Commit 63b6971a authored by Cornelia Huck's avatar Cornelia Huck Committed by Greg Kroah-Hartman
Browse files

Driver core: Cleanup get_device_parent() in device_add() and device_move() 

Make setup_parent() void as get_device_parent() will always return
either a valid kobject or NULL.
Introduce cleanup_glue_dir() to drop reference grabbed on "glue"
directory by get_device_parent(). Use it for cleanup in device_move()
and device_add() on errors.

This should fix the refcounting problem reported in
http://marc.info/?l=linux-kernel&m=120052487909200&w=2



Signed-off-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
Cc: Dave Young <hidave.darkstar@gmail.com>
Cc: Gabor Gombas <gombasg@sztaki.hu>
Cc: Tejun Heo <htejun@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: David Miller <davem@davemloft.net>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 4f014691

drivers/base/core.c

+14 −15
Original line number Diff line number Diff line
@@ -552,6 +552,8 @@ static struct kobject *get_device_parent(struct device *dev, 
}



static inline void cleanup_device_parent(struct device *dev) {}

static inline void cleanup_glue_dir(struct device *dev,

				    struct kobject *glue_dir) {}

#else

static struct kobject *virtual_device_parent(struct device *dev)

{
@@ -616,27 +618,27 @@ static struct kobject *get_device_parent(struct device *dev, 
	return NULL;

}



static void cleanup_device_parent(struct device *dev)

static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)

{

	struct kobject *glue_dir = dev->kobj.parent;



	/* see if we live in a "glue" directory */

	if (!dev->class || glue_dir->kset != &dev->class->class_dirs)

		return;



	kobject_put(glue_dir);

}



static void cleanup_device_parent(struct device *dev)

{

	cleanup_glue_dir(dev, dev->kobj.parent);

}

#endif



static int setup_parent(struct device *dev, struct device *parent)

static void setup_parent(struct device *dev, struct device *parent)

{

	struct kobject *kobj;

	kobj = get_device_parent(dev, parent);

	if (IS_ERR(kobj))

		return PTR_ERR(kobj);

	if (kobj)

		dev->kobj.parent = kobj;

	return 0;

}



static int device_add_class_symlinks(struct device *dev)
@@ -784,9 +786,7 @@ int device_add(struct device *dev) 
	pr_debug("device: '%s': %s\n", dev->bus_id, __FUNCTION__);



	parent = get_device(dev->parent);

	error = setup_parent(dev, parent);

	if (error)

		goto Error;

	setup_parent(dev, parent);



	/* first, register with generic layer. */

	error = kobject_add(&dev->kobj, dev->kobj.parent, "%s", dev->bus_id);
@@ -864,6 +864,7 @@ int device_add(struct device *dev) 
	kobject_uevent(&dev->kobj, KOBJ_REMOVE);

	kobject_del(&dev->kobj);

 Error:

	cleanup_device_parent(dev);

	if (parent)

		put_device(parent);

	goto Done;
@@ -1344,15 +1345,12 @@ int device_move(struct device *dev, struct device *new_parent) 


	new_parent = get_device(new_parent);

	new_parent_kobj = get_device_parent (dev, new_parent);

	if (IS_ERR(new_parent_kobj)) {

		error = PTR_ERR(new_parent_kobj);

		put_device(new_parent);

		goto out;

	}



	pr_debug("device: '%s': %s: moving to '%s'\n", dev->bus_id,

		 __FUNCTION__, new_parent ? new_parent->bus_id : "<NULL>");

	error = kobject_move(&dev->kobj, new_parent_kobj);

	if (error) {

		cleanup_glue_dir(dev, new_parent_kobj);

		put_device(new_parent);

		goto out;

	}
@@ -1375,6 +1373,7 @@ int device_move(struct device *dev, struct device *new_parent) 
				klist_add_tail(&dev->knode_parent,

					       &old_parent->klist_children);

		}

		cleanup_glue_dir(dev, new_parent_kobj);

		put_device(new_parent);

		goto out;

	}

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