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From:   Andrey Konovalov <andreyknvl@gmail.com>
Date:   Wed, 19 Oct 2022 21:48:42 +0200
Message-ID: <CA+fCnZcea7UrA11HyRB80WgrUXMtEkK0AjdxEN=H-pMuWBhQyQ@mail.gmail.com>
Subject: Re: [PATCH] kasan: Enable KUnit integration whenever CONFIG_KUNIT is enabled
To:     David Gow <davidgow@google.com>
Cc:     Andrey Konovalov <andreyknvl@google.com>,
        Alexander Potapenko <glider@google.com>,
        Andrey Ryabinin <ryabinin.a.a@gmail.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Vincenzo Frascino <vincenzo.frascino@arm.com>,
        kasan-dev@googlegroups.com, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, Daniel Latypov <dlatypov@google.com>,
        Brendan Higgins <brendanhiggins@google.com>,
        linux-kselftest@vger.kernel.org, kunit-dev@googlegroups.com
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On Wed, Oct 19, 2022 at 5:06 PM David Gow <davidgow@google.com> wrote:
>
> > How does KUnit detect a KASAN failure for other tests than the KASAN
> > ones? I thought this was only implemented for KASAN tests. At least, I
> > don't see any code querying kunit_kasan_status outside of KASAN tests.
>
> Yeah, there aren't any other tests which set up a "kasan_status"
> resource to expect specific failures, but we still want the fallback
> call to kunit_set_failure() so that any test which causes a KASAN
> report will fail:
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/mm/kasan/report.c#n130

Ah, right. Thanks for the explanation!

> > I'm currently switching KASAN tests from using KUnit resources to
> > console tracepoints [1], and those patches will be in conflict with
> > yours.
>
> Ah, sorry -- I'd seen these go past, and totally forgot about them! I
> think all we really want to keep is the ability to fail tests if a
> KASAN report occurs. The tricky bit is then disabling that for the
> KASAN tests, so that they can have "expected" failures.

I wonder what's the best solution to support this, assuming KASAN
tests are switched to using tracepoints... I guess we could still keep
the per-task KUnit flag, and only use it for non-KASAN tests. However,
they will still suffer from the same issue tracepoints solve for KASAN
tests: if a bug is triggered in a context other than the current task,
the test will succeed.