2 files changed, 7 insertions, 1 deletions

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index 5d405a1bfbe3..7710a6a77d97 100644
--- a/drivers/char/tty_io.c
+++ b/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/fs/proc/proc_tty.c b/fs/proc/proc_tty.c
index c1bbfbeb035e..b3a473b0a191 100644
--- a/fs/proc/proc_tty.c
+++ b/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 = {