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 59240C83007 for ; Wed, 29 Apr 2020 22:08:52 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id F14A221775 for ; Wed, 29 Apr 2020 22:08:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F14A221775 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 3253A8E000A; Wed, 29 Apr 2020 18:08:44 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 287778E000B; Wed, 29 Apr 2020 18:08:44 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 179598E000A; Wed, 29 Apr 2020 18:08:43 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0209.hostedemail.com [216.40.44.209]) by kanga.kvack.org (Postfix) with ESMTP id E34068E0008 for ; Wed, 29 Apr 2020 18:08:43 -0400 (EDT) Received: from smtpin14.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id AD218180AD815 for ; Wed, 29 Apr 2020 22:08:43 +0000 (UTC) X-FDA: 76762282926.14.fight19_11e7c1be91d29 X-HE-Tag: fight19_11e7c1be91d29 X-Filterd-Recvd-Size: 4911 Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) by imf09.hostedemail.com (Postfix) with ESMTP for ; Wed, 29 Apr 2020 22:08:42 +0000 (UTC) IronPort-SDR: +1Ya2PrWC1cBnFDpWUxw8TbWoRl1dMxVz8ZTEoG+mB8sR7GQCRCTHbKEv7ChNPf0PyrOR/x8J6 6Lqq/JYfzMug== 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 15:08:42 -0700 IronPort-SDR: rkCyd4MEbRBcVRLk9asgG/r/BHUdH6pFX5SaolLMaG4cC/bBBEq2dq4lza1tP+mjdFUUotFfrD 4cfGOnyZcUDA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,333,1583222400"; d="scan'208";a="276308861" Received: from yyu32-desk.sc.intel.com ([143.183.136.146]) by orsmga002.jf.intel.com with ESMTP; 29 Apr 2020 15:08:41 -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 05/26] x86/cet/shstk: Add Kconfig option for user-mode Shadow Stack Date: Wed, 29 Apr 2020 15:07:11 -0700 Message-Id: <20200429220732.31602-6-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: Shadow Stack provides protection against function return address corruption. It is active when the processor supports it, the kernel has CONFIG_X86_INTEL_SHADOW_STACK_USER, and the application is built for the feature. This is only implemented for the 64-bit kernel. When it is enabled, legacy non-shadow stack applications continue to work, but witho= ut protection. Signed-off-by: Yu-cheng Yu --- 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 | 30 +++++++++++++++++++++++++++ scripts/as-x86_64-has-shadow-stack.sh | 4 ++++ 2 files changed, 34 insertions(+) create mode 100755 scripts/as-x86_64-has-shadow-stack.sh diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 1197b5596d5a..c98f82fffe85 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1947,6 +1947,36 @@ 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_INTEL_CET + def_bool n + +config ARCH_HAS_SHADOW_STACK + def_bool n + +config X86_INTEL_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_INTEL_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. + + If unsure, say y. + 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