OA65906: ABEND0C4 IN IGC121 +X'454' (Z/OS 2.5 BASE)

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• ABEND0C4-11 in IGC121 when using HPU
  
  ANALYSIS:
  VSAM was attempting to pull the JSTCB from the ASCB (address
  space control block) and update the JSTCB field in the IOMB.
  VSAM pulls a TCB from the TCB dispatcher queue. At the time of
  error VSAM was running under an SRB which had been suspended.
  While the SRB was suspended the TCB VSAM had picked up from the
  ASCB had terminated and storage was cleared. When the SRB was
  resumed, VSAM attempted to touch this area of storage which had
  been freed resulting in the ABEND0C4.
  
  KNOWN IMPACT:
  ABEND0C4-11 in IGC121 +x'454' (z/OS 2.5 base)
  
  VERIFICATION STEPS:
  A dump is generated with the following title "Dump Title:
  COMP=VSAM-ABP,COMPID=5695DF106,ISSUER=IDA121F1"
  Reg12 points to a TCB address where storage is not available.
  
  CATKEYS: VSAM2023 VSAMABEND VSAMHPU
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * All VSAM users running in SRB or XMM mode.                   *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * ABEND0C4-11 in IGC121 when running                           *
  * in SRB or XMM mode.                                          *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Apply PTF.                                                   *
  ****************************************************************
  VSAM I/O routine is picking up the jobstep TCB address from the
  last TCB in the dispatching queue while running under a SRB or
  in XMM mode.
  
  A rare timing problem is possible when the last TCB in the
  dispatching queue is detached at the same time VSAM is
  trying to use the address to reference the jobstep TCB.
  If this happens, an ABEND0C4 may occur.
  

Problem conclusion

• VSAM I/O routine is now corrected to use the jobstep TCB that
  was saved during OPEN time while running under a SRB or in XMM
  mode.
  

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:

  UJ94769 UJ94770 UJ94771

Modules/Macros

• IGC121
  

Fix information

• Fixed component name

  DFSMS VSAM

• Fixed component ID

  5695DF106

Applicable component levels

• R310 PSY UJ94769

     UP24/03/27 P F403

• R250 PSY UJ94771

     UP24/03/27 P F403

• R240 PSY UJ94770

     UP24/03/27 P F403

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.