killpg1
static int killpg1(struct thread *td, int sig, int pgid, int all,
return (killpg1(td, signum, 0, 1, &ksi));
return (killpg1(td, signum, 0, 0, &ksi));
return (killpg1(td, signum, -pid, 0, &ksi));
return (killpg1(td, uap->signum, uap->pgid, 0, &ksi));