Re: [PATCH v10 17/40] arm64/traps: Handle GCS exceptions

Catalin Marinas
2024-08-19T09:12:53Z

On Thu, Aug 01, 2024 at 01:06:44PM +0100, Mark Brown wrote:
> A new exception code is defined for GCS specific faults other than
> standard load/store faults, for example GCS token validation failures,
> add handling for this. These faults are reported to userspace as
> segfaults with code SEGV_CPERR (protection error), mirroring the
> reporting for x86 shadow stack errors.
>
> GCS faults due to memory load/store operations generate data aborts with
> a flag set, these will be handled separately as part of the data abort
> handling.
>
> Since we do not currently enable GCS for EL1 we should not get any faults
> there but while we're at it we wire things up there, treating any GCS
> fault as fatal.
>
> Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org>
> Signed-off-by: Mark Brown <broonie@kernel.org>

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>