Re: [PATCH 3/3] kselftest/arm64: Specify SVE data when testing VL set in sve-ptrace

[Mark Rutland <mark.rutland@arm.com>]

On Fri, May 23, 2025 at 04:27:14PM +0100, Mark Brown wrote:
> Since f916dd32a943 ("arm64/fpsimd: ptrace: Mandate SVE payload for
> streaming-mode state") we reject attempts to write to the streaming mode
> regset even if there is no register data supplied, causing the tests for
> setting vector lengths and setting SVE_VL_INHERIT in sve-ptrace to
> spuriously fail. Set the flag to avoid the issue, we still support not
> supplying register data.
> 
> Signed-off-by: Mark Brown <broonie@kernel.org>

Acked-by: Mark Rutland <mark.rutland@arm.com>

Mark.

> ---
>  tools/testing/selftests/arm64/fp/sve-ptrace.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/testing/selftests/arm64/fp/sve-ptrace.c b/tools/testing/selftests/arm64/fp/sve-ptrace.c
> index 7e259907805b..7f9b6a61d369 100644
> --- a/tools/testing/selftests/arm64/fp/sve-ptrace.c
> +++ b/tools/testing/selftests/arm64/fp/sve-ptrace.c
> @@ -170,7 +170,7 @@ static void ptrace_set_get_inherit(pid_t child, const struct vec_type *type)
>  	memset(&sve, 0, sizeof(sve));
>  	sve.size = sizeof(sve);
>  	sve.vl = sve_vl_from_vq(SVE_VQ_MIN);
> -	sve.flags = SVE_PT_VL_INHERIT;
> +	sve.flags = SVE_PT_VL_INHERIT | SVE_PT_REGS_SVE;
>  	ret = set_sve(child, type, &sve);
>  	if (ret != 0) {
>  		ksft_test_result_fail("Failed to set %s SVE_PT_VL_INHERIT\n",
> @@ -235,6 +235,7 @@ static void ptrace_set_get_vl(pid_t child, const struct vec_type *type,
>  	/* Set the VL by doing a set with no register payload */
>  	memset(&sve, 0, sizeof(sve));
>  	sve.size = sizeof(sve);
> +	sve.flags = SVE_PT_REGS_SVE;
>  	sve.vl = vl;
>  	ret = set_sve(child, type, &sve);
>  	if (ret != 0) {
> 
> -- 
> 2.39.5
>