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

[harold seigel]

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