A fix is available
APAR status
Closed as program error.
Error description
CICS region loops at shutdown. The looping task is the TCP task due to Kernel stacks that end up pointing to themselves. The problem is in DFHMQDSC due to Reg13 addressing the CSA on a call to the MQ Error message builder module, DFHMQERR. . The 2 tasks involved are TCP and the CKAM task. DFHMQDSC is running under the CKAM task. In the DELETE_OPEN_TCBS proc, Reg13 is set up to address the CSA (previously Reg13 was addressing DFHEISTG storage). The message routine is called to put out message: . DFHMQ0334 Adapter shutdown successful . This involves a call to DFHMQERR to put out the message. On the call to DFHMQERR, R13 is still addressing the CSA. DFHMQERR then saves the registers in the CSA register save area. However, during processing of the DFHMQ0334 message, CKAM is suspended on the TDIPLOCK. While CKAM is suspended, the TCP task runs and the CSA register save area is used on behalf of the TCP task. . When the CKAM task is resumed, it completes it's message processing and attempts to return to DFHMQDSC. However, as the registers are now associated with the TCP task, processing now goes awry. Additional Symptom(s) Search Keywords(s): KIXREVRER . DFHZRAC LIFO stack back pointer points to itself.
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: All * **************************************************************** * PROBLEM DESCRIPTION: The TCP task loops at shutdown, with * * the kernel stack pointing to itself. * **************************************************************** * RECOMMENDATION: * **************************************************************** DFHMQDSC routines delete_open_tcbs and write_uss_stats_to_smf_and_reset fail to reset R13 to address the EISTG upon exit. When DFHMQDSC calls DFHMQERR to issue message DFHMQ0334, register 13 is still addressing the CSA. DFHMQERR saves its registers into the CSA save area CSAOSRSA because of this. During processing of the DFHMQ0334 message, the CKAM task is suspended on a wait for the intrapartition TD TDIPLOCK. While CKAM is suspended, the TCP task runs and the CSA register save area is used on behalf of the TCP task. When the CKAM task is resumed, it completes its message processing and attempts to return to DFHMQDSC. However, as the registers are now associated with the TCP task, processing now goes awry. The result is a looping TCP task. KEYWORDS: msgdfhmq0334 mq0334 0334 334 mq wmq
Problem conclusion
DFHMQDSC has been changed to correctly restore the eistg address into R13 upon exit from delete_open_tcbs and write_uss_stats_to_smf_and_reset.
Temporary fix
FIX AVAILABLE BY PTF ONLY
Comments
APAR Information
APAR number
PK76043
Reported component name
CICSTS V3 Z/OS
Reported component ID
5655M1500
Reported release
500
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2008-11-19
Closed date
2009-02-24
Last modified date
2009-03-03
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UK44273
Modules/Macros
DFHMQDSC
Fix information
Fixed component name
CICSTS V3 Z/OS
Fixed component ID
5655M1500
Applicable component levels
R500 PSY UK44273
UP09/02/26 P F902
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:
03 March 2009