FIX: ESP Not Updated Correctly After PUSHFD, POPFD

 Last reviewed: September 16, 1997
Article ID: Q87549
3.00 3.11 3.14 4.00 4.01 4.05 | 3.00 3.11 3.12 3.50 | 3.x 4.00 4.01 
MS-DOS                        | OS/2                | WINDOWS
kbtool kbcode kbbuglist kbfixlist

The information in this article applies to:

  • Microsoft CodeView for MS-DOS, versions 3.0, 3.11, 3.14, 4.0, 4.01, and 4.05
  • Microsoft CodeView for OS/2, versions 3.0, 3.11, 3.12, and 3.5
  • Microsoft CodeView for Windows, versions 3.0, 3.05, 3.06, 3.07, 4.0, and 4.01

SYMPTOMS

When single-stepping through a PUSHFD or a POPFD in Microsoft CodeView versions 3.0, 3.11, 3.12, 3.14, 3.5, 4.0, 4.01, and 4.05 the ESP register is changed by only 2 bytes rather than 4 bytes.

RESOLUTION

The problem only occurs when single-stepping. Placing the cursor on the next instruction and pressing F7 will result in CodeView correctly updating the ESP register. If you use this workaround, make sure the next instruction does not modify the stack pointer.

STATUS

Microsoft has confirmed this to be a problem in CodeView versions 3.0, 3.11, 3.12, 3.14, 3.5, 4.0, 4.01, and 4.05. This problem was corrected in CodeView version 4.1.

MORE INFORMATION

The following sample code demonstrates the problem. Single-step over the instructions to see ESP change by only 2 bytes. Restart and run to the first NOP and then the second to see that ESP is then correctly updated.

Sample Code

; Assembly options needed: /Zi

_text segment word public 'code' 

   ASSUME cs:_text, ds:_text
.386 
   PUSHFD
   NOP
   POPFD
   NOP

   MOV ah, 4ch
   INT 21h
_text ENDS 
   END

Additional reference words: 3.00 3.50 4.00
KBCategory: kbtool kbcode kbbuglist kbfixlist
KBSubcategory: CvwIss
Keywords : kb16bitonly
Solution Type : kbfix

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.

Last reviewed: September 16, 1997
© 1998 Microsoft Corporation. All rights reserved. Terms of Use.