1 /*
2 * Copyright (c) 2016, 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 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;
42
43 static {
44 String archStr = System.getProperty("os.arch").toLowerCase();
45 if (archStr.equals("aarch64")) {
46 // AArch64 is a special case: it uses 48-bit addresses.
47 byte[] non_oop_word = {-1, -1, -1, -1, -1, -1, 0, 0};
48 minusOneSlot = non_oop_word;
49 } else {
50 byte[] non_oop_word = {-1, -1, -1, -1, -1, -1, -1, -1};
51 minusOneSlot = non_oop_word;
52 }
53 }
54
55 JavaCallSiteRelocationSymbol(CompiledMethodInfo mi, Call call, CallSiteRelocationInfo callSiteRelocation, BinaryContainer binaryContainer) {
56 super(createPltEntrySymbol(binaryContainer, mi, call, callSiteRelocation));
57 StubInformation stub = getStub(mi, call);
58 addRelocations(mi, stub, binaryContainer, call, callSiteRelocation);
59 }
60
61 /**
62 * Returns a unique symbol name with the {@code suffix} appended.
63 */
64 private static String relocationSymbolName(String suffix, CompiledMethodInfo mi, Call call, CallSiteRelocationInfo callSiteRelocation) {
65 return "M" + mi.getCodeId() + "_" + call.pcOffset + "_" + callSiteRelocation.targetSymbol + "_" + suffix;
66 }
67
68 private static Symbol createPltEntrySymbol(BinaryContainer binaryContainer, CompiledMethodInfo mi, Call call, CallSiteRelocationInfo callSiteRelocation) {
69 String symbolName = relocationSymbolName("plt.entry", mi, call, callSiteRelocation);
70 StubInformation stub = getStub(mi, call);
71 return createCodeContainerSymbol(binaryContainer, symbolName, stub.getOffset());
72 }
73
74 private static StubInformation getStub(CompiledMethodInfo mi, Call call) {
75 HotSpotResolvedJavaMethod callTarget = (HotSpotResolvedJavaMethod) call.target;
76 String callTargetSymbol = JavaMethodInfo.uniqueMethodName(callTarget) + ".at." + call.pcOffset;
77 return mi.getStubFor(callTargetSymbol);
78 }
79
80 /**
81 * Add all the required relocations.
82 */
83 private static void addRelocations(CompiledMethodInfo mi, StubInformation stub, BinaryContainer binaryContainer, Call call, CallSiteRelocationInfo callSiteRelocation) {
84 final boolean isVirtualCall = CallInfo.isVirtualCall(mi, call);
85
86 final int gotStartOffset = binaryContainer.appendExtLinkageGotBytes(zeroSlot, 0, zeroSlot.length);
87 if (isVirtualCall) {
88 // Nothing.
89 } else {
90 // For c2i stub we need slot with -1 value.
91 binaryContainer.appendExtLinkageGotBytes(minusOneSlot, 0, minusOneSlot.length);
92 }
93
94 // Add relocation to GOT cell for call resolution jump.
95 // This GOT cell will be initialized during JVM startup with address
96 // of JVM runtime call resolution function.
97 String gotSymbolName = "got." + getResolveSymbolName(mi, call);
98 Symbol gotSymbol = binaryContainer.getGotSymbol(gotSymbolName);
99 addExternalPltToGotRelocation(binaryContainer, gotSymbol, stub.getResolveJumpOffset());
100
101 // Add relocation to resolve call jump instruction address for GOT cell.
102 // This GOT cell will be initialized with address of resolution jump instruction and
103 // will be updated with call destination address by JVM runtime call resolution code.
104 String pltJmpSymbolName = relocationSymbolName("plt.jmp", mi, call, callSiteRelocation);
105 addCodeContainerRelocation(binaryContainer, pltJmpSymbolName, stub.getResolveJumpStart(), gotStartOffset);
106
107 // Add relocation to GOT cell for dispatch jump.
108 // The dispatch jump loads destination address from this GOT cell.
109 String gotEntrySymbolName = relocationSymbolName("got.entry", mi, call, callSiteRelocation);
110 addExtLinkageGotContainerRelocation(binaryContainer, gotEntrySymbolName, gotStartOffset, stub.getDispatchJumpOffset());
111
112 // Virtual call needs initial -1 value for Klass pointer.
113 // Non virtual call needs initial 0 value for Method pointer to call c2i adapter.
114 byte[] slot = isVirtualCall ? minusOneSlot : zeroSlot;
115 final int gotMetaOffset = binaryContainer.appendExtLinkageGotBytes(slot, 0, slot.length);
116
117 // Add relocation to GOT cell for move instruction (Klass* for virtual, Method* otherwise).
118 String gotMoveSymbolName = relocationSymbolName("got.move", mi, call, callSiteRelocation);
119 addExtLinkageGotContainerRelocation(binaryContainer, gotMoveSymbolName, gotMetaOffset, stub.getMovOffset());
120
121 if (isVirtualCall) {
122 // Nothing.
123 } else {
124 // Add relocation to GOT cell for c2i adapter jump.
125 // The c2i jump instruction loads destination address from this GOT cell.
126 // This GOT cell is initialized with -1 and will be updated
127 // by JVM runtime call resolution code.
128 String gotC2ISymbolName = relocationSymbolName("got.c2i", mi, call, callSiteRelocation);
129 addExtLinkageGotContainerRelocation(binaryContainer, gotC2ISymbolName, gotStartOffset + 8, stub.getC2IJumpOffset());
130 }
131 }
132
133 /**
134 * Returns the name of the resolve method for this particular call.
135 */
136 private static String getResolveSymbolName(CompiledMethodInfo mi, Call call) {
137 String resolveSymbolName;
138 String name = call.target.toString();
139 if (CallInfo.isStaticCall(call)) {
140 assert mi.hasMark(call, MarkId.INVOKESTATIC);
141 resolveSymbolName = BinaryContainer.getResolveStaticEntrySymbolName();
142 } else if (CallInfo.isSpecialCall(call)) {
143 resolveSymbolName = BinaryContainer.getResolveOptVirtualEntrySymbolName();
144 } else if (CallInfo.isOptVirtualCall(mi, call)) {
145 resolveSymbolName = BinaryContainer.getResolveOptVirtualEntrySymbolName();
146 } else if (CallInfo.isVirtualCall(mi, call)) {
147 resolveSymbolName = BinaryContainer.getResolveVirtualEntrySymbolName();
148 } else {
149 throw new InternalError("Unknown call type in " + mi.asTag() + " @ " + call.pcOffset + " for call" + call.target);
150 }
151 return resolveSymbolName;
152 }
153
154 }