DOCUMENT:Q326808  12-AUG-2002  [sna]
TITLE   :SNA Server Access Violation in Function s1prmsnd
PRODUCT :Microsoft SNA Server
PROD/VER::4.0,4.0 SP1,4.0 SP2,4.0 SP3,4.0 SP4
OPER/SYS:
KEYWORDS:

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

 - Microsoft SNA Server, versions 4.0, 4.0 SP1, 4.0 SP2, 4.0 SP3, 4.0 SP4 
 - Microsoft Host Integration Server 2000 
-------------------------------------------------------------------------------

SYMPTOMS
========

The SNA Server service may quit unexpectedly and cause all users who are
connected to lose their existing host sessions. The results may be a .log file
in the debugger, and a message in the Windows NT Application Event Log, as
follows:

 - If the default debugger on the system is Dr. Watson (Drwtsn32.exe), it
   generates a Drwtsn32.log file similar to the following:

   Application exception occurred:
              App: exe\snaservr.dbg (pid=<process id>)
              When: <date> @ <time>
              Exception number: c0000005 (access violation)

   [...]

   State Dump for Thread Id 0x151
    
   eax=00000000 ebx=00000000 ecx=00000017 edx=00000000 esi=01315a70 edi=0118846c
   eip=0101ca8f esp=00baff50 ebp=00000001 iopl=0         nv up ei ng nz ac po cy
   cs=001b  ss=0023  ds=0023  es=0023  fs=003b  gs=0000             efl=00000297
    
    
   function: s1prmsnd
           0101ca74 e8c78bfeff       call    sbpenq (01005640)
           0101ca79 5f               pop     edi
           0101ca7a 5e               pop     esi
           0101ca7b 5d               pop     ebp
           0101ca7c 5b               pop     ebx
           0101ca7d 83c408           add     esp,0x8
           0101ca80 c3               ret
           0101ca81 668b470a         mov     ax,[edi+0xa]               ds:025a6e73=????
           0101ca85 0fbfd0           movsx   edx,ax
           0101ca88 8b1495bcf40e01                                  ds:00000000=????????
                                     mov     edx,[s1rcb+0xe25c (010ef4bc)+edx*4]
   FAULT ->0101ca8f 0fbf5210         movsx   edx,word ptr [edx+0x10]    ds:0141ea07=????
           0101ca93 8b1495dc520b01                                  ds:00000000=????????
                                     mov     edx,[G_comp_flat2+0x59fc (010b52dc)+edx*4]
           0101ca9a 66395a02         cmp     [edx+0x2],bx               ds:0141ea07=????
           0101ca9e 741e             jz      s1prmsnd+0x15e (0101cabe)
           0101caa0 33d2             xor     edx,edx
           0101caa2 80f917           cmp     cl,0x17
           0101caa5 0f95c2           setne   dl
           0101caa8 83c204           add     edx,0x4
           0101caab 50               push    eax
           0101caac 668b4616         mov     ax,[esi+0x16]              ds:02734477=????
           0101cab0 8bca             mov     ecx,edx
           0101cab2 668b5614         mov     dx,[esi+0x14]              ds:02734477=????
    
   *----> Stack Back Trace <----*
    
   FramePtr ReturnAd Param#1  Param#2  Param#3  Param#4  Function Name
   00000001 00000000 00000000 00000000 00000000 00000000 snaservr!s1prmsnd  (FPO: [EBP 0x00000000] [0,2,4])
   00000009 00000000 00000000 00000000 00000000 00000000 snaservr!<nosymbols>

 - The SNA Server generates a message similar to the following in the Windows NT
   Application Event Log:

   Event ID: 624
   Source: SNA Server
   Description: Creating dump file <snaroot>\traces\snadump.log for
   snaservr.exe.

CAUSE
=====

In certain situations, the SNA Server service retains a pointer to an internal
control block that has already been freed. If the SNA Server service tries to
free this control block a second time, the access violation occurs.

RESOLUTION
==========

Host Integration Server 2000
----------------------------

No fix is available at this time.


SNA Server 4.0 SP4
------------------

A supported fix is now available from Microsoft, but it is only intended to
correct the problem that is described in this article. Apply it only to
computers that are experiencing this specific problem. This fix may receive
additional testing. Therefore, if you are not severely affected by this problem,
Microsoft recommends that you wait for the next Microsoft SNA Server version 4.0
service pack that contains this fix.

To resolve this problem immediately, contact Microsoft Product Support Services
to obtain the fix. For a complete list of Microsoft Product Support Services
phone numbers and information about support costs, visit the following Microsoft
Web site:

   http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS

NOTE: In special cases, charges that are ordinarily incurred for support calls
may be canceled if a Microsoft Support Professional determines that a specific
update will resolve your problem. The typical support costs will apply to
additional support questions and issues that do not qualify for the specific
update in question.

The English version of this fix has the file attributes (or later) that are
listed in the following table. The dates and times for these files are listed in
coordinated universal time (UTC). When you view the file information, it is
converted to local time. To find the difference between UTC and local time, use
the Time Zone tab in the Date and Time tool in Control Panel.

   Date         Time   Version      Size    File name
   -----------------------------------------------------
   29-Jul-2002  07:10  4.0.0.606   468,864  Snaservr.exe
   29-Jul-2002  07:10  4.0.0.606   935,344  Trcservr.exe

NOTE: Because of file dependencies, the most recent fix that contains the above
files may also contain additional files.



STATUS
======

Microsoft has confirmed that this is a problem in Host Integration Server 2000
and Microsoft SNA Server version 4.0, 4.0 SP1, 4.0 SP2, 4.0 SP3, 4.0 SP4.

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

If you examine a crash dump file of the access violation, and matching symbols
in a debugging tool such as WinDBG, you can see a stack trace similar to the
following:

   (fa.151): Access violation - code c0000005 (!!! second chance !!!)
   eax=00000000 ebx=00000000 ecx=00000017 edx=00000000 esi=01315a70 edi=0118846c
   eip=0101ca8f esp=00baff50 ebp=00000001 iopl=0         nv up ei ng nz ac po cy
   cs=001b  ss=0023  ds=0023  es=0023  fs=003b  gs=0000             efl=00000297
   snaservr!s1prmsnd+12f:
   0101ca8f 0fbf5210         movsx edx,word ptr [edx+0x10] ds:0023:00000010=????
   0:001> kv
   ChildEBP RetAddr  Args to Child              
   00baff64 01034367 0100536b 0000001f 77f0178b snaservr!s1prmsnd+0x12f (FPO: [EBP 0x01186f5d] [0,2,4])
   00baff68 0100536b 0000001f 77f0178b 00075b98 snaservr!s1pgdisp+0xf7 (FPO: [1,0,0])
   00baff88 01005b15 64001281 00000001 00075b98 snaservr!sbpsched+0xdb (FPO: [EBP 0x77f0178b] [0,2,4])
   00baff8c 64001281 00000001 00075b98 77f9d850 snaservr!sbpgmain+0x25 (FPO: [0,0,0])
   00baffa8 77dd8bec 00000001 00075b98 ffffffff SNASVC!ServiceMainFunction+0x131 (FPO: [EBP 0x00075b90] [2,1,3])
   00baffb8 77f04ee8 00075b90 77f9d850 ffffffff ADVAPI32!ScSvcctrlThreadA+0xe (FPO: [1,0,1])
   00baffc4 ffffffff 00075b90 c0000005 00baffc4 KERNEL32!BaseThreadStart+0x51 (FPO: [Non-Fpo])
   77f9d850 77f8e58f 77f8e596 0052005c 00670065 0xffffffff
   ffffffff 00000000 00000000 00000000 00000000 ntdll!RtlpFreeToHeapLookaside+0x5b (FPO: [Non-Fpo])

For additional information about configuring Drwtsn32.exe as the default
debugger, click the article number below to view the article in the Microsoft
Knowledge Base:

   Q188296 How to Disable Dr. Watson for Windows NT

For more information about WinDBG, symbols, and other Microsoft debugging tools,
visit the following Microsoft Web site:

   Microsoft Debugging Tools
   http://www.microsoft.com/ddk/debugging/

Additional query words:

======================================================================
Keywords          :  
Technology        : kbAudDeveloper kbSNAServSearch kbHostIntegServ2000 kbSNAServ400 kbSNAServ400SP1 kbSNAServ400SP2 kbSNAServ400SP3 kbSNAServ400SP4
Version           : :4.0,4.0 SP1,4.0 SP2,4.0 SP3,4.0 SP4
Issue type        : kbbug
Solution Type     : kbfix

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

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