+static int evdev_ff_effect_from_user(const char __user *buffer, size_t size,
+ struct ff_effect *effect)
+{
+ if (COMPAT_TEST) {
+ struct ff_effect_compat *compat_effect;
+
+ if (size != sizeof(struct ff_effect_compat))
+ return -EINVAL;
+
+ /*
+ * It so happens that the pointer which needs to be changed
+ * is the last field in the structure, so we can copy the
+ * whole thing and replace just the pointer.
+ */
+
+ compat_effect = (struct ff_effect_compat *)effect;
+
+ if (copy_from_user(compat_effect, buffer,
+ sizeof(struct ff_effect_compat)))
+ return -EFAULT;
+
+ if (compat_effect->type == FF_PERIODIC &&
+ compat_effect->u.periodic.waveform == FF_CUSTOM)
+ effect->u.periodic.custom_data =
+ compat_ptr(compat_effect->u.periodic.custom_data);
+ } else {
+ if (size != sizeof(struct ff_effect))
+ return -EINVAL;
+
+ if (copy_from_user(effect, buffer, sizeof(struct ff_effect)))
+ return -EFAULT;
+ }
+
+ return 0;
+}
+