info reg是有信息的，而且我看@zhuliang那篇帖子里，也会显示No such file or directory，如下：
This GDB was configured as "arm-apple-darwin".
/private/var/root/12416: No such file or directory
Attaching to process 12416.
Reading symbols for shared libraries . done
Reading symbols for shared libraries ............................................................................................................................................. done
Reading symbols for shared libraries + done
0x39556eb4 in mach_msg_trap ()
但是后面的信息不一样，我也怀疑attaching出错了，每次只显示个
0x3c051eb4 in ()
就是不知道出什么错了，现在无从下手
