1 /*
2 * Copyright (c) 2003, 2019, 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 "precompiled.hpp"
26 #include "classfile/symbolTable.hpp"
27 #include "classfile/systemDictionaryShared.hpp"
28 #include "classfile/verificationType.hpp"
29 #include "classfile/verifier.hpp"
30 #include "logging/log.hpp"
31 #include "runtime/handles.inline.hpp"
32
33 VerificationType VerificationType::from_tag(u1 tag) {
34 switch (tag) {
35 case ITEM_Top: return bogus_type();
36 case ITEM_Integer: return integer_type();
37 case ITEM_Float: return float_type();
38 case ITEM_Double: return double_type();
39 case ITEM_Long: return long_type();
40 case ITEM_Null: return null_type();
41 default:
42 ShouldNotReachHere();
43 return bogus_type();
44 }
45 }
46
47 bool VerificationType::resolve_and_check_assignability(InstanceKlass* klass, Symbol* name,
48 Symbol* from_name, bool from_field_is_protected, bool from_is_array, bool from_is_object, TRAPS) {
49 HandleMark hm(THREAD);
50 Klass* this_class = SystemDictionary::resolve_or_fail(
51 name, Handle(THREAD, klass->class_loader()),
52 Handle(THREAD, klass->protection_domain()), true, CHECK_false);
53 klass->class_loader_data()->record_dependency(this_class);
54 if (log_is_enabled(Debug, class, resolve)) {
55 Verifier::trace_class_resolution(this_class, klass);
56 }
57
58 if (this_class->access_flags().is_value_type()) return false;
59 if (this_class->is_interface() && (!from_field_is_protected ||
60 from_name != vmSymbols::java_lang_Object())) {
61 // If we are not trying to access a protected field or method in
62 // java.lang.Object then, for arrays, we only allow assignability
63 // to interfaces java.lang.Cloneable and java.io.Serializable.
64 // Otherwise, we treat interfaces as java.lang.Object.
65 return !from_is_array ||
66 this_class == SystemDictionary::Cloneable_klass() ||
67 this_class == SystemDictionary::Serializable_klass();
68 } else if (from_is_object) {
69 Klass* from_class = SystemDictionary::resolve_or_fail(
70 from_name, Handle(THREAD, klass->class_loader()),
71 Handle(THREAD, klass->protection_domain()), true, CHECK_false);
72 klass->class_loader_data()->record_dependency(from_class);
73 if (log_is_enabled(Debug, class, resolve)) {
74 Verifier::trace_class_resolution(from_class, klass);
75 }
76 return InstanceKlass::cast(from_class)->is_subclass_of(this_class);
77 }
78
79 return false;
80 }
81
82 bool VerificationType::is_reference_assignable_from(
83 const VerificationType& from, ClassVerifier* context,
84 bool from_field_is_protected, TRAPS) const {
85 InstanceKlass* klass = context->current_class();
86 if (from.is_null()) {
87 // null is assignable to any reference
88 return true;
89 } else if (is_null()) {
90 return false;
91 } else if (name() == from.name()) {
92 return true;
93 } else if (is_object()) {
94 // We need check the class hierarchy to check assignability
95 if (name() == vmSymbols::java_lang_Object()) {
96 // any object or array is assignable to java.lang.Object
97 return true;
98 }
99
100 if (DumpSharedSpaces && SystemDictionaryShared::add_verification_constraint(klass,
101 name(), from.name(), from_field_is_protected, from.is_array(),
102 from.is_object())) {
103 // If add_verification_constraint() returns true, the resolution/check should be
104 // delayed until runtime.
105 return true;
106 }
107
108 return resolve_and_check_assignability(klass, name(), from.name(),
109 from_field_is_protected, from.is_array(), from.is_object(), THREAD);
110 } else if (is_array() && from.is_array()) {
111 VerificationType comp_this = get_component(context, CHECK_false);
112 VerificationType comp_from = from.get_component(context, CHECK_false);
113
114 // This code implements non-covariance between value type arrays and both
115 // arrays of objects and arrays of interface types. If covariance is
116 // supported for value type arrays then this code should be removed.
117 if (comp_from.is_valuetype() && !comp_this.is_null() && comp_this.is_reference()) {
118 // An array of value types is not assignable to an array of java.lang.Objects.
119 if (comp_this.name() == vmSymbols::java_lang_Object()) {
120 return false;
121 }
122
123 // Need to load 'comp_this' to see if it is an interface.
124 InstanceKlass* klass = context->current_class();
125 {
126 HandleMark hm(THREAD);
127 Klass* comp_this_class = SystemDictionary::resolve_or_fail(
128 comp_this.name(), Handle(THREAD, klass->class_loader()),
129 Handle(THREAD, klass->protection_domain()), true, CHECK_false);
130 klass->class_loader_data()->record_dependency(comp_this_class);
131 if (log_is_enabled(Debug, class, resolve)) {
132 Verifier::trace_class_resolution(comp_this_class, klass);
133 }
134 // An array of value types is not assignable to an array of interface types.
135 if (comp_this_class->is_interface()) {
136 return false;
137 }
138 }
139 }
140
141 if (!comp_this.is_bogus() && !comp_from.is_bogus()) {
142 return comp_this.is_component_assignable_from(comp_from, context,
143 from_field_is_protected, THREAD);
144 }
145 }
146 return false;
147 }
148
149 bool VerificationType::is_valuetype_assignable_from(const VerificationType& from) const {
150 // Check that 'from' is not null, is a value type, and is the same value type.
151 assert(is_valuetype(), "called with a non-valuetype type");
152 assert(!is_null(), "valuetype is not null");
153 assert(name() != vmSymbols::java_lang_Object(), "java.lang.Object is a value type?");
154 return (!from.is_null() && from.is_valuetype() && name() == from.name());
155 }
156
157 bool VerificationType::is_ref_assignable_from_value_type(const VerificationType& from, ClassVerifier* context, TRAPS) const {
158 assert(!from.is_null(), "Value type should not be null");
159 if (!is_null() && (name()->is_same_fundamental_type(from.name()) ||
160 name() == vmSymbols::java_lang_Object())) {
161 return true;
162 }
163
164 // Need to load 'this' to see if it is an interface.
165 InstanceKlass* klass = context->current_class();
166 {
167 HandleMark hm(THREAD);
168 Klass* this_class = SystemDictionary::resolve_or_fail(
169 name(), Handle(THREAD, klass->class_loader()),
170 Handle(THREAD, klass->protection_domain()), true, CHECK_false);
171 klass->class_loader_data()->record_dependency(this_class);
172 if (log_is_enabled(Debug, class, resolve)) {
173 Verifier::trace_class_resolution(this_class, klass);
174 }
175 return (this_class->is_interface());
176 }
177 }
178
179 VerificationType VerificationType::get_component(ClassVerifier *context, TRAPS) const {
180 assert(is_array() && name()->utf8_length() >= 2, "Must be a valid array");
181 Symbol* component;
182 switch (name()->char_at(1)) {
183 case 'Z': return VerificationType(Boolean);
184 case 'B': return VerificationType(Byte);
185 case 'C': return VerificationType(Char);
186 case 'S': return VerificationType(Short);
187 case 'I': return VerificationType(Integer);
188 case 'J': return VerificationType(Long);
189 case 'F': return VerificationType(Float);
190 case 'D': return VerificationType(Double);
191 case '[':
192 component = context->create_temporary_symbol(
193 name(), 1, name()->utf8_length(),
194 CHECK_(VerificationType::bogus_type()));
195 return VerificationType::reference_type(component);
196 case 'L':
197 component = context->create_temporary_symbol(
198 name(), 2, name()->utf8_length() - 1,
199 CHECK_(VerificationType::bogus_type()));
200 return VerificationType::reference_type(component);
201 case 'Q':
202 component = context->create_temporary_symbol(
203 name(), 2, name()->utf8_length() - 1,
204 CHECK_(VerificationType::bogus_type()));
205 return VerificationType::valuetype_type(component);
206 default:
207 // Met an invalid type signature, e.g. [X
208 return VerificationType::bogus_type();
209 }
210 }
211
212 void VerificationType::print_on(outputStream* st) const {
213 switch (_u._data) {
214 case Bogus: st->print("top"); break;
215 case Category1: st->print("category1"); break;
216 case Category2: st->print("category2"); break;
217 case Category2_2nd: st->print("category2_2nd"); break;
218 case Boolean: st->print("boolean"); break;
219 case Byte: st->print("byte"); break;
220 case Short: st->print("short"); break;
221 case Char: st->print("char"); break;
222 case Integer: st->print("integer"); break;
223 case Float: st->print("float"); break;
224 case Long: st->print("long"); break;
225 case Double: st->print("double"); break;
226 case Long_2nd: st->print("long_2nd"); break;
227 case Double_2nd: st->print("double_2nd"); break;
228 case Null: st->print("null"); break;
229 case ReferenceQuery: st->print("reference type"); break;
230 case ValueTypeQuery: st->print("value type"); break;
231 case NonScalarQuery: st->print("reference or value type"); break;
232 case Category1Query: st->print("category1 type"); break;
233 case Category2Query: st->print("category2 type"); break;
234 case Category2_2ndQuery: st->print("category2_2nd type"); break;
235 default:
236 if (is_uninitialized_this()) {
237 st->print("uninitializedThis");
238 } else if (is_uninitialized()) {
239 st->print("uninitialized %d", bci());
240 } else if (is_valuetype()) {
241 name()->print_Qvalue_on(st);
242 } else {
243 if (name() != NULL) {
244 name()->print_value_on(st);
245 } else {
246 st->print_cr("NULL");
247 }
248 }
249 }
250 }