1 /*
2 * Copyright (c) 2003, 2025, 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 #include "cds/cdsConfig.hpp"
26 #include "classfile/symbolTable.hpp"
27 #include "classfile/systemDictionary.hpp"
28 #include "classfile/systemDictionaryShared.hpp"
29 #include "classfile/verificationType.hpp"
30 #include "classfile/verifier.hpp"
31 #include "classfile/vmClasses.hpp"
32 #include "classfile/vmSymbols.hpp"
33 #include "logging/log.hpp"
34 #include "oops/klass.inline.hpp"
35 #include "runtime/handles.inline.hpp"
36
37 VerificationType VerificationType::from_tag(u1 tag) {
38 switch (tag) {
39 case ITEM_Top: return bogus_type();
40 case ITEM_Integer: return integer_type();
41 case ITEM_Float: return float_type();
42 case ITEM_Double: return double_type();
43 case ITEM_Long: return long_type();
44 case ITEM_Null: return null_type();
45 default:
46 ShouldNotReachHere();
47 return bogus_type();
48 }
49 }
50
51 // Potentially resolve the target class and from class, and check whether the from class is assignable
52 // to the target class. The current_klass is the class being verified - it could also be the target in some
53 // cases, and otherwise is needed to obtain the correct classloader for resolving the other classes.
54 bool VerificationType::resolve_and_check_assignability(InstanceKlass* current_klass, Symbol* target_name, Symbol* from_name,
55 bool from_field_is_protected, bool from_is_array,
56 bool from_is_object, bool* target_is_interface, TRAPS) {
57 HandleMark hm(THREAD);
58 Klass* target_klass;
59 if (current_klass->is_hidden() && current_klass->name() == target_name) {
60 target_klass = current_klass;
61 } else {
62 target_klass = SystemDictionary::resolve_or_fail(
63 target_name, Handle(THREAD, current_klass->class_loader()), true, CHECK_false);
64 if (log_is_enabled(Debug, class, resolve)) {
65 Verifier::trace_class_resolution(target_klass, current_klass);
66 }
67 }
68
69 bool is_intf = target_klass->is_interface();
70 if (target_is_interface != nullptr) {
71 *target_is_interface = is_intf;
72 }
73
74 if (is_intf && (!from_field_is_protected ||
75 from_name != vmSymbols::java_lang_Object())) {
76 // If we are not trying to access a protected field or method in
77 // java.lang.Object then, for arrays, we only allow assignability
78 // to interfaces java.lang.Cloneable and java.io.Serializable.
79 // Otherwise, we treat interfaces as java.lang.Object.
80 return !from_is_array ||
81 target_klass == vmClasses::Cloneable_klass() ||
82 target_klass == vmClasses::Serializable_klass();
83 } else if (from_is_object) {
84 Klass* from_klass;
85 if (current_klass->is_hidden() && current_klass->name() == from_name) {
86 from_klass = current_klass;
87 } else {
88 from_klass = SystemDictionary::resolve_or_fail(
89 from_name, Handle(THREAD, current_klass->class_loader()), true, CHECK_false);
90 if (log_is_enabled(Debug, class, resolve)) {
91 Verifier::trace_class_resolution(from_klass, current_klass);
92 }
93 }
94 return from_klass->is_subclass_of(target_klass);
95 }
96
97 return false;
98 }
99
100 bool VerificationType::is_reference_assignable_from(
101 const VerificationType& from, ClassVerifier* context,
102 bool from_field_is_protected, bool* this_is_interface, TRAPS) const {
103
104 if (from.is_null()) {
105 // null is assignable to any reference
106 return true;
107 } else if (is_null()) {
108 return false;
109 } else if (name() == from.name()) {
110 return true;
111 } else if (is_object()) {
112 // We need check the class hierarchy to check assignability
113 if (name() == vmSymbols::java_lang_Object()) {
114 // any object or array is assignable to java.lang.Object
115 return true;
116 }
117
118 #if INCLUDE_CDS
119 if (CDSConfig::is_dumping_archive()) {
120 bool skip_assignability_check = false;
121 SystemDictionaryShared::add_verification_constraint(context->current_class(),
122 name(), from.name(), from_field_is_protected, from.is_array(),
123 from.is_object(), &skip_assignability_check);
124 if (skip_assignability_check) {
125 // We are not able to resolve name() or from.name(). The actual assignability check
126 // will be delayed until runtime.
127 return true;
128 }
129 }
130 #endif
131 return resolve_and_check_assignability(context->current_class(), name(), from.name(),
132 from_field_is_protected, from.is_array(),
133 from.is_object(), this_is_interface, THREAD);
134 } else if (is_array() && from.is_array()) {
135 VerificationType comp_this = get_component(context);
136 VerificationType comp_from = from.get_component(context);
137 if (!comp_this.is_bogus() && !comp_from.is_bogus()) {
138 return comp_this.is_component_assignable_from(comp_from, context,
139 from_field_is_protected, THREAD);
140 }
141 }
142 return false;
143 }
144
145 VerificationType VerificationType::get_component(ClassVerifier *context) const {
146 assert(is_array() && name()->utf8_length() >= 2, "Must be a valid array");
147 SignatureStream ss(name(), false);
148 ss.skip_array_prefix(1);
149 switch (ss.type()) {
150 case T_BOOLEAN: return VerificationType(Boolean);
151 case T_BYTE: return VerificationType(Byte);
152 case T_CHAR: return VerificationType(Char);
153 case T_SHORT: return VerificationType(Short);
154 case T_INT: return VerificationType(Integer);
155 case T_LONG: return VerificationType(Long);
156 case T_FLOAT: return VerificationType(Float);
157 case T_DOUBLE: return VerificationType(Double);
158 case T_ARRAY:
159 case T_OBJECT: {
160 guarantee(ss.is_reference(), "unchecked verifier input?");
161 Symbol* component = ss.as_symbol();
162 // Create another symbol to save as signature stream unreferences this symbol.
163 Symbol* component_copy = context->create_temporary_symbol(component);
164 assert(component_copy == component, "symbols don't match");
165 return VerificationType::reference_type(component_copy);
166 }
167 default:
168 // Met an invalid type signature, e.g. [X
169 return VerificationType::bogus_type();
170 }
171 }
172
173 void VerificationType::print_on(outputStream* st) const {
174 switch (_u._data) {
175 case Bogus: st->print("top"); break;
176 case Category1: st->print("category1"); break;
177 case Category2: st->print("category2"); break;
178 case Category2_2nd: st->print("category2_2nd"); break;
179 case Boolean: st->print("boolean"); break;
180 case Byte: st->print("byte"); break;
181 case Short: st->print("short"); break;
182 case Char: st->print("char"); break;
183 case Integer: st->print("integer"); break;
184 case Float: st->print("float"); break;
185 case Long: st->print("long"); break;
186 case Double: st->print("double"); break;
187 case Long_2nd: st->print("long_2nd"); break;
188 case Double_2nd: st->print("double_2nd"); break;
189 case Null: st->print("null"); break;
190 case ReferenceQuery: st->print("reference type"); break;
191 case Category1Query: st->print("category1 type"); break;
192 case Category2Query: st->print("category2 type"); break;
193 case Category2_2ndQuery: st->print("category2_2nd type"); break;
194 default:
195 if (is_uninitialized_this()) {
196 st->print("uninitializedThis");
197 } else if (is_uninitialized()) {
198 st->print("uninitialized %d", bci());
199 } else {
200 if (name() != nullptr) {
201 name()->print_value_on(st);
202 } else {
203 st->print_cr("null");
204 }
205 }
206 }
207 }