Input: define separate EVIOCGKEYCODE_V2/EVIOCSKEYCODE_V2

The desire to keep old names for the EVIOCGKEYCODE/EVIOCSKEYCODE while
extending them to support large scancodes was a mistake. While we tried
to keep ABI intact (and we succeeded in doing that, programs compiled
on older kernels will work on newer ones) there is still a problem with
recompiling existing software with newer kernel headers.

New kernel headers will supply updated ioctl numbers and kernel will
expect that userspace will use struct input_keymap_entry to set and
retrieve keymap data. But since the names of ioctls are still the same
userspace will happily compile even if not adjusted to make use of the
new structure and will start miraculously fail in the field.

To avoid this issue let's revert EVIOCGKEYCODE/EVIOCSKEYCODE definitions
and add EVIOCGKEYCODE_V2/EVIOCSKEYCODE_V2 so that userspace can explicitly
select the style of ioctls it wants to employ.

Reviewed-by: Henrik Rydberg <rydberg@euromail.se>
Acked-by: Jarod Wilson <jarod@redhat.com>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

1 files changed, 4 insertions, 2 deletions

diff --git a/include/linux/input.h b/include/linux/input.h
index a8af21d42bc1..9777668883be 100644
--- a/include/linux/input.h
+++ b/include/linux/input.h
@@ -104,8 +104,10 @@ struct input_keymap_entry {
 #define EVIOCGREP               _IOR('E', 0x03, unsigned int[2])        /* get repeat settings */
 #define EVIOCSREP               _IOW('E', 0x03, unsigned int[2])        /* set repeat settings */
 
-#define EVIOCGKEYCODE           _IOR('E', 0x04, struct input_keymap_entry)      /* get keycode */
-#define EVIOCSKEYCODE           _IOW('E', 0x04, struct input_keymap_entry)      /* set keycode */
+#define EVIOCGKEYCODE           _IOR('E', 0x04, unsigned int[2])        /* get keycode */
+#define EVIOCGKEYCODE_V2        _IOR('E', 0x04, struct input_keymap_entry)
+#define EVIOCSKEYCODE           _IOW('E', 0x04, unsigned int[2])        /* set keycode */
+#define EVIOCSKEYCODE_V2        _IOW('E', 0x04, struct input_keymap_entry)
 
 #define EVIOCGNAME(len)         _IOC(_IOC_READ, 'E', 0x06, len)         /* get device name */
 #define EVIOCGPHYS(len)         _IOC(_IOC_READ, 'E', 0x07, len)         /* get physical location */