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->is_interface() && (!from_field_is_protected ||
  58       from_name != vmSymbols::java_lang_Object())) {
  59     // If we are not trying to access a protected field or method in
  60     // java.lang.Object then, for arrays, we only allow assignability
  61     // to interfaces java.lang.Cloneable and java.io.Serializable.
  62     // Otherwise, we treat interfaces as java.lang.Object.
  63     return !from_is_array ||
  64       this_class == SystemDictionary::Cloneable_klass() ||
  65       this_class == SystemDictionary::Serializable_klass();
  66   } else if (from_is_object) {
  67     Klass* from_class = SystemDictionary::resolve_or_fail(
  68         from_name, Handle(THREAD, klass->class_loader()),
  69         Handle(THREAD, klass->protection_domain()), true, CHECK_false);
  70     if (log_is_enabled(Debug, class, resolve)) {
  71       Verifier::trace_class_resolution(from_class, klass);
  72     }
  73     return InstanceKlass::cast(from_class)->is_subclass_of(this_class);
  74   }
  75 
  76   return false;
  77 }
  78 
  79 bool VerificationType::is_reference_assignable_from(
  80     const VerificationType& from, ClassVerifier* context,
  81     bool from_field_is_protected, TRAPS) const {
  82   InstanceKlass* klass = context->current_class();
  83   if (from.is_null()) {
  84     // null is assignable to any reference
  85     return true;
  86   } else if (is_null()) {
  87     return false;
  88   } else if (name() == from.name()) {
  89     return true;
  90   } else if (is_object()) {
  91     // We need check the class hierarchy to check assignability
  92     if (name() == vmSymbols::java_lang_Object()) {
  93       // any object or array is assignable to java.lang.Object
  94       return true;
  95     }
  96 
  97     if (Arguments::is_dumping_archive()) {
  98       if (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 
 107     return resolve_and_check_assignability(klass, name(), from.name(),
 108           from_field_is_protected, from.is_array(), from.is_object(), THREAD);
 109   } else if (is_array() && from.is_array()) {
 110     VerificationType comp_this = get_component(context, CHECK_false);
 111     VerificationType comp_from = from.get_component(context, CHECK_false);
 112     if (!comp_this.is_bogus() && !comp_from.is_bogus()) {
 113       return comp_this.is_component_assignable_from(comp_from, context,
 114                                                     from_field_is_protected, THREAD);
 115     }
 116   }
 117   return false;
 118 }
 119 
 120 VerificationType VerificationType::get_component(ClassVerifier *context, TRAPS) const {
 121   assert(is_array() && name()->utf8_length() >= 2, "Must be a valid array");
 122   Symbol* component;
 123   switch (name()->char_at(1)) {
 124     case 'Z': return VerificationType(Boolean);
 125     case 'B': return VerificationType(Byte);
 126     case 'C': return VerificationType(Char);
 127     case 'S': return VerificationType(Short);
 128     case 'I': return VerificationType(Integer);
 129     case 'J': return VerificationType(Long);
 130     case 'F': return VerificationType(Float);
 131     case 'D': return VerificationType(Double);
 132     case '[':
 133       component = context->create_temporary_symbol(
 134         name(), 1, name()->utf8_length());
 135       return VerificationType::reference_type(component);
 136     case 'L':
 137       component = context->create_temporary_symbol(
 138         name(), 2, name()->utf8_length() - 1);
 139       return VerificationType::reference_type(component);
 140     default:
 141       // Met an invalid type signature, e.g. [X
 142       return VerificationType::bogus_type();
 143   }
 144 }
 145 
 146 void VerificationType::print_on(outputStream* st) const {
 147   switch (_u._data) {
 148     case Bogus:            st->print("top"); break;
 149     case Category1:        st->print("category1"); break;
 150     case Category2:        st->print("category2"); break;
 151     case Category2_2nd:    st->print("category2_2nd"); break;
 152     case Boolean:          st->print("boolean"); break;
 153     case Byte:             st->print("byte"); break;
 154     case Short:            st->print("short"); break;
 155     case Char:             st->print("char"); break;
 156     case Integer:          st->print("integer"); break;
 157     case Float:            st->print("float"); break;
 158     case Long:             st->print("long"); break;
 159     case Double:           st->print("double"); break;
 160     case Long_2nd:         st->print("long_2nd"); break;
 161     case Double_2nd:       st->print("double_2nd"); break;
 162     case Null:             st->print("null"); break;
 163     case ReferenceQuery:   st->print("reference type"); break;
 164     case Category1Query:   st->print("category1 type"); break;
 165     case Category2Query:   st->print("category2 type"); break;
 166     case Category2_2ndQuery: st->print("category2_2nd type"); break;
 167     default:
 168       if (is_uninitialized_this()) {
 169         st->print("uninitializedThis");
 170       } else if (is_uninitialized()) {
 171         st->print("uninitialized %d", bci());
 172       } else {
 173         if (name() != NULL) {
 174           name()->print_value_on(st);
 175         } else {
 176           st->print_cr("NULL");
 177         }
 178       }
 179   }
 180 }