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 initialize the data field properly. . To obtain the fix: Install build 20091127 or later
Temporary fix
Comments
APAR Information
APAR number
IZ64807
Reported component name
JAVA 5 JIT
Reported component ID
620500124
Reported release
500
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
JAVA 5 JIT
Fixed component ID
620500124
Applicable component levels
R500 PSN
UP
[{"Business Unit":{"code":"BU048","label":"IBM Software"},"Product":{"code":"SSC9HBA","label":"Just In Time (JIT) Compiler"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"5.0","Edition":"","Line of Business":{"code":"","label":""}}]
Document Information
Modified date:
17 December 2009