Re: [RFC 0/3] kunit: add support to use modules

From: Kees Cook
Date: Wed Jul 15 2020 - 22:41:45 EST


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