selftests/mm: create uffd-common.[ch]

Move common utility functions into uffd-common.[ch] files from the
original userfaultfd.c.  This prepares for a split of userfaultfd.c into
two tests: one to only cover the old but powerful stress test, the other
one covers all the functional tests.

This movement is kind of a brute-force effort for now, with light
touch-ups but nothing should really change.  There's chances to optimize
more, but let's leave that for later.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Peter Xu <[email protected]>
Reviewed-by: Mike Rapoport (IBM) <[email protected]>
Reviewed-by: Axel Rasmussen <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Dmitry Safonov <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Zach O'Keefe <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions