MDP_STEP
if (oproc && (oproc->p_md.md_flags & MDP_STEP))
if (nproc->p_md.md_flags & MDP_STEP) {
if (p->p_md.md_flags & MDP_STEP)
p->p_md.md_flags |= MDP_STEP;
p->p_md.md_flags &= ~MDP_STEP;