kern_wait6
error = kern_wait6(td, uap->idtype, PAIR32TO64(id_t, uap->id),
error = kern_wait6(td, idtype, id, &status, options,
ret = kern_wait6(td, idtype, id, status, options, wrup, NULL);
error = kern_wait6(td, idtype, id, &status, uap->options, wrup, sip);
int kern_wait6(struct thread *td, enum idtype idtype, id_t id, int *status,