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path: root/drivers/tty/tty_io.c
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Diffstat (limited to 'drivers/tty/tty_io.c')
-rw-r--r--drivers/tty/tty_io.c26
1 files changed, 18 insertions, 8 deletions
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index bfe9ad85b362..5fa250157025 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -513,6 +513,8 @@ static const struct file_operations hung_up_tty_fops = {
static DEFINE_SPINLOCK(redirect_lock);
static struct file *redirect;
+extern void tty_sysctl_init(void);
+
/**
* tty_wakeup - request more data
* @tty: terminal
@@ -1256,7 +1258,8 @@ static void tty_driver_remove_tty(struct tty_driver *driver, struct tty_struct *
static int tty_reopen(struct tty_struct *tty)
{
struct tty_driver *driver = tty->driver;
- int retval;
+ struct tty_ldisc *ld;
+ int retval = 0;
if (driver->type == TTY_DRIVER_TYPE_PTY &&
driver->subtype == PTY_TYPE_MASTER)
@@ -1268,13 +1271,18 @@ static int tty_reopen(struct tty_struct *tty)
if (test_bit(TTY_EXCLUSIVE, &tty->flags) && !capable(CAP_SYS_ADMIN))
return -EBUSY;
- retval = tty_ldisc_lock(tty, 5 * HZ);
- if (retval)
- return retval;
+ ld = tty_ldisc_ref_wait(tty);
+ if (ld) {
+ tty_ldisc_deref(ld);
+ } else {
+ retval = tty_ldisc_lock(tty, 5 * HZ);
+ if (retval)
+ return retval;
- if (!tty->ldisc)
- retval = tty_ldisc_reinit(tty, tty->termios.c_line);
- tty_ldisc_unlock(tty);
+ if (!tty->ldisc)
+ retval = tty_ldisc_reinit(tty, tty->termios.c_line);
+ tty_ldisc_unlock(tty);
+ }
if (retval == 0)
tty->count++;
@@ -2183,7 +2191,8 @@ static int tiocsti(struct tty_struct *tty, char __user *p)
ld = tty_ldisc_ref_wait(tty);
if (!ld)
return -EIO;
- ld->ops->receive_buf(tty, &ch, &mbz, 1);
+ if (ld->ops->receive_buf)
+ ld->ops->receive_buf(tty, &ch, &mbz, 1);
tty_ldisc_deref(ld);
return 0;
}
@@ -3476,6 +3485,7 @@ void console_sysfs_notify(void)
*/
int __init tty_init(void)
{
+ tty_sysctl_init();
cdev_init(&tty_cdev, &tty_fops);
if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) ||
register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0)