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>
This commit is contained in:
Peter Hurley 2016-01-09 21:13:52 -08:00 committed by Greg Kroah-Hartman
parent c2bb524b2e
commit 11e1d4aa4d

View file

@ -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 @@ static int tty_open(struct inode *inode, struct file *filp)
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 @@ static int tty_open(struct inode *inode, struct file *filp)
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 @@ static int tty_open(struct inode *inode, struct file *filp)
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 &&