+/*
+ * Routine: ipc_kmsg_prealloc
+ * Purpose:
+ * Wraper to ipc_kmsg_alloc() to account for
+ * header expansion requirements.
+ */
+ipc_kmsg_t
+ipc_kmsg_prealloc(mach_msg_size_t size)
+{
+#if defined(__LP64__)
+ if (size > MACH_MSG_SIZE_MAX - LEGACY_HEADER_SIZE_DELTA)
+ return IKM_NULL;
+
+ size += LEGACY_HEADER_SIZE_DELTA;
+#endif
+ return ipc_kmsg_alloc(size);
+}