lop*_*pan 5 c windbg windows-kernel
只有当嵌套结构中的字符串作为参数匹配我选择的特定模式时,我一直试图在函数内部触发断点,如下所示:
bp `main.c:2236` ".block { .if ( $spat(\"@@(stNames->NameComponent.Buffer)\", \"*ab*\" )){.echo \"BKP HIT! \"; .printf \"%mu str\n\",> @@(NameInfo->FinalComponent.Buffer); } .else {.echo \"NO HIT \"; .printf \"%mu str:\n\", @@(stNames->NameComponent.Buffer); gc;} } "
在已经解析参数符号之后,此断点设置在函数的开头.它表现得很奇怪,即使$ spat中的模式不匹配,有时它也会一直被击中,有时即使模式匹配也不会命中.
我也试过这个没有运气,因为我无法找到一个方法在嵌套结构的这种情况下使用POI()命令.片段波纹管:
bp Kernel32!CreateFileW ".printf \"%mu\\n\", poi(esp+4); as /mu ${/v:FileName} poi(esp+4); .block{.if $spat(\"${FileName}\", \"*target*\") {.echo Hit} .else {.echo Not Yet;g;}}"
该表达式 \"@@(stNames->NameComponent.Buffer)\"可能does not evaluate to a quoted string独立评估
在编写条件语句时，将条件语句分解得尽可能小，
然后将其放到txt文件中，并将脚本文件提供给
类似 bp：32 的断点" $$>a< c:\\windscrypted.txt ，则更容易理解
如果问题具有可独立复制的内容，则提供正确答案也将有所帮助
由于我无法评估问题中无法理解的表达方式，因此我在下面提供了一个演示，以查看是否要问这个问题
编译和链接的助手
structnest:\>type "c:\Program Files\Microsoft Visual Studio 10.0\VC\compile.bat"
@ECHO OFF
REM Compile and Link Helper Utility.
REM Add New Entry CompileMe in Visual_Studio_IDE->Tools->ExternalTools.
REM Provide path to this bat file in command
REM Provide $(ItemFileName)$(ItemExt) as Arguments
REM $(BinDir) as Initial Directory
REM Enjoy One Click Compile & link Simple Single File Demo Sources
@call "C:\Program Files\Microsoft Visual Studio 10.0\VC\vcvarsall.bat" x86
cl /Zi /nologo /W4 /analyze %1% /link /RELEASE
pause
源文件详细信息
structnest:\>dir /b
structnest.cpp
structnest:\>type structnest.cpp
#include <windows.h>
#include <winternl.h>
#include <stdio.h>
#define SOMESIZE 20
typedef VOID (NTAPI *g_RtlInitUnicodeString) (PUNICODE_STRING DestinationStri
ng, PCWSTR SourceString );
#pragma pack (1)
typedef struct _OUTNEST
{
int a;
int b;
short c;
UNICODE_STRING Nestin;
}OutNest,*POutNest;
#pragma pack()
int main (void)
{
POutNest MyNest = ( POutNest ) calloc ( 0x01 , sizeof(OutNest) );
PWSTR buff = ( PWSTR ) calloc ( 0x30 , sizeof(wchar_t) );
HMODULE hMod = LoadLibrary("ntdll.dll");
if ( (hMod != NULL) && (MyNest != NULL) && (buff != NULL))
{
g_RtlInitUnicodeString RtlInitUnicodeString = ( g_RtlInitUnicodeString )
GetProcAddress ( hMod , "RtlInitUnicodeString");
if (RtlInitUnicodeString != NULL )
{
for (int i = 0; i< SOMESIZE; i++)
{
swprintf_s(buff, 0x29 , L"this is string number %.2d",i);
RtlInitUnicodeString(&MyNest->Nestin,buff);
printf("%S\n",MyNest->Nestin.Buffer);
}
printf("done\n");
goto getout;
}
printf("GetprocAddress failed\n");
goto getout;
}
printf("calloc() %p %p LoadLib %p failed\n" , MyNest,buff,hMod);
getout:
if (MyNest)
free(MyNest);
if(buff)
free(buff);
if(hMod)
FreeLibrary(hMod);
return 0;
}
structnest:\>"c:\Program Files\Microsoft Visual Studio 10.0\VC\compile.bat" stru
ctnest.cpp
Setting environment for using Microsoft Visual Studio 2010 x86 tools.
structnest.cpp
Press any key to continue . . .
structnest:\>dir /b *.exe
structnest.exe
structnest:\>structnest.exe
this is string number 00
this is string number 01
this is string number 02
this is string number 03
this is string number 04
this is string number 05
this is string number 06
this is string number 07
this is string number 08
this is string number 09
this is string number 10
this is string number 11
this is string number 12
this is string number 13
this is string number 14
this is string number 15
this is string number 16
this is string number 17
this is string number 18
this is string number 19
done
脚本文件详细信息
structnest:\>type c:\nestedbreak.txt
as /mu ${/v:mystr} @@( MyNest->Nestin.Buffer );
.block { r $t0 = $spat( "${mystr}", "*11" ); }
.if( @$t0 != 1 ) { gc } ;
explanation of script file
as /mu ${/v:mystr}
Sets the alias equivalent equal to the null-terminated Unicode string
that begins at Address @@( MyNest->Nestin.Buffer ).
.block {} to force alias evaluation.
a Pseudo register $t0 is set to the result of $spat() can be 0 or 1
"${mystr}" on alias evaluation will become "this is string number 00"
a Double Quoted string not address or some other expression
"*11" is again a Double Quoted wild card pattern string it will match "11"
at any position in the Input String .
.if is a conditinal that will break only when @$t0 == 1
现在我们有了一个更容易理解的条件，其中每个表达式都可以独立验证，我们继续在断点处使用它
执行细节
structnest:\>cdb -c ".lines;g main;r;.echo SET A CONDITINAL BREAK POINT AND RUN
THE EXE;bp `:32` \" $$^>a^< c:\\nestedbreak.txt \";g ;.lastevent;.echo why did w
e break here ? now that we broke lets go again;g;q " structnest.exe
explanation as follows
cdb.exe console mode windbg;
.lines; load line information (lineinfo default off in cdb.exe needed to set bp on src lines)
g main; ( we are interested in our code for which we have src not some random system module)
r; print the registers to confirm we reached main properly
.echo just a signal to show that we are alive and kicking
`:32` "$$>a< c:\\nestedbreak.txt" conditional break point on src line 32 ( inner double quotes/ unaccpetable > < chars escaped )
g; run the exe
.lastevent; shows the reason why we broke;
.echo a signal to indicate that we broke
g;q; finish running the exe and quit debugger
执行输出详细信息
structnest:\>cdb -c ".lines;g main;r;.echo SET A CONDITINAL BREAK POINT AND RUN
THE EXE;bp `:32` \" $$^>a^< c:\\nestedbreak.txt \";g ;.lastevent;.echo why did w
e break here ? now that we broke lets go again;g;q " structnest.exe
Microsoft (R) Windows Debugger Version 6.12.0002.633 X86
0:000> cdb: Reading initial command '.lines;g main;r;.echo SET A CONDITINAL BREA
K POINT AND RUN THE EXE;bp `:32` " $$>a< c:\\nestedbreak.txt ";g ;.lastevent;.ec
ho why did we break here ? now that we broke lets go again;g;q '
Line number information will be loaded
eax=00034180 ebx=7ffd6000 ecx=00000001 edx=0041a5f0 esi=00000000 edi=00000000
eip=00401000 esp=0013ff7c ebp=0013ffc0 iopl=0 nv up ei pl zr na pe nc
cs=001b ss=0023 ds=0023 es=0023 fs=003b gs=0000 efl=00000246
structnest!main:
00401000 55 push ebp
SET A CONDITINAL BREAK POINT AND RUN THE EXE
this is string number 00
this is string number 01
this is string number 02
this is string number 03
this is string number 04
this is string number 05
this is string number 06
this is string number 07
this is string number 08
this is string number 09
this is string number 10
Last event: 16d0.2784: Hit breakpoint 0
debugger time: Thu May 15 16:10:10.625 2014 (UTC + 5:30)
why did we break here ? now that we broke lets go again
this is string number 11
this is string number 12
this is string number 13
this is string number 14
this is string number 15
this is string number 16
this is string number 17
this is string number 18
this is string number 19
done
quit:
structnest:\>