A fix is available
APAR status
Closed as unreproducible in next release.
Error description
You are running CICS TS 5.5 and the region suddenly becomes unresponsive. The region is running with Fault Analyzer and happens to be processing transaction abend codes for dumpcode EC4120. In the joblog you see the following messages: +DFHKE0201 ABOUT TO TAKE SDUMP. DUMPCODE: KERNDUMP, DUMPID: 0/0000. (MODULE DFHKESTX). +DFHKE0201 ABOUT TO TAKE SDUMP. DUMPCODE: KERNDUMP, DUMPID: 0/0000. (MODULE DFHKESTX). +DFHKE0201 ABOUT TO TAKE SDUMP. DUMPCODE: KERNDUMP, DUMPID: 0/0000. (MODULE DFHKESTX). BPXP018I THREAD 1F72100000000000, IN PROCESS 1332, ENDED WITHOUT BEING UNDUBBED WITH COMPLETION CODE 940C4000 +DFHME0118 An error has occurred when calling the Message User Exit for message DFHSJ0904 +DFHME0118 An error has occurred when calling the Message User Exit for message DFHAP0001 BPXP018I THREAD 1F9308000010331E, IN PROCESS 16777931, ENDED WITHOUT BEING UNDUBBED WITH COMPLETION CODE 0033E000 +IDI0095W Unexpected condition found in IDI:347: STATIC INVOCATION OF EXIT NOT SUPPORTED Looking at a KERNDUMP, found a task, running on the QR TCB, looping overlaying CICS DSA storage above the line. The task had abended, and Fault Anayzer was in in control gathering information about the abend. CICS internal trace showed it issued and INQUIRE_TASK_STORAGE call to CICS. CICS keeps track of task storage for each individual task in a SMX control block, anchored off the Storage Manager Anchor Block. FA was inquiring on a task that Just recently ended. Here is that trace: QR SM 0E01 SMMC2 ENTRY INQUIRE_TASK_STORAGE TRANSACTION_NUMBER(0085979C) ELEMENT_BUFFER(27100008 , 0012E4F0 , 0012E4F0) LENGTH_BUFFER(28500008 , 0012E4F0 , 0012E4F0) Task 85979 recently terminated, but Storage manager had not completely finished its clean up of control blocks for this task. This caused code in DFHSMMC2 to reference low core - address 0000000, thinking it was chaning through CICS control blocks, This was updating the buffer storage - 27100008 with information from low core, which happened to be the CVT address. This overlaid many CICS control blocks, as well as causing storage violations. Here is an example of this overlay, which happens to be the address of the CVT- 00FD6380: 27100000 E4F0F0F8 F5F9F2F9 00FD6380 00FD6380 27100010 00FD6380 00FD6380 00FD6380 00FD6380 27100020.:2743D43F. LENGTH(X'33D420')--Same as above Additional Symptoms: KIXREVDAM quickcell SM0102 DFHSM0102 DFHEC4120
Local fix
disable Fault Analyzer
Problem summary
**************************************************************** * USERS AFFECTED: All CICS users. * **************************************************************** * PROBLEM DESCRIPTION: Corruption of storage during * * DFHSMMCX XPI (INQUIRE_TASK_STORAGE) * * processing. * **************************************************************** The DFHSMMCX (INQUIRE_TASK_STORAGE) TRANSACTION_NUMBER() is called to inquire upon a task which has not got any task storage subpools (either because they have not yet been allocated, or they have been de-allocated). The INQUIRE_TASK_STORAGE mechanism returns invalid pointers to the caller, corrupting storage. In the reported case, many instances of a fullword which contained the address of the CVT were returned.
Problem conclusion
Temporary fix
Comments
DFHSMMCX (INQUIRE_TASK_STORAGE) has been changed to ignore subpools which are not allocated. . IBM Publications for CICS, will be updated at section:"The INQUIRE_TASK_STORAGE call", operand: NUMBER_OF_ELEMENTS to state: "NUMBER_OF_ELEMENTS can be zero."
APAR Information
APAR number
PH61398
Reported component name
CICS TS Z/OS V5
Reported component ID
5655Y0400
Reported release
200
Status
CLOSED UR1
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2024-05-17
Closed date
2024-06-13
Last modified date
2024-07-01
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UI97311 UI97312
Modules/Macros
DFHSMMC2
Fix information
Fixed component name
CICS TS Z/OS V5
Fixed component ID
5655Y0400
Applicable component levels
Fix is available
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Document Information
Modified date:
02 July 2024