1 /* Copyright (C) 2017 The Android Open Source Project 2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 3 * 4 * This file implements interfaces from the file jvmti.h. This implementation 5 * is licensed under the same terms as the file jvmti.h. The 6 * copyright and license information for the file jvmti.h follows. 7 * 8 * Copyright (c) 2003, 2011, Oracle and/or its affiliates. All rights reserved. 9 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 10 * 11 * This code is free software; you can redistribute it and/or modify it 12 * under the terms of the GNU General Public License version 2 only, as 13 * published by the Free Software Foundation. Oracle designates this 14 * particular file as subject to the "Classpath" exception as provided 15 * by Oracle in the LICENSE file that accompanied this code. 16 * 17 * This code is distributed in the hope that it will be useful, but WITHOUT 18 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 19 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 20 * version 2 for more details (a copy is included in the LICENSE file that 21 * accompanied this code). 22 * 23 * You should have received a copy of the GNU General Public License version 24 * 2 along with this work; if not, write to the Free Software Foundation, 25 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 26 * 27 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 28 * or visit www.oracle.com if you need additional information or have any 29 * questions. 30 */ 31 32 #ifndef ART_OPENJDKJVMTI_TI_CLASS_DEFINITION_H_ 33 #define ART_OPENJDKJVMTI_TI_CLASS_DEFINITION_H_ 34 35 #include <stddef.h> 36 #include <sys/mman.h> 37 #include <sys/types.h> 38 39 #include "art_jvmti.h" 40 41 #include "base/array_ref.h" 42 #include "base/mem_map.h" 43 44 namespace openjdkjvmti { 45 46 // A struct that stores data needed for redefining/transforming classes. This structure should only 47 // even be accessed from a single thread and must not survive past the completion of the 48 // redefinition/retransformation function that created it. 49 class ArtClassDefinition { 50 public: 51 // If we support doing a on-demand dex-dequickening using signal handlers. 52 static constexpr bool kEnableOnDemandDexDequicken = true; 53 54 ArtClassDefinition() 55 : klass_(nullptr), 56 loader_(nullptr), 57 name_(), 58 protection_domain_(nullptr), 59 dex_data_mmap_(), 60 temp_mmap_(), 61 dex_data_memory_(), 62 initial_dex_file_unquickened_(nullptr), 63 dex_data_(), 64 current_dex_memory_(), 65 current_dex_file_(), 66 redefined_(false), 67 from_class_ext_(false), 68 initialized_(false) {} 69 70 void InitFirstLoad(const char* descriptor, 71 art::Handle<art::mirror::ClassLoader> klass_loader, 72 const art::DexFile& dex_file); 73 jvmtiError Init(art::Thread* self, jclass klass); 74 jvmtiError Init(art::Thread* self, const jvmtiClassDefinition& def); 75 76 ArtClassDefinition(ArtClassDefinition&& o) = default; 77 ArtClassDefinition& operator=(ArtClassDefinition&& o) = default; 78 79 void SetNewDexData(jint new_dex_len, unsigned char* new_dex_data) { 80 DCHECK(IsInitialized()); 81 if (new_dex_data == nullptr) { 82 return; 83 } else { 84 art::ArrayRef<const unsigned char> new_data(new_dex_data, new_dex_len); 85 if (new_data != dex_data_) { 86 dex_data_memory_.resize(new_dex_len); 87 memcpy(dex_data_memory_.data(), new_dex_data, new_dex_len); 88 dex_data_ = art::ArrayRef<const unsigned char>(dex_data_memory_); 89 } 90 } 91 } 92 93 art::ArrayRef<const unsigned char> GetNewOriginalDexFile() const { 94 DCHECK(IsInitialized()); 95 if (redefined_) { 96 return current_dex_file_; 97 } else { 98 return art::ArrayRef<const unsigned char>(); 99 } 100 } 101 102 bool ContainsAddress(uintptr_t ptr) const { 103 return dex_data_mmap_.IsValid() && 104 reinterpret_cast<uintptr_t>(dex_data_mmap_.Begin()) <= ptr && 105 reinterpret_cast<uintptr_t>(dex_data_mmap_.End()) > ptr; 106 } 107 108 bool IsModified() const REQUIRES_SHARED(art::Locks::mutator_lock_); 109 110 bool IsInitialized() const { 111 return initialized_; 112 } 113 114 jclass GetClass() const { 115 DCHECK(IsInitialized()); 116 return klass_; 117 } 118 119 jobject GetLoader() const { 120 DCHECK(IsInitialized()); 121 return loader_; 122 } 123 124 const std::string& GetName() const { 125 DCHECK(IsInitialized()); 126 return name_; 127 } 128 129 bool IsLazyDefinition() const { 130 DCHECK(IsInitialized()); 131 return dex_data_mmap_.IsValid() && 132 dex_data_.data() == dex_data_mmap_.Begin() && 133 dex_data_mmap_.GetProtect() == PROT_NONE; 134 } 135 136 jobject GetProtectionDomain() const { 137 DCHECK(IsInitialized()); 138 return protection_domain_; 139 } 140 141 art::ArrayRef<const unsigned char> GetDexData() const { 142 DCHECK(IsInitialized()); 143 return dex_data_; 144 } 145 146 void InitializeMemory() const; 147 148 private: 149 jvmtiError InitCommon(art::Thread* self, jclass klass); 150 151 template<typename GetOriginalDexFile> 152 void InitWithDex(GetOriginalDexFile get_original, const art::DexFile* quick_dex) 153 REQUIRES_SHARED(art::Locks::mutator_lock_); 154 155 jclass klass_; 156 jobject loader_; 157 std::string name_; 158 jobject protection_domain_; 159 160 // Mmap that will be filled with the original-dex-file lazily if it needs to be de-quickened or 161 // de-compact-dex'd 162 mutable art::MemMap dex_data_mmap_; 163 // This is a temporary mmap we will use to be able to fill the dex file data atomically. 164 mutable art::MemMap temp_mmap_; 165 166 // A unique_ptr to the current dex_data if it needs to be cleaned up. 167 std::vector<unsigned char> dex_data_memory_; 168 169 const art::DexFile* initial_dex_file_unquickened_; 170 171 // A ref to the current dex data. This is either dex_data_memory_, or current_dex_file_. This is 172 // what the dex file will be turned into. 173 art::ArrayRef<const unsigned char> dex_data_; 174 175 // This is only used if we failed to create a mmap to store the dequickened data 176 std::vector<unsigned char> current_dex_memory_; 177 178 // This is a dequickened version of what is loaded right now. It is either current_dex_memory_ (if 179 // no other redefinition has ever happened to this) or the current dex_file_ directly (if this 180 // class has been redefined, thus it cannot have any quickened stuff). 181 art::ArrayRef<const unsigned char> current_dex_file_; 182 183 bool redefined_; 184 185 // If we got the initial dex_data_ from a class_ext 186 bool from_class_ext_; 187 188 bool initialized_; 189 190 DISALLOW_COPY_AND_ASSIGN(ArtClassDefinition); 191 }; 192 193 } // namespace openjdkjvmti 194 195 #endif // ART_OPENJDKJVMTI_TI_CLASS_DEFINITION_H_ 196
