On Wed, Aug 04, 2021 at 01:09:07PM -0700, Kuppuswamy, Sathyanarayanan wrote:

On 8/4/21 12:50 PM, Andi Kleen wrote:

quoted

quoted

And what's wrong with the current method of removing drivers from
devices that you do not want them to be bound to?  We offer that support
for all busses now that want to do it, what driver types are you needing
to "control" here that does not take advantage of the existing
infrastructure that we currently have for this type of thing?

I'm not sure what mechanism you're referring to here, but in general
don't want the drivers to initialize at all because they might get
exploited in any code that they execute.The intention is to disable all
drivers except for a small allow list, because it's not practical to
harden all 25M lines of Linux code.

Yes, we are not trying to remove the drivers via sysfs. If driver
filter is enabled, "allowed" sysfs file is used to view the driver
filter status (allowed/denied). And a write to that file changes
the allowed/denied status of the driver. It has nothing to do
with bind/unbind operations.

Again, we have this already today, with full sysfs control in userspace.
Why add yet-another-way to do this?  What is lacking in the existing
functionality that needs to be expanded on?

greg k-h