From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-5.8 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=unavailable autolearn_force=no version=3.4.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id 24F297D8D4 for ; Thu, 11 Oct 2018 15:22:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728858AbeJKWtW (ORCPT ); Thu, 11 Oct 2018 18:49:22 -0400 Received: from mga18.intel.com ([134.134.136.126]:64714 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728607AbeJKWtW (ORCPT ); Thu, 11 Oct 2018 18:49:22 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 11 Oct 2018 08:21:43 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.54,368,1534834800"; d="scan'208";a="77271617" Received: from 2b52.sc.intel.com ([143.183.136.147]) by fmsmga007.fm.intel.com with ESMTP; 11 Oct 2018 08:21:42 -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 , 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 Cc: Yu-cheng Yu Subject: [PATCH v5 01/11] x86/cet/ibt: Add Kconfig option for user-mode Indirect Branch Tracking Date: Thu, 11 Oct 2018 08:16:44 -0700 Message-Id: <20181011151654.27221-2-yu-cheng.yu@intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181011151654.27221-1-yu-cheng.yu@intel.com> References: <20181011151654.27221-1-yu-cheng.yu@intel.com> Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org The user-mode indirect branch tracking support is done mostly by GCC to insert ENDBR64/ENDBR32 instructions at branch targets. The kernel provides CPUID enumeration, feature MSR setup and the allocation of legacy bitmap. Signed-off-by: Yu-cheng Yu --- arch/x86/Kconfig | 16 ++++++++++++++++ arch/x86/Makefile | 7 +++++++ 2 files changed, 23 insertions(+) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index ac2244896a18..dd65dae3c5cb 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1919,6 +1919,9 @@ config X86_INTEL_CET config ARCH_HAS_SHSTK def_bool n +config ARCH_HAS_AS_LIMIT + def_bool n + config ARCH_HAS_PROGRAM_PROPERTIES def_bool n @@ -1943,6 +1946,19 @@ config X86_INTEL_SHADOW_STACK_USER If unsure, say y. +config X86_INTEL_BRANCH_TRACKING_USER + prompt "Intel Indirect Branch Tracking for user-mode" + def_bool n + depends on CPU_SUP_INTEL && X86_64 + select X86_INTEL_CET + select ARCH_HAS_AS_LIMIT + select ARCH_HAS_PROGRAM_PROPERTIES + ---help--- + Indirect Branch Tracking provides hardware protection against return-/jmp- + oriented programming attacks. + + If unsure, say y + config EFI bool "EFI runtime service support" depends on ACPI diff --git a/arch/x86/Makefile b/arch/x86/Makefile index b28842b80295..ff652bba849f 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -159,6 +159,13 @@ ifdef CONFIG_X86_INTEL_SHADOW_STACK_USER endif endif +# Check compiler ibt support +ifdef CONFIG_X86_INTEL_BRANCH_TRACKING_USER + ifeq ($(call cc-option-yn, -fcf-protection=branch), n) + $(error CONFIG_X86_INTEL_BRANCH_TRACKING_USER not supported by compiler) + endif +endif + # # If the function graph tracer is used with mcount instead of fentry, # '-maccumulate-outgoing-args' is needed to prevent a GCC bug -- 2.17.1