PQ76129: AppServer jvm crashes in libjitc.a in a bytecode_optimization native method.

 A fix is available

***SUPERCEDED*** 1.3.1 Java SDK, Java Tech Edition for WebSphere v5



APAR status
Closed as program error.

Error description
External Symptoms:
AppServer restarts.  The tracefile shows that the AppServer goes
from Started to Restarting in the tracefile.  This is message
ADMS0028I: Restarting server: AppServerName
.
javacore files and/or core files are generated on the failing
system.  The java stack trace of the failing thread will look
like this (this is jcore output):
SIGSEGV raised in libjitc.a


(ip)=D360A618  at  libjitc.a  .NullCheck_Init_DataFlow_V + 0878
    unwinding (old_sp=7F8DB56C old_ip=D360A618)
(ip)=D36141F4  at  libjitc.a  .Init_DataFlow + 0034
    unwinding (old_sp=7F8DB5AC old_ip=D36141F4)
(ip)=D360E664  at  libjitc.a  .dataflow_nullcheck + 01B4
    unwinding (old_sp=7F8DC02C old_ip=D360E664)
(ip)=D35F48F0  at  libjitc.a  .bytecode_optimization_driver +
0230
    unwinding (old_sp=7F8DC08C old_ip=D35F48F0)
(ip)=D35F742C  at  libjitc.a  .bytecode_optimization + 0168
    unwinding (old_sp=7F8DC0CC old_ip=D35F742C)
(ip)=D3557360  at  libjitc.a  .JITGenNativeCode + 029C
    unwinding (old_sp=7F8DC25C old_ip=D3557360)
(ip)=D357D994  at  libjitc.a  .jit_compile_a_method_locked +
041C
Local fix
unwinding (old_sp=7F8DC86C old_ip=D357D994)
(ip)=D357EF44  at  libjitc.a  .jit_compiler_entry + 0620
    unwinding (old_sp=7F8DCB0C old_ip=D357EF44)
(ip)=D357F4A4  at  libjitc.a  ._jit_fast_compile + 0350
    unwinding (old_sp=7F8DCBCC old_ip=D357F4A4)
.
This was found in jdk ca131w-20030425.
.
This is SOV defect,
It is fixed in ca131w-?????
LOCAL FIX:
1. Disable the jit entirely
2. export JITC_COMPILEOPT=NQNULLCHECK{class}{method} to skip the
 NQNULLCHECK jit process for the specified class and method.
Which method to skip this for needs to be determined by an
analysis of the Java stack trace of the failing method.
Problem summary
****************************************************************
* USERS AFFECTED: All WebSphere Application Server 4.0 users   *
*                 of IBM Developer Kit prior to verion         *
*                 ca131-20021107 .                             *
****************************************************************
* PROBLEM DESCRIPTION: The application server jvm crashes in   *
*                      libjitc.a in the bytecode_optimization  *
*                      native method.                          *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
The tracefile shows that the application server goes from
Started to Restarting.  The message is:
ADMS0028I: Restarting server: AppServerName .

Java core files are generated on the failing system.  The Java
stack trace of the failing thread will look
like this (this is jcore output):

The java call stack for this crash is
(ip)=D360A618  at  libjitc.a  .NullCheck_Init_DataFlow_V + 0878
    unwinding (old_sp=7F8DB56C old_ip=D360A618)
(ip)=D36141F4  at  libjitc.a  .Init_DataFlow + 0034
    unwinding (old_sp=7F8DB5AC old_ip=D36141F4)
(ip)=D360E664  at  libjitc.a  .dataflow_nullcheck + 01B4
    unwinding (old_sp=7F8DC02C old_ip=D360E664)
(ip)=D35F48F0  at  libjitc.a  .bytecode_optimization_driver +
    0230  unwinding (old_sp=7F8DC08C old_ip=D35F48F0)
(ip)=D35F742C  at  libjitc.a  .bytecode_optimization + 0168
    unwinding (old_sp=7F8DC0CC old_ip=D35F742C)
(ip)=D3557360  at  libjitc.a  .JITGenNativeCode + 029C
    unwinding (old_sp=7F8DC25C old_ip=D3557360)
(ip)=D357D994  at  libjitc.a  .jit_compile_a_method_locked +
    041C unwinding (old_sp=7F8DC86C old_ip=D357D994)
(ip)=D357EF44  at  libjitc.a  .jit_compiler_entry + 0620
    unwinding (old_sp=7F8DCB0C old_ip=D357EF44)
(ip)=D357F4A4  at  libjitc.a  ._jit_fast_compile + 0350
    unwinding (old_sp=7F8DCBCC old_ip=D357F4A4)
The method being jit compiled is a jsp .
Problem conclusion
This is a IBM Developer Kit defect. JTC has provided a
JITC_COMPILEOPT option that can be set to try to prevent the
core from occurring in production.  The option to set is :

   export JITC_COMPILEOPT=NQNULLCHECK{*}{_jspService}

This can be added to startupServer.sh or it can added to the
environment variables of the specific AppServer that is
crashing. The JTC believes that it is the NULLCHECK part of
the jit that is crashing & skipping this step in the jit
processing for the _jspService method will prevent the IBM
Development Kit from crashing in production.
Alternatively, upgrading the IBM Development Kit to
ca131-20030425 seems to fix this problem.
Temporary fix Comments
APAR information
APAR number PQ76129
Reported component name WEBSPHERE AE AI
Reported component ID 5630A2200
Reported release 400
Status CLOSED PER
PE NoPE
HIPER NoHIPER
Submitted date 2003-07-08
Closed date 2003-08-13
Last modified date 2003-08-13

APAR is sysrouted FROM one or more of the following:

APAR is sysrouted TO one or more of the following:

Modules/Macros
JDK          

SRLS

Fix information

Applicable component levels
R400 PSY    UP


Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server > General
Operating system(s):
Software version: 400
Software edition:
Reference #: PQ76129
IBM Group: Software Group
Modified date: Aug 13, 2003