image_writer.cc revision ef7d42fca18c16fbaf103822ad16f23246e2905d 
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.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_imt_conflict_trampoline_offset_ =
108      oat_file_->GetOatHeader().GetQuickImtConflictTrampolineOffset();
109  quick_resolution_trampoline_offset_ =
110      oat_file_->GetOatHeader().GetQuickResolutionTrampolineOffset();
111  quick_to_interpreter_bridge_offset_ =
112      oat_file_->GetOatHeader().GetQuickToInterpreterBridgeOffset();
113  {
114    Thread::Current()->TransitionFromSuspendedToRunnable();
115    PruneNonImageClasses();  // Remove junk
116    ComputeLazyFieldsForImageClasses();  // Add useful information
117    ComputeEagerResolvedStrings();
118    Thread::Current()->TransitionFromRunnableToSuspended(kNative);
119  }
120  gc::Heap* heap = Runtime::Current()->GetHeap();
121  heap->CollectGarbage(false);  // Remove garbage.
122
123  if (!AllocMemory()) {
124    return false;
125  }
126
127  if (kIsDebugBuild) {
128    ScopedObjectAccess soa(Thread::Current());
129    CheckNonImageClassesRemoved();
130  }
131
132  Thread::Current()->TransitionFromSuspendedToRunnable();
133  size_t oat_loaded_size = 0;
134  size_t oat_data_offset = 0;
135  ElfWriter::GetOatElfInformation(oat_file.get(), oat_loaded_size, oat_data_offset);
136  CalculateNewObjectOffsets(oat_loaded_size, oat_data_offset);
137  CopyAndFixupObjects();
138  PatchOatCodeAndMethods();
139  Thread::Current()->TransitionFromRunnableToSuspended(kNative);
140
141  UniquePtr<File> image_file(OS::CreateEmptyFile(image_filename.c_str()));
142  ImageHeader* image_header = reinterpret_cast<ImageHeader*>(image_->Begin());
143  if (image_file.get() == NULL) {
144    LOG(ERROR) << "Failed to open image file " << image_filename;
145    return false;
146  }
147  if (fchmod(image_file->Fd(), 0644) != 0) {
148    PLOG(ERROR) << "Failed to make image file world readable: " << image_filename;
149    return EXIT_FAILURE;
150  }
151
152  // Write out the image.
153  CHECK_EQ(image_end_, image_header->GetImageSize());
154  if (!image_file->WriteFully(image_->Begin(), image_end_)) {
155    PLOG(ERROR) << "Failed to write image file " << image_filename;
156    return false;
157  }
158
159  // Write out the image bitmap at the page aligned start of the image end.
160  CHECK_ALIGNED(image_header->GetImageBitmapOffset(), kPageSize);
161  if (!image_file->Write(reinterpret_cast<char*>(image_bitmap_->Begin()),
162                         image_header->GetImageBitmapSize(),
163                         image_header->GetImageBitmapOffset())) {
164    PLOG(ERROR) << "Failed to write image file " << image_filename;
165    return false;
166  }
167
168  return true;
169}
170
171void ImageWriter::SetImageOffset(mirror::Object* object, size_t offset) {
172  DCHECK(object != nullptr);
173  DCHECK_NE(offset, 0U);
174  DCHECK(!IsImageOffsetAssigned(object));
175  mirror::Object* obj = reinterpret_cast<mirror::Object*>(image_->Begin() + offset);
176  DCHECK_ALIGNED(obj, kObjectAlignment);
177  image_bitmap_->Set(obj);
178  // Before we stomp over the lock word, save the hash code for later.
179  Monitor::Deflate(Thread::Current(), object);;
180  LockWord lw(object->GetLockWord());
181  switch (lw.GetState()) {
182    case LockWord::kFatLocked: {
183      LOG(FATAL) << "Fat locked object " << obj << " found during object copy";
184      break;
185    }
186    case LockWord::kThinLocked: {
187      LOG(FATAL) << "Thin locked object " << obj << " found during object copy";
188      break;
189    }
190    case LockWord::kUnlocked:
191      // No hash, don't need to save it.
192      break;
193    case LockWord::kHashCode:
194      saved_hashes_.push_back(std::make_pair(obj, lw.GetHashCode()));
195      break;
196    default:
197      LOG(FATAL) << "Unreachable.";
198      break;
199  }
200  object->SetLockWord(LockWord::FromForwardingAddress(offset));
201  DCHECK(IsImageOffsetAssigned(object));
202}
203
204void ImageWriter::AssignImageOffset(mirror::Object* object) {
205  DCHECK(object != nullptr);
206  SetImageOffset(object, image_end_);
207  image_end_ += RoundUp(object->SizeOf(), 8);  // 64-bit alignment
208  DCHECK_LT(image_end_, image_->Size());
209}
210
211bool ImageWriter::IsImageOffsetAssigned(mirror::Object* object) const {
212  DCHECK(object != nullptr);
213  return object->GetLockWord().GetState() == LockWord::kForwardingAddress;
214}
215
216size_t ImageWriter::GetImageOffset(mirror::Object* object) const {
217  DCHECK(object != nullptr);
218  DCHECK(IsImageOffsetAssigned(object));
219  LockWord lock_word = object->GetLockWord();
220  size_t offset = lock_word.ForwardingAddress();
221  DCHECK_LT(offset, image_end_);
222  return offset;
223}
224
225bool ImageWriter::AllocMemory() {
226  size_t length = RoundUp(Runtime::Current()->GetHeap()->GetTotalMemory(), kPageSize);
227  std::string error_msg;
228  image_.reset(MemMap::MapAnonymous("image writer image", NULL, length, PROT_READ | PROT_WRITE,
229                                    true, &error_msg));
230  if (UNLIKELY(image_.get() == nullptr)) {
231    LOG(ERROR) << "Failed to allocate memory for image file generation: " << error_msg;
232    return false;
233  }
234
235  // Create the image bitmap.
236  image_bitmap_.reset(gc::accounting::SpaceBitmap::Create("image bitmap", image_->Begin(),
237                                                          length));
238  if (image_bitmap_.get() == nullptr) {
239    LOG(ERROR) << "Failed to allocate memory for image bitmap";
240    return false;
241  }
242  return true;
243}
244
245void ImageWriter::ComputeLazyFieldsForImageClasses() {
246  ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
247  class_linker->VisitClassesWithoutClassesLock(ComputeLazyFieldsForClassesVisitor, NULL);
248}
249
250bool ImageWriter::ComputeLazyFieldsForClassesVisitor(Class* c, void* /*arg*/) {
251  c->ComputeName();
252  return true;
253}
254
255void ImageWriter::ComputeEagerResolvedStringsCallback(Object* obj, void* arg) {
256  if (!obj->GetClass()->IsStringClass()) {
257    return;
258  }
259  mirror::String* string = obj->AsString();
260  const uint16_t* utf16_string = string->GetCharArray()->GetData() + string->GetOffset();
261  for (DexCache* dex_cache : Runtime::Current()->GetClassLinker()->GetDexCaches()) {
262    const DexFile& dex_file = *dex_cache->GetDexFile();
263    const DexFile::StringId* string_id;
264    if (UNLIKELY(string->GetLength() == 0)) {
265      string_id = dex_file.FindStringId("");
266    } else {
267      string_id = dex_file.FindStringId(utf16_string);
268    }
269    if (string_id != nullptr) {
270      // This string occurs in this dex file, assign the dex cache entry.
271      uint32_t string_idx = dex_file.GetIndexForStringId(*string_id);
272      if (dex_cache->GetResolvedString(string_idx) == NULL) {
273        dex_cache->SetResolvedString(string_idx, string);
274      }
275    }
276  }
277}
278
279void ImageWriter::ComputeEagerResolvedStrings() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
280  ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_);
281  Runtime::Current()->GetHeap()->VisitObjects(ComputeEagerResolvedStringsCallback, this);
282}
283
284bool ImageWriter::IsImageClass(Class* klass) {
285  return compiler_driver_.IsImageClass(ClassHelper(klass).GetDescriptor());
286}
287
288struct NonImageClasses {
289  ImageWriter* image_writer;
290  std::set<std::string>* non_image_classes;
291};
292
293void ImageWriter::PruneNonImageClasses() {
294  if (compiler_driver_.GetImageClasses() == NULL) {
295    return;
296  }
297  Runtime* runtime = Runtime::Current();
298  ClassLinker* class_linker = runtime->GetClassLinker();
299
300  // Make a list of classes we would like to prune.
301  std::set<std::string> non_image_classes;
302  NonImageClasses context;
303  context.image_writer = this;
304  context.non_image_classes = &non_image_classes;
305  class_linker->VisitClasses(NonImageClassesVisitor, &context);
306
307  // Remove the undesired classes from the class roots.
308  for (const std::string& it : non_image_classes) {
309    class_linker->RemoveClass(it.c_str(), NULL);
310  }
311
312  // Clear references to removed classes from the DexCaches.
313  ArtMethod* resolution_method = runtime->GetResolutionMethod();
314  for (DexCache* dex_cache : class_linker->GetDexCaches()) {
315    for (size_t i = 0; i < dex_cache->NumResolvedTypes(); i++) {
316      Class* klass = dex_cache->GetResolvedType(i);
317      if (klass != NULL && !IsImageClass(klass)) {
318        dex_cache->SetResolvedType(i, NULL);
319      }
320    }
321    for (size_t i = 0; i < dex_cache->NumResolvedMethods(); i++) {
322      ArtMethod* method = dex_cache->GetResolvedMethod(i);
323      if (method != NULL && !IsImageClass(method->GetDeclaringClass())) {
324        dex_cache->SetResolvedMethod(i, resolution_method);
325      }
326    }
327    for (size_t i = 0; i < dex_cache->NumResolvedFields(); i++) {
328      ArtField* field = dex_cache->GetResolvedField(i);
329      if (field != NULL && !IsImageClass(field->GetDeclaringClass())) {
330        dex_cache->SetResolvedField(i, NULL);
331      }
332    }
333  }
334}
335
336bool ImageWriter::NonImageClassesVisitor(Class* klass, void* arg) {
337  NonImageClasses* context = reinterpret_cast<NonImageClasses*>(arg);
338  if (!context->image_writer->IsImageClass(klass)) {
339    context->non_image_classes->insert(ClassHelper(klass).GetDescriptor());
340  }
341  return true;
342}
343
344void ImageWriter::CheckNonImageClassesRemoved()
345    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
346  if (compiler_driver_.GetImageClasses() != nullptr) {
347    gc::Heap* heap = Runtime::Current()->GetHeap();
348    ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_);
349    heap->VisitObjects(CheckNonImageClassesRemovedCallback, this);
350  }
351}
352
353void ImageWriter::CheckNonImageClassesRemovedCallback(Object* obj, void* arg) {
354  ImageWriter* image_writer = reinterpret_cast<ImageWriter*>(arg);
355  if (obj->IsClass()) {
356    Class* klass = obj->AsClass();
357    if (!image_writer->IsImageClass(klass)) {
358      image_writer->DumpImageClasses();
359      CHECK(image_writer->IsImageClass(klass)) << ClassHelper(klass).GetDescriptor()
360                                               << " " << PrettyDescriptor(klass);
361    }
362  }
363}
364
365void ImageWriter::DumpImageClasses() {
366  CompilerDriver::DescriptorSet* image_classes = compiler_driver_.GetImageClasses();
367  CHECK(image_classes != NULL);
368  for (const std::string& image_class : *image_classes) {
369    LOG(INFO) << " " << image_class;
370  }
371}
372
373void ImageWriter::CalculateObjectOffsets(Object* obj) {
374  DCHECK(obj != NULL);
375  // if it is a string, we want to intern it if its not interned.
376  if (obj->GetClass()->IsStringClass()) {
377    // we must be an interned string that was forward referenced and already assigned
378    if (IsImageOffsetAssigned(obj)) {
379      DCHECK_EQ(obj, obj->AsString()->Intern());
380      return;
381    }
382    Thread* self = Thread::Current();
383    SirtRef<Object> sirt_obj(self, obj);
384    mirror::String* interned = obj->AsString()->Intern();
385    if (sirt_obj.get() != interned) {
386      if (!IsImageOffsetAssigned(interned)) {
387        // interned obj is after us, allocate its location early
388        AssignImageOffset(interned);
389      }
390      // point those looking for this object to the interned version.
391      SetImageOffset(sirt_obj.get(), GetImageOffset(interned));
392      return;
393    }
394    // else (obj == interned), nothing to do but fall through to the normal case
395  }
396
397  AssignImageOffset(obj);
398}
399
400ObjectArray<Object>* ImageWriter::CreateImageRoots() const {
401  Runtime* runtime = Runtime::Current();
402  ClassLinker* class_linker = runtime->GetClassLinker();
403  Thread* self = Thread::Current();
404  SirtRef<Class> object_array_class(self, class_linker->FindSystemClass("[Ljava/lang/Object;"));
405
406  // build an Object[] of all the DexCaches used in the source_space_
407  ObjectArray<Object>* dex_caches = ObjectArray<Object>::Alloc(self, object_array_class.get(),
408                                                               class_linker->GetDexCaches().size());
409  int i = 0;
410  for (DexCache* dex_cache : class_linker->GetDexCaches()) {
411    dex_caches->Set(i++, dex_cache);
412  }
413
414  // build an Object[] of the roots needed to restore the runtime
415  SirtRef<ObjectArray<Object> > image_roots(
416      self, ObjectArray<Object>::Alloc(self, object_array_class.get(), ImageHeader::kImageRootsMax));
417  image_roots->Set(ImageHeader::kResolutionMethod, runtime->GetResolutionMethod());
418  image_roots->Set(ImageHeader::kImtConflictMethod, runtime->GetImtConflictMethod());
419  image_roots->Set(ImageHeader::kDefaultImt, runtime->GetDefaultImt());
420  image_roots->Set(ImageHeader::kCalleeSaveMethod,
421                   runtime->GetCalleeSaveMethod(Runtime::kSaveAll));
422  image_roots->Set(ImageHeader::kRefsOnlySaveMethod,
423                   runtime->GetCalleeSaveMethod(Runtime::kRefsOnly));
424  image_roots->Set(ImageHeader::kRefsAndArgsSaveMethod,
425                   runtime->GetCalleeSaveMethod(Runtime::kRefsAndArgs));
426  image_roots->Set(ImageHeader::kOatLocation,
427                   String::AllocFromModifiedUtf8(self, oat_file_->GetLocation().c_str()));
428  image_roots->Set(ImageHeader::kDexCaches, dex_caches);
429  image_roots->Set(ImageHeader::kClassRoots, class_linker->GetClassRoots());
430  for (int i = 0; i < ImageHeader::kImageRootsMax; i++) {
431    CHECK(image_roots->Get(i) != NULL);
432  }
433  return image_roots.get();
434}
435
436// Walk instance fields of the given Class. Separate function to allow recursion on the super
437// class.
438void ImageWriter::WalkInstanceFields(mirror::Object* obj, mirror::Class* klass) {
439  // Visit fields of parent classes first.
440  SirtRef<mirror::Class> sirt_class(Thread::Current(), klass);
441  mirror::Class* super = sirt_class->GetSuperClass();
442  if (super != nullptr) {
443    WalkInstanceFields(obj, super);
444  }
445  //
446  size_t num_reference_fields = sirt_class->NumReferenceInstanceFields();
447  for (size_t i = 0; i < num_reference_fields; ++i) {
448    mirror::ArtField* field = sirt_class->GetInstanceField(i);
449    MemberOffset field_offset = field->GetOffset();
450    mirror::Object* value = obj->GetFieldObject<mirror::Object>(field_offset, false);
451    if (value != nullptr) {
452      WalkFieldsInOrder(value);
453    }
454  }
455}
456
457// For an unvisited object, visit it then all its children found via fields.
458void ImageWriter::WalkFieldsInOrder(mirror::Object* obj) {
459  if (!IsImageOffsetAssigned(obj)) {
460    // Walk instance fields of all objects
461    Thread* self = Thread::Current();
462    SirtRef<mirror::Object> sirt_obj(self, obj);
463    SirtRef<mirror::Class> klass(self, obj->GetClass());
464    // visit the object itself.
465    CalculateObjectOffsets(sirt_obj.get());
466    WalkInstanceFields(sirt_obj.get(), klass.get());
467    // Walk static fields of a Class.
468    if (sirt_obj->IsClass()) {
469      size_t num_static_fields = klass->NumReferenceStaticFields();
470      for (size_t i = 0; i < num_static_fields; ++i) {
471        mirror::ArtField* field = klass->GetStaticField(i);
472        MemberOffset field_offset = field->GetOffset();
473        mirror::Object* value = sirt_obj->GetFieldObject<mirror::Object>(field_offset, false);
474        if (value != nullptr) {
475          WalkFieldsInOrder(value);
476        }
477      }
478    } else if (sirt_obj->IsObjectArray()) {
479      // Walk elements of an object array.
480      int32_t length = sirt_obj->AsObjectArray<mirror::Object>()->GetLength();
481      for (int32_t i = 0; i < length; i++) {
482        mirror::ObjectArray<mirror::Object>* obj_array = sirt_obj->AsObjectArray<mirror::Object>();
483        mirror::Object* value = obj_array->Get(i);
484        if (value != nullptr) {
485          WalkFieldsInOrder(value);
486        }
487      }
488    }
489  }
490}
491
492void ImageWriter::WalkFieldsCallback(mirror::Object* obj, void* arg) {
493  ImageWriter* writer = reinterpret_cast<ImageWriter*>(arg);
494  DCHECK(writer != nullptr);
495  writer->WalkFieldsInOrder(obj);
496}
497
498void ImageWriter::CalculateNewObjectOffsets(size_t oat_loaded_size, size_t oat_data_offset) {
499  CHECK_NE(0U, oat_loaded_size);
500  Thread* self = Thread::Current();
501  SirtRef<ObjectArray<Object> > image_roots(self, CreateImageRoots());
502
503  gc::Heap* heap = Runtime::Current()->GetHeap();
504  DCHECK_EQ(0U, image_end_);
505
506  // Leave space for the header, but do not write it yet, we need to
507  // know where image_roots is going to end up
508  image_end_ += RoundUp(sizeof(ImageHeader), 8);  // 64-bit-alignment
509
510  {
511    WriterMutexLock mu(self, *Locks::heap_bitmap_lock_);
512    // TODO: Image spaces only?
513    const char* old = self->StartAssertNoThreadSuspension("ImageWriter");
514    DCHECK_LT(image_end_, image_->Size());
515    // Clear any pre-existing monitors which may have been in the monitor words.
516    heap->VisitObjects(WalkFieldsCallback, this);
517    self->EndAssertNoThreadSuspension(old);
518  }
519
520  const byte* oat_file_begin = image_begin_ + RoundUp(image_end_, kPageSize);
521  const byte* oat_file_end = oat_file_begin + oat_loaded_size;
522  oat_data_begin_ = oat_file_begin + oat_data_offset;
523  const byte* oat_data_end = oat_data_begin_ + oat_file_->Size();
524
525  // Return to write header at start of image with future location of image_roots. At this point,
526  // image_end_ is the size of the image (excluding bitmaps).
527  const size_t heap_bytes_per_bitmap_byte = kBitsPerByte * gc::accounting::SpaceBitmap::kAlignment;
528  const size_t bitmap_bytes = RoundUp(image_end_, heap_bytes_per_bitmap_byte) /
529      heap_bytes_per_bitmap_byte;
530  ImageHeader image_header(PointerToLowMemUInt32(image_begin_),
531                           static_cast<uint32_t>(image_end_),
532                           RoundUp(image_end_, kPageSize),
533                           RoundUp(bitmap_bytes, kPageSize),
534                           PointerToLowMemUInt32(GetImageAddress(image_roots.get())),
535                           oat_file_->GetOatHeader().GetChecksum(),
536                           PointerToLowMemUInt32(oat_file_begin),
537                           PointerToLowMemUInt32(oat_data_begin_),
538                           PointerToLowMemUInt32(oat_data_end),
539                           PointerToLowMemUInt32(oat_file_end));
540  memcpy(image_->Begin(), &image_header, sizeof(image_header));
541
542  // Note that image_end_ is left at end of used space
543}
544
545void ImageWriter::CopyAndFixupObjects()
546    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
547  Thread* self = Thread::Current();
548  const char* old_cause = self->StartAssertNoThreadSuspension("ImageWriter");
549  gc::Heap* heap = Runtime::Current()->GetHeap();
550  // TODO: heap validation can't handle this fix up pass
551  heap->DisableObjectValidation();
552  // TODO: Image spaces only?
553  WriterMutexLock mu(self, *Locks::heap_bitmap_lock_);
554  heap->VisitObjects(CopyAndFixupObjectsCallback, this);
555  // Fix up the object previously had hash codes.
556  for (const std::pair<mirror::Object*, uint32_t>& hash_pair : saved_hashes_) {
557    hash_pair.first->SetLockWord(LockWord::FromHashCode(hash_pair.second));
558  }
559  saved_hashes_.clear();
560  self->EndAssertNoThreadSuspension(old_cause);
561}
562
563void ImageWriter::CopyAndFixupObjectsCallback(Object* obj, void* arg) {
564  DCHECK(obj != NULL);
565  DCHECK(arg != NULL);
566  ImageWriter* image_writer = reinterpret_cast<ImageWriter*>(arg);
567  // see GetLocalAddress for similar computation
568  size_t offset = image_writer->GetImageOffset(obj);
569  byte* dst = image_writer->image_->Begin() + offset;
570  const byte* src = reinterpret_cast<const byte*>(obj);
571  size_t n = obj->SizeOf();
572  DCHECK_LT(offset + n, image_writer->image_->Size());
573  memcpy(dst, src, n);
574  Object* copy = reinterpret_cast<Object*>(dst);
575  // Write in a hash code of objects which have inflated monitors or a hash code in their monitor
576  // word.
577  copy->SetLockWord(LockWord());
578  image_writer->FixupObject(obj, copy);
579}
580
581void ImageWriter::FixupObject(Object* orig, Object* copy) {
582  DCHECK(orig != NULL);
583  DCHECK(copy != NULL);
584  copy->SetClass(down_cast<Class*>(GetImageAddress(orig->GetClass())));
585  // TODO: special case init of pointers to malloc data (or removal of these pointers)
586  if (orig->IsClass()) {
587    FixupClass(orig->AsClass(), down_cast<Class*>(copy));
588  } else if (orig->IsObjectArray()) {
589    FixupObjectArray(orig->AsObjectArray<Object>(), down_cast<ObjectArray<Object>*>(copy));
590  } else if (orig->IsArtMethod()) {
591    FixupMethod(orig->AsArtMethod(), down_cast<ArtMethod*>(copy));
592  } else {
593    FixupInstanceFields(orig, copy);
594  }
595}
596
597void ImageWriter::FixupClass(Class* orig, Class* copy) {
598  FixupInstanceFields(orig, copy);
599  FixupStaticFields(orig, copy);
600}
601
602void ImageWriter::FixupMethod(ArtMethod* orig, ArtMethod* copy) {
603  FixupInstanceFields(orig, copy);
604
605  // OatWriter replaces the code_ with an offset value. Here we re-adjust to a pointer relative to
606  // oat_begin_
607
608  // The resolution method has a special trampoline to call.
609  if (UNLIKELY(orig == Runtime::Current()->GetResolutionMethod())) {
610    copy->SetEntryPointFromPortableCompiledCode(GetOatAddress(portable_resolution_trampoline_offset_));
611    copy->SetEntryPointFromQuickCompiledCode(GetOatAddress(quick_resolution_trampoline_offset_));
612  } else if (UNLIKELY(orig == Runtime::Current()->GetImtConflictMethod())) {
613    copy->SetEntryPointFromPortableCompiledCode(GetOatAddress(portable_imt_conflict_trampoline_offset_));
614    copy->SetEntryPointFromQuickCompiledCode(GetOatAddress(quick_imt_conflict_trampoline_offset_));
615  } else {
616    // We assume all methods have code. If they don't currently then we set them to the use the
617    // resolution trampoline. Abstract methods never have code and so we need to make sure their
618    // use results in an AbstractMethodError. We use the interpreter to achieve this.
619    if (UNLIKELY(orig->IsAbstract())) {
620      copy->SetEntryPointFromPortableCompiledCode(GetOatAddress(portable_to_interpreter_bridge_offset_));
621      copy->SetEntryPointFromQuickCompiledCode(GetOatAddress(quick_to_interpreter_bridge_offset_));
622      copy->SetEntryPointFromInterpreter(reinterpret_cast<EntryPointFromInterpreter*>
623          (const_cast<byte*>(GetOatAddress(interpreter_to_interpreter_bridge_offset_))));
624    } else {
625      copy->SetEntryPointFromInterpreter(reinterpret_cast<EntryPointFromInterpreter*>
626          (const_cast<byte*>(GetOatAddress(interpreter_to_compiled_code_bridge_offset_))));
627      // Use original code if it exists. Otherwise, set the code pointer to the resolution
628      // trampoline.
629      const byte* quick_code = GetOatAddress(orig->GetQuickOatCodeOffset());
630      if (quick_code != nullptr) {
631        copy->SetEntryPointFromQuickCompiledCode(quick_code);
632      } else {
633        copy->SetEntryPointFromQuickCompiledCode(GetOatAddress(quick_resolution_trampoline_offset_));
634      }
635      const byte* portable_code = GetOatAddress(orig->GetPortableOatCodeOffset());
636      if (portable_code != nullptr) {
637        copy->SetEntryPointFromPortableCompiledCode(portable_code);
638      } else {
639        copy->SetEntryPointFromPortableCompiledCode(GetOatAddress(portable_resolution_trampoline_offset_));
640      }
641      if (orig->IsNative()) {
642        // The native method's pointer is set to a stub to lookup via dlsym.
643        // Note this is not the code_ pointer, that is handled above.
644        copy->SetNativeMethod(GetOatAddress(jni_dlsym_lookup_offset_));
645      } else {
646        // Normal (non-abstract non-native) methods have various tables to relocate.
647        uint32_t mapping_table_off = orig->GetOatMappingTableOffset();
648        const byte* mapping_table = GetOatAddress(mapping_table_off);
649        copy->SetMappingTable(mapping_table);
650
651        uint32_t vmap_table_offset = orig->GetOatVmapTableOffset();
652        const byte* vmap_table = GetOatAddress(vmap_table_offset);
653        copy->SetVmapTable(vmap_table);
654
655        uint32_t native_gc_map_offset = orig->GetOatNativeGcMapOffset();
656        const byte* native_gc_map = GetOatAddress(native_gc_map_offset);
657        copy->SetNativeGcMap(reinterpret_cast<const uint8_t*>(native_gc_map));
658      }
659    }
660  }
661}
662
663void ImageWriter::FixupObjectArray(ObjectArray<Object>* orig, ObjectArray<Object>* copy) {
664  for (int32_t i = 0; i < orig->GetLength(); ++i) {
665    Object* element = orig->Get(i);
666    copy->SetWithoutChecksAndWriteBarrier(i, GetImageAddress(element));
667  }
668}
669
670void ImageWriter::FixupInstanceFields(Object* orig, Object* copy) {
671  DCHECK(orig != NULL);
672  DCHECK(copy != NULL);
673  Class* klass = orig->GetClass();
674  DCHECK(klass != NULL);
675  FixupFields(orig, copy, klass->GetReferenceInstanceOffsets(), false);
676}
677
678void ImageWriter::FixupStaticFields(Class* orig, Class* copy) {
679  DCHECK(orig != NULL);
680  DCHECK(copy != NULL);
681  FixupFields(orig, copy, orig->GetReferenceStaticOffsets(), true);
682}
683
684void ImageWriter::FixupFields(Object* orig,
685                              Object* copy,
686                              uint32_t ref_offsets,
687                              bool is_static) {
688  if (ref_offsets != CLASS_WALK_SUPER) {
689    // Found a reference offset bitmap.  Fixup the specified offsets.
690    while (ref_offsets != 0) {
691      size_t right_shift = CLZ(ref_offsets);
692      MemberOffset byte_offset = CLASS_OFFSET_FROM_CLZ(right_shift);
693      Object* ref = orig->GetFieldObject<Object>(byte_offset, false);
694      // Use SetFieldObjectWithoutWriteBarrier to avoid card marking since we are writing to the
695      // image.
696      copy->SetFieldObjectWithoutWriteBarrier(byte_offset, GetImageAddress(ref), false);
697      ref_offsets &= ~(CLASS_HIGH_BIT >> right_shift);
698    }
699  } else {
700    // There is no reference offset bitmap.  In the non-static case,
701    // walk up the class inheritance hierarchy and find reference
702    // offsets the hard way. In the static case, just consider this
703    // class.
704    for (Class *klass = is_static ? orig->AsClass() : orig->GetClass();
705         klass != NULL;
706         klass = is_static ? NULL : klass->GetSuperClass()) {
707      size_t num_reference_fields = (is_static
708                                     ? klass->NumReferenceStaticFields()
709                                     : klass->NumReferenceInstanceFields());
710      for (size_t i = 0; i < num_reference_fields; ++i) {
711        ArtField* field = (is_static
712                           ? klass->GetStaticField(i)
713                           : klass->GetInstanceField(i));
714        MemberOffset field_offset = field->GetOffset();
715        Object* ref = orig->GetFieldObject<Object>(field_offset, false);
716        // Use SetFieldObjectWithoutWriteBarrier to avoid card marking since we are writing to the
717        // image.
718        copy->SetFieldObjectWithoutWriteBarrier(field_offset, GetImageAddress(ref), false);
719      }
720    }
721  }
722  if (!is_static && orig->IsReferenceInstance()) {
723    // Fix-up referent, that isn't marked as an object field, for References.
724    ArtField* field = orig->GetClass()->FindInstanceField("referent", "Ljava/lang/Object;");
725    MemberOffset field_offset = field->GetOffset();
726    Object* ref = orig->GetFieldObject<Object>(field_offset, false);
727    // Use SetFieldObjectWithoutWriteBarrier to avoid card marking since we are writing to the
728    // image.
729    copy->SetFieldObjectWithoutWriteBarrier(field_offset, GetImageAddress(ref), false);
730  }
731}
732
733static ArtMethod* GetTargetMethod(const CompilerDriver::CallPatchInformation* patch)
734    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
735  ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
736  Thread* self = Thread::Current();
737  SirtRef<mirror::DexCache> dex_cache(self, class_linker->FindDexCache(patch->GetDexFile()));
738  SirtRef<mirror::ClassLoader> class_loader(self, nullptr);
739  ArtMethod* method = class_linker->ResolveMethod(patch->GetDexFile(),
740                                                  patch->GetTargetMethodIdx(),
741                                                  dex_cache,
742                                                  class_loader,
743                                                  NULL,
744                                                  patch->GetTargetInvokeType());
745  CHECK(method != NULL)
746    << patch->GetDexFile().GetLocation() << " " << patch->GetTargetMethodIdx();
747  CHECK(!method->IsRuntimeMethod())
748    << patch->GetDexFile().GetLocation() << " " << patch->GetTargetMethodIdx();
749  CHECK(dex_cache->GetResolvedMethods()->Get(patch->GetTargetMethodIdx()) == method)
750    << patch->GetDexFile().GetLocation() << " " << patch->GetReferrerMethodIdx() << " "
751    << PrettyMethod(dex_cache->GetResolvedMethods()->Get(patch->GetTargetMethodIdx())) << " "
752    << PrettyMethod(method);
753  return method;
754}
755
756static Class* GetTargetType(const CompilerDriver::TypePatchInformation* 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  Class* klass = class_linker->ResolveType(patch->GetDexFile(),
763                                           patch->GetTargetTypeIdx(),
764                                           dex_cache,
765                                           class_loader);
766  CHECK(klass != NULL)
767    << patch->GetDexFile().GetLocation() << " " << patch->GetTargetTypeIdx();
768  CHECK(dex_cache->GetResolvedTypes()->Get(patch->GetTargetTypeIdx()) == klass)
769    << patch->GetDexFile().GetLocation() << " " << patch->GetReferrerMethodIdx() << " "
770    << PrettyClass(dex_cache->GetResolvedTypes()->Get(patch->GetTargetTypeIdx())) << " "
771    << PrettyClass(klass);
772  return klass;
773}
774
775void ImageWriter::PatchOatCodeAndMethods() {
776  Thread* self = Thread::Current();
777  ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
778  const char* old_cause = self->StartAssertNoThreadSuspension("ImageWriter");
779
780  typedef std::vector<const CompilerDriver::CallPatchInformation*> CallPatches;
781  const CallPatches& code_to_patch = compiler_driver_.GetCodeToPatch();
782  for (size_t i = 0; i < code_to_patch.size(); i++) {
783    const CompilerDriver::CallPatchInformation* patch = code_to_patch[i];
784    ArtMethod* target = GetTargetMethod(patch);
785    uintptr_t quick_code = reinterpret_cast<uintptr_t>(class_linker->GetQuickOatCodeFor(target));
786    uintptr_t code_base = reinterpret_cast<uintptr_t>(&oat_file_->GetOatHeader());
787    uintptr_t code_offset = quick_code - code_base;
788    SetPatchLocation(patch, PointerToLowMemUInt32(GetOatAddress(code_offset)));
789  }
790
791  const CallPatches& methods_to_patch = compiler_driver_.GetMethodsToPatch();
792  for (size_t i = 0; i < methods_to_patch.size(); i++) {
793    const CompilerDriver::CallPatchInformation* patch = methods_to_patch[i];
794    ArtMethod* target = GetTargetMethod(patch);
795    SetPatchLocation(patch, PointerToLowMemUInt32(GetImageAddress(target)));
796  }
797
798  const std::vector<const CompilerDriver::TypePatchInformation*>& classes_to_patch =
799      compiler_driver_.GetClassesToPatch();
800  for (size_t i = 0; i < classes_to_patch.size(); i++) {
801    const CompilerDriver::TypePatchInformation* patch = classes_to_patch[i];
802    Class* target = GetTargetType(patch);
803    SetPatchLocation(patch, PointerToLowMemUInt32(GetImageAddress(target)));
804  }
805
806  // Update the image header with the new checksum after patching
807  ImageHeader* image_header = reinterpret_cast<ImageHeader*>(image_->Begin());
808  image_header->SetOatChecksum(oat_file_->GetOatHeader().GetChecksum());
809  self->EndAssertNoThreadSuspension(old_cause);
810}
811
812void ImageWriter::SetPatchLocation(const CompilerDriver::PatchInformation* patch, uint32_t value) {
813  ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
814  const void* quick_oat_code = class_linker->GetQuickOatCodeFor(patch->GetDexFile(),
815                                                                patch->GetReferrerClassDefIdx(),
816                                                                patch->GetReferrerMethodIdx());
817  OatHeader& oat_header = const_cast<OatHeader&>(oat_file_->GetOatHeader());
818  // TODO: make this Thumb2 specific
819  uint8_t* base = reinterpret_cast<uint8_t*>(reinterpret_cast<uintptr_t>(quick_oat_code) & ~0x1);
820  uint32_t* patch_location = reinterpret_cast<uint32_t*>(base + patch->GetLiteralOffset());
821  if (kIsDebugBuild) {
822    if (patch->IsCall()) {
823      const CompilerDriver::CallPatchInformation* cpatch = patch->AsCall();
824      const DexFile::MethodId& id = cpatch->GetDexFile().GetMethodId(cpatch->GetTargetMethodIdx());
825      uintptr_t expected = reinterpret_cast<uintptr_t>(&id);
826      uint32_t actual = *patch_location;
827      CHECK(actual == expected || actual == value) << std::hex
828          << "actual=" << actual
829          << "expected=" << expected
830          << "value=" << value;
831    }
832    if (patch->IsType()) {
833      const CompilerDriver::TypePatchInformation* tpatch = patch->AsType();
834      const DexFile::TypeId& id = tpatch->GetDexFile().GetTypeId(tpatch->GetTargetTypeIdx());
835      uintptr_t expected = reinterpret_cast<uintptr_t>(&id);
836      uint32_t actual = *patch_location;
837      CHECK(actual == expected || actual == value) << std::hex
838          << "actual=" << actual
839          << "expected=" << expected
840          << "value=" << value;
841    }
842  }
843  *patch_location = value;
844  oat_header.UpdateChecksum(patch_location, sizeof(value));
845}
846
847}  // namespace art
848