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Commit f4203e30 authored by Borislav Petkov's avatar Borislav Petkov Committed by Greg Kroah-Hartman
Browse files

sysdev: Do not register with sysdev when erroring on add 



When encountering an error while executing the driver's ->add method, we
should cancel registration and unwind what we've regged so far. The low
level ->add methods do return proper error codes but those aren't looked
at in sysdev_driver_register(). Fix that by sharing the unregistering
code.

Signed-off-by: default avatarBorislav Petkov <borislav.petkov@amd.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 1f7da214

drivers/base/sys.c

+44 −17
Original line number Diff line number Diff line
@@ -166,6 +166,36 @@ EXPORT_SYMBOL_GPL(sysdev_class_unregister); 


static DEFINE_MUTEX(sysdev_drivers_lock);



/*

 * @dev != NULL means that we're unwinding because some drv->add()

 * failed for some reason. You need to grab sysdev_drivers_lock before

 * calling this.

 */

static void __sysdev_driver_remove(struct sysdev_class *cls,

				   struct sysdev_driver *drv,

				   struct sys_device *from_dev)

{

	struct sys_device *dev = from_dev;



	list_del_init(&drv->entry);

	if (!cls)

		return;



	if (!drv->remove)

		goto kset_put;



	if (dev)

		list_for_each_entry_continue_reverse(dev, &cls->kset.list,

						     kobj.entry)

			drv->remove(dev);

	else

		list_for_each_entry(dev, &cls->kset.list, kobj.entry)

			drv->remove(dev);



kset_put:

	kset_put(&cls->kset);

}



/**

 *	sysdev_driver_register - Register auxillary driver

 *	@cls:	Device class driver belongs to.
@@ -175,9 +205,9 @@ static DEFINE_MUTEX(sysdev_drivers_lock); 
 *	called on each operation on devices of that class. The refcount

 *	of @cls is incremented.

 */



int sysdev_driver_register(struct sysdev_class *cls, struct sysdev_driver *drv)

{

	struct sys_device *dev = NULL;

	int err = 0;



	if (!cls) {
@@ -198,19 +228,27 @@ int sysdev_driver_register(struct sysdev_class *cls, struct sysdev_driver *drv) 


		/* If devices of this class already exist, tell the driver */

		if (drv->add) {

			struct sys_device *dev;

			list_for_each_entry(dev, &cls->kset.list, kobj.entry)

				drv->add(dev);

			list_for_each_entry(dev, &cls->kset.list, kobj.entry) {

				err = drv->add(dev);

				if (err)

					goto unwind;

			}

		}

	} else {

		err = -EINVAL;

		WARN(1, KERN_ERR "%s: invalid device class\n", __func__);

	}



	goto unlock;



unwind:

	__sysdev_driver_remove(cls, drv, dev);



unlock:

	mutex_unlock(&sysdev_drivers_lock);

	return err;

}





/**

 *	sysdev_driver_unregister - Remove an auxillary driver.

 *	@cls:	Class driver belongs to.
@@ -220,23 +258,12 @@ void sysdev_driver_unregister(struct sysdev_class *cls, 
			      struct sysdev_driver *drv)

{

	mutex_lock(&sysdev_drivers_lock);

	list_del_init(&drv->entry);

	if (cls) {

		if (drv->remove) {

			struct sys_device *dev;

			list_for_each_entry(dev, &cls->kset.list, kobj.entry)

				drv->remove(dev);

		}

		kset_put(&cls->kset);

	}

	__sysdev_driver_remove(cls, drv, NULL);

	mutex_unlock(&sysdev_drivers_lock);

}



EXPORT_SYMBOL_GPL(sysdev_driver_register);

EXPORT_SYMBOL_GPL(sysdev_driver_unregister);







/**

 *	sysdev_register - add a system device to the tree

 *	@sysdev:	device in question