JRE 6 Update 18 b07 JVM showed four identical incidents of crashes:

 hs_err Date of crash elapsed time
 ----------------------------------------------------------------
 hs_err_pid17587.log Sun Mar 21 10:04:15 2010 13064 seconds
 hs_err_pid17296.log Sun Mar 21 11:43:36 2010 17634 seconds
 hs_err_pid17299.log Sun Mar 21 14:49:13 2010 28760 seconds
 hs_err_pid18174.log Sun Mar 21 14:55:02 2010 29835 seconds


% grep "# SIGSEGV" *.log
hs_err_pid17296.log:# SIGSEGV (0xb) at pc=0xfeb1938c, pid=17296, tid=38
hs_err_pid17299.log:# SIGSEGV (0xb) at pc=0xfeb1938c, pid=17299, tid=36
hs_err_pid17587.log:# SIGSEGV (0xb) at pc=0xfeb1938c, pid=17587, tid=39
hs_err_pid18174.log:# SIGSEGV (0xb) at pc=0xfeb1938c, pid=18174, tid=39
%


# A fatal error has been detected by the Java Runtime Environment:
#
# SIGSEGV (0xb) at pc=0xfeb1938c, pid=17587, tid=39
#
# JRE version: 6.0_18-b07
# Java VM: Java HotSpot(TM) Server VM (16.0-b13 mixed mode solaris-sparc )
# Problematic frame:
# V [libjvm.so+0x71938c]


In all 4 incidents the C2 compiler failed to compile the following code:

Current CompileTask:
C2:148% ! com.xxx.security.web.servlet.filters.CSPCookieFilter.getCSPCookieData(Ljavax/servlet/http/HttpServletRequest;Ljavax/servlet/http/HttpServletResponse;)Ljavax/servlet/http/HttpServletRequestWrapper; @ 31 (943 bytes)



 Stack trace:

 Stack: [0x56a80000,0x56b00000], sp=0x56afe220, free space=1f8feb1938ck
 Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
 V [libjvm.so+0x71938c] bool Node::rematerialize()const+0x0
 V [libjvm.so+0x1a5018] void PhaseChaitin::Register_Allocate()+0x534
 V [libjvm.so+0x1a7fd0] void Compile::Code_Gen()+0x3a0
 V [libjvm.so+0x40addc] Compile::Compile(ciEnv*,C2Compiler*,ciMethod*,int,bool,bool)+0xed4
 V [libjvm.so+0x1c1da8] void C2Compiler::compile_method(ciEnv*,ciMethod*,int)+0xb8
 V [libjvm.so+0x1c2c34] void CompileBroker::invoke_compiler_on_method(CompileTask*)+0xa04
 V [libjvm.so+0x23aadc] void CompileBroker::compiler_thread_loop()+0x664
 V [libjvm.so+0x7f8368] void JavaThread::thread_main_inner()+0x50
 V [libjvm.so+0x728448] java_start+0x234