RFR(S): 8167299: -XX:+PrintRelocations crashes the VM

[Tobias Hartmann]

Hi Volker,

On 21.10.2016 16:02, Volker Simonis wrote:
> PING - can I please have a sponsor for this change?

Sure, please send me the patch and I'll sponsor your change.

Best regards,
Tobias

> 
> Thanks,
> Volker
> 
> 
> On Thu, Oct 6, 2016 at 7:15 PM, Vladimir Kozlov
> <vladimir.kozlov at oracle.com> wrote:
>> Looks good.
>>
>> Thanks,
>> Vladimir
>>
>>
>> On 10/6/16 9:32 AM, Volker Simonis wrote:
>>>
>>> Hi,
>>>
>>> can I please have a review and sponsor for this small fix which
>>> re-enables the usage of -XX:+PrintRelocations:
>>>
>>> https://bugs.openjdk.java.net/browse/JDK-8167299
>>> http://cr.openjdk.java.net/~simonis/webrevs/2016/8167299/
>>>
>>> If we're running with "PrintNMethods" (which is as debug option) a
>>> call to Relocation::code() in Relocation::method_value() may return
>>> NULL. We must check this and handle it appropriately.
>>>
>>> Also, if running with "-XX:+WizardMode",
>>> RelocIterator::print_current() calls oop->print_value_on() without
>>> checking if oop is actually a valid oop. This can be easily fixed by
>>> calling oop->is_oop() before calling oop->print_value_on().
>>>
>>> Thank you and best regards,
>>> Volker
>>>
>>