SDEAD
if (child->p_stat == SDEAD) {
if (child->p_stat == SZOMB || child->p_stat == SDEAD ||
p->p_stat = SDEAD;
KASSERT(p->p_stat == SDEAD || mutex_owned(p->p_lock));
if (p->p_stat != SZOMB && p->p_stat != SDEAD) {
KASSERT(p->p_stat == SDYING || p->p_stat == SDEAD);
p->p_stat = SDEAD;
if (p->p_stat == SDEAD)
((p)->p_stat == SZOMB || (p)->p_stat == SDYING || (p)->p_stat == SDEAD)