8216549: Mismatched unsafe access to non escaping object fails
authorroland
Fri, 11 Jan 2019 10:03:00 +0100
changeset 53288 f0490430ef7a
parent 53287 6b963dd96b5e
child 53289 5022a4915fe9
8216549: Mismatched unsafe access to non escaping object fails Reviewed-by: vlivanov, kvn, thartmann
src/hotspot/share/opto/escape.cpp
test/hotspot/jtreg/compiler/unsafe/MismatchedUnsafeLoadFromNewObject.java
--- a/src/hotspot/share/opto/escape.cpp	Fri Jan 11 11:42:23 2019 -0800
+++ b/src/hotspot/share/opto/escape.cpp	Fri Jan 11 10:03:00 2019 +0100
@@ -1727,7 +1727,8 @@
     //
     Node* n = field->ideal_node();
     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
-      if (n->fast_out(i)->is_LoadStore()) {
+      Node* u = n->fast_out(i);
+      if (u->is_LoadStore() || (u->is_Mem() && u->as_Mem()->is_mismatched_access())) {
         jobj->set_scalar_replaceable(false);
         return;
       }
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/compiler/unsafe/MismatchedUnsafeLoadFromNewObject.java	Fri Jan 11 10:03:00 2019 +0100
@@ -0,0 +1,93 @@
+/*
+ * Copyright (c) 2019, Red Hat, Inc. 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 8216549
+ * @summary Mismatched unsafe access to non escaping object fails
+ *
+ * @modules java.base/jdk.internal.misc
+ * @run main/othervm -XX:-UseOnStackReplacement -XX:-BackgroundCompilation MismatchedUnsafeLoadFromNewObject
+ */
+
+import java.lang.reflect.Field;
+import jdk.internal.misc.Unsafe;
+
+public class MismatchedUnsafeLoadFromNewObject {
+    public volatile int f_int = -1;
+    public volatile int f_int2 = -1;
+
+    public static Unsafe unsafe = Unsafe.getUnsafe();
+    public static final long f_int_off;
+    public static final long f_int2_off;
+
+    static {
+        Field f_int_field = null;
+        Field f_int2_field = null;
+        try {
+            f_int_field = MismatchedUnsafeLoadFromNewObject.class.getField("f_int");
+            f_int2_field = MismatchedUnsafeLoadFromNewObject.class.getField("f_int2");
+        } catch (Exception e) {
+            System.out.println("reflection failed " + e);
+            e.printStackTrace();
+        }
+        f_int_off = unsafe.objectFieldOffset(f_int_field);
+        f_int2_off = unsafe.objectFieldOffset(f_int2_field);
+    }
+
+    static public void main(String[] args) {
+        for (int i = 0; i < 20_000; i++) {
+            byte res = test1();
+            if (res != -1) {
+                throw new RuntimeException("Incorrect result: " + res);
+            }
+            res = test2();
+            if (res != -1) {
+                throw new RuntimeException("Incorrect result: " + res);
+            }
+            int res2 = test3();
+            if (res2 != -1) {
+                throw new RuntimeException("Incorrect result: " + res2);
+            }
+        }
+    }
+
+    static byte test1() {
+        MismatchedUnsafeLoadFromNewObject t = new MismatchedUnsafeLoadFromNewObject();
+        return unsafe.getByte(t, f_int_off);
+    }
+
+    static byte test2() {
+        MismatchedUnsafeLoadFromNewObject t = new MismatchedUnsafeLoadFromNewObject();
+        return unsafe.getByte(t, f_int_off+1);
+    }
+
+    static int test3() {
+        MismatchedUnsafeLoadFromNewObject t = new MismatchedUnsafeLoadFromNewObject();
+        if (f_int_off < f_int2_off) {
+            return unsafe.getIntUnaligned(t, f_int_off+1);
+        } else {
+            return unsafe.getIntUnaligned(t, f_int2_off+1);
+        }
+    }
+}