new_reg->start_addr = start_addr;
new_reg->size = size;
new_reg->data = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
new_reg->start_addr = start_addr;
new_reg->size = size;
new_reg->data = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);