Re: [PATCH v11 35/40] kselftest/arm64: signal: Handle ZA signal context in core code

[Shuah Khan <skhan@linuxfoundation.org>]

On 2/7/22 8:21 AM, Mark Brown wrote:
> As part of the generic code for signal handling test cases we parse all
> signal frames to make sure they have at least the basic form we expect
> and that there are no unexpected frames present in the signal context.
> Add coverage of the ZA signal frame to this code.
> 
> Signed-off-by: Mark Brown <broonie@kernel.org>
> ---
>   .../arm64/signal/testcases/testcases.c        | 36 +++++++++++++++++++
>   .../arm64/signal/testcases/testcases.h        |  3 +-
>   2 files changed, 38 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/testing/selftests/arm64/signal/testcases/testcases.c b/tools/testing/selftests/arm64/signal/testcases/testcases.c
> index 8c2a57fc2f9c..84c36bee4d82 100644
> --- a/tools/testing/selftests/arm64/signal/testcases/testcases.c
> +++ b/tools/testing/selftests/arm64/signal/testcases/testcases.c
> @@ -75,6 +75,31 @@ bool validate_sve_context(struct sve_context *sve, char **err)
>   	return true;
>   }
>   
> +bool validate_za_context(struct za_context *za, char **err)
> +{
> +	/* Size will be rounded up to a multiple of 16 bytes */
> +	size_t regs_size
> +		= ((ZA_SIG_CONTEXT_SIZE(sve_vq_from_vl(za->vl)) + 15) / 16) * 16;
> +
> +	if (!za || !err)
> +		return false;
> +
> +	/* Either a bare za_context or a za_context followed by regs data */
> +	if ((za->head.size != sizeof(struct za_context)) &&
> +	    (za->head.size != regs_size)) {
> +		*err = "bad size for ZA context";
> +		return false;
> +	}
> +
> +	if (!sve_vl_valid(za->vl)) {
> +		*err = "SME VL in ZA context invalid";
> +
> +		return false;
> +	}
> +
> +	return true;
> +}
> +
>   bool validate_reserved(ucontext_t *uc, size_t resv_sz, char **err)
>   {
>   	bool terminated = false;
> @@ -82,6 +107,7 @@ bool validate_reserved(ucontext_t *uc, size_t resv_sz, char **err)
>   	int flags = 0;
>   	struct extra_context *extra = NULL;
>   	struct sve_context *sve = NULL;
> +	struct za_context *za = NULL;
>   	struct _aarch64_ctx *head =
>   		(struct _aarch64_ctx *)uc->uc_mcontext.__reserved;
>   
> @@ -120,6 +146,13 @@ bool validate_reserved(ucontext_t *uc, size_t resv_sz, char **err)
>   			sve = (struct sve_context *)head;
>   			flags |= SVE_CTX;
>   			break;
> +		case ZA_MAGIC:
> +			if (flags & ZA_CTX)
> +				*err = "Multiple ZA_MAGIC";

Is this considered an error?

> +			/* Size is validated in validate_za_context() */
> +			za = (struct za_context *)head;
> +			flags |= ZA_CTX;
> +			break;
>   		case EXTRA_MAGIC:
>   			if (flags & EXTRA_CTX)
>   				*err = "Multiple EXTRA_MAGIC";
> @@ -165,6 +198,9 @@ bool validate_reserved(ucontext_t *uc, size_t resv_sz, char **err)
>   		if (flags & SVE_CTX)
>   			if (!validate_sve_context(sve, err))
>   				return false;
> +		if (flags & ZA_CTX)
> +			if (!validate_za_context(za, err))

If validate_za_context() finds an error, the above "Multiple ZA_MAGIC" will
be overwritten? Is that the intent?

> +				return false;
>   
>   		head = GET_RESV_NEXT_HEAD(head);
>   	}
> diff --git a/tools/testing/selftests/arm64/signal/testcases/testcases.h b/tools/testing/selftests/arm64/signal/testcases/testcases.h
> index ad884c135314..49f1d5de7b5b 100644
> --- a/tools/testing/selftests/arm64/signal/testcases/testcases.h
> +++ b/tools/testing/selftests/arm64/signal/testcases/testcases.h
> @@ -16,7 +16,8 @@
>   
>   #define FPSIMD_CTX	(1 << 0)
>   #define SVE_CTX		(1 << 1)
> -#define EXTRA_CTX	(1 << 2)
> +#define ZA_CTX		(1 << 2)
> +#define EXTRA_CTX	(1 << 3)
>   
>   #define KSFT_BAD_MAGIC	0xdeadbeef
>   
> 

With these explained or fixed:

Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>

thanks,
-- Shuah
thanks,
-- Shuah

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