APAR status
Closed as program error.
Error description
When a COBOL CLLE control block is overlaid, a looping condition may occur in IGZXAPI when attempting to obtain WSA.
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: Users of Enterprise COBOL 5 and later * * releases running programs which call * * the IGZXAPI API with function * * code 7 or 8. * **************************************************************** * PROBLEM DESCRIPTION: A call to IGZXAPI with function code 7 * * or 8 may never return, leading to * * appear as if it's a program hang. * * * * When a system dump is taken for the * * hang and IPCS is used to read the dump * * via VERBEXIT LEDATA 'ALL', the * * following message may appear: * * * WARNING Formatting of control block * * chain stopped. Possible loop in chain. * **************************************************************** * RECOMMENDATION: Install the provided PTF. * **************************************************************** If a user application corrupts memory out of the application's scope and abends, any usage of system control blocks after that point may produce random results. In this case, an abend handler that got control during an abend tried to call the IGZXAPI to retrieve some specific program information. The corruption of system control blocks lead to a recursive loop in the control blocks. IGZXAPI retrieves information from the COBOL internal control block called CLLE. When these control blocks are accidentally corrupted prior to the call to IGZXAPI, a recursive loop may occur within the IGZXAPI routine. In particular a sequence of x'40' (blank characters) written over these control blocks will cause the loop. COB0501T/K COB0502T/K COB0601T/K COB0602T/K COB0603T/K COB0604/K
Problem conclusion
Due to the corruption of control blocks a recursive chain was created. A fix to try to determine this condition has been developed and should catch the looping condition. For details on IGZXAPI function code 7 and 8 see the URL at: https://www.ibm.com/support/pages/node/242521 https://www.ibm.com/support/pages/node/6243414
Temporary fix
Comments
APAR Information
APAR number
PH52347
Reported component name
LE ENT COBOL LI
Reported component ID
568819812
Reported release
7D0
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2023-02-02
Closed date
2023-03-17
Last modified date
2023-03-27
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Modules/Macros
IGZCEV4 IGZCJNI2 IGZLLIBV 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
R7C0 PSY UP
C
R7D0 PSY UP
C
[{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SS6SG3","label":"Enterprise COBOL for z\/OS"},"Platform":[{"code":"PF054","label":"z Systems"}],"Version":"7D0","Line of Business":{"code":"LOB35","label":"Mainframe SW"}}]
Document Information
Modified date:
27 March 2023