Calling my dll like rundll32 does causes a MSVCRT abnormal program termination

[pke]

I want to call the ANSI method "Popup" defined like a standard rundll32 callable entry proc.

Code Select Expand


extern "C" void CALLBACK Popup(HWND, HINSTANCE, LPSTR commandLine, int) {
}


The code below loads the dll successfully and can call the proc. However something in the proc does something with the MSVCRT and this generates the "Abnormal Program Termination" message box.

---------------------------
Microsoft Visual C++ Runtime Library
---------------------------
Runtime Error!

Program: ...\Test.exe



This application has requested the Runtime to terminate it in an unusual way.
Please contact the application's support team for more information.


---------------------------
OK   
---------------------------

Is there something I have to call inside my asm code to initialize the msvcrt? I have checked the WINE port rundll32.c file and could not see any unusual going on there in regards to MSVCRT initialization.

Code Select Expand


.386
.model flat, stdcall
option casemap:none

include \masm32\include\windows.inc
include \masm32\include\kernel32.inc
include \masm32\include\user32.inc
include \masm32\include\shlwapi.inc

includelib \masm32\lib\kernel32.lib
includelib \masm32\lib\user32.lib
includelib \masm32\lib\shlwapi.lib



.data
dllName db "test",0
funcName db "Popup",0
moduleName db 256 dup (0)

.data?
instance HINSTANCE ?
commandLine LPSTR ?
popupFunc dd ?

.code
start:

invoke GetModuleFileNameA, NULL, addr moduleName, 256
invoke PathStripPathA, addr moduleName
;invoke MessageBoxA,NULL, addr moduleName, NULL, MB_OK
invoke lstrlenA, addr moduleName
mov ebx,eax

invoke GetCommandLineA
add ebx, eax
mov commandLine, ebx
;invoke MessageBoxA,NULL, commandLine, NULL, MB_OK

invoke LoadLibrary, addr dllName
.if eax != NULL
  mov instance,eax
  invoke GetProcAddress, instance, addr funcName
  .if eax  != NULL
    mov popupFunc, eax
    push SW_SHOWDEFAULT
    push commandLine
    push instance
    push 0 ; hwnd   
    call [popupFunc] ; Crashes in msvcrt
  .endif
.else
  ;invoke MessageBox,NULL,addr dllName, NULL, MB_ICONERROR
.endif

invoke ExitProcess,0

end start



Any ideas?

[Vortex]

It's difficult to comment your case without seeing the DLL and the source code. Does your DLL import function(s) from msvcrt.dll ?