Re: [PATCH v2 09/19] Input: serio - use the compatibility driver attachment API

[Leon Romanovsky <leon@kernel.org>]

On Tue, Nov 10, 2026 at 07:35:18AM +0000, sashiko-bot@kernel.org wrote:
> Thank you for your contribution! Sashiko AI review found 1 potential
> issue to consider:
> - [High] Input: serio: serio_bind_driver() fails with -EPERM under
>   default boot policy
> --
> 
> commit 3fd95316c0bff9166a7d599c0aa06fa861dbf4de
> Author: Leon Romanovsky <leon@kernel.org>
> 
> Input: serio - use the compatibility driver attachment API
> 
> This commit replaces the manual driver connect and bind sequence in
> serio_bind_driver() with device_driver_attach_full().
> 
> > diff --git a/drivers/input/serio/serio.c b/drivers/input/serio/serio.c
> > index 54dd26249b027..b54072769ab68 100644
> > --- a/drivers/input/serio/serio.c
> > +++ b/drivers/input/serio/serio.c
> > @@ -81,28 +81,10 @@ static int serio_match_port(const struct serio_device_id *ids, struct serio *ser
> >  
> >  static int serio_bind_driver(struct serio *serio, struct serio_driver *drv)
> >  {
> > -	int error;
> > -
> > -	if (serio_match_port(drv->id_table, serio)) {
> > -
> > -		serio->dev.driver = &drv->driver;
> > -		if (serio_connect_driver(serio, drv)) {
> > -			serio->dev.driver = NULL;
> > -			return -ENODEV;
> > -		}
> > +	if (!serio_match_port(drv->id_table, serio))
> > +		return 0;
> >  
> > -		error = device_bind_driver(&serio->dev);
> > -		if (error) {
> > -			dev_warn(&serio->dev,
> > -				 "device_bind_driver() failed for %s (%s) and %s, error: %d\n",
> > -				 serio->phys, serio->name,
> > -				 drv->description, error);
> > -			serio_disconnect_driver(serio);
> > -			serio->dev.driver = NULL;
> > -			return error;
> > -		}
> > -	}
> > -	return 0;
> > +	return device_driver_attach_full(&drv->driver, &serio->dev);
> >  }
> 
> [Severity: High]
> As reported by Dmitry Torokhov on v1 [1], serio_bind_driver() is only
> called for explicit user-initiated binding via the drvctl sysfs attribute,
> and it was requested that this patch be dropped from the series.
> 
> In addition, does switching serio_bind_driver() to
> device_driver_attach_full() break manual binding via drvctl on default
> boots?  Later in this series (commit "driver core: Introduce a generic
> device trust level" and commit "driver core: Accept device trust policy on
> the kernel command line"), device_driver_attach_full() calls
> device_trust_prepare_full(), which returns -EPERM unless
> device_trust.default=full was passed on the kernel command line.  When
> userspace writes a driver name such as serio_raw to drvctl, drvctl_store()
> disconnects the existing driver via serio_disconnect_port() and then
> serio_bind_driver() fails with -EPERM, leaving the port unbound.

No. serio was converted to the compatibility API intentionally. Anyone who
needs serio must use the "full" trust level.

Thanks

> 
> [1] https://lore.kernel.org/r/auy2plYVi723Qt42@google.com
> 
> -- 
> Sashiko AI review · https://sashiko.dev/#/patchset/20261109-device-trust-core-v2-0-3b12d9a9f861@nvidia.com?part=9
>