[PATCH v1 2/5] selftests/arm64: Allow zero tags in mte_switch_mode()

[Shuah Khan]

On 5/10/22 10:45 AM, Mark Brown wrote:
> mte_switch_mode() currently rejects attempts to set a zero tag however
> there are tests such as check_tags_inclusion which attempt to cover cases
> with zero tags using mte_switch_mode(). Since it is not clear why we are
> rejecting zero tags change the test to accept them.
> 
> The issue has not previously been as apparent as it should be since the
> return value of mte_switch_mode() was not always checked in the callers
> and the tests weren't otherwise failing.
> 
> Signed-off-by: Mark Brown <broonie at kernel.org>
> ---
>   tools/testing/selftests/arm64/mte/mte_common_util.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/testing/selftests/arm64/mte/mte_common_util.c b/tools/testing/selftests/arm64/mte/mte_common_util.c
> index 260206f4dce0..6ff4c4bcbff1 100644
> --- a/tools/testing/selftests/arm64/mte/mte_common_util.c
> +++ b/tools/testing/selftests/arm64/mte/mte_common_util.c
> @@ -283,7 +283,7 @@ int mte_switch_mode(int mte_option, unsigned long incl_mask)
>   		return -EINVAL;
>   	}
>   
> -	if (!(incl_mask <= MTE_ALLOW_NON_ZERO_TAG)) {
> +	if (incl_mask & ~MT_INCLUDE_TAG_MASK) {
>   		ksft_print_msg("FAIL: Invalid incl_mask %lx\n", incl_mask);
>   		return -EINVAL;
>   	}
> 

Looks good to me.

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

thanks,
-- Shuah