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OA56384: ABEND C0D IN IECVEXSM ABEND 0C4 IN IECVEXSM

A fix is available

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APAR status

  • Closed as program error.

Error description

  • Abend C0D in IOS module IECVEXSM, EXCP Storage Manager because a
    private block is chained together with the SQA large blocks.
    
    The private block should have been removed from the chain
    earlier in EXCP I/O clean up processing before the chain of
    blocks was returned to the EXCP storage manager to be returned
    to the pool for use by another I/O request.
    
    Abend C0D is declared for any block that does not have the
    allocation byte field set to x'76'. Since the private blocks
    have already been returned to storage by the time the EXCP
    storage manager is checking, the storage referenced will be all
    0's.
    
    This error can also be seen as a 0C4-11 in IECVEXSM with a
    translation exception that points to the private blocks area
    that was just freemained in the system trace.
    
    ANALYSIS:
    Registers at the time of the dump:
    Reg. 1 - Abend Code - C0D
    Reg. 3 - Reason Code - 04 - Large Block Free Request
    Reg. 5 - Forward Chain Pointer
    Reg. 11 - Current Chain Pointer
    Reg. 13 - Save Area that points to register values at time of
    entry to IECVEXSM.
    
    In the syslog the EXCP request for the I/O will have a Getmain
    before the SSCH and the SRB tied to the completed I/O will have
    a freemain in IECVPBLK just before the C0D abend.
    
    KNOWN IMPACT:
    Abend occurs after the I/O is complete during clean up of
    control blocks. No impact on current or successive I/O's.
    
    VERIFICATION STEPS:
    Using the save area, the first entry is Reg. 1 on entry to
    IECVEXSM which is the first block on the chain. Run the chain
    and verify that the final block on the chain points to a private
    block area and not into SQA.
    
    From syslog (complete I/O trace):
    SVC      0 00000000_36E9EF78  00F04E80 386E8570 000303C0  Excp
               47850400 80000000
    SSRV    78          810961EE  0000E676 00001000 7F6DF000 Getmain
                                  004B0000
    SSCH 12185 00  02   020C512C  02760700 83C2F781 3C77D0E8
                                           007B9700
    SVCR     0 00000000_36E9EF78  00000000 00000200 000303C0
               47850400 80000000
    I/O  12185 00000000_36E59D08  80C04007 37405360 0C000000
               47852001 80000000           02760700 0001000D
    SRB        00000000_013A1370  0000004B 020C5100 020C512C
               47040000 80000000  007F8588 80
    SSRV    78          81096300  0000E603 00001000 7F6DF000
                          004B0000                  Freemain
    *SVCE    D 00000000_01753FAE  01753DA8 00001000 00C0D000
               47041000 80000000  00000004
    
    The final block on the chain should point into the page that was
    freemained just before the abend.
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    *  Users at HBB77A0 and above who use EXCP                     *
    *                 with 64 bit IDAWS.                           *
    *                                                              *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    *  ABENDC0D or ABEND0C4 in IECVEXSM                            *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    Abend C0D or abend 0C4 in IECVEXSM when using EXCP with 64 bit
    IDAWs.
    

Problem conclusion

  • IECVXCCW is updated to eliminate the C0D or 0C4 when using
    64-bit IDAWS.
    

Temporary fix

Comments

APAR Information

  • APAR number

    OA56384

  • Reported component name

    EXCP

  • Reported component ID

    5752SC1C6

  • Reported release

    7A0

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2018-10-25

  • Closed date

    2019-03-12

  • Last modified date

    2019-04-02

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

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

    UA98745 UA98746

Modules/Macros

  • IECVXCCW
    

Fix information

  • Fixed component name

    EXCP

  • Fixed component ID

    5752SC1C6

Applicable component levels

  • R7A0 PSY UA98746

       UP19/03/27 P F903

  • R7B0 PSY UA98745

       UP19/03/27 P F903

Fix is available

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Document Information

Modified date:
02 April 2019