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 <yu-cheng.yu@xxxxxxxxx> --- arch/x86/Kconfig | 12 ++++++++++++ arch/x86/Makefile | 7 +++++++ 2 files changed, 19 insertions(+) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 768343768643..01de9743efe6 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1945,6 +1945,18 @@ 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 ad1314e5ef65..a7913de34866 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -164,6 +164,13 @@ 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
