IV12616: JNI APPLICATION USING SIGNALS HANDLERS CRASHES IBM LINUX JVM AFTER APPLYING IZ86774

APAR status

• Closed as program error.

Error description

• Error Message: A JNI application using its own signal
  handlers crashes IBM Linux JVM as below
  "main" J9VMThread:0x00007F2938032800,
  j9thread_t:0x00007F29380078F0,
  java/lang/Thread:0x00007F29306132F8, state:R, prio=5 (native
  thread ID:0x12D0, native priority:0x5, native
  policy:UNKNOWN)
  
  (native stack address range
  from:0x00007F293C702000,to:0x00007F293D103000, size:0xA01000)
  Native callstack:
  (0x00007F2937ECBF12 <OSB>libj9prt26.so+0x11f12<CSB>)
  (0x00007F2937ED934F <OSB>libj9prt26.so+0x1f34f<CSB>)
  (0x00007F2937ECBC5B <OSB>libj9prt26.so+0x11c5b<CSB>)
  (0x00007F2937ECBD57 <OSB>libj9prt26.so+0x11d57<CSB>)
  .....
  .
  Stack Trace: N/A
  .
  

Local fix

• Use JVM command line option -Xrs to disable IBM JVM signal
  handling
  

Problem summary

• IBM Linux JVM application is not able to register its native
  signal handler through JNI on top of the JVM's signal handler,
  instead it is being chained to JVM handler via libjsig.so. The
  application would experiance a crash in this scenario.
  

Problem conclusion

• This defect will be fixed in:
  6.0.1 SR2
  6.0.0 SR10 FP1
  7.0.0 SR1
  .
  IBM JVM has been updated to prevent the crash from occuring when
  a signal handler is registered through a JNI function.
  With this APAR the functionality provided in APAR IZ86774 on
  Linux platform will not work. In order to get the functionality
  in IZ86774 on Linux, set the env var LD_PRELOAD to point at
  libjsig.so, as documented in the JDK user guide
  http://publib.boulder.ibm.com/infocenter/javasdk/v6r0/topic/com.
  ibm.java.doc.user.lnx.60/user/native_signals.html
  

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

  JAVA CLASS LIBS

• Fixed component ID

  620700130

Applicable component levels

• R600 PSY

     UP

• R700 PSY

     UP