dogetitimer
error = dogetitimer(p, SCARG(uap, which), &aitv);
dogetitimer(l->l_proc, which, &b_oitv);
if ((error = dogetitimer(p, ITIMER_REAL, &oitv)) != 0) {
error = dogetitimer(p, SCARG(uap, which), &aitv);
error = dogetitimer(p, SCARG(uap, which), &aitv);
error = dogetitimer(p, SCARG(uap, which), &aitv);
int dogetitimer(struct proc *, int, struct itimerval *);