[PATCH libinput 1/9] evdev: Dynamically allocate slot array

Jonas Ådahl jadahl at gmail.com
Wed Apr 9 13:45:08 PDT 2014


On Wed, Apr 09, 2014 at 10:12:11PM +0200, Hardening wrote:
> Le 09/04/2014 21:02, Jonas Ådahl a écrit :
> >Don't have a hard coded (previously 16) slot array size; instead
> >allocate dynamically depending what slots are assigned. There is still a
> >hard coded max though, to protect from invalid input, but its changed
> >to 60.
> >
> >Signed-off-by: Jonas Ådahl <jadahl at gmail.com>
> >---
> >  src/evdev.c | 82 +++++++++++++++++++++++++++++++++++++++++++++----------------
> >  src/evdev.h | 13 ++++++----
> >  2 files changed, 69 insertions(+), 26 deletions(-)
> >
> >diff --git a/src/evdev.c b/src/evdev.c
> >index 72e4086..cc0c4bf 100644
> >--- a/src/evdev.c
> >+++ b/src/evdev.c
> >@@ -280,6 +280,36 @@ evdev_process_key(struct evdev_device *device, struct input_event *e, int time)
> >  	}
> >  }
> >
> >+static int
> >+alloc_mt_slot_states(struct evdev_device *device, int len)
> >+{
> >+	struct mt_slot *slots = device->mt.slots;
> >+	int i;
> >+
> >+	slots = realloc(slots, sizeof(struct mt_slot) * len);
> >+	if (!slots)
> >+		return -1;
> 
> slots will be leaked in this case (realloc don't touch original
> block when it fails, check man realloc).

It won't leak because it'll be free:ed on destruction (see
evdev_device_destroy()).

> 
> >+
> >+	for (i = device->mt.slots_len; i < len; ++i) {
> >+		slots[i].seat_slot = -1;
> >+		slots[i].x = 0;
> >+		slots[i].y = 0;
> >+	}
> >+	device->mt.slots = slots;
> >+	device->mt.slots_len = len;
> >+
> >+	return 0;
> >+}
> >+
> >+static void
> >+set_active_slot(struct evdev_device *device, int32_t slot)
> >+{
> >+	slot = min(slot, MAX_SLOTS);
> >+	if (slot >= device->mt.slots_len)
> >+		alloc_mt_slot_states(device, device->mt.slots_len * 2);
> >+	device->mt.slot = min(slot, device->mt.slots_len - 1);
> >+}
> >+
> >  static void
> >  evdev_process_touch(struct evdev_device *device,
> >  		    struct input_event *e,
> >@@ -288,7 +318,7 @@ evdev_process_touch(struct evdev_device *device,
> >  	switch (e->code) {
> >  	case ABS_MT_SLOT:
> >  		evdev_flush_pending_event(device, time);
> >-		device->mt.slot = e->value;
> >+		set_active_slot(device, e->value);
> >  		break;
> >  	case ABS_MT_TRACKING_ID:
> >  		if (device->pending_event != EVDEV_NONE &&
> >@@ -543,9 +573,11 @@ evdev_device_dispatch(void *data)
> >  static int
> >  evdev_configure_device(struct evdev_device *device)
> >  {
> >+	struct libevdev *evdev = device->evdev;
> >  	const struct input_absinfo *absinfo;
> >  	int has_abs, has_rel, has_mt;
> >  	int has_button, has_keyboard, has_touch;
> >+	int active_slot;
> >  	unsigned int i;
> >
> >  	has_rel = 0;
> >@@ -555,14 +587,14 @@ evdev_configure_device(struct evdev_device *device)
> >  	has_keyboard = 0;
> >  	has_touch = 0;
> >
> >-	if (libevdev_has_event_type(device->evdev, EV_ABS)) {
> >+	if (libevdev_has_event_type(evdev, EV_ABS)) {
> >
> >-		if ((absinfo = libevdev_get_abs_info(device->evdev, ABS_X))) {
> >+		if ((absinfo = libevdev_get_abs_info(evdev, ABS_X))) {
> >  			device->abs.min_x = absinfo->minimum;
> >  			device->abs.max_x = absinfo->maximum;
> >  			has_abs = 1;
> >  		}
> >-		if ((absinfo = libevdev_get_abs_info(device->evdev, ABS_Y))) {
> >+		if ((absinfo = libevdev_get_abs_info(evdev, ABS_Y))) {
> >  			device->abs.min_y = absinfo->minimum;
> >  			device->abs.max_y = absinfo->maximum;
> >  			has_abs = 1;
> >@@ -570,56 +602,58 @@ evdev_configure_device(struct evdev_device *device)
> >                  /* We only handle the slotted Protocol B in weston.
> >                     Devices with ABS_MT_POSITION_* but not ABS_MT_SLOT
> >                     require mtdev for conversion. */
> >-		if (libevdev_has_event_code(device->evdev, EV_ABS, ABS_MT_POSITION_X) &&
> >-		    libevdev_has_event_code(device->evdev, EV_ABS, ABS_MT_POSITION_Y)) {
> >-			absinfo = libevdev_get_abs_info(device->evdev, ABS_MT_POSITION_X);
> >+		if (libevdev_has_event_code(evdev, EV_ABS, ABS_MT_POSITION_X) &&
> >+		    libevdev_has_event_code(evdev, EV_ABS, ABS_MT_POSITION_Y)) {
> >+			absinfo = libevdev_get_abs_info(evdev, ABS_MT_POSITION_X);
> >  			device->abs.min_x = absinfo->minimum;
> >  			device->abs.max_x = absinfo->maximum;
> >-			absinfo = libevdev_get_abs_info(device->evdev, ABS_MT_POSITION_Y);
> >+			absinfo = libevdev_get_abs_info(evdev, ABS_MT_POSITION_Y);
> >  			device->abs.min_y = absinfo->minimum;
> >  			device->abs.max_y = absinfo->maximum;
> >  			device->is_mt = 1;
> >  			has_touch = 1;
> >  			has_mt = 1;
> >
> >-			if (!libevdev_has_event_code(device->evdev, EV_ABS, ABS_MT_SLOT)) {
> >+			if (!libevdev_has_event_code(evdev,
> >+						     EV_ABS, ABS_MT_SLOT)) {
> >  				device->mtdev = mtdev_new_open(device->fd);
> >  				if (!device->mtdev)
> >  					return -1;
> >-				device->mt.slot = device->mtdev->caps.slot.value;
> >+				active_slot = device->mtdev->caps.slot.value;
> >  			} else {
> >-				device->mt.slot = libevdev_get_current_slot(device->evdev);
> >+				active_slot = libevdev_get_current_slot(evdev);
> >  			}
> >+			set_active_slot(device, active_slot);
> >  		}
> >  	}
> >-	if (libevdev_has_event_code(device->evdev, EV_REL, REL_X) ||
> >-	    libevdev_has_event_code(device->evdev, EV_REL, REL_Y))
> >+	if (libevdev_has_event_code(evdev, EV_REL, REL_X) ||
> >+	    libevdev_has_event_code(evdev, EV_REL, REL_Y))
> >  			has_rel = 1;
> >
> >-	if (libevdev_has_event_type(device->evdev, EV_KEY)) {
> >-		if (libevdev_has_event_code(device->evdev, EV_KEY, BTN_TOOL_FINGER) &&
> >-		    !libevdev_has_event_code(device->evdev, EV_KEY, BTN_TOOL_PEN) &&
> >+	if (libevdev_has_event_type(evdev, EV_KEY)) {
> >+		if (libevdev_has_event_code(evdev, EV_KEY, BTN_TOOL_FINGER) &&
> >+		    !libevdev_has_event_code(evdev, EV_KEY, BTN_TOOL_PEN) &&
> >  		    (has_abs || has_mt)) {
> >  			device->dispatch = evdev_mt_touchpad_create(device);
> >  		}
> >  		for (i = KEY_ESC; i < KEY_MAX; i++) {
> >  			if (i >= BTN_MISC && i < KEY_OK)
> >  				continue;
> >-			if (libevdev_has_event_code(device->evdev, EV_KEY, i)) {
> >+			if (libevdev_has_event_code(evdev, EV_KEY, i)) {
> >  				has_keyboard = 1;
> >  				break;
> >  			}
> >  		}
> >-		if (libevdev_has_event_code(device->evdev, EV_KEY, BTN_TOUCH))
> >+		if (libevdev_has_event_code(evdev, EV_KEY, BTN_TOUCH))
> >  			has_touch = 1;
> >  		for (i = BTN_MISC; i < BTN_JOYSTICK; i++) {
> >-			if (libevdev_has_event_code(device->evdev, EV_KEY, i)) {
> >+			if (libevdev_has_event_code(evdev, EV_KEY, i)) {
> >  				has_button = 1;
> >  				break;
> >  			}
> >  		}
> >  	}
> >-	if (libevdev_has_event_type(device->evdev, EV_LED))
> >+	if (libevdev_has_event_type(evdev, EV_LED))
> >  		has_keyboard = 1;
> >
> >  	if ((has_abs || has_rel) && has_button)
> >@@ -670,7 +704,6 @@ evdev_device_create(struct libinput_seat *seat,
> >  	device->mtdev = NULL;
> >  	device->devnode = strdup(devnode);
> >  	device->sysname = strdup(sysname);
> 
> I know that it's not part of your patch but strdup() results should
> be checked.
> 
> >-	device->mt.slot = -1;
> >  	device->rel.dx = 0;
> >  	device->rel.dy = 0;
> >  	device->dispatch = NULL;
> >@@ -680,6 +713,12 @@ evdev_device_create(struct libinput_seat *seat,
> >
> >  	libinput_seat_ref(seat);
> >
> >+	device->mt.slot = -1;
> >+	device->mt.slots = NULL;
> >+	device->mt.slots_len = 0;
> >+	if (alloc_mt_slot_states(device, 4) == -1)
> >+		goto err;
> >+
> >  	if (evdev_configure_device(device) == -1)
> >  		goto err;
> >
> >@@ -786,6 +825,7 @@ evdev_device_destroy(struct evdev_device *device)
> >
> >  	libinput_seat_unref(device->base.seat);
> >  	libevdev_free(device->evdev);
> >+	free(device->mt.slots);
> >  	free(device->devnode);
> >  	free(device->sysname);
> >  	free(device);
> >diff --git a/src/evdev.h b/src/evdev.h
> >index 0ab9572..4ec387a 100644
> 
> [...]
> 
> Regards.
> 
> -- 
> David FORT

Thanks for the review,

Jonas

> website: http://www.hardening-consulting.com/
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