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. This removes: BTN_DPAD_UP(0x220)..BTN_DPAD_RIGHT(0x223) Empty space 0x224..0x229 Emtpy space 0x2bd..0x2bf BTN_TRIGGER_HAPPY(0x2c0)..BTN_TRIGGER_HAPPY40(0x2e7) Empty space 0x2e8..0x2ff The modalias shrinks from 2082 to 1754 bytes. [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> --- drivers/input/misc/xen-kbdfront.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/input/misc/xen-kbdfront.c b/drivers/input/misc/xen-kbdfront.c index 8d8ebdc2039b..23f37211be78 100644 --- a/drivers/input/misc/xen-kbdfront.c +++ b/drivers/input/misc/xen-kbdfront.c @@ -256,7 +256,14 @@ static int xenkbd_probe(struct xenbus_device *dev, __set_bit(EV_KEY, kbd->evbit); for (i = KEY_ESC; i < KEY_UNKNOWN; i++) __set_bit(i, kbd->keybit); - for (i = KEY_OK; i < KEY_MAX; i++) + /* In theory we want to go KEY_OK..KEY_MAX, but that grows the + * modalias line too long. KEY_KBD_LCD_MENU5 is the last + * defined non-button key. There is a gap of buttons from + * BTN_DPAD_UP..BTN_DPAD_RIGHT and KEY_ALS_TOGGLE is the next + * defined. */ + for (i = KEY_OK; i < BTN_DPAD_UP; i++) + __set_bit(i, kbd->keybit); + for (i = KEY_ALS_TOGGLE; i <= KEY_KBD_LCD_MENU5; i++) __set_bit(i, kbd->keybit); ret = input_register_device(kbd); -- 2.37.3
