Drop the mt_sync_state in our device struct

Replace it with a stack-allocated one. This saves us a bunch of confusing
allocations and size calculations.

And in the process use uint32_t/int32_t to ensure the struct is actually the
expected size.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

diff --git a/libevdev/libevdev-int.h b/libevdev/libevdev-int.h
index ee834db..ec8e48b 100644 (file)
--- a/libevdev/libevdev-int.h
+++ b/libevdev/libevdev-int.h
@@ -55,11 +55,6 @@ enum SyncState {
        SYNC_IN_PROGRESS,
 };
 
-struct mt_sync_state {
-       int code;
-       int val[];
-};
-
 /**
  * Internal only: log data used to send messages to the respective log
  * handler. We re-use the same struct for a global and inside
@@ -113,8 +108,6 @@ struct libevdev {
        struct timeval last_event_time;
 
        struct {
-               struct mt_sync_state *mt_state;
-               size_t mt_state_sz;              /* in bytes */
                unsigned long *slot_update;
                size_t slot_update_sz;           /* in bytes */
                unsigned long *tracking_id_changes;

diff --git a/libevdev/libevdev.c b/libevdev/libevdev.c
index 14ada21..a91878d 100644 (file)
--- a/libevdev/libevdev.c
+++ b/libevdev/libevdev.c
@@ -28,6 +28,7 @@
 #include <limits.h>
 #include <unistd.h>
 #include <stdarg.h>
+#include <stdint.h>
 #include <stdbool.h>
 
 #include "libevdev.h"
@@ -199,7 +200,6 @@ libevdev_reset(struct libevdev *dev)
        free(dev->phys);
        free(dev->uniq);
        free(dev->mt_slot_vals);
-       free(dev->mt_sync.mt_state);
        free(dev->mt_sync.tracking_id_changes);
        free(dev->mt_sync.slot_update);
        memset(dev, 0, sizeof(*dev));
@@ -333,11 +333,9 @@ free_slots(struct libevdev *dev)
        free(dev->mt_slot_vals);
        free(dev->mt_sync.tracking_id_changes);
        free(dev->mt_sync.slot_update);
-       free(dev->mt_sync.mt_state);
        dev->mt_slot_vals = NULL;
        dev->mt_sync.tracking_id_changes = NULL;
        dev->mt_sync.slot_update = NULL;
-       dev->mt_sync.mt_state = NULL;
 }
 
 static int
@@ -349,11 +347,9 @@ init_slots(struct libevdev *dev)
        free(dev->mt_slot_vals);
        free(dev->mt_sync.tracking_id_changes);
        free(dev->mt_sync.slot_update);
-       free(dev->mt_sync.mt_state);
        dev->mt_slot_vals = NULL;
        dev->mt_sync.tracking_id_changes = NULL;
        dev->mt_sync.slot_update = NULL;
-       dev->mt_sync.mt_state = NULL;
 
        /* devices with ABS_RESERVED aren't MT devices,
           see the documentation for multitouch-related
@@ -377,10 +373,6 @@ init_slots(struct libevdev *dev)
        }
        dev->current_slot = abs_info->value;
 
-       dev->mt_sync.mt_state_sz = sizeof(*dev->mt_sync.mt_state) +
-                                  (dev->num_slots) * sizeof(int);
-       dev->mt_sync.mt_state = calloc(1, dev->mt_sync.mt_state_sz);
-
        dev->mt_sync.tracking_id_changes_sz = NLONGS(dev->num_slots) * sizeof(long);
        dev->mt_sync.tracking_id_changes = malloc(dev->mt_sync.tracking_id_changes_sz);
 
@@ -388,8 +380,7 @@ init_slots(struct libevdev *dev)
        dev->mt_sync.slot_update = malloc(dev->mt_sync.slot_update_sz);
 
        if (!dev->mt_sync.tracking_id_changes ||
-           !dev->mt_sync.slot_update ||
-           !dev->mt_sync.mt_state) {
+           !dev->mt_sync.slot_update) {
                rc = -ENOMEM;
                goto out;
        }
@@ -691,7 +682,6 @@ sync_mt_state(struct libevdev *dev, int create_events)
        int rc;
        int axis, slot;
        int last_reported_slot = 0;
-       struct mt_sync_state *mt_state = dev->mt_sync.mt_state;
        unsigned long *slot_update = dev->mt_sync.slot_update;
        unsigned long *tracking_id_changes = dev->mt_sync.tracking_id_changes;
        int need_tracking_id_changes = 0;
@@ -703,30 +693,35 @@ sync_mt_state(struct libevdev *dev, int create_events)
 #define AXISBIT(_slot, _axis) (_slot * ABS_MT_CNT + _axis - ABS_MT_MIN)
 
        for (axis = ABS_MT_MIN; axis <= ABS_MT_MAX; axis++) {
+               /* EVIOCGMTSLOTS required format */
+               struct mt_sync_state {
+                       uint32_t code;
+                       int32_t val[dev->num_slots];
+               } mt_state;
+
                if (axis == ABS_MT_SLOT)
                        continue;
 
                if (!libevdev_has_event_code(dev, EV_ABS, axis))
                        continue;
 
-               mt_state->code = axis;
-               rc = ioctl(dev->fd, EVIOCGMTSLOTS(dev->mt_sync.mt_state_sz), mt_state);
+               mt_state.code = axis;
+               rc = ioctl(dev->fd, EVIOCGMTSLOTS(sizeof(mt_state)), &mt_state);
                if (rc < 0)
                        goto out;
 
                for (slot = 0; slot < dev->num_slots; slot++) {
-
-                       if (*slot_value(dev, slot, axis) == mt_state->val[slot])
+                       if (*slot_value(dev, slot, axis) == mt_state.val[slot])
                                continue;
 
                        if (axis == ABS_MT_TRACKING_ID &&
                            *slot_value(dev, slot, axis) != -1 &&
-                           mt_state->val[slot] != -1) {
+                           mt_state.val[slot] != -1) {
                                set_bit(tracking_id_changes, slot);
                                need_tracking_id_changes = 1;
                        }
 
-                       *slot_value(dev, slot, axis) = mt_state->val[slot];
+                       *slot_value(dev, slot, axis) = mt_state.val[slot];
 
                        set_bit(slot_update, AXISBIT(slot, axis));
                        /* note that this slot has updates */