A fix is available
APAR status
Closed as program error.
Error description
TCPIP HUNG. A Logical Device host can hang following a Diagnose x'7C' Terminate function issued for a dialed logical device. In this case one ldev is dialed to another. The dialed to ldev issued the RESET for the dialed ldev. This caused CP to destroy the dialed ldev. Before the destroy processing completed the logical device host issued a Diagnose x'7C' Terminate, causing the logical device host to become hung in simulation wait.
Local fix
N/A
Problem summary
**************************************************************** * USERS AFFECTED: All users of z/VM Logical Device Support * * Facility. * **************************************************************** * PROBLEM DESCRIPTION: * **************************************************************** * RECOMMENDATION: APPLY PTF * **************************************************************** TCPIP hung while terminating a logical device with a Diagnose X'7C' Terminate function. The logical device getting terminated was dialed to another logical device. The Diagnose X'7C' Terminate occurred while the same logical device was being destroyed as a result of a RESET command. The RESET command processing turned off the RDEVDED bit in the logical RDEV. Before the destroy processing completed the terminate processing continued to HCPLDADR. In HCPLDADR, the processing did not take the path for dialed devices because the RDEVDED bit was off. Instead, dispatching was switched to the logical device user and HCPQCNSY was called to quiesce all terminal activity while TCPIP was in simulation-wait. We never returned from HCPQCNSY, leaving TCPIP hung.
Problem conclusion
HCPDIUDR was changed to set a new bit in the RDEV when the RDEVDED bit is turned off. This new bit is checked in HCPLDADR. When this bit is on processing will take the dialed device path, and HCPQCNSY will not be called.
Temporary fix
FOR RELEASE VM/ESA CP/ESA R640 : PREREQ: VM66258 VM66095 CO-REQ: NONE IF-REQ: NONE FOR RELEASE VM/ESACP/ESAR710 : PREREQ: VM66258 VM66219 CO-REQ: NONE IF-REQ: NONE
Comments
APAR Information
APAR number
VM66360
Reported component name
VM CP
Reported component ID
568411202
Reported release
640
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2020-02-03
Closed date
2020-02-26
Last modified date
2021-06-29
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UM35601 UM35602
Modules/Macros
HCPDIU HCPLDA HCPLDDBK HCPRDEV
Fix information
Fixed component name
VM CP
Fixed component ID
568411202
Applicable component levels
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:
30 June 2021