Commit 944fe915 authored by John Keeping's avatar John Keeping Committed by Greg Kroah-Hartman
Browse files

usb: gadget: f_hid: tidy error handling in hidg_alloc 



Unify error handling at the end of the function, reducing the risk of
missing something on one of the error paths.

Moving the increment of opts->refcnt later means there is no need to
decrement it on the error path and is safe as this is guarded by
opts->lock which is held for this entire section.

Tested-by: default avatarLee Jones <lee@kernel.org>
Reviewed-by: default avatarAndrzej Pietrasiewicz <andrzej.p@collabora.com>
Reviewed-by: default avatarLee Jones <lee@kernel.org>
Signed-off-by: default avatarJohn Keeping <john@metanate.com>
Link: https://lore.kernel.org/r/20221122123523.3068034-4-john@metanate.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 70a3288a

drivers/usb/gadget/function/f_hid.c

+11 −10
Original line number Diff line number Diff line
@@ -1269,18 +1269,14 @@ static struct usb_function *hidg_alloc(struct usb_function_instance *fi) 
	opts = container_of(fi, struct f_hid_opts, func_inst);



	mutex_lock(&opts->lock);

	++opts->refcnt;



	device_initialize(&hidg->dev);

	hidg->dev.release = hidg_release;

	hidg->dev.class = hidg_class;

	hidg->dev.devt = MKDEV(major, opts->minor);

	ret = dev_set_name(&hidg->dev, "hidg%d", opts->minor);

	if (ret) {

		--opts->refcnt;

		mutex_unlock(&opts->lock);

		return ERR_PTR(ret);

	}

	if (ret)

		goto err_unlock;



	hidg->bInterfaceSubClass = opts->subclass;

	hidg->bInterfaceProtocol = opts->protocol;
@@ -1291,14 +1287,13 @@ static struct usb_function *hidg_alloc(struct usb_function_instance *fi) 
						 opts->report_desc_length,

						 GFP_KERNEL);

		if (!hidg->report_desc) {

			put_device(&hidg->dev);

			--opts->refcnt;

			mutex_unlock(&opts->lock);

			return ERR_PTR(-ENOMEM);

			ret = -ENOMEM;

			goto err_put_device;

		}

	}

	hidg->use_out_ep = !opts->no_out_endpoint;



	++opts->refcnt;

	mutex_unlock(&opts->lock);



	hidg->func.name    = "hid";
@@ -1313,6 +1308,12 @@ static struct usb_function *hidg_alloc(struct usb_function_instance *fi) 
	hidg->qlen	   = 4;



	return &hidg->func;



err_put_device:

	put_device(&hidg->dev);

err_unlock:

	mutex_unlock(&opts->lock);

	return ERR_PTR(ret);

}



DECLARE_USB_FUNCTION_INIT(hid, hidg_alloc_inst, hidg_alloc);