trace_user_fault_read
buf = trace_user_fault_read(trace_user_buffer, ubuf, cnt, NULL, NULL);
buf = trace_user_fault_read(trace_user_buffer, ubuf, cnt, NULL, NULL);
char *trace_user_fault_read(struct trace_user_buf_info *tinfo,
buffer = trace_user_fault_read(&sbuf->buf, NULL, size,