IT11620: REQUESTS TO ABORT READAHEAD OPERATIONS MAY NOT BE NOTICED BY THE READAHEAD DAEMON LEADING TO POTENTIAL FOR MEMORY CORRUPTION

APAR status

• Closed as fixed if next.

Error description

• Following the submission of a request to read ahead index or
  data pages the requesting thread may issue an abort request for
  that request if the pages are no longer required. The request is
  processed by one of the readahead threads but this may not
  notice the abort request either during or prior to commencement
  of the request processing. When this happens there is the
  potential for the unintentional modification of memory in the
  thread associated with the original request.
  
  Depending on the activities of the originating thread such
  modification may go unnoticed or may lead to an Assert Failure.
  There could be many different stacks seen for the AF but two
  scenarios have been seen during the exit processing of the
  thread. One is an Assert Failure for a bad block header and the
  other is a crash with a stack such as:
  
  (oninit) afstack
  (oninit) mt_ex_throw_sig
  (oninit) afsig_handler
  (Linux) <signal frame>
  (oninit) opfree
  (oninit) rscleanup
  (oninit) sqscb_cleanup
  (oninit) destroy_session
  (oninit) sq_exit
  (oninit) sqmain
  (oninit) spawn_thread
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * When readahead is active                                     *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * See Error Description                                        *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Upgrade to 12.10.xC6                                         *
  ****************************************************************
  

Problem conclusion

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

Applicable component levels

• RA10 PSN

     UP

• RA10 PSY

     UP

• RB10 PSN

     UP

• RB10 PSY

     UP

• RC10 PSN

     UP

• RC10 PSY

     UP