diff --git a/[refs] b/[refs]
index 3ad343aa3aa5..c470842c0b78 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: ef51c97623b94f51e439ac91d2736aab3d1b6594
+refs/heads/master: ca509f69dec7fa564005aa7e9fcf0cd46de3f7d6
diff --git a/trunk/drivers/char/tty_io.c b/trunk/drivers/char/tty_io.c
index 5d405a1bfbe3..7710a6a77d97 100644
--- a/trunk/drivers/char/tty_io.c
+++ b/trunk/drivers/char/tty_io.c
@@ -3770,7 +3770,9 @@ int tty_register_driver(struct tty_driver *driver)
 	if (!driver->put_char)
 		driver->put_char = tty_default_put_char;
 	
+	mutex_lock(&tty_mutex);
 	list_add(&driver->tty_drivers, &tty_drivers);
+	mutex_unlock(&tty_mutex);
 	
 	if ( !(driver->flags & TTY_DRIVER_DYNAMIC_DEV) ) {
 		for(i = 0; i < driver->num; i++)
@@ -3796,8 +3798,9 @@ int tty_unregister_driver(struct tty_driver *driver)
 
 	unregister_chrdev_region(MKDEV(driver->major, driver->minor_start),
 				driver->num);
-
+	mutex_lock(&tty_mutex);
 	list_del(&driver->tty_drivers);
+	mutex_unlock(&tty_mutex);
 
 	/*
 	 * Free the termios and termios_locked structures because
diff --git a/trunk/fs/proc/proc_tty.c b/trunk/fs/proc/proc_tty.c
index c1bbfbeb035e..b3a473b0a191 100644
--- a/trunk/fs/proc/proc_tty.c
+++ b/trunk/fs/proc/proc_tty.c
@@ -108,6 +108,8 @@ static void *t_start(struct seq_file *m, loff_t *pos)
 {
 	struct list_head *p;
 	loff_t l = *pos;
+
+	mutex_lock(&tty_mutex);
 	list_for_each(p, &tty_drivers)
 		if (!l--)
 			return list_entry(p, struct tty_driver, tty_drivers);
@@ -124,6 +126,7 @@ static void *t_next(struct seq_file *m, void *v, loff_t *pos)
 
 static void t_stop(struct seq_file *m, void *v)
 {
+	mutex_unlock(&tty_mutex);
 }
 
 static struct seq_operations tty_drivers_op = {