在我使用 WinDbg 切换到进程上下文后，有没有办法切换回原始上下文？我用过这些命令：
获取进程地址：
!process 0 0 myprocess.exe
然后切换到 myprocess.exe 上下文这个命令：
.process /i /r /p <address>
现在我怎样才能切换回物理地址？我想调试一个从 myprocess.exe 中的系统调用开始的函数到使用 WinDbg 的整个路径之后的 ntdll 函数，但是一旦我在进程上下文中，我不知道如何返回物理地址以便系统调用完成后继续调试 ntdll。
我已经尝试在网上搜索但找不到答案，谢谢。
Assuming You Have a Proper Kernel Debugging Environment Setup You can Trace From user Mode into KernelMode and Back To User Mode
As An Example shown Below is a Stripped Lowlevel CreateFile Call
It Starts from the last leg of Journey in usermode at ntdll.dll
compile link and transfer the executable to the target machine
and use either ntsd -d exe from target
or use !gflag +ksl; sxe ld:ntcfile in host windbg
sxe ld: is once per boot
for ntsd -d you need windbg installed in target
Read Documentation about both ways first
you can also look at some of my old answers
//poc and Demo code using fragile semi-documented functions and magic constants
//compiled and linked in vs2017 community in x86 as x86 with cmd dev prompt
// will produce a barebone ~1kb exe on successful execution will create or
//open a zero byte text file testfile.txt in c:\
#include <windows.h>
#include <winternl.h>
#pragma comment(lib ,"ntdll.lib")
UNICODE_STRING FileName = { 38,40, L"\\??\\C:\\testfile.txt" };
OBJECT_ATTRIBUTES Ob = { 0x18,NULL,&FileName,0x40,NULL,NULL };
IO_STATUS_BLOCK ioStatus;
HANDLE Out;
int main(void) {
NtCreateFile(&Out,0x80000000,&Ob,&ioStatus,NULL,0x80,0,3,0,NULL,0);
return (int)Out;
}
compiled linked executed and verified
:\>ls -lg c:\testfile.txt
ls: c:\testfile.txt: No such file or directory
:\>cl /Zi /W4 /analyze /Od /nologo ntcfile.cpp /link /release /entry:main /subsystem:windows /fixed
ntcfile.cpp
:\>powershell -c "(Start-Process -PassThru -Wait .\ntcfile.exe).ExitCode"
12
:\>ls -lg c:\testfile.txt
-rw-rw-rw- 1 0 0 2021-01-04 01:21 c:\testfile.txt
shown below is a walk through using the code above in a host and target
$$ on executing ntsd -d in target you get a user mode prompt in kernel debugger
$$ issue .breakin to change mode
.breakin
Break instruction exception - code 80000003 (first chance)
nt!RtlpBreakWithStatusInstruction:
82882d00 cc int 3
look for EPROCESS of interest
kd> !process 0 0 ntcfile.exe
PROCESS 84386828 SessionId: 1 Cid: 04d8 Peb: 7ffdf000 ParentCid: 01a4
DirBase: 0b1eb000 ObjectTable: 96f2a970 HandleCount: 4.
Image: ntcfile.exe
Set Process Specific Breakpoint on kernel mode ddi wrt user mode api
( mostly same named function in ntdll) and continue (f5 or g->enter)
you will return back to user mode prompt debug as you normally debug
an user mode executable if youstep into a sysenter for which have set
a kernel modebreakpoint your will break in kernel mode in proper
process context
kd> bp /p 84386828 nt!NtCreateFile
kd> bl
0 e Disable Clear 82a7642e 0001 (0001) nt!NtCreateFile
Match process data 84386828
kd> g
0:000> g @$exentry
g @$exentry
eax=77533c33 ebx=7ffdf000 ecx=00000000 edx=00401000 esi=00000000 edi=00000000
eip=00401000 esp=0012ff8c ebp=0012ff94 iopl=0 nv up ei pl zr na pe nc
cs=001b ss=0023 ds=0023 es=0023 fs=003b gs=0000 efl=00000246
ntcfile!main:
00401000 55 push ebp
reload symbols in user mode it will load the transferred pdb in target ntsd
0:000> .reload /f ntcfile.exe=0x400000,4000
.reload /f ntcfile.exe=0x400000,4000
0:000> lmm ntc*
lmm ntc*
start end module name
00400000 00404000 ntcfile (private pdb symbols) c:\Users\winsev\Desktop\ntcfile.pdb
0:000> $$ this pdb is in target transferred along with binary for ntsd -d to work
$$ this pdb is in target transferred along with binary for ntsd -d to work
disassembly of the main
0:000> uf .
uf .
ntcfile!main:
00401000 55 push ebp
00401001 8bec mov ebp,esp
00401003 6a00 push 0
00401005 6a00 push 0
00401007 6a00 push 0
00401009 6a03 push 3
0040100b 6a00 push 0
0040100d 6880000000 push 80h
00401012 6a00 push 0
00401014 6820304000 push offset ntcfile!ioStatus (00403020)
00401019 6808304000 push offset ntcfile!Ob (00403008)
0040101e 6800000080 push 80000000h
00401023 6828304000 push offset ntcfile!Out (00403028)
00401028 e807000000 call ntcfile!NtCreateFile (00401034)
0040102d a128304000 mov eax,dword ptr [ntcfile!Out (00403028)]
00401032 5d pop ebp
00401033 c3 ret
stepping through until sysenter for ntdll!NtCreateFile to break in nt!NtCreateFile
0:000> pc
ntcfile!main+0x28:
00401028 e807000000 call ntcfile!NtCreateFile (00401034)
0:000> t
ntcfile!NtCreateFile:
00401034 ff2500204000 jmp dword ptr [ntcfile!_imp__NtCreateFile (00402000)] ds:0023:00402000={ntdll!NtCreateFile (773e55c8)}
0:000> t
ntdll!NtCreateFile:
773e55c8 b842000000 mov eax,42h
0:000> t
ntdll!NtCreateFile+0x5:
773e55cd ba0003fe7f mov edx,offset SharedUserData!SystemCallStub (7ffe0300)
0:000> t
ntdll!NtCreateFile+0xa:
773e55d2 ff12 call dword ptr [edx] ds:0023:7ffe0300={ntdll!KiFastSystemCall (773e70b0)}
0:000> t
ntdll!KiFastSystemCall:
773e70b0 8bd4 mov edx,esp
0:000> t
773e70b2 0f34 sysenter
0:000> t
your are in kernel mode now
Breakpoint 0 hit
nt!NtCreateFile:
82a7642e 8bff mov edi,edi
kd> kb
# ChildEBP RetAddr Args to Child
00 961bbd00 8285f87a 00403028 80000000 00403008 nt!NtCreateFile
01 961bbd00 773e70b4 00403028 80000000 00403008 nt!KiFastCallEntry+0x12a
02 0012ff50 773e55d4 0040102d 00403028 80000000 ntdll!KiFastSystemCallRet
03 0012ff54 0040102d 00403028 80000000 00403008 ntdll!NtCreateFile+0xc
04 0012ff88 77533c45 7ffdf000 0012ffd4 774037f5 ntcfile!main+0x2d [c:\users\hp\desktop\ntcfile\ntcfile.cpp @ 14]
05 0012ff94 774037f5 7ffdf000 775c0f6b 00000000 kernel32!BaseThreadInitThunk+0xe
06 0012ffd4 774037c8 00401000 7ffdf000 00000000 ntdll!__RtlUserThreadStart+0x70
07 0012ffec 00000000 00401000 7ffdf000 00000000 ntdll!_RtlUserThreadStart+0x1b
kd> $$ stack consists of both user mode and kernle mode components