gdb -p pid
set args -i 135.240.1.1 -j 135.240.1.2
usnavsvmh13.ndc.lucent.com>> gdb -s
/bld/jkuo/1apx10/bin/cdnia32/CDNap -c core.16671
Reading symbols from /bld/jkuo/1apx10/bin/cdnia32/CDNap...done.
[New Thread 16671]
...
Core was generated by `AMMSPServ -l 1 -i 135.3.46.120 -j 135.3.46.121 -s 31089'.
Program terminated with signal 1!
1, Segmentation fault.
#0 0xf7616f96 in ?? ()
(gdb) break frik.c:13 thread 28 if bartab > lim
(gdb) break func
(gdb) commands
> watch var
> continue
> end
----------
watch optlen
break + 行号 + if + 条件 break 10 if i==3 用于设置条件断点,在循环中使用非常方便
awatch/watch + 变量 awatch/watch i 设置一个观察点,当变量被读出或写入时程序被暂停
rwatch + 变量 rwatch i 设置一个观察点,当变量被读出时,程序被暂停
watch i > 999
一旦i > 999,程序就会被中断,GDB指出改变条件的代码。(有多个i,到底看的是哪一个???)
----------------
常用命令
notes: gdb attach pid
b file:line
c
ctrl +z
fg 回来
用gdb -g debug 必须源码在同一个folder
***********************************************************
转载常用命令:http://blog.youkuaiyun.com/hairetz/article/details/6170658
1. 查看寄存器
(gdb) i r
(gdb) i r a # 查看所有寄存器(包括浮点、多媒体)
(gdb) i r esp
(gdb) i r pc
2. 查看内存
(gdb) x /wx 0x80040000 # 以16进制显示指定地址处的数据
(gdb) x /8x $esp
(gdb) x /16x $esp+12
(gdb) x /16s 0x86468700 # 以字符串形式显示指定地址处的数据
(gdb) x /24i 0x8048a51 # 以指令形式显示指定地址处的数据(24条)
3. 修改寄存器的值
(gdb) set $v0 = 0x004000000
(gdb) set $epc = 0xbfc00000
4. 修改内存的值
(gdb) set {unsigned int}0x8048a51=0x0
(gdb) set *(unsigned int*)0x8048a54=0x55aa55aa
5. 内存搜索
Usage: find <start> <end> <count> <value>
(gdb) define find
set $ptr = $arg0
set $cnt = 0
while ( ($ptr<=$arg1) && ($cnt<$arg2) )
if ( *(unsigned int *)$ptr == $arg3 )
x /wx $ptr
set $cnt = $cnt + 1
end
set $ptr = $ptr + 4
end
end
6. 断点、监测点
(gdb) b *0x80400000
(gdb) watch *(unsigned int *)0xbffff400==0x90909090
附录:GDB详解 http://www.cnblogs.com/ggjucheng/archive/2011/12/14/2288004.html
和菜鸟一起学linux之GCC内嵌汇编简单实例 https://blog.youkuaiyun.com/fdsafwagdagadg6576/article/details/44647239
和菜鸟一起学c之gcc编译过程及其常用编译选项: https://blog.youkuaiyun.com/fdsafwagdagadg6576/article/details/44647079