On Fri, Jan 06, 2017 at 02:14:16AM +0900, Akinobu Mita wrote:
> The sysrq input handler should be attached to the input device which has
> a left alt key.
>
> On 32-bit kernels, some input devices which has a left alt key cannot
> attach sysrq handler. Because the keybit bitmap in struct input_device_id
> for sysrq is not correctly initialized. KEY_LEFTALT is 56 which is
> greater than BITS_PER_LONG on 32-bit kernels.
>
> I found this problem when using a matrix keypad device which defines
> a KEY_LEFTALT (56) but doesn't have a KEY_O (24 == 56%32).
>
> Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org>
> Cc: Jiri Slaby <jsl...@suse.com>
> Cc: Dmitry Torokhov <dmitry.torok...@gmail.com>
> Signed-off-by: Akinobu Mita <akinobu.m...@gmail.com>
Acked-by: Dmitry Torokhov <dmitry.torok...@gmail.com>
I guess Greg will take it through TTY tree. Might go to stable as well,
although apparently not pressing since it was only noticed now.
> ---
> drivers/tty/sysrq.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c
> index 52bbd27..701c085 100644
> --- a/drivers/tty/sysrq.c
> +++ b/drivers/tty/sysrq.c
> @@ -946,8 +946,8 @@ static const struct input_device_id sysrq_ids[] = {
> {
> .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
> INPUT_DEVICE_ID_MATCH_KEYBIT,
> - .evbit = { BIT_MASK(EV_KEY) },
> - .keybit = { BIT_MASK(KEY_LEFTALT) },
> + .evbit = { [BIT_WORD(EV_KEY)] = BIT_MASK(EV_KEY) },
> + .keybit = { [BIT_WORD(KEY_LEFTALT)] = BIT_MASK(KEY_LEFTALT) },
> },
> { },
> };
> --
> 2.7.4
>
Thanks.
--
Dmitry
