I _HATE_ crashes. The lptread() call needs to check LP_BYPASS, because

if one tries to use read() on an LP_BYPASS'd dev_t, the softc will be
initialized mainly with NULLs, so...

sys/dev/ppbus/lpt.c

@@ -695,6 +695,11 @@ lptread(dev_t dev, struct uio *uio, int ioflag)
         device_t ppbus = device_get_parent(lptdev);
 	int error = 0, len;
 
+	if (sc->sc_flags & LP_BYPASS) {
+		/* we can't do reads in bypass mode */
+		return (EPERM);
+	}
+
 	if ((error = ppb_1284_negociate(ppbus, PPB_NIBBLE, 0)))
 		return (error);