T_PAGEFLT
trapsignal(p, signal, T_PAGEFLT, sicode, sv);
case T_PAGEFLT: /* allow page faults in kernel mode */
case T_PAGEFLT: /* page fault */
trapsignal(p, signal, T_PAGEFLT, sicode, sv);
case T_PAGEFLT:
case T_PAGEFLT|T_USER: { /* page fault */