Trap and Exeption Popup Message Reference

The trap screen and has in two basic formats:

The application exception (SYS0147, SYS317x, SYS3190) messages.

The Internal Processing Error (IPE).

Application Trap/Exception

Application exeption popups are logged in the POPUPLOG.OS2 file of which the following is an example. They are also displayed in a popup window in a slightly abbreviated form.

Control of exception logging and popup displays may be done from the TRAPLOG command or SUPPRESSPOPUPS CONFIG.SYS statement.

01-> 02-25-1999  10:58:35  SYS3175  PID 00b2  TID 0001  Slot 0068
02-> E:\CLASSES\LABS\LAB26\BEDBUG.EXE
03-> c0000005
04-> 1bf94e24
05-> P1=00000001  P2=00000000  P3=XXXXXXXX  P4=XXXXXXXX
06-> EAX=00000000  EBX=00060210  ECX=0002881c  EDX=00060210
07-> ESI=00000001  EDI=00000002
08-> DS=0053  DSACC=d0f3  DSLIM=1fffffff
09-> ES=0053  ESACC=d0f3  ESLIM=1fffffff
10-> FS=150b  FSACC=00f3  FSLIM=00000030
11-> GS=0000  GSACC=****  GSLIM=********
12-> CS:EIP=005b:1bf94e24  CSACC=d0df  CSLIM=1fffffff
13-> SS:ESP=0053:000287ec  SSACC=d0f3  SSLIM=1fffffff
14-> EBP=000287f8  FLG=00012206

15-> DOSCALL1.DLL 0002:00004e24

The information presented varies slightly according to circumstance. In general, inapplicable information is either omitted, or overlayed with asterisks (*) or exes (X).

Each line of the trap screen conveys the following meaning:

• Date and Time or Trap, Trap message Id and Failing Process Id, Thread Id and Thread Slot.

• Failing process. In general this will not be the trapping module.

• OS/2 System Exception code. See OS/2 System Exception Codes for a complete set of system generated exceptions.

• 32-bit Instruction address at time of exception.

• Exception Information Parameters. taken from the Exception Report Record. See OS/2 System Exception Codes for the exception information parameters that are associated with each system exception.

  Note:

  When P1=00000000 and P2=FFFFFFFF, this frequently indicates that the trap occurred while executing a system API and that the previous instruction in the user's code was a call gate. When this happen a bad parameter has been passed to the system from the application.

  If in addition the EFLAGS register has high word 0019xxxx then Virtual Machine Extensions may indirectly be causing a problem. Try VME=NO in CONFIG.SYS.

  6.
  The EAX, EXB, EXC and EDX registers at the time the exception was reported.
  7.
  The ESI and EDI registers at the time the exception was reported.
  8.
  The DS selector at the time the exception was reported.

  This information is presented in the form:

  xS=nnnn

  The selector value.
  xSACC=nnnn
  The descriptor access bits.

  Reading from right to left the bits of the access field are assigned the following meaning: 0

  (A) 1=Accessed
  1
  (W) 1=Writeable
  2
  (E) 1=Executable
  3
  0
  4
  (S) 1=Application 0=System
  5 & 6
  (DPL) Privilege Level
  7
  (P) 1=Segment present
  8 - 11
  0
  12
  (AVL) 1=UVIRT allocation
  13
  (D) 1=32-bit Operands/Data
  14
  0
  15
  (G) 1=4K granularity limit, 0=byte granularity limit
  See the "INTEL Pentium User's Guide, Volume 3" for more information on descriptor formats.
  xSLIM=nnnnnnnn
  The limit field from the descriptor.
  9.
  The ES selector at the time the exception was reported.
  10.
  The FS selector at the time the exception was reported.
  11.
  The GS selector at the time the exception was reported.
  12.
  The instruction address at the time the exception was reported, followed by the CS selector Limit and Access fields.
  13.
  The stack address at the time the exception was reported, followed by the SS selector Limit and Access fields.
  14.
  The EBP register and EFLAGS register.
  15.
  The module name and relative object and offset within the module that corresponds to the exception address reported on line 4.

  Notes:

  Lines 3-5 are formatted from the Exception Report Record generated at the time the exception occurred.

  Lines 6-14 are formatted from the Exception Context Record generated at the time the exception occurred.

  Exception report and Context records can be modified by exception handlers so it is possible that the information displayed might not be correct.

  Exception popups will not be generated if an exception handler attepts recovery by returning XCPT_CONTINUE_EXECUTION to the system. However this does not guarantee that the program will continue to operate correctly. When recovery is not successful it might be necessary to disable exception handlers. For Presentation Manager and the Workplace Shell this can be done by specifying SET SHAPIEXCEPTIONHANDLER=OFF and SHELLEXCEPTIONHANDLER=OFF in CONFIG.SYS. This can also be done from the kernel debugger by setting the first double-word of a thread's TIB to 0xffffffff. An alternative approach is to use system trace to log exception handler dispatching. Minor codes 361, 362 and 363 of DOSCALL1 will log exception report and context records before and after they have been processed by and exception handler. Minor code 361 logs the original exception information, while minor code 363 logs the exception information that is returned to the system (and used for the popup log). Minor code 262 logs exception information before each exception handler is called. The Exception Registration Record is also logged by the tracepoint.

  To activate these tracepoints issue the following command sequence:

        TRACE ON /B:512 /D:PROCNAME,TID
        TRACE ON DOSCALL1(361,362,363)
  
  

  The first command defines a system trace buffer of 512Kb and turns on logging of Process name and Thread Id with each trace record. The second command activates the tracepoints. Use the TRACEGET and/or the TRACEFMT commands to extract and view the traced events.

  Using trace to log exceptions will also provide full trap information for floating point exception, which is not provided by any other means.

  The exception address reported in line 4 in most cases agrees with the CS:EIP reported in line 12. However, when a nested exception occurs, the register information will relate to the most recent exception. A particular example of this is where an Exit List Handler traps. Exit List Handlers are called when a process terminates, after any exception handling. The system first generates an XCPT_PROCESS_TERMINATE exception, which may be handled by exception handlers. If this exception is not recovered then process termination continues with Exit List processing. Once this starts, application exception handlers will not be called if any further exceptions are generated. If a further exception is generated then it will become a nested exception of the original XCPT_PROCESS_TERMINATE. If an Exit List Handler traps, a SYS3170 popup will be generated with the register information in lines 6 - 14 corresponding to the nested exception and lines 3 - 5 and 15 corresponding to the original XCPT_PROCESS_TERMINATE exception.

  If the system is unable to generate an exception popup message then a SYS0147 is generated. This can happen when there is insuffiencent kernel heap memory left to allocate a HARDERR request packet. This is not the only cause of a SYS0147, PM resource (heap) shortages also cause this message. is exhausted this can occur.

  SYS3190 occurs because of a TRAP 6. The application is incorrectly using LOCK prefixes either deliberately or possibly it had taken a wild jump to a non-instuction boundary.

  System Internal Processing Error (IPE)

  The IPE message appears because of a fatal internal error condition. This may or may not be a trap, though the IPE trap is the most common.

  The IPE message has the general format:

  1-> <IPE specific Message>
  
  2->  THE SYSTEM DETECTED AN INTERNAL PROCESSING
       ERROR AT LOCATION ##xxxx:yyyyyyyy - aaaa:bbbb
  
  3->  lllll , ffff
  4->  038600d1
  5-> INTERNAL REVISION 6 . 307  DATE: 92/03/01
  
  

  The parts of the IPE message are:

  • IPE specific message, which could be a simple line of text, for example:

           CPS: Empty allocation block--not supported.
    
    

    or a formatted register dump for a system trap, such as:

     TRAP 0002        ERRCD= 0000  ERACC= ****  ERLIM= ********
      EAX= 7d240a58  EBX= ff202fdc  ECX= 00064423  EDX= 00003624
      ESI= fff3272c  EDI= 7d240004  EBP= 00004a44  FLG= 00003202
      CS:EIP= 0160 : fff702a6  CSACC= c09d  CSLIM= ffffffff
      SS:ESP= 0030 : 00004a38  SSACC= 1097  SSLIM= 00003fff
      DS= 0158  DSACC= c0f3  DSLIM= ffffffff  CR0= fffffffb
      ES= 0158  ESACC= c0f3  ESLIM= ffffffff  CR2= 1a060014
      FS= 0000  FSACC= ****  FSLIM= ********
      GS= 0000  GSACC= ****  GSLIM= ********
    

  • The CS:EIP of the caller to the kernel panic routine is shown as ##xxxx:yyyyyyyy. For traps this will always be an address within the trap handler and not the address at which the error occurred - that is given in the error specific message.

    The CS:EIP is prefixed with either ## to indicate protect mode, paging enables in accordance with the Kernel Debugger command prompt.

    The kernel relative object:offset address is shown as aaaa:bbbb.

  • lllll is intended to be the source line number at which the panic occurred. Values greater then 60000 are generated panic sequence numbers. ffff is the source file number.

    Note: These values are mostly arbitrary and therefore not particularly useful. There is no published cross reference.

    4.
    The processor ID.
    5.
    The kernel revision information.

    An example of the IPE trap screen is show in the following diagram:

    1->  TRAP 0002        ERRCD= 0000  ERACC= ****  ERLIM= ********
          EAX= 7d240a58  EBX= ff202fdc  ECX= 00064423  EDX= 00003624
          ESI= fff3272c  EDI= 7d240004  EBP= 00004a44  FLG= 00003202
    2->   CS:EIP= 0160 : fff702a6  CSACC= c09d  CSLIM= ffffffff
          SS:ESP= 0030 : 00004a38  SSACC= 1097  SSLIM= 00003fff
    3->   DS= 0158  DSACC= c0f3  DSLIM= ffffffff  CR0= fffffffb
    4->   ES= 0158  ESACC= c0f3  ESLIM= ffffffff  CR2= 1a060014
          FS= 0000  FSACC= ****  FSLIM= ********
          GS= 0000  GSACC= ****  GSLIM= ********
         THE SYSTEM DETECTED AN INTERNAL PROCESSING
         ERROR AT LOCATION ##0160:fff6453f - 000d:a53f
    
         60000 , 9084
         038600d1
         INTERNAL REVISION 6 . 307  DATE: 92/03/01
    
    
    

    The register information may be interpreted as for application trap screens, with the following points notes:

    • This line shows the Trap number followed by the INTEL error code. Most often the associated error code is a selector number. When this is the case, this line formats the selector's access and limit values.

    • This line shows the address at which the trap occurred.

    • The value of control register 0 (CR0) is formatted after the DS register.

      CR0 contains processor control mode settings.

    • The value of control register 2 (CR2) is formatted after the ES register.

      CR2 contains the fault address for TRAP E errors.

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