PK95407: DFHAP0001 ABEND (CODE 0C4/AKEA) HAS OCCURRED AT OFFSET X'7AE0' IN DFHMQTRU

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• During shutdown of the CICS-MQ Adapter, an abend0C4 occurs in
  load module DFHMQTRU offset x'7AE0'. The last messages seen are:
  .
  DFHMQ0341 I STOP requested by alert monitor CKAM.
  DFHMQ0107 I A request to end CKTI has been received. CKTI ended.
  ...
  DFHMQ0713 I CKBR 28341 CICS-MQ Bridge terminated normally.
  DFHAP0707 An abend (code 0C4/AKEA) has occurred in task related
            user exit program DFHMQTRU.
  DFHAP0001 An abend (code 0C4/AKEA) has occurred at offset
            X'00007AE0' in module DFHMQTRU.
  .
  The abend0C4 actually occurs in program DFHMQTRQ offset x'3F4'
  on a LOAD instruction (5820 2058) in the CLEANUP_QINI proc.
  Reg2 contains 40's, and was supposed to be pointing to mail
  associated with the CKTI task. At the time of the 0C4, DFHMQTRQ
  is trying to free all of the mail chained from CKTI's MQLOT
  +x'1C'. The next mail address for CKTI is chained from the mail
  storage +x'58' -- field PNEXTMAIL. This mail storage lives in
  shared storage, length x'60'.
  .
  The problem is that DFHMQTRQ first issues the FREEMAIN for each
  piece of mail storage, then attempts to reference the freed
  storage to get the next mail address. The CKTI task is running
  on an L8 TCB. Meanwhile, a CKAM task running on the QR TCB
  acquires the same storage address and builds a PEB in it. After
  the FREEMAIN, DFHTRQ gets control back and now references the
  freed storage to get the next mail pointer. Since the storage
  is now a PEB, the next mail address now contains something other
  than zeroes. DFHMQTRQ attempts to free this address, gets an
  invalid freemain response and then takes the abend0C4.
  .
  Additional Symptom(s) Search Keyword(s):
  KIXREVEAA  Address_is_outside_DSA S0C4 abendS0C4 7AE0
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All                                          *
  ****************************************************************
  * PROBLEM DESCRIPTION: During shutdown of the CICS-MQ Adapter  *
  *                      an abend0C4 occurs in load module       *
  *                      DFHMQTRU at offset x'7AE0'.             *
  *                                                              *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  During shutdown of the CICS-MQ Adapter, an abend0C4 occurred in
  load module DFHMQTRU offset x'7AE0'.
  
  DFHMQ0107 I A request to end CKTI has been received. CKTI ended.
  ...
  DFHAP0707 An abend (code 0C4/AKEA) has occurred in task related
            user exit program DFHMQTRU.
  DFHAP0001 An abend (code 0C4/AKEA) has occurred at offset
            X'00007AE0' in module DFHMQTRU.
  
  The abend0C4 actually occurred in program DFHMQTRQ offset x'3F4'
  on a LOAD instruction (5820 2058) in the CLEANUP_QINI proc.
  Reg2 which contained x'40404040' was supposed to be pointing to
  mail associated with the CKTI task. At the time of the 0C4,
  DFHMQTRQ was trying to free all of the mail chained from CKTI's
  MQLOT +x'1C'. The next mail address for CKTI is chained from the
  mail storage +x'58' -- field PNEXTMAIL. This mail storage lives
  in shared storage, length x'60'.
  
  The problem is that DFHMQTRQ first issues the FREEMAIN for each
  piece of mail storage, and then attempts to reference the freed
  storage to get the next mail address. The CKTI task was running
  on an L8 TCB.  Meanwhile, a CKAM task running on the QR TCB
  acquired the same storage address and overwrote it.
  After the FREEMAIN, DFHMQTRQ got control back and referenced
  the freed storage to get the next mail pointer.
  However the next mail address now contained blanks, x'40404040'
  and DFHMQTRQ attempted to free this address, which resulted in
  an invalid freemain response and an abend0C4.
  
  Additional keywords:
  SM0D07 SM 0D07 ABENDS0C4 S0C4 0C4 msgMQ0107 msgAP0707 msgAP0001
  

Problem conclusion

• The cleanup_qini proc in module DFHMQTRU has been changed so
  that field pNextMail is saved prior to the FREEMAIN, and the
  saved field is used as the next mail address upon return from
  the FREEMAIN.
  

Temporary fix

• FIX AVAILABLE BY PTF ONLY
  

Comments

APAR Information

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

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

  UK53607 PM13072

Modules/Macros

• DFHMQTRQ
  

Fix information

• Fixed component name

  CICS TS Z/OS V4

• Fixed component ID

  5655S9700

Applicable component levels

• R600 PSY UK53607

     UP10/01/22 P F001

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.