DOCUMENT:Q78627 30-OCT-1999 [utilities] TITLE :FIX: Address Label Offset Incorrect in USE32 Data Segment PRODUCT :Microsoft Programming Utilities PROD/VER:MS-DOS:3.x,4.x,5.0x,5.1x,5.2; OS/2:5.0x,5.1,5.11,5.13,5.15 OPER/SYS: KEYWORDS:kb16bitonly ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft LINK for MS-DOS, versions 3.x, 4.x, 5.0x, 5.1x, 5.2 - Microsoft LINK for OS/2, versions 5.0x, 5.1, 5.11, 5.13, 5.15 ------------------------------------------------------------------------------- SYMPTOMS ======== When a label corresponds to an absolute address and the label is defined in a USE32 data segment, LINK generates the incorrect offset for the label. As a result, the application accesses incorrect data through the label. STATUS ====== Microsoft has confirmed this to be a problem in LINK versions 3.6, 3.61, 3.64, 3.65, 3.69, 5.01, 5.1, 5.11, 5.13, 5.15 and 5.2 for MS-DOS and versions 5.01, 5.11, 5.13, and 5.15 for OS/2. This problem was corrected in LINK version 5.3 for MS-DOS. MORE INFORMATION ================ A label can represent an absolute address XXXX:YYYY by placing the label in a segment with the type "at XXXX" and after an org directive "org YYYY." The following code example demonstrates this problem. The Microsoft Macro Assembler (MASM) generated the first listing. Note that the offset of Vector is 20h, as it should be. The CodeView debugger generated the second listing. Note that the offset of Vector is 28h, which is incorrect. Sample Code ----------- ; Assemble options needed: none .model small,c .386 0000 Zero segment use32 at 0 org 32 0020 Vector label dword 0020 Zero ends 0000 .code assume es:Zero 0000 start: 0000 67& 66| 26: A3 mov [Vector], eax 00000020 R end start ; CodeView listing 1: .model small,c 2: .386 3: 4: Zero segment use32 at 0 5: org 32 6: 7: Vector label dword 8: 9: Zero ends 10: 11: .code 12: 13: assume es:Zero 14: 15: start: 16: 17: mov [Vector], eax 6A8F:0000 676626A32800000MOV DWord Ptr ES:[00000028],EAX 18: 19: end start Additional query words: 3.60 3.61 3.64 3.65 3.69 5.01.20 5.01.21 buglist5.11 buglist5.13 buglist5.15 buglist5.20 fixlist5.30 5.02 5.03 5.05 5.10 5.20 ====================================================================== Keywords : kb16bitonly Technology : kbAudDeveloper kbZNotKeyword3 kbLINKSearch kbLINK3xDOSSearch kbLINK4xDOSSearch kbLINK50xDOSSearch kbLINK510xDOSSearch kbLINK50xOS2Search kbLINK520DOS kbLINK510OS2 kbLINK511OS2 kbLINK513OS2 kbLINK515OS2 Version : MS-DOS:3.x,4.x,5.0x,5.1x,5.2; OS/2:5.0x,5.1,5.11,5.13,5.15 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. Copyright Microsoft Corporation 1999.