1 /*
   2  * Copyright (c) 2017, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 
  25 package org.graalvm.compiler.hotspot.meta;
  26 
  27 import static org.graalvm.compiler.hotspot.GraalHotSpotVMConfig.INJECTED_VMCONFIG;
  28 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.doingUnsafeAccessOffset;
  29 
  30 import org.graalvm.compiler.api.replacements.ClassSubstitution;
  31 import org.graalvm.compiler.api.replacements.MethodSubstitution;
  32 import org.graalvm.compiler.hotspot.HotSpotBackend;
  33 import org.graalvm.compiler.hotspot.nodes.CurrentJavaThreadNode;
  34 import org.graalvm.compiler.nodes.ComputeObjectAddressNode;
  35 import org.graalvm.compiler.serviceprovider.JavaVersionUtil;
  36 import org.graalvm.compiler.word.Word;
  37 import jdk.internal.vm.compiler.word.LocationIdentity;
  38 import jdk.internal.vm.compiler.word.WordFactory;
  39 
  40 @ClassSubstitution(className = {"jdk.internal.misc.Unsafe", "sun.misc.Unsafe"})
  41 public class HotSpotUnsafeSubstitutions {
  42 
  43     public static final String copyMemoryName = JavaVersionUtil.JAVA_SPEC <= 8 ? "copyMemory" : "copyMemory0";
  44 
  45     @SuppressWarnings("unused")
  46     @MethodSubstitution(isStatic = false)
  47     static void copyMemory(Object receiver, Object srcBase, long srcOffset, Object destBase, long destOffset, long bytes) {
  48         Word srcAddr = WordFactory.unsigned(ComputeObjectAddressNode.get(srcBase, srcOffset));
  49         Word dstAddr = WordFactory.unsigned(ComputeObjectAddressNode.get(destBase, destOffset));
  50         Word size = WordFactory.signed(bytes);
  51 
  52         HotSpotBackend.unsafeArraycopy(srcAddr, dstAddr, size);
  53     }
  54 
  55     @SuppressWarnings("unused")
  56     @MethodSubstitution(value = "copyMemory", isStatic = false)
  57     static void copyMemoryGuarded(Object receiver, Object srcBase, long srcOffset, Object destBase, long destOffset, long bytes) {
  58         Word srcAddr = WordFactory.unsigned(ComputeObjectAddressNode.get(srcBase, srcOffset));
  59         Word dstAddr = WordFactory.unsigned(ComputeObjectAddressNode.get(destBase, destOffset));
  60         Word size = WordFactory.signed(bytes);
  61         Word javaThread = CurrentJavaThreadNode.get();
  62         int offset = doingUnsafeAccessOffset(INJECTED_VMCONFIG);
  63         LocationIdentity any = LocationIdentity.any();
  64 
  65         /* Set doingUnsafeAccess to guard and handle unsafe memory access failures */
  66         javaThread.writeByte(offset, (byte) 1, any);
  67         HotSpotBackend.unsafeArraycopy(srcAddr, dstAddr, size);
  68         /* Reset doingUnsafeAccess */
  69         javaThread.writeByte(offset, (byte) 0, any);
  70     }
  71 }