[v8,26/38] arm64: Add Kconfig for Guarded Control Stack (GCS)

Message ID 20240203-arm64-gcs-v8-26-c9fec77673ef@kernel.org
State New
Headers
Series arm64/gcs: Provide support for GCS in userspace |

Commit Message

Mark Brown Feb. 3, 2024, 12:25 p.m. UTC
  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 | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
  

Patch

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index aa7c1d435139..e0048e4660cf 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -2098,6 +2098,26 @@  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_HAS_USER_SHADOW_STACK
+	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