image_writer.cc revision a8e8f9c0a8e259a807d7b99a148d14104c24209d 
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::ContinuousSpaceBitmap::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 * kObjectAlignment;
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
582class FixupVisitor {
583 public:
584  FixupVisitor(ImageWriter* image_writer, Object* copy) : image_writer_(image_writer), copy_(copy) {
585  }
586
587  void operator()(Object* obj, MemberOffset offset, bool /*is_static*/) const
588      EXCLUSIVE_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) {
589    Object* ref = obj->GetFieldObject<Object, kVerifyNone>(offset, false);
590    // Use SetFieldObjectWithoutWriteBarrier to avoid card marking since we are writing to the
591    // image.
592    copy_->SetFieldObjectWithoutWriteBarrier<false, true, kVerifyNone>(
593        offset, image_writer_->GetImageAddress(ref), false);
594  }
595
596  // java.lang.ref.Reference visitor.
597  void operator()(mirror::Class* /*klass*/, mirror::Reference* ref) const
598      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_)
599      EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_) {
600    copy_->SetFieldObjectWithoutWriteBarrier<false, true, kVerifyNone>(
601        mirror::Reference::ReferentOffset(), image_writer_->GetImageAddress(ref->GetReferent()),
602        false);
603  }
604
605 private:
606  ImageWriter* const image_writer_;
607  mirror::Object* const copy_;
608};
609
610void ImageWriter::FixupObject(Object* orig, Object* copy) {
611  DCHECK(orig != nullptr);
612  DCHECK(copy != nullptr);
613  if (kUseBakerOrBrooksReadBarrier) {
614    orig->AssertReadBarrierPointer();
615    if (kUseBrooksReadBarrier) {
616      // Note the address 'copy' isn't the same as the image address of 'orig'.
617      copy->SetReadBarrierPointer(GetImageAddress(orig));
618      DCHECK_EQ(copy->GetReadBarrierPointer(), GetImageAddress(orig));
619    }
620  }
621  FixupVisitor visitor(this, copy);
622  orig->VisitReferences<true /*visit class*/>(visitor, visitor);
623  if (orig->IsArtMethod<kVerifyNone>()) {
624    FixupMethod(orig->AsArtMethod<kVerifyNone>(), down_cast<ArtMethod*>(copy));
625  }
626}
627
628void ImageWriter::FixupMethod(ArtMethod* orig, ArtMethod* copy) {
629  // OatWriter replaces the code_ with an offset value. Here we re-adjust to a pointer relative to
630  // oat_begin_
631
632  // The resolution method has a special trampoline to call.
633  if (UNLIKELY(orig == Runtime::Current()->GetResolutionMethod())) {
634    copy->SetEntryPointFromPortableCompiledCode<kVerifyNone>(GetOatAddress(portable_resolution_trampoline_offset_));
635    copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(GetOatAddress(quick_resolution_trampoline_offset_));
636  } else if (UNLIKELY(orig == Runtime::Current()->GetImtConflictMethod())) {
637    copy->SetEntryPointFromPortableCompiledCode<kVerifyNone>(GetOatAddress(portable_imt_conflict_trampoline_offset_));
638    copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(GetOatAddress(quick_imt_conflict_trampoline_offset_));
639  } else {
640    // We assume all methods have code. If they don't currently then we set them to the use the
641    // resolution trampoline. Abstract methods never have code and so we need to make sure their
642    // use results in an AbstractMethodError. We use the interpreter to achieve this.
643    if (UNLIKELY(orig->IsAbstract())) {
644      copy->SetEntryPointFromPortableCompiledCode<kVerifyNone>(GetOatAddress(portable_to_interpreter_bridge_offset_));
645      copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(GetOatAddress(quick_to_interpreter_bridge_offset_));
646      copy->SetEntryPointFromInterpreter<kVerifyNone>(reinterpret_cast<EntryPointFromInterpreter*>
647          (const_cast<byte*>(GetOatAddress(interpreter_to_interpreter_bridge_offset_))));
648    } else {
649      copy->SetEntryPointFromInterpreter<kVerifyNone>(reinterpret_cast<EntryPointFromInterpreter*>
650          (const_cast<byte*>(GetOatAddress(interpreter_to_compiled_code_bridge_offset_))));
651      // Use original code if it exists. Otherwise, set the code pointer to the resolution
652      // trampoline.
653      const byte* quick_code = GetOatAddress(orig->GetQuickOatCodeOffset());
654      if (quick_code != nullptr &&
655          (!orig->IsStatic() || orig->IsConstructor() || orig->GetDeclaringClass()->IsInitialized())) {
656        // We have code for a non-static or initialized method, just use the code.
657        copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(quick_code);
658      } else if (quick_code == nullptr && orig->IsNative() &&
659          (!orig->IsStatic() || orig->GetDeclaringClass()->IsInitialized())) {
660        // Non-static or initialized native method missing compiled code, use generic JNI version.
661        copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(GetOatAddress(quick_generic_jni_trampoline_offset_));
662      } else if (quick_code == nullptr && !orig->IsNative()) {
663        // We don't have code at all for a non-native method, use the interpreter.
664        copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(GetOatAddress(quick_to_interpreter_bridge_offset_));
665      } else {
666        CHECK(!orig->GetDeclaringClass()->IsInitialized());
667        // We have code for a static method, but need to go through the resolution stub for class
668        // initialization.
669        copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(GetOatAddress(quick_resolution_trampoline_offset_));
670      }
671      const byte* portable_code = GetOatAddress(orig->GetPortableOatCodeOffset());
672      if (portable_code != nullptr) {
673        copy->SetEntryPointFromPortableCompiledCode<kVerifyNone>(portable_code);
674      } else {
675        copy->SetEntryPointFromPortableCompiledCode<kVerifyNone>(GetOatAddress(portable_resolution_trampoline_offset_));
676      }
677      if (orig->IsNative()) {
678        // The native method's pointer is set to a stub to lookup via dlsym.
679        // Note this is not the code_ pointer, that is handled above.
680        copy->SetNativeMethod<kVerifyNone>(GetOatAddress(jni_dlsym_lookup_offset_));
681      } else {
682        // Normal (non-abstract non-native) methods have various tables to relocate.
683        uint32_t mapping_table_off = orig->GetOatMappingTableOffset();
684        const byte* mapping_table = GetOatAddress(mapping_table_off);
685        copy->SetMappingTable<kVerifyNone>(mapping_table);
686
687        uint32_t vmap_table_offset = orig->GetOatVmapTableOffset();
688        const byte* vmap_table = GetOatAddress(vmap_table_offset);
689        copy->SetVmapTable<kVerifyNone>(vmap_table);
690
691        uint32_t native_gc_map_offset = orig->GetOatNativeGcMapOffset();
692        const byte* native_gc_map = GetOatAddress(native_gc_map_offset);
693        copy->SetNativeGcMap<kVerifyNone>(reinterpret_cast<const uint8_t*>(native_gc_map));
694      }
695    }
696  }
697}
698
699static ArtMethod* GetTargetMethod(const CompilerDriver::CallPatchInformation* patch)
700    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
701  ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
702  Thread* self = Thread::Current();
703  SirtRef<mirror::DexCache> dex_cache(self, class_linker->FindDexCache(*patch->GetTargetDexFile()));
704  SirtRef<mirror::ClassLoader> class_loader(self, nullptr);
705  ArtMethod* method = class_linker->ResolveMethod(*patch->GetTargetDexFile(),
706                                                  patch->GetTargetMethodIdx(),
707                                                  dex_cache,
708                                                  class_loader,
709                                                  NULL,
710                                                  patch->GetTargetInvokeType());
711  CHECK(method != NULL)
712    << patch->GetTargetDexFile()->GetLocation() << " " << patch->GetTargetMethodIdx();
713  CHECK(!method->IsRuntimeMethod())
714    << patch->GetTargetDexFile()->GetLocation() << " " << patch->GetTargetMethodIdx();
715  CHECK(dex_cache->GetResolvedMethods()->Get(patch->GetTargetMethodIdx()) == method)
716    << patch->GetTargetDexFile()->GetLocation() << " " << patch->GetReferrerMethodIdx() << " "
717    << PrettyMethod(dex_cache->GetResolvedMethods()->Get(patch->GetTargetMethodIdx())) << " "
718    << PrettyMethod(method);
719  return method;
720}
721
722static Class* GetTargetType(const CompilerDriver::TypePatchInformation* patch)
723    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
724  ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
725  Thread* self = Thread::Current();
726  SirtRef<mirror::DexCache> dex_cache(self, class_linker->FindDexCache(patch->GetDexFile()));
727  SirtRef<mirror::ClassLoader> class_loader(self, nullptr);
728  Class* klass = class_linker->ResolveType(patch->GetDexFile(),
729                                           patch->GetTargetTypeIdx(),
730                                           dex_cache,
731                                           class_loader);
732  CHECK(klass != NULL)
733    << patch->GetDexFile().GetLocation() << " " << patch->GetTargetTypeIdx();
734  CHECK(dex_cache->GetResolvedTypes()->Get(patch->GetTargetTypeIdx()) == klass)
735    << patch->GetDexFile().GetLocation() << " " << patch->GetReferrerMethodIdx() << " "
736    << PrettyClass(dex_cache->GetResolvedTypes()->Get(patch->GetTargetTypeIdx())) << " "
737    << PrettyClass(klass);
738  return klass;
739}
740
741void ImageWriter::PatchOatCodeAndMethods() {
742  Thread* self = Thread::Current();
743  ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
744  const char* old_cause = self->StartAssertNoThreadSuspension("ImageWriter");
745
746  typedef std::vector<const CompilerDriver::CallPatchInformation*> CallPatches;
747  const CallPatches& code_to_patch = compiler_driver_.GetCodeToPatch();
748  for (size_t i = 0; i < code_to_patch.size(); i++) {
749    const CompilerDriver::CallPatchInformation* patch = code_to_patch[i];
750    ArtMethod* target = GetTargetMethod(patch);
751    uintptr_t quick_code = reinterpret_cast<uintptr_t>(class_linker->GetQuickOatCodeFor(target));
752    uintptr_t code_base = reinterpret_cast<uintptr_t>(&oat_file_->GetOatHeader());
753    uintptr_t code_offset = quick_code - code_base;
754    if (patch->IsRelative()) {
755      // value to patch is relative to the location being patched
756      const void* quick_oat_code =
757        class_linker->GetQuickOatCodeFor(patch->GetDexFile(),
758                                         patch->GetReferrerClassDefIdx(),
759                                         patch->GetReferrerMethodIdx());
760      uintptr_t base = reinterpret_cast<uintptr_t>(quick_oat_code);
761      uintptr_t patch_location = base + patch->GetLiteralOffset();
762      uintptr_t value = quick_code - patch_location + patch->RelativeOffset();
763      SetPatchLocation(patch, value);
764    } else {
765      if (quick_code == reinterpret_cast<uintptr_t>(GetQuickToInterpreterBridge())) {
766        if (target->IsNative()) {
767          // generic JNI, not interpreter bridge from GetQuickOatCodeFor().
768          code_offset = quick_generic_jni_trampoline_offset_;
769        } else {
770          code_offset = quick_to_interpreter_bridge_offset_;
771        }
772      }
773      SetPatchLocation(patch, PointerToLowMemUInt32(GetOatAddress(code_offset)));
774    }
775  }
776
777  const CallPatches& methods_to_patch = compiler_driver_.GetMethodsToPatch();
778  for (size_t i = 0; i < methods_to_patch.size(); i++) {
779    const CompilerDriver::CallPatchInformation* patch = methods_to_patch[i];
780    ArtMethod* target = GetTargetMethod(patch);
781    SetPatchLocation(patch, PointerToLowMemUInt32(GetImageAddress(target)));
782  }
783
784  const std::vector<const CompilerDriver::TypePatchInformation*>& classes_to_patch =
785      compiler_driver_.GetClassesToPatch();
786  for (size_t i = 0; i < classes_to_patch.size(); i++) {
787    const CompilerDriver::TypePatchInformation* patch = classes_to_patch[i];
788    Class* target = GetTargetType(patch);
789    SetPatchLocation(patch, PointerToLowMemUInt32(GetImageAddress(target)));
790  }
791
792  // Update the image header with the new checksum after patching
793  ImageHeader* image_header = reinterpret_cast<ImageHeader*>(image_->Begin());
794  image_header->SetOatChecksum(oat_file_->GetOatHeader().GetChecksum());
795  self->EndAssertNoThreadSuspension(old_cause);
796}
797
798void ImageWriter::SetPatchLocation(const CompilerDriver::PatchInformation* patch, uint32_t value) {
799  ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
800  const void* quick_oat_code = class_linker->GetQuickOatCodeFor(patch->GetDexFile(),
801                                                                patch->GetReferrerClassDefIdx(),
802                                                                patch->GetReferrerMethodIdx());
803  OatHeader& oat_header = const_cast<OatHeader&>(oat_file_->GetOatHeader());
804  // TODO: make this Thumb2 specific
805  uint8_t* base = reinterpret_cast<uint8_t*>(reinterpret_cast<uintptr_t>(quick_oat_code) & ~0x1);
806  uint32_t* patch_location = reinterpret_cast<uint32_t*>(base + patch->GetLiteralOffset());
807  if (kIsDebugBuild) {
808    if (patch->IsCall()) {
809      const CompilerDriver::CallPatchInformation* cpatch = patch->AsCall();
810      const DexFile::MethodId& id = cpatch->GetTargetDexFile()->GetMethodId(cpatch->GetTargetMethodIdx());
811      uint32_t expected = reinterpret_cast<uintptr_t>(&id) & 0xFFFFFFFF;
812      uint32_t actual = *patch_location;
813      CHECK(actual == expected || actual == value) << std::hex
814          << "actual=" << actual
815          << "expected=" << expected
816          << "value=" << value;
817    }
818    if (patch->IsType()) {
819      const CompilerDriver::TypePatchInformation* tpatch = patch->AsType();
820      const DexFile::TypeId& id = tpatch->GetDexFile().GetTypeId(tpatch->GetTargetTypeIdx());
821      uint32_t expected = reinterpret_cast<uintptr_t>(&id) & 0xFFFFFFFF;
822      uint32_t actual = *patch_location;
823      CHECK(actual == expected || actual == value) << std::hex
824          << "actual=" << actual
825          << "expected=" << expected
826          << "value=" << value;
827    }
828  }
829  *patch_location = value;
830  oat_header.UpdateChecksum(patch_location, sizeof(value));
831}
832
833}  // namespace art
834