Currently one can open multiple instances of /dev/ttyU* since ucom(4)
just checks 'TS_ISOPEN' against /dev/cuaU* access. There are quiet a
lot of flags in ucom.c so it's a bit difficult to understand what the
initial idea was. But moving the 'TS_ISOPEN' check before the UCOMCUA
branch makes /dev/ttyU* access also return EBUSY if already opened.
Ok? Or better ideas to fix this?
Index: ucom.c
===================================================================
RCS file: /cvs/src/sys/dev/usb/ucom.c,v
retrieving revision 1.65
diff -u -p -u -p -r1.65 ucom.c
--- ucom.c 14 Mar 2015 03:38:49 -0000 1.65
+++ ucom.c 11 Jun 2016 12:08:20 -0000
@@ -474,12 +474,13 @@ ucom_do_open(dev_t dev, int flag, int mo
else
s = spltty();
+ if (ISSET(tp->t_state, TS_ISOPEN)) {
+ /* Someone is already dialed in */
+ splx(s);
+ return (EBUSY);
+ }
+
if (UCOMCUA(dev)) {
- if (ISSET(tp->t_state, TS_ISOPEN)) {
- /* Someone is already dialed in */
- splx(s);
- return (EBUSY);
- }
sc->sc_cua = 1;
} else {
/* tty (not cua) device, wait for carrier */
