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/Math/MultiplicationTests.java

@@ -0,0 +1,149 @@
+/*
+ * Copyright (c) 2016, 2021, 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
+ * @library /test/lib
+ * @build jdk.test.lib.RandomFactory
+ * @run main MultiplicationTests
+ * @bug 5100935 8188044
+ * @summary Tests for multiplication methods (use -Dseed=X to set PRNG seed)
+ * @key randomness
+ */
+
+import java.math.BigInteger;
+import java.util.function.BiFunction;
+import jdk.test.lib.RandomFactory;
+
+public class MultiplicationTests {
+    private MultiplicationTests(){}
+
+    // Number of random products to test.
+    private static final int COUNT = 1 << 16;
+
+    // Initialize shared random number generator
+    private static java.util.Random rnd = RandomFactory.getRandom();
+
+    // Calculate high 64 bits of 128 product using BigInteger.
+    private static long multiplyHighBigInt(long x, long y) {
+        return BigInteger.valueOf(x).multiply(BigInteger.valueOf(y))
+            .shiftRight(64).longValue();
+    }
+
+    // Calculate high 64 bits of unsigned 128 product using signed multiply
+    private static long unsignedMultiplyHigh(long x, long y) {
+        long x0 = x & 0xffffffffL;
+        long x1 = x >>> 32;
+        long y0 = y & 0xffffffffL;
+        long y1 = y >>> 32;
+
+        long t = x1 * y0 + ((x0 * y0) >>> 32);
+        long z0 = x0 * y1 + (t & 0xffffffffL);
+        long z1 = t >>> 32;
+
+        return x1 * y1 + z1 + (z0 >>> 32);
+    }
+
+    // Compare results of two functions for a pair of values
+    private static boolean check(BiFunction<Long,Long,Long> reference,
+        BiFunction<Long,Long,Long> multiply, long x, long y) {
+        long p1 = reference.apply(x, y);
+        long p2 = multiply.apply(x, y);
+        if (p1 != p2) {
+            System.err.printf("Error - x:%d y:%d p1:%d p2:%d\n", x, y, p1, p2);
+            return false;
+        } else {
+            return true;
+        }
+    }
+
+    // Check Math.multiplyHigh(x,y) against multiplyHighBigInt(x,y)
+    private static boolean checkSigned(long x, long y) {
+        return check((a,b) -> multiplyHighBigInt(a,b),
+            (a,b) -> Math.multiplyHigh(a, b), x, y);
+    }
+
+    // Check Math.unsignedMultiplyHigh(x,y) against unsignedMultiplyHigh(x,y)
+    private static boolean checkUnsigned(long x, long y) {
+        return check((a,b) -> unsignedMultiplyHigh(a,b),
+            (a,b) -> Math.unsignedMultiplyHigh(a, b), x, y);
+    }
+
+    private static int test(BiFunction<Long,Long,Boolean> chk) {
+        int failures = 0;
+
+        // check some boundary cases
+        long[][] v = new long[][]{
+            {0L, 0L},
+            {-1L, 0L},
+            {0L, -1L},
+            {1L, 0L},
+            {0L, 1L},
+            {-1L, -1L},
+            {-1L, 1L},
+            {1L, -1L},
+            {1L, 1L},
+            {Long.MAX_VALUE, Long.MAX_VALUE},
+            {Long.MAX_VALUE, -Long.MAX_VALUE},
+            {-Long.MAX_VALUE, Long.MAX_VALUE},
+            {Long.MAX_VALUE, Long.MIN_VALUE},
+            {Long.MIN_VALUE, Long.MAX_VALUE},
+            {Long.MIN_VALUE, Long.MIN_VALUE}
+        };
+
+        for (long[] xy : v) {
+            if(!chk.apply(xy[0], xy[1])) {
+                failures++;
+            }
+        }
+
+        // check some random values
+        for (int i = 0; i < COUNT; i++) {
+            if (!chk.apply(rnd.nextLong(), rnd.nextLong())) {
+                failures++;
+            }
+        }
+
+        return failures;
+    }
+
+    private static int testMultiplyHigh() {
+        return test((x,y) -> checkSigned(x,y));
+    }
+
+    private static int testUnsignedMultiplyHigh() {
+        return test((x,y) -> checkUnsigned(x,y));
+    }
+
+    public static void main(String argv[]) {
+        int failures = testMultiplyHigh() + testUnsignedMultiplyHigh();
+
+        if (failures > 0) {
+            System.err.println("Multiplication testing encountered "
+                               + failures + " failures.");
+            throw new RuntimeException();
+        } else {
+            System.out.println("MultiplicationTests succeeded");
+        }
+    }
+}