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=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 9E4DEC433E7 for ; Fri, 9 Oct 2020 18:33:25 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 553BC22284 for ; Fri, 9 Oct 2020 18:33:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 553BC22284 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 6360D6B0071; Fri, 9 Oct 2020 14:33:17 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 6115A6B0072; Fri, 9 Oct 2020 14:33:17 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3F0DF6B0074; Fri, 9 Oct 2020 14:33:17 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0040.hostedemail.com [216.40.44.40]) by kanga.kvack.org (Postfix) with ESMTP id EC8FA6B0073 for ; Fri, 9 Oct 2020 14:33:16 -0400 (EDT) Received: from smtpin03.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 83CA51EF2 for ; Fri, 9 Oct 2020 18:33:16 +0000 (UTC) X-FDA: 77353234392.03.seat41_020d8bb271e2 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin03.hostedemail.com (Postfix) with ESMTP id 6145128A4E8 for ; Fri, 9 Oct 2020 18:33:16 +0000 (UTC) X-HE-Tag: seat41_020d8bb271e2 X-Filterd-Recvd-Size: 5348 Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by imf47.hostedemail.com (Postfix) with ESMTP for ; Fri, 9 Oct 2020 18:33:15 +0000 (UTC) IronPort-SDR: Osa9kPJct/4HdT5H8c9yE9RDskGe0VhMXsSvlR7GiGOL+jdySWJlORNJOen7yOTq1RwiDD7jXB uvVksf3DhvQw== X-IronPort-AV: E=McAfee;i="6000,8403,9769"; a="145390205" X-IronPort-AV: E=Sophos;i="5.77,355,1596524400"; d="scan'208";a="145390205" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Oct 2020 11:33:13 -0700 IronPort-SDR: AnsvOg3ftbUY5GVbbBfdSqHuV+7OId3FEb3JM2h+sl8ejNnxytJ7yCESZofgNo3agZ9uZrFaCG rXUU1fYiQsBw== X-IronPort-AV: E=Sophos;i="5.77,355,1596524400"; d="scan'208";a="529031121" Received: from yyu32-desk.sc.intel.com ([143.183.136.146]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Oct 2020 11:33:12 -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 Cc: Yu-cheng Yu Subject: [PATCH v14 05/26] x86/cet/shstk: Add Kconfig option for user-mode Shadow Stack Date: Fri, 9 Oct 2020 11:32:09 -0700 Message-Id: <20201009183230.26717-6-yu-cheng.yu@intel.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20201009183230.26717-1-yu-cheng.yu@intel.com> References: <20201009183230.26717-1-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: Shadow Stack provides protection against function return address corruption. It is active when the processor supports it, the kernel has CONFIG_X86_SHADOW_STACK_USER, and the application is built for the featur= e. This is only implemented for the 64-bit kernel. When it is enabled, lega= cy non-shadow stack applications continue to work, but without protection. Signed-off-by: Yu-cheng Yu v13: - Update help text, and change default to N. - Change X86_INTEL_* to X86_*. v10: - Change SHSTK to shadow stack in the help text. - Change build-time check to config-time check. - Change ARCH_HAS_SHSTK to ARCH_HAS_SHADOW_STACK. --- arch/x86/Kconfig | 33 +++++++++++++++++++++++++++ scripts/as-x86_64-has-shadow-stack.sh | 4 ++++ 2 files changed, 37 insertions(+) create mode 100755 scripts/as-x86_64-has-shadow-stack.sh diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 7101ac64bb20..415fcc869afc 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1927,6 +1927,39 @@ config X86_INTEL_TSX_MODE_AUTO side channel attacks- equals the tsx=3Dauto command line parameter. endchoice =20 +config AS_HAS_SHADOW_STACK + def_bool $(success,$(srctree)/scripts/as-x86_64-has-shadow-stack.sh $(C= C)) + help + Test the assembler for shadow stack instructions. + +config X86_CET + def_bool n + +config ARCH_HAS_SHADOW_STACK + def_bool n + +config X86_SHADOW_STACK_USER + prompt "Intel Shadow Stacks for user-mode" + def_bool n + depends on CPU_SUP_INTEL && X86_64 + depends on AS_HAS_SHADOW_STACK + select ARCH_USES_HIGH_VMA_FLAGS + select X86_CET + select ARCH_HAS_SHADOW_STACK + help + Shadow Stacks provides protection against program stack + corruption. It's a hardware feature. This only matters + if you have the right hardware. It's a security hardening + feature and apps must be enabled to use it. You get no + protection "for free" on old userspace. The hardware can + support user and kernel, but this option is for user space + only. + Support for this feature is only known to be present on + processors released in 2020 or later. CET features are also + known to increase kernel text size by 3.7 KB. + + If unsure, say N. + config EFI bool "EFI runtime service support" depends on ACPI diff --git a/scripts/as-x86_64-has-shadow-stack.sh b/scripts/as-x86_64-ha= s-shadow-stack.sh new file mode 100755 index 000000000000..fac1d363a1b8 --- /dev/null +++ b/scripts/as-x86_64-has-shadow-stack.sh @@ -0,0 +1,4 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 + +echo "wrussq %rax, (%rbx)" | $* -x assembler -c - --=20 2.21.0