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 assert mi.hasMark(call, MarkId.INVOKESTATIC);
128 resolveSymbolName = BinaryContainer.getResolveStaticEntrySymbolName();
129 } else if (CallInfo.isSpecialCall(call)) {
130 resolveSymbolName = BinaryContainer.getResolveOptVirtualEntrySymbolName();
131 } else if (CallInfo.isOptVirtualCall(mi, call)) {
132 resolveSymbolName = BinaryContainer.getResolveOptVirtualEntrySymbolName();
133 } else if (CallInfo.isVirtualCall(mi, call)) {
134 resolveSymbolName = BinaryContainer.getResolveVirtualEntrySymbolName();
135 } else {
136 throw new InternalError("Unknown call type in " + mi.asTag() + " @ " + call.pcOffset + " for call" + call.target);
137 }
138 return resolveSymbolName;
139 }
140
141 }