3 files changed, 6 insertions, 0 deletions

diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
index 2728afe52eea..c32690862671 100644
--- a/drivers/tty/pty.c
+++ b/drivers/tty/pty.c
@@ -345,6 +345,7 @@ static int pty_common_install(struct tty_driver *driver, struct tty_struct *tty,
         tty_port_init(ports[1]);
         o_tty->port = ports[0];
         tty->port = ports[1];
+        o_tty->port->itty = o_tty;
 
         tty_driver_kref_get(driver);
         tty->count++;
@@ -371,6 +372,7 @@ static void pty_unix98_shutdown(struct tty_struct *tty)
 
 static void pty_cleanup(struct tty_struct *tty)
 {
+        tty->port->itty = NULL;
         kfree(tty->port);
 }
 
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index f90b6217b3ba..202008f38ca3 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -1417,6 +1417,8 @@ struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx)
                         "%s: %s driver does not set tty->port. This will crash the kernel later. Fix the driver!\n",
                         __func__, tty->driver->name);
 
+        tty->port->itty = tty;
+
         /*
          * Structures all installed ... call the ldisc open routines.
          * If we fail here just call release_tty to clean up.  No need
@@ -1552,6 +1554,7 @@ static void release_tty(struct tty_struct *tty, int idx)
                 tty->ops->shutdown(tty);
         tty_free_termios(tty);
         tty_driver_remove_tty(tty->driver, tty);
+        tty->port->itty = NULL;
 
         if (tty->link)
                 tty_kref_put(tty->link);
diff --git a/include/linux/tty.h b/include/linux/tty.h
index b4b3c568d242..9be74d649a51 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -189,6 +189,7 @@ struct tty_port_operations {
         
 struct tty_port {
         struct tty_struct       *tty;           /* Back pointer */
+        struct tty_struct       *itty;          /* internal back ptr */
         const struct tty_port_operations *ops;  /* Port operations */
         spinlock_t              lock;           /* Lock protecting tty field */
         int                     blocked_open;   /* Waiting to open */