diff options
| -rw-r--r-- | drivers/char/tty_io.c | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c index f40298e9873..2e96ce0fddc 100644 --- a/drivers/char/tty_io.c +++ b/drivers/char/tty_io.c @@ -1227,7 +1227,8 @@ static void tty_line_name(struct tty_driver *driver, int index, char *p) * init_dev - initialise a tty device * @driver: tty driver we are opening a device on * @idx: device index - * @tty: returned tty structure + * @ret_tty: returned tty structure + * @first_ok: ok to open a new device (used by ptmx) * * Prepare a tty device. This may not be a "new" clean device but * could also be an active device. The pty drivers require special @@ -1248,7 +1249,7 @@ static void tty_line_name(struct tty_driver *driver, int index, char *p) */ static int init_dev(struct tty_driver *driver, int idx, - struct tty_struct **ret_tty) + struct tty_struct **ret_tty, int first_ok) { struct tty_struct *tty, *o_tty; struct ktermios *tp, **tp_loc, *o_tp, **o_tp_loc; @@ -1279,6 +1280,11 @@ static int init_dev(struct tty_driver *driver, int idx, } if (tty) goto fast_track; + if (driver->subtype == PTY_TYPE_MASTER && + (driver->flags & TTY_DRIVER_DEVPTS_MEM) && !first_ok) { + retval = -EIO; + goto end_init; + } /* * First time open is complex, especially for PTY devices. * This code guarantees that either everything succeeds and the @@ -1413,7 +1419,7 @@ static int init_dev(struct tty_driver *driver, int idx, if (retval) goto release_mem_out; - goto success; + goto success; /* * This fast open can be used if the tty is already open. @@ -1795,7 +1801,7 @@ static void release_dev(struct file *filp) } /** - * tty_open - open a tty device + * __tty_open - open a tty device * @inode: inode of device file * @filp: file pointer to tty * @@ -1874,7 +1880,7 @@ retry_open: return -ENODEV; } got_driver: - retval = init_dev(driver, index, &tty); + retval = init_dev(driver, index, &tty, 0); mutex_unlock(&tty_mutex); if (retval) return retval; @@ -1971,7 +1977,7 @@ static int __ptmx_open(struct inode *inode, struct file *filp) return index; mutex_lock(&tty_mutex); - retval = init_dev(ptm_driver, index, &tty); + retval = init_dev(ptm_driver, index, &tty, 1); mutex_unlock(&tty_mutex); if (retval) |