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From:   Dmitry Vyukov <dvyukov@google.com>
Date:   Sun, 1 Mar 2020 07:39:22 +0100
Message-ID: <CACT4Y+YTNZRfKLH1=FibrtGj34MY=naDJY6GWVnpMvgShSLFhg@mail.gmail.com>
Subject: Re: [RFC PATCH 1/2] Port KASAN Tests to KUnit
To:     Patricia Alfonso <trishalfonso@google.com>,
        Kees Cook <keescook@google.com>
Cc:     Andrey Ryabinin <aryabinin@virtuozzo.com>,
        Brendan Higgins <brendanhiggins@google.com>,
        David Gow <davidgow@google.com>,
        Ingo Molnar <mingo@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Juri Lelli <juri.lelli@redhat.com>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        LKML <linux-kernel@vger.kernel.org>,
        kasan-dev <kasan-dev@googlegroups.com>,
        "open list:KERNEL SELFTEST FRAMEWORK" 
        <linux-kselftest@vger.kernel.org>, kunit-dev@googlegroups.com
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On Sat, Feb 29, 2020 at 2:56 AM Patricia Alfonso
<trishalfonso@google.com> wrote:
> On Thu, Feb 27, 2020 at 6:19 AM Dmitry Vyukov <dvyukov@google.com> wrote:
> >
> > .On Thu, Feb 27, 2020 at 3:44 AM Patricia Alfonso
> > > -       pr_info("out-of-bounds in copy_from_user()\n");
> > > -       unused = copy_from_user(kmem, usermem, size + 1);
> >
> > Why is all of this removed?
> > Most of these tests are hard earned and test some special corner cases.
> >
> I just moved it inside IS_MODULE(CONFIG_TEST_KASAN) instead because I
> don't think there is a way to rewrite this without it being a module.

You mean these are unconditionally crashing the machine? If yes,
please add a comment about this.

Theoretically we could have a notion of "death tests" similar to gunit:
https://stackoverflow.com/questions/3698718/what-are-google-test-death-tests
KUnit test runner wrapper would need to spawn a separete process per
each such test. Under non-KUnit test runner these should probably be
disabled by default and only run if specifically requested (a-la
--gunit_filter/--gunit_also_run_disabled_tests).
Could also be used to test other things that unconditionally panic,
e.g. +Kees may be happy for unit tests for some of the
hardening/fortification features.
I am not asking to bundle this with this change of course.