PH35082: STORAGE VIOLATION IN CONTROL BLOCK DFHXFPC-COMM FOLLOWED BY ABEND0C4 ON REMOTE DPL REQUEST WHEN COMMAREA IS 32K

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• In CICS version 5.6 the restriction on the COMMAREA that its
  length cannot be greater than 24KB for DPLs over MRO connections
  between CICS TS regions has been removed. If both regions are
  at the level of CICS TS V5.6 or above, then a COMMAREA that is
  greater than 24KB is shipped by using the DFHTRANSACTION
  channel. If the transaction issuing the LINK doesn't have a
  DFHTRANSACTION channel, one is created.
  
  The problem occurs when a transaction issues a remote DPL
  request with the EXEC CICS LINK having a commarea length greater
  than 24K followed by another EXEC CICS LINK with a commarea
  length less than 24K. The DFHXFP transformer code in the remote
  region uses the correct length when issuing a GETMAIN for the
  DFHXFPC-COMM commarea storage to pass to the application program
  for the second request. However, the code then attempts to move
  data into that storage using the longer length specified on the
  earlier request.
  
  The overwrite may cause storage violations:
  
  DFHSM0102 applid CSMI 00056 A storage violation (code X'0F0C')
  has been detected by module DFHSMAR.
  
  Additional symptoms:
  DFHSM0102 CSMI A storage violation (code X'0F0C') has been
            detected by module DFHSMAR.
  DFHPG0001 An abend (code ---/AKEA) has occurred at
            offset X'4F6E' in module DFHPGXE
  DFHSM0002 A severe error (code X'031E') has occurred in
            module DFHSMGF
  The overlay affected Quickcell Page Headers or QPH's for
  various subpools- LI_PLB  ZCTCTTEL  ZCNIBD  SMTP.
  The dump formatter can display errors when attempting
  to display TCTTE  and TIOA control blocks.
  
  abend0C4 0C4 DFHAPLI3  AEXZ
  Subpool lock failed tid_smgf_subpool_lock_failed
  

Local fix

• n/a
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICS users.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: DFHSM0102 reports a storage violation   *
  *                      for transaction CSMI.                   *
  ****************************************************************
  An application issued several EXEC CICS LINK with COMMAREA
  requests to a remote CICS region over an MRO CONNECTION.
  The problem happened when a DPL request with a COMMAREA longer
  than 24K was followed by one with a COMMAREA shorter than 24K.
  CICS used the DFHTRANSACTION CHANNEL to transmit the longer
  COMMAREA and a TIOA for the shorter.
  
  When processing the later request, the DFHXFP transformer code
  on the remote region used the correct length to GETMAIN storage
  for passing the COMMAREA to the application. However it then
  imported the longer DFHTRANSACTION CHANNEL data, from the
  earlier DPL request, rather than copying the data from the TIOA.
  This caused the overwrite and subsequent storage violations.
  
  Additional keywords: SM0102 MSGDFHSM0102 AXG2
  

Problem conclusion

• DFHXFP has been changed to ensure data is always copied from the
  TIOA when a DPL request passes a COMMAREA shorter than 24K to a
  remote region.
  
  The fix changes code in Transformer_1 and Transformer_2 so must
  be applied on both the region issuing the DPL and on the remote
  region for it to be effective.
  

Temporary fix

Comments

APAR Information

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

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

  UI75558

Modules/Macros

• DFHXFP   DFHXFQ
  

Fix information

• Fixed component name

  CICS TS Z/OS V5

• Fixed component ID

  5655Y0400

Applicable component levels

• R300 PSY UI75558

     UP21/05/26 P F105 ¢

Fix is available

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