A fix is available
APAR status
Closed as program error.
Error description
While a CWXN task is running, the TCPIPService that it is using gets set IMMCLOSE. The storage associated with the STE for this task gets FREEMAINED by the IMMCLOSE, but as the task has not terminated yet, a pointer to this storage still exists, held as the SO token for the task in transaction manager. The storage may get used several times before the task pointing to the storage finally terminates. When it does, during task termination DFHSOXM decrements ste_txn_count by 1. This is at offset x'24' into the STE. However, the storage that it is referencing is no longer an STE. In the situation which brought about this APAR, the storage was now a QPH. When DFHSOXM decrements the QPH +24, or field QPH_FIRST_FREE_CELL, it corrupts this address. In our case it was a QPH for subpool RMOFRMUW, though it could just as well be any other subpool or piece of task storage. Additional Keywords: MINUS ONE 1 -1 S0C4 ABENDS0C4 MSGDFHWB0002 WB0002 SUBTRACT OFF LESS DFHSM0002 has been seen hitting various subpools: LI_PLB XMTRANS LD_CSECT PGLLE PGHTB LD_APES the key is the first free QPH+24 always contains an address that is 1 less or minus 1 from the address that it should contain.
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: All. * **************************************************************** * PROBLEM DESCRIPTION: When a TCPIPSERVICE is set IMMCLOSE, * * storage related to the STE is * * FREEMAINed, but any remaining CWXN * * tasks will attempt to use this storage * * at task termination. * **************************************************************** * RECOMMENDATION: * **************************************************************** While a CWXN task is running, the TCPIPSERVICE that it is using is IMMCLOSEd. The storage associated with the STE for this task gets FREEMAINed by the IMMCLOSE, but as the task has not yet terminated, a pointer to this storage still exists. When the task terminates, DFHSOXM attempts to decrement STE_TXN_COUNT by 1, but the storage that contains this field is no longer an STE, and may have been reused by some other function. DFHSOXM will decrement the storage at the address that was previously an STE, but its current contents are now unpredictable. Additional keywords: MINUS ONE 1 -1 MSGDFHWB0002 WB0002 SUBTRACT S0C4 ABENDS0C4 0C4 ABEND0C4
Problem conclusion
DFHSOXM has been changed to check that the STE storage is still valid before attempting to decrement STE_TXN_COUNT.
Temporary fix
********* * HIPER * ********* FIX AVAILABLE BY PTF ONLY
Comments
APAR Information
APAR number
PK27738
Reported component name
CICSTS 3.1 Z/OS
Reported component ID
5655M1500
Reported release
400
Status
CLOSED PER
PE
NoPE
HIPER
YesHIPER
Special Attention
NoSpecatt
Submitted date
2006-07-10
Closed date
2006-07-26
Last modified date
2006-08-02
APAR is sysrouted FROM one or more of the following:
PK26484
APAR is sysrouted TO one or more of the following:
UK16522
Modules/Macros
DESSOXM DFHSOXM
Fix information
Fixed component name
CICSTS 3.1 Z/OS
Fixed component ID
5655M1500
Applicable component levels
R400 PSY UK16522
UP06/07/29 P F607
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.
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Document Information
Modified date:
02 August 2006