Re: [PATCH 03/11] kselftest/arm64: Move exit calls out of fp-stress loads

[Lorenzo Stoakes (ARM)]

On Tue, Sep 01, 2026 at 06:06:43PM +0100, Mark Brown wrote:
> When they detect corruption the fp-stress test loads print load specific
> diagnostics and exits with a failure status.  In preparation for
> building versions intended to run as KVM guests factor the exits into

Maybe nice to say 'bare metal guests' here, though not sure if that's the usual
terminology?

In any case, to me it's a bit unclear in what sense you mean they're running as
KVM guests here.

> No functional change.

I don't think this is accurate, as you're changing the register into which a
value is loaded (x0 instead of x1).

That seems to be correct to me, but worth calling out that you're fixing that up
in the commit message and dropping this line.

>
> Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>

Looks sensible to me, with commit msg nits addressed:

Reviewed-by: Lorenzo Stoakes (ARM) <ljs@xxxxxxxxxx>

> diff --git a/tools/testing/selftests/arm64/fp/asm-utils-linux.S b/tools/testing/selftests/arm64/fp/asm-utils-linux.S
> index 3effeb1fbf50..9cd31dc47709 100644
> --- a/tools/testing/selftests/arm64/fp/asm-utils-linux.S
> +++ b/tools/testing/selftests/arm64/fp/asm-utils-linux.S

> +// Terminate the program, reporting failure.  Does not return.
> +function exit_error
> +	mov	x0, #1
> +	mov	x8, #__NR_exit
> +	svc	#0

And looking this up, svc = SuperVisor Call = -> EL1 essentially syscall(__NR_exit) :)

> diff --git a/tools/testing/selftests/arm64/fp/fpsimd-test.S b/tools/testing/selftests/arm64/fp/fpsimd-test.S
> index 9db7b5419397..5ee8ef51ea4e 100644
> --- a/tools/testing/selftests/arm64/fp/fpsimd-test.S
> +++ b/tools/testing/selftests/arm64/fp/fpsimd-test.S
> @@ -298,7 +298,5 @@ function barf
>  	bl	dumphex
>  	puts	"]\n"
>
> -	mov	x8, #__NR_exit
> -	mov	x1, #1
> -	svc	#0
> +	b	exit_error

Looking it up I see that 'b' is the unconditional variant, but it makes sense to
use it in the case of an exception being raised.

--
Cheers, Lorenzo