Re: WMI and Kernel:User interface

From: Greg Kroah-Hartman
Date: Wed Jun 14 2017 - 00:39:11 EST


On Tue, Jun 13, 2017 at 10:07:19AM -0700, Darren Hart wrote:
> On Tue, Jun 13, 2017 at 06:52:47PM +0200, Greg Kroah-Hartman wrote:
> > > As a concrete example, Dell has specifically made the request that we
> > > work on a solution that doesn't require them to come back to the kernel
> > > community each time they add a WMI GUID to their BIOS. They would like
> > > to see those GUIDs automatically exposed.
> >
> > What do you mean exactly by "exposed"? What do they do with these? Why
>
> By exposed I meant: the chardev for the WMI GUID is created
>
> The idea being the kernel maps WMI GUIDs to chardevs and shepherds the
> userspace calls through to the ACPI method evaluation and back. But the
> kernel wmi driver doesn't, in general, have specific knowledge of the
> methods or input and output formats.

Hah, and those people who insist on "secure boot" are going to allow
userspace access to ACPI methods like this? Well, I guess as Windows
does it, it must be ok...

I'll shut up now and just wait for patches :)

thanks,

greg k-h