PH65174: IMS ABENDU4038 IN COBOL-JAVA MIX AFTER ACTIVATING XXNOSUBALLOC32BITMEM

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• AbendU4038 and CEE0802C Heap storage control information was
  damaged.
  After several tests it looks like it is not an issue of
  nosuballoc32bitmem but rather an issue of
  the filesize of //DD STDENV in IMS-Processing DFSJVM36.
  A one byte overlay occurs because IMS is moving too much
  data into the buffer allocated for the options string.
  Additional symptoms -
  abendU4087 CEE0802C on JVM startup in DFSJVM36
  

Local fix

• Shorten the input string.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * All users of IMS v15 with application programs running in a  *
  * Java environment                                             *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * While processing a JVM request, a storage overlay may occur, *
  * resulting in heap damage.                                    *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * INSTALL CORRECTIVE SERVICE FOR APAR/PTF                      *
  ****************************************************************
  In the C programming language, a null character is placed at the
  end of a String to denote the end of the string.  The strlen
  function returns the length of a string, not including this null
  character.  The strcpy function copies a string, including the
  null character, so that  the result of a copy is a valid string.
  Therefore, when using strlen to determine how much storage must
  be allocated to contain a string, it is necessary to add one
  additional byte to account for the null character.  In multiple
  places within the JVM processing modules, this was not done,
  resulting in a possible one byte storage overlay.
  
  Because malloc rounds the length up to the next multiple of
  eight to ensure doubleword alignment, the overlay is not
  guaranteed to occur.  In particular, the precise length of the
  Java options string can determine whether or not this issue
  appears.
  
  External symptom:  ABENDU4038.  It is possible for other
  symptoms to appear instead of this one, depending on the precise
  location of the overlaid storage.
  

Problem conclusion

• In modules DFSJVM00, DFSJVM36, and DFSJVM64, all occurrences of
  malloc that allocate insufficient storage are corrected to
  ensure that the correct amount of storage is allocated.  These
  occurrences include:
  1.  When allocating storage to hold the  JZOS_OUTPUT_ENCODING
  environment variable setting
  2.  In the Trim subroutine, which trims leading and trailing
  spaces
  3.  When allocating storage to hold the -Xoptionsfile setting
  
  Debug statements are added which will print a message in the
  application program job output indicating whether or not a
  storage overlay is detected.  These messages are only displayed
  if DEBUG=Y is specified, except in the case of the CreateJVM
  function, for which debug statements are printed whether or not
  DEBUG=Y is specified.
  

Temporary fix

• *********
  * HIPER *
  *********
  

Comments

APAR Information

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

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

  UO03516

Modules/Macros

• DFSJVM00 DFSJVM36 DFSJVM64
  

Fix information

• Fixed component name

  IMS V15

• Fixed component ID

  5635A0600

Applicable component levels

• R500 PSY UO03516

     UP25/06/07 P F506 ¢

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.