For 32-bit JVM on linux jstack -l shows '????????' in stacktrace where system functions are expected:
$JAVA_HOME/bin/java Test &
kill -11 $!
$JAVA_HOME/bin/jstack -l -m $JAVA_HOME/bin/java ./core
Attaching to core ./core.2097 from executable jdk1.6.0_60/bin/java, please wait...
Debugger attached successfully.
Client compiler detected.
JVM version is 20.60-b01
Finding object size using Printezis bits and skipping over...
Deadlock Detection:
No deadlocks found.
----------------- 2098 -----------------
0xb5264924 * Test.main(java.lang.String[]) bci:0 line:3 (Interpreted frame)
0xb5256366 <StubRoutines>
0xb7866701 _ZN9JavaCalls11call_helperEP9JavaValueP12methodHandleP17JavaCallArgumentsP6Thread + 0x1c1
0xb79a1a18 _ZN2os20os_exception_wrapperEPFvP9JavaValueP12methodHandleP17JavaCallArgumentsP6ThreadES1_S3_S5_S7_ + 0x18
0xb786652f _ZN9JavaCalls4callEP9JavaValue12methodHandleP17JavaCallArgumentsP6Thread + 0x2f
0xb789a3a4 _Z17jni_invoke_staticP7JNIEnv_P9JavaValueP8_jobject11JNICallTypeP10_jmethodIDP18JNI_ArgumentPusherP6Thread + 0x124
0xb7889cec jni_CallStaticVoidMethod + 0x14c
0x08049b98 JavaMain + 0x2c8
0x00527832 start_thread + 0xe2
Locked ownable synchronizers:
- None
----------------- 2099 -----------------
0xb7f55402 ????????
0x19ad6510 ????????
----------------- 2100 -----------------
0xb7f55402 ????????
0xb79a27ae _ZN2os13PlatformEvent4parkEv + 0xee
0xb799339b _ZN13ObjectMonitor4waitExbP6Thread + 0x5fb
0xb7a17283 _ZN18ObjectSynchronizer4waitE6HandlexP6Thread + 0x53
0xb78c73e0 JVM_MonitorWait + 0x240
0xb52600dd * java.lang.Object.wait(long) bci:0 (Interpreted frame)
0xb525904d * java.lang.Object.wait() bci:2 line:485 (Interpreted frame)
0xb525904d * java.lang.ref.Reference$ReferenceHandler.run() bci:46 line:116 (Interpreted frame)
0xb5256366 <StubRoutines>
0xb7866701 _ZN9JavaCalls11call_helperEP9JavaValueP12methodHandleP17JavaCallArgumentsP6Thread + 0x1c1
0xb79a1a18 _ZN2os20os_exception_wrapperEPFvP9JavaValueP12methodHandleP17JavaCallArgumentsP6ThreadES1_S3_S5_S7_ + 0x18
0xb7865fa7 _ZN9JavaCalls12call_virtualEP9JavaValue11KlassHandle12symbolHandleS3_P17JavaCallArgumentsP6Thread + 0xb7
0xb7866038 _ZN9JavaCalls12call_virtualEP9JavaValue6Handle11KlassHandle12symbolHandleS4_P6Thread + 0x58
0xb78e9118 _Z12thread_entryP10JavaThreadP6Thread + 0xa8
0xb7a496af _ZN10JavaThread3runEv + 0x11f
0xb79a326e _Z10java_startP6Thread + 0x14e
0x00527832 start_thread + 0xe2
Locked ownable synchronizers:
- None
...
It is not a regression. Issue could be reproduced with JDK 6,7,8.