On 04.12.2024 10:33, Greg Kroah-Hartman wrote:
> On Tue, Dec 03, 2024 at 09:10:05PM +0100, Heiner Kallweit wrote:
>> In preparation of removing class_compat support, add a helper for
>> creating a pseudo class in sysfs. This way we can keep class_kset
>> private to driver core. This helper will be used by vfio/mdev,
>> replacing the call to class_compat_create().
>>
>> Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
>> ---
>> drivers/base/class.c | 14 ++++++++++++++
>> include/linux/device/class.h | 1 +
>> 2 files changed, 15 insertions(+)
>>
>> diff --git a/drivers/base/class.c b/drivers/base/class.c
>> index 582b5a02a..f812236e2 100644
>> --- a/drivers/base/class.c
>> +++ b/drivers/base/class.c
>> @@ -578,6 +578,20 @@ struct class_compat *class_compat_register(const char *name)
>> }
>> EXPORT_SYMBOL_GPL(class_compat_register);
>>
>> +/**
>> + * class_pseudo_register - create a pseudo class entry in sysfs
>> + * @name: the name of the child
>> + *
>> + * Helper for creating a pseudo class in sysfs, keeps class_kset private
>> + *
>> + * Returns: the created kobject
>> + */
>> +struct kobject *class_pseudo_register(const char *name)
>> +{
>> + return kobject_create_and_add(name, &class_kset->kobj);
>> +}
>> +EXPORT_SYMBOL_GPL(class_pseudo_register);
>
> I see the goal here, but let's not continue on and create fake kobjects
> in places where there should NOT be any kobjects. Also, you might get
> in trouble when removing this kobject as it thinks it is a 'struct
> class' but yet it isn't, right? Did you test that?
>
It's removed using kobject_put(), same as what class_compat_unregister() does.
I only compile-tested the changes.
> thanks,
>
> greg k-h
