Re: [PATCH v3] HID: hidraw - add HIDIOCREVOKE ioctl

[Peter Hutterer <peter.hutterer@who-t.net>]

Hi Jiri,

On Wed, Aug 21, 2024 at 02:31:32AM +0200, Jiri Kosina wrote:
> On Mon, 12 Aug 2024, Peter Hutterer wrote:
> 
> > There is a need for userspace applications to open HID devices directly.
> > Use-cases include configuration of gaming mice or direct access to
> > joystick devices. The latter is currently handled by the uaccess tag in
> > systemd, other devices include more custom/local configurations or just
> > sudo.
> > 
> > A better approach is what we already have for evdev devices: give the
> > application a file descriptor and revoke it when it may no longer access
> > that device.
> > 
> > This patch is the hidraw equivalent to the EVIOCREVOKE ioctl, see
> > commit c7dc65737c9a607d3e6f8478659876074ad129b8 for full details.
> > 
> > An MR for systemd-logind has been filed here:
> > https://github.com/systemd/systemd/pull/33970
> > 
> > hidraw_is_revoked() and hidraw_open_errno() are both defined as weak
> > functions to allow for a BPF program to deny access to a /dev/hidraw
> > device. The function returns 0 on success or a negative errno
> > otherwise that is returned to the caller.
> > 
> > As a use-case example, a gamepad-managing process could attach a BPF
> > program that defaults to -EACCESS for all hidraw devices except those
> > with ID_INPUT_JOYSTICK set by udev.
> > 
> > Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
> 
> Thanks Peter. Now queued in hid.git#for-6.12/hidraw.

Benjamin just messaged me about a HID CI pipeline failure caused by this
patch, looks like it's buggy. Can you please revert it again?  I'll send
out a fixed version ASAP, thanks.

Cheeres,
  Peter