[PATCH v4 25/36] arm64: Add Kconfig for Guarded Control Stack (GCS)

Mark Brown
2023-08-07T22:04:53Z

Provide a Kconfig option allowing the user to select if GCS support is
built into the kernel.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
arch/arm64/Kconfig | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index a2511b30d0f6..b5ef1a698770 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -2093,6 +2093,25 @@ config ARM64_EPAN
if the cpu does not implement the feature.
endmenu # "ARMv8.7 architectural features"

+menu "v9.4 architectural features"
+
+config ARM64_GCS
+ bool "Enable support for Guarded Control Stack (GCS)"
+ default y
+ select ARCH_USES_HIGH_VMA_FLAGS
+ help
+ Guarded Control Stack (GCS) provides support for a separate
+ stack with restricted access which contains only return
+ addresses. This can be used to harden against some attacks
+ by comparing return address used by the program with what is
+ stored in the GCS, and may also be used to efficiently obtain
+ the call stack for applications such as profiling.
+
+ The feature is detected at runtime, and will remain disabled
+ if the system does not implement the feature.
+
+endmenu # "v9.4 architectural features"
+
config ARM64_SVE
bool "ARM Scalable Vector Extension support"
default y

--
2.30.2