PM65749: MULTIPLE 0C4 ABENDS SEEN IN DFHXCTRP DUE TO A CORRUPTED TRA_AVLEN FIELD

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Multiple 0C4 abends and random overlays of EXCI control
  blocks occur when field TRA_AVLEN has been corrupted within
  the EXCI trace anchor block. At CICS/TS 4.2 code has been
  changed to use 64 bit registers. The corruption of TRA_AVLEN
  happens when a new trace block is acquired and the first 4
  bytes of 64 bit register 9 is not clean on entry to DFHXCTRP.
  
  Additional Symptom(s) Search Keyword(s): KIXREVDAM
  VERBX LEDATA:
   15                   +000036E6              DFHXCPRX
   16       ....*DFHXCPRH....0670I....HCI6700 .-CICS 5655-S97
                        +00004896              DFHXCPRX
   17       baseEXCIPipeOperation
                        +00000242              *PATHNAM
   18       openEXCIPipe+00000084              *PATHNAM
   21       MVS_CcicsECI+0000051E              *PATHNAM
   22       Java_com_ibm_ctg_server_ServerECIRequest_CcicsECI
  ... java code occurs here in stack ...
  Javacore:
  com/ibm/ctg/server/ServerECIRequest.CcicsECI(Native Method)
  com/ibm/ctg/server/ServerECIRequest.executeECINative
  com/ibm/ctg/server/ServerECIRequest.executeECI
  com/ibm/ctg/server/ServerECIRequest.execute
  com/ibm/ctg/client/LocalWorker.execute
  .
  Customers may also see the following messages when attempting
  to make an EXCI call to a CICS region that is unavailable:
  DFHEX0114  Incorrect data has been passed for EXCI tracing
  causing a program check in DFHXCTRP.
  DFHEX0001  An abend (code 0C4/----) has occurred in module
  DFHXCTRP.
  MSGDFHEX0114 MSGDFHEX0001 ABEND0C4 ABENDS0C4
  ABEND0C4 in DFHXCTRP + x'420'
  0C4-11 abend in CSQADELT due to BLOA being overlaid.
  It's storage happened to follow EXCI trace control blocks.
  

Local fix

• Local Fix￘
  Use CICS/TS 4.1 code within the SDFHEXCI library
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICS users.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: Program check (x'0c4') is reported in   *
  *                      DFHXCTRP while moving trace data from   *
  *                      DFHXCPRH to last trace block.           *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  DFHXCTRP was changed at CICS/TS 4.2 to support 64 bit
  mode although it still run in 31 bit mode. TRA_NAB and
  TRA_AVLEN are defined as 64 bit value marking the next byte
  address and left space in internal trace block.
  When one block is full and the other block is needed,
  NEW_BLOCK is invoked to address the new block. R8 and R9 are
  used in that routine to set new value of TRA_NAB and TRA_AVLEN.
  Load Address (LA) is used in update the only last 4 bytes of
  register and eventually the value in R8 and R9 are restored
  to TRA_NAB and TRA_AVLEN. Most of the time it is OK but when
  it happens that the top 4 bytes of R9, is not x'00000000',
  TRA_AVLEN will be updated with a large value , like
  x'0000000B FFF94C62'.
  The trace entry is written into the new block until the
  trace block is full. DFHXCTRP check TRA_AVLEN to see if there
  is enough space for new trace entry. Because TRA_AVLEN is
  very large, trace entry writing will continue until access
  the invalid address.
  Additional Keywords: S0C4 ABEND0C4
  

Problem conclusion

• DFHXCTRP is changed to clear R8 and R9.
  

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:

  UK80223

Modules/Macros

•    DFHXCTRP
  

Fix information

• Fixed component name

  CICS TS Z/OS V4

• Fixed component ID

  5655S9700

Applicable component levels

• R700 PSY UK80223

     UP12/07/21 P F207

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.