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

[Harold Seigel]

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

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> 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
>>
>> JBS Bug: 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
>>