Hi Laurent,
On 11/25/2012 01:41 AM, Laurent Pinchart wrote:
When subdev registration fails the subdev v4l2_dev field is left to a
non-NULL value. Later calls to v4l2_device_unregister_subdev() will
consider the subdev as registered and will module_put() the subdev
module without any matching module_get().
Fix this by setting the subdev v4l2_dev field to NULL in
v4l2_device_register_subdev() when the function fails.
Signed-off-by: Laurent Pinchart<laurent.pinchart@xxxxxxxxxxxxxxxx>
Acked-by: Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx>
I'm just wondering whether including this patch in stable kernel releases
could potentially break anything.
---
drivers/media/v4l2-core/v4l2-device.c | 30 ++++++++++++++----------------
1 files changed, 14 insertions(+), 16 deletions(-)
diff --git a/drivers/media/v4l2-core/v4l2-device.c b/drivers/media/v4l2-core/v4l2-device.c
index 513969f..98a7f5e 100644
--- a/drivers/media/v4l2-core/v4l2-device.c
+++ b/drivers/media/v4l2-core/v4l2-device.c
@@ -159,31 +159,21 @@ int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
sd->v4l2_dev = v4l2_dev;
if (sd->internal_ops&& sd->internal_ops->registered) {
err = sd->internal_ops->registered(sd);
- if (err) {
- module_put(sd->owner);
- return err;
- }
+ if (err)
+ goto error_module;
}
/* This just returns 0 if either of the two args is NULL */
err = v4l2_ctrl_add_handler(v4l2_dev->ctrl_handler, sd->ctrl_handler, NULL);
- if (err) {
- if (sd->internal_ops&& sd->internal_ops->unregistered)
- sd->internal_ops->unregistered(sd);
- module_put(sd->owner);
- return err;
- }
+ if (err)
+ goto error_unregister;
#if defined(CONFIG_MEDIA_CONTROLLER)
/* Register the entity. */
if (v4l2_dev->mdev) {
err = media_device_register_entity(v4l2_dev->mdev, entity);
- if (err< 0) {
- if (sd->internal_ops&& sd->internal_ops->unregistered)
- sd->internal_ops->unregistered(sd);
- module_put(sd->owner);
- return err;
- }
+ if (err< 0)
+ goto error_unregister;
}
#endif
@@ -192,6 +182,14 @@ int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
spin_unlock(&v4l2_dev->lock);
return 0;
+
+error_unregister:
+ if (sd->internal_ops&& sd->internal_ops->unregistered)
+ sd->internal_ops->unregistered(sd);
+error_module:
+ module_put(sd->owner);
+ sd->v4l2_dev = NULL;
+ return err;
}
EXPORT_SYMBOL_GPL(v4l2_device_register_subdev);
--
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