PSL_TRACEVFORK
return (p->p_slflag & (PSL_TRACEVFORK|PSL_TRACED)) ==
(PSL_TRACEVFORK|PSL_TRACED) && (flags & FORK_PPWAIT) != 0;
pe.pe_set_event |= ISSET(t->p_slflag, PSL_TRACEVFORK) ?
SET(t->p_slflag, PSL_TRACEVFORK);
CLR(t->p_slflag, PSL_TRACEVFORK);