Fix (APAR):  PK66358

Status:  Fix

Release:  6.1

Operating System:  Linux,Linux pSeries,Windows

Supersedes Fixes:  

CMVC Defect:  133667

Byte size of APAR:  265335054

Date: 2008-07-15

Abstract:  A SIGSEGV or GPF is received when an object field in a newly constructed object is used.

Description/symptom of problem:  
PK66358 resolves the following problem:

ERROR DESCRIPTION:                                              
Error Message: A SIGSEGV/GPF is received when an object field in
a newly constructed object is used, e.g. when its fields are    
read, when a method is invoked on it, or when the garbage       
collector tries to process or collect it.                       
.                                                               
Stack Trace: N/A                                                
.                                                               

LOCAL FIX:                                                      
This issue can be worked around using the                       
-Xjit:disableExplicitNewInitialization option.                  

PROBLEM SUMMARY

USERS AFFECTED:
 IBM WebSphere Application Server V6.1 users

PROBLEM DESCRIPTION:
A SIGSEGV or GPF is received when an
object field in a newly constructed
object is used.

RECOMMENDATION:
None

The JIT compiler optimizes object allocations to make them
faster. The problem occurs when the a bug in this optimization
prevents a compiled method from fully initializing all object
fields in a new object. As a result, those uninitialized fields
can contain invalid addresses which, when accessed, cause the
JVM to crash.
This APAR ships an interim fix for IBM Software Developer's
Kit APARs IZ14883 and IZ20301. Please see APARs IZ14883 and
IZ20301 for additional technical details.










PROBLEM CONCLUSION:                                             
This defect will be fixed in:                                   
5.0.0 SR8                                                       
.                                                               
The JIT compiler has been updated to perform the optimization   
correctly.                                                      
.                                                               
To obtain the fix:                                              
Install build 20080510 or later                                 


Directions to apply fix:  
NOTE: Choose the:
1) Release the fix applies to
2) The Editions that apply
3) Delete the Editions & Methods that do not apply and this Note

Fix applies to Editions:
Release 6.0
__ Application Server (Express or BASE)
__ Network Deployment (ND)
__ WebSphere Business Integration Server Foundation (WBISF)
__ Edge Components
__ Developer
__ Extended Deployment (XD)

Install Fix to:
Method:
__ Application Server Nodes
__ Deployment Manager Nodes
__ Both

NOTE:
The user must:
* Have Administrative rights in Windows, or be the Actual Root User in a UNIX environments.
* Logged in with the same authority level when unpacking a fix, fix pack or refresh pack.
* Be at V6.0.2.2 or newer of the Update Installer. This can be checked by reviewing the level of the Update Installer in file <was_root>/updateinstaller/version.txt.

The Update Installer can be downloaded from the following link:
http://www.ibm.com/support/docview.wss?rs=180&uid=swg21205991

For detailed instructions to Extract the Update Installer see the following Technote:
http://www-1.ibm.com/support/docview.wss?rs=180&uid=swg21205400

1) Copy pak file directly to the maintenance directory

2) Shutdown WebSphere
Manually execute setupCmdLine.bat in Windows or . ./setupCmdLine.sh in Unix from the WebSphere instance that maintenance is being applied to.

3) Launch Update Installer

4) Enter the installation location of the WebSphere product you want to update.

5) Select the "Install maintenance package" operation.

6) Enter the file name of the maintenance package to install (pak file which was copied in the maintenance directory).

7) Install the maintenance package.

8) Restart WebSphere

Directions to remove fix:  
NOTE:
* The user must have Administrative rights in Windows, or be the Actual Root User in a UNIX environments.
* FIXES MUST BE REMOVED IN THE ORDER THEY WERE APPLIED
* DO NOT REMOVE A FIX UNLESS ALL FIXES APPLIED AFTER IT HAVE FIRST BEEN REMOVED
* YOU MAY REAPPLY ANY REMOVED FIX

Example: If your system has fix1, fix2, and fix3 applied in that order and fix2 is to be removed, fix3 must be removed first, fix2 removed, and fix3 re-applied.

1) Shutdown WebSphere
Manually execute setupCmdLine.bat in Windows or . ./setupCmdLine.sh in Unix from the WebSphere instance that uninstall is being run against.

2) Start Update Installer

3) Enter the installation location of the WebSphere product you want to remove the fix.

4) Select  "Uninstall maintenance package" operation.

5) Enter the file name of the maintenance package to uninstall (pak).

6) UnInstall maintenance package.

7) Restart WebSphere

Directions to re-apply fix:  
1) Shutdown WebSphere.

2) Follow the Fix instructions to apply the fix.

3) Restart WebSphere.



Additional Information: