Uploaded image for project: 'JDK'
  1. JDK
  2. JDK-8147805

C1 segmentation fault due to inline Unsafe::getAndSetObject

    XMLWordPrintable

Details

    • Bug
    • Resolution: Fixed
    • P4
    • 9
    • None
    • hotspot
    • None
    • b105
    • aarch64
    • generic

    Description

      crash with following small case, root cause is on aarch64 when C1 inline Unsafe::getAndSetObject(obj) in compressed reference mode, it covert "obj" register to compressed point before store, but "obj" register might be used later and wrong.

      import java.util.concurrent.atomic.AtomicReference;
      import sun.misc.Unsafe;
      public class TestUnsafe extends AtomicReference<Node>{
        public static void main(String[] args) {
          for (int i = 0; i < 10000; i++) {
              Node n1 = new Node(i);
              Node n2 = new Node(i+1);
              TestUnsafe t = new TestUnsafe(n1);
              Node old = t.foo(n2);
       
              if(old.next.v > 20000) {
                 System.out.println("not enter here" + old.next.v);
              }
          }
        }
        TestUnsafe(Node n) {super(n);}
       
        public Node foo(Node n) {
          Node old;
          old = this.getAndSet(n); // inline sun.misc.Unsafe::getAndSetObject here
          old.next = n;
          return old;
        }
      }
      class Node
      {
         int v;
         Node next;
         Node(int i) {v = i; next = null;}
      }

      java -XX:TieredStopAtLevel=3 -XX:+TieredCompilation -Xms4G -Xmx4G TestUnsafe

      #
      # A fatal error has been detected by the Java Runtime Environment:
      #
      # SIGSEGV (0xb) at pc=0x0000007fa409c094, pid=20559, tid=548430631424
      #
      # JRE version: OpenJDK Runtime Environment (8.0) (build 1.8.0-internal-shihui_2016_01_20_13_25-b00)
      # Java VM: OpenJDK 64-Bit Server VM (25.60-b23 mixed mode linux-aarch64 compressed oops)
      # Problematic frame:
      # j TestUnsafe.main([Ljava/lang/String;)V+42
      #

      Attachments

        Issue Links

          Activity

            People

              hshi Hui Shi
              hshi Hui Shi
              Votes:
              0 Vote for this issue
              Watchers:
              2 Start watching this issue

              Dates

                Created:
                Updated:
                Resolved: