On Thu, May 02, 2024 at 11:42:29AM GMT, Sean Christopherson wrote:
> +kvm
>
> On Tue, Mar 05, 2024, Mickaël Salaün wrote:
> > On Tue, Mar 05, 2024 at 01:43:14AM -0800, Kees Cook wrote:
> > > On Mon, Mar 04, 2024 at 03:39:02PM -0800, Jakub Kicinski wrote:
> > > > On Mon, 4 Mar 2024 15:14:04 -0800 Kees Cook wrote:
> > > > > > Ugh, I'm guessing vfork() "eats" the signal, IOW grandchild signals,
> > > > > > child exits? vfork() and signals.. I'd rather leave to Kees || Mickael.
> > > > >
> > > > > Oh no, that does seem bad. Since Mickaël is also seeing weird issues,
> > > > > can we drop the vfork changes for now?
> > > >
> > > > Seems doable, but won't be a simple revert. "drop" means we'd need
> > > > to bring ->step back. More or less go back to v3.
> > >
> > > I think we have to -- other CIs are now showing the most of seccomp
> > > failing now. (And I can confirm this now -- I had only tested seccomp
> > > on earlier versions of the series.)
> >
> > Sorry for the trouble, I found and fixed the vfork issues.
>
> Heh, you found and fixed _some of_ the vfork issues. This whole mess completely
> breaks existing tests that use TEST_F() and exit() with non-zero values to
> indicate failure, including failures that occur during FIXTURE_SETUP().
>
> E.g. all of the KVM selftests that use KVM_ONE_VCPU_TEST() are broken and will
> always show all tests as passing.
>
> The below gets things working for KVM selftests again, but (a) I have no idea if
> it's a complete fix, (b) I don't know if it will break other users of the harness,
> and (c) I don't understand why spawning a grandchild is the default behavior, i.e.
> why usage that has zero need of separating teardown from setup+run is subjected to
> the complexity of the handful of tests that do.
Thanks for the fix. I think it covers almost all cases. I'd handle the
same way the remaining _exit() though. The grandchild changes was a
long due patch from the time I added kselftest_harness.h and forked the
TEST_F() macro. I'll send a new patch series with this fix.
>
> diff --git a/tools/testing/selftests/kselftest_harness.h b/tools/testing/selftests/kselftest_harness.h
> index 4fd735e48ee7..24e95828976f 100644
> --- a/tools/testing/selftests/kselftest_harness.h
> +++ b/tools/testing/selftests/kselftest_harness.h
> @@ -391,7 +391,7 @@
> fixture_name##_setup(_metadata, &self, variant->data); \
> /* Let setup failure terminate early. */ \
> if (_metadata->exit_code) \
> - _exit(0); \
> + _exit(_metadata->exit_code); \
> _metadata->setup_completed = true; \
> fixture_name##_##test_name(_metadata, &self, variant->data); \
> } else if (child < 0 || child != waitpid(child, &status, 0)) { \
> @@ -406,8 +406,10 @@
> } \
> if (_metadata->setup_completed && _metadata->teardown_parent) \
> fixture_name##_teardown(_metadata, &self, variant->data); \
> - if (!WIFEXITED(status) && WIFSIGNALED(status)) \
> - /* Forward signal to __wait_for_test(). */ \
> + /* Forward exit codes and signals to __wait_for_test(). */ \
> + if (WIFEXITED(status)) \
> + _exit(WEXITSTATUS(status)); \
> + else if (WIFSIGNALED(status)) \
> kill(getpid(), WTERMSIG(status)); \
> __test_check_assert(_metadata); \
> } \
>
