RFR(S) 8140665: SIGSEGV when a primitive type's class is used as the host class in a call to DefineAnonymousClass call

[Karen Kinnear]

Agree with Coleen on both points.

thanks,
Karen

> On Mar 22, 2016, at 11:59 AM, harold seigel <harold.seigel at oracle.com> wrote:
> 
> Hi Coleen,
> 
> Thanks for the review.  I'll add the comment.
> 
> I don't know about future plans for accessing Unsafe.
> 
> Harold
> 
> On 3/22/2016 11:36 AM, Coleen Phillimore wrote:
>> 
>> Hi Harold, This looks good but a single line comment that primitive types have NULL Klass* fields in their java.lang.Class instances would be helpful, especially if this is changed in the future.
>> 
>> Since the hostClass is checked in the caller, my vote is to not add another check in the vm.
>> 
>> In the test, is there going to be another way to get to Unsafe in the future, or present?
>> 
>> Thanks,
>> Coleen
>> 
>> 
>> On 3/22/16 11:19 AM, harold seigel wrote:
>>> Hi Karen,
>>> 
>>> Thanks for looking at the changes.  The JDK caller of Unsafe_DefineAnonymousClass_impl() is in java.base/share/classes/jdk/internal/misc/Unsafe.java.  It checks for NULL args and throws NPE:
>>> 
>>>    public Class<?> defineAnonymousClass(Class<?> hostClass, byte[] data, Object[] cpPatches) {
>>>        if (hostClass == null || data == null) {
>>>            throw new NullPointerException();
>>>        }
>>>        return defineAnonymousClass0(hostClass, data, cpPatches);
>>>    }
>>> 
>>> If somehow a null host_class was passed to Unsafe_DefineAnonymousClass_impl() then it would probably seg fault in product.  Perhaps that's okay because it is an Unsafe_... API.
>>> 
>>> Thanks, Harold
>>> 
>>> On 3/22/2016 10:57 AM, Karen Kinnear wrote:
>>>> Harold,
>>>> 
>>>> Thank you for fixing this. Looks good.
>>>> 
>>>> One question -
>>>> 
>>>> 1. If you were to pass in a null host_class in product - what happens?
>>>> The way I read the resolve_non_null, it asserts in debug that you did not pass in a null, which suggests to me that it assumes
>>>> we have already made that check. I would expect and if (host_class == NULL) || … 0> IllegalArgumentException ?
>>>> 
>>>> thanks,
>>>> Karen
>>>> 
>>>>> On Mar 22, 2016, at 10:23 AM, harold seigel <harold.seigel at oracle.com> wrote:
>>>>> 
>>>>> Hi,
>>>>> 
>>>>> Please review this small change to fix bug 8140665.
>>>>> 
>>>>> Instead of asserting or getting a SIGSEGV when trying to define an anonymous class when the host class is a primitive type, this fix throws an IllegalArgumentException.
>>>>> 
>>>>> Webrev: http://cr.openjdk.java.net/~hseigel/bug_8140665/
>>>>> 
>>>>> JBS Bug: https://bugs.openjdk.java.net/browse/JDK-8140665
>>>>> 
>>>>> The fix was tested with JCK Lang and VM java_lang tests, the UTE non-collated quick tests, and the hotspot, JDK vm, java/io, java/lang, java/util and JFR JTreg tests, and the test included in this RFR.
>>>>> 
>>>>> Thanks, Harold
>>> 
>> 
>