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/Thread/virtual/StackFrames.java

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+/*
+ * Copyright (c) 2020, 2024, 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
+ * @summary Test stack traces in exceptions, stack frames walked by the StackWalker,
+ *    and the stack trace returned by Thread.getStackTrace
+ * @requires vm.continuations
+ * @modules java.base/java.lang:+open java.management
+ * @library /test/lib
+ * @run junit StackFrames
+ * @run junit/othervm -XX:+UnlockDiagnosticVMOptions -XX:+ShowCarrierFrames StackFrames
+ */
+
+import java.lang.management.ManagementFactory;
+import java.util.Arrays;
+import java.util.Set;
+import java.util.concurrent.Executor;
+import java.util.concurrent.ForkJoinPool;
+import java.util.concurrent.ForkJoinWorkerThread;
+import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicReference;
+import java.util.stream.Stream;
+import static java.lang.StackWalker.Option.*;
+
+import jdk.test.lib.thread.VThreadRunner;
+import jdk.test.lib.thread.VThreadScheduler;
+import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.*;
+
+class StackFrames {
+
+    /**
+     * Test that the stack trace in exceptions does not include the carrier thread
+     * frames, except when running with -XX:+ShowCarrierFrames.
+     */
+    @Test
+    void testStackTraceException() throws Exception {
+        VThreadRunner.run(() -> {
+            Exception e = new Exception();
+            boolean found = Arrays.stream(e.getStackTrace())
+                    .map(StackTraceElement::getClassName)
+                    .anyMatch("java.util.concurrent.ForkJoinPool"::equals);
+            assertTrue(found == hasJvmArgument("-XX:+ShowCarrierFrames"));
+        });
+    }
+
+    /**
+     * Test that StackWalker does not include carrier thread frames in the stream of
+     * stack frames.
+     */
+    @Test
+    void testStackWalker() throws Exception {
+        VThreadRunner.run(() -> {
+            StackWalker walker = StackWalker.getInstance(Set.of(RETAIN_CLASS_REFERENCE));
+            boolean found = walker.walk(sf ->
+                    sf.map(StackWalker.StackFrame::getDeclaringClass)
+                            .anyMatch(c -> c == ForkJoinPool.class));
+            assertFalse(found);
+        });
+    }
+
+    /**
+     * Test Thread.getStackTrace returns the expected bottom frame for both the carrier
+     * and virtual thread.
+     */
+    @Test
+    void testBottomFrames() throws Exception {
+        try (ForkJoinPool pool = new ForkJoinPool(1)) {
+            var carrierRef = new AtomicReference<Thread>();
+            Executor scheduler = task -> {
+                pool.submit(() -> {
+                    carrierRef.set(Thread.currentThread());
+                    task.run();
+                });
+            };
+            ThreadFactory factory = VThreadScheduler.virtualThreadFactory(scheduler);
+
+            var ready = new AtomicBoolean();
+            var done = new AtomicBoolean();
+
+            // create virtual thread to use custom scheduler
+            var vthread = factory.newThread(() -> {
+                ready.set(true);
+                while (!done.get()) {
+                    Thread.onSpinWait();
+                }
+            });
+
+            vthread.start();
+            try {
+                awaitTrue(ready);
+
+                // get carrier Thread
+                Thread carrier = carrierRef.get();
+                assertTrue(carrier instanceof ForkJoinWorkerThread);
+
+                // bottom-most frame of virtual thread should be VirtualThread.run
+                System.err.println(vthread);
+                StackTraceElement[] vthreadStack = vthread.getStackTrace();
+                Stream.of(vthreadStack).forEach(e -> System.err.println("    " + e));
+                StackTraceElement bottomFrame = vthreadStack[vthreadStack.length - 1];
+                assertEquals("java.lang.VirtualThread.run",
+                        bottomFrame.getClassName() + "." + bottomFrame.getMethodName());
+
+                // bottom-most frame of carrier thread should be Thread.run
+                System.err.println(carrier);
+                StackTraceElement[] carrierStack = carrier.getStackTrace();
+                Stream.of(carrierStack).forEach(e -> System.err.println("    " + e));
+                bottomFrame = carrierStack[carrierStack.length - 1];
+                assertEquals("java.util.concurrent.ForkJoinWorkerThread.run",
+                        bottomFrame.getClassName() + "." + bottomFrame.getMethodName());
+
+            } finally {
+                done.set(true);
+                vthread.join();
+            }
+        }
+    }
+
+    /**
+     * Returns true if started with the given VM option.
+     */
+    private static boolean hasJvmArgument(String arg) {
+        for (String argument : ManagementFactory.getRuntimeMXBean().getInputArguments()) {
+            if (argument.equals(arg)) return true;
+        }
+        return false;
+    }
+
+    /**
+     * Waits for the boolean value to become true.
+     */
+    private static void awaitTrue(AtomicBoolean ref) throws InterruptedException {
+        while (!ref.get()) {
+            Thread.sleep(20);
+        }
+    }
+}