The jdk is 1.4.2_06

dbx>where                                                                    
current thread: t@13
=>[1] ContiguousSpace::oop_iterate(0x2fdfd8, 0xfcd7fe34, 0x734968, 0x0, 0xc7c00000, 0xc80cb698), at 0xfd4d0e24
  [2] ContiguousSpace::oop_iterate(0x2fdfd8, 0xfcd7fc88, 0xfcd7fe34, 0xfcd7fd50, 0x460ee0, 0xfd158e24), at 0xfd4d0ef8
  [3] GenerationOopIterateClosure::do_space(0xfcd7fd50, 0x2fdfd8, 0xfcd7fab8, 0x0, 0x1, 0x0), at 0xfd39b5ec
  [4] DefNewGeneration::space_iterate(0x2fd798, 0xfcd7fd50, 0x0, 0x2fd798, 0x0, 0x0), at 0xfd260248
  [5] Generation::oop_iterate(0x2fd798, 0xfcd7fe34, 0x0, 0x0, 0x0, 0x0), at 0xfd39a9c4
  [6] GenCollectedHeap::process_strong_roots(0xfd582000, 0xfcd7fe34, 0xfd5d5d34, 0x1, 0x1, 0x0), at 0xfd224a20
  [7] CMSParRemarkTask::work(0xfa1ffb74, 0x1, 0x0, 0x4000, 0x4194, 0x1), at 0xfd370c54
  [8] GangWorker::run(0x2fbab0, 0xd, 0x40, 0x0, 0x40, 0x0), at 0xfd4fdeb0
  [9] _start(0x2fbab0, 0x0, 0x0, 0x0, 0x0, 0x0), at 0xfd264648

dbx>where -l
current thread: t@13
=>[1] libjvm.so:ContiguousSpace::oop_iterate(0x2fdfd8, 0xfcd7fe34, 0x734968, 0x0, 0xc7c00000, 0xc80cb698), at 0xfd4d0e24
  [2] libjvm.so:ContiguousSpace::oop_iterate(0x2fdfd8, 0xfcd7fc88, 0xfcd7fe34, 0xfcd7fd50, 0x460ee0, 0xfd158e24), at 0xfd4d0ef8
  [3] libjvm.so:GenerationOopIterateClosure::do_space(0xfcd7fd50, 0x2fdfd8, 0xfcd7fab8, 0x0, 0x1, 0x0), at 0xfd39b5ec
  [4] libjvm.so:DefNewGeneration::space_iterate(0x2fd798, 0xfcd7fd50, 0x0, 0x2fd798, 0x0, 0x0), at 0xfd260248
  [5] libjvm.so:Generation::oop_iterate(0x2fd798, 0xfcd7fe34, 0x0, 0x0, 0x0, 0x0), at 0xfd39a9c4
  [6] libjvm.so:GenCollectedHeap::process_strong_roots(0xfd582000, 0xfcd7fe34, 0xfd5d5d34, 0x1, 0x1, 0x0), at 0xfd224a20
  [7] libjvm.so:CMSParRemarkTask::work(0xfa1ffb74, 0x1, 0x0, 0x4000, 0x4194, 0x1), at 0xfd370c54
  [8] libjvm.so:GangWorker::run(0x2fbab0, 0xd, 0x40, 0x0, 0x40, 0x0), at 0xfd4fdeb0
  [9] libjvm.so:_start(0x2fbab0, 0x0, 0x0, 0x0, 0x0, 0x0), at 0xfd264648

The events that took place before it crashes

/net/tsg.singapore/export/calls/ftp/pub/10571075/20041129/logs-conf/ccfInstance/server.log

[29/Nov/2004:03:06:03] WARNING ( 7332): CORE3283: stderr: 30861.284: [CMS-concurrent-mark-start]
[29/Nov/2004:03:06:04] WARNING ( 7332): CORE3283: stderr: 30862.130: [CMS-concurrent-mark: 0.831/0.846 secs]
[29/Nov/2004:03:06:04] WARNING ( 7332): CORE3283: stderr: 30862.130: [CMS-concurrent-preclean-start]
[29/Nov/2004:03:06:04] WARNING ( 7332): CORE3283: stderr: 30862.168: [CMS-concurrent-preclean: 0.037/0.037 secs]
[29/Nov/2004:03:06:04] FATAL ( 7332): CORE3260: Server crash detected (signal SIGSEGV)
[29/Nov/2004:03:06:04] INFO ( 7332): CORE3262: Crash occurred in function sysThreadAvailableStackWithSlack from module /usr/j2se/jre/lib/sparc/server/libjvm.so
[29/Nov/2004:03:08:10] SEVERE ( 7331): CORE3107: Child process closed admin channel
[29/Nov/2004:03:08:13] INFO ( 6069): CORE3016: daemon is running as super-user

The java flags
==============

    <jvm-options>-Djava.security.policy=/var/opt/SUNWappserver7/domains/domain1/ccfInstance/config/server.policy</jvm-options>
    <jvm-options>-Djava.security.auth.login.config=/var/opt/SUNWappserver7/domains/domain1/ccfInstance/config/login.conf</jvm-options>
    <jvm-options>-Djava.util.logging.manager=com.iplanet.ias.server.logging.ServerLogManager</jvm-options>
    <jvm-options>-Dcom.sun.aas.configRoot=/etc/opt/SUNWappserver7</jvm-options>
    <jvm-options>-Dcom.sun.aas.imqLib=/usr/share/lib/imq</jvm-options>
    <jvm-options>-Dcom.sun.aas.imqBin=/usr/bin</jvm-options>
    <jvm-options>-Dcom.sun.aas.webServicesLib=/usr/share/lib</jvm-options>
    <jvm-options>-Dorg.xml.sax.parser=org.xml.sax.helpers.XMLReaderAdapter</jvm-options>
    <jvm-options>-Dorg.xml.sax.driver=org.apache.crimson.parser.XMLReaderImpl</jvm-options>
    <jvm-options>-Dcom.sun.jdo.api.persistence.model.multipleClassLoaders=reload</jvm-options>
    <jvm-options>-Dsun.rmi.dgc.server.gcInterval=3600000</jvm-options>
    <jvm-options>-verbose:gc -XX:+PrintGCTimeStamps -XX:+PrintGCDetails</jvm-options>
    <jvm-options>-XX:+DisableExplicitGC</jvm-options>
    <jvm-options>-XX:+UseConcMarkSweepGC -XX:+CMSParallelRemarkEnabled</jvm-options>
    <jvm-options>-XX:MaxTenuringThreshold=0 -XX:CMSInitiatingOccupancyFraction=60</jvm-options>
    <jvm-options>-XX:PermSize=256M -XX:MaxPermSize=512M</jvm-options>
    <jvm-options>-Xms256m -Xmx256m ��~@~SXX:NewSize=16m</jvm-options>
    <jvm-options>-XX:+UseParNewGC -XX:ParallelGCThreads=3</jvm-options>

Suspecting threads ..... 

-----------------  lwp# 13 / thread# 13  --------------------
 fd4d0e24 void ContiguousSpace::oop_iterate(OopClosure*) (2fdfd8, fcd7fe34, 734968, 0, c7c00000, c80cb698) + 38
 fd4d0ef8 void ContiguousSpace::oop_iterate(MemRegion,OopClosure*) (2fdfd8, fcd7fc88, fcd7fe34, fcd7fd50, 460ee0, fd158e24) + a0
 fd39b5ec void GenerationOopIterateClosure::do_space(Space*) (fcd7fd50, 2fdfd8, fcd7fab8, 0, 1, 0) + 2c
 fd260248 void DefNewGeneration::space_iterate(SpaceClosure*,int) (2fd798, fcd7fd50, 0, 2fd798, 0, 0) + 14
 fd39a9c4 void Generation::oop_iterate(OopClosure*) (2fd798, fcd7fe34, 0, 0, 0, 0) + 4c
 fd224a20 void GenCollectedHeap::process_strong_roots(int,int,int,GenCollectedHeap::ClassScanningOption,OopsInGenClosure*,OopsInGenClosure*) (fd582000, fcd7fe34, fd5d5d34, 1, 1, 0) + 280
 fd370c54 void CMSParRemarkTask::work(int) (fa1ffb74, 1, 0, 4000, 4194, 1) + 1f0
 fd4fdeb0 void GangWorker::run() (2fbab0, d, 40, 0, 40, 0) + ac
 fd264648 _start   (2fbab0, 0, 0, 0, 0, 0) + 134
 fe0257b4 _lwp_start (0, 0, 0, 0, 0, 0)  
-----------------  lwp# 14 / thread# 14  --------------------
 fd3a8f88 int instanceKlass::oop_oop_iterate_nv(oopDesc*,Par_MarkRefsIntoAndScanClosure*) (1, d0b6a938, fc77fe34, fc77fe28, 44b8b4, fd3ad710) + b8
 fd3ad704 int instanceRefKlass::oop_oop_iterate_nv(oopDesc*,Par_MarkRefsIntoAndScanClosure*) (d7c201b8, d0b6a938, fc77fe34, fc77fe28, 1, 0) + c
 fd370d18 void CMSParRemarkTask::work(int) (fa1ffb74, 0, 0, 4000, 4194, 1) + 2b4
 fd4fdeb0 void GangWorker::run() (2fc420, e, 40, 0, 40, 0) + ac
 fd264648 _start   (2fc420, 0, 0, 0, 0, 0) + 134
 fe0257b4 _lwp_start (0, 0, 0, 0, 0, 0)  
-----------------  lwp# 15 / thread# 15  --------------------
 fe0259b0 lwp_yield (2fcd90, 0, 0, 0, 44b8b4, fd3ad710) + 8
 fd4d95f0 int ParallelTaskTerminator::offer_termination() (fa1ffb94, 2, d0db0, fc67fe28, 1, 0) + 40
 fd370d28 void CMSParRemarkTask::work(int) (fa1ffb74, 2, 0, 4000, 4194, 1) + 2c4 
 fd4fdeb0 void GangWorker::run() (2fcd90, f, 40, 0, 40, 0) + ac
 fd264648 _start   (2fcd90, 0, 0, 0, 0, 0) + 134
 fe0257b4 _lwp_start (0, 0, 0, 0, 0, 0)
-----------------  lwp# 16 / thread# 16  --------------------
 fdf9f95c ___lwp_cond_wait (2fba90, 2fba78, 0, 27df30, 4b80e0, ff00) + 8 
 fd193e64 int Monitor::wait(int,long) (2fba48, 0, 0, 4000, 4194, 220d20) + 104
 fd4fdc48 void WorkGang::run_task(AbstractGangTask*) (2fba18, fa1ffb74, fd566f4c, 1, fa1ffb94, fd582000) + 6c
 fd3711a8 void CMSCollector::do_remark_parallel() (385700, fd5386a6, 1, 0, 0, 6) + d8
 fd37097c void CMSCollector::checkpointRootsFinalWork(int,int,int) (385700, 1, 0, 0, 290710, fd1e09b4) + 1a4
 fd373118 void CMSCollector::do_CMS_operation(CMSCollector::CMS_op_type) (fd5c1238, 1, 5000, 5100, 5000, 0) + 2d4
 fd373418 int CMSCollector::stop_world_and_do(CMSCollector::CMS_op_type) (385700, 1, fd538647, 3fa3238a, 2efeac54, 0) + 118
 fd36d0d4 void CMSCollector::collect_in_background(int) (fd538647, fd36cb80, fd5c118c, fd5c102c, 4194, 0) + 514
 fd3771ec void ConcurrentMarkSweepThread::run() (3c00, 4c00, 5400, 5614, 4000, 4014) + 438
 fd264648 _start   (3e5b50, 0, 0, 0, 0, 0) + 134
 fe0257b4 _lwp_start (0, 0, 0, 0, 0, 0)
-----------------  lwp# 17 / thread# 17  --------------------