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

[Zhengyu Gu]

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/


Thanks,

-Zhengyu

[1] https://bugs.openjdk.java.net/browse/JDK-8195100