1 /* 2 * Copyright (c) 2016, 2017, 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 package jdk.tools.jaotc; 25 26 import jdk.tools.jaotc.binformat.BinaryContainer; 27 import jdk.tools.jaotc.binformat.Symbol; 28 import jdk.tools.jaotc.StubInformation; 29 30 import jdk.vm.ci.code.site.Call; 31 import jdk.vm.ci.hotspot.HotSpotResolvedJavaMethod; 32 33 /** 34 * Symbol for a regular Java call. This method also creates additional relocations for {@code .plt} 35 * to {@code .got} and {@code .got} to {@code .plt}. 36 */ 37 final class JavaCallSiteRelocationSymbol extends CallSiteRelocationSymbol { 38 39 private static final byte[] zeroSlot = new byte[8]; 40 // -1 represents Universe::non_oop_word() value 41 private static final byte[] minusOneSlot = {-1, -1, -1, -1, -1, -1, -1, -1}; 42 43 JavaCallSiteRelocationSymbol(CompiledMethodInfo mi, Call call, CallSiteRelocationInfo callSiteRelocation, BinaryContainer binaryContainer) { 44 super(createPltEntrySymbol(binaryContainer, mi, call, callSiteRelocation)); 45 StubInformation stub = getStub(mi, call); 46 addRelocations(mi, stub, binaryContainer, call, callSiteRelocation); 47 } 48 49 /** 50 * Returns a unique symbol name with the {@code suffix} appended. 51 */ 52 private static String relocationSymbolName(String suffix, CompiledMethodInfo mi, Call call, CallSiteRelocationInfo callSiteRelocation) { 53 return "M" + mi.getCodeId() + "_" + call.pcOffset + "_" + callSiteRelocation.targetSymbol + "_" + suffix; 54 } 55 56 private static Symbol createPltEntrySymbol(BinaryContainer binaryContainer, CompiledMethodInfo mi, Call call, CallSiteRelocationInfo callSiteRelocation) { 57 String symbolName = relocationSymbolName("plt.entry", mi, call, callSiteRelocation); 58 StubInformation stub = getStub(mi, call); 59 return createCodeContainerSymbol(binaryContainer, symbolName, stub.getOffset()); 60 } 61 62 private static StubInformation getStub(CompiledMethodInfo mi, Call call) { 63 HotSpotResolvedJavaMethod callTarget = (HotSpotResolvedJavaMethod) call.target; 64 String callTargetSymbol = JavaMethodInfo.uniqueMethodName(callTarget) + ".at." + call.pcOffset; 65 return mi.getStubFor(callTargetSymbol); 66 } 67 68 /** 69 * Add all the required relocations. 70 */ 71 private static void addRelocations(CompiledMethodInfo mi, StubInformation stub, BinaryContainer binaryContainer, Call call, CallSiteRelocationInfo callSiteRelocation) { 72 final boolean isVirtualCall = CallInfo.isVirtualCall(mi, call); 73 74 final int gotStartOffset = binaryContainer.appendExtLinkageGotBytes(zeroSlot, 0, zeroSlot.length); 75 if (isVirtualCall) { 76 // Nothing. 77 } else { 78 // For c2i stub we need slot with -1 value. 79 binaryContainer.appendExtLinkageGotBytes(minusOneSlot, 0, minusOneSlot.length); 80 } 81 82 // Add relocation to GOT cell for call resolution jump. 83 // This GOT cell will be initialized during JVM startup with address 84 // of JVM runtime call resolution function. 85 String gotSymbolName = "got." + getResolveSymbolName(mi, call); 86 Symbol gotSymbol = binaryContainer.getGotSymbol(gotSymbolName); 87 addExternalPltToGotRelocation(binaryContainer, gotSymbol, stub.getResolveJumpOffset()); 88 89 // Add relocation to resolve call jump instruction address for GOT cell. 90 // This GOT cell will be initialized with address of resolution jump instruction and 91 // will be updated with call destination address by JVM runtime call resolution code. 92 String pltJmpSymbolName = relocationSymbolName("plt.jmp", mi, call, callSiteRelocation); 93 addCodeContainerRelocation(binaryContainer, pltJmpSymbolName, stub.getResolveJumpStart(), gotStartOffset); 94 95 // Add relocation to GOT cell for dispatch jump. 96 // The dispatch jump loads destination address from this GOT cell. 97 String gotEntrySymbolName = relocationSymbolName("got.entry", mi, call, callSiteRelocation); 98 addExtLinkageGotContainerRelocation(binaryContainer, gotEntrySymbolName, gotStartOffset, stub.getDispatchJumpOffset()); 99 100 // Virtual call needs initial -1 value for Klass pointer. 101 // Non virtual call needs initial 0 value for Method pointer to call c2i adapter. 102 byte[] slot = isVirtualCall ? minusOneSlot : zeroSlot; 103 final int gotMetaOffset = binaryContainer.appendExtLinkageGotBytes(slot, 0, slot.length); 104 105 // Add relocation to GOT cell for move instruction (Klass* for virtual, Method* otherwise). 106 String gotMoveSymbolName = relocationSymbolName("got.move", mi, call, callSiteRelocation); 107 addExtLinkageGotContainerRelocation(binaryContainer, gotMoveSymbolName, gotMetaOffset, stub.getMovOffset()); 108 109 if (isVirtualCall) { 110 // Nothing. 111 } else { 112 // Add relocation to GOT cell for c2i adapter jump. 113 // The c2i jump instruction loads destination address from this GOT cell. 114 // This GOT cell is initialized with -1 and will be updated 115 // by JVM runtime call resolution code. 116 String gotC2ISymbolName = relocationSymbolName("got.c2i", mi, call, callSiteRelocation); 117 addExtLinkageGotContainerRelocation(binaryContainer, gotC2ISymbolName, gotStartOffset + 8, stub.getC2IJumpOffset()); 118 } 119 } 120 121 /** 122 * Returns the name of the resolve method for this particular call. 123 */ 124 private static String getResolveSymbolName(CompiledMethodInfo mi, Call call) { 125 String resolveSymbolName; 126 if (CallInfo.isStaticCall(call)) { 127 resolveSymbolName = BinaryContainer.getResolveStaticEntrySymbolName(); 128 } else if (CallInfo.isSpecialCall(call)) { 129 resolveSymbolName = BinaryContainer.getResolveOptVirtualEntrySymbolName(); 130 } else if (CallInfo.isOptVirtualCall(mi, call)) { 131 resolveSymbolName = BinaryContainer.getResolveOptVirtualEntrySymbolName(); 132 } else if (CallInfo.isVirtualCall(mi, call)) { 133 resolveSymbolName = BinaryContainer.getResolveVirtualEntrySymbolName(); 134 } else { 135 throw new InternalError("Unknown call type in " + mi.asTag() + " @ " + call.pcOffset + " for call" + call.target); 136 } 137 return resolveSymbolName; 138 } 139 140 }