Re: [PATCH 2/5] kselftest: Fix vdso_test_time to pass on skips

[Vincenzo Frascino <vincenzo.frascino@arm.com>]

Hi Cristian,

On 1/26/22 10:27 AM, Cristian Marussi wrote:
> When a vDSO symbol is not found, all the testcases in vdso_test_abi usually
> report a SKIP, which, in turn, is reported back to Kselftest as a PASS.
> 
> Testcase vdso_test_time, instead, reporting a SKIP, causes the whole set of
> tests within vdso_test_abi to be considered FAIL when symbol is not found.
> 
> Fix it reporting a PASS when vdso_test_time cannot find the vdso symbol.
> 
> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
> Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
> ---
> Seen as a failure on both a JUNO and a Dragonboard on both recent and old
> kernels/testruns:
> 
> root@deb-buster-arm64:~# /opt/ksft/vDSO/vdso_test_abi
> [vDSO kselftest] VDSO_VERSION: LINUX_2.6.39
> The time is 1637922136.675304
> The time is 1637922136.675361000
> The resolution is 0 1
> clock_id: CLOCK_REALTIME [PASS]
> The time is 1927.760604900
> The resolution is 0 1
> clock_id: CLOCK_BOOTTIME [PASS]
> The time is 1637922136.675649700
> The resolution is 0 1
> clock_id: CLOCK_TAI [PASS]
> The time is 1637922136.672000000
> The resolution is 0 4000000
> clock_id: CLOCK_REALTIME_COARSE [PASS]
> The time is 1927.761005600
> The resolution is 0 1
> clock_id: CLOCK_MONOTONIC [PASS]
> The time is 1927.761132780
> The resolution is 0 1
> clock_id: CLOCK_MONOTONIC_RAW [PASS]
> The time is 1927.757093740
> The resolution is 0 4000000
> clock_id: CLOCK_MONOTONIC_COARSE [PASS]
> Could not find __kernel_time              <<< This caused a FAIL as a whole
> root@deb-buster-arm64:~# echo $?
> 1
> 
> e.g.: https://lkft.validation.linaro.org/scheduler/job/2192570#L27778
> ---
>  tools/testing/selftests/vDSO/vdso_test_abi.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/testing/selftests/vDSO/vdso_test_abi.c b/tools/testing/selftests/vDSO/vdso_test_abi.c
> index 3d603f1394af..7dcc66d1cecf 100644
> --- a/tools/testing/selftests/vDSO/vdso_test_abi.c
> +++ b/tools/testing/selftests/vDSO/vdso_test_abi.c
> @@ -90,8 +90,9 @@ static int vdso_test_time(void)
>  		(vdso_time_t)vdso_sym(version, name[2]);
>  
>  	if (!vdso_time) {
> +		/* Skip if symbol not found: consider skipped tests as passed */
>  		printf("Could not find %s\n", name[2]);
> -		return KSFT_SKIP;
> +		return KSFT_PASS;

My preference would be to keep "KSFT_SKIP" here and verify separately the return
status of each test. This would maintain compliance with the kselftest API.
Could you please test the patch in-reply-to this one (will be sent shortly) and
let me know if it works for you?

If it does feel free to fold it in the next version of your series with your
"Tested-by:" otherwise let me know.

Thanks!

>  	}
>  
>  	long ret = vdso_time(NULL);
> 

-- 
Regards,
Vincenzo