[PATCH v12 1/8] x86/cet/ibt: Add Kconfig option for user-mode Indirect Branch Tracking

From: Yu-cheng Yu
Date: Fri Sep 18 2020 - 15:24:23 EST


Introduce Kconfig option X86_INTEL_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>
---
v10:
- Change build-time CET check to config depends on.

arch/x86/Kconfig | 16 ++++++++++++++++
1 file changed, 16 insertions(+)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 6b6dad011763..b047e0a8d1c2 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1963,6 +1963,22 @@ 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
+ depends on $(cc-option,-fcf-protection)
+ select X86_INTEL_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.
+
+ If unsure, say y
+
config EFI
bool "EFI runtime service support"
depends on ACPI
--
2.21.0