So, I appreciate that you implemented this idea, but I *REALLY* wish
you had gotten your changed reviewed here first.

Several issues:

* Doing an open() and close() on each call not only introduces more
  overhead, but it specifically introduces jitter.  This is bad.

* The structure arguments to the ioctl(2)s should be the same as the
  system calls.  They don't need to be copied.

* The way you handle 64-bit return values looks totally wrong.  If
  there's a big-endian platform (sparc64 would be the only possible
  one) that requires the shifting, it's broken.

* My intent was that ntpd(8) would use this interface exclusively; not
  use it for some things and the syscall path for others.  In
  addition, it could easily be handled by a few one-line #ifdefs in
  ntpd(8) itself, not by hacking up the system call stubs.  Especially
  since it requires changes to ntpd(8) anyway.