RFR: 8042235: redefining method used by multiple MethodHandles crashes VM

[serguei.spitsyn at oracle.com]

Hi Kevin,

src/share/vm/prims/jvm.cpp

  645     new_obj = instanceKlass::register_finalizer(instanceOop(new_obj_oop), CHECK_NULL);

The above looks incorrect.
The new_obj() must be used in stead of the new_obj_oop.

Thanks,
Serguei


On 12/17/14 7:48 AM, KEVIN WALLS wrote:
> Hi,
>
> This is a request for review of a backport to 7u of 8042235. There are 
> a few changes from the original, hence the request here.
>
> On JDK7 this is not a crash, but we run the wrong method, i.e. 
> invocation through a MethodHandle invokes the old version of the 
> method, if it has been redefined.
>
> The test is different also: in jdk8 we have the ASM library, and can 
> visit methods and bytecodes.  Here in 7, I wrote a non-bytecode aware 
> byte replacer method, and replaced some literal bytecode sequence with 
> another.   As we're crafting a method that we will rewrite, we can do 
> something that avoids use of the constant pool (which we haven't 
> actually understood in this trivial rewriter), so we rewrite some 
> simple arithmetic, and from the result of the method it's obvious 
> whether we are running the correct code.
>
> Coleen: thanks for your earlier hints on oop / obj_field vs. 
> address_field.
>
> bug
> https://bugs.openjdk.java.net/browse/JDK-8042235
>
> webrev
> http://cr.openjdk.java.net/~kevinw/8042235/webrev.00/
>
> Thanks
> Kevin