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Date: Tue, 13 Jun 2017 18:05:47 +0200
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Darren Hart <dvhart@infradead.org>
Cc: Pali =?iso-8859-1?Q?Roh=E1r?= <pali.rohar@gmail.com>,
        Christoph Hellwig <hch@infradead.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
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        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
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        Andy Lutomirski <luto@amacapital.net>,
        LKML <linux-kernel@vger.kernel.org>,
        platform-driver-x86@vger.kernel.org
Subject: Re: WMI and Kernel:User interface
Message-ID: <20170613160547.GA25404@kroah.com>
References: <20170509231639.GB11404@fury>
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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