From patchwork Wed Feb 5 18:19:14 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu-cheng Yu X-Patchwork-Id: 11366917 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C3B86921 for ; Wed, 5 Feb 2020 18:20:49 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 99B2321927 for ; Wed, 5 Feb 2020 18:20:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 99B2321927 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 B16206B000D; Wed, 5 Feb 2020 13:20:31 -0500 (EST) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id ABE396B0037; Wed, 5 Feb 2020 13:20:31 -0500 (EST) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7FD206B000E; Wed, 5 Feb 2020 13:20:31 -0500 (EST) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0069.hostedemail.com [216.40.44.69]) by kanga.kvack.org (Postfix) with ESMTP id 607466B0032 for ; Wed, 5 Feb 2020 13:20:31 -0500 (EST) Received: from smtpin05.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id DD8E54404 for ; Wed, 5 Feb 2020 18:20:30 +0000 (UTC) X-FDA: 76456888620.05.tree38_78d0e2f65f810 X-Spam-Summary: 1,0,0,,d41d8cd98f00b204,yu-cheng.yu@intel.com,:x86@kernel.org:hpa@zytor.com:tglx@linutronix.de:mingo@redhat.com:linux-kernel@vger.kernel.org:linux-doc@vger.kernel.org::linux-arch@vger.kernel.org:linux-api@vger.kernel.org:arnd@arndb.de:luto@kernel.org:bsingharora@gmail.com:bp@alien8.de:gorcunov@gmail.com:dave.hansen@linux.intel.com:esyr@redhat.com:fweimer@redhat.com:hjl.tools@gmail.com:jannh@google.com:corbet@lwn.net:keescook@chromium.org:mike.kravetz@oracle.com:nadav.amit@gmail.com:oleg@redhat.com:pavel@ucw.cz:peterz@infradead.org:rdunlap@infradead.org:ravi.v.shankar@intel.com:vedvyas.shanbhogue@intel.com:dave.martin@arm.com:x86-patch-review@intel.com:yu-cheng.yu@intel.com,RULES_HIT:30054:30056:30064,0,RBL:134.134.136.20:@intel.com:.lbl8.mailshell.net-62.50.0.100 64.95.201.95,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:ft,MSBL:0,DNSBL:neutral,Custom_rules:0:0:0,LFtime:35,LUA_SUMMARY:none X-HE-Tag: tree38_78d0e2f65f810 X-Filterd-Recvd-Size: 4797 Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by imf16.hostedemail.com (Postfix) with ESMTP for ; Wed, 5 Feb 2020 18:20:30 +0000 (UTC) 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/DHE-RSA-AES256-GCM-SHA384; 05 Feb 2020 10:20:25 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,406,1574150400"; d="scan'208";a="279447762" Received: from yyu32-desk.sc.intel.com ([143.183.136.146]) by FMSMGA003.fm.intel.com with ESMTP; 05 Feb 2020 10:20:25 -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 , x86-patch-review@intel.com Cc: Yu-cheng Yu Subject: [RFC PATCH v9 06/27] mm: Introduce VM_SHSTK for Shadow Stack memory Date: Wed, 5 Feb 2020 10:19:14 -0800 Message-Id: <20200205181935.3712-7-yu-cheng.yu@intel.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20200205181935.3712-1-yu-cheng.yu@intel.com> References: <20200205181935.3712-1-yu-cheng.yu@intel.com> MIME-Version: 1.0 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 (SHSTK) 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 and a new VM flag is necessary for tracking SHSTK VMAs. v9: - Add VM_SHSTK case to arch_vma_name(). - Revise the commit log to explain why a new VM flag is needed. Signed-off-by: Yu-cheng Yu Reviewed-by: Kees Cook --- 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 aae9a933dfd4..482813b4c659 100644 --- a/arch/x86/mm/mmap.c +++ b/arch/x86/mm/mmap.c @@ -165,6 +165,8 @@ const char *arch_vma_name(struct vm_area_struct *vma) { if (vma->vm_flags & VM_MPX) return "[mpx]"; + else if (vma->vm_flags & VM_SHSTK) + return "[shadow stack]"; return NULL; } diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 9442631fd4af..590b58ee008a 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -687,6 +687,9 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma) [ilog2(VM_PKEY_BIT4)] = "", #endif #endif /* CONFIG_ARCH_HAS_PKEYS */ +#ifdef CONFIG_X86_INTEL_SHADOW_STACK_USER + [ilog2(VM_SHSTK)] = "ss", +#endif }; size_t i; diff --git a/include/linux/mm.h b/include/linux/mm.h index cfaa8feecfe8..b5145fbe102e 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -298,11 +298,13 @@ 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 */ #ifdef CONFIG_ARCH_HAS_PKEYS @@ -340,6 +342,12 @@ extern unsigned int kobjsize(const void *objp); # define VM_MPX VM_NONE #endif +#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