IBM Support

IT16342: Channel processes terminate abnormally with probe ID XC130031 amqrmppa gets SIGSEGV in zsqATCBAfter

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You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • An IBM MQ v8.0.0.5 queue manager with activity tracing enabled,
    channel processes abnormally terminated with SIGSEGV: address
    not mapped
    
    Error log shows
    AMQ7159: A FASTPATH application has ended unexpectedly.
    
    FDC generated with:
    
    Probe Id          :- XC130003
    Program Name      :- amqrmppa
    Thread            :- 211    AsyncConsume
    Probe Type        :- HALT6109
    Major Errorcode   :- STOP
    Comment1          :- SIGSEGV: address not mapped(0x8)
    
    MQM Function Stack
    zlaMainThread
    zlaProcessMessage
    zlaProcessMQIRequest
    zlaMQCB
    zsqMQCB
    zsqATCBAfter
    xcsFFST
    

Local fix

  • Turn off activity tracing.
    

Problem summary

  • ****************************************************************
    USERS AFFECTED:
    Users of activity tracing tracing and with fastpath channels
    enabled are at risk of being affected by this issue.
    
    
    Platforms affected:
    MultiPlatform
    
    ****************************************************************
    PROBLEM DESCRIPTION:
    When an IBM MQ queue manager is configured to use fastpath
    channels (MQIBindType=FASTPATH in qm.ini) and activity trace is
    enabled, then changing a queue so that it becomes get inhibited
    can cause a SIGSEGV to occur and the channel process will end.
     The SIGSEGV is caused by IBM MQ referencing a piece of data
    which is not valid when the channel process is connected using
    fastpath MQI bindings.
    

Problem conclusion

  • The code was modified to include a check that the data was valid
    before attempting to access it.
    
    It should be noted that when running with FASTPATH bindings then
    certain MQCBD fields may be missing from MQCB activity trace, as
    unused fields within the MQCBD will not be initialized in
    FASTPATH mode, and omitted from the output accordingly.
    
    ---------------------------------------------------------------
    The fix is targeted for delivery in the following PTFs:
    
    Version    Maintenance Level
    v7.5       7.5.0.8
    v8.0       8.0.0.6
    v9.0 CD    9.0.1
    v9.0 LTS   9.0.0.1
    
    The latest available maintenance can be obtained from
    'WebSphere MQ Recommended Fixes'
    http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006037
    
    If the maintenance level is not yet available information on
    its planned availability can be found in 'WebSphere MQ
    Planned Maintenance Release Dates'
    http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006309
    ---------------------------------------------------------------
    

Temporary fix

Comments

APAR Information

  • APAR number

    IT16342

  • Reported component name

    WMQ BASE MULTIP

  • Reported component ID

    5724H7251

  • Reported release

    800

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2016-07-28

  • Closed date

    2016-08-25

  • Last modified date

    2017-06-01

  • APAR is sysrouted FROM one or more of the following:

  • APAR is sysrouted TO one or more of the following:

Fix information

  • Fixed component name

    WMQ BASE MULTIP

  • Fixed component ID

    5724H7251

Applicable component levels

  • R800 PSY

       UP

[{"Line of Business":{"code":"LOB36","label":"IBM Automation"},"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSYHRD","label":"IBM MQ"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"8.0.0.0"}]

Document Information

Modified date:
10 September 2020