Skipping tests that are unimplemented in 32-bit emulation

[Mark Johnston]

On Tue, Aug 07, 2018 at 09:08:39AM -0600, Alan Somers wrote:
> On Tue, Aug 7, 2018 at 9:03 AM, Mark Johnston <markj at freebsd.org> wrote:
> 
> > On Mon, Aug 06, 2018 at 02:18:35PM -0600, Alan Somers wrote:
> > > On Mon, Aug 6, 2018 at 1:14 PM, Mark Johnston <markj at freebsd.org> wrote:
> > >
> > > > On Sun, Jul 29, 2018 at 11:23:33AM -0600, Alan Somers wrote:
> > > > > I recently tried running the i386 test suite in a chroot on an amd64
> > > > > system.  162 tests failed, and 33 were broken.  Some of the failures
> > were
> > > > > due to system calls that haven't been implemented in 32-bit
> > emulation.
> > > > > setfib(2) is an example.  I think it's unlikely that anybody will
> > ever
> > > > need
> > > > > 32-bit emulation for setfib(2), so perhaps we should just skip the
> > test?
> > > > > What's the best way to do that?  I can come up with two ways:
> > > > >
> > > > > 1) At runtime, check the hw.machine sysctl and see if it matches some
> > > > > compile time preprocessor constant.  I don't know what constant to
> > use,
> > > > > though.  Checking __amd64__ would only work for i386 binaries on
> > amd64
> > > > > kernels, and not something else like mips binaries on mips64 kernels
> > (I
> > > > > don't know if we support that, but I don't want to rule it out).
> > > > >
> > > > > 2) At buildtime, put an "allowed_architectures=i386" metadata
> > property
> > > > into
> > > > > the Kyuafile for that test program.  This would require support in
> > > > > /usr/share/mk/bsd.test.mk.  It would also require patching Kyua
> > itself,
> > > > > because currently "Kyua config" returns the architecture for which
> > it was
> > > > > built, not the one on which it's running.
> > > > >
> > > > > Thoughts?
> > > >
> > > > I don't have any particular suggestions, but I'd personally rather
> > avoid
> > > > a solution that requires tests to opt-in to running under 32-bit
> > > > emulation, which I think excludes 2).  I'd be happy to help annotate
> > > > any failing tests as required.  It bugs me that the test suite
> > currently
> > > > doesn't cover such relatively complicated functions as
> > > > freebsd32_copy_msg_out().
> > >
> > > I don't think that 2 would necessarily be opt-in, because an undefined
> > > value for allowed_architectures is interpreted as meaning "all".  It
> > could
> > > be opt-out instead.  But it could still be a little awkward.  Option 1
> > > could be accomplished for atf-c testcases by comparing the value of
> > > __LP64__ to a hardcoded list of known 64-bit processors as returned by
> > > uname(3).  But I don't know how to implement 1 for atf-sh programs.  An
> > > atf-sh program would need to know the architecture of any binary that it
> > > might invoke.  Is there anything in /etc indicating what architecture the
> > > image was built for?  Should we just use "file /lib/libc.so.*"?
> >
> > Could we instead build and install a /usr/tests32 suite on systems that
> > can support it, and use a top-level Kyuafile and kyua.conf that overrides
> > the "architecture" variable?
> >
> 
> It's not enough to build and install the atf-c tests in 32-bit mode.  We
> would need an entire 32-bit chroot in order to run the atf-sh tests in
> 32-bit mode.

Oops, right.  For 2), then, couldn't we define test_suite("FreeBSD32")
in the kyuafiles for the 32-bit test suite and set a
test_suite.FreeBSD32.compat32=true variable in kyua.conf?  Then a test
which uses, say, setfib(1) can query that variable and skip if it's set.