KnowledgeBase Archive

An Archive of Early Microsoft KnowledgeBase Articles

View on GitHub

Q184826: Symbol Checksum Error Reported When Kernel Debugging

Article: Q184826
Product(s): Microsoft Windows NT
Version(s): winnt:4.0,4.0 SP4,4.0 SP5,4.0 SP6,4.0 SP6a
Operating System(s): 
Keyword(s): kbFEA kbWinNT400sp4feakbfaq
Last Modified: 09-AUG-2001

-------------------------------------------------------------------------------
The information in this article applies to:

- Microsoft Windows NT Workstation versions 4.0 SP4, 4.0 SP5, 4.0 SP6, 4.0 SP6a 
- Microsoft Windows NT Server versions 4.0 SP4, 4.0 SP5, 4.0 SP6, 4.0 SP6a 
- Microsoft Windows NT Server versions 4.0, 4.0 SP4, 4.0 SP5, 4.0 SP6, Terminal Server Edition 
-------------------------------------------------------------------------------

SUMMARY
=======

When you are loading symbols for a kernel debug against a computer running
Windows NT 4.0 Service Pack 4 (SP4), the debugger reports a checksum error,
symbol mismatch, against the following components:

  Win32k.sys
  Ntdll.dll
  Kernel32.dll
  Winsrv.dll

The symbols that are being used are correct, and should not report this error.


MORE INFORMATION
================

This behavior is by design, assuming you are debugging a computer with a single
processor.

If you install SP4 on a computer with a single processor, you smash the lock
prefix instructions. This matches the behavior of Windows NT setup. This
behavior is new to SP4 and did not occur with Service Pack 3, so lock prefixes
were left intact even on computers with a single processor.

The lock x86 instruction only comes into play on multiprocessor computers. When
SP4 is installed on a computer with a single processor, we replace the lock
instruction (0xF0) with a NOOP instruction (0x90).

Newer versions of Windbg know about this behavior and don't display the warning
for these files. Click the link belwo to download the most recent version of
Windbg from the Microsoft Web site:

  http://www.microsoft.com/ddk/debugger

Additional query words: debugref

======================================================================
Keywords          : kbFEA kbWinNT400sp4fea kbfaq
Technology        : kbWinNTsearch kbWinNTWsearch kbWinNTW400search kbWinNT400search kbWinNTW400sp5 kbWinNTW400sp4 kbWinNTSsearch kbWinNTS400sp6 kbWinNTS400sp5 kbWinNTS400sp4 kbWinNTS400search kbNTTermServ400 kbNTTermServ400sp4 kbNTTermServ400sp5 kbNTTermServ400sp6 kbNTTermServSearch kbWinNTW400sp6 kbWinNTW400SP6a
Version           : winnt:4.0,4.0 SP4,4.0 SP5,4.0 SP6,4.0 SP6a
Hardware          : x86
Issue type        : kbinfo

=============================================================================

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.