IBM Support

IT24765: TIMING ISSUE IN PACKAGE CACHE WORKSPACE MAY CAUSE PANIC

Subscribe to this APAR

By subscribing, you receive periodic emails alerting you to the status of the APAR, along with a link to the fix after it becomes available. You can track this item individually or track all items by product.

Notify me when this APAR changes.

Notify me when an APAR for this component changes.

 

APAR status

  • Closed as program error.

Error description

  • There is a timing issue where there is a brief moment in time
    that the state of a sibling entry in package cache workspace can
    be set to a particular state outside of latch control, so the
    entry might be reused or freed up from the lru lists in the
    cache by someone else, as a result, panic may happen due to
    memory corruption.
    
    The stack can be vary:
    
    Stack 1:
     sqle_panic
     sqloCrashOnCriticalMemoryValidationFailure
     SQLO_MEM_POOL::diagnoseMemoryCorruptionAndCrash
     sqloDiagnoseFreeBlockFailure
     sqlofmblkEx
     sqlra_sqlW_mem_free_sibling_list
     sqlra_sqlW_mem_freespace
     sqlra_sqlW_check_for_cleanup
     sqlra_sqlW_get_dynamic_section_new
     sqlra_load_var
     sqlra_get_var
     sqlrr_execimmd
     sqlrr_execimmd
    
    Stack 2:
    
    PID     : 1704972              TID : 79974          PROC :
    db2sysc 0
    INSTANCE: db2inst1             NODE : 000           DB   :
    SAMPLE
    APPHDL  : 0-360                APPID:
    *LOCAL.db2inst1.180203112927
    AUTHID  : DB2INST1             HOSTNAME: MYHOST
    EDUID   : 79974                EDUNAME: db2agent (SAMPLE) 0
    FUNCTION: DB2 UDB, SQO Latch Tracing,
    SQLO_SLATCH_CAS64::getConflictComplex, probe:210
    MESSAGE :
    ZRC=0x870F00FD=-2029059843=SQLO_SLATCH_ERROR_HELDS_WITH_SHARED_W
    AITER
              "A latch with X starvation policy should StarveX latch
    should not be held shared and have a shared waiter."
    CALLED  : OS, -, unspecified_system_function
    DATA #1 : String, 13 bytes
    invalid latch
    DATA #2 : File name, 16 bytes
    sqloLatchCAS64.C
    DATA #3 : Source file line number, 8 bytes
    592
    DATA #4 : Codepath, 8 bytes
    0
    DATA #5 : String, 136 bytes
    0xFAB0A00020002EA0: {
       held X: 0
       reserved for X: 0
       shared holders: 11936
       firstSharIndex: 0x200
       firstExclIndex: 0x1D5850
    }
    DATA #6 : LatchMode, PD_TYPE_LATCH_MODE, 8 bytes
    0x10000 (SQLO_LATCH_MODE_EXCLUSIVE)
    DATA #7 : String, 397 bytes
    {
       state         = 0xFAB0A00020002EA0
                     = {
                           held X: 0
                           reserved for X: 0
                           shared holders: 11936
                           firstSharIndex: 0x200
                           firstExclIndex: 0x1D5850
                       }
       starve X mode = true
       xWaitCount    = 0
       requestCount  = 0
       identity      = NO_IDENTITY (0)
    }
    DATA #8 : Pointer, 8 bytes
    0x0a00020002ede448
    DATA #9 : Hexdump, 16 bytes
    0x0A00020002EDE448 : FAB0 A000 2000 2EA0 0A00 0200 02ED E108
    .... ...........
    CALLSTCK: (Static functions may not be resolved correctly, as
    they are resolved to the nearest symbol)
      [0] 0x090000000DC8088C
    dumpDiagInfoAndPanic__17SQLO_SLATCH_CAS64CFCPCcCUiCUlT3ClT3CiT1T
    3T7 + 0x2FC
      [1] 0x090000000CA0C814
    getConflictComplex__17SQLO_SLATCH_CAS64FCUl + 0xE8C
      [2] 0x090000000CE80D54 getConflict__17SQLO_SLATCH_CAS64FCUl +
    0x118
      [3] 0x090000000B8D9F2C
    sqlra_sqlW_mem_freespace__FP8sqlrr_cbUlPUli + 0x1C4
      [4] 0x090000000B8A561C
    sqlra_sqlW_check_for_cleanup__FP8sqlrr_cbUlP7OSSTick + 0x264
      [5] 0x090000000B899D7C
    sqlra_sqlW_get_dynamic_section_new__FP8sqlrr_cbP16sqlra_cached_v
    ar + 0x14B8
      [6] 0x090000000B89ADF8
    sqlra_load_var__FP8sqlrr_cbP16sqlra_cached_varP14SQLP_LOCK_INFOP
    b + 0xAC
      [7] 0x090000000B89AA8C sqlra_get_var__FP8sqlrr_cbiT2bPbT5 +
    0x884
      [8] 0x090000000C587808
    sqlrr_execute__FP14db2UCinterfaceP9UCstpInfo + 0x114
      [9] 0x090000000C587B10
    sqlrr_execute__FP14db2UCinterfaceP9UCstpInfo + 0x41C
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * N/A                                                          *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * See Error Description                                        *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Upgrade to Db2 v10.5 FP10 or later.                          *
    ****************************************************************
    

Problem conclusion

  • The problem is firstly fixed on Db2 v10.5 FP10.
    

Temporary fix

Comments

APAR Information

  • APAR number

    IT24765

  • Reported component name

    DB2 FOR LUW

  • Reported component ID

    DB2FORLUW

  • Reported release

    A50

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2018-04-17

  • Closed date

    2018-07-12

  • Last modified date

    2018-07-12

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

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

    IT27178

Fix information

  • Fixed component name

    DB2 FOR LUW

  • Fixed component ID

    DB2FORLUW

Applicable component levels

[{"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSEPGG","label":"Db2 for Linux, UNIX and Windows"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"10.5","Edition":"","Line of Business":{"code":"LOB10","label":"Data and AI"}}]

Document Information

Modified date:
12 July 2018