undefect. CWE-407 — 63 sites patched across 27 ecosystems

Authors: russell@unturf.com · brackishbert@gmail.com · foxhop.net · TimeHexOn.com

Patches, unit tests, benchmarks, whitepaper, and outreach briefs.
Public domain — no copyright claimed. Use freely.

test/jdk/java/lang/ref/ReachabilityFenceTest.java

@@ -0,0 +1,147 @@
+/*
+ * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/* @test
+ * @bug 8133348
+ * @summary Tests if reachabilityFence is working
+ *
+ * @requires vm.opt.DeoptimizeALot != true
+ *
+ * @run main/othervm -Xint                           -Dpremature=false ReachabilityFenceTest
+ * @run main/othervm -Xbatch -XX:TieredStopAtLevel=1 -Dpremature=true  ReachabilityFenceTest
+ * @run main/othervm -Xbatch -XX:TieredStopAtLevel=2 -Dpremature=true  ReachabilityFenceTest
+ * @run main/othervm -Xbatch -XX:TieredStopAtLevel=3 -Dpremature=true  ReachabilityFenceTest
+ * @run main/othervm -Xbatch -XX:TieredStopAtLevel=4 -Dpremature=true  ReachabilityFenceTest
+ */
+
+import java.lang.ref.Reference;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+public class ReachabilityFenceTest {
+
+    /*
+     * Implementation notes:
+     *
+     * This test has positive and negative parts.
+     *
+     * Negative test is "nonFenced", and it tests that absent of reachabilityFence, the object can
+     * be prematurely finalized -- this validates the test itself. Not every VM mode is expected to
+     * prematurely finalize the objects, and -Dpremature option communicates that to test. If a VM mode
+     * passes the negative test, then our understanding of what could happen is correct, and we can
+     * go forward.
+     *
+     * Positive test is "fenced", and it checks that given the reachabilityFence at the end of the block,
+     * the object cannot be finalized. There is no sense running a positive test when premature finalization
+     * is not expected. It is a job for negative test to verify that invariant.
+     *
+     * The test methods should be appropriately compiled, therefore we do several iterations and run with -Xbatch.
+     */
+
+    // Enough to OSR and compile
+    static final int LOOP_ITERS = Integer.getInteger("LOOP_ITERS", 50000);
+
+    // Enough after which to start triggering GC and finalization
+    static final int WARMUP_LOOP_ITERS = LOOP_ITERS - Integer.getInteger("GC_ITERS", 100);
+
+    // Enough to switch from an OSR'ed method to compiled method
+    static final int MAIN_ITERS = 3;
+
+    static final boolean PREMATURE_FINALIZATION = Boolean.getBoolean("premature");
+
+    public static void main(String... args) {
+        // Negative test
+        boolean finalized = false;
+        for (int c = 0; !finalized && c < MAIN_ITERS; c++) {
+            finalized |= nonFenced();
+        }
+
+        if (PREMATURE_FINALIZATION && !finalized) {
+            throw new IllegalStateException("The object had never been finalized before timeout reached.");
+        }
+
+        if (!PREMATURE_FINALIZATION && finalized) {
+            throw new IllegalStateException("The object had been finalized without a fence, even though we don't expect it.");
+        }
+
+        if (!PREMATURE_FINALIZATION)
+            return;
+
+        // Positive test
+        finalized = false;
+        for (int c = 0; !finalized && c < MAIN_ITERS; c++) {
+            finalized |= fenced();
+        }
+
+        if (finalized) {
+            throw new IllegalStateException("The object had been prematurely finalized.");
+        }
+    }
+
+    public static boolean nonFenced() {
+        AtomicBoolean finalized = new AtomicBoolean();
+        MyFinalizeable o = new MyFinalizeable(finalized);
+
+        for (int i = 0; i < LOOP_ITERS; i++) {
+            if (finalized.get()) break;
+            if (i > WARMUP_LOOP_ITERS) {
+                System.gc();
+                System.runFinalization();
+            }
+        }
+
+        return finalized.get();
+    }
+
+    public static boolean fenced() {
+        AtomicBoolean finalized = new AtomicBoolean();
+        MyFinalizeable o = new MyFinalizeable(finalized);
+
+        for (int i = 0; i < LOOP_ITERS; i++) {
+            if (finalized.get()) break;
+            if (i > WARMUP_LOOP_ITERS) {
+                System.gc();
+                System.runFinalization();
+            }
+        }
+
+        try {
+            return finalized.get();
+        } finally {
+            Reference.reachabilityFence(o);
+        }
+    }
+
+    private static class MyFinalizeable {
+        private final AtomicBoolean finalized;
+
+        public MyFinalizeable(AtomicBoolean b) {
+            this.finalized = b;
+        }
+
+        @Override
+        protected void finalize() throws Throwable {
+            super.finalize();
+            finalized.set(true);
+        }
+    }
+}