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/hotspot/jtreg/runtime/handshake/HandshakeWalkStackTest.java

@@ -0,0 +1,119 @@
+/*
+ * Copyright (c) 2016, 2025, 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 HandshakeWalkStackTest
+ * @requires test.thread.factory == null
+ * @library /testlibrary /test/lib
+ * @build HandshakeWalkStackTest
+ * @run driver jdk.test.lib.helpers.ClassFileInstaller jdk.test.whitebox.WhiteBox
+ * @run main/othervm -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI HandshakeWalkStackTest
+ */
+
+import jdk.test.lib.Asserts;
+import jdk.test.whitebox.WhiteBox;
+
+public class HandshakeWalkStackTest {
+
+    public static void main(String... args) throws Exception {
+        int iterations = 3;
+        if (args.length > 0) {
+            iterations = Integer.parseInt(args[0]);
+        }
+        test(iterations);
+    }
+
+    private static void test(int iterations) throws Exception {
+        Thread loop_thread  = new Thread(() -> run_loop(create_list()));
+        Thread alloc_thread = new Thread(() -> run_alloc());
+        Thread wait_thread  = new Thread(() -> run_wait(new Object() {}));
+        loop_thread.start();
+        alloc_thread.start();
+        wait_thread.start();
+
+        WhiteBox wb = WhiteBox.getWhiteBox();
+        int walked = 0;
+        for (int i = 0; i < iterations; i++) {
+            System.out.println("Iteration " + i);
+            System.out.flush();
+            Thread.sleep(200);
+            walked = wb.handshakeWalkStack(loop_thread, false);
+            Asserts.assertEQ(walked, 1, "Must have walked one thread stack");
+            Thread.sleep(200);
+            walked = wb.handshakeWalkStack(alloc_thread, false);
+            Asserts.assertEQ(walked, 1, "Must have walked one thread stack");
+            Thread.sleep(200);
+            walked = wb.handshakeWalkStack(wait_thread, false);
+            Asserts.assertEQ(walked, 1, "Must have walked one thread stack");
+            Thread.sleep(200);
+            walked = wb.handshakeWalkStack(Thread.currentThread(), false);
+            Asserts.assertEQ(walked, 1, "Must have walked one thread stack");
+        }
+        Thread.sleep(200);
+        walked = wb.handshakeWalkStack(null, true);
+        Asserts.assertGT(walked, 4, "Must have walked more than three thread stacks");
+    }
+
+    static class List {
+        List next;
+
+        List(List next) {
+            this.next = next;
+        }
+    }
+
+    public static List create_list() {
+        List head = new List(null);
+        List elem = new List(head);
+        List elem2 = new List(elem);
+        List elem3 = new List(elem2);
+        List elem4 = new List(elem3);
+        head.next = elem4;
+
+        return head;
+    }
+
+    public static void run_loop(List loop) {
+        while (loop.next != null) {
+            loop = loop.next;
+        }
+    }
+
+    public static byte[] array;
+
+    public static void run_alloc() {
+        while (true) {
+            // Write to public static to ensure the byte array escapes.
+            array = new byte[4096];
+        }
+    }
+
+    public static void run_wait(Object lock) {
+        synchronized (lock) {
+            try {
+                lock.wait();
+            } catch (InterruptedException ie) {}
+        }
+    }
+}