Re: [PATCH 26/35] arm64: Add Kconfig for Guarded Control Stack (GCS)

On Sun, 16 Jul 2023 22:51:22 +0100 Mark Brown broonie@kernel.org wrote:

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 7856c3a3e35a..e1aeeda13c52 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -2091,6 +2091,25 @@ 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 # "2022 archiectural features"

Inconsistent naming and spelling mistake.

config ARM64_SVE bool "ARM Scalable Vector Extension support" default y