WinDBG(CDB)实践1-新手指南

 

Step1
下载最新的Debugging Tools for windows http://www.microsoft.com/whdc/devtools/debugging/installx86.mspx
最新版本是6.6.7.5 http://msdl.microsoft.com/download/symbols/debuggers/dbg_x86_6.6.07.5.exe
(BTW,如果使用老版本可能出现"The call to LoadLibrary(ext) failed, Win32 error 127. The specified procedure could not be found."这样的错误信息)

Step2
设置好symbol server的环境变量
Set _NT_SYMBOL_PATH=srv*c:/symbols*http://msdl.microsoft.com/download/symbols
创建好c:/symbols目录
(BTW,如果要设置http代理set _NT_SYMBOL_PROXY=proxy_server:port)

Step3
把WinDBG(CDB)安装路径加到path中(默认是C:/Program Files/Debugging Tools for Windows)
设置CDB为默认的JIT debugger
C:/>cdb -iae

Step4
使用vc6创建一个控制台程序Crash，主程序为crash.cpp

 1  //  Crash.cpp : Defines the entry point  for  the console application.
 2  //
 3 
 4  #include  " stdafx.h "
 5 
 6  int  main( int  argc, char *  argv[])
 7  {
 8       for ( int  i = 0 ;i < 10 ; ++ i)
 9          printf( " Hello World!%s/n " ,i);
10      return  0 ;
11  }

可以看到该程序就第九行有一个错误,%s应该写成%d

Step 5
编译生成release版本(这里我主要针对Release程序)
注意设置





最后会生成Crash.exe和Crash.pdb和其他一些中间文件

Step 6
运行Release版本的crash.exe会出现crash,这时CDB会自动attach到该进程，开始调试
出现如下画面

Hello World!(null)

Microsoft (R) Windows Debugger  Version 6.6.0007.5
Copyright (c) Microsoft Corporation. All rights reserved.
*** wait with pending attach                                                                                  
Symbol search path is: srv*c:/symbols*http://msdl.microsoft.com/download/symbols
Executable search path is:                                                                                      
ModLoad: 00400000 0040c000   D:/Test/Crash/Release/Crash.exe                       
ModLoad: 77f80000 77ffc000   C:/WINNT/system32/ntdll.dll                                
ModLoad: 7c570000 7c624000   C:/WINNT/system32/KERNEL32.dll                
(e04.f18): Access violation - code c0000005 (!!! second chance !!!)                       
eax=00000001 ebx=7ffdf073 ecx=00000001 edx=7fffffff esi=7ffffffe edi=00000800
eip=004016dd esp=0012fcf8 ebp=0012ff50 iopl=0         nv up ei pl nz na pe nc       
cs=001b  ss=0023  ds=0023  es=0023  fs=0038  gs=0000             efl=00000206   
*** WARNING: Unable to verify checksum for D:/Test/Crash/Release/Crash.exe    
Crash!_output+0x49a:                                                                                               
004016dd 803800          cmp     byte ptr [eax],0           ds:0023:00000001=??          
0:000>

输入.lines load source code information
输入k命令查看堆栈

0:000> .lines
Line number information will be loaded
0:000> k
ChildEBP RetAddr
0012ff50 0040103f Crash!_output+0x49a
0012ff70 0040100e Crash!printf+0x1f
0012ff80 00401105 Crash!main+0xe [D:/Test/Crash/Crash.cpp @ 9]
0012ffc0 7c5989a5 Crash!mainCRTStartup+0xb4
0012fff0 00000000 KERNEL32!BaseProcessStart+0x3d

可以发现程序在Crash.cpp第9行crash

输入q命令退出cdb,结束调试。