class_linker.cc revision 0fc16a09b4d2323f9c2b6aabc81ce120b278329b
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 // To grab the boot oat, look at the dex files in the boot classpath. Any of those is fine, as 812 // they were all compiled into the same oat file. So grab the first one, which is guaranteed to 813 // exist if the boot class-path isn't empty. 814 if (boot_class_path_.empty()) { 815 return nullptr; 816 } 817 const DexFile* boot_dex_file = boot_class_path_[0]; 818 // Is it from an oat file? 819 if (boot_dex_file->GetOatDexFile() != nullptr) { 820 return boot_dex_file->GetOatDexFile()->GetOatFile(); 821 } 822 return nullptr; 823} 824 825const OatFile* ClassLinker::GetPrimaryOatFile() { 826 ReaderMutexLock mu(Thread::Current(), dex_lock_); 827 const OatFile* boot_oat_file = GetBootOatFile(); 828 if (boot_oat_file != nullptr) { 829 for (const OatFile* oat_file : oat_files_) { 830 if (oat_file != boot_oat_file) { 831 return oat_file; 832 } 833 } 834 } 835 return nullptr; 836} 837 838// Check for class-def collisions in dex files. 839// 840// This works by maintaining a heap with one class from each dex file, sorted by the class 841// descriptor. Then a dex-file/class pair is continually removed from the heap and compared 842// against the following top element. If the descriptor is the same, it is now checked whether 843// the two elements agree on whether their dex file was from an already-loaded oat-file or the 844// new oat file. Any disagreement indicates a collision. 845bool ClassLinker::HasCollisions(const OatFile* oat_file, std::string* error_msg) { 846 if (!kDuplicateClassesCheck) { 847 return false; 848 } 849 850 // Dex files are registered late - once a class is actually being loaded. We have to compare 851 // against the open oat files. Take the dex_lock_ that protects oat_files_ accesses. 852 ReaderMutexLock mu(Thread::Current(), dex_lock_); 853 854 std::priority_queue<DexFileAndClassPair> queue; 855 856 // Add dex files from already loaded oat files, but skip boot. 857 { 858 const OatFile* boot_oat = GetBootOatFile(); 859 for (const OatFile* loaded_oat_file : oat_files_) { 860 if (loaded_oat_file == boot_oat) { 861 continue; 862 } 863 AddDexFilesFromOat(loaded_oat_file, true, &queue); 864 } 865 } 866 867 if (queue.empty()) { 868 // No other oat files, return early. 869 return false; 870 } 871 872 // Add dex files from the oat file to check. 873 AddDexFilesFromOat(oat_file, false, &queue); 874 875 // Now drain the queue. 876 while (!queue.empty()) { 877 DexFileAndClassPair compare_pop = queue.top(); 878 queue.pop(); 879 880 // Compare against the following elements. 881 while (!queue.empty()) { 882 DexFileAndClassPair top = queue.top(); 883 884 if (strcmp(compare_pop.GetCachedDescriptor(), top.GetCachedDescriptor()) == 0) { 885 // Same descriptor. Check whether it's crossing old-oat-files to new-oat-files. 886 if (compare_pop.FromLoadedOat() != top.FromLoadedOat()) { 887 *error_msg = 888 StringPrintf("Found duplicated class when checking oat files: '%s' in %s and %s", 889 compare_pop.GetCachedDescriptor(), 890 compare_pop.GetDexFile()->GetLocation().c_str(), 891 top.GetDexFile()->GetLocation().c_str()); 892 FreeDexFilesInHeap(&queue); 893 return true; 894 } 895 // Pop it. 896 queue.pop(); 897 AddNext(&top, &queue); 898 } else { 899 // Something else. Done here. 900 break; 901 } 902 } 903 AddNext(&compare_pop, &queue); 904 } 905 906 return false; 907} 908 909std::vector<std::unique_ptr<const DexFile>> ClassLinker::OpenDexFilesFromOat( 910 const char* dex_location, const char* oat_location, 911 std::vector<std::string>* error_msgs) { 912 CHECK(error_msgs != nullptr); 913 914 // Verify we aren't holding the mutator lock, which could starve GC if we 915 // have to generate or relocate an oat file. 916 Locks::mutator_lock_->AssertNotHeld(Thread::Current()); 917 918 OatFileAssistant oat_file_assistant(dex_location, oat_location, kRuntimeISA, 919 !Runtime::Current()->IsAotCompiler()); 920 921 // Lock the target oat location to avoid races generating and loading the 922 // oat file. 923 std::string error_msg; 924 if (!oat_file_assistant.Lock(&error_msg)) { 925 // Don't worry too much if this fails. If it does fail, it's unlikely we 926 // can generate an oat file anyway. 927 VLOG(class_linker) << "OatFileAssistant::Lock: " << error_msg; 928 } 929 930 // Check if we already have an up-to-date oat file open. 931 const OatFile* source_oat_file = nullptr; 932 { 933 ReaderMutexLock mu(Thread::Current(), dex_lock_); 934 for (const OatFile* oat_file : oat_files_) { 935 CHECK(oat_file != nullptr); 936 if (oat_file_assistant.GivenOatFileIsUpToDate(*oat_file)) { 937 source_oat_file = oat_file; 938 break; 939 } 940 } 941 } 942 943 // If we didn't have an up-to-date oat file open, try to load one from disk. 944 if (source_oat_file == nullptr) { 945 // Update the oat file on disk if we can. This may fail, but that's okay. 946 // Best effort is all that matters here. 947 if (!oat_file_assistant.MakeUpToDate(&error_msg)) { 948 LOG(WARNING) << error_msg; 949 } 950 951 // Get the oat file on disk. 952 std::unique_ptr<OatFile> oat_file = oat_file_assistant.GetBestOatFile(); 953 if (oat_file.get() != nullptr) { 954 // Take the file only if it has no collisions, or we must take it because of preopting. 955 bool accept_oat_file = !HasCollisions(oat_file.get(), &error_msg); 956 if (!accept_oat_file) { 957 // Failed the collision check. Print warning. 958 if (Runtime::Current()->IsDexFileFallbackEnabled()) { 959 LOG(WARNING) << "Found duplicate classes, falling back to interpreter mode for " 960 << dex_location; 961 } else { 962 LOG(WARNING) << "Found duplicate classes, dex-file-fallback disabled, will be failing to " 963 " load classes for " << dex_location; 964 } 965 LOG(WARNING) << error_msg; 966 967 // However, if the app was part of /system and preopted, there is no original dex file 968 // available. In that case grudgingly accept the oat file. 969 if (!DexFile::MaybeDex(dex_location)) { 970 accept_oat_file = true; 971 LOG(WARNING) << "Dex location " << dex_location << " does not seem to include dex file. " 972 << "Allow oat file use. This is potentially dangerous."; 973 } 974 } 975 976 if (accept_oat_file) { 977 source_oat_file = oat_file.release(); 978 RegisterOatFile(source_oat_file); 979 } 980 } 981 } 982 983 std::vector<std::unique_ptr<const DexFile>> dex_files; 984 985 // Load the dex files from the oat file. 986 if (source_oat_file != nullptr) { 987 dex_files = oat_file_assistant.LoadDexFiles(*source_oat_file, dex_location); 988 if (dex_files.empty()) { 989 error_msgs->push_back("Failed to open dex files from " 990 + source_oat_file->GetLocation()); 991 } 992 } 993 994 // Fall back to running out of the original dex file if we couldn't load any 995 // dex_files from the oat file. 996 if (dex_files.empty()) { 997 if (Runtime::Current()->IsDexFileFallbackEnabled()) { 998 if (!DexFile::Open(dex_location, dex_location, &error_msg, &dex_files)) { 999 LOG(WARNING) << error_msg; 1000 error_msgs->push_back("Failed to open dex files from " + std::string(dex_location)); 1001 } 1002 } else { 1003 error_msgs->push_back("Fallback mode disabled, skipping dex files."); 1004 } 1005 } 1006 return dex_files; 1007} 1008 1009const OatFile* ClassLinker::FindOpenedOatFileFromOatLocation(const std::string& oat_location) { 1010 ReaderMutexLock mu(Thread::Current(), dex_lock_); 1011 for (size_t i = 0; i < oat_files_.size(); i++) { 1012 const OatFile* oat_file = oat_files_[i]; 1013 DCHECK(oat_file != nullptr); 1014 if (oat_file->GetLocation() == oat_location) { 1015 return oat_file; 1016 } 1017 } 1018 return nullptr; 1019} 1020 1021static void SanityCheckArtMethod(ArtMethod* m, mirror::Class* expected_class, 1022 gc::space::ImageSpace* space) 1023 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1024 if (m->IsRuntimeMethod()) { 1025 CHECK(m->GetDeclaringClass() == nullptr) << PrettyMethod(m); 1026 } else if (m->IsMiranda()) { 1027 CHECK(m->GetDeclaringClass() != nullptr) << PrettyMethod(m); 1028 } else if (expected_class != nullptr) { 1029 CHECK_EQ(m->GetDeclaringClassUnchecked(), expected_class) << PrettyMethod(m); 1030 } 1031 if (space != nullptr) { 1032 auto& header = space->GetImageHeader(); 1033 auto& methods = header.GetMethodsSection(); 1034 auto offset = reinterpret_cast<uint8_t*>(m) - space->Begin(); 1035 CHECK(methods.Contains(offset)) << m << " not in " << methods; 1036 } 1037} 1038 1039static void SanityCheckArtMethodPointerArray( 1040 mirror::PointerArray* arr, mirror::Class* expected_class, size_t pointer_size, 1041 gc::space::ImageSpace* space) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1042 CHECK(arr != nullptr); 1043 for (int32_t j = 0; j < arr->GetLength(); ++j) { 1044 auto* method = arr->GetElementPtrSize<ArtMethod*>(j, pointer_size); 1045 // expected_class == null means we are a dex cache. 1046 if (expected_class != nullptr) { 1047 CHECK(method != nullptr); 1048 } 1049 if (method != nullptr) { 1050 SanityCheckArtMethod(method, expected_class, space); 1051 } 1052 } 1053} 1054 1055static void SanityCheckObjectsCallback(mirror::Object* obj, void* arg ATTRIBUTE_UNUSED) 1056 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1057 DCHECK(obj != nullptr); 1058 CHECK(obj->GetClass() != nullptr) << "Null class " << obj; 1059 CHECK(obj->GetClass()->GetClass() != nullptr) << "Null class class " << obj; 1060 if (obj->IsClass()) { 1061 auto klass = obj->AsClass(); 1062 ArtField* fields[2] = { klass->GetSFields(), klass->GetIFields() }; 1063 size_t num_fields[2] = { klass->NumStaticFields(), klass->NumInstanceFields() }; 1064 for (size_t i = 0; i < 2; ++i) { 1065 for (size_t j = 0; j < num_fields[i]; ++j) { 1066 CHECK_EQ(fields[i][j].GetDeclaringClass(), klass); 1067 } 1068 } 1069 auto* runtime = Runtime::Current(); 1070 auto* image_space = runtime->GetHeap()->GetImageSpace(); 1071 auto pointer_size = runtime->GetClassLinker()->GetImagePointerSize(); 1072 for (auto& m : klass->GetDirectMethods(pointer_size)) { 1073 SanityCheckArtMethod(&m, klass, image_space); 1074 } 1075 for (auto& m : klass->GetVirtualMethods(pointer_size)) { 1076 SanityCheckArtMethod(&m, klass, image_space); 1077 } 1078 auto* vtable = klass->GetVTable(); 1079 if (vtable != nullptr) { 1080 SanityCheckArtMethodPointerArray(vtable, nullptr, pointer_size, image_space); 1081 } 1082 if (klass->ShouldHaveEmbeddedImtAndVTable()) { 1083 for (size_t i = 0; i < mirror::Class::kImtSize; ++i) { 1084 SanityCheckArtMethod(klass->GetEmbeddedImTableEntry(i, pointer_size), nullptr, image_space); 1085 } 1086 for (int32_t i = 0; i < klass->GetEmbeddedVTableLength(); ++i) { 1087 SanityCheckArtMethod(klass->GetEmbeddedVTableEntry(i, pointer_size), nullptr, image_space); 1088 } 1089 } 1090 auto* iftable = klass->GetIfTable(); 1091 if (iftable != nullptr) { 1092 for (int32_t i = 0; i < klass->GetIfTableCount(); ++i) { 1093 if (iftable->GetMethodArrayCount(i) > 0) { 1094 SanityCheckArtMethodPointerArray(iftable->GetMethodArray(i), nullptr, pointer_size, 1095 image_space); 1096 } 1097 } 1098 } 1099 } 1100} 1101 1102void ClassLinker::InitFromImage() { 1103 VLOG(startup) << "ClassLinker::InitFromImage entering"; 1104 CHECK(!init_done_); 1105 1106 Runtime* const runtime = Runtime::Current(); 1107 Thread* const self = Thread::Current(); 1108 gc::Heap* const heap = runtime->GetHeap(); 1109 gc::space::ImageSpace* const space = heap->GetImageSpace(); 1110 CHECK(space != nullptr); 1111 image_pointer_size_ = space->GetImageHeader().GetPointerSize(); 1112 dex_cache_image_class_lookup_required_ = true; 1113 OatFile& oat_file = GetImageOatFile(space); 1114 CHECK_EQ(oat_file.GetOatHeader().GetImageFileLocationOatChecksum(), 0U); 1115 CHECK_EQ(oat_file.GetOatHeader().GetImageFileLocationOatDataBegin(), 0U); 1116 const char* image_file_location = oat_file.GetOatHeader(). 1117 GetStoreValueByKey(OatHeader::kImageLocationKey); 1118 CHECK(image_file_location == nullptr || *image_file_location == 0); 1119 quick_resolution_trampoline_ = oat_file.GetOatHeader().GetQuickResolutionTrampoline(); 1120 quick_imt_conflict_trampoline_ = oat_file.GetOatHeader().GetQuickImtConflictTrampoline(); 1121 quick_generic_jni_trampoline_ = oat_file.GetOatHeader().GetQuickGenericJniTrampoline(); 1122 quick_to_interpreter_bridge_trampoline_ = oat_file.GetOatHeader().GetQuickToInterpreterBridge(); 1123 mirror::Object* dex_caches_object = space->GetImageHeader().GetImageRoot(ImageHeader::kDexCaches); 1124 mirror::ObjectArray<mirror::DexCache>* dex_caches = 1125 dex_caches_object->AsObjectArray<mirror::DexCache>(); 1126 1127 StackHandleScope<1> hs(self); 1128 Handle<mirror::ObjectArray<mirror::Class>> class_roots(hs.NewHandle( 1129 space->GetImageHeader().GetImageRoot(ImageHeader::kClassRoots)-> 1130 AsObjectArray<mirror::Class>())); 1131 class_roots_ = GcRoot<mirror::ObjectArray<mirror::Class>>(class_roots.Get()); 1132 1133 // Special case of setting up the String class early so that we can test arbitrary objects 1134 // as being Strings or not 1135 mirror::String::SetClass(GetClassRoot(kJavaLangString)); 1136 1137 CHECK_EQ(oat_file.GetOatHeader().GetDexFileCount(), 1138 static_cast<uint32_t>(dex_caches->GetLength())); 1139 for (int32_t i = 0; i < dex_caches->GetLength(); i++) { 1140 StackHandleScope<1> hs2(self); 1141 Handle<mirror::DexCache> dex_cache(hs2.NewHandle(dex_caches->Get(i))); 1142 const std::string& dex_file_location(dex_cache->GetLocation()->ToModifiedUtf8()); 1143 const OatFile::OatDexFile* oat_dex_file = oat_file.GetOatDexFile(dex_file_location.c_str(), 1144 nullptr); 1145 CHECK(oat_dex_file != nullptr) << oat_file.GetLocation() << " " << dex_file_location; 1146 std::string error_msg; 1147 std::unique_ptr<const DexFile> dex_file = oat_dex_file->OpenDexFile(&error_msg); 1148 if (dex_file.get() == nullptr) { 1149 LOG(FATAL) << "Failed to open dex file " << dex_file_location 1150 << " from within oat file " << oat_file.GetLocation() 1151 << " error '" << error_msg << "'"; 1152 UNREACHABLE(); 1153 } 1154 1155 if (kSanityCheckObjects) { 1156 SanityCheckArtMethodPointerArray(dex_cache->GetResolvedMethods(), nullptr, 1157 image_pointer_size_, space); 1158 } 1159 1160 CHECK_EQ(dex_file->GetLocationChecksum(), oat_dex_file->GetDexFileLocationChecksum()); 1161 1162 AppendToBootClassPath(*dex_file.get(), dex_cache); 1163 opened_dex_files_.push_back(std::move(dex_file)); 1164 } 1165 1166 CHECK(ValidPointerSize(image_pointer_size_)) << image_pointer_size_; 1167 1168 // Set classes on AbstractMethod early so that IsMethod tests can be performed during the live 1169 // bitmap walk. 1170 if (!runtime->IsAotCompiler()) { 1171 // Only the Aot compiler supports having an image with a different pointer size than the 1172 // runtime. This happens on the host for compile 32 bit tests since we use a 64 bit libart 1173 // compiler. We may also use 32 bit dex2oat on a system with 64 bit apps. 1174 CHECK_EQ(image_pointer_size_, sizeof(void*)); 1175 } 1176 1177 if (kSanityCheckObjects) { 1178 for (int32_t i = 0; i < dex_caches->GetLength(); i++) { 1179 auto* dex_cache = dex_caches->Get(i); 1180 for (size_t j = 0; j < dex_cache->NumResolvedFields(); ++j) { 1181 auto* field = dex_cache->GetResolvedField(j, image_pointer_size_); 1182 if (field != nullptr) { 1183 CHECK(field->GetDeclaringClass()->GetClass() != nullptr); 1184 } 1185 } 1186 } 1187 heap->VisitObjects(SanityCheckObjectsCallback, nullptr); 1188 } 1189 1190 // Set entry point to interpreter if in InterpretOnly mode. 1191 if (!runtime->IsAotCompiler() && runtime->GetInstrumentation()->InterpretOnly()) { 1192 const auto& header = space->GetImageHeader(); 1193 const auto& methods = header.GetMethodsSection(); 1194 const auto art_method_size = ArtMethod::ObjectSize(image_pointer_size_); 1195 for (uintptr_t pos = 0; pos < methods.Size(); pos += art_method_size) { 1196 auto* method = reinterpret_cast<ArtMethod*>(space->Begin() + pos + methods.Offset()); 1197 if (kIsDebugBuild && !method->IsRuntimeMethod()) { 1198 CHECK(method->GetDeclaringClass() != nullptr); 1199 } 1200 if (!method->IsNative()) { 1201 method->SetEntryPointFromInterpreterPtrSize( 1202 artInterpreterToInterpreterBridge, image_pointer_size_); 1203 if (!method->IsRuntimeMethod() && method != runtime->GetResolutionMethod()) { 1204 method->SetEntryPointFromQuickCompiledCodePtrSize(GetQuickToInterpreterBridge(), 1205 image_pointer_size_); 1206 } 1207 } 1208 } 1209 } 1210 1211 // reinit class_roots_ 1212 mirror::Class::SetClassClass(class_roots->Get(kJavaLangClass)); 1213 class_roots_ = GcRoot<mirror::ObjectArray<mirror::Class>>(class_roots.Get()); 1214 1215 // reinit array_iftable_ from any array class instance, they should be == 1216 array_iftable_ = GcRoot<mirror::IfTable>(GetClassRoot(kObjectArrayClass)->GetIfTable()); 1217 DCHECK_EQ(array_iftable_.Read(), GetClassRoot(kBooleanArrayClass)->GetIfTable()); 1218 // String class root was set above 1219 mirror::Field::SetClass(GetClassRoot(kJavaLangReflectField)); 1220 mirror::Field::SetArrayClass(GetClassRoot(kJavaLangReflectFieldArrayClass)); 1221 mirror::Constructor::SetClass(GetClassRoot(kJavaLangReflectConstructor)); 1222 mirror::Constructor::SetArrayClass(GetClassRoot(kJavaLangReflectConstructorArrayClass)); 1223 mirror::Method::SetClass(GetClassRoot(kJavaLangReflectMethod)); 1224 mirror::Method::SetArrayClass(GetClassRoot(kJavaLangReflectMethodArrayClass)); 1225 mirror::Reference::SetClass(GetClassRoot(kJavaLangRefReference)); 1226 mirror::BooleanArray::SetArrayClass(GetClassRoot(kBooleanArrayClass)); 1227 mirror::ByteArray::SetArrayClass(GetClassRoot(kByteArrayClass)); 1228 mirror::CharArray::SetArrayClass(GetClassRoot(kCharArrayClass)); 1229 mirror::DoubleArray::SetArrayClass(GetClassRoot(kDoubleArrayClass)); 1230 mirror::FloatArray::SetArrayClass(GetClassRoot(kFloatArrayClass)); 1231 mirror::IntArray::SetArrayClass(GetClassRoot(kIntArrayClass)); 1232 mirror::LongArray::SetArrayClass(GetClassRoot(kLongArrayClass)); 1233 mirror::ShortArray::SetArrayClass(GetClassRoot(kShortArrayClass)); 1234 mirror::Throwable::SetClass(GetClassRoot(kJavaLangThrowable)); 1235 mirror::StackTraceElement::SetClass(GetClassRoot(kJavaLangStackTraceElement)); 1236 1237 FinishInit(self); 1238 1239 VLOG(startup) << "ClassLinker::InitFromImage exiting"; 1240} 1241 1242bool ClassLinker::ClassInClassTable(mirror::Class* klass) { 1243 ReaderMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); 1244 auto it = class_table_.Find(GcRoot<mirror::Class>(klass)); 1245 if (it == class_table_.end()) { 1246 return false; 1247 } 1248 return it->Read() == klass; 1249} 1250 1251void ClassLinker::VisitClassRoots(RootVisitor* visitor, VisitRootFlags flags) { 1252 WriterMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); 1253 BufferedRootVisitor<kDefaultBufferedRootCount> buffered_visitor( 1254 visitor, RootInfo(kRootStickyClass)); 1255 if ((flags & kVisitRootFlagAllRoots) != 0) { 1256 // Argument for how root visiting deals with ArtField and ArtMethod roots. 1257 // There is 3 GC cases to handle: 1258 // Non moving concurrent: 1259 // This case is easy to handle since the reference members of ArtMethod and ArtFields are held 1260 // live by the class and class roots. In this case we probably don't even need to call 1261 // VisitNativeRoots. 1262 // 1263 // Moving non-concurrent: 1264 // This case needs to call visit VisitNativeRoots in case the classes or dex cache arrays move. 1265 // To prevent missing roots, this case needs to ensure that there is no 1266 // suspend points between the point which we allocate ArtMethod arrays and place them in a 1267 // class which is in the class table. 1268 // 1269 // Moving concurrent: 1270 // Need to make sure to not copy ArtMethods without doing read barriers since the roots are 1271 // marked concurrently and we don't hold the classlinker_classes_lock_ when we do the copy. 1272 for (GcRoot<mirror::Class>& root : class_table_) { 1273 buffered_visitor.VisitRoot(root); 1274 if ((flags & kVisitRootFlagNonMoving) == 0) { 1275 // Don't bother visiting ArtField and ArtMethod if kVisitRootFlagNonMoving is set since 1276 // these roots are all reachable from the class or dex cache. 1277 root.Read()->VisitNativeRoots(buffered_visitor, image_pointer_size_); 1278 } 1279 } 1280 // PreZygote classes can't move so we won't need to update fields' declaring classes. 1281 for (GcRoot<mirror::Class>& root : pre_zygote_class_table_) { 1282 buffered_visitor.VisitRoot(root); 1283 if ((flags & kVisitRootFlagNonMoving) == 0) { 1284 root.Read()->VisitNativeRoots(buffered_visitor, image_pointer_size_); 1285 } 1286 } 1287 } else if ((flags & kVisitRootFlagNewRoots) != 0) { 1288 for (auto& root : new_class_roots_) { 1289 mirror::Class* old_ref = root.Read<kWithoutReadBarrier>(); 1290 old_ref->VisitNativeRoots(buffered_visitor, image_pointer_size_); 1291 root.VisitRoot(visitor, RootInfo(kRootStickyClass)); 1292 mirror::Class* new_ref = root.Read<kWithoutReadBarrier>(); 1293 if (UNLIKELY(new_ref != old_ref)) { 1294 // Uh ohes, GC moved a root in the log. Need to search the class_table and update the 1295 // corresponding object. This is slow, but luckily for us, this may only happen with a 1296 // concurrent moving GC. 1297 auto it = class_table_.Find(GcRoot<mirror::Class>(old_ref)); 1298 DCHECK(it != class_table_.end()); 1299 *it = GcRoot<mirror::Class>(new_ref); 1300 } 1301 } 1302 } 1303 buffered_visitor.Flush(); // Flush before clearing new_class_roots_. 1304 if ((flags & kVisitRootFlagClearRootLog) != 0) { 1305 new_class_roots_.clear(); 1306 } 1307 if ((flags & kVisitRootFlagStartLoggingNewRoots) != 0) { 1308 log_new_class_table_roots_ = true; 1309 } else if ((flags & kVisitRootFlagStopLoggingNewRoots) != 0) { 1310 log_new_class_table_roots_ = false; 1311 } 1312 // We deliberately ignore the class roots in the image since we 1313 // handle image roots by using the MS/CMS rescanning of dirty cards. 1314} 1315 1316// Keep in sync with InitCallback. Anything we visit, we need to 1317// reinit references to when reinitializing a ClassLinker from a 1318// mapped image. 1319void ClassLinker::VisitRoots(RootVisitor* visitor, VisitRootFlags flags) { 1320 class_roots_.VisitRoot(visitor, RootInfo(kRootVMInternal)); 1321 Thread* const self = Thread::Current(); 1322 { 1323 ReaderMutexLock mu(self, dex_lock_); 1324 if ((flags & kVisitRootFlagAllRoots) != 0) { 1325 for (GcRoot<mirror::DexCache>& dex_cache : dex_caches_) { 1326 dex_cache.VisitRoot(visitor, RootInfo(kRootVMInternal)); 1327 } 1328 } else if ((flags & kVisitRootFlagNewRoots) != 0) { 1329 for (size_t index : new_dex_cache_roots_) { 1330 dex_caches_[index].VisitRoot(visitor, RootInfo(kRootVMInternal)); 1331 } 1332 } 1333 if ((flags & kVisitRootFlagClearRootLog) != 0) { 1334 new_dex_cache_roots_.clear(); 1335 } 1336 if ((flags & kVisitRootFlagStartLoggingNewRoots) != 0) { 1337 log_new_dex_caches_roots_ = true; 1338 } else if ((flags & kVisitRootFlagStopLoggingNewRoots) != 0) { 1339 log_new_dex_caches_roots_ = false; 1340 } 1341 } 1342 VisitClassRoots(visitor, flags); 1343 array_iftable_.VisitRoot(visitor, RootInfo(kRootVMInternal)); 1344 for (size_t i = 0; i < kFindArrayCacheSize; ++i) { 1345 find_array_class_cache_[i].VisitRootIfNonNull(visitor, RootInfo(kRootVMInternal)); 1346 } 1347} 1348 1349void ClassLinker::VisitClasses(ClassVisitor* visitor, void* arg) { 1350 if (dex_cache_image_class_lookup_required_) { 1351 MoveImageClassesToClassTable(); 1352 } 1353 // TODO: why isn't this a ReaderMutexLock? 1354 WriterMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); 1355 for (GcRoot<mirror::Class>& root : class_table_) { 1356 if (!visitor(root.Read(), arg)) { 1357 return; 1358 } 1359 } 1360 for (GcRoot<mirror::Class>& root : pre_zygote_class_table_) { 1361 if (!visitor(root.Read(), arg)) { 1362 return; 1363 } 1364 } 1365} 1366 1367static bool GetClassesVisitorSet(mirror::Class* c, void* arg) { 1368 std::set<mirror::Class*>* classes = reinterpret_cast<std::set<mirror::Class*>*>(arg); 1369 classes->insert(c); 1370 return true; 1371} 1372 1373struct GetClassesVisitorArrayArg { 1374 Handle<mirror::ObjectArray<mirror::Class>>* classes; 1375 int32_t index; 1376 bool success; 1377}; 1378 1379static bool GetClassesVisitorArray(mirror::Class* c, void* varg) 1380 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1381 GetClassesVisitorArrayArg* arg = reinterpret_cast<GetClassesVisitorArrayArg*>(varg); 1382 if (arg->index < (*arg->classes)->GetLength()) { 1383 (*arg->classes)->Set(arg->index, c); 1384 arg->index++; 1385 return true; 1386 } else { 1387 arg->success = false; 1388 return false; 1389 } 1390} 1391 1392void ClassLinker::VisitClassesWithoutClassesLock(ClassVisitor* visitor, void* arg) { 1393 // TODO: it may be possible to avoid secondary storage if we iterate over dex caches. The problem 1394 // is avoiding duplicates. 1395 if (!kMovingClasses) { 1396 std::set<mirror::Class*> classes; 1397 VisitClasses(GetClassesVisitorSet, &classes); 1398 for (mirror::Class* klass : classes) { 1399 if (!visitor(klass, arg)) { 1400 return; 1401 } 1402 } 1403 } else { 1404 Thread* self = Thread::Current(); 1405 StackHandleScope<1> hs(self); 1406 MutableHandle<mirror::ObjectArray<mirror::Class>> classes = 1407 hs.NewHandle<mirror::ObjectArray<mirror::Class>>(nullptr); 1408 GetClassesVisitorArrayArg local_arg; 1409 local_arg.classes = &classes; 1410 local_arg.success = false; 1411 // We size the array assuming classes won't be added to the class table during the visit. 1412 // If this assumption fails we iterate again. 1413 while (!local_arg.success) { 1414 size_t class_table_size; 1415 { 1416 ReaderMutexLock mu(self, *Locks::classlinker_classes_lock_); 1417 class_table_size = class_table_.Size() + pre_zygote_class_table_.Size(); 1418 } 1419 mirror::Class* class_type = mirror::Class::GetJavaLangClass(); 1420 mirror::Class* array_of_class = FindArrayClass(self, &class_type); 1421 classes.Assign( 1422 mirror::ObjectArray<mirror::Class>::Alloc(self, array_of_class, class_table_size)); 1423 CHECK(classes.Get() != nullptr); // OOME. 1424 local_arg.index = 0; 1425 local_arg.success = true; 1426 VisitClasses(GetClassesVisitorArray, &local_arg); 1427 } 1428 for (int32_t i = 0; i < classes->GetLength(); ++i) { 1429 // If the class table shrank during creation of the clases array we expect null elements. If 1430 // the class table grew then the loop repeats. If classes are created after the loop has 1431 // finished then we don't visit. 1432 mirror::Class* klass = classes->Get(i); 1433 if (klass != nullptr && !visitor(klass, arg)) { 1434 return; 1435 } 1436 } 1437 } 1438} 1439 1440ClassLinker::~ClassLinker() { 1441 mirror::Class::ResetClass(); 1442 mirror::Constructor::ResetClass(); 1443 mirror::Field::ResetClass(); 1444 mirror::Method::ResetClass(); 1445 mirror::Reference::ResetClass(); 1446 mirror::StackTraceElement::ResetClass(); 1447 mirror::String::ResetClass(); 1448 mirror::Throwable::ResetClass(); 1449 mirror::BooleanArray::ResetArrayClass(); 1450 mirror::ByteArray::ResetArrayClass(); 1451 mirror::CharArray::ResetArrayClass(); 1452 mirror::Constructor::ResetArrayClass(); 1453 mirror::DoubleArray::ResetArrayClass(); 1454 mirror::Field::ResetArrayClass(); 1455 mirror::FloatArray::ResetArrayClass(); 1456 mirror::Method::ResetArrayClass(); 1457 mirror::IntArray::ResetArrayClass(); 1458 mirror::LongArray::ResetArrayClass(); 1459 mirror::ShortArray::ResetArrayClass(); 1460 STLDeleteElements(&oat_files_); 1461} 1462 1463mirror::PointerArray* ClassLinker::AllocPointerArray(Thread* self, size_t length) { 1464 return down_cast<mirror::PointerArray*>(image_pointer_size_ == 8u ? 1465 static_cast<mirror::Array*>(mirror::LongArray::Alloc(self, length)) : 1466 static_cast<mirror::Array*>(mirror::IntArray::Alloc(self, length))); 1467} 1468 1469mirror::DexCache* ClassLinker::AllocDexCache(Thread* self, const DexFile& dex_file) { 1470 StackHandleScope<6> hs(self); 1471 auto dex_cache(hs.NewHandle(down_cast<mirror::DexCache*>( 1472 GetClassRoot(kJavaLangDexCache)->AllocObject(self)))); 1473 if (dex_cache.Get() == nullptr) { 1474 self->AssertPendingOOMException(); 1475 return nullptr; 1476 } 1477 auto location(hs.NewHandle(intern_table_->InternStrong(dex_file.GetLocation().c_str()))); 1478 if (location.Get() == nullptr) { 1479 self->AssertPendingOOMException(); 1480 return nullptr; 1481 } 1482 auto strings(hs.NewHandle(AllocStringArray(self, dex_file.NumStringIds()))); 1483 if (strings.Get() == nullptr) { 1484 self->AssertPendingOOMException(); 1485 return nullptr; 1486 } 1487 auto types(hs.NewHandle(AllocClassArray(self, dex_file.NumTypeIds()))); 1488 if (types.Get() == nullptr) { 1489 self->AssertPendingOOMException(); 1490 return nullptr; 1491 } 1492 auto methods(hs.NewHandle(AllocPointerArray(self, dex_file.NumMethodIds()))); 1493 if (methods.Get() == nullptr) { 1494 self->AssertPendingOOMException(); 1495 return nullptr; 1496 } 1497 auto fields(hs.NewHandle(AllocPointerArray(self, dex_file.NumFieldIds()))); 1498 if (fields.Get() == nullptr) { 1499 self->AssertPendingOOMException(); 1500 return nullptr; 1501 } 1502 dex_cache->Init(&dex_file, location.Get(), strings.Get(), types.Get(), methods.Get(), 1503 fields.Get(), image_pointer_size_); 1504 return dex_cache.Get(); 1505} 1506 1507mirror::Class* ClassLinker::AllocClass(Thread* self, mirror::Class* java_lang_Class, 1508 uint32_t class_size) { 1509 DCHECK_GE(class_size, sizeof(mirror::Class)); 1510 gc::Heap* heap = Runtime::Current()->GetHeap(); 1511 mirror::Class::InitializeClassVisitor visitor(class_size); 1512 mirror::Object* k = kMovingClasses ? 1513 heap->AllocObject<true>(self, java_lang_Class, class_size, visitor) : 1514 heap->AllocNonMovableObject<true>(self, java_lang_Class, class_size, visitor); 1515 if (UNLIKELY(k == nullptr)) { 1516 self->AssertPendingOOMException(); 1517 return nullptr; 1518 } 1519 return k->AsClass(); 1520} 1521 1522mirror::Class* ClassLinker::AllocClass(Thread* self, uint32_t class_size) { 1523 return AllocClass(self, GetClassRoot(kJavaLangClass), class_size); 1524} 1525 1526mirror::ObjectArray<mirror::StackTraceElement>* ClassLinker::AllocStackTraceElementArray( 1527 Thread* self, size_t length) { 1528 return mirror::ObjectArray<mirror::StackTraceElement>::Alloc( 1529 self, GetClassRoot(kJavaLangStackTraceElementArrayClass), length); 1530} 1531 1532mirror::Class* ClassLinker::EnsureResolved(Thread* self, const char* descriptor, 1533 mirror::Class* klass) { 1534 DCHECK(klass != nullptr); 1535 1536 // For temporary classes we must wait for them to be retired. 1537 if (init_done_ && klass->IsTemp()) { 1538 CHECK(!klass->IsResolved()); 1539 if (klass->IsErroneous()) { 1540 ThrowEarlierClassFailure(klass); 1541 return nullptr; 1542 } 1543 StackHandleScope<1> hs(self); 1544 Handle<mirror::Class> h_class(hs.NewHandle(klass)); 1545 ObjectLock<mirror::Class> lock(self, h_class); 1546 // Loop and wait for the resolving thread to retire this class. 1547 while (!h_class->IsRetired() && !h_class->IsErroneous()) { 1548 lock.WaitIgnoringInterrupts(); 1549 } 1550 if (h_class->IsErroneous()) { 1551 ThrowEarlierClassFailure(h_class.Get()); 1552 return nullptr; 1553 } 1554 CHECK(h_class->IsRetired()); 1555 // Get the updated class from class table. 1556 klass = LookupClass(self, descriptor, ComputeModifiedUtf8Hash(descriptor), 1557 h_class.Get()->GetClassLoader()); 1558 } 1559 1560 // Wait for the class if it has not already been linked. 1561 if (!klass->IsResolved() && !klass->IsErroneous()) { 1562 StackHandleScope<1> hs(self); 1563 HandleWrapper<mirror::Class> h_class(hs.NewHandleWrapper(&klass)); 1564 ObjectLock<mirror::Class> lock(self, h_class); 1565 // Check for circular dependencies between classes. 1566 if (!h_class->IsResolved() && h_class->GetClinitThreadId() == self->GetTid()) { 1567 ThrowClassCircularityError(h_class.Get()); 1568 mirror::Class::SetStatus(h_class, mirror::Class::kStatusError, self); 1569 return nullptr; 1570 } 1571 // Wait for the pending initialization to complete. 1572 while (!h_class->IsResolved() && !h_class->IsErroneous()) { 1573 lock.WaitIgnoringInterrupts(); 1574 } 1575 } 1576 1577 if (klass->IsErroneous()) { 1578 ThrowEarlierClassFailure(klass); 1579 return nullptr; 1580 } 1581 // Return the loaded class. No exceptions should be pending. 1582 CHECK(klass->IsResolved()) << PrettyClass(klass); 1583 self->AssertNoPendingException(); 1584 return klass; 1585} 1586 1587typedef std::pair<const DexFile*, const DexFile::ClassDef*> ClassPathEntry; 1588 1589// Search a collection of DexFiles for a descriptor 1590ClassPathEntry FindInClassPath(const char* descriptor, 1591 size_t hash, const std::vector<const DexFile*>& class_path) { 1592 for (const DexFile* dex_file : class_path) { 1593 const DexFile::ClassDef* dex_class_def = dex_file->FindClassDef(descriptor, hash); 1594 if (dex_class_def != nullptr) { 1595 return ClassPathEntry(dex_file, dex_class_def); 1596 } 1597 } 1598 return ClassPathEntry(nullptr, nullptr); 1599} 1600 1601static bool IsBootClassLoader(ScopedObjectAccessAlreadyRunnable& soa, 1602 mirror::ClassLoader* class_loader) 1603 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1604 return class_loader == nullptr || 1605 class_loader->GetClass() == 1606 soa.Decode<mirror::Class*>(WellKnownClasses::java_lang_BootClassLoader); 1607} 1608 1609bool ClassLinker::FindClassInPathClassLoader(ScopedObjectAccessAlreadyRunnable& soa, 1610 Thread* self, const char* descriptor, 1611 size_t hash, 1612 Handle<mirror::ClassLoader> class_loader, 1613 mirror::Class** result) { 1614 // Termination case: boot class-loader. 1615 if (IsBootClassLoader(soa, class_loader.Get())) { 1616 // The boot class loader, search the boot class path. 1617 ClassPathEntry pair = FindInClassPath(descriptor, hash, boot_class_path_); 1618 if (pair.second != nullptr) { 1619 mirror::Class* klass = LookupClass(self, descriptor, hash, nullptr); 1620 if (klass != nullptr) { 1621 *result = EnsureResolved(self, descriptor, klass); 1622 } else { 1623 *result = DefineClass(self, descriptor, hash, NullHandle<mirror::ClassLoader>(), 1624 *pair.first, *pair.second); 1625 } 1626 if (*result == nullptr) { 1627 CHECK(self->IsExceptionPending()) << descriptor; 1628 self->ClearException(); 1629 } 1630 } else { 1631 *result = nullptr; 1632 } 1633 return true; 1634 } 1635 1636 // Unsupported class-loader? 1637 if (class_loader->GetClass() != 1638 soa.Decode<mirror::Class*>(WellKnownClasses::dalvik_system_PathClassLoader)) { 1639 *result = nullptr; 1640 return false; 1641 } 1642 1643 // Handles as RegisterDexFile may allocate dex caches (and cause thread suspension). 1644 StackHandleScope<4> hs(self); 1645 Handle<mirror::ClassLoader> h_parent(hs.NewHandle(class_loader->GetParent())); 1646 bool recursive_result = FindClassInPathClassLoader(soa, self, descriptor, hash, h_parent, result); 1647 1648 if (!recursive_result) { 1649 // Something wrong up the chain. 1650 return false; 1651 } 1652 1653 if (*result != nullptr) { 1654 // Found the class up the chain. 1655 return true; 1656 } 1657 1658 // Handle this step. 1659 // Handle as if this is the child PathClassLoader. 1660 // The class loader is a PathClassLoader which inherits from BaseDexClassLoader. 1661 // We need to get the DexPathList and loop through it. 1662 ArtField* const cookie_field = soa.DecodeField(WellKnownClasses::dalvik_system_DexFile_cookie); 1663 ArtField* const dex_file_field = 1664 soa.DecodeField(WellKnownClasses::dalvik_system_DexPathList__Element_dexFile); 1665 mirror::Object* dex_path_list = 1666 soa.DecodeField(WellKnownClasses::dalvik_system_PathClassLoader_pathList)-> 1667 GetObject(class_loader.Get()); 1668 if (dex_path_list != nullptr && dex_file_field != nullptr && cookie_field != nullptr) { 1669 // DexPathList has an array dexElements of Elements[] which each contain a dex file. 1670 mirror::Object* dex_elements_obj = 1671 soa.DecodeField(WellKnownClasses::dalvik_system_DexPathList_dexElements)-> 1672 GetObject(dex_path_list); 1673 // Loop through each dalvik.system.DexPathList$Element's dalvik.system.DexFile and look 1674 // at the mCookie which is a DexFile vector. 1675 if (dex_elements_obj != nullptr) { 1676 Handle<mirror::ObjectArray<mirror::Object>> dex_elements = 1677 hs.NewHandle(dex_elements_obj->AsObjectArray<mirror::Object>()); 1678 for (int32_t i = 0; i < dex_elements->GetLength(); ++i) { 1679 mirror::Object* element = dex_elements->GetWithoutChecks(i); 1680 if (element == nullptr) { 1681 // Should never happen, fall back to java code to throw a NPE. 1682 break; 1683 } 1684 mirror::Object* dex_file = dex_file_field->GetObject(element); 1685 if (dex_file != nullptr) { 1686 mirror::LongArray* long_array = cookie_field->GetObject(dex_file)->AsLongArray(); 1687 if (long_array == nullptr) { 1688 // This should never happen so log a warning. 1689 LOG(WARNING) << "Null DexFile::mCookie for " << descriptor; 1690 break; 1691 } 1692 int32_t long_array_size = long_array->GetLength(); 1693 for (int32_t j = 0; j < long_array_size; ++j) { 1694 const DexFile* cp_dex_file = reinterpret_cast<const DexFile*>(static_cast<uintptr_t>( 1695 long_array->GetWithoutChecks(j))); 1696 const DexFile::ClassDef* dex_class_def = cp_dex_file->FindClassDef(descriptor, hash); 1697 if (dex_class_def != nullptr) { 1698 RegisterDexFile(*cp_dex_file); 1699 mirror::Class* klass = DefineClass(self, descriptor, hash, class_loader, 1700 *cp_dex_file, *dex_class_def); 1701 if (klass == nullptr) { 1702 CHECK(self->IsExceptionPending()) << descriptor; 1703 self->ClearException(); 1704 // TODO: Is it really right to break here, and not check the other dex files? 1705 return true; 1706 } 1707 *result = klass; 1708 return true; 1709 } 1710 } 1711 } 1712 } 1713 } 1714 self->AssertNoPendingException(); 1715 } 1716 1717 // Result is still null from the parent call, no need to set it again... 1718 return true; 1719} 1720 1721mirror::Class* ClassLinker::FindClass(Thread* self, const char* descriptor, 1722 Handle<mirror::ClassLoader> class_loader) { 1723 DCHECK_NE(*descriptor, '\0') << "descriptor is empty string"; 1724 DCHECK(self != nullptr); 1725 self->AssertNoPendingException(); 1726 if (descriptor[1] == '\0') { 1727 // only the descriptors of primitive types should be 1 character long, also avoid class lookup 1728 // for primitive classes that aren't backed by dex files. 1729 return FindPrimitiveClass(descriptor[0]); 1730 } 1731 const size_t hash = ComputeModifiedUtf8Hash(descriptor); 1732 // Find the class in the loaded classes table. 1733 mirror::Class* klass = LookupClass(self, descriptor, hash, class_loader.Get()); 1734 if (klass != nullptr) { 1735 return EnsureResolved(self, descriptor, klass); 1736 } 1737 // Class is not yet loaded. 1738 if (descriptor[0] == '[') { 1739 return CreateArrayClass(self, descriptor, hash, class_loader); 1740 } else if (class_loader.Get() == nullptr) { 1741 // The boot class loader, search the boot class path. 1742 ClassPathEntry pair = FindInClassPath(descriptor, hash, boot_class_path_); 1743 if (pair.second != nullptr) { 1744 return DefineClass(self, descriptor, hash, NullHandle<mirror::ClassLoader>(), *pair.first, 1745 *pair.second); 1746 } else { 1747 // The boot class loader is searched ahead of the application class loader, failures are 1748 // expected and will be wrapped in a ClassNotFoundException. Use the pre-allocated error to 1749 // trigger the chaining with a proper stack trace. 1750 mirror::Throwable* pre_allocated = Runtime::Current()->GetPreAllocatedNoClassDefFoundError(); 1751 self->SetException(pre_allocated); 1752 return nullptr; 1753 } 1754 } else { 1755 ScopedObjectAccessUnchecked soa(self); 1756 mirror::Class* cp_klass; 1757 if (FindClassInPathClassLoader(soa, self, descriptor, hash, class_loader, &cp_klass)) { 1758 // The chain was understood. So the value in cp_klass is either the class we were looking 1759 // for, or not found. 1760 if (cp_klass != nullptr) { 1761 return cp_klass; 1762 } 1763 // TODO: We handle the boot classpath loader in FindClassInPathClassLoader. Try to unify this 1764 // and the branch above. TODO: throw the right exception here. 1765 1766 // We'll let the Java-side rediscover all this and throw the exception with the right stack 1767 // trace. 1768 } 1769 1770 if (Runtime::Current()->IsAotCompiler()) { 1771 // Oops, compile-time, can't run actual class-loader code. 1772 mirror::Throwable* pre_allocated = Runtime::Current()->GetPreAllocatedNoClassDefFoundError(); 1773 self->SetException(pre_allocated); 1774 return nullptr; 1775 } 1776 1777 ScopedLocalRef<jobject> class_loader_object(soa.Env(), 1778 soa.AddLocalReference<jobject>(class_loader.Get())); 1779 std::string class_name_string(DescriptorToDot(descriptor)); 1780 ScopedLocalRef<jobject> result(soa.Env(), nullptr); 1781 { 1782 ScopedThreadStateChange tsc(self, kNative); 1783 ScopedLocalRef<jobject> class_name_object(soa.Env(), 1784 soa.Env()->NewStringUTF(class_name_string.c_str())); 1785 if (class_name_object.get() == nullptr) { 1786 DCHECK(self->IsExceptionPending()); // OOME. 1787 return nullptr; 1788 } 1789 CHECK(class_loader_object.get() != nullptr); 1790 result.reset(soa.Env()->CallObjectMethod(class_loader_object.get(), 1791 WellKnownClasses::java_lang_ClassLoader_loadClass, 1792 class_name_object.get())); 1793 } 1794 if (self->IsExceptionPending()) { 1795 // If the ClassLoader threw, pass that exception up. 1796 return nullptr; 1797 } else if (result.get() == nullptr) { 1798 // broken loader - throw NPE to be compatible with Dalvik 1799 ThrowNullPointerException(StringPrintf("ClassLoader.loadClass returned null for %s", 1800 class_name_string.c_str()).c_str()); 1801 return nullptr; 1802 } else { 1803 // success, return mirror::Class* 1804 return soa.Decode<mirror::Class*>(result.get()); 1805 } 1806 } 1807 UNREACHABLE(); 1808} 1809 1810mirror::Class* ClassLinker::DefineClass(Thread* self, const char* descriptor, size_t hash, 1811 Handle<mirror::ClassLoader> class_loader, 1812 const DexFile& dex_file, 1813 const DexFile::ClassDef& dex_class_def) { 1814 StackHandleScope<3> hs(self); 1815 auto klass = hs.NewHandle<mirror::Class>(nullptr); 1816 1817 // Load the class from the dex file. 1818 if (UNLIKELY(!init_done_)) { 1819 // finish up init of hand crafted class_roots_ 1820 if (strcmp(descriptor, "Ljava/lang/Object;") == 0) { 1821 klass.Assign(GetClassRoot(kJavaLangObject)); 1822 } else if (strcmp(descriptor, "Ljava/lang/Class;") == 0) { 1823 klass.Assign(GetClassRoot(kJavaLangClass)); 1824 } else if (strcmp(descriptor, "Ljava/lang/String;") == 0) { 1825 klass.Assign(GetClassRoot(kJavaLangString)); 1826 } else if (strcmp(descriptor, "Ljava/lang/ref/Reference;") == 0) { 1827 klass.Assign(GetClassRoot(kJavaLangRefReference)); 1828 } else if (strcmp(descriptor, "Ljava/lang/DexCache;") == 0) { 1829 klass.Assign(GetClassRoot(kJavaLangDexCache)); 1830 } 1831 } 1832 1833 if (klass.Get() == nullptr) { 1834 // Allocate a class with the status of not ready. 1835 // Interface object should get the right size here. Regular class will 1836 // figure out the right size later and be replaced with one of the right 1837 // size when the class becomes resolved. 1838 klass.Assign(AllocClass(self, SizeOfClassWithoutEmbeddedTables(dex_file, dex_class_def))); 1839 } 1840 if (UNLIKELY(klass.Get() == nullptr)) { 1841 CHECK(self->IsExceptionPending()); // Expect an OOME. 1842 return nullptr; 1843 } 1844 klass->SetDexCache(FindDexCache(dex_file)); 1845 1846 SetupClass(dex_file, dex_class_def, klass, class_loader.Get()); 1847 1848 // Mark the string class by setting its access flag. 1849 if (UNLIKELY(!init_done_)) { 1850 if (strcmp(descriptor, "Ljava/lang/String;") == 0) { 1851 klass->SetStringClass(); 1852 } 1853 } 1854 1855 ObjectLock<mirror::Class> lock(self, klass); 1856 klass->SetClinitThreadId(self->GetTid()); 1857 1858 // Add the newly loaded class to the loaded classes table. 1859 mirror::Class* existing = InsertClass(descriptor, klass.Get(), hash); 1860 if (existing != nullptr) { 1861 // We failed to insert because we raced with another thread. Calling EnsureResolved may cause 1862 // this thread to block. 1863 return EnsureResolved(self, descriptor, existing); 1864 } 1865 1866 // Load the fields and other things after we are inserted in the table. This is so that we don't 1867 // end up allocating unfree-able linear alloc resources and then lose the race condition. The 1868 // other reason is that the field roots are only visited from the class table. So we need to be 1869 // inserted before we allocate / fill in these fields. 1870 LoadClass(self, dex_file, dex_class_def, klass); 1871 if (self->IsExceptionPending()) { 1872 // An exception occured during load, set status to erroneous while holding klass' lock in case 1873 // notification is necessary. 1874 if (!klass->IsErroneous()) { 1875 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 1876 } 1877 return nullptr; 1878 } 1879 1880 // Finish loading (if necessary) by finding parents 1881 CHECK(!klass->IsLoaded()); 1882 if (!LoadSuperAndInterfaces(klass, dex_file)) { 1883 // Loading failed. 1884 if (!klass->IsErroneous()) { 1885 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 1886 } 1887 return nullptr; 1888 } 1889 CHECK(klass->IsLoaded()); 1890 // Link the class (if necessary) 1891 CHECK(!klass->IsResolved()); 1892 // TODO: Use fast jobjects? 1893 auto interfaces = hs.NewHandle<mirror::ObjectArray<mirror::Class>>(nullptr); 1894 1895 MutableHandle<mirror::Class> h_new_class = hs.NewHandle<mirror::Class>(nullptr); 1896 if (!LinkClass(self, descriptor, klass, interfaces, &h_new_class)) { 1897 // Linking failed. 1898 if (!klass->IsErroneous()) { 1899 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 1900 } 1901 return nullptr; 1902 } 1903 self->AssertNoPendingException(); 1904 CHECK(h_new_class.Get() != nullptr) << descriptor; 1905 CHECK(h_new_class->IsResolved()) << descriptor; 1906 1907 // Instrumentation may have updated entrypoints for all methods of all 1908 // classes. However it could not update methods of this class while we 1909 // were loading it. Now the class is resolved, we can update entrypoints 1910 // as required by instrumentation. 1911 if (Runtime::Current()->GetInstrumentation()->AreExitStubsInstalled()) { 1912 // We must be in the kRunnable state to prevent instrumentation from 1913 // suspending all threads to update entrypoints while we are doing it 1914 // for this class. 1915 DCHECK_EQ(self->GetState(), kRunnable); 1916 Runtime::Current()->GetInstrumentation()->InstallStubsForClass(h_new_class.Get()); 1917 } 1918 1919 /* 1920 * We send CLASS_PREPARE events to the debugger from here. The 1921 * definition of "preparation" is creating the static fields for a 1922 * class and initializing them to the standard default values, but not 1923 * executing any code (that comes later, during "initialization"). 1924 * 1925 * We did the static preparation in LinkClass. 1926 * 1927 * The class has been prepared and resolved but possibly not yet verified 1928 * at this point. 1929 */ 1930 Dbg::PostClassPrepare(h_new_class.Get()); 1931 1932 return h_new_class.Get(); 1933} 1934 1935uint32_t ClassLinker::SizeOfClassWithoutEmbeddedTables(const DexFile& dex_file, 1936 const DexFile::ClassDef& dex_class_def) { 1937 const uint8_t* class_data = dex_file.GetClassData(dex_class_def); 1938 size_t num_ref = 0; 1939 size_t num_8 = 0; 1940 size_t num_16 = 0; 1941 size_t num_32 = 0; 1942 size_t num_64 = 0; 1943 if (class_data != nullptr) { 1944 for (ClassDataItemIterator it(dex_file, class_data); it.HasNextStaticField(); it.Next()) { 1945 const DexFile::FieldId& field_id = dex_file.GetFieldId(it.GetMemberIndex()); 1946 const char* descriptor = dex_file.GetFieldTypeDescriptor(field_id); 1947 char c = descriptor[0]; 1948 switch (c) { 1949 case 'L': 1950 case '[': 1951 num_ref++; 1952 break; 1953 case 'J': 1954 case 'D': 1955 num_64++; 1956 break; 1957 case 'I': 1958 case 'F': 1959 num_32++; 1960 break; 1961 case 'S': 1962 case 'C': 1963 num_16++; 1964 break; 1965 case 'B': 1966 case 'Z': 1967 num_8++; 1968 break; 1969 default: 1970 LOG(FATAL) << "Unknown descriptor: " << c; 1971 UNREACHABLE(); 1972 } 1973 } 1974 } 1975 return mirror::Class::ComputeClassSize(false, 0, num_8, num_16, num_32, num_64, num_ref, 1976 image_pointer_size_); 1977} 1978 1979OatFile::OatClass ClassLinker::FindOatClass(const DexFile& dex_file, uint16_t class_def_idx, 1980 bool* found) { 1981 DCHECK_NE(class_def_idx, DexFile::kDexNoIndex16); 1982 const OatFile::OatDexFile* oat_dex_file = dex_file.GetOatDexFile(); 1983 if (oat_dex_file == nullptr) { 1984 *found = false; 1985 return OatFile::OatClass::Invalid(); 1986 } 1987 *found = true; 1988 return oat_dex_file->GetOatClass(class_def_idx); 1989} 1990 1991static uint32_t GetOatMethodIndexFromMethodIndex(const DexFile& dex_file, uint16_t class_def_idx, 1992 uint32_t method_idx) { 1993 const DexFile::ClassDef& class_def = dex_file.GetClassDef(class_def_idx); 1994 const uint8_t* class_data = dex_file.GetClassData(class_def); 1995 CHECK(class_data != nullptr); 1996 ClassDataItemIterator it(dex_file, class_data); 1997 // Skip fields 1998 while (it.HasNextStaticField()) { 1999 it.Next(); 2000 } 2001 while (it.HasNextInstanceField()) { 2002 it.Next(); 2003 } 2004 // Process methods 2005 size_t class_def_method_index = 0; 2006 while (it.HasNextDirectMethod()) { 2007 if (it.GetMemberIndex() == method_idx) { 2008 return class_def_method_index; 2009 } 2010 class_def_method_index++; 2011 it.Next(); 2012 } 2013 while (it.HasNextVirtualMethod()) { 2014 if (it.GetMemberIndex() == method_idx) { 2015 return class_def_method_index; 2016 } 2017 class_def_method_index++; 2018 it.Next(); 2019 } 2020 DCHECK(!it.HasNext()); 2021 LOG(FATAL) << "Failed to find method index " << method_idx << " in " << dex_file.GetLocation(); 2022 UNREACHABLE(); 2023} 2024 2025const OatFile::OatMethod ClassLinker::FindOatMethodFor(ArtMethod* method, bool* found) { 2026 // Although we overwrite the trampoline of non-static methods, we may get here via the resolution 2027 // method for direct methods (or virtual methods made direct). 2028 mirror::Class* declaring_class = method->GetDeclaringClass(); 2029 size_t oat_method_index; 2030 if (method->IsStatic() || method->IsDirect()) { 2031 // Simple case where the oat method index was stashed at load time. 2032 oat_method_index = method->GetMethodIndex(); 2033 } else { 2034 // We're invoking a virtual method directly (thanks to sharpening), compute the oat_method_index 2035 // by search for its position in the declared virtual methods. 2036 oat_method_index = declaring_class->NumDirectMethods(); 2037 size_t end = declaring_class->NumVirtualMethods(); 2038 bool found_virtual = false; 2039 for (size_t i = 0; i < end; i++) { 2040 // Check method index instead of identity in case of duplicate method definitions. 2041 if (method->GetDexMethodIndex() == 2042 declaring_class->GetVirtualMethod(i, image_pointer_size_)->GetDexMethodIndex()) { 2043 found_virtual = true; 2044 break; 2045 } 2046 oat_method_index++; 2047 } 2048 CHECK(found_virtual) << "Didn't find oat method index for virtual method: " 2049 << PrettyMethod(method); 2050 } 2051 DCHECK_EQ(oat_method_index, 2052 GetOatMethodIndexFromMethodIndex(*declaring_class->GetDexCache()->GetDexFile(), 2053 method->GetDeclaringClass()->GetDexClassDefIndex(), 2054 method->GetDexMethodIndex())); 2055 OatFile::OatClass oat_class = FindOatClass(*declaring_class->GetDexCache()->GetDexFile(), 2056 declaring_class->GetDexClassDefIndex(), 2057 found); 2058 if (!(*found)) { 2059 return OatFile::OatMethod::Invalid(); 2060 } 2061 return oat_class.GetOatMethod(oat_method_index); 2062} 2063 2064// Special case to get oat code without overwriting a trampoline. 2065const void* ClassLinker::GetQuickOatCodeFor(ArtMethod* method) { 2066 CHECK(!method->IsAbstract()) << PrettyMethod(method); 2067 if (method->IsProxyMethod()) { 2068 return GetQuickProxyInvokeHandler(); 2069 } 2070 bool found; 2071 OatFile::OatMethod oat_method = FindOatMethodFor(method, &found); 2072 if (found) { 2073 auto* code = oat_method.GetQuickCode(); 2074 if (code != nullptr) { 2075 return code; 2076 } 2077 } 2078 jit::Jit* const jit = Runtime::Current()->GetJit(); 2079 if (jit != nullptr) { 2080 auto* code = jit->GetCodeCache()->GetCodeFor(method); 2081 if (code != nullptr) { 2082 return code; 2083 } 2084 } 2085 if (method->IsNative()) { 2086 // No code and native? Use generic trampoline. 2087 return GetQuickGenericJniStub(); 2088 } 2089 return GetQuickToInterpreterBridge(); 2090} 2091 2092const void* ClassLinker::GetOatMethodQuickCodeFor(ArtMethod* method) { 2093 if (method->IsNative() || method->IsAbstract() || method->IsProxyMethod()) { 2094 return nullptr; 2095 } 2096 bool found; 2097 OatFile::OatMethod oat_method = FindOatMethodFor(method, &found); 2098 if (found) { 2099 return oat_method.GetQuickCode(); 2100 } 2101 jit::Jit* jit = Runtime::Current()->GetJit(); 2102 if (jit != nullptr) { 2103 auto* code = jit->GetCodeCache()->GetCodeFor(method); 2104 if (code != nullptr) { 2105 return code; 2106 } 2107 } 2108 return nullptr; 2109} 2110 2111const void* ClassLinker::GetQuickOatCodeFor(const DexFile& dex_file, uint16_t class_def_idx, 2112 uint32_t method_idx) { 2113 bool found; 2114 OatFile::OatClass oat_class = FindOatClass(dex_file, class_def_idx, &found); 2115 if (!found) { 2116 return nullptr; 2117 } 2118 uint32_t oat_method_idx = GetOatMethodIndexFromMethodIndex(dex_file, class_def_idx, method_idx); 2119 return oat_class.GetOatMethod(oat_method_idx).GetQuickCode(); 2120} 2121 2122// Returns true if the method must run with interpreter, false otherwise. 2123static bool NeedsInterpreter(ArtMethod* method, const void* quick_code) 2124 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2125 if (quick_code == nullptr) { 2126 // No code: need interpreter. 2127 // May return true for native code, in the case of generic JNI 2128 // DCHECK(!method->IsNative()); 2129 return true; 2130 } 2131 // If interpreter mode is enabled, every method (except native and proxy) must 2132 // be run with interpreter. 2133 return Runtime::Current()->GetInstrumentation()->InterpretOnly() && 2134 !method->IsNative() && !method->IsProxyMethod(); 2135} 2136 2137void ClassLinker::FixupStaticTrampolines(mirror::Class* klass) { 2138 DCHECK(klass->IsInitialized()) << PrettyDescriptor(klass); 2139 if (klass->NumDirectMethods() == 0) { 2140 return; // No direct methods => no static methods. 2141 } 2142 Runtime* runtime = Runtime::Current(); 2143 if (!runtime->IsStarted()) { 2144 if (runtime->IsAotCompiler() || runtime->GetHeap()->HasImageSpace()) { 2145 return; // OAT file unavailable. 2146 } 2147 } 2148 2149 const DexFile& dex_file = klass->GetDexFile(); 2150 const DexFile::ClassDef* dex_class_def = klass->GetClassDef(); 2151 CHECK(dex_class_def != nullptr); 2152 const uint8_t* class_data = dex_file.GetClassData(*dex_class_def); 2153 // There should always be class data if there were direct methods. 2154 CHECK(class_data != nullptr) << PrettyDescriptor(klass); 2155 ClassDataItemIterator it(dex_file, class_data); 2156 // Skip fields 2157 while (it.HasNextStaticField()) { 2158 it.Next(); 2159 } 2160 while (it.HasNextInstanceField()) { 2161 it.Next(); 2162 } 2163 bool has_oat_class; 2164 OatFile::OatClass oat_class = FindOatClass(dex_file, klass->GetDexClassDefIndex(), 2165 &has_oat_class); 2166 // Link the code of methods skipped by LinkCode. 2167 for (size_t method_index = 0; it.HasNextDirectMethod(); ++method_index, it.Next()) { 2168 ArtMethod* method = klass->GetDirectMethod(method_index, image_pointer_size_); 2169 if (!method->IsStatic()) { 2170 // Only update static methods. 2171 continue; 2172 } 2173 const void* quick_code = nullptr; 2174 if (has_oat_class) { 2175 OatFile::OatMethod oat_method = oat_class.GetOatMethod(method_index); 2176 quick_code = oat_method.GetQuickCode(); 2177 } 2178 const bool enter_interpreter = NeedsInterpreter(method, quick_code); 2179 if (enter_interpreter) { 2180 // Use interpreter entry point. 2181 // Check whether the method is native, in which case it's generic JNI. 2182 if (quick_code == nullptr && method->IsNative()) { 2183 quick_code = GetQuickGenericJniStub(); 2184 } else { 2185 quick_code = GetQuickToInterpreterBridge(); 2186 } 2187 } 2188 runtime->GetInstrumentation()->UpdateMethodsCode(method, quick_code); 2189 } 2190 // Ignore virtual methods on the iterator. 2191} 2192 2193void ClassLinker::LinkCode(ArtMethod* method, const OatFile::OatClass* oat_class, 2194 uint32_t class_def_method_index) { 2195 Runtime* const runtime = Runtime::Current(); 2196 if (runtime->IsAotCompiler()) { 2197 // The following code only applies to a non-compiler runtime. 2198 return; 2199 } 2200 // Method shouldn't have already been linked. 2201 DCHECK(method->GetEntryPointFromQuickCompiledCode() == nullptr); 2202 if (oat_class != nullptr) { 2203 // Every kind of method should at least get an invoke stub from the oat_method. 2204 // non-abstract methods also get their code pointers. 2205 const OatFile::OatMethod oat_method = oat_class->GetOatMethod(class_def_method_index); 2206 oat_method.LinkMethod(method); 2207 } 2208 2209 // Install entry point from interpreter. 2210 bool enter_interpreter = NeedsInterpreter(method, method->GetEntryPointFromQuickCompiledCode()); 2211 if (enter_interpreter && !method->IsNative()) { 2212 method->SetEntryPointFromInterpreter(artInterpreterToInterpreterBridge); 2213 } else { 2214 method->SetEntryPointFromInterpreter(artInterpreterToCompiledCodeBridge); 2215 } 2216 2217 if (method->IsAbstract()) { 2218 method->SetEntryPointFromQuickCompiledCode(GetQuickToInterpreterBridge()); 2219 return; 2220 } 2221 2222 if (method->IsStatic() && !method->IsConstructor()) { 2223 // For static methods excluding the class initializer, install the trampoline. 2224 // It will be replaced by the proper entry point by ClassLinker::FixupStaticTrampolines 2225 // after initializing class (see ClassLinker::InitializeClass method). 2226 method->SetEntryPointFromQuickCompiledCode(GetQuickResolutionStub()); 2227 } else if (enter_interpreter) { 2228 if (!method->IsNative()) { 2229 // Set entry point from compiled code if there's no code or in interpreter only mode. 2230 method->SetEntryPointFromQuickCompiledCode(GetQuickToInterpreterBridge()); 2231 } else { 2232 method->SetEntryPointFromQuickCompiledCode(GetQuickGenericJniStub()); 2233 } 2234 } 2235 2236 if (method->IsNative()) { 2237 // Unregistering restores the dlsym lookup stub. 2238 method->UnregisterNative(); 2239 2240 if (enter_interpreter) { 2241 // We have a native method here without code. Then it should have either the generic JNI 2242 // trampoline as entrypoint (non-static), or the resolution trampoline (static). 2243 // TODO: this doesn't handle all the cases where trampolines may be installed. 2244 const void* entry_point = method->GetEntryPointFromQuickCompiledCode(); 2245 DCHECK(IsQuickGenericJniStub(entry_point) || IsQuickResolutionStub(entry_point)); 2246 } 2247 } 2248} 2249 2250void ClassLinker::SetupClass(const DexFile& dex_file, const DexFile::ClassDef& dex_class_def, 2251 Handle<mirror::Class> klass, mirror::ClassLoader* class_loader) { 2252 CHECK(klass.Get() != nullptr); 2253 CHECK(klass->GetDexCache() != nullptr); 2254 CHECK_EQ(mirror::Class::kStatusNotReady, klass->GetStatus()); 2255 const char* descriptor = dex_file.GetClassDescriptor(dex_class_def); 2256 CHECK(descriptor != nullptr); 2257 2258 klass->SetClass(GetClassRoot(kJavaLangClass)); 2259 uint32_t access_flags = dex_class_def.GetJavaAccessFlags(); 2260 CHECK_EQ(access_flags & ~kAccJavaFlagsMask, 0U); 2261 klass->SetAccessFlags(access_flags); 2262 klass->SetClassLoader(class_loader); 2263 DCHECK_EQ(klass->GetPrimitiveType(), Primitive::kPrimNot); 2264 mirror::Class::SetStatus(klass, mirror::Class::kStatusIdx, nullptr); 2265 2266 klass->SetDexClassDefIndex(dex_file.GetIndexForClassDef(dex_class_def)); 2267 klass->SetDexTypeIndex(dex_class_def.class_idx_); 2268 CHECK(klass->GetDexCacheStrings() != nullptr); 2269} 2270 2271void ClassLinker::LoadClass(Thread* self, const DexFile& dex_file, 2272 const DexFile::ClassDef& dex_class_def, 2273 Handle<mirror::Class> klass) { 2274 const uint8_t* class_data = dex_file.GetClassData(dex_class_def); 2275 if (class_data == nullptr) { 2276 return; // no fields or methods - for example a marker interface 2277 } 2278 bool has_oat_class = false; 2279 if (Runtime::Current()->IsStarted() && !Runtime::Current()->IsAotCompiler()) { 2280 OatFile::OatClass oat_class = FindOatClass(dex_file, klass->GetDexClassDefIndex(), 2281 &has_oat_class); 2282 if (has_oat_class) { 2283 LoadClassMembers(self, dex_file, class_data, klass, &oat_class); 2284 } 2285 } 2286 if (!has_oat_class) { 2287 LoadClassMembers(self, dex_file, class_data, klass, nullptr); 2288 } 2289} 2290 2291ArtField* ClassLinker::AllocArtFieldArray(Thread* self, size_t length) { 2292 auto* const la = Runtime::Current()->GetLinearAlloc(); 2293 auto* ptr = reinterpret_cast<ArtField*>(la->AllocArray<ArtField>(self, length)); 2294 CHECK(ptr!= nullptr); 2295 std::uninitialized_fill_n(ptr, length, ArtField()); 2296 return ptr; 2297} 2298 2299ArtMethod* ClassLinker::AllocArtMethodArray(Thread* self, size_t length) { 2300 const size_t method_size = ArtMethod::ObjectSize(image_pointer_size_); 2301 uintptr_t ptr = reinterpret_cast<uintptr_t>( 2302 Runtime::Current()->GetLinearAlloc()->Alloc(self, method_size * length)); 2303 CHECK_NE(ptr, 0u); 2304 for (size_t i = 0; i < length; ++i) { 2305 new(reinterpret_cast<void*>(ptr + i * method_size)) ArtMethod; 2306 } 2307 return reinterpret_cast<ArtMethod*>(ptr); 2308} 2309 2310void ClassLinker::LoadClassMembers(Thread* self, const DexFile& dex_file, 2311 const uint8_t* class_data, 2312 Handle<mirror::Class> klass, 2313 const OatFile::OatClass* oat_class) { 2314 { 2315 // Note: We cannot have thread suspension until the field and method arrays are setup or else 2316 // Class::VisitFieldRoots may miss some fields or methods. 2317 ScopedAssertNoThreadSuspension nts(self, __FUNCTION__); 2318 // Load static fields. 2319 ClassDataItemIterator it(dex_file, class_data); 2320 const size_t num_sfields = it.NumStaticFields(); 2321 ArtField* sfields = num_sfields != 0 ? AllocArtFieldArray(self, num_sfields) : nullptr; 2322 for (size_t i = 0; it.HasNextStaticField(); i++, it.Next()) { 2323 CHECK_LT(i, num_sfields); 2324 LoadField(it, klass, &sfields[i]); 2325 } 2326 klass->SetSFields(sfields); 2327 klass->SetNumStaticFields(num_sfields); 2328 DCHECK_EQ(klass->NumStaticFields(), num_sfields); 2329 // Load instance fields. 2330 const size_t num_ifields = it.NumInstanceFields(); 2331 ArtField* ifields = num_ifields != 0 ? AllocArtFieldArray(self, num_ifields) : nullptr; 2332 for (size_t i = 0; it.HasNextInstanceField(); i++, it.Next()) { 2333 CHECK_LT(i, num_ifields); 2334 LoadField(it, klass, &ifields[i]); 2335 } 2336 klass->SetIFields(ifields); 2337 klass->SetNumInstanceFields(num_ifields); 2338 DCHECK_EQ(klass->NumInstanceFields(), num_ifields); 2339 // Load methods. 2340 if (it.NumDirectMethods() != 0) { 2341 klass->SetDirectMethodsPtr(AllocArtMethodArray(self, it.NumDirectMethods())); 2342 } 2343 klass->SetNumDirectMethods(it.NumDirectMethods()); 2344 if (it.NumVirtualMethods() != 0) { 2345 klass->SetVirtualMethodsPtr(AllocArtMethodArray(self, it.NumVirtualMethods())); 2346 } 2347 klass->SetNumVirtualMethods(it.NumVirtualMethods()); 2348 size_t class_def_method_index = 0; 2349 uint32_t last_dex_method_index = DexFile::kDexNoIndex; 2350 size_t last_class_def_method_index = 0; 2351 for (size_t i = 0; it.HasNextDirectMethod(); i++, it.Next()) { 2352 ArtMethod* method = klass->GetDirectMethodUnchecked(i, image_pointer_size_); 2353 LoadMethod(self, dex_file, it, klass, method); 2354 LinkCode(method, oat_class, class_def_method_index); 2355 uint32_t it_method_index = it.GetMemberIndex(); 2356 if (last_dex_method_index == it_method_index) { 2357 // duplicate case 2358 method->SetMethodIndex(last_class_def_method_index); 2359 } else { 2360 method->SetMethodIndex(class_def_method_index); 2361 last_dex_method_index = it_method_index; 2362 last_class_def_method_index = class_def_method_index; 2363 } 2364 class_def_method_index++; 2365 } 2366 for (size_t i = 0; it.HasNextVirtualMethod(); i++, it.Next()) { 2367 ArtMethod* method = klass->GetVirtualMethodUnchecked(i, image_pointer_size_); 2368 LoadMethod(self, dex_file, it, klass, method); 2369 DCHECK_EQ(class_def_method_index, it.NumDirectMethods() + i); 2370 LinkCode(method, oat_class, class_def_method_index); 2371 class_def_method_index++; 2372 } 2373 DCHECK(!it.HasNext()); 2374 } 2375 self->AllowThreadSuspension(); 2376} 2377 2378void ClassLinker::LoadField(const ClassDataItemIterator& it, Handle<mirror::Class> klass, 2379 ArtField* dst) { 2380 const uint32_t field_idx = it.GetMemberIndex(); 2381 dst->SetDexFieldIndex(field_idx); 2382 dst->SetDeclaringClass(klass.Get()); 2383 dst->SetAccessFlags(it.GetFieldAccessFlags()); 2384} 2385 2386void ClassLinker::LoadMethod(Thread* self, const DexFile& dex_file, const ClassDataItemIterator& it, 2387 Handle<mirror::Class> klass, ArtMethod* dst) { 2388 uint32_t dex_method_idx = it.GetMemberIndex(); 2389 const DexFile::MethodId& method_id = dex_file.GetMethodId(dex_method_idx); 2390 const char* method_name = dex_file.StringDataByIdx(method_id.name_idx_); 2391 2392 ScopedAssertNoThreadSuspension ants(self, "LoadMethod"); 2393 dst->SetDexMethodIndex(dex_method_idx); 2394 dst->SetDeclaringClass(klass.Get()); 2395 dst->SetCodeItemOffset(it.GetMethodCodeItemOffset()); 2396 2397 dst->SetDexCacheResolvedMethods(klass->GetDexCache()->GetResolvedMethods()); 2398 dst->SetDexCacheResolvedTypes(klass->GetDexCache()->GetResolvedTypes()); 2399 2400 uint32_t access_flags = it.GetMethodAccessFlags(); 2401 2402 if (UNLIKELY(strcmp("finalize", method_name) == 0)) { 2403 // Set finalizable flag on declaring class. 2404 if (strcmp("V", dex_file.GetShorty(method_id.proto_idx_)) == 0) { 2405 // Void return type. 2406 if (klass->GetClassLoader() != nullptr) { // All non-boot finalizer methods are flagged. 2407 klass->SetFinalizable(); 2408 } else { 2409 std::string temp; 2410 const char* klass_descriptor = klass->GetDescriptor(&temp); 2411 // The Enum class declares a "final" finalize() method to prevent subclasses from 2412 // introducing a finalizer. We don't want to set the finalizable flag for Enum or its 2413 // subclasses, so we exclude it here. 2414 // We also want to avoid setting the flag on Object, where we know that finalize() is 2415 // empty. 2416 if (strcmp(klass_descriptor, "Ljava/lang/Object;") != 0 && 2417 strcmp(klass_descriptor, "Ljava/lang/Enum;") != 0) { 2418 klass->SetFinalizable(); 2419 } 2420 } 2421 } 2422 } else if (method_name[0] == '<') { 2423 // Fix broken access flags for initializers. Bug 11157540. 2424 bool is_init = (strcmp("<init>", method_name) == 0); 2425 bool is_clinit = !is_init && (strcmp("<clinit>", method_name) == 0); 2426 if (UNLIKELY(!is_init && !is_clinit)) { 2427 LOG(WARNING) << "Unexpected '<' at start of method name " << method_name; 2428 } else { 2429 if (UNLIKELY((access_flags & kAccConstructor) == 0)) { 2430 LOG(WARNING) << method_name << " didn't have expected constructor access flag in class " 2431 << PrettyDescriptor(klass.Get()) << " in dex file " << dex_file.GetLocation(); 2432 access_flags |= kAccConstructor; 2433 } 2434 } 2435 } 2436 dst->SetAccessFlags(access_flags); 2437} 2438 2439void ClassLinker::AppendToBootClassPath(Thread* self, const DexFile& dex_file) { 2440 StackHandleScope<1> hs(self); 2441 Handle<mirror::DexCache> dex_cache(hs.NewHandle(AllocDexCache(self, dex_file))); 2442 CHECK(dex_cache.Get() != nullptr) << "Failed to allocate dex cache for " 2443 << dex_file.GetLocation(); 2444 AppendToBootClassPath(dex_file, dex_cache); 2445} 2446 2447void ClassLinker::AppendToBootClassPath(const DexFile& dex_file, 2448 Handle<mirror::DexCache> dex_cache) { 2449 CHECK(dex_cache.Get() != nullptr) << dex_file.GetLocation(); 2450 boot_class_path_.push_back(&dex_file); 2451 RegisterDexFile(dex_file, dex_cache); 2452} 2453 2454bool ClassLinker::IsDexFileRegisteredLocked(const DexFile& dex_file) { 2455 dex_lock_.AssertSharedHeld(Thread::Current()); 2456 for (size_t i = 0; i != dex_caches_.size(); ++i) { 2457 mirror::DexCache* dex_cache = GetDexCache(i); 2458 if (dex_cache->GetDexFile() == &dex_file) { 2459 return true; 2460 } 2461 } 2462 return false; 2463} 2464 2465bool ClassLinker::IsDexFileRegistered(const DexFile& dex_file) { 2466 ReaderMutexLock mu(Thread::Current(), dex_lock_); 2467 return IsDexFileRegisteredLocked(dex_file); 2468} 2469 2470void ClassLinker::RegisterDexFileLocked(const DexFile& dex_file, 2471 Handle<mirror::DexCache> dex_cache) { 2472 dex_lock_.AssertExclusiveHeld(Thread::Current()); 2473 CHECK(dex_cache.Get() != nullptr) << dex_file.GetLocation(); 2474 CHECK(dex_cache->GetLocation()->Equals(dex_file.GetLocation())) 2475 << dex_cache->GetLocation()->ToModifiedUtf8() << " " << dex_file.GetLocation(); 2476 dex_caches_.push_back(GcRoot<mirror::DexCache>(dex_cache.Get())); 2477 dex_cache->SetDexFile(&dex_file); 2478 if (log_new_dex_caches_roots_) { 2479 // TODO: This is not safe if we can remove dex caches. 2480 new_dex_cache_roots_.push_back(dex_caches_.size() - 1); 2481 } 2482} 2483 2484void ClassLinker::RegisterDexFile(const DexFile& dex_file) { 2485 Thread* self = Thread::Current(); 2486 { 2487 ReaderMutexLock mu(self, dex_lock_); 2488 if (IsDexFileRegisteredLocked(dex_file)) { 2489 return; 2490 } 2491 } 2492 // Don't alloc while holding the lock, since allocation may need to 2493 // suspend all threads and another thread may need the dex_lock_ to 2494 // get to a suspend point. 2495 StackHandleScope<1> hs(self); 2496 Handle<mirror::DexCache> dex_cache(hs.NewHandle(AllocDexCache(self, dex_file))); 2497 CHECK(dex_cache.Get() != nullptr) << "Failed to allocate dex cache for " 2498 << dex_file.GetLocation(); 2499 { 2500 WriterMutexLock mu(self, dex_lock_); 2501 if (IsDexFileRegisteredLocked(dex_file)) { 2502 return; 2503 } 2504 RegisterDexFileLocked(dex_file, dex_cache); 2505 } 2506} 2507 2508void ClassLinker::RegisterDexFile(const DexFile& dex_file, 2509 Handle<mirror::DexCache> dex_cache) { 2510 WriterMutexLock mu(Thread::Current(), dex_lock_); 2511 RegisterDexFileLocked(dex_file, dex_cache); 2512} 2513 2514mirror::DexCache* ClassLinker::FindDexCache(const DexFile& dex_file) { 2515 ReaderMutexLock mu(Thread::Current(), dex_lock_); 2516 // Search assuming unique-ness of dex file. 2517 for (size_t i = 0; i != dex_caches_.size(); ++i) { 2518 mirror::DexCache* dex_cache = GetDexCache(i); 2519 if (dex_cache->GetDexFile() == &dex_file) { 2520 return dex_cache; 2521 } 2522 } 2523 // Search matching by location name. 2524 std::string location(dex_file.GetLocation()); 2525 for (size_t i = 0; i != dex_caches_.size(); ++i) { 2526 mirror::DexCache* dex_cache = GetDexCache(i); 2527 if (dex_cache->GetDexFile()->GetLocation() == location) { 2528 return dex_cache; 2529 } 2530 } 2531 // Failure, dump diagnostic and abort. 2532 for (size_t i = 0; i != dex_caches_.size(); ++i) { 2533 mirror::DexCache* dex_cache = GetDexCache(i); 2534 LOG(ERROR) << "Registered dex file " << i << " = " << dex_cache->GetDexFile()->GetLocation(); 2535 } 2536 LOG(FATAL) << "Failed to find DexCache for DexFile " << location; 2537 UNREACHABLE(); 2538} 2539 2540void ClassLinker::FixupDexCaches(ArtMethod* resolution_method) { 2541 ReaderMutexLock mu(Thread::Current(), dex_lock_); 2542 for (auto& dex_cache : dex_caches_) { 2543 dex_cache.Read()->Fixup(resolution_method, image_pointer_size_); 2544 } 2545} 2546 2547mirror::Class* ClassLinker::CreatePrimitiveClass(Thread* self, Primitive::Type type) { 2548 mirror::Class* klass = AllocClass(self, mirror::Class::PrimitiveClassSize(image_pointer_size_)); 2549 if (UNLIKELY(klass == nullptr)) { 2550 self->AssertPendingOOMException(); 2551 return nullptr; 2552 } 2553 return InitializePrimitiveClass(klass, type); 2554} 2555 2556mirror::Class* ClassLinker::InitializePrimitiveClass(mirror::Class* primitive_class, 2557 Primitive::Type type) { 2558 CHECK(primitive_class != nullptr); 2559 // Must hold lock on object when initializing. 2560 Thread* self = Thread::Current(); 2561 StackHandleScope<1> hs(self); 2562 Handle<mirror::Class> h_class(hs.NewHandle(primitive_class)); 2563 ObjectLock<mirror::Class> lock(self, h_class); 2564 h_class->SetAccessFlags(kAccPublic | kAccFinal | kAccAbstract); 2565 h_class->SetPrimitiveType(type); 2566 mirror::Class::SetStatus(h_class, mirror::Class::kStatusInitialized, self); 2567 const char* descriptor = Primitive::Descriptor(type); 2568 mirror::Class* existing = InsertClass(descriptor, h_class.Get(), 2569 ComputeModifiedUtf8Hash(descriptor)); 2570 CHECK(existing == nullptr) << "InitPrimitiveClass(" << type << ") failed"; 2571 return h_class.Get(); 2572} 2573 2574// Create an array class (i.e. the class object for the array, not the 2575// array itself). "descriptor" looks like "[C" or "[[[[B" or 2576// "[Ljava/lang/String;". 2577// 2578// If "descriptor" refers to an array of primitives, look up the 2579// primitive type's internally-generated class object. 2580// 2581// "class_loader" is the class loader of the class that's referring to 2582// us. It's used to ensure that we're looking for the element type in 2583// the right context. It does NOT become the class loader for the 2584// array class; that always comes from the base element class. 2585// 2586// Returns null with an exception raised on failure. 2587mirror::Class* ClassLinker::CreateArrayClass(Thread* self, const char* descriptor, size_t hash, 2588 Handle<mirror::ClassLoader> class_loader) { 2589 // Identify the underlying component type 2590 CHECK_EQ('[', descriptor[0]); 2591 StackHandleScope<2> hs(self); 2592 MutableHandle<mirror::Class> component_type(hs.NewHandle(FindClass(self, descriptor + 1, 2593 class_loader))); 2594 if (component_type.Get() == nullptr) { 2595 DCHECK(self->IsExceptionPending()); 2596 // We need to accept erroneous classes as component types. 2597 const size_t component_hash = ComputeModifiedUtf8Hash(descriptor + 1); 2598 component_type.Assign(LookupClass(self, descriptor + 1, component_hash, class_loader.Get())); 2599 if (component_type.Get() == nullptr) { 2600 DCHECK(self->IsExceptionPending()); 2601 return nullptr; 2602 } else { 2603 self->ClearException(); 2604 } 2605 } 2606 if (UNLIKELY(component_type->IsPrimitiveVoid())) { 2607 ThrowNoClassDefFoundError("Attempt to create array of void primitive type"); 2608 return nullptr; 2609 } 2610 // See if the component type is already loaded. Array classes are 2611 // always associated with the class loader of their underlying 2612 // element type -- an array of Strings goes with the loader for 2613 // java/lang/String -- so we need to look for it there. (The 2614 // caller should have checked for the existence of the class 2615 // before calling here, but they did so with *their* class loader, 2616 // not the component type's loader.) 2617 // 2618 // If we find it, the caller adds "loader" to the class' initiating 2619 // loader list, which should prevent us from going through this again. 2620 // 2621 // This call is unnecessary if "loader" and "component_type->GetClassLoader()" 2622 // are the same, because our caller (FindClass) just did the 2623 // lookup. (Even if we get this wrong we still have correct behavior, 2624 // because we effectively do this lookup again when we add the new 2625 // class to the hash table --- necessary because of possible races with 2626 // other threads.) 2627 if (class_loader.Get() != component_type->GetClassLoader()) { 2628 mirror::Class* new_class = LookupClass(self, descriptor, hash, component_type->GetClassLoader()); 2629 if (new_class != nullptr) { 2630 return new_class; 2631 } 2632 } 2633 2634 // Fill out the fields in the Class. 2635 // 2636 // It is possible to execute some methods against arrays, because 2637 // all arrays are subclasses of java_lang_Object_, so we need to set 2638 // up a vtable. We can just point at the one in java_lang_Object_. 2639 // 2640 // Array classes are simple enough that we don't need to do a full 2641 // link step. 2642 auto new_class = hs.NewHandle<mirror::Class>(nullptr); 2643 if (UNLIKELY(!init_done_)) { 2644 // Classes that were hand created, ie not by FindSystemClass 2645 if (strcmp(descriptor, "[Ljava/lang/Class;") == 0) { 2646 new_class.Assign(GetClassRoot(kClassArrayClass)); 2647 } else if (strcmp(descriptor, "[Ljava/lang/Object;") == 0) { 2648 new_class.Assign(GetClassRoot(kObjectArrayClass)); 2649 } else if (strcmp(descriptor, GetClassRootDescriptor(kJavaLangStringArrayClass)) == 0) { 2650 new_class.Assign(GetClassRoot(kJavaLangStringArrayClass)); 2651 } else if (strcmp(descriptor, "[C") == 0) { 2652 new_class.Assign(GetClassRoot(kCharArrayClass)); 2653 } else if (strcmp(descriptor, "[I") == 0) { 2654 new_class.Assign(GetClassRoot(kIntArrayClass)); 2655 } else if (strcmp(descriptor, "[J") == 0) { 2656 new_class.Assign(GetClassRoot(kLongArrayClass)); 2657 } 2658 } 2659 if (new_class.Get() == nullptr) { 2660 new_class.Assign(AllocClass(self, mirror::Array::ClassSize(image_pointer_size_))); 2661 if (new_class.Get() == nullptr) { 2662 self->AssertPendingOOMException(); 2663 return nullptr; 2664 } 2665 new_class->SetComponentType(component_type.Get()); 2666 } 2667 ObjectLock<mirror::Class> lock(self, new_class); // Must hold lock on object when initializing. 2668 DCHECK(new_class->GetComponentType() != nullptr); 2669 mirror::Class* java_lang_Object = GetClassRoot(kJavaLangObject); 2670 new_class->SetSuperClass(java_lang_Object); 2671 new_class->SetVTable(java_lang_Object->GetVTable()); 2672 new_class->SetPrimitiveType(Primitive::kPrimNot); 2673 new_class->SetClassLoader(component_type->GetClassLoader()); 2674 mirror::Class::SetStatus(new_class, mirror::Class::kStatusLoaded, self); 2675 { 2676 ArtMethod* imt[mirror::Class::kImtSize]; 2677 std::fill_n(imt, arraysize(imt), Runtime::Current()->GetImtUnimplementedMethod()); 2678 new_class->PopulateEmbeddedImtAndVTable(imt, image_pointer_size_); 2679 } 2680 mirror::Class::SetStatus(new_class, mirror::Class::kStatusInitialized, self); 2681 // don't need to set new_class->SetObjectSize(..) 2682 // because Object::SizeOf delegates to Array::SizeOf 2683 2684 2685 // All arrays have java/lang/Cloneable and java/io/Serializable as 2686 // interfaces. We need to set that up here, so that stuff like 2687 // "instanceof" works right. 2688 // 2689 // Note: The GC could run during the call to FindSystemClass, 2690 // so we need to make sure the class object is GC-valid while we're in 2691 // there. Do this by clearing the interface list so the GC will just 2692 // think that the entries are null. 2693 2694 2695 // Use the single, global copies of "interfaces" and "iftable" 2696 // (remember not to free them for arrays). 2697 { 2698 mirror::IfTable* array_iftable = array_iftable_.Read(); 2699 CHECK(array_iftable != nullptr); 2700 new_class->SetIfTable(array_iftable); 2701 } 2702 2703 // Inherit access flags from the component type. 2704 int access_flags = new_class->GetComponentType()->GetAccessFlags(); 2705 // Lose any implementation detail flags; in particular, arrays aren't finalizable. 2706 access_flags &= kAccJavaFlagsMask; 2707 // Arrays can't be used as a superclass or interface, so we want to add "abstract final" 2708 // and remove "interface". 2709 access_flags |= kAccAbstract | kAccFinal; 2710 access_flags &= ~kAccInterface; 2711 2712 new_class->SetAccessFlags(access_flags); 2713 2714 mirror::Class* existing = InsertClass(descriptor, new_class.Get(), hash); 2715 if (existing == nullptr) { 2716 return new_class.Get(); 2717 } 2718 // Another thread must have loaded the class after we 2719 // started but before we finished. Abandon what we've 2720 // done. 2721 // 2722 // (Yes, this happens.) 2723 2724 return existing; 2725} 2726 2727mirror::Class* ClassLinker::FindPrimitiveClass(char type) { 2728 switch (type) { 2729 case 'B': 2730 return GetClassRoot(kPrimitiveByte); 2731 case 'C': 2732 return GetClassRoot(kPrimitiveChar); 2733 case 'D': 2734 return GetClassRoot(kPrimitiveDouble); 2735 case 'F': 2736 return GetClassRoot(kPrimitiveFloat); 2737 case 'I': 2738 return GetClassRoot(kPrimitiveInt); 2739 case 'J': 2740 return GetClassRoot(kPrimitiveLong); 2741 case 'S': 2742 return GetClassRoot(kPrimitiveShort); 2743 case 'Z': 2744 return GetClassRoot(kPrimitiveBoolean); 2745 case 'V': 2746 return GetClassRoot(kPrimitiveVoid); 2747 default: 2748 break; 2749 } 2750 std::string printable_type(PrintableChar(type)); 2751 ThrowNoClassDefFoundError("Not a primitive type: %s", printable_type.c_str()); 2752 return nullptr; 2753} 2754 2755mirror::Class* ClassLinker::InsertClass(const char* descriptor, mirror::Class* klass, 2756 size_t hash) { 2757 if (VLOG_IS_ON(class_linker)) { 2758 mirror::DexCache* dex_cache = klass->GetDexCache(); 2759 std::string source; 2760 if (dex_cache != nullptr) { 2761 source += " from "; 2762 source += dex_cache->GetLocation()->ToModifiedUtf8(); 2763 } 2764 LOG(INFO) << "Loaded class " << descriptor << source; 2765 } 2766 WriterMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); 2767 mirror::Class* existing = LookupClassFromTableLocked(descriptor, klass->GetClassLoader(), hash); 2768 if (existing != nullptr) { 2769 return existing; 2770 } 2771 if (kIsDebugBuild && !klass->IsTemp() && klass->GetClassLoader() == nullptr && 2772 dex_cache_image_class_lookup_required_) { 2773 // Check a class loaded with the system class loader matches one in the image if the class 2774 // is in the image. 2775 existing = LookupClassFromImage(descriptor); 2776 if (existing != nullptr) { 2777 CHECK_EQ(klass, existing); 2778 } 2779 } 2780 VerifyObject(klass); 2781 class_table_.InsertWithHash(GcRoot<mirror::Class>(klass), hash); 2782 if (log_new_class_table_roots_) { 2783 new_class_roots_.push_back(GcRoot<mirror::Class>(klass)); 2784 } 2785 return nullptr; 2786} 2787 2788void ClassLinker::UpdateClassVirtualMethods(mirror::Class* klass, ArtMethod* new_methods, 2789 size_t new_num_methods) { 2790 // classlinker_classes_lock_ is used to guard against races between root marking and changing the 2791 // direct and virtual method pointers. 2792 WriterMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); 2793 klass->SetNumVirtualMethods(new_num_methods); 2794 klass->SetVirtualMethodsPtr(new_methods); 2795 if (log_new_class_table_roots_) { 2796 new_class_roots_.push_back(GcRoot<mirror::Class>(klass)); 2797 } 2798} 2799 2800mirror::Class* ClassLinker::UpdateClass(const char* descriptor, mirror::Class* klass, 2801 size_t hash) { 2802 WriterMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); 2803 auto existing_it = class_table_.FindWithHash(std::make_pair(descriptor, klass->GetClassLoader()), 2804 hash); 2805 CHECK(existing_it != class_table_.end()); 2806 mirror::Class* existing = existing_it->Read(); 2807 CHECK_NE(existing, klass) << descriptor; 2808 CHECK(!existing->IsResolved()) << descriptor; 2809 CHECK_EQ(klass->GetStatus(), mirror::Class::kStatusResolving) << descriptor; 2810 2811 CHECK(!klass->IsTemp()) << descriptor; 2812 if (kIsDebugBuild && klass->GetClassLoader() == nullptr && 2813 dex_cache_image_class_lookup_required_) { 2814 // Check a class loaded with the system class loader matches one in the image if the class 2815 // is in the image. 2816 existing = LookupClassFromImage(descriptor); 2817 if (existing != nullptr) { 2818 CHECK_EQ(klass, existing) << descriptor; 2819 } 2820 } 2821 VerifyObject(klass); 2822 2823 // Update the element in the hash set. 2824 *existing_it = GcRoot<mirror::Class>(klass); 2825 if (log_new_class_table_roots_) { 2826 new_class_roots_.push_back(GcRoot<mirror::Class>(klass)); 2827 } 2828 2829 return existing; 2830} 2831 2832bool ClassLinker::RemoveClass(const char* descriptor, mirror::ClassLoader* class_loader) { 2833 WriterMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); 2834 auto pair = std::make_pair(descriptor, class_loader); 2835 auto it = class_table_.Find(pair); 2836 if (it != class_table_.end()) { 2837 class_table_.Erase(it); 2838 return true; 2839 } 2840 it = pre_zygote_class_table_.Find(pair); 2841 if (it != pre_zygote_class_table_.end()) { 2842 pre_zygote_class_table_.Erase(it); 2843 return true; 2844 } 2845 return false; 2846} 2847 2848mirror::Class* ClassLinker::LookupClass(Thread* self, const char* descriptor, size_t hash, 2849 mirror::ClassLoader* class_loader) { 2850 { 2851 ReaderMutexLock mu(self, *Locks::classlinker_classes_lock_); 2852 mirror::Class* result = LookupClassFromTableLocked(descriptor, class_loader, hash); 2853 if (result != nullptr) { 2854 return result; 2855 } 2856 } 2857 if (class_loader != nullptr || !dex_cache_image_class_lookup_required_) { 2858 return nullptr; 2859 } else { 2860 // Lookup failed but need to search dex_caches_. 2861 mirror::Class* result = LookupClassFromImage(descriptor); 2862 if (result != nullptr) { 2863 InsertClass(descriptor, result, hash); 2864 } else { 2865 // Searching the image dex files/caches failed, we don't want to get into this situation 2866 // often as map searches are faster, so after kMaxFailedDexCacheLookups move all image 2867 // classes into the class table. 2868 constexpr uint32_t kMaxFailedDexCacheLookups = 1000; 2869 if (++failed_dex_cache_class_lookups_ > kMaxFailedDexCacheLookups) { 2870 MoveImageClassesToClassTable(); 2871 } 2872 } 2873 return result; 2874 } 2875} 2876 2877mirror::Class* ClassLinker::LookupClassFromTableLocked(const char* descriptor, 2878 mirror::ClassLoader* class_loader, 2879 size_t hash) { 2880 auto descriptor_pair = std::make_pair(descriptor, class_loader); 2881 auto it = pre_zygote_class_table_.FindWithHash(descriptor_pair, hash); 2882 if (it == pre_zygote_class_table_.end()) { 2883 it = class_table_.FindWithHash(descriptor_pair, hash); 2884 if (it == class_table_.end()) { 2885 return nullptr; 2886 } 2887 } 2888 return it->Read(); 2889} 2890 2891static mirror::ObjectArray<mirror::DexCache>* GetImageDexCaches() 2892 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2893 gc::space::ImageSpace* image = Runtime::Current()->GetHeap()->GetImageSpace(); 2894 CHECK(image != nullptr); 2895 mirror::Object* root = image->GetImageHeader().GetImageRoot(ImageHeader::kDexCaches); 2896 return root->AsObjectArray<mirror::DexCache>(); 2897} 2898 2899void ClassLinker::MoveImageClassesToClassTable() { 2900 Thread* self = Thread::Current(); 2901 WriterMutexLock mu(self, *Locks::classlinker_classes_lock_); 2902 if (!dex_cache_image_class_lookup_required_) { 2903 return; // All dex cache classes are already in the class table. 2904 } 2905 ScopedAssertNoThreadSuspension ants(self, "Moving image classes to class table"); 2906 mirror::ObjectArray<mirror::DexCache>* dex_caches = GetImageDexCaches(); 2907 std::string temp; 2908 for (int32_t i = 0; i < dex_caches->GetLength(); i++) { 2909 mirror::DexCache* dex_cache = dex_caches->Get(i); 2910 mirror::ObjectArray<mirror::Class>* types = dex_cache->GetResolvedTypes(); 2911 for (int32_t j = 0; j < types->GetLength(); j++) { 2912 mirror::Class* klass = types->Get(j); 2913 if (klass != nullptr) { 2914 DCHECK(klass->GetClassLoader() == nullptr); 2915 const char* descriptor = klass->GetDescriptor(&temp); 2916 size_t hash = ComputeModifiedUtf8Hash(descriptor); 2917 mirror::Class* existing = LookupClassFromTableLocked(descriptor, nullptr, hash); 2918 if (existing != nullptr) { 2919 CHECK_EQ(existing, klass) << PrettyClassAndClassLoader(existing) << " != " 2920 << PrettyClassAndClassLoader(klass); 2921 } else { 2922 class_table_.Insert(GcRoot<mirror::Class>(klass)); 2923 if (log_new_class_table_roots_) { 2924 new_class_roots_.push_back(GcRoot<mirror::Class>(klass)); 2925 } 2926 } 2927 } 2928 } 2929 } 2930 dex_cache_image_class_lookup_required_ = false; 2931} 2932 2933void ClassLinker::MoveClassTableToPreZygote() { 2934 WriterMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); 2935 DCHECK(pre_zygote_class_table_.Empty()); 2936 pre_zygote_class_table_ = std::move(class_table_); 2937 class_table_.Clear(); 2938} 2939 2940mirror::Class* ClassLinker::LookupClassFromImage(const char* descriptor) { 2941 ScopedAssertNoThreadSuspension ants(Thread::Current(), "Image class lookup"); 2942 mirror::ObjectArray<mirror::DexCache>* dex_caches = GetImageDexCaches(); 2943 for (int32_t i = 0; i < dex_caches->GetLength(); ++i) { 2944 mirror::DexCache* dex_cache = dex_caches->Get(i); 2945 const DexFile* dex_file = dex_cache->GetDexFile(); 2946 // Try binary searching the string/type index. 2947 const DexFile::StringId* string_id = dex_file->FindStringId(descriptor); 2948 if (string_id != nullptr) { 2949 const DexFile::TypeId* type_id = 2950 dex_file->FindTypeId(dex_file->GetIndexForStringId(*string_id)); 2951 if (type_id != nullptr) { 2952 uint16_t type_idx = dex_file->GetIndexForTypeId(*type_id); 2953 mirror::Class* klass = dex_cache->GetResolvedType(type_idx); 2954 if (klass != nullptr) { 2955 return klass; 2956 } 2957 } 2958 } 2959 } 2960 return nullptr; 2961} 2962 2963void ClassLinker::LookupClasses(const char* descriptor, std::vector<mirror::Class*>& result) { 2964 result.clear(); 2965 if (dex_cache_image_class_lookup_required_) { 2966 MoveImageClassesToClassTable(); 2967 } 2968 WriterMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); 2969 while (true) { 2970 auto it = class_table_.Find(descriptor); 2971 if (it == class_table_.end()) { 2972 break; 2973 } 2974 result.push_back(it->Read()); 2975 class_table_.Erase(it); 2976 } 2977 for (mirror::Class* k : result) { 2978 class_table_.Insert(GcRoot<mirror::Class>(k)); 2979 } 2980 size_t pre_zygote_start = result.size(); 2981 // Now handle the pre zygote table. 2982 // Note: This dirties the pre-zygote table but shouldn't be an issue since LookupClasses is only 2983 // called from the debugger. 2984 while (true) { 2985 auto it = pre_zygote_class_table_.Find(descriptor); 2986 if (it == pre_zygote_class_table_.end()) { 2987 break; 2988 } 2989 result.push_back(it->Read()); 2990 pre_zygote_class_table_.Erase(it); 2991 } 2992 for (size_t i = pre_zygote_start; i < result.size(); ++i) { 2993 pre_zygote_class_table_.Insert(GcRoot<mirror::Class>(result[i])); 2994 } 2995} 2996 2997void ClassLinker::VerifyClass(Thread* self, Handle<mirror::Class> klass) { 2998 // TODO: assert that the monitor on the Class is held 2999 ObjectLock<mirror::Class> lock(self, klass); 3000 3001 // Don't attempt to re-verify if already sufficiently verified. 3002 if (klass->IsVerified()) { 3003 EnsurePreverifiedMethods(klass); 3004 return; 3005 } 3006 if (klass->IsCompileTimeVerified() && Runtime::Current()->IsAotCompiler()) { 3007 return; 3008 } 3009 3010 // The class might already be erroneous, for example at compile time if we attempted to verify 3011 // this class as a parent to another. 3012 if (klass->IsErroneous()) { 3013 ThrowEarlierClassFailure(klass.Get()); 3014 return; 3015 } 3016 3017 if (klass->GetStatus() == mirror::Class::kStatusResolved) { 3018 mirror::Class::SetStatus(klass, mirror::Class::kStatusVerifying, self); 3019 } else { 3020 CHECK_EQ(klass->GetStatus(), mirror::Class::kStatusRetryVerificationAtRuntime) 3021 << PrettyClass(klass.Get()); 3022 CHECK(!Runtime::Current()->IsAotCompiler()); 3023 mirror::Class::SetStatus(klass, mirror::Class::kStatusVerifyingAtRuntime, self); 3024 } 3025 3026 // Skip verification if disabled. 3027 if (!Runtime::Current()->IsVerificationEnabled()) { 3028 mirror::Class::SetStatus(klass, mirror::Class::kStatusVerified, self); 3029 EnsurePreverifiedMethods(klass); 3030 return; 3031 } 3032 3033 // Verify super class. 3034 StackHandleScope<2> hs(self); 3035 Handle<mirror::Class> super(hs.NewHandle(klass->GetSuperClass())); 3036 if (super.Get() != nullptr) { 3037 // Acquire lock to prevent races on verifying the super class. 3038 ObjectLock<mirror::Class> super_lock(self, super); 3039 3040 if (!super->IsVerified() && !super->IsErroneous()) { 3041 VerifyClass(self, super); 3042 } 3043 if (!super->IsCompileTimeVerified()) { 3044 std::string error_msg( 3045 StringPrintf("Rejecting class %s that attempts to sub-class erroneous class %s", 3046 PrettyDescriptor(klass.Get()).c_str(), 3047 PrettyDescriptor(super.Get()).c_str())); 3048 LOG(WARNING) << error_msg << " in " << klass->GetDexCache()->GetLocation()->ToModifiedUtf8(); 3049 Handle<mirror::Throwable> cause(hs.NewHandle(self->GetException())); 3050 if (cause.Get() != nullptr) { 3051 self->ClearException(); 3052 } 3053 ThrowVerifyError(klass.Get(), "%s", error_msg.c_str()); 3054 if (cause.Get() != nullptr) { 3055 self->GetException()->SetCause(cause.Get()); 3056 } 3057 ClassReference ref(klass->GetDexCache()->GetDexFile(), klass->GetDexClassDefIndex()); 3058 if (Runtime::Current()->IsAotCompiler()) { 3059 Runtime::Current()->GetCompilerCallbacks()->ClassRejected(ref); 3060 } 3061 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 3062 return; 3063 } 3064 } 3065 3066 // Try to use verification information from the oat file, otherwise do runtime verification. 3067 const DexFile& dex_file = *klass->GetDexCache()->GetDexFile(); 3068 mirror::Class::Status oat_file_class_status(mirror::Class::kStatusNotReady); 3069 bool preverified = VerifyClassUsingOatFile(dex_file, klass.Get(), oat_file_class_status); 3070 if (oat_file_class_status == mirror::Class::kStatusError) { 3071 VLOG(class_linker) << "Skipping runtime verification of erroneous class " 3072 << PrettyDescriptor(klass.Get()) << " in " 3073 << klass->GetDexCache()->GetLocation()->ToModifiedUtf8(); 3074 ThrowVerifyError(klass.Get(), "Rejecting class %s because it failed compile-time verification", 3075 PrettyDescriptor(klass.Get()).c_str()); 3076 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 3077 return; 3078 } 3079 verifier::MethodVerifier::FailureKind verifier_failure = verifier::MethodVerifier::kNoFailure; 3080 std::string error_msg; 3081 if (!preverified) { 3082 verifier_failure = verifier::MethodVerifier::VerifyClass(self, klass.Get(), 3083 Runtime::Current()->IsAotCompiler(), 3084 &error_msg); 3085 } 3086 if (preverified || verifier_failure != verifier::MethodVerifier::kHardFailure) { 3087 if (!preverified && verifier_failure != verifier::MethodVerifier::kNoFailure) { 3088 VLOG(class_linker) << "Soft verification failure in class " << PrettyDescriptor(klass.Get()) 3089 << " in " << klass->GetDexCache()->GetLocation()->ToModifiedUtf8() 3090 << " because: " << error_msg; 3091 } 3092 self->AssertNoPendingException(); 3093 // Make sure all classes referenced by catch blocks are resolved. 3094 ResolveClassExceptionHandlerTypes(dex_file, klass); 3095 if (verifier_failure == verifier::MethodVerifier::kNoFailure) { 3096 // Even though there were no verifier failures we need to respect whether the super-class 3097 // was verified or requiring runtime reverification. 3098 if (super.Get() == nullptr || super->IsVerified()) { 3099 mirror::Class::SetStatus(klass, mirror::Class::kStatusVerified, self); 3100 } else { 3101 CHECK_EQ(super->GetStatus(), mirror::Class::kStatusRetryVerificationAtRuntime); 3102 mirror::Class::SetStatus(klass, mirror::Class::kStatusRetryVerificationAtRuntime, self); 3103 // Pretend a soft failure occured so that we don't consider the class verified below. 3104 verifier_failure = verifier::MethodVerifier::kSoftFailure; 3105 } 3106 } else { 3107 CHECK_EQ(verifier_failure, verifier::MethodVerifier::kSoftFailure); 3108 // Soft failures at compile time should be retried at runtime. Soft 3109 // failures at runtime will be handled by slow paths in the generated 3110 // code. Set status accordingly. 3111 if (Runtime::Current()->IsAotCompiler()) { 3112 mirror::Class::SetStatus(klass, mirror::Class::kStatusRetryVerificationAtRuntime, self); 3113 } else { 3114 mirror::Class::SetStatus(klass, mirror::Class::kStatusVerified, self); 3115 // As this is a fake verified status, make sure the methods are _not_ marked preverified 3116 // later. 3117 klass->SetPreverified(); 3118 } 3119 } 3120 } else { 3121 LOG(WARNING) << "Verification failed on class " << PrettyDescriptor(klass.Get()) 3122 << " in " << klass->GetDexCache()->GetLocation()->ToModifiedUtf8() 3123 << " because: " << error_msg; 3124 self->AssertNoPendingException(); 3125 ThrowVerifyError(klass.Get(), "%s", error_msg.c_str()); 3126 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 3127 } 3128 if (preverified || verifier_failure == verifier::MethodVerifier::kNoFailure) { 3129 // Class is verified so we don't need to do any access check on its methods. 3130 // Let the interpreter know it by setting the kAccPreverified flag onto each 3131 // method. 3132 // Note: we're going here during compilation and at runtime. When we set the 3133 // kAccPreverified flag when compiling image classes, the flag is recorded 3134 // in the image and is set when loading the image. 3135 EnsurePreverifiedMethods(klass); 3136 } 3137} 3138 3139void ClassLinker::EnsurePreverifiedMethods(Handle<mirror::Class> klass) { 3140 if (!klass->IsPreverified()) { 3141 klass->SetPreverifiedFlagOnAllMethods(image_pointer_size_); 3142 klass->SetPreverified(); 3143 } 3144} 3145 3146bool ClassLinker::VerifyClassUsingOatFile(const DexFile& dex_file, mirror::Class* klass, 3147 mirror::Class::Status& oat_file_class_status) { 3148 // If we're compiling, we can only verify the class using the oat file if 3149 // we are not compiling the image or if the class we're verifying is not part of 3150 // the app. In other words, we will only check for preverification of bootclasspath 3151 // classes. 3152 if (Runtime::Current()->IsAotCompiler()) { 3153 // Are we compiling the bootclasspath? 3154 if (Runtime::Current()->GetCompilerCallbacks()->IsBootImage()) { 3155 return false; 3156 } 3157 // We are compiling an app (not the image). 3158 3159 // Is this an app class? (I.e. not a bootclasspath class) 3160 if (klass->GetClassLoader() != nullptr) { 3161 return false; 3162 } 3163 } 3164 3165 const OatFile::OatDexFile* oat_dex_file = dex_file.GetOatDexFile(); 3166 // In case we run without an image there won't be a backing oat file. 3167 if (oat_dex_file == nullptr) { 3168 return false; 3169 } 3170 3171 // We may be running with a preopted oat file but without image. In this case, 3172 // we don't skip verification of preverified classes to ensure we initialize 3173 // dex caches with all types resolved during verification. 3174 // We need to trust image classes, as these might be coming out of a pre-opted, quickened boot 3175 // image (that we just failed loading), and the verifier can't be run on quickened opcodes when 3176 // the runtime isn't started. On the other hand, app classes can be re-verified even if they are 3177 // already pre-opted, as then the runtime is started. 3178 if (!Runtime::Current()->IsAotCompiler() && 3179 !Runtime::Current()->GetHeap()->HasImageSpace() && 3180 klass->GetClassLoader() != nullptr) { 3181 return false; 3182 } 3183 3184 uint16_t class_def_index = klass->GetDexClassDefIndex(); 3185 oat_file_class_status = oat_dex_file->GetOatClass(class_def_index).GetStatus(); 3186 if (oat_file_class_status == mirror::Class::kStatusVerified || 3187 oat_file_class_status == mirror::Class::kStatusInitialized) { 3188 return true; 3189 } 3190 if (oat_file_class_status == mirror::Class::kStatusRetryVerificationAtRuntime) { 3191 // Compile time verification failed with a soft error. Compile time verification can fail 3192 // because we have incomplete type information. Consider the following: 3193 // class ... { 3194 // Foo x; 3195 // .... () { 3196 // if (...) { 3197 // v1 gets assigned a type of resolved class Foo 3198 // } else { 3199 // v1 gets assigned a type of unresolved class Bar 3200 // } 3201 // iput x = v1 3202 // } } 3203 // when we merge v1 following the if-the-else it results in Conflict 3204 // (see verifier::RegType::Merge) as we can't know the type of Bar and we could possibly be 3205 // allowing an unsafe assignment to the field x in the iput (javac may have compiled this as 3206 // it knew Bar was a sub-class of Foo, but for us this may have been moved into a separate apk 3207 // at compile time). 3208 return false; 3209 } 3210 if (oat_file_class_status == mirror::Class::kStatusError) { 3211 // Compile time verification failed with a hard error. This is caused by invalid instructions 3212 // in the class. These errors are unrecoverable. 3213 return false; 3214 } 3215 if (oat_file_class_status == mirror::Class::kStatusNotReady) { 3216 // Status is uninitialized if we couldn't determine the status at compile time, for example, 3217 // not loading the class. 3218 // TODO: when the verifier doesn't rely on Class-es failing to resolve/load the type hierarchy 3219 // isn't a problem and this case shouldn't occur 3220 return false; 3221 } 3222 std::string temp; 3223 LOG(FATAL) << "Unexpected class status: " << oat_file_class_status 3224 << " " << dex_file.GetLocation() << " " << PrettyClass(klass) << " " 3225 << klass->GetDescriptor(&temp); 3226 UNREACHABLE(); 3227} 3228 3229void ClassLinker::ResolveClassExceptionHandlerTypes(const DexFile& dex_file, 3230 Handle<mirror::Class> klass) { 3231 for (size_t i = 0; i < klass->NumDirectMethods(); i++) { 3232 ResolveMethodExceptionHandlerTypes(dex_file, klass->GetDirectMethod(i, image_pointer_size_)); 3233 } 3234 for (size_t i = 0; i < klass->NumVirtualMethods(); i++) { 3235 ResolveMethodExceptionHandlerTypes(dex_file, klass->GetVirtualMethod(i, image_pointer_size_)); 3236 } 3237} 3238 3239void ClassLinker::ResolveMethodExceptionHandlerTypes(const DexFile& dex_file, 3240 ArtMethod* method) { 3241 // similar to DexVerifier::ScanTryCatchBlocks and dex2oat's ResolveExceptionsForMethod. 3242 const DexFile::CodeItem* code_item = dex_file.GetCodeItem(method->GetCodeItemOffset()); 3243 if (code_item == nullptr) { 3244 return; // native or abstract method 3245 } 3246 if (code_item->tries_size_ == 0) { 3247 return; // nothing to process 3248 } 3249 const uint8_t* handlers_ptr = DexFile::GetCatchHandlerData(*code_item, 0); 3250 uint32_t handlers_size = DecodeUnsignedLeb128(&handlers_ptr); 3251 ClassLinker* linker = Runtime::Current()->GetClassLinker(); 3252 for (uint32_t idx = 0; idx < handlers_size; idx++) { 3253 CatchHandlerIterator iterator(handlers_ptr); 3254 for (; iterator.HasNext(); iterator.Next()) { 3255 // Ensure exception types are resolved so that they don't need resolution to be delivered, 3256 // unresolved exception types will be ignored by exception delivery 3257 if (iterator.GetHandlerTypeIndex() != DexFile::kDexNoIndex16) { 3258 mirror::Class* exception_type = linker->ResolveType(iterator.GetHandlerTypeIndex(), method); 3259 if (exception_type == nullptr) { 3260 DCHECK(Thread::Current()->IsExceptionPending()); 3261 Thread::Current()->ClearException(); 3262 } 3263 } 3264 } 3265 handlers_ptr = iterator.EndDataPointer(); 3266 } 3267} 3268 3269mirror::Class* ClassLinker::CreateProxyClass(ScopedObjectAccessAlreadyRunnable& soa, jstring name, 3270 jobjectArray interfaces, jobject loader, 3271 jobjectArray methods, jobjectArray throws) { 3272 Thread* self = soa.Self(); 3273 StackHandleScope<10> hs(self); 3274 MutableHandle<mirror::Class> klass(hs.NewHandle( 3275 AllocClass(self, GetClassRoot(kJavaLangClass), sizeof(mirror::Class)))); 3276 if (klass.Get() == nullptr) { 3277 CHECK(self->IsExceptionPending()); // OOME. 3278 return nullptr; 3279 } 3280 DCHECK(klass->GetClass() != nullptr); 3281 klass->SetObjectSize(sizeof(mirror::Proxy)); 3282 // Set the class access flags incl. preverified, so we do not try to set the flag on the methods. 3283 klass->SetAccessFlags(kAccClassIsProxy | kAccPublic | kAccFinal | kAccPreverified); 3284 klass->SetClassLoader(soa.Decode<mirror::ClassLoader*>(loader)); 3285 DCHECK_EQ(klass->GetPrimitiveType(), Primitive::kPrimNot); 3286 klass->SetName(soa.Decode<mirror::String*>(name)); 3287 klass->SetDexCache(GetClassRoot(kJavaLangReflectProxy)->GetDexCache()); 3288 mirror::Class::SetStatus(klass, mirror::Class::kStatusIdx, self); 3289 std::string descriptor(GetDescriptorForProxy(klass.Get())); 3290 size_t hash = ComputeModifiedUtf8Hash(descriptor.c_str()); 3291 3292 // Insert the class before loading the fields as the field roots 3293 // (ArtField::declaring_class_) are only visited from the class 3294 // table. There can't be any suspend points between inserting the 3295 // class and setting the field arrays below. 3296 mirror::Class* existing = InsertClass(descriptor.c_str(), klass.Get(), hash); 3297 CHECK(existing == nullptr); 3298 3299 // Instance fields are inherited, but we add a couple of static fields... 3300 const size_t num_fields = 2; 3301 ArtField* sfields = AllocArtFieldArray(self, num_fields); 3302 klass->SetSFields(sfields); 3303 klass->SetNumStaticFields(num_fields); 3304 3305 // 1. Create a static field 'interfaces' that holds the _declared_ interfaces implemented by 3306 // our proxy, so Class.getInterfaces doesn't return the flattened set. 3307 ArtField* interfaces_sfield = &sfields[0]; 3308 interfaces_sfield->SetDexFieldIndex(0); 3309 interfaces_sfield->SetDeclaringClass(klass.Get()); 3310 interfaces_sfield->SetAccessFlags(kAccStatic | kAccPublic | kAccFinal); 3311 3312 // 2. Create a static field 'throws' that holds exceptions thrown by our methods. 3313 ArtField* throws_sfield = &sfields[1]; 3314 throws_sfield->SetDexFieldIndex(1); 3315 throws_sfield->SetDeclaringClass(klass.Get()); 3316 throws_sfield->SetAccessFlags(kAccStatic | kAccPublic | kAccFinal); 3317 3318 // Proxies have 1 direct method, the constructor 3319 auto* directs = AllocArtMethodArray(self, 1); 3320 // Currently AllocArtMethodArray cannot return null, but the OOM logic is left there in case we 3321 // want to throw OOM in the future. 3322 if (UNLIKELY(directs == nullptr)) { 3323 self->AssertPendingOOMException(); 3324 return nullptr; 3325 } 3326 klass->SetDirectMethodsPtr(directs); 3327 klass->SetNumDirectMethods(1u); 3328 CreateProxyConstructor(klass, klass->GetDirectMethodUnchecked(0, image_pointer_size_)); 3329 3330 // Create virtual method using specified prototypes. 3331 auto h_methods = hs.NewHandle(soa.Decode<mirror::ObjectArray<mirror::Method>*>(methods)); 3332 DCHECK_EQ(h_methods->GetClass(), mirror::Method::ArrayClass()) 3333 << PrettyClass(h_methods->GetClass()); 3334 const size_t num_virtual_methods = h_methods->GetLength(); 3335 auto* virtuals = AllocArtMethodArray(self, num_virtual_methods); 3336 // Currently AllocArtMethodArray cannot return null, but the OOM logic is left there in case we 3337 // want to throw OOM in the future. 3338 if (UNLIKELY(virtuals == nullptr)) { 3339 self->AssertPendingOOMException(); 3340 return nullptr; 3341 } 3342 klass->SetVirtualMethodsPtr(virtuals); 3343 klass->SetNumVirtualMethods(num_virtual_methods); 3344 for (size_t i = 0; i < num_virtual_methods; ++i) { 3345 auto* virtual_method = klass->GetVirtualMethodUnchecked(i, image_pointer_size_); 3346 auto* prototype = h_methods->Get(i)->GetArtMethod(); 3347 CreateProxyMethod(klass, prototype, virtual_method); 3348 DCHECK(virtual_method->GetDeclaringClass() != nullptr); 3349 DCHECK(prototype->GetDeclaringClass() != nullptr); 3350 } 3351 3352 // The super class is java.lang.reflect.Proxy 3353 klass->SetSuperClass(GetClassRoot(kJavaLangReflectProxy)); 3354 // Now effectively in the loaded state. 3355 mirror::Class::SetStatus(klass, mirror::Class::kStatusLoaded, self); 3356 self->AssertNoPendingException(); 3357 3358 MutableHandle<mirror::Class> new_class = hs.NewHandle<mirror::Class>(nullptr); 3359 { 3360 // Must hold lock on object when resolved. 3361 ObjectLock<mirror::Class> resolution_lock(self, klass); 3362 // Link the fields and virtual methods, creating vtable and iftables. 3363 // The new class will replace the old one in the class table. 3364 Handle<mirror::ObjectArray<mirror::Class>> h_interfaces( 3365 hs.NewHandle(soa.Decode<mirror::ObjectArray<mirror::Class>*>(interfaces))); 3366 if (!LinkClass(self, descriptor.c_str(), klass, h_interfaces, &new_class)) { 3367 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 3368 return nullptr; 3369 } 3370 } 3371 CHECK(klass->IsRetired()); 3372 CHECK_NE(klass.Get(), new_class.Get()); 3373 klass.Assign(new_class.Get()); 3374 3375 CHECK_EQ(interfaces_sfield->GetDeclaringClass(), klass.Get()); 3376 interfaces_sfield->SetObject<false>(klass.Get(), 3377 soa.Decode<mirror::ObjectArray<mirror::Class>*>(interfaces)); 3378 CHECK_EQ(throws_sfield->GetDeclaringClass(), klass.Get()); 3379 throws_sfield->SetObject<false>(klass.Get(), 3380 soa.Decode<mirror::ObjectArray<mirror::ObjectArray<mirror::Class> >*>(throws)); 3381 3382 { 3383 // Lock on klass is released. Lock new class object. 3384 ObjectLock<mirror::Class> initialization_lock(self, klass); 3385 mirror::Class::SetStatus(klass, mirror::Class::kStatusInitialized, self); 3386 } 3387 3388 // sanity checks 3389 if (kIsDebugBuild) { 3390 CHECK(klass->GetIFields() == nullptr); 3391 CheckProxyConstructor(klass->GetDirectMethod(0, image_pointer_size_)); 3392 3393 for (size_t i = 0; i < num_virtual_methods; ++i) { 3394 auto* virtual_method = klass->GetVirtualMethodUnchecked(i, image_pointer_size_); 3395 auto* prototype = h_methods->Get(i++)->GetArtMethod(); 3396 CheckProxyMethod(virtual_method, prototype); 3397 } 3398 3399 StackHandleScope<1> hs2(self); 3400 Handle<mirror::String> decoded_name = hs2.NewHandle(soa.Decode<mirror::String*>(name)); 3401 std::string interfaces_field_name(StringPrintf("java.lang.Class[] %s.interfaces", 3402 decoded_name->ToModifiedUtf8().c_str())); 3403 CHECK_EQ(PrettyField(klass->GetStaticField(0)), interfaces_field_name); 3404 3405 std::string throws_field_name(StringPrintf("java.lang.Class[][] %s.throws", 3406 decoded_name->ToModifiedUtf8().c_str())); 3407 CHECK_EQ(PrettyField(klass->GetStaticField(1)), throws_field_name); 3408 3409 CHECK_EQ(klass.Get()->GetInterfaces(), 3410 soa.Decode<mirror::ObjectArray<mirror::Class>*>(interfaces)); 3411 CHECK_EQ(klass.Get()->GetThrows(), 3412 soa.Decode<mirror::ObjectArray<mirror::ObjectArray<mirror::Class>>*>(throws)); 3413 } 3414 return klass.Get(); 3415} 3416 3417std::string ClassLinker::GetDescriptorForProxy(mirror::Class* proxy_class) { 3418 DCHECK(proxy_class->IsProxyClass()); 3419 mirror::String* name = proxy_class->GetName(); 3420 DCHECK(name != nullptr); 3421 return DotToDescriptor(name->ToModifiedUtf8().c_str()); 3422} 3423 3424ArtMethod* ClassLinker::FindMethodForProxy(mirror::Class* proxy_class, 3425 ArtMethod* proxy_method) { 3426 DCHECK(proxy_class->IsProxyClass()); 3427 DCHECK(proxy_method->IsProxyMethod()); 3428 { 3429 ReaderMutexLock mu(Thread::Current(), dex_lock_); 3430 // Locate the dex cache of the original interface/Object 3431 for (const GcRoot<mirror::DexCache>& root : dex_caches_) { 3432 auto* dex_cache = root.Read(); 3433 if (proxy_method->HasSameDexCacheResolvedTypes(dex_cache->GetResolvedTypes())) { 3434 ArtMethod* resolved_method = dex_cache->GetResolvedMethod( 3435 proxy_method->GetDexMethodIndex(), image_pointer_size_); 3436 CHECK(resolved_method != nullptr); 3437 return resolved_method; 3438 } 3439 } 3440 } 3441 LOG(FATAL) << "Didn't find dex cache for " << PrettyClass(proxy_class) << " " 3442 << PrettyMethod(proxy_method); 3443 UNREACHABLE(); 3444} 3445 3446void ClassLinker::CreateProxyConstructor(Handle<mirror::Class> klass, ArtMethod* out) { 3447 // Create constructor for Proxy that must initialize the method. 3448 CHECK_EQ(GetClassRoot(kJavaLangReflectProxy)->NumDirectMethods(), 16u); 3449 ArtMethod* proxy_constructor = GetClassRoot(kJavaLangReflectProxy)->GetDirectMethodUnchecked( 3450 2, image_pointer_size_); 3451 // Ensure constructor is in dex cache so that we can use the dex cache to look up the overridden 3452 // constructor method. 3453 GetClassRoot(kJavaLangReflectProxy)->GetDexCache()->SetResolvedMethod( 3454 proxy_constructor->GetDexMethodIndex(), proxy_constructor, image_pointer_size_); 3455 // Clone the existing constructor of Proxy (our constructor would just invoke it so steal its 3456 // code_ too) 3457 DCHECK(out != nullptr); 3458 out->CopyFrom(proxy_constructor, image_pointer_size_); 3459 // Make this constructor public and fix the class to be our Proxy version 3460 out->SetAccessFlags((out->GetAccessFlags() & ~kAccProtected) | kAccPublic); 3461 out->SetDeclaringClass(klass.Get()); 3462} 3463 3464void ClassLinker::CheckProxyConstructor(ArtMethod* constructor) const { 3465 CHECK(constructor->IsConstructor()); 3466 auto* np = constructor->GetInterfaceMethodIfProxy(image_pointer_size_); 3467 CHECK_STREQ(np->GetName(), "<init>"); 3468 CHECK_STREQ(np->GetSignature().ToString().c_str(), "(Ljava/lang/reflect/InvocationHandler;)V"); 3469 DCHECK(constructor->IsPublic()); 3470} 3471 3472void ClassLinker::CreateProxyMethod(Handle<mirror::Class> klass, ArtMethod* prototype, 3473 ArtMethod* out) { 3474 // Ensure prototype is in dex cache so that we can use the dex cache to look up the overridden 3475 // prototype method 3476 auto* dex_cache = prototype->GetDeclaringClass()->GetDexCache(); 3477 // Avoid dirtying the dex cache unless we need to. 3478 if (dex_cache->GetResolvedMethod(prototype->GetDexMethodIndex(), image_pointer_size_) != 3479 prototype) { 3480 dex_cache->SetResolvedMethod( 3481 prototype->GetDexMethodIndex(), prototype, image_pointer_size_); 3482 } 3483 // We steal everything from the prototype (such as DexCache, invoke stub, etc.) then specialize 3484 // as necessary 3485 DCHECK(out != nullptr); 3486 out->CopyFrom(prototype, image_pointer_size_); 3487 3488 // Set class to be the concrete proxy class and clear the abstract flag, modify exceptions to 3489 // the intersection of throw exceptions as defined in Proxy 3490 out->SetDeclaringClass(klass.Get()); 3491 out->SetAccessFlags((out->GetAccessFlags() & ~kAccAbstract) | kAccFinal); 3492 3493 // At runtime the method looks like a reference and argument saving method, clone the code 3494 // related parameters from this method. 3495 out->SetEntryPointFromQuickCompiledCode(GetQuickProxyInvokeHandler()); 3496 out->SetEntryPointFromInterpreter(artInterpreterToCompiledCodeBridge); 3497} 3498 3499void ClassLinker::CheckProxyMethod(ArtMethod* method, ArtMethod* prototype) const { 3500 // Basic sanity 3501 CHECK(!prototype->IsFinal()); 3502 CHECK(method->IsFinal()); 3503 CHECK(!method->IsAbstract()); 3504 3505 // The proxy method doesn't have its own dex cache or dex file and so it steals those of its 3506 // interface prototype. The exception to this are Constructors and the Class of the Proxy itself. 3507 CHECK(prototype->HasSameDexCacheResolvedMethods(method)); 3508 CHECK(prototype->HasSameDexCacheResolvedTypes(method)); 3509 auto* np = method->GetInterfaceMethodIfProxy(image_pointer_size_); 3510 CHECK_EQ(prototype->GetDeclaringClass()->GetDexCache(), np->GetDexCache()); 3511 CHECK_EQ(prototype->GetDexMethodIndex(), method->GetDexMethodIndex()); 3512 3513 CHECK_STREQ(np->GetName(), prototype->GetName()); 3514 CHECK_STREQ(np->GetShorty(), prototype->GetShorty()); 3515 // More complex sanity - via dex cache 3516 CHECK_EQ(np->GetReturnType(), prototype->GetReturnType()); 3517} 3518 3519bool ClassLinker::CanWeInitializeClass(mirror::Class* klass, bool can_init_statics, 3520 bool can_init_parents) { 3521 if (can_init_statics && can_init_parents) { 3522 return true; 3523 } 3524 if (!can_init_statics) { 3525 // Check if there's a class initializer. 3526 ArtMethod* clinit = klass->FindClassInitializer(image_pointer_size_); 3527 if (clinit != nullptr) { 3528 return false; 3529 } 3530 // Check if there are encoded static values needing initialization. 3531 if (klass->NumStaticFields() != 0) { 3532 const DexFile::ClassDef* dex_class_def = klass->GetClassDef(); 3533 DCHECK(dex_class_def != nullptr); 3534 if (dex_class_def->static_values_off_ != 0) { 3535 return false; 3536 } 3537 } 3538 } 3539 if (klass->IsInterface() || !klass->HasSuperClass()) { 3540 return true; 3541 } 3542 mirror::Class* super_class = klass->GetSuperClass(); 3543 if (!can_init_parents && !super_class->IsInitialized()) { 3544 return false; 3545 } 3546 return CanWeInitializeClass(super_class, can_init_statics, can_init_parents); 3547} 3548 3549bool ClassLinker::InitializeClass(Thread* self, Handle<mirror::Class> klass, 3550 bool can_init_statics, bool can_init_parents) { 3551 // see JLS 3rd edition, 12.4.2 "Detailed Initialization Procedure" for the locking protocol 3552 3553 // Are we already initialized and therefore done? 3554 // Note: we differ from the JLS here as we don't do this under the lock, this is benign as 3555 // an initialized class will never change its state. 3556 if (klass->IsInitialized()) { 3557 return true; 3558 } 3559 3560 // Fast fail if initialization requires a full runtime. Not part of the JLS. 3561 if (!CanWeInitializeClass(klass.Get(), can_init_statics, can_init_parents)) { 3562 return false; 3563 } 3564 3565 self->AllowThreadSuspension(); 3566 uint64_t t0; 3567 { 3568 ObjectLock<mirror::Class> lock(self, klass); 3569 3570 // Re-check under the lock in case another thread initialized ahead of us. 3571 if (klass->IsInitialized()) { 3572 return true; 3573 } 3574 3575 // Was the class already found to be erroneous? Done under the lock to match the JLS. 3576 if (klass->IsErroneous()) { 3577 ThrowEarlierClassFailure(klass.Get()); 3578 VlogClassInitializationFailure(klass); 3579 return false; 3580 } 3581 3582 CHECK(klass->IsResolved()) << PrettyClass(klass.Get()) << ": state=" << klass->GetStatus(); 3583 3584 if (!klass->IsVerified()) { 3585 VerifyClass(self, klass); 3586 if (!klass->IsVerified()) { 3587 // We failed to verify, expect either the klass to be erroneous or verification failed at 3588 // compile time. 3589 if (klass->IsErroneous()) { 3590 CHECK(self->IsExceptionPending()); 3591 VlogClassInitializationFailure(klass); 3592 } else { 3593 CHECK(Runtime::Current()->IsAotCompiler()); 3594 CHECK_EQ(klass->GetStatus(), mirror::Class::kStatusRetryVerificationAtRuntime); 3595 } 3596 return false; 3597 } else { 3598 self->AssertNoPendingException(); 3599 } 3600 } 3601 3602 // If the class is kStatusInitializing, either this thread is 3603 // initializing higher up the stack or another thread has beat us 3604 // to initializing and we need to wait. Either way, this 3605 // invocation of InitializeClass will not be responsible for 3606 // running <clinit> and will return. 3607 if (klass->GetStatus() == mirror::Class::kStatusInitializing) { 3608 // Could have got an exception during verification. 3609 if (self->IsExceptionPending()) { 3610 VlogClassInitializationFailure(klass); 3611 return false; 3612 } 3613 // We caught somebody else in the act; was it us? 3614 if (klass->GetClinitThreadId() == self->GetTid()) { 3615 // Yes. That's fine. Return so we can continue initializing. 3616 return true; 3617 } 3618 // No. That's fine. Wait for another thread to finish initializing. 3619 return WaitForInitializeClass(klass, self, lock); 3620 } 3621 3622 if (!ValidateSuperClassDescriptors(klass)) { 3623 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 3624 return false; 3625 } 3626 self->AllowThreadSuspension(); 3627 3628 CHECK_EQ(klass->GetStatus(), mirror::Class::kStatusVerified) << PrettyClass(klass.Get()); 3629 3630 // From here out other threads may observe that we're initializing and so changes of state 3631 // require the a notification. 3632 klass->SetClinitThreadId(self->GetTid()); 3633 mirror::Class::SetStatus(klass, mirror::Class::kStatusInitializing, self); 3634 3635 t0 = NanoTime(); 3636 } 3637 3638 // Initialize super classes, must be done while initializing for the JLS. 3639 if (!klass->IsInterface() && klass->HasSuperClass()) { 3640 mirror::Class* super_class = klass->GetSuperClass(); 3641 if (!super_class->IsInitialized()) { 3642 CHECK(!super_class->IsInterface()); 3643 CHECK(can_init_parents); 3644 StackHandleScope<1> hs(self); 3645 Handle<mirror::Class> handle_scope_super(hs.NewHandle(super_class)); 3646 bool super_initialized = InitializeClass(self, handle_scope_super, can_init_statics, true); 3647 if (!super_initialized) { 3648 // The super class was verified ahead of entering initializing, we should only be here if 3649 // the super class became erroneous due to initialization. 3650 CHECK(handle_scope_super->IsErroneous() && self->IsExceptionPending()) 3651 << "Super class initialization failed for " 3652 << PrettyDescriptor(handle_scope_super.Get()) 3653 << " that has unexpected status " << handle_scope_super->GetStatus() 3654 << "\nPending exception:\n" 3655 << (self->GetException() != nullptr ? self->GetException()->Dump() : ""); 3656 ObjectLock<mirror::Class> lock(self, klass); 3657 // Initialization failed because the super-class is erroneous. 3658 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 3659 return false; 3660 } 3661 } 3662 } 3663 3664 const size_t num_static_fields = klass->NumStaticFields(); 3665 if (num_static_fields > 0) { 3666 const DexFile::ClassDef* dex_class_def = klass->GetClassDef(); 3667 CHECK(dex_class_def != nullptr); 3668 const DexFile& dex_file = klass->GetDexFile(); 3669 StackHandleScope<3> hs(self); 3670 Handle<mirror::ClassLoader> class_loader(hs.NewHandle(klass->GetClassLoader())); 3671 Handle<mirror::DexCache> dex_cache(hs.NewHandle(klass->GetDexCache())); 3672 3673 // Eagerly fill in static fields so that the we don't have to do as many expensive 3674 // Class::FindStaticField in ResolveField. 3675 for (size_t i = 0; i < num_static_fields; ++i) { 3676 ArtField* field = klass->GetStaticField(i); 3677 const uint32_t field_idx = field->GetDexFieldIndex(); 3678 ArtField* resolved_field = dex_cache->GetResolvedField(field_idx, image_pointer_size_); 3679 if (resolved_field == nullptr) { 3680 dex_cache->SetResolvedField(field_idx, field, image_pointer_size_); 3681 } else { 3682 DCHECK_EQ(field, resolved_field); 3683 } 3684 } 3685 3686 EncodedStaticFieldValueIterator value_it(dex_file, &dex_cache, &class_loader, 3687 this, *dex_class_def); 3688 const uint8_t* class_data = dex_file.GetClassData(*dex_class_def); 3689 ClassDataItemIterator field_it(dex_file, class_data); 3690 if (value_it.HasNext()) { 3691 DCHECK(field_it.HasNextStaticField()); 3692 CHECK(can_init_statics); 3693 for ( ; value_it.HasNext(); value_it.Next(), field_it.Next()) { 3694 ArtField* field = ResolveField( 3695 dex_file, field_it.GetMemberIndex(), dex_cache, class_loader, true); 3696 if (Runtime::Current()->IsActiveTransaction()) { 3697 value_it.ReadValueToField<true>(field); 3698 } else { 3699 value_it.ReadValueToField<false>(field); 3700 } 3701 DCHECK(!value_it.HasNext() || field_it.HasNextStaticField()); 3702 } 3703 } 3704 } 3705 3706 ArtMethod* clinit = klass->FindClassInitializer(image_pointer_size_); 3707 if (clinit != nullptr) { 3708 CHECK(can_init_statics); 3709 JValue result; 3710 clinit->Invoke(self, nullptr, 0, &result, "V"); 3711 } 3712 3713 self->AllowThreadSuspension(); 3714 uint64_t t1 = NanoTime(); 3715 3716 bool success = true; 3717 { 3718 ObjectLock<mirror::Class> lock(self, klass); 3719 3720 if (self->IsExceptionPending()) { 3721 WrapExceptionInInitializer(klass); 3722 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 3723 success = false; 3724 } else if (Runtime::Current()->IsTransactionAborted()) { 3725 // The exception thrown when the transaction aborted has been caught and cleared 3726 // so we need to throw it again now. 3727 VLOG(compiler) << "Return from class initializer of " << PrettyDescriptor(klass.Get()) 3728 << " without exception while transaction was aborted: re-throw it now."; 3729 Runtime::Current()->ThrowTransactionAbortError(self); 3730 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 3731 success = false; 3732 } else { 3733 RuntimeStats* global_stats = Runtime::Current()->GetStats(); 3734 RuntimeStats* thread_stats = self->GetStats(); 3735 ++global_stats->class_init_count; 3736 ++thread_stats->class_init_count; 3737 global_stats->class_init_time_ns += (t1 - t0); 3738 thread_stats->class_init_time_ns += (t1 - t0); 3739 // Set the class as initialized except if failed to initialize static fields. 3740 mirror::Class::SetStatus(klass, mirror::Class::kStatusInitialized, self); 3741 if (VLOG_IS_ON(class_linker)) { 3742 std::string temp; 3743 LOG(INFO) << "Initialized class " << klass->GetDescriptor(&temp) << " from " << 3744 klass->GetLocation(); 3745 } 3746 // Opportunistically set static method trampolines to their destination. 3747 FixupStaticTrampolines(klass.Get()); 3748 } 3749 } 3750 return success; 3751} 3752 3753bool ClassLinker::WaitForInitializeClass(Handle<mirror::Class> klass, Thread* self, 3754 ObjectLock<mirror::Class>& lock) 3755 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 3756 while (true) { 3757 self->AssertNoPendingException(); 3758 CHECK(!klass->IsInitialized()); 3759 lock.WaitIgnoringInterrupts(); 3760 3761 // When we wake up, repeat the test for init-in-progress. If 3762 // there's an exception pending (only possible if 3763 // we were not using WaitIgnoringInterrupts), bail out. 3764 if (self->IsExceptionPending()) { 3765 WrapExceptionInInitializer(klass); 3766 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 3767 return false; 3768 } 3769 // Spurious wakeup? Go back to waiting. 3770 if (klass->GetStatus() == mirror::Class::kStatusInitializing) { 3771 continue; 3772 } 3773 if (klass->GetStatus() == mirror::Class::kStatusVerified && 3774 Runtime::Current()->IsAotCompiler()) { 3775 // Compile time initialization failed. 3776 return false; 3777 } 3778 if (klass->IsErroneous()) { 3779 // The caller wants an exception, but it was thrown in a 3780 // different thread. Synthesize one here. 3781 ThrowNoClassDefFoundError("<clinit> failed for class %s; see exception in other thread", 3782 PrettyDescriptor(klass.Get()).c_str()); 3783 VlogClassInitializationFailure(klass); 3784 return false; 3785 } 3786 if (klass->IsInitialized()) { 3787 return true; 3788 } 3789 LOG(FATAL) << "Unexpected class status. " << PrettyClass(klass.Get()) << " is " 3790 << klass->GetStatus(); 3791 } 3792 UNREACHABLE(); 3793} 3794 3795static void ThrowSignatureCheckResolveReturnTypeException(Handle<mirror::Class> klass, 3796 Handle<mirror::Class> super_klass, 3797 ArtMethod* method, 3798 ArtMethod* m) 3799 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 3800 DCHECK(Thread::Current()->IsExceptionPending()); 3801 DCHECK(!m->IsProxyMethod()); 3802 const DexFile* dex_file = m->GetDexFile(); 3803 const DexFile::MethodId& method_id = dex_file->GetMethodId(m->GetDexMethodIndex()); 3804 const DexFile::ProtoId& proto_id = dex_file->GetMethodPrototype(method_id); 3805 uint16_t return_type_idx = proto_id.return_type_idx_; 3806 std::string return_type = PrettyType(return_type_idx, *dex_file); 3807 std::string class_loader = PrettyTypeOf(m->GetDeclaringClass()->GetClassLoader()); 3808 ThrowWrappedLinkageError(klass.Get(), 3809 "While checking class %s method %s signature against %s %s: " 3810 "Failed to resolve return type %s with %s", 3811 PrettyDescriptor(klass.Get()).c_str(), 3812 PrettyMethod(method).c_str(), 3813 super_klass->IsInterface() ? "interface" : "superclass", 3814 PrettyDescriptor(super_klass.Get()).c_str(), 3815 return_type.c_str(), class_loader.c_str()); 3816} 3817 3818static void ThrowSignatureCheckResolveArgException(Handle<mirror::Class> klass, 3819 Handle<mirror::Class> super_klass, 3820 ArtMethod* method, 3821 ArtMethod* m, 3822 uint32_t index, uint32_t arg_type_idx) 3823 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 3824 DCHECK(Thread::Current()->IsExceptionPending()); 3825 DCHECK(!m->IsProxyMethod()); 3826 const DexFile* dex_file = m->GetDexFile(); 3827 std::string arg_type = PrettyType(arg_type_idx, *dex_file); 3828 std::string class_loader = PrettyTypeOf(m->GetDeclaringClass()->GetClassLoader()); 3829 ThrowWrappedLinkageError(klass.Get(), 3830 "While checking class %s method %s signature against %s %s: " 3831 "Failed to resolve arg %u type %s with %s", 3832 PrettyDescriptor(klass.Get()).c_str(), 3833 PrettyMethod(method).c_str(), 3834 super_klass->IsInterface() ? "interface" : "superclass", 3835 PrettyDescriptor(super_klass.Get()).c_str(), 3836 index, arg_type.c_str(), class_loader.c_str()); 3837} 3838 3839static void ThrowSignatureMismatch(Handle<mirror::Class> klass, 3840 Handle<mirror::Class> super_klass, 3841 ArtMethod* method, 3842 const std::string& error_msg) 3843 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 3844 ThrowLinkageError(klass.Get(), 3845 "Class %s method %s resolves differently in %s %s: %s", 3846 PrettyDescriptor(klass.Get()).c_str(), 3847 PrettyMethod(method).c_str(), 3848 super_klass->IsInterface() ? "interface" : "superclass", 3849 PrettyDescriptor(super_klass.Get()).c_str(), 3850 error_msg.c_str()); 3851} 3852 3853static bool HasSameSignatureWithDifferentClassLoaders(Thread* self, 3854 Handle<mirror::Class> klass, 3855 Handle<mirror::Class> super_klass, 3856 ArtMethod* method1, 3857 ArtMethod* method2) 3858 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 3859 { 3860 StackHandleScope<1> hs(self); 3861 Handle<mirror::Class> return_type(hs.NewHandle(method1->GetReturnType())); 3862 if (UNLIKELY(return_type.Get() == nullptr)) { 3863 ThrowSignatureCheckResolveReturnTypeException(klass, super_klass, method1, method1); 3864 return false; 3865 } 3866 mirror::Class* other_return_type = method2->GetReturnType(); 3867 if (UNLIKELY(other_return_type == nullptr)) { 3868 ThrowSignatureCheckResolveReturnTypeException(klass, super_klass, method1, method2); 3869 return false; 3870 } 3871 if (UNLIKELY(other_return_type != return_type.Get())) { 3872 ThrowSignatureMismatch(klass, super_klass, method1, 3873 StringPrintf("Return types mismatch: %s(%p) vs %s(%p)", 3874 PrettyClassAndClassLoader(return_type.Get()).c_str(), 3875 return_type.Get(), 3876 PrettyClassAndClassLoader(other_return_type).c_str(), 3877 other_return_type)); 3878 return false; 3879 } 3880 } 3881 const DexFile::TypeList* types1 = method1->GetParameterTypeList(); 3882 const DexFile::TypeList* types2 = method2->GetParameterTypeList(); 3883 if (types1 == nullptr) { 3884 if (types2 != nullptr && types2->Size() != 0) { 3885 ThrowSignatureMismatch(klass, super_klass, method1, 3886 StringPrintf("Type list mismatch with %s", 3887 PrettyMethod(method2, true).c_str())); 3888 return false; 3889 } 3890 return true; 3891 } else if (UNLIKELY(types2 == nullptr)) { 3892 if (types1->Size() != 0) { 3893 ThrowSignatureMismatch(klass, super_klass, method1, 3894 StringPrintf("Type list mismatch with %s", 3895 PrettyMethod(method2, true).c_str())); 3896 return false; 3897 } 3898 return true; 3899 } 3900 uint32_t num_types = types1->Size(); 3901 if (UNLIKELY(num_types != types2->Size())) { 3902 ThrowSignatureMismatch(klass, super_klass, method1, 3903 StringPrintf("Type list mismatch with %s", 3904 PrettyMethod(method2, true).c_str())); 3905 return false; 3906 } 3907 for (uint32_t i = 0; i < num_types; ++i) { 3908 StackHandleScope<1> hs(self); 3909 uint32_t param_type_idx = types1->GetTypeItem(i).type_idx_; 3910 Handle<mirror::Class> param_type(hs.NewHandle( 3911 method1->GetClassFromTypeIndex(param_type_idx, true))); 3912 if (UNLIKELY(param_type.Get() == nullptr)) { 3913 ThrowSignatureCheckResolveArgException(klass, super_klass, method1, 3914 method1, i, param_type_idx); 3915 return false; 3916 } 3917 uint32_t other_param_type_idx = types2->GetTypeItem(i).type_idx_; 3918 mirror::Class* other_param_type = 3919 method2->GetClassFromTypeIndex(other_param_type_idx, true); 3920 if (UNLIKELY(other_param_type == nullptr)) { 3921 ThrowSignatureCheckResolveArgException(klass, super_klass, method1, 3922 method2, i, other_param_type_idx); 3923 return false; 3924 } 3925 if (UNLIKELY(param_type.Get() != other_param_type)) { 3926 ThrowSignatureMismatch(klass, super_klass, method1, 3927 StringPrintf("Parameter %u type mismatch: %s(%p) vs %s(%p)", 3928 i, 3929 PrettyClassAndClassLoader(param_type.Get()).c_str(), 3930 param_type.Get(), 3931 PrettyClassAndClassLoader(other_param_type).c_str(), 3932 other_param_type)); 3933 return false; 3934 } 3935 } 3936 return true; 3937} 3938 3939 3940bool ClassLinker::ValidateSuperClassDescriptors(Handle<mirror::Class> klass) { 3941 if (klass->IsInterface()) { 3942 return true; 3943 } 3944 // Begin with the methods local to the superclass. 3945 Thread* self = Thread::Current(); 3946 StackHandleScope<1> hs(self); 3947 MutableHandle<mirror::Class> super_klass(hs.NewHandle<mirror::Class>(nullptr)); 3948 if (klass->HasSuperClass() && 3949 klass->GetClassLoader() != klass->GetSuperClass()->GetClassLoader()) { 3950 super_klass.Assign(klass->GetSuperClass()); 3951 for (int i = klass->GetSuperClass()->GetVTableLength() - 1; i >= 0; --i) { 3952 auto* m = klass->GetVTableEntry(i, image_pointer_size_); 3953 auto* super_m = klass->GetSuperClass()->GetVTableEntry(i, image_pointer_size_); 3954 if (m != super_m) { 3955 if (UNLIKELY(!HasSameSignatureWithDifferentClassLoaders(self, klass, super_klass, 3956 m, super_m))) { 3957 self->AssertPendingException(); 3958 return false; 3959 } 3960 } 3961 } 3962 } 3963 for (int32_t i = 0; i < klass->GetIfTableCount(); ++i) { 3964 super_klass.Assign(klass->GetIfTable()->GetInterface(i)); 3965 if (klass->GetClassLoader() != super_klass->GetClassLoader()) { 3966 uint32_t num_methods = super_klass->NumVirtualMethods(); 3967 for (uint32_t j = 0; j < num_methods; ++j) { 3968 auto* m = klass->GetIfTable()->GetMethodArray(i)->GetElementPtrSize<ArtMethod*>( 3969 j, image_pointer_size_); 3970 auto* super_m = super_klass->GetVirtualMethod(j, image_pointer_size_); 3971 if (m != super_m) { 3972 if (UNLIKELY(!HasSameSignatureWithDifferentClassLoaders(self, klass, super_klass, 3973 m, super_m))) { 3974 self->AssertPendingException(); 3975 return false; 3976 } 3977 } 3978 } 3979 } 3980 } 3981 return true; 3982} 3983 3984bool ClassLinker::EnsureInitialized(Thread* self, Handle<mirror::Class> c, bool can_init_fields, 3985 bool can_init_parents) { 3986 DCHECK(c.Get() != nullptr); 3987 if (c->IsInitialized()) { 3988 EnsurePreverifiedMethods(c); 3989 return true; 3990 } 3991 const bool success = InitializeClass(self, c, can_init_fields, can_init_parents); 3992 if (!success) { 3993 if (can_init_fields && can_init_parents) { 3994 CHECK(self->IsExceptionPending()) << PrettyClass(c.Get()); 3995 } 3996 } else { 3997 self->AssertNoPendingException(); 3998 } 3999 return success; 4000} 4001 4002void ClassLinker::FixupTemporaryDeclaringClass(mirror::Class* temp_class, 4003 mirror::Class* new_class) { 4004 ArtField* fields = new_class->GetIFields(); 4005 DCHECK_EQ(temp_class->NumInstanceFields(), new_class->NumInstanceFields()); 4006 for (size_t i = 0, count = new_class->NumInstanceFields(); i < count; i++) { 4007 if (fields[i].GetDeclaringClass() == temp_class) { 4008 fields[i].SetDeclaringClass(new_class); 4009 } 4010 } 4011 4012 fields = new_class->GetSFields(); 4013 DCHECK_EQ(temp_class->NumStaticFields(), new_class->NumStaticFields()); 4014 for (size_t i = 0, count = new_class->NumStaticFields(); i < count; i++) { 4015 if (fields[i].GetDeclaringClass() == temp_class) { 4016 fields[i].SetDeclaringClass(new_class); 4017 } 4018 } 4019 4020 DCHECK_EQ(temp_class->NumDirectMethods(), new_class->NumDirectMethods()); 4021 for (auto& method : new_class->GetDirectMethods(image_pointer_size_)) { 4022 if (method.GetDeclaringClass() == temp_class) { 4023 method.SetDeclaringClass(new_class); 4024 } 4025 } 4026 4027 DCHECK_EQ(temp_class->NumVirtualMethods(), new_class->NumVirtualMethods()); 4028 for (auto& method : new_class->GetVirtualMethods(image_pointer_size_)) { 4029 if (method.GetDeclaringClass() == temp_class) { 4030 method.SetDeclaringClass(new_class); 4031 } 4032 } 4033} 4034 4035bool ClassLinker::LinkClass(Thread* self, const char* descriptor, Handle<mirror::Class> klass, 4036 Handle<mirror::ObjectArray<mirror::Class>> interfaces, 4037 MutableHandle<mirror::Class>* h_new_class_out) { 4038 CHECK_EQ(mirror::Class::kStatusLoaded, klass->GetStatus()); 4039 4040 if (!LinkSuperClass(klass)) { 4041 return false; 4042 } 4043 ArtMethod* imt[mirror::Class::kImtSize]; 4044 std::fill_n(imt, arraysize(imt), Runtime::Current()->GetImtUnimplementedMethod()); 4045 if (!LinkMethods(self, klass, interfaces, imt)) { 4046 return false; 4047 } 4048 if (!LinkInstanceFields(self, klass)) { 4049 return false; 4050 } 4051 size_t class_size; 4052 if (!LinkStaticFields(self, klass, &class_size)) { 4053 return false; 4054 } 4055 CreateReferenceInstanceOffsets(klass); 4056 CHECK_EQ(mirror::Class::kStatusLoaded, klass->GetStatus()); 4057 4058 if (!klass->IsTemp() || (!init_done_ && klass->GetClassSize() == class_size)) { 4059 // We don't need to retire this class as it has no embedded tables or it was created the 4060 // correct size during class linker initialization. 4061 CHECK_EQ(klass->GetClassSize(), class_size) << PrettyDescriptor(klass.Get()); 4062 4063 if (klass->ShouldHaveEmbeddedImtAndVTable()) { 4064 klass->PopulateEmbeddedImtAndVTable(imt, image_pointer_size_); 4065 } 4066 4067 // This will notify waiters on klass that saw the not yet resolved 4068 // class in the class_table_ during EnsureResolved. 4069 mirror::Class::SetStatus(klass, mirror::Class::kStatusResolved, self); 4070 h_new_class_out->Assign(klass.Get()); 4071 } else { 4072 CHECK(!klass->IsResolved()); 4073 // Retire the temporary class and create the correctly sized resolved class. 4074 StackHandleScope<1> hs(self); 4075 auto h_new_class = hs.NewHandle(klass->CopyOf(self, class_size, imt, image_pointer_size_)); 4076 if (UNLIKELY(h_new_class.Get() == nullptr)) { 4077 self->AssertPendingOOMException(); 4078 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 4079 return false; 4080 } 4081 4082 CHECK_EQ(h_new_class->GetClassSize(), class_size); 4083 ObjectLock<mirror::Class> lock(self, h_new_class); 4084 FixupTemporaryDeclaringClass(klass.Get(), h_new_class.Get()); 4085 mirror::Class* existing = UpdateClass(descriptor, h_new_class.Get(), 4086 ComputeModifiedUtf8Hash(descriptor)); 4087 CHECK(existing == nullptr || existing == klass.Get()); 4088 4089 // This will notify waiters on temp class that saw the not yet resolved class in the 4090 // class_table_ during EnsureResolved. 4091 mirror::Class::SetStatus(klass, mirror::Class::kStatusRetired, self); 4092 4093 CHECK_EQ(h_new_class->GetStatus(), mirror::Class::kStatusResolving); 4094 // This will notify waiters on new_class that saw the not yet resolved 4095 // class in the class_table_ during EnsureResolved. 4096 mirror::Class::SetStatus(h_new_class, mirror::Class::kStatusResolved, self); 4097 // Return the new class. 4098 h_new_class_out->Assign(h_new_class.Get()); 4099 } 4100 return true; 4101} 4102 4103static void CountMethodsAndFields(ClassDataItemIterator& dex_data, 4104 size_t* virtual_methods, 4105 size_t* direct_methods, 4106 size_t* static_fields, 4107 size_t* instance_fields) { 4108 *virtual_methods = *direct_methods = *static_fields = *instance_fields = 0; 4109 4110 while (dex_data.HasNextStaticField()) { 4111 dex_data.Next(); 4112 (*static_fields)++; 4113 } 4114 while (dex_data.HasNextInstanceField()) { 4115 dex_data.Next(); 4116 (*instance_fields)++; 4117 } 4118 while (dex_data.HasNextDirectMethod()) { 4119 (*direct_methods)++; 4120 dex_data.Next(); 4121 } 4122 while (dex_data.HasNextVirtualMethod()) { 4123 (*virtual_methods)++; 4124 dex_data.Next(); 4125 } 4126 DCHECK(!dex_data.HasNext()); 4127} 4128 4129static void DumpClass(std::ostream& os, 4130 const DexFile& dex_file, const DexFile::ClassDef& dex_class_def, 4131 const char* suffix) { 4132 ClassDataItemIterator dex_data(dex_file, dex_file.GetClassData(dex_class_def)); 4133 os << dex_file.GetClassDescriptor(dex_class_def) << suffix << ":\n"; 4134 os << " Static fields:\n"; 4135 while (dex_data.HasNextStaticField()) { 4136 const DexFile::FieldId& id = dex_file.GetFieldId(dex_data.GetMemberIndex()); 4137 os << " " << dex_file.GetFieldTypeDescriptor(id) << " " << dex_file.GetFieldName(id) << "\n"; 4138 dex_data.Next(); 4139 } 4140 os << " Instance fields:\n"; 4141 while (dex_data.HasNextInstanceField()) { 4142 const DexFile::FieldId& id = dex_file.GetFieldId(dex_data.GetMemberIndex()); 4143 os << " " << dex_file.GetFieldTypeDescriptor(id) << " " << dex_file.GetFieldName(id) << "\n"; 4144 dex_data.Next(); 4145 } 4146 os << " Direct methods:\n"; 4147 while (dex_data.HasNextDirectMethod()) { 4148 const DexFile::MethodId& id = dex_file.GetMethodId(dex_data.GetMemberIndex()); 4149 os << " " << dex_file.GetMethodName(id) << dex_file.GetMethodSignature(id).ToString() << "\n"; 4150 dex_data.Next(); 4151 } 4152 os << " Virtual methods:\n"; 4153 while (dex_data.HasNextVirtualMethod()) { 4154 const DexFile::MethodId& id = dex_file.GetMethodId(dex_data.GetMemberIndex()); 4155 os << " " << dex_file.GetMethodName(id) << dex_file.GetMethodSignature(id).ToString() << "\n"; 4156 dex_data.Next(); 4157 } 4158} 4159 4160static std::string DumpClasses(const DexFile& dex_file1, const DexFile::ClassDef& dex_class_def1, 4161 const DexFile& dex_file2, const DexFile::ClassDef& dex_class_def2) { 4162 std::ostringstream os; 4163 DumpClass(os, dex_file1, dex_class_def1, " (Compile time)"); 4164 DumpClass(os, dex_file2, dex_class_def2, " (Runtime)"); 4165 return os.str(); 4166} 4167 4168 4169// Very simple structural check on whether the classes match. Only compares the number of 4170// methods and fields. 4171static bool SimpleStructuralCheck(const DexFile& dex_file1, const DexFile::ClassDef& dex_class_def1, 4172 const DexFile& dex_file2, const DexFile::ClassDef& dex_class_def2, 4173 std::string* error_msg) { 4174 ClassDataItemIterator dex_data1(dex_file1, dex_file1.GetClassData(dex_class_def1)); 4175 ClassDataItemIterator dex_data2(dex_file2, dex_file2.GetClassData(dex_class_def2)); 4176 4177 // Counters for current dex file. 4178 size_t dex_virtual_methods1, dex_direct_methods1, dex_static_fields1, dex_instance_fields1; 4179 CountMethodsAndFields(dex_data1, &dex_virtual_methods1, &dex_direct_methods1, &dex_static_fields1, 4180 &dex_instance_fields1); 4181 // Counters for compile-time dex file. 4182 size_t dex_virtual_methods2, dex_direct_methods2, dex_static_fields2, dex_instance_fields2; 4183 CountMethodsAndFields(dex_data2, &dex_virtual_methods2, &dex_direct_methods2, &dex_static_fields2, 4184 &dex_instance_fields2); 4185 4186 if (dex_virtual_methods1 != dex_virtual_methods2) { 4187 std::string class_dump = DumpClasses(dex_file1, dex_class_def1, dex_file2, dex_class_def2); 4188 *error_msg = StringPrintf("Virtual method count off: %zu vs %zu\n%s", dex_virtual_methods1, 4189 dex_virtual_methods2, class_dump.c_str()); 4190 return false; 4191 } 4192 if (dex_direct_methods1 != dex_direct_methods2) { 4193 std::string class_dump = DumpClasses(dex_file1, dex_class_def1, dex_file2, dex_class_def2); 4194 *error_msg = StringPrintf("Direct method count off: %zu vs %zu\n%s", dex_direct_methods1, 4195 dex_direct_methods2, class_dump.c_str()); 4196 return false; 4197 } 4198 if (dex_static_fields1 != dex_static_fields2) { 4199 std::string class_dump = DumpClasses(dex_file1, dex_class_def1, dex_file2, dex_class_def2); 4200 *error_msg = StringPrintf("Static field count off: %zu vs %zu\n%s", dex_static_fields1, 4201 dex_static_fields2, class_dump.c_str()); 4202 return false; 4203 } 4204 if (dex_instance_fields1 != dex_instance_fields2) { 4205 std::string class_dump = DumpClasses(dex_file1, dex_class_def1, dex_file2, dex_class_def2); 4206 *error_msg = StringPrintf("Instance field count off: %zu vs %zu\n%s", dex_instance_fields1, 4207 dex_instance_fields2, class_dump.c_str()); 4208 return false; 4209 } 4210 4211 return true; 4212} 4213 4214// Checks whether a the super-class changed from what we had at compile-time. This would 4215// invalidate quickening. 4216static bool CheckSuperClassChange(Handle<mirror::Class> klass, 4217 const DexFile& dex_file, 4218 const DexFile::ClassDef& class_def, 4219 mirror::Class* super_class) 4220 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 4221 // Check for unexpected changes in the superclass. 4222 // Quick check 1) is the super_class class-loader the boot class loader? This always has 4223 // precedence. 4224 if (super_class->GetClassLoader() != nullptr && 4225 // Quick check 2) different dex cache? Breaks can only occur for different dex files, 4226 // which is implied by different dex cache. 4227 klass->GetDexCache() != super_class->GetDexCache()) { 4228 // Now comes the expensive part: things can be broken if (a) the klass' dex file has a 4229 // definition for the super-class, and (b) the files are in separate oat files. The oat files 4230 // are referenced from the dex file, so do (b) first. Only relevant if we have oat files. 4231 const OatDexFile* class_oat_dex_file = dex_file.GetOatDexFile(); 4232 const OatFile* class_oat_file = nullptr; 4233 if (class_oat_dex_file != nullptr) { 4234 class_oat_file = class_oat_dex_file->GetOatFile(); 4235 } 4236 4237 if (class_oat_file != nullptr) { 4238 const OatDexFile* loaded_super_oat_dex_file = super_class->GetDexFile().GetOatDexFile(); 4239 const OatFile* loaded_super_oat_file = nullptr; 4240 if (loaded_super_oat_dex_file != nullptr) { 4241 loaded_super_oat_file = loaded_super_oat_dex_file->GetOatFile(); 4242 } 4243 4244 if (loaded_super_oat_file != nullptr && class_oat_file != loaded_super_oat_file) { 4245 // Now check (a). 4246 const DexFile::ClassDef* super_class_def = dex_file.FindClassDef(class_def.superclass_idx_); 4247 if (super_class_def != nullptr) { 4248 // Uh-oh, we found something. Do our check. 4249 std::string error_msg; 4250 if (!SimpleStructuralCheck(dex_file, *super_class_def, 4251 super_class->GetDexFile(), *super_class->GetClassDef(), 4252 &error_msg)) { 4253 // Print a warning to the log. This exception might be caught, e.g., as common in test 4254 // drivers. When the class is later tried to be used, we re-throw a new instance, as we 4255 // only save the type of the exception. 4256 LOG(WARNING) << "Incompatible structural change detected: " << 4257 StringPrintf( 4258 "Structural change of %s is hazardous (%s at compile time, %s at runtime): %s", 4259 PrettyType(super_class_def->class_idx_, dex_file).c_str(), 4260 class_oat_file->GetLocation().c_str(), 4261 loaded_super_oat_file->GetLocation().c_str(), 4262 error_msg.c_str()); 4263 ThrowIncompatibleClassChangeError(klass.Get(), 4264 "Structural change of %s is hazardous (%s at compile time, %s at runtime): %s", 4265 PrettyType(super_class_def->class_idx_, dex_file).c_str(), 4266 class_oat_file->GetLocation().c_str(), 4267 loaded_super_oat_file->GetLocation().c_str(), 4268 error_msg.c_str()); 4269 return false; 4270 } 4271 } 4272 } 4273 } 4274 } 4275 return true; 4276} 4277 4278bool ClassLinker::LoadSuperAndInterfaces(Handle<mirror::Class> klass, const DexFile& dex_file) { 4279 CHECK_EQ(mirror::Class::kStatusIdx, klass->GetStatus()); 4280 const DexFile::ClassDef& class_def = dex_file.GetClassDef(klass->GetDexClassDefIndex()); 4281 uint16_t super_class_idx = class_def.superclass_idx_; 4282 if (super_class_idx != DexFile::kDexNoIndex16) { 4283 mirror::Class* super_class = ResolveType(dex_file, super_class_idx, klass.Get()); 4284 if (super_class == nullptr) { 4285 DCHECK(Thread::Current()->IsExceptionPending()); 4286 return false; 4287 } 4288 // Verify 4289 if (!klass->CanAccess(super_class)) { 4290 ThrowIllegalAccessError(klass.Get(), "Class %s extended by class %s is inaccessible", 4291 PrettyDescriptor(super_class).c_str(), 4292 PrettyDescriptor(klass.Get()).c_str()); 4293 return false; 4294 } 4295 CHECK(super_class->IsResolved()); 4296 klass->SetSuperClass(super_class); 4297 4298 if (!CheckSuperClassChange(klass, dex_file, class_def, super_class)) { 4299 DCHECK(Thread::Current()->IsExceptionPending()); 4300 return false; 4301 } 4302 } 4303 const DexFile::TypeList* interfaces = dex_file.GetInterfacesList(class_def); 4304 if (interfaces != nullptr) { 4305 for (size_t i = 0; i < interfaces->Size(); i++) { 4306 uint16_t idx = interfaces->GetTypeItem(i).type_idx_; 4307 mirror::Class* interface = ResolveType(dex_file, idx, klass.Get()); 4308 if (interface == nullptr) { 4309 DCHECK(Thread::Current()->IsExceptionPending()); 4310 return false; 4311 } 4312 // Verify 4313 if (!klass->CanAccess(interface)) { 4314 // TODO: the RI seemed to ignore this in my testing. 4315 ThrowIllegalAccessError(klass.Get(), "Interface %s implemented by class %s is inaccessible", 4316 PrettyDescriptor(interface).c_str(), 4317 PrettyDescriptor(klass.Get()).c_str()); 4318 return false; 4319 } 4320 } 4321 } 4322 // Mark the class as loaded. 4323 mirror::Class::SetStatus(klass, mirror::Class::kStatusLoaded, nullptr); 4324 return true; 4325} 4326 4327bool ClassLinker::LinkSuperClass(Handle<mirror::Class> klass) { 4328 CHECK(!klass->IsPrimitive()); 4329 mirror::Class* super = klass->GetSuperClass(); 4330 if (klass.Get() == GetClassRoot(kJavaLangObject)) { 4331 if (super != nullptr) { 4332 ThrowClassFormatError(klass.Get(), "java.lang.Object must not have a superclass"); 4333 return false; 4334 } 4335 return true; 4336 } 4337 if (super == nullptr) { 4338 ThrowLinkageError(klass.Get(), "No superclass defined for class %s", 4339 PrettyDescriptor(klass.Get()).c_str()); 4340 return false; 4341 } 4342 // Verify 4343 if (super->IsFinal() || super->IsInterface()) { 4344 ThrowIncompatibleClassChangeError(klass.Get(), "Superclass %s of %s is %s", 4345 PrettyDescriptor(super).c_str(), 4346 PrettyDescriptor(klass.Get()).c_str(), 4347 super->IsFinal() ? "declared final" : "an interface"); 4348 return false; 4349 } 4350 if (!klass->CanAccess(super)) { 4351 ThrowIllegalAccessError(klass.Get(), "Superclass %s is inaccessible to class %s", 4352 PrettyDescriptor(super).c_str(), 4353 PrettyDescriptor(klass.Get()).c_str()); 4354 return false; 4355 } 4356 4357 // Inherit kAccClassIsFinalizable from the superclass in case this 4358 // class doesn't override finalize. 4359 if (super->IsFinalizable()) { 4360 klass->SetFinalizable(); 4361 } 4362 4363 // Inherit reference flags (if any) from the superclass. 4364 int reference_flags = (super->GetAccessFlags() & kAccReferenceFlagsMask); 4365 if (reference_flags != 0) { 4366 klass->SetAccessFlags(klass->GetAccessFlags() | reference_flags); 4367 } 4368 // Disallow custom direct subclasses of java.lang.ref.Reference. 4369 if (init_done_ && super == GetClassRoot(kJavaLangRefReference)) { 4370 ThrowLinkageError(klass.Get(), 4371 "Class %s attempts to subclass java.lang.ref.Reference, which is not allowed", 4372 PrettyDescriptor(klass.Get()).c_str()); 4373 return false; 4374 } 4375 4376 if (kIsDebugBuild) { 4377 // Ensure super classes are fully resolved prior to resolving fields.. 4378 while (super != nullptr) { 4379 CHECK(super->IsResolved()); 4380 super = super->GetSuperClass(); 4381 } 4382 } 4383 return true; 4384} 4385 4386// Populate the class vtable and itable. Compute return type indices. 4387bool ClassLinker::LinkMethods(Thread* self, Handle<mirror::Class> klass, 4388 Handle<mirror::ObjectArray<mirror::Class>> interfaces, 4389 ArtMethod** out_imt) { 4390 self->AllowThreadSuspension(); 4391 if (klass->IsInterface()) { 4392 // No vtable. 4393 size_t count = klass->NumVirtualMethods(); 4394 if (!IsUint<16>(count)) { 4395 ThrowClassFormatError(klass.Get(), "Too many methods on interface: %zd", count); 4396 return false; 4397 } 4398 for (size_t i = 0; i < count; ++i) { 4399 klass->GetVirtualMethodDuringLinking(i, image_pointer_size_)->SetMethodIndex(i); 4400 } 4401 } else if (!LinkVirtualMethods(self, klass)) { // Link virtual methods first. 4402 return false; 4403 } 4404 return LinkInterfaceMethods(self, klass, interfaces, out_imt); // Link interface method last. 4405} 4406 4407// Comparator for name and signature of a method, used in finding overriding methods. Implementation 4408// avoids the use of handles, if it didn't then rather than compare dex files we could compare dex 4409// caches in the implementation below. 4410class MethodNameAndSignatureComparator FINAL : public ValueObject { 4411 public: 4412 explicit MethodNameAndSignatureComparator(ArtMethod* method) 4413 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) : 4414 dex_file_(method->GetDexFile()), mid_(&dex_file_->GetMethodId(method->GetDexMethodIndex())), 4415 name_(nullptr), name_len_(0) { 4416 DCHECK(!method->IsProxyMethod()) << PrettyMethod(method); 4417 } 4418 4419 const char* GetName() { 4420 if (name_ == nullptr) { 4421 name_ = dex_file_->StringDataAndUtf16LengthByIdx(mid_->name_idx_, &name_len_); 4422 } 4423 return name_; 4424 } 4425 4426 bool HasSameNameAndSignature(ArtMethod* other) 4427 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 4428 DCHECK(!other->IsProxyMethod()) << PrettyMethod(other); 4429 const DexFile* other_dex_file = other->GetDexFile(); 4430 const DexFile::MethodId& other_mid = other_dex_file->GetMethodId(other->GetDexMethodIndex()); 4431 if (dex_file_ == other_dex_file) { 4432 return mid_->name_idx_ == other_mid.name_idx_ && mid_->proto_idx_ == other_mid.proto_idx_; 4433 } 4434 GetName(); // Only used to make sure its calculated. 4435 uint32_t other_name_len; 4436 const char* other_name = other_dex_file->StringDataAndUtf16LengthByIdx(other_mid.name_idx_, 4437 &other_name_len); 4438 if (name_len_ != other_name_len || strcmp(name_, other_name) != 0) { 4439 return false; 4440 } 4441 return dex_file_->GetMethodSignature(*mid_) == other_dex_file->GetMethodSignature(other_mid); 4442 } 4443 4444 private: 4445 // Dex file for the method to compare against. 4446 const DexFile* const dex_file_; 4447 // MethodId for the method to compare against. 4448 const DexFile::MethodId* const mid_; 4449 // Lazily computed name from the dex file's strings. 4450 const char* name_; 4451 // Lazily computed name length. 4452 uint32_t name_len_; 4453}; 4454 4455class LinkVirtualHashTable { 4456 public: 4457 LinkVirtualHashTable(Handle<mirror::Class> klass, size_t hash_size, uint32_t* hash_table, 4458 size_t image_pointer_size) 4459 : klass_(klass), hash_size_(hash_size), hash_table_(hash_table), 4460 image_pointer_size_(image_pointer_size) { 4461 std::fill(hash_table_, hash_table_ + hash_size_, invalid_index_); 4462 } 4463 void Add(uint32_t virtual_method_index) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 4464 ArtMethod* local_method = klass_->GetVirtualMethodDuringLinking( 4465 virtual_method_index, image_pointer_size_); 4466 const char* name = local_method->GetInterfaceMethodIfProxy(image_pointer_size_)->GetName(); 4467 uint32_t hash = ComputeModifiedUtf8Hash(name); 4468 uint32_t index = hash % hash_size_; 4469 // Linear probe until we have an empty slot. 4470 while (hash_table_[index] != invalid_index_) { 4471 if (++index == hash_size_) { 4472 index = 0; 4473 } 4474 } 4475 hash_table_[index] = virtual_method_index; 4476 } 4477 uint32_t FindAndRemove(MethodNameAndSignatureComparator* comparator) 4478 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 4479 const char* name = comparator->GetName(); 4480 uint32_t hash = ComputeModifiedUtf8Hash(name); 4481 size_t index = hash % hash_size_; 4482 while (true) { 4483 const uint32_t value = hash_table_[index]; 4484 // Since linear probe makes continuous blocks, hitting an invalid index means we are done 4485 // the block and can safely assume not found. 4486 if (value == invalid_index_) { 4487 break; 4488 } 4489 if (value != removed_index_) { // This signifies not already overriden. 4490 ArtMethod* virtual_method = 4491 klass_->GetVirtualMethodDuringLinking(value, image_pointer_size_); 4492 if (comparator->HasSameNameAndSignature( 4493 virtual_method->GetInterfaceMethodIfProxy(image_pointer_size_))) { 4494 hash_table_[index] = removed_index_; 4495 return value; 4496 } 4497 } 4498 if (++index == hash_size_) { 4499 index = 0; 4500 } 4501 } 4502 return GetNotFoundIndex(); 4503 } 4504 static uint32_t GetNotFoundIndex() { 4505 return invalid_index_; 4506 } 4507 4508 private: 4509 static const uint32_t invalid_index_; 4510 static const uint32_t removed_index_; 4511 4512 Handle<mirror::Class> klass_; 4513 const size_t hash_size_; 4514 uint32_t* const hash_table_; 4515 const size_t image_pointer_size_; 4516}; 4517 4518const uint32_t LinkVirtualHashTable::invalid_index_ = std::numeric_limits<uint32_t>::max(); 4519const uint32_t LinkVirtualHashTable::removed_index_ = std::numeric_limits<uint32_t>::max() - 1; 4520 4521bool ClassLinker::LinkVirtualMethods(Thread* self, Handle<mirror::Class> klass) { 4522 const size_t num_virtual_methods = klass->NumVirtualMethods(); 4523 if (klass->HasSuperClass()) { 4524 const size_t super_vtable_length = klass->GetSuperClass()->GetVTableLength(); 4525 const size_t max_count = num_virtual_methods + super_vtable_length; 4526 StackHandleScope<2> hs(self); 4527 Handle<mirror::Class> super_class(hs.NewHandle(klass->GetSuperClass())); 4528 MutableHandle<mirror::PointerArray> vtable; 4529 if (super_class->ShouldHaveEmbeddedImtAndVTable()) { 4530 vtable = hs.NewHandle(AllocPointerArray(self, max_count)); 4531 if (UNLIKELY(vtable.Get() == nullptr)) { 4532 self->AssertPendingOOMException(); 4533 return false; 4534 } 4535 for (size_t i = 0; i < super_vtable_length; i++) { 4536 vtable->SetElementPtrSize( 4537 i, super_class->GetEmbeddedVTableEntry(i, image_pointer_size_), image_pointer_size_); 4538 } 4539 if (num_virtual_methods == 0) { 4540 klass->SetVTable(vtable.Get()); 4541 return true; 4542 } 4543 } else { 4544 auto* super_vtable = super_class->GetVTable(); 4545 CHECK(super_vtable != nullptr) << PrettyClass(super_class.Get()); 4546 if (num_virtual_methods == 0) { 4547 klass->SetVTable(super_vtable); 4548 return true; 4549 } 4550 vtable = hs.NewHandle(down_cast<mirror::PointerArray*>( 4551 super_vtable->CopyOf(self, max_count))); 4552 if (UNLIKELY(vtable.Get() == nullptr)) { 4553 self->AssertPendingOOMException(); 4554 return false; 4555 } 4556 } 4557 // How the algorithm works: 4558 // 1. Populate hash table by adding num_virtual_methods from klass. The values in the hash 4559 // table are: invalid_index for unused slots, index super_vtable_length + i for a virtual 4560 // method which has not been matched to a vtable method, and j if the virtual method at the 4561 // index overrode the super virtual method at index j. 4562 // 2. Loop through super virtual methods, if they overwrite, update hash table to j 4563 // (j < super_vtable_length) to avoid redundant checks. (TODO maybe use this info for reducing 4564 // the need for the initial vtable which we later shrink back down). 4565 // 3. Add non overridden methods to the end of the vtable. 4566 static constexpr size_t kMaxStackHash = 250; 4567 const size_t hash_table_size = num_virtual_methods * 3; 4568 uint32_t* hash_table_ptr; 4569 std::unique_ptr<uint32_t[]> hash_heap_storage; 4570 if (hash_table_size <= kMaxStackHash) { 4571 hash_table_ptr = reinterpret_cast<uint32_t*>( 4572 alloca(hash_table_size * sizeof(*hash_table_ptr))); 4573 } else { 4574 hash_heap_storage.reset(new uint32_t[hash_table_size]); 4575 hash_table_ptr = hash_heap_storage.get(); 4576 } 4577 LinkVirtualHashTable hash_table(klass, hash_table_size, hash_table_ptr, image_pointer_size_); 4578 // Add virtual methods to the hash table. 4579 for (size_t i = 0; i < num_virtual_methods; ++i) { 4580 DCHECK(klass->GetVirtualMethodDuringLinking( 4581 i, image_pointer_size_)->GetDeclaringClass() != nullptr); 4582 hash_table.Add(i); 4583 } 4584 // Loop through each super vtable method and see if they are overriden by a method we added to 4585 // the hash table. 4586 for (size_t j = 0; j < super_vtable_length; ++j) { 4587 // Search the hash table to see if we are overidden by any method. 4588 ArtMethod* super_method = vtable->GetElementPtrSize<ArtMethod*>(j, image_pointer_size_); 4589 MethodNameAndSignatureComparator super_method_name_comparator( 4590 super_method->GetInterfaceMethodIfProxy(image_pointer_size_)); 4591 uint32_t hash_index = hash_table.FindAndRemove(&super_method_name_comparator); 4592 if (hash_index != hash_table.GetNotFoundIndex()) { 4593 ArtMethod* virtual_method = klass->GetVirtualMethodDuringLinking( 4594 hash_index, image_pointer_size_); 4595 if (klass->CanAccessMember(super_method->GetDeclaringClass(), 4596 super_method->GetAccessFlags())) { 4597 if (super_method->IsFinal()) { 4598 ThrowLinkageError(klass.Get(), "Method %s overrides final method in class %s", 4599 PrettyMethod(virtual_method).c_str(), 4600 super_method->GetDeclaringClassDescriptor()); 4601 return false; 4602 } 4603 vtable->SetElementPtrSize(j, virtual_method, image_pointer_size_); 4604 virtual_method->SetMethodIndex(j); 4605 } else { 4606 LOG(WARNING) << "Before Android 4.1, method " << PrettyMethod(virtual_method) 4607 << " would have incorrectly overridden the package-private method in " 4608 << PrettyDescriptor(super_method->GetDeclaringClassDescriptor()); 4609 } 4610 } 4611 } 4612 // Add the non overridden methods at the end. 4613 size_t actual_count = super_vtable_length; 4614 for (size_t i = 0; i < num_virtual_methods; ++i) { 4615 ArtMethod* local_method = klass->GetVirtualMethodDuringLinking(i, image_pointer_size_); 4616 size_t method_idx = local_method->GetMethodIndexDuringLinking(); 4617 if (method_idx < super_vtable_length && 4618 local_method == vtable->GetElementPtrSize<ArtMethod*>(method_idx, image_pointer_size_)) { 4619 continue; 4620 } 4621 vtable->SetElementPtrSize(actual_count, local_method, image_pointer_size_); 4622 local_method->SetMethodIndex(actual_count); 4623 ++actual_count; 4624 } 4625 if (!IsUint<16>(actual_count)) { 4626 ThrowClassFormatError(klass.Get(), "Too many methods defined on class: %zd", actual_count); 4627 return false; 4628 } 4629 // Shrink vtable if possible 4630 CHECK_LE(actual_count, max_count); 4631 if (actual_count < max_count) { 4632 vtable.Assign(down_cast<mirror::PointerArray*>(vtable->CopyOf(self, actual_count))); 4633 if (UNLIKELY(vtable.Get() == nullptr)) { 4634 self->AssertPendingOOMException(); 4635 return false; 4636 } 4637 } 4638 klass->SetVTable(vtable.Get()); 4639 } else { 4640 CHECK_EQ(klass.Get(), GetClassRoot(kJavaLangObject)); 4641 if (!IsUint<16>(num_virtual_methods)) { 4642 ThrowClassFormatError(klass.Get(), "Too many methods: %d", 4643 static_cast<int>(num_virtual_methods)); 4644 return false; 4645 } 4646 auto* vtable = AllocPointerArray(self, num_virtual_methods); 4647 if (UNLIKELY(vtable == nullptr)) { 4648 self->AssertPendingOOMException(); 4649 return false; 4650 } 4651 for (size_t i = 0; i < num_virtual_methods; ++i) { 4652 ArtMethod* virtual_method = klass->GetVirtualMethodDuringLinking(i, image_pointer_size_); 4653 vtable->SetElementPtrSize(i, virtual_method, image_pointer_size_); 4654 virtual_method->SetMethodIndex(i & 0xFFFF); 4655 } 4656 klass->SetVTable(vtable); 4657 } 4658 return true; 4659} 4660 4661bool ClassLinker::LinkInterfaceMethods(Thread* self, Handle<mirror::Class> klass, 4662 Handle<mirror::ObjectArray<mirror::Class>> interfaces, 4663 ArtMethod** out_imt) { 4664 StackHandleScope<3> hs(self); 4665 Runtime* const runtime = Runtime::Current(); 4666 const bool has_superclass = klass->HasSuperClass(); 4667 const size_t super_ifcount = has_superclass ? klass->GetSuperClass()->GetIfTableCount() : 0U; 4668 const bool have_interfaces = interfaces.Get() != nullptr; 4669 const size_t num_interfaces = 4670 have_interfaces ? interfaces->GetLength() : klass->NumDirectInterfaces(); 4671 const size_t method_size = ArtMethod::ObjectSize(image_pointer_size_); 4672 if (num_interfaces == 0) { 4673 if (super_ifcount == 0) { 4674 // Class implements no interfaces. 4675 DCHECK_EQ(klass->GetIfTableCount(), 0); 4676 DCHECK(klass->GetIfTable() == nullptr); 4677 return true; 4678 } 4679 // Class implements same interfaces as parent, are any of these not marker interfaces? 4680 bool has_non_marker_interface = false; 4681 mirror::IfTable* super_iftable = klass->GetSuperClass()->GetIfTable(); 4682 for (size_t i = 0; i < super_ifcount; ++i) { 4683 if (super_iftable->GetMethodArrayCount(i) > 0) { 4684 has_non_marker_interface = true; 4685 break; 4686 } 4687 } 4688 // Class just inherits marker interfaces from parent so recycle parent's iftable. 4689 if (!has_non_marker_interface) { 4690 klass->SetIfTable(super_iftable); 4691 return true; 4692 } 4693 } 4694 size_t ifcount = super_ifcount + num_interfaces; 4695 for (size_t i = 0; i < num_interfaces; i++) { 4696 mirror::Class* interface = have_interfaces ? 4697 interfaces->GetWithoutChecks(i) : mirror::Class::GetDirectInterface(self, klass, i); 4698 DCHECK(interface != nullptr); 4699 if (UNLIKELY(!interface->IsInterface())) { 4700 std::string temp; 4701 ThrowIncompatibleClassChangeError(klass.Get(), "Class %s implements non-interface class %s", 4702 PrettyDescriptor(klass.Get()).c_str(), 4703 PrettyDescriptor(interface->GetDescriptor(&temp)).c_str()); 4704 return false; 4705 } 4706 ifcount += interface->GetIfTableCount(); 4707 } 4708 MutableHandle<mirror::IfTable> iftable(hs.NewHandle(AllocIfTable(self, ifcount))); 4709 if (UNLIKELY(iftable.Get() == nullptr)) { 4710 self->AssertPendingOOMException(); 4711 return false; 4712 } 4713 if (super_ifcount != 0) { 4714 mirror::IfTable* super_iftable = klass->GetSuperClass()->GetIfTable(); 4715 for (size_t i = 0; i < super_ifcount; i++) { 4716 mirror::Class* super_interface = super_iftable->GetInterface(i); 4717 iftable->SetInterface(i, super_interface); 4718 } 4719 } 4720 self->AllowThreadSuspension(); 4721 // Flatten the interface inheritance hierarchy. 4722 size_t idx = super_ifcount; 4723 for (size_t i = 0; i < num_interfaces; i++) { 4724 mirror::Class* interface = have_interfaces ? interfaces->Get(i) : 4725 mirror::Class::GetDirectInterface(self, klass, i); 4726 // Check if interface is already in iftable 4727 bool duplicate = false; 4728 for (size_t j = 0; j < idx; j++) { 4729 mirror::Class* existing_interface = iftable->GetInterface(j); 4730 if (existing_interface == interface) { 4731 duplicate = true; 4732 break; 4733 } 4734 } 4735 if (!duplicate) { 4736 // Add this non-duplicate interface. 4737 iftable->SetInterface(idx++, interface); 4738 // Add this interface's non-duplicate super-interfaces. 4739 for (int32_t j = 0; j < interface->GetIfTableCount(); j++) { 4740 mirror::Class* super_interface = interface->GetIfTable()->GetInterface(j); 4741 bool super_duplicate = false; 4742 for (size_t k = 0; k < idx; k++) { 4743 mirror::Class* existing_interface = iftable->GetInterface(k); 4744 if (existing_interface == super_interface) { 4745 super_duplicate = true; 4746 break; 4747 } 4748 } 4749 if (!super_duplicate) { 4750 iftable->SetInterface(idx++, super_interface); 4751 } 4752 } 4753 } 4754 } 4755 self->AllowThreadSuspension(); 4756 // Shrink iftable in case duplicates were found 4757 if (idx < ifcount) { 4758 DCHECK_NE(num_interfaces, 0U); 4759 iftable.Assign(down_cast<mirror::IfTable*>( 4760 iftable->CopyOf(self, idx * mirror::IfTable::kMax))); 4761 if (UNLIKELY(iftable.Get() == nullptr)) { 4762 self->AssertPendingOOMException(); 4763 return false; 4764 } 4765 ifcount = idx; 4766 } else { 4767 DCHECK_EQ(idx, ifcount); 4768 } 4769 klass->SetIfTable(iftable.Get()); 4770 // If we're an interface, we don't need the vtable pointers, so we're done. 4771 if (klass->IsInterface()) { 4772 return true; 4773 } 4774 // These are allocated on the heap to begin, we then transfer to linear alloc when we re-create 4775 // the virtual methods array. 4776 // Need to use low 4GB arenas for compiler or else the pointers wont fit in 32 bit method array 4777 // during cross compilation. 4778 // Use the linear alloc pool since this one is in the low 4gb for the compiler. 4779 ArenaStack stack(runtime->GetLinearAlloc()->GetArenaPool()); 4780 ScopedArenaAllocator allocator(&stack); 4781 ScopedArenaVector<ArtMethod*> miranda_methods(allocator.Adapter()); 4782 4783 MutableHandle<mirror::PointerArray> vtable(hs.NewHandle(klass->GetVTableDuringLinking())); 4784 ArtMethod* const unimplemented_method = runtime->GetImtUnimplementedMethod(); 4785 ArtMethod* const conflict_method = runtime->GetImtConflictMethod(); 4786 // Copy the IMT from the super class if possible. 4787 bool extend_super_iftable = false; 4788 if (has_superclass) { 4789 mirror::Class* super_class = klass->GetSuperClass(); 4790 extend_super_iftable = true; 4791 if (super_class->ShouldHaveEmbeddedImtAndVTable()) { 4792 for (size_t i = 0; i < mirror::Class::kImtSize; ++i) { 4793 out_imt[i] = super_class->GetEmbeddedImTableEntry(i, image_pointer_size_); 4794 } 4795 } else { 4796 // No imt in the super class, need to reconstruct from the iftable. 4797 mirror::IfTable* if_table = super_class->GetIfTable(); 4798 const size_t length = super_class->GetIfTableCount(); 4799 for (size_t i = 0; i < length; ++i) { 4800 mirror::Class* interface = iftable->GetInterface(i); 4801 const size_t num_virtuals = interface->NumVirtualMethods(); 4802 const size_t method_array_count = if_table->GetMethodArrayCount(i); 4803 DCHECK_EQ(num_virtuals, method_array_count); 4804 if (method_array_count == 0) { 4805 continue; 4806 } 4807 auto* method_array = if_table->GetMethodArray(i); 4808 for (size_t j = 0; j < num_virtuals; ++j) { 4809 auto method = method_array->GetElementPtrSize<ArtMethod*>(j, image_pointer_size_); 4810 DCHECK(method != nullptr) << PrettyClass(super_class); 4811 if (method->IsMiranda()) { 4812 continue; 4813 } 4814 ArtMethod* interface_method = interface->GetVirtualMethod(j, image_pointer_size_); 4815 uint32_t imt_index = interface_method->GetDexMethodIndex() % mirror::Class::kImtSize; 4816 auto*& imt_ref = out_imt[imt_index]; 4817 if (imt_ref == unimplemented_method) { 4818 imt_ref = method; 4819 } else if (imt_ref != conflict_method) { 4820 imt_ref = conflict_method; 4821 } 4822 } 4823 } 4824 } 4825 } 4826 // Allocate method arrays before since we don't want miss visiting miranda method roots due to 4827 // thread suspension. 4828 for (size_t i = 0; i < ifcount; ++i) { 4829 size_t num_methods = iftable->GetInterface(i)->NumVirtualMethods(); 4830 if (num_methods > 0) { 4831 const bool is_super = i < super_ifcount; 4832 const bool super_interface = is_super && extend_super_iftable; 4833 mirror::PointerArray* method_array; 4834 if (super_interface) { 4835 mirror::IfTable* if_table = klass->GetSuperClass()->GetIfTable(); 4836 DCHECK(if_table != nullptr); 4837 DCHECK(if_table->GetMethodArray(i) != nullptr); 4838 // If we are working on a super interface, try extending the existing method array. 4839 method_array = down_cast<mirror::PointerArray*>(if_table->GetMethodArray(i)->Clone(self)); 4840 } else { 4841 method_array = AllocPointerArray(self, num_methods); 4842 } 4843 if (UNLIKELY(method_array == nullptr)) { 4844 self->AssertPendingOOMException(); 4845 return false; 4846 } 4847 iftable->SetMethodArray(i, method_array); 4848 } 4849 } 4850 4851 auto* old_cause = self->StartAssertNoThreadSuspension( 4852 "Copying ArtMethods for LinkInterfaceMethods"); 4853 for (size_t i = 0; i < ifcount; ++i) { 4854 size_t num_methods = iftable->GetInterface(i)->NumVirtualMethods(); 4855 if (num_methods > 0) { 4856 StackHandleScope<2> hs2(self); 4857 const bool is_super = i < super_ifcount; 4858 const bool super_interface = is_super && extend_super_iftable; 4859 auto method_array(hs2.NewHandle(iftable->GetMethodArray(i))); 4860 4861 ArtMethod* input_virtual_methods = nullptr; 4862 Handle<mirror::PointerArray> input_vtable_array = NullHandle<mirror::PointerArray>(); 4863 int32_t input_array_length = 0; 4864 if (super_interface) { 4865 // We are overwriting a super class interface, try to only virtual methods instead of the 4866 // whole vtable. 4867 input_virtual_methods = klass->GetVirtualMethodsPtr(); 4868 input_array_length = klass->NumVirtualMethods(); 4869 } else { 4870 // A new interface, we need the whole vtable in case a new interface method is implemented 4871 // in the whole superclass. 4872 input_vtable_array = vtable; 4873 input_array_length = input_vtable_array->GetLength(); 4874 } 4875 if (input_array_length == 0) { 4876 // If the added virtual methods is empty, do nothing. 4877 DCHECK(super_interface); 4878 continue; 4879 } 4880 for (size_t j = 0; j < num_methods; ++j) { 4881 auto* interface_method = iftable->GetInterface(i)->GetVirtualMethod( 4882 j, image_pointer_size_); 4883 MethodNameAndSignatureComparator interface_name_comparator( 4884 interface_method->GetInterfaceMethodIfProxy(image_pointer_size_)); 4885 int32_t k; 4886 // For each method listed in the interface's method list, find the 4887 // matching method in our class's method list. We want to favor the 4888 // subclass over the superclass, which just requires walking 4889 // back from the end of the vtable. (This only matters if the 4890 // superclass defines a private method and this class redefines 4891 // it -- otherwise it would use the same vtable slot. In .dex files 4892 // those don't end up in the virtual method table, so it shouldn't 4893 // matter which direction we go. We walk it backward anyway.) 4894 for (k = input_array_length - 1; k >= 0; --k) { 4895 ArtMethod* vtable_method = input_virtual_methods != nullptr ? 4896 reinterpret_cast<ArtMethod*>( 4897 reinterpret_cast<uintptr_t>(input_virtual_methods) + method_size * k) : 4898 input_vtable_array->GetElementPtrSize<ArtMethod*>(k, image_pointer_size_); 4899 ArtMethod* vtable_method_for_name_comparison = 4900 vtable_method->GetInterfaceMethodIfProxy(image_pointer_size_); 4901 if (interface_name_comparator.HasSameNameAndSignature( 4902 vtable_method_for_name_comparison)) { 4903 if (!vtable_method->IsAbstract() && !vtable_method->IsPublic()) { 4904 ThrowIllegalAccessError(klass.Get(), 4905 "Method '%s' implementing interface method '%s' is not public", 4906 PrettyMethod(vtable_method).c_str(), PrettyMethod(interface_method).c_str()); 4907 return false; 4908 } 4909 method_array->SetElementPtrSize(j, vtable_method, image_pointer_size_); 4910 // Place method in imt if entry is empty, place conflict otherwise. 4911 uint32_t imt_index = interface_method->GetDexMethodIndex() % mirror::Class::kImtSize; 4912 auto** imt_ref = &out_imt[imt_index]; 4913 if (*imt_ref == unimplemented_method) { 4914 *imt_ref = vtable_method; 4915 } else if (*imt_ref != conflict_method) { 4916 // If we are not a conflict and we have the same signature and name as the imt entry, 4917 // it must be that we overwrote a superclass vtable entry. 4918 MethodNameAndSignatureComparator imt_comparator( 4919 (*imt_ref)->GetInterfaceMethodIfProxy(image_pointer_size_)); 4920 *imt_ref = imt_comparator.HasSameNameAndSignature(vtable_method_for_name_comparison) ? 4921 vtable_method : conflict_method; 4922 } 4923 break; 4924 } 4925 } 4926 if (k < 0 && !super_interface) { 4927 ArtMethod* miranda_method = nullptr; 4928 for (auto& mir_method : miranda_methods) { 4929 if (interface_name_comparator.HasSameNameAndSignature(mir_method)) { 4930 miranda_method = mir_method; 4931 break; 4932 } 4933 } 4934 if (miranda_method == nullptr) { 4935 size_t size = ArtMethod::ObjectSize(image_pointer_size_); 4936 miranda_method = reinterpret_cast<ArtMethod*>(allocator.Alloc(size)); 4937 CHECK(miranda_method != nullptr); 4938 // Point the interface table at a phantom slot. 4939 new(miranda_method) ArtMethod(*interface_method, image_pointer_size_); 4940 miranda_methods.push_back(miranda_method); 4941 } 4942 method_array->SetElementPtrSize(j, miranda_method, image_pointer_size_); 4943 } 4944 } 4945 } 4946 } 4947 if (!miranda_methods.empty()) { 4948 const size_t old_method_count = klass->NumVirtualMethods(); 4949 const size_t new_method_count = old_method_count + miranda_methods.size(); 4950 // Attempt to realloc to save RAM if possible. 4951 ArtMethod* old_virtuals = klass->GetVirtualMethodsPtr(); 4952 // The Realloced virtual methods aren't visiblef from the class roots, so there is no issue 4953 // where GCs could attempt to mark stale pointers due to memcpy. And since we overwrite the 4954 // realloced memory with out->CopyFrom, we are guaranteed to have objects in the to space since 4955 // CopyFrom has internal read barriers. 4956 auto* virtuals = reinterpret_cast<ArtMethod*>(runtime->GetLinearAlloc()->Realloc( 4957 self, old_virtuals, old_method_count * method_size, new_method_count * method_size)); 4958 if (UNLIKELY(virtuals == nullptr)) { 4959 self->AssertPendingOOMException(); 4960 return false; 4961 } 4962 ScopedArenaUnorderedMap<ArtMethod*, ArtMethod*> move_table(allocator.Adapter()); 4963 if (virtuals != old_virtuals) { 4964 // Maps from heap allocated miranda method to linear alloc miranda method. 4965 StrideIterator<ArtMethod> out(reinterpret_cast<uintptr_t>(virtuals), method_size); 4966 // Copy over the old methods + miranda methods. 4967 for (auto& m : klass->GetVirtualMethods(image_pointer_size_)) { 4968 move_table.emplace(&m, &*out); 4969 // The CopyFrom is only necessary to not miss read barriers since Realloc won't do read 4970 // barriers when it copies. 4971 out->CopyFrom(&m, image_pointer_size_); 4972 ++out; 4973 } 4974 } 4975 UpdateClassVirtualMethods(klass.Get(), virtuals, new_method_count); 4976 // Done copying methods, they are all reachable from the class now, so we can end the no thread 4977 // suspension assert. 4978 self->EndAssertNoThreadSuspension(old_cause); 4979 4980 size_t old_vtable_count = vtable->GetLength(); 4981 const size_t new_vtable_count = old_vtable_count + miranda_methods.size(); 4982 vtable.Assign(down_cast<mirror::PointerArray*>(vtable->CopyOf(self, new_vtable_count))); 4983 if (UNLIKELY(vtable.Get() == nullptr)) { 4984 self->AssertPendingOOMException(); 4985 return false; 4986 } 4987 StrideIterator<ArtMethod> out( 4988 reinterpret_cast<uintptr_t>(virtuals) + old_method_count * method_size, method_size); 4989 for (auto* mir_method : miranda_methods) { 4990 ArtMethod* out_method = &*out; 4991 out->CopyFrom(mir_method, image_pointer_size_); 4992 // Leave the declaring class alone as type indices are relative to it 4993 out_method->SetAccessFlags(out_method->GetAccessFlags() | kAccMiranda); 4994 out_method->SetMethodIndex(0xFFFF & old_vtable_count); 4995 vtable->SetElementPtrSize(old_vtable_count, out_method, image_pointer_size_); 4996 move_table.emplace(mir_method, out_method); 4997 ++out; 4998 ++old_vtable_count; 4999 } 5000 5001 // Update old vtable methods. 5002 for (size_t i = 0; i < old_vtable_count - miranda_methods.size(); ++i) { 5003 auto* m = vtable->GetElementPtrSize<ArtMethod*>(i, image_pointer_size_); 5004 DCHECK(m != nullptr) << PrettyClass(klass.Get()); 5005 auto it = move_table.find(m); 5006 if (it != move_table.end()) { 5007 auto* new_m = it->second; 5008 DCHECK(new_m != nullptr) << PrettyClass(klass.Get()); 5009 vtable->SetElementPtrSize(i, new_m, image_pointer_size_); 5010 } 5011 } 5012 klass->SetVTable(vtable.Get()); 5013 CHECK_EQ(old_vtable_count, new_vtable_count); 5014 // Go fix up all the stale miranda pointers. 5015 for (size_t i = 0; i < ifcount; ++i) { 5016 for (size_t j = 0, count = iftable->GetMethodArrayCount(i); j < count; ++j) { 5017 auto* method_array = iftable->GetMethodArray(i); 5018 auto* m = method_array->GetElementPtrSize<ArtMethod*>(j, image_pointer_size_); 5019 DCHECK(m != nullptr) << PrettyClass(klass.Get()); 5020 auto it = move_table.find(m); 5021 if (it != move_table.end()) { 5022 auto* new_m = it->second; 5023 DCHECK(new_m != nullptr) << PrettyClass(klass.Get()); 5024 method_array->SetElementPtrSize(j, new_m, image_pointer_size_); 5025 } 5026 } 5027 } 5028 // Fix up IMT in case it has any miranda methods in it. 5029 for (size_t i = 0; i < mirror::Class::kImtSize; ++i) { 5030 auto it = move_table.find(out_imt[i]); 5031 if (it != move_table.end()) { 5032 out_imt[i] = it->second; 5033 } 5034 } 5035 // Check that there are no stale methods are in the dex cache array. 5036 if (kIsDebugBuild) { 5037 auto* resolved_methods = klass->GetDexCache()->GetResolvedMethods(); 5038 for (size_t i = 0, count = resolved_methods->GetLength(); i < count; ++i) { 5039 auto* m = resolved_methods->GetElementPtrSize<ArtMethod*>(i, image_pointer_size_); 5040 CHECK(move_table.find(m) == move_table.end()) << PrettyMethod(m); 5041 } 5042 } 5043 // Put some random garbage in old virtuals to help find stale pointers. 5044 if (virtuals != old_virtuals) { 5045 memset(old_virtuals, 0xFEu, ArtMethod::ObjectSize(image_pointer_size_) * old_method_count); 5046 } 5047 } else { 5048 self->EndAssertNoThreadSuspension(old_cause); 5049 } 5050 if (kIsDebugBuild) { 5051 auto* check_vtable = klass->GetVTableDuringLinking(); 5052 for (int i = 0; i < check_vtable->GetLength(); ++i) { 5053 CHECK(check_vtable->GetElementPtrSize<ArtMethod*>(i, image_pointer_size_) != nullptr); 5054 } 5055 } 5056 return true; 5057} 5058 5059bool ClassLinker::LinkInstanceFields(Thread* self, Handle<mirror::Class> klass) { 5060 CHECK(klass.Get() != nullptr); 5061 return LinkFields(self, klass, false, nullptr); 5062} 5063 5064bool ClassLinker::LinkStaticFields(Thread* self, Handle<mirror::Class> klass, size_t* class_size) { 5065 CHECK(klass.Get() != nullptr); 5066 return LinkFields(self, klass, true, class_size); 5067} 5068 5069struct LinkFieldsComparator { 5070 explicit LinkFieldsComparator() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 5071 } 5072 // No thread safety analysis as will be called from STL. Checked lock held in constructor. 5073 bool operator()(ArtField* field1, ArtField* field2) 5074 NO_THREAD_SAFETY_ANALYSIS { 5075 // First come reference fields, then 64-bit, then 32-bit, and then 16-bit, then finally 8-bit. 5076 Primitive::Type type1 = field1->GetTypeAsPrimitiveType(); 5077 Primitive::Type type2 = field2->GetTypeAsPrimitiveType(); 5078 if (type1 != type2) { 5079 if (type1 == Primitive::kPrimNot) { 5080 // Reference always goes first. 5081 return true; 5082 } 5083 if (type2 == Primitive::kPrimNot) { 5084 // Reference always goes first. 5085 return false; 5086 } 5087 size_t size1 = Primitive::ComponentSize(type1); 5088 size_t size2 = Primitive::ComponentSize(type2); 5089 if (size1 != size2) { 5090 // Larger primitive types go first. 5091 return size1 > size2; 5092 } 5093 // Primitive types differ but sizes match. Arbitrarily order by primitive type. 5094 return type1 < type2; 5095 } 5096 // Same basic group? Then sort by dex field index. This is guaranteed to be sorted 5097 // by name and for equal names by type id index. 5098 // NOTE: This works also for proxies. Their static fields are assigned appropriate indexes. 5099 return field1->GetDexFieldIndex() < field2->GetDexFieldIndex(); 5100 } 5101}; 5102 5103bool ClassLinker::LinkFields(Thread* self, Handle<mirror::Class> klass, bool is_static, 5104 size_t* class_size) { 5105 self->AllowThreadSuspension(); 5106 const size_t num_fields = is_static ? klass->NumStaticFields() : klass->NumInstanceFields(); 5107 ArtField* const fields = is_static ? klass->GetSFields() : klass->GetIFields(); 5108 5109 // Initialize field_offset 5110 MemberOffset field_offset(0); 5111 if (is_static) { 5112 field_offset = klass->GetFirstReferenceStaticFieldOffsetDuringLinking(image_pointer_size_); 5113 } else { 5114 mirror::Class* super_class = klass->GetSuperClass(); 5115 if (super_class != nullptr) { 5116 CHECK(super_class->IsResolved()) 5117 << PrettyClass(klass.Get()) << " " << PrettyClass(super_class); 5118 field_offset = MemberOffset(super_class->GetObjectSize()); 5119 } 5120 } 5121 5122 CHECK_EQ(num_fields == 0, fields == nullptr) << PrettyClass(klass.Get()); 5123 5124 // we want a relatively stable order so that adding new fields 5125 // minimizes disruption of C++ version such as Class and Method. 5126 std::deque<ArtField*> grouped_and_sorted_fields; 5127 const char* old_no_suspend_cause = self->StartAssertNoThreadSuspension( 5128 "Naked ArtField references in deque"); 5129 for (size_t i = 0; i < num_fields; i++) { 5130 grouped_and_sorted_fields.push_back(&fields[i]); 5131 } 5132 std::sort(grouped_and_sorted_fields.begin(), grouped_and_sorted_fields.end(), 5133 LinkFieldsComparator()); 5134 5135 // References should be at the front. 5136 size_t current_field = 0; 5137 size_t num_reference_fields = 0; 5138 FieldGaps gaps; 5139 5140 for (; current_field < num_fields; current_field++) { 5141 ArtField* field = grouped_and_sorted_fields.front(); 5142 Primitive::Type type = field->GetTypeAsPrimitiveType(); 5143 bool isPrimitive = type != Primitive::kPrimNot; 5144 if (isPrimitive) { 5145 break; // past last reference, move on to the next phase 5146 } 5147 if (UNLIKELY(!IsAligned<sizeof(mirror::HeapReference<mirror::Object>)>( 5148 field_offset.Uint32Value()))) { 5149 MemberOffset old_offset = field_offset; 5150 field_offset = MemberOffset(RoundUp(field_offset.Uint32Value(), 4)); 5151 AddFieldGap(old_offset.Uint32Value(), field_offset.Uint32Value(), &gaps); 5152 } 5153 DCHECK(IsAligned<sizeof(mirror::HeapReference<mirror::Object>)>(field_offset.Uint32Value())); 5154 grouped_and_sorted_fields.pop_front(); 5155 num_reference_fields++; 5156 field->SetOffset(field_offset); 5157 field_offset = MemberOffset(field_offset.Uint32Value() + 5158 sizeof(mirror::HeapReference<mirror::Object>)); 5159 } 5160 // Gaps are stored as a max heap which means that we must shuffle from largest to smallest 5161 // otherwise we could end up with suboptimal gap fills. 5162 ShuffleForward<8>(¤t_field, &field_offset, &grouped_and_sorted_fields, &gaps); 5163 ShuffleForward<4>(¤t_field, &field_offset, &grouped_and_sorted_fields, &gaps); 5164 ShuffleForward<2>(¤t_field, &field_offset, &grouped_and_sorted_fields, &gaps); 5165 ShuffleForward<1>(¤t_field, &field_offset, &grouped_and_sorted_fields, &gaps); 5166 CHECK(grouped_and_sorted_fields.empty()) << "Missed " << grouped_and_sorted_fields.size() << 5167 " fields."; 5168 self->EndAssertNoThreadSuspension(old_no_suspend_cause); 5169 5170 // We lie to the GC about the java.lang.ref.Reference.referent field, so it doesn't scan it. 5171 if (!is_static && klass->DescriptorEquals("Ljava/lang/ref/Reference;")) { 5172 // We know there are no non-reference fields in the Reference classes, and we know 5173 // that 'referent' is alphabetically last, so this is easy... 5174 CHECK_EQ(num_reference_fields, num_fields) << PrettyClass(klass.Get()); 5175 CHECK_STREQ(fields[num_fields - 1].GetName(), "referent") << PrettyClass(klass.Get()); 5176 --num_reference_fields; 5177 } 5178 5179 size_t size = field_offset.Uint32Value(); 5180 // Update klass 5181 if (is_static) { 5182 klass->SetNumReferenceStaticFields(num_reference_fields); 5183 *class_size = size; 5184 } else { 5185 klass->SetNumReferenceInstanceFields(num_reference_fields); 5186 if (!klass->IsVariableSize()) { 5187 std::string temp; 5188 DCHECK_GE(size, sizeof(mirror::Object)) << klass->GetDescriptor(&temp); 5189 size_t previous_size = klass->GetObjectSize(); 5190 if (previous_size != 0) { 5191 // Make sure that we didn't originally have an incorrect size. 5192 CHECK_EQ(previous_size, size) << klass->GetDescriptor(&temp); 5193 } 5194 klass->SetObjectSize(size); 5195 } 5196 } 5197 5198 if (kIsDebugBuild) { 5199 // Make sure that the fields array is ordered by name but all reference 5200 // offsets are at the beginning as far as alignment allows. 5201 MemberOffset start_ref_offset = is_static 5202 ? klass->GetFirstReferenceStaticFieldOffsetDuringLinking(image_pointer_size_) 5203 : klass->GetFirstReferenceInstanceFieldOffset(); 5204 MemberOffset end_ref_offset(start_ref_offset.Uint32Value() + 5205 num_reference_fields * 5206 sizeof(mirror::HeapReference<mirror::Object>)); 5207 MemberOffset current_ref_offset = start_ref_offset; 5208 for (size_t i = 0; i < num_fields; i++) { 5209 ArtField* field = &fields[i]; 5210 VLOG(class_linker) << "LinkFields: " << (is_static ? "static" : "instance") 5211 << " class=" << PrettyClass(klass.Get()) << " field=" << PrettyField(field) << " offset=" 5212 << field->GetOffset(); 5213 if (i != 0) { 5214 ArtField* const prev_field = &fields[i - 1]; 5215 // NOTE: The field names can be the same. This is not possible in the Java language 5216 // but it's valid Java/dex bytecode and for example proguard can generate such bytecode. 5217 CHECK_LE(strcmp(prev_field->GetName(), field->GetName()), 0); 5218 } 5219 Primitive::Type type = field->GetTypeAsPrimitiveType(); 5220 bool is_primitive = type != Primitive::kPrimNot; 5221 if (klass->DescriptorEquals("Ljava/lang/ref/Reference;") && 5222 strcmp("referent", field->GetName()) == 0) { 5223 is_primitive = true; // We lied above, so we have to expect a lie here. 5224 } 5225 MemberOffset offset = field->GetOffsetDuringLinking(); 5226 if (is_primitive) { 5227 if (offset.Uint32Value() < end_ref_offset.Uint32Value()) { 5228 // Shuffled before references. 5229 size_t type_size = Primitive::ComponentSize(type); 5230 CHECK_LT(type_size, sizeof(mirror::HeapReference<mirror::Object>)); 5231 CHECK_LT(offset.Uint32Value(), start_ref_offset.Uint32Value()); 5232 CHECK_LE(offset.Uint32Value() + type_size, start_ref_offset.Uint32Value()); 5233 CHECK(!IsAligned<sizeof(mirror::HeapReference<mirror::Object>)>(offset.Uint32Value())); 5234 } 5235 } else { 5236 CHECK_EQ(current_ref_offset.Uint32Value(), offset.Uint32Value()); 5237 current_ref_offset = MemberOffset(current_ref_offset.Uint32Value() + 5238 sizeof(mirror::HeapReference<mirror::Object>)); 5239 } 5240 } 5241 CHECK_EQ(current_ref_offset.Uint32Value(), end_ref_offset.Uint32Value()); 5242 } 5243 return true; 5244} 5245 5246// Set the bitmap of reference instance field offsets. 5247void ClassLinker::CreateReferenceInstanceOffsets(Handle<mirror::Class> klass) { 5248 uint32_t reference_offsets = 0; 5249 mirror::Class* super_class = klass->GetSuperClass(); 5250 // Leave the reference offsets as 0 for mirror::Object (the class field is handled specially). 5251 if (super_class != nullptr) { 5252 reference_offsets = super_class->GetReferenceInstanceOffsets(); 5253 // Compute reference offsets unless our superclass overflowed. 5254 if (reference_offsets != mirror::Class::kClassWalkSuper) { 5255 size_t num_reference_fields = klass->NumReferenceInstanceFieldsDuringLinking(); 5256 if (num_reference_fields != 0u) { 5257 // All of the fields that contain object references are guaranteed be grouped in memory 5258 // starting at an appropriately aligned address after super class object data. 5259 uint32_t start_offset = RoundUp(super_class->GetObjectSize(), 5260 sizeof(mirror::HeapReference<mirror::Object>)); 5261 uint32_t start_bit = (start_offset - mirror::kObjectHeaderSize) / 5262 sizeof(mirror::HeapReference<mirror::Object>); 5263 if (start_bit + num_reference_fields > 32) { 5264 reference_offsets = mirror::Class::kClassWalkSuper; 5265 } else { 5266 reference_offsets |= (0xffffffffu << start_bit) & 5267 (0xffffffffu >> (32 - (start_bit + num_reference_fields))); 5268 } 5269 } 5270 } 5271 } 5272 klass->SetReferenceInstanceOffsets(reference_offsets); 5273} 5274 5275mirror::String* ClassLinker::ResolveString(const DexFile& dex_file, uint32_t string_idx, 5276 Handle<mirror::DexCache> dex_cache) { 5277 DCHECK(dex_cache.Get() != nullptr); 5278 mirror::String* resolved = dex_cache->GetResolvedString(string_idx); 5279 if (resolved != nullptr) { 5280 return resolved; 5281 } 5282 uint32_t utf16_length; 5283 const char* utf8_data = dex_file.StringDataAndUtf16LengthByIdx(string_idx, &utf16_length); 5284 mirror::String* string = intern_table_->InternStrong(utf16_length, utf8_data); 5285 dex_cache->SetResolvedString(string_idx, string); 5286 return string; 5287} 5288 5289mirror::Class* ClassLinker::ResolveType(const DexFile& dex_file, uint16_t type_idx, 5290 mirror::Class* referrer) { 5291 StackHandleScope<2> hs(Thread::Current()); 5292 Handle<mirror::DexCache> dex_cache(hs.NewHandle(referrer->GetDexCache())); 5293 Handle<mirror::ClassLoader> class_loader(hs.NewHandle(referrer->GetClassLoader())); 5294 return ResolveType(dex_file, type_idx, dex_cache, class_loader); 5295} 5296 5297mirror::Class* ClassLinker::ResolveType(const DexFile& dex_file, uint16_t type_idx, 5298 Handle<mirror::DexCache> dex_cache, 5299 Handle<mirror::ClassLoader> class_loader) { 5300 DCHECK(dex_cache.Get() != nullptr); 5301 mirror::Class* resolved = dex_cache->GetResolvedType(type_idx); 5302 if (resolved == nullptr) { 5303 Thread* self = Thread::Current(); 5304 const char* descriptor = dex_file.StringByTypeIdx(type_idx); 5305 resolved = FindClass(self, descriptor, class_loader); 5306 if (resolved != nullptr) { 5307 // TODO: we used to throw here if resolved's class loader was not the 5308 // boot class loader. This was to permit different classes with the 5309 // same name to be loaded simultaneously by different loaders 5310 dex_cache->SetResolvedType(type_idx, resolved); 5311 } else { 5312 CHECK(self->IsExceptionPending()) 5313 << "Expected pending exception for failed resolution of: " << descriptor; 5314 // Convert a ClassNotFoundException to a NoClassDefFoundError. 5315 StackHandleScope<1> hs(self); 5316 Handle<mirror::Throwable> cause(hs.NewHandle(self->GetException())); 5317 if (cause->InstanceOf(GetClassRoot(kJavaLangClassNotFoundException))) { 5318 DCHECK(resolved == nullptr); // No Handle needed to preserve resolved. 5319 self->ClearException(); 5320 ThrowNoClassDefFoundError("Failed resolution of: %s", descriptor); 5321 self->GetException()->SetCause(cause.Get()); 5322 } 5323 } 5324 } 5325 DCHECK((resolved == nullptr) || resolved->IsResolved() || resolved->IsErroneous()) 5326 << PrettyDescriptor(resolved) << " " << resolved->GetStatus(); 5327 return resolved; 5328} 5329 5330ArtMethod* ClassLinker::ResolveMethod(const DexFile& dex_file, uint32_t method_idx, 5331 Handle<mirror::DexCache> dex_cache, 5332 Handle<mirror::ClassLoader> class_loader, 5333 ArtMethod* referrer, InvokeType type) { 5334 DCHECK(dex_cache.Get() != nullptr); 5335 // Check for hit in the dex cache. 5336 ArtMethod* resolved = dex_cache->GetResolvedMethod(method_idx, image_pointer_size_); 5337 if (resolved != nullptr && !resolved->IsRuntimeMethod()) { 5338 DCHECK(resolved->GetDeclaringClassUnchecked() != nullptr) << resolved->GetDexMethodIndex(); 5339 return resolved; 5340 } 5341 // Fail, get the declaring class. 5342 const DexFile::MethodId& method_id = dex_file.GetMethodId(method_idx); 5343 mirror::Class* klass = ResolveType(dex_file, method_id.class_idx_, dex_cache, class_loader); 5344 if (klass == nullptr) { 5345 DCHECK(Thread::Current()->IsExceptionPending()); 5346 return nullptr; 5347 } 5348 // Scan using method_idx, this saves string compares but will only hit for matching dex 5349 // caches/files. 5350 switch (type) { 5351 case kDirect: // Fall-through. 5352 case kStatic: 5353 resolved = klass->FindDirectMethod(dex_cache.Get(), method_idx, image_pointer_size_); 5354 DCHECK(resolved == nullptr || resolved->GetDeclaringClassUnchecked() != nullptr); 5355 break; 5356 case kInterface: 5357 resolved = klass->FindInterfaceMethod(dex_cache.Get(), method_idx, image_pointer_size_); 5358 DCHECK(resolved == nullptr || resolved->GetDeclaringClass()->IsInterface()); 5359 break; 5360 case kSuper: // Fall-through. 5361 case kVirtual: 5362 resolved = klass->FindVirtualMethod(dex_cache.Get(), method_idx, image_pointer_size_); 5363 break; 5364 default: 5365 LOG(FATAL) << "Unreachable - invocation type: " << type; 5366 UNREACHABLE(); 5367 } 5368 if (resolved == nullptr) { 5369 // Search by name, which works across dex files. 5370 const char* name = dex_file.StringDataByIdx(method_id.name_idx_); 5371 const Signature signature = dex_file.GetMethodSignature(method_id); 5372 switch (type) { 5373 case kDirect: // Fall-through. 5374 case kStatic: 5375 resolved = klass->FindDirectMethod(name, signature, image_pointer_size_); 5376 DCHECK(resolved == nullptr || resolved->GetDeclaringClassUnchecked() != nullptr); 5377 break; 5378 case kInterface: 5379 resolved = klass->FindInterfaceMethod(name, signature, image_pointer_size_); 5380 DCHECK(resolved == nullptr || resolved->GetDeclaringClass()->IsInterface()); 5381 break; 5382 case kSuper: // Fall-through. 5383 case kVirtual: 5384 resolved = klass->FindVirtualMethod(name, signature, image_pointer_size_); 5385 break; 5386 } 5387 } 5388 // If we found a method, check for incompatible class changes. 5389 if (LIKELY(resolved != nullptr && !resolved->CheckIncompatibleClassChange(type))) { 5390 // Be a good citizen and update the dex cache to speed subsequent calls. 5391 dex_cache->SetResolvedMethod(method_idx, resolved, image_pointer_size_); 5392 return resolved; 5393 } else { 5394 // If we had a method, it's an incompatible-class-change error. 5395 if (resolved != nullptr) { 5396 ThrowIncompatibleClassChangeError(type, resolved->GetInvokeType(), resolved, referrer); 5397 } else { 5398 // We failed to find the method which means either an access error, an incompatible class 5399 // change, or no such method. First try to find the method among direct and virtual methods. 5400 const char* name = dex_file.StringDataByIdx(method_id.name_idx_); 5401 const Signature signature = dex_file.GetMethodSignature(method_id); 5402 switch (type) { 5403 case kDirect: 5404 case kStatic: 5405 resolved = klass->FindVirtualMethod(name, signature, image_pointer_size_); 5406 // Note: kDirect and kStatic are also mutually exclusive, but in that case we would 5407 // have had a resolved method before, which triggers the "true" branch above. 5408 break; 5409 case kInterface: 5410 case kVirtual: 5411 case kSuper: 5412 resolved = klass->FindDirectMethod(name, signature, image_pointer_size_); 5413 break; 5414 } 5415 5416 // If we found something, check that it can be accessed by the referrer. 5417 bool exception_generated = false; 5418 if (resolved != nullptr && referrer != nullptr) { 5419 mirror::Class* methods_class = resolved->GetDeclaringClass(); 5420 mirror::Class* referring_class = referrer->GetDeclaringClass(); 5421 if (!referring_class->CanAccess(methods_class)) { 5422 ThrowIllegalAccessErrorClassForMethodDispatch(referring_class, methods_class, resolved, 5423 type); 5424 exception_generated = true; 5425 } else if (!referring_class->CanAccessMember(methods_class, resolved->GetAccessFlags())) { 5426 ThrowIllegalAccessErrorMethod(referring_class, resolved); 5427 exception_generated = true; 5428 } 5429 } 5430 if (!exception_generated) { 5431 // Otherwise, throw an IncompatibleClassChangeError if we found something, and check 5432 // interface methods and throw if we find the method there. If we find nothing, throw a 5433 // NoSuchMethodError. 5434 switch (type) { 5435 case kDirect: 5436 case kStatic: 5437 if (resolved != nullptr) { 5438 ThrowIncompatibleClassChangeError(type, kVirtual, resolved, referrer); 5439 } else { 5440 resolved = klass->FindInterfaceMethod(name, signature, image_pointer_size_); 5441 if (resolved != nullptr) { 5442 ThrowIncompatibleClassChangeError(type, kInterface, resolved, referrer); 5443 } else { 5444 ThrowNoSuchMethodError(type, klass, name, signature); 5445 } 5446 } 5447 break; 5448 case kInterface: 5449 if (resolved != nullptr) { 5450 ThrowIncompatibleClassChangeError(type, kDirect, resolved, referrer); 5451 } else { 5452 resolved = klass->FindVirtualMethod(name, signature, image_pointer_size_); 5453 if (resolved != nullptr) { 5454 ThrowIncompatibleClassChangeError(type, kVirtual, resolved, referrer); 5455 } else { 5456 ThrowNoSuchMethodError(type, klass, name, signature); 5457 } 5458 } 5459 break; 5460 case kSuper: 5461 if (resolved != nullptr) { 5462 ThrowIncompatibleClassChangeError(type, kDirect, resolved, referrer); 5463 } else { 5464 ThrowNoSuchMethodError(type, klass, name, signature); 5465 } 5466 break; 5467 case kVirtual: 5468 if (resolved != nullptr) { 5469 ThrowIncompatibleClassChangeError(type, kDirect, resolved, referrer); 5470 } else { 5471 resolved = klass->FindInterfaceMethod(name, signature, image_pointer_size_); 5472 if (resolved != nullptr) { 5473 ThrowIncompatibleClassChangeError(type, kInterface, resolved, referrer); 5474 } else { 5475 ThrowNoSuchMethodError(type, klass, name, signature); 5476 } 5477 } 5478 break; 5479 } 5480 } 5481 } 5482 Thread::Current()->AssertPendingException(); 5483 return nullptr; 5484 } 5485} 5486 5487ArtField* ClassLinker::ResolveField(const DexFile& dex_file, uint32_t field_idx, 5488 Handle<mirror::DexCache> dex_cache, 5489 Handle<mirror::ClassLoader> class_loader, bool is_static) { 5490 DCHECK(dex_cache.Get() != nullptr); 5491 ArtField* resolved = dex_cache->GetResolvedField(field_idx, image_pointer_size_); 5492 if (resolved != nullptr) { 5493 return resolved; 5494 } 5495 const DexFile::FieldId& field_id = dex_file.GetFieldId(field_idx); 5496 Thread* const self = Thread::Current(); 5497 StackHandleScope<1> hs(self); 5498 Handle<mirror::Class> klass( 5499 hs.NewHandle(ResolveType(dex_file, field_id.class_idx_, dex_cache, class_loader))); 5500 if (klass.Get() == nullptr) { 5501 DCHECK(Thread::Current()->IsExceptionPending()); 5502 return nullptr; 5503 } 5504 5505 if (is_static) { 5506 resolved = mirror::Class::FindStaticField(self, klass, dex_cache.Get(), field_idx); 5507 } else { 5508 resolved = klass->FindInstanceField(dex_cache.Get(), field_idx); 5509 } 5510 5511 if (resolved == nullptr) { 5512 const char* name = dex_file.GetFieldName(field_id); 5513 const char* type = dex_file.GetFieldTypeDescriptor(field_id); 5514 if (is_static) { 5515 resolved = mirror::Class::FindStaticField(self, klass, name, type); 5516 } else { 5517 resolved = klass->FindInstanceField(name, type); 5518 } 5519 if (resolved == nullptr) { 5520 ThrowNoSuchFieldError(is_static ? "static " : "instance ", klass.Get(), type, name); 5521 return nullptr; 5522 } 5523 } 5524 dex_cache->SetResolvedField(field_idx, resolved, image_pointer_size_); 5525 return resolved; 5526} 5527 5528ArtField* ClassLinker::ResolveFieldJLS(const DexFile& dex_file, uint32_t field_idx, 5529 Handle<mirror::DexCache> dex_cache, 5530 Handle<mirror::ClassLoader> class_loader) { 5531 DCHECK(dex_cache.Get() != nullptr); 5532 ArtField* resolved = dex_cache->GetResolvedField(field_idx, image_pointer_size_); 5533 if (resolved != nullptr) { 5534 return resolved; 5535 } 5536 const DexFile::FieldId& field_id = dex_file.GetFieldId(field_idx); 5537 Thread* self = Thread::Current(); 5538 StackHandleScope<1> hs(self); 5539 Handle<mirror::Class> klass( 5540 hs.NewHandle(ResolveType(dex_file, field_id.class_idx_, dex_cache, class_loader))); 5541 if (klass.Get() == nullptr) { 5542 DCHECK(Thread::Current()->IsExceptionPending()); 5543 return nullptr; 5544 } 5545 5546 StringPiece name(dex_file.StringDataByIdx(field_id.name_idx_)); 5547 StringPiece type(dex_file.StringDataByIdx( 5548 dex_file.GetTypeId(field_id.type_idx_).descriptor_idx_)); 5549 resolved = mirror::Class::FindField(self, klass, name, type); 5550 if (resolved != nullptr) { 5551 dex_cache->SetResolvedField(field_idx, resolved, image_pointer_size_); 5552 } else { 5553 ThrowNoSuchFieldError("", klass.Get(), type, name); 5554 } 5555 return resolved; 5556} 5557 5558const char* ClassLinker::MethodShorty(uint32_t method_idx, ArtMethod* referrer, 5559 uint32_t* length) { 5560 mirror::Class* declaring_class = referrer->GetDeclaringClass(); 5561 mirror::DexCache* dex_cache = declaring_class->GetDexCache(); 5562 const DexFile& dex_file = *dex_cache->GetDexFile(); 5563 const DexFile::MethodId& method_id = dex_file.GetMethodId(method_idx); 5564 return dex_file.GetMethodShorty(method_id, length); 5565} 5566 5567void ClassLinker::DumpAllClasses(int flags) { 5568 if (dex_cache_image_class_lookup_required_) { 5569 MoveImageClassesToClassTable(); 5570 } 5571 // TODO: at the time this was written, it wasn't safe to call PrettyField with the ClassLinker 5572 // lock held, because it might need to resolve a field's type, which would try to take the lock. 5573 std::vector<mirror::Class*> all_classes; 5574 { 5575 ReaderMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); 5576 for (GcRoot<mirror::Class>& it : class_table_) { 5577 all_classes.push_back(it.Read()); 5578 } 5579 } 5580 5581 for (size_t i = 0; i < all_classes.size(); ++i) { 5582 all_classes[i]->DumpClass(std::cerr, flags); 5583 } 5584} 5585 5586static OatFile::OatMethod CreateOatMethod(const void* code) { 5587 CHECK(code != nullptr); 5588 const uint8_t* base = reinterpret_cast<const uint8_t*>(code); // Base of data points at code. 5589 base -= sizeof(void*); // Move backward so that code_offset != 0. 5590 const uint32_t code_offset = sizeof(void*); 5591 return OatFile::OatMethod(base, code_offset); 5592} 5593 5594bool ClassLinker::IsQuickResolutionStub(const void* entry_point) const { 5595 return (entry_point == GetQuickResolutionStub()) || 5596 (quick_resolution_trampoline_ == entry_point); 5597} 5598 5599bool ClassLinker::IsQuickToInterpreterBridge(const void* entry_point) const { 5600 return (entry_point == GetQuickToInterpreterBridge()) || 5601 (quick_to_interpreter_bridge_trampoline_ == entry_point); 5602} 5603 5604bool ClassLinker::IsQuickGenericJniStub(const void* entry_point) const { 5605 return (entry_point == GetQuickGenericJniStub()) || 5606 (quick_generic_jni_trampoline_ == entry_point); 5607} 5608 5609const void* ClassLinker::GetRuntimeQuickGenericJniStub() const { 5610 return GetQuickGenericJniStub(); 5611} 5612 5613void ClassLinker::SetEntryPointsToCompiledCode(ArtMethod* method, 5614 const void* method_code) const { 5615 OatFile::OatMethod oat_method = CreateOatMethod(method_code); 5616 oat_method.LinkMethod(method); 5617 method->SetEntryPointFromInterpreter(artInterpreterToCompiledCodeBridge); 5618} 5619 5620void ClassLinker::SetEntryPointsToInterpreter(ArtMethod* method) const { 5621 if (!method->IsNative()) { 5622 method->SetEntryPointFromInterpreter(artInterpreterToInterpreterBridge); 5623 method->SetEntryPointFromQuickCompiledCode(GetQuickToInterpreterBridge()); 5624 } else { 5625 const void* quick_method_code = GetQuickGenericJniStub(); 5626 OatFile::OatMethod oat_method = CreateOatMethod(quick_method_code); 5627 oat_method.LinkMethod(method); 5628 method->SetEntryPointFromInterpreter(artInterpreterToCompiledCodeBridge); 5629 } 5630} 5631 5632void ClassLinker::DumpForSigQuit(std::ostream& os) { 5633 Thread* self = Thread::Current(); 5634 if (dex_cache_image_class_lookup_required_) { 5635 ScopedObjectAccess soa(self); 5636 MoveImageClassesToClassTable(); 5637 } 5638 ReaderMutexLock mu(self, *Locks::classlinker_classes_lock_); 5639 os << "Zygote loaded classes=" << pre_zygote_class_table_.Size() << " post zygote classes=" 5640 << class_table_.Size() << "\n"; 5641} 5642 5643size_t ClassLinker::NumLoadedClasses() { 5644 if (dex_cache_image_class_lookup_required_) { 5645 MoveImageClassesToClassTable(); 5646 } 5647 ReaderMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); 5648 // Only return non zygote classes since these are the ones which apps which care about. 5649 return class_table_.Size(); 5650} 5651 5652pid_t ClassLinker::GetClassesLockOwner() { 5653 return Locks::classlinker_classes_lock_->GetExclusiveOwnerTid(); 5654} 5655 5656pid_t ClassLinker::GetDexLockOwner() { 5657 return dex_lock_.GetExclusiveOwnerTid(); 5658} 5659 5660void ClassLinker::SetClassRoot(ClassRoot class_root, mirror::Class* klass) { 5661 DCHECK(!init_done_); 5662 5663 DCHECK(klass != nullptr); 5664 DCHECK(klass->GetClassLoader() == nullptr); 5665 5666 mirror::ObjectArray<mirror::Class>* class_roots = class_roots_.Read(); 5667 DCHECK(class_roots != nullptr); 5668 DCHECK(class_roots->Get(class_root) == nullptr); 5669 class_roots->Set<false>(class_root, klass); 5670} 5671 5672const char* ClassLinker::GetClassRootDescriptor(ClassRoot class_root) { 5673 static const char* class_roots_descriptors[] = { 5674 "Ljava/lang/Class;", 5675 "Ljava/lang/Object;", 5676 "[Ljava/lang/Class;", 5677 "[Ljava/lang/Object;", 5678 "Ljava/lang/String;", 5679 "Ljava/lang/DexCache;", 5680 "Ljava/lang/ref/Reference;", 5681 "Ljava/lang/reflect/Constructor;", 5682 "Ljava/lang/reflect/Field;", 5683 "Ljava/lang/reflect/Method;", 5684 "Ljava/lang/reflect/Proxy;", 5685 "[Ljava/lang/String;", 5686 "[Ljava/lang/reflect/Constructor;", 5687 "[Ljava/lang/reflect/Field;", 5688 "[Ljava/lang/reflect/Method;", 5689 "Ljava/lang/ClassLoader;", 5690 "Ljava/lang/Throwable;", 5691 "Ljava/lang/ClassNotFoundException;", 5692 "Ljava/lang/StackTraceElement;", 5693 "Z", 5694 "B", 5695 "C", 5696 "D", 5697 "F", 5698 "I", 5699 "J", 5700 "S", 5701 "V", 5702 "[Z", 5703 "[B", 5704 "[C", 5705 "[D", 5706 "[F", 5707 "[I", 5708 "[J", 5709 "[S", 5710 "[Ljava/lang/StackTraceElement;", 5711 }; 5712 static_assert(arraysize(class_roots_descriptors) == size_t(kClassRootsMax), 5713 "Mismatch between class descriptors and class-root enum"); 5714 5715 const char* descriptor = class_roots_descriptors[class_root]; 5716 CHECK(descriptor != nullptr); 5717 return descriptor; 5718} 5719 5720std::size_t ClassLinker::ClassDescriptorHashEquals::operator()(const GcRoot<mirror::Class>& root) 5721 const { 5722 std::string temp; 5723 return ComputeModifiedUtf8Hash(root.Read()->GetDescriptor(&temp)); 5724} 5725 5726bool ClassLinker::ClassDescriptorHashEquals::operator()(const GcRoot<mirror::Class>& a, 5727 const GcRoot<mirror::Class>& b) const { 5728 if (a.Read()->GetClassLoader() != b.Read()->GetClassLoader()) { 5729 return false; 5730 } 5731 std::string temp; 5732 return a.Read()->DescriptorEquals(b.Read()->GetDescriptor(&temp)); 5733} 5734 5735std::size_t ClassLinker::ClassDescriptorHashEquals::operator()( 5736 const std::pair<const char*, mirror::ClassLoader*>& element) const { 5737 return ComputeModifiedUtf8Hash(element.first); 5738} 5739 5740bool ClassLinker::ClassDescriptorHashEquals::operator()( 5741 const GcRoot<mirror::Class>& a, const std::pair<const char*, mirror::ClassLoader*>& b) const { 5742 if (a.Read()->GetClassLoader() != b.second) { 5743 return false; 5744 } 5745 return a.Read()->DescriptorEquals(b.first); 5746} 5747 5748bool ClassLinker::ClassDescriptorHashEquals::operator()(const GcRoot<mirror::Class>& a, 5749 const char* descriptor) const { 5750 return a.Read()->DescriptorEquals(descriptor); 5751} 5752 5753std::size_t ClassLinker::ClassDescriptorHashEquals::operator()(const char* descriptor) const { 5754 return ComputeModifiedUtf8Hash(descriptor); 5755} 5756 5757bool ClassLinker::MayBeCalledWithDirectCodePointer(ArtMethod* m) { 5758 if (Runtime::Current()->UseJit()) { 5759 // JIT can have direct code pointers from any method to any other method. 5760 return true; 5761 } 5762 // Non-image methods don't use direct code pointer. 5763 if (!m->GetDeclaringClass()->IsBootStrapClassLoaded()) { 5764 return false; 5765 } 5766 if (m->IsPrivate()) { 5767 // The method can only be called inside its own oat file. Therefore it won't be called using 5768 // its direct code if the oat file has been compiled in PIC mode. 5769 const DexFile& dex_file = m->GetDeclaringClass()->GetDexFile(); 5770 const OatFile::OatDexFile* oat_dex_file = dex_file.GetOatDexFile(); 5771 if (oat_dex_file == nullptr) { 5772 // No oat file: the method has not been compiled. 5773 return false; 5774 } 5775 const OatFile* oat_file = oat_dex_file->GetOatFile(); 5776 return oat_file != nullptr && !oat_file->IsPic(); 5777 } else { 5778 // The method can be called outside its own oat file. Therefore it won't be called using its 5779 // direct code pointer only if all loaded oat files have been compiled in PIC mode. 5780 ReaderMutexLock mu(Thread::Current(), dex_lock_); 5781 for (const OatFile* oat_file : oat_files_) { 5782 if (!oat_file->IsPic()) { 5783 return true; 5784 } 5785 } 5786 return false; 5787 } 5788} 5789 5790jobject ClassLinker::CreatePathClassLoader(Thread* self, std::vector<const DexFile*>& dex_files) { 5791 // SOAAlreadyRunnable is protected, and we need something to add a global reference. 5792 // We could move the jobject to the callers, but all call-sites do this... 5793 ScopedObjectAccessUnchecked soa(self); 5794 5795 // Register the dex files. 5796 for (const DexFile* dex_file : dex_files) { 5797 RegisterDexFile(*dex_file); 5798 } 5799 5800 // For now, create a libcore-level DexFile for each ART DexFile. This "explodes" multidex. 5801 StackHandleScope<10> hs(self); 5802 5803 ArtField* dex_elements_field = 5804 soa.DecodeField(WellKnownClasses::dalvik_system_DexPathList_dexElements); 5805 5806 mirror::Class* dex_elements_class = dex_elements_field->GetType<true>(); 5807 DCHECK(dex_elements_class != nullptr); 5808 DCHECK(dex_elements_class->IsArrayClass()); 5809 Handle<mirror::ObjectArray<mirror::Object>> h_dex_elements(hs.NewHandle( 5810 mirror::ObjectArray<mirror::Object>::Alloc(self, dex_elements_class, dex_files.size()))); 5811 Handle<mirror::Class> h_dex_element_class = 5812 hs.NewHandle(dex_elements_class->GetComponentType()); 5813 5814 ArtField* element_file_field = 5815 soa.DecodeField(WellKnownClasses::dalvik_system_DexPathList__Element_dexFile); 5816 DCHECK_EQ(h_dex_element_class.Get(), element_file_field->GetDeclaringClass()); 5817 5818 ArtField* cookie_field = soa.DecodeField(WellKnownClasses::dalvik_system_DexFile_cookie); 5819 DCHECK_EQ(cookie_field->GetDeclaringClass(), element_file_field->GetType<false>()); 5820 5821 // Fill the elements array. 5822 int32_t index = 0; 5823 for (const DexFile* dex_file : dex_files) { 5824 StackHandleScope<3> hs2(self); 5825 5826 Handle<mirror::LongArray> h_long_array = hs2.NewHandle(mirror::LongArray::Alloc(self, 1)); 5827 DCHECK(h_long_array.Get() != nullptr); 5828 h_long_array->Set(0, reinterpret_cast<intptr_t>(dex_file)); 5829 5830 Handle<mirror::Object> h_dex_file = hs2.NewHandle( 5831 cookie_field->GetDeclaringClass()->AllocObject(self)); 5832 DCHECK(h_dex_file.Get() != nullptr); 5833 cookie_field->SetObject<false>(h_dex_file.Get(), h_long_array.Get()); 5834 5835 Handle<mirror::Object> h_element = hs2.NewHandle(h_dex_element_class->AllocObject(self)); 5836 DCHECK(h_element.Get() != nullptr); 5837 element_file_field->SetObject<false>(h_element.Get(), h_dex_file.Get()); 5838 5839 h_dex_elements->Set(index, h_element.Get()); 5840 index++; 5841 } 5842 DCHECK_EQ(index, h_dex_elements->GetLength()); 5843 5844 // Create DexPathList. 5845 Handle<mirror::Object> h_dex_path_list = hs.NewHandle( 5846 dex_elements_field->GetDeclaringClass()->AllocObject(self)); 5847 DCHECK(h_dex_path_list.Get() != nullptr); 5848 // Set elements. 5849 dex_elements_field->SetObject<false>(h_dex_path_list.Get(), h_dex_elements.Get()); 5850 5851 // Create PathClassLoader. 5852 Handle<mirror::Class> h_path_class_class = hs.NewHandle( 5853 soa.Decode<mirror::Class*>(WellKnownClasses::dalvik_system_PathClassLoader)); 5854 Handle<mirror::Object> h_path_class_loader = hs.NewHandle( 5855 h_path_class_class->AllocObject(self)); 5856 DCHECK(h_path_class_loader.Get() != nullptr); 5857 // Set DexPathList. 5858 ArtField* path_list_field = 5859 soa.DecodeField(WellKnownClasses::dalvik_system_PathClassLoader_pathList); 5860 DCHECK(path_list_field != nullptr); 5861 path_list_field->SetObject<false>(h_path_class_loader.Get(), h_dex_path_list.Get()); 5862 5863 // Make a pretend boot-classpath. 5864 // TODO: Should we scan the image? 5865 ArtField* const parent_field = 5866 mirror::Class::FindField(self, hs.NewHandle(h_path_class_loader->GetClass()), "parent", 5867 "Ljava/lang/ClassLoader;"); 5868 DCHECK(parent_field!= nullptr); 5869 mirror::Object* boot_cl = 5870 soa.Decode<mirror::Class*>(WellKnownClasses::java_lang_BootClassLoader)->AllocObject(self); 5871 parent_field->SetObject<false>(h_path_class_loader.Get(), boot_cl); 5872 5873 // Make it a global ref and return. 5874 ScopedLocalRef<jobject> local_ref( 5875 soa.Env(), soa.Env()->AddLocalReference<jobject>(h_path_class_loader.Get())); 5876 return soa.Env()->NewGlobalRef(local_ref.get()); 5877} 5878 5879ArtMethod* ClassLinker::CreateRuntimeMethod() { 5880 ArtMethod* method = AllocArtMethodArray(Thread::Current(), 1); 5881 CHECK(method != nullptr); 5882 method->SetDexMethodIndex(DexFile::kDexNoIndex); 5883 CHECK(method->IsRuntimeMethod()); 5884 return method; 5885} 5886 5887void ClassLinker::DropFindArrayClassCache() { 5888 std::fill_n(find_array_class_cache_, kFindArrayCacheSize, GcRoot<mirror::Class>(nullptr)); 5889 find_array_class_cache_next_victim_ = 0; 5890} 5891 5892} // namespace art 5893