PH71932: CALL TO A COBOL PROGRAM CAUSES AN ABEND WHEN ITS ALIASES IS DELETED FROM THE CEEPIPI TABLE

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• When a COBOL program is entered into the CEEPIPI table under
  different aliases, and when one of those aliases is deleted, a
  subsequent call to the COBOL program with the secondary alias
  leads to an abend.
  

Local fix

• N/A
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: Users of Enterprise COBOL 5 and later        *
  *                 releases running aliased programs            *
  *                 with the CEEPIPI interface.                  *
  *                                                              *
  *                 Users of IMS or tools that submit            *
  *                 the IMS UPDATE PGM(REFRESH) command and      *
  *                 run transactions using aliased               *
  *                 COBOL 5/6 programs through the CEEPIPI       *
  *                 interface.                                   *
  ****************************************************************
  * PROBLEM DESCRIPTION: An application (transaction) is         *
  *                      terminated with an abend code or        *
  *                      misbehaves because an unexpected        *
  *                      program or code flow is executed.       *
  *                                                              *
  *                      When a system dump is taken and         *
  *                      the CEEPIPI table entries are inspected *
  *                      using IPCS via VERBEXIT LEDATA 'ALL',   *
  *                      identical entry points and function     *
  *                      pointers are found across distinct      *
  *                      table entries.                          *
  *                                                              *
  *                      For example, using IPCS, the following  *
  *                      CEEPIPI table entry information         *
  *                      shows that programs X1 and X2 share     *
  *                      the same Entry Point (BCBF7000) and     *
  *                      function pointer (BCF05048), indicating *
  *                      aliased programs:                       *
  *                                                              *
  *                      ...                                     *
  *                      CEEPIPI Table Index 1                   *
  *                       Routine Name  = X1                     *
  *                       Routine Type  = COBOLV5+               *
  *                       Routine Entry Point  = BCBF7000        *
  *                       Routine Function Pointer  = BCF05048   *
  *                                                              *
  *                      CEEPIPI Table Index 2                   *
  *                       Routine Name  = X2                     *
  *                       Routine Type  = COBOLV5+               *
  *                       Routine Entry Point  = BCBF7000        *
  *                       Routine Function Pointer  = BCF05048   *
  *                       ...                                    *
  ****************************************************************
  * RECOMMENDATION: Install the provided PTF.                    *
  ****************************************************************
  The problem can be reproduced as follows:
  
  1) Create a COBOL 5/6 release program, namely X1.
  2) Create another program (X2) aliased to X1 using
     the Binder control statement at link-edit:
       ...
       ALIAS X2
       NAME  X1
       ...
  3) Add X1 and X2 to the CEEPIPI table (add_entry).
  4) Delete X2 (delete_entry).
  5) Call X1 (call_sub).
  
  In step 3, when X1 and X2 are added to the table, they share the
  same function pointer, which refers to an internal structure
  describing the entry point and attributes of the program.
  
  In step 4, the deletion of X2 frees the internal structure
  to which the function pointer refers.
  
  In step 5, calling X1 can result in an abend or execute an
  unexpected program because the function pointer still points to
  the freed internal structure, which may have been overwritten
  with unpredictable data by another process.
  
  COB0501T/K COB0502T/K COB0601T/K COB0602T/K COB0603T/K
  COB0604T/K COB0605T/K
  

Problem conclusion

• The COBOL Runtime logic has been fixed. In the scenario where
  X1 and X2 are aliased and X1 is called after the deletion of X2
  within CEEPIPI, the call to X1 completes successfully.
  
  The COBOL Runtime now detects requests to create or delete a
  COBOL function pointer via the LE Event Code 40
  within the CEEPIPI environment. The COBOL Runtime maintains a
  usage count for these requests using a newly introduced internal
  counter. The function pointer is retained until the counter
  reaches 0 and all other internal criteria are satisfied.
  
  Under the new logic, the COBOL Runtime also evaluates the entry
  point address to detect aliases, as a target program and its
  aliases share the same entry point address. The updated counter
  and per-module metadata are retained within COBOL Runtime
  internal control blocks.
  

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:

  UO09745 UO09746 UO09747

Modules/Macros

• IGZBXITA IGZCCCHK IGZCER4  IGZCEV4  IGZCFREM IGZCGETI IGZCGETM
  IGZCJNI2 IGZCLOAD IGZGLUE  IGZLLIBV IGZQR004 IGZRIDT  IGZRTMON
  IGZSETRT IGZTRUE  IGZXAPI  IGZXCA31 IGZXCDA  IGZXD24  IGZXDMR
  IGZXJNI2 IGZXLPIO IGZXLPKA IGZXLPKB IGZXLPKC IGZXLPKD IGZXLPKE
  IGZXLPKF IGZXLPKG IGZXPK2
  

Fix information

• Fixed component name

  LE ENT COBOL LI

• Fixed component ID

  568819812

Applicable component levels

• R7D0 PSY UO09745

     UP26/10/03 I 1000

• R7E0 PSY UO09746

     UP26/10/03 I 1000

• R7F0 PSY UO09747

     UP26/10/03 I 1000

Fix is available

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