IJ27400: AOT FIELD OFFSET OFF BY N BYTES

APAR status

• Closed as program error.

Error description

• Error Message: Segmentation fault, vmState=0x00000000 when
  conflicting class versions are found in cache (see
  https://github.com/eclipse/openj9/issues/9710)
  .
  Stack Trace: Unhandled exception
  Type=Segmentation error vmState=0x00000000
  J9Generic_Signal_Number=00000018 Signal_Number=0000000b
  Error_Value=00000000 Signal_Code=00000001
  Handler1=00007F9E1F2FDED0 Handler2=00007F9E1EBEF9F0
  InaccessibleAddress=0000000000000008
  RDI=0000000000C08618 RSI=0000000000000008 RAX=0000000000000850
  RBX=00007F9DBE5DF187
  RCX=0000000000C08550 RDX=0000000000000008 R8=0000000000000000
  R9=00000000FD921428
  R10=00000000FD921428 R11=00000000000000FF R12=0000000000C08548
  R13=0000000002C8F4D0
  R14=00007F9DBE5DF18C R15=00007F9DF97B29D0
  RIP=00007F9E1F285ADB GS=0000 FS=0000 RSP=00007F9DF97B2650
  EFlags=0000000000010202 CS=0033 RBP=0000000000000001
  ERR=0000000000000004
  TRAPNO=000000000000000E OLDMASK=0000000000000000
  CR2=0000000000000008
  xmm0 0000000000000006 (f: 6.000000, d: 2.964394e-323)
  xmm1 00000000fdd32bb8 (f: 4258475008.000000, d: 2.103966e-314)
  xmm2 00007f9df97b2a00 (f: 4185598464.000000, d: 6.932555e-310)
  xmm3 00007f9df97b2a00 (f: 4185598464.000000, d: 6.932555e-310)
  xmm4 43e0000000000000 (f: 0.000000, d: 9.223372e+18)
  xmm5 000000003d01e9e2 (f: 1023535616.000000, d: 5.056938e-315)
  xmm6 000000004aef5a72 (f: 1257200256.000000, d: 6.211394e-315)
  xmm7 0000000000000000 (f: 0.000000, d: 0.000000e+00)
  xmm8 0000000047e38180 (f: 1206092160.000000, d: 5.958887e-315)
  xmm9 000000003f6451c0 (f: 1063539136.000000, d: 5.254582e-315)
  xmm10 42b255f50e94e148 (f: 244638016.000000, d: 2.016039e+13)
  xmm11 00000000411567aa (f: 1091921792.000000, d: 5.394811e-315)
  xmm12 000000004252ece6 (f: 1112730880.000000, d: 5.497621e-315)
  xmm13 3f847ae147ae147b (f: 1202590848.000000, d: 1.000000e-02)
  xmm14 4014000000000000 (f: 0.000000, d: 5.000000e+00)
  xmm15 414f79ffb262a5ad (f: 2992809472.000000, d: 4.125695e+06)
  Module=/opt/java/openjdk/lib/compressedrefs/libj9vm29.so
  Module_base_address=00007F9E1F26B000
  Target=2_90_20200416_574 (Linux 4.15.0-1082-azure)
  CPU=amd64 (4 logical CPUs) (0x3e92f0000 RAM)
  ----------- Stack Backtrace -----------
  (0x00007F9E1F285ADB <OSB>libj9vm29.so+0x1aadb<CSB>)
  (0x00007F9E1F27DB30 <OSB>libj9vm29.so+0x12b30<CSB>)
  (0x00007F9E1F339B02 <OSB>libj9vm29.so+0xceb02<CSB>)
  ---------------------------------------
  .
  

Local fix

• Destroy the Shared Class Cache.
  

Problem summary

• If some class, that is cached in the Shared Classes Cache, is
  modified on disk, the JVM will invalidate the cached class and
  add the new one (if there is space). The JIT compiler missed a
  validation check for hierarchy of the class of the method being
  compiled. This resulted in invalid AOT code if the hierarchy
  changed.
  

Problem conclusion

• The JIT Compiler has been updated to perform the necessary
  check. (see https://github.com/eclipse/openj9/pull/10159)
  .
  This APAR will be fixed in the following Java Releases:
     8    SR6 FP16  (8.0.6.16)
  .
  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 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