tty: Consolidate noctty checks in tty_open()

Evaluate the conditions which prevent this tty being the controlling
terminal in one place, just before setting the controlling terminal.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 6cffe0d57d7057f6c7276cea8474b272d4711cbf..741a0d7f51ce14e55630e8927281931aedaf9ff9 100644 (file)
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -1960,7 +1960,7 @@ static struct tty_struct *tty_open_current_tty(dev_t device, struct file *filp)
  *     Locking: tty_mutex protects get_tty_driver
  */
 static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp,
-               int *noctty, int *index)
+               int *index)
 {
        struct tty_driver *driver;
 
@@ -1970,7 +1970,6 @@ static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp,
                extern struct tty_driver *console_driver;
                driver = tty_driver_kref_get(console_driver);
                *index = fg_console;
-               *noctty = 1;
                break;
        }
 #endif
@@ -1981,7 +1980,6 @@ static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp,
                        if (driver) {
                                /* Don't let /dev/console block */
                                filp->f_flags |= O_NONBLOCK;
-                               *noctty = 1;
                                break;
                        }
                }
@@ -2036,14 +2034,13 @@ retry_open:
        if (retval)
                return -ENOMEM;
 
-       noctty = filp->f_flags & O_NOCTTY;
        index  = -1;
        retval = 0;
 
        tty = tty_open_current_tty(device, filp);
        if (!tty) {
                mutex_lock(&tty_mutex);
-               driver = tty_lookup_driver(device, filp, &noctty, &index);
+               driver = tty_lookup_driver(device, filp, &index);
                if (IS_ERR(driver)) {
                        retval = PTR_ERR(driver);
                        goto err_unlock;
@@ -2091,10 +2088,6 @@ retry_open:
        tty_add_file(tty, filp);
 
        check_tty_count(tty, __func__);
-       if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
-           tty->driver->subtype == PTY_TYPE_MASTER)
-               noctty = 1;
-
        tty_debug_hangup(tty, "opening (count=%d)\n", tty->count);
 
        if (tty->ops->open)
@@ -2127,6 +2120,12 @@ retry_open:
 
        read_lock(&tasklist_lock);
        spin_lock_irq(&current->sighand->siglock);
+       noctty = (filp->f_flags & O_NOCTTY) ||
+                       device == MKDEV(TTY_MAJOR, 0) ||
+                       device == MKDEV(TTYAUX_MAJOR, 1) ||
+                       (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
+                        tty->driver->subtype == PTY_TYPE_MASTER);
+
        if (!noctty &&
            current->signal->leader &&
            !current->signal->tty &&