RFR 8226798: JVM crash in klassItable::initialize_itable_for_interface(int, InstanceKlass*, bool, Thread*)

[Karen Kinnear]

Looks good to me.

Thank you very much,
Karen

> On Jul 10, 2019, at 2:34 PM, Harold Seigel <harold.seigel at oracle.com <mailto:harold.seigel at oracle.com>> wrote:
> 
> Hi Karen,
> 
> Thanks for looking at this.
> 
> Please review this updated webrev that includes your suggestions.
> 
> http://cr.openjdk.java.net/~hseigel/bug_8226798.2/webrev/index.html <http://cr.openjdk.java.net/~hseigel/bug_8226798.2/webrev/index.html>
> Thanks! Harold
> 
> On 7/10/2019 12:22 PM, Karen Kinnear wrote:
>> Harold,
>> 
>> Thank you for figuring out a fix for this. The code looks good for the fix. Thank you
>> for the assertions.
>> 
>> A suggestion on the code:
>> 
>> After the initial large loop, instead of if (!found_pkg_prvt_method) { do the check }
>> Replace that with
>> 
>> "If found_pkg_prvt_method is set, then the ONLY matching method in the
>> superclasses is package private in another package. That matching method will
>> prevent a miranda vtable entry from being created. Because the target method can not
>> override the package private method in another package, then it needs to be the root
>> for its own vtable entry."
>>   if (found_pkg_prvt_method) {
>>      return true;
>>   }
>> 
>> Then leave the old code and comment alone.
>> 
>> ——
>> Suggestion on the first set of comments:
>> 
>> “But, that package private method does “override” any matching methods in super interfaces,
>> so there will be no miranda vtable entry created. So, set flag to TRUE  for use below, in case there are no
>> methods in super classes that this target method overrides."
>> 
>> thank you so much,
>> Karen
>> 
>>> On Jul 10, 2019, at 8:09 AM, Harold Seigel <harold.seigel at oracle.com> <mailto:harold.seigel at oracle.com> wrote:
>>> 
>>> Hi,
>>> 
>>> Please review this JDK-14 fix for 8226798.  At class load time, the JVM was incorrectly calculating the size of a class's vtable in cases where a super class, in another package, contained a package private method that was also in a super interface.
>>> 
>>> Open Webrev: http://cr.openjdk.java.net/~hseigel/bug_8226798/webrev/index.html <http://cr.openjdk.java.net/~hseigel/bug_8226798/webrev/index.html>
>>> 
>>> JBS Bug: https://bugs.openjdk.java.net/browse/JDK-8226798 <https://bugs.openjdk.java.net/browse/JDK-8226798>
>>> 
>>> The fix was regression tested by running Mach5 tiers 1 and 2 tests and builds on Linux-x64, Solaris, Windows, and Mac OS X, by running Mach5 tiers 3-5 tests on Linux-x64, and JCK lang and VM tests on Linux-x64.
>>> 
>>> Thanks, Harold
>>>