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Date:   Wed, 15 Jul 2020 19:41:41 -0700
From:   Kees Cook <keescook@chromium.org>
To:     David Gow <davidgow@google.com>
Cc:     Vitor Massaru Iha <vitor@massaru.org>,
        KUnit Development <kunit-dev@googlegroups.com>,
        "open list:KERNEL SELFTEST FRAMEWORK" 
        <linux-kselftest@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Brendan Higgins <brendanhiggins@google.com>,
        Shuah Khan <skhan@linuxfoundation.org>,
        linux-kernel-mentees@lists.linuxfoundation.org
Subject: Re: [RFC 0/3] kunit: add support to use modules
Message-ID: <202007151939.62EFE6F@keescook>
References: <20200715031120.1002016-1-vitor@massaru.org>
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On Wed, Jul 15, 2020 at 11:47:11AM +0800, David Gow wrote:
> - The inheriting of the mm stuff still means that
> copy_{from,to}_user() will only work if loaded as a module. This
> really needs to be documented. (Ideally, we'd find a way of having
> this work even for built-in tests, but I don't have any real ideas as
> to how that could be done).

I'd like to better understand this ... are there conditions where
vm_mmap() doesn't work? I thought this would either use current() (e.g.
how LKDTM uses it when getting triggered from debugfs), or use init_mm.

I'd really like to see the mm patch more well described/justified.

-- 
Kees Cook