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Date:   Wed, 4 May 2022 14:12:30 -0700
From:   Luis Chamberlain <mcgrof@kernel.org>
To:     Daniel Latypov <dlatypov@google.com>,
        Shuah Khan <skhan@linuxfoundation.org>
Cc:     David Gow <davidgow@google.com>,
        Lucas De Marchi <lucas.demarchi@intel.com>,
        Aaron Tomlin <atomlin@redhat.com>,
        linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org,
        Brendan Higgins <brendanhiggins@google.com>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Jonathan Corbet <corbet@lwn.net>,
        Andrew Morton <akpm@linux-foundation.org>,
        Kees Cook <keescook@chromium.org>,
        Greg KH <gregkh@linuxfoundation.org>,
        "Guilherme G . Piccoli" <gpiccoli@igalia.com>,
        Sebastian Reichel <sre@kernel.org>,
        John Ogness <john.ogness@linutronix.de>,
        Joe Fradley <joefradley@google.com>,
        kunit-dev@googlegroups.com, linux-kselftest@vger.kernel.org,
        linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
        Jani Nikula <jani.nikula@linux.intel.com>
Subject: Re: [PATCH v2] kunit: Taint kernel if any tests run
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On Wed, May 04, 2022 at 02:19:59PM -0500, Daniel Latypov wrote:
> On Wed, May 4, 2022 at 1:46 PM Luis Chamberlain <mcgrof@kernel.org> wrote:
> > OK so, we can just skip tainting considerations for selftests which
> > don't use modules for now. There may be selftests which do wonky
> > things in userspace but indeed I agree the userspace taint would
> > be better for those but I don't think it may be worth bother
> > worrying about those at this point in time.
> >
> > But my point in that sharing a taint between kunit / selftests modules
> > does make sense and is easily possible. The unfortunate aspect is just
> 
> Yes, I 100% agree that we should share a taint for kernelspace testing
> from both kunit/kselftest.
> Someone running the system won't care what framework was used.

OK do you mind doing the nasty work of manually adding the new
MODULE_TAINT() to the selftests as part of your effort?

*Alternatively*, if we *moved* all sefltests modules to a new
lib/debug/selftests/ directory or something like that then t would
seem modpost *could* add the taint flag automagically for us without
having to edit or require it on new drivers. We have similar type of
taint for staging, see add_staging_flag().

I would *highly* prefer this approach, event though it is more work,
because I think this is a step we should take anyway.

However, I just checked modules on lib/ and well, some of them are
already in their own directory, like lib/math/test_div64.c. So not
sure, maybe just move a few modules which are just in lib/*.c for now
and then just sprinkle the MODULE_TAINT() to the others?

> > that selftests don't have a centralized runner, because I can just
> > run tools/testing/selftests/sysctl/sysctl.sh for example and that's it.
> > So I think we have no other option but to just add the module info
> > manually for selftests at this time.
> 
> Somewhat tangential: there's a number of other test modules that
> aren't explicitly part of kselftest.

Oh interesting, like which one?

> Long-term, I think most of them should be converted to kselftest or
> kunit as appropriate, so they'll get taken care of eventually.

Makes sense.

  Luis