USB: serial: set driver owner when registering drivers

Modules registering drivers with usb_serial_register_drivers() might
forget to set .owner field.  The field is used by some of other kernel
parts for reference counting (try_module_get()), so it is expected that
drivers will set it.

Solve the problem by moving this task away from the drivers to the core
USB serial code, just like we did for platform_driver in
commit 9447057 ("platform_device: use a macro instead of
platform_driver_register").

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
[ johan: amend commit summary ]
Signed-off-by: Johan Hovold <johan@kernel.org>

Author: krzk

drivers/usb/serial/usb-serial.c

@@ -1459,17 +1459,18 @@ static void usb_serial_deregister(struct usb_serial_driver *device)
 }
 
 /**
- * usb_serial_register_drivers - register drivers for a usb-serial module
+ * __usb_serial_register_drivers - register drivers for a usb-serial module
  * @serial_drivers: NULL-terminated array of pointers to drivers to be registered
+ * @owner: owning module
  * @name: name of the usb_driver for this set of @serial_drivers
  * @id_table: list of all devices this @serial_drivers set binds to
  *
  * Registers all the drivers in the @serial_drivers array, and dynamically
  * creates a struct usb_driver with the name @name and id_table of @id_table.
  */
-int usb_serial_register_drivers(struct usb_serial_driver *const serial_drivers[],
-				const char *name,
-				const struct usb_device_id *id_table)
+int __usb_serial_register_drivers(struct usb_serial_driver *const serial_drivers[],
+				  struct module *owner, const char *name,
+				  const struct usb_device_id *id_table)
 {
 	int rc;
 	struct usb_driver *udriver;
@@ -1514,6 +1515,7 @@ int usb_serial_register_drivers(struct usb_serial_driver *const serial_drivers[]
 
 	for (sd = serial_drivers; *sd; ++sd) {
 		(*sd)->usb_driver = udriver;
+		(*sd)->driver.owner = owner;
 		rc = usb_serial_register(*sd);
 		if (rc)
 			goto err_deregister_drivers;
@@ -1532,7 +1534,7 @@ int usb_serial_register_drivers(struct usb_serial_driver *const serial_drivers[]
 	kfree(udriver);
 	return rc;
 }
-EXPORT_SYMBOL_GPL(usb_serial_register_drivers);
+EXPORT_SYMBOL_GPL(__usb_serial_register_drivers);
 
 /**
  * usb_serial_deregister_drivers - deregister drivers for a usb-serial module

include/linux/usb/serial.h

@@ -311,8 +311,11 @@ struct usb_serial_driver {
 #define to_usb_serial_driver(d) \
 	container_of(d, struct usb_serial_driver, driver)
 
-int usb_serial_register_drivers(struct usb_serial_driver *const serial_drivers[],
-		const char *name, const struct usb_device_id *id_table);
+#define usb_serial_register_drivers(serial_drivers, name, id_table) \
+	__usb_serial_register_drivers(serial_drivers, THIS_MODULE, name, id_table)
+int __usb_serial_register_drivers(struct usb_serial_driver *const serial_drivers[],
+				  struct module *owner, const char *name,
+				  const struct usb_device_id *id_table);
 void usb_serial_deregister_drivers(struct usb_serial_driver *const serial_drivers[]);
 void usb_serial_port_softint(struct usb_serial_port *port);