[11u] RFR: 8212160: JVMTI agent crashes with "assert(_value != 0LL) failed: resolving NULL _value"

Fri Nov 27 09:05:43 UTC 2020

Hi Richard, 

Another try: 
http://cr.openjdk.java.net/~goetz/wr20/8212160-jvmti_crash_resolving-jdk11/06/

Best regards,
  Goetz


> -----Original Message-----
> From: Reingruber, Richard <richard.reingruber at sap.com>
> Sent: Thursday, November 26, 2020 3:58 PM
> To: Lindenmaier, Goetz <goetz.lindenmaier at sap.com>; jdk-updates-
> dev at openjdk.java.net
> Subject: RE: [11u] RFR: 8212160: JVMTI agent crashes with "assert(_value !=
> 0LL) failed: resolving NULL _value"
> 
> Hi Götz,
> 
> > Oops, fixed:
> > http://cr.openjdk.java.net/~goetz/wr20/8212160-jvmti_crash_resolving-
> jdk11/05/
> 
> Great. We're almost there now. The original patch has two occurences of
> the following:
> 
> +    // Requires a lock, because threads can be adding to this queue.
> 
> Your patch lacks one and the one you've got has trailing whitespace.
> 
> Cheers, Richard.
> 
> -----Original Message-----
> From: Lindenmaier, Goetz <goetz.lindenmaier at sap.com>
> Sent: Donnerstag, 26. November 2020 10:05
> To: Reingruber, Richard <richard.reingruber at sap.com>; jdk-updates-
> dev at openjdk.java.net
> Subject: RE: [11u] RFR: 8212160: JVMTI agent crashes with "assert(_value !=
> 0LL) failed: resolving NULL _value"
> 
> Hi Richard,
> 
> Oops, fixed:
> http://cr.openjdk.java.net/~goetz/wr20/8212160-jvmti_crash_resolving-
> jdk11/05/
> 
> Best regards,
>   Goetz
> 
> > -----Original Message-----
> > From: Reingruber, Richard <richard.reingruber at sap.com>
> > Sent: Tuesday, November 24, 2020 4:35 PM
> > To: Lindenmaier, Goetz <goetz.lindenmaier at sap.com>; jdk-updates-
> > dev at openjdk.java.net
> > Subject: RE: [11u] RFR: 8212160: JVMTI agent crashes with
> "assert(_value !=
> > 0LL) failed: resolving NULL _value"
> >
> > Hi Götz,
> >
> > > This affects the patch of this change, so I made a new webrev.
> > > It also incorporates the comment I missed:
> > > http://cr.openjdk.java.net/~goetz/wr20/8212160-jvmti_crash_resolving-
> > jdk11/04/
> >
> > Seems you forgot to remove the commented-out version of
> > JvmtiExport::post_compiled_method_load(JvmtiEnv* env, nmethod *nm)
> >
> > See http://cr.openjdk.java.net/~goetz/wr20/8212160-
> jvmti_crash_resolving-
> > jdk11/04/src/hotspot/share/prims/jvmtiExport.cpp.udiff.html
> >
> > Cheers, Richard.
> >
> > -----Original Message-----
> > From: Lindenmaier, Goetz <goetz.lindenmaier at sap.com>
> > Sent: Dienstag, 24. November 2020 08:57
> > To: Reingruber, Richard <richard.reingruber at sap.com>; jdk-updates-
> > dev at openjdk.java.net
> > Subject: RE: [11u] RFR: 8212160: JVMTI agent crashes with
> "assert(_value !=
> > 0LL) failed: resolving NULL _value"
> >
> > Hi Richard,
> >
> > Thanks for reviewing!
> >
> > Yes, you are right, downporting the predecessor makes sense.
> > It is a limited change and a pure fix as I understand.
> > I requested downport and sent a RFR for it:
> > http://mail.openjdk.java.net/pipermail/jdk-updates-dev/2020-
> > November/004220.html
> >
> > This affects the patch of this change, so I made a new webrev.
> > It also incorporates the comment I missed:
> > http://cr.openjdk.java.net/~goetz/wr20/8212160-jvmti_crash_resolving-
> > jdk11/04/
> >
> > Best regards,
> >   Goetz.
> >
> > > -----Original Message-----
> > > From: Reingruber, Richard <richard.reingruber at sap.com>
> > > Sent: Thursday, November 19, 2020 6:17 PM
> > > To: Lindenmaier, Goetz <goetz.lindenmaier at sap.com>; jdk-updates-
> > > dev at openjdk.java.net
> > > Subject: RE: [11u] RFR: 8212160: JVMTI agent crashes with
> > "assert(_value !=
> > > 0LL) failed: resolving NULL _value"
> > >
> > > Hi Götz,
> > >
> > > --- src/hotspot/share/prims/jvmtiExport.cpp
> > >
> > > > I added void JvmtiExport::post_compiled_method_load(JvmtiEnv* env,
> > > nmethod *nm)
> > > > from head which is called in
> > >
> > > It would be cleaner to downport the original bugfix but I'm ok with your
> > > solution.
> > >
> > > --- src/hotspot/share/runtime/serviceThread.cpp
> > >
> > > the patch you prepared seems to be missing the change marked with !!!
> of
> > > the original patch
> > >
> > > @@ -209,7 +219,8 @@
> > >      if (_jvmti_event != NULL) {
> > >        _jvmti_event->nmethods_do(cf);
> > >      }
> > > +    // Requires a lock, because threads can be adding to this queue.     !!!
> > >      MutexLocker ml(Service_lock, Mutex::_no_safepoint_check_flag);
> > > -    JvmtiDeferredEventQueue::nmethods_do(cf);
> > > +    _jvmti_service_queue.nmethods_do(cf);
> > >
> > > This is inadvertently, isn't it?
> > >
> > > The rest is good looking ;)
> > >
> > > Cheers, Richard.
> > >
> > > -----Original Message-----
> > > From: jdk-updates-dev <jdk-updates-dev-retn at openjdk.java.net> On
> > Behalf
> > > Of Reingruber, Richard
> > > Sent: Mittwoch, 18. November 2020 22:29
> > > To: Lindenmaier, Goetz <goetz.lindenmaier at sap.com>; jdk-updates-
> > > dev at openjdk.java.net
> > > Subject: RE: [11u] RFR: 8212160: JVMTI agent crashes with
> > "assert(_value !=
> > > 0LL) failed: resolving NULL _value"
> > >
> > > Hi Götz,
> > >
> > > I'm getting ready to review this.
> > >
> > > If I'm not mistaken, your patch has 8173658 as prerequisite which is
> > currently
> > > out for review. It took me a few keystrokes and mouse clicks to figure
> this
> > > out. I'd suggest informing about prerequisite patches in the RFR mail.
> > >
> > > Cheers, Richard.
> > >
> > > -----Original Message-----
> > > From: jdk-updates-dev <jdk-updates-dev-retn at openjdk.java.net> On
> > Behalf
> > > Of Lindenmaier, Goetz
> > > Sent: Dienstag, 17. November 2020 15:03
> > > To: jdk-updates-dev at openjdk.java.net
> > > Subject: [CAUTION] RE: [11u] RFR: 8212160: JVMTI agent crashes with
> > > "assert(_value != 0LL) failed: resolving NULL _value"
> > >
> > > Hi,
> > >
> > > I have another update to this change.
> > > I had to resolve it again because of the Minimal VM fix 8235218 pushed
> > > after 8173361.
> > > http://cr.openjdk.java.net/~goetz/wr20/8212160-jvmti_crash_resolving-
> > > jdk11/03/
> > >
> > > Also, I reqested downport for Minimal VM fixes required after this change:
> > > JDK-8236124 Minimal VM slowdebug build failed after JDK-8212160
> > > JDK-8235456 Minimal VM is broken after JDK-8212160
> > > These both are clean downports once this is pushed.
> > >
> > > I would appreciate reviews ��
> > >
> > > Best regards,
> > >   Goetz.
> > >
> > >
> > > Hi,
> > >
> > > Please look at
> > > http://cr.openjdk.java.net/~goetz/wr20/8212160-jvmti_crash_resolving-
> > > jdk11/02/
> > >
> > > I had lost the changes to the test file because of C/C++ mismatch.
> > >
> > > Best regards,
> > >   Goetz.
> > >
> > >
> > > -----Original Message-----
> > > From: Lindenmaier, Goetz
> > > Sent: Freitag, 6. November 2020 09:39
> > > To: jdk-updates-dev at openjdk.java.net
> > > Subject: [11u] RFR: 8212160: JVMTI agent crashes with "assert(_value !=
> > 0LL)
> > > failed: resolving NULL _value"
> > >
> > > Hi
> > >
> > > I am downporting this for parity with 11.0.10-oracle.
> > >
> > > http://cr.openjdk.java.net/~goetz/wr20/8212160-jvmti_crash_resolving-
> > > jdk11/01/
> > > I had to resolve and fis in quite some places:
> > >
> > > src/hotspot/share/code/nmethod.cpp
> > > Resolved. Few differences in code, e.g. MutexLocker --> MutexLockerEx.
> > >
> > > Added 'this' to call of
> > JvmtiDeferredEvent::compiled_method_unload_event()
> > >
> > > src/hotspot/share/code/nmethod.hpp
> > > Trivial, resolved.
> > >
> > > src/hotspot/share/prims/jvmtiCodeBlobEvents.cpp
> > > Resolved. Few differences in code, e.g. MutexLocker --> MutexLockerEx.
> > >
> > > I removed NMethodIterator::only_alive_and_not_unloading and call
> > > next_alive instead.
> > > The NMethodIterator differs in head a lot.
> > >
> > > src/hotspot/share/prims/jvmtiExport.cpp
> > > Resolved. Few differences in code, e.g. MutexLocker --> MutexLockerEx.
> > >
> > > I added void JvmtiExport::post_compiled_method_load(JvmtiEnv* env,
> > > nmethod *nm)
> > > from head which is called in
> > >
> > > src/hotspot/share/prims/jvmtiExport.hpp
> > > Resolved. Deleted method has different arguments.
> > >
> > > src/hotspot/share/prims/jvmtiImpl.hpp
> > > Resolved.
> > >
> > > src/hotspot/share/runtime/serviceThread.cpp
> > > Context different.
> > >
> > > Please review.
> > > https://bugs.openjdk.java.net/browse/JDK-8212160
> > > https://hg.openjdk.java.net/jdk/jdk/rev/366c0f357ee6
> > >
> > > Best regards,
> > >   Goetz