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 <yu-cheng.yu@xxxxxxxxx> --- 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
