8 @@ unsigned long get_mmap_base(int is_legacy) =20 const char *arch_vma_name(struct vm_area_struct *vma) { + if (vma->vm_flags & VM_SHSTK) + return "[shadow stack]"; return NULL; } =20 diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 8d382d4ec067..434692759265 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -657,6 +657,9 @@ static void show_smap_vma_flags(struct seq_file *m, s= truct vm_area_struct *vma) [ilog2(VM_PKEY_BIT4)] =3D "", #endif #endif /* CONFIG_ARCH_HAS_PKEYS */ +#ifdef CONFIG_X86_INTEL_SHADOW_STACK_USER + [ilog2(VM_SHSTK)] =3D "ss", +#endif }; size_t i; =20 diff --git a/include/linux/mm.h b/include/linux/mm.h index 5a323422d783..54bb4cd9fee8 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -294,11 +294,13 @@ extern unsigned int kobjsize(const void *objp); #define VM_HIGH_ARCH_BIT_2 34 /* bit only usable on 64-bit architectures= */ #define VM_HIGH_ARCH_BIT_3 35 /* bit only usable on 64-bit architectures= */ #define VM_HIGH_ARCH_BIT_4 36 /* bit only usable on 64-bit architectures= */ +#define VM_HIGH_ARCH_BIT_5 37 /* bit only usable on 64-bit architectures= */ #define VM_HIGH_ARCH_0 BIT(VM_HIGH_ARCH_BIT_0) #define VM_HIGH_ARCH_1 BIT(VM_HIGH_ARCH_BIT_1) #define VM_HIGH_ARCH_2 BIT(VM_HIGH_ARCH_BIT_2) #define VM_HIGH_ARCH_3 BIT(VM_HIGH_ARCH_BIT_3) #define VM_HIGH_ARCH_4 BIT(VM_HIGH_ARCH_BIT_4) +#define VM_HIGH_ARCH_5 BIT(VM_HIGH_ARCH_BIT_5) #endif /* CONFIG_ARCH_USES_HIGH_VMA_FLAGS */ =20 #ifdef CONFIG_ARCH_HAS_PKEYS @@ -336,6 +338,12 @@ extern unsigned int kobjsize(const void *objp); # define VM_MPX VM_NONE #endif =20 +#ifdef CONFIG_X86_INTEL_SHADOW_STACK_USER +# define VM_SHSTK VM_HIGH_ARCH_5 +#else +# define VM_SHSTK VM_NONE +#endif + #ifndef VM_GROWSUP # define VM_GROWSUP VM_NONE #endif --=20 2.21.0