Re: [PATCH v2] Input: xen-kbdfront - drop keys to shrink modalias

[Jason Andryuk <jandryuk@xxxxxxxxx>]

On Wed, Mar 8, 2023 at 11:26 AM Jason Andryuk <jandryuk@xxxxxxxxx> wrote:
>
> On Thu, Dec 15, 2022 at 8:54 AM Mattijs Korpershoek
> <mkorpershoek@xxxxxxxxxxxx> wrote:
> >
> > On Fri, Dec 09, 2022 at 09:26, Jason Andryuk <jandryuk@xxxxxxxxx> wrote:
> >
> > > xen kbdfront registers itself as being able to deliver *any* key since
> > > it doesn't know what keys the backend may produce.
> > >
> > > Unfortunately, the generated modalias gets too large and uevent creation
> > > fails with -ENOMEM.
> > >
> > > This can lead to gdm not using the keyboard since there is no seat
> > > associated [1] and the debian installer crashing [2].
> > >
> > > Trim the ranges of key capabilities by removing some BTN_* ranges.
> > > While doing this, some neighboring undefined ranges are removed to trim
> > > it further.
> > >
> > > An upper limit of KEY_KBD_LCD_MENU5 is still too large.  Use an upper
> > > limit of KEY_BRIGHTNESS_MENU.
> > >
> > > This removes:
> > > BTN_DPAD_UP(0x220)..BTN_DPAD_RIGHT(0x223)
> > > Empty space 0x224..0x229
> > >
> > > Empty space 0x28a..0x28f
> > > KEY_MACRO1(0x290)..KEY_MACRO30(0x2ad)
> > > KEY_MACRO_RECORD_START          0x2b0
> > > KEY_MACRO_RECORD_STOP           0x2b1
> > > KEY_MACRO_PRESET_CYCLE          0x2b2
> > > KEY_MACRO_PRESET1(0x2b3)..KEY_MACRO_PRESET3(0xb5)
> > > Empty space 0x2b6..0x2b7
> > > KEY_KBD_LCD_MENU1(0x2b8)..KEY_KBD_LCD_MENU5(0x2bc)
> > > Empty space 0x2bd..0x2bf
> > > BTN_TRIGGER_HAPPY(0x2c0)..BTN_TRIGGER_HAPPY40(0x2e7)
> > > Empty space 0x2e8..0x2ff
> > >
> > > The modalias shrinks from 2082 to 1550 bytes.
> > >
> > > A chunk of keys need to be removed to allow the keyboard to be used.
> > > This may break some functionality, but the hope is these macro keys are
> > > uncommon and don't affect any users.
> > >
> > > [1] https://github.com/systemd/systemd/issues/22944
> > > [2] https://lore.kernel.org/xen-devel/87o8dw52jc.fsf@xxxxxxxxxxxxxxxx/T/
> > >
> > > Cc: Phillip Susi <phill@xxxxxxxxxxxx>
> > > Cc: stable@xxxxxxxxxxxxxxx
> > > Signed-off-by: Jason Andryuk <jandryuk@xxxxxxxxx>
> >
> > Reviewed-by: Mattijs Korpershoek <mkorpershoek@xxxxxxxxxxxx>
>
> Thank you, Mattjis.

Thank you, Mattijs.  My apologies.

Regards,
Jason