From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf1-f199.google.com (mail-pf1-f199.google.com [209.85.210.199]) by kanga.kvack.org (Postfix) with ESMTP id B7F986B5240 for ; Thu, 30 Aug 2018 10:44:44 -0400 (EDT) Received: by mail-pf1-f199.google.com with SMTP id x85-v6so4877531pfe.13 for ; Thu, 30 Aug 2018 07:44:44 -0700 (PDT) Received: from mga18.intel.com (mga18.intel.com. [134.134.136.126]) by mx.google.com with ESMTPS id t10-v6si6980653pgn.667.2018.08.30.07.44.43 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 30 Aug 2018 07:44:43 -0700 (PDT) From: Yu-cheng Yu Subject: [RFC PATCH v3 1/8] x86/cet/ibt: Add Kconfig option for user-mode Indirect Branch Tracking Date: Thu, 30 Aug 2018 07:40:02 -0700 Message-Id: <20180830144009.3314-2-yu-cheng.yu@intel.com> In-Reply-To: <20180830144009.3314-1-yu-cheng.yu@intel.com> References: <20180830144009.3314-1-yu-cheng.yu@intel.com> Sender: owner-linux-mm@kvack.org List-ID: 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 , Florian Weimer , "H.J. Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Peter Zijlstra , "Ravi V. Shankar" , Vedvyas Shanbhogue Cc: Yu-cheng Yu 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 | 12 ++++++++++++ arch/x86/Makefile | 7 +++++++ 2 files changed, 19 insertions(+) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 2cfe11e1cf7f..0d97b03f35f6 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1941,6 +1941,18 @@ 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_PROGRAM_PROPERTIES + ---help--- + Indirect Branch Tracking provides hardware protection against return-/jmp- + oriented programing 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 00927853e409..0da5121c30db 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