image_writer.cc revision 1a5706611bffa5d6ed6843ee5e320f504590e097 
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 "image_writer.h"
18
19#include <sys/stat.h>
20
21#include <vector>
22
23#include "base/logging.h"
24#include "base/unix_file/fd_file.h"
25#include "class_linker.h"
26#include "compiled_method.h"
27#include "dex_file-inl.h"
28#include "driver/compiler_driver.h"
29#include "elf_writer.h"
30#include "gc/accounting/card_table-inl.h"
31#include "gc/accounting/heap_bitmap.h"
32#include "gc/accounting/space_bitmap-inl.h"
33#include "gc/heap.h"
34#include "gc/space/large_object_space.h"
35#include "gc/space/space-inl.h"
36#include "globals.h"
37#include "image.h"
38#include "intern_table.h"
39#include "lock_word.h"
40#include "mirror/art_field-inl.h"
41#include "mirror/art_method-inl.h"
42#include "mirror/array-inl.h"
43#include "mirror/class-inl.h"
44#include "mirror/class_loader.h"
45#include "mirror/dex_cache-inl.h"
46#include "mirror/object-inl.h"
47#include "mirror/object_array-inl.h"
48#include "oat.h"
49#include "oat_file.h"
50#include "object_utils.h"
51#include "runtime.h"
52#include "scoped_thread_state_change.h"
53#include "sirt_ref-inl.h"
54#include "UniquePtr.h"
55#include "utils.h"
56
57using ::art::mirror::ArtField;
58using ::art::mirror::ArtMethod;
59using ::art::mirror::Class;
60using ::art::mirror::DexCache;
61using ::art::mirror::EntryPointFromInterpreter;
62using ::art::mirror::Object;
63using ::art::mirror::ObjectArray;
64using ::art::mirror::String;
65
66namespace art {
67
68bool ImageWriter::Write(const std::string& image_filename,
69                        uintptr_t image_begin,
70                        const std::string& oat_filename,
71                        const std::string& oat_location) {
72  CHECK(!image_filename.empty());
73
74  CHECK_NE(image_begin, 0U);
75  image_begin_ = reinterpret_cast<byte*>(image_begin);
76
77  ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
78
79  UniquePtr<File> oat_file(OS::OpenFileReadWrite(oat_filename.c_str()));
80  if (oat_file.get() == NULL) {
81    LOG(ERROR) << "Failed to open oat file " << oat_filename << " for " << oat_location;
82    return false;
83  }
84  std::string error_msg;
85  oat_file_ = OatFile::OpenWritable(oat_file.get(), oat_location, &error_msg);
86  if (oat_file_ == nullptr) {
87    LOG(ERROR) << "Failed to open writable oat file " << oat_filename << " for " << oat_location
88        << ": " << error_msg;
89    return false;
90  }
91  CHECK_EQ(class_linker->RegisterOatFile(oat_file_), oat_file_);
92
93  interpreter_to_interpreter_bridge_offset_ =
94      oat_file_->GetOatHeader().GetInterpreterToInterpreterBridgeOffset();
95  interpreter_to_compiled_code_bridge_offset_ =
96      oat_file_->GetOatHeader().GetInterpreterToCompiledCodeBridgeOffset();
97
98  jni_dlsym_lookup_offset_ = oat_file_->GetOatHeader().GetJniDlsymLookupOffset();
99
100  portable_imt_conflict_trampoline_offset_ =
101      oat_file_->GetOatHeader().GetPortableImtConflictTrampolineOffset();
102  portable_resolution_trampoline_offset_ =
103      oat_file_->GetOatHeader().GetPortableResolutionTrampolineOffset();
104  portable_to_interpreter_bridge_offset_ =
105      oat_file_->GetOatHeader().GetPortableToInterpreterBridgeOffset();
106
107  quick_generic_jni_trampoline_offset_ =
108      oat_file_->GetOatHeader().GetQuickGenericJniTrampolineOffset();
109  quick_imt_conflict_trampoline_offset_ =
110      oat_file_->GetOatHeader().GetQuickImtConflictTrampolineOffset();
111  quick_resolution_trampoline_offset_ =
112      oat_file_->GetOatHeader().GetQuickResolutionTrampolineOffset();
113  quick_to_interpreter_bridge_offset_ =
114      oat_file_->GetOatHeader().GetQuickToInterpreterBridgeOffset();
115  {
116    Thread::Current()->TransitionFromSuspendedToRunnable();
117    PruneNonImageClasses();  // Remove junk
118    ComputeLazyFieldsForImageClasses();  // Add useful information
119    ComputeEagerResolvedStrings();
120    Thread::Current()->TransitionFromRunnableToSuspended(kNative);
121  }
122  gc::Heap* heap = Runtime::Current()->GetHeap();
123  heap->CollectGarbage(false);  // Remove garbage.
124
125  if (!AllocMemory()) {
126    return false;
127  }
128
129  if (kIsDebugBuild) {
130    ScopedObjectAccess soa(Thread::Current());
131    CheckNonImageClassesRemoved();
132  }
133
134  Thread::Current()->TransitionFromSuspendedToRunnable();
135  size_t oat_loaded_size = 0;
136  size_t oat_data_offset = 0;
137  ElfWriter::GetOatElfInformation(oat_file.get(), oat_loaded_size, oat_data_offset);
138  CalculateNewObjectOffsets(oat_loaded_size, oat_data_offset);
139  CopyAndFixupObjects();
140  PatchOatCodeAndMethods();
141  Thread::Current()->TransitionFromRunnableToSuspended(kNative);
142
143  UniquePtr<File> image_file(OS::CreateEmptyFile(image_filename.c_str()));
144  ImageHeader* image_header = reinterpret_cast<ImageHeader*>(image_->Begin());
145  if (image_file.get() == NULL) {
146    LOG(ERROR) << "Failed to open image file " << image_filename;
147    return false;
148  }
149  if (fchmod(image_file->Fd(), 0644) != 0) {
150    PLOG(ERROR) << "Failed to make image file world readable: " << image_filename;
151    return EXIT_FAILURE;
152  }
153
154  // Write out the image.
155  CHECK_EQ(image_end_, image_header->GetImageSize());
156  if (!image_file->WriteFully(image_->Begin(), image_end_)) {
157    PLOG(ERROR) << "Failed to write image file " << image_filename;
158    return false;
159  }
160
161  // Write out the image bitmap at the page aligned start of the image end.
162  CHECK_ALIGNED(image_header->GetImageBitmapOffset(), kPageSize);
163  if (!image_file->Write(reinterpret_cast<char*>(image_bitmap_->Begin()),
164                         image_header->GetImageBitmapSize(),
165                         image_header->GetImageBitmapOffset())) {
166    PLOG(ERROR) << "Failed to write image file " << image_filename;
167    return false;
168  }
169
170  return true;
171}
172
173void ImageWriter::SetImageOffset(mirror::Object* object, size_t offset) {
174  DCHECK(object != nullptr);
175  DCHECK_NE(offset, 0U);
176  DCHECK(!IsImageOffsetAssigned(object));
177  mirror::Object* obj = reinterpret_cast<mirror::Object*>(image_->Begin() + offset);
178  DCHECK_ALIGNED(obj, kObjectAlignment);
179  image_bitmap_->Set(obj);
180  // Before we stomp over the lock word, save the hash code for later.
181  Monitor::Deflate(Thread::Current(), object);;
182  LockWord lw(object->GetLockWord());
183  switch (lw.GetState()) {
184    case LockWord::kFatLocked: {
185      LOG(FATAL) << "Fat locked object " << obj << " found during object copy";
186      break;
187    }
188    case LockWord::kThinLocked: {
189      LOG(FATAL) << "Thin locked object " << obj << " found during object copy";
190      break;
191    }
192    case LockWord::kUnlocked:
193      // No hash, don't need to save it.
194      break;
195    case LockWord::kHashCode:
196      saved_hashes_.push_back(std::make_pair(obj, lw.GetHashCode()));
197      break;
198    default:
199      LOG(FATAL) << "Unreachable.";
200      break;
201  }
202  object->SetLockWord(LockWord::FromForwardingAddress(offset));
203  DCHECK(IsImageOffsetAssigned(object));
204}
205
206void ImageWriter::AssignImageOffset(mirror::Object* object) {
207  DCHECK(object != nullptr);
208  SetImageOffset(object, image_end_);
209  image_end_ += RoundUp(object->SizeOf(), 8);  // 64-bit alignment
210  DCHECK_LT(image_end_, image_->Size());
211}
212
213bool ImageWriter::IsImageOffsetAssigned(mirror::Object* object) const {
214  DCHECK(object != nullptr);
215  return object->GetLockWord().GetState() == LockWord::kForwardingAddress;
216}
217
218size_t ImageWriter::GetImageOffset(mirror::Object* object) const {
219  DCHECK(object != nullptr);
220  DCHECK(IsImageOffsetAssigned(object));
221  LockWord lock_word = object->GetLockWord();
222  size_t offset = lock_word.ForwardingAddress();
223  DCHECK_LT(offset, image_end_);
224  return offset;
225}
226
227bool ImageWriter::AllocMemory() {
228  size_t length = RoundUp(Runtime::Current()->GetHeap()->GetTotalMemory(), kPageSize);
229  std::string error_msg;
230  image_.reset(MemMap::MapAnonymous("image writer image", NULL, length, PROT_READ | PROT_WRITE,
231                                    true, &error_msg));
232  if (UNLIKELY(image_.get() == nullptr)) {
233    LOG(ERROR) << "Failed to allocate memory for image file generation: " << error_msg;
234    return false;
235  }
236
237  // Create the image bitmap.
238  image_bitmap_.reset(gc::accounting::SpaceBitmap::Create("image bitmap", image_->Begin(),
239                                                          length));
240  if (image_bitmap_.get() == nullptr) {
241    LOG(ERROR) << "Failed to allocate memory for image bitmap";
242    return false;
243  }
244  return true;
245}
246
247void ImageWriter::ComputeLazyFieldsForImageClasses() {
248  ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
249  class_linker->VisitClassesWithoutClassesLock(ComputeLazyFieldsForClassesVisitor, NULL);
250}
251
252bool ImageWriter::ComputeLazyFieldsForClassesVisitor(Class* c, void* /*arg*/) {
253  c->ComputeName();
254  return true;
255}
256
257void ImageWriter::ComputeEagerResolvedStringsCallback(Object* obj, void* arg) {
258  if (!obj->GetClass()->IsStringClass()) {
259    return;
260  }
261  mirror::String* string = obj->AsString();
262  const uint16_t* utf16_string = string->GetCharArray()->GetData() + string->GetOffset();
263  for (DexCache* dex_cache : Runtime::Current()->GetClassLinker()->GetDexCaches()) {
264    const DexFile& dex_file = *dex_cache->GetDexFile();
265    const DexFile::StringId* string_id;
266    if (UNLIKELY(string->GetLength() == 0)) {
267      string_id = dex_file.FindStringId("");
268    } else {
269      string_id = dex_file.FindStringId(utf16_string);
270    }
271    if (string_id != nullptr) {
272      // This string occurs in this dex file, assign the dex cache entry.
273      uint32_t string_idx = dex_file.GetIndexForStringId(*string_id);
274      if (dex_cache->GetResolvedString(string_idx) == NULL) {
275        dex_cache->SetResolvedString(string_idx, string);
276      }
277    }
278  }
279}
280
281void ImageWriter::ComputeEagerResolvedStrings() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
282  ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_);
283  Runtime::Current()->GetHeap()->VisitObjects(ComputeEagerResolvedStringsCallback, this);
284}
285
286bool ImageWriter::IsImageClass(Class* klass) {
287  return compiler_driver_.IsImageClass(ClassHelper(klass).GetDescriptor());
288}
289
290struct NonImageClasses {
291  ImageWriter* image_writer;
292  std::set<std::string>* non_image_classes;
293};
294
295void ImageWriter::PruneNonImageClasses() {
296  if (compiler_driver_.GetImageClasses() == NULL) {
297    return;
298  }
299  Runtime* runtime = Runtime::Current();
300  ClassLinker* class_linker = runtime->GetClassLinker();
301
302  // Make a list of classes we would like to prune.
303  std::set<std::string> non_image_classes;
304  NonImageClasses context;
305  context.image_writer = this;
306  context.non_image_classes = &non_image_classes;
307  class_linker->VisitClasses(NonImageClassesVisitor, &context);
308
309  // Remove the undesired classes from the class roots.
310  for (const std::string& it : non_image_classes) {
311    class_linker->RemoveClass(it.c_str(), NULL);
312  }
313
314  // Clear references to removed classes from the DexCaches.
315  ArtMethod* resolution_method = runtime->GetResolutionMethod();
316  for (DexCache* dex_cache : class_linker->GetDexCaches()) {
317    for (size_t i = 0; i < dex_cache->NumResolvedTypes(); i++) {
318      Class* klass = dex_cache->GetResolvedType(i);
319      if (klass != NULL && !IsImageClass(klass)) {
320        dex_cache->SetResolvedType(i, NULL);
321      }
322    }
323    for (size_t i = 0; i < dex_cache->NumResolvedMethods(); i++) {
324      ArtMethod* method = dex_cache->GetResolvedMethod(i);
325      if (method != NULL && !IsImageClass(method->GetDeclaringClass())) {
326        dex_cache->SetResolvedMethod(i, resolution_method);
327      }
328    }
329    for (size_t i = 0; i < dex_cache->NumResolvedFields(); i++) {
330      ArtField* field = dex_cache->GetResolvedField(i);
331      if (field != NULL && !IsImageClass(field->GetDeclaringClass())) {
332        dex_cache->SetResolvedField(i, NULL);
333      }
334    }
335  }
336}
337
338bool ImageWriter::NonImageClassesVisitor(Class* klass, void* arg) {
339  NonImageClasses* context = reinterpret_cast<NonImageClasses*>(arg);
340  if (!context->image_writer->IsImageClass(klass)) {
341    context->non_image_classes->insert(ClassHelper(klass).GetDescriptor());
342  }
343  return true;
344}
345
346void ImageWriter::CheckNonImageClassesRemoved()
347    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
348  if (compiler_driver_.GetImageClasses() != nullptr) {
349    gc::Heap* heap = Runtime::Current()->GetHeap();
350    ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_);
351    heap->VisitObjects(CheckNonImageClassesRemovedCallback, this);
352  }
353}
354
355void ImageWriter::CheckNonImageClassesRemovedCallback(Object* obj, void* arg) {
356  ImageWriter* image_writer = reinterpret_cast<ImageWriter*>(arg);
357  if (obj->IsClass()) {
358    Class* klass = obj->AsClass();
359    if (!image_writer->IsImageClass(klass)) {
360      image_writer->DumpImageClasses();
361      CHECK(image_writer->IsImageClass(klass)) << ClassHelper(klass).GetDescriptor()
362                                               << " " << PrettyDescriptor(klass);
363    }
364  }
365}
366
367void ImageWriter::DumpImageClasses() {
368  CompilerDriver::DescriptorSet* image_classes = compiler_driver_.GetImageClasses();
369  CHECK(image_classes != NULL);
370  for (const std::string& image_class : *image_classes) {
371    LOG(INFO) << " " << image_class;
372  }
373}
374
375void ImageWriter::CalculateObjectOffsets(Object* obj) {
376  DCHECK(obj != NULL);
377  // if it is a string, we want to intern it if its not interned.
378  if (obj->GetClass()->IsStringClass()) {
379    // we must be an interned string that was forward referenced and already assigned
380    if (IsImageOffsetAssigned(obj)) {
381      DCHECK_EQ(obj, obj->AsString()->Intern());
382      return;
383    }
384    Thread* self = Thread::Current();
385    SirtRef<Object> sirt_obj(self, obj);
386    mirror::String* interned = obj->AsString()->Intern();
387    if (sirt_obj.get() != interned) {
388      if (!IsImageOffsetAssigned(interned)) {
389        // interned obj is after us, allocate its location early
390        AssignImageOffset(interned);
391      }
392      // point those looking for this object to the interned version.
393      SetImageOffset(sirt_obj.get(), GetImageOffset(interned));
394      return;
395    }
396    // else (obj == interned), nothing to do but fall through to the normal case
397  }
398
399  AssignImageOffset(obj);
400}
401
402ObjectArray<Object>* ImageWriter::CreateImageRoots() const {
403  Runtime* runtime = Runtime::Current();
404  ClassLinker* class_linker = runtime->GetClassLinker();
405  Thread* self = Thread::Current();
406  SirtRef<Class> object_array_class(self, class_linker->FindSystemClass(self,
407                                                                        "[Ljava/lang/Object;"));
408
409  // build an Object[] of all the DexCaches used in the source_space_
410  ObjectArray<Object>* dex_caches = ObjectArray<Object>::Alloc(self, object_array_class.get(),
411                                                               class_linker->GetDexCaches().size());
412  int i = 0;
413  for (DexCache* dex_cache : class_linker->GetDexCaches()) {
414    dex_caches->Set<false>(i++, dex_cache);
415  }
416
417  // build an Object[] of the roots needed to restore the runtime
418  SirtRef<ObjectArray<Object> > image_roots(
419      self, ObjectArray<Object>::Alloc(self, object_array_class.get(), ImageHeader::kImageRootsMax));
420  image_roots->Set<false>(ImageHeader::kResolutionMethod, runtime->GetResolutionMethod());
421  image_roots->Set<false>(ImageHeader::kImtConflictMethod, runtime->GetImtConflictMethod());
422  image_roots->Set<false>(ImageHeader::kDefaultImt, runtime->GetDefaultImt());
423  image_roots->Set<false>(ImageHeader::kCalleeSaveMethod,
424                          runtime->GetCalleeSaveMethod(Runtime::kSaveAll));
425  image_roots->Set<false>(ImageHeader::kRefsOnlySaveMethod,
426                          runtime->GetCalleeSaveMethod(Runtime::kRefsOnly));
427  image_roots->Set<false>(ImageHeader::kRefsAndArgsSaveMethod,
428                          runtime->GetCalleeSaveMethod(Runtime::kRefsAndArgs));
429  image_roots->Set<false>(ImageHeader::kDexCaches, dex_caches);
430  image_roots->Set<false>(ImageHeader::kClassRoots, class_linker->GetClassRoots());
431  for (int i = 0; i < ImageHeader::kImageRootsMax; i++) {
432    CHECK(image_roots->Get(i) != NULL);
433  }
434  return image_roots.get();
435}
436
437// Walk instance fields of the given Class. Separate function to allow recursion on the super
438// class.
439void ImageWriter::WalkInstanceFields(mirror::Object* obj, mirror::Class* klass) {
440  // Visit fields of parent classes first.
441  SirtRef<mirror::Class> sirt_class(Thread::Current(), klass);
442  mirror::Class* super = sirt_class->GetSuperClass();
443  if (super != nullptr) {
444    WalkInstanceFields(obj, super);
445  }
446  //
447  size_t num_reference_fields = sirt_class->NumReferenceInstanceFields();
448  for (size_t i = 0; i < num_reference_fields; ++i) {
449    mirror::ArtField* field = sirt_class->GetInstanceField(i);
450    MemberOffset field_offset = field->GetOffset();
451    mirror::Object* value = obj->GetFieldObject<mirror::Object>(field_offset, false);
452    if (value != nullptr) {
453      WalkFieldsInOrder(value);
454    }
455  }
456}
457
458// For an unvisited object, visit it then all its children found via fields.
459void ImageWriter::WalkFieldsInOrder(mirror::Object* obj) {
460  if (!IsImageOffsetAssigned(obj)) {
461    // Walk instance fields of all objects
462    Thread* self = Thread::Current();
463    SirtRef<mirror::Object> sirt_obj(self, obj);
464    SirtRef<mirror::Class> klass(self, obj->GetClass());
465    // visit the object itself.
466    CalculateObjectOffsets(sirt_obj.get());
467    WalkInstanceFields(sirt_obj.get(), klass.get());
468    // Walk static fields of a Class.
469    if (sirt_obj->IsClass()) {
470      size_t num_static_fields = klass->NumReferenceStaticFields();
471      for (size_t i = 0; i < num_static_fields; ++i) {
472        mirror::ArtField* field = klass->GetStaticField(i);
473        MemberOffset field_offset = field->GetOffset();
474        mirror::Object* value = sirt_obj->GetFieldObject<mirror::Object>(field_offset, false);
475        if (value != nullptr) {
476          WalkFieldsInOrder(value);
477        }
478      }
479    } else if (sirt_obj->IsObjectArray()) {
480      // Walk elements of an object array.
481      int32_t length = sirt_obj->AsObjectArray<mirror::Object>()->GetLength();
482      for (int32_t i = 0; i < length; i++) {
483        mirror::ObjectArray<mirror::Object>* obj_array = sirt_obj->AsObjectArray<mirror::Object>();
484        mirror::Object* value = obj_array->Get(i);
485        if (value != nullptr) {
486          WalkFieldsInOrder(value);
487        }
488      }
489    }
490  }
491}
492
493void ImageWriter::WalkFieldsCallback(mirror::Object* obj, void* arg) {
494  ImageWriter* writer = reinterpret_cast<ImageWriter*>(arg);
495  DCHECK(writer != nullptr);
496  writer->WalkFieldsInOrder(obj);
497}
498
499void ImageWriter::CalculateNewObjectOffsets(size_t oat_loaded_size, size_t oat_data_offset) {
500  CHECK_NE(0U, oat_loaded_size);
501  Thread* self = Thread::Current();
502  SirtRef<ObjectArray<Object> > image_roots(self, CreateImageRoots());
503
504  gc::Heap* heap = Runtime::Current()->GetHeap();
505  DCHECK_EQ(0U, image_end_);
506
507  // Leave space for the header, but do not write it yet, we need to
508  // know where image_roots is going to end up
509  image_end_ += RoundUp(sizeof(ImageHeader), 8);  // 64-bit-alignment
510
511  {
512    WriterMutexLock mu(self, *Locks::heap_bitmap_lock_);
513    // TODO: Image spaces only?
514    const char* old = self->StartAssertNoThreadSuspension("ImageWriter");
515    DCHECK_LT(image_end_, image_->Size());
516    // Clear any pre-existing monitors which may have been in the monitor words.
517    heap->VisitObjects(WalkFieldsCallback, this);
518    self->EndAssertNoThreadSuspension(old);
519  }
520
521  const byte* oat_file_begin = image_begin_ + RoundUp(image_end_, kPageSize);
522  const byte* oat_file_end = oat_file_begin + oat_loaded_size;
523  oat_data_begin_ = oat_file_begin + oat_data_offset;
524  const byte* oat_data_end = oat_data_begin_ + oat_file_->Size();
525
526  // Return to write header at start of image with future location of image_roots. At this point,
527  // image_end_ is the size of the image (excluding bitmaps).
528  const size_t heap_bytes_per_bitmap_byte = kBitsPerByte * gc::accounting::SpaceBitmap::kAlignment;
529  const size_t bitmap_bytes = RoundUp(image_end_, heap_bytes_per_bitmap_byte) /
530      heap_bytes_per_bitmap_byte;
531  ImageHeader image_header(PointerToLowMemUInt32(image_begin_),
532                           static_cast<uint32_t>(image_end_),
533                           RoundUp(image_end_, kPageSize),
534                           RoundUp(bitmap_bytes, kPageSize),
535                           PointerToLowMemUInt32(GetImageAddress(image_roots.get())),
536                           oat_file_->GetOatHeader().GetChecksum(),
537                           PointerToLowMemUInt32(oat_file_begin),
538                           PointerToLowMemUInt32(oat_data_begin_),
539                           PointerToLowMemUInt32(oat_data_end),
540                           PointerToLowMemUInt32(oat_file_end));
541  memcpy(image_->Begin(), &image_header, sizeof(image_header));
542
543  // Note that image_end_ is left at end of used space
544}
545
546void ImageWriter::CopyAndFixupObjects()
547    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
548  Thread* self = Thread::Current();
549  const char* old_cause = self->StartAssertNoThreadSuspension("ImageWriter");
550  gc::Heap* heap = Runtime::Current()->GetHeap();
551  // TODO: heap validation can't handle this fix up pass
552  heap->DisableObjectValidation();
553  // TODO: Image spaces only?
554  WriterMutexLock mu(self, *Locks::heap_bitmap_lock_);
555  heap->VisitObjects(CopyAndFixupObjectsCallback, this);
556  // Fix up the object previously had hash codes.
557  for (const std::pair<mirror::Object*, uint32_t>& hash_pair : saved_hashes_) {
558    hash_pair.first->SetLockWord(LockWord::FromHashCode(hash_pair.second));
559  }
560  saved_hashes_.clear();
561  self->EndAssertNoThreadSuspension(old_cause);
562}
563
564void ImageWriter::CopyAndFixupObjectsCallback(Object* obj, void* arg) {
565  DCHECK(obj != NULL);
566  DCHECK(arg != NULL);
567  ImageWriter* image_writer = reinterpret_cast<ImageWriter*>(arg);
568  // see GetLocalAddress for similar computation
569  size_t offset = image_writer->GetImageOffset(obj);
570  byte* dst = image_writer->image_->Begin() + offset;
571  const byte* src = reinterpret_cast<const byte*>(obj);
572  size_t n = obj->SizeOf();
573  DCHECK_LT(offset + n, image_writer->image_->Size());
574  memcpy(dst, src, n);
575  Object* copy = reinterpret_cast<Object*>(dst);
576  // Write in a hash code of objects which have inflated monitors or a hash code in their monitor
577  // word.
578  copy->SetLockWord(LockWord());
579  image_writer->FixupObject(obj, copy);
580}
581
582void ImageWriter::FixupObject(Object* orig, Object* copy) {
583  DCHECK(orig != NULL);
584  DCHECK(copy != NULL);
585  copy->SetClass<kVerifyNone>(down_cast<Class*>(GetImageAddress(orig->GetClass())));
586  if (kUseBrooksPointer) {
587    orig->AssertSelfBrooksPointer();
588    // Note the address 'copy' isn't the same as the image address of 'orig'.
589    copy->SetBrooksPointer(GetImageAddress(orig));
590    DCHECK(copy->GetBrooksPointer() == GetImageAddress(orig));
591  }
592  // TODO: special case init of pointers to malloc data (or removal of these pointers)
593  if (orig->IsClass<kVerifyNone>()) {
594    FixupClass(orig->AsClass<kVerifyNone>(), down_cast<Class*>(copy));
595  } else if (orig->IsObjectArray<kVerifyNone>()) {
596    FixupObjectArray(orig->AsObjectArray<Object, kVerifyNone>(),
597                     down_cast<ObjectArray<Object>*>(copy));
598  } else if (orig->IsArtMethod<kVerifyNone>()) {
599    FixupMethod(orig->AsArtMethod<kVerifyNone>(), down_cast<ArtMethod*>(copy));
600  } else {
601    FixupInstanceFields(orig, copy);
602  }
603}
604
605void ImageWriter::FixupClass(Class* orig, Class* copy) {
606  FixupInstanceFields(orig, copy);
607  FixupStaticFields(orig, copy);
608}
609
610void ImageWriter::FixupMethod(ArtMethod* orig, ArtMethod* copy) {
611  FixupInstanceFields(orig, copy);
612
613  // OatWriter replaces the code_ with an offset value. Here we re-adjust to a pointer relative to
614  // oat_begin_
615
616  // The resolution method has a special trampoline to call.
617  if (UNLIKELY(orig == Runtime::Current()->GetResolutionMethod())) {
618    copy->SetEntryPointFromPortableCompiledCode<kVerifyNone>(GetOatAddress(portable_resolution_trampoline_offset_));
619    copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(GetOatAddress(quick_resolution_trampoline_offset_));
620  } else if (UNLIKELY(orig == Runtime::Current()->GetImtConflictMethod())) {
621    copy->SetEntryPointFromPortableCompiledCode<kVerifyNone>(GetOatAddress(portable_imt_conflict_trampoline_offset_));
622    copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(GetOatAddress(quick_imt_conflict_trampoline_offset_));
623  } else {
624    // We assume all methods have code. If they don't currently then we set them to the use the
625    // resolution trampoline. Abstract methods never have code and so we need to make sure their
626    // use results in an AbstractMethodError. We use the interpreter to achieve this.
627    if (UNLIKELY(orig->IsAbstract())) {
628      copy->SetEntryPointFromPortableCompiledCode<kVerifyNone>(GetOatAddress(portable_to_interpreter_bridge_offset_));
629      copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(GetOatAddress(quick_to_interpreter_bridge_offset_));
630      copy->SetEntryPointFromInterpreter<kVerifyNone>(reinterpret_cast<EntryPointFromInterpreter*>
631          (const_cast<byte*>(GetOatAddress(interpreter_to_interpreter_bridge_offset_))));
632    } else {
633      copy->SetEntryPointFromInterpreter<kVerifyNone>(reinterpret_cast<EntryPointFromInterpreter*>
634          (const_cast<byte*>(GetOatAddress(interpreter_to_compiled_code_bridge_offset_))));
635      // Use original code if it exists. Otherwise, set the code pointer to the resolution
636      // trampoline.
637      const byte* quick_code = GetOatAddress(orig->GetQuickOatCodeOffset());
638      if (quick_code != nullptr &&
639          (!orig->IsStatic() || orig->IsConstructor() || orig->GetDeclaringClass()->IsInitialized())) {
640        // We have code for a non-static or initialized method, just use the code.
641        copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(quick_code);
642      } else if (quick_code == nullptr && orig->IsNative() &&
643          (!orig->IsStatic() || orig->GetDeclaringClass()->IsInitialized())) {
644        // Non-static or initialized native method missing compiled code, use generic JNI version.
645        copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(GetOatAddress(quick_generic_jni_trampoline_offset_));
646      } else if (quick_code == nullptr && !orig->IsNative()) {
647        // We don't have code at all for a non-native method, use the interpreter.
648        copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(GetOatAddress(quick_to_interpreter_bridge_offset_));
649      } else {
650        CHECK(!orig->GetDeclaringClass()->IsInitialized());
651        // We have code for a static method, but need to go through the resolution stub for class
652        // initialization.
653        copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(GetOatAddress(quick_resolution_trampoline_offset_));
654      }
655      const byte* portable_code = GetOatAddress(orig->GetPortableOatCodeOffset());
656      if (portable_code != nullptr) {
657        copy->SetEntryPointFromPortableCompiledCode<kVerifyNone>(portable_code);
658      } else {
659        copy->SetEntryPointFromPortableCompiledCode<kVerifyNone>(GetOatAddress(portable_resolution_trampoline_offset_));
660      }
661      if (orig->IsNative()) {
662        // The native method's pointer is set to a stub to lookup via dlsym.
663        // Note this is not the code_ pointer, that is handled above.
664        copy->SetNativeMethod<kVerifyNone>(GetOatAddress(jni_dlsym_lookup_offset_));
665      } else {
666        // Normal (non-abstract non-native) methods have various tables to relocate.
667        uint32_t mapping_table_off = orig->GetOatMappingTableOffset();
668        const byte* mapping_table = GetOatAddress(mapping_table_off);
669        copy->SetMappingTable<kVerifyNone>(mapping_table);
670
671        uint32_t vmap_table_offset = orig->GetOatVmapTableOffset();
672        const byte* vmap_table = GetOatAddress(vmap_table_offset);
673        copy->SetVmapTable<kVerifyNone>(vmap_table);
674
675        uint32_t native_gc_map_offset = orig->GetOatNativeGcMapOffset();
676        const byte* native_gc_map = GetOatAddress(native_gc_map_offset);
677        copy->SetNativeGcMap<kVerifyNone>(reinterpret_cast<const uint8_t*>(native_gc_map));
678      }
679    }
680  }
681}
682
683void ImageWriter::FixupObjectArray(ObjectArray<Object>* orig, ObjectArray<Object>* copy) {
684  for (int32_t i = 0; i < orig->GetLength(); ++i) {
685    Object* element = orig->Get(i);
686    copy->SetWithoutChecksAndWriteBarrier<false, true, kVerifyNone>(i, GetImageAddress(element));
687  }
688}
689
690void ImageWriter::FixupInstanceFields(Object* orig, Object* copy) {
691  DCHECK(orig != NULL);
692  DCHECK(copy != NULL);
693  Class* klass = orig->GetClass();
694  DCHECK(klass != NULL);
695  FixupFields(orig, copy, klass->GetReferenceInstanceOffsets(), false);
696}
697
698void ImageWriter::FixupStaticFields(Class* orig, Class* copy) {
699  DCHECK(orig != NULL);
700  DCHECK(copy != NULL);
701  FixupFields(orig, copy, orig->GetReferenceStaticOffsets(), true);
702}
703
704void ImageWriter::FixupFields(Object* orig,
705                              Object* copy,
706                              uint32_t ref_offsets,
707                              bool is_static) {
708  if (ref_offsets != CLASS_WALK_SUPER) {
709    // Found a reference offset bitmap.  Fixup the specified offsets.
710    while (ref_offsets != 0) {
711      size_t right_shift = CLZ(ref_offsets);
712      MemberOffset byte_offset = CLASS_OFFSET_FROM_CLZ(right_shift);
713      Object* ref = orig->GetFieldObject<Object, kVerifyNone>(byte_offset, false);
714      // Use SetFieldObjectWithoutWriteBarrier to avoid card marking since we are writing to the
715      // image.
716      copy->SetFieldObjectWithoutWriteBarrier<false, true, kVerifyNone>(
717          byte_offset, GetImageAddress(ref), false);
718      ref_offsets &= ~(CLASS_HIGH_BIT >> right_shift);
719    }
720  } else {
721    // There is no reference offset bitmap.  In the non-static case,
722    // walk up the class inheritance hierarchy and find reference
723    // offsets the hard way. In the static case, just consider this
724    // class.
725    for (Class *klass = is_static ? orig->AsClass() : orig->GetClass();
726         klass != NULL;
727         klass = is_static ? NULL : klass->GetSuperClass()) {
728      size_t num_reference_fields = (is_static
729                                     ? klass->NumReferenceStaticFields()
730                                     : klass->NumReferenceInstanceFields());
731      for (size_t i = 0; i < num_reference_fields; ++i) {
732        ArtField* field = (is_static
733                           ? klass->GetStaticField(i)
734                           : klass->GetInstanceField(i));
735        MemberOffset field_offset = field->GetOffset();
736        Object* ref = orig->GetFieldObject<Object, kVerifyNone>(field_offset, false);
737        // Use SetFieldObjectWithoutWriteBarrier to avoid card marking since we are writing to the
738        // image.
739        copy->SetFieldObjectWithoutWriteBarrier<false, true, kVerifyNone>(
740            field_offset, GetImageAddress(ref), false);
741      }
742    }
743  }
744  if (!is_static && orig->IsReferenceInstance()) {
745    // Fix-up referent, that isn't marked as an object field, for References.
746    ArtField* field = orig->GetClass()->FindInstanceField("referent", "Ljava/lang/Object;");
747    MemberOffset field_offset = field->GetOffset();
748    Object* ref = orig->GetFieldObject<Object>(field_offset, false);
749    // Use SetFieldObjectWithoutWriteBarrier to avoid card marking since we are writing to the
750    // image.
751    copy->SetFieldObjectWithoutWriteBarrier<false, true, kVerifyNone>(
752        field_offset, GetImageAddress(ref), false);
753  }
754}
755
756static ArtMethod* GetTargetMethod(const CompilerDriver::CallPatchInformation* patch)
757    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
758  ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
759  Thread* self = Thread::Current();
760  SirtRef<mirror::DexCache> dex_cache(self, class_linker->FindDexCache(patch->GetDexFile()));
761  SirtRef<mirror::ClassLoader> class_loader(self, nullptr);
762  ArtMethod* method = class_linker->ResolveMethod(patch->GetDexFile(),
763                                                  patch->GetTargetMethodIdx(),
764                                                  dex_cache,
765                                                  class_loader,
766                                                  NULL,
767                                                  patch->GetTargetInvokeType());
768  CHECK(method != NULL)
769    << patch->GetDexFile().GetLocation() << " " << patch->GetTargetMethodIdx();
770  CHECK(!method->IsRuntimeMethod())
771    << patch->GetDexFile().GetLocation() << " " << patch->GetTargetMethodIdx();
772  CHECK(dex_cache->GetResolvedMethods()->Get(patch->GetTargetMethodIdx()) == method)
773    << patch->GetDexFile().GetLocation() << " " << patch->GetReferrerMethodIdx() << " "
774    << PrettyMethod(dex_cache->GetResolvedMethods()->Get(patch->GetTargetMethodIdx())) << " "
775    << PrettyMethod(method);
776  return method;
777}
778
779static Class* GetTargetType(const CompilerDriver::TypePatchInformation* patch)
780    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
781  ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
782  Thread* self = Thread::Current();
783  SirtRef<mirror::DexCache> dex_cache(self, class_linker->FindDexCache(patch->GetDexFile()));
784  SirtRef<mirror::ClassLoader> class_loader(self, nullptr);
785  Class* klass = class_linker->ResolveType(patch->GetDexFile(),
786                                           patch->GetTargetTypeIdx(),
787                                           dex_cache,
788                                           class_loader);
789  CHECK(klass != NULL)
790    << patch->GetDexFile().GetLocation() << " " << patch->GetTargetTypeIdx();
791  CHECK(dex_cache->GetResolvedTypes()->Get(patch->GetTargetTypeIdx()) == klass)
792    << patch->GetDexFile().GetLocation() << " " << patch->GetReferrerMethodIdx() << " "
793    << PrettyClass(dex_cache->GetResolvedTypes()->Get(patch->GetTargetTypeIdx())) << " "
794    << PrettyClass(klass);
795  return klass;
796}
797
798void ImageWriter::PatchOatCodeAndMethods() {
799  Thread* self = Thread::Current();
800  ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
801  const char* old_cause = self->StartAssertNoThreadSuspension("ImageWriter");
802
803  typedef std::vector<const CompilerDriver::CallPatchInformation*> CallPatches;
804  const CallPatches& code_to_patch = compiler_driver_.GetCodeToPatch();
805  for (size_t i = 0; i < code_to_patch.size(); i++) {
806    const CompilerDriver::CallPatchInformation* patch = code_to_patch[i];
807    ArtMethod* target = GetTargetMethod(patch);
808    uintptr_t quick_code = reinterpret_cast<uintptr_t>(class_linker->GetQuickOatCodeFor(target));
809    uintptr_t code_base = reinterpret_cast<uintptr_t>(&oat_file_->GetOatHeader());
810    uintptr_t code_offset = quick_code - code_base;
811    if (patch->IsRelative()) {
812      // value to patch is relative to the location being patched
813      const void* quick_oat_code =
814        class_linker->GetQuickOatCodeFor(patch->GetDexFile(),
815                                         patch->GetReferrerClassDefIdx(),
816                                         patch->GetReferrerMethodIdx());
817      uintptr_t base = reinterpret_cast<uintptr_t>(quick_oat_code);
818      uintptr_t patch_location = base + patch->GetLiteralOffset();
819      uintptr_t value = quick_code - patch_location + patch->RelativeOffset();
820      SetPatchLocation(patch, value);
821    } else {
822      if (quick_code == reinterpret_cast<uintptr_t>(GetQuickToInterpreterBridge())) {
823        if (target->IsNative()) {
824          // generic JNI, not interpreter bridge from GetQuickOatCodeFor().
825          code_offset = quick_generic_jni_trampoline_offset_;
826        } else {
827          code_offset = quick_to_interpreter_bridge_offset_;
828        }
829      }
830      SetPatchLocation(patch, PointerToLowMemUInt32(GetOatAddress(code_offset)));
831    }
832  }
833
834  const CallPatches& methods_to_patch = compiler_driver_.GetMethodsToPatch();
835  for (size_t i = 0; i < methods_to_patch.size(); i++) {
836    const CompilerDriver::CallPatchInformation* patch = methods_to_patch[i];
837    ArtMethod* target = GetTargetMethod(patch);
838    SetPatchLocation(patch, PointerToLowMemUInt32(GetImageAddress(target)));
839  }
840
841  const std::vector<const CompilerDriver::TypePatchInformation*>& classes_to_patch =
842      compiler_driver_.GetClassesToPatch();
843  for (size_t i = 0; i < classes_to_patch.size(); i++) {
844    const CompilerDriver::TypePatchInformation* patch = classes_to_patch[i];
845    Class* target = GetTargetType(patch);
846    SetPatchLocation(patch, PointerToLowMemUInt32(GetImageAddress(target)));
847  }
848
849  // Update the image header with the new checksum after patching
850  ImageHeader* image_header = reinterpret_cast<ImageHeader*>(image_->Begin());
851  image_header->SetOatChecksum(oat_file_->GetOatHeader().GetChecksum());
852  self->EndAssertNoThreadSuspension(old_cause);
853}
854
855void ImageWriter::SetPatchLocation(const CompilerDriver::PatchInformation* patch, uint32_t value) {
856  ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
857  const void* quick_oat_code = class_linker->GetQuickOatCodeFor(patch->GetDexFile(),
858                                                                patch->GetReferrerClassDefIdx(),
859                                                                patch->GetReferrerMethodIdx());
860  OatHeader& oat_header = const_cast<OatHeader&>(oat_file_->GetOatHeader());
861  // TODO: make this Thumb2 specific
862  uint8_t* base = reinterpret_cast<uint8_t*>(reinterpret_cast<uintptr_t>(quick_oat_code) & ~0x1);
863  uint32_t* patch_location = reinterpret_cast<uint32_t*>(base + patch->GetLiteralOffset());
864  if (kIsDebugBuild) {
865    if (patch->IsCall()) {
866      const CompilerDriver::CallPatchInformation* cpatch = patch->AsCall();
867      const DexFile::MethodId& id = cpatch->GetDexFile().GetMethodId(cpatch->GetTargetMethodIdx());
868      uint32_t expected = reinterpret_cast<uintptr_t>(&id) & 0xFFFFFFFF;
869      uint32_t actual = *patch_location;
870      CHECK(actual == expected || actual == value) << std::hex
871          << "actual=" << actual
872          << "expected=" << expected
873          << "value=" << value;
874    }
875    if (patch->IsType()) {
876      const CompilerDriver::TypePatchInformation* tpatch = patch->AsType();
877      const DexFile::TypeId& id = tpatch->GetDexFile().GetTypeId(tpatch->GetTargetTypeIdx());
878      uint32_t expected = reinterpret_cast<uintptr_t>(&id) & 0xFFFFFFFF;
879      uint32_t actual = *patch_location;
880      CHECK(actual == expected || actual == value) << std::hex
881          << "actual=" << actual
882          << "expected=" << expected
883          << "value=" << value;
884    }
885  }
886  *patch_location = value;
887  oat_header.UpdateChecksum(patch_location, sizeof(value));
888}
889
890}  // namespace art
891