Preopen
if (Preopen(P) == 0)
if (Pstate(P) == PS_LOST && Preopen(P) == -1) {
if (Preopen(Proc) == 0) { /* we got control back */
if (Preopen(P) == 0)
(void) Preopen(pctx->Pr);
Preopen(P) != 0) { /* and we can't get it back */
extern int Preopen(struct ps_prochandle *);