PM66034: CICS TS 4.2 PROCESSING DLI REQUEST GOES INTO TIGHT LOOP IN DFHXFP - TRANSFORMER 4 CODE

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• You are running CICS Transaction Server 4.2 and your region
  hangs and needs to be recycled.
  From a dump taken at the time of the hang we find CICS
  is in a tight loop.  System trace shows a constant psw
  address for the QR tcb pointing to offset x'5DE' into
  module DFHXFP.   The instruction at this offset is a
  hard branch to R14-  BCR   X'F',R14.
  From the registers under the TCB we find that R14 points
  to this branch instruction at offset x'5DE' causing the
  tight loop.
  The stack shows it is processing a DLI request.
  The last trace entry in CICS is:
  D900 XFP   ENTRY - TRANSFORMER_4 PLIST_ADDR(21565180)
  FUNCTION(4002)
  .
  R14 contained an incorrect address and was loaded from field
  XFRRESRE. Changes were made to DFHXFP to use relative
  addressing.
  The instruction setting up this field XFRRESRE is an
  LA- Load Address and should be a LARL - Load Address Relative
  Long.
  Addiional symptoms: hang hung looping DL1 transformer 4 xform4
                      resumption address
  KIXREVEPH
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICS users.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: CICS region hangs and needs to be       *
  *                      recycled while processing a DLI         *
  *                      request using LU62.                     *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  CICS issue a DLI request cross LU62 connection to remote
  CICS region. DFHXFP transformer1 is used to prepare the
  request. In DFHXFP, DLSC0100 used R9 as a based register.
  A call to TRMSTG is issued to getmain some terminal storage.
  TRMSTG calls LU6ATT00 to build an ATTACH FMH.
  In LU6ATT00 if the TCTTE session is LU62, ISSUE-ATTACH call
  is issued and at last LU6ATT00 returned to TRMSTG which
  return back to DLSC0100 with R9 pointing at label LU6ATT04.
  At the end of DLSC0100 XFRRESRE is initialized with address
  of original offset DLSC0400 basing on DLSC0100 plus updated
  R9 point to LU6ATT04.
  XFRRESRE should have been pointer at label DLSC0400 but get
  loaded with the address of XFP +x'5DE' which is the  'BR RE'.
  A response is received and DFHISP call DFHXFP transformer 4
  to unwrap the response. R9 and RE are restored with
  XFRRESR9 and XFRRESRE. Branch to RE resulting in the tight
  loop.
  If there is RUNAWAY time set, task will be abended while
  RUNAWAY timeout from tight loop.
  

Problem conclusion

• DFHXFDL is changed to use LARL instead of LA in DLSC0170.
  

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:

  UK80802

Modules/Macros

•    DFHXFP   DFHXFQ
  

Fix information

• Fixed component name

  CICS TS Z/OS V4

• Fixed component ID

  5655S9700

Applicable component levels

• R700 PSY UK80802

     UP12/08/10 P F208

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.