PI50378: PLB_ENTRY_POINT BECOMES INCONSISTENT AFTER A PROGRAM COMPRESSION AND START TRANSID('CSSF'). ABENDS RESULT.

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Program DFHSFP runs for the first time; PPTE/PLB linkage is
  created and the program is loaded into storage.
  Then program DFHSFP is removed due to program compression.
  Subsequent, invocations of DFHSFP will re-load the program into
  storage and recreate the PPTE/PLB linkage. This is how it should
  work - no problem.
  However, after Program DFHSFP is removed due to program
  compression and the following occurs we get the problem ..
  - A transaction issues a START request for transaction "CSSF".
  (This is an older sign off transaction. It is no longer
  supported.)
  - This transaction (CSSF) invokes program DFHRTC which issues an
  ACQUIRE_PROGRAM for program DFHSFP. This will cause the Loader
  to reload DFHSFP into storage at a new location. BUT the PPTE
  and PLB are not updated.
  - Some time later, a CESF transaction runs. This drives an
  INITIAL_LINK to DFHSFP, and runs the acquire_for_link code.
  - LDLD ACQUIRE_PROGRAM is driven, but the program is already
  in storage so "OLD_COPY" is returned. Function acquire_for_link
  does NOT invalidate PPTE_LANG_DEDUCED.
  - The initial link continues, passes the PLB to APLI
   START_PROGRAM but this is an old version of the PLB. The PLB
  was not updated when the program DFHSFP was loaded.
  -  DFHAPLI picks up the old entry point and branches to it -
  random results may occur, including abend0C1s and storage
  corruption.
  

Local fix

• amend the user program to use transaction_id 'CESF' instead of
  'CSSF'. reduce the number of program compressions be providing
  sufficicnet DSA storage.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICS users.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: Attempts to LINK to program DFHSFP      *
  *                      result in branch to undefined location. *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  DFHSFP is removed from storage due to program compression. An
  EXEC CICS START request for the CSSF transaction is issued. This
  transaction has been replaced by CESF, and is no longer
  supported.
  Transaction CSSF executes program DFHRTC, which issues a DFHLDLD
  ACQUIRE_PROGRAM request for DFHSFP. This causes DFHSFP to be
  reloaded into storage, allowing DFHRTC to branch to it.
  Transaction CESF is then invoked, which causes an INITIAL_LINK
  to DFHSFP. This runs DFHAPLI START_PROGRAM for DFHSFP, passing
  the PLB. The PLB was built when DFHSFP was first loaded, but was
  not updated when DFHSFP was reloaded (following its removal by
  program compression). Therefore the PLB_ENTRY_POINT passed to
  START_PROGRAM contains a stale entry point. A program check will
  occur when control is passed to this location.
  .
  Additional Keywords: S0C4 0C4 abendS0C4 abend0C4 PLB_LOAD_POINT
                       S0C1 0C1 abendS0C1 abend0C1
  

Problem conclusion

• The definition of DFHSFP has been updated to specify
  RESIDENT(YES). This will prevent it from being removed
  from storage by program compression, and thereby prevent
  the PLB_ENTRY_POINT from being invalidated.
  

Temporary fix

• FIX AVAILABLE BY PTF ONLY
  

Comments

APAR Information

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

  PI49985

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

  UI32736 UI32737

Modules/Macros

• DFHCURDI DFHCURDM
  

Fix information

• Fixed component name

  CICS TS Z/OS V5

• Fixed component ID

  5655Y0400

Applicable component levels

• R800 PSY UI32736

     UP15/11/12 P F511

• R900 PSY UI32737

     UP15/11/12 P F511

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.