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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 C493BC41537 for ; Mon, 30 Aug 2021 18:23:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B04EC60FE6 for ; Mon, 30 Aug 2021 18:23:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238515AbhH3SYE (ORCPT ); Mon, 30 Aug 2021 14:24:04 -0400 Received: from mga05.intel.com ([192.55.52.43]:57612 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229839AbhH3SYD (ORCPT ); Mon, 30 Aug 2021 14:24:03 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10092"; a="303905709" X-IronPort-AV: E=Sophos;i="5.84,364,1620716400"; d="scan'208";a="303905709" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Aug 2021 11:23:09 -0700 X-IronPort-AV: E=Sophos;i="5.84,364,1620716400"; d="scan'208";a="540650943" Received: from yyu32-desk.sc.intel.com ([143.183.136.146]) by fmsmga002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Aug 2021 11:23:08 -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" , Dave Martin , Weijiang Yang , Pengfei Xu , Haitao Huang , Rick P Edgecombe Cc: Yu-cheng Yu Subject: [PATCH v30 01/10] x86/cet/ibt: Add Kconfig option for Indirect Branch Tracking Date: Mon, 30 Aug 2021 11:22:12 -0700 Message-Id: <20210830182221.3535-2-yu-cheng.yu@intel.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20210830182221.3535-1-yu-cheng.yu@intel.com> References: <20210830182221.3535-1-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 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 Reviewed-by: Kees Cook --- arch/x86/Kconfig | 19 +++++++++++++++++++ arch/x86/include/asm/disabled-features.h | 8 +++++++- 2 files changed, 26 insertions(+), 1 deletion(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 34692f02118c..b063d6d2491f 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1932,6 +1932,25 @@ config X86_SHADOW_STACK If unsure, say N. +config X86_IBT + prompt "Intel Indirect Branch Tracking" + def_bool n + depends on X86_SHADOW_STACK + depends on $(cc-option,-fcf-protection) + 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 present on Tiger Lake family of + processors released in 2020 or later. Enabling this feature + increases kernel text size by 3.7 KB. + See Documentation/x86/intel_cet.rst for more information. + + If unsure, say N. + config EFI bool "EFI runtime service support" depends on ACPI diff --git a/arch/x86/include/asm/disabled-features.h b/arch/x86/include/asm/disabled-features.h index b7728f7afb2b..e3a08fcd72f4 100644 --- a/arch/x86/include/asm/disabled-features.h +++ b/arch/x86/include/asm/disabled-features.h @@ -71,6 +71,12 @@ #define DISABLE_SHSTK (1 << (X86_FEATURE_SHSTK & 31)) #endif +#ifdef CONFIG_X86_IBT +#define DISABLE_IBT 0 +#else +#define DISABLE_IBT (1 << (X86_FEATURE_IBT & 31)) +#endif + /* * Make sure to add features to the correct mask */ @@ -93,7 +99,7 @@ #define DISABLED_MASK16 (DISABLE_PKU|DISABLE_OSPKE|DISABLE_LA57|DISABLE_UMIP| \ DISABLE_ENQCMD|DISABLE_SHSTK) #define DISABLED_MASK17 0 -#define DISABLED_MASK18 0 +#define DISABLED_MASK18 (DISABLE_IBT) #define DISABLED_MASK19 0 #define DISABLED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 20) -- 2.21.0