Re: WMI and Kernel:User interface

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Tue, Jun 13, 2017 at 08:44:19AM -0700, Darren Hart wrote:
> > In some cases filter function can be simple in some cases hard. I can
> > image that usage of while listing, plus in some cases also filtering
> > (when it would be relatively easy to implement).
> 
> See my response to Christoph - to address the concern of breaking userspace
> later, if we consider this a proxy instead of a filter, we can make it
> transparent to userspace and maintain kernel driver state. The driver can
> register a wmi_method_proxy callback which can choose to proxy the method call
> or not. If it does, it can update it's own state and perform the requested
> action through it's own infrastructure, populate the out buffer and send it back
> up to userspace. I would hope to see as few of these as possible, but they would
> allow for protecting the kernel drivers while still enabling userspace usage of
> WMI.

Ok, I think we need to see some real code here to get any further with
this.  There's a reason we don't do big design discussions without
patches, as that usually answers all of the questions involved.

Please, let's see some code before anything else.

thanks,

greg k-h