PI79384: ABEND0C4 DFSYLUS0 AT OFFSET X'61E0' DUE TO A BAD R2.

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• S0C4 RC10 on ICM instruction at offset X'61E0' with R2 bad
  containing X'C540C1E3' that is part ofthe text of message
  DFS199E. R2 is loaded from field CLBLU6WA.
  This is occurring on a transaction coming into IMS via APPC, the
  transaction is processed but a SEND (ATBSEND) error is received
  when we try to send the output to the APPC LU.  The Message
  Control/Error exit routine DFSCMUX0 is active and defined to
  re-route the output message to the IMS SMTO Lterm, to the same
  terminal IMS send both DFS1965E and DFS1995E resulting from the
  ATBSEND failure. Later on during Synchpoint Phase 2 module
  DFSYLUS0 is called with CLB6LUWA pointing to the area where we
  have moved message DFS1995E and ABEND trying to use the TPIPE
  pointer we should have in R2.
  An additional symptom due to the same error is an ABEND0C4 on
  module DFS6LUS0 offset X'1FE0' in the SEND_SERVICE routine.
  

Local fix

• No Local FIX
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * All IMS 14 APPC users of user exit DFSCMUX0.                 *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * ABENDS0C4 in DFSYLUS0 after user exit                        *
  * DFSCMUX0 reroutes APPC output to a                           *
  * non-APPC lterm.                                              *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * INSTALL CORRECTIVE SERVICE FOR APAR/PTF                      *
  ****************************************************************
  1. An APPC client invoked an IMS transaction.
  2. IMS attempted to send the transaction output to APPC,
     but a SEND (ATBSEND) error was received.
  3. IMS invoked user exit DFSCMUX0 in order to determine what
     to do with the output message.
  4. DFSCMUX0 specified that the output should be re-routed to
     the IMS secondary master terminal lterm (SMTO).
  5. During Synchpoint Phase 2, because the transaction was
     invoked by APPC, module DFSFXC30 issued DFSLUMIF FUNC=PH2,
     which calls DFS6LUS3.  However, instead of passing the
     APPC TIB's CNT address, DFSFXC30 passed the SMTO CNT address.
  6. DFS6LUS3 failed to detect that the CNT address was not
     associated with an APPC or OTMA TIB.  Instead, it assumed
     that it was APPC or OTMA, and attempted to access the TIB
     address from CLBLU6WA.  For the SMTO, this is
     unpredicatable - in the customer's case, it pointed to
     a message buffer.
  7. DFS6LUS3 checked TIB_OTMA_INDICATOR to determine if the
     TIB was APPC or OTMA.  In the SMTO's message buffer,
     the corresponding flag was on, so DFS6LUS3 thought that
     OTMA processing was required.
  8. DFS6LUS3 invoked DFSYLUS0.  The ABENDS0C4 occurred when
     DFSYLUS0 used the SMTO's CNT address as if it were
     associated with an OTMA TIB.
  
  Because of the random nature of this scenario, an abend is
  not always the result.
  
  DFS6LUS3 may invoke DFS6LUS0, in which case the re-routed
  message would be correctly delivered to the SMTO lterm.
  
  The customer also experienced an ABENDS0C4 in DFS6LUS0
  during Send-service processing, which was a delayed result
  of incorrectly invoking DFSYLUS0.  In this case, DFSYLUS0
  did not abend, but it did cause syncpoint processing
  to proceed along an invalid path resulting in the
  DFS6LUS0 abend.
  
  In IMS 13, DFSLUMIF invoked DFS6LUS0, which detects
  whether the CNT is non-APPC/OTMA.
  In IMS 14, DFS6LUS3 is a front-end to DFS6LUS0 or DFSYLUS0,
  and the logic to detect non-APPC/OTMA CNTs is missing.
  
  Additional keywords: S0C4 ABEND0C4 0C4
  

Problem conclusion

• DFS6LUS3 has been modified to detect a non-APPC/OTMA lterm.
  When detected, processing will invoke DFS6LUS0.
  This restores the original DFSLUMIF processing path so that
  control can be properly returned to the caller.
  

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:

  PI80882 UI47160

Modules/Macros

• DFS6LUS3
  

Fix information

• Fixed component name

  IMS V14

• Fixed component ID

  5635A0500

Applicable component levels

• R400 PSY UI47160

     UP17/05/19 P F705 ¢

Fix is available

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