The following test that fills Java heap with objects of different types, forces JVM to dump core and dumps heap from core file using jmap -dump:format=b fails because of jmap crash:
heapdump/JMapHeapCore
Here is the failure log:
Below 'Unexpected error' is actually expected - JVM is forced to dump core
time(cpu-seconds) unlimited
file(blocks) unlimited
coredump(blocks) unlimited
data(kbytes) unlimited
stack(kbytes) unlimited
lockedmem(kbytes) unlimited
memory(kbytes) unlimited
nofiles(descriptors) 1024
processes 16383
Starting eating heap.
#
# An unexpected error has been detected by Java Runtime Environment:
#
# SIGSEGV (0xb) at pc=0x0000002a9567400f, pid=18371, tid=182900688064
#
# Java VM: Java HotSpot(TM) 64-Bit Server VM (1.6.0-beta2-b82 compiled mode)
# Problematic frame:
# C [libpthread.so.0+0x700f] pthread_join+0xbf
#
# An error report file with more information is saved as hs_err_pid18371.log
#
# If you would like to submit a bug report, please visit:
# http://java.sun.com/webapps/bugreport/crash.jsp
#


Abort (core dumped)
Attaching to core core.18371 from executable /net/vmsqe.russia/export1/vmsqe/jdk-builds/latest/linux-amd64/bin/java, please wait...
#
# An unexpected error has been detected by Java Runtime Environment:
#
# SIGSEGV (0xb) at pc=0x0000002abec7e012, pid=18390, tid=1076017504
#
# Java VM: Java HotSpot(TM) 64-Bit Server VM (1.6.0-beta2-b82 mixed mode)
# Problematic frame:
# C [libsaproc.so+0x4012]
#
# An error report file with more information is saved as hs_err_pid18390.log
#
# If you would like to submit a bug report, please visit:
# http://java.sun.com/webapps/bugreport/crash.jsp
#
Abort (core dumped)
jmap exited with exit status 134
TEST FAILED

JMap hs_err file is attached.
See Comments for details on how to reproduce it.