[ 043/173] usb: gadget: uvc: fix error path in uvc_function_bind()

From: Ben Hutchings
Date: Fri Dec 28 2012 - 14:26:12 EST


3.2-stable review patch. If anyone has any objections, please let me know.

------------------

From: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>

commit 0f9df939385527049c8062a099fbfa1479fe7ce0 upstream.

The "video->minor = -1" assigment is done in V4L2 by
video_register_device() so it is removed here.
Now. uvc_function_bind() calls in error case uvc_function_unbind() for
cleanup. The problem is that uvc_function_unbind() frees the uvc struct
and uvc_bind_config() does as well in error case of usb_add_function().
Removing kfree() in usb_add_function() would make the patch smaller but
it would look odd because the new allocated memory is not cleaned up.
However it is not guaranteed that if we call usb_add_function() we also
get to the bind function.
Therefore the patch extracts the conditional cleanup from
uvc_function_unbind() applies to uvc_function_bind().
uvc_function_unbind() now contains only the complete cleanup which is
required once everything has been registrated.

Cc: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Cc: Bhupesh Sharma <bhupesh.sharma@xxxxxx>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Signed-off-by: Felipe Balbi <balbi@xxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
drivers/usb/gadget/f_uvc.c | 39 +++++++++++++++++++++------------------
1 file changed, 21 insertions(+), 18 deletions(-)

diff --git a/drivers/usb/gadget/f_uvc.c b/drivers/usb/gadget/f_uvc.c
index 2a8bf06..10f13c1 100644
--- a/drivers/usb/gadget/f_uvc.c
+++ b/drivers/usb/gadget/f_uvc.c
@@ -417,7 +417,6 @@ uvc_register_video(struct uvc_device *uvc)
return -ENOMEM;

video->parent = &cdev->gadget->dev;
- video->minor = -1;
video->fops = &uvc_v4l2_fops;
video->release = video_device_release;
strncpy(video->name, cdev->gadget->name, sizeof(video->name));
@@ -577,23 +576,12 @@ uvc_function_unbind(struct usb_configuration *c, struct usb_function *f)

INFO(cdev, "uvc_function_unbind\n");

- if (uvc->vdev) {
- if (uvc->vdev->minor == -1)
- video_device_release(uvc->vdev);
- else
- video_unregister_device(uvc->vdev);
- uvc->vdev = NULL;
- }
-
- if (uvc->control_ep)
- uvc->control_ep->driver_data = NULL;
- if (uvc->video.ep)
- uvc->video.ep->driver_data = NULL;
+ video_unregister_device(uvc->vdev);
+ uvc->control_ep->driver_data = NULL;
+ uvc->video.ep->driver_data = NULL;

- if (uvc->control_req) {
- usb_ep_free_request(cdev->gadget->ep0, uvc->control_req);
- kfree(uvc->control_buf);
- }
+ usb_ep_free_request(cdev->gadget->ep0, uvc->control_req);
+ kfree(uvc->control_buf);

kfree(f->descriptors);
kfree(f->hs_descriptors);
@@ -740,7 +728,22 @@ uvc_function_bind(struct usb_configuration *c, struct usb_function *f)
return 0;

error:
- uvc_function_unbind(c, f);
+ if (uvc->vdev)
+ video_device_release(uvc->vdev);
+
+ if (uvc->control_ep)
+ uvc->control_ep->driver_data = NULL;
+ if (uvc->video.ep)
+ uvc->video.ep->driver_data = NULL;
+
+ if (uvc->control_req) {
+ usb_ep_free_request(cdev->gadget->ep0, uvc->control_req);
+ kfree(uvc->control_buf);
+ }
+
+ kfree(f->descriptors);
+ kfree(f->hs_descriptors);
+ kfree(f->ss_descriptors);
return ret;
}



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