PI76708: GETTING THE FOLLOWING ABENDS, DFHSM0102, DFHAP0001, DFHRM0002 AND DFHAP0002.

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• The problem is noticed by getting the following message and the
  Region crashes.
  .
  DFHRM0002 LOCALRGN A severe error (code X'0377') has occurred
  in module DFHRMLSO.
  .
  Looking further into the LOG backing up to see what occurs
  before this you see.
  .
  DFHSM0102 LOCALRGN A storage violation (code X'0D05') has been
  detected by module DFHSMMF.
  .
  DFHAP0001 LOCALRGN An abend (code ---/ACTL) has occurred at
  offset X'169A' in module DFHCRIU.
  .
  In the eyecatcher area of the DFHSM0102 message above you see
  the following.
  .
  *e.....F4."..........DFHAC2206 09*
  *:53:52 REMOTRGN Transaction TRAN *
  *failed with abend AXGA. Updates *
  *to local recoverable resources b*
  *                                *
  .
  So in the Remote Region you see the following error.
  .
  DFHAP0002 REMOTRGN A severe error (code X'4E12') has occurred
  in module DFHAPCR.
  .
  The problem is caused by an Application that performs a DPL
  request with a large COMMAREA and causes a TIOA to be allocated
  that exceeds the TIOA size limit.  The limit for a TIOA to do a
  DPL request is 32767.  To send a DPL request, DFHXFP need to
  build some headers, like FMH5 and FMH43. The request can also
  include ORD, ACD,and ICRX data.  In the customer case the
  COMMAREA length is 32453 bytes long.  ODR data is also present
  and it account for 523 bytes.  There is also a DFHTRANSACTION
  CHANNEL which is  117 Bytes in length.  Totalling 33093.
  There is also an extra 65 bytes for FMH and argument codes and
  length which bring the total length of the data to 33158.
  DFHXTP will only GETMAIN a TIOA to it's maximum value of 32767.
  After the GETMAIN, DFHXTP move the data into the TIOA which is
  33158 long causing the overlay.  The overlay will only be
  detected when the TIOA storage get FREEMAIN.  It can also cause
  other problem for any other task using the storage that has
  been overlaid.  So the result could be unpredictable.
  .
  The CICS/TS knowledge center warn the customer that a safe
  value for a COMMAREA size is 24K.
  .
  This is the quote from the knowledge center under the LINK
  command for the LENGTH value:
  .
  This value should not exceed 24 KB if the COMMAREA is to be
  passed between any two CICS servers (for any combination of
  product/version/release), otherwise, if you are confident
   that the COMMAREA will not be passed on a further LINK
  request, you can use a COMMAREA up to 32763 in length.
  .
  This limitation is when using a COMMAREA on the LINK request.
  The 24k is a safe value and the customer can use a bigger
  COMMAREA for DPL request which will work until the limit of the
  session TIOA size has been exceeded.  The recommendation will
  be for a CHANNEL and CONTAINERS to be used instead of COMMAREA.
  However, the code in DFHXFP is not very clever at determining
  if the limit has been hit when using COMMAREA which has a
  disastrous consequences for the customer.  The code could do
  better by issuing an abend or message or both
  instead of overlaying storage.
  
  
  
  Additional Symptom(s) Search Keyword(s): KIXREVWRW
  

Local fix

• n/a
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICS users.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: Message DFHSM0102 'A storage violation  *
  *                      (code X'0D05') has been detected by     *
  *                      module DFHSMMF' is issued during a      *
  *                      DPL request.                            *
  ****************************************************************
  A distributed program link (DPL request) from Region A to
  Region B passes a user CHANNEL and the DFHTRANSACTION CHANNEL
  on an MRO connection.
  The user program in Region B then issues a DPL request to
  Region C with a large COMMAREA.
  The session TIOA is restricted to 32K when the DFHTRANSACTION
  CHANNEL and COMMAREA are being passed. However, the total
  length needed for the large COMMAREA, the DFHTRANSACTION
  CHANNEL header and other data, such as the Origin Description
  Record (ODR), is greater than that.
  DFHAPCR EXPORT_ALL fails to create the CHANNEL header but
  returns an OK response.
  DFHXFP then overlays beyond the end of the TIOA when moving the
  COMMAREA data into it.
  The DPL request is sent to Region C and the unflatten for the
  DFHTRANSACTION CHANNEL fails with abend AXGA because there is
  no CHANNEL header.
  The error leads to an ATNI on return to Region B. There is no
  FREEMAIN for the TIOA at this point.
  A subsequent task issues a DPL request on the same MRO session
  and needs a larger TIOA. A FREEMAIN is issued for the overlaid
  TIOA and CICS terminates with message DFHSM0102 code X'0D05'
  for the storage violation.
  

Problem conclusion

• CICS is changed to check if a COMMAREA and the DFHTRANSACTION
  CHANNEL are being passed on a DPL request.
  If so, CICS checks that all the request data, other than the
  CHANNEL header which has yet to be created by DFHAPCR,
  will fit into 31K. This leaves plenty of space for the CHANNEL
  header.
  If the request data exceeds 31K, the transaction abends with
  new abend code AXGE.
  
  The CICS Transaction Server for z/OS v5.2 CICS Messages and
  Codes Vol 1 (GC34-7283-00) and the CICS Transaction Server
  for z/OS v5.3 CICS Messages and Codes Vol 1 (GC34-7418-00)
  will be updated to include the following explanation for new
  transaction abend code AXGE:
  
  AXGE
  Explanation: A distributed program link (DPL) request,
  specifying channel name DFHTRANSACTION, has also specified a
  COMMAREA that is too large for the terminal I/O area (TIOA).
  
  System Action: The task is abnormally terminated with a
  transaction dump.
  
  User Response: Check if the request is using the correct
  length for the COMMAREA.  If a DFHTRANSACTION channel is
  specified the COMMAREA size should not exceed 24 KB.  In this
  case to accommodate a size greater than 24 KB specify a user
  channel instead of a COMMAREA.
  
  Module: DFHXFP
  

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:

  UI45562 UI45565

Modules/Macros

• DFHXFP   DFHXFQ
  

Fix information

• Fixed component name

  CICS TS Z/OS V5

• Fixed component ID

  5655Y0400

Applicable component levels

• R000 PSY UI45562

     UP17/03/16 P F703 ¢

• R900 PSY UI45565

     UP17/03/16 P F703 ¢

Fix is available

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