程序段错误，无源码，如何修复？

gdb：
Program received signal SIGSEGV, Segmentation fault.
0x0014a0a8 in __libc_start_main () from /lib/i386-linux-gnu/libc.so.6

本人小白无经验
这是一个题目，修复elf
修复成功应该显示key

gdb 调试没看到 执行到哪句 段错误的？ ./ 执行后 报错贴出来

scr@ubuntu:~/Linux第四题$ gdb ./brokenelf
GNU gdb (Ubuntu/Linaro 7.3-0ubuntu2) 7.3-2011.08
Copyright (C) 2011 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type "show copying"
and "show warranty" for details.
This GDB was configured as "i686-linux-gnu".
For bug reporting instructions, please see:
<http://bugs.launchpad.net/gdb-linaro/>...
Reading symbols from /home/scr/Linux第四题/brokenelf...(no debugging symbols found)...done.

(gdb) r
Starting program: /home/scr/Linux第四题/brokenelf 

Program received signal SIGSEGV, Segmentation fault.
0x0014a0a8 in __libc_start_main () from /lib/i386-linux-gnu/libc.so.6

scr@ubuntu:~/Linux第四题$ gdb ./brokenelf core
GNU gdb (Ubuntu/Linaro 7.3-0ubuntu2) 7.3-2011.08
Copyright (C) 2011 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type "show copying"
and "show warranty" for details.
This GDB was configured as "i686-linux-gnu".
For bug reporting instructions, please see:
<http://bugs.launchpad.net/gdb-linaro/>...
Reading symbols from /home/scr/Linux第四题/brokenelf...(no debugging symbols found)...done.
[New LWP 6293]

warning: Can't read pathname for load map: 输入/输出错误.
Core was generated by `./brokenelf'.
Program terminated with signal 11, Segmentation fault.
#0 0x001290a8 in __libc_start_main () from /lib/i386-linux-gnu/libc.so.6

源码发出来

没有源码啊~~~~~只有一个可执行文件~~~~~

。。。。。。。。。。warning: Can't read pathname for load map: 输入/输出错误.


这什么程序 怎么没源码

我们学校娱乐比赛的~应该是逆向的~~我以前没弄过gcc编程~~一点不懂啊~~~