LI77140: STACK DEALLOCATE AT -O3 CAUSES CORRUPT STACK

April 2013 Update for XL C/C++ for Linux, V12.1
XL C/C++ for Linux Fix Pack 8 (October 2015 Update) for 12.1
December 2012 Update for XL C/C++ for Linux, V12.1
XL C/C++ for Linux Fix Pack 4 (October 2013 Update) for 12.1
XL C/C++ for Linux Fix Pack 5 (December 2013 Update) for 12.1
XL C/C++ for Linux Fix Pack 6 (February 2014 Update) for 12.1
XL C/C++ for Linux Fix Pack 7 (May 2014 Update) for 12.1

APAR status

• Closed as program error.

Error description

• Compiling at -O3 is causing a function's stack frame to be
  deallocated before the end of the function.  Local stack
  variables that are still live may be used invalidly, and writing
  to them might cause stack corruption.
  

Local fix

• - Do not use optimization
  

Problem summary

• PROBLEM DESCRIPTION:
  Arithmetic on address values leads to an optimization error.
  
  USERS AFFECTED:
  Users performing arithmetic on address values which otherwise
  do not appear to be stored.  This mainly affects buffers
  allocated as objects on the stack or statics with no linkage.
  

Problem conclusion

• Code analysis was modified to consider operands of arithmetic
  operations.  The issue is now resolved.
  

Temporary fix

Comments

APAR Information

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

  IV23847

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

Fix information

• Fixed component name

  XL C/C++ FOR LI

• Fixed component ID

  5725C7300

Applicable component levels

• RC10 PSN IV23847

     UP06/09/13