read_fd_into_buffer
err = read_fd_into_buffer(iter_fd, task_vma_output + len,
err = read_fd_into_buffer(proc_maps_fd, proc_maps_output, CMP_BUFFER_SIZE);
err = read_fd_into_buffer(iter_fd, task_vma_output, CMP_BUFFER_SIZE);
err = read_fd_into_buffer(iter_fd, buf, TASKBUFSZ);