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 <algorithm> 20#include <deque> 21#include <iostream> 22#include <memory> 23#include <queue> 24#include <string> 25#include <tuple> 26#include <unistd.h> 27#include <unordered_map> 28#include <utility> 29#include <vector> 30 31#include "art_field-inl.h" 32#include "art_method-inl.h" 33#include "base/arena_allocator.h" 34#include "base/casts.h" 35#include "base/logging.h" 36#include "base/scoped_arena_containers.h" 37#include "base/scoped_flock.h" 38#include "base/stl_util.h" 39#include "base/systrace.h" 40#include "base/time_utils.h" 41#include "base/unix_file/fd_file.h" 42#include "base/value_object.h" 43#include "class_linker-inl.h" 44#include "class_table-inl.h" 45#include "compiler_callbacks.h" 46#include "debugger.h" 47#include "dex_file-inl.h" 48#include "entrypoints/entrypoint_utils.h" 49#include "entrypoints/runtime_asm_entrypoints.h" 50#include "experimental_flags.h" 51#include "gc_root-inl.h" 52#include "gc/accounting/card_table-inl.h" 53#include "gc/accounting/heap_bitmap-inl.h" 54#include "gc/heap.h" 55#include "gc/scoped_gc_critical_section.h" 56#include "gc/space/image_space.h" 57#include "handle_scope-inl.h" 58#include "image-inl.h" 59#include "intern_table.h" 60#include "interpreter/interpreter.h" 61#include "jit/jit.h" 62#include "jit/jit_code_cache.h" 63#include "jit/offline_profiling_info.h" 64#include "leb128.h" 65#include "linear_alloc.h" 66#include "mirror/class.h" 67#include "mirror/class-inl.h" 68#include "mirror/class_loader.h" 69#include "mirror/dex_cache-inl.h" 70#include "mirror/field.h" 71#include "mirror/iftable-inl.h" 72#include "mirror/method.h" 73#include "mirror/object-inl.h" 74#include "mirror/object_array-inl.h" 75#include "mirror/proxy.h" 76#include "mirror/reference-inl.h" 77#include "mirror/stack_trace_element.h" 78#include "mirror/string-inl.h" 79#include "native/dalvik_system_DexFile.h" 80#include "oat.h" 81#include "oat_file.h" 82#include "oat_file-inl.h" 83#include "oat_file_assistant.h" 84#include "oat_file_manager.h" 85#include "object_lock.h" 86#include "os.h" 87#include "runtime.h" 88#include "ScopedLocalRef.h" 89#include "scoped_thread_state_change.h" 90#include "thread-inl.h" 91#include "trace.h" 92#include "utils.h" 93#include "utils/dex_cache_arrays_layout-inl.h" 94#include "verifier/method_verifier.h" 95#include "well_known_classes.h" 96 97namespace art { 98 99static constexpr bool kSanityCheckObjects = kIsDebugBuild; 100static constexpr bool kVerifyArtMethodDeclaringClasses = kIsDebugBuild; 101 102static void ThrowNoClassDefFoundError(const char* fmt, ...) 103 __attribute__((__format__(__printf__, 1, 2))) 104 SHARED_REQUIRES(Locks::mutator_lock_); 105static void ThrowNoClassDefFoundError(const char* fmt, ...) { 106 va_list args; 107 va_start(args, fmt); 108 Thread* self = Thread::Current(); 109 self->ThrowNewExceptionV("Ljava/lang/NoClassDefFoundError;", fmt, args); 110 va_end(args); 111} 112 113static bool HasInitWithString(Thread* self, ClassLinker* class_linker, const char* descriptor) 114 SHARED_REQUIRES(Locks::mutator_lock_) { 115 ArtMethod* method = self->GetCurrentMethod(nullptr); 116 StackHandleScope<1> hs(self); 117 Handle<mirror::ClassLoader> class_loader(hs.NewHandle(method != nullptr ? 118 method->GetDeclaringClass()->GetClassLoader() : nullptr)); 119 mirror::Class* exception_class = class_linker->FindClass(self, descriptor, class_loader); 120 121 if (exception_class == nullptr) { 122 // No exc class ~ no <init>-with-string. 123 CHECK(self->IsExceptionPending()); 124 self->ClearException(); 125 return false; 126 } 127 128 ArtMethod* exception_init_method = exception_class->FindDeclaredDirectMethod( 129 "<init>", "(Ljava/lang/String;)V", class_linker->GetImagePointerSize()); 130 return exception_init_method != nullptr; 131} 132 133// Helper for ThrowEarlierClassFailure. Throws the stored error. 134static void HandleEarlierVerifyError(Thread* self, ClassLinker* class_linker, mirror::Class* c) 135 SHARED_REQUIRES(Locks::mutator_lock_) { 136 mirror::Object* obj = c->GetVerifyError(); 137 DCHECK(obj != nullptr); 138 self->AssertNoPendingException(); 139 if (obj->IsClass()) { 140 // Previous error has been stored as class. Create a new exception of that type. 141 142 // It's possible the exception doesn't have a <init>(String). 143 std::string temp; 144 const char* descriptor = obj->AsClass()->GetDescriptor(&temp); 145 146 if (HasInitWithString(self, class_linker, descriptor)) { 147 self->ThrowNewException(descriptor, PrettyDescriptor(c).c_str()); 148 } else { 149 self->ThrowNewException(descriptor, nullptr); 150 } 151 } else { 152 // Previous error has been stored as an instance. Just rethrow. 153 mirror::Class* throwable_class = 154 self->DecodeJObject(WellKnownClasses::java_lang_Throwable)->AsClass(); 155 mirror::Class* error_class = obj->GetClass(); 156 CHECK(throwable_class->IsAssignableFrom(error_class)); 157 self->SetException(obj->AsThrowable()); 158 } 159 self->AssertPendingException(); 160} 161 162void ClassLinker::ThrowEarlierClassFailure(mirror::Class* c, bool wrap_in_no_class_def) { 163 // The class failed to initialize on a previous attempt, so we want to throw 164 // a NoClassDefFoundError (v2 2.17.5). The exception to this rule is if we 165 // failed in verification, in which case v2 5.4.1 says we need to re-throw 166 // the previous error. 167 Runtime* const runtime = Runtime::Current(); 168 if (!runtime->IsAotCompiler()) { // Give info if this occurs at runtime. 169 std::string extra; 170 if (c->GetVerifyError() != nullptr) { 171 mirror::Object* verify_error = c->GetVerifyError(); 172 if (verify_error->IsClass()) { 173 extra = PrettyDescriptor(verify_error->AsClass()); 174 } else { 175 extra = verify_error->AsThrowable()->Dump(); 176 } 177 } 178 LOG(INFO) << "Rejecting re-init on previously-failed class " << PrettyClass(c) << ": " << extra; 179 } 180 181 CHECK(c->IsErroneous()) << PrettyClass(c) << " " << c->GetStatus(); 182 Thread* self = Thread::Current(); 183 if (runtime->IsAotCompiler()) { 184 // At compile time, accurate errors and NCDFE are disabled to speed compilation. 185 mirror::Throwable* pre_allocated = runtime->GetPreAllocatedNoClassDefFoundError(); 186 self->SetException(pre_allocated); 187 } else { 188 if (c->GetVerifyError() != nullptr) { 189 // Rethrow stored error. 190 HandleEarlierVerifyError(self, this, c); 191 } 192 if (c->GetVerifyError() == nullptr || wrap_in_no_class_def) { 193 // If there isn't a recorded earlier error, or this is a repeat throw from initialization, 194 // the top-level exception must be a NoClassDefFoundError. The potentially already pending 195 // exception will be a cause. 196 self->ThrowNewWrappedException("Ljava/lang/NoClassDefFoundError;", 197 PrettyDescriptor(c).c_str()); 198 } 199 } 200} 201 202static void VlogClassInitializationFailure(Handle<mirror::Class> klass) 203 SHARED_REQUIRES(Locks::mutator_lock_) { 204 if (VLOG_IS_ON(class_linker)) { 205 std::string temp; 206 LOG(INFO) << "Failed to initialize class " << klass->GetDescriptor(&temp) << " from " 207 << klass->GetLocation() << "\n" << Thread::Current()->GetException()->Dump(); 208 } 209} 210 211static void WrapExceptionInInitializer(Handle<mirror::Class> klass) 212 SHARED_REQUIRES(Locks::mutator_lock_) { 213 Thread* self = Thread::Current(); 214 JNIEnv* env = self->GetJniEnv(); 215 216 ScopedLocalRef<jthrowable> cause(env, env->ExceptionOccurred()); 217 CHECK(cause.get() != nullptr); 218 219 env->ExceptionClear(); 220 bool is_error = env->IsInstanceOf(cause.get(), WellKnownClasses::java_lang_Error); 221 env->Throw(cause.get()); 222 223 // We only wrap non-Error exceptions; an Error can just be used as-is. 224 if (!is_error) { 225 self->ThrowNewWrappedException("Ljava/lang/ExceptionInInitializerError;", nullptr); 226 } 227 VlogClassInitializationFailure(klass); 228} 229 230// Gap between two fields in object layout. 231struct FieldGap { 232 uint32_t start_offset; // The offset from the start of the object. 233 uint32_t size; // The gap size of 1, 2, or 4 bytes. 234}; 235struct FieldGapsComparator { 236 explicit FieldGapsComparator() { 237 } 238 bool operator() (const FieldGap& lhs, const FieldGap& rhs) 239 NO_THREAD_SAFETY_ANALYSIS { 240 // Sort by gap size, largest first. Secondary sort by starting offset. 241 // Note that the priority queue returns the largest element, so operator() 242 // should return true if lhs is less than rhs. 243 return lhs.size < rhs.size || (lhs.size == rhs.size && lhs.start_offset > rhs.start_offset); 244 } 245}; 246typedef std::priority_queue<FieldGap, std::vector<FieldGap>, FieldGapsComparator> FieldGaps; 247 248// Adds largest aligned gaps to queue of gaps. 249static void AddFieldGap(uint32_t gap_start, uint32_t gap_end, FieldGaps* gaps) { 250 DCHECK(gaps != nullptr); 251 252 uint32_t current_offset = gap_start; 253 while (current_offset != gap_end) { 254 size_t remaining = gap_end - current_offset; 255 if (remaining >= sizeof(uint32_t) && IsAligned<4>(current_offset)) { 256 gaps->push(FieldGap {current_offset, sizeof(uint32_t)}); 257 current_offset += sizeof(uint32_t); 258 } else if (remaining >= sizeof(uint16_t) && IsAligned<2>(current_offset)) { 259 gaps->push(FieldGap {current_offset, sizeof(uint16_t)}); 260 current_offset += sizeof(uint16_t); 261 } else { 262 gaps->push(FieldGap {current_offset, sizeof(uint8_t)}); 263 current_offset += sizeof(uint8_t); 264 } 265 DCHECK_LE(current_offset, gap_end) << "Overran gap"; 266 } 267} 268// Shuffle fields forward, making use of gaps whenever possible. 269template<int n> 270static void ShuffleForward(size_t* current_field_idx, 271 MemberOffset* field_offset, 272 std::deque<ArtField*>* grouped_and_sorted_fields, 273 FieldGaps* gaps) 274 SHARED_REQUIRES(Locks::mutator_lock_) { 275 DCHECK(current_field_idx != nullptr); 276 DCHECK(grouped_and_sorted_fields != nullptr); 277 DCHECK(gaps != nullptr); 278 DCHECK(field_offset != nullptr); 279 280 DCHECK(IsPowerOfTwo(n)); 281 while (!grouped_and_sorted_fields->empty()) { 282 ArtField* field = grouped_and_sorted_fields->front(); 283 Primitive::Type type = field->GetTypeAsPrimitiveType(); 284 if (Primitive::ComponentSize(type) < n) { 285 break; 286 } 287 if (!IsAligned<n>(field_offset->Uint32Value())) { 288 MemberOffset old_offset = *field_offset; 289 *field_offset = MemberOffset(RoundUp(field_offset->Uint32Value(), n)); 290 AddFieldGap(old_offset.Uint32Value(), field_offset->Uint32Value(), gaps); 291 } 292 CHECK(type != Primitive::kPrimNot) << PrettyField(field); // should be primitive types 293 grouped_and_sorted_fields->pop_front(); 294 if (!gaps->empty() && gaps->top().size >= n) { 295 FieldGap gap = gaps->top(); 296 gaps->pop(); 297 DCHECK_ALIGNED(gap.start_offset, n); 298 field->SetOffset(MemberOffset(gap.start_offset)); 299 if (gap.size > n) { 300 AddFieldGap(gap.start_offset + n, gap.start_offset + gap.size, gaps); 301 } 302 } else { 303 DCHECK_ALIGNED(field_offset->Uint32Value(), n); 304 field->SetOffset(*field_offset); 305 *field_offset = MemberOffset(field_offset->Uint32Value() + n); 306 } 307 ++(*current_field_idx); 308 } 309} 310 311ClassLinker::ClassLinker(InternTable* intern_table) 312 // dex_lock_ is recursive as it may be used in stack dumping. 313 : dex_lock_("ClassLinker dex lock", kDefaultMutexLevel), 314 dex_cache_boot_image_class_lookup_required_(false), 315 failed_dex_cache_class_lookups_(0), 316 class_roots_(nullptr), 317 array_iftable_(nullptr), 318 find_array_class_cache_next_victim_(0), 319 init_done_(false), 320 log_new_class_table_roots_(false), 321 intern_table_(intern_table), 322 quick_resolution_trampoline_(nullptr), 323 quick_imt_conflict_trampoline_(nullptr), 324 quick_generic_jni_trampoline_(nullptr), 325 quick_to_interpreter_bridge_trampoline_(nullptr), 326 image_pointer_size_(sizeof(void*)) { 327 CHECK(intern_table_ != nullptr); 328 static_assert(kFindArrayCacheSize == arraysize(find_array_class_cache_), 329 "Array cache size wrong."); 330 std::fill_n(find_array_class_cache_, kFindArrayCacheSize, GcRoot<mirror::Class>(nullptr)); 331} 332 333void ClassLinker::CheckSystemClass(Thread* self, Handle<mirror::Class> c1, const char* descriptor) { 334 mirror::Class* c2 = FindSystemClass(self, descriptor); 335 if (c2 == nullptr) { 336 LOG(FATAL) << "Could not find class " << descriptor; 337 UNREACHABLE(); 338 } 339 if (c1.Get() != c2) { 340 std::ostringstream os1, os2; 341 c1->DumpClass(os1, mirror::Class::kDumpClassFullDetail); 342 c2->DumpClass(os2, mirror::Class::kDumpClassFullDetail); 343 LOG(FATAL) << "InitWithoutImage: Class mismatch for " << descriptor 344 << ". This is most likely the result of a broken build. Make sure that " 345 << "libcore and art projects match.\n\n" 346 << os1.str() << "\n\n" << os2.str(); 347 UNREACHABLE(); 348 } 349} 350 351bool ClassLinker::InitWithoutImage(std::vector<std::unique_ptr<const DexFile>> boot_class_path, 352 std::string* error_msg) { 353 VLOG(startup) << "ClassLinker::Init"; 354 355 Thread* const self = Thread::Current(); 356 Runtime* const runtime = Runtime::Current(); 357 gc::Heap* const heap = runtime->GetHeap(); 358 359 CHECK(!heap->HasBootImageSpace()) << "Runtime has image. We should use it."; 360 CHECK(!init_done_); 361 362 // Use the pointer size from the runtime since we are probably creating the image. 363 image_pointer_size_ = InstructionSetPointerSize(runtime->GetInstructionSet()); 364 if (!ValidPointerSize(image_pointer_size_)) { 365 *error_msg = StringPrintf("Invalid image pointer size: %zu", image_pointer_size_); 366 return false; 367 } 368 369 // java_lang_Class comes first, it's needed for AllocClass 370 // The GC can't handle an object with a null class since we can't get the size of this object. 371 heap->IncrementDisableMovingGC(self); 372 StackHandleScope<64> hs(self); // 64 is picked arbitrarily. 373 auto class_class_size = mirror::Class::ClassClassSize(image_pointer_size_); 374 Handle<mirror::Class> java_lang_Class(hs.NewHandle(down_cast<mirror::Class*>( 375 heap->AllocNonMovableObject<true>(self, nullptr, class_class_size, VoidFunctor())))); 376 CHECK(java_lang_Class.Get() != nullptr); 377 mirror::Class::SetClassClass(java_lang_Class.Get()); 378 java_lang_Class->SetClass(java_lang_Class.Get()); 379 if (kUseBakerOrBrooksReadBarrier) { 380 java_lang_Class->AssertReadBarrierPointer(); 381 } 382 java_lang_Class->SetClassSize(class_class_size); 383 java_lang_Class->SetPrimitiveType(Primitive::kPrimNot); 384 heap->DecrementDisableMovingGC(self); 385 // AllocClass(mirror::Class*) can now be used 386 387 // Class[] is used for reflection support. 388 auto class_array_class_size = mirror::ObjectArray<mirror::Class>::ClassSize(image_pointer_size_); 389 Handle<mirror::Class> class_array_class(hs.NewHandle( 390 AllocClass(self, java_lang_Class.Get(), class_array_class_size))); 391 class_array_class->SetComponentType(java_lang_Class.Get()); 392 393 // java_lang_Object comes next so that object_array_class can be created. 394 Handle<mirror::Class> java_lang_Object(hs.NewHandle( 395 AllocClass(self, java_lang_Class.Get(), mirror::Object::ClassSize(image_pointer_size_)))); 396 CHECK(java_lang_Object.Get() != nullptr); 397 // backfill Object as the super class of Class. 398 java_lang_Class->SetSuperClass(java_lang_Object.Get()); 399 mirror::Class::SetStatus(java_lang_Object, mirror::Class::kStatusLoaded, self); 400 401 java_lang_Object->SetObjectSize(sizeof(mirror::Object)); 402 // Allocate in non-movable so that it's possible to check if a JNI weak global ref has been 403 // cleared without triggering the read barrier and unintentionally mark the sentinel alive. 404 runtime->SetSentinel(heap->AllocNonMovableObject<true>(self, 405 java_lang_Object.Get(), 406 java_lang_Object->GetObjectSize(), 407 VoidFunctor())); 408 409 // Object[] next to hold class roots. 410 Handle<mirror::Class> object_array_class(hs.NewHandle( 411 AllocClass(self, java_lang_Class.Get(), 412 mirror::ObjectArray<mirror::Object>::ClassSize(image_pointer_size_)))); 413 object_array_class->SetComponentType(java_lang_Object.Get()); 414 415 // Setup the char (primitive) class to be used for char[]. 416 Handle<mirror::Class> char_class(hs.NewHandle( 417 AllocClass(self, java_lang_Class.Get(), 418 mirror::Class::PrimitiveClassSize(image_pointer_size_)))); 419 // The primitive char class won't be initialized by 420 // InitializePrimitiveClass until line 459, but strings (and 421 // internal char arrays) will be allocated before that and the 422 // component size, which is computed from the primitive type, needs 423 // to be set here. 424 char_class->SetPrimitiveType(Primitive::kPrimChar); 425 426 // Setup the char[] class to be used for String. 427 Handle<mirror::Class> char_array_class(hs.NewHandle( 428 AllocClass(self, java_lang_Class.Get(), mirror::Array::ClassSize(image_pointer_size_)))); 429 char_array_class->SetComponentType(char_class.Get()); 430 mirror::CharArray::SetArrayClass(char_array_class.Get()); 431 432 // Setup String. 433 Handle<mirror::Class> java_lang_String(hs.NewHandle( 434 AllocClass(self, java_lang_Class.Get(), mirror::String::ClassSize(image_pointer_size_)))); 435 java_lang_String->SetStringClass(); 436 mirror::String::SetClass(java_lang_String.Get()); 437 mirror::Class::SetStatus(java_lang_String, mirror::Class::kStatusResolved, self); 438 439 // Setup java.lang.ref.Reference. 440 Handle<mirror::Class> java_lang_ref_Reference(hs.NewHandle( 441 AllocClass(self, java_lang_Class.Get(), mirror::Reference::ClassSize(image_pointer_size_)))); 442 mirror::Reference::SetClass(java_lang_ref_Reference.Get()); 443 java_lang_ref_Reference->SetObjectSize(mirror::Reference::InstanceSize()); 444 mirror::Class::SetStatus(java_lang_ref_Reference, mirror::Class::kStatusResolved, self); 445 446 // Create storage for root classes, save away our work so far (requires descriptors). 447 class_roots_ = GcRoot<mirror::ObjectArray<mirror::Class>>( 448 mirror::ObjectArray<mirror::Class>::Alloc(self, object_array_class.Get(), 449 kClassRootsMax)); 450 CHECK(!class_roots_.IsNull()); 451 SetClassRoot(kJavaLangClass, java_lang_Class.Get()); 452 SetClassRoot(kJavaLangObject, java_lang_Object.Get()); 453 SetClassRoot(kClassArrayClass, class_array_class.Get()); 454 SetClassRoot(kObjectArrayClass, object_array_class.Get()); 455 SetClassRoot(kCharArrayClass, char_array_class.Get()); 456 SetClassRoot(kJavaLangString, java_lang_String.Get()); 457 SetClassRoot(kJavaLangRefReference, java_lang_ref_Reference.Get()); 458 459 // Setup the primitive type classes. 460 SetClassRoot(kPrimitiveBoolean, CreatePrimitiveClass(self, Primitive::kPrimBoolean)); 461 SetClassRoot(kPrimitiveByte, CreatePrimitiveClass(self, Primitive::kPrimByte)); 462 SetClassRoot(kPrimitiveShort, CreatePrimitiveClass(self, Primitive::kPrimShort)); 463 SetClassRoot(kPrimitiveInt, CreatePrimitiveClass(self, Primitive::kPrimInt)); 464 SetClassRoot(kPrimitiveLong, CreatePrimitiveClass(self, Primitive::kPrimLong)); 465 SetClassRoot(kPrimitiveFloat, CreatePrimitiveClass(self, Primitive::kPrimFloat)); 466 SetClassRoot(kPrimitiveDouble, CreatePrimitiveClass(self, Primitive::kPrimDouble)); 467 SetClassRoot(kPrimitiveVoid, CreatePrimitiveClass(self, Primitive::kPrimVoid)); 468 469 // Create array interface entries to populate once we can load system classes. 470 array_iftable_ = GcRoot<mirror::IfTable>(AllocIfTable(self, 2)); 471 472 // Create int array type for AllocDexCache (done in AppendToBootClassPath). 473 Handle<mirror::Class> int_array_class(hs.NewHandle( 474 AllocClass(self, java_lang_Class.Get(), mirror::Array::ClassSize(image_pointer_size_)))); 475 int_array_class->SetComponentType(GetClassRoot(kPrimitiveInt)); 476 mirror::IntArray::SetArrayClass(int_array_class.Get()); 477 SetClassRoot(kIntArrayClass, int_array_class.Get()); 478 479 // Create long array type for AllocDexCache (done in AppendToBootClassPath). 480 Handle<mirror::Class> long_array_class(hs.NewHandle( 481 AllocClass(self, java_lang_Class.Get(), mirror::Array::ClassSize(image_pointer_size_)))); 482 long_array_class->SetComponentType(GetClassRoot(kPrimitiveLong)); 483 mirror::LongArray::SetArrayClass(long_array_class.Get()); 484 SetClassRoot(kLongArrayClass, long_array_class.Get()); 485 486 // now that these are registered, we can use AllocClass() and AllocObjectArray 487 488 // Set up DexCache. This cannot be done later since AppendToBootClassPath calls AllocDexCache. 489 Handle<mirror::Class> java_lang_DexCache(hs.NewHandle( 490 AllocClass(self, java_lang_Class.Get(), mirror::DexCache::ClassSize(image_pointer_size_)))); 491 SetClassRoot(kJavaLangDexCache, java_lang_DexCache.Get()); 492 java_lang_DexCache->SetDexCacheClass(); 493 java_lang_DexCache->SetObjectSize(mirror::DexCache::InstanceSize()); 494 mirror::Class::SetStatus(java_lang_DexCache, mirror::Class::kStatusResolved, self); 495 496 // Set up array classes for string, field, method 497 Handle<mirror::Class> object_array_string(hs.NewHandle( 498 AllocClass(self, java_lang_Class.Get(), 499 mirror::ObjectArray<mirror::String>::ClassSize(image_pointer_size_)))); 500 object_array_string->SetComponentType(java_lang_String.Get()); 501 SetClassRoot(kJavaLangStringArrayClass, object_array_string.Get()); 502 503 LinearAlloc* linear_alloc = runtime->GetLinearAlloc(); 504 // Create runtime resolution and imt conflict methods. 505 runtime->SetResolutionMethod(runtime->CreateResolutionMethod()); 506 runtime->SetImtConflictMethod(runtime->CreateImtConflictMethod(linear_alloc)); 507 runtime->SetImtUnimplementedMethod(runtime->CreateImtConflictMethod(linear_alloc)); 508 509 // Setup boot_class_path_ and register class_path now that we can use AllocObjectArray to create 510 // DexCache instances. Needs to be after String, Field, Method arrays since AllocDexCache uses 511 // these roots. 512 if (boot_class_path.empty()) { 513 *error_msg = "Boot classpath is empty."; 514 return false; 515 } 516 for (auto& dex_file : boot_class_path) { 517 if (dex_file.get() == nullptr) { 518 *error_msg = "Null dex file."; 519 return false; 520 } 521 AppendToBootClassPath(self, *dex_file); 522 boot_dex_files_.push_back(std::move(dex_file)); 523 } 524 525 // now we can use FindSystemClass 526 527 // run char class through InitializePrimitiveClass to finish init 528 InitializePrimitiveClass(char_class.Get(), Primitive::kPrimChar); 529 SetClassRoot(kPrimitiveChar, char_class.Get()); // needs descriptor 530 531 // Set up GenericJNI entrypoint. That is mainly a hack for common_compiler_test.h so that 532 // we do not need friend classes or a publicly exposed setter. 533 quick_generic_jni_trampoline_ = GetQuickGenericJniStub(); 534 if (!runtime->IsAotCompiler()) { 535 // We need to set up the generic trampolines since we don't have an image. 536 quick_resolution_trampoline_ = GetQuickResolutionStub(); 537 quick_imt_conflict_trampoline_ = GetQuickImtConflictStub(); 538 quick_to_interpreter_bridge_trampoline_ = GetQuickToInterpreterBridge(); 539 } 540 541 // Object, String and DexCache need to be rerun through FindSystemClass to finish init 542 mirror::Class::SetStatus(java_lang_Object, mirror::Class::kStatusNotReady, self); 543 CheckSystemClass(self, java_lang_Object, "Ljava/lang/Object;"); 544 CHECK_EQ(java_lang_Object->GetObjectSize(), mirror::Object::InstanceSize()); 545 mirror::Class::SetStatus(java_lang_String, mirror::Class::kStatusNotReady, self); 546 CheckSystemClass(self, java_lang_String, "Ljava/lang/String;"); 547 mirror::Class::SetStatus(java_lang_DexCache, mirror::Class::kStatusNotReady, self); 548 CheckSystemClass(self, java_lang_DexCache, "Ljava/lang/DexCache;"); 549 CHECK_EQ(java_lang_DexCache->GetObjectSize(), mirror::DexCache::InstanceSize()); 550 551 // Setup the primitive array type classes - can't be done until Object has a vtable. 552 SetClassRoot(kBooleanArrayClass, FindSystemClass(self, "[Z")); 553 mirror::BooleanArray::SetArrayClass(GetClassRoot(kBooleanArrayClass)); 554 555 SetClassRoot(kByteArrayClass, FindSystemClass(self, "[B")); 556 mirror::ByteArray::SetArrayClass(GetClassRoot(kByteArrayClass)); 557 558 CheckSystemClass(self, char_array_class, "[C"); 559 560 SetClassRoot(kShortArrayClass, FindSystemClass(self, "[S")); 561 mirror::ShortArray::SetArrayClass(GetClassRoot(kShortArrayClass)); 562 563 CheckSystemClass(self, int_array_class, "[I"); 564 CheckSystemClass(self, long_array_class, "[J"); 565 566 SetClassRoot(kFloatArrayClass, FindSystemClass(self, "[F")); 567 mirror::FloatArray::SetArrayClass(GetClassRoot(kFloatArrayClass)); 568 569 SetClassRoot(kDoubleArrayClass, FindSystemClass(self, "[D")); 570 mirror::DoubleArray::SetArrayClass(GetClassRoot(kDoubleArrayClass)); 571 572 // Run Class through FindSystemClass. This initializes the dex_cache_ fields and register it 573 // in class_table_. 574 CheckSystemClass(self, java_lang_Class, "Ljava/lang/Class;"); 575 576 CheckSystemClass(self, class_array_class, "[Ljava/lang/Class;"); 577 CheckSystemClass(self, object_array_class, "[Ljava/lang/Object;"); 578 579 // Setup the single, global copy of "iftable". 580 auto java_lang_Cloneable = hs.NewHandle(FindSystemClass(self, "Ljava/lang/Cloneable;")); 581 CHECK(java_lang_Cloneable.Get() != nullptr); 582 auto java_io_Serializable = hs.NewHandle(FindSystemClass(self, "Ljava/io/Serializable;")); 583 CHECK(java_io_Serializable.Get() != nullptr); 584 // We assume that Cloneable/Serializable don't have superinterfaces -- normally we'd have to 585 // crawl up and explicitly list all of the supers as well. 586 array_iftable_.Read()->SetInterface(0, java_lang_Cloneable.Get()); 587 array_iftable_.Read()->SetInterface(1, java_io_Serializable.Get()); 588 589 // Sanity check Class[] and Object[]'s interfaces. GetDirectInterface may cause thread 590 // suspension. 591 CHECK_EQ(java_lang_Cloneable.Get(), 592 mirror::Class::GetDirectInterface(self, class_array_class, 0)); 593 CHECK_EQ(java_io_Serializable.Get(), 594 mirror::Class::GetDirectInterface(self, class_array_class, 1)); 595 CHECK_EQ(java_lang_Cloneable.Get(), 596 mirror::Class::GetDirectInterface(self, object_array_class, 0)); 597 CHECK_EQ(java_io_Serializable.Get(), 598 mirror::Class::GetDirectInterface(self, object_array_class, 1)); 599 600 CHECK_EQ(object_array_string.Get(), 601 FindSystemClass(self, GetClassRootDescriptor(kJavaLangStringArrayClass))); 602 603 // End of special init trickery, all subsequent classes may be loaded via FindSystemClass. 604 605 // Create java.lang.reflect.Proxy root. 606 SetClassRoot(kJavaLangReflectProxy, FindSystemClass(self, "Ljava/lang/reflect/Proxy;")); 607 608 // Create java.lang.reflect.Field.class root. 609 auto* class_root = FindSystemClass(self, "Ljava/lang/reflect/Field;"); 610 CHECK(class_root != nullptr); 611 SetClassRoot(kJavaLangReflectField, class_root); 612 mirror::Field::SetClass(class_root); 613 614 // Create java.lang.reflect.Field array root. 615 class_root = FindSystemClass(self, "[Ljava/lang/reflect/Field;"); 616 CHECK(class_root != nullptr); 617 SetClassRoot(kJavaLangReflectFieldArrayClass, class_root); 618 mirror::Field::SetArrayClass(class_root); 619 620 // Create java.lang.reflect.Constructor.class root and array root. 621 class_root = FindSystemClass(self, "Ljava/lang/reflect/Constructor;"); 622 CHECK(class_root != nullptr); 623 SetClassRoot(kJavaLangReflectConstructor, class_root); 624 mirror::Constructor::SetClass(class_root); 625 class_root = FindSystemClass(self, "[Ljava/lang/reflect/Constructor;"); 626 CHECK(class_root != nullptr); 627 SetClassRoot(kJavaLangReflectConstructorArrayClass, class_root); 628 mirror::Constructor::SetArrayClass(class_root); 629 630 // Create java.lang.reflect.Method.class root and array root. 631 class_root = FindSystemClass(self, "Ljava/lang/reflect/Method;"); 632 CHECK(class_root != nullptr); 633 SetClassRoot(kJavaLangReflectMethod, class_root); 634 mirror::Method::SetClass(class_root); 635 class_root = FindSystemClass(self, "[Ljava/lang/reflect/Method;"); 636 CHECK(class_root != nullptr); 637 SetClassRoot(kJavaLangReflectMethodArrayClass, class_root); 638 mirror::Method::SetArrayClass(class_root); 639 640 // java.lang.ref classes need to be specially flagged, but otherwise are normal classes 641 // finish initializing Reference class 642 mirror::Class::SetStatus(java_lang_ref_Reference, mirror::Class::kStatusNotReady, self); 643 CheckSystemClass(self, java_lang_ref_Reference, "Ljava/lang/ref/Reference;"); 644 CHECK_EQ(java_lang_ref_Reference->GetObjectSize(), mirror::Reference::InstanceSize()); 645 CHECK_EQ(java_lang_ref_Reference->GetClassSize(), 646 mirror::Reference::ClassSize(image_pointer_size_)); 647 class_root = FindSystemClass(self, "Ljava/lang/ref/FinalizerReference;"); 648 CHECK_EQ(class_root->GetClassFlags(), mirror::kClassFlagNormal); 649 class_root->SetClassFlags(class_root->GetClassFlags() | mirror::kClassFlagFinalizerReference); 650 class_root = FindSystemClass(self, "Ljava/lang/ref/PhantomReference;"); 651 CHECK_EQ(class_root->GetClassFlags(), mirror::kClassFlagNormal); 652 class_root->SetClassFlags(class_root->GetClassFlags() | mirror::kClassFlagPhantomReference); 653 class_root = FindSystemClass(self, "Ljava/lang/ref/SoftReference;"); 654 CHECK_EQ(class_root->GetClassFlags(), mirror::kClassFlagNormal); 655 class_root->SetClassFlags(class_root->GetClassFlags() | mirror::kClassFlagSoftReference); 656 class_root = FindSystemClass(self, "Ljava/lang/ref/WeakReference;"); 657 CHECK_EQ(class_root->GetClassFlags(), mirror::kClassFlagNormal); 658 class_root->SetClassFlags(class_root->GetClassFlags() | mirror::kClassFlagWeakReference); 659 660 // Setup the ClassLoader, verifying the object_size_. 661 class_root = FindSystemClass(self, "Ljava/lang/ClassLoader;"); 662 class_root->SetClassLoaderClass(); 663 CHECK_EQ(class_root->GetObjectSize(), mirror::ClassLoader::InstanceSize()); 664 SetClassRoot(kJavaLangClassLoader, class_root); 665 666 // Set up java.lang.Throwable, java.lang.ClassNotFoundException, and 667 // java.lang.StackTraceElement as a convenience. 668 SetClassRoot(kJavaLangThrowable, FindSystemClass(self, "Ljava/lang/Throwable;")); 669 mirror::Throwable::SetClass(GetClassRoot(kJavaLangThrowable)); 670 SetClassRoot(kJavaLangClassNotFoundException, 671 FindSystemClass(self, "Ljava/lang/ClassNotFoundException;")); 672 SetClassRoot(kJavaLangStackTraceElement, FindSystemClass(self, "Ljava/lang/StackTraceElement;")); 673 SetClassRoot(kJavaLangStackTraceElementArrayClass, 674 FindSystemClass(self, "[Ljava/lang/StackTraceElement;")); 675 mirror::StackTraceElement::SetClass(GetClassRoot(kJavaLangStackTraceElement)); 676 677 // Ensure void type is resolved in the core's dex cache so java.lang.Void is correctly 678 // initialized. 679 { 680 const DexFile& dex_file = java_lang_Object->GetDexFile(); 681 const DexFile::TypeId* void_type_id = dex_file.FindTypeId("V"); 682 CHECK(void_type_id != nullptr); 683 uint16_t void_type_idx = dex_file.GetIndexForTypeId(*void_type_id); 684 // Now we resolve void type so the dex cache contains it. We use java.lang.Object class 685 // as referrer so the used dex cache is core's one. 686 mirror::Class* resolved_type = ResolveType(dex_file, void_type_idx, java_lang_Object.Get()); 687 CHECK_EQ(resolved_type, GetClassRoot(kPrimitiveVoid)); 688 self->AssertNoPendingException(); 689 } 690 691 // Create conflict tables that depend on the class linker. 692 runtime->FixupConflictTables(); 693 694 FinishInit(self); 695 696 VLOG(startup) << "ClassLinker::InitFromCompiler exiting"; 697 698 return true; 699} 700 701void ClassLinker::FinishInit(Thread* self) { 702 VLOG(startup) << "ClassLinker::FinishInit entering"; 703 704 // Let the heap know some key offsets into java.lang.ref instances 705 // Note: we hard code the field indexes here rather than using FindInstanceField 706 // as the types of the field can't be resolved prior to the runtime being 707 // fully initialized 708 mirror::Class* java_lang_ref_Reference = GetClassRoot(kJavaLangRefReference); 709 mirror::Class* java_lang_ref_FinalizerReference = 710 FindSystemClass(self, "Ljava/lang/ref/FinalizerReference;"); 711 712 ArtField* pendingNext = java_lang_ref_Reference->GetInstanceField(0); 713 CHECK_STREQ(pendingNext->GetName(), "pendingNext"); 714 CHECK_STREQ(pendingNext->GetTypeDescriptor(), "Ljava/lang/ref/Reference;"); 715 716 ArtField* queue = java_lang_ref_Reference->GetInstanceField(1); 717 CHECK_STREQ(queue->GetName(), "queue"); 718 CHECK_STREQ(queue->GetTypeDescriptor(), "Ljava/lang/ref/ReferenceQueue;"); 719 720 ArtField* queueNext = java_lang_ref_Reference->GetInstanceField(2); 721 CHECK_STREQ(queueNext->GetName(), "queueNext"); 722 CHECK_STREQ(queueNext->GetTypeDescriptor(), "Ljava/lang/ref/Reference;"); 723 724 ArtField* referent = java_lang_ref_Reference->GetInstanceField(3); 725 CHECK_STREQ(referent->GetName(), "referent"); 726 CHECK_STREQ(referent->GetTypeDescriptor(), "Ljava/lang/Object;"); 727 728 ArtField* zombie = java_lang_ref_FinalizerReference->GetInstanceField(2); 729 CHECK_STREQ(zombie->GetName(), "zombie"); 730 CHECK_STREQ(zombie->GetTypeDescriptor(), "Ljava/lang/Object;"); 731 732 // ensure all class_roots_ are initialized 733 for (size_t i = 0; i < kClassRootsMax; i++) { 734 ClassRoot class_root = static_cast<ClassRoot>(i); 735 mirror::Class* klass = GetClassRoot(class_root); 736 CHECK(klass != nullptr); 737 DCHECK(klass->IsArrayClass() || klass->IsPrimitive() || klass->GetDexCache() != nullptr); 738 // note SetClassRoot does additional validation. 739 // if possible add new checks there to catch errors early 740 } 741 742 CHECK(!array_iftable_.IsNull()); 743 744 // disable the slow paths in FindClass and CreatePrimitiveClass now 745 // that Object, Class, and Object[] are setup 746 init_done_ = true; 747 748 VLOG(startup) << "ClassLinker::FinishInit exiting"; 749} 750 751void ClassLinker::RunRootClinits() { 752 Thread* self = Thread::Current(); 753 for (size_t i = 0; i < ClassLinker::kClassRootsMax; ++i) { 754 mirror::Class* c = GetClassRoot(ClassRoot(i)); 755 if (!c->IsArrayClass() && !c->IsPrimitive()) { 756 StackHandleScope<1> hs(self); 757 Handle<mirror::Class> h_class(hs.NewHandle(GetClassRoot(ClassRoot(i)))); 758 EnsureInitialized(self, h_class, true, true); 759 self->AssertNoPendingException(); 760 } 761 } 762} 763 764static void SanityCheckArtMethod(ArtMethod* m, 765 mirror::Class* expected_class, 766 const std::vector<gc::space::ImageSpace*>& spaces) 767 SHARED_REQUIRES(Locks::mutator_lock_) { 768 if (m->IsRuntimeMethod()) { 769 mirror::Class* declaring_class = m->GetDeclaringClassUnchecked(); 770 CHECK(declaring_class == nullptr) << declaring_class << " " << PrettyMethod(m); 771 } else if (m->IsCopied()) { 772 CHECK(m->GetDeclaringClass() != nullptr) << PrettyMethod(m); 773 } else if (expected_class != nullptr) { 774 CHECK_EQ(m->GetDeclaringClassUnchecked(), expected_class) << PrettyMethod(m); 775 } 776 if (!spaces.empty()) { 777 bool contains = false; 778 for (gc::space::ImageSpace* space : spaces) { 779 auto& header = space->GetImageHeader(); 780 size_t offset = reinterpret_cast<uint8_t*>(m) - space->Begin(); 781 782 const ImageSection& methods = header.GetMethodsSection(); 783 contains = contains || methods.Contains(offset); 784 785 const ImageSection& runtime_methods = header.GetRuntimeMethodsSection(); 786 contains = contains || runtime_methods.Contains(offset); 787 } 788 CHECK(contains) << m << " not found"; 789 } 790} 791 792static void SanityCheckArtMethodPointerArray(mirror::PointerArray* arr, 793 mirror::Class* expected_class, 794 size_t pointer_size, 795 const std::vector<gc::space::ImageSpace*>& spaces) 796 SHARED_REQUIRES(Locks::mutator_lock_) { 797 CHECK(arr != nullptr); 798 for (int32_t j = 0; j < arr->GetLength(); ++j) { 799 auto* method = arr->GetElementPtrSize<ArtMethod*>(j, pointer_size); 800 // expected_class == null means we are a dex cache. 801 if (expected_class != nullptr) { 802 CHECK(method != nullptr); 803 } 804 if (method != nullptr) { 805 SanityCheckArtMethod(method, expected_class, spaces); 806 } 807 } 808} 809 810static void SanityCheckArtMethodPointerArray(ArtMethod** arr, 811 size_t size, 812 size_t pointer_size, 813 const std::vector<gc::space::ImageSpace*>& spaces) 814 SHARED_REQUIRES(Locks::mutator_lock_) { 815 CHECK_EQ(arr != nullptr, size != 0u); 816 if (arr != nullptr) { 817 bool contains = false; 818 for (auto space : spaces) { 819 auto offset = reinterpret_cast<uint8_t*>(arr) - space->Begin(); 820 if (space->GetImageHeader().GetImageSection( 821 ImageHeader::kSectionDexCacheArrays).Contains(offset)) { 822 contains = true; 823 break; 824 } 825 } 826 CHECK(contains); 827 } 828 for (size_t j = 0; j < size; ++j) { 829 ArtMethod* method = mirror::DexCache::GetElementPtrSize(arr, j, pointer_size); 830 // expected_class == null means we are a dex cache. 831 if (method != nullptr) { 832 SanityCheckArtMethod(method, nullptr, spaces); 833 } 834 } 835} 836 837static void SanityCheckObjectsCallback(mirror::Object* obj, void* arg ATTRIBUTE_UNUSED) 838 SHARED_REQUIRES(Locks::mutator_lock_) { 839 DCHECK(obj != nullptr); 840 CHECK(obj->GetClass() != nullptr) << "Null class in object " << obj; 841 CHECK(obj->GetClass()->GetClass() != nullptr) << "Null class class " << obj; 842 if (obj->IsClass()) { 843 auto klass = obj->AsClass(); 844 for (ArtField& field : klass->GetIFields()) { 845 CHECK_EQ(field.GetDeclaringClass(), klass); 846 } 847 for (ArtField& field : klass->GetSFields()) { 848 CHECK_EQ(field.GetDeclaringClass(), klass); 849 } 850 auto* runtime = Runtime::Current(); 851 auto image_spaces = runtime->GetHeap()->GetBootImageSpaces(); 852 auto pointer_size = runtime->GetClassLinker()->GetImagePointerSize(); 853 for (auto& m : klass->GetMethods(pointer_size)) { 854 SanityCheckArtMethod(&m, klass, image_spaces); 855 } 856 auto* vtable = klass->GetVTable(); 857 if (vtable != nullptr) { 858 SanityCheckArtMethodPointerArray(vtable, nullptr, pointer_size, image_spaces); 859 } 860 if (klass->ShouldHaveImt()) { 861 ImTable* imt = klass->GetImt(pointer_size); 862 for (size_t i = 0; i < ImTable::kSize; ++i) { 863 SanityCheckArtMethod(imt->Get(i, pointer_size), nullptr, image_spaces); 864 } 865 } 866 if (klass->ShouldHaveEmbeddedVTable()) { 867 for (int32_t i = 0; i < klass->GetEmbeddedVTableLength(); ++i) { 868 SanityCheckArtMethod(klass->GetEmbeddedVTableEntry(i, pointer_size), nullptr, image_spaces); 869 } 870 } 871 auto* iftable = klass->GetIfTable(); 872 if (iftable != nullptr) { 873 for (int32_t i = 0; i < klass->GetIfTableCount(); ++i) { 874 if (iftable->GetMethodArrayCount(i) > 0) { 875 SanityCheckArtMethodPointerArray( 876 iftable->GetMethodArray(i), nullptr, pointer_size, image_spaces); 877 } 878 } 879 } 880 } 881} 882 883// Set image methods' entry point to interpreter. 884class SetInterpreterEntrypointArtMethodVisitor : public ArtMethodVisitor { 885 public: 886 explicit SetInterpreterEntrypointArtMethodVisitor(size_t image_pointer_size) 887 : image_pointer_size_(image_pointer_size) {} 888 889 void Visit(ArtMethod* method) OVERRIDE SHARED_REQUIRES(Locks::mutator_lock_) { 890 if (kIsDebugBuild && !method->IsRuntimeMethod()) { 891 CHECK(method->GetDeclaringClass() != nullptr); 892 } 893 if (!method->IsNative() && !method->IsRuntimeMethod() && !method->IsResolutionMethod()) { 894 method->SetEntryPointFromQuickCompiledCodePtrSize(GetQuickToInterpreterBridge(), 895 image_pointer_size_); 896 } 897 } 898 899 private: 900 const size_t image_pointer_size_; 901 902 DISALLOW_COPY_AND_ASSIGN(SetInterpreterEntrypointArtMethodVisitor); 903}; 904 905struct TrampolineCheckData { 906 const void* quick_resolution_trampoline; 907 const void* quick_imt_conflict_trampoline; 908 const void* quick_generic_jni_trampoline; 909 const void* quick_to_interpreter_bridge_trampoline; 910 size_t pointer_size; 911 ArtMethod* m; 912 bool error; 913}; 914 915static void CheckTrampolines(mirror::Object* obj, void* arg) NO_THREAD_SAFETY_ANALYSIS { 916 if (obj->IsClass()) { 917 mirror::Class* klass = obj->AsClass(); 918 TrampolineCheckData* d = reinterpret_cast<TrampolineCheckData*>(arg); 919 for (ArtMethod& m : klass->GetMethods(d->pointer_size)) { 920 const void* entrypoint = m.GetEntryPointFromQuickCompiledCodePtrSize(d->pointer_size); 921 if (entrypoint == d->quick_resolution_trampoline || 922 entrypoint == d->quick_imt_conflict_trampoline || 923 entrypoint == d->quick_generic_jni_trampoline || 924 entrypoint == d->quick_to_interpreter_bridge_trampoline) { 925 d->m = &m; 926 d->error = true; 927 return; 928 } 929 } 930 } 931} 932 933bool ClassLinker::InitFromBootImage(std::string* error_msg) { 934 VLOG(startup) << __FUNCTION__ << " entering"; 935 CHECK(!init_done_); 936 937 Runtime* const runtime = Runtime::Current(); 938 Thread* const self = Thread::Current(); 939 gc::Heap* const heap = runtime->GetHeap(); 940 std::vector<gc::space::ImageSpace*> spaces = heap->GetBootImageSpaces(); 941 CHECK(!spaces.empty()); 942 image_pointer_size_ = spaces[0]->GetImageHeader().GetPointerSize(); 943 if (!ValidPointerSize(image_pointer_size_)) { 944 *error_msg = StringPrintf("Invalid image pointer size: %zu", image_pointer_size_); 945 return false; 946 } 947 if (!runtime->IsAotCompiler()) { 948 // Only the Aot compiler supports having an image with a different pointer size than the 949 // runtime. This happens on the host for compiling 32 bit tests since we use a 64 bit libart 950 // compiler. We may also use 32 bit dex2oat on a system with 64 bit apps. 951 if (image_pointer_size_ != sizeof(void*)) { 952 *error_msg = StringPrintf("Runtime must use current image pointer size: %zu vs %zu", 953 image_pointer_size_, 954 sizeof(void*)); 955 return false; 956 } 957 } 958 dex_cache_boot_image_class_lookup_required_ = true; 959 std::vector<const OatFile*> oat_files = 960 runtime->GetOatFileManager().RegisterImageOatFiles(spaces); 961 DCHECK(!oat_files.empty()); 962 const OatHeader& default_oat_header = oat_files[0]->GetOatHeader(); 963 CHECK_EQ(default_oat_header.GetImageFileLocationOatChecksum(), 0U); 964 CHECK_EQ(default_oat_header.GetImageFileLocationOatDataBegin(), 0U); 965 const char* image_file_location = oat_files[0]->GetOatHeader(). 966 GetStoreValueByKey(OatHeader::kImageLocationKey); 967 CHECK(image_file_location == nullptr || *image_file_location == 0); 968 quick_resolution_trampoline_ = default_oat_header.GetQuickResolutionTrampoline(); 969 quick_imt_conflict_trampoline_ = default_oat_header.GetQuickImtConflictTrampoline(); 970 quick_generic_jni_trampoline_ = default_oat_header.GetQuickGenericJniTrampoline(); 971 quick_to_interpreter_bridge_trampoline_ = default_oat_header.GetQuickToInterpreterBridge(); 972 if (kIsDebugBuild) { 973 // Check that the other images use the same trampoline. 974 for (size_t i = 1; i < oat_files.size(); ++i) { 975 const OatHeader& ith_oat_header = oat_files[i]->GetOatHeader(); 976 const void* ith_quick_resolution_trampoline = 977 ith_oat_header.GetQuickResolutionTrampoline(); 978 const void* ith_quick_imt_conflict_trampoline = 979 ith_oat_header.GetQuickImtConflictTrampoline(); 980 const void* ith_quick_generic_jni_trampoline = 981 ith_oat_header.GetQuickGenericJniTrampoline(); 982 const void* ith_quick_to_interpreter_bridge_trampoline = 983 ith_oat_header.GetQuickToInterpreterBridge(); 984 if (ith_quick_resolution_trampoline != quick_resolution_trampoline_ || 985 ith_quick_imt_conflict_trampoline != quick_imt_conflict_trampoline_ || 986 ith_quick_generic_jni_trampoline != quick_generic_jni_trampoline_ || 987 ith_quick_to_interpreter_bridge_trampoline != quick_to_interpreter_bridge_trampoline_) { 988 // Make sure that all methods in this image do not contain those trampolines as 989 // entrypoints. Otherwise the class-linker won't be able to work with a single set. 990 TrampolineCheckData data; 991 data.error = false; 992 data.pointer_size = GetImagePointerSize(); 993 data.quick_resolution_trampoline = ith_quick_resolution_trampoline; 994 data.quick_imt_conflict_trampoline = ith_quick_imt_conflict_trampoline; 995 data.quick_generic_jni_trampoline = ith_quick_generic_jni_trampoline; 996 data.quick_to_interpreter_bridge_trampoline = ith_quick_to_interpreter_bridge_trampoline; 997 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 998 spaces[i]->GetLiveBitmap()->Walk(CheckTrampolines, &data); 999 if (data.error) { 1000 ArtMethod* m = data.m; 1001 LOG(ERROR) << "Found a broken ArtMethod: " << PrettyMethod(m); 1002 *error_msg = "Found an ArtMethod with a bad entrypoint"; 1003 return false; 1004 } 1005 } 1006 } 1007 } 1008 1009 class_roots_ = GcRoot<mirror::ObjectArray<mirror::Class>>( 1010 down_cast<mirror::ObjectArray<mirror::Class>*>( 1011 spaces[0]->GetImageHeader().GetImageRoot(ImageHeader::kClassRoots))); 1012 mirror::Class::SetClassClass(class_roots_.Read()->Get(kJavaLangClass)); 1013 1014 // Special case of setting up the String class early so that we can test arbitrary objects 1015 // as being Strings or not 1016 mirror::String::SetClass(GetClassRoot(kJavaLangString)); 1017 1018 mirror::Class* java_lang_Object = GetClassRoot(kJavaLangObject); 1019 java_lang_Object->SetObjectSize(sizeof(mirror::Object)); 1020 // Allocate in non-movable so that it's possible to check if a JNI weak global ref has been 1021 // cleared without triggering the read barrier and unintentionally mark the sentinel alive. 1022 runtime->SetSentinel(heap->AllocNonMovableObject<true>( 1023 self, java_lang_Object, java_lang_Object->GetObjectSize(), VoidFunctor())); 1024 1025 // reinit array_iftable_ from any array class instance, they should be == 1026 array_iftable_ = GcRoot<mirror::IfTable>(GetClassRoot(kObjectArrayClass)->GetIfTable()); 1027 DCHECK_EQ(array_iftable_.Read(), GetClassRoot(kBooleanArrayClass)->GetIfTable()); 1028 // String class root was set above 1029 mirror::Field::SetClass(GetClassRoot(kJavaLangReflectField)); 1030 mirror::Field::SetArrayClass(GetClassRoot(kJavaLangReflectFieldArrayClass)); 1031 mirror::Constructor::SetClass(GetClassRoot(kJavaLangReflectConstructor)); 1032 mirror::Constructor::SetArrayClass(GetClassRoot(kJavaLangReflectConstructorArrayClass)); 1033 mirror::Method::SetClass(GetClassRoot(kJavaLangReflectMethod)); 1034 mirror::Method::SetArrayClass(GetClassRoot(kJavaLangReflectMethodArrayClass)); 1035 mirror::Reference::SetClass(GetClassRoot(kJavaLangRefReference)); 1036 mirror::BooleanArray::SetArrayClass(GetClassRoot(kBooleanArrayClass)); 1037 mirror::ByteArray::SetArrayClass(GetClassRoot(kByteArrayClass)); 1038 mirror::CharArray::SetArrayClass(GetClassRoot(kCharArrayClass)); 1039 mirror::DoubleArray::SetArrayClass(GetClassRoot(kDoubleArrayClass)); 1040 mirror::FloatArray::SetArrayClass(GetClassRoot(kFloatArrayClass)); 1041 mirror::IntArray::SetArrayClass(GetClassRoot(kIntArrayClass)); 1042 mirror::LongArray::SetArrayClass(GetClassRoot(kLongArrayClass)); 1043 mirror::ShortArray::SetArrayClass(GetClassRoot(kShortArrayClass)); 1044 mirror::Throwable::SetClass(GetClassRoot(kJavaLangThrowable)); 1045 mirror::StackTraceElement::SetClass(GetClassRoot(kJavaLangStackTraceElement)); 1046 1047 for (gc::space::ImageSpace* image_space : spaces) { 1048 // Boot class loader, use a null handle. 1049 std::vector<std::unique_ptr<const DexFile>> dex_files; 1050 if (!AddImageSpace(image_space, 1051 ScopedNullHandle<mirror::ClassLoader>(), 1052 /*dex_elements*/nullptr, 1053 /*dex_location*/nullptr, 1054 /*out*/&dex_files, 1055 error_msg)) { 1056 return false; 1057 } 1058 // Append opened dex files at the end. 1059 boot_dex_files_.insert(boot_dex_files_.end(), 1060 std::make_move_iterator(dex_files.begin()), 1061 std::make_move_iterator(dex_files.end())); 1062 } 1063 FinishInit(self); 1064 1065 VLOG(startup) << __FUNCTION__ << " exiting"; 1066 return true; 1067} 1068 1069bool ClassLinker::IsBootClassLoader(ScopedObjectAccessAlreadyRunnable& soa, 1070 mirror::ClassLoader* class_loader) { 1071 return class_loader == nullptr || 1072 class_loader->GetClass() == 1073 soa.Decode<mirror::Class*>(WellKnownClasses::java_lang_BootClassLoader); 1074} 1075 1076static mirror::String* GetDexPathListElementName(ScopedObjectAccessUnchecked& soa, 1077 mirror::Object* element) 1078 SHARED_REQUIRES(Locks::mutator_lock_) { 1079 ArtField* const dex_file_field = 1080 soa.DecodeField(WellKnownClasses::dalvik_system_DexPathList__Element_dexFile); 1081 ArtField* const dex_file_name_field = 1082 soa.DecodeField(WellKnownClasses::dalvik_system_DexFile_fileName); 1083 DCHECK(dex_file_field != nullptr); 1084 DCHECK(dex_file_name_field != nullptr); 1085 DCHECK(element != nullptr); 1086 CHECK_EQ(dex_file_field->GetDeclaringClass(), element->GetClass()) << PrettyTypeOf(element); 1087 mirror::Object* dex_file = dex_file_field->GetObject(element); 1088 if (dex_file == nullptr) { 1089 return nullptr; 1090 } 1091 mirror::Object* const name_object = dex_file_name_field->GetObject(dex_file); 1092 if (name_object != nullptr) { 1093 return name_object->AsString(); 1094 } 1095 return nullptr; 1096} 1097 1098static bool FlattenPathClassLoader(mirror::ClassLoader* class_loader, 1099 std::list<mirror::String*>* out_dex_file_names, 1100 std::string* error_msg) 1101 SHARED_REQUIRES(Locks::mutator_lock_) { 1102 DCHECK(out_dex_file_names != nullptr); 1103 DCHECK(error_msg != nullptr); 1104 ScopedObjectAccessUnchecked soa(Thread::Current()); 1105 ArtField* const dex_path_list_field = 1106 soa.DecodeField(WellKnownClasses::dalvik_system_PathClassLoader_pathList); 1107 ArtField* const dex_elements_field = 1108 soa.DecodeField(WellKnownClasses::dalvik_system_DexPathList_dexElements); 1109 CHECK(dex_path_list_field != nullptr); 1110 CHECK(dex_elements_field != nullptr); 1111 while (!ClassLinker::IsBootClassLoader(soa, class_loader)) { 1112 if (class_loader->GetClass() != 1113 soa.Decode<mirror::Class*>(WellKnownClasses::dalvik_system_PathClassLoader)) { 1114 *error_msg = StringPrintf("Unknown class loader type %s", PrettyTypeOf(class_loader).c_str()); 1115 // Unsupported class loader. 1116 return false; 1117 } 1118 mirror::Object* dex_path_list = dex_path_list_field->GetObject(class_loader); 1119 if (dex_path_list != nullptr) { 1120 // DexPathList has an array dexElements of Elements[] which each contain a dex file. 1121 mirror::Object* dex_elements_obj = dex_elements_field->GetObject(dex_path_list); 1122 // Loop through each dalvik.system.DexPathList$Element's dalvik.system.DexFile and look 1123 // at the mCookie which is a DexFile vector. 1124 if (dex_elements_obj != nullptr) { 1125 mirror::ObjectArray<mirror::Object>* dex_elements = 1126 dex_elements_obj->AsObjectArray<mirror::Object>(); 1127 // Reverse order since we insert the parent at the front. 1128 for (int32_t i = dex_elements->GetLength() - 1; i >= 0; --i) { 1129 mirror::Object* const element = dex_elements->GetWithoutChecks(i); 1130 if (element == nullptr) { 1131 *error_msg = StringPrintf("Null dex element at index %d", i); 1132 return false; 1133 } 1134 mirror::String* const name = GetDexPathListElementName(soa, element); 1135 if (name == nullptr) { 1136 *error_msg = StringPrintf("Null name for dex element at index %d", i); 1137 return false; 1138 } 1139 out_dex_file_names->push_front(name); 1140 } 1141 } 1142 } 1143 class_loader = class_loader->GetParent(); 1144 } 1145 return true; 1146} 1147 1148class FixupArtMethodArrayVisitor : public ArtMethodVisitor { 1149 public: 1150 explicit FixupArtMethodArrayVisitor(const ImageHeader& header) : header_(header) {} 1151 1152 virtual void Visit(ArtMethod* method) SHARED_REQUIRES(Locks::mutator_lock_) { 1153 GcRoot<mirror::Class>* resolved_types = method->GetDexCacheResolvedTypes(sizeof(void*)); 1154 const bool is_copied = method->IsCopied(); 1155 if (resolved_types != nullptr) { 1156 bool in_image_space = false; 1157 if (kIsDebugBuild || is_copied) { 1158 in_image_space = header_.GetImageSection(ImageHeader::kSectionDexCacheArrays).Contains( 1159 reinterpret_cast<const uint8_t*>(resolved_types) - header_.GetImageBegin()); 1160 } 1161 // Must be in image space for non-miranda method. 1162 DCHECK(is_copied || in_image_space) 1163 << resolved_types << " is not in image starting at " 1164 << reinterpret_cast<void*>(header_.GetImageBegin()); 1165 if (!is_copied || in_image_space) { 1166 // Go through the array so that we don't need to do a slow map lookup. 1167 method->SetDexCacheResolvedTypes(*reinterpret_cast<GcRoot<mirror::Class>**>(resolved_types), 1168 sizeof(void*)); 1169 } 1170 } 1171 ArtMethod** resolved_methods = method->GetDexCacheResolvedMethods(sizeof(void*)); 1172 if (resolved_methods != nullptr) { 1173 bool in_image_space = false; 1174 if (kIsDebugBuild || is_copied) { 1175 in_image_space = header_.GetImageSection(ImageHeader::kSectionDexCacheArrays).Contains( 1176 reinterpret_cast<const uint8_t*>(resolved_methods) - header_.GetImageBegin()); 1177 } 1178 // Must be in image space for non-miranda method. 1179 DCHECK(is_copied || in_image_space) 1180 << resolved_methods << " is not in image starting at " 1181 << reinterpret_cast<void*>(header_.GetImageBegin()); 1182 if (!is_copied || in_image_space) { 1183 // Go through the array so that we don't need to do a slow map lookup. 1184 method->SetDexCacheResolvedMethods(*reinterpret_cast<ArtMethod***>(resolved_methods), 1185 sizeof(void*)); 1186 } 1187 } 1188 } 1189 1190 private: 1191 const ImageHeader& header_; 1192}; 1193 1194class VerifyClassInTableArtMethodVisitor : public ArtMethodVisitor { 1195 public: 1196 explicit VerifyClassInTableArtMethodVisitor(ClassTable* table) : table_(table) {} 1197 1198 virtual void Visit(ArtMethod* method) 1199 SHARED_REQUIRES(Locks::mutator_lock_, Locks::classlinker_classes_lock_) { 1200 mirror::Class* klass = method->GetDeclaringClass(); 1201 if (klass != nullptr && !Runtime::Current()->GetHeap()->ObjectIsInBootImageSpace(klass)) { 1202 CHECK_EQ(table_->LookupByDescriptor(klass), klass) << PrettyClass(klass); 1203 } 1204 } 1205 1206 private: 1207 ClassTable* const table_; 1208}; 1209 1210class VerifyDeclaringClassVisitor : public ArtMethodVisitor { 1211 public: 1212 VerifyDeclaringClassVisitor() SHARED_REQUIRES(Locks::mutator_lock_, Locks::heap_bitmap_lock_) 1213 : live_bitmap_(Runtime::Current()->GetHeap()->GetLiveBitmap()) {} 1214 1215 virtual void Visit(ArtMethod* method) 1216 SHARED_REQUIRES(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1217 mirror::Class* klass = method->GetDeclaringClassUnchecked(); 1218 if (klass != nullptr) { 1219 CHECK(live_bitmap_->Test(klass)) << "Image method has unmarked declaring class"; 1220 } 1221 } 1222 1223 private: 1224 gc::accounting::HeapBitmap* const live_bitmap_; 1225}; 1226 1227bool ClassLinker::UpdateAppImageClassLoadersAndDexCaches( 1228 gc::space::ImageSpace* space, 1229 Handle<mirror::ClassLoader> class_loader, 1230 Handle<mirror::ObjectArray<mirror::DexCache>> dex_caches, 1231 ClassTable::ClassSet* new_class_set, 1232 bool* out_forward_dex_cache_array, 1233 std::string* out_error_msg) { 1234 DCHECK(out_forward_dex_cache_array != nullptr); 1235 DCHECK(out_error_msg != nullptr); 1236 Thread* const self = Thread::Current(); 1237 gc::Heap* const heap = Runtime::Current()->GetHeap(); 1238 const ImageHeader& header = space->GetImageHeader(); 1239 { 1240 // Add image classes into the class table for the class loader, and fixup the dex caches and 1241 // class loader fields. 1242 WriterMutexLock mu(self, *Locks::classlinker_classes_lock_); 1243 ClassTable* table = InsertClassTableForClassLoader(class_loader.Get()); 1244 // Dex cache array fixup is all or nothing, we must reject app images that have mixed since we 1245 // rely on clobering the dex cache arrays in the image to forward to bss. 1246 size_t num_dex_caches_with_bss_arrays = 0; 1247 const size_t num_dex_caches = dex_caches->GetLength(); 1248 for (size_t i = 0; i < num_dex_caches; i++) { 1249 mirror::DexCache* const dex_cache = dex_caches->Get(i); 1250 const DexFile* const dex_file = dex_cache->GetDexFile(); 1251 const OatFile::OatDexFile* oat_dex_file = dex_file->GetOatDexFile(); 1252 if (oat_dex_file != nullptr && oat_dex_file->GetDexCacheArrays() != nullptr) { 1253 ++num_dex_caches_with_bss_arrays; 1254 } 1255 } 1256 *out_forward_dex_cache_array = num_dex_caches_with_bss_arrays != 0; 1257 if (*out_forward_dex_cache_array) { 1258 if (num_dex_caches_with_bss_arrays != num_dex_caches) { 1259 // Reject application image since we cannot forward only some of the dex cache arrays. 1260 // TODO: We could get around this by having a dedicated forwarding slot. It should be an 1261 // uncommon case. 1262 *out_error_msg = StringPrintf("Dex caches in bss does not match total: %zu vs %zu", 1263 num_dex_caches_with_bss_arrays, 1264 num_dex_caches); 1265 return false; 1266 } 1267 } 1268 // Only add the classes to the class loader after the points where we can return false. 1269 for (size_t i = 0; i < num_dex_caches; i++) { 1270 mirror::DexCache* const dex_cache = dex_caches->Get(i); 1271 const DexFile* const dex_file = dex_cache->GetDexFile(); 1272 const OatFile::OatDexFile* oat_dex_file = dex_file->GetOatDexFile(); 1273 if (oat_dex_file != nullptr && oat_dex_file->GetDexCacheArrays() != nullptr) { 1274 // If the oat file expects the dex cache arrays to be in the BSS, then allocate there and 1275 // copy over the arrays. 1276 DCHECK(dex_file != nullptr); 1277 const size_t num_strings = dex_file->NumStringIds(); 1278 const size_t num_types = dex_file->NumTypeIds(); 1279 const size_t num_methods = dex_file->NumMethodIds(); 1280 const size_t num_fields = dex_file->NumFieldIds(); 1281 CHECK_EQ(num_strings, dex_cache->NumStrings()); 1282 CHECK_EQ(num_types, dex_cache->NumResolvedTypes()); 1283 CHECK_EQ(num_methods, dex_cache->NumResolvedMethods()); 1284 CHECK_EQ(num_fields, dex_cache->NumResolvedFields()); 1285 DexCacheArraysLayout layout(image_pointer_size_, dex_file); 1286 uint8_t* const raw_arrays = oat_dex_file->GetDexCacheArrays(); 1287 // The space is not yet visible to the GC, we can avoid the read barriers and use 1288 // std::copy_n. 1289 if (num_strings != 0u) { 1290 GcRoot<mirror::String>* const image_resolved_strings = dex_cache->GetStrings(); 1291 GcRoot<mirror::String>* const strings = 1292 reinterpret_cast<GcRoot<mirror::String>*>(raw_arrays + layout.StringsOffset()); 1293 for (size_t j = 0; kIsDebugBuild && j < num_strings; ++j) { 1294 DCHECK(strings[j].IsNull()); 1295 } 1296 std::copy_n(image_resolved_strings, num_strings, strings); 1297 dex_cache->SetStrings(strings); 1298 } 1299 if (num_types != 0u) { 1300 GcRoot<mirror::Class>* const image_resolved_types = dex_cache->GetResolvedTypes(); 1301 GcRoot<mirror::Class>* const types = 1302 reinterpret_cast<GcRoot<mirror::Class>*>(raw_arrays + layout.TypesOffset()); 1303 for (size_t j = 0; kIsDebugBuild && j < num_types; ++j) { 1304 DCHECK(types[j].IsNull()); 1305 } 1306 std::copy_n(image_resolved_types, num_types, types); 1307 // Store a pointer to the new location for fast ArtMethod patching without requiring map. 1308 // This leaves random garbage at the start of the dex cache array, but nobody should ever 1309 // read from it again. 1310 *reinterpret_cast<GcRoot<mirror::Class>**>(image_resolved_types) = types; 1311 dex_cache->SetResolvedTypes(types); 1312 } 1313 if (num_methods != 0u) { 1314 ArtMethod** const methods = reinterpret_cast<ArtMethod**>( 1315 raw_arrays + layout.MethodsOffset()); 1316 ArtMethod** const image_resolved_methods = dex_cache->GetResolvedMethods(); 1317 for (size_t j = 0; kIsDebugBuild && j < num_methods; ++j) { 1318 DCHECK(methods[j] == nullptr); 1319 } 1320 std::copy_n(image_resolved_methods, num_methods, methods); 1321 // Store a pointer to the new location for fast ArtMethod patching without requiring map. 1322 *reinterpret_cast<ArtMethod***>(image_resolved_methods) = methods; 1323 dex_cache->SetResolvedMethods(methods); 1324 } 1325 if (num_fields != 0u) { 1326 ArtField** const fields = 1327 reinterpret_cast<ArtField**>(raw_arrays + layout.FieldsOffset()); 1328 for (size_t j = 0; kIsDebugBuild && j < num_fields; ++j) { 1329 DCHECK(fields[j] == nullptr); 1330 } 1331 std::copy_n(dex_cache->GetResolvedFields(), num_fields, fields); 1332 dex_cache->SetResolvedFields(fields); 1333 } 1334 } 1335 { 1336 WriterMutexLock mu2(self, dex_lock_); 1337 // Make sure to do this after we update the arrays since we store the resolved types array 1338 // in DexCacheData in RegisterDexFileLocked. We need the array pointer to be the one in the 1339 // BSS. 1340 mirror::DexCache* existing_dex_cache = FindDexCacheLocked(self, 1341 *dex_file, 1342 /*allow_failure*/true); 1343 CHECK(existing_dex_cache == nullptr); 1344 StackHandleScope<1> hs3(self); 1345 RegisterDexFileLocked(*dex_file, hs3.NewHandle(dex_cache)); 1346 } 1347 GcRoot<mirror::Class>* const types = dex_cache->GetResolvedTypes(); 1348 const size_t num_types = dex_cache->NumResolvedTypes(); 1349 if (new_class_set == nullptr) { 1350 for (int32_t j = 0; j < static_cast<int32_t>(num_types); j++) { 1351 // The image space is not yet added to the heap, avoid read barriers. 1352 mirror::Class* klass = types[j].Read(); 1353 // There may also be boot image classes, 1354 if (space->HasAddress(klass)) { 1355 DCHECK_NE(klass->GetStatus(), mirror::Class::kStatusError); 1356 // Update the class loader from the one in the image class loader to the one that loaded 1357 // the app image. 1358 klass->SetClassLoader(class_loader.Get()); 1359 // The resolved type could be from another dex cache, go through the dex cache just in 1360 // case. May be null for array classes. 1361 if (klass->GetDexCacheStrings() != nullptr) { 1362 DCHECK(!klass->IsArrayClass()); 1363 klass->SetDexCacheStrings(klass->GetDexCache()->GetStrings()); 1364 } 1365 // If there are multiple dex caches, there may be the same class multiple times 1366 // in different dex caches. Check for this since inserting will add duplicates 1367 // otherwise. 1368 if (num_dex_caches > 1) { 1369 mirror::Class* existing = table->LookupByDescriptor(klass); 1370 if (existing != nullptr) { 1371 DCHECK_EQ(existing, klass) << PrettyClass(klass); 1372 } else { 1373 table->Insert(klass); 1374 } 1375 } else { 1376 table->Insert(klass); 1377 } 1378 // Double checked VLOG to avoid overhead. 1379 if (VLOG_IS_ON(image)) { 1380 VLOG(image) << PrettyClass(klass) << " " << klass->GetStatus(); 1381 if (!klass->IsArrayClass()) { 1382 VLOG(image) << "From " << klass->GetDexCache()->GetDexFile()->GetBaseLocation(); 1383 } 1384 VLOG(image) << "Direct methods"; 1385 for (ArtMethod& m : klass->GetDirectMethods(sizeof(void*))) { 1386 VLOG(image) << PrettyMethod(&m); 1387 } 1388 VLOG(image) << "Virtual methods"; 1389 for (ArtMethod& m : klass->GetVirtualMethods(sizeof(void*))) { 1390 VLOG(image) << PrettyMethod(&m); 1391 } 1392 } 1393 } else { 1394 DCHECK(klass == nullptr || heap->ObjectIsInBootImageSpace(klass)) 1395 << klass << " " << PrettyClass(klass); 1396 } 1397 } 1398 } 1399 if (kIsDebugBuild) { 1400 for (int32_t j = 0; j < static_cast<int32_t>(num_types); j++) { 1401 // The image space is not yet added to the heap, avoid read barriers. 1402 mirror::Class* klass = types[j].Read(); 1403 if (space->HasAddress(klass)) { 1404 DCHECK_NE(klass->GetStatus(), mirror::Class::kStatusError); 1405 if (kIsDebugBuild) { 1406 if (new_class_set != nullptr) { 1407 auto it = new_class_set->Find(GcRoot<mirror::Class>(klass)); 1408 DCHECK(it != new_class_set->end()); 1409 DCHECK_EQ(it->Read(), klass); 1410 mirror::Class* super_class = klass->GetSuperClass(); 1411 if (super_class != nullptr && !heap->ObjectIsInBootImageSpace(super_class)) { 1412 auto it2 = new_class_set->Find(GcRoot<mirror::Class>(super_class)); 1413 DCHECK(it2 != new_class_set->end()); 1414 DCHECK_EQ(it2->Read(), super_class); 1415 } 1416 } else { 1417 DCHECK_EQ(table->LookupByDescriptor(klass), klass); 1418 mirror::Class* super_class = klass->GetSuperClass(); 1419 if (super_class != nullptr && !heap->ObjectIsInBootImageSpace(super_class)) { 1420 CHECK_EQ(table->LookupByDescriptor(super_class), super_class); 1421 } 1422 } 1423 } 1424 if (kIsDebugBuild) { 1425 for (ArtMethod& m : klass->GetDirectMethods(sizeof(void*))) { 1426 const void* code = m.GetEntryPointFromQuickCompiledCode(); 1427 const void* oat_code = m.IsInvokable() ? GetQuickOatCodeFor(&m) : code; 1428 if (!IsQuickResolutionStub(code) && 1429 !IsQuickGenericJniStub(code) && 1430 !IsQuickToInterpreterBridge(code) && 1431 !m.IsNative()) { 1432 DCHECK_EQ(code, oat_code) << PrettyMethod(&m); 1433 } 1434 } 1435 for (ArtMethod& m : klass->GetVirtualMethods(sizeof(void*))) { 1436 const void* code = m.GetEntryPointFromQuickCompiledCode(); 1437 const void* oat_code = m.IsInvokable() ? GetQuickOatCodeFor(&m) : code; 1438 if (!IsQuickResolutionStub(code) && 1439 !IsQuickGenericJniStub(code) && 1440 !IsQuickToInterpreterBridge(code) && 1441 !m.IsNative()) { 1442 DCHECK_EQ(code, oat_code) << PrettyMethod(&m); 1443 } 1444 } 1445 } 1446 } 1447 } 1448 } 1449 } 1450 } 1451 if (*out_forward_dex_cache_array) { 1452 ScopedTrace timing("Fixup ArtMethod dex cache arrays"); 1453 FixupArtMethodArrayVisitor visitor(header); 1454 header.VisitPackedArtMethods(&visitor, space->Begin(), sizeof(void*)); 1455 Runtime::Current()->GetHeap()->WriteBarrierEveryFieldOf(class_loader.Get()); 1456 } 1457 if (kVerifyArtMethodDeclaringClasses) { 1458 ScopedTrace timing("Verify declaring classes"); 1459 ReaderMutexLock rmu(self, *Locks::heap_bitmap_lock_); 1460 VerifyDeclaringClassVisitor visitor; 1461 header.VisitPackedArtMethods(&visitor, space->Begin(), sizeof(void*)); 1462 } 1463 return true; 1464} 1465 1466// Update the class loader and resolved string dex cache array of classes. Should only be used on 1467// classes in the image space. 1468class UpdateClassLoaderAndResolvedStringsVisitor { 1469 public: 1470 UpdateClassLoaderAndResolvedStringsVisitor(gc::space::ImageSpace* space, 1471 mirror::ClassLoader* class_loader, 1472 bool forward_strings) 1473 : space_(space), 1474 class_loader_(class_loader), 1475 forward_strings_(forward_strings) {} 1476 1477 bool operator()(mirror::Class* klass) const SHARED_REQUIRES(Locks::mutator_lock_) { 1478 if (forward_strings_) { 1479 GcRoot<mirror::String>* strings = klass->GetDexCacheStrings(); 1480 if (strings != nullptr) { 1481 DCHECK( 1482 space_->GetImageHeader().GetImageSection(ImageHeader::kSectionDexCacheArrays).Contains( 1483 reinterpret_cast<uint8_t*>(strings) - space_->Begin())) 1484 << "String dex cache array for " << PrettyClass(klass) << " is not in app image"; 1485 // Dex caches have already been updated, so take the strings pointer from there. 1486 GcRoot<mirror::String>* new_strings = klass->GetDexCache()->GetStrings(); 1487 DCHECK_NE(strings, new_strings); 1488 klass->SetDexCacheStrings(new_strings); 1489 } 1490 } 1491 // Finally, update class loader. 1492 klass->SetClassLoader(class_loader_); 1493 return true; 1494 } 1495 1496 gc::space::ImageSpace* const space_; 1497 mirror::ClassLoader* const class_loader_; 1498 const bool forward_strings_; 1499}; 1500 1501static std::unique_ptr<const DexFile> OpenOatDexFile(const OatFile* oat_file, 1502 const char* location, 1503 std::string* error_msg) 1504 SHARED_REQUIRES(Locks::mutator_lock_) { 1505 DCHECK(error_msg != nullptr); 1506 std::unique_ptr<const DexFile> dex_file; 1507 const OatFile::OatDexFile* oat_dex_file = oat_file->GetOatDexFile(location, nullptr); 1508 if (oat_dex_file == nullptr) { 1509 *error_msg = StringPrintf("Failed finding oat dex file for %s %s", 1510 oat_file->GetLocation().c_str(), 1511 location); 1512 return std::unique_ptr<const DexFile>(); 1513 } 1514 std::string inner_error_msg; 1515 dex_file = oat_dex_file->OpenDexFile(&inner_error_msg); 1516 if (dex_file == nullptr) { 1517 *error_msg = StringPrintf("Failed to open dex file %s from within oat file %s error '%s'", 1518 location, 1519 oat_file->GetLocation().c_str(), 1520 inner_error_msg.c_str()); 1521 return std::unique_ptr<const DexFile>(); 1522 } 1523 1524 if (dex_file->GetLocationChecksum() != oat_dex_file->GetDexFileLocationChecksum()) { 1525 *error_msg = StringPrintf("Checksums do not match for %s: %x vs %x", 1526 location, 1527 dex_file->GetLocationChecksum(), 1528 oat_dex_file->GetDexFileLocationChecksum()); 1529 return std::unique_ptr<const DexFile>(); 1530 } 1531 return dex_file; 1532} 1533 1534bool ClassLinker::OpenImageDexFiles(gc::space::ImageSpace* space, 1535 std::vector<std::unique_ptr<const DexFile>>* out_dex_files, 1536 std::string* error_msg) { 1537 ScopedAssertNoThreadSuspension nts(Thread::Current(), __FUNCTION__); 1538 const ImageHeader& header = space->GetImageHeader(); 1539 mirror::Object* dex_caches_object = header.GetImageRoot(ImageHeader::kDexCaches); 1540 DCHECK(dex_caches_object != nullptr); 1541 mirror::ObjectArray<mirror::DexCache>* dex_caches = 1542 dex_caches_object->AsObjectArray<mirror::DexCache>(); 1543 const OatFile* oat_file = space->GetOatFile(); 1544 for (int32_t i = 0; i < dex_caches->GetLength(); i++) { 1545 mirror::DexCache* dex_cache = dex_caches->Get(i); 1546 std::string dex_file_location(dex_cache->GetLocation()->ToModifiedUtf8()); 1547 std::unique_ptr<const DexFile> dex_file = OpenOatDexFile(oat_file, 1548 dex_file_location.c_str(), 1549 error_msg); 1550 if (dex_file == nullptr) { 1551 return false; 1552 } 1553 dex_cache->SetDexFile(dex_file.get()); 1554 out_dex_files->push_back(std::move(dex_file)); 1555 } 1556 return true; 1557} 1558 1559bool ClassLinker::AddImageSpace( 1560 gc::space::ImageSpace* space, 1561 Handle<mirror::ClassLoader> class_loader, 1562 jobjectArray dex_elements, 1563 const char* dex_location, 1564 std::vector<std::unique_ptr<const DexFile>>* out_dex_files, 1565 std::string* error_msg) { 1566 DCHECK(out_dex_files != nullptr); 1567 DCHECK(error_msg != nullptr); 1568 const uint64_t start_time = NanoTime(); 1569 const bool app_image = class_loader.Get() != nullptr; 1570 const ImageHeader& header = space->GetImageHeader(); 1571 mirror::Object* dex_caches_object = header.GetImageRoot(ImageHeader::kDexCaches); 1572 DCHECK(dex_caches_object != nullptr); 1573 Runtime* const runtime = Runtime::Current(); 1574 gc::Heap* const heap = runtime->GetHeap(); 1575 Thread* const self = Thread::Current(); 1576 StackHandleScope<2> hs(self); 1577 Handle<mirror::ObjectArray<mirror::DexCache>> dex_caches( 1578 hs.NewHandle(dex_caches_object->AsObjectArray<mirror::DexCache>())); 1579 Handle<mirror::ObjectArray<mirror::Class>> class_roots(hs.NewHandle( 1580 header.GetImageRoot(ImageHeader::kClassRoots)->AsObjectArray<mirror::Class>())); 1581 const OatFile* oat_file = space->GetOatFile(); 1582 std::unordered_set<mirror::ClassLoader*> image_class_loaders; 1583 // Check that the image is what we are expecting. 1584 if (image_pointer_size_ != space->GetImageHeader().GetPointerSize()) { 1585 *error_msg = StringPrintf("Application image pointer size does not match runtime: %zu vs %zu", 1586 static_cast<size_t>(space->GetImageHeader().GetPointerSize()), 1587 image_pointer_size_); 1588 return false; 1589 } 1590 DCHECK(class_roots.Get() != nullptr); 1591 if (class_roots->GetLength() != static_cast<int32_t>(kClassRootsMax)) { 1592 *error_msg = StringPrintf("Expected %d class roots but got %d", 1593 class_roots->GetLength(), 1594 static_cast<int32_t>(kClassRootsMax)); 1595 return false; 1596 } 1597 // Check against existing class roots to make sure they match the ones in the boot image. 1598 for (size_t i = 0; i < kClassRootsMax; i++) { 1599 if (class_roots->Get(i) != GetClassRoot(static_cast<ClassRoot>(i))) { 1600 *error_msg = "App image class roots must have pointer equality with runtime ones."; 1601 return false; 1602 } 1603 } 1604 if (oat_file->GetOatHeader().GetDexFileCount() != 1605 static_cast<uint32_t>(dex_caches->GetLength())) { 1606 *error_msg = "Dex cache count and dex file count mismatch while trying to initialize from " 1607 "image"; 1608 return false; 1609 } 1610 1611 StackHandleScope<1> hs2(self); 1612 MutableHandle<mirror::DexCache> h_dex_cache(hs2.NewHandle<mirror::DexCache>(nullptr)); 1613 for (int32_t i = 0; i < dex_caches->GetLength(); i++) { 1614 h_dex_cache.Assign(dex_caches->Get(i)); 1615 std::string dex_file_location(h_dex_cache->GetLocation()->ToModifiedUtf8()); 1616 // TODO: Only store qualified paths. 1617 // If non qualified, qualify it. 1618 if (dex_file_location.find('/') == std::string::npos) { 1619 std::string dex_location_path = dex_location; 1620 const size_t pos = dex_location_path.find_last_of('/'); 1621 CHECK_NE(pos, std::string::npos); 1622 dex_location_path = dex_location_path.substr(0, pos + 1); // Keep trailing '/' 1623 dex_file_location = dex_location_path + dex_file_location; 1624 } 1625 std::unique_ptr<const DexFile> dex_file = OpenOatDexFile(oat_file, 1626 dex_file_location.c_str(), 1627 error_msg); 1628 if (dex_file == nullptr) { 1629 return false; 1630 } 1631 1632 if (app_image) { 1633 // The current dex file field is bogus, overwrite it so that we can get the dex file in the 1634 // loop below. 1635 h_dex_cache->SetDexFile(dex_file.get()); 1636 // Check that each class loader resolved the same way. 1637 // TODO: Store image class loaders as image roots. 1638 GcRoot<mirror::Class>* const types = h_dex_cache->GetResolvedTypes(); 1639 for (int32_t j = 0, num_types = h_dex_cache->NumResolvedTypes(); j < num_types; j++) { 1640 mirror::Class* klass = types[j].Read(); 1641 if (klass != nullptr) { 1642 DCHECK_NE(klass->GetStatus(), mirror::Class::kStatusError); 1643 mirror::ClassLoader* image_class_loader = klass->GetClassLoader(); 1644 image_class_loaders.insert(image_class_loader); 1645 } 1646 } 1647 } else { 1648 if (kSanityCheckObjects) { 1649 SanityCheckArtMethodPointerArray(h_dex_cache->GetResolvedMethods(), 1650 h_dex_cache->NumResolvedMethods(), 1651 image_pointer_size_, 1652 heap->GetBootImageSpaces()); 1653 } 1654 // Register dex files, keep track of existing ones that are conflicts. 1655 AppendToBootClassPath(*dex_file.get(), h_dex_cache); 1656 } 1657 out_dex_files->push_back(std::move(dex_file)); 1658 } 1659 1660 if (app_image) { 1661 ScopedObjectAccessUnchecked soa(Thread::Current()); 1662 // Check that the class loader resolves the same way as the ones in the image. 1663 // Image class loader [A][B][C][image dex files] 1664 // Class loader = [???][dex_elements][image dex files] 1665 // Need to ensure that [???][dex_elements] == [A][B][C]. 1666 // For each class loader, PathClassLoader, the laoder checks the parent first. Also the logic 1667 // for PathClassLoader does this by looping through the array of dex files. To ensure they 1668 // resolve the same way, simply flatten the hierarchy in the way the resolution order would be, 1669 // and check that the dex file names are the same. 1670 for (mirror::ClassLoader* image_class_loader : image_class_loaders) { 1671 if (IsBootClassLoader(soa, image_class_loader)) { 1672 // The dex cache can reference types from the boot class loader. 1673 continue; 1674 } 1675 std::list<mirror::String*> image_dex_file_names; 1676 std::string temp_error_msg; 1677 if (!FlattenPathClassLoader(image_class_loader, &image_dex_file_names, &temp_error_msg)) { 1678 *error_msg = StringPrintf("Failed to flatten image class loader hierarchy '%s'", 1679 temp_error_msg.c_str()); 1680 return false; 1681 } 1682 std::list<mirror::String*> loader_dex_file_names; 1683 if (!FlattenPathClassLoader(class_loader.Get(), &loader_dex_file_names, &temp_error_msg)) { 1684 *error_msg = StringPrintf("Failed to flatten class loader hierarchy '%s'", 1685 temp_error_msg.c_str()); 1686 return false; 1687 } 1688 // Add the temporary dex path list elements at the end. 1689 auto* elements = soa.Decode<mirror::ObjectArray<mirror::Object>*>(dex_elements); 1690 for (size_t i = 0, num_elems = elements->GetLength(); i < num_elems; ++i) { 1691 mirror::Object* element = elements->GetWithoutChecks(i); 1692 if (element != nullptr) { 1693 // If we are somewhere in the middle of the array, there may be nulls at the end. 1694 loader_dex_file_names.push_back(GetDexPathListElementName(soa, element)); 1695 } 1696 } 1697 // Ignore the number of image dex files since we are adding those to the class loader anyways. 1698 CHECK_GE(static_cast<size_t>(image_dex_file_names.size()), 1699 static_cast<size_t>(dex_caches->GetLength())); 1700 size_t image_count = image_dex_file_names.size() - dex_caches->GetLength(); 1701 // Check that the dex file names match. 1702 bool equal = image_count == loader_dex_file_names.size(); 1703 if (equal) { 1704 auto it1 = image_dex_file_names.begin(); 1705 auto it2 = loader_dex_file_names.begin(); 1706 for (size_t i = 0; equal && i < image_count; ++i, ++it1, ++it2) { 1707 equal = equal && (*it1)->Equals(*it2); 1708 } 1709 } 1710 if (!equal) { 1711 VLOG(image) << "Image dex files " << image_dex_file_names.size(); 1712 for (mirror::String* name : image_dex_file_names) { 1713 VLOG(image) << name->ToModifiedUtf8(); 1714 } 1715 VLOG(image) << "Loader dex files " << loader_dex_file_names.size(); 1716 for (mirror::String* name : loader_dex_file_names) { 1717 VLOG(image) << name->ToModifiedUtf8(); 1718 } 1719 *error_msg = "Rejecting application image due to class loader mismatch"; 1720 // Ignore class loader mismatch for now since these would just use possibly incorrect 1721 // oat code anyways. The structural class check should be done in the parent. 1722 } 1723 } 1724 } 1725 1726 if (kSanityCheckObjects) { 1727 for (int32_t i = 0; i < dex_caches->GetLength(); i++) { 1728 auto* dex_cache = dex_caches->Get(i); 1729 for (size_t j = 0; j < dex_cache->NumResolvedFields(); ++j) { 1730 auto* field = dex_cache->GetResolvedField(j, image_pointer_size_); 1731 if (field != nullptr) { 1732 CHECK(field->GetDeclaringClass()->GetClass() != nullptr); 1733 } 1734 } 1735 } 1736 if (!app_image) { 1737 heap->VisitObjects(SanityCheckObjectsCallback, nullptr); 1738 } 1739 } 1740 1741 // Set entry point to interpreter if in InterpretOnly mode. 1742 if (!runtime->IsAotCompiler() && runtime->GetInstrumentation()->InterpretOnly()) { 1743 SetInterpreterEntrypointArtMethodVisitor visitor(image_pointer_size_); 1744 header.VisitPackedArtMethods(&visitor, space->Begin(), image_pointer_size_); 1745 } 1746 1747 ClassTable* class_table = nullptr; 1748 { 1749 WriterMutexLock mu(self, *Locks::classlinker_classes_lock_); 1750 class_table = InsertClassTableForClassLoader(class_loader.Get()); 1751 } 1752 // If we have a class table section, read it and use it for verification in 1753 // UpdateAppImageClassLoadersAndDexCaches. 1754 ClassTable::ClassSet temp_set; 1755 const ImageSection& class_table_section = header.GetImageSection(ImageHeader::kSectionClassTable); 1756 const bool added_class_table = class_table_section.Size() > 0u; 1757 if (added_class_table) { 1758 const uint64_t start_time2 = NanoTime(); 1759 size_t read_count = 0; 1760 temp_set = ClassTable::ClassSet(space->Begin() + class_table_section.Offset(), 1761 /*make copy*/false, 1762 &read_count); 1763 if (!app_image) { 1764 dex_cache_boot_image_class_lookup_required_ = false; 1765 } 1766 VLOG(image) << "Adding class table classes took " << PrettyDuration(NanoTime() - start_time2); 1767 } 1768 if (app_image) { 1769 bool forward_dex_cache_arrays = false; 1770 if (!UpdateAppImageClassLoadersAndDexCaches(space, 1771 class_loader, 1772 dex_caches, 1773 added_class_table ? &temp_set : nullptr, 1774 /*out*/&forward_dex_cache_arrays, 1775 /*out*/error_msg)) { 1776 return false; 1777 } 1778 // Update class loader and resolved strings. If added_class_table is false, the resolved 1779 // strings were forwarded UpdateAppImageClassLoadersAndDexCaches. 1780 UpdateClassLoaderAndResolvedStringsVisitor visitor(space, 1781 class_loader.Get(), 1782 forward_dex_cache_arrays); 1783 if (added_class_table) { 1784 for (GcRoot<mirror::Class>& root : temp_set) { 1785 visitor(root.Read()); 1786 } 1787 } 1788 // forward_dex_cache_arrays is true iff we copied all of the dex cache arrays into the .bss. 1789 // In this case, madvise away the dex cache arrays section of the image to reduce RAM usage and 1790 // mark as PROT_NONE to catch any invalid accesses. 1791 if (forward_dex_cache_arrays) { 1792 const ImageSection& dex_cache_section = header.GetImageSection( 1793 ImageHeader::kSectionDexCacheArrays); 1794 uint8_t* section_begin = AlignUp(space->Begin() + dex_cache_section.Offset(), kPageSize); 1795 uint8_t* section_end = AlignDown(space->Begin() + dex_cache_section.End(), kPageSize); 1796 if (section_begin < section_end) { 1797 madvise(section_begin, section_end - section_begin, MADV_DONTNEED); 1798 mprotect(section_begin, section_end - section_begin, PROT_NONE); 1799 VLOG(image) << "Released and protected dex cache array image section from " 1800 << reinterpret_cast<const void*>(section_begin) << "-" 1801 << reinterpret_cast<const void*>(section_end); 1802 } 1803 } 1804 } 1805 if (added_class_table) { 1806 WriterMutexLock mu(self, *Locks::classlinker_classes_lock_); 1807 class_table->AddClassSet(std::move(temp_set)); 1808 } 1809 if (kIsDebugBuild && app_image) { 1810 // This verification needs to happen after the classes have been added to the class loader. 1811 // Since it ensures classes are in the class table. 1812 VerifyClassInTableArtMethodVisitor visitor2(class_table); 1813 header.VisitPackedArtMethods(&visitor2, space->Begin(), sizeof(void*)); 1814 } 1815 VLOG(class_linker) << "Adding image space took " << PrettyDuration(NanoTime() - start_time); 1816 return true; 1817} 1818 1819bool ClassLinker::ClassInClassTable(mirror::Class* klass) { 1820 ClassTable* const class_table = ClassTableForClassLoader(klass->GetClassLoader()); 1821 return class_table != nullptr && class_table->Contains(klass); 1822} 1823 1824void ClassLinker::VisitClassRoots(RootVisitor* visitor, VisitRootFlags flags) { 1825 // Acquire tracing_enabled before locking class linker lock to prevent lock order violation. Since 1826 // enabling tracing requires the mutator lock, there are no race conditions here. 1827 const bool tracing_enabled = Trace::IsTracingEnabled(); 1828 Thread* const self = Thread::Current(); 1829 WriterMutexLock mu(self, *Locks::classlinker_classes_lock_); 1830 BufferedRootVisitor<kDefaultBufferedRootCount> buffered_visitor( 1831 visitor, RootInfo(kRootStickyClass)); 1832 if ((flags & kVisitRootFlagAllRoots) != 0) { 1833 // Argument for how root visiting deals with ArtField and ArtMethod roots. 1834 // There is 3 GC cases to handle: 1835 // Non moving concurrent: 1836 // This case is easy to handle since the reference members of ArtMethod and ArtFields are held 1837 // live by the class and class roots. 1838 // 1839 // Moving non-concurrent: 1840 // This case needs to call visit VisitNativeRoots in case the classes or dex cache arrays move. 1841 // To prevent missing roots, this case needs to ensure that there is no 1842 // suspend points between the point which we allocate ArtMethod arrays and place them in a 1843 // class which is in the class table. 1844 // 1845 // Moving concurrent: 1846 // Need to make sure to not copy ArtMethods without doing read barriers since the roots are 1847 // marked concurrently and we don't hold the classlinker_classes_lock_ when we do the copy. 1848 boot_class_table_.VisitRoots(buffered_visitor); 1849 1850 // If tracing is enabled, then mark all the class loaders to prevent unloading. 1851 if ((flags & kVisitRootFlagClassLoader) != 0 || tracing_enabled) { 1852 for (const ClassLoaderData& data : class_loaders_) { 1853 GcRoot<mirror::Object> root(GcRoot<mirror::Object>(self->DecodeJObject(data.weak_root))); 1854 root.VisitRoot(visitor, RootInfo(kRootVMInternal)); 1855 } 1856 } 1857 } else if ((flags & kVisitRootFlagNewRoots) != 0) { 1858 for (auto& root : new_class_roots_) { 1859 mirror::Class* old_ref = root.Read<kWithoutReadBarrier>(); 1860 root.VisitRoot(visitor, RootInfo(kRootStickyClass)); 1861 mirror::Class* new_ref = root.Read<kWithoutReadBarrier>(); 1862 // Concurrent moving GC marked new roots through the to-space invariant. 1863 CHECK_EQ(new_ref, old_ref); 1864 } 1865 } 1866 buffered_visitor.Flush(); // Flush before clearing new_class_roots_. 1867 if ((flags & kVisitRootFlagClearRootLog) != 0) { 1868 new_class_roots_.clear(); 1869 } 1870 if ((flags & kVisitRootFlagStartLoggingNewRoots) != 0) { 1871 log_new_class_table_roots_ = true; 1872 } else if ((flags & kVisitRootFlagStopLoggingNewRoots) != 0) { 1873 log_new_class_table_roots_ = false; 1874 } 1875 // We deliberately ignore the class roots in the image since we 1876 // handle image roots by using the MS/CMS rescanning of dirty cards. 1877} 1878 1879// Keep in sync with InitCallback. Anything we visit, we need to 1880// reinit references to when reinitializing a ClassLinker from a 1881// mapped image. 1882void ClassLinker::VisitRoots(RootVisitor* visitor, VisitRootFlags flags) { 1883 class_roots_.VisitRootIfNonNull(visitor, RootInfo(kRootVMInternal)); 1884 VisitClassRoots(visitor, flags); 1885 array_iftable_.VisitRootIfNonNull(visitor, RootInfo(kRootVMInternal)); 1886 // Instead of visiting the find_array_class_cache_ drop it so that it doesn't prevent class 1887 // unloading if we are marking roots. 1888 DropFindArrayClassCache(); 1889} 1890 1891class VisitClassLoaderClassesVisitor : public ClassLoaderVisitor { 1892 public: 1893 explicit VisitClassLoaderClassesVisitor(ClassVisitor* visitor) 1894 : visitor_(visitor), 1895 done_(false) {} 1896 1897 void Visit(mirror::ClassLoader* class_loader) 1898 SHARED_REQUIRES(Locks::classlinker_classes_lock_, Locks::mutator_lock_) OVERRIDE { 1899 ClassTable* const class_table = class_loader->GetClassTable(); 1900 if (!done_ && class_table != nullptr && !class_table->Visit(*visitor_)) { 1901 // If the visitor ClassTable returns false it means that we don't need to continue. 1902 done_ = true; 1903 } 1904 } 1905 1906 private: 1907 ClassVisitor* const visitor_; 1908 // If done is true then we don't need to do any more visiting. 1909 bool done_; 1910}; 1911 1912void ClassLinker::VisitClassesInternal(ClassVisitor* visitor) { 1913 if (boot_class_table_.Visit(*visitor)) { 1914 VisitClassLoaderClassesVisitor loader_visitor(visitor); 1915 VisitClassLoaders(&loader_visitor); 1916 } 1917} 1918 1919void ClassLinker::VisitClasses(ClassVisitor* visitor) { 1920 if (dex_cache_boot_image_class_lookup_required_) { 1921 AddBootImageClassesToClassTable(); 1922 } 1923 Thread* const self = Thread::Current(); 1924 ReaderMutexLock mu(self, *Locks::classlinker_classes_lock_); 1925 // Not safe to have thread suspension when we are holding a lock. 1926 if (self != nullptr) { 1927 ScopedAssertNoThreadSuspension nts(self, __FUNCTION__); 1928 VisitClassesInternal(visitor); 1929 } else { 1930 VisitClassesInternal(visitor); 1931 } 1932} 1933 1934class GetClassesInToVector : public ClassVisitor { 1935 public: 1936 bool operator()(mirror::Class* klass) OVERRIDE { 1937 classes_.push_back(klass); 1938 return true; 1939 } 1940 std::vector<mirror::Class*> classes_; 1941}; 1942 1943class GetClassInToObjectArray : public ClassVisitor { 1944 public: 1945 explicit GetClassInToObjectArray(mirror::ObjectArray<mirror::Class>* arr) 1946 : arr_(arr), index_(0) {} 1947 1948 bool operator()(mirror::Class* klass) OVERRIDE SHARED_REQUIRES(Locks::mutator_lock_) { 1949 ++index_; 1950 if (index_ <= arr_->GetLength()) { 1951 arr_->Set(index_ - 1, klass); 1952 return true; 1953 } 1954 return false; 1955 } 1956 1957 bool Succeeded() const SHARED_REQUIRES(Locks::mutator_lock_) { 1958 return index_ <= arr_->GetLength(); 1959 } 1960 1961 private: 1962 mirror::ObjectArray<mirror::Class>* const arr_; 1963 int32_t index_; 1964}; 1965 1966void ClassLinker::VisitClassesWithoutClassesLock(ClassVisitor* visitor) { 1967 // TODO: it may be possible to avoid secondary storage if we iterate over dex caches. The problem 1968 // is avoiding duplicates. 1969 Thread* const self = Thread::Current(); 1970 if (!kMovingClasses) { 1971 ScopedAssertNoThreadSuspension nts(self, __FUNCTION__); 1972 GetClassesInToVector accumulator; 1973 VisitClasses(&accumulator); 1974 for (mirror::Class* klass : accumulator.classes_) { 1975 if (!visitor->operator()(klass)) { 1976 return; 1977 } 1978 } 1979 } else { 1980 StackHandleScope<1> hs(self); 1981 auto classes = hs.NewHandle<mirror::ObjectArray<mirror::Class>>(nullptr); 1982 // We size the array assuming classes won't be added to the class table during the visit. 1983 // If this assumption fails we iterate again. 1984 while (true) { 1985 size_t class_table_size; 1986 { 1987 ReaderMutexLock mu(self, *Locks::classlinker_classes_lock_); 1988 // Add 100 in case new classes get loaded when we are filling in the object array. 1989 class_table_size = NumZygoteClasses() + NumNonZygoteClasses() + 100; 1990 } 1991 mirror::Class* class_type = mirror::Class::GetJavaLangClass(); 1992 mirror::Class* array_of_class = FindArrayClass(self, &class_type); 1993 classes.Assign( 1994 mirror::ObjectArray<mirror::Class>::Alloc(self, array_of_class, class_table_size)); 1995 CHECK(classes.Get() != nullptr); // OOME. 1996 GetClassInToObjectArray accumulator(classes.Get()); 1997 VisitClasses(&accumulator); 1998 if (accumulator.Succeeded()) { 1999 break; 2000 } 2001 } 2002 for (int32_t i = 0; i < classes->GetLength(); ++i) { 2003 // If the class table shrank during creation of the clases array we expect null elements. If 2004 // the class table grew then the loop repeats. If classes are created after the loop has 2005 // finished then we don't visit. 2006 mirror::Class* klass = classes->Get(i); 2007 if (klass != nullptr && !visitor->operator()(klass)) { 2008 return; 2009 } 2010 } 2011 } 2012} 2013 2014ClassLinker::~ClassLinker() { 2015 mirror::Class::ResetClass(); 2016 mirror::Constructor::ResetClass(); 2017 mirror::Field::ResetClass(); 2018 mirror::Method::ResetClass(); 2019 mirror::Reference::ResetClass(); 2020 mirror::StackTraceElement::ResetClass(); 2021 mirror::String::ResetClass(); 2022 mirror::Throwable::ResetClass(); 2023 mirror::BooleanArray::ResetArrayClass(); 2024 mirror::ByteArray::ResetArrayClass(); 2025 mirror::CharArray::ResetArrayClass(); 2026 mirror::Constructor::ResetArrayClass(); 2027 mirror::DoubleArray::ResetArrayClass(); 2028 mirror::Field::ResetArrayClass(); 2029 mirror::FloatArray::ResetArrayClass(); 2030 mirror::Method::ResetArrayClass(); 2031 mirror::IntArray::ResetArrayClass(); 2032 mirror::LongArray::ResetArrayClass(); 2033 mirror::ShortArray::ResetArrayClass(); 2034 Thread* const self = Thread::Current(); 2035 for (const ClassLoaderData& data : class_loaders_) { 2036 DeleteClassLoader(self, data); 2037 } 2038 class_loaders_.clear(); 2039} 2040 2041void ClassLinker::DeleteClassLoader(Thread* self, const ClassLoaderData& data) { 2042 Runtime* const runtime = Runtime::Current(); 2043 JavaVMExt* const vm = runtime->GetJavaVM(); 2044 vm->DeleteWeakGlobalRef(self, data.weak_root); 2045 // Notify the JIT that we need to remove the methods and/or profiling info. 2046 if (runtime->GetJit() != nullptr) { 2047 jit::JitCodeCache* code_cache = runtime->GetJit()->GetCodeCache(); 2048 if (code_cache != nullptr) { 2049 code_cache->RemoveMethodsIn(self, *data.allocator); 2050 } 2051 } 2052 delete data.allocator; 2053 delete data.class_table; 2054} 2055 2056mirror::PointerArray* ClassLinker::AllocPointerArray(Thread* self, size_t length) { 2057 return down_cast<mirror::PointerArray*>(image_pointer_size_ == 8u ? 2058 static_cast<mirror::Array*>(mirror::LongArray::Alloc(self, length)) : 2059 static_cast<mirror::Array*>(mirror::IntArray::Alloc(self, length))); 2060} 2061 2062mirror::DexCache* ClassLinker::AllocDexCache(Thread* self, 2063 const DexFile& dex_file, 2064 LinearAlloc* linear_alloc) { 2065 StackHandleScope<6> hs(self); 2066 auto dex_cache(hs.NewHandle(down_cast<mirror::DexCache*>( 2067 GetClassRoot(kJavaLangDexCache)->AllocObject(self)))); 2068 if (dex_cache.Get() == nullptr) { 2069 self->AssertPendingOOMException(); 2070 return nullptr; 2071 } 2072 auto location(hs.NewHandle(intern_table_->InternStrong(dex_file.GetLocation().c_str()))); 2073 if (location.Get() == nullptr) { 2074 self->AssertPendingOOMException(); 2075 return nullptr; 2076 } 2077 DexCacheArraysLayout layout(image_pointer_size_, &dex_file); 2078 uint8_t* raw_arrays = nullptr; 2079 if (dex_file.GetOatDexFile() != nullptr && 2080 dex_file.GetOatDexFile()->GetDexCacheArrays() != nullptr) { 2081 raw_arrays = dex_file.GetOatDexFile()->GetDexCacheArrays(); 2082 } else if (dex_file.NumStringIds() != 0u || dex_file.NumTypeIds() != 0u || 2083 dex_file.NumMethodIds() != 0u || dex_file.NumFieldIds() != 0u) { 2084 // NOTE: We "leak" the raw_arrays because we never destroy the dex cache. 2085 DCHECK(image_pointer_size_ == 4u || image_pointer_size_ == 8u); 2086 // Zero-initialized. 2087 raw_arrays = reinterpret_cast<uint8_t*>(linear_alloc->Alloc(self, layout.Size())); 2088 } 2089 GcRoot<mirror::String>* strings = (dex_file.NumStringIds() == 0u) ? nullptr : 2090 reinterpret_cast<GcRoot<mirror::String>*>(raw_arrays + layout.StringsOffset()); 2091 GcRoot<mirror::Class>* types = (dex_file.NumTypeIds() == 0u) ? nullptr : 2092 reinterpret_cast<GcRoot<mirror::Class>*>(raw_arrays + layout.TypesOffset()); 2093 ArtMethod** methods = (dex_file.NumMethodIds() == 0u) ? nullptr : 2094 reinterpret_cast<ArtMethod**>(raw_arrays + layout.MethodsOffset()); 2095 ArtField** fields = (dex_file.NumFieldIds() == 0u) ? nullptr : 2096 reinterpret_cast<ArtField**>(raw_arrays + layout.FieldsOffset()); 2097 if (kIsDebugBuild) { 2098 // Sanity check to make sure all the dex cache arrays are empty. b/28992179 2099 for (size_t i = 0; i < dex_file.NumStringIds(); ++i) { 2100 CHECK(strings[i].Read<kWithoutReadBarrier>() == nullptr); 2101 } 2102 for (size_t i = 0; i < dex_file.NumTypeIds(); ++i) { 2103 CHECK(types[i].Read<kWithoutReadBarrier>() == nullptr); 2104 } 2105 for (size_t i = 0; i < dex_file.NumMethodIds(); ++i) { 2106 CHECK(mirror::DexCache::GetElementPtrSize(methods, i, image_pointer_size_) == nullptr); 2107 } 2108 for (size_t i = 0; i < dex_file.NumFieldIds(); ++i) { 2109 CHECK(mirror::DexCache::GetElementPtrSize(fields, i, image_pointer_size_) == nullptr); 2110 } 2111 } 2112 dex_cache->Init(&dex_file, 2113 location.Get(), 2114 strings, 2115 dex_file.NumStringIds(), 2116 types, 2117 dex_file.NumTypeIds(), 2118 methods, 2119 dex_file.NumMethodIds(), 2120 fields, 2121 dex_file.NumFieldIds(), 2122 image_pointer_size_); 2123 return dex_cache.Get(); 2124} 2125 2126mirror::Class* ClassLinker::AllocClass(Thread* self, mirror::Class* java_lang_Class, 2127 uint32_t class_size) { 2128 DCHECK_GE(class_size, sizeof(mirror::Class)); 2129 gc::Heap* heap = Runtime::Current()->GetHeap(); 2130 mirror::Class::InitializeClassVisitor visitor(class_size); 2131 mirror::Object* k = kMovingClasses ? 2132 heap->AllocObject<true>(self, java_lang_Class, class_size, visitor) : 2133 heap->AllocNonMovableObject<true>(self, java_lang_Class, class_size, visitor); 2134 if (UNLIKELY(k == nullptr)) { 2135 self->AssertPendingOOMException(); 2136 return nullptr; 2137 } 2138 return k->AsClass(); 2139} 2140 2141mirror::Class* ClassLinker::AllocClass(Thread* self, uint32_t class_size) { 2142 return AllocClass(self, GetClassRoot(kJavaLangClass), class_size); 2143} 2144 2145mirror::ObjectArray<mirror::StackTraceElement>* ClassLinker::AllocStackTraceElementArray( 2146 Thread* self, 2147 size_t length) { 2148 return mirror::ObjectArray<mirror::StackTraceElement>::Alloc( 2149 self, GetClassRoot(kJavaLangStackTraceElementArrayClass), length); 2150} 2151 2152mirror::Class* ClassLinker::EnsureResolved(Thread* self, 2153 const char* descriptor, 2154 mirror::Class* klass) { 2155 DCHECK(klass != nullptr); 2156 2157 // For temporary classes we must wait for them to be retired. 2158 if (init_done_ && klass->IsTemp()) { 2159 CHECK(!klass->IsResolved()); 2160 if (klass->IsErroneous()) { 2161 ThrowEarlierClassFailure(klass); 2162 return nullptr; 2163 } 2164 StackHandleScope<1> hs(self); 2165 Handle<mirror::Class> h_class(hs.NewHandle(klass)); 2166 ObjectLock<mirror::Class> lock(self, h_class); 2167 // Loop and wait for the resolving thread to retire this class. 2168 while (!h_class->IsRetired() && !h_class->IsErroneous()) { 2169 lock.WaitIgnoringInterrupts(); 2170 } 2171 if (h_class->IsErroneous()) { 2172 ThrowEarlierClassFailure(h_class.Get()); 2173 return nullptr; 2174 } 2175 CHECK(h_class->IsRetired()); 2176 // Get the updated class from class table. 2177 klass = LookupClass(self, descriptor, ComputeModifiedUtf8Hash(descriptor), 2178 h_class.Get()->GetClassLoader()); 2179 } 2180 2181 // Wait for the class if it has not already been linked. 2182 size_t index = 0; 2183 // Maximum number of yield iterations until we start sleeping. 2184 static const size_t kNumYieldIterations = 1000; 2185 // How long each sleep is in us. 2186 static const size_t kSleepDurationUS = 1000; // 1 ms. 2187 while (!klass->IsResolved() && !klass->IsErroneous()) { 2188 StackHandleScope<1> hs(self); 2189 HandleWrapper<mirror::Class> h_class(hs.NewHandleWrapper(&klass)); 2190 { 2191 ObjectTryLock<mirror::Class> lock(self, h_class); 2192 // Can not use a monitor wait here since it may block when returning and deadlock if another 2193 // thread has locked klass. 2194 if (lock.Acquired()) { 2195 // Check for circular dependencies between classes, the lock is required for SetStatus. 2196 if (!h_class->IsResolved() && h_class->GetClinitThreadId() == self->GetTid()) { 2197 ThrowClassCircularityError(h_class.Get()); 2198 mirror::Class::SetStatus(h_class, mirror::Class::kStatusError, self); 2199 return nullptr; 2200 } 2201 } 2202 } 2203 { 2204 // Handle wrapper deals with klass moving. 2205 ScopedThreadSuspension sts(self, kSuspended); 2206 if (index < kNumYieldIterations) { 2207 sched_yield(); 2208 } else { 2209 usleep(kSleepDurationUS); 2210 } 2211 } 2212 ++index; 2213 } 2214 2215 if (klass->IsErroneous()) { 2216 ThrowEarlierClassFailure(klass); 2217 return nullptr; 2218 } 2219 // Return the loaded class. No exceptions should be pending. 2220 CHECK(klass->IsResolved()) << PrettyClass(klass); 2221 self->AssertNoPendingException(); 2222 return klass; 2223} 2224 2225typedef std::pair<const DexFile*, const DexFile::ClassDef*> ClassPathEntry; 2226 2227// Search a collection of DexFiles for a descriptor 2228ClassPathEntry FindInClassPath(const char* descriptor, 2229 size_t hash, const std::vector<const DexFile*>& class_path) { 2230 for (const DexFile* dex_file : class_path) { 2231 const DexFile::ClassDef* dex_class_def = dex_file->FindClassDef(descriptor, hash); 2232 if (dex_class_def != nullptr) { 2233 return ClassPathEntry(dex_file, dex_class_def); 2234 } 2235 } 2236 return ClassPathEntry(nullptr, nullptr); 2237} 2238 2239bool ClassLinker::FindClassInPathClassLoader(ScopedObjectAccessAlreadyRunnable& soa, 2240 Thread* self, 2241 const char* descriptor, 2242 size_t hash, 2243 Handle<mirror::ClassLoader> class_loader, 2244 mirror::Class** result) { 2245 // Termination case: boot class-loader. 2246 if (IsBootClassLoader(soa, class_loader.Get())) { 2247 // The boot class loader, search the boot class path. 2248 ClassPathEntry pair = FindInClassPath(descriptor, hash, boot_class_path_); 2249 if (pair.second != nullptr) { 2250 mirror::Class* klass = LookupClass(self, descriptor, hash, nullptr); 2251 if (klass != nullptr) { 2252 *result = EnsureResolved(self, descriptor, klass); 2253 } else { 2254 *result = DefineClass(self, 2255 descriptor, 2256 hash, 2257 ScopedNullHandle<mirror::ClassLoader>(), 2258 *pair.first, 2259 *pair.second); 2260 } 2261 if (*result == nullptr) { 2262 CHECK(self->IsExceptionPending()) << descriptor; 2263 self->ClearException(); 2264 } 2265 } else { 2266 *result = nullptr; 2267 } 2268 return true; 2269 } 2270 2271 // Unsupported class-loader? 2272 if (class_loader->GetClass() != 2273 soa.Decode<mirror::Class*>(WellKnownClasses::dalvik_system_PathClassLoader)) { 2274 *result = nullptr; 2275 return false; 2276 } 2277 2278 // Handles as RegisterDexFile may allocate dex caches (and cause thread suspension). 2279 StackHandleScope<4> hs(self); 2280 Handle<mirror::ClassLoader> h_parent(hs.NewHandle(class_loader->GetParent())); 2281 bool recursive_result = FindClassInPathClassLoader(soa, self, descriptor, hash, h_parent, result); 2282 2283 if (!recursive_result) { 2284 // Something wrong up the chain. 2285 return false; 2286 } 2287 2288 if (*result != nullptr) { 2289 // Found the class up the chain. 2290 return true; 2291 } 2292 2293 // Handle this step. 2294 // Handle as if this is the child PathClassLoader. 2295 // The class loader is a PathClassLoader which inherits from BaseDexClassLoader. 2296 // We need to get the DexPathList and loop through it. 2297 ArtField* const cookie_field = soa.DecodeField(WellKnownClasses::dalvik_system_DexFile_cookie); 2298 ArtField* const dex_file_field = 2299 soa.DecodeField(WellKnownClasses::dalvik_system_DexPathList__Element_dexFile); 2300 mirror::Object* dex_path_list = 2301 soa.DecodeField(WellKnownClasses::dalvik_system_PathClassLoader_pathList)-> 2302 GetObject(class_loader.Get()); 2303 if (dex_path_list != nullptr && dex_file_field != nullptr && cookie_field != nullptr) { 2304 // DexPathList has an array dexElements of Elements[] which each contain a dex file. 2305 mirror::Object* dex_elements_obj = 2306 soa.DecodeField(WellKnownClasses::dalvik_system_DexPathList_dexElements)-> 2307 GetObject(dex_path_list); 2308 // Loop through each dalvik.system.DexPathList$Element's dalvik.system.DexFile and look 2309 // at the mCookie which is a DexFile vector. 2310 if (dex_elements_obj != nullptr) { 2311 Handle<mirror::ObjectArray<mirror::Object>> dex_elements = 2312 hs.NewHandle(dex_elements_obj->AsObjectArray<mirror::Object>()); 2313 for (int32_t i = 0; i < dex_elements->GetLength(); ++i) { 2314 mirror::Object* element = dex_elements->GetWithoutChecks(i); 2315 if (element == nullptr) { 2316 // Should never happen, fall back to java code to throw a NPE. 2317 break; 2318 } 2319 mirror::Object* dex_file = dex_file_field->GetObject(element); 2320 if (dex_file != nullptr) { 2321 mirror::LongArray* long_array = cookie_field->GetObject(dex_file)->AsLongArray(); 2322 if (long_array == nullptr) { 2323 // This should never happen so log a warning. 2324 LOG(WARNING) << "Null DexFile::mCookie for " << descriptor; 2325 break; 2326 } 2327 int32_t long_array_size = long_array->GetLength(); 2328 // First element is the oat file. 2329 for (int32_t j = kDexFileIndexStart; j < long_array_size; ++j) { 2330 const DexFile* cp_dex_file = reinterpret_cast<const DexFile*>(static_cast<uintptr_t>( 2331 long_array->GetWithoutChecks(j))); 2332 const DexFile::ClassDef* dex_class_def = cp_dex_file->FindClassDef(descriptor, hash); 2333 if (dex_class_def != nullptr) { 2334 mirror::Class* klass = DefineClass(self, 2335 descriptor, 2336 hash, 2337 class_loader, 2338 *cp_dex_file, 2339 *dex_class_def); 2340 if (klass == nullptr) { 2341 CHECK(self->IsExceptionPending()) << descriptor; 2342 self->ClearException(); 2343 // TODO: Is it really right to break here, and not check the other dex files? 2344 return true; 2345 } 2346 *result = klass; 2347 return true; 2348 } 2349 } 2350 } 2351 } 2352 } 2353 self->AssertNoPendingException(); 2354 } 2355 2356 // Result is still null from the parent call, no need to set it again... 2357 return true; 2358} 2359 2360mirror::Class* ClassLinker::FindClass(Thread* self, 2361 const char* descriptor, 2362 Handle<mirror::ClassLoader> class_loader) { 2363 DCHECK_NE(*descriptor, '\0') << "descriptor is empty string"; 2364 DCHECK(self != nullptr); 2365 self->AssertNoPendingException(); 2366 if (descriptor[1] == '\0') { 2367 // only the descriptors of primitive types should be 1 character long, also avoid class lookup 2368 // for primitive classes that aren't backed by dex files. 2369 return FindPrimitiveClass(descriptor[0]); 2370 } 2371 const size_t hash = ComputeModifiedUtf8Hash(descriptor); 2372 // Find the class in the loaded classes table. 2373 mirror::Class* klass = LookupClass(self, descriptor, hash, class_loader.Get()); 2374 if (klass != nullptr) { 2375 return EnsureResolved(self, descriptor, klass); 2376 } 2377 // Class is not yet loaded. 2378 if (descriptor[0] == '[') { 2379 return CreateArrayClass(self, descriptor, hash, class_loader); 2380 } else if (class_loader.Get() == nullptr) { 2381 // The boot class loader, search the boot class path. 2382 ClassPathEntry pair = FindInClassPath(descriptor, hash, boot_class_path_); 2383 if (pair.second != nullptr) { 2384 return DefineClass(self, 2385 descriptor, 2386 hash, 2387 ScopedNullHandle<mirror::ClassLoader>(), 2388 *pair.first, 2389 *pair.second); 2390 } else { 2391 // The boot class loader is searched ahead of the application class loader, failures are 2392 // expected and will be wrapped in a ClassNotFoundException. Use the pre-allocated error to 2393 // trigger the chaining with a proper stack trace. 2394 mirror::Throwable* pre_allocated = Runtime::Current()->GetPreAllocatedNoClassDefFoundError(); 2395 self->SetException(pre_allocated); 2396 return nullptr; 2397 } 2398 } else { 2399 ScopedObjectAccessUnchecked soa(self); 2400 mirror::Class* cp_klass; 2401 if (FindClassInPathClassLoader(soa, self, descriptor, hash, class_loader, &cp_klass)) { 2402 // The chain was understood. So the value in cp_klass is either the class we were looking 2403 // for, or not found. 2404 if (cp_klass != nullptr) { 2405 return cp_klass; 2406 } 2407 // TODO: We handle the boot classpath loader in FindClassInPathClassLoader. Try to unify this 2408 // and the branch above. TODO: throw the right exception here. 2409 2410 // We'll let the Java-side rediscover all this and throw the exception with the right stack 2411 // trace. 2412 if (!self->CanCallIntoJava()) { 2413 // Oops, we can't call into java so we can't run actual class-loader code. 2414 // This is true for e.g. for the compiler (jit or aot). 2415 mirror::Throwable* pre_allocated = 2416 Runtime::Current()->GetPreAllocatedNoClassDefFoundError(); 2417 self->SetException(pre_allocated); 2418 return nullptr; 2419 } 2420 } 2421 2422 if (Runtime::Current()->IsAotCompiler()) { 2423 // Oops, compile-time, can't run actual class-loader code. 2424 mirror::Throwable* pre_allocated = Runtime::Current()->GetPreAllocatedNoClassDefFoundError(); 2425 self->SetException(pre_allocated); 2426 return nullptr; 2427 } 2428 2429 ScopedLocalRef<jobject> class_loader_object(soa.Env(), 2430 soa.AddLocalReference<jobject>(class_loader.Get())); 2431 std::string class_name_string(DescriptorToDot(descriptor)); 2432 ScopedLocalRef<jobject> result(soa.Env(), nullptr); 2433 { 2434 ScopedThreadStateChange tsc(self, kNative); 2435 ScopedLocalRef<jobject> class_name_object(soa.Env(), 2436 soa.Env()->NewStringUTF(class_name_string.c_str())); 2437 if (class_name_object.get() == nullptr) { 2438 DCHECK(self->IsExceptionPending()); // OOME. 2439 return nullptr; 2440 } 2441 CHECK(class_loader_object.get() != nullptr); 2442 result.reset(soa.Env()->CallObjectMethod(class_loader_object.get(), 2443 WellKnownClasses::java_lang_ClassLoader_loadClass, 2444 class_name_object.get())); 2445 } 2446 if (self->IsExceptionPending()) { 2447 // If the ClassLoader threw, pass that exception up. 2448 return nullptr; 2449 } else if (result.get() == nullptr) { 2450 // broken loader - throw NPE to be compatible with Dalvik 2451 ThrowNullPointerException(StringPrintf("ClassLoader.loadClass returned null for %s", 2452 class_name_string.c_str()).c_str()); 2453 return nullptr; 2454 } else { 2455 // success, return mirror::Class* 2456 return soa.Decode<mirror::Class*>(result.get()); 2457 } 2458 } 2459 UNREACHABLE(); 2460} 2461 2462mirror::Class* ClassLinker::DefineClass(Thread* self, 2463 const char* descriptor, 2464 size_t hash, 2465 Handle<mirror::ClassLoader> class_loader, 2466 const DexFile& dex_file, 2467 const DexFile::ClassDef& dex_class_def) { 2468 StackHandleScope<3> hs(self); 2469 auto klass = hs.NewHandle<mirror::Class>(nullptr); 2470 2471 // Load the class from the dex file. 2472 if (UNLIKELY(!init_done_)) { 2473 // finish up init of hand crafted class_roots_ 2474 if (strcmp(descriptor, "Ljava/lang/Object;") == 0) { 2475 klass.Assign(GetClassRoot(kJavaLangObject)); 2476 } else if (strcmp(descriptor, "Ljava/lang/Class;") == 0) { 2477 klass.Assign(GetClassRoot(kJavaLangClass)); 2478 } else if (strcmp(descriptor, "Ljava/lang/String;") == 0) { 2479 klass.Assign(GetClassRoot(kJavaLangString)); 2480 } else if (strcmp(descriptor, "Ljava/lang/ref/Reference;") == 0) { 2481 klass.Assign(GetClassRoot(kJavaLangRefReference)); 2482 } else if (strcmp(descriptor, "Ljava/lang/DexCache;") == 0) { 2483 klass.Assign(GetClassRoot(kJavaLangDexCache)); 2484 } 2485 } 2486 2487 if (klass.Get() == nullptr) { 2488 // Allocate a class with the status of not ready. 2489 // Interface object should get the right size here. Regular class will 2490 // figure out the right size later and be replaced with one of the right 2491 // size when the class becomes resolved. 2492 klass.Assign(AllocClass(self, SizeOfClassWithoutEmbeddedTables(dex_file, dex_class_def))); 2493 } 2494 if (UNLIKELY(klass.Get() == nullptr)) { 2495 self->AssertPendingOOMException(); 2496 return nullptr; 2497 } 2498 mirror::DexCache* dex_cache = RegisterDexFile(dex_file, class_loader.Get()); 2499 if (dex_cache == nullptr) { 2500 self->AssertPendingOOMException(); 2501 return nullptr; 2502 } 2503 klass->SetDexCache(dex_cache); 2504 SetupClass(dex_file, dex_class_def, klass, class_loader.Get()); 2505 2506 // Mark the string class by setting its access flag. 2507 if (UNLIKELY(!init_done_)) { 2508 if (strcmp(descriptor, "Ljava/lang/String;") == 0) { 2509 klass->SetStringClass(); 2510 } 2511 } 2512 2513 ObjectLock<mirror::Class> lock(self, klass); 2514 klass->SetClinitThreadId(self->GetTid()); 2515 2516 // Add the newly loaded class to the loaded classes table. 2517 mirror::Class* existing = InsertClass(descriptor, klass.Get(), hash); 2518 if (existing != nullptr) { 2519 // We failed to insert because we raced with another thread. Calling EnsureResolved may cause 2520 // this thread to block. 2521 return EnsureResolved(self, descriptor, existing); 2522 } 2523 2524 // Load the fields and other things after we are inserted in the table. This is so that we don't 2525 // end up allocating unfree-able linear alloc resources and then lose the race condition. The 2526 // other reason is that the field roots are only visited from the class table. So we need to be 2527 // inserted before we allocate / fill in these fields. 2528 LoadClass(self, dex_file, dex_class_def, klass); 2529 if (self->IsExceptionPending()) { 2530 VLOG(class_linker) << self->GetException()->Dump(); 2531 // An exception occured during load, set status to erroneous while holding klass' lock in case 2532 // notification is necessary. 2533 if (!klass->IsErroneous()) { 2534 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 2535 } 2536 return nullptr; 2537 } 2538 2539 // Finish loading (if necessary) by finding parents 2540 CHECK(!klass->IsLoaded()); 2541 if (!LoadSuperAndInterfaces(klass, dex_file)) { 2542 // Loading failed. 2543 if (!klass->IsErroneous()) { 2544 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 2545 } 2546 return nullptr; 2547 } 2548 CHECK(klass->IsLoaded()); 2549 // Link the class (if necessary) 2550 CHECK(!klass->IsResolved()); 2551 // TODO: Use fast jobjects? 2552 auto interfaces = hs.NewHandle<mirror::ObjectArray<mirror::Class>>(nullptr); 2553 2554 MutableHandle<mirror::Class> h_new_class = hs.NewHandle<mirror::Class>(nullptr); 2555 if (!LinkClass(self, descriptor, klass, interfaces, &h_new_class)) { 2556 // Linking failed. 2557 if (!klass->IsErroneous()) { 2558 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 2559 } 2560 return nullptr; 2561 } 2562 self->AssertNoPendingException(); 2563 CHECK(h_new_class.Get() != nullptr) << descriptor; 2564 CHECK(h_new_class->IsResolved()) << descriptor; 2565 2566 // Instrumentation may have updated entrypoints for all methods of all 2567 // classes. However it could not update methods of this class while we 2568 // were loading it. Now the class is resolved, we can update entrypoints 2569 // as required by instrumentation. 2570 if (Runtime::Current()->GetInstrumentation()->AreExitStubsInstalled()) { 2571 // We must be in the kRunnable state to prevent instrumentation from 2572 // suspending all threads to update entrypoints while we are doing it 2573 // for this class. 2574 DCHECK_EQ(self->GetState(), kRunnable); 2575 Runtime::Current()->GetInstrumentation()->InstallStubsForClass(h_new_class.Get()); 2576 } 2577 2578 /* 2579 * We send CLASS_PREPARE events to the debugger from here. The 2580 * definition of "preparation" is creating the static fields for a 2581 * class and initializing them to the standard default values, but not 2582 * executing any code (that comes later, during "initialization"). 2583 * 2584 * We did the static preparation in LinkClass. 2585 * 2586 * The class has been prepared and resolved but possibly not yet verified 2587 * at this point. 2588 */ 2589 Dbg::PostClassPrepare(h_new_class.Get()); 2590 2591 // Notify native debugger of the new class and its layout. 2592 jit::Jit::NewTypeLoadedIfUsingJit(h_new_class.Get()); 2593 2594 return h_new_class.Get(); 2595} 2596 2597uint32_t ClassLinker::SizeOfClassWithoutEmbeddedTables(const DexFile& dex_file, 2598 const DexFile::ClassDef& dex_class_def) { 2599 const uint8_t* class_data = dex_file.GetClassData(dex_class_def); 2600 size_t num_ref = 0; 2601 size_t num_8 = 0; 2602 size_t num_16 = 0; 2603 size_t num_32 = 0; 2604 size_t num_64 = 0; 2605 if (class_data != nullptr) { 2606 // We allow duplicate definitions of the same field in a class_data_item 2607 // but ignore the repeated indexes here, b/21868015. 2608 uint32_t last_field_idx = DexFile::kDexNoIndex; 2609 for (ClassDataItemIterator it(dex_file, class_data); it.HasNextStaticField(); it.Next()) { 2610 uint32_t field_idx = it.GetMemberIndex(); 2611 // Ordering enforced by DexFileVerifier. 2612 DCHECK(last_field_idx == DexFile::kDexNoIndex || last_field_idx <= field_idx); 2613 if (UNLIKELY(field_idx == last_field_idx)) { 2614 continue; 2615 } 2616 last_field_idx = field_idx; 2617 const DexFile::FieldId& field_id = dex_file.GetFieldId(field_idx); 2618 const char* descriptor = dex_file.GetFieldTypeDescriptor(field_id); 2619 char c = descriptor[0]; 2620 switch (c) { 2621 case 'L': 2622 case '[': 2623 num_ref++; 2624 break; 2625 case 'J': 2626 case 'D': 2627 num_64++; 2628 break; 2629 case 'I': 2630 case 'F': 2631 num_32++; 2632 break; 2633 case 'S': 2634 case 'C': 2635 num_16++; 2636 break; 2637 case 'B': 2638 case 'Z': 2639 num_8++; 2640 break; 2641 default: 2642 LOG(FATAL) << "Unknown descriptor: " << c; 2643 UNREACHABLE(); 2644 } 2645 } 2646 } 2647 return mirror::Class::ComputeClassSize(false, 2648 0, 2649 num_8, 2650 num_16, 2651 num_32, 2652 num_64, 2653 num_ref, 2654 image_pointer_size_); 2655} 2656 2657OatFile::OatClass ClassLinker::FindOatClass(const DexFile& dex_file, 2658 uint16_t class_def_idx, 2659 bool* found) { 2660 DCHECK_NE(class_def_idx, DexFile::kDexNoIndex16); 2661 const OatFile::OatDexFile* oat_dex_file = dex_file.GetOatDexFile(); 2662 if (oat_dex_file == nullptr) { 2663 *found = false; 2664 return OatFile::OatClass::Invalid(); 2665 } 2666 *found = true; 2667 return oat_dex_file->GetOatClass(class_def_idx); 2668} 2669 2670static uint32_t GetOatMethodIndexFromMethodIndex(const DexFile& dex_file, 2671 uint16_t class_def_idx, 2672 uint32_t method_idx) { 2673 const DexFile::ClassDef& class_def = dex_file.GetClassDef(class_def_idx); 2674 const uint8_t* class_data = dex_file.GetClassData(class_def); 2675 CHECK(class_data != nullptr); 2676 ClassDataItemIterator it(dex_file, class_data); 2677 // Skip fields 2678 while (it.HasNextStaticField()) { 2679 it.Next(); 2680 } 2681 while (it.HasNextInstanceField()) { 2682 it.Next(); 2683 } 2684 // Process methods 2685 size_t class_def_method_index = 0; 2686 while (it.HasNextDirectMethod()) { 2687 if (it.GetMemberIndex() == method_idx) { 2688 return class_def_method_index; 2689 } 2690 class_def_method_index++; 2691 it.Next(); 2692 } 2693 while (it.HasNextVirtualMethod()) { 2694 if (it.GetMemberIndex() == method_idx) { 2695 return class_def_method_index; 2696 } 2697 class_def_method_index++; 2698 it.Next(); 2699 } 2700 DCHECK(!it.HasNext()); 2701 LOG(FATAL) << "Failed to find method index " << method_idx << " in " << dex_file.GetLocation(); 2702 UNREACHABLE(); 2703} 2704 2705const OatFile::OatMethod ClassLinker::FindOatMethodFor(ArtMethod* method, bool* found) { 2706 // Although we overwrite the trampoline of non-static methods, we may get here via the resolution 2707 // method for direct methods (or virtual methods made direct). 2708 mirror::Class* declaring_class = method->GetDeclaringClass(); 2709 size_t oat_method_index; 2710 if (method->IsStatic() || method->IsDirect()) { 2711 // Simple case where the oat method index was stashed at load time. 2712 oat_method_index = method->GetMethodIndex(); 2713 } else { 2714 // We're invoking a virtual method directly (thanks to sharpening), compute the oat_method_index 2715 // by search for its position in the declared virtual methods. 2716 oat_method_index = declaring_class->NumDirectMethods(); 2717 bool found_virtual = false; 2718 for (ArtMethod& art_method : declaring_class->GetVirtualMethods(image_pointer_size_)) { 2719 // Check method index instead of identity in case of duplicate method definitions. 2720 if (method->GetDexMethodIndex() == art_method.GetDexMethodIndex()) { 2721 found_virtual = true; 2722 break; 2723 } 2724 oat_method_index++; 2725 } 2726 CHECK(found_virtual) << "Didn't find oat method index for virtual method: " 2727 << PrettyMethod(method); 2728 } 2729 DCHECK_EQ(oat_method_index, 2730 GetOatMethodIndexFromMethodIndex(*declaring_class->GetDexCache()->GetDexFile(), 2731 method->GetDeclaringClass()->GetDexClassDefIndex(), 2732 method->GetDexMethodIndex())); 2733 OatFile::OatClass oat_class = FindOatClass(*declaring_class->GetDexCache()->GetDexFile(), 2734 declaring_class->GetDexClassDefIndex(), 2735 found); 2736 if (!(*found)) { 2737 return OatFile::OatMethod::Invalid(); 2738 } 2739 return oat_class.GetOatMethod(oat_method_index); 2740} 2741 2742// Special case to get oat code without overwriting a trampoline. 2743const void* ClassLinker::GetQuickOatCodeFor(ArtMethod* method) { 2744 CHECK(method->IsInvokable()) << PrettyMethod(method); 2745 if (method->IsProxyMethod()) { 2746 return GetQuickProxyInvokeHandler(); 2747 } 2748 bool found; 2749 OatFile::OatMethod oat_method = FindOatMethodFor(method, &found); 2750 if (found) { 2751 auto* code = oat_method.GetQuickCode(); 2752 if (code != nullptr) { 2753 return code; 2754 } 2755 } 2756 if (method->IsNative()) { 2757 // No code and native? Use generic trampoline. 2758 return GetQuickGenericJniStub(); 2759 } 2760 return GetQuickToInterpreterBridge(); 2761} 2762 2763const void* ClassLinker::GetOatMethodQuickCodeFor(ArtMethod* method) { 2764 if (method->IsNative() || !method->IsInvokable() || method->IsProxyMethod()) { 2765 return nullptr; 2766 } 2767 bool found; 2768 OatFile::OatMethod oat_method = FindOatMethodFor(method, &found); 2769 if (found) { 2770 return oat_method.GetQuickCode(); 2771 } 2772 return nullptr; 2773} 2774 2775bool ClassLinker::ShouldUseInterpreterEntrypoint(ArtMethod* method, const void* quick_code) { 2776 if (UNLIKELY(method->IsNative() || method->IsProxyMethod())) { 2777 return false; 2778 } 2779 2780 if (quick_code == nullptr) { 2781 return true; 2782 } 2783 2784 Runtime* runtime = Runtime::Current(); 2785 instrumentation::Instrumentation* instr = runtime->GetInstrumentation(); 2786 if (instr->InterpretOnly()) { 2787 return true; 2788 } 2789 2790 if (runtime->GetClassLinker()->IsQuickToInterpreterBridge(quick_code)) { 2791 // Doing this check avoids doing compiled/interpreter transitions. 2792 return true; 2793 } 2794 2795 if (Dbg::IsForcedInterpreterNeededForCalling(Thread::Current(), method)) { 2796 // Force the use of interpreter when it is required by the debugger. 2797 return true; 2798 } 2799 2800 if (runtime->IsNativeDebuggable()) { 2801 DCHECK(runtime->UseJitCompilation() && runtime->GetJit()->JitAtFirstUse()); 2802 // If we are doing native debugging, ignore application's AOT code, 2803 // since we want to JIT it with extra stackmaps for native debugging. 2804 // On the other hand, keep all AOT code from the boot image, since the 2805 // blocking JIT would results in non-negligible performance impact. 2806 return !runtime->GetHeap()->IsInBootImageOatFile(quick_code); 2807 } 2808 2809 if (Dbg::IsDebuggerActive()) { 2810 // Boot image classes may be AOT-compiled as non-debuggable. 2811 // This is not suitable for the Java debugger, so ignore the AOT code. 2812 return runtime->GetHeap()->IsInBootImageOatFile(quick_code); 2813 } 2814 2815 return false; 2816} 2817 2818void ClassLinker::FixupStaticTrampolines(mirror::Class* klass) { 2819 DCHECK(klass->IsInitialized()) << PrettyDescriptor(klass); 2820 if (klass->NumDirectMethods() == 0) { 2821 return; // No direct methods => no static methods. 2822 } 2823 Runtime* runtime = Runtime::Current(); 2824 if (!runtime->IsStarted()) { 2825 if (runtime->IsAotCompiler() || runtime->GetHeap()->HasBootImageSpace()) { 2826 return; // OAT file unavailable. 2827 } 2828 } 2829 2830 const DexFile& dex_file = klass->GetDexFile(); 2831 const DexFile::ClassDef* dex_class_def = klass->GetClassDef(); 2832 CHECK(dex_class_def != nullptr); 2833 const uint8_t* class_data = dex_file.GetClassData(*dex_class_def); 2834 // There should always be class data if there were direct methods. 2835 CHECK(class_data != nullptr) << PrettyDescriptor(klass); 2836 ClassDataItemIterator it(dex_file, class_data); 2837 // Skip fields 2838 while (it.HasNextStaticField()) { 2839 it.Next(); 2840 } 2841 while (it.HasNextInstanceField()) { 2842 it.Next(); 2843 } 2844 bool has_oat_class; 2845 OatFile::OatClass oat_class = FindOatClass(dex_file, 2846 klass->GetDexClassDefIndex(), 2847 &has_oat_class); 2848 // Link the code of methods skipped by LinkCode. 2849 for (size_t method_index = 0; it.HasNextDirectMethod(); ++method_index, it.Next()) { 2850 ArtMethod* method = klass->GetDirectMethod(method_index, image_pointer_size_); 2851 if (!method->IsStatic()) { 2852 // Only update static methods. 2853 continue; 2854 } 2855 const void* quick_code = nullptr; 2856 if (has_oat_class) { 2857 OatFile::OatMethod oat_method = oat_class.GetOatMethod(method_index); 2858 quick_code = oat_method.GetQuickCode(); 2859 } 2860 // Check whether the method is native, in which case it's generic JNI. 2861 if (quick_code == nullptr && method->IsNative()) { 2862 quick_code = GetQuickGenericJniStub(); 2863 } else if (ShouldUseInterpreterEntrypoint(method, quick_code)) { 2864 // Use interpreter entry point. 2865 quick_code = GetQuickToInterpreterBridge(); 2866 } 2867 runtime->GetInstrumentation()->UpdateMethodsCode(method, quick_code); 2868 } 2869 // Ignore virtual methods on the iterator. 2870} 2871 2872void ClassLinker::EnsureThrowsInvocationError(ArtMethod* method) { 2873 DCHECK(method != nullptr); 2874 DCHECK(!method->IsInvokable()); 2875 method->SetEntryPointFromQuickCompiledCodePtrSize(quick_to_interpreter_bridge_trampoline_, 2876 image_pointer_size_); 2877} 2878 2879void ClassLinker::LinkCode(ArtMethod* method, const OatFile::OatClass* oat_class, 2880 uint32_t class_def_method_index) { 2881 Runtime* const runtime = Runtime::Current(); 2882 if (runtime->IsAotCompiler()) { 2883 // The following code only applies to a non-compiler runtime. 2884 return; 2885 } 2886 // Method shouldn't have already been linked. 2887 DCHECK(method->GetEntryPointFromQuickCompiledCode() == nullptr); 2888 if (oat_class != nullptr) { 2889 // Every kind of method should at least get an invoke stub from the oat_method. 2890 // non-abstract methods also get their code pointers. 2891 const OatFile::OatMethod oat_method = oat_class->GetOatMethod(class_def_method_index); 2892 oat_method.LinkMethod(method); 2893 } 2894 2895 // Install entry point from interpreter. 2896 const void* quick_code = method->GetEntryPointFromQuickCompiledCode(); 2897 bool enter_interpreter = ShouldUseInterpreterEntrypoint(method, quick_code); 2898 2899 if (!method->IsInvokable()) { 2900 EnsureThrowsInvocationError(method); 2901 return; 2902 } 2903 2904 if (method->IsStatic() && !method->IsConstructor()) { 2905 // For static methods excluding the class initializer, install the trampoline. 2906 // It will be replaced by the proper entry point by ClassLinker::FixupStaticTrampolines 2907 // after initializing class (see ClassLinker::InitializeClass method). 2908 method->SetEntryPointFromQuickCompiledCode(GetQuickResolutionStub()); 2909 } else if (quick_code == nullptr && method->IsNative()) { 2910 method->SetEntryPointFromQuickCompiledCode(GetQuickGenericJniStub()); 2911 } else if (enter_interpreter) { 2912 // Set entry point from compiled code if there's no code or in interpreter only mode. 2913 method->SetEntryPointFromQuickCompiledCode(GetQuickToInterpreterBridge()); 2914 } 2915 2916 if (method->IsNative()) { 2917 // Unregistering restores the dlsym lookup stub. 2918 method->UnregisterNative(); 2919 2920 if (enter_interpreter || quick_code == nullptr) { 2921 // We have a native method here without code. Then it should have either the generic JNI 2922 // trampoline as entrypoint (non-static), or the resolution trampoline (static). 2923 // TODO: this doesn't handle all the cases where trampolines may be installed. 2924 const void* entry_point = method->GetEntryPointFromQuickCompiledCode(); 2925 DCHECK(IsQuickGenericJniStub(entry_point) || IsQuickResolutionStub(entry_point)); 2926 } 2927 } 2928} 2929 2930void ClassLinker::SetupClass(const DexFile& dex_file, 2931 const DexFile::ClassDef& dex_class_def, 2932 Handle<mirror::Class> klass, 2933 mirror::ClassLoader* class_loader) { 2934 CHECK(klass.Get() != nullptr); 2935 CHECK(klass->GetDexCache() != nullptr); 2936 CHECK_EQ(mirror::Class::kStatusNotReady, klass->GetStatus()); 2937 const char* descriptor = dex_file.GetClassDescriptor(dex_class_def); 2938 CHECK(descriptor != nullptr); 2939 2940 klass->SetClass(GetClassRoot(kJavaLangClass)); 2941 uint32_t access_flags = dex_class_def.GetJavaAccessFlags(); 2942 CHECK_EQ(access_flags & ~kAccJavaFlagsMask, 0U); 2943 klass->SetAccessFlags(access_flags); 2944 klass->SetClassLoader(class_loader); 2945 DCHECK_EQ(klass->GetPrimitiveType(), Primitive::kPrimNot); 2946 mirror::Class::SetStatus(klass, mirror::Class::kStatusIdx, nullptr); 2947 2948 klass->SetDexClassDefIndex(dex_file.GetIndexForClassDef(dex_class_def)); 2949 klass->SetDexTypeIndex(dex_class_def.class_idx_); 2950 CHECK(klass->GetDexCacheStrings() != nullptr); 2951} 2952 2953void ClassLinker::LoadClass(Thread* self, 2954 const DexFile& dex_file, 2955 const DexFile::ClassDef& dex_class_def, 2956 Handle<mirror::Class> klass) { 2957 const uint8_t* class_data = dex_file.GetClassData(dex_class_def); 2958 if (class_data == nullptr) { 2959 return; // no fields or methods - for example a marker interface 2960 } 2961 bool has_oat_class = false; 2962 if (Runtime::Current()->IsStarted() && !Runtime::Current()->IsAotCompiler()) { 2963 OatFile::OatClass oat_class = FindOatClass(dex_file, klass->GetDexClassDefIndex(), 2964 &has_oat_class); 2965 if (has_oat_class) { 2966 LoadClassMembers(self, dex_file, class_data, klass, &oat_class); 2967 } 2968 } 2969 if (!has_oat_class) { 2970 LoadClassMembers(self, dex_file, class_data, klass, nullptr); 2971 } 2972} 2973 2974LengthPrefixedArray<ArtField>* ClassLinker::AllocArtFieldArray(Thread* self, 2975 LinearAlloc* allocator, 2976 size_t length) { 2977 if (length == 0) { 2978 return nullptr; 2979 } 2980 // If the ArtField alignment changes, review all uses of LengthPrefixedArray<ArtField>. 2981 static_assert(alignof(ArtField) == 4, "ArtField alignment is expected to be 4."); 2982 size_t storage_size = LengthPrefixedArray<ArtField>::ComputeSize(length); 2983 void* array_storage = allocator->Alloc(self, storage_size); 2984 auto* ret = new(array_storage) LengthPrefixedArray<ArtField>(length); 2985 CHECK(ret != nullptr); 2986 std::uninitialized_fill_n(&ret->At(0), length, ArtField()); 2987 return ret; 2988} 2989 2990LengthPrefixedArray<ArtMethod>* ClassLinker::AllocArtMethodArray(Thread* self, 2991 LinearAlloc* allocator, 2992 size_t length) { 2993 if (length == 0) { 2994 return nullptr; 2995 } 2996 const size_t method_alignment = ArtMethod::Alignment(image_pointer_size_); 2997 const size_t method_size = ArtMethod::Size(image_pointer_size_); 2998 const size_t storage_size = 2999 LengthPrefixedArray<ArtMethod>::ComputeSize(length, method_size, method_alignment); 3000 void* array_storage = allocator->Alloc(self, storage_size); 3001 auto* ret = new (array_storage) LengthPrefixedArray<ArtMethod>(length); 3002 CHECK(ret != nullptr); 3003 for (size_t i = 0; i < length; ++i) { 3004 new(reinterpret_cast<void*>(&ret->At(i, method_size, method_alignment))) ArtMethod; 3005 } 3006 return ret; 3007} 3008 3009LinearAlloc* ClassLinker::GetAllocatorForClassLoader(mirror::ClassLoader* class_loader) { 3010 if (class_loader == nullptr) { 3011 return Runtime::Current()->GetLinearAlloc(); 3012 } 3013 LinearAlloc* allocator = class_loader->GetAllocator(); 3014 DCHECK(allocator != nullptr); 3015 return allocator; 3016} 3017 3018LinearAlloc* ClassLinker::GetOrCreateAllocatorForClassLoader(mirror::ClassLoader* class_loader) { 3019 if (class_loader == nullptr) { 3020 return Runtime::Current()->GetLinearAlloc(); 3021 } 3022 WriterMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); 3023 LinearAlloc* allocator = class_loader->GetAllocator(); 3024 if (allocator == nullptr) { 3025 RegisterClassLoader(class_loader); 3026 allocator = class_loader->GetAllocator(); 3027 CHECK(allocator != nullptr); 3028 } 3029 return allocator; 3030} 3031 3032void ClassLinker::LoadClassMembers(Thread* self, 3033 const DexFile& dex_file, 3034 const uint8_t* class_data, 3035 Handle<mirror::Class> klass, 3036 const OatFile::OatClass* oat_class) { 3037 { 3038 // Note: We cannot have thread suspension until the field and method arrays are setup or else 3039 // Class::VisitFieldRoots may miss some fields or methods. 3040 ScopedAssertNoThreadSuspension nts(self, __FUNCTION__); 3041 // Load static fields. 3042 // We allow duplicate definitions of the same field in a class_data_item 3043 // but ignore the repeated indexes here, b/21868015. 3044 LinearAlloc* const allocator = GetAllocatorForClassLoader(klass->GetClassLoader()); 3045 ClassDataItemIterator it(dex_file, class_data); 3046 LengthPrefixedArray<ArtField>* sfields = AllocArtFieldArray(self, 3047 allocator, 3048 it.NumStaticFields()); 3049 size_t num_sfields = 0; 3050 uint32_t last_field_idx = 0u; 3051 for (; it.HasNextStaticField(); it.Next()) { 3052 uint32_t field_idx = it.GetMemberIndex(); 3053 DCHECK_GE(field_idx, last_field_idx); // Ordering enforced by DexFileVerifier. 3054 if (num_sfields == 0 || LIKELY(field_idx > last_field_idx)) { 3055 DCHECK_LT(num_sfields, it.NumStaticFields()); 3056 LoadField(it, klass, &sfields->At(num_sfields)); 3057 ++num_sfields; 3058 last_field_idx = field_idx; 3059 } 3060 } 3061 // Load instance fields. 3062 LengthPrefixedArray<ArtField>* ifields = AllocArtFieldArray(self, 3063 allocator, 3064 it.NumInstanceFields()); 3065 size_t num_ifields = 0u; 3066 last_field_idx = 0u; 3067 for (; it.HasNextInstanceField(); it.Next()) { 3068 uint32_t field_idx = it.GetMemberIndex(); 3069 DCHECK_GE(field_idx, last_field_idx); // Ordering enforced by DexFileVerifier. 3070 if (num_ifields == 0 || LIKELY(field_idx > last_field_idx)) { 3071 DCHECK_LT(num_ifields, it.NumInstanceFields()); 3072 LoadField(it, klass, &ifields->At(num_ifields)); 3073 ++num_ifields; 3074 last_field_idx = field_idx; 3075 } 3076 } 3077 if (UNLIKELY(num_sfields != it.NumStaticFields()) || 3078 UNLIKELY(num_ifields != it.NumInstanceFields())) { 3079 LOG(WARNING) << "Duplicate fields in class " << PrettyDescriptor(klass.Get()) 3080 << " (unique static fields: " << num_sfields << "/" << it.NumStaticFields() 3081 << ", unique instance fields: " << num_ifields << "/" << it.NumInstanceFields() << ")"; 3082 // NOTE: Not shrinking the over-allocated sfields/ifields, just setting size. 3083 if (sfields != nullptr) { 3084 sfields->SetSize(num_sfields); 3085 } 3086 if (ifields != nullptr) { 3087 ifields->SetSize(num_ifields); 3088 } 3089 } 3090 // Set the field arrays. 3091 klass->SetSFieldsPtr(sfields); 3092 DCHECK_EQ(klass->NumStaticFields(), num_sfields); 3093 klass->SetIFieldsPtr(ifields); 3094 DCHECK_EQ(klass->NumInstanceFields(), num_ifields); 3095 // Load methods. 3096 klass->SetMethodsPtr( 3097 AllocArtMethodArray(self, allocator, it.NumDirectMethods() + it.NumVirtualMethods()), 3098 it.NumDirectMethods(), 3099 it.NumVirtualMethods()); 3100 size_t class_def_method_index = 0; 3101 uint32_t last_dex_method_index = DexFile::kDexNoIndex; 3102 size_t last_class_def_method_index = 0; 3103 // TODO These should really use the iterators. 3104 for (size_t i = 0; it.HasNextDirectMethod(); i++, it.Next()) { 3105 ArtMethod* method = klass->GetDirectMethodUnchecked(i, image_pointer_size_); 3106 LoadMethod(self, dex_file, it, klass, method); 3107 LinkCode(method, oat_class, class_def_method_index); 3108 uint32_t it_method_index = it.GetMemberIndex(); 3109 if (last_dex_method_index == it_method_index) { 3110 // duplicate case 3111 method->SetMethodIndex(last_class_def_method_index); 3112 } else { 3113 method->SetMethodIndex(class_def_method_index); 3114 last_dex_method_index = it_method_index; 3115 last_class_def_method_index = class_def_method_index; 3116 } 3117 class_def_method_index++; 3118 } 3119 for (size_t i = 0; it.HasNextVirtualMethod(); i++, it.Next()) { 3120 ArtMethod* method = klass->GetVirtualMethodUnchecked(i, image_pointer_size_); 3121 LoadMethod(self, dex_file, it, klass, method); 3122 DCHECK_EQ(class_def_method_index, it.NumDirectMethods() + i); 3123 LinkCode(method, oat_class, class_def_method_index); 3124 class_def_method_index++; 3125 } 3126 DCHECK(!it.HasNext()); 3127 } 3128 // Ensure that the card is marked so that remembered sets pick up native roots. 3129 Runtime::Current()->GetHeap()->WriteBarrierEveryFieldOf(klass.Get()); 3130 self->AllowThreadSuspension(); 3131} 3132 3133void ClassLinker::LoadField(const ClassDataItemIterator& it, 3134 Handle<mirror::Class> klass, 3135 ArtField* dst) { 3136 const uint32_t field_idx = it.GetMemberIndex(); 3137 dst->SetDexFieldIndex(field_idx); 3138 dst->SetDeclaringClass(klass.Get()); 3139 dst->SetAccessFlags(it.GetFieldAccessFlags()); 3140} 3141 3142void ClassLinker::LoadMethod(Thread* self, 3143 const DexFile& dex_file, 3144 const ClassDataItemIterator& it, 3145 Handle<mirror::Class> klass, 3146 ArtMethod* dst) { 3147 uint32_t dex_method_idx = it.GetMemberIndex(); 3148 const DexFile::MethodId& method_id = dex_file.GetMethodId(dex_method_idx); 3149 const char* method_name = dex_file.StringDataByIdx(method_id.name_idx_); 3150 3151 ScopedAssertNoThreadSuspension ants(self, "LoadMethod"); 3152 dst->SetDexMethodIndex(dex_method_idx); 3153 dst->SetDeclaringClass(klass.Get()); 3154 dst->SetCodeItemOffset(it.GetMethodCodeItemOffset()); 3155 3156 dst->SetDexCacheResolvedMethods(klass->GetDexCache()->GetResolvedMethods(), image_pointer_size_); 3157 dst->SetDexCacheResolvedTypes(klass->GetDexCache()->GetResolvedTypes(), image_pointer_size_); 3158 3159 uint32_t access_flags = it.GetMethodAccessFlags(); 3160 3161 if (UNLIKELY(strcmp("finalize", method_name) == 0)) { 3162 // Set finalizable flag on declaring class. 3163 if (strcmp("V", dex_file.GetShorty(method_id.proto_idx_)) == 0) { 3164 // Void return type. 3165 if (klass->GetClassLoader() != nullptr) { // All non-boot finalizer methods are flagged. 3166 klass->SetFinalizable(); 3167 } else { 3168 std::string temp; 3169 const char* klass_descriptor = klass->GetDescriptor(&temp); 3170 // The Enum class declares a "final" finalize() method to prevent subclasses from 3171 // introducing a finalizer. We don't want to set the finalizable flag for Enum or its 3172 // subclasses, so we exclude it here. 3173 // We also want to avoid setting the flag on Object, where we know that finalize() is 3174 // empty. 3175 if (strcmp(klass_descriptor, "Ljava/lang/Object;") != 0 && 3176 strcmp(klass_descriptor, "Ljava/lang/Enum;") != 0) { 3177 klass->SetFinalizable(); 3178 } 3179 } 3180 } 3181 } else if (method_name[0] == '<') { 3182 // Fix broken access flags for initializers. Bug 11157540. 3183 bool is_init = (strcmp("<init>", method_name) == 0); 3184 bool is_clinit = !is_init && (strcmp("<clinit>", method_name) == 0); 3185 if (UNLIKELY(!is_init && !is_clinit)) { 3186 LOG(WARNING) << "Unexpected '<' at start of method name " << method_name; 3187 } else { 3188 if (UNLIKELY((access_flags & kAccConstructor) == 0)) { 3189 LOG(WARNING) << method_name << " didn't have expected constructor access flag in class " 3190 << PrettyDescriptor(klass.Get()) << " in dex file " << dex_file.GetLocation(); 3191 access_flags |= kAccConstructor; 3192 } 3193 } 3194 } 3195 dst->SetAccessFlags(access_flags); 3196} 3197 3198void ClassLinker::AppendToBootClassPath(Thread* self, const DexFile& dex_file) { 3199 StackHandleScope<1> hs(self); 3200 Handle<mirror::DexCache> dex_cache(hs.NewHandle(AllocDexCache( 3201 self, 3202 dex_file, 3203 Runtime::Current()->GetLinearAlloc()))); 3204 CHECK(dex_cache.Get() != nullptr) << "Failed to allocate dex cache for " 3205 << dex_file.GetLocation(); 3206 AppendToBootClassPath(dex_file, dex_cache); 3207} 3208 3209void ClassLinker::AppendToBootClassPath(const DexFile& dex_file, 3210 Handle<mirror::DexCache> dex_cache) { 3211 CHECK(dex_cache.Get() != nullptr) << dex_file.GetLocation(); 3212 boot_class_path_.push_back(&dex_file); 3213 RegisterDexFile(dex_file, dex_cache); 3214} 3215 3216void ClassLinker::RegisterDexFileLocked(const DexFile& dex_file, 3217 Handle<mirror::DexCache> dex_cache) { 3218 Thread* const self = Thread::Current(); 3219 dex_lock_.AssertExclusiveHeld(self); 3220 CHECK(dex_cache.Get() != nullptr) << dex_file.GetLocation(); 3221 // For app images, the dex cache location may be a suffix of the dex file location since the 3222 // dex file location is an absolute path. 3223 const std::string dex_cache_location = dex_cache->GetLocation()->ToModifiedUtf8(); 3224 const size_t dex_cache_length = dex_cache_location.length(); 3225 CHECK_GT(dex_cache_length, 0u) << dex_file.GetLocation(); 3226 std::string dex_file_location = dex_file.GetLocation(); 3227 CHECK_GE(dex_file_location.length(), dex_cache_length) 3228 << dex_cache_location << " " << dex_file.GetLocation(); 3229 // Take suffix. 3230 const std::string dex_file_suffix = dex_file_location.substr( 3231 dex_file_location.length() - dex_cache_length, 3232 dex_cache_length); 3233 // Example dex_cache location is SettingsProvider.apk and 3234 // dex file location is /system/priv-app/SettingsProvider/SettingsProvider.apk 3235 CHECK_EQ(dex_cache_location, dex_file_suffix); 3236 // Clean up pass to remove null dex caches. 3237 // Null dex caches can occur due to class unloading and we are lazily removing null entries. 3238 JavaVMExt* const vm = self->GetJniEnv()->vm; 3239 for (auto it = dex_caches_.begin(); it != dex_caches_.end(); ) { 3240 DexCacheData data = *it; 3241 if (self->IsJWeakCleared(data.weak_root)) { 3242 vm->DeleteWeakGlobalRef(self, data.weak_root); 3243 it = dex_caches_.erase(it); 3244 } else { 3245 ++it; 3246 } 3247 } 3248 jweak dex_cache_jweak = vm->AddWeakGlobalRef(self, dex_cache.Get()); 3249 dex_cache->SetDexFile(&dex_file); 3250 DexCacheData data; 3251 data.weak_root = dex_cache_jweak; 3252 data.dex_file = dex_cache->GetDexFile(); 3253 data.resolved_types = dex_cache->GetResolvedTypes(); 3254 dex_caches_.push_back(data); 3255} 3256 3257mirror::DexCache* ClassLinker::RegisterDexFile(const DexFile& dex_file, 3258 mirror::ClassLoader* class_loader) { 3259 Thread* self = Thread::Current(); 3260 { 3261 ReaderMutexLock mu(self, dex_lock_); 3262 mirror::DexCache* dex_cache = FindDexCacheLocked(self, dex_file, true); 3263 if (dex_cache != nullptr) { 3264 return dex_cache; 3265 } 3266 } 3267 LinearAlloc* const linear_alloc = GetOrCreateAllocatorForClassLoader(class_loader); 3268 DCHECK(linear_alloc != nullptr); 3269 ClassTable* table; 3270 { 3271 WriterMutexLock mu(self, *Locks::classlinker_classes_lock_); 3272 table = InsertClassTableForClassLoader(class_loader); 3273 } 3274 // Don't alloc while holding the lock, since allocation may need to 3275 // suspend all threads and another thread may need the dex_lock_ to 3276 // get to a suspend point. 3277 StackHandleScope<1> hs(self); 3278 Handle<mirror::DexCache> h_dex_cache(hs.NewHandle(AllocDexCache(self, dex_file, linear_alloc))); 3279 { 3280 WriterMutexLock mu(self, dex_lock_); 3281 mirror::DexCache* dex_cache = FindDexCacheLocked(self, dex_file, true); 3282 if (dex_cache != nullptr) { 3283 return dex_cache; 3284 } 3285 if (h_dex_cache.Get() == nullptr) { 3286 self->AssertPendingOOMException(); 3287 return nullptr; 3288 } 3289 RegisterDexFileLocked(dex_file, h_dex_cache); 3290 } 3291 table->InsertStrongRoot(h_dex_cache.Get()); 3292 return h_dex_cache.Get(); 3293} 3294 3295void ClassLinker::RegisterDexFile(const DexFile& dex_file, 3296 Handle<mirror::DexCache> dex_cache) { 3297 WriterMutexLock mu(Thread::Current(), dex_lock_); 3298 RegisterDexFileLocked(dex_file, dex_cache); 3299} 3300 3301mirror::DexCache* ClassLinker::FindDexCache(Thread* self, 3302 const DexFile& dex_file, 3303 bool allow_failure) { 3304 ReaderMutexLock mu(self, dex_lock_); 3305 return FindDexCacheLocked(self, dex_file, allow_failure); 3306} 3307 3308mirror::DexCache* ClassLinker::FindDexCacheLocked(Thread* self, 3309 const DexFile& dex_file, 3310 bool allow_failure) { 3311 // Search assuming unique-ness of dex file. 3312 for (const DexCacheData& data : dex_caches_) { 3313 // Avoid decoding (and read barriers) other unrelated dex caches. 3314 if (data.dex_file == &dex_file) { 3315 mirror::DexCache* dex_cache = 3316 down_cast<mirror::DexCache*>(self->DecodeJObject(data.weak_root)); 3317 if (dex_cache != nullptr) { 3318 return dex_cache; 3319 } else { 3320 break; 3321 } 3322 } 3323 } 3324 if (allow_failure) { 3325 return nullptr; 3326 } 3327 std::string location(dex_file.GetLocation()); 3328 // Failure, dump diagnostic and abort. 3329 for (const DexCacheData& data : dex_caches_) { 3330 mirror::DexCache* dex_cache = down_cast<mirror::DexCache*>(self->DecodeJObject(data.weak_root)); 3331 if (dex_cache != nullptr) { 3332 LOG(ERROR) << "Registered dex file " << dex_cache->GetDexFile()->GetLocation(); 3333 } 3334 } 3335 LOG(FATAL) << "Failed to find DexCache for DexFile " << location; 3336 UNREACHABLE(); 3337} 3338 3339void ClassLinker::FixupDexCaches(ArtMethod* resolution_method) { 3340 Thread* const self = Thread::Current(); 3341 ReaderMutexLock mu(self, dex_lock_); 3342 for (const DexCacheData& data : dex_caches_) { 3343 if (!self->IsJWeakCleared(data.weak_root)) { 3344 mirror::DexCache* dex_cache = down_cast<mirror::DexCache*>( 3345 self->DecodeJObject(data.weak_root)); 3346 if (dex_cache != nullptr) { 3347 dex_cache->Fixup(resolution_method, image_pointer_size_); 3348 } 3349 } 3350 } 3351} 3352 3353mirror::Class* ClassLinker::CreatePrimitiveClass(Thread* self, Primitive::Type type) { 3354 mirror::Class* klass = AllocClass(self, mirror::Class::PrimitiveClassSize(image_pointer_size_)); 3355 if (UNLIKELY(klass == nullptr)) { 3356 self->AssertPendingOOMException(); 3357 return nullptr; 3358 } 3359 return InitializePrimitiveClass(klass, type); 3360} 3361 3362mirror::Class* ClassLinker::InitializePrimitiveClass(mirror::Class* primitive_class, 3363 Primitive::Type type) { 3364 CHECK(primitive_class != nullptr); 3365 // Must hold lock on object when initializing. 3366 Thread* self = Thread::Current(); 3367 StackHandleScope<1> hs(self); 3368 Handle<mirror::Class> h_class(hs.NewHandle(primitive_class)); 3369 ObjectLock<mirror::Class> lock(self, h_class); 3370 h_class->SetAccessFlags(kAccPublic | kAccFinal | kAccAbstract); 3371 h_class->SetPrimitiveType(type); 3372 mirror::Class::SetStatus(h_class, mirror::Class::kStatusInitialized, self); 3373 const char* descriptor = Primitive::Descriptor(type); 3374 mirror::Class* existing = InsertClass(descriptor, h_class.Get(), 3375 ComputeModifiedUtf8Hash(descriptor)); 3376 CHECK(existing == nullptr) << "InitPrimitiveClass(" << type << ") failed"; 3377 return h_class.Get(); 3378} 3379 3380// Create an array class (i.e. the class object for the array, not the 3381// array itself). "descriptor" looks like "[C" or "[[[[B" or 3382// "[Ljava/lang/String;". 3383// 3384// If "descriptor" refers to an array of primitives, look up the 3385// primitive type's internally-generated class object. 3386// 3387// "class_loader" is the class loader of the class that's referring to 3388// us. It's used to ensure that we're looking for the element type in 3389// the right context. It does NOT become the class loader for the 3390// array class; that always comes from the base element class. 3391// 3392// Returns null with an exception raised on failure. 3393mirror::Class* ClassLinker::CreateArrayClass(Thread* self, const char* descriptor, size_t hash, 3394 Handle<mirror::ClassLoader> class_loader) { 3395 // Identify the underlying component type 3396 CHECK_EQ('[', descriptor[0]); 3397 StackHandleScope<2> hs(self); 3398 MutableHandle<mirror::Class> component_type(hs.NewHandle(FindClass(self, descriptor + 1, 3399 class_loader))); 3400 if (component_type.Get() == nullptr) { 3401 DCHECK(self->IsExceptionPending()); 3402 // We need to accept erroneous classes as component types. 3403 const size_t component_hash = ComputeModifiedUtf8Hash(descriptor + 1); 3404 component_type.Assign(LookupClass(self, descriptor + 1, component_hash, class_loader.Get())); 3405 if (component_type.Get() == nullptr) { 3406 DCHECK(self->IsExceptionPending()); 3407 return nullptr; 3408 } else { 3409 self->ClearException(); 3410 } 3411 } 3412 if (UNLIKELY(component_type->IsPrimitiveVoid())) { 3413 ThrowNoClassDefFoundError("Attempt to create array of void primitive type"); 3414 return nullptr; 3415 } 3416 // See if the component type is already loaded. Array classes are 3417 // always associated with the class loader of their underlying 3418 // element type -- an array of Strings goes with the loader for 3419 // java/lang/String -- so we need to look for it there. (The 3420 // caller should have checked for the existence of the class 3421 // before calling here, but they did so with *their* class loader, 3422 // not the component type's loader.) 3423 // 3424 // If we find it, the caller adds "loader" to the class' initiating 3425 // loader list, which should prevent us from going through this again. 3426 // 3427 // This call is unnecessary if "loader" and "component_type->GetClassLoader()" 3428 // are the same, because our caller (FindClass) just did the 3429 // lookup. (Even if we get this wrong we still have correct behavior, 3430 // because we effectively do this lookup again when we add the new 3431 // class to the hash table --- necessary because of possible races with 3432 // other threads.) 3433 if (class_loader.Get() != component_type->GetClassLoader()) { 3434 mirror::Class* new_class = LookupClass(self, descriptor, hash, component_type->GetClassLoader()); 3435 if (new_class != nullptr) { 3436 return new_class; 3437 } 3438 } 3439 3440 // Fill out the fields in the Class. 3441 // 3442 // It is possible to execute some methods against arrays, because 3443 // all arrays are subclasses of java_lang_Object_, so we need to set 3444 // up a vtable. We can just point at the one in java_lang_Object_. 3445 // 3446 // Array classes are simple enough that we don't need to do a full 3447 // link step. 3448 auto new_class = hs.NewHandle<mirror::Class>(nullptr); 3449 if (UNLIKELY(!init_done_)) { 3450 // Classes that were hand created, ie not by FindSystemClass 3451 if (strcmp(descriptor, "[Ljava/lang/Class;") == 0) { 3452 new_class.Assign(GetClassRoot(kClassArrayClass)); 3453 } else if (strcmp(descriptor, "[Ljava/lang/Object;") == 0) { 3454 new_class.Assign(GetClassRoot(kObjectArrayClass)); 3455 } else if (strcmp(descriptor, GetClassRootDescriptor(kJavaLangStringArrayClass)) == 0) { 3456 new_class.Assign(GetClassRoot(kJavaLangStringArrayClass)); 3457 } else if (strcmp(descriptor, "[C") == 0) { 3458 new_class.Assign(GetClassRoot(kCharArrayClass)); 3459 } else if (strcmp(descriptor, "[I") == 0) { 3460 new_class.Assign(GetClassRoot(kIntArrayClass)); 3461 } else if (strcmp(descriptor, "[J") == 0) { 3462 new_class.Assign(GetClassRoot(kLongArrayClass)); 3463 } 3464 } 3465 if (new_class.Get() == nullptr) { 3466 new_class.Assign(AllocClass(self, mirror::Array::ClassSize(image_pointer_size_))); 3467 if (new_class.Get() == nullptr) { 3468 self->AssertPendingOOMException(); 3469 return nullptr; 3470 } 3471 new_class->SetComponentType(component_type.Get()); 3472 } 3473 ObjectLock<mirror::Class> lock(self, new_class); // Must hold lock on object when initializing. 3474 DCHECK(new_class->GetComponentType() != nullptr); 3475 mirror::Class* java_lang_Object = GetClassRoot(kJavaLangObject); 3476 new_class->SetSuperClass(java_lang_Object); 3477 new_class->SetVTable(java_lang_Object->GetVTable()); 3478 new_class->SetPrimitiveType(Primitive::kPrimNot); 3479 new_class->SetClassLoader(component_type->GetClassLoader()); 3480 if (component_type->IsPrimitive()) { 3481 new_class->SetClassFlags(mirror::kClassFlagNoReferenceFields); 3482 } else { 3483 new_class->SetClassFlags(mirror::kClassFlagObjectArray); 3484 } 3485 mirror::Class::SetStatus(new_class, mirror::Class::kStatusLoaded, self); 3486 new_class->PopulateEmbeddedVTable(image_pointer_size_); 3487 ImTable* object_imt = java_lang_Object->GetImt(image_pointer_size_); 3488 new_class->SetImt(object_imt, image_pointer_size_); 3489 mirror::Class::SetStatus(new_class, mirror::Class::kStatusInitialized, self); 3490 // don't need to set new_class->SetObjectSize(..) 3491 // because Object::SizeOf delegates to Array::SizeOf 3492 3493 // All arrays have java/lang/Cloneable and java/io/Serializable as 3494 // interfaces. We need to set that up here, so that stuff like 3495 // "instanceof" works right. 3496 // 3497 // Note: The GC could run during the call to FindSystemClass, 3498 // so we need to make sure the class object is GC-valid while we're in 3499 // there. Do this by clearing the interface list so the GC will just 3500 // think that the entries are null. 3501 3502 3503 // Use the single, global copies of "interfaces" and "iftable" 3504 // (remember not to free them for arrays). 3505 { 3506 mirror::IfTable* array_iftable = array_iftable_.Read(); 3507 CHECK(array_iftable != nullptr); 3508 new_class->SetIfTable(array_iftable); 3509 } 3510 3511 // Inherit access flags from the component type. 3512 int access_flags = new_class->GetComponentType()->GetAccessFlags(); 3513 // Lose any implementation detail flags; in particular, arrays aren't finalizable. 3514 access_flags &= kAccJavaFlagsMask; 3515 // Arrays can't be used as a superclass or interface, so we want to add "abstract final" 3516 // and remove "interface". 3517 access_flags |= kAccAbstract | kAccFinal; 3518 access_flags &= ~kAccInterface; 3519 3520 new_class->SetAccessFlags(access_flags); 3521 3522 mirror::Class* existing = InsertClass(descriptor, new_class.Get(), hash); 3523 if (existing == nullptr) { 3524 jit::Jit::NewTypeLoadedIfUsingJit(new_class.Get()); 3525 return new_class.Get(); 3526 } 3527 // Another thread must have loaded the class after we 3528 // started but before we finished. Abandon what we've 3529 // done. 3530 // 3531 // (Yes, this happens.) 3532 3533 return existing; 3534} 3535 3536mirror::Class* ClassLinker::FindPrimitiveClass(char type) { 3537 switch (type) { 3538 case 'B': 3539 return GetClassRoot(kPrimitiveByte); 3540 case 'C': 3541 return GetClassRoot(kPrimitiveChar); 3542 case 'D': 3543 return GetClassRoot(kPrimitiveDouble); 3544 case 'F': 3545 return GetClassRoot(kPrimitiveFloat); 3546 case 'I': 3547 return GetClassRoot(kPrimitiveInt); 3548 case 'J': 3549 return GetClassRoot(kPrimitiveLong); 3550 case 'S': 3551 return GetClassRoot(kPrimitiveShort); 3552 case 'Z': 3553 return GetClassRoot(kPrimitiveBoolean); 3554 case 'V': 3555 return GetClassRoot(kPrimitiveVoid); 3556 default: 3557 break; 3558 } 3559 std::string printable_type(PrintableChar(type)); 3560 ThrowNoClassDefFoundError("Not a primitive type: %s", printable_type.c_str()); 3561 return nullptr; 3562} 3563 3564mirror::Class* ClassLinker::InsertClass(const char* descriptor, mirror::Class* klass, size_t hash) { 3565 if (VLOG_IS_ON(class_linker)) { 3566 mirror::DexCache* dex_cache = klass->GetDexCache(); 3567 std::string source; 3568 if (dex_cache != nullptr) { 3569 source += " from "; 3570 source += dex_cache->GetLocation()->ToModifiedUtf8(); 3571 } 3572 LOG(INFO) << "Loaded class " << descriptor << source; 3573 } 3574 { 3575 WriterMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); 3576 mirror::ClassLoader* const class_loader = klass->GetClassLoader(); 3577 ClassTable* const class_table = InsertClassTableForClassLoader(class_loader); 3578 mirror::Class* existing = class_table->Lookup(descriptor, hash); 3579 if (existing != nullptr) { 3580 return existing; 3581 } 3582 if (kIsDebugBuild && 3583 !klass->IsTemp() && 3584 class_loader == nullptr && 3585 dex_cache_boot_image_class_lookup_required_) { 3586 // Check a class loaded with the system class loader matches one in the image if the class 3587 // is in the image. 3588 existing = LookupClassFromBootImage(descriptor); 3589 if (existing != nullptr) { 3590 CHECK_EQ(klass, existing); 3591 } 3592 } 3593 VerifyObject(klass); 3594 class_table->InsertWithHash(klass, hash); 3595 if (class_loader != nullptr) { 3596 // This is necessary because we need to have the card dirtied for remembered sets. 3597 Runtime::Current()->GetHeap()->WriteBarrierEveryFieldOf(class_loader); 3598 } 3599 if (log_new_class_table_roots_) { 3600 new_class_roots_.push_back(GcRoot<mirror::Class>(klass)); 3601 } 3602 } 3603 if (kIsDebugBuild) { 3604 // Test that copied methods correctly can find their holder. 3605 for (ArtMethod& method : klass->GetCopiedMethods(image_pointer_size_)) { 3606 CHECK_EQ(GetHoldingClassOfCopiedMethod(&method), klass); 3607 } 3608 } 3609 return nullptr; 3610} 3611 3612// TODO This should really be in mirror::Class. 3613void ClassLinker::UpdateClassMethods(mirror::Class* klass, 3614 LengthPrefixedArray<ArtMethod>* new_methods) { 3615 klass->SetMethodsPtrUnchecked(new_methods, 3616 klass->NumDirectMethods(), 3617 klass->NumDeclaredVirtualMethods()); 3618 // Need to mark the card so that the remembered sets and mod union tables get updated. 3619 Runtime::Current()->GetHeap()->WriteBarrierEveryFieldOf(klass); 3620} 3621 3622bool ClassLinker::RemoveClass(const char* descriptor, mirror::ClassLoader* class_loader) { 3623 WriterMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); 3624 ClassTable* const class_table = ClassTableForClassLoader(class_loader); 3625 return class_table != nullptr && class_table->Remove(descriptor); 3626} 3627 3628mirror::Class* ClassLinker::LookupClass(Thread* self, 3629 const char* descriptor, 3630 size_t hash, 3631 mirror::ClassLoader* class_loader) { 3632 { 3633 ReaderMutexLock mu(self, *Locks::classlinker_classes_lock_); 3634 ClassTable* const class_table = ClassTableForClassLoader(class_loader); 3635 if (class_table != nullptr) { 3636 mirror::Class* result = class_table->Lookup(descriptor, hash); 3637 if (result != nullptr) { 3638 return result; 3639 } 3640 } 3641 } 3642 if (class_loader != nullptr || !dex_cache_boot_image_class_lookup_required_) { 3643 return nullptr; 3644 } 3645 // Lookup failed but need to search dex_caches_. 3646 mirror::Class* result = LookupClassFromBootImage(descriptor); 3647 if (result != nullptr) { 3648 result = InsertClass(descriptor, result, hash); 3649 } else { 3650 // Searching the image dex files/caches failed, we don't want to get into this situation 3651 // often as map searches are faster, so after kMaxFailedDexCacheLookups move all image 3652 // classes into the class table. 3653 constexpr uint32_t kMaxFailedDexCacheLookups = 1000; 3654 if (++failed_dex_cache_class_lookups_ > kMaxFailedDexCacheLookups) { 3655 AddBootImageClassesToClassTable(); 3656 } 3657 } 3658 return result; 3659} 3660 3661static std::vector<mirror::ObjectArray<mirror::DexCache>*> GetImageDexCaches( 3662 std::vector<gc::space::ImageSpace*> image_spaces) SHARED_REQUIRES(Locks::mutator_lock_) { 3663 CHECK(!image_spaces.empty()); 3664 std::vector<mirror::ObjectArray<mirror::DexCache>*> dex_caches_vector; 3665 for (gc::space::ImageSpace* image_space : image_spaces) { 3666 mirror::Object* root = image_space->GetImageHeader().GetImageRoot(ImageHeader::kDexCaches); 3667 DCHECK(root != nullptr); 3668 dex_caches_vector.push_back(root->AsObjectArray<mirror::DexCache>()); 3669 } 3670 return dex_caches_vector; 3671} 3672 3673void ClassLinker::AddBootImageClassesToClassTable() { 3674 if (dex_cache_boot_image_class_lookup_required_) { 3675 AddImageClassesToClassTable(Runtime::Current()->GetHeap()->GetBootImageSpaces(), 3676 /*class_loader*/nullptr); 3677 dex_cache_boot_image_class_lookup_required_ = false; 3678 } 3679} 3680 3681void ClassLinker::AddImageClassesToClassTable(std::vector<gc::space::ImageSpace*> image_spaces, 3682 mirror::ClassLoader* class_loader) { 3683 Thread* self = Thread::Current(); 3684 WriterMutexLock mu(self, *Locks::classlinker_classes_lock_); 3685 ScopedAssertNoThreadSuspension ants(self, "Moving image classes to class table"); 3686 3687 ClassTable* const class_table = InsertClassTableForClassLoader(class_loader); 3688 3689 std::string temp; 3690 std::vector<mirror::ObjectArray<mirror::DexCache>*> dex_caches_vector = 3691 GetImageDexCaches(image_spaces); 3692 for (mirror::ObjectArray<mirror::DexCache>* dex_caches : dex_caches_vector) { 3693 for (int32_t i = 0; i < dex_caches->GetLength(); i++) { 3694 mirror::DexCache* dex_cache = dex_caches->Get(i); 3695 GcRoot<mirror::Class>* types = dex_cache->GetResolvedTypes(); 3696 for (int32_t j = 0, num_types = dex_cache->NumResolvedTypes(); j < num_types; j++) { 3697 mirror::Class* klass = types[j].Read(); 3698 if (klass != nullptr) { 3699 DCHECK_EQ(klass->GetClassLoader(), class_loader); 3700 const char* descriptor = klass->GetDescriptor(&temp); 3701 size_t hash = ComputeModifiedUtf8Hash(descriptor); 3702 mirror::Class* existing = class_table->Lookup(descriptor, hash); 3703 if (existing != nullptr) { 3704 CHECK_EQ(existing, klass) << PrettyClassAndClassLoader(existing) << " != " 3705 << PrettyClassAndClassLoader(klass); 3706 } else { 3707 class_table->Insert(klass); 3708 if (log_new_class_table_roots_) { 3709 new_class_roots_.push_back(GcRoot<mirror::Class>(klass)); 3710 } 3711 } 3712 } 3713 } 3714 } 3715 } 3716} 3717 3718class MoveClassTableToPreZygoteVisitor : public ClassLoaderVisitor { 3719 public: 3720 explicit MoveClassTableToPreZygoteVisitor() {} 3721 3722 void Visit(mirror::ClassLoader* class_loader) 3723 REQUIRES(Locks::classlinker_classes_lock_) 3724 SHARED_REQUIRES(Locks::mutator_lock_) OVERRIDE { 3725 ClassTable* const class_table = class_loader->GetClassTable(); 3726 if (class_table != nullptr) { 3727 class_table->FreezeSnapshot(); 3728 } 3729 } 3730}; 3731 3732void ClassLinker::MoveClassTableToPreZygote() { 3733 WriterMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); 3734 boot_class_table_.FreezeSnapshot(); 3735 MoveClassTableToPreZygoteVisitor visitor; 3736 VisitClassLoaders(&visitor); 3737} 3738 3739mirror::Class* ClassLinker::LookupClassFromBootImage(const char* descriptor) { 3740 ScopedAssertNoThreadSuspension ants(Thread::Current(), "Image class lookup"); 3741 std::vector<mirror::ObjectArray<mirror::DexCache>*> dex_caches_vector = 3742 GetImageDexCaches(Runtime::Current()->GetHeap()->GetBootImageSpaces()); 3743 for (mirror::ObjectArray<mirror::DexCache>* dex_caches : dex_caches_vector) { 3744 for (int32_t i = 0; i < dex_caches->GetLength(); ++i) { 3745 mirror::DexCache* dex_cache = dex_caches->Get(i); 3746 const DexFile* dex_file = dex_cache->GetDexFile(); 3747 // Try binary searching the type index by descriptor. 3748 const DexFile::TypeId* type_id = dex_file->FindTypeId(descriptor); 3749 if (type_id != nullptr) { 3750 uint16_t type_idx = dex_file->GetIndexForTypeId(*type_id); 3751 mirror::Class* klass = dex_cache->GetResolvedType(type_idx); 3752 if (klass != nullptr) { 3753 return klass; 3754 } 3755 } 3756 } 3757 } 3758 return nullptr; 3759} 3760 3761// Look up classes by hash and descriptor and put all matching ones in the result array. 3762class LookupClassesVisitor : public ClassLoaderVisitor { 3763 public: 3764 LookupClassesVisitor(const char* descriptor, size_t hash, std::vector<mirror::Class*>* result) 3765 : descriptor_(descriptor), 3766 hash_(hash), 3767 result_(result) {} 3768 3769 void Visit(mirror::ClassLoader* class_loader) 3770 SHARED_REQUIRES(Locks::classlinker_classes_lock_, Locks::mutator_lock_) OVERRIDE { 3771 ClassTable* const class_table = class_loader->GetClassTable(); 3772 mirror::Class* klass = class_table->Lookup(descriptor_, hash_); 3773 if (klass != nullptr) { 3774 result_->push_back(klass); 3775 } 3776 } 3777 3778 private: 3779 const char* const descriptor_; 3780 const size_t hash_; 3781 std::vector<mirror::Class*>* const result_; 3782}; 3783 3784void ClassLinker::LookupClasses(const char* descriptor, std::vector<mirror::Class*>& result) { 3785 result.clear(); 3786 if (dex_cache_boot_image_class_lookup_required_) { 3787 AddBootImageClassesToClassTable(); 3788 } 3789 Thread* const self = Thread::Current(); 3790 ReaderMutexLock mu(self, *Locks::classlinker_classes_lock_); 3791 const size_t hash = ComputeModifiedUtf8Hash(descriptor); 3792 mirror::Class* klass = boot_class_table_.Lookup(descriptor, hash); 3793 if (klass != nullptr) { 3794 result.push_back(klass); 3795 } 3796 LookupClassesVisitor visitor(descriptor, hash, &result); 3797 VisitClassLoaders(&visitor); 3798} 3799 3800bool ClassLinker::AttemptSupertypeVerification(Thread* self, 3801 Handle<mirror::Class> klass, 3802 Handle<mirror::Class> supertype) { 3803 DCHECK(self != nullptr); 3804 DCHECK(klass.Get() != nullptr); 3805 DCHECK(supertype.Get() != nullptr); 3806 3807 if (!supertype->IsVerified() && !supertype->IsErroneous()) { 3808 VerifyClass(self, supertype); 3809 } 3810 if (supertype->IsCompileTimeVerified()) { 3811 // Either we are verified or we soft failed and need to retry at runtime. 3812 return true; 3813 } 3814 // If we got this far then we have a hard failure. 3815 std::string error_msg = 3816 StringPrintf("Rejecting class %s that attempts to sub-type erroneous class %s", 3817 PrettyDescriptor(klass.Get()).c_str(), 3818 PrettyDescriptor(supertype.Get()).c_str()); 3819 LOG(WARNING) << error_msg << " in " << klass->GetDexCache()->GetLocation()->ToModifiedUtf8(); 3820 StackHandleScope<1> hs(self); 3821 Handle<mirror::Throwable> cause(hs.NewHandle(self->GetException())); 3822 if (cause.Get() != nullptr) { 3823 // Set during VerifyClass call (if at all). 3824 self->ClearException(); 3825 } 3826 // Change into a verify error. 3827 ThrowVerifyError(klass.Get(), "%s", error_msg.c_str()); 3828 if (cause.Get() != nullptr) { 3829 self->GetException()->SetCause(cause.Get()); 3830 } 3831 ClassReference ref(klass->GetDexCache()->GetDexFile(), klass->GetDexClassDefIndex()); 3832 if (Runtime::Current()->IsAotCompiler()) { 3833 Runtime::Current()->GetCompilerCallbacks()->ClassRejected(ref); 3834 } 3835 // Need to grab the lock to change status. 3836 ObjectLock<mirror::Class> super_lock(self, klass); 3837 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 3838 return false; 3839} 3840 3841void ClassLinker::VerifyClass(Thread* self, Handle<mirror::Class> klass, LogSeverity log_level) { 3842 { 3843 // TODO: assert that the monitor on the Class is held 3844 ObjectLock<mirror::Class> lock(self, klass); 3845 3846 // Is somebody verifying this now? 3847 mirror::Class::Status old_status = klass->GetStatus(); 3848 while (old_status == mirror::Class::kStatusVerifying || 3849 old_status == mirror::Class::kStatusVerifyingAtRuntime) { 3850 lock.WaitIgnoringInterrupts(); 3851 CHECK(klass->IsErroneous() || (klass->GetStatus() > old_status)) 3852 << "Class '" << PrettyClass(klass.Get()) << "' performed an illegal verification state " 3853 << "transition from " << old_status << " to " << klass->GetStatus(); 3854 old_status = klass->GetStatus(); 3855 } 3856 3857 // The class might already be erroneous, for example at compile time if we attempted to verify 3858 // this class as a parent to another. 3859 if (klass->IsErroneous()) { 3860 ThrowEarlierClassFailure(klass.Get()); 3861 return; 3862 } 3863 3864 // Don't attempt to re-verify if already sufficiently verified. 3865 if (klass->IsVerified()) { 3866 EnsureSkipAccessChecksMethods(klass); 3867 return; 3868 } 3869 if (klass->IsCompileTimeVerified() && Runtime::Current()->IsAotCompiler()) { 3870 return; 3871 } 3872 3873 if (klass->GetStatus() == mirror::Class::kStatusResolved) { 3874 mirror::Class::SetStatus(klass, mirror::Class::kStatusVerifying, self); 3875 } else { 3876 CHECK_EQ(klass->GetStatus(), mirror::Class::kStatusRetryVerificationAtRuntime) 3877 << PrettyClass(klass.Get()); 3878 CHECK(!Runtime::Current()->IsAotCompiler()); 3879 mirror::Class::SetStatus(klass, mirror::Class::kStatusVerifyingAtRuntime, self); 3880 } 3881 3882 // Skip verification if disabled. 3883 if (!Runtime::Current()->IsVerificationEnabled()) { 3884 mirror::Class::SetStatus(klass, mirror::Class::kStatusVerified, self); 3885 EnsureSkipAccessChecksMethods(klass); 3886 return; 3887 } 3888 } 3889 3890 // Verify super class. 3891 StackHandleScope<2> hs(self); 3892 MutableHandle<mirror::Class> supertype(hs.NewHandle(klass->GetSuperClass())); 3893 // If we have a superclass and we get a hard verification failure we can return immediately. 3894 if (supertype.Get() != nullptr && !AttemptSupertypeVerification(self, klass, supertype)) { 3895 CHECK(self->IsExceptionPending()) << "Verification error should be pending."; 3896 return; 3897 } 3898 3899 // Verify all default super-interfaces. 3900 // 3901 // (1) Don't bother if the superclass has already had a soft verification failure. 3902 // 3903 // (2) Interfaces shouldn't bother to do this recursive verification because they cannot cause 3904 // recursive initialization by themselves. This is because when an interface is initialized 3905 // directly it must not initialize its superinterfaces. We are allowed to verify regardless 3906 // but choose not to for an optimization. If the interfaces is being verified due to a class 3907 // initialization (which would need all the default interfaces to be verified) the class code 3908 // will trigger the recursive verification anyway. 3909 if ((supertype.Get() == nullptr || supertype->IsVerified()) // See (1) 3910 && !klass->IsInterface()) { // See (2) 3911 int32_t iftable_count = klass->GetIfTableCount(); 3912 MutableHandle<mirror::Class> iface(hs.NewHandle<mirror::Class>(nullptr)); 3913 // Loop through all interfaces this class has defined. It doesn't matter the order. 3914 for (int32_t i = 0; i < iftable_count; i++) { 3915 iface.Assign(klass->GetIfTable()->GetInterface(i)); 3916 DCHECK(iface.Get() != nullptr); 3917 // We only care if we have default interfaces and can skip if we are already verified... 3918 if (LIKELY(!iface->HasDefaultMethods() || iface->IsVerified())) { 3919 continue; 3920 } else if (UNLIKELY(!AttemptSupertypeVerification(self, klass, iface))) { 3921 // We had a hard failure while verifying this interface. Just return immediately. 3922 CHECK(self->IsExceptionPending()) << "Verification error should be pending."; 3923 return; 3924 } else if (UNLIKELY(!iface->IsVerified())) { 3925 // We softly failed to verify the iface. Stop checking and clean up. 3926 // Put the iface into the supertype handle so we know what caused us to fail. 3927 supertype.Assign(iface.Get()); 3928 break; 3929 } 3930 } 3931 } 3932 3933 // At this point if verification failed, then supertype is the "first" supertype that failed 3934 // verification (without a specific order). If verification succeeded, then supertype is either 3935 // null or the original superclass of klass and is verified. 3936 DCHECK(supertype.Get() == nullptr || 3937 supertype.Get() == klass->GetSuperClass() || 3938 !supertype->IsVerified()); 3939 3940 // Try to use verification information from the oat file, otherwise do runtime verification. 3941 const DexFile& dex_file = *klass->GetDexCache()->GetDexFile(); 3942 mirror::Class::Status oat_file_class_status(mirror::Class::kStatusNotReady); 3943 bool preverified = VerifyClassUsingOatFile(dex_file, klass.Get(), oat_file_class_status); 3944 // If the oat file says the class had an error, re-run the verifier. That way we will get a 3945 // precise error message. To ensure a rerun, test: 3946 // oat_file_class_status == mirror::Class::kStatusError => !preverified 3947 DCHECK(!(oat_file_class_status == mirror::Class::kStatusError) || !preverified); 3948 3949 verifier::MethodVerifier::FailureKind verifier_failure = verifier::MethodVerifier::kNoFailure; 3950 std::string error_msg; 3951 if (!preverified) { 3952 Runtime* runtime = Runtime::Current(); 3953 verifier_failure = verifier::MethodVerifier::VerifyClass(self, 3954 klass.Get(), 3955 runtime->GetCompilerCallbacks(), 3956 runtime->IsAotCompiler(), 3957 log_level, 3958 &error_msg); 3959 } 3960 3961 // Verification is done, grab the lock again. 3962 ObjectLock<mirror::Class> lock(self, klass); 3963 3964 if (preverified || verifier_failure != verifier::MethodVerifier::kHardFailure) { 3965 if (!preverified && verifier_failure != verifier::MethodVerifier::kNoFailure) { 3966 VLOG(class_linker) << "Soft verification failure in class " << PrettyDescriptor(klass.Get()) 3967 << " in " << klass->GetDexCache()->GetLocation()->ToModifiedUtf8() 3968 << " because: " << error_msg; 3969 } 3970 self->AssertNoPendingException(); 3971 // Make sure all classes referenced by catch blocks are resolved. 3972 ResolveClassExceptionHandlerTypes(klass); 3973 if (verifier_failure == verifier::MethodVerifier::kNoFailure) { 3974 // Even though there were no verifier failures we need to respect whether the super-class and 3975 // super-default-interfaces were verified or requiring runtime reverification. 3976 if (supertype.Get() == nullptr || supertype->IsVerified()) { 3977 mirror::Class::SetStatus(klass, mirror::Class::kStatusVerified, self); 3978 } else { 3979 CHECK_EQ(supertype->GetStatus(), mirror::Class::kStatusRetryVerificationAtRuntime); 3980 mirror::Class::SetStatus(klass, mirror::Class::kStatusRetryVerificationAtRuntime, self); 3981 // Pretend a soft failure occurred so that we don't consider the class verified below. 3982 verifier_failure = verifier::MethodVerifier::kSoftFailure; 3983 } 3984 } else { 3985 CHECK_EQ(verifier_failure, verifier::MethodVerifier::kSoftFailure); 3986 // Soft failures at compile time should be retried at runtime. Soft 3987 // failures at runtime will be handled by slow paths in the generated 3988 // code. Set status accordingly. 3989 if (Runtime::Current()->IsAotCompiler()) { 3990 mirror::Class::SetStatus(klass, mirror::Class::kStatusRetryVerificationAtRuntime, self); 3991 } else { 3992 mirror::Class::SetStatus(klass, mirror::Class::kStatusVerified, self); 3993 // As this is a fake verified status, make sure the methods are _not_ marked 3994 // kAccSkipAccessChecks later. 3995 klass->SetVerificationAttempted(); 3996 } 3997 } 3998 } else { 3999 VLOG(verifier) << "Verification failed on class " << PrettyDescriptor(klass.Get()) 4000 << " in " << klass->GetDexCache()->GetLocation()->ToModifiedUtf8() 4001 << " because: " << error_msg; 4002 self->AssertNoPendingException(); 4003 ThrowVerifyError(klass.Get(), "%s", error_msg.c_str()); 4004 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 4005 } 4006 if (preverified || verifier_failure == verifier::MethodVerifier::kNoFailure) { 4007 // Class is verified so we don't need to do any access check on its methods. 4008 // Let the interpreter know it by setting the kAccSkipAccessChecks flag onto each 4009 // method. 4010 // Note: we're going here during compilation and at runtime. When we set the 4011 // kAccSkipAccessChecks flag when compiling image classes, the flag is recorded 4012 // in the image and is set when loading the image. 4013 4014 if (UNLIKELY(Runtime::Current()->IsVerificationSoftFail())) { 4015 // Never skip access checks if the verification soft fail is forced. 4016 // Mark the class as having a verification attempt to avoid re-running the verifier. 4017 klass->SetVerificationAttempted(); 4018 } else { 4019 EnsureSkipAccessChecksMethods(klass); 4020 } 4021 } 4022} 4023 4024void ClassLinker::EnsureSkipAccessChecksMethods(Handle<mirror::Class> klass) { 4025 if (!klass->WasVerificationAttempted()) { 4026 klass->SetSkipAccessChecksFlagOnAllMethods(image_pointer_size_); 4027 klass->SetVerificationAttempted(); 4028 } 4029} 4030 4031bool ClassLinker::VerifyClassUsingOatFile(const DexFile& dex_file, 4032 mirror::Class* klass, 4033 mirror::Class::Status& oat_file_class_status) { 4034 // If we're compiling, we can only verify the class using the oat file if 4035 // we are not compiling the image or if the class we're verifying is not part of 4036 // the app. In other words, we will only check for preverification of bootclasspath 4037 // classes. 4038 if (Runtime::Current()->IsAotCompiler()) { 4039 // Are we compiling the bootclasspath? 4040 if (Runtime::Current()->GetCompilerCallbacks()->IsBootImage()) { 4041 return false; 4042 } 4043 // We are compiling an app (not the image). 4044 4045 // Is this an app class? (I.e. not a bootclasspath class) 4046 if (klass->GetClassLoader() != nullptr) { 4047 return false; 4048 } 4049 } 4050 4051 const OatFile::OatDexFile* oat_dex_file = dex_file.GetOatDexFile(); 4052 // In case we run without an image there won't be a backing oat file. 4053 if (oat_dex_file == nullptr) { 4054 return false; 4055 } 4056 4057 // We may be running with a preopted oat file but without image. In this case, 4058 // we don't skip verification of skip_access_checks classes to ensure we initialize 4059 // dex caches with all types resolved during verification. 4060 // We need to trust image classes, as these might be coming out of a pre-opted, quickened boot 4061 // image (that we just failed loading), and the verifier can't be run on quickened opcodes when 4062 // the runtime isn't started. On the other hand, app classes can be re-verified even if they are 4063 // already pre-opted, as then the runtime is started. 4064 if (!Runtime::Current()->IsAotCompiler() && 4065 !Runtime::Current()->GetHeap()->HasBootImageSpace() && 4066 klass->GetClassLoader() != nullptr) { 4067 return false; 4068 } 4069 4070 uint16_t class_def_index = klass->GetDexClassDefIndex(); 4071 oat_file_class_status = oat_dex_file->GetOatClass(class_def_index).GetStatus(); 4072 if (oat_file_class_status == mirror::Class::kStatusVerified || 4073 oat_file_class_status == mirror::Class::kStatusInitialized) { 4074 return true; 4075 } 4076 // If we only verified a subset of the classes at compile time, we can end up with classes that 4077 // were resolved by the verifier. 4078 if (oat_file_class_status == mirror::Class::kStatusResolved) { 4079 return false; 4080 } 4081 if (oat_file_class_status == mirror::Class::kStatusRetryVerificationAtRuntime) { 4082 // Compile time verification failed with a soft error. Compile time verification can fail 4083 // because we have incomplete type information. Consider the following: 4084 // class ... { 4085 // Foo x; 4086 // .... () { 4087 // if (...) { 4088 // v1 gets assigned a type of resolved class Foo 4089 // } else { 4090 // v1 gets assigned a type of unresolved class Bar 4091 // } 4092 // iput x = v1 4093 // } } 4094 // when we merge v1 following the if-the-else it results in Conflict 4095 // (see verifier::RegType::Merge) as we can't know the type of Bar and we could possibly be 4096 // allowing an unsafe assignment to the field x in the iput (javac may have compiled this as 4097 // it knew Bar was a sub-class of Foo, but for us this may have been moved into a separate apk 4098 // at compile time). 4099 return false; 4100 } 4101 if (oat_file_class_status == mirror::Class::kStatusError) { 4102 // Compile time verification failed with a hard error. This is caused by invalid instructions 4103 // in the class. These errors are unrecoverable. 4104 return false; 4105 } 4106 if (oat_file_class_status == mirror::Class::kStatusNotReady) { 4107 // Status is uninitialized if we couldn't determine the status at compile time, for example, 4108 // not loading the class. 4109 // TODO: when the verifier doesn't rely on Class-es failing to resolve/load the type hierarchy 4110 // isn't a problem and this case shouldn't occur 4111 return false; 4112 } 4113 std::string temp; 4114 LOG(FATAL) << "Unexpected class status: " << oat_file_class_status 4115 << " " << dex_file.GetLocation() << " " << PrettyClass(klass) << " " 4116 << klass->GetDescriptor(&temp); 4117 UNREACHABLE(); 4118} 4119 4120void ClassLinker::ResolveClassExceptionHandlerTypes(Handle<mirror::Class> klass) { 4121 for (ArtMethod& method : klass->GetMethods(image_pointer_size_)) { 4122 ResolveMethodExceptionHandlerTypes(&method); 4123 } 4124} 4125 4126void ClassLinker::ResolveMethodExceptionHandlerTypes(ArtMethod* method) { 4127 // similar to DexVerifier::ScanTryCatchBlocks and dex2oat's ResolveExceptionsForMethod. 4128 const DexFile::CodeItem* code_item = 4129 method->GetDexFile()->GetCodeItem(method->GetCodeItemOffset()); 4130 if (code_item == nullptr) { 4131 return; // native or abstract method 4132 } 4133 if (code_item->tries_size_ == 0) { 4134 return; // nothing to process 4135 } 4136 const uint8_t* handlers_ptr = DexFile::GetCatchHandlerData(*code_item, 0); 4137 uint32_t handlers_size = DecodeUnsignedLeb128(&handlers_ptr); 4138 for (uint32_t idx = 0; idx < handlers_size; idx++) { 4139 CatchHandlerIterator iterator(handlers_ptr); 4140 for (; iterator.HasNext(); iterator.Next()) { 4141 // Ensure exception types are resolved so that they don't need resolution to be delivered, 4142 // unresolved exception types will be ignored by exception delivery 4143 if (iterator.GetHandlerTypeIndex() != DexFile::kDexNoIndex16) { 4144 mirror::Class* exception_type = ResolveType(iterator.GetHandlerTypeIndex(), method); 4145 if (exception_type == nullptr) { 4146 DCHECK(Thread::Current()->IsExceptionPending()); 4147 Thread::Current()->ClearException(); 4148 } 4149 } 4150 } 4151 handlers_ptr = iterator.EndDataPointer(); 4152 } 4153} 4154 4155mirror::Class* ClassLinker::CreateProxyClass(ScopedObjectAccessAlreadyRunnable& soa, 4156 jstring name, 4157 jobjectArray interfaces, 4158 jobject loader, 4159 jobjectArray methods, 4160 jobjectArray throws) { 4161 Thread* self = soa.Self(); 4162 StackHandleScope<10> hs(self); 4163 MutableHandle<mirror::Class> klass(hs.NewHandle( 4164 AllocClass(self, GetClassRoot(kJavaLangClass), sizeof(mirror::Class)))); 4165 if (klass.Get() == nullptr) { 4166 CHECK(self->IsExceptionPending()); // OOME. 4167 return nullptr; 4168 } 4169 DCHECK(klass->GetClass() != nullptr); 4170 klass->SetObjectSize(sizeof(mirror::Proxy)); 4171 // Set the class access flags incl. VerificationAttempted, so we do not try to set the flag on 4172 // the methods. 4173 klass->SetAccessFlags(kAccClassIsProxy | kAccPublic | kAccFinal | kAccVerificationAttempted); 4174 klass->SetClassLoader(soa.Decode<mirror::ClassLoader*>(loader)); 4175 DCHECK_EQ(klass->GetPrimitiveType(), Primitive::kPrimNot); 4176 klass->SetName(soa.Decode<mirror::String*>(name)); 4177 klass->SetDexCache(GetClassRoot(kJavaLangReflectProxy)->GetDexCache()); 4178 mirror::Class::SetStatus(klass, mirror::Class::kStatusIdx, self); 4179 std::string descriptor(GetDescriptorForProxy(klass.Get())); 4180 const size_t hash = ComputeModifiedUtf8Hash(descriptor.c_str()); 4181 4182 // Needs to be before we insert the class so that the allocator field is set. 4183 LinearAlloc* const allocator = GetOrCreateAllocatorForClassLoader(klass->GetClassLoader()); 4184 4185 // Insert the class before loading the fields as the field roots 4186 // (ArtField::declaring_class_) are only visited from the class 4187 // table. There can't be any suspend points between inserting the 4188 // class and setting the field arrays below. 4189 mirror::Class* existing = InsertClass(descriptor.c_str(), klass.Get(), hash); 4190 CHECK(existing == nullptr); 4191 4192 // Instance fields are inherited, but we add a couple of static fields... 4193 const size_t num_fields = 2; 4194 LengthPrefixedArray<ArtField>* sfields = AllocArtFieldArray(self, allocator, num_fields); 4195 klass->SetSFieldsPtr(sfields); 4196 4197 // 1. Create a static field 'interfaces' that holds the _declared_ interfaces implemented by 4198 // our proxy, so Class.getInterfaces doesn't return the flattened set. 4199 ArtField& interfaces_sfield = sfields->At(0); 4200 interfaces_sfield.SetDexFieldIndex(0); 4201 interfaces_sfield.SetDeclaringClass(klass.Get()); 4202 interfaces_sfield.SetAccessFlags(kAccStatic | kAccPublic | kAccFinal); 4203 4204 // 2. Create a static field 'throws' that holds exceptions thrown by our methods. 4205 ArtField& throws_sfield = sfields->At(1); 4206 throws_sfield.SetDexFieldIndex(1); 4207 throws_sfield.SetDeclaringClass(klass.Get()); 4208 throws_sfield.SetAccessFlags(kAccStatic | kAccPublic | kAccFinal); 4209 4210 // Proxies have 1 direct method, the constructor 4211 const size_t num_direct_methods = 1; 4212 4213 // They have as many virtual methods as the array 4214 auto h_methods = hs.NewHandle(soa.Decode<mirror::ObjectArray<mirror::Method>*>(methods)); 4215 DCHECK_EQ(h_methods->GetClass(), mirror::Method::ArrayClass()) 4216 << PrettyClass(h_methods->GetClass()); 4217 const size_t num_virtual_methods = h_methods->GetLength(); 4218 4219 // Create the methods array. 4220 LengthPrefixedArray<ArtMethod>* proxy_class_methods = AllocArtMethodArray( 4221 self, allocator, num_direct_methods + num_virtual_methods); 4222 // Currently AllocArtMethodArray cannot return null, but the OOM logic is left there in case we 4223 // want to throw OOM in the future. 4224 if (UNLIKELY(proxy_class_methods == nullptr)) { 4225 self->AssertPendingOOMException(); 4226 return nullptr; 4227 } 4228 klass->SetMethodsPtr(proxy_class_methods, num_direct_methods, num_virtual_methods); 4229 4230 // Create the single direct method. 4231 CreateProxyConstructor(klass, klass->GetDirectMethodUnchecked(0, image_pointer_size_)); 4232 4233 // Create virtual method using specified prototypes. 4234 // TODO These should really use the iterators. 4235 for (size_t i = 0; i < num_virtual_methods; ++i) { 4236 auto* virtual_method = klass->GetVirtualMethodUnchecked(i, image_pointer_size_); 4237 auto* prototype = h_methods->Get(i)->GetArtMethod(); 4238 CreateProxyMethod(klass, prototype, virtual_method); 4239 DCHECK(virtual_method->GetDeclaringClass() != nullptr); 4240 DCHECK(prototype->GetDeclaringClass() != nullptr); 4241 } 4242 4243 // The super class is java.lang.reflect.Proxy 4244 klass->SetSuperClass(GetClassRoot(kJavaLangReflectProxy)); 4245 // Now effectively in the loaded state. 4246 mirror::Class::SetStatus(klass, mirror::Class::kStatusLoaded, self); 4247 self->AssertNoPendingException(); 4248 4249 MutableHandle<mirror::Class> new_class = hs.NewHandle<mirror::Class>(nullptr); 4250 { 4251 // Must hold lock on object when resolved. 4252 ObjectLock<mirror::Class> resolution_lock(self, klass); 4253 // Link the fields and virtual methods, creating vtable and iftables. 4254 // The new class will replace the old one in the class table. 4255 Handle<mirror::ObjectArray<mirror::Class>> h_interfaces( 4256 hs.NewHandle(soa.Decode<mirror::ObjectArray<mirror::Class>*>(interfaces))); 4257 if (!LinkClass(self, descriptor.c_str(), klass, h_interfaces, &new_class)) { 4258 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 4259 return nullptr; 4260 } 4261 } 4262 CHECK(klass->IsRetired()); 4263 CHECK_NE(klass.Get(), new_class.Get()); 4264 klass.Assign(new_class.Get()); 4265 4266 CHECK_EQ(interfaces_sfield.GetDeclaringClass(), klass.Get()); 4267 interfaces_sfield.SetObject<false>(klass.Get(), 4268 soa.Decode<mirror::ObjectArray<mirror::Class>*>(interfaces)); 4269 CHECK_EQ(throws_sfield.GetDeclaringClass(), klass.Get()); 4270 throws_sfield.SetObject<false>( 4271 klass.Get(), soa.Decode<mirror::ObjectArray<mirror::ObjectArray<mirror::Class> >*>(throws)); 4272 4273 { 4274 // Lock on klass is released. Lock new class object. 4275 ObjectLock<mirror::Class> initialization_lock(self, klass); 4276 mirror::Class::SetStatus(klass, mirror::Class::kStatusInitialized, self); 4277 } 4278 4279 // sanity checks 4280 if (kIsDebugBuild) { 4281 CHECK(klass->GetIFieldsPtr() == nullptr); 4282 CheckProxyConstructor(klass->GetDirectMethod(0, image_pointer_size_)); 4283 4284 for (size_t i = 0; i < num_virtual_methods; ++i) { 4285 auto* virtual_method = klass->GetVirtualMethodUnchecked(i, image_pointer_size_); 4286 auto* prototype = h_methods->Get(i++)->GetArtMethod(); 4287 CheckProxyMethod(virtual_method, prototype); 4288 } 4289 4290 StackHandleScope<1> hs2(self); 4291 Handle<mirror::String> decoded_name = hs2.NewHandle(soa.Decode<mirror::String*>(name)); 4292 std::string interfaces_field_name(StringPrintf("java.lang.Class[] %s.interfaces", 4293 decoded_name->ToModifiedUtf8().c_str())); 4294 CHECK_EQ(PrettyField(klass->GetStaticField(0)), interfaces_field_name); 4295 4296 std::string throws_field_name(StringPrintf("java.lang.Class[][] %s.throws", 4297 decoded_name->ToModifiedUtf8().c_str())); 4298 CHECK_EQ(PrettyField(klass->GetStaticField(1)), throws_field_name); 4299 4300 CHECK_EQ(klass.Get()->GetInterfaces(), 4301 soa.Decode<mirror::ObjectArray<mirror::Class>*>(interfaces)); 4302 CHECK_EQ(klass.Get()->GetThrows(), 4303 soa.Decode<mirror::ObjectArray<mirror::ObjectArray<mirror::Class>>*>(throws)); 4304 } 4305 return klass.Get(); 4306} 4307 4308std::string ClassLinker::GetDescriptorForProxy(mirror::Class* proxy_class) { 4309 DCHECK(proxy_class->IsProxyClass()); 4310 mirror::String* name = proxy_class->GetName(); 4311 DCHECK(name != nullptr); 4312 return DotToDescriptor(name->ToModifiedUtf8().c_str()); 4313} 4314 4315ArtMethod* ClassLinker::FindMethodForProxy(mirror::Class* proxy_class, ArtMethod* proxy_method) { 4316 DCHECK(proxy_class->IsProxyClass()); 4317 DCHECK(proxy_method->IsProxyMethod()); 4318 { 4319 Thread* const self = Thread::Current(); 4320 ReaderMutexLock mu(self, dex_lock_); 4321 // Locate the dex cache of the original interface/Object 4322 for (const DexCacheData& data : dex_caches_) { 4323 if (!self->IsJWeakCleared(data.weak_root) && 4324 proxy_method->HasSameDexCacheResolvedTypes(data.resolved_types, 4325 image_pointer_size_)) { 4326 mirror::DexCache* dex_cache = down_cast<mirror::DexCache*>( 4327 self->DecodeJObject(data.weak_root)); 4328 if (dex_cache != nullptr) { 4329 ArtMethod* resolved_method = dex_cache->GetResolvedMethod( 4330 proxy_method->GetDexMethodIndex(), image_pointer_size_); 4331 CHECK(resolved_method != nullptr); 4332 return resolved_method; 4333 } 4334 } 4335 } 4336 } 4337 LOG(FATAL) << "Didn't find dex cache for " << PrettyClass(proxy_class) << " " 4338 << PrettyMethod(proxy_method); 4339 UNREACHABLE(); 4340} 4341 4342void ClassLinker::CreateProxyConstructor(Handle<mirror::Class> klass, ArtMethod* out) { 4343 // Create constructor for Proxy that must initialize the method. 4344 CHECK_EQ(GetClassRoot(kJavaLangReflectProxy)->NumDirectMethods(), 18u); 4345 ArtMethod* proxy_constructor = GetClassRoot(kJavaLangReflectProxy)->GetDirectMethodUnchecked( 4346 2, image_pointer_size_); 4347 DCHECK_EQ(std::string(proxy_constructor->GetName()), "<init>"); 4348 // Ensure constructor is in dex cache so that we can use the dex cache to look up the overridden 4349 // constructor method. 4350 GetClassRoot(kJavaLangReflectProxy)->GetDexCache()->SetResolvedMethod( 4351 proxy_constructor->GetDexMethodIndex(), proxy_constructor, image_pointer_size_); 4352 // Clone the existing constructor of Proxy (our constructor would just invoke it so steal its 4353 // code_ too) 4354 DCHECK(out != nullptr); 4355 out->CopyFrom(proxy_constructor, image_pointer_size_); 4356 // Make this constructor public and fix the class to be our Proxy version 4357 out->SetAccessFlags((out->GetAccessFlags() & ~kAccProtected) | kAccPublic); 4358 out->SetDeclaringClass(klass.Get()); 4359} 4360 4361void ClassLinker::CheckProxyConstructor(ArtMethod* constructor) const { 4362 CHECK(constructor->IsConstructor()); 4363 auto* np = constructor->GetInterfaceMethodIfProxy(image_pointer_size_); 4364 CHECK_STREQ(np->GetName(), "<init>"); 4365 CHECK_STREQ(np->GetSignature().ToString().c_str(), "(Ljava/lang/reflect/InvocationHandler;)V"); 4366 DCHECK(constructor->IsPublic()); 4367} 4368 4369void ClassLinker::CreateProxyMethod(Handle<mirror::Class> klass, ArtMethod* prototype, 4370 ArtMethod* out) { 4371 // Ensure prototype is in dex cache so that we can use the dex cache to look up the overridden 4372 // prototype method 4373 auto* dex_cache = prototype->GetDeclaringClass()->GetDexCache(); 4374 // Avoid dirtying the dex cache unless we need to. 4375 if (dex_cache->GetResolvedMethod(prototype->GetDexMethodIndex(), image_pointer_size_) != 4376 prototype) { 4377 dex_cache->SetResolvedMethod( 4378 prototype->GetDexMethodIndex(), prototype, image_pointer_size_); 4379 } 4380 // We steal everything from the prototype (such as DexCache, invoke stub, etc.) then specialize 4381 // as necessary 4382 DCHECK(out != nullptr); 4383 out->CopyFrom(prototype, image_pointer_size_); 4384 4385 // Set class to be the concrete proxy class. 4386 out->SetDeclaringClass(klass.Get()); 4387 // Clear the abstract, default and conflict flags to ensure that defaults aren't picked in 4388 // preference to the invocation handler. 4389 const uint32_t kRemoveFlags = kAccAbstract | kAccDefault | kAccDefaultConflict; 4390 // Make the method final. 4391 const uint32_t kAddFlags = kAccFinal; 4392 out->SetAccessFlags((out->GetAccessFlags() & ~kRemoveFlags) | kAddFlags); 4393 4394 // Clear the dex_code_item_offset_. It needs to be 0 since proxy methods have no CodeItems but the 4395 // method they copy might (if it's a default method). 4396 out->SetCodeItemOffset(0); 4397 4398 // At runtime the method looks like a reference and argument saving method, clone the code 4399 // related parameters from this method. 4400 out->SetEntryPointFromQuickCompiledCode(GetQuickProxyInvokeHandler()); 4401} 4402 4403void ClassLinker::CheckProxyMethod(ArtMethod* method, ArtMethod* prototype) const { 4404 // Basic sanity 4405 CHECK(!prototype->IsFinal()); 4406 CHECK(method->IsFinal()); 4407 CHECK(method->IsInvokable()); 4408 4409 // The proxy method doesn't have its own dex cache or dex file and so it steals those of its 4410 // interface prototype. The exception to this are Constructors and the Class of the Proxy itself. 4411 CHECK(prototype->HasSameDexCacheResolvedMethods(method, image_pointer_size_)); 4412 CHECK(prototype->HasSameDexCacheResolvedTypes(method, image_pointer_size_)); 4413 auto* np = method->GetInterfaceMethodIfProxy(image_pointer_size_); 4414 CHECK_EQ(prototype->GetDeclaringClass()->GetDexCache(), np->GetDexCache()); 4415 CHECK_EQ(prototype->GetDexMethodIndex(), method->GetDexMethodIndex()); 4416 4417 CHECK_STREQ(np->GetName(), prototype->GetName()); 4418 CHECK_STREQ(np->GetShorty(), prototype->GetShorty()); 4419 // More complex sanity - via dex cache 4420 CHECK_EQ(np->GetReturnType(true /* resolve */, image_pointer_size_), 4421 prototype->GetReturnType(true /* resolve */, image_pointer_size_)); 4422} 4423 4424bool ClassLinker::CanWeInitializeClass(mirror::Class* klass, bool can_init_statics, 4425 bool can_init_parents) { 4426 if (can_init_statics && can_init_parents) { 4427 return true; 4428 } 4429 if (!can_init_statics) { 4430 // Check if there's a class initializer. 4431 ArtMethod* clinit = klass->FindClassInitializer(image_pointer_size_); 4432 if (clinit != nullptr) { 4433 return false; 4434 } 4435 // Check if there are encoded static values needing initialization. 4436 if (klass->NumStaticFields() != 0) { 4437 const DexFile::ClassDef* dex_class_def = klass->GetClassDef(); 4438 DCHECK(dex_class_def != nullptr); 4439 if (dex_class_def->static_values_off_ != 0) { 4440 return false; 4441 } 4442 } 4443 // If we are a class we need to initialize all interfaces with default methods when we are 4444 // initialized. Check all of them. 4445 if (!klass->IsInterface()) { 4446 size_t num_interfaces = klass->GetIfTableCount(); 4447 for (size_t i = 0; i < num_interfaces; i++) { 4448 mirror::Class* iface = klass->GetIfTable()->GetInterface(i); 4449 if (iface->HasDefaultMethods() && 4450 !CanWeInitializeClass(iface, can_init_statics, can_init_parents)) { 4451 return false; 4452 } 4453 } 4454 } 4455 } 4456 if (klass->IsInterface() || !klass->HasSuperClass()) { 4457 return true; 4458 } 4459 mirror::Class* super_class = klass->GetSuperClass(); 4460 if (!can_init_parents && !super_class->IsInitialized()) { 4461 return false; 4462 } 4463 return CanWeInitializeClass(super_class, can_init_statics, can_init_parents); 4464} 4465 4466bool ClassLinker::InitializeClass(Thread* self, Handle<mirror::Class> klass, 4467 bool can_init_statics, bool can_init_parents) { 4468 // see JLS 3rd edition, 12.4.2 "Detailed Initialization Procedure" for the locking protocol 4469 4470 // Are we already initialized and therefore done? 4471 // Note: we differ from the JLS here as we don't do this under the lock, this is benign as 4472 // an initialized class will never change its state. 4473 if (klass->IsInitialized()) { 4474 return true; 4475 } 4476 4477 // Fast fail if initialization requires a full runtime. Not part of the JLS. 4478 if (!CanWeInitializeClass(klass.Get(), can_init_statics, can_init_parents)) { 4479 return false; 4480 } 4481 4482 self->AllowThreadSuspension(); 4483 uint64_t t0; 4484 { 4485 ObjectLock<mirror::Class> lock(self, klass); 4486 4487 // Re-check under the lock in case another thread initialized ahead of us. 4488 if (klass->IsInitialized()) { 4489 return true; 4490 } 4491 4492 // Was the class already found to be erroneous? Done under the lock to match the JLS. 4493 if (klass->IsErroneous()) { 4494 ThrowEarlierClassFailure(klass.Get(), true); 4495 VlogClassInitializationFailure(klass); 4496 return false; 4497 } 4498 4499 CHECK(klass->IsResolved()) << PrettyClass(klass.Get()) << ": state=" << klass->GetStatus(); 4500 4501 if (!klass->IsVerified()) { 4502 VerifyClass(self, klass); 4503 if (!klass->IsVerified()) { 4504 // We failed to verify, expect either the klass to be erroneous or verification failed at 4505 // compile time. 4506 if (klass->IsErroneous()) { 4507 // The class is erroneous. This may be a verifier error, or another thread attempted 4508 // verification and/or initialization and failed. We can distinguish those cases by 4509 // whether an exception is already pending. 4510 if (self->IsExceptionPending()) { 4511 // Check that it's a VerifyError. 4512 DCHECK_EQ("java.lang.Class<java.lang.VerifyError>", 4513 PrettyClass(self->GetException()->GetClass())); 4514 } else { 4515 // Check that another thread attempted initialization. 4516 DCHECK_NE(0, klass->GetClinitThreadId()); 4517 DCHECK_NE(self->GetTid(), klass->GetClinitThreadId()); 4518 // Need to rethrow the previous failure now. 4519 ThrowEarlierClassFailure(klass.Get(), true); 4520 } 4521 VlogClassInitializationFailure(klass); 4522 } else { 4523 CHECK(Runtime::Current()->IsAotCompiler()); 4524 CHECK_EQ(klass->GetStatus(), mirror::Class::kStatusRetryVerificationAtRuntime); 4525 } 4526 return false; 4527 } else { 4528 self->AssertNoPendingException(); 4529 } 4530 4531 // A separate thread could have moved us all the way to initialized. A "simple" example 4532 // involves a subclass of the current class being initialized at the same time (which 4533 // will implicitly initialize the superclass, if scheduled that way). b/28254258 4534 DCHECK_NE(mirror::Class::kStatusError, klass->GetStatus()); 4535 if (klass->IsInitialized()) { 4536 return true; 4537 } 4538 } 4539 4540 // If the class is kStatusInitializing, either this thread is 4541 // initializing higher up the stack or another thread has beat us 4542 // to initializing and we need to wait. Either way, this 4543 // invocation of InitializeClass will not be responsible for 4544 // running <clinit> and will return. 4545 if (klass->GetStatus() == mirror::Class::kStatusInitializing) { 4546 // Could have got an exception during verification. 4547 if (self->IsExceptionPending()) { 4548 VlogClassInitializationFailure(klass); 4549 return false; 4550 } 4551 // We caught somebody else in the act; was it us? 4552 if (klass->GetClinitThreadId() == self->GetTid()) { 4553 // Yes. That's fine. Return so we can continue initializing. 4554 return true; 4555 } 4556 // No. That's fine. Wait for another thread to finish initializing. 4557 return WaitForInitializeClass(klass, self, lock); 4558 } 4559 4560 if (!ValidateSuperClassDescriptors(klass)) { 4561 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 4562 return false; 4563 } 4564 self->AllowThreadSuspension(); 4565 4566 CHECK_EQ(klass->GetStatus(), mirror::Class::kStatusVerified) << PrettyClass(klass.Get()) 4567 << " self.tid=" << self->GetTid() << " clinit.tid=" << klass->GetClinitThreadId(); 4568 4569 // From here out other threads may observe that we're initializing and so changes of state 4570 // require the a notification. 4571 klass->SetClinitThreadId(self->GetTid()); 4572 mirror::Class::SetStatus(klass, mirror::Class::kStatusInitializing, self); 4573 4574 t0 = NanoTime(); 4575 } 4576 4577 // Initialize super classes, must be done while initializing for the JLS. 4578 if (!klass->IsInterface() && klass->HasSuperClass()) { 4579 mirror::Class* super_class = klass->GetSuperClass(); 4580 if (!super_class->IsInitialized()) { 4581 CHECK(!super_class->IsInterface()); 4582 CHECK(can_init_parents); 4583 StackHandleScope<1> hs(self); 4584 Handle<mirror::Class> handle_scope_super(hs.NewHandle(super_class)); 4585 bool super_initialized = InitializeClass(self, handle_scope_super, can_init_statics, true); 4586 if (!super_initialized) { 4587 // The super class was verified ahead of entering initializing, we should only be here if 4588 // the super class became erroneous due to initialization. 4589 CHECK(handle_scope_super->IsErroneous() && self->IsExceptionPending()) 4590 << "Super class initialization failed for " 4591 << PrettyDescriptor(handle_scope_super.Get()) 4592 << " that has unexpected status " << handle_scope_super->GetStatus() 4593 << "\nPending exception:\n" 4594 << (self->GetException() != nullptr ? self->GetException()->Dump() : ""); 4595 ObjectLock<mirror::Class> lock(self, klass); 4596 // Initialization failed because the super-class is erroneous. 4597 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 4598 return false; 4599 } 4600 } 4601 } 4602 4603 if (!klass->IsInterface()) { 4604 // Initialize interfaces with default methods for the JLS. 4605 size_t num_direct_interfaces = klass->NumDirectInterfaces(); 4606 // Only setup the (expensive) handle scope if we actually need to. 4607 if (UNLIKELY(num_direct_interfaces > 0)) { 4608 StackHandleScope<1> hs_iface(self); 4609 MutableHandle<mirror::Class> handle_scope_iface(hs_iface.NewHandle<mirror::Class>(nullptr)); 4610 for (size_t i = 0; i < num_direct_interfaces; i++) { 4611 handle_scope_iface.Assign(mirror::Class::GetDirectInterface(self, klass, i)); 4612 CHECK(handle_scope_iface.Get() != nullptr); 4613 CHECK(handle_scope_iface->IsInterface()); 4614 if (handle_scope_iface->HasBeenRecursivelyInitialized()) { 4615 // We have already done this for this interface. Skip it. 4616 continue; 4617 } 4618 // We cannot just call initialize class directly because we need to ensure that ALL 4619 // interfaces with default methods are initialized. Non-default interface initialization 4620 // will not affect other non-default super-interfaces. 4621 bool iface_initialized = InitializeDefaultInterfaceRecursive(self, 4622 handle_scope_iface, 4623 can_init_statics, 4624 can_init_parents); 4625 if (!iface_initialized) { 4626 ObjectLock<mirror::Class> lock(self, klass); 4627 // Initialization failed because one of our interfaces with default methods is erroneous. 4628 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 4629 return false; 4630 } 4631 } 4632 } 4633 } 4634 4635 const size_t num_static_fields = klass->NumStaticFields(); 4636 if (num_static_fields > 0) { 4637 const DexFile::ClassDef* dex_class_def = klass->GetClassDef(); 4638 CHECK(dex_class_def != nullptr); 4639 const DexFile& dex_file = klass->GetDexFile(); 4640 StackHandleScope<3> hs(self); 4641 Handle<mirror::ClassLoader> class_loader(hs.NewHandle(klass->GetClassLoader())); 4642 Handle<mirror::DexCache> dex_cache(hs.NewHandle(klass->GetDexCache())); 4643 4644 // Eagerly fill in static fields so that the we don't have to do as many expensive 4645 // Class::FindStaticField in ResolveField. 4646 for (size_t i = 0; i < num_static_fields; ++i) { 4647 ArtField* field = klass->GetStaticField(i); 4648 const uint32_t field_idx = field->GetDexFieldIndex(); 4649 ArtField* resolved_field = dex_cache->GetResolvedField(field_idx, image_pointer_size_); 4650 if (resolved_field == nullptr) { 4651 dex_cache->SetResolvedField(field_idx, field, image_pointer_size_); 4652 } else { 4653 DCHECK_EQ(field, resolved_field); 4654 } 4655 } 4656 4657 EncodedStaticFieldValueIterator value_it(dex_file, &dex_cache, &class_loader, 4658 this, *dex_class_def); 4659 const uint8_t* class_data = dex_file.GetClassData(*dex_class_def); 4660 ClassDataItemIterator field_it(dex_file, class_data); 4661 if (value_it.HasNext()) { 4662 DCHECK(field_it.HasNextStaticField()); 4663 CHECK(can_init_statics); 4664 for ( ; value_it.HasNext(); value_it.Next(), field_it.Next()) { 4665 ArtField* field = ResolveField( 4666 dex_file, field_it.GetMemberIndex(), dex_cache, class_loader, true); 4667 if (Runtime::Current()->IsActiveTransaction()) { 4668 value_it.ReadValueToField<true>(field); 4669 } else { 4670 value_it.ReadValueToField<false>(field); 4671 } 4672 if (self->IsExceptionPending()) { 4673 break; 4674 } 4675 DCHECK(!value_it.HasNext() || field_it.HasNextStaticField()); 4676 } 4677 } 4678 } 4679 4680 4681 if (!self->IsExceptionPending()) { 4682 ArtMethod* clinit = klass->FindClassInitializer(image_pointer_size_); 4683 if (clinit != nullptr) { 4684 CHECK(can_init_statics); 4685 JValue result; 4686 clinit->Invoke(self, nullptr, 0, &result, "V"); 4687 } 4688 } 4689 self->AllowThreadSuspension(); 4690 uint64_t t1 = NanoTime(); 4691 4692 bool success = true; 4693 { 4694 ObjectLock<mirror::Class> lock(self, klass); 4695 4696 if (self->IsExceptionPending()) { 4697 WrapExceptionInInitializer(klass); 4698 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 4699 success = false; 4700 } else if (Runtime::Current()->IsTransactionAborted()) { 4701 // The exception thrown when the transaction aborted has been caught and cleared 4702 // so we need to throw it again now. 4703 VLOG(compiler) << "Return from class initializer of " << PrettyDescriptor(klass.Get()) 4704 << " without exception while transaction was aborted: re-throw it now."; 4705 Runtime::Current()->ThrowTransactionAbortError(self); 4706 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 4707 success = false; 4708 } else { 4709 RuntimeStats* global_stats = Runtime::Current()->GetStats(); 4710 RuntimeStats* thread_stats = self->GetStats(); 4711 ++global_stats->class_init_count; 4712 ++thread_stats->class_init_count; 4713 global_stats->class_init_time_ns += (t1 - t0); 4714 thread_stats->class_init_time_ns += (t1 - t0); 4715 // Set the class as initialized except if failed to initialize static fields. 4716 mirror::Class::SetStatus(klass, mirror::Class::kStatusInitialized, self); 4717 if (VLOG_IS_ON(class_linker)) { 4718 std::string temp; 4719 LOG(INFO) << "Initialized class " << klass->GetDescriptor(&temp) << " from " << 4720 klass->GetLocation(); 4721 } 4722 // Opportunistically set static method trampolines to their destination. 4723 FixupStaticTrampolines(klass.Get()); 4724 } 4725 } 4726 return success; 4727} 4728 4729// We recursively run down the tree of interfaces. We need to do this in the order they are declared 4730// and perform the initialization only on those interfaces that contain default methods. 4731bool ClassLinker::InitializeDefaultInterfaceRecursive(Thread* self, 4732 Handle<mirror::Class> iface, 4733 bool can_init_statics, 4734 bool can_init_parents) { 4735 CHECK(iface->IsInterface()); 4736 size_t num_direct_ifaces = iface->NumDirectInterfaces(); 4737 // Only create the (expensive) handle scope if we need it. 4738 if (UNLIKELY(num_direct_ifaces > 0)) { 4739 StackHandleScope<1> hs(self); 4740 MutableHandle<mirror::Class> handle_super_iface(hs.NewHandle<mirror::Class>(nullptr)); 4741 // First we initialize all of iface's super-interfaces recursively. 4742 for (size_t i = 0; i < num_direct_ifaces; i++) { 4743 mirror::Class* super_iface = mirror::Class::GetDirectInterface(self, iface, i); 4744 if (!super_iface->HasBeenRecursivelyInitialized()) { 4745 // Recursive step 4746 handle_super_iface.Assign(super_iface); 4747 if (!InitializeDefaultInterfaceRecursive(self, 4748 handle_super_iface, 4749 can_init_statics, 4750 can_init_parents)) { 4751 return false; 4752 } 4753 } 4754 } 4755 } 4756 4757 bool result = true; 4758 // Then we initialize 'iface' if it has default methods. We do not need to (and in fact must not) 4759 // initialize if we don't have default methods. 4760 if (iface->HasDefaultMethods()) { 4761 result = EnsureInitialized(self, iface, can_init_statics, can_init_parents); 4762 } 4763 4764 // Mark that this interface has undergone recursive default interface initialization so we know we 4765 // can skip it on any later class initializations. We do this even if we are not a default 4766 // interface since we can still avoid the traversal. This is purely a performance optimization. 4767 if (result) { 4768 // TODO This should be done in a better way 4769 ObjectLock<mirror::Class> lock(self, iface); 4770 iface->SetRecursivelyInitialized(); 4771 } 4772 return result; 4773} 4774 4775bool ClassLinker::WaitForInitializeClass(Handle<mirror::Class> klass, 4776 Thread* self, 4777 ObjectLock<mirror::Class>& lock) 4778 SHARED_REQUIRES(Locks::mutator_lock_) { 4779 while (true) { 4780 self->AssertNoPendingException(); 4781 CHECK(!klass->IsInitialized()); 4782 lock.WaitIgnoringInterrupts(); 4783 4784 // When we wake up, repeat the test for init-in-progress. If 4785 // there's an exception pending (only possible if 4786 // we were not using WaitIgnoringInterrupts), bail out. 4787 if (self->IsExceptionPending()) { 4788 WrapExceptionInInitializer(klass); 4789 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 4790 return false; 4791 } 4792 // Spurious wakeup? Go back to waiting. 4793 if (klass->GetStatus() == mirror::Class::kStatusInitializing) { 4794 continue; 4795 } 4796 if (klass->GetStatus() == mirror::Class::kStatusVerified && 4797 Runtime::Current()->IsAotCompiler()) { 4798 // Compile time initialization failed. 4799 return false; 4800 } 4801 if (klass->IsErroneous()) { 4802 // The caller wants an exception, but it was thrown in a 4803 // different thread. Synthesize one here. 4804 ThrowNoClassDefFoundError("<clinit> failed for class %s; see exception in other thread", 4805 PrettyDescriptor(klass.Get()).c_str()); 4806 VlogClassInitializationFailure(klass); 4807 return false; 4808 } 4809 if (klass->IsInitialized()) { 4810 return true; 4811 } 4812 LOG(FATAL) << "Unexpected class status. " << PrettyClass(klass.Get()) << " is " 4813 << klass->GetStatus(); 4814 } 4815 UNREACHABLE(); 4816} 4817 4818static void ThrowSignatureCheckResolveReturnTypeException(Handle<mirror::Class> klass, 4819 Handle<mirror::Class> super_klass, 4820 ArtMethod* method, 4821 ArtMethod* m) 4822 SHARED_REQUIRES(Locks::mutator_lock_) { 4823 DCHECK(Thread::Current()->IsExceptionPending()); 4824 DCHECK(!m->IsProxyMethod()); 4825 const DexFile* dex_file = m->GetDexFile(); 4826 const DexFile::MethodId& method_id = dex_file->GetMethodId(m->GetDexMethodIndex()); 4827 const DexFile::ProtoId& proto_id = dex_file->GetMethodPrototype(method_id); 4828 uint16_t return_type_idx = proto_id.return_type_idx_; 4829 std::string return_type = PrettyType(return_type_idx, *dex_file); 4830 std::string class_loader = PrettyTypeOf(m->GetDeclaringClass()->GetClassLoader()); 4831 ThrowWrappedLinkageError(klass.Get(), 4832 "While checking class %s method %s signature against %s %s: " 4833 "Failed to resolve return type %s with %s", 4834 PrettyDescriptor(klass.Get()).c_str(), 4835 PrettyMethod(method).c_str(), 4836 super_klass->IsInterface() ? "interface" : "superclass", 4837 PrettyDescriptor(super_klass.Get()).c_str(), 4838 return_type.c_str(), class_loader.c_str()); 4839} 4840 4841static void ThrowSignatureCheckResolveArgException(Handle<mirror::Class> klass, 4842 Handle<mirror::Class> super_klass, 4843 ArtMethod* method, 4844 ArtMethod* m, 4845 uint32_t index, 4846 uint32_t arg_type_idx) 4847 SHARED_REQUIRES(Locks::mutator_lock_) { 4848 DCHECK(Thread::Current()->IsExceptionPending()); 4849 DCHECK(!m->IsProxyMethod()); 4850 const DexFile* dex_file = m->GetDexFile(); 4851 std::string arg_type = PrettyType(arg_type_idx, *dex_file); 4852 std::string class_loader = PrettyTypeOf(m->GetDeclaringClass()->GetClassLoader()); 4853 ThrowWrappedLinkageError(klass.Get(), 4854 "While checking class %s method %s signature against %s %s: " 4855 "Failed to resolve arg %u type %s with %s", 4856 PrettyDescriptor(klass.Get()).c_str(), 4857 PrettyMethod(method).c_str(), 4858 super_klass->IsInterface() ? "interface" : "superclass", 4859 PrettyDescriptor(super_klass.Get()).c_str(), 4860 index, arg_type.c_str(), class_loader.c_str()); 4861} 4862 4863static void ThrowSignatureMismatch(Handle<mirror::Class> klass, 4864 Handle<mirror::Class> super_klass, 4865 ArtMethod* method, 4866 const std::string& error_msg) 4867 SHARED_REQUIRES(Locks::mutator_lock_) { 4868 ThrowLinkageError(klass.Get(), 4869 "Class %s method %s resolves differently in %s %s: %s", 4870 PrettyDescriptor(klass.Get()).c_str(), 4871 PrettyMethod(method).c_str(), 4872 super_klass->IsInterface() ? "interface" : "superclass", 4873 PrettyDescriptor(super_klass.Get()).c_str(), 4874 error_msg.c_str()); 4875} 4876 4877static bool HasSameSignatureWithDifferentClassLoaders(Thread* self, 4878 size_t pointer_size, 4879 Handle<mirror::Class> klass, 4880 Handle<mirror::Class> super_klass, 4881 ArtMethod* method1, 4882 ArtMethod* method2) 4883 SHARED_REQUIRES(Locks::mutator_lock_) { 4884 { 4885 StackHandleScope<1> hs(self); 4886 Handle<mirror::Class> return_type(hs.NewHandle(method1->GetReturnType(true /* resolve */, 4887 pointer_size))); 4888 if (UNLIKELY(return_type.Get() == nullptr)) { 4889 ThrowSignatureCheckResolveReturnTypeException(klass, super_klass, method1, method1); 4890 return false; 4891 } 4892 mirror::Class* other_return_type = method2->GetReturnType(true /* resolve */, 4893 pointer_size); 4894 if (UNLIKELY(other_return_type == nullptr)) { 4895 ThrowSignatureCheckResolveReturnTypeException(klass, super_klass, method1, method2); 4896 return false; 4897 } 4898 if (UNLIKELY(other_return_type != return_type.Get())) { 4899 ThrowSignatureMismatch(klass, super_klass, method1, 4900 StringPrintf("Return types mismatch: %s(%p) vs %s(%p)", 4901 PrettyClassAndClassLoader(return_type.Get()).c_str(), 4902 return_type.Get(), 4903 PrettyClassAndClassLoader(other_return_type).c_str(), 4904 other_return_type)); 4905 return false; 4906 } 4907 } 4908 const DexFile::TypeList* types1 = method1->GetParameterTypeList(); 4909 const DexFile::TypeList* types2 = method2->GetParameterTypeList(); 4910 if (types1 == nullptr) { 4911 if (types2 != nullptr && types2->Size() != 0) { 4912 ThrowSignatureMismatch(klass, super_klass, method1, 4913 StringPrintf("Type list mismatch with %s", 4914 PrettyMethod(method2, true).c_str())); 4915 return false; 4916 } 4917 return true; 4918 } else if (UNLIKELY(types2 == nullptr)) { 4919 if (types1->Size() != 0) { 4920 ThrowSignatureMismatch(klass, super_klass, method1, 4921 StringPrintf("Type list mismatch with %s", 4922 PrettyMethod(method2, true).c_str())); 4923 return false; 4924 } 4925 return true; 4926 } 4927 uint32_t num_types = types1->Size(); 4928 if (UNLIKELY(num_types != types2->Size())) { 4929 ThrowSignatureMismatch(klass, super_klass, method1, 4930 StringPrintf("Type list mismatch with %s", 4931 PrettyMethod(method2, true).c_str())); 4932 return false; 4933 } 4934 for (uint32_t i = 0; i < num_types; ++i) { 4935 StackHandleScope<1> hs(self); 4936 uint32_t param_type_idx = types1->GetTypeItem(i).type_idx_; 4937 Handle<mirror::Class> param_type(hs.NewHandle( 4938 method1->GetClassFromTypeIndex(param_type_idx, true /* resolve */, pointer_size))); 4939 if (UNLIKELY(param_type.Get() == nullptr)) { 4940 ThrowSignatureCheckResolveArgException(klass, super_klass, method1, 4941 method1, i, param_type_idx); 4942 return false; 4943 } 4944 uint32_t other_param_type_idx = types2->GetTypeItem(i).type_idx_; 4945 mirror::Class* other_param_type = 4946 method2->GetClassFromTypeIndex(other_param_type_idx, true /* resolve */, pointer_size); 4947 if (UNLIKELY(other_param_type == nullptr)) { 4948 ThrowSignatureCheckResolveArgException(klass, super_klass, method1, 4949 method2, i, other_param_type_idx); 4950 return false; 4951 } 4952 if (UNLIKELY(param_type.Get() != other_param_type)) { 4953 ThrowSignatureMismatch(klass, super_klass, method1, 4954 StringPrintf("Parameter %u type mismatch: %s(%p) vs %s(%p)", 4955 i, 4956 PrettyClassAndClassLoader(param_type.Get()).c_str(), 4957 param_type.Get(), 4958 PrettyClassAndClassLoader(other_param_type).c_str(), 4959 other_param_type)); 4960 return false; 4961 } 4962 } 4963 return true; 4964} 4965 4966 4967bool ClassLinker::ValidateSuperClassDescriptors(Handle<mirror::Class> klass) { 4968 if (klass->IsInterface()) { 4969 return true; 4970 } 4971 // Begin with the methods local to the superclass. 4972 Thread* self = Thread::Current(); 4973 StackHandleScope<1> hs(self); 4974 MutableHandle<mirror::Class> super_klass(hs.NewHandle<mirror::Class>(nullptr)); 4975 if (klass->HasSuperClass() && 4976 klass->GetClassLoader() != klass->GetSuperClass()->GetClassLoader()) { 4977 super_klass.Assign(klass->GetSuperClass()); 4978 for (int i = klass->GetSuperClass()->GetVTableLength() - 1; i >= 0; --i) { 4979 auto* m = klass->GetVTableEntry(i, image_pointer_size_); 4980 auto* super_m = klass->GetSuperClass()->GetVTableEntry(i, image_pointer_size_); 4981 if (m != super_m) { 4982 if (UNLIKELY(!HasSameSignatureWithDifferentClassLoaders(self, image_pointer_size_, 4983 klass, super_klass, 4984 m, super_m))) { 4985 self->AssertPendingException(); 4986 return false; 4987 } 4988 } 4989 } 4990 } 4991 for (int32_t i = 0; i < klass->GetIfTableCount(); ++i) { 4992 super_klass.Assign(klass->GetIfTable()->GetInterface(i)); 4993 if (klass->GetClassLoader() != super_klass->GetClassLoader()) { 4994 uint32_t num_methods = super_klass->NumVirtualMethods(); 4995 for (uint32_t j = 0; j < num_methods; ++j) { 4996 auto* m = klass->GetIfTable()->GetMethodArray(i)->GetElementPtrSize<ArtMethod*>( 4997 j, image_pointer_size_); 4998 auto* super_m = super_klass->GetVirtualMethod(j, image_pointer_size_); 4999 if (m != super_m) { 5000 if (UNLIKELY(!HasSameSignatureWithDifferentClassLoaders(self, image_pointer_size_, 5001 klass, super_klass, 5002 m, super_m))) { 5003 self->AssertPendingException(); 5004 return false; 5005 } 5006 } 5007 } 5008 } 5009 } 5010 return true; 5011} 5012 5013bool ClassLinker::EnsureInitialized(Thread* self, Handle<mirror::Class> c, bool can_init_fields, 5014 bool can_init_parents) { 5015 DCHECK(c.Get() != nullptr); 5016 if (c->IsInitialized()) { 5017 EnsureSkipAccessChecksMethods(c); 5018 return true; 5019 } 5020 const bool success = InitializeClass(self, c, can_init_fields, can_init_parents); 5021 if (!success) { 5022 if (can_init_fields && can_init_parents) { 5023 CHECK(self->IsExceptionPending()) << PrettyClass(c.Get()); 5024 } 5025 } else { 5026 self->AssertNoPendingException(); 5027 } 5028 return success; 5029} 5030 5031void ClassLinker::FixupTemporaryDeclaringClass(mirror::Class* temp_class, 5032 mirror::Class* new_class) { 5033 DCHECK_EQ(temp_class->NumInstanceFields(), 0u); 5034 for (ArtField& field : new_class->GetIFields()) { 5035 if (field.GetDeclaringClass() == temp_class) { 5036 field.SetDeclaringClass(new_class); 5037 } 5038 } 5039 5040 DCHECK_EQ(temp_class->NumStaticFields(), 0u); 5041 for (ArtField& field : new_class->GetSFields()) { 5042 if (field.GetDeclaringClass() == temp_class) { 5043 field.SetDeclaringClass(new_class); 5044 } 5045 } 5046 5047 DCHECK_EQ(temp_class->NumDirectMethods(), 0u); 5048 DCHECK_EQ(temp_class->NumVirtualMethods(), 0u); 5049 for (auto& method : new_class->GetMethods(image_pointer_size_)) { 5050 if (method.GetDeclaringClass() == temp_class) { 5051 method.SetDeclaringClass(new_class); 5052 } 5053 } 5054 5055 // Make sure the remembered set and mod-union tables know that we updated some of the native 5056 // roots. 5057 Runtime::Current()->GetHeap()->WriteBarrierEveryFieldOf(new_class); 5058} 5059 5060void ClassLinker::RegisterClassLoader(mirror::ClassLoader* class_loader) { 5061 CHECK(class_loader->GetAllocator() == nullptr); 5062 CHECK(class_loader->GetClassTable() == nullptr); 5063 Thread* const self = Thread::Current(); 5064 ClassLoaderData data; 5065 data.weak_root = self->GetJniEnv()->vm->AddWeakGlobalRef(self, class_loader); 5066 // Create and set the class table. 5067 data.class_table = new ClassTable; 5068 class_loader->SetClassTable(data.class_table); 5069 // Create and set the linear allocator. 5070 data.allocator = Runtime::Current()->CreateLinearAlloc(); 5071 class_loader->SetAllocator(data.allocator); 5072 // Add to the list so that we know to free the data later. 5073 class_loaders_.push_back(data); 5074} 5075 5076ClassTable* ClassLinker::InsertClassTableForClassLoader(mirror::ClassLoader* class_loader) { 5077 if (class_loader == nullptr) { 5078 return &boot_class_table_; 5079 } 5080 ClassTable* class_table = class_loader->GetClassTable(); 5081 if (class_table == nullptr) { 5082 RegisterClassLoader(class_loader); 5083 class_table = class_loader->GetClassTable(); 5084 DCHECK(class_table != nullptr); 5085 } 5086 return class_table; 5087} 5088 5089ClassTable* ClassLinker::ClassTableForClassLoader(mirror::ClassLoader* class_loader) { 5090 return class_loader == nullptr ? &boot_class_table_ : class_loader->GetClassTable(); 5091} 5092 5093static ImTable* FindSuperImt(mirror::Class* klass, size_t pointer_size) 5094 SHARED_REQUIRES(Locks::mutator_lock_) { 5095 while (klass->HasSuperClass()) { 5096 klass = klass->GetSuperClass(); 5097 if (klass->ShouldHaveImt()) { 5098 return klass->GetImt(pointer_size); 5099 } 5100 } 5101 return nullptr; 5102} 5103 5104bool ClassLinker::LinkClass(Thread* self, 5105 const char* descriptor, 5106 Handle<mirror::Class> klass, 5107 Handle<mirror::ObjectArray<mirror::Class>> interfaces, 5108 MutableHandle<mirror::Class>* h_new_class_out) { 5109 CHECK_EQ(mirror::Class::kStatusLoaded, klass->GetStatus()); 5110 5111 if (!LinkSuperClass(klass)) { 5112 return false; 5113 } 5114 ArtMethod* imt_data[ImTable::kSize]; 5115 // If there are any new conflicts compared to super class. 5116 bool new_conflict = false; 5117 std::fill_n(imt_data, arraysize(imt_data), Runtime::Current()->GetImtUnimplementedMethod()); 5118 if (!LinkMethods(self, klass, interfaces, &new_conflict, imt_data)) { 5119 return false; 5120 } 5121 if (!LinkInstanceFields(self, klass)) { 5122 return false; 5123 } 5124 size_t class_size; 5125 if (!LinkStaticFields(self, klass, &class_size)) { 5126 return false; 5127 } 5128 CreateReferenceInstanceOffsets(klass); 5129 CHECK_EQ(mirror::Class::kStatusLoaded, klass->GetStatus()); 5130 5131 ImTable* imt = nullptr; 5132 if (klass->ShouldHaveImt()) { 5133 // If there are any new conflicts compared to the super class we can not make a copy. There 5134 // can be cases where both will have a conflict method at the same slot without having the same 5135 // set of conflicts. In this case, we can not share the IMT since the conflict table slow path 5136 // will possibly create a table that is incorrect for either of the classes. 5137 // Same IMT with new_conflict does not happen very often. 5138 if (!new_conflict) { 5139 ImTable* super_imt = FindSuperImt(klass.Get(), image_pointer_size_); 5140 if (super_imt != nullptr) { 5141 bool imt_equals = true; 5142 for (size_t i = 0; i < ImTable::kSize && imt_equals; ++i) { 5143 imt_equals = imt_equals && (super_imt->Get(i, image_pointer_size_) == imt_data[i]); 5144 } 5145 if (imt_equals) { 5146 imt = super_imt; 5147 } 5148 } 5149 } 5150 if (imt == nullptr) { 5151 LinearAlloc* allocator = GetAllocatorForClassLoader(klass->GetClassLoader()); 5152 imt = reinterpret_cast<ImTable*>( 5153 allocator->Alloc(self, ImTable::SizeInBytes(image_pointer_size_))); 5154 if (imt == nullptr) { 5155 return false; 5156 } 5157 imt->Populate(imt_data, image_pointer_size_); 5158 } 5159 } 5160 5161 if (!klass->IsTemp() || (!init_done_ && klass->GetClassSize() == class_size)) { 5162 // We don't need to retire this class as it has no embedded tables or it was created the 5163 // correct size during class linker initialization. 5164 CHECK_EQ(klass->GetClassSize(), class_size) << PrettyDescriptor(klass.Get()); 5165 5166 if (klass->ShouldHaveEmbeddedVTable()) { 5167 klass->PopulateEmbeddedVTable(image_pointer_size_); 5168 } 5169 if (klass->ShouldHaveImt()) { 5170 klass->SetImt(imt, image_pointer_size_); 5171 } 5172 // This will notify waiters on klass that saw the not yet resolved 5173 // class in the class_table_ during EnsureResolved. 5174 mirror::Class::SetStatus(klass, mirror::Class::kStatusResolved, self); 5175 h_new_class_out->Assign(klass.Get()); 5176 } else { 5177 CHECK(!klass->IsResolved()); 5178 // Retire the temporary class and create the correctly sized resolved class. 5179 StackHandleScope<1> hs(self); 5180 auto h_new_class = hs.NewHandle(klass->CopyOf(self, class_size, imt, image_pointer_size_)); 5181 // Set arrays to null since we don't want to have multiple classes with the same ArtField or 5182 // ArtMethod array pointers. If this occurs, it causes bugs in remembered sets since the GC 5183 // may not see any references to the target space and clean the card for a class if another 5184 // class had the same array pointer. 5185 klass->SetMethodsPtrUnchecked(nullptr, 0, 0); 5186 klass->SetSFieldsPtrUnchecked(nullptr); 5187 klass->SetIFieldsPtrUnchecked(nullptr); 5188 if (UNLIKELY(h_new_class.Get() == nullptr)) { 5189 self->AssertPendingOOMException(); 5190 mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); 5191 return false; 5192 } 5193 5194 CHECK_EQ(h_new_class->GetClassSize(), class_size); 5195 ObjectLock<mirror::Class> lock(self, h_new_class); 5196 FixupTemporaryDeclaringClass(klass.Get(), h_new_class.Get()); 5197 5198 { 5199 WriterMutexLock mu(self, *Locks::classlinker_classes_lock_); 5200 mirror::ClassLoader* const class_loader = h_new_class.Get()->GetClassLoader(); 5201 ClassTable* const table = InsertClassTableForClassLoader(class_loader); 5202 mirror::Class* existing = table->UpdateClass(descriptor, h_new_class.Get(), 5203 ComputeModifiedUtf8Hash(descriptor)); 5204 if (class_loader != nullptr) { 5205 // We updated the class in the class table, perform the write barrier so that the GC knows 5206 // about the change. 5207 Runtime::Current()->GetHeap()->WriteBarrierEveryFieldOf(class_loader); 5208 } 5209 CHECK_EQ(existing, klass.Get()); 5210 if (kIsDebugBuild && class_loader == nullptr && dex_cache_boot_image_class_lookup_required_) { 5211 // Check a class loaded with the system class loader matches one in the image if the class 5212 // is in the image. 5213 mirror::Class* const image_class = LookupClassFromBootImage(descriptor); 5214 if (image_class != nullptr) { 5215 CHECK_EQ(klass.Get(), existing) << descriptor; 5216 } 5217 } 5218 if (log_new_class_table_roots_) { 5219 new_class_roots_.push_back(GcRoot<mirror::Class>(h_new_class.Get())); 5220 } 5221 } 5222 5223 // This will notify waiters on temp class that saw the not yet resolved class in the 5224 // class_table_ during EnsureResolved. 5225 mirror::Class::SetStatus(klass, mirror::Class::kStatusRetired, self); 5226 5227 CHECK_EQ(h_new_class->GetStatus(), mirror::Class::kStatusResolving); 5228 // This will notify waiters on new_class that saw the not yet resolved 5229 // class in the class_table_ during EnsureResolved. 5230 mirror::Class::SetStatus(h_new_class, mirror::Class::kStatusResolved, self); 5231 // Return the new class. 5232 h_new_class_out->Assign(h_new_class.Get()); 5233 } 5234 return true; 5235} 5236 5237static void CountMethodsAndFields(ClassDataItemIterator& dex_data, 5238 size_t* virtual_methods, 5239 size_t* direct_methods, 5240 size_t* static_fields, 5241 size_t* instance_fields) { 5242 *virtual_methods = *direct_methods = *static_fields = *instance_fields = 0; 5243 5244 while (dex_data.HasNextStaticField()) { 5245 dex_data.Next(); 5246 (*static_fields)++; 5247 } 5248 while (dex_data.HasNextInstanceField()) { 5249 dex_data.Next(); 5250 (*instance_fields)++; 5251 } 5252 while (dex_data.HasNextDirectMethod()) { 5253 (*direct_methods)++; 5254 dex_data.Next(); 5255 } 5256 while (dex_data.HasNextVirtualMethod()) { 5257 (*virtual_methods)++; 5258 dex_data.Next(); 5259 } 5260 DCHECK(!dex_data.HasNext()); 5261} 5262 5263static void DumpClass(std::ostream& os, 5264 const DexFile& dex_file, const DexFile::ClassDef& dex_class_def, 5265 const char* suffix) { 5266 ClassDataItemIterator dex_data(dex_file, dex_file.GetClassData(dex_class_def)); 5267 os << dex_file.GetClassDescriptor(dex_class_def) << suffix << ":\n"; 5268 os << " Static fields:\n"; 5269 while (dex_data.HasNextStaticField()) { 5270 const DexFile::FieldId& id = dex_file.GetFieldId(dex_data.GetMemberIndex()); 5271 os << " " << dex_file.GetFieldTypeDescriptor(id) << " " << dex_file.GetFieldName(id) << "\n"; 5272 dex_data.Next(); 5273 } 5274 os << " Instance fields:\n"; 5275 while (dex_data.HasNextInstanceField()) { 5276 const DexFile::FieldId& id = dex_file.GetFieldId(dex_data.GetMemberIndex()); 5277 os << " " << dex_file.GetFieldTypeDescriptor(id) << " " << dex_file.GetFieldName(id) << "\n"; 5278 dex_data.Next(); 5279 } 5280 os << " Direct methods:\n"; 5281 while (dex_data.HasNextDirectMethod()) { 5282 const DexFile::MethodId& id = dex_file.GetMethodId(dex_data.GetMemberIndex()); 5283 os << " " << dex_file.GetMethodName(id) << dex_file.GetMethodSignature(id).ToString() << "\n"; 5284 dex_data.Next(); 5285 } 5286 os << " Virtual methods:\n"; 5287 while (dex_data.HasNextVirtualMethod()) { 5288 const DexFile::MethodId& id = dex_file.GetMethodId(dex_data.GetMemberIndex()); 5289 os << " " << dex_file.GetMethodName(id) << dex_file.GetMethodSignature(id).ToString() << "\n"; 5290 dex_data.Next(); 5291 } 5292} 5293 5294static std::string DumpClasses(const DexFile& dex_file1, 5295 const DexFile::ClassDef& dex_class_def1, 5296 const DexFile& dex_file2, 5297 const DexFile::ClassDef& dex_class_def2) { 5298 std::ostringstream os; 5299 DumpClass(os, dex_file1, dex_class_def1, " (Compile time)"); 5300 DumpClass(os, dex_file2, dex_class_def2, " (Runtime)"); 5301 return os.str(); 5302} 5303 5304 5305// Very simple structural check on whether the classes match. Only compares the number of 5306// methods and fields. 5307static bool SimpleStructuralCheck(const DexFile& dex_file1, 5308 const DexFile::ClassDef& dex_class_def1, 5309 const DexFile& dex_file2, 5310 const DexFile::ClassDef& dex_class_def2, 5311 std::string* error_msg) { 5312 ClassDataItemIterator dex_data1(dex_file1, dex_file1.GetClassData(dex_class_def1)); 5313 ClassDataItemIterator dex_data2(dex_file2, dex_file2.GetClassData(dex_class_def2)); 5314 5315 // Counters for current dex file. 5316 size_t dex_virtual_methods1, dex_direct_methods1, dex_static_fields1, dex_instance_fields1; 5317 CountMethodsAndFields(dex_data1, 5318 &dex_virtual_methods1, 5319 &dex_direct_methods1, 5320 &dex_static_fields1, 5321 &dex_instance_fields1); 5322 // Counters for compile-time dex file. 5323 size_t dex_virtual_methods2, dex_direct_methods2, dex_static_fields2, dex_instance_fields2; 5324 CountMethodsAndFields(dex_data2, 5325 &dex_virtual_methods2, 5326 &dex_direct_methods2, 5327 &dex_static_fields2, 5328 &dex_instance_fields2); 5329 5330 if (dex_virtual_methods1 != dex_virtual_methods2) { 5331 std::string class_dump = DumpClasses(dex_file1, dex_class_def1, dex_file2, dex_class_def2); 5332 *error_msg = StringPrintf("Virtual method count off: %zu vs %zu\n%s", 5333 dex_virtual_methods1, 5334 dex_virtual_methods2, 5335 class_dump.c_str()); 5336 return false; 5337 } 5338 if (dex_direct_methods1 != dex_direct_methods2) { 5339 std::string class_dump = DumpClasses(dex_file1, dex_class_def1, dex_file2, dex_class_def2); 5340 *error_msg = StringPrintf("Direct method count off: %zu vs %zu\n%s", 5341 dex_direct_methods1, 5342 dex_direct_methods2, 5343 class_dump.c_str()); 5344 return false; 5345 } 5346 if (dex_static_fields1 != dex_static_fields2) { 5347 std::string class_dump = DumpClasses(dex_file1, dex_class_def1, dex_file2, dex_class_def2); 5348 *error_msg = StringPrintf("Static field count off: %zu vs %zu\n%s", 5349 dex_static_fields1, 5350 dex_static_fields2, 5351 class_dump.c_str()); 5352 return false; 5353 } 5354 if (dex_instance_fields1 != dex_instance_fields2) { 5355 std::string class_dump = DumpClasses(dex_file1, dex_class_def1, dex_file2, dex_class_def2); 5356 *error_msg = StringPrintf("Instance field count off: %zu vs %zu\n%s", 5357 dex_instance_fields1, 5358 dex_instance_fields2, 5359 class_dump.c_str()); 5360 return false; 5361 } 5362 5363 return true; 5364} 5365 5366// Checks whether a the super-class changed from what we had at compile-time. This would 5367// invalidate quickening. 5368static bool CheckSuperClassChange(Handle<mirror::Class> klass, 5369 const DexFile& dex_file, 5370 const DexFile::ClassDef& class_def, 5371 mirror::Class* super_class) 5372 SHARED_REQUIRES(Locks::mutator_lock_) { 5373 // Check for unexpected changes in the superclass. 5374 // Quick check 1) is the super_class class-loader the boot class loader? This always has 5375 // precedence. 5376 if (super_class->GetClassLoader() != nullptr && 5377 // Quick check 2) different dex cache? Breaks can only occur for different dex files, 5378 // which is implied by different dex cache. 5379 klass->GetDexCache() != super_class->GetDexCache()) { 5380 // Now comes the expensive part: things can be broken if (a) the klass' dex file has a 5381 // definition for the super-class, and (b) the files are in separate oat files. The oat files 5382 // are referenced from the dex file, so do (b) first. Only relevant if we have oat files. 5383 const OatDexFile* class_oat_dex_file = dex_file.GetOatDexFile(); 5384 const OatFile* class_oat_file = nullptr; 5385 if (class_oat_dex_file != nullptr) { 5386 class_oat_file = class_oat_dex_file->GetOatFile(); 5387 } 5388 5389 if (class_oat_file != nullptr) { 5390 const OatDexFile* loaded_super_oat_dex_file = super_class->GetDexFile().GetOatDexFile(); 5391 const OatFile* loaded_super_oat_file = nullptr; 5392 if (loaded_super_oat_dex_file != nullptr) { 5393 loaded_super_oat_file = loaded_super_oat_dex_file->GetOatFile(); 5394 } 5395 5396 if (loaded_super_oat_file != nullptr && class_oat_file != loaded_super_oat_file) { 5397 // Now check (a). 5398 const DexFile::ClassDef* super_class_def = dex_file.FindClassDef(class_def.superclass_idx_); 5399 if (super_class_def != nullptr) { 5400 // Uh-oh, we found something. Do our check. 5401 std::string error_msg; 5402 if (!SimpleStructuralCheck(dex_file, *super_class_def, 5403 super_class->GetDexFile(), *super_class->GetClassDef(), 5404 &error_msg)) { 5405 // Print a warning to the log. This exception might be caught, e.g., as common in test 5406 // drivers. When the class is later tried to be used, we re-throw a new instance, as we 5407 // only save the type of the exception. 5408 LOG(WARNING) << "Incompatible structural change detected: " << 5409 StringPrintf( 5410 "Structural change of %s is hazardous (%s at compile time, %s at runtime): %s", 5411 PrettyType(super_class_def->class_idx_, dex_file).c_str(), 5412 class_oat_file->GetLocation().c_str(), 5413 loaded_super_oat_file->GetLocation().c_str(), 5414 error_msg.c_str()); 5415 ThrowIncompatibleClassChangeError(klass.Get(), 5416 "Structural change of %s is hazardous (%s at compile time, %s at runtime): %s", 5417 PrettyType(super_class_def->class_idx_, dex_file).c_str(), 5418 class_oat_file->GetLocation().c_str(), 5419 loaded_super_oat_file->GetLocation().c_str(), 5420 error_msg.c_str()); 5421 return false; 5422 } 5423 } 5424 } 5425 } 5426 } 5427 return true; 5428} 5429 5430bool ClassLinker::LoadSuperAndInterfaces(Handle<mirror::Class> klass, const DexFile& dex_file) { 5431 CHECK_EQ(mirror::Class::kStatusIdx, klass->GetStatus()); 5432 const DexFile::ClassDef& class_def = dex_file.GetClassDef(klass->GetDexClassDefIndex()); 5433 uint16_t super_class_idx = class_def.superclass_idx_; 5434 if (super_class_idx != DexFile::kDexNoIndex16) { 5435 // Check that a class does not inherit from itself directly. 5436 // 5437 // TODO: This is a cheap check to detect the straightforward case 5438 // of a class extending itself (b/28685551), but we should do a 5439 // proper cycle detection on loaded classes, to detect all cases 5440 // of class circularity errors (b/28830038). 5441 if (super_class_idx == class_def.class_idx_) { 5442 ThrowClassCircularityError(klass.Get(), 5443 "Class %s extends itself", 5444 PrettyDescriptor(klass.Get()).c_str()); 5445 return false; 5446 } 5447 5448 mirror::Class* super_class = ResolveType(dex_file, super_class_idx, klass.Get()); 5449 if (super_class == nullptr) { 5450 DCHECK(Thread::Current()->IsExceptionPending()); 5451 return false; 5452 } 5453 // Verify 5454 if (!klass->CanAccess(super_class)) { 5455 ThrowIllegalAccessError(klass.Get(), "Class %s extended by class %s is inaccessible", 5456 PrettyDescriptor(super_class).c_str(), 5457 PrettyDescriptor(klass.Get()).c_str()); 5458 return false; 5459 } 5460 CHECK(super_class->IsResolved()); 5461 klass->SetSuperClass(super_class); 5462 5463 if (!CheckSuperClassChange(klass, dex_file, class_def, super_class)) { 5464 DCHECK(Thread::Current()->IsExceptionPending()); 5465 return false; 5466 } 5467 } 5468 const DexFile::TypeList* interfaces = dex_file.GetInterfacesList(class_def); 5469 if (interfaces != nullptr) { 5470 for (size_t i = 0; i < interfaces->Size(); i++) { 5471 uint16_t idx = interfaces->GetTypeItem(i).type_idx_; 5472 mirror::Class* interface = ResolveType(dex_file, idx, klass.Get()); 5473 if (interface == nullptr) { 5474 DCHECK(Thread::Current()->IsExceptionPending()); 5475 return false; 5476 } 5477 // Verify 5478 if (!klass->CanAccess(interface)) { 5479 // TODO: the RI seemed to ignore this in my testing. 5480 ThrowIllegalAccessError(klass.Get(), 5481 "Interface %s implemented by class %s is inaccessible", 5482 PrettyDescriptor(interface).c_str(), 5483 PrettyDescriptor(klass.Get()).c_str()); 5484 return false; 5485 } 5486 } 5487 } 5488 // Mark the class as loaded. 5489 mirror::Class::SetStatus(klass, mirror::Class::kStatusLoaded, nullptr); 5490 return true; 5491} 5492 5493bool ClassLinker::LinkSuperClass(Handle<mirror::Class> klass) { 5494 CHECK(!klass->IsPrimitive()); 5495 mirror::Class* super = klass->GetSuperClass(); 5496 if (klass.Get() == GetClassRoot(kJavaLangObject)) { 5497 if (super != nullptr) { 5498 ThrowClassFormatError(klass.Get(), "java.lang.Object must not have a superclass"); 5499 return false; 5500 } 5501 return true; 5502 } 5503 if (super == nullptr) { 5504 ThrowLinkageError(klass.Get(), "No superclass defined for class %s", 5505 PrettyDescriptor(klass.Get()).c_str()); 5506 return false; 5507 } 5508 // Verify 5509 if (super->IsFinal() || super->IsInterface()) { 5510 ThrowIncompatibleClassChangeError(klass.Get(), 5511 "Superclass %s of %s is %s", 5512 PrettyDescriptor(super).c_str(), 5513 PrettyDescriptor(klass.Get()).c_str(), 5514 super->IsFinal() ? "declared final" : "an interface"); 5515 return false; 5516 } 5517 if (!klass->CanAccess(super)) { 5518 ThrowIllegalAccessError(klass.Get(), "Superclass %s is inaccessible to class %s", 5519 PrettyDescriptor(super).c_str(), 5520 PrettyDescriptor(klass.Get()).c_str()); 5521 return false; 5522 } 5523 5524 // Inherit kAccClassIsFinalizable from the superclass in case this 5525 // class doesn't override finalize. 5526 if (super->IsFinalizable()) { 5527 klass->SetFinalizable(); 5528 } 5529 5530 // Inherit class loader flag form super class. 5531 if (super->IsClassLoaderClass()) { 5532 klass->SetClassLoaderClass(); 5533 } 5534 5535 // Inherit reference flags (if any) from the superclass. 5536 uint32_t reference_flags = (super->GetClassFlags() & mirror::kClassFlagReference); 5537 if (reference_flags != 0) { 5538 CHECK_EQ(klass->GetClassFlags(), 0u); 5539 klass->SetClassFlags(klass->GetClassFlags() | reference_flags); 5540 } 5541 // Disallow custom direct subclasses of java.lang.ref.Reference. 5542 if (init_done_ && super == GetClassRoot(kJavaLangRefReference)) { 5543 ThrowLinkageError(klass.Get(), 5544 "Class %s attempts to subclass java.lang.ref.Reference, which is not allowed", 5545 PrettyDescriptor(klass.Get()).c_str()); 5546 return false; 5547 } 5548 5549 if (kIsDebugBuild) { 5550 // Ensure super classes are fully resolved prior to resolving fields.. 5551 while (super != nullptr) { 5552 CHECK(super->IsResolved()); 5553 super = super->GetSuperClass(); 5554 } 5555 } 5556 return true; 5557} 5558 5559// Populate the class vtable and itable. Compute return type indices. 5560bool ClassLinker::LinkMethods(Thread* self, 5561 Handle<mirror::Class> klass, 5562 Handle<mirror::ObjectArray<mirror::Class>> interfaces, 5563 bool* out_new_conflict, 5564 ArtMethod** out_imt) { 5565 self->AllowThreadSuspension(); 5566 // A map from vtable indexes to the method they need to be updated to point to. Used because we 5567 // need to have default methods be in the virtuals array of each class but we don't set that up 5568 // until LinkInterfaceMethods. 5569 std::unordered_map<size_t, ClassLinker::MethodTranslation> default_translations; 5570 // Link virtual methods then interface methods. 5571 // We set up the interface lookup table first because we need it to determine if we need to update 5572 // any vtable entries with new default method implementations. 5573 return SetupInterfaceLookupTable(self, klass, interfaces) 5574 && LinkVirtualMethods(self, klass, /*out*/ &default_translations) 5575 && LinkInterfaceMethods(self, klass, default_translations, out_new_conflict, out_imt); 5576} 5577 5578// Comparator for name and signature of a method, used in finding overriding methods. Implementation 5579// avoids the use of handles, if it didn't then rather than compare dex files we could compare dex 5580// caches in the implementation below. 5581class MethodNameAndSignatureComparator FINAL : public ValueObject { 5582 public: 5583 explicit MethodNameAndSignatureComparator(ArtMethod* method) 5584 SHARED_REQUIRES(Locks::mutator_lock_) : 5585 dex_file_(method->GetDexFile()), mid_(&dex_file_->GetMethodId(method->GetDexMethodIndex())), 5586 name_(nullptr), name_len_(0) { 5587 DCHECK(!method->IsProxyMethod()) << PrettyMethod(method); 5588 } 5589 5590 const char* GetName() { 5591 if (name_ == nullptr) { 5592 name_ = dex_file_->StringDataAndUtf16LengthByIdx(mid_->name_idx_, &name_len_); 5593 } 5594 return name_; 5595 } 5596 5597 bool HasSameNameAndSignature(ArtMethod* other) 5598 SHARED_REQUIRES(Locks::mutator_lock_) { 5599 DCHECK(!other->IsProxyMethod()) << PrettyMethod(other); 5600 const DexFile* other_dex_file = other->GetDexFile(); 5601 const DexFile::MethodId& other_mid = other_dex_file->GetMethodId(other->GetDexMethodIndex()); 5602 if (dex_file_ == other_dex_file) { 5603 return mid_->name_idx_ == other_mid.name_idx_ && mid_->proto_idx_ == other_mid.proto_idx_; 5604 } 5605 GetName(); // Only used to make sure its calculated. 5606 uint32_t other_name_len; 5607 const char* other_name = other_dex_file->StringDataAndUtf16LengthByIdx(other_mid.name_idx_, 5608 &other_name_len); 5609 if (name_len_ != other_name_len || strcmp(name_, other_name) != 0) { 5610 return false; 5611 } 5612 return dex_file_->GetMethodSignature(*mid_) == other_dex_file->GetMethodSignature(other_mid); 5613 } 5614 5615 private: 5616 // Dex file for the method to compare against. 5617 const DexFile* const dex_file_; 5618 // MethodId for the method to compare against. 5619 const DexFile::MethodId* const mid_; 5620 // Lazily computed name from the dex file's strings. 5621 const char* name_; 5622 // Lazily computed name length. 5623 uint32_t name_len_; 5624}; 5625 5626class LinkVirtualHashTable { 5627 public: 5628 LinkVirtualHashTable(Handle<mirror::Class> klass, 5629 size_t hash_size, 5630 uint32_t* hash_table, 5631 size_t image_pointer_size) 5632 : klass_(klass), 5633 hash_size_(hash_size), 5634 hash_table_(hash_table), 5635 image_pointer_size_(image_pointer_size) { 5636 std::fill(hash_table_, hash_table_ + hash_size_, invalid_index_); 5637 } 5638 5639 void Add(uint32_t virtual_method_index) SHARED_REQUIRES(Locks::mutator_lock_) { 5640 ArtMethod* local_method = klass_->GetVirtualMethodDuringLinking( 5641 virtual_method_index, image_pointer_size_); 5642 const char* name = local_method->GetInterfaceMethodIfProxy(image_pointer_size_)->GetName(); 5643 uint32_t hash = ComputeModifiedUtf8Hash(name); 5644 uint32_t index = hash % hash_size_; 5645 // Linear probe until we have an empty slot. 5646 while (hash_table_[index] != invalid_index_) { 5647 if (++index == hash_size_) { 5648 index = 0; 5649 } 5650 } 5651 hash_table_[index] = virtual_method_index; 5652 } 5653 5654 uint32_t FindAndRemove(MethodNameAndSignatureComparator* comparator) 5655 SHARED_REQUIRES(Locks::mutator_lock_) { 5656 const char* name = comparator->GetName(); 5657 uint32_t hash = ComputeModifiedUtf8Hash(name); 5658 size_t index = hash % hash_size_; 5659 while (true) { 5660 const uint32_t value = hash_table_[index]; 5661 // Since linear probe makes continuous blocks, hitting an invalid index means we are done 5662 // the block and can safely assume not found. 5663 if (value == invalid_index_) { 5664 break; 5665 } 5666 if (value != removed_index_) { // This signifies not already overriden. 5667 ArtMethod* virtual_method = 5668 klass_->GetVirtualMethodDuringLinking(value, image_pointer_size_); 5669 if (comparator->HasSameNameAndSignature( 5670 virtual_method->GetInterfaceMethodIfProxy(image_pointer_size_))) { 5671 hash_table_[index] = removed_index_; 5672 return value; 5673 } 5674 } 5675 if (++index == hash_size_) { 5676 index = 0; 5677 } 5678 } 5679 return GetNotFoundIndex(); 5680 } 5681 5682 static uint32_t GetNotFoundIndex() { 5683 return invalid_index_; 5684 } 5685 5686 private: 5687 static const uint32_t invalid_index_; 5688 static const uint32_t removed_index_; 5689 5690 Handle<mirror::Class> klass_; 5691 const size_t hash_size_; 5692 uint32_t* const hash_table_; 5693 const size_t image_pointer_size_; 5694}; 5695 5696const uint32_t LinkVirtualHashTable::invalid_index_ = std::numeric_limits<uint32_t>::max(); 5697const uint32_t LinkVirtualHashTable::removed_index_ = std::numeric_limits<uint32_t>::max() - 1; 5698 5699bool ClassLinker::LinkVirtualMethods( 5700 Thread* self, 5701 Handle<mirror::Class> klass, 5702 /*out*/std::unordered_map<size_t, ClassLinker::MethodTranslation>* default_translations) { 5703 const size_t num_virtual_methods = klass->NumVirtualMethods(); 5704 if (klass->IsInterface()) { 5705 // No vtable. 5706 if (!IsUint<16>(num_virtual_methods)) { 5707 ThrowClassFormatError(klass.Get(), "Too many methods on interface: %zu", num_virtual_methods); 5708 return false; 5709 } 5710 bool has_defaults = false; 5711 // Assign each method an IMT index and set the default flag. 5712 for (size_t i = 0; i < num_virtual_methods; ++i) { 5713 ArtMethod* m = klass->GetVirtualMethodDuringLinking(i, image_pointer_size_); 5714 m->SetMethodIndex(i); 5715 if (!m->IsAbstract()) { 5716 m->SetAccessFlags(m->GetAccessFlags() | kAccDefault); 5717 has_defaults = true; 5718 } 5719 } 5720 // Mark that we have default methods so that we won't need to scan the virtual_methods_ array 5721 // during initialization. This is a performance optimization. We could simply traverse the 5722 // virtual_methods_ array again during initialization. 5723 if (has_defaults) { 5724 klass->SetHasDefaultMethods(); 5725 } 5726 return true; 5727 } else if (klass->HasSuperClass()) { 5728 const size_t super_vtable_length = klass->GetSuperClass()->GetVTableLength(); 5729 const size_t max_count = num_virtual_methods + super_vtable_length; 5730 StackHandleScope<2> hs(self); 5731 Handle<mirror::Class> super_class(hs.NewHandle(klass->GetSuperClass())); 5732 MutableHandle<mirror::PointerArray> vtable; 5733 if (super_class->ShouldHaveEmbeddedVTable()) { 5734 vtable = hs.NewHandle(AllocPointerArray(self, max_count)); 5735 if (UNLIKELY(vtable.Get() == nullptr)) { 5736 self->AssertPendingOOMException(); 5737 return false; 5738 } 5739 for (size_t i = 0; i < super_vtable_length; i++) { 5740 vtable->SetElementPtrSize( 5741 i, super_class->GetEmbeddedVTableEntry(i, image_pointer_size_), image_pointer_size_); 5742 } 5743 // We might need to change vtable if we have new virtual methods or new interfaces (since that 5744 // might give us new default methods). If no new interfaces then we can skip the rest since 5745 // the class cannot override any of the super-class's methods. This is required for 5746 // correctness since without it we might not update overridden default method vtable entries 5747 // correctly. 5748 if (num_virtual_methods == 0 && super_class->GetIfTableCount() == klass->GetIfTableCount()) { 5749 klass->SetVTable(vtable.Get()); 5750 return true; 5751 } 5752 } else { 5753 DCHECK(super_class->IsAbstract() && !super_class->IsArrayClass()); 5754 auto* super_vtable = super_class->GetVTable(); 5755 CHECK(super_vtable != nullptr) << PrettyClass(super_class.Get()); 5756 // We might need to change vtable if we have new virtual methods or new interfaces (since that 5757 // might give us new default methods). See comment above. 5758 if (num_virtual_methods == 0 && super_class->GetIfTableCount() == klass->GetIfTableCount()) { 5759 klass->SetVTable(super_vtable); 5760 return true; 5761 } 5762 vtable = hs.NewHandle(down_cast<mirror::PointerArray*>( 5763 super_vtable->CopyOf(self, max_count))); 5764 if (UNLIKELY(vtable.Get() == nullptr)) { 5765 self->AssertPendingOOMException(); 5766 return false; 5767 } 5768 } 5769 // How the algorithm works: 5770 // 1. Populate hash table by adding num_virtual_methods from klass. The values in the hash 5771 // table are: invalid_index for unused slots, index super_vtable_length + i for a virtual 5772 // method which has not been matched to a vtable method, and j if the virtual method at the 5773 // index overrode the super virtual method at index j. 5774 // 2. Loop through super virtual methods, if they overwrite, update hash table to j 5775 // (j < super_vtable_length) to avoid redundant checks. (TODO maybe use this info for reducing 5776 // the need for the initial vtable which we later shrink back down). 5777 // 3. Add non overridden methods to the end of the vtable. 5778 static constexpr size_t kMaxStackHash = 250; 5779 // + 1 so that even if we only have new default methods we will still be able to use this hash 5780 // table (i.e. it will never have 0 size). 5781 const size_t hash_table_size = num_virtual_methods * 3 + 1; 5782 uint32_t* hash_table_ptr; 5783 std::unique_ptr<uint32_t[]> hash_heap_storage; 5784 if (hash_table_size <= kMaxStackHash) { 5785 hash_table_ptr = reinterpret_cast<uint32_t*>( 5786 alloca(hash_table_size * sizeof(*hash_table_ptr))); 5787 } else { 5788 hash_heap_storage.reset(new uint32_t[hash_table_size]); 5789 hash_table_ptr = hash_heap_storage.get(); 5790 } 5791 LinkVirtualHashTable hash_table(klass, hash_table_size, hash_table_ptr, image_pointer_size_); 5792 // Add virtual methods to the hash table. 5793 for (size_t i = 0; i < num_virtual_methods; ++i) { 5794 DCHECK(klass->GetVirtualMethodDuringLinking( 5795 i, image_pointer_size_)->GetDeclaringClass() != nullptr); 5796 hash_table.Add(i); 5797 } 5798 // Loop through each super vtable method and see if they are overridden by a method we added to 5799 // the hash table. 5800 for (size_t j = 0; j < super_vtable_length; ++j) { 5801 // Search the hash table to see if we are overridden by any method. 5802 ArtMethod* super_method = vtable->GetElementPtrSize<ArtMethod*>(j, image_pointer_size_); 5803 MethodNameAndSignatureComparator super_method_name_comparator( 5804 super_method->GetInterfaceMethodIfProxy(image_pointer_size_)); 5805 uint32_t hash_index = hash_table.FindAndRemove(&super_method_name_comparator); 5806 if (hash_index != hash_table.GetNotFoundIndex()) { 5807 ArtMethod* virtual_method = klass->GetVirtualMethodDuringLinking( 5808 hash_index, image_pointer_size_); 5809 if (klass->CanAccessMember(super_method->GetDeclaringClass(), 5810 super_method->GetAccessFlags())) { 5811 if (super_method->IsFinal()) { 5812 ThrowLinkageError(klass.Get(), "Method %s overrides final method in class %s", 5813 PrettyMethod(virtual_method).c_str(), 5814 super_method->GetDeclaringClassDescriptor()); 5815 return false; 5816 } 5817 vtable->SetElementPtrSize(j, virtual_method, image_pointer_size_); 5818 virtual_method->SetMethodIndex(j); 5819 } else { 5820 LOG(WARNING) << "Before Android 4.1, method " << PrettyMethod(virtual_method) 5821 << " would have incorrectly overridden the package-private method in " 5822 << PrettyDescriptor(super_method->GetDeclaringClassDescriptor()); 5823 } 5824 } else if (super_method->IsOverridableByDefaultMethod()) { 5825 // We didn't directly override this method but we might through default methods... 5826 // Check for default method update. 5827 ArtMethod* default_method = nullptr; 5828 switch (FindDefaultMethodImplementation(self, 5829 super_method, 5830 klass, 5831 /*out*/&default_method)) { 5832 case DefaultMethodSearchResult::kDefaultConflict: { 5833 // A conflict was found looking for default methods. Note this (assuming it wasn't 5834 // pre-existing) in the translations map. 5835 if (UNLIKELY(!super_method->IsDefaultConflicting())) { 5836 // Don't generate another conflict method to reduce memory use as an optimization. 5837 default_translations->insert( 5838 {j, ClassLinker::MethodTranslation::CreateConflictingMethod()}); 5839 } 5840 break; 5841 } 5842 case DefaultMethodSearchResult::kAbstractFound: { 5843 // No conflict but method is abstract. 5844 // We note that this vtable entry must be made abstract. 5845 if (UNLIKELY(!super_method->IsAbstract())) { 5846 default_translations->insert( 5847 {j, ClassLinker::MethodTranslation::CreateAbstractMethod()}); 5848 } 5849 break; 5850 } 5851 case DefaultMethodSearchResult::kDefaultFound: { 5852 if (UNLIKELY(super_method->IsDefaultConflicting() || 5853 default_method->GetDeclaringClass() != super_method->GetDeclaringClass())) { 5854 // Found a default method implementation that is new. 5855 // TODO Refactor this add default methods to virtuals here and not in 5856 // LinkInterfaceMethods maybe. 5857 // The problem is default methods might override previously present 5858 // default-method or miranda-method vtable entries from the superclass. 5859 // Unfortunately we need these to be entries in this class's virtuals. We do not 5860 // give these entries there until LinkInterfaceMethods so we pass this map around 5861 // to let it know which vtable entries need to be updated. 5862 // Make a note that vtable entry j must be updated, store what it needs to be updated 5863 // to. We will allocate a virtual method slot in LinkInterfaceMethods and fix it up 5864 // then. 5865 default_translations->insert( 5866 {j, ClassLinker::MethodTranslation::CreateTranslatedMethod(default_method)}); 5867 VLOG(class_linker) << "Method " << PrettyMethod(super_method) 5868 << " overridden by default " << PrettyMethod(default_method) 5869 << " in " << PrettyClass(klass.Get()); 5870 } 5871 break; 5872 } 5873 } 5874 } 5875 } 5876 size_t actual_count = super_vtable_length; 5877 // Add the non-overridden methods at the end. 5878 for (size_t i = 0; i < num_virtual_methods; ++i) { 5879 ArtMethod* local_method = klass->GetVirtualMethodDuringLinking(i, image_pointer_size_); 5880 size_t method_idx = local_method->GetMethodIndexDuringLinking(); 5881 if (method_idx < super_vtable_length && 5882 local_method == vtable->GetElementPtrSize<ArtMethod*>(method_idx, image_pointer_size_)) { 5883 continue; 5884 } 5885 vtable->SetElementPtrSize(actual_count, local_method, image_pointer_size_); 5886 local_method->SetMethodIndex(actual_count); 5887 ++actual_count; 5888 } 5889 if (!IsUint<16>(actual_count)) { 5890 ThrowClassFormatError(klass.Get(), "Too many methods defined on class: %zd", actual_count); 5891 return false; 5892 } 5893 // Shrink vtable if possible 5894 CHECK_LE(actual_count, max_count); 5895 if (actual_count < max_count) { 5896 vtable.Assign(down_cast<mirror::PointerArray*>(vtable->CopyOf(self, actual_count))); 5897 if (UNLIKELY(vtable.Get() == nullptr)) { 5898 self->AssertPendingOOMException(); 5899 return false; 5900 } 5901 } 5902 klass->SetVTable(vtable.Get()); 5903 } else { 5904 CHECK_EQ(klass.Get(), GetClassRoot(kJavaLangObject)); 5905 if (!IsUint<16>(num_virtual_methods)) { 5906 ThrowClassFormatError(klass.Get(), "Too many methods: %d", 5907 static_cast<int>(num_virtual_methods)); 5908 return false; 5909 } 5910 auto* vtable = AllocPointerArray(self, num_virtual_methods); 5911 if (UNLIKELY(vtable == nullptr)) { 5912 self->AssertPendingOOMException(); 5913 return false; 5914 } 5915 for (size_t i = 0; i < num_virtual_methods; ++i) { 5916 ArtMethod* virtual_method = klass->GetVirtualMethodDuringLinking(i, image_pointer_size_); 5917 vtable->SetElementPtrSize(i, virtual_method, image_pointer_size_); 5918 virtual_method->SetMethodIndex(i & 0xFFFF); 5919 } 5920 klass->SetVTable(vtable); 5921 } 5922 return true; 5923} 5924 5925// Determine if the given iface has any subinterface in the given list that declares the method 5926// specified by 'target'. 5927// 5928// Arguments 5929// - self: The thread we are running on 5930// - target: A comparator that will match any method that overrides the method we are checking for 5931// - iftable: The iftable we are searching for an overriding method on. 5932// - ifstart: The index of the interface we are checking to see if anything overrides 5933// - iface: The interface we are checking to see if anything overrides. 5934// - image_pointer_size: 5935// The image pointer size. 5936// 5937// Returns 5938// - True: There is some method that matches the target comparator defined in an interface that 5939// is a subtype of iface. 5940// - False: There is no method that matches the target comparator in any interface that is a subtype 5941// of iface. 5942static bool ContainsOverridingMethodOf(Thread* self, 5943 MethodNameAndSignatureComparator& target, 5944 Handle<mirror::IfTable> iftable, 5945 size_t ifstart, 5946 Handle<mirror::Class> iface, 5947 size_t image_pointer_size) 5948 SHARED_REQUIRES(Locks::mutator_lock_) { 5949 DCHECK(self != nullptr); 5950 DCHECK(iface.Get() != nullptr); 5951 DCHECK(iftable.Get() != nullptr); 5952 DCHECK_GE(ifstart, 0u); 5953 DCHECK_LT(ifstart, iftable->Count()); 5954 DCHECK_EQ(iface.Get(), iftable->GetInterface(ifstart)); 5955 DCHECK(iface->IsInterface()); 5956 5957 size_t iftable_count = iftable->Count(); 5958 StackHandleScope<1> hs(self); 5959 MutableHandle<mirror::Class> current_iface(hs.NewHandle<mirror::Class>(nullptr)); 5960 for (size_t k = ifstart + 1; k < iftable_count; k++) { 5961 // Skip ifstart since our current interface obviously cannot override itself. 5962 current_iface.Assign(iftable->GetInterface(k)); 5963 // Iterate through every method on this interface. The order does not matter. 5964 for (ArtMethod& current_method : current_iface->GetDeclaredVirtualMethods(image_pointer_size)) { 5965 if (UNLIKELY(target.HasSameNameAndSignature( 5966 current_method.GetInterfaceMethodIfProxy(image_pointer_size)))) { 5967 // Check if the i'th interface is a subtype of this one. 5968 if (iface->IsAssignableFrom(current_iface.Get())) { 5969 return true; 5970 } 5971 break; 5972 } 5973 } 5974 } 5975 return false; 5976} 5977 5978// Find the default method implementation for 'interface_method' in 'klass'. Stores it into 5979// out_default_method and returns kDefaultFound on success. If no default method was found return 5980// kAbstractFound and store nullptr into out_default_method. If an error occurs (such as a 5981// default_method conflict) it will return kDefaultConflict. 5982ClassLinker::DefaultMethodSearchResult ClassLinker::FindDefaultMethodImplementation( 5983 Thread* self, 5984 ArtMethod* target_method, 5985 Handle<mirror::Class> klass, 5986 /*out*/ArtMethod** out_default_method) const { 5987 DCHECK(self != nullptr); 5988 DCHECK(target_method != nullptr); 5989 DCHECK(out_default_method != nullptr); 5990 5991 *out_default_method = nullptr; 5992 5993 // We organize the interface table so that, for interface I any subinterfaces J follow it in the 5994 // table. This lets us walk the table backwards when searching for default methods. The first one 5995 // we encounter is the best candidate since it is the most specific. Once we have found it we keep 5996 // track of it and then continue checking all other interfaces, since we need to throw an error if 5997 // we encounter conflicting default method implementations (one is not a subtype of the other). 5998 // 5999 // The order of unrelated interfaces does not matter and is not defined. 6000 size_t iftable_count = klass->GetIfTableCount(); 6001 if (iftable_count == 0) { 6002 // No interfaces. We have already reset out to null so just return kAbstractFound. 6003 return DefaultMethodSearchResult::kAbstractFound; 6004 } 6005 6006 StackHandleScope<3> hs(self); 6007 MutableHandle<mirror::Class> chosen_iface(hs.NewHandle<mirror::Class>(nullptr)); 6008 MutableHandle<mirror::IfTable> iftable(hs.NewHandle(klass->GetIfTable())); 6009 MutableHandle<mirror::Class> iface(hs.NewHandle<mirror::Class>(nullptr)); 6010 MethodNameAndSignatureComparator target_name_comparator( 6011 target_method->GetInterfaceMethodIfProxy(image_pointer_size_)); 6012 // Iterates over the klass's iftable in reverse 6013 for (size_t k = iftable_count; k != 0; ) { 6014 --k; 6015 6016 DCHECK_LT(k, iftable->Count()); 6017 6018 iface.Assign(iftable->GetInterface(k)); 6019 // Iterate through every declared method on this interface. The order does not matter. 6020 for (auto& method_iter : iface->GetDeclaredVirtualMethods(image_pointer_size_)) { 6021 ArtMethod* current_method = &method_iter; 6022 // Skip abstract methods and methods with different names. 6023 if (current_method->IsAbstract() || 6024 !target_name_comparator.HasSameNameAndSignature( 6025 current_method->GetInterfaceMethodIfProxy(image_pointer_size_))) { 6026 continue; 6027 } else if (!current_method->IsPublic()) { 6028 // The verifier should have caught the non-public method for dex version 37. Just warn and 6029 // skip it since this is from before default-methods so we don't really need to care that it 6030 // has code. 6031 LOG(WARNING) << "Interface method " << PrettyMethod(current_method) << " is not public! " 6032 << "This will be a fatal error in subsequent versions of android. " 6033 << "Continuing anyway."; 6034 } 6035 if (UNLIKELY(chosen_iface.Get() != nullptr)) { 6036 // We have multiple default impls of the same method. This is a potential default conflict. 6037 // We need to check if this possibly conflicting method is either a superclass of the chosen 6038 // default implementation or is overridden by a non-default interface method. In either case 6039 // there is no conflict. 6040 if (!iface->IsAssignableFrom(chosen_iface.Get()) && 6041 !ContainsOverridingMethodOf(self, 6042 target_name_comparator, 6043 iftable, 6044 k, 6045 iface, 6046 image_pointer_size_)) { 6047 VLOG(class_linker) << "Conflicting default method implementations found: " 6048 << PrettyMethod(current_method) << " and " 6049 << PrettyMethod(*out_default_method) << " in class " 6050 << PrettyClass(klass.Get()) << " conflict."; 6051 *out_default_method = nullptr; 6052 return DefaultMethodSearchResult::kDefaultConflict; 6053 } else { 6054 break; // Continue checking at the next interface. 6055 } 6056 } else { 6057 // chosen_iface == null 6058 if (!ContainsOverridingMethodOf(self, 6059 target_name_comparator, 6060 iftable, 6061 k, 6062 iface, 6063 image_pointer_size_)) { 6064 // Don't set this as the chosen interface if something else is overriding it (because that 6065 // other interface would be potentially chosen instead if it was default). If the other 6066 // interface was abstract then we wouldn't select this interface as chosen anyway since 6067 // the abstract method masks it. 6068 *out_default_method = current_method; 6069 chosen_iface.Assign(iface.Get()); 6070 // We should now finish traversing the graph to find if we have default methods that 6071 // conflict. 6072 } else { 6073 VLOG(class_linker) << "A default method '" << PrettyMethod(current_method) << "' was " 6074 << "skipped because it was overridden by an abstract method in a " 6075 << "subinterface on class '" << PrettyClass(klass.Get()) << "'"; 6076 } 6077 } 6078 break; 6079 } 6080 } 6081 if (*out_default_method != nullptr) { 6082 VLOG(class_linker) << "Default method '" << PrettyMethod(*out_default_method) << "' selected " 6083 << "as the implementation for '" << PrettyMethod(target_method) << "' " 6084 << "in '" << PrettyClass(klass.Get()) << "'"; 6085 return DefaultMethodSearchResult::kDefaultFound; 6086 } else { 6087 return DefaultMethodSearchResult::kAbstractFound; 6088 } 6089} 6090 6091ArtMethod* ClassLinker::AddMethodToConflictTable(mirror::Class* klass, 6092 ArtMethod* conflict_method, 6093 ArtMethod* interface_method, 6094 ArtMethod* method, 6095 bool force_new_conflict_method) { 6096 ImtConflictTable* current_table = conflict_method->GetImtConflictTable(sizeof(void*)); 6097 Runtime* const runtime = Runtime::Current(); 6098 LinearAlloc* linear_alloc = GetAllocatorForClassLoader(klass->GetClassLoader()); 6099 bool new_entry = conflict_method == runtime->GetImtConflictMethod() || force_new_conflict_method; 6100 6101 // Create a new entry if the existing one is the shared conflict method. 6102 ArtMethod* new_conflict_method = new_entry 6103 ? runtime->CreateImtConflictMethod(linear_alloc) 6104 : conflict_method; 6105 6106 // Allocate a new table. Note that we will leak this table at the next conflict, 6107 // but that's a tradeoff compared to making the table fixed size. 6108 void* data = linear_alloc->Alloc( 6109 Thread::Current(), ImtConflictTable::ComputeSizeWithOneMoreEntry(current_table, 6110 image_pointer_size_)); 6111 if (data == nullptr) { 6112 LOG(ERROR) << "Failed to allocate conflict table"; 6113 return conflict_method; 6114 } 6115 ImtConflictTable* new_table = new (data) ImtConflictTable(current_table, 6116 interface_method, 6117 method, 6118 image_pointer_size_); 6119 6120 // Do a fence to ensure threads see the data in the table before it is assigned 6121 // to the conflict method. 6122 // Note that there is a race in the presence of multiple threads and we may leak 6123 // memory from the LinearAlloc, but that's a tradeoff compared to using 6124 // atomic operations. 6125 QuasiAtomic::ThreadFenceRelease(); 6126 new_conflict_method->SetImtConflictTable(new_table, image_pointer_size_); 6127 return new_conflict_method; 6128} 6129 6130void ClassLinker::SetIMTRef(ArtMethod* unimplemented_method, 6131 ArtMethod* imt_conflict_method, 6132 ArtMethod* current_method, 6133 /*out*/bool* new_conflict, 6134 /*out*/ArtMethod** imt_ref) { 6135 // Place method in imt if entry is empty, place conflict otherwise. 6136 if (*imt_ref == unimplemented_method) { 6137 *imt_ref = current_method; 6138 } else if (!(*imt_ref)->IsRuntimeMethod()) { 6139 // If we are not a conflict and we have the same signature and name as the imt 6140 // entry, it must be that we overwrote a superclass vtable entry. 6141 // Note that we have checked IsRuntimeMethod, as there may be multiple different 6142 // conflict methods. 6143 MethodNameAndSignatureComparator imt_comparator( 6144 (*imt_ref)->GetInterfaceMethodIfProxy(image_pointer_size_)); 6145 if (imt_comparator.HasSameNameAndSignature( 6146 current_method->GetInterfaceMethodIfProxy(image_pointer_size_))) { 6147 *imt_ref = current_method; 6148 } else { 6149 *imt_ref = imt_conflict_method; 6150 *new_conflict = true; 6151 } 6152 } else { 6153 // Place the default conflict method. Note that there may be an existing conflict 6154 // method in the IMT, but it could be one tailored to the super class, with a 6155 // specific ImtConflictTable. 6156 *imt_ref = imt_conflict_method; 6157 *new_conflict = true; 6158 } 6159} 6160 6161void ClassLinker::FillIMTAndConflictTables(mirror::Class* klass) { 6162 DCHECK(klass->ShouldHaveImt()) << PrettyClass(klass); 6163 DCHECK(!klass->IsTemp()) << PrettyClass(klass); 6164 ArtMethod* imt_data[ImTable::kSize]; 6165 Runtime* const runtime = Runtime::Current(); 6166 ArtMethod* const unimplemented_method = runtime->GetImtUnimplementedMethod(); 6167 ArtMethod* const conflict_method = runtime->GetImtConflictMethod(); 6168 std::fill_n(imt_data, arraysize(imt_data), unimplemented_method); 6169 if (klass->GetIfTable() != nullptr) { 6170 bool new_conflict = false; 6171 FillIMTFromIfTable(klass->GetIfTable(), 6172 unimplemented_method, 6173 conflict_method, 6174 klass, 6175 /*create_conflict_tables*/true, 6176 /*ignore_copied_methods*/false, 6177 &new_conflict, 6178 &imt_data[0]); 6179 } 6180 if (!klass->ShouldHaveImt()) { 6181 return; 6182 } 6183 // Compare the IMT with the super class including the conflict methods. If they are equivalent, 6184 // we can just use the same pointer. 6185 ImTable* imt = nullptr; 6186 mirror::Class* super_class = klass->GetSuperClass(); 6187 if (super_class != nullptr && super_class->ShouldHaveImt()) { 6188 ImTable* super_imt = super_class->GetImt(image_pointer_size_); 6189 bool same = true; 6190 for (size_t i = 0; same && i < ImTable::kSize; ++i) { 6191 ArtMethod* method = imt_data[i]; 6192 ArtMethod* super_method = super_imt->Get(i, image_pointer_size_); 6193 if (method != super_method) { 6194 bool is_conflict_table = method->IsRuntimeMethod() && 6195 method != unimplemented_method && 6196 method != conflict_method; 6197 // Verify conflict contents. 6198 bool super_conflict_table = super_method->IsRuntimeMethod() && 6199 super_method != unimplemented_method && 6200 super_method != conflict_method; 6201 if (!is_conflict_table || !super_conflict_table) { 6202 same = false; 6203 } else { 6204 ImtConflictTable* table1 = method->GetImtConflictTable(image_pointer_size_); 6205 ImtConflictTable* table2 = super_method->GetImtConflictTable(image_pointer_size_); 6206 same = same && table1->Equals(table2, image_pointer_size_); 6207 } 6208 } 6209 } 6210 if (same) { 6211 imt = super_imt; 6212 } 6213 } 6214 if (imt == nullptr) { 6215 imt = klass->GetImt(image_pointer_size_); 6216 DCHECK(imt != nullptr); 6217 imt->Populate(imt_data, image_pointer_size_); 6218 } else { 6219 klass->SetImt(imt, image_pointer_size_); 6220 } 6221} 6222 6223static inline uint32_t GetIMTIndex(ArtMethod* interface_method) 6224 SHARED_REQUIRES(Locks::mutator_lock_) { 6225 return interface_method->GetDexMethodIndex() % ImTable::kSize; 6226} 6227 6228ImtConflictTable* ClassLinker::CreateImtConflictTable(size_t count, 6229 LinearAlloc* linear_alloc, 6230 size_t image_pointer_size) { 6231 void* data = linear_alloc->Alloc(Thread::Current(), 6232 ImtConflictTable::ComputeSize(count, 6233 image_pointer_size)); 6234 return (data != nullptr) ? new (data) ImtConflictTable(count, image_pointer_size) : nullptr; 6235} 6236 6237ImtConflictTable* ClassLinker::CreateImtConflictTable(size_t count, LinearAlloc* linear_alloc) { 6238 return CreateImtConflictTable(count, linear_alloc, image_pointer_size_); 6239} 6240 6241void ClassLinker::FillIMTFromIfTable(mirror::IfTable* if_table, 6242 ArtMethod* unimplemented_method, 6243 ArtMethod* imt_conflict_method, 6244 mirror::Class* klass, 6245 bool create_conflict_tables, 6246 bool ignore_copied_methods, 6247 /*out*/bool* new_conflict, 6248 /*out*/ArtMethod** imt) { 6249 uint32_t conflict_counts[ImTable::kSize] = {}; 6250 for (size_t i = 0, length = if_table->Count(); i < length; ++i) { 6251 mirror::Class* interface = if_table->GetInterface(i); 6252 const size_t num_virtuals = interface->NumVirtualMethods(); 6253 const size_t method_array_count = if_table->GetMethodArrayCount(i); 6254 // Virtual methods can be larger than the if table methods if there are default methods. 6255 DCHECK_GE(num_virtuals, method_array_count); 6256 if (kIsDebugBuild) { 6257 if (klass->IsInterface()) { 6258 DCHECK_EQ(method_array_count, 0u); 6259 } else { 6260 DCHECK_EQ(interface->NumDeclaredVirtualMethods(), method_array_count); 6261 } 6262 } 6263 if (method_array_count == 0) { 6264 continue; 6265 } 6266 auto* method_array = if_table->GetMethodArray(i); 6267 for (size_t j = 0; j < method_array_count; ++j) { 6268 ArtMethod* implementation_method = 6269 method_array->GetElementPtrSize<ArtMethod*>(j, image_pointer_size_); 6270 if (ignore_copied_methods && implementation_method->IsCopied()) { 6271 continue; 6272 } 6273 DCHECK(implementation_method != nullptr); 6274 // Miranda methods cannot be used to implement an interface method, but they are safe to put 6275 // in the IMT since their entrypoint is the interface trampoline. If we put any copied methods 6276 // or interface methods in the IMT here they will not create extra conflicts since we compare 6277 // names and signatures in SetIMTRef. 6278 ArtMethod* interface_method = interface->GetVirtualMethod(j, image_pointer_size_); 6279 const uint32_t imt_index = GetIMTIndex(interface_method); 6280 6281 // There is only any conflicts if all of the interface methods for an IMT slot don't have 6282 // the same implementation method, keep track of this to avoid creating a conflict table in 6283 // this case. 6284 6285 // Conflict table size for each IMT slot. 6286 ++conflict_counts[imt_index]; 6287 6288 SetIMTRef(unimplemented_method, 6289 imt_conflict_method, 6290 implementation_method, 6291 /*out*/new_conflict, 6292 /*out*/&imt[imt_index]); 6293 } 6294 } 6295 6296 if (create_conflict_tables) { 6297 // Create the conflict tables. 6298 LinearAlloc* linear_alloc = GetAllocatorForClassLoader(klass->GetClassLoader()); 6299 for (size_t i = 0; i < ImTable::kSize; ++i) { 6300 size_t conflicts = conflict_counts[i]; 6301 if (imt[i] == imt_conflict_method) { 6302 ImtConflictTable* new_table = CreateImtConflictTable(conflicts, linear_alloc); 6303 if (new_table != nullptr) { 6304 ArtMethod* new_conflict_method = 6305 Runtime::Current()->CreateImtConflictMethod(linear_alloc); 6306 new_conflict_method->SetImtConflictTable(new_table, image_pointer_size_); 6307 imt[i] = new_conflict_method; 6308 } else { 6309 LOG(ERROR) << "Failed to allocate conflict table"; 6310 imt[i] = imt_conflict_method; 6311 } 6312 } else { 6313 DCHECK_NE(imt[i], imt_conflict_method); 6314 } 6315 } 6316 6317 for (size_t i = 0, length = if_table->Count(); i < length; ++i) { 6318 mirror::Class* interface = if_table->GetInterface(i); 6319 const size_t method_array_count = if_table->GetMethodArrayCount(i); 6320 // Virtual methods can be larger than the if table methods if there are default methods. 6321 if (method_array_count == 0) { 6322 continue; 6323 } 6324 auto* method_array = if_table->GetMethodArray(i); 6325 for (size_t j = 0; j < method_array_count; ++j) { 6326 ArtMethod* implementation_method = 6327 method_array->GetElementPtrSize<ArtMethod*>(j, image_pointer_size_); 6328 if (ignore_copied_methods && implementation_method->IsCopied()) { 6329 continue; 6330 } 6331 DCHECK(implementation_method != nullptr); 6332 ArtMethod* interface_method = interface->GetVirtualMethod(j, image_pointer_size_); 6333 const uint32_t imt_index = GetIMTIndex(interface_method); 6334 if (!imt[imt_index]->IsRuntimeMethod() || 6335 imt[imt_index] == unimplemented_method || 6336 imt[imt_index] == imt_conflict_method) { 6337 continue; 6338 } 6339 ImtConflictTable* table = imt[imt_index]->GetImtConflictTable(image_pointer_size_); 6340 const size_t num_entries = table->NumEntries(image_pointer_size_); 6341 table->SetInterfaceMethod(num_entries, image_pointer_size_, interface_method); 6342 table->SetImplementationMethod(num_entries, image_pointer_size_, implementation_method); 6343 } 6344 } 6345 } 6346} 6347 6348// Simple helper function that checks that no subtypes of 'val' are contained within the 'classes' 6349// set. 6350static bool NotSubinterfaceOfAny(const std::unordered_set<mirror::Class*>& classes, 6351 mirror::Class* val) 6352 REQUIRES(Roles::uninterruptible_) 6353 SHARED_REQUIRES(Locks::mutator_lock_) { 6354 DCHECK(val != nullptr); 6355 for (auto c : classes) { 6356 if (val->IsAssignableFrom(&*c)) { 6357 return false; 6358 } 6359 } 6360 return true; 6361} 6362 6363// Fills in and flattens the interface inheritance hierarchy. 6364// 6365// By the end of this function all interfaces in the transitive closure of to_process are added to 6366// the iftable and every interface precedes all of its sub-interfaces in this list. 6367// 6368// all I, J: Interface | I <: J implies J precedes I 6369// 6370// (note A <: B means that A is a subtype of B) 6371// 6372// This returns the total number of items in the iftable. The iftable might be resized down after 6373// this call. 6374// 6375// We order this backwards so that we do not need to reorder superclass interfaces when new 6376// interfaces are added in subclass's interface tables. 6377// 6378// Upon entry into this function iftable is a copy of the superclass's iftable with the first 6379// super_ifcount entries filled in with the transitive closure of the interfaces of the superclass. 6380// The other entries are uninitialized. We will fill in the remaining entries in this function. The 6381// iftable must be large enough to hold all interfaces without changing its size. 6382static size_t FillIfTable(mirror::IfTable* iftable, 6383 size_t super_ifcount, 6384 std::vector<mirror::Class*> to_process) 6385 REQUIRES(Roles::uninterruptible_) 6386 SHARED_REQUIRES(Locks::mutator_lock_) { 6387 // This is the set of all class's already in the iftable. Used to make checking if a class has 6388 // already been added quicker. 6389 std::unordered_set<mirror::Class*> classes_in_iftable; 6390 // The first super_ifcount elements are from the superclass. We note that they are already added. 6391 for (size_t i = 0; i < super_ifcount; i++) { 6392 mirror::Class* iface = iftable->GetInterface(i); 6393 DCHECK(NotSubinterfaceOfAny(classes_in_iftable, iface)) << "Bad ordering."; 6394 classes_in_iftable.insert(iface); 6395 } 6396 size_t filled_ifcount = super_ifcount; 6397 for (mirror::Class* interface : to_process) { 6398 // Let us call the first filled_ifcount elements of iftable the current-iface-list. 6399 // At this point in the loop current-iface-list has the invariant that: 6400 // for every pair of interfaces I,J within it: 6401 // if index_of(I) < index_of(J) then I is not a subtype of J 6402 6403 // If we have already seen this element then all of its super-interfaces must already be in the 6404 // current-iface-list so we can skip adding it. 6405 if (!ContainsElement(classes_in_iftable, interface)) { 6406 // We haven't seen this interface so add all of its super-interfaces onto the 6407 // current-iface-list, skipping those already on it. 6408 int32_t ifcount = interface->GetIfTableCount(); 6409 for (int32_t j = 0; j < ifcount; j++) { 6410 mirror::Class* super_interface = interface->GetIfTable()->GetInterface(j); 6411 if (!ContainsElement(classes_in_iftable, super_interface)) { 6412 DCHECK(NotSubinterfaceOfAny(classes_in_iftable, super_interface)) << "Bad ordering."; 6413 classes_in_iftable.insert(super_interface); 6414 iftable->SetInterface(filled_ifcount, super_interface); 6415 filled_ifcount++; 6416 } 6417 } 6418 DCHECK(NotSubinterfaceOfAny(classes_in_iftable, interface)) << "Bad ordering"; 6419 // Place this interface onto the current-iface-list after all of its super-interfaces. 6420 classes_in_iftable.insert(interface); 6421 iftable->SetInterface(filled_ifcount, interface); 6422 filled_ifcount++; 6423 } else if (kIsDebugBuild) { 6424 // Check all super-interfaces are already in the list. 6425 int32_t ifcount = interface->GetIfTableCount(); 6426 for (int32_t j = 0; j < ifcount; j++) { 6427 mirror::Class* super_interface = interface->GetIfTable()->GetInterface(j); 6428 DCHECK(ContainsElement(classes_in_iftable, super_interface)) 6429 << "Iftable does not contain " << PrettyClass(super_interface) 6430 << ", a superinterface of " << PrettyClass(interface); 6431 } 6432 } 6433 } 6434 if (kIsDebugBuild) { 6435 // Check that the iftable is ordered correctly. 6436 for (size_t i = 0; i < filled_ifcount; i++) { 6437 mirror::Class* if_a = iftable->GetInterface(i); 6438 for (size_t j = i + 1; j < filled_ifcount; j++) { 6439 mirror::Class* if_b = iftable->GetInterface(j); 6440 // !(if_a <: if_b) 6441 CHECK(!if_b->IsAssignableFrom(if_a)) 6442 << "Bad interface order: " << PrettyClass(if_a) << " (index " << i << ") extends " 6443 << PrettyClass(if_b) << " (index " << j << ") and so should be after it in the " 6444 << "interface list."; 6445 } 6446 } 6447 } 6448 return filled_ifcount; 6449} 6450 6451bool ClassLinker::SetupInterfaceLookupTable(Thread* self, Handle<mirror::Class> klass, 6452 Handle<mirror::ObjectArray<mirror::Class>> interfaces) { 6453 StackHandleScope<1> hs(self); 6454 const size_t super_ifcount = 6455 klass->HasSuperClass() ? klass->GetSuperClass()->GetIfTableCount() : 0U; 6456 const bool have_interfaces = interfaces.Get() != nullptr; 6457 const size_t num_interfaces = 6458 have_interfaces ? interfaces->GetLength() : klass->NumDirectInterfaces(); 6459 if (num_interfaces == 0) { 6460 if (super_ifcount == 0) { 6461 // Class implements no interfaces. 6462 DCHECK_EQ(klass->GetIfTableCount(), 0); 6463 DCHECK(klass->GetIfTable() == nullptr); 6464 return true; 6465 } 6466 // Class implements same interfaces as parent, are any of these not marker interfaces? 6467 bool has_non_marker_interface = false; 6468 mirror::IfTable* super_iftable = klass->GetSuperClass()->GetIfTable(); 6469 for (size_t i = 0; i < super_ifcount; ++i) { 6470 if (super_iftable->GetMethodArrayCount(i) > 0) { 6471 has_non_marker_interface = true; 6472 break; 6473 } 6474 } 6475 // Class just inherits marker interfaces from parent so recycle parent's iftable. 6476 if (!has_non_marker_interface) { 6477 klass->SetIfTable(super_iftable); 6478 return true; 6479 } 6480 } 6481 size_t ifcount = super_ifcount + num_interfaces; 6482 // Check that every class being implemented is an interface. 6483 for (size_t i = 0; i < num_interfaces; i++) { 6484 mirror::Class* interface = have_interfaces 6485 ? interfaces->GetWithoutChecks(i) 6486 : mirror::Class::GetDirectInterface(self, klass, i); 6487 DCHECK(interface != nullptr); 6488 if (UNLIKELY(!interface->IsInterface())) { 6489 std::string temp; 6490 ThrowIncompatibleClassChangeError(klass.Get(), 6491 "Class %s implements non-interface class %s", 6492 PrettyDescriptor(klass.Get()).c_str(), 6493 PrettyDescriptor(interface->GetDescriptor(&temp)).c_str()); 6494 return false; 6495 } 6496 ifcount += interface->GetIfTableCount(); 6497 } 6498 // Create the interface function table. 6499 MutableHandle<mirror::IfTable> iftable(hs.NewHandle(AllocIfTable(self, ifcount))); 6500 if (UNLIKELY(iftable.Get() == nullptr)) { 6501 self->AssertPendingOOMException(); 6502 return false; 6503 } 6504 // Fill in table with superclass's iftable. 6505 if (super_ifcount != 0) { 6506 mirror::IfTable* super_iftable = klass->GetSuperClass()->GetIfTable(); 6507 for (size_t i = 0; i < super_ifcount; i++) { 6508 mirror::Class* super_interface = super_iftable->GetInterface(i); 6509 iftable->SetInterface(i, super_interface); 6510 } 6511 } 6512 6513 // Note that AllowThreadSuspension is to thread suspension as pthread_testcancel is to pthread 6514 // cancellation. That is it will suspend if one has a pending suspend request but otherwise 6515 // doesn't really do anything. 6516 self->AllowThreadSuspension(); 6517 6518 size_t new_ifcount; 6519 { 6520 ScopedAssertNoThreadSuspension nts(self, "Copying mirror::Class*'s for FillIfTable"); 6521 std::vector<mirror::Class*> to_add; 6522 for (size_t i = 0; i < num_interfaces; i++) { 6523 mirror::Class* interface = have_interfaces ? interfaces->Get(i) : 6524 mirror::Class::GetDirectInterface(self, klass, i); 6525 to_add.push_back(interface); 6526 } 6527 6528 new_ifcount = FillIfTable(iftable.Get(), super_ifcount, std::move(to_add)); 6529 } 6530 6531 self->AllowThreadSuspension(); 6532 6533 // Shrink iftable in case duplicates were found 6534 if (new_ifcount < ifcount) { 6535 DCHECK_NE(num_interfaces, 0U); 6536 iftable.Assign(down_cast<mirror::IfTable*>( 6537 iftable->CopyOf(self, new_ifcount * mirror::IfTable::kMax))); 6538 if (UNLIKELY(iftable.Get() == nullptr)) { 6539 self->AssertPendingOOMException(); 6540 return false; 6541 } 6542 ifcount = new_ifcount; 6543 } else { 6544 DCHECK_EQ(new_ifcount, ifcount); 6545 } 6546 klass->SetIfTable(iftable.Get()); 6547 return true; 6548} 6549 6550// Finds the method with a name/signature that matches cmp in the given lists of methods. The list 6551// of methods must be unique. 6552static ArtMethod* FindSameNameAndSignature(MethodNameAndSignatureComparator& cmp ATTRIBUTE_UNUSED) { 6553 return nullptr; 6554} 6555 6556template <typename ... Types> 6557static ArtMethod* FindSameNameAndSignature(MethodNameAndSignatureComparator& cmp, 6558 const ScopedArenaVector<ArtMethod*>& list, 6559 const Types& ... rest) 6560 SHARED_REQUIRES(Locks::mutator_lock_) { 6561 for (ArtMethod* method : list) { 6562 if (cmp.HasSameNameAndSignature(method)) { 6563 return method; 6564 } 6565 } 6566 return FindSameNameAndSignature(cmp, rest...); 6567} 6568 6569// Check that all vtable entries are present in this class's virtuals or are the same as a 6570// superclasses vtable entry. 6571static void CheckClassOwnsVTableEntries(Thread* self, 6572 Handle<mirror::Class> klass, 6573 size_t pointer_size) 6574 SHARED_REQUIRES(Locks::mutator_lock_) { 6575 StackHandleScope<2> hs(self); 6576 Handle<mirror::PointerArray> check_vtable(hs.NewHandle(klass->GetVTableDuringLinking())); 6577 mirror::Class* super_temp = (klass->HasSuperClass()) ? klass->GetSuperClass() : nullptr; 6578 Handle<mirror::Class> superclass(hs.NewHandle(super_temp)); 6579 int32_t super_vtable_length = (superclass.Get() != nullptr) ? superclass->GetVTableLength() : 0; 6580 for (int32_t i = 0; i < check_vtable->GetLength(); ++i) { 6581 ArtMethod* m = check_vtable->GetElementPtrSize<ArtMethod*>(i, pointer_size); 6582 CHECK(m != nullptr); 6583 6584 CHECK_EQ(m->GetMethodIndexDuringLinking(), i) 6585 << PrettyMethod(m) << " has an unexpected method index for its spot in the vtable for class" 6586 << PrettyClass(klass.Get()); 6587 ArraySlice<ArtMethod> virtuals = klass->GetVirtualMethodsSliceUnchecked(pointer_size); 6588 auto is_same_method = [m] (const ArtMethod& meth) { 6589 return &meth == m; 6590 }; 6591 CHECK((super_vtable_length > i && superclass->GetVTableEntry(i, pointer_size) == m) || 6592 std::find_if(virtuals.begin(), virtuals.end(), is_same_method) != virtuals.end()) 6593 << PrettyMethod(m) << " does not seem to be owned by current class " 6594 << PrettyClass(klass.Get()) << " or any of its superclasses!"; 6595 } 6596} 6597 6598// Check to make sure the vtable does not have duplicates. Duplicates could cause problems when a 6599// method is overridden in a subclass. 6600static void CheckVTableHasNoDuplicates(Thread* self, 6601 Handle<mirror::Class> klass, 6602 size_t pointer_size) 6603 SHARED_REQUIRES(Locks::mutator_lock_) { 6604 StackHandleScope<1> hs(self); 6605 Handle<mirror::PointerArray> vtable(hs.NewHandle(klass->GetVTableDuringLinking())); 6606 int32_t num_entries = vtable->GetLength(); 6607 for (int32_t i = 0; i < num_entries; i++) { 6608 ArtMethod* vtable_entry = vtable->GetElementPtrSize<ArtMethod*>(i, pointer_size); 6609 // Don't bother if we cannot 'see' the vtable entry (i.e. it is a package-private member maybe). 6610 if (!klass->CanAccessMember(vtable_entry->GetDeclaringClass(), 6611 vtable_entry->GetAccessFlags())) { 6612 continue; 6613 } 6614 MethodNameAndSignatureComparator name_comparator( 6615 vtable_entry->GetInterfaceMethodIfProxy(pointer_size)); 6616 for (int32_t j = i+1; j < num_entries; j++) { 6617 ArtMethod* other_entry = vtable->GetElementPtrSize<ArtMethod*>(j, pointer_size); 6618 CHECK(vtable_entry != other_entry && 6619 !name_comparator.HasSameNameAndSignature( 6620 other_entry->GetInterfaceMethodIfProxy(pointer_size))) 6621 << "vtable entries " << i << " and " << j << " are identical for " 6622 << PrettyClass(klass.Get()) << " in method " << PrettyMethod(vtable_entry) << " and " 6623 << PrettyMethod(other_entry); 6624 } 6625 } 6626} 6627 6628static void SanityCheckVTable(Thread* self, Handle<mirror::Class> klass, size_t pointer_size) 6629 SHARED_REQUIRES(Locks::mutator_lock_) { 6630 CheckClassOwnsVTableEntries(self, klass, pointer_size); 6631 CheckVTableHasNoDuplicates(self, klass, pointer_size); 6632} 6633 6634void ClassLinker::FillImtFromSuperClass(Handle<mirror::Class> klass, 6635 ArtMethod* unimplemented_method, 6636 ArtMethod* imt_conflict_method, 6637 bool* new_conflict, 6638 ArtMethod** imt) { 6639 DCHECK(klass->HasSuperClass()); 6640 mirror::Class* super_class = klass->GetSuperClass(); 6641 if (super_class->ShouldHaveImt()) { 6642 ImTable* super_imt = super_class->GetImt(image_pointer_size_); 6643 for (size_t i = 0; i < ImTable::kSize; ++i) { 6644 imt[i] = super_imt->Get(i, image_pointer_size_); 6645 } 6646 } else { 6647 // No imt in the super class, need to reconstruct from the iftable. 6648 mirror::IfTable* if_table = super_class->GetIfTable(); 6649 if (if_table != nullptr) { 6650 // Ignore copied methods since we will handle these in LinkInterfaceMethods. 6651 FillIMTFromIfTable(if_table, 6652 unimplemented_method, 6653 imt_conflict_method, 6654 klass.Get(), 6655 /*create_conflict_table*/false, 6656 /*ignore_copied_methods*/true, 6657 /*out*/new_conflict, 6658 /*out*/imt); 6659 } 6660 } 6661} 6662 6663// TODO This method needs to be split up into several smaller methods. 6664bool ClassLinker::LinkInterfaceMethods( 6665 Thread* self, 6666 Handle<mirror::Class> klass, 6667 const std::unordered_map<size_t, ClassLinker::MethodTranslation>& default_translations, 6668 bool* out_new_conflict, 6669 ArtMethod** out_imt) { 6670 StackHandleScope<3> hs(self); 6671 Runtime* const runtime = Runtime::Current(); 6672 6673 const bool is_interface = klass->IsInterface(); 6674 const bool has_superclass = klass->HasSuperClass(); 6675 const bool fill_tables = !is_interface; 6676 const size_t super_ifcount = has_superclass ? klass->GetSuperClass()->GetIfTableCount() : 0U; 6677 const size_t method_alignment = ArtMethod::Alignment(image_pointer_size_); 6678 const size_t method_size = ArtMethod::Size(image_pointer_size_); 6679 const size_t ifcount = klass->GetIfTableCount(); 6680 6681 MutableHandle<mirror::IfTable> iftable(hs.NewHandle(klass->GetIfTable())); 6682 6683 // These are allocated on the heap to begin, we then transfer to linear alloc when we re-create 6684 // the virtual methods array. 6685 // Need to use low 4GB arenas for compiler or else the pointers wont fit in 32 bit method array 6686 // during cross compilation. 6687 // Use the linear alloc pool since this one is in the low 4gb for the compiler. 6688 ArenaStack stack(runtime->GetLinearAlloc()->GetArenaPool()); 6689 ScopedArenaAllocator allocator(&stack); 6690 6691 ScopedArenaVector<ArtMethod*> default_conflict_methods(allocator.Adapter()); 6692 ScopedArenaVector<ArtMethod*> overriding_default_conflict_methods(allocator.Adapter()); 6693 ScopedArenaVector<ArtMethod*> miranda_methods(allocator.Adapter()); 6694 ScopedArenaVector<ArtMethod*> default_methods(allocator.Adapter()); 6695 ScopedArenaVector<ArtMethod*> overriding_default_methods(allocator.Adapter()); 6696 6697 MutableHandle<mirror::PointerArray> vtable(hs.NewHandle(klass->GetVTableDuringLinking())); 6698 ArtMethod* const unimplemented_method = runtime->GetImtUnimplementedMethod(); 6699 ArtMethod* const imt_conflict_method = runtime->GetImtConflictMethod(); 6700 // Copy the IMT from the super class if possible. 6701 const bool extend_super_iftable = has_superclass; 6702 if (has_superclass && fill_tables) { 6703 FillImtFromSuperClass(klass, 6704 unimplemented_method, 6705 imt_conflict_method, 6706 out_new_conflict, 6707 out_imt); 6708 } 6709 // Allocate method arrays before since we don't want miss visiting miranda method roots due to 6710 // thread suspension. 6711 if (fill_tables) { 6712 for (size_t i = 0; i < ifcount; ++i) { 6713 size_t num_methods = iftable->GetInterface(i)->NumDeclaredVirtualMethods(); 6714 if (num_methods > 0) { 6715 const bool is_super = i < super_ifcount; 6716 // This is an interface implemented by a super-class. Therefore we can just copy the method 6717 // array from the superclass. 6718 const bool super_interface = is_super && extend_super_iftable; 6719 mirror::PointerArray* method_array; 6720 if (super_interface) { 6721 mirror::IfTable* if_table = klass->GetSuperClass()->GetIfTable(); 6722 DCHECK(if_table != nullptr); 6723 DCHECK(if_table->GetMethodArray(i) != nullptr); 6724 // If we are working on a super interface, try extending the existing method array. 6725 method_array = down_cast<mirror::PointerArray*>(if_table->GetMethodArray(i)->Clone(self)); 6726 } else { 6727 method_array = AllocPointerArray(self, num_methods); 6728 } 6729 if (UNLIKELY(method_array == nullptr)) { 6730 self->AssertPendingOOMException(); 6731 return false; 6732 } 6733 iftable->SetMethodArray(i, method_array); 6734 } 6735 } 6736 } 6737 6738 auto* old_cause = self->StartAssertNoThreadSuspension( 6739 "Copying ArtMethods for LinkInterfaceMethods"); 6740 // Going in reverse to ensure that we will hit abstract methods that override defaults before the 6741 // defaults. This means we don't need to do any trickery when creating the Miranda methods, since 6742 // they will already be null. This has the additional benefit that the declarer of a miranda 6743 // method will actually declare an abstract method. 6744 for (size_t i = ifcount; i != 0; ) { 6745 --i; 6746 6747 DCHECK_GE(i, 0u); 6748 DCHECK_LT(i, ifcount); 6749 6750 size_t num_methods = iftable->GetInterface(i)->NumDeclaredVirtualMethods(); 6751 if (num_methods > 0) { 6752 StackHandleScope<2> hs2(self); 6753 const bool is_super = i < super_ifcount; 6754 const bool super_interface = is_super && extend_super_iftable; 6755 // We don't actually create or fill these tables for interfaces, we just copy some methods for 6756 // conflict methods. Just set this as nullptr in those cases. 6757 Handle<mirror::PointerArray> method_array(fill_tables 6758 ? hs2.NewHandle(iftable->GetMethodArray(i)) 6759 : hs2.NewHandle<mirror::PointerArray>(nullptr)); 6760 6761 ArraySlice<ArtMethod> input_virtual_methods; 6762 ScopedNullHandle<mirror::PointerArray> null_handle; 6763 Handle<mirror::PointerArray> input_vtable_array(null_handle); 6764 int32_t input_array_length = 0; 6765 6766 // TODO Cleanup Needed: In the presence of default methods this optimization is rather dirty 6767 // and confusing. Default methods should always look through all the superclasses 6768 // because they are the last choice of an implementation. We get around this by looking 6769 // at the super-classes iftable methods (copied into method_array previously) when we are 6770 // looking for the implementation of a super-interface method but that is rather dirty. 6771 bool using_virtuals; 6772 if (super_interface || is_interface) { 6773 // If we are overwriting a super class interface, try to only virtual methods instead of the 6774 // whole vtable. 6775 using_virtuals = true; 6776 input_virtual_methods = klass->GetDeclaredMethodsSlice(image_pointer_size_); 6777 input_array_length = input_virtual_methods.size(); 6778 } else { 6779 // For a new interface, however, we need the whole vtable in case a new 6780 // interface method is implemented in the whole superclass. 6781 using_virtuals = false; 6782 DCHECK(vtable.Get() != nullptr); 6783 input_vtable_array = vtable; 6784 input_array_length = input_vtable_array->GetLength(); 6785 } 6786 6787 // For each method in interface 6788 for (size_t j = 0; j < num_methods; ++j) { 6789 auto* interface_method = iftable->GetInterface(i)->GetVirtualMethod(j, image_pointer_size_); 6790 MethodNameAndSignatureComparator interface_name_comparator( 6791 interface_method->GetInterfaceMethodIfProxy(image_pointer_size_)); 6792 uint32_t imt_index = GetIMTIndex(interface_method); 6793 ArtMethod** imt_ptr = &out_imt[imt_index]; 6794 // For each method listed in the interface's method list, find the 6795 // matching method in our class's method list. We want to favor the 6796 // subclass over the superclass, which just requires walking 6797 // back from the end of the vtable. (This only matters if the 6798 // superclass defines a private method and this class redefines 6799 // it -- otherwise it would use the same vtable slot. In .dex files 6800 // those don't end up in the virtual method table, so it shouldn't 6801 // matter which direction we go. We walk it backward anyway.) 6802 // 6803 // To find defaults we need to do the same but also go over interfaces. 6804 bool found_impl = false; 6805 ArtMethod* vtable_impl = nullptr; 6806 for (int32_t k = input_array_length - 1; k >= 0; --k) { 6807 ArtMethod* vtable_method = using_virtuals ? 6808 &input_virtual_methods[k] : 6809 input_vtable_array->GetElementPtrSize<ArtMethod*>(k, image_pointer_size_); 6810 ArtMethod* vtable_method_for_name_comparison = 6811 vtable_method->GetInterfaceMethodIfProxy(image_pointer_size_); 6812 if (interface_name_comparator.HasSameNameAndSignature( 6813 vtable_method_for_name_comparison)) { 6814 if (!vtable_method->IsAbstract() && !vtable_method->IsPublic()) { 6815 // Must do EndAssertNoThreadSuspension before throw since the throw can cause 6816 // allocations. 6817 self->EndAssertNoThreadSuspension(old_cause); 6818 ThrowIllegalAccessError(klass.Get(), 6819 "Method '%s' implementing interface method '%s' is not public", 6820 PrettyMethod(vtable_method).c_str(), PrettyMethod(interface_method).c_str()); 6821 return false; 6822 } else if (UNLIKELY(vtable_method->IsOverridableByDefaultMethod())) { 6823 // We might have a newer, better, default method for this, so we just skip it. If we 6824 // are still using this we will select it again when scanning for default methods. To 6825 // obviate the need to copy the method again we will make a note that we already found 6826 // a default here. 6827 // TODO This should be much cleaner. 6828 vtable_impl = vtable_method; 6829 break; 6830 } else { 6831 found_impl = true; 6832 if (LIKELY(fill_tables)) { 6833 method_array->SetElementPtrSize(j, vtable_method, image_pointer_size_); 6834 // Place method in imt if entry is empty, place conflict otherwise. 6835 SetIMTRef(unimplemented_method, 6836 imt_conflict_method, 6837 vtable_method, 6838 /*out*/out_new_conflict, 6839 /*out*/imt_ptr); 6840 } 6841 break; 6842 } 6843 } 6844 } 6845 // Continue on to the next method if we are done. 6846 if (LIKELY(found_impl)) { 6847 continue; 6848 } else if (LIKELY(super_interface)) { 6849 // Don't look for a default implementation when the super-method is implemented directly 6850 // by the class. 6851 // 6852 // See if we can use the superclasses method and skip searching everything else. 6853 // Note: !found_impl && super_interface 6854 CHECK(extend_super_iftable); 6855 // If this is a super_interface method it is possible we shouldn't override it because a 6856 // superclass could have implemented it directly. We get the method the superclass used 6857 // to implement this to know if we can override it with a default method. Doing this is 6858 // safe since we know that the super_iftable is filled in so we can simply pull it from 6859 // there. We don't bother if this is not a super-classes interface since in that case we 6860 // have scanned the entire vtable anyway and would have found it. 6861 // TODO This is rather dirty but it is faster than searching through the entire vtable 6862 // every time. 6863 ArtMethod* supers_method = 6864 method_array->GetElementPtrSize<ArtMethod*>(j, image_pointer_size_); 6865 DCHECK(supers_method != nullptr); 6866 DCHECK(interface_name_comparator.HasSameNameAndSignature(supers_method)); 6867 if (LIKELY(!supers_method->IsOverridableByDefaultMethod())) { 6868 // The method is not overridable by a default method (i.e. it is directly implemented 6869 // in some class). Therefore move onto the next interface method. 6870 continue; 6871 } else { 6872 // If the super-classes method is override-able by a default method we need to keep 6873 // track of it since though it is override-able it is not guaranteed to be 'overridden'. 6874 // If it turns out not to be overridden and we did not keep track of it we might add it 6875 // to the vtable twice, causing corruption in this class and possibly any subclasses. 6876 DCHECK(vtable_impl == nullptr || vtable_impl == supers_method) 6877 << "vtable_impl was " << PrettyMethod(vtable_impl) << " and not 'nullptr' or " 6878 << PrettyMethod(supers_method) << " as expected. IFTable appears to be corrupt!"; 6879 vtable_impl = supers_method; 6880 } 6881 } 6882 // If we haven't found it yet we should search through the interfaces for default methods. 6883 ArtMethod* current_method = nullptr; 6884 switch (FindDefaultMethodImplementation(self, 6885 interface_method, 6886 klass, 6887 /*out*/¤t_method)) { 6888 case DefaultMethodSearchResult::kDefaultConflict: { 6889 // Default method conflict. 6890 DCHECK(current_method == nullptr); 6891 ArtMethod* default_conflict_method = nullptr; 6892 if (vtable_impl != nullptr && vtable_impl->IsDefaultConflicting()) { 6893 // We can reuse the method from the superclass, don't bother adding it to virtuals. 6894 default_conflict_method = vtable_impl; 6895 } else { 6896 // See if we already have a conflict method for this method. 6897 ArtMethod* preexisting_conflict = FindSameNameAndSignature( 6898 interface_name_comparator, 6899 default_conflict_methods, 6900 overriding_default_conflict_methods); 6901 if (LIKELY(preexisting_conflict != nullptr)) { 6902 // We already have another conflict we can reuse. 6903 default_conflict_method = preexisting_conflict; 6904 } else { 6905 // Note that we do this even if we are an interface since we need to create this and 6906 // cannot reuse another classes. 6907 // Create a new conflict method for this to use. 6908 default_conflict_method = 6909 reinterpret_cast<ArtMethod*>(allocator.Alloc(method_size)); 6910 new(default_conflict_method) ArtMethod(interface_method, image_pointer_size_); 6911 if (vtable_impl == nullptr) { 6912 // Save the conflict method. We need to add it to the vtable. 6913 default_conflict_methods.push_back(default_conflict_method); 6914 } else { 6915 // Save the conflict method but it is already in the vtable. 6916 overriding_default_conflict_methods.push_back(default_conflict_method); 6917 } 6918 } 6919 } 6920 current_method = default_conflict_method; 6921 break; 6922 } // case kDefaultConflict 6923 case DefaultMethodSearchResult::kDefaultFound: { 6924 DCHECK(current_method != nullptr); 6925 // Found a default method. 6926 if (vtable_impl != nullptr && 6927 current_method->GetDeclaringClass() == vtable_impl->GetDeclaringClass()) { 6928 // We found a default method but it was the same one we already have from our 6929 // superclass. Don't bother adding it to our vtable again. 6930 current_method = vtable_impl; 6931 } else if (LIKELY(fill_tables)) { 6932 // Interfaces don't need to copy default methods since they don't have vtables. 6933 // Only record this default method if it is new to save space. 6934 // TODO It might be worthwhile to copy default methods on interfaces anyway since it 6935 // would make lookup for interface super much faster. (We would only need to scan 6936 // the iftable to find if there is a NSME or AME.) 6937 ArtMethod* old = FindSameNameAndSignature(interface_name_comparator, 6938 default_methods, 6939 overriding_default_methods); 6940 if (old == nullptr) { 6941 // We found a default method implementation and there were no conflicts. 6942 if (vtable_impl == nullptr) { 6943 // Save the default method. We need to add it to the vtable. 6944 default_methods.push_back(current_method); 6945 } else { 6946 // Save the default method but it is already in the vtable. 6947 overriding_default_methods.push_back(current_method); 6948 } 6949 } else { 6950 CHECK(old == current_method) << "Multiple default implementations selected!"; 6951 } 6952 } 6953 break; 6954 } // case kDefaultFound 6955 case DefaultMethodSearchResult::kAbstractFound: { 6956 DCHECK(current_method == nullptr); 6957 // Abstract method masks all defaults. 6958 if (vtable_impl != nullptr && 6959 vtable_impl->IsAbstract() && 6960 !vtable_impl->IsDefaultConflicting()) { 6961 // We need to make this an abstract method but the version in the vtable already is so 6962 // don't do anything. 6963 current_method = vtable_impl; 6964 } 6965 break; 6966 } // case kAbstractFound 6967 } 6968 if (LIKELY(fill_tables)) { 6969 if (current_method == nullptr && !super_interface) { 6970 // We could not find an implementation for this method and since it is a brand new 6971 // interface we searched the entire vtable (and all default methods) for an 6972 // implementation but couldn't find one. We therefore need to make a miranda method. 6973 // 6974 // Find out if there is already a miranda method we can use. 6975 ArtMethod* miranda_method = FindSameNameAndSignature(interface_name_comparator, 6976 miranda_methods); 6977 if (miranda_method == nullptr) { 6978 DCHECK(interface_method->IsAbstract()) << PrettyMethod(interface_method); 6979 miranda_method = reinterpret_cast<ArtMethod*>(allocator.Alloc(method_size)); 6980 CHECK(miranda_method != nullptr); 6981 // Point the interface table at a phantom slot. 6982 new(miranda_method) ArtMethod(interface_method, image_pointer_size_); 6983 miranda_methods.push_back(miranda_method); 6984 } 6985 current_method = miranda_method; 6986 } 6987 6988 if (current_method != nullptr) { 6989 // We found a default method implementation. Record it in the iftable and IMT. 6990 method_array->SetElementPtrSize(j, current_method, image_pointer_size_); 6991 SetIMTRef(unimplemented_method, 6992 imt_conflict_method, 6993 current_method, 6994 /*out*/out_new_conflict, 6995 /*out*/imt_ptr); 6996 } 6997 } 6998 } // For each method in interface end. 6999 } // if (num_methods > 0) 7000 } // For each interface. 7001 const bool has_new_virtuals = !(miranda_methods.empty() && 7002 default_methods.empty() && 7003 overriding_default_methods.empty() && 7004 overriding_default_conflict_methods.empty() && 7005 default_conflict_methods.empty()); 7006 // TODO don't extend virtuals of interface unless necessary (when is it?). 7007 if (has_new_virtuals) { 7008 DCHECK(!is_interface || (default_methods.empty() && miranda_methods.empty())) 7009 << "Interfaces should only have default-conflict methods appended to them."; 7010 VLOG(class_linker) << PrettyClass(klass.Get()) << ": miranda_methods=" << miranda_methods.size() 7011 << " default_methods=" << default_methods.size() 7012 << " overriding_default_methods=" << overriding_default_methods.size() 7013 << " default_conflict_methods=" << default_conflict_methods.size() 7014 << " overriding_default_conflict_methods=" 7015 << overriding_default_conflict_methods.size(); 7016 const size_t old_method_count = klass->NumMethods(); 7017 const size_t new_method_count = old_method_count + 7018 miranda_methods.size() + 7019 default_methods.size() + 7020 overriding_default_conflict_methods.size() + 7021 overriding_default_methods.size() + 7022 default_conflict_methods.size(); 7023 // Attempt to realloc to save RAM if possible. 7024 LengthPrefixedArray<ArtMethod>* old_methods = klass->GetMethodsPtr(); 7025 // The Realloced virtual methods aren't visible from the class roots, so there is no issue 7026 // where GCs could attempt to mark stale pointers due to memcpy. And since we overwrite the 7027 // realloced memory with out->CopyFrom, we are guaranteed to have objects in the to space since 7028 // CopyFrom has internal read barriers. 7029 // 7030 // TODO We should maybe move some of this into mirror::Class or at least into another method. 7031 const size_t old_size = LengthPrefixedArray<ArtMethod>::ComputeSize(old_method_count, 7032 method_size, 7033 method_alignment); 7034 const size_t new_size = LengthPrefixedArray<ArtMethod>::ComputeSize(new_method_count, 7035 method_size, 7036 method_alignment); 7037 const size_t old_methods_ptr_size = (old_methods != nullptr) ? old_size : 0; 7038 auto* methods = reinterpret_cast<LengthPrefixedArray<ArtMethod>*>( 7039 runtime->GetLinearAlloc()->Realloc(self, old_methods, old_methods_ptr_size, new_size)); 7040 if (UNLIKELY(methods == nullptr)) { 7041 self->AssertPendingOOMException(); 7042 self->EndAssertNoThreadSuspension(old_cause); 7043 return false; 7044 } 7045 ScopedArenaUnorderedMap<ArtMethod*, ArtMethod*> move_table(allocator.Adapter()); 7046 if (methods != old_methods) { 7047 // Maps from heap allocated miranda method to linear alloc miranda method. 7048 StrideIterator<ArtMethod> out = methods->begin(method_size, method_alignment); 7049 // Copy over the old methods. 7050 for (auto& m : klass->GetMethods(image_pointer_size_)) { 7051 move_table.emplace(&m, &*out); 7052 // The CopyFrom is only necessary to not miss read barriers since Realloc won't do read 7053 // barriers when it copies. 7054 out->CopyFrom(&m, image_pointer_size_); 7055 ++out; 7056 } 7057 } 7058 StrideIterator<ArtMethod> out(methods->begin(method_size, method_alignment) + old_method_count); 7059 // Copy over miranda methods before copying vtable since CopyOf may cause thread suspension and 7060 // we want the roots of the miranda methods to get visited. 7061 for (ArtMethod* mir_method : miranda_methods) { 7062 ArtMethod& new_method = *out; 7063 new_method.CopyFrom(mir_method, image_pointer_size_); 7064 new_method.SetAccessFlags(new_method.GetAccessFlags() | kAccMiranda | kAccCopied); 7065 DCHECK_NE(new_method.GetAccessFlags() & kAccAbstract, 0u) 7066 << "Miranda method should be abstract!"; 7067 move_table.emplace(mir_method, &new_method); 7068 ++out; 7069 } 7070 // We need to copy the default methods into our own method table since the runtime requires that 7071 // every method on a class's vtable be in that respective class's virtual method table. 7072 // NOTE This means that two classes might have the same implementation of a method from the same 7073 // interface but will have different ArtMethod*s for them. This also means we cannot compare a 7074 // default method found on a class with one found on the declaring interface directly and must 7075 // look at the declaring class to determine if they are the same. 7076 for (const ScopedArenaVector<ArtMethod*>& methods_vec : {default_methods, 7077 overriding_default_methods}) { 7078 for (ArtMethod* def_method : methods_vec) { 7079 ArtMethod& new_method = *out; 7080 new_method.CopyFrom(def_method, image_pointer_size_); 7081 // Clear the kAccSkipAccessChecks flag if it is present. Since this class hasn't been 7082 // verified yet it shouldn't have methods that are skipping access checks. 7083 // TODO This is rather arbitrary. We should maybe support classes where only some of its 7084 // methods are skip_access_checks. 7085 constexpr uint32_t kSetFlags = kAccDefault | kAccCopied; 7086 constexpr uint32_t kMaskFlags = ~kAccSkipAccessChecks; 7087 new_method.SetAccessFlags((new_method.GetAccessFlags() | kSetFlags) & kMaskFlags); 7088 move_table.emplace(def_method, &new_method); 7089 ++out; 7090 } 7091 } 7092 for (const ScopedArenaVector<ArtMethod*>& methods_vec : {default_conflict_methods, 7093 overriding_default_conflict_methods}) { 7094 for (ArtMethod* conf_method : methods_vec) { 7095 ArtMethod& new_method = *out; 7096 new_method.CopyFrom(conf_method, image_pointer_size_); 7097 // This is a type of default method (there are default method impls, just a conflict) so 7098 // mark this as a default, non-abstract method, since thats what it is. Also clear the 7099 // kAccSkipAccessChecks bit since this class hasn't been verified yet it shouldn't have 7100 // methods that are skipping access checks. 7101 constexpr uint32_t kSetFlags = kAccDefault | kAccDefaultConflict | kAccCopied; 7102 constexpr uint32_t kMaskFlags = ~(kAccAbstract | kAccSkipAccessChecks); 7103 new_method.SetAccessFlags((new_method.GetAccessFlags() | kSetFlags) & kMaskFlags); 7104 DCHECK(new_method.IsDefaultConflicting()); 7105 // The actual method might or might not be marked abstract since we just copied it from a 7106 // (possibly default) interface method. We need to set it entry point to be the bridge so 7107 // that the compiler will not invoke the implementation of whatever method we copied from. 7108 EnsureThrowsInvocationError(&new_method); 7109 move_table.emplace(conf_method, &new_method); 7110 ++out; 7111 } 7112 } 7113 methods->SetSize(new_method_count); 7114 UpdateClassMethods(klass.Get(), methods); 7115 // Done copying methods, they are all roots in the class now, so we can end the no thread 7116 // suspension assert. 7117 self->EndAssertNoThreadSuspension(old_cause); 7118 7119 if (fill_tables) { 7120 // Update the vtable to the new method structures. We can skip this for interfaces since they 7121 // do not have vtables. 7122 const size_t old_vtable_count = vtable->GetLength(); 7123 const size_t new_vtable_count = old_vtable_count + 7124 miranda_methods.size() + 7125 default_methods.size() + 7126 default_conflict_methods.size(); 7127 7128 vtable.Assign(down_cast<mirror::PointerArray*>(vtable->CopyOf(self, new_vtable_count))); 7129 if (UNLIKELY(vtable.Get() == nullptr)) { 7130 self->AssertPendingOOMException(); 7131 return false; 7132 } 7133 size_t vtable_pos = old_vtable_count; 7134 // Update all the newly copied method's indexes so they denote their placement in the vtable. 7135 for (const ScopedArenaVector<ArtMethod*>& methods_vec : {default_methods, 7136 default_conflict_methods, 7137 miranda_methods}) { 7138 // These are the functions that are not already in the vtable! 7139 for (ArtMethod* new_method : methods_vec) { 7140 auto translated_method_it = move_table.find(new_method); 7141 CHECK(translated_method_it != move_table.end()) 7142 << "We must have a translation for methods added to the classes methods_ array! We " 7143 << "could not find the ArtMethod added for " << PrettyMethod(new_method); 7144 ArtMethod* new_vtable_method = translated_method_it->second; 7145 // Leave the declaring class alone the method's dex_code_item_offset_ and dex_method_index_ 7146 // fields are references into the dex file the method was defined in. Since the ArtMethod 7147 // does not store that information it uses declaring_class_->dex_cache_. 7148 new_vtable_method->SetMethodIndex(0xFFFF & vtable_pos); 7149 vtable->SetElementPtrSize(vtable_pos, new_vtable_method, image_pointer_size_); 7150 ++vtable_pos; 7151 } 7152 } 7153 CHECK_EQ(vtable_pos, new_vtable_count); 7154 // Update old vtable methods. We use the default_translations map to figure out what each 7155 // vtable entry should be updated to, if they need to be at all. 7156 for (size_t i = 0; i < old_vtable_count; ++i) { 7157 ArtMethod* translated_method = vtable->GetElementPtrSize<ArtMethod*>( 7158 i, image_pointer_size_); 7159 // Try and find what we need to change this method to. 7160 auto translation_it = default_translations.find(i); 7161 bool found_translation = false; 7162 if (translation_it != default_translations.end()) { 7163 if (translation_it->second.IsInConflict()) { 7164 // Find which conflict method we are to use for this method. 7165 MethodNameAndSignatureComparator old_method_comparator( 7166 translated_method->GetInterfaceMethodIfProxy(image_pointer_size_)); 7167 // We only need to look through overriding_default_conflict_methods since this is an 7168 // overridden method we are fixing up here. 7169 ArtMethod* new_conflict_method = FindSameNameAndSignature( 7170 old_method_comparator, overriding_default_conflict_methods); 7171 CHECK(new_conflict_method != nullptr) << "Expected a conflict method!"; 7172 translated_method = new_conflict_method; 7173 } else if (translation_it->second.IsAbstract()) { 7174 // Find which miranda method we are to use for this method. 7175 MethodNameAndSignatureComparator old_method_comparator( 7176 translated_method->GetInterfaceMethodIfProxy(image_pointer_size_)); 7177 ArtMethod* miranda_method = FindSameNameAndSignature(old_method_comparator, 7178 miranda_methods); 7179 DCHECK(miranda_method != nullptr); 7180 translated_method = miranda_method; 7181 } else { 7182 // Normal default method (changed from an older default or abstract interface method). 7183 DCHECK(translation_it->second.IsTranslation()); 7184 translated_method = translation_it->second.GetTranslation(); 7185 } 7186 found_translation = true; 7187 } 7188 DCHECK(translated_method != nullptr); 7189 auto it = move_table.find(translated_method); 7190 if (it != move_table.end()) { 7191 auto* new_method = it->second; 7192 DCHECK(new_method != nullptr); 7193 // Make sure the new_methods index is set. 7194 if (new_method->GetMethodIndexDuringLinking() != i) { 7195 DCHECK_LE(reinterpret_cast<uintptr_t>(&*methods->begin(method_size, method_alignment)), 7196 reinterpret_cast<uintptr_t>(new_method)); 7197 DCHECK_LT(reinterpret_cast<uintptr_t>(new_method), 7198 reinterpret_cast<uintptr_t>(&*methods->end(method_size, method_alignment))); 7199 new_method->SetMethodIndex(0xFFFF & i); 7200 } 7201 vtable->SetElementPtrSize(i, new_method, image_pointer_size_); 7202 } else { 7203 // If it was not going to be updated we wouldn't have put it into the default_translations 7204 // map. 7205 CHECK(!found_translation) << "We were asked to update this vtable entry. Must not fail."; 7206 } 7207 } 7208 klass->SetVTable(vtable.Get()); 7209 7210 // Go fix up all the stale iftable pointers. 7211 for (size_t i = 0; i < ifcount; ++i) { 7212 for (size_t j = 0, count = iftable->GetMethodArrayCount(i); j < count; ++j) { 7213 auto* method_array = iftable->GetMethodArray(i); 7214 auto* m = method_array->GetElementPtrSize<ArtMethod*>(j, image_pointer_size_); 7215 DCHECK(m != nullptr) << PrettyClass(klass.Get()); 7216 auto it = move_table.find(m); 7217 if (it != move_table.end()) { 7218 auto* new_m = it->second; 7219 DCHECK(new_m != nullptr) << PrettyClass(klass.Get()); 7220 method_array->SetElementPtrSize(j, new_m, image_pointer_size_); 7221 } 7222 } 7223 } 7224 7225 // Fix up IMT next 7226 for (size_t i = 0; i < ImTable::kSize; ++i) { 7227 auto it = move_table.find(out_imt[i]); 7228 if (it != move_table.end()) { 7229 out_imt[i] = it->second; 7230 } 7231 } 7232 } 7233 7234 // Check that there are no stale methods are in the dex cache array. 7235 if (kIsDebugBuild) { 7236 auto* resolved_methods = klass->GetDexCache()->GetResolvedMethods(); 7237 for (size_t i = 0, count = klass->GetDexCache()->NumResolvedMethods(); i < count; ++i) { 7238 auto* m = mirror::DexCache::GetElementPtrSize(resolved_methods, i, image_pointer_size_); 7239 CHECK(move_table.find(m) == move_table.end() || 7240 // The original versions of copied methods will still be present so allow those too. 7241 // Note that if the first check passes this might fail to GetDeclaringClass(). 7242 std::find_if(m->GetDeclaringClass()->GetMethods(image_pointer_size_).begin(), 7243 m->GetDeclaringClass()->GetMethods(image_pointer_size_).end(), 7244 [m] (ArtMethod& meth) { 7245 return &meth == m; 7246 }) != m->GetDeclaringClass()->GetMethods(image_pointer_size_).end()) 7247 << "Obsolete methods " << PrettyMethod(m) << " is in dex cache!"; 7248 } 7249 } 7250 // Put some random garbage in old methods to help find stale pointers. 7251 if (methods != old_methods && old_methods != nullptr && kIsDebugBuild) { 7252 // Need to make sure the GC is not running since it could be scanning the methods we are 7253 // about to overwrite. 7254 ScopedThreadStateChange tsc(self, kSuspended); 7255 gc::ScopedGCCriticalSection gcs(self, 7256 gc::kGcCauseClassLinker, 7257 gc::kCollectorTypeClassLinker); 7258 memset(old_methods, 0xFEu, old_size); 7259 } 7260 } else { 7261 self->EndAssertNoThreadSuspension(old_cause); 7262 } 7263 if (kIsDebugBuild && !is_interface) { 7264 SanityCheckVTable(self, klass, image_pointer_size_); 7265 } 7266 return true; 7267} 7268 7269bool ClassLinker::LinkInstanceFields(Thread* self, Handle<mirror::Class> klass) { 7270 CHECK(klass.Get() != nullptr); 7271 return LinkFields(self, klass, false, nullptr); 7272} 7273 7274bool ClassLinker::LinkStaticFields(Thread* self, Handle<mirror::Class> klass, size_t* class_size) { 7275 CHECK(klass.Get() != nullptr); 7276 return LinkFields(self, klass, true, class_size); 7277} 7278 7279struct LinkFieldsComparator { 7280 explicit LinkFieldsComparator() SHARED_REQUIRES(Locks::mutator_lock_) { 7281 } 7282 // No thread safety analysis as will be called from STL. Checked lock held in constructor. 7283 bool operator()(ArtField* field1, ArtField* field2) 7284 NO_THREAD_SAFETY_ANALYSIS { 7285 // First come reference fields, then 64-bit, then 32-bit, and then 16-bit, then finally 8-bit. 7286 Primitive::Type type1 = field1->GetTypeAsPrimitiveType(); 7287 Primitive::Type type2 = field2->GetTypeAsPrimitiveType(); 7288 if (type1 != type2) { 7289 if (type1 == Primitive::kPrimNot) { 7290 // Reference always goes first. 7291 return true; 7292 } 7293 if (type2 == Primitive::kPrimNot) { 7294 // Reference always goes first. 7295 return false; 7296 } 7297 size_t size1 = Primitive::ComponentSize(type1); 7298 size_t size2 = Primitive::ComponentSize(type2); 7299 if (size1 != size2) { 7300 // Larger primitive types go first. 7301 return size1 > size2; 7302 } 7303 // Primitive types differ but sizes match. Arbitrarily order by primitive type. 7304 return type1 < type2; 7305 } 7306 // Same basic group? Then sort by dex field index. This is guaranteed to be sorted 7307 // by name and for equal names by type id index. 7308 // NOTE: This works also for proxies. Their static fields are assigned appropriate indexes. 7309 return field1->GetDexFieldIndex() < field2->GetDexFieldIndex(); 7310 } 7311}; 7312 7313bool ClassLinker::LinkFields(Thread* self, 7314 Handle<mirror::Class> klass, 7315 bool is_static, 7316 size_t* class_size) { 7317 self->AllowThreadSuspension(); 7318 const size_t num_fields = is_static ? klass->NumStaticFields() : klass->NumInstanceFields(); 7319 LengthPrefixedArray<ArtField>* const fields = is_static ? klass->GetSFieldsPtr() : 7320 klass->GetIFieldsPtr(); 7321 7322 // Initialize field_offset 7323 MemberOffset field_offset(0); 7324 if (is_static) { 7325 field_offset = klass->GetFirstReferenceStaticFieldOffsetDuringLinking(image_pointer_size_); 7326 } else { 7327 mirror::Class* super_class = klass->GetSuperClass(); 7328 if (super_class != nullptr) { 7329 CHECK(super_class->IsResolved()) 7330 << PrettyClass(klass.Get()) << " " << PrettyClass(super_class); 7331 field_offset = MemberOffset(super_class->GetObjectSize()); 7332 } 7333 } 7334 7335 CHECK_EQ(num_fields == 0, fields == nullptr) << PrettyClass(klass.Get()); 7336 7337 // we want a relatively stable order so that adding new fields 7338 // minimizes disruption of C++ version such as Class and Method. 7339 // 7340 // The overall sort order order is: 7341 // 1) All object reference fields, sorted alphabetically. 7342 // 2) All java long (64-bit) integer fields, sorted alphabetically. 7343 // 3) All java double (64-bit) floating point fields, sorted alphabetically. 7344 // 4) All java int (32-bit) integer fields, sorted alphabetically. 7345 // 5) All java float (32-bit) floating point fields, sorted alphabetically. 7346 // 6) All java char (16-bit) integer fields, sorted alphabetically. 7347 // 7) All java short (16-bit) integer fields, sorted alphabetically. 7348 // 8) All java boolean (8-bit) integer fields, sorted alphabetically. 7349 // 9) All java byte (8-bit) integer fields, sorted alphabetically. 7350 // 7351 // Once the fields are sorted in this order we will attempt to fill any gaps that might be present 7352 // in the memory layout of the structure. See ShuffleForward for how this is done. 7353 std::deque<ArtField*> grouped_and_sorted_fields; 7354 const char* old_no_suspend_cause = self->StartAssertNoThreadSuspension( 7355 "Naked ArtField references in deque"); 7356 for (size_t i = 0; i < num_fields; i++) { 7357 grouped_and_sorted_fields.push_back(&fields->At(i)); 7358 } 7359 std::sort(grouped_and_sorted_fields.begin(), grouped_and_sorted_fields.end(), 7360 LinkFieldsComparator()); 7361 7362 // References should be at the front. 7363 size_t current_field = 0; 7364 size_t num_reference_fields = 0; 7365 FieldGaps gaps; 7366 7367 for (; current_field < num_fields; current_field++) { 7368 ArtField* field = grouped_and_sorted_fields.front(); 7369 Primitive::Type type = field->GetTypeAsPrimitiveType(); 7370 bool isPrimitive = type != Primitive::kPrimNot; 7371 if (isPrimitive) { 7372 break; // past last reference, move on to the next phase 7373 } 7374 if (UNLIKELY(!IsAligned<sizeof(mirror::HeapReference<mirror::Object>)>( 7375 field_offset.Uint32Value()))) { 7376 MemberOffset old_offset = field_offset; 7377 field_offset = MemberOffset(RoundUp(field_offset.Uint32Value(), 4)); 7378 AddFieldGap(old_offset.Uint32Value(), field_offset.Uint32Value(), &gaps); 7379 } 7380 DCHECK_ALIGNED(field_offset.Uint32Value(), sizeof(mirror::HeapReference<mirror::Object>)); 7381 grouped_and_sorted_fields.pop_front(); 7382 num_reference_fields++; 7383 field->SetOffset(field_offset); 7384 field_offset = MemberOffset(field_offset.Uint32Value() + 7385 sizeof(mirror::HeapReference<mirror::Object>)); 7386 } 7387 // Gaps are stored as a max heap which means that we must shuffle from largest to smallest 7388 // otherwise we could end up with suboptimal gap fills. 7389 ShuffleForward<8>(¤t_field, &field_offset, &grouped_and_sorted_fields, &gaps); 7390 ShuffleForward<4>(¤t_field, &field_offset, &grouped_and_sorted_fields, &gaps); 7391 ShuffleForward<2>(¤t_field, &field_offset, &grouped_and_sorted_fields, &gaps); 7392 ShuffleForward<1>(¤t_field, &field_offset, &grouped_and_sorted_fields, &gaps); 7393 CHECK(grouped_and_sorted_fields.empty()) << "Missed " << grouped_and_sorted_fields.size() << 7394 " fields."; 7395 self->EndAssertNoThreadSuspension(old_no_suspend_cause); 7396 7397 // We lie to the GC about the java.lang.ref.Reference.referent field, so it doesn't scan it. 7398 if (!is_static && klass->DescriptorEquals("Ljava/lang/ref/Reference;")) { 7399 // We know there are no non-reference fields in the Reference classes, and we know 7400 // that 'referent' is alphabetically last, so this is easy... 7401 CHECK_EQ(num_reference_fields, num_fields) << PrettyClass(klass.Get()); 7402 CHECK_STREQ(fields->At(num_fields - 1).GetName(), "referent") 7403 << PrettyClass(klass.Get()); 7404 --num_reference_fields; 7405 } 7406 7407 size_t size = field_offset.Uint32Value(); 7408 // Update klass 7409 if (is_static) { 7410 klass->SetNumReferenceStaticFields(num_reference_fields); 7411 *class_size = size; 7412 } else { 7413 klass->SetNumReferenceInstanceFields(num_reference_fields); 7414 mirror::Class* super_class = klass->GetSuperClass(); 7415 if (num_reference_fields == 0 || super_class == nullptr) { 7416 // object has one reference field, klass, but we ignore it since we always visit the class. 7417 // super_class is null iff the class is java.lang.Object. 7418 if (super_class == nullptr || 7419 (super_class->GetClassFlags() & mirror::kClassFlagNoReferenceFields) != 0) { 7420 klass->SetClassFlags(klass->GetClassFlags() | mirror::kClassFlagNoReferenceFields); 7421 } 7422 } 7423 if (kIsDebugBuild) { 7424 DCHECK_EQ(super_class == nullptr, klass->DescriptorEquals("Ljava/lang/Object;")); 7425 size_t total_reference_instance_fields = 0; 7426 mirror::Class* cur_super = klass.Get(); 7427 while (cur_super != nullptr) { 7428 total_reference_instance_fields += cur_super->NumReferenceInstanceFieldsDuringLinking(); 7429 cur_super = cur_super->GetSuperClass(); 7430 } 7431 if (super_class == nullptr) { 7432 CHECK_EQ(total_reference_instance_fields, 1u) << PrettyDescriptor(klass.Get()); 7433 } else { 7434 // Check that there is at least num_reference_fields other than Object.class. 7435 CHECK_GE(total_reference_instance_fields, 1u + num_reference_fields) 7436 << PrettyClass(klass.Get()); 7437 } 7438 } 7439 if (!klass->IsVariableSize()) { 7440 std::string temp; 7441 DCHECK_GE(size, sizeof(mirror::Object)) << klass->GetDescriptor(&temp); 7442 size_t previous_size = klass->GetObjectSize(); 7443 if (previous_size != 0) { 7444 // Make sure that we didn't originally have an incorrect size. 7445 CHECK_EQ(previous_size, size) << klass->GetDescriptor(&temp); 7446 } 7447 klass->SetObjectSize(size); 7448 } 7449 } 7450 7451 if (kIsDebugBuild) { 7452 // Make sure that the fields array is ordered by name but all reference 7453 // offsets are at the beginning as far as alignment allows. 7454 MemberOffset start_ref_offset = is_static 7455 ? klass->GetFirstReferenceStaticFieldOffsetDuringLinking(image_pointer_size_) 7456 : klass->GetFirstReferenceInstanceFieldOffset(); 7457 MemberOffset end_ref_offset(start_ref_offset.Uint32Value() + 7458 num_reference_fields * 7459 sizeof(mirror::HeapReference<mirror::Object>)); 7460 MemberOffset current_ref_offset = start_ref_offset; 7461 for (size_t i = 0; i < num_fields; i++) { 7462 ArtField* field = &fields->At(i); 7463 VLOG(class_linker) << "LinkFields: " << (is_static ? "static" : "instance") 7464 << " class=" << PrettyClass(klass.Get()) << " field=" << PrettyField(field) << " offset=" 7465 << field->GetOffsetDuringLinking(); 7466 if (i != 0) { 7467 ArtField* const prev_field = &fields->At(i - 1); 7468 // NOTE: The field names can be the same. This is not possible in the Java language 7469 // but it's valid Java/dex bytecode and for example proguard can generate such bytecode. 7470 DCHECK_LE(strcmp(prev_field->GetName(), field->GetName()), 0); 7471 } 7472 Primitive::Type type = field->GetTypeAsPrimitiveType(); 7473 bool is_primitive = type != Primitive::kPrimNot; 7474 if (klass->DescriptorEquals("Ljava/lang/ref/Reference;") && 7475 strcmp("referent", field->GetName()) == 0) { 7476 is_primitive = true; // We lied above, so we have to expect a lie here. 7477 } 7478 MemberOffset offset = field->GetOffsetDuringLinking(); 7479 if (is_primitive) { 7480 if (offset.Uint32Value() < end_ref_offset.Uint32Value()) { 7481 // Shuffled before references. 7482 size_t type_size = Primitive::ComponentSize(type); 7483 CHECK_LT(type_size, sizeof(mirror::HeapReference<mirror::Object>)); 7484 CHECK_LT(offset.Uint32Value(), start_ref_offset.Uint32Value()); 7485 CHECK_LE(offset.Uint32Value() + type_size, start_ref_offset.Uint32Value()); 7486 CHECK(!IsAligned<sizeof(mirror::HeapReference<mirror::Object>)>(offset.Uint32Value())); 7487 } 7488 } else { 7489 CHECK_EQ(current_ref_offset.Uint32Value(), offset.Uint32Value()); 7490 current_ref_offset = MemberOffset(current_ref_offset.Uint32Value() + 7491 sizeof(mirror::HeapReference<mirror::Object>)); 7492 } 7493 } 7494 CHECK_EQ(current_ref_offset.Uint32Value(), end_ref_offset.Uint32Value()); 7495 } 7496 return true; 7497} 7498 7499// Set the bitmap of reference instance field offsets. 7500void ClassLinker::CreateReferenceInstanceOffsets(Handle<mirror::Class> klass) { 7501 uint32_t reference_offsets = 0; 7502 mirror::Class* super_class = klass->GetSuperClass(); 7503 // Leave the reference offsets as 0 for mirror::Object (the class field is handled specially). 7504 if (super_class != nullptr) { 7505 reference_offsets = super_class->GetReferenceInstanceOffsets(); 7506 // Compute reference offsets unless our superclass overflowed. 7507 if (reference_offsets != mirror::Class::kClassWalkSuper) { 7508 size_t num_reference_fields = klass->NumReferenceInstanceFieldsDuringLinking(); 7509 if (num_reference_fields != 0u) { 7510 // All of the fields that contain object references are guaranteed be grouped in memory 7511 // starting at an appropriately aligned address after super class object data. 7512 uint32_t start_offset = RoundUp(super_class->GetObjectSize(), 7513 sizeof(mirror::HeapReference<mirror::Object>)); 7514 uint32_t start_bit = (start_offset - mirror::kObjectHeaderSize) / 7515 sizeof(mirror::HeapReference<mirror::Object>); 7516 if (start_bit + num_reference_fields > 32) { 7517 reference_offsets = mirror::Class::kClassWalkSuper; 7518 } else { 7519 reference_offsets |= (0xffffffffu << start_bit) & 7520 (0xffffffffu >> (32 - (start_bit + num_reference_fields))); 7521 } 7522 } 7523 } 7524 } 7525 klass->SetReferenceInstanceOffsets(reference_offsets); 7526} 7527 7528mirror::String* ClassLinker::ResolveString(const DexFile& dex_file, 7529 uint32_t string_idx, 7530 Handle<mirror::DexCache> dex_cache) { 7531 DCHECK(dex_cache.Get() != nullptr); 7532 mirror::String* resolved = dex_cache->GetResolvedString(string_idx); 7533 if (resolved != nullptr) { 7534 return resolved; 7535 } 7536 uint32_t utf16_length; 7537 const char* utf8_data = dex_file.StringDataAndUtf16LengthByIdx(string_idx, &utf16_length); 7538 mirror::String* string = intern_table_->InternStrong(utf16_length, utf8_data); 7539 dex_cache->SetResolvedString(string_idx, string); 7540 return string; 7541} 7542 7543mirror::String* ClassLinker::LookupString(const DexFile& dex_file, 7544 uint32_t string_idx, 7545 Handle<mirror::DexCache> dex_cache) { 7546 DCHECK(dex_cache.Get() != nullptr); 7547 mirror::String* resolved = dex_cache->GetResolvedString(string_idx); 7548 if (resolved != nullptr) { 7549 return resolved; 7550 } 7551 uint32_t utf16_length; 7552 const char* utf8_data = dex_file.StringDataAndUtf16LengthByIdx(string_idx, &utf16_length); 7553 mirror::String* string = intern_table_->LookupStrong(Thread::Current(), utf16_length, utf8_data); 7554 if (string != nullptr) { 7555 dex_cache->SetResolvedString(string_idx, string); 7556 } 7557 return string; 7558} 7559 7560mirror::Class* ClassLinker::ResolveType(const DexFile& dex_file, 7561 uint16_t type_idx, 7562 mirror::Class* referrer) { 7563 StackHandleScope<2> hs(Thread::Current()); 7564 Handle<mirror::DexCache> dex_cache(hs.NewHandle(referrer->GetDexCache())); 7565 Handle<mirror::ClassLoader> class_loader(hs.NewHandle(referrer->GetClassLoader())); 7566 return ResolveType(dex_file, type_idx, dex_cache, class_loader); 7567} 7568 7569mirror::Class* ClassLinker::ResolveType(const DexFile& dex_file, 7570 uint16_t type_idx, 7571 Handle<mirror::DexCache> dex_cache, 7572 Handle<mirror::ClassLoader> class_loader) { 7573 DCHECK(dex_cache.Get() != nullptr); 7574 mirror::Class* resolved = dex_cache->GetResolvedType(type_idx); 7575 if (resolved == nullptr) { 7576 Thread* self = Thread::Current(); 7577 const char* descriptor = dex_file.StringByTypeIdx(type_idx); 7578 resolved = FindClass(self, descriptor, class_loader); 7579 if (resolved != nullptr) { 7580 // TODO: we used to throw here if resolved's class loader was not the 7581 // boot class loader. This was to permit different classes with the 7582 // same name to be loaded simultaneously by different loaders 7583 dex_cache->SetResolvedType(type_idx, resolved); 7584 } else { 7585 CHECK(self->IsExceptionPending()) 7586 << "Expected pending exception for failed resolution of: " << descriptor; 7587 // Convert a ClassNotFoundException to a NoClassDefFoundError. 7588 StackHandleScope<1> hs(self); 7589 Handle<mirror::Throwable> cause(hs.NewHandle(self->GetException())); 7590 if (cause->InstanceOf(GetClassRoot(kJavaLangClassNotFoundException))) { 7591 DCHECK(resolved == nullptr); // No Handle needed to preserve resolved. 7592 self->ClearException(); 7593 ThrowNoClassDefFoundError("Failed resolution of: %s", descriptor); 7594 self->GetException()->SetCause(cause.Get()); 7595 } 7596 } 7597 } 7598 DCHECK((resolved == nullptr) || resolved->IsResolved() || resolved->IsErroneous()) 7599 << PrettyDescriptor(resolved) << " " << resolved->GetStatus(); 7600 return resolved; 7601} 7602 7603template <ClassLinker::ResolveMode kResolveMode> 7604ArtMethod* ClassLinker::ResolveMethod(const DexFile& dex_file, 7605 uint32_t method_idx, 7606 Handle<mirror::DexCache> dex_cache, 7607 Handle<mirror::ClassLoader> class_loader, 7608 ArtMethod* referrer, 7609 InvokeType type) { 7610 DCHECK(dex_cache.Get() != nullptr); 7611 // Check for hit in the dex cache. 7612 ArtMethod* resolved = dex_cache->GetResolvedMethod(method_idx, image_pointer_size_); 7613 if (resolved != nullptr && !resolved->IsRuntimeMethod()) { 7614 DCHECK(resolved->GetDeclaringClassUnchecked() != nullptr) << resolved->GetDexMethodIndex(); 7615 if (kResolveMode == ClassLinker::kForceICCECheck) { 7616 if (resolved->CheckIncompatibleClassChange(type)) { 7617 ThrowIncompatibleClassChangeError(type, resolved->GetInvokeType(), resolved, referrer); 7618 return nullptr; 7619 } 7620 } 7621 return resolved; 7622 } 7623 // Fail, get the declaring class. 7624 const DexFile::MethodId& method_id = dex_file.GetMethodId(method_idx); 7625 mirror::Class* klass = ResolveType(dex_file, method_id.class_idx_, dex_cache, class_loader); 7626 if (klass == nullptr) { 7627 DCHECK(Thread::Current()->IsExceptionPending()); 7628 return nullptr; 7629 } 7630 // Scan using method_idx, this saves string compares but will only hit for matching dex 7631 // caches/files. 7632 switch (type) { 7633 case kDirect: // Fall-through. 7634 case kStatic: 7635 resolved = klass->FindDirectMethod(dex_cache.Get(), method_idx, image_pointer_size_); 7636 DCHECK(resolved == nullptr || resolved->GetDeclaringClassUnchecked() != nullptr); 7637 break; 7638 case kInterface: 7639 // We have to check whether the method id really belongs to an interface (dex static bytecode 7640 // constraint A15). Otherwise you must not invoke-interface on it. 7641 // 7642 // This is not symmetric to A12-A14 (direct, static, virtual), as using FindInterfaceMethod 7643 // assumes that the given type is an interface, and will check the interface table if the 7644 // method isn't declared in the class. So it may find an interface method (usually by name 7645 // in the handling below, but we do the constraint check early). In that case, 7646 // CheckIncompatibleClassChange will succeed (as it is called on an interface method) 7647 // unexpectedly. 7648 // Example: 7649 // interface I { 7650 // foo() 7651 // } 7652 // class A implements I { 7653 // ... 7654 // } 7655 // class B extends A { 7656 // ... 7657 // } 7658 // invoke-interface B.foo 7659 // -> FindInterfaceMethod finds I.foo (interface method), not A.foo (miranda method) 7660 if (UNLIKELY(!klass->IsInterface())) { 7661 ThrowIncompatibleClassChangeError(klass, 7662 "Found class %s, but interface was expected", 7663 PrettyDescriptor(klass).c_str()); 7664 return nullptr; 7665 } else { 7666 resolved = klass->FindInterfaceMethod(dex_cache.Get(), method_idx, image_pointer_size_); 7667 DCHECK(resolved == nullptr || resolved->GetDeclaringClass()->IsInterface()); 7668 } 7669 break; 7670 case kSuper: 7671 if (klass->IsInterface()) { 7672 resolved = klass->FindInterfaceMethod(dex_cache.Get(), method_idx, image_pointer_size_); 7673 } else { 7674 resolved = klass->FindVirtualMethod(dex_cache.Get(), method_idx, image_pointer_size_); 7675 } 7676 break; 7677 case kVirtual: 7678 resolved = klass->FindVirtualMethod(dex_cache.Get(), method_idx, image_pointer_size_); 7679 break; 7680 default: 7681 LOG(FATAL) << "Unreachable - invocation type: " << type; 7682 UNREACHABLE(); 7683 } 7684 if (resolved == nullptr) { 7685 // Search by name, which works across dex files. 7686 const char* name = dex_file.StringDataByIdx(method_id.name_idx_); 7687 const Signature signature = dex_file.GetMethodSignature(method_id); 7688 switch (type) { 7689 case kDirect: // Fall-through. 7690 case kStatic: 7691 resolved = klass->FindDirectMethod(name, signature, image_pointer_size_); 7692 DCHECK(resolved == nullptr || resolved->GetDeclaringClassUnchecked() != nullptr); 7693 break; 7694 case kInterface: 7695 resolved = klass->FindInterfaceMethod(name, signature, image_pointer_size_); 7696 DCHECK(resolved == nullptr || resolved->GetDeclaringClass()->IsInterface()); 7697 break; 7698 case kSuper: 7699 if (klass->IsInterface()) { 7700 resolved = klass->FindInterfaceMethod(name, signature, image_pointer_size_); 7701 } else { 7702 resolved = klass->FindVirtualMethod(name, signature, image_pointer_size_); 7703 } 7704 break; 7705 case kVirtual: 7706 resolved = klass->FindVirtualMethod(name, signature, image_pointer_size_); 7707 break; 7708 } 7709 } 7710 // If we found a method, check for incompatible class changes. 7711 if (LIKELY(resolved != nullptr && !resolved->CheckIncompatibleClassChange(type))) { 7712 // Be a good citizen and update the dex cache to speed subsequent calls. 7713 dex_cache->SetResolvedMethod(method_idx, resolved, image_pointer_size_); 7714 return resolved; 7715 } else { 7716 // If we had a method, it's an incompatible-class-change error. 7717 if (resolved != nullptr) { 7718 ThrowIncompatibleClassChangeError(type, resolved->GetInvokeType(), resolved, referrer); 7719 } else { 7720 // We failed to find the method which means either an access error, an incompatible class 7721 // change, or no such method. First try to find the method among direct and virtual methods. 7722 const char* name = dex_file.StringDataByIdx(method_id.name_idx_); 7723 const Signature signature = dex_file.GetMethodSignature(method_id); 7724 switch (type) { 7725 case kDirect: 7726 case kStatic: 7727 resolved = klass->FindVirtualMethod(name, signature, image_pointer_size_); 7728 // Note: kDirect and kStatic are also mutually exclusive, but in that case we would 7729 // have had a resolved method before, which triggers the "true" branch above. 7730 break; 7731 case kInterface: 7732 case kVirtual: 7733 case kSuper: 7734 resolved = klass->FindDirectMethod(name, signature, image_pointer_size_); 7735 break; 7736 } 7737 7738 // If we found something, check that it can be accessed by the referrer. 7739 bool exception_generated = false; 7740 if (resolved != nullptr && referrer != nullptr) { 7741 mirror::Class* methods_class = resolved->GetDeclaringClass(); 7742 mirror::Class* referring_class = referrer->GetDeclaringClass(); 7743 if (!referring_class->CanAccess(methods_class)) { 7744 ThrowIllegalAccessErrorClassForMethodDispatch(referring_class, 7745 methods_class, 7746 resolved, 7747 type); 7748 exception_generated = true; 7749 } else if (!referring_class->CanAccessMember(methods_class, resolved->GetAccessFlags())) { 7750 ThrowIllegalAccessErrorMethod(referring_class, resolved); 7751 exception_generated = true; 7752 } 7753 } 7754 if (!exception_generated) { 7755 // Otherwise, throw an IncompatibleClassChangeError if we found something, and check 7756 // interface methods and throw if we find the method there. If we find nothing, throw a 7757 // NoSuchMethodError. 7758 switch (type) { 7759 case kDirect: 7760 case kStatic: 7761 if (resolved != nullptr) { 7762 ThrowIncompatibleClassChangeError(type, kVirtual, resolved, referrer); 7763 } else { 7764 resolved = klass->FindInterfaceMethod(name, signature, image_pointer_size_); 7765 if (resolved != nullptr) { 7766 ThrowIncompatibleClassChangeError(type, kInterface, resolved, referrer); 7767 } else { 7768 ThrowNoSuchMethodError(type, klass, name, signature); 7769 } 7770 } 7771 break; 7772 case kInterface: 7773 if (resolved != nullptr) { 7774 ThrowIncompatibleClassChangeError(type, kDirect, resolved, referrer); 7775 } else { 7776 resolved = klass->FindVirtualMethod(name, signature, image_pointer_size_); 7777 if (resolved != nullptr) { 7778 ThrowIncompatibleClassChangeError(type, kVirtual, resolved, referrer); 7779 } else { 7780 ThrowNoSuchMethodError(type, klass, name, signature); 7781 } 7782 } 7783 break; 7784 case kSuper: 7785 if (resolved != nullptr) { 7786 ThrowIncompatibleClassChangeError(type, kDirect, resolved, referrer); 7787 } else { 7788 ThrowNoSuchMethodError(type, klass, name, signature); 7789 } 7790 break; 7791 case kVirtual: 7792 if (resolved != nullptr) { 7793 ThrowIncompatibleClassChangeError(type, kDirect, resolved, referrer); 7794 } else { 7795 resolved = klass->FindInterfaceMethod(name, signature, image_pointer_size_); 7796 if (resolved != nullptr) { 7797 ThrowIncompatibleClassChangeError(type, kInterface, resolved, referrer); 7798 } else { 7799 ThrowNoSuchMethodError(type, klass, name, signature); 7800 } 7801 } 7802 break; 7803 } 7804 } 7805 } 7806 Thread::Current()->AssertPendingException(); 7807 return nullptr; 7808 } 7809} 7810 7811ArtMethod* ClassLinker::ResolveMethodWithoutInvokeType(const DexFile& dex_file, 7812 uint32_t method_idx, 7813 Handle<mirror::DexCache> dex_cache, 7814 Handle<mirror::ClassLoader> class_loader) { 7815 ArtMethod* resolved = dex_cache->GetResolvedMethod(method_idx, image_pointer_size_); 7816 if (resolved != nullptr && !resolved->IsRuntimeMethod()) { 7817 DCHECK(resolved->GetDeclaringClassUnchecked() != nullptr) << resolved->GetDexMethodIndex(); 7818 return resolved; 7819 } 7820 // Fail, get the declaring class. 7821 const DexFile::MethodId& method_id = dex_file.GetMethodId(method_idx); 7822 mirror::Class* klass = ResolveType(dex_file, method_id.class_idx_, dex_cache, class_loader); 7823 if (klass == nullptr) { 7824 Thread::Current()->AssertPendingException(); 7825 return nullptr; 7826 } 7827 if (klass->IsInterface()) { 7828 LOG(FATAL) << "ResolveAmbiguousMethod: unexpected method in interface: " << PrettyClass(klass); 7829 return nullptr; 7830 } 7831 7832 // Search both direct and virtual methods 7833 resolved = klass->FindDirectMethod(dex_cache.Get(), method_idx, image_pointer_size_); 7834 if (resolved == nullptr) { 7835 resolved = klass->FindVirtualMethod(dex_cache.Get(), method_idx, image_pointer_size_); 7836 } 7837 7838 return resolved; 7839} 7840 7841ArtField* ClassLinker::ResolveField(const DexFile& dex_file, 7842 uint32_t field_idx, 7843 Handle<mirror::DexCache> dex_cache, 7844 Handle<mirror::ClassLoader> class_loader, 7845 bool is_static) { 7846 DCHECK(dex_cache.Get() != nullptr); 7847 ArtField* resolved = dex_cache->GetResolvedField(field_idx, image_pointer_size_); 7848 if (resolved != nullptr) { 7849 return resolved; 7850 } 7851 const DexFile::FieldId& field_id = dex_file.GetFieldId(field_idx); 7852 Thread* const self = Thread::Current(); 7853 StackHandleScope<1> hs(self); 7854 Handle<mirror::Class> klass( 7855 hs.NewHandle(ResolveType(dex_file, field_id.class_idx_, dex_cache, class_loader))); 7856 if (klass.Get() == nullptr) { 7857 DCHECK(Thread::Current()->IsExceptionPending()); 7858 return nullptr; 7859 } 7860 7861 if (is_static) { 7862 resolved = mirror::Class::FindStaticField(self, klass, dex_cache.Get(), field_idx); 7863 } else { 7864 resolved = klass->FindInstanceField(dex_cache.Get(), field_idx); 7865 } 7866 7867 if (resolved == nullptr) { 7868 const char* name = dex_file.GetFieldName(field_id); 7869 const char* type = dex_file.GetFieldTypeDescriptor(field_id); 7870 if (is_static) { 7871 resolved = mirror::Class::FindStaticField(self, klass, name, type); 7872 } else { 7873 resolved = klass->FindInstanceField(name, type); 7874 } 7875 if (resolved == nullptr) { 7876 ThrowNoSuchFieldError(is_static ? "static " : "instance ", klass.Get(), type, name); 7877 return nullptr; 7878 } 7879 } 7880 dex_cache->SetResolvedField(field_idx, resolved, image_pointer_size_); 7881 return resolved; 7882} 7883 7884ArtField* ClassLinker::ResolveFieldJLS(const DexFile& dex_file, 7885 uint32_t field_idx, 7886 Handle<mirror::DexCache> dex_cache, 7887 Handle<mirror::ClassLoader> class_loader) { 7888 DCHECK(dex_cache.Get() != nullptr); 7889 ArtField* resolved = dex_cache->GetResolvedField(field_idx, image_pointer_size_); 7890 if (resolved != nullptr) { 7891 return resolved; 7892 } 7893 const DexFile::FieldId& field_id = dex_file.GetFieldId(field_idx); 7894 Thread* self = Thread::Current(); 7895 StackHandleScope<1> hs(self); 7896 Handle<mirror::Class> klass( 7897 hs.NewHandle(ResolveType(dex_file, field_id.class_idx_, dex_cache, class_loader))); 7898 if (klass.Get() == nullptr) { 7899 DCHECK(Thread::Current()->IsExceptionPending()); 7900 return nullptr; 7901 } 7902 7903 StringPiece name(dex_file.StringDataByIdx(field_id.name_idx_)); 7904 StringPiece type(dex_file.StringDataByIdx( 7905 dex_file.GetTypeId(field_id.type_idx_).descriptor_idx_)); 7906 resolved = mirror::Class::FindField(self, klass, name, type); 7907 if (resolved != nullptr) { 7908 dex_cache->SetResolvedField(field_idx, resolved, image_pointer_size_); 7909 } else { 7910 ThrowNoSuchFieldError("", klass.Get(), type, name); 7911 } 7912 return resolved; 7913} 7914 7915const char* ClassLinker::MethodShorty(uint32_t method_idx, 7916 ArtMethod* referrer, 7917 uint32_t* length) { 7918 mirror::Class* declaring_class = referrer->GetDeclaringClass(); 7919 mirror::DexCache* dex_cache = declaring_class->GetDexCache(); 7920 const DexFile& dex_file = *dex_cache->GetDexFile(); 7921 const DexFile::MethodId& method_id = dex_file.GetMethodId(method_idx); 7922 return dex_file.GetMethodShorty(method_id, length); 7923} 7924 7925class DumpClassVisitor : public ClassVisitor { 7926 public: 7927 explicit DumpClassVisitor(int flags) : flags_(flags) {} 7928 7929 bool operator()(mirror::Class* klass) OVERRIDE SHARED_REQUIRES(Locks::mutator_lock_) { 7930 klass->DumpClass(LOG(ERROR), flags_); 7931 return true; 7932 } 7933 7934 private: 7935 const int flags_; 7936}; 7937 7938void ClassLinker::DumpAllClasses(int flags) { 7939 DumpClassVisitor visitor(flags); 7940 VisitClasses(&visitor); 7941} 7942 7943static OatFile::OatMethod CreateOatMethod(const void* code) { 7944 CHECK(code != nullptr); 7945 const uint8_t* base = reinterpret_cast<const uint8_t*>(code); // Base of data points at code. 7946 base -= sizeof(void*); // Move backward so that code_offset != 0. 7947 const uint32_t code_offset = sizeof(void*); 7948 return OatFile::OatMethod(base, code_offset); 7949} 7950 7951bool ClassLinker::IsQuickResolutionStub(const void* entry_point) const { 7952 return (entry_point == GetQuickResolutionStub()) || 7953 (quick_resolution_trampoline_ == entry_point); 7954} 7955 7956bool ClassLinker::IsQuickToInterpreterBridge(const void* entry_point) const { 7957 return (entry_point == GetQuickToInterpreterBridge()) || 7958 (quick_to_interpreter_bridge_trampoline_ == entry_point); 7959} 7960 7961bool ClassLinker::IsQuickGenericJniStub(const void* entry_point) const { 7962 return (entry_point == GetQuickGenericJniStub()) || 7963 (quick_generic_jni_trampoline_ == entry_point); 7964} 7965 7966const void* ClassLinker::GetRuntimeQuickGenericJniStub() const { 7967 return GetQuickGenericJniStub(); 7968} 7969 7970void ClassLinker::SetEntryPointsToCompiledCode(ArtMethod* method, 7971 const void* method_code) const { 7972 OatFile::OatMethod oat_method = CreateOatMethod(method_code); 7973 oat_method.LinkMethod(method); 7974} 7975 7976void ClassLinker::SetEntryPointsToInterpreter(ArtMethod* method) const { 7977 if (!method->IsNative()) { 7978 method->SetEntryPointFromQuickCompiledCode(GetQuickToInterpreterBridge()); 7979 } else { 7980 const void* quick_method_code = GetQuickGenericJniStub(); 7981 OatFile::OatMethod oat_method = CreateOatMethod(quick_method_code); 7982 oat_method.LinkMethod(method); 7983 } 7984} 7985 7986void ClassLinker::DumpForSigQuit(std::ostream& os) { 7987 ScopedObjectAccess soa(Thread::Current()); 7988 if (dex_cache_boot_image_class_lookup_required_) { 7989 AddBootImageClassesToClassTable(); 7990 } 7991 ReaderMutexLock mu(soa.Self(), *Locks::classlinker_classes_lock_); 7992 os << "Zygote loaded classes=" << NumZygoteClasses() << " post zygote classes=" 7993 << NumNonZygoteClasses() << "\n"; 7994} 7995 7996class CountClassesVisitor : public ClassLoaderVisitor { 7997 public: 7998 CountClassesVisitor() : num_zygote_classes(0), num_non_zygote_classes(0) {} 7999 8000 void Visit(mirror::ClassLoader* class_loader) 8001 SHARED_REQUIRES(Locks::classlinker_classes_lock_, Locks::mutator_lock_) OVERRIDE { 8002 ClassTable* const class_table = class_loader->GetClassTable(); 8003 if (class_table != nullptr) { 8004 num_zygote_classes += class_table->NumZygoteClasses(); 8005 num_non_zygote_classes += class_table->NumNonZygoteClasses(); 8006 } 8007 } 8008 8009 size_t num_zygote_classes; 8010 size_t num_non_zygote_classes; 8011}; 8012 8013size_t ClassLinker::NumZygoteClasses() const { 8014 CountClassesVisitor visitor; 8015 VisitClassLoaders(&visitor); 8016 return visitor.num_zygote_classes + boot_class_table_.NumZygoteClasses(); 8017} 8018 8019size_t ClassLinker::NumNonZygoteClasses() const { 8020 CountClassesVisitor visitor; 8021 VisitClassLoaders(&visitor); 8022 return visitor.num_non_zygote_classes + boot_class_table_.NumNonZygoteClasses(); 8023} 8024 8025size_t ClassLinker::NumLoadedClasses() { 8026 if (dex_cache_boot_image_class_lookup_required_) { 8027 AddBootImageClassesToClassTable(); 8028 } 8029 ReaderMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); 8030 // Only return non zygote classes since these are the ones which apps which care about. 8031 return NumNonZygoteClasses(); 8032} 8033 8034pid_t ClassLinker::GetClassesLockOwner() { 8035 return Locks::classlinker_classes_lock_->GetExclusiveOwnerTid(); 8036} 8037 8038pid_t ClassLinker::GetDexLockOwner() { 8039 return dex_lock_.GetExclusiveOwnerTid(); 8040} 8041 8042void ClassLinker::SetClassRoot(ClassRoot class_root, mirror::Class* klass) { 8043 DCHECK(!init_done_); 8044 8045 DCHECK(klass != nullptr); 8046 DCHECK(klass->GetClassLoader() == nullptr); 8047 8048 mirror::ObjectArray<mirror::Class>* class_roots = class_roots_.Read(); 8049 DCHECK(class_roots != nullptr); 8050 DCHECK(class_roots->Get(class_root) == nullptr); 8051 class_roots->Set<false>(class_root, klass); 8052} 8053 8054const char* ClassLinker::GetClassRootDescriptor(ClassRoot class_root) { 8055 static const char* class_roots_descriptors[] = { 8056 "Ljava/lang/Class;", 8057 "Ljava/lang/Object;", 8058 "[Ljava/lang/Class;", 8059 "[Ljava/lang/Object;", 8060 "Ljava/lang/String;", 8061 "Ljava/lang/DexCache;", 8062 "Ljava/lang/ref/Reference;", 8063 "Ljava/lang/reflect/Constructor;", 8064 "Ljava/lang/reflect/Field;", 8065 "Ljava/lang/reflect/Method;", 8066 "Ljava/lang/reflect/Proxy;", 8067 "[Ljava/lang/String;", 8068 "[Ljava/lang/reflect/Constructor;", 8069 "[Ljava/lang/reflect/Field;", 8070 "[Ljava/lang/reflect/Method;", 8071 "Ljava/lang/ClassLoader;", 8072 "Ljava/lang/Throwable;", 8073 "Ljava/lang/ClassNotFoundException;", 8074 "Ljava/lang/StackTraceElement;", 8075 "Z", 8076 "B", 8077 "C", 8078 "D", 8079 "F", 8080 "I", 8081 "J", 8082 "S", 8083 "V", 8084 "[Z", 8085 "[B", 8086 "[C", 8087 "[D", 8088 "[F", 8089 "[I", 8090 "[J", 8091 "[S", 8092 "[Ljava/lang/StackTraceElement;", 8093 }; 8094 static_assert(arraysize(class_roots_descriptors) == size_t(kClassRootsMax), 8095 "Mismatch between class descriptors and class-root enum"); 8096 8097 const char* descriptor = class_roots_descriptors[class_root]; 8098 CHECK(descriptor != nullptr); 8099 return descriptor; 8100} 8101 8102jobject ClassLinker::CreatePathClassLoader(Thread* self, 8103 const std::vector<const DexFile*>& dex_files) { 8104 // SOAAlreadyRunnable is protected, and we need something to add a global reference. 8105 // We could move the jobject to the callers, but all call-sites do this... 8106 ScopedObjectAccessUnchecked soa(self); 8107 8108 // For now, create a libcore-level DexFile for each ART DexFile. This "explodes" multidex. 8109 StackHandleScope<10> hs(self); 8110 8111 ArtField* dex_elements_field = 8112 soa.DecodeField(WellKnownClasses::dalvik_system_DexPathList_dexElements); 8113 8114 mirror::Class* dex_elements_class = dex_elements_field->GetType<true>(); 8115 DCHECK(dex_elements_class != nullptr); 8116 DCHECK(dex_elements_class->IsArrayClass()); 8117 Handle<mirror::ObjectArray<mirror::Object>> h_dex_elements(hs.NewHandle( 8118 mirror::ObjectArray<mirror::Object>::Alloc(self, dex_elements_class, dex_files.size()))); 8119 Handle<mirror::Class> h_dex_element_class = 8120 hs.NewHandle(dex_elements_class->GetComponentType()); 8121 8122 ArtField* element_file_field = 8123 soa.DecodeField(WellKnownClasses::dalvik_system_DexPathList__Element_dexFile); 8124 DCHECK_EQ(h_dex_element_class.Get(), element_file_field->GetDeclaringClass()); 8125 8126 ArtField* cookie_field = soa.DecodeField(WellKnownClasses::dalvik_system_DexFile_cookie); 8127 DCHECK_EQ(cookie_field->GetDeclaringClass(), element_file_field->GetType<false>()); 8128 8129 ArtField* file_name_field = soa.DecodeField(WellKnownClasses::dalvik_system_DexFile_fileName); 8130 DCHECK_EQ(file_name_field->GetDeclaringClass(), element_file_field->GetType<false>()); 8131 8132 // Fill the elements array. 8133 int32_t index = 0; 8134 for (const DexFile* dex_file : dex_files) { 8135 StackHandleScope<4> hs2(self); 8136 8137 // CreatePathClassLoader is only used by gtests. Index 0 of h_long_array is supposed to be the 8138 // oat file but we can leave it null. 8139 Handle<mirror::LongArray> h_long_array = hs2.NewHandle(mirror::LongArray::Alloc( 8140 self, 8141 kDexFileIndexStart + 1)); 8142 DCHECK(h_long_array.Get() != nullptr); 8143 h_long_array->Set(kDexFileIndexStart, reinterpret_cast<intptr_t>(dex_file)); 8144 8145 Handle<mirror::Object> h_dex_file = hs2.NewHandle( 8146 cookie_field->GetDeclaringClass()->AllocObject(self)); 8147 DCHECK(h_dex_file.Get() != nullptr); 8148 cookie_field->SetObject<false>(h_dex_file.Get(), h_long_array.Get()); 8149 8150 Handle<mirror::String> h_file_name = hs2.NewHandle( 8151 mirror::String::AllocFromModifiedUtf8(self, dex_file->GetLocation().c_str())); 8152 DCHECK(h_file_name.Get() != nullptr); 8153 file_name_field->SetObject<false>(h_dex_file.Get(), h_file_name.Get()); 8154 8155 Handle<mirror::Object> h_element = hs2.NewHandle(h_dex_element_class->AllocObject(self)); 8156 DCHECK(h_element.Get() != nullptr); 8157 element_file_field->SetObject<false>(h_element.Get(), h_dex_file.Get()); 8158 8159 h_dex_elements->Set(index, h_element.Get()); 8160 index++; 8161 } 8162 DCHECK_EQ(index, h_dex_elements->GetLength()); 8163 8164 // Create DexPathList. 8165 Handle<mirror::Object> h_dex_path_list = hs.NewHandle( 8166 dex_elements_field->GetDeclaringClass()->AllocObject(self)); 8167 DCHECK(h_dex_path_list.Get() != nullptr); 8168 // Set elements. 8169 dex_elements_field->SetObject<false>(h_dex_path_list.Get(), h_dex_elements.Get()); 8170 8171 // Create PathClassLoader. 8172 Handle<mirror::Class> h_path_class_class = hs.NewHandle( 8173 soa.Decode<mirror::Class*>(WellKnownClasses::dalvik_system_PathClassLoader)); 8174 Handle<mirror::Object> h_path_class_loader = hs.NewHandle( 8175 h_path_class_class->AllocObject(self)); 8176 DCHECK(h_path_class_loader.Get() != nullptr); 8177 // Set DexPathList. 8178 ArtField* path_list_field = 8179 soa.DecodeField(WellKnownClasses::dalvik_system_PathClassLoader_pathList); 8180 DCHECK(path_list_field != nullptr); 8181 path_list_field->SetObject<false>(h_path_class_loader.Get(), h_dex_path_list.Get()); 8182 8183 // Make a pretend boot-classpath. 8184 // TODO: Should we scan the image? 8185 ArtField* const parent_field = 8186 mirror::Class::FindField(self, hs.NewHandle(h_path_class_loader->GetClass()), "parent", 8187 "Ljava/lang/ClassLoader;"); 8188 DCHECK(parent_field != nullptr); 8189 mirror::Object* boot_cl = 8190 soa.Decode<mirror::Class*>(WellKnownClasses::java_lang_BootClassLoader)->AllocObject(self); 8191 parent_field->SetObject<false>(h_path_class_loader.Get(), boot_cl); 8192 8193 // Make it a global ref and return. 8194 ScopedLocalRef<jobject> local_ref( 8195 soa.Env(), soa.Env()->AddLocalReference<jobject>(h_path_class_loader.Get())); 8196 return soa.Env()->NewGlobalRef(local_ref.get()); 8197} 8198 8199ArtMethod* ClassLinker::CreateRuntimeMethod(LinearAlloc* linear_alloc) { 8200 const size_t method_alignment = ArtMethod::Alignment(image_pointer_size_); 8201 const size_t method_size = ArtMethod::Size(image_pointer_size_); 8202 LengthPrefixedArray<ArtMethod>* method_array = AllocArtMethodArray( 8203 Thread::Current(), 8204 linear_alloc, 8205 1); 8206 ArtMethod* method = &method_array->At(0, method_size, method_alignment); 8207 CHECK(method != nullptr); 8208 method->SetDexMethodIndex(DexFile::kDexNoIndex); 8209 CHECK(method->IsRuntimeMethod()); 8210 return method; 8211} 8212 8213void ClassLinker::DropFindArrayClassCache() { 8214 std::fill_n(find_array_class_cache_, kFindArrayCacheSize, GcRoot<mirror::Class>(nullptr)); 8215 find_array_class_cache_next_victim_ = 0; 8216} 8217 8218void ClassLinker::ClearClassTableStrongRoots() const { 8219 Thread* const self = Thread::Current(); 8220 WriterMutexLock mu(self, *Locks::classlinker_classes_lock_); 8221 for (const ClassLoaderData& data : class_loaders_) { 8222 if (data.class_table != nullptr) { 8223 data.class_table->ClearStrongRoots(); 8224 } 8225 } 8226} 8227 8228void ClassLinker::VisitClassLoaders(ClassLoaderVisitor* visitor) const { 8229 Thread* const self = Thread::Current(); 8230 for (const ClassLoaderData& data : class_loaders_) { 8231 // Need to use DecodeJObject so that we get null for cleared JNI weak globals. 8232 auto* const class_loader = down_cast<mirror::ClassLoader*>(self->DecodeJObject(data.weak_root)); 8233 if (class_loader != nullptr) { 8234 visitor->Visit(class_loader); 8235 } 8236 } 8237} 8238 8239void ClassLinker::InsertDexFileInToClassLoader(mirror::Object* dex_file, 8240 mirror::ClassLoader* class_loader) { 8241 DCHECK(dex_file != nullptr); 8242 Thread* const self = Thread::Current(); 8243 WriterMutexLock mu(self, *Locks::classlinker_classes_lock_); 8244 ClassTable* const table = ClassTableForClassLoader(class_loader); 8245 DCHECK(table != nullptr); 8246 if (table->InsertStrongRoot(dex_file) && class_loader != nullptr) { 8247 // It was not already inserted, perform the write barrier to let the GC know the class loader's 8248 // class table was modified. 8249 Runtime::Current()->GetHeap()->WriteBarrierEveryFieldOf(class_loader); 8250 } 8251} 8252 8253void ClassLinker::CleanupClassLoaders() { 8254 Thread* const self = Thread::Current(); 8255 std::vector<ClassLoaderData> to_delete; 8256 // Do the delete outside the lock to avoid lock violation in jit code cache. 8257 { 8258 WriterMutexLock mu(self, *Locks::classlinker_classes_lock_); 8259 for (auto it = class_loaders_.begin(); it != class_loaders_.end(); ) { 8260 const ClassLoaderData& data = *it; 8261 // Need to use DecodeJObject so that we get null for cleared JNI weak globals. 8262 auto* const class_loader = 8263 down_cast<mirror::ClassLoader*>(self->DecodeJObject(data.weak_root)); 8264 if (class_loader != nullptr) { 8265 ++it; 8266 } else { 8267 VLOG(class_linker) << "Freeing class loader"; 8268 to_delete.push_back(data); 8269 it = class_loaders_.erase(it); 8270 } 8271 } 8272 } 8273 for (ClassLoaderData& data : to_delete) { 8274 DeleteClassLoader(self, data); 8275 } 8276} 8277 8278std::set<DexCacheResolvedClasses> ClassLinker::GetResolvedClasses(bool ignore_boot_classes) { 8279 ScopedTrace trace(__PRETTY_FUNCTION__); 8280 ScopedObjectAccess soa(Thread::Current()); 8281 ScopedAssertNoThreadSuspension ants(soa.Self(), __FUNCTION__); 8282 std::set<DexCacheResolvedClasses> ret; 8283 VLOG(class_linker) << "Collecting resolved classes"; 8284 const uint64_t start_time = NanoTime(); 8285 ReaderMutexLock mu(soa.Self(), *DexLock()); 8286 // Loop through all the dex caches and inspect resolved classes. 8287 for (const ClassLinker::DexCacheData& data : GetDexCachesData()) { 8288 if (soa.Self()->IsJWeakCleared(data.weak_root)) { 8289 continue; 8290 } 8291 mirror::DexCache* dex_cache = 8292 down_cast<mirror::DexCache*>(soa.Self()->DecodeJObject(data.weak_root)); 8293 if (dex_cache == nullptr) { 8294 continue; 8295 } 8296 const DexFile* dex_file = dex_cache->GetDexFile(); 8297 const std::string& location = dex_file->GetLocation(); 8298 const size_t num_class_defs = dex_file->NumClassDefs(); 8299 // Use the resolved types, this will miss array classes. 8300 const size_t num_types = dex_file->NumTypeIds(); 8301 VLOG(class_linker) << "Collecting class profile for dex file " << location 8302 << " types=" << num_types << " class_defs=" << num_class_defs; 8303 DexCacheResolvedClasses resolved_classes(dex_file->GetLocation(), 8304 dex_file->GetBaseLocation(), 8305 dex_file->GetLocationChecksum()); 8306 size_t num_resolved = 0; 8307 std::unordered_set<uint16_t> class_set; 8308 CHECK_EQ(num_types, dex_cache->NumResolvedTypes()); 8309 for (size_t i = 0; i < num_types; ++i) { 8310 mirror::Class* klass = dex_cache->GetResolvedType(i); 8311 // Filter out null class loader since that is the boot class loader. 8312 if (klass == nullptr || (ignore_boot_classes && klass->GetClassLoader() == nullptr)) { 8313 continue; 8314 } 8315 ++num_resolved; 8316 DCHECK(!klass->IsProxyClass()); 8317 if (!klass->IsResolved()) { 8318 DCHECK(klass->IsErroneous()); 8319 continue; 8320 } 8321 mirror::DexCache* klass_dex_cache = klass->GetDexCache(); 8322 if (klass_dex_cache == dex_cache) { 8323 const size_t class_def_idx = klass->GetDexClassDefIndex(); 8324 DCHECK(klass->IsResolved()); 8325 CHECK_LT(class_def_idx, num_class_defs); 8326 class_set.insert(class_def_idx); 8327 } 8328 } 8329 8330 if (!class_set.empty()) { 8331 auto it = ret.find(resolved_classes); 8332 if (it != ret.end()) { 8333 // Already have the key, union the class def idxs. 8334 it->AddClasses(class_set.begin(), class_set.end()); 8335 } else { 8336 resolved_classes.AddClasses(class_set.begin(), class_set.end()); 8337 ret.insert(resolved_classes); 8338 } 8339 } 8340 8341 VLOG(class_linker) << "Dex location " << location << " has " << num_resolved << " / " 8342 << num_class_defs << " resolved classes"; 8343 } 8344 VLOG(class_linker) << "Collecting class profile took " << PrettyDuration(NanoTime() - start_time); 8345 return ret; 8346} 8347 8348std::unordered_set<std::string> ClassLinker::GetClassDescriptorsForProfileKeys( 8349 const std::set<DexCacheResolvedClasses>& classes) { 8350 ScopedTrace trace(__PRETTY_FUNCTION__); 8351 std::unordered_set<std::string> ret; 8352 Thread* const self = Thread::Current(); 8353 std::unordered_map<std::string, const DexFile*> location_to_dex_file; 8354 ScopedObjectAccess soa(self); 8355 ScopedAssertNoThreadSuspension ants(soa.Self(), __FUNCTION__); 8356 ReaderMutexLock mu(self, *DexLock()); 8357 for (const ClassLinker::DexCacheData& data : GetDexCachesData()) { 8358 if (!self->IsJWeakCleared(data.weak_root)) { 8359 mirror::DexCache* dex_cache = 8360 down_cast<mirror::DexCache*>(soa.Self()->DecodeJObject(data.weak_root)); 8361 if (dex_cache != nullptr) { 8362 const DexFile* dex_file = dex_cache->GetDexFile(); 8363 // There could be duplicates if two dex files with the same location are mapped. 8364 location_to_dex_file.emplace( 8365 ProfileCompilationInfo::GetProfileDexFileKey(dex_file->GetLocation()), dex_file); 8366 } 8367 } 8368 } 8369 for (const DexCacheResolvedClasses& info : classes) { 8370 const std::string& profile_key = info.GetDexLocation(); 8371 auto found = location_to_dex_file.find(profile_key); 8372 if (found != location_to_dex_file.end()) { 8373 const DexFile* dex_file = found->second; 8374 VLOG(profiler) << "Found opened dex file for " << dex_file->GetLocation() << " with " 8375 << info.GetClasses().size() << " classes"; 8376 DCHECK_EQ(dex_file->GetLocationChecksum(), info.GetLocationChecksum()); 8377 for (uint16_t class_def_idx : info.GetClasses()) { 8378 if (class_def_idx >= dex_file->NumClassDefs()) { 8379 LOG(WARNING) << "Class def index " << class_def_idx << " >= " << dex_file->NumClassDefs(); 8380 continue; 8381 } 8382 const DexFile::TypeId& type_id = dex_file->GetTypeId( 8383 dex_file->GetClassDef(class_def_idx).class_idx_); 8384 const char* descriptor = dex_file->GetTypeDescriptor(type_id); 8385 ret.insert(descriptor); 8386 } 8387 } else { 8388 VLOG(class_linker) << "Failed to find opened dex file for profile key " << profile_key; 8389 } 8390 } 8391 return ret; 8392} 8393 8394class ClassLinker::FindVirtualMethodHolderVisitor : public ClassVisitor { 8395 public: 8396 FindVirtualMethodHolderVisitor(const ArtMethod* method, size_t pointer_size) 8397 : method_(method), 8398 pointer_size_(pointer_size) {} 8399 8400 bool operator()(mirror::Class* klass) SHARED_REQUIRES(Locks::mutator_lock_) OVERRIDE { 8401 if (klass->GetVirtualMethodsSliceUnchecked(pointer_size_).Contains(method_)) { 8402 holder_ = klass; 8403 } 8404 // Return false to stop searching if holder_ is not null. 8405 return holder_ == nullptr; 8406 } 8407 8408 mirror::Class* holder_ = nullptr; 8409 const ArtMethod* const method_; 8410 const size_t pointer_size_; 8411}; 8412 8413mirror::Class* ClassLinker::GetHoldingClassOfCopiedMethod(ArtMethod* method) { 8414 ScopedTrace trace(__FUNCTION__); // Since this function is slow, have a trace to notify people. 8415 CHECK(method->IsCopied()); 8416 FindVirtualMethodHolderVisitor visitor(method, image_pointer_size_); 8417 VisitClasses(&visitor); 8418 return visitor.holder_; 8419} 8420 8421// Instantiate ResolveMethod. 8422template ArtMethod* ClassLinker::ResolveMethod<ClassLinker::kForceICCECheck>( 8423 const DexFile& dex_file, 8424 uint32_t method_idx, 8425 Handle<mirror::DexCache> dex_cache, 8426 Handle<mirror::ClassLoader> class_loader, 8427 ArtMethod* referrer, 8428 InvokeType type); 8429template ArtMethod* ClassLinker::ResolveMethod<ClassLinker::kNoICCECheckForCache>( 8430 const DexFile& dex_file, 8431 uint32_t method_idx, 8432 Handle<mirror::DexCache> dex_cache, 8433 Handle<mirror::ClassLoader> class_loader, 8434 ArtMethod* referrer, 8435 InvokeType type); 8436 8437} // namespace art 8438