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

[Severin Gehwolf]

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