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=-12.8 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 56FB1C47428 for ; Fri, 25 Sep 2020 14:58:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 381FC23718 for ; Fri, 25 Sep 2020 14:58:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729161AbgIYO6R (ORCPT ); Fri, 25 Sep 2020 10:58:17 -0400 Received: from mga07.intel.com ([134.134.136.100]:47916 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729121AbgIYO6O (ORCPT ); Fri, 25 Sep 2020 10:58:14 -0400 IronPort-SDR: Oe46mJDGs+3qY9GgVe5mGiqMh5b6dSsZW6RaJzuvRb0MjiOecPx3Ycr1SyUF4osjozSt6BNT1i KS53JoKwvprA== X-IronPort-AV: E=McAfee;i="6000,8403,9755"; a="225704476" X-IronPort-AV: E=Sophos;i="5.77,302,1596524400"; d="scan'208";a="225704476" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Sep 2020 07:58:13 -0700 IronPort-SDR: dZdetEM4DRg4Hr3m0uJ4dfSizhMqgJIu94nv7NFPov8SDaS6Butg10uJnfPMdKSCpqlxx8PNcf FomTkBPzAl2g== X-IronPort-AV: E=Sophos;i="5.77,302,1596524400"; d="scan'208";a="512916957" Received: from yyu32-desk.sc.intel.com ([143.183.136.146]) by fmsmga005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Sep 2020 07:58:13 -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 v13 1/8] x86/cet/ibt: Add Kconfig option for user-mode Indirect Branch Tracking Date: Fri, 25 Sep 2020 07:57:57 -0700 Message-Id: <20200925145804.5821-2-yu-cheng.yu@intel.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20200925145804.5821-1-yu-cheng.yu@intel.com> References: <20200925145804.5821-1-yu-cheng.yu@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org Introduce Kconfig option X86_BRANCH_TRACKING_USER. Indirect Branch Tracking (IBT) provides protection against CALL-/JMP- oriented programming attacks. It is active when the kernel has this feature enabled, and the processor and the application support it. When this feature is enabled, legacy non-IBT applications continue to work, but without IBT protection. Signed-off-by: Yu-cheng Yu --- v13: - Update help text, and change default to N. - Change X86_INTEL_* to X86_*. v10: - Change build-time CET check to config depends on. arch/x86/Kconfig | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 4b28a0ce4594..15c7f2606c9d 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1966,6 +1966,25 @@ config X86_SHADOW_STACK_USER If unsure, say N. +config X86_BRANCH_TRACKING_USER + prompt "Intel Indirect Branch Tracking for user-mode" + def_bool n + depends on CPU_SUP_INTEL && X86_64 + depends on $(cc-option,-fcf-protection) + select X86_CET + help + Indirect Branch Tracking (IBT) provides protection against + CALL-/JMP-oriented programming attacks. It is active when + the kernel has this feature enabled, and the processor and + the application support it. When this feature is enabled, + legacy non-IBT applications continue to work, but without + IBT protection. + 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 -- 2.21.0