IV88431: OPERATIONRACE CONDITION BETWEEN CTRC SUSPEND AND TRACE APPLIES TO AIX 7100-03

APAR status

• Closed as program error.

Error description

• System crash and the last couple of entries in the trace back
  are as follows
  
  KDB(7)> f pvthread+097800 STACK:  Ý00014AC0¨.ct_hook5+0000C0 ()
  Ý05CC7634¨entcore_ctrc_new+000134 (??, ??, ??, ??, ??, ??, ??,
  ??)
  

Local fix

Problem summary

• System crash and the last couple of entries in the trace back
  are as follows
  
  KDB(7)> f pvthread+097800 STACK:   00014AC0 .ct_hook5+0000C0 ()
   05CC7634 entcore_ctrc_new+000134 (??, ??, ??, ??, ??, ??, ??,
  ??)
  

Problem conclusion

• The crash is due to a race condition of performing a trace
  operation after a ctctrl memtracesuspend operation where
  we have validated we can trace but have not taken the trace
  lock yet.  The solution is to check if we can trace again
  after acquiring the lock to close the race condition.
  

Temporary fix

Comments

APAR Information

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

  IV86237

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

Fix information

• Fixed component name

  AIX V7.1

• Fixed component ID

  5765H4000

Applicable component levels

• R710 PSY U876079

     UP17/02/08 I 1000