IT28499: Memory exception in MQDISC in client application and FDC record with XC130006 xehExceptionHandler

APAR status

• Closed as program error.

Error description

• The application MQDISC call fails.
  
  A failure data capture (FDC) record is generated showing:
  
  Probe Id :- XC130006
  Component :- xehExceptionHandler
  Program Name :- <UsersProgramName>
  UserApp :- TRUE
  Comment1 :- SIGSEGV: address not mapped(0x32)
  
  MQM Function Stack ends with:
  ccigsk_unload
  xcsUnloadFunction
  xcsFFST
  
  Later in the FDC record, the following appears showing a
  LoadedCount of 8, where it should normally be 4.
  
  GSKFn
    :
    LoadedCount       8
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  Any user of a multi-threaded MQ C client application that calls
  MQCONN and MQDISC freely on multiple threads concurrently.
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  Library loading code in MQCONN and MQDISC was relying on state
  data in a global variable but this state data was not protected
  by a mutex, where it should have been.
  

Problem conclusion

• A mutex is now used to protect this state data, and so the
  problem no longer exists.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v8.0       8.0.0.5
  v9.1 CD    9.1.4
  
  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 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 BASE MP

• Fixed component ID

  5724H7251

Applicable component levels