IBM Support

IT27163: SIGSEGV under rriDeleteStatusEntry/xcsRequestMutexSemFn is reported and the channel becomes unusable.

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APAR status

  • Closed as program error.

Error description

  • A SIGSEGV failure data capture (FDC) record is reported with the
    following signature during queue manager shutdown:
    
    | Probe Id          :- XC130003
                                                  |
    ...
    | Program Name      :- amqrmppa
                                                  |
    ...
    | Comment1          :- SIGSEGV: address not mapped((nil))
                        |
    |
                  |
    +---------------------------------------------------------------
    --------------+
    
    O/S Call Stack for current thread
    /opt/mqm/lib64/libmqmcs_r.so(xcsPrintStackForCurrentThread+0x3e)
    [0x7ffe67e0be0e]
    /opt/mqm/lib64/libmqmcs_r.so(+0x11731d)[0x7ffe67e2a31d]
    /opt/mqm/lib64/libmqmcs_r.so(PrepareDumpAreas+0xd14)[0x7ffe67e25
    3b4]
    /opt/mqm/lib64/libmqmcs_r.so(xcsFFSTFn+0x19e0)[0x7ffe67e27f20]
    /opt/mqm/lib64/libmqmcs_r.so(xehExceptionHandler+0x965)[0x7ffe67
    e22c15]
    /lib64/libpthread.so.0(+0xf710)[0x7ffe67551710]
    /opt/mqm/lib64/libmqmcs_r.so(xcsRequestMutexSemFn+0x90)[0x7ffe67
    e42a00]
    /opt/mqm/lib64/libmqmr_r.so(rriDeleteStatusEntry+0x2c9)[0x7ffe68
    b17069]
    /opt/mqm/lib64/libmqmr_r.so(rriWriteCompMsg+0x33e)[0x7ffe68b80a1
    e]
    /opt/mqm/lib64/libmqmr_r.so(rriFreeSess+0xda5)[0x7ffe68b89d95]
    /opt/mqm/lib64/libmqmr_r.so(rriAsyncConvControl+0x41a)[0x7ffe68b
    6500a]
    /opt/mqm/lib64/libmqmr_r.so(cciEndConv+0x217)[0x7ffe689b1927]
    /opt/mqm/lib64/libmqmr_r.so(ccxReceiveThreadCleanup+0xdf)[0x7ffe
    689b3eff]
    /opt/mqm/lib64/libmqmr_r.so(ccxReceiveThreadFn+0xbf)[0x7ffe689b7
    c5f]
    /opt/mqm/lib64/libmqmr_r.so(rrxResponder+0x73f)[0x7ffe68b7efff]
    /opt/mqm/lib64/libmqmr_r.so(ccxResponder+0x29b)[0x7ffe689c1f2b]
    /opt/mqm/lib64/libmqmr_r.so(cciResponderThread+0x8f)[0x7ffe689c2
    01f]
    /opt/mqm/lib64/libmqmcs_r.so(+0x170d6c)[0x7ffe67e83d6c]
    /lib64/libpthread.so.0(+0x79d1)[0x7ffe675499d1]
    /lib64/libc.so.6(clone+0x6d)[0x7ffe67092a4d]
    
    MQM Function Stack
    ccxResponder
    rrxResponder
    ccxReceiveThreadFn
    ccxReceiveThreadCleanup
    cciEndConv
    rriAsyncConvControl
    rriFreeSess
    rriWriteCompMsg
    rriDeleteStatusEntry
    xcsFFST
    
    Afterwards the channel is unusable until a queue manager
    restart.
    

Local fix

Problem summary

  • ****************************************************************
    USERS AFFECTED:
    Users who connect to IBM MQ via client applications may be
    affected by this issue.
    
    
    Platforms affected:
    MultiPlatform
    
    ****************************************************************
    PROBLEM DESCRIPTION:
    When ending the queue manager a thread in the channel agent
    attempted to take a lock.  This lock had already been freed by
    another thread and so a SIGSEGV occurs.
    

Problem conclusion

  • It was not possible to identify root cause of the premature
    freeing of the lock and so a defensive code change was added to
    avoid the SIGSEGV if the problem were to occur again.  Instead
    of a SIGSEGV then one RM028010 FFST per process affected will be
    generated to report that the lock has been freed prematurely.
    This should be reported to IBM MQ Support for further
    investigation.
    
    ---------------------------------------------------------------
    The fix is targeted for delivery in the following PTFs:
    
    Version    Maintenance Level
    v8.0       8.0.0.12
    v9.0 LTS   9.0.0.7
    v9.1 CD    9.1.2
    
    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

    IT27163

  • Reported component name

    IBM MQ APPL M20

  • Reported component ID

    5725Z0900

  • Reported release

    800

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2018-12-03

  • Closed date

    2019-01-22

  • Last modified date

    2019-01-22

  • 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

    IBM MQ APPL M20

  • Fixed component ID

    5725Z0900

Applicable component levels

[{"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SS5K6E","label":"IBM MQ Appliance"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"8.0","Edition":"","Line of Business":{"code":"LOB36","label":"IBM Automation"}}]

Document Information

Modified date:
22 January 2019