PI16059: RECEIVING DFHSO0001 ABEND 0C4 IN DFHSOCK AT OFFSET X'24C4'.

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• A situation occurred and all the IPIC connections started
  releasing.  At this time several of the CICS regions received
  DFHSO0001 0c4 in DFHSOCK at offset x'24C4'.  Looking at the
  Trace we can see that TASK CISR suffers the abend due to the
  following.
  .
  0203 SOCK  *EXC* - RECOVERY_ENTERED
                     FUNCTION(SEND_SSL_DATA)
                     RESPONSE(EXCEPTION)
                     REASON(CONNECTION_CLOSED)
                     SEND_BUFFER
                     (300D7178 , 00000000 , 0000012D)
  .
  Backing up we see this exception is issued due to the following:
  .
  0004 LMLM EXIT - FUNCTION(UNLOCK)
                   RESPONSE(EXCEPTION)
                   REASON(LOCK_TOKEN_NOT_FOUND)
  .
  Backing up from here to see what happened to the token we
  see that TASK CIST deleted the token.
  .
  0003 LMLM ENTRY - FUNCTION(DELETE_LOCK)
                    LOCK_TOKEN(2F8E2260)
  .
  This problem is caused by an interleaving of CISR and CIST
  tasks.  The CISR task detects that a socket being used by
  an IPCONN has been unexpectedly closed.  CISR attaches CIST
  to terminate the IPCONN.
  .
  Data is still arriving on other sockets so CISR is busy
  using the IPCONN at the same time as CIST is trying to
  terminate it.  Eventually CIST has closed 3 of the sockets
  and is about to close the final one when a PING request
  arrives on that socket.  CISR receives the PING and begins
  to send the response because the associated web session has
  not yet been closed by CIST.
  .
  When the PING response is sent CISR finds that the connection
  has now been closed by the other system.  It attempts to
  issue message DFHSO1000 for this failure.  That causes CISR
  to lose control switching to QR and also waiting for the TD
  lock.  During this period CIST closes the socket and
  freemains its storage.
  .
  After issuing the message CISR returns to DFHSOCK
  SEND_SSL_DATA routine where it tries to set the gsk_closed
  flag.  This flag lives in the SOCKSSL area which has been
  freed and its address set to null.  This causes the 0C4
  trying to manipulate a bit in low core.
  
  Additional Symptom(s) Search Keyword(s): KIXREVDAM
  ABEND0C4 ABENDS0C4 MSGDFHSO0001
  

Local fix

• n/a
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All                                          *
  ****************************************************************
  * PROBLEM DESCRIPTION: MSGDFHSO0001 dumpcode SO0001 at end of  *
  *                      DFHSOCK SEND_SSL_DATA call when socket  *
  *                      is closed.                              *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  The IPIC system task - CISR is issuing an SSL socket send of a
  PING response from a partner CICS system. In parallel with this
  send, the IPIC sockets for the connection are closed by the
  partner. This error triggers the attach of a CIST task to
  terminate the IPCONN.
  The socket send fails with a SOCK_CONNECTION_CLOSED EXCEPTION.
  The completion of this send is delayed when message DFHSO1000
  is issued and by the switch back to the S8 TCB used for SSL.
  In parallel with this, the CIST task closes and deletes the
  socket which has just been used for the socket send.
  Eventually, CISR resumes processing in DFHSOCK SEND_SSL_DATA.
  SEND_SSL_DATA detects the socket send exception and attempts to
  set a state flag in the SSL extension of the socket object.
  However, the socket and the SSL extension have been removed from
  the active socket collection and freemained. The SEND_SSL_DATA
  routine program checks because the pointer to the SSL extension
  was zeroed when the socket object was freed. This causes a
  DFHSO0001 severe error and SO0001 system dump.
  

Problem conclusion

• DFHSOCK routine SEND_SSL_DATA has been changed to verify that
  the socket is still valid before attempting to update any
  socket state information on completion of the send.
  

Temporary fix

• FIX AVAILABLE BY PTF ONLY
  

Comments

APAR Information

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

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

  UI18779

Modules/Macros

• DFHSOCK
  

Fix information

• Fixed component name

  CICS TS Z/OS V5

• Fixed component ID

  5655Y0400

Applicable component levels

• R800 PSY UI18779

     UP14/06/20 P F406

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.