[11u] RFR 8263558: Possible NULL dereference in fast path arena free if ZapResourceArea is true

[Zhengyu Gu]

Thanks, Severin.

Tagged for an approval.

-Zhengyu

On 4/7/21 4:43 AM, Severin Gehwolf wrote:
> Hi Zhengyu,
> 
> On Tue, 2021-04-06 at 14:01 -0400, Zhengyu Gu wrote:
>> I would like to backport this patch to 11u for parity with Oracle
>> 11.0.12-oracle.
>>
>> The original bug: https://bugs.openjdk.java.net/browse/JDK-8263558
>> The original patch: https://github.com/openjdk/jdk/commit/d2c137d4
>>
>> The original patch does not apply cleanly. The conflict is due to
>> JDK-8195100 [1], which changed Afree() method signature.
>>
>> diff -r 490ba2d4ad94 src/hotspot/share/memory/arena.hpp
>> --- a/src/hotspot/share/memory/arena.hpp        Sat Mar 20 09:06:53
>> 2021
>> +0000
>> +++ b/src/hotspot/share/memory/arena.hpp        Tue Apr 06 13:53:44
>> 2021
>> -0400
>> @@ -201,7 +201,7 @@
>>      // Fast delete in area.  Common case is: NOP (except for storage
>> reclaimed)
>>      void Afree(void *ptr, size_t size) {
>>        if (ptr == NULL) {
>> -      return true; // as with free(3), freeing NULL is a noop.
>> +      return; // as with free(3), freeing NULL is a noop.
>>        }
>>
>>
>> 11u webrev:
>> http://cr.openjdk.java.net/~zgu/JDK-8263558-11u/webrev.00/
> 
> Looks fine to me.
> 
> Thanks,
> Severin
>