_lwp_ctl
int _lwp_ctl(int, struct lwpctl **);
if (_lwp_ctl(LWPCTL_FEATURE_CURCPU, &self->pt_lwpctl)) {
if (_lwp_ctl(LWPCTL_FEATURE_CURCPU, &first->pt_lwpctl) != 0) {
if (_lwp_ctl(LWPCTL_FEATURE_CURCPU, &self->pt_lwpctl)) {
ATF_REQUIRE(_lwp_ctl(LWPCTL_FEATURE_PCTR, &lc) == 0);