This adds a new PID_TO_PTR() macro, plus PTR_TO_PID() and makes use of
it wherever we maintain processes in a hash table. Previously we
sometimes used LONG_TO_PTR() and other times ULONG_TO_PTR() for that,
hence let's make this more explicit and clean up things.
Making the array static allows gcc -O2 to generate smaller code:
"size systemd" before:
text data bss dec hex filename
1377286 128608 2632 1508526 1704ae systemd
After:
text data bss dec hex filename
1374326 128572 2664 1505562 16f91a systemd
(IN_SET still results in worse generated code than using
"x == FOO || x == BAR || ...". I don't think we'll be able to match
that with the C preprocessor.)
This change limits the use of IN_SET to sets with constant elements. All
present callers use constants. The compiler would report an "initializer
element is not constant" error otherwise.
Putting the set elements in an array variable and using ELEMENTSOF makes
it clearer what's going on.
Incidentally, it also makes gcc -O2 generate slightly smaller code:
"size systemd", before:
text data bss dec hex filename
1378318 128608 2632 1509558 1708b6 systemd
After:
text data bss dec hex filename
1377286 128608 2632 1508526 1704ae systemd
Given a container "foo", that maps user id $UID to container user, using
user namespaces, this NSS module extenstion will now map the $UID to a
name "vu-foo-$TUID" for the translated UID $UID.
Similar, userns groups are mapped to "vg-foo-$TGID" for translated GIDs
of $GID.
This simple change should make userns users more discoverable. Also,
given that many tools like "adduser" check NSS before allocating a UID,
should lower the chance of UID range conflicts between tools.
If we call EPOLL_CTL_DEL, we *REALLY* expect the file-descriptor to be
present in that given epoll-set. We actually track such state via our
s->io.registered flag, so it better be true.
Make sure if that's not true, we treat it similar to assert_return() (ie.,
print a loud warning).