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From: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Date: Fri, 03 May 2024 12:10:52 +0200
Subject: [PATCH v2 1/2] USB: serial: store owner from modules with
 usb_serial_register_drivers()
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Message-Id: <20240503-module-owner-usb-serial-v2-1-7887769dbeff@linaro.org>
References: <20240503-module-owner-usb-serial-v2-0-7887769dbeff@linaro.org>
In-Reply-To: <20240503-module-owner-usb-serial-v2-0-7887769dbeff@linaro.org>
To: Johan Hovold <johan@kernel.org>, 
 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, 
 Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Modules registering driver 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 9447057eaff8 ("platform_device: use a macro instead of
platform_driver_register").

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
---
 drivers/usb/serial/usb-serial.c | 12 +++++++-----
 include/linux/usb/serial.h      |  7 +++++--
 2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index f1e91eb7f8a4..df6a2ae0bf42 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/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
diff --git a/include/linux/usb/serial.h b/include/linux/usb/serial.h
index 1a0a4dc87980..75b2b763f1ba 100644
--- a/include/linux/usb/serial.h
+++ b/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);
 

-- 
2.43.0