Linux Virtualization - Sep 2021 - [PATCH v2 1/6] driver core: Move the "authorized" attribute from USB/Thunderbolt to core

On Wed, Sep 29, 2021 at 06:05:06PM -0700, Kuppuswamy Sathyanarayanan
wrote:
> Currently bus drivers like "USB" or "Thunderbolt"
implement a custom
> version of device authorization to selectively authorize the driver
> probes. Since there is a common requirement, move the
"authorized"
> attribute support to the driver core in order to allow it to be used
> by other subsystems / buses.
> 
> Similar requirements have been discussed in the PCI [1] community for
> PCI bus drivers as well.
> 
> No functional changes are intended. It just converts authorized
> attribute from int to bool and moves it to the driver core. There
> should be no user-visible change in the location or semantics of
> attributes for USB devices.
> 
> Regarding thunderbolt driver, although it declares sw->authorized as
> "int" and allows 0,1,2 as valid values for sw->authorized
attribute,
> but within the driver, in all authorized attribute related checks,
> it is treated as bool value. So when converting the authorized
> attribute from int to bool value, there should be no functional
> changes other than value 2 being not visible to the user.
> 
> [1]:
https://lore.kernel.org/all/CACK8Z6E8pjVeC934oFgr=VB3pULx_GyT2NkzAogdRQJ9TKSX9A
at mail.gmail.com/
> 
> Reviewed-by: Dan Williams <dan.j.williams at intel.com>
> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy at
linux.intel.com>
Since you're moving the authorized flag from the USB core to the
driver core, the corresponding sysfs attribute functions should be
moved as well.

Also, you ignored the usb_[de]authorize_interface() functions and 
their friends.

Alan Stern

On Wed, Sep 29, 2021 at 6:43 PM Alan Stern <stern at rowland.harvard.edu>
wrote:
>
> On Wed, Sep 29, 2021 at 06:05:06PM -0700, Kuppuswamy Sathyanarayanan wrote:
> > Currently bus drivers like "USB" or "Thunderbolt"
implement a custom
> > version of device authorization to selectively authorize the driver
> > probes. Since there is a common requirement, move the
"authorized"
> > attribute support to the driver core in order to allow it to be used
> > by other subsystems / buses.
> >
> > Similar requirements have been discussed in the PCI [1] community for
> > PCI bus drivers as well.
> >
> > No functional changes are intended. It just converts authorized
> > attribute from int to bool and moves it to the driver core. There
> > should be no user-visible change in the location or semantics of
> > attributes for USB devices.
> >
> > Regarding thunderbolt driver, although it declares sw->authorized
as
> > "int" and allows 0,1,2 as valid values for sw->authorized
attribute,
> > but within the driver, in all authorized attribute related checks,
> > it is treated as bool value. So when converting the authorized
> > attribute from int to bool value, there should be no functional
> > changes other than value 2 being not visible to the user.
> >
> > [1]:
https://lore.kernel.org/all/CACK8Z6E8pjVeC934oFgr=VB3pULx_GyT2NkzAogdRQJ9TKSX9A
at mail.gmail.com/
> >
> > Reviewed-by: Dan Williams <dan.j.williams at intel.com>
> > Signed-off-by: Kuppuswamy Sathyanarayanan
<sathyanarayanan.kuppuswamy at linux.intel.com>
>
> Since you're moving the authorized flag from the USB core to the
> driver core, the corresponding sysfs attribute functions should be
> moved as well.
Unlike when 'removable' moved from USB to the driver core there
isn't
a common definition for how the 'authorized' sysfs-attribute behaves
across buses. The only common piece is where this flag is stored in
the data structure, i.e. the 'authorized' sysfs interface is
purposefully left bus specific.
> Also, you ignored the usb_[de]authorize_interface() functions and
> their friends.
Ugh, yes.