userfaultfd: selftest: test UFFDIO_ZEROPAGE on all memory types

userfaultfd: selftest: test UFFDIO_ZEROPAGE on all memory types

This will verify -EINVAL is returned with hugetlbfs/shmem and it'll do a
functional test of UFFDIO_ZEROPAGE on anonymous memory.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Andrea Arcangeli <[email protected]>
Cc: "Dr. David Alan Gilbert" <[email protected]>
Cc: Hillf Danton <[email protected]>
Cc: Michael Rapoport <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Pavel Emelyanov <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>