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