The architecture defines a format for guarded control stack caps, used to mark the top of an unused GCS in order to limit the potential for exploitation via stack switching. Add definitions associated with these.
Reviewed-by: Thiago Jung Bauermann <thiago.bauerm...@linaro.org> Acked-by: Catalin Marinas <catalin.mari...@arm.com> Signed-off-by: Mark Brown <broo...@kernel.org> --- arch/arm64/include/asm/sysreg.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index 9ea97dddefc4..9c98ff448bd9 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -1101,6 +1101,26 @@ /* Initial value for Permission Overlay Extension for EL0 */ #define POR_EL0_INIT POE_RXW +/* + * Definitions for Guarded Control Stack + */ + +#define GCS_CAP_ADDR_MASK GENMASK(63, 12) +#define GCS_CAP_ADDR_SHIFT 12 +#define GCS_CAP_ADDR_WIDTH 52 +#define GCS_CAP_ADDR(x) FIELD_GET(GCS_CAP_ADDR_MASK, x) + +#define GCS_CAP_TOKEN_MASK GENMASK(11, 0) +#define GCS_CAP_TOKEN_SHIFT 0 +#define GCS_CAP_TOKEN_WIDTH 12 +#define GCS_CAP_TOKEN(x) FIELD_GET(GCS_CAP_TOKEN_MASK, x) + +#define GCS_CAP_VALID_TOKEN 0x1 +#define GCS_CAP_IN_PROGRESS_TOKEN 0x5 + +#define GCS_CAP(x) ((((unsigned long)x) & GCS_CAP_ADDR_MASK) | \ + GCS_CAP_VALID_TOKEN) + #define ARM64_FEATURE_FIELD_BITS 4 /* Defined for compatibility only, do not add new users. */ -- 2.39.2
