class_linker.cc revision 22e0ce3a73760757e509032a324bbbb9a1a93f5e
1/* 2 * Copyright (C) 2011 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17#include "class_linker.h" 18 19#include <deque> 20#include <iostream> 21#include <memory> 22#include <queue> 23#include <string> 24#include <unistd.h> 25#include <utility> 26#include <vector> 27 28#include "art_field-inl.h" 29#include "art_method-inl.h" 30#include "base/arena_allocator.h" 31#include "base/casts.h" 32#include "base/logging.h" 33#include "base/scoped_arena_containers.h" 34#include "base/scoped_flock.h" 35#include "base/stl_util.h" 36#include "base/time_utils.h" 37#include "base/unix_file/fd_file.h" 38#include "base/value_object.h" 39#include "class_linker-inl.h" 40#include "compiler_callbacks.h" 41#include "debugger.h" 42#include "dex_file-inl.h" 43#include "entrypoints/runtime_asm_entrypoints.h" 44#include "gc_root-inl.h" 45#include "gc/accounting/card_table-inl.h" 46#include "gc/accounting/heap_bitmap.h" 47#include "gc/heap.h" 48#include "gc/space/image_space.h" 49#include "handle_scope.h" 50#include "intern_table.h" 51#include "interpreter/interpreter.h" 52#include "jit/jit.h" 53#include "jit/jit_code_cache.h" 54#include "leb128.h" 55#include "linear_alloc.h" 56#include "oat.h" 57#include "oat_file.h" 58#include "oat_file_assistant.h" 59#include "object_lock.h" 60#include "mirror/class.h" 61#include "mirror/class-inl.h" 62#include "mirror/class_loader.h" 63#include "mirror/dex_cache-inl.h" 64#include "mirror/field.h" 65#include "mirror/iftable-inl.h" 66#include "mirror/method.h" 67#include "mirror/object-inl.h" 68#include "mirror/object_array-inl.h" 69#include "mirror/proxy.h" 70#include "mirror/reference-inl.h" 71#include "mirror/stack_trace_element.h" 72#include "mirror/string-inl.h" 73#include "os.h" 74#include "runtime.h" 75#include "entrypoints/entrypoint_utils.h" 76#include "ScopedLocalRef.h" 77#include "scoped_thread_state_change.h" 78#include "handle_scope-inl.h" 79#include "thread-inl.h" 80#include "utils.h" 81#include "verifier/method_verifier.h" 82#include "well_known_classes.h" 83 84namespace art { 85 86static constexpr bool kSanityCheckObjects = kIsDebugBuild; 87 88// For b/21333911. 89static constexpr bool kDuplicateClassesCheck = false; 90 91static void ThrowNoClassDefFoundError(const char* fmt, ...) 92 __attribute__((__format__(__printf__, 1, 2))) 93 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 94static void ThrowNoClassDefFoundError(const char* fmt, ...) { 95 va_list args; 96 va_start(args, fmt); 97 Thread* self = Thread::Current(); 98 self->ThrowNewExceptionV("Ljava/lang/NoClassDefFoundError;", fmt, args); 99 va_end(args); 100} 101 102bool ClassLinker::HasInitWithString( 103 Thread* self, ClassLinker* class_linker, const char* descriptor) { 104 ArtMethod* method = self->GetCurrentMethod(nullptr); 105 StackHandleScope<1> hs(self); 106 Handle<mirror::ClassLoader> class_loader(hs.NewHandle(method != nullptr ? 107 method->GetDeclaringClass()->GetClassLoader() 108 : nullptr)); 109 mirror::Class* exception_class = class_linker->FindClass(self, descriptor, class_loader); 110 111 if (exception_class == nullptr) { 112 // No exc class ~ no <init>-with-string. 113 CHECK(self->IsExceptionPending()); 114 self->ClearException(); 115 return false; 116 } 117 118 ArtMethod* exception_init_method = exception_class->FindDeclaredDirectMethod( 119 "<init>", "(Ljava/lang/String;)V", image_pointer_size_); 120 return exception_init_method != nullptr; 121} 122 123void ClassLinker::ThrowEarlierClassFailure(mirror::Class* c) { 124 // The class failed to initialize on a previous attempt, so we want to throw 125 // a NoClassDefFoundError (v2 2.17.5). The exception to this rule is if we 126 // failed in verification, in which case v2 5.4.1 says we need to re-throw 127 // the previous error. 128 Runtime* const runtime = Runtime::Current(); 129 if (!runtime->IsAotCompiler()) { // Give info if this occurs at runtime. 130 LOG(INFO) << "Rejecting re-init on previously-failed class " << PrettyClass(c); 131 } 132 133 CHECK(c->IsErroneous()) << PrettyClass(c) << " " << c->GetStatus(); 134 Thread* self = Thread::Current(); 135 if (runtime->IsAotCompiler()) { 136 // At compile time, accurate errors and NCDFE are disabled to speed compilation. 137 mirror::Throwable* pre_allocated = runtime->GetPreAllocatedNoClassDefFoundError(); 138 self->SetException(pre_allocated); 139 } else { 140 if (c->GetVerifyErrorClass() != nullptr) { 141 // TODO: change the verifier to store an _instance_, with a useful detail message? 142 // It's possible the exception doesn't have a <init>(String). 143 std::string temp; 144 const char* descriptor = c->GetVerifyErrorClass()->GetDescriptor(&temp); 145 146 if (HasInitWithString(self, this, descriptor)) { 147 self->ThrowNewException(descriptor, PrettyDescriptor(c).c_str()); 148 } else { 149 self->ThrowNewException(descriptor, nullptr); 150 } 151 } else { 152 self->ThrowNewException("Ljava/lang/NoClassDefFoundError;", 153 PrettyDescriptor(c).c_str()); 154 } 155 } 156} 157 158static void VlogClassInitializationFailure(Handle<mirror::Class> klass) 159 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 160 if (VLOG_IS_ON(class_linker)) { 161 std::string temp; 162 LOG(INFO) << "Failed to initialize class " << klass->GetDescriptor(&temp) << " from " 163 << klass->GetLocation() << "\n" << Thread::Current()->GetException()->Dump(); 164 } 165} 166 167static void WrapExceptionInInitializer(Handle<mirror::Class> klass) 168 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 169 Thread* self = Thread::Current(); 170 JNIEnv* env = self->GetJniEnv(); 171 172 ScopedLocalRef<jthrowable> cause(env, env->ExceptionOccurred()); 173 CHECK(cause.get() != nullptr); 174 175 env->ExceptionClear(); 176 bool is_error = env->IsInstanceOf(cause.get(), WellKnownClasses::java_lang_Error); 177 env->Throw(cause.get()); 178 179 // We only wrap non-Error exceptions; an Error can just be used as-is. 180 if (!is_error) { 181 self->ThrowNewWrappedException("Ljava/lang/ExceptionInInitializerError;", nullptr); 182 } 183 VlogClassInitializationFailure(klass); 184} 185 186// Gap between two fields in object layout. 187struct FieldGap { 188 uint32_t start_offset; // The offset from the start of the object. 189 uint32_t size; // The gap size of 1, 2, or 4 bytes. 190}; 191struct FieldGapsComparator { 192 explicit FieldGapsComparator() { 193 } 194 bool operator() (const FieldGap& lhs, const FieldGap& rhs) 195 NO_THREAD_SAFETY_ANALYSIS { 196 // Sort by gap size, largest first. Secondary sort by starting offset. 197 return lhs.size > rhs.size || (lhs.size == rhs.size && lhs.start_offset < rhs.start_offset); 198 } 199}; 200typedef std::priority_queue<FieldGap, std::vector<FieldGap>, FieldGapsComparator> FieldGaps; 201 202// Adds largest aligned gaps to queue of gaps. 203static void AddFieldGap(uint32_t gap_start, uint32_t gap_end, FieldGaps* gaps) { 204 DCHECK(gaps != nullptr); 205 206 uint32_t current_offset = gap_start; 207 while (current_offset != gap_end) { 208 size_t remaining = gap_end - current_offset; 209 if (remaining >= sizeof(uint32_t) && IsAligned<4>(current_offset)) { 210 gaps->push(FieldGap {current_offset, sizeof(uint32_t)}); 211 current_offset += sizeof(uint32_t); 212 } else if (remaining >= sizeof(uint16_t) && IsAligned<2>(current_offset)) { 213 gaps->push(FieldGap {current_offset, sizeof(uint16_t)}); 214 current_offset += sizeof(uint16_t); 215 } else { 216 gaps->push(FieldGap {current_offset, sizeof(uint8_t)}); 217 current_offset += sizeof(uint8_t); 218 } 219 DCHECK_LE(current_offset, gap_end) << "Overran gap"; 220 } 221} 222// Shuffle fields forward, making use of gaps whenever possible. 223template<int n> 224static void ShuffleForward(size_t* current_field_idx, 225 MemberOffset* field_offset, 226 std::deque<ArtField*>* grouped_and_sorted_fields, 227 FieldGaps* gaps) 228 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 229 DCHECK(current_field_idx != nullptr); 230 DCHECK(grouped_and_sorted_fields != nullptr); 231 DCHECK(gaps != nullptr); 232 DCHECK(field_offset != nullptr); 233 234 DCHECK(IsPowerOfTwo(n)); 235 while (!grouped_and_sorted_fields->empty()) { 236 ArtField* field = grouped_and_sorted_fields->front(); 237 Primitive::Type type = field->GetTypeAsPrimitiveType(); 238 if (Primitive::ComponentSize(type) < n) { 239 break; 240 } 241 if (!IsAligned<n>(field_offset->Uint32Value())) { 242 MemberOffset old_offset = *field_offset; 243 *field_offset = MemberOffset(RoundUp(field_offset->Uint32Value(), n)); 244 AddFieldGap(old_offset.Uint32Value(), field_offset->Uint32Value(), gaps); 245 } 246 CHECK(type != Primitive::kPrimNot) << PrettyField(field); // should be primitive types 247 grouped_and_sorted_fields->pop_front(); 248 if (!gaps->empty() && gaps->top().size >= n) { 249 FieldGap gap = gaps->top(); 250 gaps->pop(); 251 DCHECK(IsAligned<n>(gap.start_offset)); 252 field->SetOffset(MemberOffset(gap.start_offset)); 253 if (gap.size > n) { 254 AddFieldGap(gap.start_offset + n, gap.start_offset + gap.size, gaps); 255 } 256 } else { 257 DCHECK(IsAligned<n>(field_offset->Uint32Value())); 258 field->SetOffset(*field_offset); 259 *field_offset = MemberOffset(field_offset->Uint32Value() + n); 260 } 261 ++(*current_field_idx); 262 } 263} 264 265ClassLinker::ClassLinker(InternTable* intern_table) 266 // dex_lock_ is recursive as it may be used in stack dumping. 267 : dex_lock_("ClassLinker dex lock", kDefaultMutexLevel), 268 dex_cache_image_class_lookup_required_(false), 269 failed_dex_cache_class_lookups_(0), 270 class_roots_(nullptr), 271 array_iftable_(nullptr), 272 find_array_class_cache_next_victim_(0), 273 init_done_(false), 274 log_new_dex_caches_roots_(false), 275 log_new_class_table_roots_(false), 276 intern_table_(intern_table), 277 quick_resolution_trampoline_(nullptr), 278 quick_imt_conflict_trampoline_(nullptr), 279 quick_generic_jni_trampoline_(nullptr), 280 quick_to_interpreter_bridge_trampoline_(nullptr), 281 image_pointer_size_(sizeof(void*)) { 282 CHECK(intern_table_ != nullptr); 283 static_assert(kFindArrayCacheSize == arraysize(find_array_class_cache_), 284 "Array cache size wrong."); 285 std::fill_n(find_array_class_cache_, kFindArrayCacheSize, GcRoot<mirror::Class>(nullptr)); 286} 287 288void ClassLinker::InitWithoutImage(std::vector<std::unique_ptr<const DexFile>> boot_class_path) { 289 VLOG(startup) << "ClassLinker::Init"; 290 291 Thread* const self = Thread::Current(); 292 Runtime* const runtime = Runtime::Current(); 293 gc::Heap* const heap = runtime->GetHeap(); 294 295 CHECK(!heap->HasImageSpace()) << "Runtime has image. We should use it."; 296 CHECK(!init_done_); 297 298 // Use the pointer size from the runtime since we are probably creating the image. 299 image_pointer_size_ = InstructionSetPointerSize(runtime->GetInstructionSet()); 300 301 // java_lang_Class comes first, it's needed for AllocClass 302 // The GC can't handle an object with a null class since we can't get the size of this object. 303 heap->IncrementDisableMovingGC(self); 304 StackHandleScope<64> hs(self); // 64 is picked arbitrarily. 305 auto class_class_size = mirror::Class::ClassClassSize(image_pointer_size_); 306 Handle<mirror::Class> java_lang_Class(hs.NewHandle(down_cast<mirror::Class*>( 307 heap->AllocNonMovableObject<true>(self, nullptr, class_class_size, VoidFunctor())))); 308 CHECK(java_lang_Class.Get() != nullptr); 309 mirror::Class::SetClassClass(java_lang_Class.Get()); 310 java_lang_Class->SetClass(java_lang_Class.Get()); 311 if (kUseBakerOrBrooksReadBarrier) { 312 java_lang_Class->AssertReadBarrierPointer(); 313 } 314 java_lang_Class->SetClassSize(class_class_size); 315 java_lang_Class->SetPrimitiveType(Primitive::kPrimNot); 316 heap->DecrementDisableMovingGC(self); 317 // AllocClass(mirror::Class*) can now be used 318 319 // Class[] is used for reflection support. 320 auto class_array_class_size = mirror::ObjectArray<mirror::Class>::ClassSize(image_pointer_size_); 321 Handle<mirror::Class> class_array_class(hs.NewHandle( 322 AllocClass(self, java_lang_Class.Get(), class_array_class_size))); 323 class_array_class->SetComponentType(java_lang_Class.Get()); 324 325 // java_lang_Object comes next so that object_array_class can be created. 326 Handle<mirror::Class> java_lang_Object(hs.NewHandle( 327 AllocClass(self, java_lang_Class.Get(), mirror::Object::ClassSize(image_pointer_size_)))); 328 CHECK(java_lang_Object.Get() != nullptr); 329 // backfill Object as the super class of Class. 330 java_lang_Class->SetSuperClass(java_lang_Object.Get()); 331 mirror::Class::SetStatus(java_lang_Object, mirror::Class::kStatusLoaded, self); 332 333 // Object[] next to hold class roots. 334 Handle<mirror::Class> object_array_class(hs.NewHandle( 335 AllocClass(self, java_lang_Class.Get(), 336 mirror::ObjectArray<mirror::Object>::ClassSize(image_pointer_size_)))); 337 object_array_class->SetComponentType(java_lang_Object.Get()); 338 339 // Setup the char (primitive) class to be used for char[]. 340 Handle<mirror::Class> char_class(hs.NewHandle( 341 AllocClass(self, java_lang_Class.Get(), 342 mirror::Class::PrimitiveClassSize(image_pointer_size_)))); 343 // The primitive char class won't be initialized by 344 // InitializePrimitiveClass until line 459, but strings (and 345 // internal char arrays) will be allocated before that and the 346 // component size, which is computed from the primitive type, needs 347 // to be set here. 348 char_class->SetPrimitiveType(Primitive::kPrimChar); 349 350 // Setup the char[] class to be used for String. 351 Handle<mirror::Class> char_array_class(hs.NewHandle( 352 AllocClass(self, java_lang_Class.Get(), mirror::Array::ClassSize(image_pointer_size_)))); 353 char_array_class->SetComponentType(char_class.Get()); 354 mirror::CharArray::SetArrayClass(char_array_class.Get()); 355 356 // Setup String. 357 Handle<mirror::Class> java_lang_String(hs.NewHandle( 358 AllocClass(self, java_lang_Class.Get(), mirror::String::ClassSize(image_pointer_size_)))); 359 mirror::String::SetClass(java_lang_String.Get()); 360 mirror::Class::SetStatus(java_lang_String, mirror::Class::kStatusResolved, self); 361 java_lang_String->SetStringClass(); 362 363 // Setup java.lang.ref.Reference. 364 Handle<mirror::Class> java_lang_ref_Reference(hs.NewHandle( 365 AllocClass(self, java_lang_Class.Get(), mirror::Reference::ClassSize(image_pointer_size_)))); 366 mirror::Reference::SetClass(java_lang_ref_Reference.Get()); 367 java_lang_ref_Reference->SetObjectSize(mirror::Reference::InstanceSize()); 368 mirror::Class::SetStatus(java_lang_ref_Reference, mirror::Class::kStatusResolved, self); 369 370 // Create storage for root classes, save away our work so far (requires descriptors). 371 class_roots_ = GcRoot<mirror::ObjectArray<mirror::Class>>( 372 mirror::ObjectArray<mirror::Class>::Alloc(self, object_array_class.Get(), 373 kClassRootsMax)); 374 CHECK(!class_roots_.IsNull()); 375 SetClassRoot(kJavaLangClass, java_lang_Class.Get()); 376 SetClassRoot(kJavaLangObject, java_lang_Object.Get()); 377 SetClassRoot(kClassArrayClass, class_array_class.Get()); 378 SetClassRoot(kObjectArrayClass, object_array_class.Get()); 379 SetClassRoot(kCharArrayClass, char_array_class.Get()); 380 SetClassRoot(kJavaLangString, java_lang_String.Get()); 381 SetClassRoot(kJavaLangRefReference, java_lang_ref_Reference.Get()); 382 383 // Setup the primitive type classes. 384 SetClassRoot(kPrimitiveBoolean, CreatePrimitiveClass(self, Primitive::kPrimBoolean)); 385 SetClassRoot(kPrimitiveByte, CreatePrimitiveClass(self, Primitive::kPrimByte)); 386 SetClassRoot(kPrimitiveShort, CreatePrimitiveClass(self, Primitive::kPrimShort)); 387 SetClassRoot(kPrimitiveInt, CreatePrimitiveClass(self, Primitive::kPrimInt)); 388 SetClassRoot(kPrimitiveLong, CreatePrimitiveClass(self, Primitive::kPrimLong)); 389 SetClassRoot(kPrimitiveFloat, CreatePrimitiveClass(self, Primitive::kPrimFloat)); 390 SetClassRoot(kPrimitiveDouble, CreatePrimitiveClass(self, Primitive::kPrimDouble)); 391 SetClassRoot(kPrimitiveVoid, CreatePrimitiveClass(self, Primitive::kPrimVoid)); 392 393 // Create array interface entries to populate once we can load system classes. 394 array_iftable_ = GcRoot<mirror::IfTable>(AllocIfTable(self, 2)); 395 396 // Create int array type for AllocDexCache (done in AppendToBootClassPath). 397 Handle<mirror::Class> int_array_class(hs.NewHandle( 398 AllocClass(self, java_lang_Class.Get(), mirror::Array::ClassSize(image_pointer_size_)))); 399 int_array_class->SetComponentType(GetClassRoot(kPrimitiveInt)); 400 mirror::IntArray::SetArrayClass(int_array_class.Get()); 401 SetClassRoot(kIntArrayClass, int_array_class.Get()); 402 403 // Create long array type for AllocDexCache (done in AppendToBootClassPath). 404 Handle<mirror::Class> long_array_class(hs.NewHandle( 405 AllocClass(self, java_lang_Class.Get(), mirror::Array::ClassSize(image_pointer_size_)))); 406 long_array_class->SetComponentType(GetClassRoot(kPrimitiveLong)); 407 mirror::LongArray::SetArrayClass(long_array_class.Get()); 408 SetClassRoot(kLongArrayClass, long_array_class.Get()); 409 410 // now that these are registered, we can use AllocClass() and AllocObjectArray 411 412 // Set up DexCache. This cannot be done later since AppendToBootClassPath calls AllocDexCache. 413 Handle<mirror::Class> java_lang_DexCache(hs.NewHandle( 414 AllocClass(self, java_lang_Class.Get(), mirror::DexCache::ClassSize(image_pointer_size_)))); 415 SetClassRoot(kJavaLangDexCache, java_lang_DexCache.Get()); 416 java_lang_DexCache->SetObjectSize(mirror::DexCache::InstanceSize()); 417 mirror::Class::SetStatus(java_lang_DexCache, mirror::Class::kStatusResolved, self); 418 419 // Set up array classes for string, field, method 420 Handle<mirror::Class> object_array_string(hs.NewHandle( 421 AllocClass(self, java_lang_Class.Get(), 422 mirror::ObjectArray<mirror::String>::ClassSize(image_pointer_size_)))); 423 object_array_string->SetComponentType(java_lang_String.Get()); 424 SetClassRoot(kJavaLangStringArrayClass, object_array_string.Get()); 425 426 // Create runtime resolution and imt conflict methods. 427 runtime->SetResolutionMethod(runtime->CreateResolutionMethod()); 428 runtime->SetImtConflictMethod(runtime->CreateImtConflictMethod()); 429 runtime->SetImtUnimplementedMethod(runtime->CreateImtConflictMethod()); 430 431 // Setup boot_class_path_ and register class_path now that we can use AllocObjectArray to create 432 // DexCache instances. Needs to be after String, Field, Method arrays since AllocDexCache uses 433 // these roots. 434 CHECK_NE(0U, boot_class_path.size()); 435 for (auto& dex_file : boot_class_path) { 436 CHECK(dex_file.get() != nullptr); 437 AppendToBootClassPath(self, *dex_file); 438 opened_dex_files_.push_back(std::move(dex_file)); 439 } 440 441 // now we can use FindSystemClass 442 443 // run char class through InitializePrimitiveClass to finish init 444 InitializePrimitiveClass(char_class.Get(), Primitive::kPrimChar); 445 SetClassRoot(kPrimitiveChar, char_class.Get()); // needs descriptor 446 447 // Set up GenericJNI entrypoint. That is mainly a hack for common_compiler_test.h so that 448 // we do not need friend classes or a publicly exposed setter. 449 quick_generic_jni_trampoline_ = GetQuickGenericJniStub(); 450 if (!runtime->IsAotCompiler()) { 451 // We need to set up the generic trampolines since we don't have an image. 452 quick_resolution_trampoline_ = GetQuickResolutionStub(); 453 quick_imt_conflict_trampoline_ = GetQuickImtConflictStub(); 454 quick_to_interpreter_bridge_trampoline_ = GetQuickToInterpreterBridge(); 455 } 456 457 // Object, String and DexCache need to be rerun through FindSystemClass to finish init 458 mirror::Class::SetStatus(java_lang_Object, mirror::Class::kStatusNotReady, self); 459 CHECK_EQ(java_lang_Object.Get(), FindSystemClass(self, "Ljava/lang/Object;")); 460 CHECK_EQ(java_lang_Object->GetObjectSize(), mirror::Object::InstanceSize()); 461 mirror::Class::SetStatus(java_lang_String, mirror::Class::kStatusNotReady, self); 462 mirror::Class* String_class = FindSystemClass(self, "Ljava/lang/String;"); 463 if (java_lang_String.Get() != String_class) { 464 std::ostringstream os1, os2; 465 java_lang_String->DumpClass(os1, mirror::Class::kDumpClassFullDetail); 466 String_class->DumpClass(os2, mirror::Class::kDumpClassFullDetail); 467 LOG(FATAL) << os1.str() << "\n\n" << os2.str(); 468 } 469 mirror::Class::SetStatus(java_lang_DexCache, mirror::Class::kStatusNotReady, self); 470 CHECK_EQ(java_lang_DexCache.Get(), FindSystemClass(self, "Ljava/lang/DexCache;")); 471 CHECK_EQ(java_lang_DexCache->GetObjectSize(), mirror::DexCache::InstanceSize()); 472 473 // Setup the primitive array type classes - can't be done until Object has a vtable. 474 SetClassRoot(kBooleanArrayClass, FindSystemClass(self, "[Z")); 475 mirror::BooleanArray::SetArrayClass(GetClassRoot(kBooleanArrayClass)); 476 477 SetClassRoot(kByteArrayClass, FindSystemClass(self, "[B")); 478 mirror::ByteArray::SetArrayClass(GetClassRoot(kByteArrayClass)); 479 480 CHECK_EQ(char_array_class.Get(), FindSystemClass(self, "[C")); 481 482 SetClassRoot(kShortArrayClass, FindSystemClass(self, "[S")); 483 mirror::ShortArray::SetArrayClass(GetClassRoot(kShortArrayClass)); 484 485 CHECK_EQ(int_array_class.Get(), FindSystemClass(self, "[I")); 486 487 CHECK_EQ(long_array_class.Get(), FindSystemClass(self, "[J")); 488 489 SetClassRoot(kFloatArrayClass, FindSystemClass(self, "[F")); 490 mirror::FloatArray::SetArrayClass(GetClassRoot(kFloatArrayClass)); 491 492 SetClassRoot(kDoubleArrayClass, FindSystemClass(self, "[D")); 493 mirror::DoubleArray::SetArrayClass(GetClassRoot(kDoubleArrayClass)); 494 495 CHECK_EQ(class_array_class.Get(), FindSystemClass(self, "[Ljava/lang/Class;")); 496 497 CHECK_EQ(object_array_class.Get(), FindSystemClass(self, "[Ljava/lang/Object;")); 498 499 // Setup the single, global copy of "iftable". 500 auto java_lang_Cloneable = hs.NewHandle(FindSystemClass(self, "Ljava/lang/Cloneable;")); 501 CHECK(java_lang_Cloneable.Get() != nullptr); 502 auto java_io_Serializable = hs.NewHandle(FindSystemClass(self, "Ljava/io/Serializable;")); 503 CHECK(java_io_Serializable.Get() != nullptr); 504 // We assume that Cloneable/Serializable don't have superinterfaces -- normally we'd have to 505 // crawl up and explicitly list all of the supers as well. 506 array_iftable_.Read()->SetInterface(0, java_lang_Cloneable.Get()); 507 array_iftable_.Read()->SetInterface(1, java_io_Serializable.Get()); 508 509 // Sanity check Class[] and Object[]'s interfaces. GetDirectInterface may cause thread 510 // suspension. 511 CHECK_EQ(java_lang_Cloneable.Get(), 512 mirror::Class::GetDirectInterface(self, class_array_class, 0)); 513 CHECK_EQ(java_io_Serializable.Get(), 514 mirror::Class::GetDirectInterface(self, class_array_class, 1)); 515 CHECK_EQ(java_lang_Cloneable.Get(), 516 mirror::Class::GetDirectInterface(self, object_array_class, 0)); 517 CHECK_EQ(java_io_Serializable.Get(), 518 mirror::Class::GetDirectInterface(self, object_array_class, 1)); 519 // Run Class, ArtField, and ArtMethod through FindSystemClass. This initializes their 520 // dex_cache_ fields and register them in class_table_. 521 CHECK_EQ(java_lang_Class.Get(), FindSystemClass(self, "Ljava/lang/Class;")); 522 523 CHECK_EQ(object_array_string.Get(), 524 FindSystemClass(self, GetClassRootDescriptor(kJavaLangStringArrayClass))); 525 526 // End of special init trickery, subsequent classes may be loaded via FindSystemClass. 527 528 // Create java.lang.reflect.Proxy root. 529 SetClassRoot(kJavaLangReflectProxy, FindSystemClass(self, "Ljava/lang/reflect/Proxy;")); 530 531 // Create java.lang.reflect.Field.class root. 532 auto* class_root = FindSystemClass(self, "Ljava/lang/reflect/Field;"); 533 CHECK(class_root != nullptr); 534 SetClassRoot(kJavaLangReflectField, class_root); 535 mirror::Field::SetClass(class_root); 536 537 // Create java.lang.reflect.Field array root. 538 class_root = FindSystemClass(self, "[Ljava/lang/reflect/Field;"); 539 CHECK(class_root != nullptr); 540 SetClassRoot(kJavaLangReflectFieldArrayClass, class_root); 541 mirror::Field::SetArrayClass(class_root); 542 543 // Create java.lang.reflect.Constructor.class root and array root. 544 class_root = FindSystemClass(self, "Ljava/lang/reflect/Constructor;"); 545 CHECK(class_root != nullptr); 546 SetClassRoot(kJavaLangReflectConstructor, class_root); 547 mirror::Constructor::SetClass(class_root); 548 class_root = FindSystemClass(self, "[Ljava/lang/reflect/Constructor;"); 549 CHECK(class_root != nullptr); 550 SetClassRoot(kJavaLangReflectConstructorArrayClass, class_root); 551 mirror::Constructor::SetArrayClass(class_root); 552 553 // Create java.lang.reflect.Method.class root and array root. 554 class_root = FindSystemClass(self, "Ljava/lang/reflect/Method;"); 555 CHECK(class_root != nullptr); 556 SetClassRoot(kJavaLangReflectMethod, class_root); 557 mirror::Method::SetClass(class_root); 558 class_root = FindSystemClass(self, "[Ljava/lang/reflect/Method;"); 559 CHECK(class_root != nullptr); 560 SetClassRoot(kJavaLangReflectMethodArrayClass, class_root); 561 mirror::Method::SetArrayClass(class_root); 562 563 // java.lang.ref classes need to be specially flagged, but otherwise are normal classes 564 // finish initializing Reference class 565 mirror::Class::SetStatus(java_lang_ref_Reference, mirror::Class::kStatusNotReady, self); 566 CHECK_EQ(java_lang_ref_Reference.Get(), FindSystemClass(self, "Ljava/lang/ref/Reference;")); 567 CHECK_EQ(java_lang_ref_Reference->GetObjectSize(), mirror::Reference::InstanceSize()); 568 CHECK_EQ(java_lang_ref_Reference->GetClassSize(), 569 mirror::Reference::ClassSize(image_pointer_size_)); 570 class_root = FindSystemClass(self, "Ljava/lang/ref/FinalizerReference;"); 571 class_root->SetAccessFlags(class_root->GetAccessFlags() | 572 kAccClassIsReference | kAccClassIsFinalizerReference); 573 class_root = FindSystemClass(self, "Ljava/lang/ref/PhantomReference;"); 574 class_root->SetAccessFlags(class_root->GetAccessFlags() | kAccClassIsReference | 575 kAccClassIsPhantomReference); 576 class_root = FindSystemClass(self, "Ljava/lang/ref/SoftReference;"); 577 class_root->SetAccessFlags(class_root->GetAccessFlags() | kAccClassIsReference); 578 class_root = FindSystemClass(self, "Ljava/lang/ref/WeakReference;"); 579 class_root->SetAccessFlags(class_root->GetAccessFlags() | kAccClassIsReference | 580 kAccClassIsWeakReference); 581 582 // Setup the ClassLoader, verifying the object_size_. 583 class_root = FindSystemClass(self, "Ljava/lang/ClassLoader;"); 584 CHECK_EQ(class_root->GetObjectSize(), mirror::ClassLoader::InstanceSize()); 585 SetClassRoot(kJavaLangClassLoader, class_root); 586 587 // Set up java.lang.Throwable, java.lang.ClassNotFoundException, and 588 // java.lang.StackTraceElement as a convenience. 589 SetClassRoot(kJavaLangThrowable, FindSystemClass(self, "Ljava/lang/Throwable;")); 590 mirror::Throwable::SetClass(GetClassRoot(kJavaLangThrowable)); 591 SetClassRoot(kJavaLangClassNotFoundException, 592 FindSystemClass(self, "Ljava/lang/ClassNotFoundException;")); 593 SetClassRoot(kJavaLangStackTraceElement, FindSystemClass(self, "Ljava/lang/StackTraceElement;")); 594 SetClassRoot(kJavaLangStackTraceElementArrayClass, 595 FindSystemClass(self, "[Ljava/lang/StackTraceElement;")); 596 mirror::StackTraceElement::SetClass(GetClassRoot(kJavaLangStackTraceElement)); 597 598 // Ensure void type is resolved in the core's dex cache so java.lang.Void is correctly 599 // initialized. 600 { 601 const DexFile& dex_file = java_lang_Object->GetDexFile(); 602 const DexFile::StringId* void_string_id = dex_file.FindStringId("V"); 603 CHECK(void_string_id != nullptr); 604 uint32_t void_string_index = dex_file.GetIndexForStringId(*void_string_id); 605 const DexFile::TypeId* void_type_id = dex_file.FindTypeId(void_string_index); 606 CHECK(void_type_id != nullptr); 607 uint16_t void_type_idx = dex_file.GetIndexForTypeId(*void_type_id); 608 // Now we resolve void type so the dex cache contains it. We use java.lang.Object class 609 // as referrer so the used dex cache is core's one. 610 mirror::Class* resolved_type = ResolveType(dex_file, void_type_idx, java_lang_Object.Get()); 611 CHECK_EQ(resolved_type, GetClassRoot(kPrimitiveVoid)); 612 self->AssertNoPendingException(); 613 } 614 615 FinishInit(self); 616 617 VLOG(startup) << "ClassLinker::InitFromCompiler exiting"; 618} 619 620void ClassLinker::FinishInit(Thread* self) { 621 VLOG(startup) << "ClassLinker::FinishInit entering"; 622 623 // Let the heap know some key offsets into java.lang.ref instances 624 // Note: we hard code the field indexes here rather than using FindInstanceField 625 // as the types of the field can't be resolved prior to the runtime being 626 // fully initialized 627 mirror::Class* java_lang_ref_Reference = GetClassRoot(kJavaLangRefReference); 628 mirror::Class* java_lang_ref_FinalizerReference = 629 FindSystemClass(self, "Ljava/lang/ref/FinalizerReference;"); 630 631 ArtField* pendingNext = java_lang_ref_Reference->GetInstanceField(0); 632 CHECK_STREQ(pendingNext->GetName(), "pendingNext"); 633 CHECK_STREQ(pendingNext->GetTypeDescriptor(), "Ljava/lang/ref/Reference;"); 634 635 ArtField* queue = java_lang_ref_Reference->GetInstanceField(1); 636 CHECK_STREQ(queue->GetName(), "queue"); 637 CHECK_STREQ(queue->GetTypeDescriptor(), "Ljava/lang/ref/ReferenceQueue;"); 638 639 ArtField* queueNext = java_lang_ref_Reference->GetInstanceField(2); 640 CHECK_STREQ(queueNext->GetName(), "queueNext"); 641 CHECK_STREQ(queueNext->GetTypeDescriptor(), "Ljava/lang/ref/Reference;"); 642 643 ArtField* referent = java_lang_ref_Reference->GetInstanceField(3); 644 CHECK_STREQ(referent->GetName(), "referent"); 645 CHECK_STREQ(referent->GetTypeDescriptor(), "Ljava/lang/Object;"); 646 647 ArtField* zombie = java_lang_ref_FinalizerReference->GetInstanceField(2); 648 CHECK_STREQ(zombie->GetName(), "zombie"); 649 CHECK_STREQ(zombie->GetTypeDescriptor(), "Ljava/lang/Object;"); 650 651 // ensure all class_roots_ are initialized 652 for (size_t i = 0; i < kClassRootsMax; i++) { 653 ClassRoot class_root = static_cast<ClassRoot>(i); 654 mirror::Class* klass = GetClassRoot(class_root); 655 CHECK(klass != nullptr); 656 DCHECK(klass->IsArrayClass() || klass->IsPrimitive() || klass->GetDexCache() != nullptr); 657 // note SetClassRoot does additional validation. 658 // if possible add new checks there to catch errors early 659 } 660 661 CHECK(!array_iftable_.IsNull()); 662 663 // disable the slow paths in FindClass and CreatePrimitiveClass now 664 // that Object, Class, and Object[] are setup 665 init_done_ = true; 666 667 VLOG(startup) << "ClassLinker::FinishInit exiting"; 668} 669 670void ClassLinker::RunRootClinits() { 671 Thread* self = Thread::Current(); 672 for (size_t i = 0; i < ClassLinker::kClassRootsMax; ++i) { 673 mirror::Class* c = GetClassRoot(ClassRoot(i)); 674 if (!c->IsArrayClass() && !c->IsPrimitive()) { 675 StackHandleScope<1> hs(self); 676 Handle<mirror::Class> h_class(hs.NewHandle(GetClassRoot(ClassRoot(i)))); 677 EnsureInitialized(self, h_class, true, true); 678 self->AssertNoPendingException(); 679 } 680 } 681} 682 683const OatFile* ClassLinker::RegisterOatFile(const OatFile* oat_file) { 684 WriterMutexLock mu(Thread::Current(), dex_lock_); 685 if (kIsDebugBuild) { 686 for (size_t i = 0; i < oat_files_.size(); ++i) { 687 CHECK_NE(oat_file, oat_files_[i]) << oat_file->GetLocation(); 688 } 689 } 690 VLOG(class_linker) << "Registering " << oat_file->GetLocation(); 691 oat_files_.push_back(oat_file); 692 return oat_file; 693} 694 695OatFile& ClassLinker::GetImageOatFile(gc::space::ImageSpace* space) { 696 VLOG(startup) << "ClassLinker::GetImageOatFile entering"; 697 OatFile* oat_file = space->ReleaseOatFile(); 698 CHECK_EQ(RegisterOatFile(oat_file), oat_file); 699 VLOG(startup) << "ClassLinker::GetImageOatFile exiting"; 700 return *oat_file; 701} 702 703class DexFileAndClassPair : ValueObject { 704 public: 705 DexFileAndClassPair(const DexFile* dex_file, size_t current_class_index, bool from_loaded_oat) 706 : cached_descriptor_(GetClassDescriptor(dex_file, current_class_index)), 707 dex_file_(dex_file), 708 current_class_index_(current_class_index), 709 from_loaded_oat_(from_loaded_oat) {} 710 711 DexFileAndClassPair(const DexFileAndClassPair&) = default; 712 713 DexFileAndClassPair& operator=(const DexFileAndClassPair& rhs) { 714 cached_descriptor_ = rhs.cached_descriptor_; 715 dex_file_ = rhs.dex_file_; 716 current_class_index_ = rhs.current_class_index_; 717 from_loaded_oat_ = rhs.from_loaded_oat_; 718 return *this; 719 } 720 721 const char* GetCachedDescriptor() const { 722 return cached_descriptor_; 723 } 724 725 bool operator<(const DexFileAndClassPair& rhs) const { 726 const char* lhsDescriptor = cached_descriptor_; 727 const char* rhsDescriptor = rhs.cached_descriptor_; 728 int cmp = strcmp(lhsDescriptor, rhsDescriptor); 729 if (cmp != 0) { 730 // Note that the order must be reversed. We want to iterate over the classes in dex files. 731 // They are sorted lexicographically. Thus, the priority-queue must be a min-queue. 732 return cmp > 0; 733 } 734 return dex_file_ < rhs.dex_file_; 735 } 736 737 bool DexFileHasMoreClasses() const { 738 return current_class_index_ + 1 < dex_file_->NumClassDefs(); 739 } 740 741 DexFileAndClassPair GetNext() const { 742 return DexFileAndClassPair(dex_file_, current_class_index_ + 1, from_loaded_oat_); 743 } 744 745 size_t GetCurrentClassIndex() const { 746 return current_class_index_; 747 } 748 749 bool FromLoadedOat() const { 750 return from_loaded_oat_; 751 } 752 753 const DexFile* GetDexFile() const { 754 return dex_file_; 755 } 756 757 void DeleteDexFile() { 758 delete dex_file_; 759 dex_file_ = nullptr; 760 } 761 762 private: 763 static const char* GetClassDescriptor(const DexFile* dex_file, size_t index) { 764 const DexFile::ClassDef& class_def = dex_file->GetClassDef(static_cast<uint16_t>(index)); 765 return dex_file->StringByTypeIdx(class_def.class_idx_); 766 } 767 768 const char* cached_descriptor_; 769 const DexFile* dex_file_; 770 size_t current_class_index_; 771 bool from_loaded_oat_; // We only need to compare mismatches between what we load now 772 // and what was loaded before. Any old duplicates must have been 773 // OK, and any new "internal" duplicates are as well (they must 774 // be from multidex, which resolves correctly). 775}; 776 777static void AddDexFilesFromOat(const OatFile* oat_file, bool already_loaded, 778 std::priority_queue<DexFileAndClassPair>* heap) { 779 const std::vector<const OatDexFile*>& oat_dex_files = oat_file->GetOatDexFiles(); 780 for (const OatDexFile* oat_dex_file : oat_dex_files) { 781 std::string error; 782 std::unique_ptr<const DexFile> dex_file = oat_dex_file->OpenDexFile(&error); 783 if (dex_file.get() == nullptr) { 784 LOG(WARNING) << "Could not create dex file from oat file: " << error; 785 } else { 786 if (dex_file->NumClassDefs() > 0U) { 787 heap->emplace(dex_file.release(), 0U, already_loaded); 788 } 789 } 790 } 791} 792 793static void AddNext(DexFileAndClassPair* original, 794 std::priority_queue<DexFileAndClassPair>* heap) { 795 if (original->DexFileHasMoreClasses()) { 796 heap->push(original->GetNext()); 797 } else { 798 // Need to delete the dex file. 799 original->DeleteDexFile(); 800 } 801} 802 803static void FreeDexFilesInHeap(std::priority_queue<DexFileAndClassPair>* heap) { 804 while (!heap->empty()) { 805 delete heap->top().GetDexFile(); 806 heap->pop(); 807 } 808} 809 810const OatFile* ClassLinker::GetBootOatFile() { 811 gc::space::ImageSpace* image_space = Runtime::Current()->GetHeap()->GetImageSpace(); 812 if (image_space == nullptr) { 813 return nullptr; 814 } 815 return image_space->GetOatFile(); 816} 817 818const OatFile* ClassLinker::GetPrimaryOatFile() { 819 ReaderMutexLock mu(Thread::Current(), dex_lock_); 820 const OatFile* boot_oat_file = GetBootOatFile(); 821 if (boot_oat_file != nullptr) { 822 for (const OatFile* oat_file : oat_files_) { 823 if (oat_file != boot_oat_file) { 824 return oat_file; 825 } 826 } 827 } 828 return nullptr; 829} 830 831// Check for class-def collisions in dex files. 832// 833// This works by maintaining a heap with one class from each dex file, sorted by the class 834// descriptor. Then a dex-file/class pair is continually removed from the heap and compared 835// against the following top element. If the descriptor is the same, it is now checked whether 836// the two elements agree on whether their dex file was from an already-loaded oat-file or the 837// new oat file. Any disagreement indicates a collision. 838bool ClassLinker::HasCollisions(const OatFile* oat_file, std::string* error_msg) { 839 if (!kDuplicateClassesCheck) { 840 return false; 841 } 842 843 // Dex files are registered late - once a class is actually being loaded. We have to compare 844 // against the open oat files. Take the dex_lock_ that protects oat_files_ accesses. 845 ReaderMutexLock mu(Thread::Current(), dex_lock_); 846 847 std::priority_queue<DexFileAndClassPair> queue; 848 849 // Add dex files from already loaded oat files, but skip boot. 850 { 851 const OatFile* boot_oat = GetBootOatFile(); 852 for (const OatFile* loaded_oat_file : oat_files_) { 853 if (loaded_oat_file == boot_oat) { 854 continue; 855 } 856 AddDexFilesFromOat(loaded_oat_file, true, &queue); 857 } 858 } 859 860 if (queue.empty()) { 861 // No other oat files, return early. 862 return false; 863 } 864 865 // Add dex files from the oat file to check. 866 AddDexFilesFromOat(oat_file, false, &queue); 867 868 // Now drain the queue. 869 while (!queue.empty()) { 870 DexFileAndClassPair compare_pop = queue.top(); 871 queue.pop(); 872 873 // Compare against the following elements. 874 while (!queue.empty()) { 875 DexFileAndClassPair top = queue.top(); 876 877 if (strcmp(compare_pop.GetCachedDescriptor(), top.GetCachedDescriptor()) == 0) { 878 // Same descriptor. Check whether it's crossing old-oat-files to new-oat-files. 879 if (compare_pop.FromLoadedOat() != top.FromLoadedOat()) { 880 *error_msg = 881 StringPrintf("Found duplicated class when checking oat files: '%s' in %s and %s", 882 compare_pop.GetCachedDescriptor(), 883 compare_pop.GetDexFile()->GetLocation().c_str(), 884 top.GetDexFile()->GetLocation().c_str()); 885 FreeDexFilesInHeap(&queue); 886 return true; 887 } 888 // Pop it. 889 queue.pop(); 890 AddNext(&top, &queue); 891 } else { 892 // Something else. Done here. 893 break; 894 } 895 } 896 AddNext(&compare_pop, &queue); 897 } 898 899 return false; 900} 901 902std::vector<std::unique_ptr<const DexFile>> ClassLinker::OpenDexFilesFromOat( 903 const char* dex_location, const char* oat_location, 904 std::vector<std::string>* error_msgs) { 905 CHECK(error_msgs != nullptr); 906 907 // Verify we aren't holding the mutator lock, which could starve GC if we 908 // have to generate or relocate an oat file. 909 Locks::mutator_lock_->AssertNotHeld(Thread::Current()); 910 911 OatFileAssistant oat_file_assistant(dex_location, oat_location, kRuntimeISA, 912 !Runtime::Current()->IsAotCompiler()); 913 914 // Lock the target oat location to avoid races generating and loading the 915 // oat file. 916 std::string error_msg; 917 if (!oat_file_assistant.Lock(&error_msg)) { 918 // Don't worry too much if this fails. If it does fail, it's unlikely we 919 // can generate an oat file anyway. 920 VLOG(class_linker) << "OatFileAssistant::Lock: " << error_msg; 921 } 922 923 // Check if we already have an up-to-date oat file open. 924 const OatFile* source_oat_file = nullptr; 925 { 926 ReaderMutexLock mu(Thread::Current(), dex_lock_); 927 for (const OatFile* oat_file : oat_files_) { 928 CHECK(oat_file != nullptr); 929 if (oat_file_assistant.GivenOatFileIsUpToDate(*oat_file)) { 930 source_oat_file = oat_file; 931 break; 932 } 933 } 934 } 935 936 // If we didn't have an up-to-date oat file open, try to load one from disk. 937 if (source_oat_file == nullptr) { 938 // Update the oat file on disk if we can. This may fail, but that's okay. 939 // Best effort is all that matters here. 940 if (!oat_file_assistant.MakeUpToDate(&error_msg)) { 941 LOG(WARNING) << error_msg; 942 } 943 944 // Get the oat file on disk. 945 std::unique_ptr<OatFile> oat_file = oat_file_assistant.GetBestOatFile(); 946 if (oat_file.get() != nullptr) { 947 // Take the file only if it has no collisions, or we must take it because of preopting. 948 bool accept_oat_file = !HasCollisions(oat_file.get(), &error_msg); 949 if (!accept_oat_file) { 950 // Failed the collision check. Print warning. 951 if (Runtime::Current()->IsDexFileFallbackEnabled()) { 952 LOG(WARNING) << "Found duplicate classes, falling back to interpreter mode for " 953 << dex_location; 954 } else { 955 LOG(WARNING) << "Found duplicate classes, dex-file-fallback disabled, will be failing to " 956 " load classes for " << dex_location; 957 } 958 LOG(WARNING) << error_msg; 959 960 // However, if the app was part of /system and preopted, there is no original dex file 961 // available. In that case grudgingly accept the oat file. 962 if (!DexFile::MaybeDex(dex_location)) { 963 accept_oat_file = true; 964 LOG(WARNING) << "Dex location " << dex_location << " does not seem to include dex file. " 965 << "Allow oat file use. This is potentially dangerous."; 966 } 967 } 968 969 if (accept_oat_file) { 970 source_oat_file = oat_file.release(); 971 RegisterOatFile(source_oat_file); 972 } 973 } 974 } 975 976 std::vector<std::unique_ptr<const DexFile>> dex_files; 977 978 // Load the dex files from the oat file. 979 if (source_oat_file != nullptr) { 980 dex_files = oat_file_assistant.LoadDexFiles(*source_oat_file, dex_location); 981 if (dex_files.empty()) { 982 error_msgs->push_back("Failed to open dex files from " 983 + source_oat_file->GetLocation()); 984 } 985 } 986 987 // Fall back to running out of the original dex file if we couldn't load any 988 // dex_files from the oat file. 989 if (dex_files.empty()) { 990 if (oat_file_assistant.HasOriginalDexFiles()) { 991 if (Runtime::Current()->IsDexFileFallbackEnabled()) { 992 if (!DexFile::Open(dex_location, dex_location, &error_msg, &dex_files)) { 993 LOG(WARNING) << error_msg; 994 error_msgs->push_back("Failed to open dex files from " + std::string(dex_location)); 995 } 996 } else { 997 error_msgs->push_back("Fallback mode disabled, skipping dex files."); 998 } 999 } else { 1000 error_msgs->push_back("No original dex files found for dex location " 1001 + std::string(dex_location)); 1002 } 1003 } 1004 return dex_files; 1005} 1006 1007const OatFile* ClassLinker::FindOpenedOatFileFromOatLocation(const std::string& oat_location) { 1008 ReaderMutexLock mu(Thread::Current(), dex_lock_); 1009 for (size_t i = 0; i < oat_files_.size(); i++) { 1010 const OatFile* oat_file = oat_files_[i]; 1011 DCHECK(oat_file != nullptr); 1012 if (oat_file->GetLocation() == oat_location) { 1013 return oat_file; 1014 } 1015 } 1016 return nullptr; 1017} 1018 1019static void SanityCheckArtMethod(ArtMethod* m, mirror::Class* expected_class, 1020 gc::space::ImageSpace* space) 1021 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1022 if (m->IsRuntimeMethod()) { 1023 CHECK(m->GetDeclaringClass() == nullptr) << PrettyMethod(m); 1024 } else if (m->IsMiranda()) { 1025 CHECK(m->GetDeclaringClass() != nullptr) << PrettyMethod(m); 1026 } else if (expected_class != nullptr) { 1027 CHECK_EQ(m->GetDeclaringClassUnchecked(), expected_class) << PrettyMethod(m); 1028 } 1029 if (space != nullptr) { 1030 auto& header = space->GetImageHeader(); 1031 auto& methods = header.GetMethodsSection(); 1032 auto offset = reinterpret_cast<uint8_t*>(m) - space->Begin(); 1033 CHECK(methods.Contains(offset)) << m << " not in " << methods; 1034 } 1035} 1036 1037static void SanityCheckArtMethodPointerArray( 1038 mirror::PointerArray* arr, mirror::Class* expected_class, size_t pointer_size, 1039 gc::space::ImageSpace* space) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1040 CHECK(arr != nullptr); 1041 for (int32_t j = 0; j < arr->GetLength(); ++j) { 1042 auto* method = arr->GetElementPtrSize<ArtMethod*>(j, pointer_size); 1043 // expected_class == null means we are a dex cache. 1044 if (expected_class != nullptr) { 1045 CHECK(method != nullptr); 1046 } 1047 if (method != nullptr) { 1048 SanityCheckArtMethod(method, expected_class, space); 1049 } 1050 } 1051} 1052 1053static void SanityCheckObjectsCallback(mirror::Object* obj, void* arg ATTRIBUTE_UNUSED) 1054 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1055 DCHECK(obj != nullptr); 1056 CHECK(obj->GetClass() != nullptr) << "Null class in object " << obj; 1057 CHECK(obj->GetClass()->GetClass() != nullptr) << "Null class class " << obj; 1058 if (obj->IsClass()) { 1059 auto klass = obj->AsClass(); 1060 ArtField* fields[2] = { klass->GetSFields(), klass->GetIFields() }; 1061 size_t num_fields[2] = { klass->NumStaticFields(), klass->NumInstanceFields() }; 1062 for (size_t i = 0; i < 2; ++i) { 1063 for (size_t j = 0; j < num_fields[i]; ++j) { 1064 CHECK_EQ(fields[i][j].GetDeclaringClass(), klass); 1065 } 1066 } 1067 auto* runtime = Runtime::Current(); 1068 auto* image_space = runtime->GetHeap()->GetImageSpace(); 1069 auto pointer_size = runtime->GetClassLinker()->GetImagePointerSize(); 1070 for (auto& m : klass->GetDirectMethods(pointer_size)) { 1071 SanityCheckArtMethod(&m, klass, image_space); 1072 } 1073 for (auto& m : klass->GetVirtualMethods(pointer_size)) { 1074 SanityCheckArtMethod(&m, klass, image_space); 1075 } 1076 auto* vtable = klass->GetVTable(); 1077 if (vtable != nullptr) { 1078 SanityCheckArtMethodPointerArray(vtable, nullptr, pointer_size, image_space); 1079 } 1080 if (klass->ShouldHaveEmbeddedImtAndVTable()) { 1081 for (size_t i = 0; i < mirror::Class::kImtSize; ++i) { 1082 SanityCheckArtMethod(klass->GetEmbeddedImTableEntry(i, pointer_size), nullptr, image_space); 1083 } 1084 for (int32_t i = 0; i < klass->GetEmbeddedVTableLength(); ++i) { 1085 SanityCheckArtMethod(klass->GetEmbeddedVTableEntry(i, pointer_size), nullptr, image_space); 1086 } 1087 } 1088 auto* iftable = klass->GetIfTable(); 1089 if (iftable != nullptr) { 1090 for (int32_t i = 0; i < klass->GetIfTableCount(); ++i) { 1091 if (iftable->GetMethodArrayCount(i) > 0) { 1092 SanityCheckArtMethodPointerArray(iftable->GetMethodArray(i), nullptr, pointer_size, 1093 image_space); 1094 } 1095 } 1096 } 1097 } 1098} 1099 1100void ClassLinker::InitFromImage() { 1101 VLOG(startup) << "ClassLinker::InitFromImage entering"; 1102 CHECK(!init_done_); 1103 1104 Runtime* const runtime = Runtime::Current(); 1105 Thread* const self = Thread::Current(); 1106 gc::Heap* const heap = runtime->GetHeap(); 1107 gc::space::ImageSpace* const space = heap->GetImageSpace(); 1108 CHECK(space != nullptr); 1109 image_pointer_size_ = space->GetImageHeader().GetPointerSize(); 1110 dex_cache_image_class_lookup_required_ = true; 1111 OatFile& oat_file = GetImageOatFile(space); 1112 CHECK_EQ(oat_file.GetOatHeader().GetImageFileLocationOatChecksum(), 0U); 1113 CHECK_EQ(oat_file.GetOatHeader().GetImageFileLocationOatDataBegin(), 0U); 1114 const char* image_file_location = oat_file.GetOatHeader(). 1115 GetStoreValueByKey(OatHeader::kImageLocationKey); 1116 CHECK(image_file_location == nullptr || *image_file_location == 0); 1117 quick_resolution_trampoline_ = oat_file.GetOatHeader().GetQuickResolutionTrampoline(); 1118 quick_imt_conflict_trampoline_ = oat_file.GetOatHeader().GetQuickImtConflictTrampoline(); 1119 quick_generic_jni_trampoline_ = oat_file.GetOatHeader().GetQuickGenericJniTrampoline(); 1120 quick_to_interpreter_bridge_trampoline_ = oat_file.GetOatHeader().GetQuickToInterpreterBridge(); 1121 mirror::Object* dex_caches_object = space->GetImageHeader().GetImageRoot(ImageHeader::kDexCaches); 1122 mirror::ObjectArray<mirror::DexCache>* dex_caches = 1123 dex_caches_object->AsObjectArray<mirror::DexCache>(); 1124 1125 StackHandleScope<1> hs(self); 1126 Handle<mirror::ObjectArray<mirror::Class>> class_roots(hs.NewHandle( 1127 space->GetImageHeader().GetImageRoot(ImageHeader::kClassRoots)-> 1128 AsObjectArray<mirror::Class>())); 1129 class_roots_ = GcRoot<mirror::ObjectArray<mirror::Class>>(class_roots.Get()); 1130 1131 // Special case of setting up the String class early so that we can test arbitrary objects 1132 // as being Strings or not 1133 mirror::String::SetClass(GetClassRoot(kJavaLangString)); 1134 1135 CHECK_EQ(oat_file.GetOatHeader().GetDexFileCount(), 1136 static_cast<uint32_t>(dex_caches->GetLength())); 1137 for (int32_t i = 0; i < dex_caches->GetLength(); i++) { 1138 StackHandleScope<1> hs2(self); 1139 Handle<mirror::DexCache> dex_cache(hs2.NewHandle(dex_caches->Get(i))); 1140 const std::string& dex_file_location(dex_cache->GetLocation()->ToModifiedUtf8()); 1141 const OatFile::OatDexFile* oat_dex_file = oat_file.GetOatDexFile(dex_file_location.c_str(), 1142 nullptr); 1143 CHECK(oat_dex_file != nullptr) << oat_file.GetLocation() << " " << dex_file_location; 1144 std::string error_msg; 1145 std::unique_ptr<const DexFile> dex_file = oat_dex_file->OpenDexFile(&error_msg); 1146 if (dex_file.get() == nullptr) { 1147 LOG(FATAL) << "Failed to open dex file " << dex_file_location 1148 << " from within oat file " << oat_file.GetLocation() 1149 << " error '" << error_msg << "'"; 1150 UNREACHABLE(); 1151 } 1152 1153 if (kSanityCheckObjects) { 1154 SanityCheckArtMethodPointerArray(dex_cache->GetResolvedMethods(), nullptr, 1155 image_pointer_size_, space); 1156 } 1157 1158 CHECK_EQ(dex_file->GetLocationChecksum(), oat_dex_file->GetDexFileLocationChecksum()); 1159 1160 AppendToBootClassPath(*dex_file.get(), dex_cache); 1161 opened_dex_files_.push_back(std::move(dex_file)); 1162 } 1163 1164 CHECK(ValidPointerSize(image_pointer_size_)) << image_pointer_size_; 1165 1166 // Set classes on AbstractMethod early so that IsMethod tests can be performed during the live 1167 // bitmap walk. 1168 if (!runtime->IsAotCompiler()) { 1169 // Only the Aot compiler supports having an image with a different pointer size than the 1170 // runtime. This happens on the host for compile 32 bit tests since we use a 64 bit libart 1171 // compiler. We may also use 32 bit dex2oat on a system with 64 bit apps. 1172 CHECK_EQ(image_pointer_size_, sizeof(void*)); 1173 } 1174 1175 if (kSanityCheckObjects) { 1176 for (int32_t i = 0; i < dex_caches->GetLength(); i++) { 1177 auto* dex_cache = dex_caches->Get(i); 1178 for (size_t j = 0; j < dex_cache->NumResolvedFields(); ++j) { 1179 auto* field = dex_cache->GetResolvedField(j, image_pointer_size_); 1180 if (field != nullptr) { 1181 CHECK(field->GetDeclaringClass()->GetClass() != nullptr); 1182 } 1183 } 1184 } 1185 heap->VisitObjects(SanityCheckObjectsCallback, nullptr); 1186 } 1187 1188 // Set entry point to interpreter if in InterpretOnly mode. 1189 if (!runtime->IsAotCompiler() && runtime->GetInstrumentation()->InterpretOnly()) { 1190 const auto& header = space->GetImageHeader(); 1191 const auto& methods = header.GetMethodsSection(); 1192 const auto art_method_size = ArtMethod::ObjectSize(image_pointer_size_); 1193 for (uintptr_t pos = 0; pos < methods.Size(); pos += art_method_size) { 1194 auto* method = reinterpret_cast<ArtMethod*>(space->Begin() + pos + methods.Offset()); 1195 if (kIsDebugBuild && !method->IsRuntimeMethod()) { 1196 CHECK(method->GetDeclaringClass() != nullptr); 1197 } 1198 if (!method->IsNative()) { 1199 method->SetEntryPointFromInterpreterPtrSize( 1200 artInterpreterToInterpreterBridge, image_pointer_size_); 1201 if (!method->IsRuntimeMethod() && method != runtime->GetResolutionMethod()) { 1202 method->SetEntryPointFromQuickCompiledCodePtrSize(GetQuickToInterpreterBridge(), 1203 image_pointer_size_); 1204 } 1205 } 1206 } 1207 } 1208 1209 // reinit class_roots_ 1210 mirror::Class::SetClassClass(class_roots->Get(kJavaLangClass)); 1211 class_roots_ = GcRoot<mirror::ObjectArray<mirror::Class>>(class_roots.Get()); 1212 1213 // reinit array_iftable_ from any array class instance, they should be == 1214 array_iftable_ = GcRoot<mirror::IfTable>(GetClassRoot(kObjectArrayClass)->GetIfTable()); 1215 DCHECK_EQ(array_iftable_.Read(), GetClassRoot(kBooleanArrayClass)->GetIfTable()); 1216 // String class root was set above 1217 mirror::Field::SetClass(GetClassRoot(kJavaLangReflectField)); 1218 mirror::Field::SetArrayClass(GetClassRoot(kJavaLangReflectFieldArrayClass)); 1219 mirror::Constructor::SetClass(GetClassRoot(kJavaLangReflectConstructor)); 1220 mirror::Constructor::SetArrayClass(GetClassRoot(kJavaLangReflectConstructorArrayClass)); 1221 mirror::Method::SetClass(GetClassRoot(kJavaLangReflectMethod)); 1222 mirror::Method::SetArrayClass(GetClassRoot(kJavaLangReflectMethodArrayClass)); 1223 mirror::Reference::SetClass(GetClassRoot(kJavaLangRefReference)); 1224 mirror::BooleanArray::SetArrayClass(GetClassRoot(kBooleanArrayClass)); 1225 mirror::ByteArray::SetArrayClass(GetClassRoot(kByteArrayClass)); 1226 mirror::CharArray::SetArrayClass(GetClassRoot(kCharArrayClass)); 1227 mirror::DoubleArray::SetArrayClass(GetClassRoot(kDoubleArrayClass)); 1228 mirror::FloatArray::SetArrayClass(GetClassRoot(kFloatArrayClass)); 1229 mirror::IntArray::SetArrayClass(GetClassRoot(kIntArrayClass)); 1230 mirror::LongArray::SetArrayClass(GetClassRoot(kLongArrayClass)); 1231 mirror::ShortArray::SetArrayClass(GetClassRoot(kShortArrayClass)); 1232 mirror::Throwable::SetClass(GetClassRoot(kJavaLangThrowable)); 1233 mirror::StackTraceElement::SetClass(GetClassRoot(kJavaLangStackTraceElement)); 1234 1235 FinishInit(self); 1236 1237 VLOG(startup) << "ClassLinker::InitFromImage exiting"; 1238} 1239 1240bool ClassLinker::ClassInClassTable(mirror::Class* klass) { 1241 ReaderMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); 1242 auto it = class_table_.Find(GcRoot<mirror::Class>(klass)); 1243 if (it == class_table_.end()) { 1244 return false; 1245 } 1246 return it->Read() == klass; 1247} 1248 1249void ClassLinker::VisitClassRoots(RootVisitor* visitor, VisitRootFlags flags) { 1250 WriterMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); 1251 BufferedRootVisitor<kDefaultBufferedRootCount> buffered_visitor( 1252 visitor, RootInfo(kRootStickyClass)); 1253 if ((flags & kVisitRootFlagAllRoots) != 0) { 1254 // Argument for how root visiting deals with ArtField and ArtMethod roots. 1255 // There is 3 GC cases to handle: 1256 // Non moving concurrent: 1257 // This case is easy to handle since the reference members of ArtMethod and ArtFields are held 1258 // live by the class and class roots. In this case we probably don't even need to call 1259 // VisitNativeRoots. 1260 // 1261 // Moving non-concurrent: 1262 // This case needs to call visit VisitNativeRoots in case the classes or dex cache arrays move. 1263 // To prevent missing roots, this case needs to ensure that there is no 1264 // suspend points between the point which we allocate ArtMethod arrays and place them in a 1265 // class which is in the class table. 1266 // 1267 // Moving concurrent: 1268 // Need to make sure to not copy ArtMethods without doing read barriers since the roots are 1269 // marked concurrently and we don't hold the classlinker_classes_lock_ when we do the copy. 1270 for (GcRoot<mirror::Class>& root : class_table_) { 1271 buffered_visitor.VisitRoot(root); 1272 if ((flags & kVisitRootFlagNonMoving) == 0) { 1273 // Don't bother visiting ArtField and ArtMethod if kVisitRootFlagNonMoving is set since 1274 // these roots are all reachable from the class or dex cache. 1275 root.Read()->VisitNativeRoots(buffered_visitor, image_pointer_size_); 1276 } 1277 } 1278 // PreZygote classes can't move so we won't need to update fields' declaring classes. 1279 for (GcRoot<mirror::Class>& root : pre_zygote_class_table_) { 1280 buffered_visitor.VisitRoot(root); 1281 if ((flags & kVisitRootFlagNonMoving) == 0) { 1282 root.Read()->VisitNativeRoots(buffered_visitor, image_pointer_size_); 1283 } 1284 } 1285 } else if ((flags & kVisitRootFlagNewRoots) != 0) { 1286 for (auto& root : new_class_roots_) { 1287 mirror::Class* old_ref = root.Read<kWithoutReadBarrier>(); 1288 old_ref->VisitNativeRoots(buffered_visitor, image_pointer_size_); 1289 root.VisitRoot(visitor, RootInfo(kRootStickyClass)); 1290 mirror::Class* new_ref = root.Read<kWithoutReadBarrier>(); 1291 if (UNLIKELY(new_ref != old_ref)) { 1292 // Uh ohes, GC moved a root in the log. Need to search the class_table and update the 1293 // corresponding object. This is slow, but luckily for us, this may only happen with a 1294 // concurrent moving GC. 1295 auto it = class_table_.Find(GcRoot<mirror::Class>(old_ref)); 1296 DCHECK(it != class_table_.end()); 1297 *it = GcRoot<mirror::Class>(new_ref); 1298 } 1299 } 1300 } 1301 buffered_visitor.Flush(); // Flush before clearing new_class_roots_. 1302 if ((flags & kVisitRootFlagClearRootLog) != 0) { 1303 new_class_roots_.clear(); 1304 } 1305 if ((flags & kVisitRootFlagStartLoggingNewRoots) != 0) { 1306 log_new_class_table_roots_ = true; 1307 } else if ((flags & kVisitRootFlagStopLoggingNewRoots) != 0) { 1308 log_new_class_table_roots_ = false; 1309 } 1310 // We deliberately ignore the class roots in the image since we 1311 // handle image roots by using the MS/CMS rescanning of dirty cards. 1312} 1313 1314// Keep in sync with InitCallback. Anything we visit, we need to 1315// reinit references to when reinitializing a ClassLinker from a 1316// mapped image. 1317void ClassLinker::VisitRoots(RootVisitor* visitor, VisitRootFlags flags) { 1318 class_roots_.VisitRootIfNonNull(visitor, RootInfo(kRootVMInternal)); 1319 Thread* const self = Thread::Current(); 1320 { 1321 ReaderMutexLock mu(self, dex_lock_); 1322 if ((flags & kVisitRootFlagAllRoots) != 0) { 1323 for (GcRoot<mirror::DexCache>& dex_cache : dex_caches_) { 1324 dex_cache.VisitRoot(visitor, RootInfo(kRootVMInternal)); 1325 } 1326 } else if ((flags & kVisitRootFlagNewRoots) != 0) { 1327 for (size_t index : new_dex_cache_roots_) { 1328 dex_caches_[index].VisitRoot(visitor, RootInfo(kRootVMInternal)); 1329 } 1330 } 1331 if ((flags & kVisitRootFlagClearRootLog) != 0) { 1332 new_dex_cache_roots_.clear(); 1333 } 1334 if ((flags & kVisitRootFlagStartLoggingNewRoots) != 0) { 1335 log_new_dex_caches_roots_ = true; 1336 } else if ((flags & kVisitRootFlagStopLoggingNewRoots) != 0) { 1337 log_new_dex_caches_roots_ = false; 1338 } 1339 } 1340 VisitClassRoots(visitor, flags); 1341 array_iftable_.VisitRootIfNonNull(visitor, RootInfo(kRootVMInternal)); 1342 for (GcRoot<mirror::Class>& root : find_array_class_cache_) { 1343 root.VisitRootIfNonNull(visitor, RootInfo(kRootVMInternal)); 1344 } 1345} 1346 1347void ClassLinker::VisitClasses(ClassVisitor* visitor, void* arg) { 1348 if (dex_cache_image_class_lookup_required_) { 1349 MoveImageClassesToClassTable(); 1350 } 1351 // TODO: why isn't this a ReaderMutexLock? 1352 WriterMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); 1353 for (GcRoot<mirror::Class>& root : class_table_) { 1354 if (!visitor(root.Read(), arg)) { 1355 return; 1356 } 1357 } 1358 for (GcRoot<mirror::Class>& root : pre_zygote_class_table_) { 1359 if (!visitor(root.Read(), arg)) { 1360 return; 1361 } 1362 } 1363} 1364 1365static bool GetClassesVisitorSet(mirror::Class* c, void* arg) { 1366 std::set<mirror::Class*>* classes = reinterpret_cast<std::set<mirror::Class*>*>(arg); 1367 classes->insert(c); 1368 return true; 1369} 1370 1371struct GetClassesVisitorArrayArg { 1372 Handle<mirror::ObjectArray<mirror::Class>>* classes; 1373 int32_t index; 1374 bool success; 1375}; 1376 1377static bool GetClassesVisitorArray(mirror::Class* c, void* varg) 1378 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1379 GetClassesVisitorArrayArg* arg = reinterpret_cast<GetClassesVisitorArrayArg*>(varg); 1380 if (arg->index < (*arg->classes)->GetLength()) { 1381 (*arg->classes)->Set(arg->index, c); 1382 arg->index++; 1383 return true; 1384 } else { 1385 arg->success = false; 1386 return false; 1387 } 1388} 1389 1390void ClassLinker::VisitClassesWithoutClassesLock(ClassVisitor* visitor, void* arg) { 1391 // TODO: it may be possible to avoid secondary storage if we iterate over dex caches. The problem 1392 // is avoiding duplicates. 1393 if (!kMovingClasses) { 1394 std::set<mirror::Class*> classes; 1395 VisitClasses(GetClassesVisitorSet, &classes); 1396 for (mirror::Class* klass : classes) { 1397 if (!visitor(klass, arg)) { 1398 return; 1399 } 1400 } 1401 } else { 1402 Thread* self = Thread::Current(); 1403 StackHandleScope<1> hs(self); 1404 MutableHandle<mirror::ObjectArray<mirror::Class>> classes = 1405 hs.NewHandle<mirror::ObjectArray<mirror::Class>>(nullptr); 1406 GetClassesVisitorArrayArg local_arg; 1407 local_arg.classes = &classes; 1408 local_arg.success = false; 1409 // We size the array assuming classes won't be added to the class table during the visit. 1410 // If this assumption fails we iterate again. 1411 while (!local_arg.success) { 1412 size_t class_table_size; 1413 { 1414 ReaderMutexLock mu(self, *Locks::classlinker_classes_lock_); 1415 class_table_size = class_table_.Size() + pre_zygote_class_table_.Size(); 1416 } 1417 mirror::Class* class_type = mirror::Class::GetJavaLangClass(); 1418 mirror::Class* array_of_class = FindArrayClass(self, &class_type); 1419 classes.Assign( 1420 mirror::ObjectArray<mirror::Class>::Alloc(self, array_of_class, class_table_size)); 1421 CHECK(classes.Get() != nullptr); // OOME. 1422 local_arg.index = 0; 1423 local_arg.success = true; 1424 VisitClasses(GetClassesVisitorArray, &local_arg); 1425 } 1426 for (int32_t i = 0; i < classes->GetLength(); ++i) { 1427 // If the class table shrank during creation of the clases array we expect null elements. If 1428 // the class table grew then the loop repeats. If classes are created after the loop has 1429 // finished then we don't visit. 1430 mirror::Class* klass = classes->Get(i); 1431 if (klass != nullptr && !visitor(klass, arg)) { 1432 return; 1433 } 1434 } 1435 } 1436} 1437 1438ClassLinker::~ClassLinker() { 1439 mirror::Class::ResetClass(); 1440 mirror::Constructor::ResetClass(); 1441 mirror::Field::ResetClass(); 1442 mirror::Method::ResetClass(); 1443 mirror::Reference::ResetClass(); 1444 mirror::StackTraceElement::ResetClass(); 1445 mirror::String::ResetClass(); 1446 mirror::Throwable::ResetClass(); 1447 mirror::BooleanArray::ResetArrayClass(); 1448 mirror::ByteArray::ResetArrayClass(); 1449 mirror::CharArray::ResetArrayClass(); 1450 mirror::Constructor::ResetArrayClass(); 1451 mirror::DoubleArray::ResetArrayClass(); 1452 mirror::Field::ResetArrayClass(); 1453 mirror::FloatArray::ResetArrayClass(); 1454 mirror::Method::ResetArrayClass(); 1455 mirror::IntArray::ResetArrayClass(); 1456 mirror::LongArray::ResetArrayClass(); 1457 mirror::ShortArray::ResetArrayClass(); 1458 STLDeleteElements(&oat_files_); 1459} 1460 1461mirror::PointerArray* ClassLinker::AllocPointerArray(Thread* self, size_t length) { 1462 return down_cast<mirror::PointerArray*>(image_pointer_size_ == 8u ? 1463 static_cast<mirror::Array*>(mirror::LongArray::Alloc(self, length)) : 1464 static_cast<mirror::Array*>(mirror::IntArray::Alloc(self, length))); 1465} 1466 1467mirror::DexCache* ClassLinker::AllocDexCache(Thread* self, const DexFile& dex_file) { 1468 StackHandleScope<6> hs(self); 1469 auto dex_cache(hs.NewHandle(down_cast<mirror::DexCache*>( 1470 GetClassRoot(kJavaLangDexCache)->AllocObject(self)))); 1471 if (dex_cache.Get() == nullptr) { 1472 self->AssertPendingOOMException(); 1473 return nullptr; 1474 } 1475 auto location(hs.NewHandle(intern_table_->InternStrong(dex_file.GetLocation().c_str()))); 1476 if (location.Get() == nullptr) { 1477 self->AssertPendingOOMException(); 1478 return nullptr; 1479 } 1480 auto strings(hs.NewHandle(AllocStringArray(self, dex_file.NumStringIds()))); 1481 if (strings.Get() == nullptr) { 1482 self->AssertPendingOOMException(); 1483 return nullptr; 1484 } 1485 auto types(hs.NewHandle(AllocClassArray(self, dex_file.NumTypeIds()))); 1486 if (types.Get() == nullptr) { 1487 self->AssertPendingOOMException(); 1488 return nullptr; 1489 } 1490 auto methods(hs.NewHandle(AllocPointerArray(self, dex_file.NumMethodIds()))); 1491 if (methods.Get() == nullptr) { 1492 self->AssertPendingOOMException(); 1493 return nullptr; 1494 } 1495 auto fields(hs.NewHandle(AllocPointerArray(self, dex_file.NumFieldIds()))); 1496 if (fields.Get() == nullptr) { 1497 self->AssertPendingOOMException(); 1498 return nullptr; 1499 } 1500 dex_cache->Init(&dex_file, location.Get(), strings.Get(), types.Get(), methods.Get(), 1501 fields.Get(), image_pointer_size_); 1502 return dex_cache.Get(); 1503} 1504 1505mirror::Class* ClassLinker::AllocClass(Thread* self, mirror::Class* java_lang_Class, 1506 uint32_t class_size) { 1507 DCHECK_GE(class_size, sizeof(mirror::Class)); 1508 gc::Heap* heap = Runtime::Current()->GetHeap(); 1509 mirror::Class::InitializeClassVisitor visitor(class_size); 1510 mirror::Object* k = kMovingClasses ? 1511 heap->AllocObject<true>(self, java_lang_Class, class_size, visitor) : 1512 heap->AllocNonMovableObject<true>(self, java_lang_Class, class_size, visitor); 1513 if (UNLIKELY(k == nullptr)) { 1514 self->AssertPendingOOMException(); 1515 return nullptr; 1516 } 1517 return k->AsClass(); 1518} 1519 1520mirror::Class* ClassLinker::AllocClass(Thread* self, uint32_t class_size) { 1521 return AllocClass(self, GetClassRoot(kJavaLangClass), class_size); 1522} 1523 1524mirror::ObjectArray<mirror::StackTraceElement>* ClassLinker::AllocStackTraceElementArray( 1525 Thread* self, size_t length) { 1526 return mirror::ObjectArray<mirror::StackTraceElement>::Alloc( 1527 self, GetClassRoot(kJavaLangStackTraceElementArrayClass), length); 1528} 1529 1530mirror::Class* ClassLinker::EnsureResolved(Thread* self, const char* descriptor, 1531 mirror::Class* klass) { 1532 DCHECK(klass != nullptr); 1533 1534 // For temporary classes we must wait for them to be retired. 1535 if (init_done_ && klass->IsTemp()) { 1536 CHECK(!klass->IsResolved()); 1537 if (klass->IsErroneous()) { 1538 ThrowEarlierClassFailure(klass); 1539 return nullptr; 1540 } 1541 StackHandleScope<1> hs(self); 1542 Handle<mirror::Class> h_class(hs.NewHandle(klass)); 1543 ObjectLock<mirror::Class> lock(self, h_class); 1544 // Loop and wait for the resolving thread to retire this class. 1545 while (!h_class->IsRetired() && !h_class->IsErroneous()) { 1546 lock.WaitIgnoringInterrupts(); 1547 } 1548 if (h_class->IsErroneous()) { 1549 ThrowEarlierClassFailure(h_class.Get()); 1550 return nullptr; 1551 } 1552 CHECK(h_class->IsRetired()); 1553 // Get the updated class from class table. 1554 klass = LookupClass(self, descriptor, ComputeModifiedUtf8Hash(descriptor), 1555 h_class.Get()->GetClassLoader()); 1556 } 1557 1558 // Wait for the class if it has not already been linked. 1559 if (!klass->IsResolved() && !klass->IsErroneous()) { 1560 StackHandleScope<1> hs(self); 1561 HandleWrapper<mirror::Class> h_class(hs.NewHandleWrapper(&klass)); 1562 ObjectLock<mirror::Class> lock(self, h_class); 1563 // Check for circular dependencies between classes. 1564 if (!h_class->IsResolved() && h_class->GetClinitThreadId() == self->GetTid()) { 1565 ThrowClassCircularityError(h_class.Get()); 1566 mirror::Class::SetStatus(h_class, mirror::Class::kStatusError, self); 1567 return nullptr; 1568 } 1569 // Wait for the pending initialization to complete. 1570 while (!h_class->IsResolved() && !h_class->IsErroneous()) { 1571 lock.WaitIgnoringInterrupts(); 1572 } 1573 } 1574 1575 if (klass->IsErroneous()) { 1576 ThrowEarlierClassFailure(klass); 1577 return nullptr; 1578 } 1579 // Return the loaded class. No exceptions should be pending. 1580 CHECK(klass->IsResolved()) << PrettyClass(klass); 1581 self->AssertNoPendingException(); 1582 return klass; 1583} 1584 1585typedef std::pair<const DexFile*, const DexFile::ClassDef*> ClassPathEntry; 1586 1587// Search a collection of DexFiles for a descriptor 1588ClassPathEntry FindInClassPath(const char* descriptor, 1589 size_t hash, const std::vector<const DexFile*>& class_path) { 1590 for (const DexFile* dex_file : class_path) { 1591 const DexFile::ClassDef* dex_class_def = dex_file->FindClassDef(descriptor, hash); 1592 if (dex_class_def != nullptr) { 1593 return ClassPathEntry(dex_file, dex_class_def); 1594 } 1595 } 1596 return ClassPathEntry(nullptr, nullptr); 1597} 1598 1599static bool IsBootClassLoader(ScopedObjectAccessAlreadyRunnable& soa, 1600 mirror::ClassLoader* class_loader) 1601 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1602 return class_loader == nullptr || 1603 class_loader->GetClass() == 1604 soa.Decode<mirror::Class*>(WellKnownClasses::java_lang_BootClassLoader); 1605} 1606 1607bool ClassLinker::FindClassInPathClassLoader(ScopedObjectAccessAlreadyRunnable& soa, 1608 Thread* self, const char* descriptor, 1609 size_t hash, 1610 Handle<mirror::ClassLoader> class_loader, 1611 mirror::Class** result) { 1612 // Termination case: boot class-loader. 1613 if (IsBootClassLoader(soa, class_loader.Get())) { 1614 // The boot class loader, search the boot class path. 1615 ClassPathEntry pair = FindInClassPath(descriptor, hash, boot_class_path_); 1616 if (pair.second != nullptr) { 1617 mirror::Class* klass = LookupClass(self, descriptor, hash, nullptr); 1618 if (klass != nullptr) { 1619 *result = EnsureResolved(self, descriptor, klass); 1620 } else { 1621 *result = DefineClass(self, descriptor, hash, NullHandle<mirror::ClassLoader>(), 1622 *pair.first, *pair.second); 1623 } 1624 if (*result == nullptr) { 1625 CHECK(self->IsExceptionPending()) << descriptor; 1626 self->ClearException(); 1627 } 1628 } else { 1629 *result = nullptr; 1630 } 1631 return true; 1632 } 1633 1634 // Unsupported class-loader? 1635 if (class_loader->GetClass() != 1636 soa.Decode<mirror::Class*>(WellKnownClasses::dalvik_system_PathClassLoader)) { 1637 *result = nullptr; 1638 return false; 1639 } 1640 1641 // Handles as RegisterDexFile may allocate dex caches (and cause thread suspension). 1642 StackHandleScope<4> hs(self); 1643 Handle<mirror::ClassLoader> h_parent(hs.NewHandle(class_loader->GetParent())); 1644 bool recursive_result = FindClassInPathClassLoader(soa, self, descriptor, hash, h_parent, result); 1645 1646 if (!recursive_result) { 1647 // Something wrong up the chain. 1648 return false; 1649 } 1650 1651 if (*result != nullptr) { 1652 // Found the class up the chain. 1653 return true; 1654 } 1655 1656 // Handle this step. 1657 // Handle as if this is the child PathClassLoader. 1658 // The class loader is a PathClassLoader which inherits from BaseDexClassLoader. 1659 // We need to get the DexPathList and loop through it. 1660 ArtField* const cookie_field = soa.DecodeField(WellKnownClasses::dalvik_system_DexFile_cookie); 1661 ArtField* const dex_file_field = 1662 soa.DecodeField(WellKnownClasses::dalvik_system_DexPathList__Element_dexFile); 1663 mirror::Object* dex_path_list = 1664 soa.DecodeField(WellKnownClasses::dalvik_system_PathClassLoader_pathList)-> 1665 GetObject(class_loader.Get()); 1666 if (dex_path_list != nullptr && dex_file_field != nullptr && cookie_field != nullptr) { 1667 // DexPathList has an array dexElements of Elements[] which each contain a dex file. 1668 mirror::Object* dex_elements_obj = 1669 soa.DecodeField(WellKnownClasses::dalvik_system_DexPathList_dexElements)-> 1670 GetObject(dex_path_list); 1671 // Loop through each dalvik.system.DexPathList$Element's dalvik.system.DexFile and look 1672 // at the mCookie which is a DexFile vector. 1673 if (dex_elements_obj != nullptr) { 1674 Handle<mirror::ObjectArray<mirror::Object>> dex_elements = 1675 hs.NewHandle(dex_elements_obj->AsObjectArray<mirror::Object>()); 1676 for (int32_t i = 0; i < dex_elements->GetLength(); ++i) { 1677 mirror::Object* element = dex_elements->GetWithoutChecks(i); 1678 if (element == nullptr) { 1679 // Should never happen, fall back to java code to throw a NPE. 1680 break; 1681 } 1682 mirror::Object* dex_file = dex_file_field->GetObject(element); 1683 if (dex_file != nullptr) { 1684 mirror::LongArray* long_array = cookie_field->GetObject(dex_file)->AsLongArray(); 1685 if (long_array == nullptr) { 1686 // This should never happen so log a warning. 1687 LOG(WARNING) << "Null DexFile::mCookie for " << descriptor; 1688 break; 1689 } 1690 int32_t long_array_size = long_array->GetLength(); 1691 for (int32_t j = 0; j < long_array_size; ++j) { 1692 const DexFile* cp_dex_file = reinterpret_cast<const DexFile*>(static_cast<uintptr_t>( 1693 long_array->GetWithoutChecks(j))); 1694 const DexFile::ClassDef* dex_class_def = cp_dex_file->FindClassDef(descriptor, hash); 1695 if (dex_class_def != nullptr) { 1696 RegisterDexFile(*cp_dex_file); 1697 mirror::Class* klass = DefineClass(self, descriptor, hash, class_loader, 1698 *cp_dex_file, *dex_class_def); 1699 if (klass == nullptr) { 1700 CHECK(self->IsExceptionPending()) << descriptor; 1701 self->ClearException(); 1702 // TODO: Is it really right to break here, and not check the other dex files? 1703 return true; 1704 } 1705 *result = klass; 1706 return true; 1707 } 1708 } 1709 } 1710 } 1711 } 1712 self->AssertNoPendingException(); 1713 } 1714 1715 // Result is still null from the parent call, no need to set it again... 1716 return true; 1717} 1718 1719mirror::Class* ClassLinker::FindClass(Thread* self, const char* descriptor, 1720 Handle<mirror::ClassLoader> class_loader) { 1721 DCHECK_NE(*descriptor, '\0') << "descriptor is empty string"; 1722 DCHECK(self != nullptr); 1723 self->AssertNoPendingException(); 1724 if (descriptor[1] == '\0') { 1725 // only the descriptors of primitive types should be 1 character long, also avoid class lookup 1726 // for primitive classes that aren't backed by dex files. 1727 return FindPrimitiveClass(descriptor[0]); 1728 } 1729 const size_t hash = ComputeModifiedUtf8Hash(descriptor); 1730 // Find the class in the loaded classes table. 1731 mirror::Class* klass = LookupClass(self, descriptor, hash, class_loader.Get()); 1732 if (klass != nullptr) { 1733 return EnsureResolved(self, descriptor, klass); 1734 } 1735 // Class is not yet loaded. 1736 if (descriptor[0] == '[') { 1737 return CreateArrayClass(self, descriptor, hash, class_loader); 1738 } else if (class_loader.Get() == nullptr) { 1739 // The boot class loader, search the boot class path. 1740 ClassPathEntry pair = FindInClassPath(descriptor, hash, boot_class_path_); 1741 if (pair.second != nullptr) { 1742 return DefineClass(self, descriptor, hash, NullHandle<mirror::ClassLoader>(), *pair.first, 1743 *pair.second); 1744 } else { 1745 // The boot class loader is searched ahead of the application class loader, failures are 1746 // expected and will be wrapped in a ClassNotFoundException. Use the pre-allocated error to 1747 // trigger the chaining with a proper stack trace. 1748 mirror::Throwable* pre_allocated = Runtime::Current()->GetPreAllocatedNoClassDefFoundError(); 1749 self->SetException(pre_allocated); 1750 return nullptr; 1751 } 1752 } else { 1753 ScopedObjectAccessUnchecked soa(self); 1754 mirror::Class* cp_klass; 1755 if (FindClassInPathClassLoader(soa, self, descriptor, hash, class_loader, &cp_klass)) { 1756 // The chain was understood. So the value in cp_klass is either the class we were looking 1757 // for, or not found. 1758 if (cp_klass != nullptr) { 1759 return cp_klass; 1760 } 1761 // TODO: We handle the boot classpath loader in FindClassInPathClassLoader. Try to unify this 1762 // and the branch above. TODO: throw the right exception here. 1763 1764 // We'll let the Java-side rediscover all this and throw the exception with the right stack 1765 // trace. 1766 } 1767 1768 if (Runtime::Current()->IsAotCompiler()) { 1769 // Oops, compile-time, can't run actual class-loader code. 1770 mirror::Throwable* pre_allocated = Runtime::Current()->GetPreAllocatedNoClassDefFoundError(); 1771 self->SetException(pre_allocated); 1772 return nullptr; 1773 } 1774 1775 ScopedLocalRef<jobject> class_loader_object(soa.Env(), 1776 soa.AddLocalReference<jobject>(class_loader.Get())); 1777 std::string class_name_string(DescriptorToDot(descriptor)); 1778 ScopedLocalRef<jobject> result(soa.Env(), nullptr); 1779 { 1780 ScopedThreadStateChange tsc(self, kNative); 1781 ScopedLocalRef<jobject> class_name_object(soa.Env(), 1782 soa.Env()->NewStringUTF(class_name_string.c_str())); 1783 if (class_name_object.get() == nullptr) { 1784 DCHECK(self->IsExceptionPending()); // OOME. 1785 return nullptr; 1786 } 1787 CHECK(class_loader_object.get() != nullptr); 1788 result.reset(soa.Env()->CallObjectMethod(class_loader_object.get(), 1789 WellKnownClasses::java_lang_ClassLoader_loadClass, 1790 class_name_object.get())); 1791 } 1792 if (self->IsExceptionPending()) { 1793 // If the ClassLoader threw, pass that exception up. 1794 return nullptr; 1795 } else if (result.get() == nullptr) { 1796 // broken loader - throw NPE to be compatible with Dalvik 1797 ThrowNullPointerException(StringPrintf("ClassLoader.loadClass returned null for %s", 1798 class_name_string.c_str()).c_str()); 1799 return nullptr; 1800 } else { 1801 // success, return mirror::Class* 1802 return soa.Decode<mirror::Class*>(result.get()); 1803 } 1804 } 1805 UNREACHABLE(); 1806} 1807 1808mirror::Class* ClassLinker::DefineClass(Thread* self, const char* descriptor, size_t hash, 1809 Handle<mirror::ClassLoader> class_loader, 1810 const DexFile& dex_file, 1811 const DexFile::ClassDef& dex_class_def) { 1812 StackHandleScope<3> hs(self); 1813 auto klass = hs.NewHandle<mirror::Class>(nullptr); 1814 1815 // Load the class from the dex file. 1816 if (UNLIKELY(!init_done_)) { 1817 // finish up init of hand crafted class_roots_ 1818 if (strcmp(descriptor, "Ljava/lang/Object;") == 0) { 1819 klass.Assign(GetClassRoot(kJavaLangObject)); 1820 } else if (strcmp(descriptor, "Ljava/lang/Class;") == 0) { 1821 klass.Assign(GetClassRoot(kJavaLangClass)); 1822 } else if (strcmp(descriptor, "Ljava/lang/String;") == 0) { 1823 klass.Assign(GetClassRoot(kJavaLangString)); 1824 } else if (strcmp(descriptor, "Ljava/lang/ref/Reference;") == 0) { 1825 klass.Assign(GetClassRoot(kJavaLangRefReference)); 1826 } else if (strcmp(descriptor, "Ljava/lang/DexCache;") == 0) { 1827 klass.Assign(GetClassRoot(kJavaLangDexCache)); 1828 } 1829 } 1830 1831 if (klass.Get() == nullptr) { 1832 // Allocate a class with the status of not ready. 1833 // Interface object should get the right size here. Regular class will 1834 // figure out the right size later and be replaced with one of the right 1835 // size when the class becomes resolved. 1836 klass.Assign(AllocClass(self, SizeOfClassWithoutEmbeddedTables(dex_file, dex_class_def))); 1837 } 1838 if (UNLIKELY(klass.Get() == nullptr)) { 1839 CHECK(self->IsExceptionPending()); // Expect an OOME. 1840 return nullptr; 1841 } 1842 klass->SetDexCache(FindDexCache(dex_file)); 1843 1844 SetupClass(dex_file, dex_class_def, klass, class_loader.Get()); 1845 1846 // Mark the string class by setting its access flag. 1847 if (UNLIKELY(!init_done_)) { 1848 if (strcmp(descriptor, "Ljava/lang/String;") == 0) { 1849 klass->SetStringClass(); 1850 } 1851 } 1852 1853 ObjectLock<mirror::Class> lock(self, klass); 1854 klass->SetClinitThreadId(self->GetTid()); 1855 1856 // Add the newly loaded class to the loaded classes table. 1857 mirror::Class* existing = InsertClass(descriptor, klass.Get(), hash); 1858 if (existing != nullptr) { 1859 // We failed to insert because we raced with another thread. Calling EnsureResolved may cause 1860 // this thread to block. 1861 return EnsureResolved(self, descriptor, existing); 1862 } 1863 1864 // Load the fields and other things after we are inserted in the table. This is so that we don't 1865 // end up allocating unfree-able linear alloc resources and then lose the race condition. The 1866 // other reason is that the field roots are only visited from the class table. So we need to be 1867 // inserted before we allocate / fill in these fields. 1868 LoadClass(self, dex_file, dex_class_def, klass); 1869 if (self->IsExceptionPending()) { 1870 // An exception occured during load, set status to erroneous while holding klass' lock in case 1871 // notification is necessary. 1872 if (!klass->IsErroneous()) { 1873 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 1874 } 1875 return nullptr; 1876 } 1877 1878 // Finish loading (if necessary) by finding parents 1879 CHECK(!klass->IsLoaded()); 1880 if (!LoadSuperAndInterfaces(klass, dex_file)) { 1881 // Loading failed. 1882 if (!klass->IsErroneous()) { 1883 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 1884 } 1885 return nullptr; 1886 } 1887 CHECK(klass->IsLoaded()); 1888 // Link the class (if necessary) 1889 CHECK(!klass->IsResolved()); 1890 // TODO: Use fast jobjects? 1891 auto interfaces = hs.NewHandle<mirror::ObjectArray<mirror::Class>>(nullptr); 1892 1893 MutableHandle<mirror::Class> h_new_class = hs.NewHandle<mirror::Class>(nullptr); 1894 if (!LinkClass(self, descriptor, klass, interfaces, &h_new_class)) { 1895 // Linking failed. 1896 if (!klass->IsErroneous()) { 1897 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 1898 } 1899 return nullptr; 1900 } 1901 self->AssertNoPendingException(); 1902 CHECK(h_new_class.Get() != nullptr) << descriptor; 1903 CHECK(h_new_class->IsResolved()) << descriptor; 1904 1905 // Instrumentation may have updated entrypoints for all methods of all 1906 // classes. However it could not update methods of this class while we 1907 // were loading it. Now the class is resolved, we can update entrypoints 1908 // as required by instrumentation. 1909 if (Runtime::Current()->GetInstrumentation()->AreExitStubsInstalled()) { 1910 // We must be in the kRunnable state to prevent instrumentation from 1911 // suspending all threads to update entrypoints while we are doing it 1912 // for this class. 1913 DCHECK_EQ(self->GetState(), kRunnable); 1914 Runtime::Current()->GetInstrumentation()->InstallStubsForClass(h_new_class.Get()); 1915 } 1916 1917 /* 1918 * We send CLASS_PREPARE events to the debugger from here. The 1919 * definition of "preparation" is creating the static fields for a 1920 * class and initializing them to the standard default values, but not 1921 * executing any code (that comes later, during "initialization"). 1922 * 1923 * We did the static preparation in LinkClass. 1924 * 1925 * The class has been prepared and resolved but possibly not yet verified 1926 * at this point. 1927 */ 1928 Dbg::PostClassPrepare(h_new_class.Get()); 1929 1930 return h_new_class.Get(); 1931} 1932 1933uint32_t ClassLinker::SizeOfClassWithoutEmbeddedTables(const DexFile& dex_file, 1934 const DexFile::ClassDef& dex_class_def) { 1935 const uint8_t* class_data = dex_file.GetClassData(dex_class_def); 1936 size_t num_ref = 0; 1937 size_t num_8 = 0; 1938 size_t num_16 = 0; 1939 size_t num_32 = 0; 1940 size_t num_64 = 0; 1941 if (class_data != nullptr) { 1942 for (ClassDataItemIterator it(dex_file, class_data); it.HasNextStaticField(); it.Next()) { 1943 const DexFile::FieldId& field_id = dex_file.GetFieldId(it.GetMemberIndex()); 1944 const char* descriptor = dex_file.GetFieldTypeDescriptor(field_id); 1945 char c = descriptor[0]; 1946 switch (c) { 1947 case 'L': 1948 case '[': 1949 num_ref++; 1950 break; 1951 case 'J': 1952 case 'D': 1953 num_64++; 1954 break; 1955 case 'I': 1956 case 'F': 1957 num_32++; 1958 break; 1959 case 'S': 1960 case 'C': 1961 num_16++; 1962 break; 1963 case 'B': 1964 case 'Z': 1965 num_8++; 1966 break; 1967 default: 1968 LOG(FATAL) << "Unknown descriptor: " << c; 1969 UNREACHABLE(); 1970 } 1971 } 1972 } 1973 return mirror::Class::ComputeClassSize(false, 0, num_8, num_16, num_32, num_64, num_ref, 1974 image_pointer_size_); 1975} 1976 1977OatFile::OatClass ClassLinker::FindOatClass(const DexFile& dex_file, uint16_t class_def_idx, 1978 bool* found) { 1979 DCHECK_NE(class_def_idx, DexFile::kDexNoIndex16); 1980 const OatFile::OatDexFile* oat_dex_file = dex_file.GetOatDexFile(); 1981 if (oat_dex_file == nullptr) { 1982 *found = false; 1983 return OatFile::OatClass::Invalid(); 1984 } 1985 *found = true; 1986 return oat_dex_file->GetOatClass(class_def_idx); 1987} 1988 1989static uint32_t GetOatMethodIndexFromMethodIndex(const DexFile& dex_file, uint16_t class_def_idx, 1990 uint32_t method_idx) { 1991 const DexFile::ClassDef& class_def = dex_file.GetClassDef(class_def_idx); 1992 const uint8_t* class_data = dex_file.GetClassData(class_def); 1993 CHECK(class_data != nullptr); 1994 ClassDataItemIterator it(dex_file, class_data); 1995 // Skip fields 1996 while (it.HasNextStaticField()) { 1997 it.Next(); 1998 } 1999 while (it.HasNextInstanceField()) { 2000 it.Next(); 2001 } 2002 // Process methods 2003 size_t class_def_method_index = 0; 2004 while (it.HasNextDirectMethod()) { 2005 if (it.GetMemberIndex() == method_idx) { 2006 return class_def_method_index; 2007 } 2008 class_def_method_index++; 2009 it.Next(); 2010 } 2011 while (it.HasNextVirtualMethod()) { 2012 if (it.GetMemberIndex() == method_idx) { 2013 return class_def_method_index; 2014 } 2015 class_def_method_index++; 2016 it.Next(); 2017 } 2018 DCHECK(!it.HasNext()); 2019 LOG(FATAL) << "Failed to find method index " << method_idx << " in " << dex_file.GetLocation(); 2020 UNREACHABLE(); 2021} 2022 2023const OatFile::OatMethod ClassLinker::FindOatMethodFor(ArtMethod* method, bool* found) { 2024 // Although we overwrite the trampoline of non-static methods, we may get here via the resolution 2025 // method for direct methods (or virtual methods made direct). 2026 mirror::Class* declaring_class = method->GetDeclaringClass(); 2027 size_t oat_method_index; 2028 if (method->IsStatic() || method->IsDirect()) { 2029 // Simple case where the oat method index was stashed at load time. 2030 oat_method_index = method->GetMethodIndex(); 2031 } else { 2032 // We're invoking a virtual method directly (thanks to sharpening), compute the oat_method_index 2033 // by search for its position in the declared virtual methods. 2034 oat_method_index = declaring_class->NumDirectMethods(); 2035 size_t end = declaring_class->NumVirtualMethods(); 2036 bool found_virtual = false; 2037 for (size_t i = 0; i < end; i++) { 2038 // Check method index instead of identity in case of duplicate method definitions. 2039 if (method->GetDexMethodIndex() == 2040 declaring_class->GetVirtualMethod(i, image_pointer_size_)->GetDexMethodIndex()) { 2041 found_virtual = true; 2042 break; 2043 } 2044 oat_method_index++; 2045 } 2046 CHECK(found_virtual) << "Didn't find oat method index for virtual method: " 2047 << PrettyMethod(method); 2048 } 2049 DCHECK_EQ(oat_method_index, 2050 GetOatMethodIndexFromMethodIndex(*declaring_class->GetDexCache()->GetDexFile(), 2051 method->GetDeclaringClass()->GetDexClassDefIndex(), 2052 method->GetDexMethodIndex())); 2053 OatFile::OatClass oat_class = FindOatClass(*declaring_class->GetDexCache()->GetDexFile(), 2054 declaring_class->GetDexClassDefIndex(), 2055 found); 2056 if (!(*found)) { 2057 return OatFile::OatMethod::Invalid(); 2058 } 2059 return oat_class.GetOatMethod(oat_method_index); 2060} 2061 2062// Special case to get oat code without overwriting a trampoline. 2063const void* ClassLinker::GetQuickOatCodeFor(ArtMethod* method) { 2064 CHECK(!method->IsAbstract()) << PrettyMethod(method); 2065 if (method->IsProxyMethod()) { 2066 return GetQuickProxyInvokeHandler(); 2067 } 2068 bool found; 2069 OatFile::OatMethod oat_method = FindOatMethodFor(method, &found); 2070 if (found) { 2071 auto* code = oat_method.GetQuickCode(); 2072 if (code != nullptr) { 2073 return code; 2074 } 2075 } 2076 jit::Jit* const jit = Runtime::Current()->GetJit(); 2077 if (jit != nullptr) { 2078 auto* code = jit->GetCodeCache()->GetCodeFor(method); 2079 if (code != nullptr) { 2080 return code; 2081 } 2082 } 2083 if (method->IsNative()) { 2084 // No code and native? Use generic trampoline. 2085 return GetQuickGenericJniStub(); 2086 } 2087 return GetQuickToInterpreterBridge(); 2088} 2089 2090const void* ClassLinker::GetOatMethodQuickCodeFor(ArtMethod* method) { 2091 if (method->IsNative() || method->IsAbstract() || method->IsProxyMethod()) { 2092 return nullptr; 2093 } 2094 bool found; 2095 OatFile::OatMethod oat_method = FindOatMethodFor(method, &found); 2096 if (found) { 2097 return oat_method.GetQuickCode(); 2098 } 2099 jit::Jit* jit = Runtime::Current()->GetJit(); 2100 if (jit != nullptr) { 2101 auto* code = jit->GetCodeCache()->GetCodeFor(method); 2102 if (code != nullptr) { 2103 return code; 2104 } 2105 } 2106 return nullptr; 2107} 2108 2109const void* ClassLinker::GetQuickOatCodeFor(const DexFile& dex_file, uint16_t class_def_idx, 2110 uint32_t method_idx) { 2111 bool found; 2112 OatFile::OatClass oat_class = FindOatClass(dex_file, class_def_idx, &found); 2113 if (!found) { 2114 return nullptr; 2115 } 2116 uint32_t oat_method_idx = GetOatMethodIndexFromMethodIndex(dex_file, class_def_idx, method_idx); 2117 return oat_class.GetOatMethod(oat_method_idx).GetQuickCode(); 2118} 2119 2120// Returns true if the method must run with interpreter, false otherwise. 2121static bool NeedsInterpreter(ArtMethod* method, const void* quick_code) 2122 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2123 if (quick_code == nullptr) { 2124 // No code: need interpreter. 2125 // May return true for native code, in the case of generic JNI 2126 // DCHECK(!method->IsNative()); 2127 return true; 2128 } 2129 // If interpreter mode is enabled, every method (except native and proxy) must 2130 // be run with interpreter. 2131 return Runtime::Current()->GetInstrumentation()->InterpretOnly() && 2132 !method->IsNative() && !method->IsProxyMethod(); 2133} 2134 2135void ClassLinker::FixupStaticTrampolines(mirror::Class* klass) { 2136 DCHECK(klass->IsInitialized()) << PrettyDescriptor(klass); 2137 if (klass->NumDirectMethods() == 0) { 2138 return; // No direct methods => no static methods. 2139 } 2140 Runtime* runtime = Runtime::Current(); 2141 if (!runtime->IsStarted()) { 2142 if (runtime->IsAotCompiler() || runtime->GetHeap()->HasImageSpace()) { 2143 return; // OAT file unavailable. 2144 } 2145 } 2146 2147 const DexFile& dex_file = klass->GetDexFile(); 2148 const DexFile::ClassDef* dex_class_def = klass->GetClassDef(); 2149 CHECK(dex_class_def != nullptr); 2150 const uint8_t* class_data = dex_file.GetClassData(*dex_class_def); 2151 // There should always be class data if there were direct methods. 2152 CHECK(class_data != nullptr) << PrettyDescriptor(klass); 2153 ClassDataItemIterator it(dex_file, class_data); 2154 // Skip fields 2155 while (it.HasNextStaticField()) { 2156 it.Next(); 2157 } 2158 while (it.HasNextInstanceField()) { 2159 it.Next(); 2160 } 2161 bool has_oat_class; 2162 OatFile::OatClass oat_class = FindOatClass(dex_file, klass->GetDexClassDefIndex(), 2163 &has_oat_class); 2164 // Link the code of methods skipped by LinkCode. 2165 for (size_t method_index = 0; it.HasNextDirectMethod(); ++method_index, it.Next()) { 2166 ArtMethod* method = klass->GetDirectMethod(method_index, image_pointer_size_); 2167 if (!method->IsStatic()) { 2168 // Only update static methods. 2169 continue; 2170 } 2171 const void* quick_code = nullptr; 2172 if (has_oat_class) { 2173 OatFile::OatMethod oat_method = oat_class.GetOatMethod(method_index); 2174 quick_code = oat_method.GetQuickCode(); 2175 } 2176 const bool enter_interpreter = NeedsInterpreter(method, quick_code); 2177 if (enter_interpreter) { 2178 // Use interpreter entry point. 2179 // Check whether the method is native, in which case it's generic JNI. 2180 if (quick_code == nullptr && method->IsNative()) { 2181 quick_code = GetQuickGenericJniStub(); 2182 } else { 2183 quick_code = GetQuickToInterpreterBridge(); 2184 } 2185 } 2186 runtime->GetInstrumentation()->UpdateMethodsCode(method, quick_code); 2187 } 2188 // Ignore virtual methods on the iterator. 2189} 2190 2191void ClassLinker::LinkCode(ArtMethod* method, const OatFile::OatClass* oat_class, 2192 uint32_t class_def_method_index) { 2193 Runtime* const runtime = Runtime::Current(); 2194 if (runtime->IsAotCompiler()) { 2195 // The following code only applies to a non-compiler runtime. 2196 return; 2197 } 2198 // Method shouldn't have already been linked. 2199 DCHECK(method->GetEntryPointFromQuickCompiledCode() == nullptr); 2200 if (oat_class != nullptr) { 2201 // Every kind of method should at least get an invoke stub from the oat_method. 2202 // non-abstract methods also get their code pointers. 2203 const OatFile::OatMethod oat_method = oat_class->GetOatMethod(class_def_method_index); 2204 oat_method.LinkMethod(method); 2205 } 2206 2207 // Install entry point from interpreter. 2208 bool enter_interpreter = NeedsInterpreter(method, method->GetEntryPointFromQuickCompiledCode()); 2209 if (enter_interpreter && !method->IsNative()) { 2210 method->SetEntryPointFromInterpreter(artInterpreterToInterpreterBridge); 2211 } else { 2212 method->SetEntryPointFromInterpreter(artInterpreterToCompiledCodeBridge); 2213 } 2214 2215 if (method->IsAbstract()) { 2216 method->SetEntryPointFromQuickCompiledCode(GetQuickToInterpreterBridge()); 2217 return; 2218 } 2219 2220 if (method->IsStatic() && !method->IsConstructor()) { 2221 // For static methods excluding the class initializer, install the trampoline. 2222 // It will be replaced by the proper entry point by ClassLinker::FixupStaticTrampolines 2223 // after initializing class (see ClassLinker::InitializeClass method). 2224 method->SetEntryPointFromQuickCompiledCode(GetQuickResolutionStub()); 2225 } else if (enter_interpreter) { 2226 if (!method->IsNative()) { 2227 // Set entry point from compiled code if there's no code or in interpreter only mode. 2228 method->SetEntryPointFromQuickCompiledCode(GetQuickToInterpreterBridge()); 2229 } else { 2230 method->SetEntryPointFromQuickCompiledCode(GetQuickGenericJniStub()); 2231 } 2232 } 2233 2234 if (method->IsNative()) { 2235 // Unregistering restores the dlsym lookup stub. 2236 method->UnregisterNative(); 2237 2238 if (enter_interpreter) { 2239 // We have a native method here without code. Then it should have either the generic JNI 2240 // trampoline as entrypoint (non-static), or the resolution trampoline (static). 2241 // TODO: this doesn't handle all the cases where trampolines may be installed. 2242 const void* entry_point = method->GetEntryPointFromQuickCompiledCode(); 2243 DCHECK(IsQuickGenericJniStub(entry_point) || IsQuickResolutionStub(entry_point)); 2244 } 2245 } 2246} 2247 2248void ClassLinker::SetupClass(const DexFile& dex_file, const DexFile::ClassDef& dex_class_def, 2249 Handle<mirror::Class> klass, mirror::ClassLoader* class_loader) { 2250 CHECK(klass.Get() != nullptr); 2251 CHECK(klass->GetDexCache() != nullptr); 2252 CHECK_EQ(mirror::Class::kStatusNotReady, klass->GetStatus()); 2253 const char* descriptor = dex_file.GetClassDescriptor(dex_class_def); 2254 CHECK(descriptor != nullptr); 2255 2256 klass->SetClass(GetClassRoot(kJavaLangClass)); 2257 uint32_t access_flags = dex_class_def.GetJavaAccessFlags(); 2258 CHECK_EQ(access_flags & ~kAccJavaFlagsMask, 0U); 2259 klass->SetAccessFlags(access_flags); 2260 klass->SetClassLoader(class_loader); 2261 DCHECK_EQ(klass->GetPrimitiveType(), Primitive::kPrimNot); 2262 mirror::Class::SetStatus(klass, mirror::Class::kStatusIdx, nullptr); 2263 2264 klass->SetDexClassDefIndex(dex_file.GetIndexForClassDef(dex_class_def)); 2265 klass->SetDexTypeIndex(dex_class_def.class_idx_); 2266 CHECK(klass->GetDexCacheStrings() != nullptr); 2267} 2268 2269void ClassLinker::LoadClass(Thread* self, const DexFile& dex_file, 2270 const DexFile::ClassDef& dex_class_def, 2271 Handle<mirror::Class> klass) { 2272 const uint8_t* class_data = dex_file.GetClassData(dex_class_def); 2273 if (class_data == nullptr) { 2274 return; // no fields or methods - for example a marker interface 2275 } 2276 bool has_oat_class = false; 2277 if (Runtime::Current()->IsStarted() && !Runtime::Current()->IsAotCompiler()) { 2278 OatFile::OatClass oat_class = FindOatClass(dex_file, klass->GetDexClassDefIndex(), 2279 &has_oat_class); 2280 if (has_oat_class) { 2281 LoadClassMembers(self, dex_file, class_data, klass, &oat_class); 2282 } 2283 } 2284 if (!has_oat_class) { 2285 LoadClassMembers(self, dex_file, class_data, klass, nullptr); 2286 } 2287} 2288 2289ArtField* ClassLinker::AllocArtFieldArray(Thread* self, size_t length) { 2290 auto* const la = Runtime::Current()->GetLinearAlloc(); 2291 auto* ptr = reinterpret_cast<ArtField*>(la->AllocArray<ArtField>(self, length)); 2292 CHECK(ptr!= nullptr); 2293 std::uninitialized_fill_n(ptr, length, ArtField()); 2294 return ptr; 2295} 2296 2297ArtMethod* ClassLinker::AllocArtMethodArray(Thread* self, size_t length) { 2298 const size_t method_size = ArtMethod::ObjectSize(image_pointer_size_); 2299 uintptr_t ptr = reinterpret_cast<uintptr_t>( 2300 Runtime::Current()->GetLinearAlloc()->Alloc(self, method_size * length)); 2301 CHECK_NE(ptr, 0u); 2302 for (size_t i = 0; i < length; ++i) { 2303 new(reinterpret_cast<void*>(ptr + i * method_size)) ArtMethod; 2304 } 2305 return reinterpret_cast<ArtMethod*>(ptr); 2306} 2307 2308void ClassLinker::LoadClassMembers(Thread* self, const DexFile& dex_file, 2309 const uint8_t* class_data, 2310 Handle<mirror::Class> klass, 2311 const OatFile::OatClass* oat_class) { 2312 { 2313 // Note: We cannot have thread suspension until the field and method arrays are setup or else 2314 // Class::VisitFieldRoots may miss some fields or methods. 2315 ScopedAssertNoThreadSuspension nts(self, __FUNCTION__); 2316 // Load static fields. 2317 ClassDataItemIterator it(dex_file, class_data); 2318 const size_t num_sfields = it.NumStaticFields(); 2319 ArtField* sfields = num_sfields != 0 ? AllocArtFieldArray(self, num_sfields) : nullptr; 2320 for (size_t i = 0; it.HasNextStaticField(); i++, it.Next()) { 2321 CHECK_LT(i, num_sfields); 2322 LoadField(it, klass, &sfields[i]); 2323 } 2324 klass->SetSFields(sfields); 2325 klass->SetNumStaticFields(num_sfields); 2326 DCHECK_EQ(klass->NumStaticFields(), num_sfields); 2327 // Load instance fields. 2328 const size_t num_ifields = it.NumInstanceFields(); 2329 ArtField* ifields = num_ifields != 0 ? AllocArtFieldArray(self, num_ifields) : nullptr; 2330 for (size_t i = 0; it.HasNextInstanceField(); i++, it.Next()) { 2331 CHECK_LT(i, num_ifields); 2332 LoadField(it, klass, &ifields[i]); 2333 } 2334 klass->SetIFields(ifields); 2335 klass->SetNumInstanceFields(num_ifields); 2336 DCHECK_EQ(klass->NumInstanceFields(), num_ifields); 2337 ArtMethod* const direct_methods = (it.NumDirectMethods() != 0) 2338 ? AllocArtMethodArray(self, it.NumDirectMethods()) 2339 : nullptr; 2340 ArtMethod* const virtual_methods = (it.NumVirtualMethods() != 0) 2341 ? AllocArtMethodArray(self, it.NumVirtualMethods()) 2342 : nullptr; 2343 { 2344 // Used to get exclusion between with VisitNativeRoots so that no thread sees a length for 2345 // one array with a pointer for a different array. 2346 WriterMutexLock mu(self, *Locks::classlinker_classes_lock_); 2347 // Load methods. 2348 klass->SetDirectMethodsPtr(direct_methods); 2349 klass->SetNumDirectMethods(it.NumDirectMethods()); 2350 klass->SetVirtualMethodsPtr(virtual_methods); 2351 klass->SetNumVirtualMethods(it.NumVirtualMethods()); 2352 } 2353 size_t class_def_method_index = 0; 2354 uint32_t last_dex_method_index = DexFile::kDexNoIndex; 2355 size_t last_class_def_method_index = 0; 2356 for (size_t i = 0; it.HasNextDirectMethod(); i++, it.Next()) { 2357 ArtMethod* method = klass->GetDirectMethodUnchecked(i, image_pointer_size_); 2358 LoadMethod(self, dex_file, it, klass, method); 2359 LinkCode(method, oat_class, class_def_method_index); 2360 uint32_t it_method_index = it.GetMemberIndex(); 2361 if (last_dex_method_index == it_method_index) { 2362 // duplicate case 2363 method->SetMethodIndex(last_class_def_method_index); 2364 } else { 2365 method->SetMethodIndex(class_def_method_index); 2366 last_dex_method_index = it_method_index; 2367 last_class_def_method_index = class_def_method_index; 2368 } 2369 class_def_method_index++; 2370 } 2371 for (size_t i = 0; it.HasNextVirtualMethod(); i++, it.Next()) { 2372 ArtMethod* method = klass->GetVirtualMethodUnchecked(i, image_pointer_size_); 2373 LoadMethod(self, dex_file, it, klass, method); 2374 DCHECK_EQ(class_def_method_index, it.NumDirectMethods() + i); 2375 LinkCode(method, oat_class, class_def_method_index); 2376 class_def_method_index++; 2377 } 2378 DCHECK(!it.HasNext()); 2379 } 2380 self->AllowThreadSuspension(); 2381} 2382 2383void ClassLinker::LoadField(const ClassDataItemIterator& it, Handle<mirror::Class> klass, 2384 ArtField* dst) { 2385 const uint32_t field_idx = it.GetMemberIndex(); 2386 dst->SetDexFieldIndex(field_idx); 2387 dst->SetDeclaringClass(klass.Get()); 2388 dst->SetAccessFlags(it.GetFieldAccessFlags()); 2389} 2390 2391void ClassLinker::LoadMethod(Thread* self, const DexFile& dex_file, const ClassDataItemIterator& it, 2392 Handle<mirror::Class> klass, ArtMethod* dst) { 2393 uint32_t dex_method_idx = it.GetMemberIndex(); 2394 const DexFile::MethodId& method_id = dex_file.GetMethodId(dex_method_idx); 2395 const char* method_name = dex_file.StringDataByIdx(method_id.name_idx_); 2396 2397 ScopedAssertNoThreadSuspension ants(self, "LoadMethod"); 2398 dst->SetDexMethodIndex(dex_method_idx); 2399 dst->SetDeclaringClass(klass.Get()); 2400 dst->SetCodeItemOffset(it.GetMethodCodeItemOffset()); 2401 2402 dst->SetDexCacheResolvedMethods(klass->GetDexCache()->GetResolvedMethods()); 2403 dst->SetDexCacheResolvedTypes(klass->GetDexCache()->GetResolvedTypes()); 2404 2405 uint32_t access_flags = it.GetMethodAccessFlags(); 2406 2407 if (UNLIKELY(strcmp("finalize", method_name) == 0)) { 2408 // Set finalizable flag on declaring class. 2409 if (strcmp("V", dex_file.GetShorty(method_id.proto_idx_)) == 0) { 2410 // Void return type. 2411 if (klass->GetClassLoader() != nullptr) { // All non-boot finalizer methods are flagged. 2412 klass->SetFinalizable(); 2413 } else { 2414 std::string temp; 2415 const char* klass_descriptor = klass->GetDescriptor(&temp); 2416 // The Enum class declares a "final" finalize() method to prevent subclasses from 2417 // introducing a finalizer. We don't want to set the finalizable flag for Enum or its 2418 // subclasses, so we exclude it here. 2419 // We also want to avoid setting the flag on Object, where we know that finalize() is 2420 // empty. 2421 if (strcmp(klass_descriptor, "Ljava/lang/Object;") != 0 && 2422 strcmp(klass_descriptor, "Ljava/lang/Enum;") != 0) { 2423 klass->SetFinalizable(); 2424 } 2425 } 2426 } 2427 } else if (method_name[0] == '<') { 2428 // Fix broken access flags for initializers. Bug 11157540. 2429 bool is_init = (strcmp("<init>", method_name) == 0); 2430 bool is_clinit = !is_init && (strcmp("<clinit>", method_name) == 0); 2431 if (UNLIKELY(!is_init && !is_clinit)) { 2432 LOG(WARNING) << "Unexpected '<' at start of method name " << method_name; 2433 } else { 2434 if (UNLIKELY((access_flags & kAccConstructor) == 0)) { 2435 LOG(WARNING) << method_name << " didn't have expected constructor access flag in class " 2436 << PrettyDescriptor(klass.Get()) << " in dex file " << dex_file.GetLocation(); 2437 access_flags |= kAccConstructor; 2438 } 2439 } 2440 } 2441 dst->SetAccessFlags(access_flags); 2442} 2443 2444void ClassLinker::AppendToBootClassPath(Thread* self, const DexFile& dex_file) { 2445 StackHandleScope<1> hs(self); 2446 Handle<mirror::DexCache> dex_cache(hs.NewHandle(AllocDexCache(self, dex_file))); 2447 CHECK(dex_cache.Get() != nullptr) << "Failed to allocate dex cache for " 2448 << dex_file.GetLocation(); 2449 AppendToBootClassPath(dex_file, dex_cache); 2450} 2451 2452void ClassLinker::AppendToBootClassPath(const DexFile& dex_file, 2453 Handle<mirror::DexCache> dex_cache) { 2454 CHECK(dex_cache.Get() != nullptr) << dex_file.GetLocation(); 2455 boot_class_path_.push_back(&dex_file); 2456 RegisterDexFile(dex_file, dex_cache); 2457} 2458 2459bool ClassLinker::IsDexFileRegisteredLocked(const DexFile& dex_file) { 2460 dex_lock_.AssertSharedHeld(Thread::Current()); 2461 for (size_t i = 0; i != dex_caches_.size(); ++i) { 2462 mirror::DexCache* dex_cache = GetDexCache(i); 2463 if (dex_cache->GetDexFile() == &dex_file) { 2464 return true; 2465 } 2466 } 2467 return false; 2468} 2469 2470bool ClassLinker::IsDexFileRegistered(const DexFile& dex_file) { 2471 ReaderMutexLock mu(Thread::Current(), dex_lock_); 2472 return IsDexFileRegisteredLocked(dex_file); 2473} 2474 2475void ClassLinker::RegisterDexFileLocked(const DexFile& dex_file, 2476 Handle<mirror::DexCache> dex_cache) { 2477 dex_lock_.AssertExclusiveHeld(Thread::Current()); 2478 CHECK(dex_cache.Get() != nullptr) << dex_file.GetLocation(); 2479 CHECK(dex_cache->GetLocation()->Equals(dex_file.GetLocation())) 2480 << dex_cache->GetLocation()->ToModifiedUtf8() << " " << dex_file.GetLocation(); 2481 dex_caches_.push_back(GcRoot<mirror::DexCache>(dex_cache.Get())); 2482 dex_cache->SetDexFile(&dex_file); 2483 if (log_new_dex_caches_roots_) { 2484 // TODO: This is not safe if we can remove dex caches. 2485 new_dex_cache_roots_.push_back(dex_caches_.size() - 1); 2486 } 2487} 2488 2489void ClassLinker::RegisterDexFile(const DexFile& dex_file) { 2490 Thread* self = Thread::Current(); 2491 { 2492 ReaderMutexLock mu(self, dex_lock_); 2493 if (IsDexFileRegisteredLocked(dex_file)) { 2494 return; 2495 } 2496 } 2497 // Don't alloc while holding the lock, since allocation may need to 2498 // suspend all threads and another thread may need the dex_lock_ to 2499 // get to a suspend point. 2500 StackHandleScope<1> hs(self); 2501 Handle<mirror::DexCache> dex_cache(hs.NewHandle(AllocDexCache(self, dex_file))); 2502 CHECK(dex_cache.Get() != nullptr) << "Failed to allocate dex cache for " 2503 << dex_file.GetLocation(); 2504 { 2505 WriterMutexLock mu(self, dex_lock_); 2506 if (IsDexFileRegisteredLocked(dex_file)) { 2507 return; 2508 } 2509 RegisterDexFileLocked(dex_file, dex_cache); 2510 } 2511} 2512 2513void ClassLinker::RegisterDexFile(const DexFile& dex_file, 2514 Handle<mirror::DexCache> dex_cache) { 2515 WriterMutexLock mu(Thread::Current(), dex_lock_); 2516 RegisterDexFileLocked(dex_file, dex_cache); 2517} 2518 2519mirror::DexCache* ClassLinker::FindDexCache(const DexFile& dex_file) { 2520 ReaderMutexLock mu(Thread::Current(), dex_lock_); 2521 // Search assuming unique-ness of dex file. 2522 for (size_t i = 0; i != dex_caches_.size(); ++i) { 2523 mirror::DexCache* dex_cache = GetDexCache(i); 2524 if (dex_cache->GetDexFile() == &dex_file) { 2525 return dex_cache; 2526 } 2527 } 2528 // Search matching by location name. 2529 std::string location(dex_file.GetLocation()); 2530 for (size_t i = 0; i != dex_caches_.size(); ++i) { 2531 mirror::DexCache* dex_cache = GetDexCache(i); 2532 if (dex_cache->GetDexFile()->GetLocation() == location) { 2533 return dex_cache; 2534 } 2535 } 2536 // Failure, dump diagnostic and abort. 2537 for (size_t i = 0; i != dex_caches_.size(); ++i) { 2538 mirror::DexCache* dex_cache = GetDexCache(i); 2539 LOG(ERROR) << "Registered dex file " << i << " = " << dex_cache->GetDexFile()->GetLocation(); 2540 } 2541 LOG(FATAL) << "Failed to find DexCache for DexFile " << location; 2542 UNREACHABLE(); 2543} 2544 2545void ClassLinker::FixupDexCaches(ArtMethod* resolution_method) { 2546 ReaderMutexLock mu(Thread::Current(), dex_lock_); 2547 for (auto& dex_cache : dex_caches_) { 2548 dex_cache.Read()->Fixup(resolution_method, image_pointer_size_); 2549 } 2550} 2551 2552mirror::Class* ClassLinker::CreatePrimitiveClass(Thread* self, Primitive::Type type) { 2553 mirror::Class* klass = AllocClass(self, mirror::Class::PrimitiveClassSize(image_pointer_size_)); 2554 if (UNLIKELY(klass == nullptr)) { 2555 self->AssertPendingOOMException(); 2556 return nullptr; 2557 } 2558 return InitializePrimitiveClass(klass, type); 2559} 2560 2561mirror::Class* ClassLinker::InitializePrimitiveClass(mirror::Class* primitive_class, 2562 Primitive::Type type) { 2563 CHECK(primitive_class != nullptr); 2564 // Must hold lock on object when initializing. 2565 Thread* self = Thread::Current(); 2566 StackHandleScope<1> hs(self); 2567 Handle<mirror::Class> h_class(hs.NewHandle(primitive_class)); 2568 ObjectLock<mirror::Class> lock(self, h_class); 2569 h_class->SetAccessFlags(kAccPublic | kAccFinal | kAccAbstract); 2570 h_class->SetPrimitiveType(type); 2571 mirror::Class::SetStatus(h_class, mirror::Class::kStatusInitialized, self); 2572 const char* descriptor = Primitive::Descriptor(type); 2573 mirror::Class* existing = InsertClass(descriptor, h_class.Get(), 2574 ComputeModifiedUtf8Hash(descriptor)); 2575 CHECK(existing == nullptr) << "InitPrimitiveClass(" << type << ") failed"; 2576 return h_class.Get(); 2577} 2578 2579// Create an array class (i.e. the class object for the array, not the 2580// array itself). "descriptor" looks like "[C" or "[[[[B" or 2581// "[Ljava/lang/String;". 2582// 2583// If "descriptor" refers to an array of primitives, look up the 2584// primitive type's internally-generated class object. 2585// 2586// "class_loader" is the class loader of the class that's referring to 2587// us. It's used to ensure that we're looking for the element type in 2588// the right context. It does NOT become the class loader for the 2589// array class; that always comes from the base element class. 2590// 2591// Returns null with an exception raised on failure. 2592mirror::Class* ClassLinker::CreateArrayClass(Thread* self, const char* descriptor, size_t hash, 2593 Handle<mirror::ClassLoader> class_loader) { 2594 // Identify the underlying component type 2595 CHECK_EQ('[', descriptor[0]); 2596 StackHandleScope<2> hs(self); 2597 MutableHandle<mirror::Class> component_type(hs.NewHandle(FindClass(self, descriptor + 1, 2598 class_loader))); 2599 if (component_type.Get() == nullptr) { 2600 DCHECK(self->IsExceptionPending()); 2601 // We need to accept erroneous classes as component types. 2602 const size_t component_hash = ComputeModifiedUtf8Hash(descriptor + 1); 2603 component_type.Assign(LookupClass(self, descriptor + 1, component_hash, class_loader.Get())); 2604 if (component_type.Get() == nullptr) { 2605 DCHECK(self->IsExceptionPending()); 2606 return nullptr; 2607 } else { 2608 self->ClearException(); 2609 } 2610 } 2611 if (UNLIKELY(component_type->IsPrimitiveVoid())) { 2612 ThrowNoClassDefFoundError("Attempt to create array of void primitive type"); 2613 return nullptr; 2614 } 2615 // See if the component type is already loaded. Array classes are 2616 // always associated with the class loader of their underlying 2617 // element type -- an array of Strings goes with the loader for 2618 // java/lang/String -- so we need to look for it there. (The 2619 // caller should have checked for the existence of the class 2620 // before calling here, but they did so with *their* class loader, 2621 // not the component type's loader.) 2622 // 2623 // If we find it, the caller adds "loader" to the class' initiating 2624 // loader list, which should prevent us from going through this again. 2625 // 2626 // This call is unnecessary if "loader" and "component_type->GetClassLoader()" 2627 // are the same, because our caller (FindClass) just did the 2628 // lookup. (Even if we get this wrong we still have correct behavior, 2629 // because we effectively do this lookup again when we add the new 2630 // class to the hash table --- necessary because of possible races with 2631 // other threads.) 2632 if (class_loader.Get() != component_type->GetClassLoader()) { 2633 mirror::Class* new_class = LookupClass(self, descriptor, hash, component_type->GetClassLoader()); 2634 if (new_class != nullptr) { 2635 return new_class; 2636 } 2637 } 2638 2639 // Fill out the fields in the Class. 2640 // 2641 // It is possible to execute some methods against arrays, because 2642 // all arrays are subclasses of java_lang_Object_, so we need to set 2643 // up a vtable. We can just point at the one in java_lang_Object_. 2644 // 2645 // Array classes are simple enough that we don't need to do a full 2646 // link step. 2647 auto new_class = hs.NewHandle<mirror::Class>(nullptr); 2648 if (UNLIKELY(!init_done_)) { 2649 // Classes that were hand created, ie not by FindSystemClass 2650 if (strcmp(descriptor, "[Ljava/lang/Class;") == 0) { 2651 new_class.Assign(GetClassRoot(kClassArrayClass)); 2652 } else if (strcmp(descriptor, "[Ljava/lang/Object;") == 0) { 2653 new_class.Assign(GetClassRoot(kObjectArrayClass)); 2654 } else if (strcmp(descriptor, GetClassRootDescriptor(kJavaLangStringArrayClass)) == 0) { 2655 new_class.Assign(GetClassRoot(kJavaLangStringArrayClass)); 2656 } else if (strcmp(descriptor, "[C") == 0) { 2657 new_class.Assign(GetClassRoot(kCharArrayClass)); 2658 } else if (strcmp(descriptor, "[I") == 0) { 2659 new_class.Assign(GetClassRoot(kIntArrayClass)); 2660 } else if (strcmp(descriptor, "[J") == 0) { 2661 new_class.Assign(GetClassRoot(kLongArrayClass)); 2662 } 2663 } 2664 if (new_class.Get() == nullptr) { 2665 new_class.Assign(AllocClass(self, mirror::Array::ClassSize(image_pointer_size_))); 2666 if (new_class.Get() == nullptr) { 2667 self->AssertPendingOOMException(); 2668 return nullptr; 2669 } 2670 new_class->SetComponentType(component_type.Get()); 2671 } 2672 ObjectLock<mirror::Class> lock(self, new_class); // Must hold lock on object when initializing. 2673 DCHECK(new_class->GetComponentType() != nullptr); 2674 mirror::Class* java_lang_Object = GetClassRoot(kJavaLangObject); 2675 new_class->SetSuperClass(java_lang_Object); 2676 new_class->SetVTable(java_lang_Object->GetVTable()); 2677 new_class->SetPrimitiveType(Primitive::kPrimNot); 2678 new_class->SetClassLoader(component_type->GetClassLoader()); 2679 mirror::Class::SetStatus(new_class, mirror::Class::kStatusLoaded, self); 2680 { 2681 ArtMethod* imt[mirror::Class::kImtSize]; 2682 std::fill_n(imt, arraysize(imt), Runtime::Current()->GetImtUnimplementedMethod()); 2683 new_class->PopulateEmbeddedImtAndVTable(imt, image_pointer_size_); 2684 } 2685 mirror::Class::SetStatus(new_class, mirror::Class::kStatusInitialized, self); 2686 // don't need to set new_class->SetObjectSize(..) 2687 // because Object::SizeOf delegates to Array::SizeOf 2688 2689 2690 // All arrays have java/lang/Cloneable and java/io/Serializable as 2691 // interfaces. We need to set that up here, so that stuff like 2692 // "instanceof" works right. 2693 // 2694 // Note: The GC could run during the call to FindSystemClass, 2695 // so we need to make sure the class object is GC-valid while we're in 2696 // there. Do this by clearing the interface list so the GC will just 2697 // think that the entries are null. 2698 2699 2700 // Use the single, global copies of "interfaces" and "iftable" 2701 // (remember not to free them for arrays). 2702 { 2703 mirror::IfTable* array_iftable = array_iftable_.Read(); 2704 CHECK(array_iftable != nullptr); 2705 new_class->SetIfTable(array_iftable); 2706 } 2707 2708 // Inherit access flags from the component type. 2709 int access_flags = new_class->GetComponentType()->GetAccessFlags(); 2710 // Lose any implementation detail flags; in particular, arrays aren't finalizable. 2711 access_flags &= kAccJavaFlagsMask; 2712 // Arrays can't be used as a superclass or interface, so we want to add "abstract final" 2713 // and remove "interface". 2714 access_flags |= kAccAbstract | kAccFinal; 2715 access_flags &= ~kAccInterface; 2716 2717 new_class->SetAccessFlags(access_flags); 2718 2719 mirror::Class* existing = InsertClass(descriptor, new_class.Get(), hash); 2720 if (existing == nullptr) { 2721 return new_class.Get(); 2722 } 2723 // Another thread must have loaded the class after we 2724 // started but before we finished. Abandon what we've 2725 // done. 2726 // 2727 // (Yes, this happens.) 2728 2729 return existing; 2730} 2731 2732mirror::Class* ClassLinker::FindPrimitiveClass(char type) { 2733 switch (type) { 2734 case 'B': 2735 return GetClassRoot(kPrimitiveByte); 2736 case 'C': 2737 return GetClassRoot(kPrimitiveChar); 2738 case 'D': 2739 return GetClassRoot(kPrimitiveDouble); 2740 case 'F': 2741 return GetClassRoot(kPrimitiveFloat); 2742 case 'I': 2743 return GetClassRoot(kPrimitiveInt); 2744 case 'J': 2745 return GetClassRoot(kPrimitiveLong); 2746 case 'S': 2747 return GetClassRoot(kPrimitiveShort); 2748 case 'Z': 2749 return GetClassRoot(kPrimitiveBoolean); 2750 case 'V': 2751 return GetClassRoot(kPrimitiveVoid); 2752 default: 2753 break; 2754 } 2755 std::string printable_type(PrintableChar(type)); 2756 ThrowNoClassDefFoundError("Not a primitive type: %s", printable_type.c_str()); 2757 return nullptr; 2758} 2759 2760mirror::Class* ClassLinker::InsertClass(const char* descriptor, mirror::Class* klass, 2761 size_t hash) { 2762 if (VLOG_IS_ON(class_linker)) { 2763 mirror::DexCache* dex_cache = klass->GetDexCache(); 2764 std::string source; 2765 if (dex_cache != nullptr) { 2766 source += " from "; 2767 source += dex_cache->GetLocation()->ToModifiedUtf8(); 2768 } 2769 LOG(INFO) << "Loaded class " << descriptor << source; 2770 } 2771 WriterMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); 2772 mirror::Class* existing = LookupClassFromTableLocked(descriptor, klass->GetClassLoader(), hash); 2773 if (existing != nullptr) { 2774 return existing; 2775 } 2776 if (kIsDebugBuild && !klass->IsTemp() && klass->GetClassLoader() == nullptr && 2777 dex_cache_image_class_lookup_required_) { 2778 // Check a class loaded with the system class loader matches one in the image if the class 2779 // is in the image. 2780 existing = LookupClassFromImage(descriptor); 2781 if (existing != nullptr) { 2782 CHECK_EQ(klass, existing); 2783 } 2784 } 2785 VerifyObject(klass); 2786 class_table_.InsertWithHash(GcRoot<mirror::Class>(klass), hash); 2787 if (log_new_class_table_roots_) { 2788 new_class_roots_.push_back(GcRoot<mirror::Class>(klass)); 2789 } 2790 return nullptr; 2791} 2792 2793void ClassLinker::UpdateClassVirtualMethods(mirror::Class* klass, ArtMethod* new_methods, 2794 size_t new_num_methods) { 2795 // classlinker_classes_lock_ is used to guard against races between root marking and changing the 2796 // direct and virtual method pointers. 2797 WriterMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); 2798 klass->SetNumVirtualMethods(new_num_methods); 2799 klass->SetVirtualMethodsPtr(new_methods); 2800 if (log_new_class_table_roots_) { 2801 new_class_roots_.push_back(GcRoot<mirror::Class>(klass)); 2802 } 2803} 2804 2805mirror::Class* ClassLinker::UpdateClass(const char* descriptor, mirror::Class* klass, 2806 size_t hash) { 2807 WriterMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); 2808 auto existing_it = class_table_.FindWithHash(std::make_pair(descriptor, klass->GetClassLoader()), 2809 hash); 2810 CHECK(existing_it != class_table_.end()); 2811 mirror::Class* existing = existing_it->Read(); 2812 CHECK_NE(existing, klass) << descriptor; 2813 CHECK(!existing->IsResolved()) << descriptor; 2814 CHECK_EQ(klass->GetStatus(), mirror::Class::kStatusResolving) << descriptor; 2815 2816 CHECK(!klass->IsTemp()) << descriptor; 2817 if (kIsDebugBuild && klass->GetClassLoader() == nullptr && 2818 dex_cache_image_class_lookup_required_) { 2819 // Check a class loaded with the system class loader matches one in the image if the class 2820 // is in the image. 2821 existing = LookupClassFromImage(descriptor); 2822 if (existing != nullptr) { 2823 CHECK_EQ(klass, existing) << descriptor; 2824 } 2825 } 2826 VerifyObject(klass); 2827 2828 // Update the element in the hash set. 2829 *existing_it = GcRoot<mirror::Class>(klass); 2830 if (log_new_class_table_roots_) { 2831 new_class_roots_.push_back(GcRoot<mirror::Class>(klass)); 2832 } 2833 2834 return existing; 2835} 2836 2837bool ClassLinker::RemoveClass(const char* descriptor, mirror::ClassLoader* class_loader) { 2838 WriterMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); 2839 auto pair = std::make_pair(descriptor, class_loader); 2840 auto it = class_table_.Find(pair); 2841 if (it != class_table_.end()) { 2842 class_table_.Erase(it); 2843 return true; 2844 } 2845 it = pre_zygote_class_table_.Find(pair); 2846 if (it != pre_zygote_class_table_.end()) { 2847 pre_zygote_class_table_.Erase(it); 2848 return true; 2849 } 2850 return false; 2851} 2852 2853mirror::Class* ClassLinker::LookupClass(Thread* self, const char* descriptor, size_t hash, 2854 mirror::ClassLoader* class_loader) { 2855 { 2856 ReaderMutexLock mu(self, *Locks::classlinker_classes_lock_); 2857 mirror::Class* result = LookupClassFromTableLocked(descriptor, class_loader, hash); 2858 if (result != nullptr) { 2859 return result; 2860 } 2861 } 2862 if (class_loader != nullptr || !dex_cache_image_class_lookup_required_) { 2863 return nullptr; 2864 } else { 2865 // Lookup failed but need to search dex_caches_. 2866 mirror::Class* result = LookupClassFromImage(descriptor); 2867 if (result != nullptr) { 2868 InsertClass(descriptor, result, hash); 2869 } else { 2870 // Searching the image dex files/caches failed, we don't want to get into this situation 2871 // often as map searches are faster, so after kMaxFailedDexCacheLookups move all image 2872 // classes into the class table. 2873 constexpr uint32_t kMaxFailedDexCacheLookups = 1000; 2874 if (++failed_dex_cache_class_lookups_ > kMaxFailedDexCacheLookups) { 2875 MoveImageClassesToClassTable(); 2876 } 2877 } 2878 return result; 2879 } 2880} 2881 2882mirror::Class* ClassLinker::LookupClassFromTableLocked(const char* descriptor, 2883 mirror::ClassLoader* class_loader, 2884 size_t hash) { 2885 auto descriptor_pair = std::make_pair(descriptor, class_loader); 2886 auto it = pre_zygote_class_table_.FindWithHash(descriptor_pair, hash); 2887 if (it == pre_zygote_class_table_.end()) { 2888 it = class_table_.FindWithHash(descriptor_pair, hash); 2889 if (it == class_table_.end()) { 2890 return nullptr; 2891 } 2892 } 2893 return it->Read(); 2894} 2895 2896static mirror::ObjectArray<mirror::DexCache>* GetImageDexCaches() 2897 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2898 gc::space::ImageSpace* image = Runtime::Current()->GetHeap()->GetImageSpace(); 2899 CHECK(image != nullptr); 2900 mirror::Object* root = image->GetImageHeader().GetImageRoot(ImageHeader::kDexCaches); 2901 return root->AsObjectArray<mirror::DexCache>(); 2902} 2903 2904void ClassLinker::MoveImageClassesToClassTable() { 2905 Thread* self = Thread::Current(); 2906 WriterMutexLock mu(self, *Locks::classlinker_classes_lock_); 2907 if (!dex_cache_image_class_lookup_required_) { 2908 return; // All dex cache classes are already in the class table. 2909 } 2910 ScopedAssertNoThreadSuspension ants(self, "Moving image classes to class table"); 2911 mirror::ObjectArray<mirror::DexCache>* dex_caches = GetImageDexCaches(); 2912 std::string temp; 2913 for (int32_t i = 0; i < dex_caches->GetLength(); i++) { 2914 mirror::DexCache* dex_cache = dex_caches->Get(i); 2915 mirror::ObjectArray<mirror::Class>* types = dex_cache->GetResolvedTypes(); 2916 for (int32_t j = 0; j < types->GetLength(); j++) { 2917 mirror::Class* klass = types->Get(j); 2918 if (klass != nullptr) { 2919 DCHECK(klass->GetClassLoader() == nullptr); 2920 const char* descriptor = klass->GetDescriptor(&temp); 2921 size_t hash = ComputeModifiedUtf8Hash(descriptor); 2922 mirror::Class* existing = LookupClassFromTableLocked(descriptor, nullptr, hash); 2923 if (existing != nullptr) { 2924 CHECK_EQ(existing, klass) << PrettyClassAndClassLoader(existing) << " != " 2925 << PrettyClassAndClassLoader(klass); 2926 } else { 2927 class_table_.Insert(GcRoot<mirror::Class>(klass)); 2928 if (log_new_class_table_roots_) { 2929 new_class_roots_.push_back(GcRoot<mirror::Class>(klass)); 2930 } 2931 } 2932 } 2933 } 2934 } 2935 dex_cache_image_class_lookup_required_ = false; 2936} 2937 2938void ClassLinker::MoveClassTableToPreZygote() { 2939 WriterMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); 2940 DCHECK(pre_zygote_class_table_.Empty()); 2941 pre_zygote_class_table_ = std::move(class_table_); 2942 class_table_.Clear(); 2943} 2944 2945mirror::Class* ClassLinker::LookupClassFromImage(const char* descriptor) { 2946 ScopedAssertNoThreadSuspension ants(Thread::Current(), "Image class lookup"); 2947 mirror::ObjectArray<mirror::DexCache>* dex_caches = GetImageDexCaches(); 2948 for (int32_t i = 0; i < dex_caches->GetLength(); ++i) { 2949 mirror::DexCache* dex_cache = dex_caches->Get(i); 2950 const DexFile* dex_file = dex_cache->GetDexFile(); 2951 // Try binary searching the string/type index. 2952 const DexFile::StringId* string_id = dex_file->FindStringId(descriptor); 2953 if (string_id != nullptr) { 2954 const DexFile::TypeId* type_id = 2955 dex_file->FindTypeId(dex_file->GetIndexForStringId(*string_id)); 2956 if (type_id != nullptr) { 2957 uint16_t type_idx = dex_file->GetIndexForTypeId(*type_id); 2958 mirror::Class* klass = dex_cache->GetResolvedType(type_idx); 2959 if (klass != nullptr) { 2960 return klass; 2961 } 2962 } 2963 } 2964 } 2965 return nullptr; 2966} 2967 2968void ClassLinker::LookupClasses(const char* descriptor, std::vector<mirror::Class*>& result) { 2969 result.clear(); 2970 if (dex_cache_image_class_lookup_required_) { 2971 MoveImageClassesToClassTable(); 2972 } 2973 WriterMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); 2974 while (true) { 2975 auto it = class_table_.Find(descriptor); 2976 if (it == class_table_.end()) { 2977 break; 2978 } 2979 result.push_back(it->Read()); 2980 class_table_.Erase(it); 2981 } 2982 for (mirror::Class* k : result) { 2983 class_table_.Insert(GcRoot<mirror::Class>(k)); 2984 } 2985 size_t pre_zygote_start = result.size(); 2986 // Now handle the pre zygote table. 2987 // Note: This dirties the pre-zygote table but shouldn't be an issue since LookupClasses is only 2988 // called from the debugger. 2989 while (true) { 2990 auto it = pre_zygote_class_table_.Find(descriptor); 2991 if (it == pre_zygote_class_table_.end()) { 2992 break; 2993 } 2994 result.push_back(it->Read()); 2995 pre_zygote_class_table_.Erase(it); 2996 } 2997 for (size_t i = pre_zygote_start; i < result.size(); ++i) { 2998 pre_zygote_class_table_.Insert(GcRoot<mirror::Class>(result[i])); 2999 } 3000} 3001 3002void ClassLinker::VerifyClass(Thread* self, Handle<mirror::Class> klass) { 3003 // TODO: assert that the monitor on the Class is held 3004 ObjectLock<mirror::Class> lock(self, klass); 3005 3006 // Don't attempt to re-verify if already sufficiently verified. 3007 if (klass->IsVerified()) { 3008 EnsurePreverifiedMethods(klass); 3009 return; 3010 } 3011 if (klass->IsCompileTimeVerified() && Runtime::Current()->IsAotCompiler()) { 3012 return; 3013 } 3014 3015 // The class might already be erroneous, for example at compile time if we attempted to verify 3016 // this class as a parent to another. 3017 if (klass->IsErroneous()) { 3018 ThrowEarlierClassFailure(klass.Get()); 3019 return; 3020 } 3021 3022 if (klass->GetStatus() == mirror::Class::kStatusResolved) { 3023 mirror::Class::SetStatus(klass, mirror::Class::kStatusVerifying, self); 3024 } else { 3025 CHECK_EQ(klass->GetStatus(), mirror::Class::kStatusRetryVerificationAtRuntime) 3026 << PrettyClass(klass.Get()); 3027 CHECK(!Runtime::Current()->IsAotCompiler()); 3028 mirror::Class::SetStatus(klass, mirror::Class::kStatusVerifyingAtRuntime, self); 3029 } 3030 3031 // Skip verification if disabled. 3032 if (!Runtime::Current()->IsVerificationEnabled()) { 3033 mirror::Class::SetStatus(klass, mirror::Class::kStatusVerified, self); 3034 EnsurePreverifiedMethods(klass); 3035 return; 3036 } 3037 3038 // Verify super class. 3039 StackHandleScope<2> hs(self); 3040 Handle<mirror::Class> super(hs.NewHandle(klass->GetSuperClass())); 3041 if (super.Get() != nullptr) { 3042 // Acquire lock to prevent races on verifying the super class. 3043 ObjectLock<mirror::Class> super_lock(self, super); 3044 3045 if (!super->IsVerified() && !super->IsErroneous()) { 3046 VerifyClass(self, super); 3047 } 3048 if (!super->IsCompileTimeVerified()) { 3049 std::string error_msg( 3050 StringPrintf("Rejecting class %s that attempts to sub-class erroneous class %s", 3051 PrettyDescriptor(klass.Get()).c_str(), 3052 PrettyDescriptor(super.Get()).c_str())); 3053 LOG(WARNING) << error_msg << " in " << klass->GetDexCache()->GetLocation()->ToModifiedUtf8(); 3054 Handle<mirror::Throwable> cause(hs.NewHandle(self->GetException())); 3055 if (cause.Get() != nullptr) { 3056 self->ClearException(); 3057 } 3058 ThrowVerifyError(klass.Get(), "%s", error_msg.c_str()); 3059 if (cause.Get() != nullptr) { 3060 self->GetException()->SetCause(cause.Get()); 3061 } 3062 ClassReference ref(klass->GetDexCache()->GetDexFile(), klass->GetDexClassDefIndex()); 3063 if (Runtime::Current()->IsAotCompiler()) { 3064 Runtime::Current()->GetCompilerCallbacks()->ClassRejected(ref); 3065 } 3066 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 3067 return; 3068 } 3069 } 3070 3071 // Try to use verification information from the oat file, otherwise do runtime verification. 3072 const DexFile& dex_file = *klass->GetDexCache()->GetDexFile(); 3073 mirror::Class::Status oat_file_class_status(mirror::Class::kStatusNotReady); 3074 bool preverified = VerifyClassUsingOatFile(dex_file, klass.Get(), oat_file_class_status); 3075 if (oat_file_class_status == mirror::Class::kStatusError) { 3076 VLOG(class_linker) << "Skipping runtime verification of erroneous class " 3077 << PrettyDescriptor(klass.Get()) << " in " 3078 << klass->GetDexCache()->GetLocation()->ToModifiedUtf8(); 3079 ThrowVerifyError(klass.Get(), "Rejecting class %s because it failed compile-time verification", 3080 PrettyDescriptor(klass.Get()).c_str()); 3081 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 3082 return; 3083 } 3084 verifier::MethodVerifier::FailureKind verifier_failure = verifier::MethodVerifier::kNoFailure; 3085 std::string error_msg; 3086 if (!preverified) { 3087 verifier_failure = verifier::MethodVerifier::VerifyClass(self, klass.Get(), 3088 Runtime::Current()->IsAotCompiler(), 3089 &error_msg); 3090 } 3091 if (preverified || verifier_failure != verifier::MethodVerifier::kHardFailure) { 3092 if (!preverified && verifier_failure != verifier::MethodVerifier::kNoFailure) { 3093 VLOG(class_linker) << "Soft verification failure in class " << PrettyDescriptor(klass.Get()) 3094 << " in " << klass->GetDexCache()->GetLocation()->ToModifiedUtf8() 3095 << " because: " << error_msg; 3096 } 3097 self->AssertNoPendingException(); 3098 // Make sure all classes referenced by catch blocks are resolved. 3099 ResolveClassExceptionHandlerTypes(dex_file, klass); 3100 if (verifier_failure == verifier::MethodVerifier::kNoFailure) { 3101 // Even though there were no verifier failures we need to respect whether the super-class 3102 // was verified or requiring runtime reverification. 3103 if (super.Get() == nullptr || super->IsVerified()) { 3104 mirror::Class::SetStatus(klass, mirror::Class::kStatusVerified, self); 3105 } else { 3106 CHECK_EQ(super->GetStatus(), mirror::Class::kStatusRetryVerificationAtRuntime); 3107 mirror::Class::SetStatus(klass, mirror::Class::kStatusRetryVerificationAtRuntime, self); 3108 // Pretend a soft failure occured so that we don't consider the class verified below. 3109 verifier_failure = verifier::MethodVerifier::kSoftFailure; 3110 } 3111 } else { 3112 CHECK_EQ(verifier_failure, verifier::MethodVerifier::kSoftFailure); 3113 // Soft failures at compile time should be retried at runtime. Soft 3114 // failures at runtime will be handled by slow paths in the generated 3115 // code. Set status accordingly. 3116 if (Runtime::Current()->IsAotCompiler()) { 3117 mirror::Class::SetStatus(klass, mirror::Class::kStatusRetryVerificationAtRuntime, self); 3118 } else { 3119 mirror::Class::SetStatus(klass, mirror::Class::kStatusVerified, self); 3120 // As this is a fake verified status, make sure the methods are _not_ marked preverified 3121 // later. 3122 klass->SetPreverified(); 3123 } 3124 } 3125 } else { 3126 LOG(WARNING) << "Verification failed on class " << PrettyDescriptor(klass.Get()) 3127 << " in " << klass->GetDexCache()->GetLocation()->ToModifiedUtf8() 3128 << " because: " << error_msg; 3129 self->AssertNoPendingException(); 3130 ThrowVerifyError(klass.Get(), "%s", error_msg.c_str()); 3131 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 3132 } 3133 if (preverified || verifier_failure == verifier::MethodVerifier::kNoFailure) { 3134 // Class is verified so we don't need to do any access check on its methods. 3135 // Let the interpreter know it by setting the kAccPreverified flag onto each 3136 // method. 3137 // Note: we're going here during compilation and at runtime. When we set the 3138 // kAccPreverified flag when compiling image classes, the flag is recorded 3139 // in the image and is set when loading the image. 3140 EnsurePreverifiedMethods(klass); 3141 } 3142} 3143 3144void ClassLinker::EnsurePreverifiedMethods(Handle<mirror::Class> klass) { 3145 if (!klass->IsPreverified()) { 3146 klass->SetPreverifiedFlagOnAllMethods(image_pointer_size_); 3147 klass->SetPreverified(); 3148 } 3149} 3150 3151bool ClassLinker::VerifyClassUsingOatFile(const DexFile& dex_file, mirror::Class* klass, 3152 mirror::Class::Status& oat_file_class_status) { 3153 // If we're compiling, we can only verify the class using the oat file if 3154 // we are not compiling the image or if the class we're verifying is not part of 3155 // the app. In other words, we will only check for preverification of bootclasspath 3156 // classes. 3157 if (Runtime::Current()->IsAotCompiler()) { 3158 // Are we compiling the bootclasspath? 3159 if (Runtime::Current()->GetCompilerCallbacks()->IsBootImage()) { 3160 return false; 3161 } 3162 // We are compiling an app (not the image). 3163 3164 // Is this an app class? (I.e. not a bootclasspath class) 3165 if (klass->GetClassLoader() != nullptr) { 3166 return false; 3167 } 3168 } 3169 3170 const OatFile::OatDexFile* oat_dex_file = dex_file.GetOatDexFile(); 3171 // In case we run without an image there won't be a backing oat file. 3172 if (oat_dex_file == nullptr) { 3173 return false; 3174 } 3175 3176 // We may be running with a preopted oat file but without image. In this case, 3177 // we don't skip verification of preverified classes to ensure we initialize 3178 // dex caches with all types resolved during verification. 3179 // We need to trust image classes, as these might be coming out of a pre-opted, quickened boot 3180 // image (that we just failed loading), and the verifier can't be run on quickened opcodes when 3181 // the runtime isn't started. On the other hand, app classes can be re-verified even if they are 3182 // already pre-opted, as then the runtime is started. 3183 if (!Runtime::Current()->IsAotCompiler() && 3184 !Runtime::Current()->GetHeap()->HasImageSpace() && 3185 klass->GetClassLoader() != nullptr) { 3186 return false; 3187 } 3188 3189 uint16_t class_def_index = klass->GetDexClassDefIndex(); 3190 oat_file_class_status = oat_dex_file->GetOatClass(class_def_index).GetStatus(); 3191 if (oat_file_class_status == mirror::Class::kStatusVerified || 3192 oat_file_class_status == mirror::Class::kStatusInitialized) { 3193 return true; 3194 } 3195 if (oat_file_class_status == mirror::Class::kStatusRetryVerificationAtRuntime) { 3196 // Compile time verification failed with a soft error. Compile time verification can fail 3197 // because we have incomplete type information. Consider the following: 3198 // class ... { 3199 // Foo x; 3200 // .... () { 3201 // if (...) { 3202 // v1 gets assigned a type of resolved class Foo 3203 // } else { 3204 // v1 gets assigned a type of unresolved class Bar 3205 // } 3206 // iput x = v1 3207 // } } 3208 // when we merge v1 following the if-the-else it results in Conflict 3209 // (see verifier::RegType::Merge) as we can't know the type of Bar and we could possibly be 3210 // allowing an unsafe assignment to the field x in the iput (javac may have compiled this as 3211 // it knew Bar was a sub-class of Foo, but for us this may have been moved into a separate apk 3212 // at compile time). 3213 return false; 3214 } 3215 if (oat_file_class_status == mirror::Class::kStatusError) { 3216 // Compile time verification failed with a hard error. This is caused by invalid instructions 3217 // in the class. These errors are unrecoverable. 3218 return false; 3219 } 3220 if (oat_file_class_status == mirror::Class::kStatusNotReady) { 3221 // Status is uninitialized if we couldn't determine the status at compile time, for example, 3222 // not loading the class. 3223 // TODO: when the verifier doesn't rely on Class-es failing to resolve/load the type hierarchy 3224 // isn't a problem and this case shouldn't occur 3225 return false; 3226 } 3227 std::string temp; 3228 LOG(FATAL) << "Unexpected class status: " << oat_file_class_status 3229 << " " << dex_file.GetLocation() << " " << PrettyClass(klass) << " " 3230 << klass->GetDescriptor(&temp); 3231 UNREACHABLE(); 3232} 3233 3234void ClassLinker::ResolveClassExceptionHandlerTypes(const DexFile& dex_file, 3235 Handle<mirror::Class> klass) { 3236 for (size_t i = 0; i < klass->NumDirectMethods(); i++) { 3237 ResolveMethodExceptionHandlerTypes(dex_file, klass->GetDirectMethod(i, image_pointer_size_)); 3238 } 3239 for (size_t i = 0; i < klass->NumVirtualMethods(); i++) { 3240 ResolveMethodExceptionHandlerTypes(dex_file, klass->GetVirtualMethod(i, image_pointer_size_)); 3241 } 3242} 3243 3244void ClassLinker::ResolveMethodExceptionHandlerTypes(const DexFile& dex_file, 3245 ArtMethod* method) { 3246 // similar to DexVerifier::ScanTryCatchBlocks and dex2oat's ResolveExceptionsForMethod. 3247 const DexFile::CodeItem* code_item = dex_file.GetCodeItem(method->GetCodeItemOffset()); 3248 if (code_item == nullptr) { 3249 return; // native or abstract method 3250 } 3251 if (code_item->tries_size_ == 0) { 3252 return; // nothing to process 3253 } 3254 const uint8_t* handlers_ptr = DexFile::GetCatchHandlerData(*code_item, 0); 3255 uint32_t handlers_size = DecodeUnsignedLeb128(&handlers_ptr); 3256 ClassLinker* linker = Runtime::Current()->GetClassLinker(); 3257 for (uint32_t idx = 0; idx < handlers_size; idx++) { 3258 CatchHandlerIterator iterator(handlers_ptr); 3259 for (; iterator.HasNext(); iterator.Next()) { 3260 // Ensure exception types are resolved so that they don't need resolution to be delivered, 3261 // unresolved exception types will be ignored by exception delivery 3262 if (iterator.GetHandlerTypeIndex() != DexFile::kDexNoIndex16) { 3263 mirror::Class* exception_type = linker->ResolveType(iterator.GetHandlerTypeIndex(), method); 3264 if (exception_type == nullptr) { 3265 DCHECK(Thread::Current()->IsExceptionPending()); 3266 Thread::Current()->ClearException(); 3267 } 3268 } 3269 } 3270 handlers_ptr = iterator.EndDataPointer(); 3271 } 3272} 3273 3274mirror::Class* ClassLinker::CreateProxyClass(ScopedObjectAccessAlreadyRunnable& soa, jstring name, 3275 jobjectArray interfaces, jobject loader, 3276 jobjectArray methods, jobjectArray throws) { 3277 Thread* self = soa.Self(); 3278 StackHandleScope<10> hs(self); 3279 MutableHandle<mirror::Class> klass(hs.NewHandle( 3280 AllocClass(self, GetClassRoot(kJavaLangClass), sizeof(mirror::Class)))); 3281 if (klass.Get() == nullptr) { 3282 CHECK(self->IsExceptionPending()); // OOME. 3283 return nullptr; 3284 } 3285 DCHECK(klass->GetClass() != nullptr); 3286 klass->SetObjectSize(sizeof(mirror::Proxy)); 3287 // Set the class access flags incl. preverified, so we do not try to set the flag on the methods. 3288 klass->SetAccessFlags(kAccClassIsProxy | kAccPublic | kAccFinal | kAccPreverified); 3289 klass->SetClassLoader(soa.Decode<mirror::ClassLoader*>(loader)); 3290 DCHECK_EQ(klass->GetPrimitiveType(), Primitive::kPrimNot); 3291 klass->SetName(soa.Decode<mirror::String*>(name)); 3292 klass->SetDexCache(GetClassRoot(kJavaLangReflectProxy)->GetDexCache()); 3293 mirror::Class::SetStatus(klass, mirror::Class::kStatusIdx, self); 3294 std::string descriptor(GetDescriptorForProxy(klass.Get())); 3295 size_t hash = ComputeModifiedUtf8Hash(descriptor.c_str()); 3296 3297 // Insert the class before loading the fields as the field roots 3298 // (ArtField::declaring_class_) are only visited from the class 3299 // table. There can't be any suspend points between inserting the 3300 // class and setting the field arrays below. 3301 mirror::Class* existing = InsertClass(descriptor.c_str(), klass.Get(), hash); 3302 CHECK(existing == nullptr); 3303 3304 // Instance fields are inherited, but we add a couple of static fields... 3305 const size_t num_fields = 2; 3306 ArtField* sfields = AllocArtFieldArray(self, num_fields); 3307 klass->SetSFields(sfields); 3308 klass->SetNumStaticFields(num_fields); 3309 3310 // 1. Create a static field 'interfaces' that holds the _declared_ interfaces implemented by 3311 // our proxy, so Class.getInterfaces doesn't return the flattened set. 3312 ArtField* interfaces_sfield = &sfields[0]; 3313 interfaces_sfield->SetDexFieldIndex(0); 3314 interfaces_sfield->SetDeclaringClass(klass.Get()); 3315 interfaces_sfield->SetAccessFlags(kAccStatic | kAccPublic | kAccFinal); 3316 3317 // 2. Create a static field 'throws' that holds exceptions thrown by our methods. 3318 ArtField* throws_sfield = &sfields[1]; 3319 throws_sfield->SetDexFieldIndex(1); 3320 throws_sfield->SetDeclaringClass(klass.Get()); 3321 throws_sfield->SetAccessFlags(kAccStatic | kAccPublic | kAccFinal); 3322 3323 // Proxies have 1 direct method, the constructor 3324 auto* directs = AllocArtMethodArray(self, 1); 3325 // Currently AllocArtMethodArray cannot return null, but the OOM logic is left there in case we 3326 // want to throw OOM in the future. 3327 if (UNLIKELY(directs == nullptr)) { 3328 self->AssertPendingOOMException(); 3329 return nullptr; 3330 } 3331 { 3332 WriterMutexLock mu(self, *Locks::classlinker_classes_lock_); 3333 klass->SetDirectMethodsPtr(directs); 3334 klass->SetNumDirectMethods(1u); 3335 } 3336 CreateProxyConstructor(klass, klass->GetDirectMethodUnchecked(0, image_pointer_size_)); 3337 3338 // Create virtual method using specified prototypes. 3339 auto h_methods = hs.NewHandle(soa.Decode<mirror::ObjectArray<mirror::Method>*>(methods)); 3340 DCHECK_EQ(h_methods->GetClass(), mirror::Method::ArrayClass()) 3341 << PrettyClass(h_methods->GetClass()); 3342 const size_t num_virtual_methods = h_methods->GetLength(); 3343 auto* virtuals = AllocArtMethodArray(self, num_virtual_methods); 3344 // Currently AllocArtMethodArray cannot return null, but the OOM logic is left there in case we 3345 // want to throw OOM in the future. 3346 if (UNLIKELY(virtuals == nullptr)) { 3347 self->AssertPendingOOMException(); 3348 return nullptr; 3349 } 3350 { 3351 WriterMutexLock mu(self, *Locks::classlinker_classes_lock_); 3352 klass->SetVirtualMethodsPtr(virtuals); 3353 klass->SetNumVirtualMethods(num_virtual_methods); 3354 } 3355 for (size_t i = 0; i < num_virtual_methods; ++i) { 3356 auto* virtual_method = klass->GetVirtualMethodUnchecked(i, image_pointer_size_); 3357 auto* prototype = h_methods->Get(i)->GetArtMethod(); 3358 CreateProxyMethod(klass, prototype, virtual_method); 3359 DCHECK(virtual_method->GetDeclaringClass() != nullptr); 3360 DCHECK(prototype->GetDeclaringClass() != nullptr); 3361 } 3362 3363 // The super class is java.lang.reflect.Proxy 3364 klass->SetSuperClass(GetClassRoot(kJavaLangReflectProxy)); 3365 // Now effectively in the loaded state. 3366 mirror::Class::SetStatus(klass, mirror::Class::kStatusLoaded, self); 3367 self->AssertNoPendingException(); 3368 3369 MutableHandle<mirror::Class> new_class = hs.NewHandle<mirror::Class>(nullptr); 3370 { 3371 // Must hold lock on object when resolved. 3372 ObjectLock<mirror::Class> resolution_lock(self, klass); 3373 // Link the fields and virtual methods, creating vtable and iftables. 3374 // The new class will replace the old one in the class table. 3375 Handle<mirror::ObjectArray<mirror::Class>> h_interfaces( 3376 hs.NewHandle(soa.Decode<mirror::ObjectArray<mirror::Class>*>(interfaces))); 3377 if (!LinkClass(self, descriptor.c_str(), klass, h_interfaces, &new_class)) { 3378 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 3379 return nullptr; 3380 } 3381 } 3382 CHECK(klass->IsRetired()); 3383 CHECK_NE(klass.Get(), new_class.Get()); 3384 klass.Assign(new_class.Get()); 3385 3386 CHECK_EQ(interfaces_sfield->GetDeclaringClass(), klass.Get()); 3387 interfaces_sfield->SetObject<false>(klass.Get(), 3388 soa.Decode<mirror::ObjectArray<mirror::Class>*>(interfaces)); 3389 CHECK_EQ(throws_sfield->GetDeclaringClass(), klass.Get()); 3390 throws_sfield->SetObject<false>(klass.Get(), 3391 soa.Decode<mirror::ObjectArray<mirror::ObjectArray<mirror::Class> >*>(throws)); 3392 3393 { 3394 // Lock on klass is released. Lock new class object. 3395 ObjectLock<mirror::Class> initialization_lock(self, klass); 3396 mirror::Class::SetStatus(klass, mirror::Class::kStatusInitialized, self); 3397 } 3398 3399 // sanity checks 3400 if (kIsDebugBuild) { 3401 CHECK(klass->GetIFields() == nullptr); 3402 CheckProxyConstructor(klass->GetDirectMethod(0, image_pointer_size_)); 3403 3404 for (size_t i = 0; i < num_virtual_methods; ++i) { 3405 auto* virtual_method = klass->GetVirtualMethodUnchecked(i, image_pointer_size_); 3406 auto* prototype = h_methods->Get(i++)->GetArtMethod(); 3407 CheckProxyMethod(virtual_method, prototype); 3408 } 3409 3410 StackHandleScope<1> hs2(self); 3411 Handle<mirror::String> decoded_name = hs2.NewHandle(soa.Decode<mirror::String*>(name)); 3412 std::string interfaces_field_name(StringPrintf("java.lang.Class[] %s.interfaces", 3413 decoded_name->ToModifiedUtf8().c_str())); 3414 CHECK_EQ(PrettyField(klass->GetStaticField(0)), interfaces_field_name); 3415 3416 std::string throws_field_name(StringPrintf("java.lang.Class[][] %s.throws", 3417 decoded_name->ToModifiedUtf8().c_str())); 3418 CHECK_EQ(PrettyField(klass->GetStaticField(1)), throws_field_name); 3419 3420 CHECK_EQ(klass.Get()->GetInterfaces(), 3421 soa.Decode<mirror::ObjectArray<mirror::Class>*>(interfaces)); 3422 CHECK_EQ(klass.Get()->GetThrows(), 3423 soa.Decode<mirror::ObjectArray<mirror::ObjectArray<mirror::Class>>*>(throws)); 3424 } 3425 return klass.Get(); 3426} 3427 3428std::string ClassLinker::GetDescriptorForProxy(mirror::Class* proxy_class) { 3429 DCHECK(proxy_class->IsProxyClass()); 3430 mirror::String* name = proxy_class->GetName(); 3431 DCHECK(name != nullptr); 3432 return DotToDescriptor(name->ToModifiedUtf8().c_str()); 3433} 3434 3435ArtMethod* ClassLinker::FindMethodForProxy(mirror::Class* proxy_class, 3436 ArtMethod* proxy_method) { 3437 DCHECK(proxy_class->IsProxyClass()); 3438 DCHECK(proxy_method->IsProxyMethod()); 3439 { 3440 ReaderMutexLock mu(Thread::Current(), dex_lock_); 3441 // Locate the dex cache of the original interface/Object 3442 for (const GcRoot<mirror::DexCache>& root : dex_caches_) { 3443 auto* dex_cache = root.Read(); 3444 if (proxy_method->HasSameDexCacheResolvedTypes(dex_cache->GetResolvedTypes())) { 3445 ArtMethod* resolved_method = dex_cache->GetResolvedMethod( 3446 proxy_method->GetDexMethodIndex(), image_pointer_size_); 3447 CHECK(resolved_method != nullptr); 3448 return resolved_method; 3449 } 3450 } 3451 } 3452 LOG(FATAL) << "Didn't find dex cache for " << PrettyClass(proxy_class) << " " 3453 << PrettyMethod(proxy_method); 3454 UNREACHABLE(); 3455} 3456 3457void ClassLinker::CreateProxyConstructor(Handle<mirror::Class> klass, ArtMethod* out) { 3458 // Create constructor for Proxy that must initialize the method. 3459 CHECK_EQ(GetClassRoot(kJavaLangReflectProxy)->NumDirectMethods(), 16u); 3460 ArtMethod* proxy_constructor = GetClassRoot(kJavaLangReflectProxy)->GetDirectMethodUnchecked( 3461 2, image_pointer_size_); 3462 // Ensure constructor is in dex cache so that we can use the dex cache to look up the overridden 3463 // constructor method. 3464 GetClassRoot(kJavaLangReflectProxy)->GetDexCache()->SetResolvedMethod( 3465 proxy_constructor->GetDexMethodIndex(), proxy_constructor, image_pointer_size_); 3466 // Clone the existing constructor of Proxy (our constructor would just invoke it so steal its 3467 // code_ too) 3468 DCHECK(out != nullptr); 3469 out->CopyFrom(proxy_constructor, image_pointer_size_); 3470 // Make this constructor public and fix the class to be our Proxy version 3471 out->SetAccessFlags((out->GetAccessFlags() & ~kAccProtected) | kAccPublic); 3472 out->SetDeclaringClass(klass.Get()); 3473} 3474 3475void ClassLinker::CheckProxyConstructor(ArtMethod* constructor) const { 3476 CHECK(constructor->IsConstructor()); 3477 auto* np = constructor->GetInterfaceMethodIfProxy(image_pointer_size_); 3478 CHECK_STREQ(np->GetName(), "<init>"); 3479 CHECK_STREQ(np->GetSignature().ToString().c_str(), "(Ljava/lang/reflect/InvocationHandler;)V"); 3480 DCHECK(constructor->IsPublic()); 3481} 3482 3483void ClassLinker::CreateProxyMethod(Handle<mirror::Class> klass, ArtMethod* prototype, 3484 ArtMethod* out) { 3485 // Ensure prototype is in dex cache so that we can use the dex cache to look up the overridden 3486 // prototype method 3487 auto* dex_cache = prototype->GetDeclaringClass()->GetDexCache(); 3488 // Avoid dirtying the dex cache unless we need to. 3489 if (dex_cache->GetResolvedMethod(prototype->GetDexMethodIndex(), image_pointer_size_) != 3490 prototype) { 3491 dex_cache->SetResolvedMethod( 3492 prototype->GetDexMethodIndex(), prototype, image_pointer_size_); 3493 } 3494 // We steal everything from the prototype (such as DexCache, invoke stub, etc.) then specialize 3495 // as necessary 3496 DCHECK(out != nullptr); 3497 out->CopyFrom(prototype, image_pointer_size_); 3498 3499 // Set class to be the concrete proxy class and clear the abstract flag, modify exceptions to 3500 // the intersection of throw exceptions as defined in Proxy 3501 out->SetDeclaringClass(klass.Get()); 3502 out->SetAccessFlags((out->GetAccessFlags() & ~kAccAbstract) | kAccFinal); 3503 3504 // At runtime the method looks like a reference and argument saving method, clone the code 3505 // related parameters from this method. 3506 out->SetEntryPointFromQuickCompiledCode(GetQuickProxyInvokeHandler()); 3507 out->SetEntryPointFromInterpreter(artInterpreterToCompiledCodeBridge); 3508} 3509 3510void ClassLinker::CheckProxyMethod(ArtMethod* method, ArtMethod* prototype) const { 3511 // Basic sanity 3512 CHECK(!prototype->IsFinal()); 3513 CHECK(method->IsFinal()); 3514 CHECK(!method->IsAbstract()); 3515 3516 // The proxy method doesn't have its own dex cache or dex file and so it steals those of its 3517 // interface prototype. The exception to this are Constructors and the Class of the Proxy itself. 3518 CHECK(prototype->HasSameDexCacheResolvedMethods(method)); 3519 CHECK(prototype->HasSameDexCacheResolvedTypes(method)); 3520 auto* np = method->GetInterfaceMethodIfProxy(image_pointer_size_); 3521 CHECK_EQ(prototype->GetDeclaringClass()->GetDexCache(), np->GetDexCache()); 3522 CHECK_EQ(prototype->GetDexMethodIndex(), method->GetDexMethodIndex()); 3523 3524 CHECK_STREQ(np->GetName(), prototype->GetName()); 3525 CHECK_STREQ(np->GetShorty(), prototype->GetShorty()); 3526 // More complex sanity - via dex cache 3527 CHECK_EQ(np->GetReturnType(), prototype->GetReturnType()); 3528} 3529 3530bool ClassLinker::CanWeInitializeClass(mirror::Class* klass, bool can_init_statics, 3531 bool can_init_parents) { 3532 if (can_init_statics && can_init_parents) { 3533 return true; 3534 } 3535 if (!can_init_statics) { 3536 // Check if there's a class initializer. 3537 ArtMethod* clinit = klass->FindClassInitializer(image_pointer_size_); 3538 if (clinit != nullptr) { 3539 return false; 3540 } 3541 // Check if there are encoded static values needing initialization. 3542 if (klass->NumStaticFields() != 0) { 3543 const DexFile::ClassDef* dex_class_def = klass->GetClassDef(); 3544 DCHECK(dex_class_def != nullptr); 3545 if (dex_class_def->static_values_off_ != 0) { 3546 return false; 3547 } 3548 } 3549 } 3550 if (klass->IsInterface() || !klass->HasSuperClass()) { 3551 return true; 3552 } 3553 mirror::Class* super_class = klass->GetSuperClass(); 3554 if (!can_init_parents && !super_class->IsInitialized()) { 3555 return false; 3556 } 3557 return CanWeInitializeClass(super_class, can_init_statics, can_init_parents); 3558} 3559 3560bool ClassLinker::InitializeClass(Thread* self, Handle<mirror::Class> klass, 3561 bool can_init_statics, bool can_init_parents) { 3562 // see JLS 3rd edition, 12.4.2 "Detailed Initialization Procedure" for the locking protocol 3563 3564 // Are we already initialized and therefore done? 3565 // Note: we differ from the JLS here as we don't do this under the lock, this is benign as 3566 // an initialized class will never change its state. 3567 if (klass->IsInitialized()) { 3568 return true; 3569 } 3570 3571 // Fast fail if initialization requires a full runtime. Not part of the JLS. 3572 if (!CanWeInitializeClass(klass.Get(), can_init_statics, can_init_parents)) { 3573 return false; 3574 } 3575 3576 self->AllowThreadSuspension(); 3577 uint64_t t0; 3578 { 3579 ObjectLock<mirror::Class> lock(self, klass); 3580 3581 // Re-check under the lock in case another thread initialized ahead of us. 3582 if (klass->IsInitialized()) { 3583 return true; 3584 } 3585 3586 // Was the class already found to be erroneous? Done under the lock to match the JLS. 3587 if (klass->IsErroneous()) { 3588 ThrowEarlierClassFailure(klass.Get()); 3589 VlogClassInitializationFailure(klass); 3590 return false; 3591 } 3592 3593 CHECK(klass->IsResolved()) << PrettyClass(klass.Get()) << ": state=" << klass->GetStatus(); 3594 3595 if (!klass->IsVerified()) { 3596 VerifyClass(self, klass); 3597 if (!klass->IsVerified()) { 3598 // We failed to verify, expect either the klass to be erroneous or verification failed at 3599 // compile time. 3600 if (klass->IsErroneous()) { 3601 CHECK(self->IsExceptionPending()); 3602 VlogClassInitializationFailure(klass); 3603 } else { 3604 CHECK(Runtime::Current()->IsAotCompiler()); 3605 CHECK_EQ(klass->GetStatus(), mirror::Class::kStatusRetryVerificationAtRuntime); 3606 } 3607 return false; 3608 } else { 3609 self->AssertNoPendingException(); 3610 } 3611 } 3612 3613 // If the class is kStatusInitializing, either this thread is 3614 // initializing higher up the stack or another thread has beat us 3615 // to initializing and we need to wait. Either way, this 3616 // invocation of InitializeClass will not be responsible for 3617 // running <clinit> and will return. 3618 if (klass->GetStatus() == mirror::Class::kStatusInitializing) { 3619 // Could have got an exception during verification. 3620 if (self->IsExceptionPending()) { 3621 VlogClassInitializationFailure(klass); 3622 return false; 3623 } 3624 // We caught somebody else in the act; was it us? 3625 if (klass->GetClinitThreadId() == self->GetTid()) { 3626 // Yes. That's fine. Return so we can continue initializing. 3627 return true; 3628 } 3629 // No. That's fine. Wait for another thread to finish initializing. 3630 return WaitForInitializeClass(klass, self, lock); 3631 } 3632 3633 if (!ValidateSuperClassDescriptors(klass)) { 3634 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 3635 return false; 3636 } 3637 self->AllowThreadSuspension(); 3638 3639 CHECK_EQ(klass->GetStatus(), mirror::Class::kStatusVerified) << PrettyClass(klass.Get()); 3640 3641 // From here out other threads may observe that we're initializing and so changes of state 3642 // require the a notification. 3643 klass->SetClinitThreadId(self->GetTid()); 3644 mirror::Class::SetStatus(klass, mirror::Class::kStatusInitializing, self); 3645 3646 t0 = NanoTime(); 3647 } 3648 3649 // Initialize super classes, must be done while initializing for the JLS. 3650 if (!klass->IsInterface() && klass->HasSuperClass()) { 3651 mirror::Class* super_class = klass->GetSuperClass(); 3652 if (!super_class->IsInitialized()) { 3653 CHECK(!super_class->IsInterface()); 3654 CHECK(can_init_parents); 3655 StackHandleScope<1> hs(self); 3656 Handle<mirror::Class> handle_scope_super(hs.NewHandle(super_class)); 3657 bool super_initialized = InitializeClass(self, handle_scope_super, can_init_statics, true); 3658 if (!super_initialized) { 3659 // The super class was verified ahead of entering initializing, we should only be here if 3660 // the super class became erroneous due to initialization. 3661 CHECK(handle_scope_super->IsErroneous() && self->IsExceptionPending()) 3662 << "Super class initialization failed for " 3663 << PrettyDescriptor(handle_scope_super.Get()) 3664 << " that has unexpected status " << handle_scope_super->GetStatus() 3665 << "\nPending exception:\n" 3666 << (self->GetException() != nullptr ? self->GetException()->Dump() : ""); 3667 ObjectLock<mirror::Class> lock(self, klass); 3668 // Initialization failed because the super-class is erroneous. 3669 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 3670 return false; 3671 } 3672 } 3673 } 3674 3675 const size_t num_static_fields = klass->NumStaticFields(); 3676 if (num_static_fields > 0) { 3677 const DexFile::ClassDef* dex_class_def = klass->GetClassDef(); 3678 CHECK(dex_class_def != nullptr); 3679 const DexFile& dex_file = klass->GetDexFile(); 3680 StackHandleScope<3> hs(self); 3681 Handle<mirror::ClassLoader> class_loader(hs.NewHandle(klass->GetClassLoader())); 3682 Handle<mirror::DexCache> dex_cache(hs.NewHandle(klass->GetDexCache())); 3683 3684 // Eagerly fill in static fields so that the we don't have to do as many expensive 3685 // Class::FindStaticField in ResolveField. 3686 for (size_t i = 0; i < num_static_fields; ++i) { 3687 ArtField* field = klass->GetStaticField(i); 3688 const uint32_t field_idx = field->GetDexFieldIndex(); 3689 ArtField* resolved_field = dex_cache->GetResolvedField(field_idx, image_pointer_size_); 3690 if (resolved_field == nullptr) { 3691 dex_cache->SetResolvedField(field_idx, field, image_pointer_size_); 3692 } else { 3693 DCHECK_EQ(field, resolved_field); 3694 } 3695 } 3696 3697 EncodedStaticFieldValueIterator value_it(dex_file, &dex_cache, &class_loader, 3698 this, *dex_class_def); 3699 const uint8_t* class_data = dex_file.GetClassData(*dex_class_def); 3700 ClassDataItemIterator field_it(dex_file, class_data); 3701 if (value_it.HasNext()) { 3702 DCHECK(field_it.HasNextStaticField()); 3703 CHECK(can_init_statics); 3704 for ( ; value_it.HasNext(); value_it.Next(), field_it.Next()) { 3705 ArtField* field = ResolveField( 3706 dex_file, field_it.GetMemberIndex(), dex_cache, class_loader, true); 3707 if (Runtime::Current()->IsActiveTransaction()) { 3708 value_it.ReadValueToField<true>(field); 3709 } else { 3710 value_it.ReadValueToField<false>(field); 3711 } 3712 DCHECK(!value_it.HasNext() || field_it.HasNextStaticField()); 3713 } 3714 } 3715 } 3716 3717 ArtMethod* clinit = klass->FindClassInitializer(image_pointer_size_); 3718 if (clinit != nullptr) { 3719 CHECK(can_init_statics); 3720 JValue result; 3721 clinit->Invoke(self, nullptr, 0, &result, "V"); 3722 } 3723 3724 self->AllowThreadSuspension(); 3725 uint64_t t1 = NanoTime(); 3726 3727 bool success = true; 3728 { 3729 ObjectLock<mirror::Class> lock(self, klass); 3730 3731 if (self->IsExceptionPending()) { 3732 WrapExceptionInInitializer(klass); 3733 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 3734 success = false; 3735 } else if (Runtime::Current()->IsTransactionAborted()) { 3736 // The exception thrown when the transaction aborted has been caught and cleared 3737 // so we need to throw it again now. 3738 VLOG(compiler) << "Return from class initializer of " << PrettyDescriptor(klass.Get()) 3739 << " without exception while transaction was aborted: re-throw it now."; 3740 Runtime::Current()->ThrowTransactionAbortError(self); 3741 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 3742 success = false; 3743 } else { 3744 RuntimeStats* global_stats = Runtime::Current()->GetStats(); 3745 RuntimeStats* thread_stats = self->GetStats(); 3746 ++global_stats->class_init_count; 3747 ++thread_stats->class_init_count; 3748 global_stats->class_init_time_ns += (t1 - t0); 3749 thread_stats->class_init_time_ns += (t1 - t0); 3750 // Set the class as initialized except if failed to initialize static fields. 3751 mirror::Class::SetStatus(klass, mirror::Class::kStatusInitialized, self); 3752 if (VLOG_IS_ON(class_linker)) { 3753 std::string temp; 3754 LOG(INFO) << "Initialized class " << klass->GetDescriptor(&temp) << " from " << 3755 klass->GetLocation(); 3756 } 3757 // Opportunistically set static method trampolines to their destination. 3758 FixupStaticTrampolines(klass.Get()); 3759 } 3760 } 3761 return success; 3762} 3763 3764bool ClassLinker::WaitForInitializeClass(Handle<mirror::Class> klass, Thread* self, 3765 ObjectLock<mirror::Class>& lock) 3766 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 3767 while (true) { 3768 self->AssertNoPendingException(); 3769 CHECK(!klass->IsInitialized()); 3770 lock.WaitIgnoringInterrupts(); 3771 3772 // When we wake up, repeat the test for init-in-progress. If 3773 // there's an exception pending (only possible if 3774 // we were not using WaitIgnoringInterrupts), bail out. 3775 if (self->IsExceptionPending()) { 3776 WrapExceptionInInitializer(klass); 3777 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 3778 return false; 3779 } 3780 // Spurious wakeup? Go back to waiting. 3781 if (klass->GetStatus() == mirror::Class::kStatusInitializing) { 3782 continue; 3783 } 3784 if (klass->GetStatus() == mirror::Class::kStatusVerified && 3785 Runtime::Current()->IsAotCompiler()) { 3786 // Compile time initialization failed. 3787 return false; 3788 } 3789 if (klass->IsErroneous()) { 3790 // The caller wants an exception, but it was thrown in a 3791 // different thread. Synthesize one here. 3792 ThrowNoClassDefFoundError("<clinit> failed for class %s; see exception in other thread", 3793 PrettyDescriptor(klass.Get()).c_str()); 3794 VlogClassInitializationFailure(klass); 3795 return false; 3796 } 3797 if (klass->IsInitialized()) { 3798 return true; 3799 } 3800 LOG(FATAL) << "Unexpected class status. " << PrettyClass(klass.Get()) << " is " 3801 << klass->GetStatus(); 3802 } 3803 UNREACHABLE(); 3804} 3805 3806static void ThrowSignatureCheckResolveReturnTypeException(Handle<mirror::Class> klass, 3807 Handle<mirror::Class> super_klass, 3808 ArtMethod* method, 3809 ArtMethod* m) 3810 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 3811 DCHECK(Thread::Current()->IsExceptionPending()); 3812 DCHECK(!m->IsProxyMethod()); 3813 const DexFile* dex_file = m->GetDexFile(); 3814 const DexFile::MethodId& method_id = dex_file->GetMethodId(m->GetDexMethodIndex()); 3815 const DexFile::ProtoId& proto_id = dex_file->GetMethodPrototype(method_id); 3816 uint16_t return_type_idx = proto_id.return_type_idx_; 3817 std::string return_type = PrettyType(return_type_idx, *dex_file); 3818 std::string class_loader = PrettyTypeOf(m->GetDeclaringClass()->GetClassLoader()); 3819 ThrowWrappedLinkageError(klass.Get(), 3820 "While checking class %s method %s signature against %s %s: " 3821 "Failed to resolve return type %s with %s", 3822 PrettyDescriptor(klass.Get()).c_str(), 3823 PrettyMethod(method).c_str(), 3824 super_klass->IsInterface() ? "interface" : "superclass", 3825 PrettyDescriptor(super_klass.Get()).c_str(), 3826 return_type.c_str(), class_loader.c_str()); 3827} 3828 3829static void ThrowSignatureCheckResolveArgException(Handle<mirror::Class> klass, 3830 Handle<mirror::Class> super_klass, 3831 ArtMethod* method, 3832 ArtMethod* m, 3833 uint32_t index, uint32_t arg_type_idx) 3834 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 3835 DCHECK(Thread::Current()->IsExceptionPending()); 3836 DCHECK(!m->IsProxyMethod()); 3837 const DexFile* dex_file = m->GetDexFile(); 3838 std::string arg_type = PrettyType(arg_type_idx, *dex_file); 3839 std::string class_loader = PrettyTypeOf(m->GetDeclaringClass()->GetClassLoader()); 3840 ThrowWrappedLinkageError(klass.Get(), 3841 "While checking class %s method %s signature against %s %s: " 3842 "Failed to resolve arg %u type %s with %s", 3843 PrettyDescriptor(klass.Get()).c_str(), 3844 PrettyMethod(method).c_str(), 3845 super_klass->IsInterface() ? "interface" : "superclass", 3846 PrettyDescriptor(super_klass.Get()).c_str(), 3847 index, arg_type.c_str(), class_loader.c_str()); 3848} 3849 3850static void ThrowSignatureMismatch(Handle<mirror::Class> klass, 3851 Handle<mirror::Class> super_klass, 3852 ArtMethod* method, 3853 const std::string& error_msg) 3854 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 3855 ThrowLinkageError(klass.Get(), 3856 "Class %s method %s resolves differently in %s %s: %s", 3857 PrettyDescriptor(klass.Get()).c_str(), 3858 PrettyMethod(method).c_str(), 3859 super_klass->IsInterface() ? "interface" : "superclass", 3860 PrettyDescriptor(super_klass.Get()).c_str(), 3861 error_msg.c_str()); 3862} 3863 3864static bool HasSameSignatureWithDifferentClassLoaders(Thread* self, 3865 Handle<mirror::Class> klass, 3866 Handle<mirror::Class> super_klass, 3867 ArtMethod* method1, 3868 ArtMethod* method2) 3869 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 3870 { 3871 StackHandleScope<1> hs(self); 3872 Handle<mirror::Class> return_type(hs.NewHandle(method1->GetReturnType())); 3873 if (UNLIKELY(return_type.Get() == nullptr)) { 3874 ThrowSignatureCheckResolveReturnTypeException(klass, super_klass, method1, method1); 3875 return false; 3876 } 3877 mirror::Class* other_return_type = method2->GetReturnType(); 3878 if (UNLIKELY(other_return_type == nullptr)) { 3879 ThrowSignatureCheckResolveReturnTypeException(klass, super_klass, method1, method2); 3880 return false; 3881 } 3882 if (UNLIKELY(other_return_type != return_type.Get())) { 3883 ThrowSignatureMismatch(klass, super_klass, method1, 3884 StringPrintf("Return types mismatch: %s(%p) vs %s(%p)", 3885 PrettyClassAndClassLoader(return_type.Get()).c_str(), 3886 return_type.Get(), 3887 PrettyClassAndClassLoader(other_return_type).c_str(), 3888 other_return_type)); 3889 return false; 3890 } 3891 } 3892 const DexFile::TypeList* types1 = method1->GetParameterTypeList(); 3893 const DexFile::TypeList* types2 = method2->GetParameterTypeList(); 3894 if (types1 == nullptr) { 3895 if (types2 != nullptr && types2->Size() != 0) { 3896 ThrowSignatureMismatch(klass, super_klass, method1, 3897 StringPrintf("Type list mismatch with %s", 3898 PrettyMethod(method2, true).c_str())); 3899 return false; 3900 } 3901 return true; 3902 } else if (UNLIKELY(types2 == nullptr)) { 3903 if (types1->Size() != 0) { 3904 ThrowSignatureMismatch(klass, super_klass, method1, 3905 StringPrintf("Type list mismatch with %s", 3906 PrettyMethod(method2, true).c_str())); 3907 return false; 3908 } 3909 return true; 3910 } 3911 uint32_t num_types = types1->Size(); 3912 if (UNLIKELY(num_types != types2->Size())) { 3913 ThrowSignatureMismatch(klass, super_klass, method1, 3914 StringPrintf("Type list mismatch with %s", 3915 PrettyMethod(method2, true).c_str())); 3916 return false; 3917 } 3918 for (uint32_t i = 0; i < num_types; ++i) { 3919 StackHandleScope<1> hs(self); 3920 uint32_t param_type_idx = types1->GetTypeItem(i).type_idx_; 3921 Handle<mirror::Class> param_type(hs.NewHandle( 3922 method1->GetClassFromTypeIndex(param_type_idx, true))); 3923 if (UNLIKELY(param_type.Get() == nullptr)) { 3924 ThrowSignatureCheckResolveArgException(klass, super_klass, method1, 3925 method1, i, param_type_idx); 3926 return false; 3927 } 3928 uint32_t other_param_type_idx = types2->GetTypeItem(i).type_idx_; 3929 mirror::Class* other_param_type = 3930 method2->GetClassFromTypeIndex(other_param_type_idx, true); 3931 if (UNLIKELY(other_param_type == nullptr)) { 3932 ThrowSignatureCheckResolveArgException(klass, super_klass, method1, 3933 method2, i, other_param_type_idx); 3934 return false; 3935 } 3936 if (UNLIKELY(param_type.Get() != other_param_type)) { 3937 ThrowSignatureMismatch(klass, super_klass, method1, 3938 StringPrintf("Parameter %u type mismatch: %s(%p) vs %s(%p)", 3939 i, 3940 PrettyClassAndClassLoader(param_type.Get()).c_str(), 3941 param_type.Get(), 3942 PrettyClassAndClassLoader(other_param_type).c_str(), 3943 other_param_type)); 3944 return false; 3945 } 3946 } 3947 return true; 3948} 3949 3950 3951bool ClassLinker::ValidateSuperClassDescriptors(Handle<mirror::Class> klass) { 3952 if (klass->IsInterface()) { 3953 return true; 3954 } 3955 // Begin with the methods local to the superclass. 3956 Thread* self = Thread::Current(); 3957 StackHandleScope<1> hs(self); 3958 MutableHandle<mirror::Class> super_klass(hs.NewHandle<mirror::Class>(nullptr)); 3959 if (klass->HasSuperClass() && 3960 klass->GetClassLoader() != klass->GetSuperClass()->GetClassLoader()) { 3961 super_klass.Assign(klass->GetSuperClass()); 3962 for (int i = klass->GetSuperClass()->GetVTableLength() - 1; i >= 0; --i) { 3963 auto* m = klass->GetVTableEntry(i, image_pointer_size_); 3964 auto* super_m = klass->GetSuperClass()->GetVTableEntry(i, image_pointer_size_); 3965 if (m != super_m) { 3966 if (UNLIKELY(!HasSameSignatureWithDifferentClassLoaders(self, klass, super_klass, 3967 m, super_m))) { 3968 self->AssertPendingException(); 3969 return false; 3970 } 3971 } 3972 } 3973 } 3974 for (int32_t i = 0; i < klass->GetIfTableCount(); ++i) { 3975 super_klass.Assign(klass->GetIfTable()->GetInterface(i)); 3976 if (klass->GetClassLoader() != super_klass->GetClassLoader()) { 3977 uint32_t num_methods = super_klass->NumVirtualMethods(); 3978 for (uint32_t j = 0; j < num_methods; ++j) { 3979 auto* m = klass->GetIfTable()->GetMethodArray(i)->GetElementPtrSize<ArtMethod*>( 3980 j, image_pointer_size_); 3981 auto* super_m = super_klass->GetVirtualMethod(j, image_pointer_size_); 3982 if (m != super_m) { 3983 if (UNLIKELY(!HasSameSignatureWithDifferentClassLoaders(self, klass, super_klass, 3984 m, super_m))) { 3985 self->AssertPendingException(); 3986 return false; 3987 } 3988 } 3989 } 3990 } 3991 } 3992 return true; 3993} 3994 3995bool ClassLinker::EnsureInitialized(Thread* self, Handle<mirror::Class> c, bool can_init_fields, 3996 bool can_init_parents) { 3997 DCHECK(c.Get() != nullptr); 3998 if (c->IsInitialized()) { 3999 EnsurePreverifiedMethods(c); 4000 return true; 4001 } 4002 const bool success = InitializeClass(self, c, can_init_fields, can_init_parents); 4003 if (!success) { 4004 if (can_init_fields && can_init_parents) { 4005 CHECK(self->IsExceptionPending()) << PrettyClass(c.Get()); 4006 } 4007 } else { 4008 self->AssertNoPendingException(); 4009 } 4010 return success; 4011} 4012 4013void ClassLinker::FixupTemporaryDeclaringClass(mirror::Class* temp_class, 4014 mirror::Class* new_class) { 4015 ArtField* fields = new_class->GetIFields(); 4016 DCHECK_EQ(temp_class->NumInstanceFields(), new_class->NumInstanceFields()); 4017 for (size_t i = 0, count = new_class->NumInstanceFields(); i < count; i++) { 4018 if (fields[i].GetDeclaringClass() == temp_class) { 4019 fields[i].SetDeclaringClass(new_class); 4020 } 4021 } 4022 4023 fields = new_class->GetSFields(); 4024 DCHECK_EQ(temp_class->NumStaticFields(), new_class->NumStaticFields()); 4025 for (size_t i = 0, count = new_class->NumStaticFields(); i < count; i++) { 4026 if (fields[i].GetDeclaringClass() == temp_class) { 4027 fields[i].SetDeclaringClass(new_class); 4028 } 4029 } 4030 4031 DCHECK_EQ(temp_class->NumDirectMethods(), new_class->NumDirectMethods()); 4032 for (auto& method : new_class->GetDirectMethods(image_pointer_size_)) { 4033 if (method.GetDeclaringClass() == temp_class) { 4034 method.SetDeclaringClass(new_class); 4035 } 4036 } 4037 4038 DCHECK_EQ(temp_class->NumVirtualMethods(), new_class->NumVirtualMethods()); 4039 for (auto& method : new_class->GetVirtualMethods(image_pointer_size_)) { 4040 if (method.GetDeclaringClass() == temp_class) { 4041 method.SetDeclaringClass(new_class); 4042 } 4043 } 4044} 4045 4046bool ClassLinker::LinkClass(Thread* self, const char* descriptor, Handle<mirror::Class> klass, 4047 Handle<mirror::ObjectArray<mirror::Class>> interfaces, 4048 MutableHandle<mirror::Class>* h_new_class_out) { 4049 CHECK_EQ(mirror::Class::kStatusLoaded, klass->GetStatus()); 4050 4051 if (!LinkSuperClass(klass)) { 4052 return false; 4053 } 4054 ArtMethod* imt[mirror::Class::kImtSize]; 4055 std::fill_n(imt, arraysize(imt), Runtime::Current()->GetImtUnimplementedMethod()); 4056 if (!LinkMethods(self, klass, interfaces, imt)) { 4057 return false; 4058 } 4059 if (!LinkInstanceFields(self, klass)) { 4060 return false; 4061 } 4062 size_t class_size; 4063 if (!LinkStaticFields(self, klass, &class_size)) { 4064 return false; 4065 } 4066 CreateReferenceInstanceOffsets(klass); 4067 CHECK_EQ(mirror::Class::kStatusLoaded, klass->GetStatus()); 4068 4069 if (!klass->IsTemp() || (!init_done_ && klass->GetClassSize() == class_size)) { 4070 // We don't need to retire this class as it has no embedded tables or it was created the 4071 // correct size during class linker initialization. 4072 CHECK_EQ(klass->GetClassSize(), class_size) << PrettyDescriptor(klass.Get()); 4073 4074 if (klass->ShouldHaveEmbeddedImtAndVTable()) { 4075 klass->PopulateEmbeddedImtAndVTable(imt, image_pointer_size_); 4076 } 4077 4078 // This will notify waiters on klass that saw the not yet resolved 4079 // class in the class_table_ during EnsureResolved. 4080 mirror::Class::SetStatus(klass, mirror::Class::kStatusResolved, self); 4081 h_new_class_out->Assign(klass.Get()); 4082 } else { 4083 CHECK(!klass->IsResolved()); 4084 // Retire the temporary class and create the correctly sized resolved class. 4085 StackHandleScope<1> hs(self); 4086 auto h_new_class = hs.NewHandle(klass->CopyOf(self, class_size, imt, image_pointer_size_)); 4087 if (UNLIKELY(h_new_class.Get() == nullptr)) { 4088 self->AssertPendingOOMException(); 4089 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 4090 return false; 4091 } 4092 4093 CHECK_EQ(h_new_class->GetClassSize(), class_size); 4094 ObjectLock<mirror::Class> lock(self, h_new_class); 4095 FixupTemporaryDeclaringClass(klass.Get(), h_new_class.Get()); 4096 mirror::Class* existing = UpdateClass(descriptor, h_new_class.Get(), 4097 ComputeModifiedUtf8Hash(descriptor)); 4098 CHECK(existing == nullptr || existing == klass.Get()); 4099 4100 // This will notify waiters on temp class that saw the not yet resolved class in the 4101 // class_table_ during EnsureResolved. 4102 mirror::Class::SetStatus(klass, mirror::Class::kStatusRetired, self); 4103 4104 CHECK_EQ(h_new_class->GetStatus(), mirror::Class::kStatusResolving); 4105 // This will notify waiters on new_class that saw the not yet resolved 4106 // class in the class_table_ during EnsureResolved. 4107 mirror::Class::SetStatus(h_new_class, mirror::Class::kStatusResolved, self); 4108 // Return the new class. 4109 h_new_class_out->Assign(h_new_class.Get()); 4110 } 4111 return true; 4112} 4113 4114static void CountMethodsAndFields(ClassDataItemIterator& dex_data, 4115 size_t* virtual_methods, 4116 size_t* direct_methods, 4117 size_t* static_fields, 4118 size_t* instance_fields) { 4119 *virtual_methods = *direct_methods = *static_fields = *instance_fields = 0; 4120 4121 while (dex_data.HasNextStaticField()) { 4122 dex_data.Next(); 4123 (*static_fields)++; 4124 } 4125 while (dex_data.HasNextInstanceField()) { 4126 dex_data.Next(); 4127 (*instance_fields)++; 4128 } 4129 while (dex_data.HasNextDirectMethod()) { 4130 (*direct_methods)++; 4131 dex_data.Next(); 4132 } 4133 while (dex_data.HasNextVirtualMethod()) { 4134 (*virtual_methods)++; 4135 dex_data.Next(); 4136 } 4137 DCHECK(!dex_data.HasNext()); 4138} 4139 4140static void DumpClass(std::ostream& os, 4141 const DexFile& dex_file, const DexFile::ClassDef& dex_class_def, 4142 const char* suffix) { 4143 ClassDataItemIterator dex_data(dex_file, dex_file.GetClassData(dex_class_def)); 4144 os << dex_file.GetClassDescriptor(dex_class_def) << suffix << ":\n"; 4145 os << " Static fields:\n"; 4146 while (dex_data.HasNextStaticField()) { 4147 const DexFile::FieldId& id = dex_file.GetFieldId(dex_data.GetMemberIndex()); 4148 os << " " << dex_file.GetFieldTypeDescriptor(id) << " " << dex_file.GetFieldName(id) << "\n"; 4149 dex_data.Next(); 4150 } 4151 os << " Instance fields:\n"; 4152 while (dex_data.HasNextInstanceField()) { 4153 const DexFile::FieldId& id = dex_file.GetFieldId(dex_data.GetMemberIndex()); 4154 os << " " << dex_file.GetFieldTypeDescriptor(id) << " " << dex_file.GetFieldName(id) << "\n"; 4155 dex_data.Next(); 4156 } 4157 os << " Direct methods:\n"; 4158 while (dex_data.HasNextDirectMethod()) { 4159 const DexFile::MethodId& id = dex_file.GetMethodId(dex_data.GetMemberIndex()); 4160 os << " " << dex_file.GetMethodName(id) << dex_file.GetMethodSignature(id).ToString() << "\n"; 4161 dex_data.Next(); 4162 } 4163 os << " Virtual methods:\n"; 4164 while (dex_data.HasNextVirtualMethod()) { 4165 const DexFile::MethodId& id = dex_file.GetMethodId(dex_data.GetMemberIndex()); 4166 os << " " << dex_file.GetMethodName(id) << dex_file.GetMethodSignature(id).ToString() << "\n"; 4167 dex_data.Next(); 4168 } 4169} 4170 4171static std::string DumpClasses(const DexFile& dex_file1, const DexFile::ClassDef& dex_class_def1, 4172 const DexFile& dex_file2, const DexFile::ClassDef& dex_class_def2) { 4173 std::ostringstream os; 4174 DumpClass(os, dex_file1, dex_class_def1, " (Compile time)"); 4175 DumpClass(os, dex_file2, dex_class_def2, " (Runtime)"); 4176 return os.str(); 4177} 4178 4179 4180// Very simple structural check on whether the classes match. Only compares the number of 4181// methods and fields. 4182static bool SimpleStructuralCheck(const DexFile& dex_file1, const DexFile::ClassDef& dex_class_def1, 4183 const DexFile& dex_file2, const DexFile::ClassDef& dex_class_def2, 4184 std::string* error_msg) { 4185 ClassDataItemIterator dex_data1(dex_file1, dex_file1.GetClassData(dex_class_def1)); 4186 ClassDataItemIterator dex_data2(dex_file2, dex_file2.GetClassData(dex_class_def2)); 4187 4188 // Counters for current dex file. 4189 size_t dex_virtual_methods1, dex_direct_methods1, dex_static_fields1, dex_instance_fields1; 4190 CountMethodsAndFields(dex_data1, &dex_virtual_methods1, &dex_direct_methods1, &dex_static_fields1, 4191 &dex_instance_fields1); 4192 // Counters for compile-time dex file. 4193 size_t dex_virtual_methods2, dex_direct_methods2, dex_static_fields2, dex_instance_fields2; 4194 CountMethodsAndFields(dex_data2, &dex_virtual_methods2, &dex_direct_methods2, &dex_static_fields2, 4195 &dex_instance_fields2); 4196 4197 if (dex_virtual_methods1 != dex_virtual_methods2) { 4198 std::string class_dump = DumpClasses(dex_file1, dex_class_def1, dex_file2, dex_class_def2); 4199 *error_msg = StringPrintf("Virtual method count off: %zu vs %zu\n%s", dex_virtual_methods1, 4200 dex_virtual_methods2, class_dump.c_str()); 4201 return false; 4202 } 4203 if (dex_direct_methods1 != dex_direct_methods2) { 4204 std::string class_dump = DumpClasses(dex_file1, dex_class_def1, dex_file2, dex_class_def2); 4205 *error_msg = StringPrintf("Direct method count off: %zu vs %zu\n%s", dex_direct_methods1, 4206 dex_direct_methods2, class_dump.c_str()); 4207 return false; 4208 } 4209 if (dex_static_fields1 != dex_static_fields2) { 4210 std::string class_dump = DumpClasses(dex_file1, dex_class_def1, dex_file2, dex_class_def2); 4211 *error_msg = StringPrintf("Static field count off: %zu vs %zu\n%s", dex_static_fields1, 4212 dex_static_fields2, class_dump.c_str()); 4213 return false; 4214 } 4215 if (dex_instance_fields1 != dex_instance_fields2) { 4216 std::string class_dump = DumpClasses(dex_file1, dex_class_def1, dex_file2, dex_class_def2); 4217 *error_msg = StringPrintf("Instance field count off: %zu vs %zu\n%s", dex_instance_fields1, 4218 dex_instance_fields2, class_dump.c_str()); 4219 return false; 4220 } 4221 4222 return true; 4223} 4224 4225// Checks whether a the super-class changed from what we had at compile-time. This would 4226// invalidate quickening. 4227static bool CheckSuperClassChange(Handle<mirror::Class> klass, 4228 const DexFile& dex_file, 4229 const DexFile::ClassDef& class_def, 4230 mirror::Class* super_class) 4231 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 4232 // Check for unexpected changes in the superclass. 4233 // Quick check 1) is the super_class class-loader the boot class loader? This always has 4234 // precedence. 4235 if (super_class->GetClassLoader() != nullptr && 4236 // Quick check 2) different dex cache? Breaks can only occur for different dex files, 4237 // which is implied by different dex cache. 4238 klass->GetDexCache() != super_class->GetDexCache()) { 4239 // Now comes the expensive part: things can be broken if (a) the klass' dex file has a 4240 // definition for the super-class, and (b) the files are in separate oat files. The oat files 4241 // are referenced from the dex file, so do (b) first. Only relevant if we have oat files. 4242 const OatDexFile* class_oat_dex_file = dex_file.GetOatDexFile(); 4243 const OatFile* class_oat_file = nullptr; 4244 if (class_oat_dex_file != nullptr) { 4245 class_oat_file = class_oat_dex_file->GetOatFile(); 4246 } 4247 4248 if (class_oat_file != nullptr) { 4249 const OatDexFile* loaded_super_oat_dex_file = super_class->GetDexFile().GetOatDexFile(); 4250 const OatFile* loaded_super_oat_file = nullptr; 4251 if (loaded_super_oat_dex_file != nullptr) { 4252 loaded_super_oat_file = loaded_super_oat_dex_file->GetOatFile(); 4253 } 4254 4255 if (loaded_super_oat_file != nullptr && class_oat_file != loaded_super_oat_file) { 4256 // Now check (a). 4257 const DexFile::ClassDef* super_class_def = dex_file.FindClassDef(class_def.superclass_idx_); 4258 if (super_class_def != nullptr) { 4259 // Uh-oh, we found something. Do our check. 4260 std::string error_msg; 4261 if (!SimpleStructuralCheck(dex_file, *super_class_def, 4262 super_class->GetDexFile(), *super_class->GetClassDef(), 4263 &error_msg)) { 4264 // Print a warning to the log. This exception might be caught, e.g., as common in test 4265 // drivers. When the class is later tried to be used, we re-throw a new instance, as we 4266 // only save the type of the exception. 4267 LOG(WARNING) << "Incompatible structural change detected: " << 4268 StringPrintf( 4269 "Structural change of %s is hazardous (%s at compile time, %s at runtime): %s", 4270 PrettyType(super_class_def->class_idx_, dex_file).c_str(), 4271 class_oat_file->GetLocation().c_str(), 4272 loaded_super_oat_file->GetLocation().c_str(), 4273 error_msg.c_str()); 4274 ThrowIncompatibleClassChangeError(klass.Get(), 4275 "Structural change of %s is hazardous (%s at compile time, %s at runtime): %s", 4276 PrettyType(super_class_def->class_idx_, dex_file).c_str(), 4277 class_oat_file->GetLocation().c_str(), 4278 loaded_super_oat_file->GetLocation().c_str(), 4279 error_msg.c_str()); 4280 return false; 4281 } 4282 } 4283 } 4284 } 4285 } 4286 return true; 4287} 4288 4289bool ClassLinker::LoadSuperAndInterfaces(Handle<mirror::Class> klass, const DexFile& dex_file) { 4290 CHECK_EQ(mirror::Class::kStatusIdx, klass->GetStatus()); 4291 const DexFile::ClassDef& class_def = dex_file.GetClassDef(klass->GetDexClassDefIndex()); 4292 uint16_t super_class_idx = class_def.superclass_idx_; 4293 if (super_class_idx != DexFile::kDexNoIndex16) { 4294 mirror::Class* super_class = ResolveType(dex_file, super_class_idx, klass.Get()); 4295 if (super_class == nullptr) { 4296 DCHECK(Thread::Current()->IsExceptionPending()); 4297 return false; 4298 } 4299 // Verify 4300 if (!klass->CanAccess(super_class)) { 4301 ThrowIllegalAccessError(klass.Get(), "Class %s extended by class %s is inaccessible", 4302 PrettyDescriptor(super_class).c_str(), 4303 PrettyDescriptor(klass.Get()).c_str()); 4304 return false; 4305 } 4306 CHECK(super_class->IsResolved()); 4307 klass->SetSuperClass(super_class); 4308 4309 if (!CheckSuperClassChange(klass, dex_file, class_def, super_class)) { 4310 DCHECK(Thread::Current()->IsExceptionPending()); 4311 return false; 4312 } 4313 } 4314 const DexFile::TypeList* interfaces = dex_file.GetInterfacesList(class_def); 4315 if (interfaces != nullptr) { 4316 for (size_t i = 0; i < interfaces->Size(); i++) { 4317 uint16_t idx = interfaces->GetTypeItem(i).type_idx_; 4318 mirror::Class* interface = ResolveType(dex_file, idx, klass.Get()); 4319 if (interface == nullptr) { 4320 DCHECK(Thread::Current()->IsExceptionPending()); 4321 return false; 4322 } 4323 // Verify 4324 if (!klass->CanAccess(interface)) { 4325 // TODO: the RI seemed to ignore this in my testing. 4326 ThrowIllegalAccessError(klass.Get(), "Interface %s implemented by class %s is inaccessible", 4327 PrettyDescriptor(interface).c_str(), 4328 PrettyDescriptor(klass.Get()).c_str()); 4329 return false; 4330 } 4331 } 4332 } 4333 // Mark the class as loaded. 4334 mirror::Class::SetStatus(klass, mirror::Class::kStatusLoaded, nullptr); 4335 return true; 4336} 4337 4338bool ClassLinker::LinkSuperClass(Handle<mirror::Class> klass) { 4339 CHECK(!klass->IsPrimitive()); 4340 mirror::Class* super = klass->GetSuperClass(); 4341 if (klass.Get() == GetClassRoot(kJavaLangObject)) { 4342 if (super != nullptr) { 4343 ThrowClassFormatError(klass.Get(), "java.lang.Object must not have a superclass"); 4344 return false; 4345 } 4346 return true; 4347 } 4348 if (super == nullptr) { 4349 ThrowLinkageError(klass.Get(), "No superclass defined for class %s", 4350 PrettyDescriptor(klass.Get()).c_str()); 4351 return false; 4352 } 4353 // Verify 4354 if (super->IsFinal() || super->IsInterface()) { 4355 ThrowIncompatibleClassChangeError(klass.Get(), "Superclass %s of %s is %s", 4356 PrettyDescriptor(super).c_str(), 4357 PrettyDescriptor(klass.Get()).c_str(), 4358 super->IsFinal() ? "declared final" : "an interface"); 4359 return false; 4360 } 4361 if (!klass->CanAccess(super)) { 4362 ThrowIllegalAccessError(klass.Get(), "Superclass %s is inaccessible to class %s", 4363 PrettyDescriptor(super).c_str(), 4364 PrettyDescriptor(klass.Get()).c_str()); 4365 return false; 4366 } 4367 4368 // Inherit kAccClassIsFinalizable from the superclass in case this 4369 // class doesn't override finalize. 4370 if (super->IsFinalizable()) { 4371 klass->SetFinalizable(); 4372 } 4373 4374 // Inherit reference flags (if any) from the superclass. 4375 int reference_flags = (super->GetAccessFlags() & kAccReferenceFlagsMask); 4376 if (reference_flags != 0) { 4377 klass->SetAccessFlags(klass->GetAccessFlags() | reference_flags); 4378 } 4379 // Disallow custom direct subclasses of java.lang.ref.Reference. 4380 if (init_done_ && super == GetClassRoot(kJavaLangRefReference)) { 4381 ThrowLinkageError(klass.Get(), 4382 "Class %s attempts to subclass java.lang.ref.Reference, which is not allowed", 4383 PrettyDescriptor(klass.Get()).c_str()); 4384 return false; 4385 } 4386 4387 if (kIsDebugBuild) { 4388 // Ensure super classes are fully resolved prior to resolving fields.. 4389 while (super != nullptr) { 4390 CHECK(super->IsResolved()); 4391 super = super->GetSuperClass(); 4392 } 4393 } 4394 return true; 4395} 4396 4397// Populate the class vtable and itable. Compute return type indices. 4398bool ClassLinker::LinkMethods(Thread* self, Handle<mirror::Class> klass, 4399 Handle<mirror::ObjectArray<mirror::Class>> interfaces, 4400 ArtMethod** out_imt) { 4401 self->AllowThreadSuspension(); 4402 if (klass->IsInterface()) { 4403 // No vtable. 4404 size_t count = klass->NumVirtualMethods(); 4405 if (!IsUint<16>(count)) { 4406 ThrowClassFormatError(klass.Get(), "Too many methods on interface: %zd", count); 4407 return false; 4408 } 4409 for (size_t i = 0; i < count; ++i) { 4410 klass->GetVirtualMethodDuringLinking(i, image_pointer_size_)->SetMethodIndex(i); 4411 } 4412 } else if (!LinkVirtualMethods(self, klass)) { // Link virtual methods first. 4413 return false; 4414 } 4415 return LinkInterfaceMethods(self, klass, interfaces, out_imt); // Link interface method last. 4416} 4417 4418// Comparator for name and signature of a method, used in finding overriding methods. Implementation 4419// avoids the use of handles, if it didn't then rather than compare dex files we could compare dex 4420// caches in the implementation below. 4421class MethodNameAndSignatureComparator FINAL : public ValueObject { 4422 public: 4423 explicit MethodNameAndSignatureComparator(ArtMethod* method) 4424 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) : 4425 dex_file_(method->GetDexFile()), mid_(&dex_file_->GetMethodId(method->GetDexMethodIndex())), 4426 name_(nullptr), name_len_(0) { 4427 DCHECK(!method->IsProxyMethod()) << PrettyMethod(method); 4428 } 4429 4430 const char* GetName() { 4431 if (name_ == nullptr) { 4432 name_ = dex_file_->StringDataAndUtf16LengthByIdx(mid_->name_idx_, &name_len_); 4433 } 4434 return name_; 4435 } 4436 4437 bool HasSameNameAndSignature(ArtMethod* other) 4438 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 4439 DCHECK(!other->IsProxyMethod()) << PrettyMethod(other); 4440 const DexFile* other_dex_file = other->GetDexFile(); 4441 const DexFile::MethodId& other_mid = other_dex_file->GetMethodId(other->GetDexMethodIndex()); 4442 if (dex_file_ == other_dex_file) { 4443 return mid_->name_idx_ == other_mid.name_idx_ && mid_->proto_idx_ == other_mid.proto_idx_; 4444 } 4445 GetName(); // Only used to make sure its calculated. 4446 uint32_t other_name_len; 4447 const char* other_name = other_dex_file->StringDataAndUtf16LengthByIdx(other_mid.name_idx_, 4448 &other_name_len); 4449 if (name_len_ != other_name_len || strcmp(name_, other_name) != 0) { 4450 return false; 4451 } 4452 return dex_file_->GetMethodSignature(*mid_) == other_dex_file->GetMethodSignature(other_mid); 4453 } 4454 4455 private: 4456 // Dex file for the method to compare against. 4457 const DexFile* const dex_file_; 4458 // MethodId for the method to compare against. 4459 const DexFile::MethodId* const mid_; 4460 // Lazily computed name from the dex file's strings. 4461 const char* name_; 4462 // Lazily computed name length. 4463 uint32_t name_len_; 4464}; 4465 4466class LinkVirtualHashTable { 4467 public: 4468 LinkVirtualHashTable(Handle<mirror::Class> klass, size_t hash_size, uint32_t* hash_table, 4469 size_t image_pointer_size) 4470 : klass_(klass), hash_size_(hash_size), hash_table_(hash_table), 4471 image_pointer_size_(image_pointer_size) { 4472 std::fill(hash_table_, hash_table_ + hash_size_, invalid_index_); 4473 } 4474 void Add(uint32_t virtual_method_index) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 4475 ArtMethod* local_method = klass_->GetVirtualMethodDuringLinking( 4476 virtual_method_index, image_pointer_size_); 4477 const char* name = local_method->GetInterfaceMethodIfProxy(image_pointer_size_)->GetName(); 4478 uint32_t hash = ComputeModifiedUtf8Hash(name); 4479 uint32_t index = hash % hash_size_; 4480 // Linear probe until we have an empty slot. 4481 while (hash_table_[index] != invalid_index_) { 4482 if (++index == hash_size_) { 4483 index = 0; 4484 } 4485 } 4486 hash_table_[index] = virtual_method_index; 4487 } 4488 uint32_t FindAndRemove(MethodNameAndSignatureComparator* comparator) 4489 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 4490 const char* name = comparator->GetName(); 4491 uint32_t hash = ComputeModifiedUtf8Hash(name); 4492 size_t index = hash % hash_size_; 4493 while (true) { 4494 const uint32_t value = hash_table_[index]; 4495 // Since linear probe makes continuous blocks, hitting an invalid index means we are done 4496 // the block and can safely assume not found. 4497 if (value == invalid_index_) { 4498 break; 4499 } 4500 if (value != removed_index_) { // This signifies not already overriden. 4501 ArtMethod* virtual_method = 4502 klass_->GetVirtualMethodDuringLinking(value, image_pointer_size_); 4503 if (comparator->HasSameNameAndSignature( 4504 virtual_method->GetInterfaceMethodIfProxy(image_pointer_size_))) { 4505 hash_table_[index] = removed_index_; 4506 return value; 4507 } 4508 } 4509 if (++index == hash_size_) { 4510 index = 0; 4511 } 4512 } 4513 return GetNotFoundIndex(); 4514 } 4515 static uint32_t GetNotFoundIndex() { 4516 return invalid_index_; 4517 } 4518 4519 private: 4520 static const uint32_t invalid_index_; 4521 static const uint32_t removed_index_; 4522 4523 Handle<mirror::Class> klass_; 4524 const size_t hash_size_; 4525 uint32_t* const hash_table_; 4526 const size_t image_pointer_size_; 4527}; 4528 4529const uint32_t LinkVirtualHashTable::invalid_index_ = std::numeric_limits<uint32_t>::max(); 4530const uint32_t LinkVirtualHashTable::removed_index_ = std::numeric_limits<uint32_t>::max() - 1; 4531 4532bool ClassLinker::LinkVirtualMethods(Thread* self, Handle<mirror::Class> klass) { 4533 const size_t num_virtual_methods = klass->NumVirtualMethods(); 4534 if (klass->HasSuperClass()) { 4535 const size_t super_vtable_length = klass->GetSuperClass()->GetVTableLength(); 4536 const size_t max_count = num_virtual_methods + super_vtable_length; 4537 StackHandleScope<2> hs(self); 4538 Handle<mirror::Class> super_class(hs.NewHandle(klass->GetSuperClass())); 4539 MutableHandle<mirror::PointerArray> vtable; 4540 if (super_class->ShouldHaveEmbeddedImtAndVTable()) { 4541 vtable = hs.NewHandle(AllocPointerArray(self, max_count)); 4542 if (UNLIKELY(vtable.Get() == nullptr)) { 4543 self->AssertPendingOOMException(); 4544 return false; 4545 } 4546 for (size_t i = 0; i < super_vtable_length; i++) { 4547 vtable->SetElementPtrSize( 4548 i, super_class->GetEmbeddedVTableEntry(i, image_pointer_size_), image_pointer_size_); 4549 } 4550 if (num_virtual_methods == 0) { 4551 klass->SetVTable(vtable.Get()); 4552 return true; 4553 } 4554 } else { 4555 auto* super_vtable = super_class->GetVTable(); 4556 CHECK(super_vtable != nullptr) << PrettyClass(super_class.Get()); 4557 if (num_virtual_methods == 0) { 4558 klass->SetVTable(super_vtable); 4559 return true; 4560 } 4561 vtable = hs.NewHandle(down_cast<mirror::PointerArray*>( 4562 super_vtable->CopyOf(self, max_count))); 4563 if (UNLIKELY(vtable.Get() == nullptr)) { 4564 self->AssertPendingOOMException(); 4565 return false; 4566 } 4567 } 4568 // How the algorithm works: 4569 // 1. Populate hash table by adding num_virtual_methods from klass. The values in the hash 4570 // table are: invalid_index for unused slots, index super_vtable_length + i for a virtual 4571 // method which has not been matched to a vtable method, and j if the virtual method at the 4572 // index overrode the super virtual method at index j. 4573 // 2. Loop through super virtual methods, if they overwrite, update hash table to j 4574 // (j < super_vtable_length) to avoid redundant checks. (TODO maybe use this info for reducing 4575 // the need for the initial vtable which we later shrink back down). 4576 // 3. Add non overridden methods to the end of the vtable. 4577 static constexpr size_t kMaxStackHash = 250; 4578 const size_t hash_table_size = num_virtual_methods * 3; 4579 uint32_t* hash_table_ptr; 4580 std::unique_ptr<uint32_t[]> hash_heap_storage; 4581 if (hash_table_size <= kMaxStackHash) { 4582 hash_table_ptr = reinterpret_cast<uint32_t*>( 4583 alloca(hash_table_size * sizeof(*hash_table_ptr))); 4584 } else { 4585 hash_heap_storage.reset(new uint32_t[hash_table_size]); 4586 hash_table_ptr = hash_heap_storage.get(); 4587 } 4588 LinkVirtualHashTable hash_table(klass, hash_table_size, hash_table_ptr, image_pointer_size_); 4589 // Add virtual methods to the hash table. 4590 for (size_t i = 0; i < num_virtual_methods; ++i) { 4591 DCHECK(klass->GetVirtualMethodDuringLinking( 4592 i, image_pointer_size_)->GetDeclaringClass() != nullptr); 4593 hash_table.Add(i); 4594 } 4595 // Loop through each super vtable method and see if they are overriden by a method we added to 4596 // the hash table. 4597 for (size_t j = 0; j < super_vtable_length; ++j) { 4598 // Search the hash table to see if we are overidden by any method. 4599 ArtMethod* super_method = vtable->GetElementPtrSize<ArtMethod*>(j, image_pointer_size_); 4600 MethodNameAndSignatureComparator super_method_name_comparator( 4601 super_method->GetInterfaceMethodIfProxy(image_pointer_size_)); 4602 uint32_t hash_index = hash_table.FindAndRemove(&super_method_name_comparator); 4603 if (hash_index != hash_table.GetNotFoundIndex()) { 4604 ArtMethod* virtual_method = klass->GetVirtualMethodDuringLinking( 4605 hash_index, image_pointer_size_); 4606 if (klass->CanAccessMember(super_method->GetDeclaringClass(), 4607 super_method->GetAccessFlags())) { 4608 if (super_method->IsFinal()) { 4609 ThrowLinkageError(klass.Get(), "Method %s overrides final method in class %s", 4610 PrettyMethod(virtual_method).c_str(), 4611 super_method->GetDeclaringClassDescriptor()); 4612 return false; 4613 } 4614 vtable->SetElementPtrSize(j, virtual_method, image_pointer_size_); 4615 virtual_method->SetMethodIndex(j); 4616 } else { 4617 LOG(WARNING) << "Before Android 4.1, method " << PrettyMethod(virtual_method) 4618 << " would have incorrectly overridden the package-private method in " 4619 << PrettyDescriptor(super_method->GetDeclaringClassDescriptor()); 4620 } 4621 } 4622 } 4623 // Add the non overridden methods at the end. 4624 size_t actual_count = super_vtable_length; 4625 for (size_t i = 0; i < num_virtual_methods; ++i) { 4626 ArtMethod* local_method = klass->GetVirtualMethodDuringLinking(i, image_pointer_size_); 4627 size_t method_idx = local_method->GetMethodIndexDuringLinking(); 4628 if (method_idx < super_vtable_length && 4629 local_method == vtable->GetElementPtrSize<ArtMethod*>(method_idx, image_pointer_size_)) { 4630 continue; 4631 } 4632 vtable->SetElementPtrSize(actual_count, local_method, image_pointer_size_); 4633 local_method->SetMethodIndex(actual_count); 4634 ++actual_count; 4635 } 4636 if (!IsUint<16>(actual_count)) { 4637 ThrowClassFormatError(klass.Get(), "Too many methods defined on class: %zd", actual_count); 4638 return false; 4639 } 4640 // Shrink vtable if possible 4641 CHECK_LE(actual_count, max_count); 4642 if (actual_count < max_count) { 4643 vtable.Assign(down_cast<mirror::PointerArray*>(vtable->CopyOf(self, actual_count))); 4644 if (UNLIKELY(vtable.Get() == nullptr)) { 4645 self->AssertPendingOOMException(); 4646 return false; 4647 } 4648 } 4649 klass->SetVTable(vtable.Get()); 4650 } else { 4651 CHECK_EQ(klass.Get(), GetClassRoot(kJavaLangObject)); 4652 if (!IsUint<16>(num_virtual_methods)) { 4653 ThrowClassFormatError(klass.Get(), "Too many methods: %d", 4654 static_cast<int>(num_virtual_methods)); 4655 return false; 4656 } 4657 auto* vtable = AllocPointerArray(self, num_virtual_methods); 4658 if (UNLIKELY(vtable == nullptr)) { 4659 self->AssertPendingOOMException(); 4660 return false; 4661 } 4662 for (size_t i = 0; i < num_virtual_methods; ++i) { 4663 ArtMethod* virtual_method = klass->GetVirtualMethodDuringLinking(i, image_pointer_size_); 4664 vtable->SetElementPtrSize(i, virtual_method, image_pointer_size_); 4665 virtual_method->SetMethodIndex(i & 0xFFFF); 4666 } 4667 klass->SetVTable(vtable); 4668 } 4669 return true; 4670} 4671 4672bool ClassLinker::LinkInterfaceMethods(Thread* self, Handle<mirror::Class> klass, 4673 Handle<mirror::ObjectArray<mirror::Class>> interfaces, 4674 ArtMethod** out_imt) { 4675 StackHandleScope<3> hs(self); 4676 Runtime* const runtime = Runtime::Current(); 4677 const bool has_superclass = klass->HasSuperClass(); 4678 const size_t super_ifcount = has_superclass ? klass->GetSuperClass()->GetIfTableCount() : 0U; 4679 const bool have_interfaces = interfaces.Get() != nullptr; 4680 const size_t num_interfaces = 4681 have_interfaces ? interfaces->GetLength() : klass->NumDirectInterfaces(); 4682 const size_t method_size = ArtMethod::ObjectSize(image_pointer_size_); 4683 if (num_interfaces == 0) { 4684 if (super_ifcount == 0) { 4685 // Class implements no interfaces. 4686 DCHECK_EQ(klass->GetIfTableCount(), 0); 4687 DCHECK(klass->GetIfTable() == nullptr); 4688 return true; 4689 } 4690 // Class implements same interfaces as parent, are any of these not marker interfaces? 4691 bool has_non_marker_interface = false; 4692 mirror::IfTable* super_iftable = klass->GetSuperClass()->GetIfTable(); 4693 for (size_t i = 0; i < super_ifcount; ++i) { 4694 if (super_iftable->GetMethodArrayCount(i) > 0) { 4695 has_non_marker_interface = true; 4696 break; 4697 } 4698 } 4699 // Class just inherits marker interfaces from parent so recycle parent's iftable. 4700 if (!has_non_marker_interface) { 4701 klass->SetIfTable(super_iftable); 4702 return true; 4703 } 4704 } 4705 size_t ifcount = super_ifcount + num_interfaces; 4706 for (size_t i = 0; i < num_interfaces; i++) { 4707 mirror::Class* interface = have_interfaces ? 4708 interfaces->GetWithoutChecks(i) : mirror::Class::GetDirectInterface(self, klass, i); 4709 DCHECK(interface != nullptr); 4710 if (UNLIKELY(!interface->IsInterface())) { 4711 std::string temp; 4712 ThrowIncompatibleClassChangeError(klass.Get(), "Class %s implements non-interface class %s", 4713 PrettyDescriptor(klass.Get()).c_str(), 4714 PrettyDescriptor(interface->GetDescriptor(&temp)).c_str()); 4715 return false; 4716 } 4717 ifcount += interface->GetIfTableCount(); 4718 } 4719 MutableHandle<mirror::IfTable> iftable(hs.NewHandle(AllocIfTable(self, ifcount))); 4720 if (UNLIKELY(iftable.Get() == nullptr)) { 4721 self->AssertPendingOOMException(); 4722 return false; 4723 } 4724 if (super_ifcount != 0) { 4725 mirror::IfTable* super_iftable = klass->GetSuperClass()->GetIfTable(); 4726 for (size_t i = 0; i < super_ifcount; i++) { 4727 mirror::Class* super_interface = super_iftable->GetInterface(i); 4728 iftable->SetInterface(i, super_interface); 4729 } 4730 } 4731 self->AllowThreadSuspension(); 4732 // Flatten the interface inheritance hierarchy. 4733 size_t idx = super_ifcount; 4734 for (size_t i = 0; i < num_interfaces; i++) { 4735 mirror::Class* interface = have_interfaces ? interfaces->Get(i) : 4736 mirror::Class::GetDirectInterface(self, klass, i); 4737 // Check if interface is already in iftable 4738 bool duplicate = false; 4739 for (size_t j = 0; j < idx; j++) { 4740 mirror::Class* existing_interface = iftable->GetInterface(j); 4741 if (existing_interface == interface) { 4742 duplicate = true; 4743 break; 4744 } 4745 } 4746 if (!duplicate) { 4747 // Add this non-duplicate interface. 4748 iftable->SetInterface(idx++, interface); 4749 // Add this interface's non-duplicate super-interfaces. 4750 for (int32_t j = 0; j < interface->GetIfTableCount(); j++) { 4751 mirror::Class* super_interface = interface->GetIfTable()->GetInterface(j); 4752 bool super_duplicate = false; 4753 for (size_t k = 0; k < idx; k++) { 4754 mirror::Class* existing_interface = iftable->GetInterface(k); 4755 if (existing_interface == super_interface) { 4756 super_duplicate = true; 4757 break; 4758 } 4759 } 4760 if (!super_duplicate) { 4761 iftable->SetInterface(idx++, super_interface); 4762 } 4763 } 4764 } 4765 } 4766 self->AllowThreadSuspension(); 4767 // Shrink iftable in case duplicates were found 4768 if (idx < ifcount) { 4769 DCHECK_NE(num_interfaces, 0U); 4770 iftable.Assign(down_cast<mirror::IfTable*>( 4771 iftable->CopyOf(self, idx * mirror::IfTable::kMax))); 4772 if (UNLIKELY(iftable.Get() == nullptr)) { 4773 self->AssertPendingOOMException(); 4774 return false; 4775 } 4776 ifcount = idx; 4777 } else { 4778 DCHECK_EQ(idx, ifcount); 4779 } 4780 klass->SetIfTable(iftable.Get()); 4781 // If we're an interface, we don't need the vtable pointers, so we're done. 4782 if (klass->IsInterface()) { 4783 return true; 4784 } 4785 // These are allocated on the heap to begin, we then transfer to linear alloc when we re-create 4786 // the virtual methods array. 4787 // Need to use low 4GB arenas for compiler or else the pointers wont fit in 32 bit method array 4788 // during cross compilation. 4789 // Use the linear alloc pool since this one is in the low 4gb for the compiler. 4790 ArenaStack stack(runtime->GetLinearAlloc()->GetArenaPool()); 4791 ScopedArenaAllocator allocator(&stack); 4792 ScopedArenaVector<ArtMethod*> miranda_methods(allocator.Adapter()); 4793 4794 MutableHandle<mirror::PointerArray> vtable(hs.NewHandle(klass->GetVTableDuringLinking())); 4795 ArtMethod* const unimplemented_method = runtime->GetImtUnimplementedMethod(); 4796 ArtMethod* const conflict_method = runtime->GetImtConflictMethod(); 4797 // Copy the IMT from the super class if possible. 4798 bool extend_super_iftable = false; 4799 if (has_superclass) { 4800 mirror::Class* super_class = klass->GetSuperClass(); 4801 extend_super_iftable = true; 4802 if (super_class->ShouldHaveEmbeddedImtAndVTable()) { 4803 for (size_t i = 0; i < mirror::Class::kImtSize; ++i) { 4804 out_imt[i] = super_class->GetEmbeddedImTableEntry(i, image_pointer_size_); 4805 } 4806 } else { 4807 // No imt in the super class, need to reconstruct from the iftable. 4808 mirror::IfTable* if_table = super_class->GetIfTable(); 4809 const size_t length = super_class->GetIfTableCount(); 4810 for (size_t i = 0; i < length; ++i) { 4811 mirror::Class* interface = iftable->GetInterface(i); 4812 const size_t num_virtuals = interface->NumVirtualMethods(); 4813 const size_t method_array_count = if_table->GetMethodArrayCount(i); 4814 DCHECK_EQ(num_virtuals, method_array_count); 4815 if (method_array_count == 0) { 4816 continue; 4817 } 4818 auto* method_array = if_table->GetMethodArray(i); 4819 for (size_t j = 0; j < num_virtuals; ++j) { 4820 auto method = method_array->GetElementPtrSize<ArtMethod*>(j, image_pointer_size_); 4821 DCHECK(method != nullptr) << PrettyClass(super_class); 4822 if (method->IsMiranda()) { 4823 continue; 4824 } 4825 ArtMethod* interface_method = interface->GetVirtualMethod(j, image_pointer_size_); 4826 uint32_t imt_index = interface_method->GetDexMethodIndex() % mirror::Class::kImtSize; 4827 auto*& imt_ref = out_imt[imt_index]; 4828 if (imt_ref == unimplemented_method) { 4829 imt_ref = method; 4830 } else if (imt_ref != conflict_method) { 4831 imt_ref = conflict_method; 4832 } 4833 } 4834 } 4835 } 4836 } 4837 // Allocate method arrays before since we don't want miss visiting miranda method roots due to 4838 // thread suspension. 4839 for (size_t i = 0; i < ifcount; ++i) { 4840 size_t num_methods = iftable->GetInterface(i)->NumVirtualMethods(); 4841 if (num_methods > 0) { 4842 const bool is_super = i < super_ifcount; 4843 const bool super_interface = is_super && extend_super_iftable; 4844 mirror::PointerArray* method_array; 4845 if (super_interface) { 4846 mirror::IfTable* if_table = klass->GetSuperClass()->GetIfTable(); 4847 DCHECK(if_table != nullptr); 4848 DCHECK(if_table->GetMethodArray(i) != nullptr); 4849 // If we are working on a super interface, try extending the existing method array. 4850 method_array = down_cast<mirror::PointerArray*>(if_table->GetMethodArray(i)->Clone(self)); 4851 } else { 4852 method_array = AllocPointerArray(self, num_methods); 4853 } 4854 if (UNLIKELY(method_array == nullptr)) { 4855 self->AssertPendingOOMException(); 4856 return false; 4857 } 4858 iftable->SetMethodArray(i, method_array); 4859 } 4860 } 4861 4862 auto* old_cause = self->StartAssertNoThreadSuspension( 4863 "Copying ArtMethods for LinkInterfaceMethods"); 4864 for (size_t i = 0; i < ifcount; ++i) { 4865 size_t num_methods = iftable->GetInterface(i)->NumVirtualMethods(); 4866 if (num_methods > 0) { 4867 StackHandleScope<2> hs2(self); 4868 const bool is_super = i < super_ifcount; 4869 const bool super_interface = is_super && extend_super_iftable; 4870 auto method_array(hs2.NewHandle(iftable->GetMethodArray(i))); 4871 4872 ArtMethod* input_virtual_methods = nullptr; 4873 Handle<mirror::PointerArray> input_vtable_array = NullHandle<mirror::PointerArray>(); 4874 int32_t input_array_length = 0; 4875 if (super_interface) { 4876 // We are overwriting a super class interface, try to only virtual methods instead of the 4877 // whole vtable. 4878 input_virtual_methods = klass->GetVirtualMethodsPtr(); 4879 input_array_length = klass->NumVirtualMethods(); 4880 } else { 4881 // A new interface, we need the whole vtable in case a new interface method is implemented 4882 // in the whole superclass. 4883 input_vtable_array = vtable; 4884 input_array_length = input_vtable_array->GetLength(); 4885 } 4886 if (input_array_length == 0) { 4887 // If the added virtual methods is empty, do nothing. 4888 DCHECK(super_interface); 4889 continue; 4890 } 4891 for (size_t j = 0; j < num_methods; ++j) { 4892 auto* interface_method = iftable->GetInterface(i)->GetVirtualMethod( 4893 j, image_pointer_size_); 4894 MethodNameAndSignatureComparator interface_name_comparator( 4895 interface_method->GetInterfaceMethodIfProxy(image_pointer_size_)); 4896 int32_t k; 4897 // For each method listed in the interface's method list, find the 4898 // matching method in our class's method list. We want to favor the 4899 // subclass over the superclass, which just requires walking 4900 // back from the end of the vtable. (This only matters if the 4901 // superclass defines a private method and this class redefines 4902 // it -- otherwise it would use the same vtable slot. In .dex files 4903 // those don't end up in the virtual method table, so it shouldn't 4904 // matter which direction we go. We walk it backward anyway.) 4905 for (k = input_array_length - 1; k >= 0; --k) { 4906 ArtMethod* vtable_method = input_virtual_methods != nullptr ? 4907 reinterpret_cast<ArtMethod*>( 4908 reinterpret_cast<uintptr_t>(input_virtual_methods) + method_size * k) : 4909 input_vtable_array->GetElementPtrSize<ArtMethod*>(k, image_pointer_size_); 4910 ArtMethod* vtable_method_for_name_comparison = 4911 vtable_method->GetInterfaceMethodIfProxy(image_pointer_size_); 4912 if (interface_name_comparator.HasSameNameAndSignature( 4913 vtable_method_for_name_comparison)) { 4914 if (!vtable_method->IsAbstract() && !vtable_method->IsPublic()) { 4915 // Must do EndAssertNoThreadSuspension before throw since the throw can cause 4916 // allocations. 4917 self->EndAssertNoThreadSuspension(old_cause); 4918 ThrowIllegalAccessError(klass.Get(), 4919 "Method '%s' implementing interface method '%s' is not public", 4920 PrettyMethod(vtable_method).c_str(), PrettyMethod(interface_method).c_str()); 4921 return false; 4922 } 4923 method_array->SetElementPtrSize(j, vtable_method, image_pointer_size_); 4924 // Place method in imt if entry is empty, place conflict otherwise. 4925 uint32_t imt_index = interface_method->GetDexMethodIndex() % mirror::Class::kImtSize; 4926 auto** imt_ref = &out_imt[imt_index]; 4927 if (*imt_ref == unimplemented_method) { 4928 *imt_ref = vtable_method; 4929 } else if (*imt_ref != conflict_method) { 4930 // If we are not a conflict and we have the same signature and name as the imt entry, 4931 // it must be that we overwrote a superclass vtable entry. 4932 MethodNameAndSignatureComparator imt_comparator( 4933 (*imt_ref)->GetInterfaceMethodIfProxy(image_pointer_size_)); 4934 *imt_ref = imt_comparator.HasSameNameAndSignature(vtable_method_for_name_comparison) ? 4935 vtable_method : conflict_method; 4936 } 4937 break; 4938 } 4939 } 4940 if (k < 0 && !super_interface) { 4941 ArtMethod* miranda_method = nullptr; 4942 for (auto& mir_method : miranda_methods) { 4943 if (interface_name_comparator.HasSameNameAndSignature(mir_method)) { 4944 miranda_method = mir_method; 4945 break; 4946 } 4947 } 4948 if (miranda_method == nullptr) { 4949 miranda_method = reinterpret_cast<ArtMethod*>(allocator.Alloc(method_size)); 4950 CHECK(miranda_method != nullptr); 4951 // Point the interface table at a phantom slot. 4952 new(miranda_method) ArtMethod(*interface_method, image_pointer_size_); 4953 miranda_methods.push_back(miranda_method); 4954 } 4955 method_array->SetElementPtrSize(j, miranda_method, image_pointer_size_); 4956 } 4957 } 4958 } 4959 } 4960 if (!miranda_methods.empty()) { 4961 const size_t old_method_count = klass->NumVirtualMethods(); 4962 const size_t new_method_count = old_method_count + miranda_methods.size(); 4963 // Attempt to realloc to save RAM if possible. 4964 ArtMethod* old_virtuals = klass->GetVirtualMethodsPtr(); 4965 // The Realloced virtual methods aren't visiblef from the class roots, so there is no issue 4966 // where GCs could attempt to mark stale pointers due to memcpy. And since we overwrite the 4967 // realloced memory with out->CopyFrom, we are guaranteed to have objects in the to space since 4968 // CopyFrom has internal read barriers. 4969 auto* virtuals = reinterpret_cast<ArtMethod*>(runtime->GetLinearAlloc()->Realloc( 4970 self, old_virtuals, old_method_count * method_size, new_method_count * method_size)); 4971 if (UNLIKELY(virtuals == nullptr)) { 4972 self->AssertPendingOOMException(); 4973 return false; 4974 } 4975 ScopedArenaUnorderedMap<ArtMethod*, ArtMethod*> move_table(allocator.Adapter()); 4976 if (virtuals != old_virtuals) { 4977 // Maps from heap allocated miranda method to linear alloc miranda method. 4978 StrideIterator<ArtMethod> out(reinterpret_cast<uintptr_t>(virtuals), method_size); 4979 // Copy over the old methods + miranda methods. 4980 for (auto& m : klass->GetVirtualMethods(image_pointer_size_)) { 4981 move_table.emplace(&m, &*out); 4982 // The CopyFrom is only necessary to not miss read barriers since Realloc won't do read 4983 // barriers when it copies. 4984 out->CopyFrom(&m, image_pointer_size_); 4985 ++out; 4986 } 4987 } 4988 StrideIterator<ArtMethod> out( 4989 reinterpret_cast<uintptr_t>(virtuals) + old_method_count * method_size, method_size); 4990 // Copy over miranda methods before copying vtable since CopyOf may cause thread suspension and 4991 // we want the roots of the miranda methods to get visited. 4992 for (ArtMethod* mir_method : miranda_methods) { 4993 out->CopyFrom(mir_method, image_pointer_size_); 4994 out->SetAccessFlags(out->GetAccessFlags() | kAccMiranda); 4995 move_table.emplace(mir_method, &*out); 4996 ++out; 4997 } 4998 UpdateClassVirtualMethods(klass.Get(), virtuals, new_method_count); 4999 // Done copying methods, they are all roots in the class now, so we can end the no thread 5000 // suspension assert. 5001 self->EndAssertNoThreadSuspension(old_cause); 5002 5003 const size_t old_vtable_count = vtable->GetLength(); 5004 const size_t new_vtable_count = old_vtable_count + miranda_methods.size(); 5005 miranda_methods.clear(); 5006 vtable.Assign(down_cast<mirror::PointerArray*>(vtable->CopyOf(self, new_vtable_count))); 5007 if (UNLIKELY(vtable.Get() == nullptr)) { 5008 self->AssertPendingOOMException(); 5009 return false; 5010 } 5011 out = StrideIterator<ArtMethod>( 5012 reinterpret_cast<uintptr_t>(virtuals) + old_method_count * method_size, method_size); 5013 size_t vtable_pos = old_vtable_count; 5014 for (size_t i = old_method_count; i < new_method_count; ++i) { 5015 // Leave the declaring class alone as type indices are relative to it 5016 out->SetMethodIndex(0xFFFF & vtable_pos); 5017 vtable->SetElementPtrSize(vtable_pos, &*out, image_pointer_size_); 5018 ++out; 5019 ++vtable_pos; 5020 } 5021 CHECK_EQ(vtable_pos, new_vtable_count); 5022 // Update old vtable methods. 5023 for (size_t i = 0; i < old_vtable_count; ++i) { 5024 auto* m = vtable->GetElementPtrSize<ArtMethod*>(i, image_pointer_size_); 5025 DCHECK(m != nullptr) << PrettyClass(klass.Get()); 5026 auto it = move_table.find(m); 5027 if (it != move_table.end()) { 5028 auto* new_m = it->second; 5029 DCHECK(new_m != nullptr) << PrettyClass(klass.Get()); 5030 vtable->SetElementPtrSize(i, new_m, image_pointer_size_); 5031 } 5032 } 5033 klass->SetVTable(vtable.Get()); 5034 // Go fix up all the stale miranda pointers. 5035 for (size_t i = 0; i < ifcount; ++i) { 5036 for (size_t j = 0, count = iftable->GetMethodArrayCount(i); j < count; ++j) { 5037 auto* method_array = iftable->GetMethodArray(i); 5038 auto* m = method_array->GetElementPtrSize<ArtMethod*>(j, image_pointer_size_); 5039 DCHECK(m != nullptr) << PrettyClass(klass.Get()); 5040 auto it = move_table.find(m); 5041 if (it != move_table.end()) { 5042 auto* new_m = it->second; 5043 DCHECK(new_m != nullptr) << PrettyClass(klass.Get()); 5044 method_array->SetElementPtrSize(j, new_m, image_pointer_size_); 5045 } 5046 } 5047 } 5048 // Fix up IMT in case it has any miranda methods in it. 5049 for (size_t i = 0; i < mirror::Class::kImtSize; ++i) { 5050 auto it = move_table.find(out_imt[i]); 5051 if (it != move_table.end()) { 5052 out_imt[i] = it->second; 5053 } 5054 } 5055 // Check that there are no stale methods are in the dex cache array. 5056 if (kIsDebugBuild) { 5057 auto* resolved_methods = klass->GetDexCache()->GetResolvedMethods(); 5058 for (size_t i = 0, count = resolved_methods->GetLength(); i < count; ++i) { 5059 auto* m = resolved_methods->GetElementPtrSize<ArtMethod*>(i, image_pointer_size_); 5060 CHECK(move_table.find(m) == move_table.end()) << PrettyMethod(m); 5061 } 5062 } 5063 // Put some random garbage in old virtuals to help find stale pointers. 5064 if (virtuals != old_virtuals) { 5065 memset(old_virtuals, 0xFEu, ArtMethod::ObjectSize(image_pointer_size_) * old_method_count); 5066 } 5067 } else { 5068 self->EndAssertNoThreadSuspension(old_cause); 5069 } 5070 if (kIsDebugBuild) { 5071 auto* check_vtable = klass->GetVTableDuringLinking(); 5072 for (int i = 0; i < check_vtable->GetLength(); ++i) { 5073 CHECK(check_vtable->GetElementPtrSize<ArtMethod*>(i, image_pointer_size_) != nullptr); 5074 } 5075 } 5076 return true; 5077} 5078 5079bool ClassLinker::LinkInstanceFields(Thread* self, Handle<mirror::Class> klass) { 5080 CHECK(klass.Get() != nullptr); 5081 return LinkFields(self, klass, false, nullptr); 5082} 5083 5084bool ClassLinker::LinkStaticFields(Thread* self, Handle<mirror::Class> klass, size_t* class_size) { 5085 CHECK(klass.Get() != nullptr); 5086 return LinkFields(self, klass, true, class_size); 5087} 5088 5089struct LinkFieldsComparator { 5090 explicit LinkFieldsComparator() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 5091 } 5092 // No thread safety analysis as will be called from STL. Checked lock held in constructor. 5093 bool operator()(ArtField* field1, ArtField* field2) 5094 NO_THREAD_SAFETY_ANALYSIS { 5095 // First come reference fields, then 64-bit, then 32-bit, and then 16-bit, then finally 8-bit. 5096 Primitive::Type type1 = field1->GetTypeAsPrimitiveType(); 5097 Primitive::Type type2 = field2->GetTypeAsPrimitiveType(); 5098 if (type1 != type2) { 5099 if (type1 == Primitive::kPrimNot) { 5100 // Reference always goes first. 5101 return true; 5102 } 5103 if (type2 == Primitive::kPrimNot) { 5104 // Reference always goes first. 5105 return false; 5106 } 5107 size_t size1 = Primitive::ComponentSize(type1); 5108 size_t size2 = Primitive::ComponentSize(type2); 5109 if (size1 != size2) { 5110 // Larger primitive types go first. 5111 return size1 > size2; 5112 } 5113 // Primitive types differ but sizes match. Arbitrarily order by primitive type. 5114 return type1 < type2; 5115 } 5116 // Same basic group? Then sort by dex field index. This is guaranteed to be sorted 5117 // by name and for equal names by type id index. 5118 // NOTE: This works also for proxies. Their static fields are assigned appropriate indexes. 5119 return field1->GetDexFieldIndex() < field2->GetDexFieldIndex(); 5120 } 5121}; 5122 5123bool ClassLinker::LinkFields(Thread* self, Handle<mirror::Class> klass, bool is_static, 5124 size_t* class_size) { 5125 self->AllowThreadSuspension(); 5126 const size_t num_fields = is_static ? klass->NumStaticFields() : klass->NumInstanceFields(); 5127 ArtField* const fields = is_static ? klass->GetSFields() : klass->GetIFields(); 5128 5129 // Initialize field_offset 5130 MemberOffset field_offset(0); 5131 if (is_static) { 5132 field_offset = klass->GetFirstReferenceStaticFieldOffsetDuringLinking(image_pointer_size_); 5133 } else { 5134 mirror::Class* super_class = klass->GetSuperClass(); 5135 if (super_class != nullptr) { 5136 CHECK(super_class->IsResolved()) 5137 << PrettyClass(klass.Get()) << " " << PrettyClass(super_class); 5138 field_offset = MemberOffset(super_class->GetObjectSize()); 5139 } 5140 } 5141 5142 CHECK_EQ(num_fields == 0, fields == nullptr) << PrettyClass(klass.Get()); 5143 5144 // we want a relatively stable order so that adding new fields 5145 // minimizes disruption of C++ version such as Class and Method. 5146 std::deque<ArtField*> grouped_and_sorted_fields; 5147 const char* old_no_suspend_cause = self->StartAssertNoThreadSuspension( 5148 "Naked ArtField references in deque"); 5149 for (size_t i = 0; i < num_fields; i++) { 5150 grouped_and_sorted_fields.push_back(&fields[i]); 5151 } 5152 std::sort(grouped_and_sorted_fields.begin(), grouped_and_sorted_fields.end(), 5153 LinkFieldsComparator()); 5154 5155 // References should be at the front. 5156 size_t current_field = 0; 5157 size_t num_reference_fields = 0; 5158 FieldGaps gaps; 5159 5160 for (; current_field < num_fields; current_field++) { 5161 ArtField* field = grouped_and_sorted_fields.front(); 5162 Primitive::Type type = field->GetTypeAsPrimitiveType(); 5163 bool isPrimitive = type != Primitive::kPrimNot; 5164 if (isPrimitive) { 5165 break; // past last reference, move on to the next phase 5166 } 5167 if (UNLIKELY(!IsAligned<sizeof(mirror::HeapReference<mirror::Object>)>( 5168 field_offset.Uint32Value()))) { 5169 MemberOffset old_offset = field_offset; 5170 field_offset = MemberOffset(RoundUp(field_offset.Uint32Value(), 4)); 5171 AddFieldGap(old_offset.Uint32Value(), field_offset.Uint32Value(), &gaps); 5172 } 5173 DCHECK(IsAligned<sizeof(mirror::HeapReference<mirror::Object>)>(field_offset.Uint32Value())); 5174 grouped_and_sorted_fields.pop_front(); 5175 num_reference_fields++; 5176 field->SetOffset(field_offset); 5177 field_offset = MemberOffset(field_offset.Uint32Value() + 5178 sizeof(mirror::HeapReference<mirror::Object>)); 5179 } 5180 // Gaps are stored as a max heap which means that we must shuffle from largest to smallest 5181 // otherwise we could end up with suboptimal gap fills. 5182 ShuffleForward<8>(¤t_field, &field_offset, &grouped_and_sorted_fields, &gaps); 5183 ShuffleForward<4>(¤t_field, &field_offset, &grouped_and_sorted_fields, &gaps); 5184 ShuffleForward<2>(¤t_field, &field_offset, &grouped_and_sorted_fields, &gaps); 5185 ShuffleForward<1>(¤t_field, &field_offset, &grouped_and_sorted_fields, &gaps); 5186 CHECK(grouped_and_sorted_fields.empty()) << "Missed " << grouped_and_sorted_fields.size() << 5187 " fields."; 5188 self->EndAssertNoThreadSuspension(old_no_suspend_cause); 5189 5190 // We lie to the GC about the java.lang.ref.Reference.referent field, so it doesn't scan it. 5191 if (!is_static && klass->DescriptorEquals("Ljava/lang/ref/Reference;")) { 5192 // We know there are no non-reference fields in the Reference classes, and we know 5193 // that 'referent' is alphabetically last, so this is easy... 5194 CHECK_EQ(num_reference_fields, num_fields) << PrettyClass(klass.Get()); 5195 CHECK_STREQ(fields[num_fields - 1].GetName(), "referent") << PrettyClass(klass.Get()); 5196 --num_reference_fields; 5197 } 5198 5199 size_t size = field_offset.Uint32Value(); 5200 // Update klass 5201 if (is_static) { 5202 klass->SetNumReferenceStaticFields(num_reference_fields); 5203 *class_size = size; 5204 } else { 5205 klass->SetNumReferenceInstanceFields(num_reference_fields); 5206 if (!klass->IsVariableSize()) { 5207 std::string temp; 5208 DCHECK_GE(size, sizeof(mirror::Object)) << klass->GetDescriptor(&temp); 5209 size_t previous_size = klass->GetObjectSize(); 5210 if (previous_size != 0) { 5211 // Make sure that we didn't originally have an incorrect size. 5212 CHECK_EQ(previous_size, size) << klass->GetDescriptor(&temp); 5213 } 5214 klass->SetObjectSize(size); 5215 } 5216 } 5217 5218 if (kIsDebugBuild) { 5219 // Make sure that the fields array is ordered by name but all reference 5220 // offsets are at the beginning as far as alignment allows. 5221 MemberOffset start_ref_offset = is_static 5222 ? klass->GetFirstReferenceStaticFieldOffsetDuringLinking(image_pointer_size_) 5223 : klass->GetFirstReferenceInstanceFieldOffset(); 5224 MemberOffset end_ref_offset(start_ref_offset.Uint32Value() + 5225 num_reference_fields * 5226 sizeof(mirror::HeapReference<mirror::Object>)); 5227 MemberOffset current_ref_offset = start_ref_offset; 5228 for (size_t i = 0; i < num_fields; i++) { 5229 ArtField* field = &fields[i]; 5230 VLOG(class_linker) << "LinkFields: " << (is_static ? "static" : "instance") 5231 << " class=" << PrettyClass(klass.Get()) << " field=" << PrettyField(field) << " offset=" 5232 << field->GetOffset(); 5233 if (i != 0) { 5234 ArtField* const prev_field = &fields[i - 1]; 5235 // NOTE: The field names can be the same. This is not possible in the Java language 5236 // but it's valid Java/dex bytecode and for example proguard can generate such bytecode. 5237 CHECK_LE(strcmp(prev_field->GetName(), field->GetName()), 0); 5238 } 5239 Primitive::Type type = field->GetTypeAsPrimitiveType(); 5240 bool is_primitive = type != Primitive::kPrimNot; 5241 if (klass->DescriptorEquals("Ljava/lang/ref/Reference;") && 5242 strcmp("referent", field->GetName()) == 0) { 5243 is_primitive = true; // We lied above, so we have to expect a lie here. 5244 } 5245 MemberOffset offset = field->GetOffsetDuringLinking(); 5246 if (is_primitive) { 5247 if (offset.Uint32Value() < end_ref_offset.Uint32Value()) { 5248 // Shuffled before references. 5249 size_t type_size = Primitive::ComponentSize(type); 5250 CHECK_LT(type_size, sizeof(mirror::HeapReference<mirror::Object>)); 5251 CHECK_LT(offset.Uint32Value(), start_ref_offset.Uint32Value()); 5252 CHECK_LE(offset.Uint32Value() + type_size, start_ref_offset.Uint32Value()); 5253 CHECK(!IsAligned<sizeof(mirror::HeapReference<mirror::Object>)>(offset.Uint32Value())); 5254 } 5255 } else { 5256 CHECK_EQ(current_ref_offset.Uint32Value(), offset.Uint32Value()); 5257 current_ref_offset = MemberOffset(current_ref_offset.Uint32Value() + 5258 sizeof(mirror::HeapReference<mirror::Object>)); 5259 } 5260 } 5261 CHECK_EQ(current_ref_offset.Uint32Value(), end_ref_offset.Uint32Value()); 5262 } 5263 return true; 5264} 5265 5266// Set the bitmap of reference instance field offsets. 5267void ClassLinker::CreateReferenceInstanceOffsets(Handle<mirror::Class> klass) { 5268 uint32_t reference_offsets = 0; 5269 mirror::Class* super_class = klass->GetSuperClass(); 5270 // Leave the reference offsets as 0 for mirror::Object (the class field is handled specially). 5271 if (super_class != nullptr) { 5272 reference_offsets = super_class->GetReferenceInstanceOffsets(); 5273 // Compute reference offsets unless our superclass overflowed. 5274 if (reference_offsets != mirror::Class::kClassWalkSuper) { 5275 size_t num_reference_fields = klass->NumReferenceInstanceFieldsDuringLinking(); 5276 if (num_reference_fields != 0u) { 5277 // All of the fields that contain object references are guaranteed be grouped in memory 5278 // starting at an appropriately aligned address after super class object data. 5279 uint32_t start_offset = RoundUp(super_class->GetObjectSize(), 5280 sizeof(mirror::HeapReference<mirror::Object>)); 5281 uint32_t start_bit = (start_offset - mirror::kObjectHeaderSize) / 5282 sizeof(mirror::HeapReference<mirror::Object>); 5283 if (start_bit + num_reference_fields > 32) { 5284 reference_offsets = mirror::Class::kClassWalkSuper; 5285 } else { 5286 reference_offsets |= (0xffffffffu << start_bit) & 5287 (0xffffffffu >> (32 - (start_bit + num_reference_fields))); 5288 } 5289 } 5290 } 5291 } 5292 klass->SetReferenceInstanceOffsets(reference_offsets); 5293} 5294 5295mirror::String* ClassLinker::ResolveString(const DexFile& dex_file, uint32_t string_idx, 5296 Handle<mirror::DexCache> dex_cache) { 5297 DCHECK(dex_cache.Get() != nullptr); 5298 mirror::String* resolved = dex_cache->GetResolvedString(string_idx); 5299 if (resolved != nullptr) { 5300 return resolved; 5301 } 5302 uint32_t utf16_length; 5303 const char* utf8_data = dex_file.StringDataAndUtf16LengthByIdx(string_idx, &utf16_length); 5304 mirror::String* string = intern_table_->InternStrong(utf16_length, utf8_data); 5305 dex_cache->SetResolvedString(string_idx, string); 5306 return string; 5307} 5308 5309mirror::Class* ClassLinker::ResolveType(const DexFile& dex_file, uint16_t type_idx, 5310 mirror::Class* referrer) { 5311 StackHandleScope<2> hs(Thread::Current()); 5312 Handle<mirror::DexCache> dex_cache(hs.NewHandle(referrer->GetDexCache())); 5313 Handle<mirror::ClassLoader> class_loader(hs.NewHandle(referrer->GetClassLoader())); 5314 return ResolveType(dex_file, type_idx, dex_cache, class_loader); 5315} 5316 5317mirror::Class* ClassLinker::ResolveType(const DexFile& dex_file, uint16_t type_idx, 5318 Handle<mirror::DexCache> dex_cache, 5319 Handle<mirror::ClassLoader> class_loader) { 5320 DCHECK(dex_cache.Get() != nullptr); 5321 mirror::Class* resolved = dex_cache->GetResolvedType(type_idx); 5322 if (resolved == nullptr) { 5323 Thread* self = Thread::Current(); 5324 const char* descriptor = dex_file.StringByTypeIdx(type_idx); 5325 resolved = FindClass(self, descriptor, class_loader); 5326 if (resolved != nullptr) { 5327 // TODO: we used to throw here if resolved's class loader was not the 5328 // boot class loader. This was to permit different classes with the 5329 // same name to be loaded simultaneously by different loaders 5330 dex_cache->SetResolvedType(type_idx, resolved); 5331 } else { 5332 CHECK(self->IsExceptionPending()) 5333 << "Expected pending exception for failed resolution of: " << descriptor; 5334 // Convert a ClassNotFoundException to a NoClassDefFoundError. 5335 StackHandleScope<1> hs(self); 5336 Handle<mirror::Throwable> cause(hs.NewHandle(self->GetException())); 5337 if (cause->InstanceOf(GetClassRoot(kJavaLangClassNotFoundException))) { 5338 DCHECK(resolved == nullptr); // No Handle needed to preserve resolved. 5339 self->ClearException(); 5340 ThrowNoClassDefFoundError("Failed resolution of: %s", descriptor); 5341 self->GetException()->SetCause(cause.Get()); 5342 } 5343 } 5344 } 5345 DCHECK((resolved == nullptr) || resolved->IsResolved() || resolved->IsErroneous()) 5346 << PrettyDescriptor(resolved) << " " << resolved->GetStatus(); 5347 return resolved; 5348} 5349 5350ArtMethod* ClassLinker::ResolveMethod(const DexFile& dex_file, uint32_t method_idx, 5351 Handle<mirror::DexCache> dex_cache, 5352 Handle<mirror::ClassLoader> class_loader, 5353 ArtMethod* referrer, InvokeType type) { 5354 DCHECK(dex_cache.Get() != nullptr); 5355 // Check for hit in the dex cache. 5356 ArtMethod* resolved = dex_cache->GetResolvedMethod(method_idx, image_pointer_size_); 5357 if (resolved != nullptr && !resolved->IsRuntimeMethod()) { 5358 DCHECK(resolved->GetDeclaringClassUnchecked() != nullptr) << resolved->GetDexMethodIndex(); 5359 return resolved; 5360 } 5361 // Fail, get the declaring class. 5362 const DexFile::MethodId& method_id = dex_file.GetMethodId(method_idx); 5363 mirror::Class* klass = ResolveType(dex_file, method_id.class_idx_, dex_cache, class_loader); 5364 if (klass == nullptr) { 5365 DCHECK(Thread::Current()->IsExceptionPending()); 5366 return nullptr; 5367 } 5368 // Scan using method_idx, this saves string compares but will only hit for matching dex 5369 // caches/files. 5370 switch (type) { 5371 case kDirect: // Fall-through. 5372 case kStatic: 5373 resolved = klass->FindDirectMethod(dex_cache.Get(), method_idx, image_pointer_size_); 5374 DCHECK(resolved == nullptr || resolved->GetDeclaringClassUnchecked() != nullptr); 5375 break; 5376 case kInterface: 5377 resolved = klass->FindInterfaceMethod(dex_cache.Get(), method_idx, image_pointer_size_); 5378 DCHECK(resolved == nullptr || resolved->GetDeclaringClass()->IsInterface()); 5379 break; 5380 case kSuper: // Fall-through. 5381 case kVirtual: 5382 resolved = klass->FindVirtualMethod(dex_cache.Get(), method_idx, image_pointer_size_); 5383 break; 5384 default: 5385 LOG(FATAL) << "Unreachable - invocation type: " << type; 5386 UNREACHABLE(); 5387 } 5388 if (resolved == nullptr) { 5389 // Search by name, which works across dex files. 5390 const char* name = dex_file.StringDataByIdx(method_id.name_idx_); 5391 const Signature signature = dex_file.GetMethodSignature(method_id); 5392 switch (type) { 5393 case kDirect: // Fall-through. 5394 case kStatic: 5395 resolved = klass->FindDirectMethod(name, signature, image_pointer_size_); 5396 DCHECK(resolved == nullptr || resolved->GetDeclaringClassUnchecked() != nullptr); 5397 break; 5398 case kInterface: 5399 resolved = klass->FindInterfaceMethod(name, signature, image_pointer_size_); 5400 DCHECK(resolved == nullptr || resolved->GetDeclaringClass()->IsInterface()); 5401 break; 5402 case kSuper: // Fall-through. 5403 case kVirtual: 5404 resolved = klass->FindVirtualMethod(name, signature, image_pointer_size_); 5405 break; 5406 } 5407 } 5408 // If we found a method, check for incompatible class changes. 5409 if (LIKELY(resolved != nullptr && !resolved->CheckIncompatibleClassChange(type))) { 5410 // Be a good citizen and update the dex cache to speed subsequent calls. 5411 dex_cache->SetResolvedMethod(method_idx, resolved, image_pointer_size_); 5412 return resolved; 5413 } else { 5414 // If we had a method, it's an incompatible-class-change error. 5415 if (resolved != nullptr) { 5416 ThrowIncompatibleClassChangeError(type, resolved->GetInvokeType(), resolved, referrer); 5417 } else { 5418 // We failed to find the method which means either an access error, an incompatible class 5419 // change, or no such method. First try to find the method among direct and virtual methods. 5420 const char* name = dex_file.StringDataByIdx(method_id.name_idx_); 5421 const Signature signature = dex_file.GetMethodSignature(method_id); 5422 switch (type) { 5423 case kDirect: 5424 case kStatic: 5425 resolved = klass->FindVirtualMethod(name, signature, image_pointer_size_); 5426 // Note: kDirect and kStatic are also mutually exclusive, but in that case we would 5427 // have had a resolved method before, which triggers the "true" branch above. 5428 break; 5429 case kInterface: 5430 case kVirtual: 5431 case kSuper: 5432 resolved = klass->FindDirectMethod(name, signature, image_pointer_size_); 5433 break; 5434 } 5435 5436 // If we found something, check that it can be accessed by the referrer. 5437 bool exception_generated = false; 5438 if (resolved != nullptr && referrer != nullptr) { 5439 mirror::Class* methods_class = resolved->GetDeclaringClass(); 5440 mirror::Class* referring_class = referrer->GetDeclaringClass(); 5441 if (!referring_class->CanAccess(methods_class)) { 5442 ThrowIllegalAccessErrorClassForMethodDispatch(referring_class, methods_class, resolved, 5443 type); 5444 exception_generated = true; 5445 } else if (!referring_class->CanAccessMember(methods_class, resolved->GetAccessFlags())) { 5446 ThrowIllegalAccessErrorMethod(referring_class, resolved); 5447 exception_generated = true; 5448 } 5449 } 5450 if (!exception_generated) { 5451 // Otherwise, throw an IncompatibleClassChangeError if we found something, and check 5452 // interface methods and throw if we find the method there. If we find nothing, throw a 5453 // NoSuchMethodError. 5454 switch (type) { 5455 case kDirect: 5456 case kStatic: 5457 if (resolved != nullptr) { 5458 ThrowIncompatibleClassChangeError(type, kVirtual, resolved, referrer); 5459 } else { 5460 resolved = klass->FindInterfaceMethod(name, signature, image_pointer_size_); 5461 if (resolved != nullptr) { 5462 ThrowIncompatibleClassChangeError(type, kInterface, resolved, referrer); 5463 } else { 5464 ThrowNoSuchMethodError(type, klass, name, signature); 5465 } 5466 } 5467 break; 5468 case kInterface: 5469 if (resolved != nullptr) { 5470 ThrowIncompatibleClassChangeError(type, kDirect, resolved, referrer); 5471 } else { 5472 resolved = klass->FindVirtualMethod(name, signature, image_pointer_size_); 5473 if (resolved != nullptr) { 5474 ThrowIncompatibleClassChangeError(type, kVirtual, resolved, referrer); 5475 } else { 5476 ThrowNoSuchMethodError(type, klass, name, signature); 5477 } 5478 } 5479 break; 5480 case kSuper: 5481 if (resolved != nullptr) { 5482 ThrowIncompatibleClassChangeError(type, kDirect, resolved, referrer); 5483 } else { 5484 ThrowNoSuchMethodError(type, klass, name, signature); 5485 } 5486 break; 5487 case kVirtual: 5488 if (resolved != nullptr) { 5489 ThrowIncompatibleClassChangeError(type, kDirect, resolved, referrer); 5490 } else { 5491 resolved = klass->FindInterfaceMethod(name, signature, image_pointer_size_); 5492 if (resolved != nullptr) { 5493 ThrowIncompatibleClassChangeError(type, kInterface, resolved, referrer); 5494 } else { 5495 ThrowNoSuchMethodError(type, klass, name, signature); 5496 } 5497 } 5498 break; 5499 } 5500 } 5501 } 5502 Thread::Current()->AssertPendingException(); 5503 return nullptr; 5504 } 5505} 5506 5507ArtField* ClassLinker::ResolveField(const DexFile& dex_file, uint32_t field_idx, 5508 Handle<mirror::DexCache> dex_cache, 5509 Handle<mirror::ClassLoader> class_loader, bool is_static) { 5510 DCHECK(dex_cache.Get() != nullptr); 5511 ArtField* resolved = dex_cache->GetResolvedField(field_idx, image_pointer_size_); 5512 if (resolved != nullptr) { 5513 return resolved; 5514 } 5515 const DexFile::FieldId& field_id = dex_file.GetFieldId(field_idx); 5516 Thread* const self = Thread::Current(); 5517 StackHandleScope<1> hs(self); 5518 Handle<mirror::Class> klass( 5519 hs.NewHandle(ResolveType(dex_file, field_id.class_idx_, dex_cache, class_loader))); 5520 if (klass.Get() == nullptr) { 5521 DCHECK(Thread::Current()->IsExceptionPending()); 5522 return nullptr; 5523 } 5524 5525 if (is_static) { 5526 resolved = mirror::Class::FindStaticField(self, klass, dex_cache.Get(), field_idx); 5527 } else { 5528 resolved = klass->FindInstanceField(dex_cache.Get(), field_idx); 5529 } 5530 5531 if (resolved == nullptr) { 5532 const char* name = dex_file.GetFieldName(field_id); 5533 const char* type = dex_file.GetFieldTypeDescriptor(field_id); 5534 if (is_static) { 5535 resolved = mirror::Class::FindStaticField(self, klass, name, type); 5536 } else { 5537 resolved = klass->FindInstanceField(name, type); 5538 } 5539 if (resolved == nullptr) { 5540 ThrowNoSuchFieldError(is_static ? "static " : "instance ", klass.Get(), type, name); 5541 return nullptr; 5542 } 5543 } 5544 dex_cache->SetResolvedField(field_idx, resolved, image_pointer_size_); 5545 return resolved; 5546} 5547 5548ArtField* ClassLinker::ResolveFieldJLS(const DexFile& dex_file, uint32_t field_idx, 5549 Handle<mirror::DexCache> dex_cache, 5550 Handle<mirror::ClassLoader> class_loader) { 5551 DCHECK(dex_cache.Get() != nullptr); 5552 ArtField* resolved = dex_cache->GetResolvedField(field_idx, image_pointer_size_); 5553 if (resolved != nullptr) { 5554 return resolved; 5555 } 5556 const DexFile::FieldId& field_id = dex_file.GetFieldId(field_idx); 5557 Thread* self = Thread::Current(); 5558 StackHandleScope<1> hs(self); 5559 Handle<mirror::Class> klass( 5560 hs.NewHandle(ResolveType(dex_file, field_id.class_idx_, dex_cache, class_loader))); 5561 if (klass.Get() == nullptr) { 5562 DCHECK(Thread::Current()->IsExceptionPending()); 5563 return nullptr; 5564 } 5565 5566 StringPiece name(dex_file.StringDataByIdx(field_id.name_idx_)); 5567 StringPiece type(dex_file.StringDataByIdx( 5568 dex_file.GetTypeId(field_id.type_idx_).descriptor_idx_)); 5569 resolved = mirror::Class::FindField(self, klass, name, type); 5570 if (resolved != nullptr) { 5571 dex_cache->SetResolvedField(field_idx, resolved, image_pointer_size_); 5572 } else { 5573 ThrowNoSuchFieldError("", klass.Get(), type, name); 5574 } 5575 return resolved; 5576} 5577 5578const char* ClassLinker::MethodShorty(uint32_t method_idx, ArtMethod* referrer, 5579 uint32_t* length) { 5580 mirror::Class* declaring_class = referrer->GetDeclaringClass(); 5581 mirror::DexCache* dex_cache = declaring_class->GetDexCache(); 5582 const DexFile& dex_file = *dex_cache->GetDexFile(); 5583 const DexFile::MethodId& method_id = dex_file.GetMethodId(method_idx); 5584 return dex_file.GetMethodShorty(method_id, length); 5585} 5586 5587void ClassLinker::DumpAllClasses(int flags) { 5588 if (dex_cache_image_class_lookup_required_) { 5589 MoveImageClassesToClassTable(); 5590 } 5591 // TODO: at the time this was written, it wasn't safe to call PrettyField with the ClassLinker 5592 // lock held, because it might need to resolve a field's type, which would try to take the lock. 5593 std::vector<mirror::Class*> all_classes; 5594 { 5595 ReaderMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); 5596 for (GcRoot<mirror::Class>& it : class_table_) { 5597 all_classes.push_back(it.Read()); 5598 } 5599 } 5600 5601 for (size_t i = 0; i < all_classes.size(); ++i) { 5602 all_classes[i]->DumpClass(std::cerr, flags); 5603 } 5604} 5605 5606static OatFile::OatMethod CreateOatMethod(const void* code) { 5607 CHECK(code != nullptr); 5608 const uint8_t* base = reinterpret_cast<const uint8_t*>(code); // Base of data points at code. 5609 base -= sizeof(void*); // Move backward so that code_offset != 0. 5610 const uint32_t code_offset = sizeof(void*); 5611 return OatFile::OatMethod(base, code_offset); 5612} 5613 5614bool ClassLinker::IsQuickResolutionStub(const void* entry_point) const { 5615 return (entry_point == GetQuickResolutionStub()) || 5616 (quick_resolution_trampoline_ == entry_point); 5617} 5618 5619bool ClassLinker::IsQuickToInterpreterBridge(const void* entry_point) const { 5620 return (entry_point == GetQuickToInterpreterBridge()) || 5621 (quick_to_interpreter_bridge_trampoline_ == entry_point); 5622} 5623 5624bool ClassLinker::IsQuickGenericJniStub(const void* entry_point) const { 5625 return (entry_point == GetQuickGenericJniStub()) || 5626 (quick_generic_jni_trampoline_ == entry_point); 5627} 5628 5629const void* ClassLinker::GetRuntimeQuickGenericJniStub() const { 5630 return GetQuickGenericJniStub(); 5631} 5632 5633void ClassLinker::SetEntryPointsToCompiledCode(ArtMethod* method, 5634 const void* method_code) const { 5635 OatFile::OatMethod oat_method = CreateOatMethod(method_code); 5636 oat_method.LinkMethod(method); 5637 method->SetEntryPointFromInterpreter(artInterpreterToCompiledCodeBridge); 5638} 5639 5640void ClassLinker::SetEntryPointsToInterpreter(ArtMethod* method) const { 5641 if (!method->IsNative()) { 5642 method->SetEntryPointFromInterpreter(artInterpreterToInterpreterBridge); 5643 method->SetEntryPointFromQuickCompiledCode(GetQuickToInterpreterBridge()); 5644 } else { 5645 const void* quick_method_code = GetQuickGenericJniStub(); 5646 OatFile::OatMethod oat_method = CreateOatMethod(quick_method_code); 5647 oat_method.LinkMethod(method); 5648 method->SetEntryPointFromInterpreter(artInterpreterToCompiledCodeBridge); 5649 } 5650} 5651 5652void ClassLinker::DumpForSigQuit(std::ostream& os) { 5653 Thread* self = Thread::Current(); 5654 if (dex_cache_image_class_lookup_required_) { 5655 ScopedObjectAccess soa(self); 5656 MoveImageClassesToClassTable(); 5657 } 5658 ReaderMutexLock mu(self, *Locks::classlinker_classes_lock_); 5659 os << "Zygote loaded classes=" << pre_zygote_class_table_.Size() << " post zygote classes=" 5660 << class_table_.Size() << "\n"; 5661} 5662 5663size_t ClassLinker::NumLoadedClasses() { 5664 if (dex_cache_image_class_lookup_required_) { 5665 MoveImageClassesToClassTable(); 5666 } 5667 ReaderMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); 5668 // Only return non zygote classes since these are the ones which apps which care about. 5669 return class_table_.Size(); 5670} 5671 5672pid_t ClassLinker::GetClassesLockOwner() { 5673 return Locks::classlinker_classes_lock_->GetExclusiveOwnerTid(); 5674} 5675 5676pid_t ClassLinker::GetDexLockOwner() { 5677 return dex_lock_.GetExclusiveOwnerTid(); 5678} 5679 5680void ClassLinker::SetClassRoot(ClassRoot class_root, mirror::Class* klass) { 5681 DCHECK(!init_done_); 5682 5683 DCHECK(klass != nullptr); 5684 DCHECK(klass->GetClassLoader() == nullptr); 5685 5686 mirror::ObjectArray<mirror::Class>* class_roots = class_roots_.Read(); 5687 DCHECK(class_roots != nullptr); 5688 DCHECK(class_roots->Get(class_root) == nullptr); 5689 class_roots->Set<false>(class_root, klass); 5690} 5691 5692const char* ClassLinker::GetClassRootDescriptor(ClassRoot class_root) { 5693 static const char* class_roots_descriptors[] = { 5694 "Ljava/lang/Class;", 5695 "Ljava/lang/Object;", 5696 "[Ljava/lang/Class;", 5697 "[Ljava/lang/Object;", 5698 "Ljava/lang/String;", 5699 "Ljava/lang/DexCache;", 5700 "Ljava/lang/ref/Reference;", 5701 "Ljava/lang/reflect/Constructor;", 5702 "Ljava/lang/reflect/Field;", 5703 "Ljava/lang/reflect/Method;", 5704 "Ljava/lang/reflect/Proxy;", 5705 "[Ljava/lang/String;", 5706 "[Ljava/lang/reflect/Constructor;", 5707 "[Ljava/lang/reflect/Field;", 5708 "[Ljava/lang/reflect/Method;", 5709 "Ljava/lang/ClassLoader;", 5710 "Ljava/lang/Throwable;", 5711 "Ljava/lang/ClassNotFoundException;", 5712 "Ljava/lang/StackTraceElement;", 5713 "Z", 5714 "B", 5715 "C", 5716 "D", 5717 "F", 5718 "I", 5719 "J", 5720 "S", 5721 "V", 5722 "[Z", 5723 "[B", 5724 "[C", 5725 "[D", 5726 "[F", 5727 "[I", 5728 "[J", 5729 "[S", 5730 "[Ljava/lang/StackTraceElement;", 5731 }; 5732 static_assert(arraysize(class_roots_descriptors) == size_t(kClassRootsMax), 5733 "Mismatch between class descriptors and class-root enum"); 5734 5735 const char* descriptor = class_roots_descriptors[class_root]; 5736 CHECK(descriptor != nullptr); 5737 return descriptor; 5738} 5739 5740std::size_t ClassLinker::ClassDescriptorHashEquals::operator()(const GcRoot<mirror::Class>& root) 5741 const { 5742 std::string temp; 5743 return ComputeModifiedUtf8Hash(root.Read()->GetDescriptor(&temp)); 5744} 5745 5746bool ClassLinker::ClassDescriptorHashEquals::operator()(const GcRoot<mirror::Class>& a, 5747 const GcRoot<mirror::Class>& b) const { 5748 if (a.Read()->GetClassLoader() != b.Read()->GetClassLoader()) { 5749 return false; 5750 } 5751 std::string temp; 5752 return a.Read()->DescriptorEquals(b.Read()->GetDescriptor(&temp)); 5753} 5754 5755std::size_t ClassLinker::ClassDescriptorHashEquals::operator()( 5756 const std::pair<const char*, mirror::ClassLoader*>& element) const { 5757 return ComputeModifiedUtf8Hash(element.first); 5758} 5759 5760bool ClassLinker::ClassDescriptorHashEquals::operator()( 5761 const GcRoot<mirror::Class>& a, const std::pair<const char*, mirror::ClassLoader*>& b) const { 5762 if (a.Read()->GetClassLoader() != b.second) { 5763 return false; 5764 } 5765 return a.Read()->DescriptorEquals(b.first); 5766} 5767 5768bool ClassLinker::ClassDescriptorHashEquals::operator()(const GcRoot<mirror::Class>& a, 5769 const char* descriptor) const { 5770 return a.Read()->DescriptorEquals(descriptor); 5771} 5772 5773std::size_t ClassLinker::ClassDescriptorHashEquals::operator()(const char* descriptor) const { 5774 return ComputeModifiedUtf8Hash(descriptor); 5775} 5776 5777bool ClassLinker::MayBeCalledWithDirectCodePointer(ArtMethod* m) { 5778 if (Runtime::Current()->UseJit()) { 5779 // JIT can have direct code pointers from any method to any other method. 5780 return true; 5781 } 5782 // Non-image methods don't use direct code pointer. 5783 if (!m->GetDeclaringClass()->IsBootStrapClassLoaded()) { 5784 return false; 5785 } 5786 if (m->IsPrivate()) { 5787 // The method can only be called inside its own oat file. Therefore it won't be called using 5788 // its direct code if the oat file has been compiled in PIC mode. 5789 const DexFile& dex_file = m->GetDeclaringClass()->GetDexFile(); 5790 const OatFile::OatDexFile* oat_dex_file = dex_file.GetOatDexFile(); 5791 if (oat_dex_file == nullptr) { 5792 // No oat file: the method has not been compiled. 5793 return false; 5794 } 5795 const OatFile* oat_file = oat_dex_file->GetOatFile(); 5796 return oat_file != nullptr && !oat_file->IsPic(); 5797 } else { 5798 // The method can be called outside its own oat file. Therefore it won't be called using its 5799 // direct code pointer only if all loaded oat files have been compiled in PIC mode. 5800 ReaderMutexLock mu(Thread::Current(), dex_lock_); 5801 for (const OatFile* oat_file : oat_files_) { 5802 if (!oat_file->IsPic()) { 5803 return true; 5804 } 5805 } 5806 return false; 5807 } 5808} 5809 5810jobject ClassLinker::CreatePathClassLoader(Thread* self, std::vector<const DexFile*>& dex_files) { 5811 // SOAAlreadyRunnable is protected, and we need something to add a global reference. 5812 // We could move the jobject to the callers, but all call-sites do this... 5813 ScopedObjectAccessUnchecked soa(self); 5814 5815 // Register the dex files. 5816 for (const DexFile* dex_file : dex_files) { 5817 RegisterDexFile(*dex_file); 5818 } 5819 5820 // For now, create a libcore-level DexFile for each ART DexFile. This "explodes" multidex. 5821 StackHandleScope<10> hs(self); 5822 5823 ArtField* dex_elements_field = 5824 soa.DecodeField(WellKnownClasses::dalvik_system_DexPathList_dexElements); 5825 5826 mirror::Class* dex_elements_class = dex_elements_field->GetType<true>(); 5827 DCHECK(dex_elements_class != nullptr); 5828 DCHECK(dex_elements_class->IsArrayClass()); 5829 Handle<mirror::ObjectArray<mirror::Object>> h_dex_elements(hs.NewHandle( 5830 mirror::ObjectArray<mirror::Object>::Alloc(self, dex_elements_class, dex_files.size()))); 5831 Handle<mirror::Class> h_dex_element_class = 5832 hs.NewHandle(dex_elements_class->GetComponentType()); 5833 5834 ArtField* element_file_field = 5835 soa.DecodeField(WellKnownClasses::dalvik_system_DexPathList__Element_dexFile); 5836 DCHECK_EQ(h_dex_element_class.Get(), element_file_field->GetDeclaringClass()); 5837 5838 ArtField* cookie_field = soa.DecodeField(WellKnownClasses::dalvik_system_DexFile_cookie); 5839 DCHECK_EQ(cookie_field->GetDeclaringClass(), element_file_field->GetType<false>()); 5840 5841 // Fill the elements array. 5842 int32_t index = 0; 5843 for (const DexFile* dex_file : dex_files) { 5844 StackHandleScope<3> hs2(self); 5845 5846 Handle<mirror::LongArray> h_long_array = hs2.NewHandle(mirror::LongArray::Alloc(self, 1)); 5847 DCHECK(h_long_array.Get() != nullptr); 5848 h_long_array->Set(0, reinterpret_cast<intptr_t>(dex_file)); 5849 5850 Handle<mirror::Object> h_dex_file = hs2.NewHandle( 5851 cookie_field->GetDeclaringClass()->AllocObject(self)); 5852 DCHECK(h_dex_file.Get() != nullptr); 5853 cookie_field->SetObject<false>(h_dex_file.Get(), h_long_array.Get()); 5854 5855 Handle<mirror::Object> h_element = hs2.NewHandle(h_dex_element_class->AllocObject(self)); 5856 DCHECK(h_element.Get() != nullptr); 5857 element_file_field->SetObject<false>(h_element.Get(), h_dex_file.Get()); 5858 5859 h_dex_elements->Set(index, h_element.Get()); 5860 index++; 5861 } 5862 DCHECK_EQ(index, h_dex_elements->GetLength()); 5863 5864 // Create DexPathList. 5865 Handle<mirror::Object> h_dex_path_list = hs.NewHandle( 5866 dex_elements_field->GetDeclaringClass()->AllocObject(self)); 5867 DCHECK(h_dex_path_list.Get() != nullptr); 5868 // Set elements. 5869 dex_elements_field->SetObject<false>(h_dex_path_list.Get(), h_dex_elements.Get()); 5870 5871 // Create PathClassLoader. 5872 Handle<mirror::Class> h_path_class_class = hs.NewHandle( 5873 soa.Decode<mirror::Class*>(WellKnownClasses::dalvik_system_PathClassLoader)); 5874 Handle<mirror::Object> h_path_class_loader = hs.NewHandle( 5875 h_path_class_class->AllocObject(self)); 5876 DCHECK(h_path_class_loader.Get() != nullptr); 5877 // Set DexPathList. 5878 ArtField* path_list_field = 5879 soa.DecodeField(WellKnownClasses::dalvik_system_PathClassLoader_pathList); 5880 DCHECK(path_list_field != nullptr); 5881 path_list_field->SetObject<false>(h_path_class_loader.Get(), h_dex_path_list.Get()); 5882 5883 // Make a pretend boot-classpath. 5884 // TODO: Should we scan the image? 5885 ArtField* const parent_field = 5886 mirror::Class::FindField(self, hs.NewHandle(h_path_class_loader->GetClass()), "parent", 5887 "Ljava/lang/ClassLoader;"); 5888 DCHECK(parent_field!= nullptr); 5889 mirror::Object* boot_cl = 5890 soa.Decode<mirror::Class*>(WellKnownClasses::java_lang_BootClassLoader)->AllocObject(self); 5891 parent_field->SetObject<false>(h_path_class_loader.Get(), boot_cl); 5892 5893 // Make it a global ref and return. 5894 ScopedLocalRef<jobject> local_ref( 5895 soa.Env(), soa.Env()->AddLocalReference<jobject>(h_path_class_loader.Get())); 5896 return soa.Env()->NewGlobalRef(local_ref.get()); 5897} 5898 5899ArtMethod* ClassLinker::CreateRuntimeMethod() { 5900 ArtMethod* method = AllocArtMethodArray(Thread::Current(), 1); 5901 CHECK(method != nullptr); 5902 method->SetDexMethodIndex(DexFile::kDexNoIndex); 5903 CHECK(method->IsRuntimeMethod()); 5904 return method; 5905} 5906 5907void ClassLinker::DropFindArrayClassCache() { 5908 std::fill_n(find_array_class_cache_, kFindArrayCacheSize, GcRoot<mirror::Class>(nullptr)); 5909 find_array_class_cache_next_victim_ = 0; 5910} 5911 5912} // namespace art 5913