PI52383: A ZERO ADDRESS DETECTION REPORT FLAGGED FOUR INSTRUCTIONS IN GDDM CODE WHICH ACCIDENTALLY REFER TO LOW STORAGE.

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• A zero address detection report flagged four instructions
  in GDDM code which accidentally refer to low storage.
  .
  ADMDASCR checks whether fields overlap previous or following
  fields (two errors) without checking whether the other field
  exists, so it references low storage when checking the first or
  last (or only) field. The code needs to check whether the
  pointer to the next or previous field is non-zero before the
  relevant check.
  .
  ADMDGWI and ADMDGCL copy a second parameter to their own
  working storage for a function which only uses one parameter,
  so reference an uninitialized pointer which is usually going to
  be zero.  The code should not copy the second parameter for a
  function which only has one parameter.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: Users of GDDM 3.2 on z/VSE                   *
  ****************************************************************
  * PROBLEM DESCRIPTION: GDDM code accidentally references low   *
  *                      storage                                 *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  A Zero-Address Detection (ZAD) report on z/OS showed that
  commonly used GDDM code was accidentally referencing low
  storage.  This occurred when checking that screen fields did not
  overlap (because of a lack of a test for whether the next or
  previous field was present) and when copying parameters to local
  storage, when the relevant function did not use the parameter so
  its address was not set.  Although these errors are unlikely to
  cause a problem, there is a tiny theoretical risk that they
  could cause program checks or unpredictable output, as well as
  showing up on a ZAD report.  The relevant GDDM code is common to
  all platforms, so is being fixed on VSE as well.
  

Problem conclusion

• The code has been fixed to avoid the accidental references to
  low storage.
  

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:

  UI33230

Modules/Macros

• ADMDASCR ADMDGCL  ADMDGWI
  

Fix information

• Fixed component name

  GDDM/VSE V3

• Fixed component ID

  568605701

Applicable component levels

• R1EA PSY UI33230

     UP15/11/25 P E620

Fix is available

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