tty: ehv_bytechan: clean up init error handling

Straighten out the initcall error handling to avoid deregistering a
never-registered tty driver (something which would lead to a
NULL-pointer dereference) in the most unlikely event that driver
registration fails (e.g. we've run out of major numbers).

Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/ehv_bytechan.c b/drivers/tty/ehv_bytechan.c
index 7ac9bcdf1e61a551bb8286a48c0afc492e4a95ee..61fe8d6fd24e1bb0cf2cdfd2a4de67ceb05123bf 100644 (file)
--- a/drivers/tty/ehv_bytechan.c
+++ b/drivers/tty/ehv_bytechan.c
@@ -764,7 +764,7 @@ static int __init ehv_bc_init(void)
        ehv_bc_driver = alloc_tty_driver(count);
        if (!ehv_bc_driver) {
                ret = -ENOMEM;
-               goto error;
+               goto err_free_bcs;
        }
 
        ehv_bc_driver->driver_name = "ehv-bc";
@@ -778,24 +778,23 @@ static int __init ehv_bc_init(void)
        ret = tty_register_driver(ehv_bc_driver);
        if (ret) {
                pr_err("ehv-bc: could not register tty driver (ret=%i)\n", ret);
-               goto error;
+               goto err_put_tty_driver;
        }
 
        ret = platform_driver_register(&ehv_bc_tty_driver);
        if (ret) {
                pr_err("ehv-bc: could not register platform driver (ret=%i)\n",
                       ret);
-               goto error;
+               goto err_deregister_tty_driver;
        }
 
        return 0;
 
-error:
-       if (ehv_bc_driver) {
-               tty_unregister_driver(ehv_bc_driver);
-               put_tty_driver(ehv_bc_driver);
-       }
-
+err_deregister_tty_driver:
+       tty_unregister_driver(ehv_bc_driver);
+err_put_tty_driver:
+       put_tty_driver(ehv_bc_driver);
+err_free_bcs:
        kfree(bcs);
 
        return ret;