On Wed, Jun 12, 2024, Muhammad Usama Anjum wrote:
> The KSFT_FAIL, exit code must be used instead of exit(254).
This needs more justification. KVM selftests have worked just fine for 6+ years
using exit(254), so stating they "must" use KSFT_FAIL is obviously not true.
I'm not personally opposed to switching to KSFT_FAIL, but it is a potentially
breaking change. E.g. some of Google's internal test infrastructure explicitly
relies on the exit code being 254. I don't _think_ that infrastructure interacts
with KVM selftests, nor do I think that forcing upstream KVM selftests to sacrifice
TAP compliance just to play nice with someone's crusty test infrastructure is a
good tradeoff, but this and all of the TAP compliance work needs to be done with
more thought and care.
> The 254 code here seems like anciant relic.
As above, AFAICT it comes from Google's internal test infrastructure (KVM selftests
came from Google).
> Its even better if we use ksft_exit_fail_msg() which will print out "Bail
> out" meaning the test exited without completing. This string is TAP protocol
> specific.
This is debatable and not obviously correct. The documentation says:
Bail out!
As an emergency measure a test script can decide that further tests are
useless (e.g. missing dependencies) and testing should stop immediately. In
that case the test script prints the magic words
which suggests that a test should only emit "Bail out!" if it wants to stop
entirely. We definitely don't want KVM selftests to bail out if a TEST_ASSERT()
fails in one testcase.
> Signed-off-by: Muhammad Usama Anjum <usama.anjum@xxxxxxxxxxxxx>
> ---
> tools/testing/selftests/kvm/lib/assert.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/kvm/lib/assert.c b/tools/testing/selftests/kvm/lib/assert.c
> index 33651f5b3a7fd..db648a7ac429b 100644
> --- a/tools/testing/selftests/kvm/lib/assert.c
> +++ b/tools/testing/selftests/kvm/lib/assert.c
> @@ -87,7 +87,7 @@ test_assert(bool exp, const char *exp_str,
>
> if (errno == EACCES)
> ksft_exit_skip("Access denied - Exiting\n");
> - exit(254);
> + ksft_exit_fail_msg("\n");
> }
>
> return;
> --
> 2.39.2
>
