1 /*
2 * Copyright (c) 2018, 2023, 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 sun.jvm.hotspot.memory;
26
27 import java.util.*;
28 import sun.jvm.hotspot.debugger.Address;
29 import sun.jvm.hotspot.runtime.VM;
30 import sun.jvm.hotspot.runtime.VMObject;
31 import sun.jvm.hotspot.runtime.VMObjectFactory;
32 import sun.jvm.hotspot.types.*;
33 import sun.jvm.hotspot.utilities.Observable;
34 import sun.jvm.hotspot.utilities.Observer;
35
36 public class FileMapInfo {
37 private static FileMapHeader headerObj;
38
39 // Fields for handling the copied C++ vtables
40 private static Address rwRegionBaseAddress;
41 private static Address rwRegionEndAddress;
42 private static Address vtablesIndex;
43
44 // HashMap created by mapping the vTable addresses in the rw region with
45 // the corresponding metadata type.
46 private static Map<Address, Type> vTableTypeMap;
47
48 private static Type metadataTypeArray[];
49
50 static {
51 VM.registerVMInitializedObserver(new Observer() {
52 public void update(Observable o, Object data) {
53 initialize(VM.getVM().getTypeDataBase());
54 }
55 });
56 }
57
58 static Address getStatic_AddressField(Type type, String fieldName) {
59 AddressField field = type.getAddressField(fieldName);
60 return field.getValue();
61 }
62
63 static Address get_AddressField(Type type, Address instance, String fieldName) {
64 AddressField field = type.getAddressField(fieldName);
65 return field.getValue(instance);
66 }
67
68 static long get_CIntegerField(Type type, Address instance, String fieldName) {
69 CIntegerField field = type.getCIntegerField(fieldName);
70 return field.getValue(instance);
71 }
72
73 // C equivalent: return &header->_regions[index];
74 static Address get_CDSFileMapRegion(Type FileMapHeader_type, Address header, int index) {
75 AddressField regionsField = FileMapHeader_type.getAddressField("_regions[0]");
76
77 // size_t offset = offsetof(FileMapHeader, _regions[0]);
78 // CDSFileMapRegion* regions_0 = ((char*)header) + offset; // regions_0 = &header->_regions[index];
79 // return ((char*)regions_0) + index * sizeof(CDSFileMapRegion);
80 long offset = regionsField.getOffset();
81 Address regions_0 = header.addOffsetTo(offset);
82 return regions_0.addOffsetTo(index * regionsField.getSize());
83 }
84
85 private static void initialize(TypeDataBase db) {
86 vTableTypeMap = null; // force vTableTypeMap to get re-initialized later
87
88 Type FileMapInfo_type = db.lookupType("FileMapInfo");
89 Type FileMapHeader_type = db.lookupType("FileMapHeader");
90 Type CDSFileMapRegion_type = db.lookupType("CDSFileMapRegion");
91
92 // FileMapInfo * info = FileMapInfo::_current_info;
93 // FileMapHeader* header = info->_header
94 Address info = getStatic_AddressField(FileMapInfo_type, "_current_info");
95 Address header = get_AddressField(FileMapInfo_type, info, "_header");
96 headerObj = VMObjectFactory.newObject(FileMapHeader.class, header);
97
98 // char* mapped_base_address = header->_mapped_base_address
99 // size_t cloned_vtable_offset = header->_cloned_vtable_offset
100 // CppVtableInfo** vtablesIndex = mapped_base_address + cloned_vtable_offset;
101 Address mapped_base_address = get_AddressField(FileMapHeader_type, header, "_mapped_base_address");
102 long cloned_vtable_offset = get_CIntegerField(FileMapHeader_type, header, "_cloned_vtables_offset");
103 vtablesIndex = mapped_base_address.addOffsetTo(cloned_vtable_offset);
104
105 // CDSFileMapRegion* rw_region = &header->_region[rw];
106 // char* rwRegionBaseAddress = rw_region->_mapped_base;
107 // size_t used = rw_region->_used;
108 // char* rwRegionEndAddress = rwRegionBaseAddress + used;
109 Address rw_region = get_CDSFileMapRegion(FileMapHeader_type, header, 0);
110 rwRegionBaseAddress = get_AddressField(CDSFileMapRegion_type, rw_region, "_mapped_base");
111 long used = get_CIntegerField(CDSFileMapRegion_type, rw_region, "_used");
112 rwRegionEndAddress = rwRegionBaseAddress.addOffsetTo(used);
113
114 populateMetadataTypeArray(db);
115 }
116
117 private static void populateMetadataTypeArray(TypeDataBase db) {
118 metadataTypeArray = new Type[9];
119
120 metadataTypeArray[0] = db.lookupType("ConstantPool");
121 metadataTypeArray[1] = db.lookupType("InstanceKlass");
122 metadataTypeArray[2] = db.lookupType("InstanceClassLoaderKlass");
123 metadataTypeArray[3] = db.lookupType("InstanceMirrorKlass");
124 metadataTypeArray[4] = db.lookupType("InstanceRefKlass");
125 metadataTypeArray[5] = db.lookupType("InstanceStackChunkKlass");
126 metadataTypeArray[6] = db.lookupType("Method");
127 metadataTypeArray[7] = db.lookupType("ObjArrayKlass");
128 metadataTypeArray[8] = db.lookupType("TypeArrayKlass");
129 }
130
131 public FileMapHeader getHeader() {
132 return headerObj;
133 }
134
135 public boolean inCopiedVtableSpace(Address vptrAddress) {
136 FileMapHeader fmHeader = getHeader();
137 return fmHeader.inCopiedVtableSpace(vptrAddress);
138 }
139
140 public Type getTypeForVptrAddress(Address vptrAddress) {
141 if (vTableTypeMap == null) {
142 getHeader().createVtableTypeMapping();
143 }
144 return vTableTypeMap.get(vptrAddress);
145 }
146
147
148 //------------------------------------------------------------------------------------------
149
150 public static class FileMapHeader extends VMObject {
151
152 public FileMapHeader(Address addr) {
153 super(addr);
154 }
155
156 public boolean inCopiedVtableSpace(Address vptrAddress) {
157 if (vptrAddress == null) {
158 return false;
159 }
160 if (vptrAddress.greaterThan(rwRegionBaseAddress) &&
161 vptrAddress.lessThanOrEqual(rwRegionEndAddress)) {
162 return true;
163 }
164 return false;
165 }
166
167 public void createVtableTypeMapping() {
168 vTableTypeMap = new HashMap<Address, Type>();
169 long addressSize = VM.getVM().getAddressSize();
170
171 // vtablesIndex points to this:
172 // class CppVtableInfo {
173 // intptr_t _vtable_size;
174 // intptr_t _cloned_vtable[1];
175 // ...
176 // };
177 // CppVtableInfo** CppVtables::_index;
178 // This is the index of all the cloned vtables. E.g., for
179 // ConstantPool* cp = ....; // an archived constant pool
180 // InstanceKlass* ik = ....;// an archived class
181 // the following holds true:
182 // &_index[ConstantPool_Kind]->_cloned_vtable[0] == ((intptr_t**)cp)[0]
183 // &_index[InstanceKlass_Kind]->_cloned_vtable[0] == ((intptr_t**)ik)[0]
184
185 for (int i=0; i < metadataTypeArray.length; i++) {
186 Address vtableInfoAddress = vtablesIndex.getAddressAt(i * addressSize); // = _index[i]
187 Address vtableAddress = vtableInfoAddress.addOffsetTo(addressSize); // = &_index[i]->_cloned_vtable[0]
188 vTableTypeMap.put(vtableAddress, metadataTypeArray[i]);
189 }
190 }
191 }
192 }