[PATCH libinput] evdev: reject devices with only one of x/y resolution

[Peter Hutterer]

This is a kernel bug, reject such devices outright. This saves us from a bunch
of extra double checks to make sure that the resolutions are always set up.

Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
---
 src/evdev.c   | 32 +++++++++++++++++-----
 test/device.c | 87 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 112 insertions(+), 7 deletions(-)

diff --git a/src/evdev.c b/src/evdev.c
index a6d6fae..243cd22 100644
--- a/src/evdev.c
+++ b/src/evdev.c
@@ -1377,13 +1377,6 @@ evdev_fix_abs_resolution(struct evdev_device *device,
 	absx = libevdev_get_abs_info(evdev, xcode);
 	absy = libevdev_get_abs_info(evdev, ycode);
 
-	if ((absx->resolution == 0 && absy->resolution != 0) ||
-	    (absx->resolution != 0 && absy->resolution == 0)) {
-		log_bug_kernel(libinput,
-			       "Kernel has only x or y resolution, not both.\n");
-		return 0;
-	}
-
 	if (absx->resolution == 0 || absx->resolution == EVDEV_FAKE_RESOLUTION) {
 		fixed = *absx;
 		fixed.resolution = xresolution;
@@ -1487,8 +1480,10 @@ evdev_check_min_max(struct evdev_device *device, unsigned int code)
 static int
 evdev_reject_device(struct evdev_device *device)
 {
+	struct libinput *libinput = device->base.seat->libinput;
 	struct libevdev *evdev = device->evdev;
 	unsigned int code;
+	const struct input_absinfo *absx, *absy;
 
 	if (libevdev_has_event_code(evdev, EV_ABS, ABS_X) ^
 	    libevdev_has_event_code(evdev, EV_ABS, ABS_Y))
@@ -1498,6 +1493,29 @@ evdev_reject_device(struct evdev_device *device)
 	    libevdev_has_event_code(evdev, EV_ABS, ABS_MT_POSITION_Y))
 		return -1;
 
+	if (libevdev_has_event_code(evdev, EV_ABS, ABS_X)) {
+		absx = libevdev_get_abs_info(evdev, ABS_X);
+		absy = libevdev_get_abs_info(evdev, ABS_Y);
+		if ((absx->resolution == 0 && absy->resolution != 0) ||
+		    (absx->resolution != 0 && absy->resolution == 0)) {
+			log_bug_kernel(libinput,
+				       "Kernel has only x or y resolution, not both.\n");
+			return -1;
+		}
+	}
+
+	if (!evdev_is_fake_mt_device(device) &&
+	    libevdev_has_event_code(evdev, EV_ABS, ABS_MT_POSITION_X)) {
+		absx = libevdev_get_abs_info(evdev, ABS_MT_POSITION_X);
+		absy = libevdev_get_abs_info(evdev, ABS_MT_POSITION_Y);
+		if ((absx->resolution == 0 && absy->resolution != 0) ||
+		    (absx->resolution != 0 && absy->resolution == 0)) {
+			log_bug_kernel(libinput,
+				       "Kernel has only x or y MT resolution, not both.\n");
+			return -1;
+		}
+	}
+
 	for (code = 0; code < ABS_CNT; code++) {
 		switch (code) {
 		case ABS_MISC:
diff --git a/test/device.c b/test/device.c
index c9d5255..cf9885a 100644
--- a/test/device.c
+++ b/test/device.c
@@ -894,6 +894,91 @@ START_TEST(abs_mt_device_no_range)
 }
 END_TEST
 
+START_TEST(abs_device_missing_res)
+{
+	struct libevdev_uinput *uinput;
+	struct libinput *li;
+	struct libinput_device *device;
+	struct input_absinfo absinfo[] = {
+		{ ABS_X, 0, 10, 0, 0, 10 },
+		{ ABS_Y, 0, 10, 0, 0, 0 },
+		{ -1, -1, -1, -1, -1, -1 }
+	};
+
+	li = litest_create_context();
+	litest_disable_log_handler(li);
+	uinput = litest_create_uinput_abs_device("test device", NULL,
+						 absinfo,
+						 EV_KEY, BTN_LEFT,
+						 EV_KEY, BTN_RIGHT,
+						 -1);
+	device = libinput_path_add_device(li,
+					  libevdev_uinput_get_devnode(uinput));
+	ck_assert(device == NULL);
+	libevdev_uinput_destroy(uinput);
+
+	absinfo[0].resolution = 0;
+	absinfo[1].resolution = 20;
+	uinput = litest_create_uinput_abs_device("test device", NULL,
+						 absinfo,
+						 EV_KEY, BTN_LEFT,
+						 EV_KEY, BTN_RIGHT,
+						 -1);
+	device = libinput_path_add_device(li,
+					  libevdev_uinput_get_devnode(uinput));
+	ck_assert(device == NULL);
+	libevdev_uinput_destroy(uinput);
+
+	litest_restore_log_handler(li);
+	libinput_unref(li);
+
+}
+END_TEST
+
+START_TEST(abs_mt_device_missing_res)
+{
+	struct libevdev_uinput *uinput;
+	struct libinput *li;
+	struct libinput_device *device;
+	struct input_absinfo absinfo[] = {
+		{ ABS_X, 0, 10, 0, 0, 10 },
+		{ ABS_Y, 0, 10, 0, 0, 10 },
+		{ ABS_MT_SLOT, 0, 2, 0, 0, 0 },
+		{ ABS_MT_TRACKING_ID, 0, 255, 0, 0, 0 },
+		{ ABS_MT_POSITION_X, 0, 10, 0, 0, 10 },
+		{ ABS_MT_POSITION_Y, 0, 10, 0, 0, 0 },
+		{ -1, -1, -1, -1, -1, -1 }
+	};
+
+	li = litest_create_context();
+	litest_disable_log_handler(li);
+	uinput = litest_create_uinput_abs_device("test device", NULL,
+						 absinfo,
+						 EV_KEY, BTN_LEFT,
+						 EV_KEY, BTN_RIGHT,
+						 -1);
+	device = libinput_path_add_device(li,
+					  libevdev_uinput_get_devnode(uinput));
+	ck_assert(device == NULL);
+	libevdev_uinput_destroy(uinput);
+
+	absinfo[4].resolution = 0;
+	absinfo[5].resolution = 20;
+	uinput = litest_create_uinput_abs_device("test device", NULL,
+						 absinfo,
+						 EV_KEY, BTN_LEFT,
+						 EV_KEY, BTN_RIGHT,
+						 -1);
+	device = libinput_path_add_device(li,
+					  libevdev_uinput_get_devnode(uinput));
+	ck_assert(device == NULL);
+	libevdev_uinput_destroy(uinput);
+
+	litest_restore_log_handler(li);
+	libinput_unref(li);
+
+}
+END_TEST
 int main (int argc, char **argv)
 {
 	litest_add("device:sendevents", device_sendevents_config, LITEST_ANY, LITEST_TOUCHPAD);
@@ -928,6 +1013,8 @@ int main (int argc, char **argv)
 	litest_add_no_device("device:invalid devices", abs_mt_device_no_absy);
 	litest_add_no_device("device:invalid devices", abs_device_no_range);
 	litest_add_no_device("device:invalid devices", abs_mt_device_no_range);
+	litest_add_no_device("device:invalid devices", abs_device_missing_res);
+	litest_add_no_device("device:invalid devices", abs_mt_device_missing_res);
 
 	return litest_run(argc, argv);
 }
-- 
2.3.4