[PATCH 4.4 63/86] tty: vt, return error when con_startup fails

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jiri Slaby <jslaby@xxxxxxx>

commit 6798df4c5fe0a7e6d2065cf79649a794e5ba7114 upstream.

When csw->con_startup() fails in do_register_con_driver, we return no
error (i.e. 0). This was changed back in 2006 by commit 3e795de763.
Before that we used to return -ENODEV.

So fix the return value to be -ENODEV in that case again.

Fixes: 3e795de763 ("VT binding: Add binding/unbinding support for the VT console")
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
Reported-by: "Dan Carpenter" <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/tty/vt/vt.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -3583,9 +3583,10 @@ static int do_register_con_driver(const
 		goto err;
 
 	desc = csw->con_startup();
-
-	if (!desc)
+	if (!desc) {
+		retval = -ENODEV;
 		goto err;
+	}
 
 	retval = -EINVAL;