USB: gadget: Add ID numbers to configfs-gadget driver names

commit 7c07553 upstream.

It is unable to use configfs to attach more than one gadget. When
attaching the second gadget, it always fails and the kernel message
prints out:

Error: Driver 'configfs-gadget' is already registered, aborting...
UDC core: g1: driver registration failed: -16

This commit fixes the problem by using the gadget name as a suffix
to each configfs_gadget's driver name, thus making the names
distinct.

Fixes: fc274c1 ("USB: gadget: Add a new bus for gadgets")
Cc: stable <stable@kernel.org>
Signed-off-by: Chanh Nguyen <chanh@os.amperecomputing.com>
Reviewed-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com>
Tested-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Frank Li <frank.li@nxp.com>
Link: https://lore.kernel.org/r/20230111065105.29205-1-chanh@os.amperecomputing.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/gadget/configfs.c

@@ -392,6 +392,7 @@ static void gadget_info_attr_release(struct config_item *item)
  WARN_ON(!list_empty(&gi->string_list));
  WARN_ON(!list_empty(&gi->available_func));
  kfree(gi->composite.gadget_driver.function);
+ kfree(gi->composite.gadget_driver.driver.name);
  kfree(gi);
 }
 
@@ -1571,7 +1572,6 @@ static const struct usb_gadget_driver configfs_driver_template = {
  .max_speed = USB_SPEED_SUPER_PLUS,
  .driver = {
  .owner = THIS_MODULE,
- .name = "configfs-gadget",
  },
  .match_existing_only = 1,
 };
@@ -1622,13 +1622,21 @@ static struct config_group *gadgets_make(
 
  gi->composite.gadget_driver = configfs_driver_template;
 
+ gi->composite.gadget_driver.driver.name = kasprintf(GFP_KERNEL,
+ "configfs-gadget.%s", name);
+ if (!gi->composite.gadget_driver.driver.name)
+ goto err;
+
  gi->composite.gadget_driver.function = kstrdup(name, GFP_KERNEL);
  gi->composite.name = gi->composite.gadget_driver.function;
 
  if (!gi->composite.gadget_driver.function)
- goto err;
+ goto out_free_driver_name;
 
  return &gi->group;
+
+out_free_driver_name:
+ kfree(gi->composite.gadget_driver.driver.name);
 err:
  kfree(gi);
  return ERR_PTR(-ENOMEM);