PI44091: VARIOUS IMS DUMP FORMATTER FIXES

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Various IMS dump formatter errors:
  Fix various IMS dump formatter errors:
  1. Storage access errors in DB formatting when using Fast Path
  64-bit buffers
  2. Unable to format DLI private IPAGEs for DLI-owned BCB blocks
  3. EDA formatter "WRITE" log extract function receives ABEND002
  4. EDA LCRE "MIN" formatting does not format assigned LCREs
  5. BPE dispatcher statistics uses wrong TCBT pointer; statistics
  can be incorrect
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * All IMS V14 dump formatter users.                            *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * Various IMS dump formatter errors.                           *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * INSTALL CORRECTIVE SERVICE FOR APAR/PTF                      *
  ****************************************************************
  This APAR fixes the following issues in the IMS dump formatter:
  
  1. When formatting the DB or DEDB options on a dump of an IMS
     that was using 64-bit Fast Path buffers, the following
     message:
  
       DFS3937I - UNABLE TO ACCESS STORAGE WHILE FORMATTING THE
                  FP DMHRS.  REQUESTED STORAGE: ADDR=xxxxxxxx,
                  ASID=yyyy, LENGTH=00001000
  
     may be received many times, followed by:
  
       FORMATTER ERROR RECURSION LIMIT REACHED, SKIPPING ON
  
     Additionally, storage may be dumped identified as a Fast
     Path buffer when it is in fact unrelated storage (storage
     at the address of the low word of a Fast Path 64-bit
     buffer).
  
     The basic IMS dump formatter does not support accessing
     dumped 64-bit virtual storage.  It is incorrectly trying to
     access the buffer using only the low word of the 64-bit FP
     buffer address, leading to the error message or invalid
     data being dumped.
  
     64-bit FP formatting is available using the EDA dump
     formatter, which does support 64-bit storage access (select
     option E from the main IMS dump formatter panel, then 3
     (Fast Path), then DMHR).
  
  2. When formatting a specific CBTE (CBTE option from low-level
     dump formatter panel 3), if the CBTE is owned by the DLI
     address space and if the block is in DLI private storage,
     the IPAGE storage access will fail or storage contents from
     the control region will be printed.  The CBTE dump formatter
     accesses all IPAGEs using the control region ASID; it should
     use the DLI region ASID for DLI-owned IPAGEs.
  
  3. When selecting the "extract log records" function using the
     panel interface in the EDA dump formatter (option E, 5,
     WRITE), an ABEND002 may occur when the IMS log record being
     extracted is greater than 24572 bytes in length, due to the
     output data set being allocated with LRECL(24572)
     BLKSIZ(24576).  The output data set needs to be allocated
     with an LRECL and BLKSIZ large enough to handle the largest
     possible IMS log record (currently, 30716 bytes for a 30K
     OLDS block size).
  
     An ABEND002 may also occur when unassigned space in the OLDS
     buffer is mistakenly interpreted as a log record when the
     length field is larger than the output dataset LRECL.  The
     code in module DFSEF180 that scans the records in each log
     buffer needs to do additional validity checking to avoid
     interpreting unassigned space as a valid log record.
  
  4. The EDA LCRE "MIN" formatting does not format assigned LCREs.
  
  5. BPE dispatcher statistics summary formatting uses the wrong
     pointer for the accessed TCBT (the buffer pointer, not the
     returned TCBT address within the buffer).  If the TCBT
     in the dump happens to be on a page boundary, then the TCB
     summary statistics are formatted correctly (since the buffer
     start address coincides with the TCBT address in the buffer).
     Otherwise, random values are printed for the TCB statistics
     summary.
  

Problem conclusion

• The following changes are made by this APAR:
  
  1. Module DBFAXCR0 is changed to skip accessing the FP buffer
     off of DMHRBUFP if the high word of the buffer pointer is
     non-zero (64-bit buffer).
  
     Module DBFADMH0 is changed to not try to dump the FP
     buffer if it is a 64-bit buffer, and instead to print a
     message:
  
       64-bit buffer not dumped - see EDA DMHR option for 64-bit
       formatting
  
  2. DFSACBT0 is changed to access IPAGE storage using the
     DLI ASID if the block is owned by DLI (CBTDLI).
  
  3. DFSEWDSN REXX exec is changed to allocate the log record
     extract data set with BLKSIZ(32760) LRECL(32756) (the
     largest IMS OLDS block size is 30720).  The space
     allocation is changed from CYL SPACE(8,24) to CYL
     SPACE(10,42) to allow for the less-efficient block size
     (one block per track instead of two).
  
     Module DFSEF180 is changed to do additional checking of
     each log record before it copies the record to the
     output data set.  The record must satisfy all of the
     following to be considered valid to be exported:
  
       - The length must be at least the length of the IMS
         log record prefix plus suffix (22 bytes).
  
       - The address of the log record plus its length must
         be within the bounds of the current buffer.
  
       - The ZZ field of the log record (3rd and 4th bytes)
         must be zero.
  
       - The log sequence number (LSN) of the record must
         be one greater than the LSN of the previously-
         extracted record.
  
     Additional information about log record TYPE and LENGTH
     are now included in the dump formatter text output data
     set for each log record exported, for improved diagnostics.
     Also, the full 8-byte log sequence number is printed
     (previously, only the low 4 bytes were printed).
  
     Old report output:
  
       Buffer contents at 00000000_23612000
           Log Sequence # 0281CB7D
           Log Sequence # 0281CB7E
           Log Sequence # 0281CB7F
            :
            :
  
     New report output:
  
       Buffer contents at 00000000_23612000
           Log Sequence # 00000000_0281CB7D  Type=50  Len=04A4
           Log Sequence # 00000000_0281CB7E  Type=50  Len=00B2
           Log Sequence # 00000000_0281CB7F  Type=50  Len=04B0
            :
            :
  
  4. In module DFSEF660 (LCRE summary), the test to see if
     the LCRE is active is changed from using
  
       b_lcrePtr->bpe001c = ' '
  
     to
  
       b_lcrePtr->lcreDcst = ' '
  
   5. In module BPEFM10 (Dispatcher formatting), the call to
     FormatTCBStat is corrected from passing the TCBT address
     using tcbtStgPtr to passing b_tcbtPtr.
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

  PI43785

• APAR is sysrouted TO one or more of the following:

  UI29788

Modules/Macros

• DBFAXCR0 BPEFM100 DFSEF180 DBFADMH0 DFSACBT0 DFSEWDSN DFSEF660
  

Fix information

• Fixed component name

  IMS V14

• Fixed component ID

  5635A0500

Applicable component levels

• R400 PSY UI29788

     UP15/07/31 P F507

Fix is available

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