APAR status
Closed as program error.
Error description
Error Message: A SIGSEGV occurs while JIT compiling a method. . Stack Trace: {libj9jit27.so}{TR_Instruction::useRegister(TR_Register*,bool)} {libj9jit27.so}{generateTrg1Src1Imm2Instruction(TR_CodeGenerator *,TR_PPCOpCodes,TR_Node*,TR_Register*,TR_Register*,int,long,TR_I nstruction*)} {libj9jit27.so}{simplifyANDRegImm(TR_Node*,TR_Register*,TR_Regis ter*,int,TR_CodeGenerator*,TR_Node*)} {libj9jit27.so}{TR_PPCTreeEvaluator::iandEvaluator(TR_Node*,TR_C odeGenerator*)} {libj9jit27.so}{TR_CodeGenerator::evaluate(TR_Node*)} {libj9jit27.so}{TR_PPCTreeEvaluator::bstoreEvaluator(TR_Node*,TR _CodeGenerator*)} {libj9jit27.so}{TR_CodeGenerator::evaluate(TR_Node*)} . The problem can only happen on POWER hardware (AIX and LinuxPPC). The issue can occur in Java 7.1 and in Java8 prior to 8.0.5.37. With 8.0.5.37 an optimization was disabled which is need to encounter this issue. The fix for this issue will be included in Java8 in case this optimization is enabled in the future or some new feature is added that makes use of byte operations. This issue cannot occur on X86 or zSeries hardware.
Local fix
The problem can be avoid by disabling the only known optimization that generates byte-subtraction code: -Xjit:disableCFGSimplification
Problem summary
The POWER JIT code generator was not prepared to handle a few byte operations because bytes in Java code are promoted to integers. One rarely exercised JIT optimization would produce a byte-subtraction which would cause the JIT compiler to crash at code generation time.
Problem conclusion
The JIT compilers POWER code generator was modified so that it could handle byte addition and subtraction operations. . This APAR will be fixed in the following Java Releases: 7 R1 SR4 FP55 (7.1.4.55) 8 SR6 (8.0.6.0) . Contact your IBM Product's Service Team for these Service Refreshes and Fix Packs. For those running stand-alone, information about the available Service Refreshes and Fix Packs can be found at: https://www.ibm.com/developerworks/java/jdk/
Temporary fix
Comments
APAR Information
APAR number
IJ18450
Reported component name
JIT
Reported component ID
620700124
Reported release
130
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2019-08-19
Closed date
2019-09-09
Last modified date
2019-09-09
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
[{"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":"130","Edition":"","Line of Business":{"code":"","label":""}}]
Document Information
Modified date:
09 September 2019