PH23554: MQ Z/OS: ABEND0C4-00000038 IN CSQXFFST FOLLOWED BY CSQX112E CSQXDISP DISPATCHER PROCESS ERROR

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• An ABEND occurred:
  IEA794I SVC DUMP HAS CAPTURED:
    DUMPID=nnn REQUESTED BY JOB (CSQ1CHIN)
    DUMP TITLE=CSQ1,ABN=0C4-00000038,C=MQ900.900.CHIN,
    M=CSQXDISP,LOC=CSQXRCTL.CSQXFFST
  CSQX112E CSQXDISP Dispatcher process error,
   TCB=nnnnnnnn reason=0C4000-00000038
  
  The failing instruction is 58B0 5014 where the 64bit
  Reg5=FFFFFFFF_nnnnnnnn.  The problem is first word of the
  register contains FFFFFFFF.
  
  The incorrect value is caused by incorrect logic in CSQYDISS
  when it sets pSKBTail for a new XEB.  In incorrect logic causes
  the high half of GR3 to be incorrectly included in the address
  stored. If this is non-zero, an incorrect address is used when
  this field is de-referenced in amode(64), such as in CSQXFFST.
  

Local fix

• N/A
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All Users of IBM MQ for z/OS Version 9       *
  *                 Release 0 Modification 0 and Release 1       *
  *                 Modification 0 and Release 2 Modification 0  *
  ****************************************************************
  * PROBLEM DESCRIPTION: When calling CSQXFFST to create an      *
  *                      FFST due to an error on a channel,      *
  *                      an 0c4 abend in CSQXFFST,               *
  *                      followed by a CSQX112E CSQXDISP         *
  *                      DISPATCHER PROCESS ERROR occurs.        *
  ****************************************************************
  The problem occurs when attempting to dereference the
  XEB.pXSKBTail pointer in amode(64).
  
  When stored, only the low half is set. Sometimes the top
  half contains a residual value, which causes dereferencing this
  pointer to fail.
  

Problem conclusion

• The high half of the XEB.pXSKBTail pointer is made clear before
  being stored.
  

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:

  UI72131 UI72132 UI72133

Modules/Macros

• CSQXDISP
  

Fix information

• Fixed component name

  IBM MQ Z/OS V9

• Fixed component ID

  5655MQ900

Applicable component levels

• R000 PSY UI72131

     UP20/12/07 P F012

• R100 PSY UI72132

     UP20/12/07 P F012

• R200 PSY UI72133

     UP20/12/07 P F012

Fix is available

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