1 files changed, 33 insertions, 19 deletions

diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 734a635e7363..a1fd3f7d487a 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -855,7 +855,7 @@ static void tty_vhangup_session(struct tty_struct *tty)
 
 int tty_hung_up_p(struct file *filp)
 {
-	return (filp->f_op == &hung_up_tty_fops);
+	return (filp && filp->f_op == &hung_up_tty_fops);
 }
 
 EXPORT_SYMBOL(tty_hung_up_p);
@@ -1745,6 +1745,37 @@ static int tty_release_checks(struct tty_struct *tty, int idx)
 }
 
 /**
+ *	tty_release_struct	-	release a tty struct
+ *	@tty: tty device
+ *	@idx: index of the tty
+ *
+ *	Performs the final steps to release and free a tty device. It is
+ *	roughly the reverse of tty_init_dev.
+ */
+void tty_release_struct(struct tty_struct *tty, int idx)
+{
+	/*
+	 * Ask the line discipline code to release its structures
+	 */
+	tty_ldisc_release(tty);
+
+	/* Wait for pending work before tty destruction commmences */
+	tty_flush_works(tty);
+
+	tty_debug_hangup(tty, "freeing structure\n");
+	/*
+	 * The release_tty function takes care of the details of clearing
+	 * the slots and preserving the termios structure. The tty_unlock_pair
+	 * should be safe as we keep a kref while the tty is locked (so the
+	 * unlock never unlocks a freed tty).
+	 */
+	mutex_lock(&tty_mutex);
+	release_tty(tty, idx);
+	mutex_unlock(&tty_mutex);
+}
+EXPORT_SYMBOL_GPL(tty_release_struct);
+
+/**
  *	tty_release		-	vfs callback for close
  *	@inode: inode of tty
  *	@filp: file pointer for handle to tty
@@ -1898,25 +1929,8 @@ int tty_release(struct inode *inode, struct file *filp)
 		return 0;
 
 	tty_debug_hangup(tty, "final close\n");
-	/*
-	 * Ask the line discipline code to release its structures
-	 */
-	tty_ldisc_release(tty);
-
-	/* Wait for pending work before tty destruction commmences */
-	tty_flush_works(tty);
-
-	tty_debug_hangup(tty, "freeing structure\n");
-	/*
-	 * The release_tty function takes care of the details of clearing
-	 * the slots and preserving the termios structure. The tty_unlock_pair
-	 * should be safe as we keep a kref while the tty is locked (so the
-	 * unlock never unlocks a freed tty).
-	 */
-	mutex_lock(&tty_mutex);
-	release_tty(tty, idx);
-	mutex_unlock(&tty_mutex);
 
+	tty_release_struct(tty, idx);
 	return 0;
 }