PH08211: Looping at some BLOCK-EXIT hooks due to bad branches when RULES(NOLAXRETURN)

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• When using RULES(NOLAXRETURN) with the TEST(HOOK) option, the
  compiler may generate branch instructions on either side of the
  BLOCK-EXIT hook branch that branch to the hook, creating a tight
  loop once control reaches that point.
  
  A ABENDS322 symptom dump will show unconditional branches on
  either side of the EXECUTE instruction for the hook which have
  the same branch offset (41E in the example), which can be shown
  to be the offset of the EXECUTE.
  
      DATA AT PSW  0F601594 - 441E4400  C1B447F0  441E4400
      refactored        [47F0]441E 4400C1B4*47F0441E
                        B          EX hook  B
  

Local fix

• Use RULES(LAXRETURN)
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: users who specify both the TEST and the      *
  *                 RULES(NOLAXRETURN) options                   *
  ****************************************************************
  When these options were specified and the program
  contained ENTRY statements, the code generated could
  lead to an infinite loop
  

Problem conclusion

• The code generation problem has been fixed
  

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:

  UI61206

Modules/Macros

• IBMZINN
  

Fix information

• Fixed component name

  ENT PL/I FOR ZO

• Fixed component ID

  5655PL500

Applicable component levels

• R520 PSY UI61206

     UP19/02/08 P F902

Fix is available

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