EnumProcessModules() weirdness

This is a question about running 32-bit applications on 64-bit machines.
It's kind of tedious...

32-bit OS = Win XP Sp1
64-bit OS = RTM Standard Server 2003 Sp1

There's some example code that's been around for a long time that shows how
to print the names of all the running processes on the system.

It goes EnumProcesses() - OpenProcess() - EnumProcessModules() -
GetModuleFileNameEx() - printf()

I modified the example to not enumerate all of the component modules - I
just want the executable name - and to put everything on one line.

To compile on 32-bits, I use:
1) Visual Studio 6
2) The IFS DDK + 32-bit Platform SDK and the build utility

(no difference in results)

To compile on 64-bit, I use the 64-bit version of option 2 above.


When I compile and run this on 32-bits, it mostly works. The few access
denied errors are acceptable. When I copy the 32-bit image to the 64-bit
machine, it mostly doesn't work. When I compile and run on 64-bits, it
works. Three outputs below:


===== 32-bit image running on 32-bit machine =====

Process ID: 00004: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
Process ID: 00504: \SystemRoot\System32\smss.exe
Process ID: 00552: *** OpenProcess() returns ERROR_ACCESS_DENIED
Process ID: 00576: \??\F:\WINDOWS\system32\winlogon.exe
Process ID: 00620: F:\WINDOWS\system32\services.exe
Process ID: 00632: F:\WINDOWS\system32\lsass.exe
Process ID: 00800: F:\WINDOWS\system32\Ati2evxx.exe
Process ID: 00816: F:\WINDOWS\system32\svchost.exe
Process ID: 00872: *** OpenProcess() returns ERROR_ACCESS_DENIED
Process ID: 00940: F:\WINDOWS\System32\svchost.exe
Process ID: 01012: *** OpenProcess() returns ERROR_ACCESS_DENIED
Process ID: 01088: *** OpenProcess() returns ERROR_ACCESS_DENIED
Process ID: 01276: F:\WINDOWS\system32\spoolsv.exe
Process ID: 01452: F:\WINDOWS\system32\Ati2evxx.exe
Process ID: 01532: F:\WINDOWS\Explorer.EXE
Process ID: 01632: F:\Program Files\ATI Technologies\ATI Control
Panel\atiptaxx.exe
Process ID: 01640: F:\Program Files\Analog Devices\SoundMAX\SMax4PNP.exe
Process ID: 01648: F:\Program Files\Analog Devices\SoundMAX\Smax4.exe
Process ID: 01660: F:\Program Files\Intel\Intel(R) Active
Monitor\imontray.exe
Process ID: 01668: F:\Program Files\HP\hpcoretech\hpcmpmgr.exe
Process ID: 01676: F:\Program Files\Roxio\Easy CD Creator
5\DirectCD\DirectCD.exe
Process ID: 01684: F:\PROGRA~1\Lavasoft\AD-AWA~1\Ad-Watch.exe
Process ID: 01692: F:\Program Files\HP\HP Software Update\HPWuSchd2.exe
Process ID: 01700: F:\Program Files\Messenger\msmsgs.exe
Process ID: 01708: F:\WINDOWS\system32\ctfmon.exe
Process ID: 01740: F:\Program Files\HP\Digital Imaging\bin\hpqtra08.exe
Process ID: 01852: F:\WINDOWS\System32\drivers\CDAC11BA.EXE
Process ID: 01876: F:\PowerPanelPlus\upssrv.exe
Process ID: 01908: F:\WINDOWS\system32\inetsrv\inetinfo.exe
Process ID: 01916: F:\PowerPanelPlus\upsio.exe
Process ID: 01952: F:\Program Files\Common Files\Microsoft
Shared\VS7Debug\mdm.exe
Process ID: 00136: F:\Program Files\Analog Devices\SoundMAX\SMAgent.exe
Process ID: 00176: F:\WINDOWS\System32\svchost.exe
Process ID: 00232: *** OpenProcess() returns ERROR_ACCESS_DENIED
Process ID: 00416: F:\Program Files\Intel\Intel(R) Active Monitor\imonnt.exe
Process ID: 02160: F:\WINDOWS\system32\wscntfy.exe
Process ID: 02588: *** OpenProcess() returns ERROR_ACCESS_DENIED
Process ID: 02792: F:\WINDOWS\System32\svchost.exe
Process ID: 02180: F:\Program Files\Outlook Express\msimn.exe
Process ID: 02780: F:\WINDOWS\system32\notepad.exe
Process ID: 00128: F:\Program Files\Microsoft Visual
Studio\Common\MSDev98\Bin\MSDEV.EXE
Process ID: 03472: F:\WINDOWS\system32\cmd.exe
Process ID: 02788: G:\Pid\objchk_wxp_x86\i386\Pid.exe

===== same 32-bit image running on 64-bit machine =====

Process ID: 00004: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
Process ID: 00360: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
Process ID: 00408: *** OpenProcess() returns ERROR_ACCESS_DENIED
Process ID: 00432: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
Process ID: 00476: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
Process ID: 00488: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
Process ID: 00696: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
Process ID: 00764: *** OpenProcess() returns ERROR_ACCESS_DENIED
Process ID: 00860: *** OpenProcess() returns ERROR_ACCESS_DENIED
Process ID: 00896: *** OpenProcess() returns ERROR_ACCESS_DENIED
Process ID: 00908: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
Process ID: 01036: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
Process ID: 01064: *** OpenProcess() returns ERROR_ACCESS_DENIED
Process ID: 01188: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
Process ID: 01228: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
Process ID: 01288: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
Process ID: 01312: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
Process ID: 01340: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
Process ID: 01424: *** OpenProcess() returns ERROR_ACCESS_DENIED
Process ID: 01524: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
Process ID: 01728: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
Process ID: 01952: E:\WINDOWS\SysWOW64\svchost.exe
Process ID: 02012: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
Process ID: 00840: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
Process ID: 02212: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
Process ID: 02540: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
Process ID: 02684: *** OpenProcess() returns ERROR_ACCESS_DENIED
Process ID: 02756: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
Process ID: 02184: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
Process ID: 01876: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
Process ID: 00392: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
Process ID: 02188: E:\Pid\32\objchk_wxp_x86\i386\Pid.exe

===== 64-bit image running on 64-bit machine =====

Process ID: 00004: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
Process ID: 00360: \SystemRoot\System32\smss.exe
Process ID: 00408: *** OpenProcess() returns ERROR_ACCESS_DENIED
Process ID: 00432: \??\E:\WINDOWS\system32\winlogon.exe
Process ID: 00476: E:\WINDOWS\system32\services.exe
Process ID: 00488: E:\WINDOWS\system32\lsass.exe
Process ID: 00696: E:\WINDOWS\system32\svchost.exe
Process ID: 00764: *** OpenProcess() returns ERROR_ACCESS_DENIED
Process ID: 00860: *** OpenProcess() returns ERROR_ACCESS_DENIED
Process ID: 00896: *** OpenProcess() returns ERROR_ACCESS_DENIED
Process ID: 00908: E:\WINDOWS\System32\svchost.exe
Process ID: 01036: E:\WINDOWS\system32\spoolsv.exe
Process ID: 01064: *** OpenProcess() returns ERROR_ACCESS_DENIED
Process ID: 01188: E:\WINDOWS\System32\dns.exe
Process ID: 01228: E:\WINDOWS\System32\svchost.exe
Process ID: 01288: E:\WINDOWS\system32\inetsrv\inetinfo.exe
Process ID: 01312: E:\WINDOWS\system32\tcpsvcs.exe
Process ID: 01340: E:\WINDOWS\system32\sfmsvc.exe
Process ID: 01424: *** OpenProcess() returns ERROR_ACCESS_DENIED
Process ID: 01524: E:\WINDOWS\System32\wins.exe
Process ID: 01728: E:\WINDOWS\System32\svchost.exe
Process ID: 01952: E:\WINDOWS\SysWOW64\svchost.exe
Process ID: 02012: E:\WINDOWS\System32\svchost.exe
Process ID: 00840: E:\WINDOWS\Explorer.EXE
Process ID: 02212: E:\WINDOWS\System32\svchost.exe
Process ID: 02540: E:\WINDOWS\system32\wuauclt.exe
Process ID: 02684: *** OpenProcess() returns ERROR_ACCESS_DENIED
Process ID: 02756: E:\WINDOWS\system32\wpabaln.exe
Process ID: 02184: E:\WINDOWS\system32\cmd.exe
Process ID: 01876: E:\WINDOWS\system32\cmd.exe
Process ID: 00392: E:\WINDOWS\system32\cmd.exe
Process ID: 00724: E:\Pid\64\objchk_wnet_amd64\amd64\Pid.exe

Anybody have any suggestions as to why EnumProcesses() and OpenProcess()
will work in either situation but EnumProcessModules() won't?

Anybody have the ability to define ERROR_PARTIAL_COPY from
EnumProcessModules()?

Regards,
Mickey.

Mickey Lane wrote:
> This is a question about running 32-bit applications on 64-bit machines.
> It's kind of tedious...
>
> 32-bit OS = Win XP Sp1
> 64-bit OS = RTM Standard Server 2003 Sp1
>
> There's some example code that's been around for a long time that shows how
> to print the names of all the running processes on the system.
>
> It goes EnumProcesses() - OpenProcess() - EnumProcessModules() -
> GetModuleFileNameEx() - printf()
>
> I modified the example to not enumerate all of the component modules - I
> just want the executable name - and to put everything on one line.
>
> To compile on 32-bits, I use:
> 1) Visual Studio 6
> 2) The IFS DDK + 32-bit Platform SDK and the build utility
>
> (no difference in results)
>
> To compile on 64-bit, I use the 64-bit version of option 2 above.
>
>
> When I compile and run this on 32-bits, it mostly works. The few access
> denied errors are acceptable. When I copy the 32-bit image to the 64-bit
> machine, it mostly doesn't work. When I compile and run on 64-bits, it
> works. Three outputs below:
>
>
> ===== 32-bit image running on 32-bit machine =====
>
> Process ID: 00004: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
> Process ID: 00504: \SystemRoot\System32\smss.exe
> Process ID: 00552: *** OpenProcess() returns ERROR_ACCESS_DENIED
> Process ID: 00576: \??\F:\WINDOWS\system32\winlogon.exe
> Process ID: 00620: F:\WINDOWS\system32\services.exe
> Process ID: 00632: F:\WINDOWS\system32\lsass.exe
> Process ID: 00800: F:\WINDOWS\system32\Ati2evxx.exe
> Process ID: 00816: F:\WINDOWS\system32\svchost.exe
> Process ID: 00872: *** OpenProcess() returns ERROR_ACCESS_DENIED
> Process ID: 00940: F:\WINDOWS\System32\svchost.exe
> Process ID: 01012: *** OpenProcess() returns ERROR_ACCESS_DENIED
> Process ID: 01088: *** OpenProcess() returns ERROR_ACCESS_DENIED
> Process ID: 01276: F:\WINDOWS\system32\spoolsv.exe
> Process ID: 01452: F:\WINDOWS\system32\Ati2evxx.exe
> Process ID: 01532: F:\WINDOWS\Explorer.EXE
> Process ID: 01632: F:\Program Files\ATI Technologies\ATI Control
> Panel\atiptaxx.exe
> Process ID: 01640: F:\Program Files\Analog Devices\SoundMAX\SMax4PNP.exe
> Process ID: 01648: F:\Program Files\Analog Devices\SoundMAX\Smax4.exe
> Process ID: 01660: F:\Program Files\Intel\Intel(R) Active
> Monitor\imontray.exe
> Process ID: 01668: F:\Program Files\HP\hpcoretech\hpcmpmgr.exe
> Process ID: 01676: F:\Program Files\Roxio\Easy CD Creator
> 5\DirectCD\DirectCD.exe
> Process ID: 01684: F:\PROGRA~1\Lavasoft\AD-AWA~1\Ad-Watch.exe
> Process ID: 01692: F:\Program Files\HP\HP Software Update\HPWuSchd2.exe
> Process ID: 01700: F:\Program Files\Messenger\msmsgs.exe
> Process ID: 01708: F:\WINDOWS\system32\ctfmon.exe
> Process ID: 01740: F:\Program Files\HP\Digital Imaging\bin\hpqtra08.exe
> Process ID: 01852: F:\WINDOWS\System32\drivers\CDAC11BA.EXE
> Process ID: 01876: F:\PowerPanelPlus\upssrv.exe
> Process ID: 01908: F:\WINDOWS\system32\inetsrv\inetinfo.exe
> Process ID: 01916: F:\PowerPanelPlus\upsio.exe
> Process ID: 01952: F:\Program Files\Common Files\Microsoft
> Shared\VS7Debug\mdm.exe
> Process ID: 00136: F:\Program Files\Analog Devices\SoundMAX\SMAgent.exe
> Process ID: 00176: F:\WINDOWS\System32\svchost.exe
> Process ID: 00232: *** OpenProcess() returns ERROR_ACCESS_DENIED
> Process ID: 00416: F:\Program Files\Intel\Intel(R) Active Monitor\imonnt.exe
> Process ID: 02160: F:\WINDOWS\system32\wscntfy.exe
> Process ID: 02588: *** OpenProcess() returns ERROR_ACCESS_DENIED
> Process ID: 02792: F:\WINDOWS\System32\svchost.exe
> Process ID: 02180: F:\Program Files\Outlook Express\msimn.exe
> Process ID: 02780: F:\WINDOWS\system32\notepad.exe
> Process ID: 00128: F:\Program Files\Microsoft Visual
> Studio\Common\MSDev98\Bin\MSDEV.EXE
> Process ID: 03472: F:\WINDOWS\system32\cmd.exe
> Process ID: 02788: G:\Pid\objchk_wxp_x86\i386\Pid.exe
>
> ===== same 32-bit image running on 64-bit machine =====
>
> Process ID: 00004: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
> Process ID: 00360: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
> Process ID: 00408: *** OpenProcess() returns ERROR_ACCESS_DENIED
> Process ID: 00432: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
> Process ID: 00476: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
> Process ID: 00488: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
> Process ID: 00696: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
> Process ID: 00764: *** OpenProcess() returns ERROR_ACCESS_DENIED
> Process ID: 00860: *** OpenProcess() returns ERROR_ACCESS_DENIED
> Process ID: 00896: *** OpenProcess() returns ERROR_ACCESS_DENIED
> Process ID: 00908: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
> Process ID: 01036: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
> Process ID: 01064: *** OpenProcess() returns ERROR_ACCESS_DENIED
> Process ID: 01188: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
> Process ID: 01228: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
> Process ID: 01288: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
> Process ID: 01312: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
> Process ID: 01340: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
> Process ID: 01424: *** OpenProcess() returns ERROR_ACCESS_DENIED
> Process ID: 01524: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
> Process ID: 01728: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
> Process ID: 01952: E:\WINDOWS\SysWOW64\svchost.exe
> Process ID: 02012: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
> Process ID: 00840: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
> Process ID: 02212: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
> Process ID: 02540: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
> Process ID: 02684: *** OpenProcess() returns ERROR_ACCESS_DENIED
> Process ID: 02756: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
> Process ID: 02184: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
> Process ID: 01876: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
> Process ID: 00392: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
> Process ID: 02188: E:\Pid\32\objchk_wxp_x86\i386\Pid.exe
>
> ===== 64-bit image running on 64-bit machine =====
>
> Process ID: 00004: *** EnumProcessModules() returns ERROR_PARTIAL_COPY
> Process ID: 00360: \SystemRoot\System32\smss.exe
> Process ID: 00408: *** OpenProcess() returns ERROR_ACCESS_DENIED
> Process ID: 00432: \??\E:\WINDOWS\system32\winlogon.exe
> Process ID: 00476: E:\WINDOWS\system32\services.exe
> Process ID: 00488: E:\WINDOWS\system32\lsass.exe
> Process ID: 00696: E:\WINDOWS\system32\svchost.exe
> Process ID: 00764: *** OpenProcess() returns ERROR_ACCESS_DENIED
> Process ID: 00860: *** OpenProcess() returns ERROR_ACCESS_DENIED
> Process ID: 00896: *** OpenProcess() returns ERROR_ACCESS_DENIED
> Process ID: 00908: E:\WINDOWS\System32\svchost.exe
> Process ID: 01036: E:\WINDOWS\system32\spoolsv.exe
> Process ID: 01064: *** OpenProcess() returns ERROR_ACCESS_DENIED
> Process ID: 01188: E:\WINDOWS\System32\dns.exe
> Process ID: 01228: E:\WINDOWS\System32\svchost.exe
> Process ID: 01288: E:\WINDOWS\system32\inetsrv\inetinfo.exe
> Process ID: 01312: E:\WINDOWS\system32\tcpsvcs.exe
> Process ID: 01340: E:\WINDOWS\system32\sfmsvc.exe
> Process ID: 01424: *** OpenProcess() returns ERROR_ACCESS_DENIED
> Process ID: 01524: E:\WINDOWS\System32\wins.exe
> Process ID: 01728: E:\WINDOWS\System32\svchost.exe
> Process ID: 01952: E:\WINDOWS\SysWOW64\svchost.exe
> Process ID: 02012: E:\WINDOWS\System32\svchost.exe
> Process ID: 00840: E:\WINDOWS\Explorer.EXE
> Process ID: 02212: E:\WINDOWS\System32\svchost.exe
> Process ID: 02540: E:\WINDOWS\system32\wuauclt.exe
> Process ID: 02684: *** OpenProcess() returns ERROR_ACCESS_DENIED
> Process ID: 02756: E:\WINDOWS\system32\wpabaln.exe
> Process ID: 02184: E:\WINDOWS\system32\cmd.exe
> Process ID: 01876: E:\WINDOWS\system32\cmd.exe
> Process ID: 00392: E:\WINDOWS\system32\cmd.exe
> Process ID: 00724: E:\Pid\64\objchk_wnet_amd64\amd64\Pid.exe
>
> Anybody have any suggestions as to why EnumProcesses() and OpenProcess()
> will work in either situation but EnumProcessModules() won't?
>
> Anybody have the ability to define ERROR_PARTIAL_COPY from
> EnumProcessModules()?
>
> Regards,
> Mickey.
>
>


This is just a guess (sorry), but do you have a large enough lphModule
array?

BOOL EnumProcessModules(
HANDLE hProcess,
HMODULE* lphModule,
DWORD cb,
LPDWORD lpcbNeeded
);

Try calling EnumProcessModules() first with cb (size of array) set to
zero. Then allocate the returned lpcbNeeded * sizeof(HMODULE) and call
EnumProcessModules() again with the new data. Hopefully this is what
ERROR_PARTIAL_COPY means. (If you have error number you can use
errlook.exe in visual studio tools directory to get a better description).

"R.B." <> wrote in message
news:e0$...
>
> This is just a guess (sorry), but do you have a large enough lphModule
> array?
>
> BOOL EnumProcessModules(
> HANDLE hProcess,
> HMODULE* lphModule,
> DWORD cb,
> LPDWORD lpcbNeeded
> );
>
> Try calling EnumProcessModules() first with cb (size of array) set to
> zero. Then allocate the returned lpcbNeeded * sizeof(HMODULE) and call
> EnumProcessModules() again with the new data. Hopefully this is what
> ERROR_PARTIAL_COPY means. (If you have error number you can use
> errlook.exe in visual studio tools directory to get a better description).

Doesn't seem to change anything. Didn't think it would. You can call the
routine with a buffer length of 1 element and get back only one handle - the
handle of the main process name.

In my test program, I had arbitrarly set the buffer size to 200 elements.
The 4th variable is then set to the number used. (or the number of bytes
used)

I even tried making sure everything was 64-bit aligned. No luck there
either.

Mickey.

Mickey Lane wrote:
> Doesn't seem to change anything. Didn't think it would. You can call the
> routine with a buffer length of 1 element and get back only one handle - the
> handle of the main process name.
>
> In my test program, I had arbitrarly set the buffer size to 200 elements.
> The 4th variable is then set to the number used. (or the number of bytes
> used)
>
> I even tried making sure everything was 64-bit aligned. No luck there
> either.
>
> Mickey.
>
>

What error number does GetLastError() return when the function fails?