On Wed, Oct 23, 2024 at 09:38:29PM +0100, Mark Brown wrote:
> The comments in the handlers for the irritator signal in the test threads
> for fp-stress suggest that the irritator will corrupt the register state
> observed by the main thread but this is not the case, instead the FPSIMD
> and SVE irritators (which are the only ones that are implemented) modify
> the current register state which is expected to be overwritten on return
> from the handler by the saved register state. Update the comment to reflect
> what the handler is actually doing.
>
> Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Mark.
> ---
> tools/testing/selftests/arm64/fp/fpsimd-test.S | 3 +--
> tools/testing/selftests/arm64/fp/sve-test.S | 3 +--
> 2 files changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/tools/testing/selftests/arm64/fp/fpsimd-test.S b/tools/testing/selftests/arm64/fp/fpsimd-test.S
> index 8b960d01ed2e0ef516893b68794078ddf8c01e1f..bdfb7cf2e4ec175fda62c1c2f38c6ebb1a1c48bf 100644
> --- a/tools/testing/selftests/arm64/fp/fpsimd-test.S
> +++ b/tools/testing/selftests/arm64/fp/fpsimd-test.S
> @@ -134,8 +134,7 @@ function check_vreg
> b memcmp
> endfunction
>
> -// Any SVE register modified here can cause corruption in the main
> -// thread -- but *only* the registers modified here.
> +// Modify live register state, the signal return will undo our changes
> function irritator_handler
> // Increment the irritation signal count (x23):
> ldr x0, [x2, #ucontext_regs + 8 * 23]
> diff --git a/tools/testing/selftests/arm64/fp/sve-test.S b/tools/testing/selftests/arm64/fp/sve-test.S
> index fff60e2a25addfd4850ef71aa3cf6535ac880ffd..e3c0d585684df29723a49265f3df6d23817498c7 100644
> --- a/tools/testing/selftests/arm64/fp/sve-test.S
> +++ b/tools/testing/selftests/arm64/fp/sve-test.S
> @@ -291,8 +291,7 @@ function check_ffr
> #endif
> endfunction
>
> -// Any SVE register modified here can cause corruption in the main
> -// thread -- but *only* the registers modified here.
> +// Modify live register state, the signal return will undo our changes
> function irritator_handler
> // Increment the irritation signal count (x23):
> ldr x0, [x2, #ucontext_regs + 8 * 23]
>
> --
> 2.39.2
>