Re: [RFC v1] USB: core: add USBDEVFS_REVOKE ioctl

[Bastien Nocera <hadess@hadess.net>]

Hey,

On Mon, 2022-04-25 at 15:23 +0200, Bastien Nocera wrote:
> Note that this variant needs to do a few things that the evdev revoke
> doesn't need to handle, particular:
> - cancelling pending async transfers
> - making sure to release claimed interfaces on revoke so they can be
>   opened by another process/user, as USB interfaces require being
>   exclusively claimed to be used.

This is a first version of the patch, untested as yet (although I at
least checked that it compiled...).

I wanted to have comments on whether I was on the right path, in terms
of coding style, but also that I had plugged all the entry points that
would allow a user to communicate with a USB device after revocation.

I also have a local patch that allows using BPF to revoke a USB device
that's trivial so would need testing before posting.

You can find links to Peter's hidraw revocation patches at:
https://github.com/systemd/systemd/pull/23140#issue-1210571942

Cheers