*sigh* /proc/*/pagemap

["Alexey Dobriyan" <adobriyan@gmail.com>]

I'm few days from my patch-sending facility, but could someone
_please_ do the following before release:

1) initialize pagemap_walk.mm to "mm" , so the code starts working as
advertised, and
2) also initialize ->private to "&pm" so it wouldn't immediately oops
in pagemap_pte_hole(), and
3) unstatic struct pagemap_walk, so two threads won't fsckup each other
   (including those started by root, including flipping ->mm when you
don't have permissions),
    and
4) remove second ptrace_may_attach(), and
5) check with microscope allocation there -- page-aligned address and size == 0
    should allocate 0 bytes, and
6) actually check that it works.