APAR status
Closed as program error.
Error description
Error Message: A SIGSEGV/GPF is raised in the JIT compiler module while a method is being compiled. The crashing function is TR_IA32VirtualGuardNOPInstruction::usesRegister(). The problem only occurs rarely on IA32. The problem may occur with both Java 5 and Java 6. . Stack Trace: j9jit23!TR_IA32VirtualGuardNOPInstruction::usesRegister+0x1d j9jit23!TR_X86CodeGenerator::pickNOPRegister+0x69 j9jit23!TR_X86CodeGenerator::generatePadding+0x4e j9jit23!TR_IA32BoundaryAvoidanceInstruction::generateBinaryEncod ing+0xc9 j9jit23!TR_Instruction::generateBinaryEncoding+0xe j9jit23!TR_X86CodeGenerator::doCodeGeneration+0x28e j9jit23!TR_CodeGenerator::generateCode+0x4b4 j9jit23!TR_Compilation::compile+0x22a j9jit23!TR_CompilationInfo::compile+0x2ed j9jit23!TR_CompilationInfo::wrappedCompile+0x3c6 J9PRT23!j9sig_protect+0x41 j9jit23!TR_CompilationInfo::compile+0x111 j9jit23!protectedCompilationThreadProc+0x1cf J9PRT23!j9sig_protect+0x41 j9jit23!compilationThreadProc+0xa5 J9THR23!thread_wrapper+0xbf .
Local fix
This issue can be avoided using the -Xjit:disableVirtualGuardNOPing option. Note that this option can incur a performance impact of approximately 4% to 10% (in the worst case), depending on the nature of the Java application.
Problem summary
The problem is caused by a defect in the JIT compiler which leaves a certain data field uninitialized. The value of the field is later used in the computation of a memory address. The incorrect memory address then causes a crash when it is accessed.
Problem conclusion
This defect will be fixed in: 5.0.0 SR12 6.0.0 SR8 . The JIT compiler has been updated to initialized the data field properly. . To obtain the fix: Install build 20091127 or later
Temporary fix
Comments
APAR Information
APAR number
IZ64833
Reported component name
JIT
Reported component ID
620700124
Reported release
600
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2009-11-11
Closed date
2009-12-17
Last modified date
2009-12-17
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Fix information
Fixed component name
JIT
Fixed component ID
620700124
Applicable component levels
R600 PSN
UP
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Document Information
Modified date:
17 December 2009