[14] RFR(T) 8230730: UseCompressedOops test crash with assertion failure

[Zhengyu Gu]

Thanks, Stefan.

-Zhengyu

On 9/7/19 1:44 AM, Stefan Karlsson wrote:
> Looks good.
> 
> Thanks,
> StefanK
> 
> On 2019-09-07 04:45, Zhengyu Gu wrote:
>> JDK-8224815 changed the assertion from:
>>
>> assert((intptr_t)base() <= (intptr_t)(Universe::heap()->base() - 
>> os::vm_page_size()) || base() == NULL, "invalid value");
>>
>> to
>>
>> assert((intptr_t)base() <= (intptr_t)(_heap_address_range.start() - 
>> os::vm_page_size()) || base() == NULL, "invalid value");
>>
>> while Universe::heap()->base() returns "address" type, 
>> _heap_address_range.start() returns "HeapWord*" type, therefore, new 
>> assertion subtracts vm_page_size * sizeof(HeapWord*) from base 
>> address, that triggers assertion failure.
>>
>> This bug is only exposed when JVM can not obtain zero-based heap.
>>
>>
>> Bug: https://bugs.openjdk.java.net/browse/JDK-8230730
>> Webrev: http://cr.openjdk.java.net/~zgu/JDK-8230730/webrev.00/
>>
>> Test:
>>   hotspot_gc (fastdebug) on Linux x86_64 and aarch64.
>>   Submit test in progress.
>>
>> Thanks,
>>
>> -Zhengyu
>