image_writer.cc revision 7d791a4df0ac5d242c800e60d5151a7a370e9e95 
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 <memory>
22#include <vector>
23
24#include "base/logging.h"
25#include "base/unix_file/fd_file.h"
26#include "class_linker.h"
27#include "compiled_method.h"
28#include "dex_file-inl.h"
29#include "driver/compiler_driver.h"
30#include "elf_writer.h"
31#include "gc/accounting/card_table-inl.h"
32#include "gc/accounting/heap_bitmap.h"
33#include "gc/accounting/space_bitmap-inl.h"
34#include "gc/heap.h"
35#include "gc/space/large_object_space.h"
36#include "gc/space/space-inl.h"
37#include "globals.h"
38#include "image.h"
39#include "intern_table.h"
40#include "lock_word.h"
41#include "mirror/art_field-inl.h"
42#include "mirror/art_method-inl.h"
43#include "mirror/array-inl.h"
44#include "mirror/class-inl.h"
45#include "mirror/class_loader.h"
46#include "mirror/dex_cache-inl.h"
47#include "mirror/object-inl.h"
48#include "mirror/object_array-inl.h"
49#include "mirror/string-inl.h"
50#include "oat.h"
51#include "oat_file.h"
52#include "object_utils.h"
53#include "runtime.h"
54#include "scoped_thread_state_change.h"
55#include "handle_scope-inl.h"
56#include "utils.h"
57
58using ::art::mirror::ArtField;
59using ::art::mirror::ArtMethod;
60using ::art::mirror::Class;
61using ::art::mirror::DexCache;
62using ::art::mirror::EntryPointFromInterpreter;
63using ::art::mirror::Object;
64using ::art::mirror::ObjectArray;
65using ::art::mirror::String;
66
67namespace art {
68
69bool ImageWriter::Write(const std::string& image_filename,
70                        uintptr_t image_begin,
71                        const std::string& oat_filename,
72                        const std::string& oat_location) {
73  CHECK(!image_filename.empty());
74
75  CHECK_NE(image_begin, 0U);
76  image_begin_ = reinterpret_cast<byte*>(image_begin);
77
78  ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
79
80  std::unique_ptr<File> oat_file(OS::OpenFileReadWrite(oat_filename.c_str()));
81  if (oat_file.get() == NULL) {
82    LOG(ERROR) << "Failed to open oat file " << oat_filename << " for " << oat_location;
83    return false;
84  }
85  std::string error_msg;
86  oat_file_ = OatFile::OpenWritable(oat_file.get(), oat_location, &error_msg);
87  if (oat_file_ == nullptr) {
88    LOG(ERROR) << "Failed to open writable oat file " << oat_filename << " for " << oat_location
89        << ": " << error_msg;
90    return false;
91  }
92  CHECK_EQ(class_linker->RegisterOatFile(oat_file_), oat_file_);
93
94  interpreter_to_interpreter_bridge_offset_ =
95      oat_file_->GetOatHeader().GetInterpreterToInterpreterBridgeOffset();
96  interpreter_to_compiled_code_bridge_offset_ =
97      oat_file_->GetOatHeader().GetInterpreterToCompiledCodeBridgeOffset();
98
99  jni_dlsym_lookup_offset_ = oat_file_->GetOatHeader().GetJniDlsymLookupOffset();
100
101  portable_imt_conflict_trampoline_offset_ =
102      oat_file_->GetOatHeader().GetPortableImtConflictTrampolineOffset();
103  portable_resolution_trampoline_offset_ =
104      oat_file_->GetOatHeader().GetPortableResolutionTrampolineOffset();
105  portable_to_interpreter_bridge_offset_ =
106      oat_file_->GetOatHeader().GetPortableToInterpreterBridgeOffset();
107
108  quick_generic_jni_trampoline_offset_ =
109      oat_file_->GetOatHeader().GetQuickGenericJniTrampolineOffset();
110  quick_imt_conflict_trampoline_offset_ =
111      oat_file_->GetOatHeader().GetQuickImtConflictTrampolineOffset();
112  quick_resolution_trampoline_offset_ =
113      oat_file_->GetOatHeader().GetQuickResolutionTrampolineOffset();
114  quick_to_interpreter_bridge_offset_ =
115      oat_file_->GetOatHeader().GetQuickToInterpreterBridgeOffset();
116  {
117    Thread::Current()->TransitionFromSuspendedToRunnable();
118    PruneNonImageClasses();  // Remove junk
119    ComputeLazyFieldsForImageClasses();  // Add useful information
120    ComputeEagerResolvedStrings();
121    Thread::Current()->TransitionFromRunnableToSuspended(kNative);
122  }
123  gc::Heap* heap = Runtime::Current()->GetHeap();
124  heap->CollectGarbage(false);  // Remove garbage.
125
126  if (!AllocMemory()) {
127    return false;
128  }
129
130  if (kIsDebugBuild) {
131    ScopedObjectAccess soa(Thread::Current());
132    CheckNonImageClassesRemoved();
133  }
134
135  Thread::Current()->TransitionFromSuspendedToRunnable();
136  size_t oat_loaded_size = 0;
137  size_t oat_data_offset = 0;
138  ElfWriter::GetOatElfInformation(oat_file.get(), oat_loaded_size, oat_data_offset);
139  CalculateNewObjectOffsets(oat_loaded_size, oat_data_offset);
140  CopyAndFixupObjects();
141  PatchOatCodeAndMethods();
142  Thread::Current()->TransitionFromRunnableToSuspended(kNative);
143
144  std::unique_ptr<File> image_file(OS::CreateEmptyFile(image_filename.c_str()));
145  ImageHeader* image_header = reinterpret_cast<ImageHeader*>(image_->Begin());
146  if (image_file.get() == NULL) {
147    LOG(ERROR) << "Failed to open image file " << image_filename;
148    return false;
149  }
150  if (fchmod(image_file->Fd(), 0644) != 0) {
151    PLOG(ERROR) << "Failed to make image file world readable: " << image_filename;
152    return EXIT_FAILURE;
153  }
154
155  // Write out the image.
156  CHECK_EQ(image_end_, image_header->GetImageSize());
157  if (!image_file->WriteFully(image_->Begin(), image_end_)) {
158    PLOG(ERROR) << "Failed to write image file " << image_filename;
159    return false;
160  }
161
162  // Write out the image bitmap at the page aligned start of the image end.
163  CHECK_ALIGNED(image_header->GetImageBitmapOffset(), kPageSize);
164  if (!image_file->Write(reinterpret_cast<char*>(image_bitmap_->Begin()),
165                         image_header->GetImageBitmapSize(),
166                         image_header->GetImageBitmapOffset())) {
167    PLOG(ERROR) << "Failed to write image file " << image_filename;
168    return false;
169  }
170
171  return true;
172}
173
174void ImageWriter::SetImageOffset(mirror::Object* object, size_t offset) {
175  DCHECK(object != nullptr);
176  DCHECK_NE(offset, 0U);
177  DCHECK(!IsImageOffsetAssigned(object));
178  mirror::Object* obj = reinterpret_cast<mirror::Object*>(image_->Begin() + offset);
179  DCHECK_ALIGNED(obj, kObjectAlignment);
180  image_bitmap_->Set(obj);
181  // Before we stomp over the lock word, save the hash code for later.
182  Monitor::Deflate(Thread::Current(), object);;
183  LockWord lw(object->GetLockWord(false));
184  switch (lw.GetState()) {
185    case LockWord::kFatLocked: {
186      LOG(FATAL) << "Fat locked object " << obj << " found during object copy";
187      break;
188    }
189    case LockWord::kThinLocked: {
190      LOG(FATAL) << "Thin locked object " << obj << " found during object copy";
191      break;
192    }
193    case LockWord::kUnlocked:
194      // No hash, don't need to save it.
195      break;
196    case LockWord::kHashCode:
197      saved_hashes_.push_back(std::make_pair(obj, lw.GetHashCode()));
198      break;
199    default:
200      LOG(FATAL) << "Unreachable.";
201      break;
202  }
203  object->SetLockWord(LockWord::FromForwardingAddress(offset), false);
204  DCHECK(IsImageOffsetAssigned(object));
205}
206
207void ImageWriter::AssignImageOffset(mirror::Object* object) {
208  DCHECK(object != nullptr);
209  SetImageOffset(object, image_end_);
210  image_end_ += RoundUp(object->SizeOf(), 8);  // 64-bit alignment
211  DCHECK_LT(image_end_, image_->Size());
212}
213
214bool ImageWriter::IsImageOffsetAssigned(mirror::Object* object) const {
215  DCHECK(object != nullptr);
216  return object->GetLockWord(false).GetState() == LockWord::kForwardingAddress;
217}
218
219size_t ImageWriter::GetImageOffset(mirror::Object* object) const {
220  DCHECK(object != nullptr);
221  DCHECK(IsImageOffsetAssigned(object));
222  LockWord lock_word = object->GetLockWord(false);
223  size_t offset = lock_word.ForwardingAddress();
224  DCHECK_LT(offset, image_end_);
225  return offset;
226}
227
228bool ImageWriter::AllocMemory() {
229  size_t length = RoundUp(Runtime::Current()->GetHeap()->GetTotalMemory(), kPageSize);
230  std::string error_msg;
231  image_.reset(MemMap::MapAnonymous("image writer image", NULL, length, PROT_READ | PROT_WRITE,
232                                    true, &error_msg));
233  if (UNLIKELY(image_.get() == nullptr)) {
234    LOG(ERROR) << "Failed to allocate memory for image file generation: " << error_msg;
235    return false;
236  }
237
238  // Create the image bitmap.
239  image_bitmap_.reset(gc::accounting::ContinuousSpaceBitmap::Create("image bitmap", image_->Begin(),
240                                                                    length));
241  if (image_bitmap_.get() == nullptr) {
242    LOG(ERROR) << "Failed to allocate memory for image bitmap";
243    return false;
244  }
245  return true;
246}
247
248void ImageWriter::ComputeLazyFieldsForImageClasses() {
249  ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
250  class_linker->VisitClassesWithoutClassesLock(ComputeLazyFieldsForClassesVisitor, NULL);
251}
252
253bool ImageWriter::ComputeLazyFieldsForClassesVisitor(Class* c, void* /*arg*/) {
254  Thread* self = Thread::Current();
255  StackHandleScope<1> hs(self);
256  mirror::Class::ComputeName(hs.NewHandle(c));
257  return true;
258}
259
260void ImageWriter::ComputeEagerResolvedStringsCallback(Object* obj, void* arg) {
261  if (!obj->GetClass()->IsStringClass()) {
262    return;
263  }
264  mirror::String* string = obj->AsString();
265  const uint16_t* utf16_string = string->GetCharArray()->GetData() + string->GetOffset();
266  for (DexCache* dex_cache : Runtime::Current()->GetClassLinker()->GetDexCaches()) {
267    const DexFile& dex_file = *dex_cache->GetDexFile();
268    const DexFile::StringId* string_id;
269    if (UNLIKELY(string->GetLength() == 0)) {
270      string_id = dex_file.FindStringId("");
271    } else {
272      string_id = dex_file.FindStringId(utf16_string);
273    }
274    if (string_id != nullptr) {
275      // This string occurs in this dex file, assign the dex cache entry.
276      uint32_t string_idx = dex_file.GetIndexForStringId(*string_id);
277      if (dex_cache->GetResolvedString(string_idx) == NULL) {
278        dex_cache->SetResolvedString(string_idx, string);
279      }
280    }
281  }
282}
283
284void ImageWriter::ComputeEagerResolvedStrings() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
285  ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_);
286  Runtime::Current()->GetHeap()->VisitObjects(ComputeEagerResolvedStringsCallback, this);
287}
288
289bool ImageWriter::IsImageClass(Class* klass) {
290  return compiler_driver_.IsImageClass(klass->GetDescriptor().c_str());
291}
292
293struct NonImageClasses {
294  ImageWriter* image_writer;
295  std::set<std::string>* non_image_classes;
296};
297
298void ImageWriter::PruneNonImageClasses() {
299  if (compiler_driver_.GetImageClasses() == NULL) {
300    return;
301  }
302  Runtime* runtime = Runtime::Current();
303  ClassLinker* class_linker = runtime->GetClassLinker();
304
305  // Make a list of classes we would like to prune.
306  std::set<std::string> non_image_classes;
307  NonImageClasses context;
308  context.image_writer = this;
309  context.non_image_classes = &non_image_classes;
310  class_linker->VisitClasses(NonImageClassesVisitor, &context);
311
312  // Remove the undesired classes from the class roots.
313  for (const std::string& it : non_image_classes) {
314    class_linker->RemoveClass(it.c_str(), NULL);
315  }
316
317  // Clear references to removed classes from the DexCaches.
318  ArtMethod* resolution_method = runtime->GetResolutionMethod();
319  for (DexCache* dex_cache : class_linker->GetDexCaches()) {
320    for (size_t i = 0; i < dex_cache->NumResolvedTypes(); i++) {
321      Class* klass = dex_cache->GetResolvedType(i);
322      if (klass != NULL && !IsImageClass(klass)) {
323        dex_cache->SetResolvedType(i, NULL);
324      }
325    }
326    for (size_t i = 0; i < dex_cache->NumResolvedMethods(); i++) {
327      ArtMethod* method = dex_cache->GetResolvedMethod(i);
328      if (method != NULL && !IsImageClass(method->GetDeclaringClass())) {
329        dex_cache->SetResolvedMethod(i, resolution_method);
330      }
331    }
332    for (size_t i = 0; i < dex_cache->NumResolvedFields(); i++) {
333      ArtField* field = dex_cache->GetResolvedField(i);
334      if (field != NULL && !IsImageClass(field->GetDeclaringClass())) {
335        dex_cache->SetResolvedField(i, NULL);
336      }
337    }
338  }
339}
340
341bool ImageWriter::NonImageClassesVisitor(Class* klass, void* arg) {
342  NonImageClasses* context = reinterpret_cast<NonImageClasses*>(arg);
343  if (!context->image_writer->IsImageClass(klass)) {
344    context->non_image_classes->insert(klass->GetDescriptor());
345  }
346  return true;
347}
348
349void ImageWriter::CheckNonImageClassesRemoved()
350    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
351  if (compiler_driver_.GetImageClasses() != nullptr) {
352    gc::Heap* heap = Runtime::Current()->GetHeap();
353    ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_);
354    heap->VisitObjects(CheckNonImageClassesRemovedCallback, this);
355  }
356}
357
358void ImageWriter::CheckNonImageClassesRemovedCallback(Object* obj, void* arg) {
359  ImageWriter* image_writer = reinterpret_cast<ImageWriter*>(arg);
360  if (obj->IsClass()) {
361    Class* klass = obj->AsClass();
362    if (!image_writer->IsImageClass(klass)) {
363      image_writer->DumpImageClasses();
364      CHECK(image_writer->IsImageClass(klass)) << klass->GetDescriptor()
365                                               << " " << PrettyDescriptor(klass);
366    }
367  }
368}
369
370void ImageWriter::DumpImageClasses() {
371  CompilerDriver::DescriptorSet* image_classes = compiler_driver_.GetImageClasses();
372  CHECK(image_classes != NULL);
373  for (const std::string& image_class : *image_classes) {
374    LOG(INFO) << " " << image_class;
375  }
376}
377
378void ImageWriter::CalculateObjectOffsets(Object* obj) {
379  DCHECK(obj != NULL);
380  // if it is a string, we want to intern it if its not interned.
381  if (obj->GetClass()->IsStringClass()) {
382    // we must be an interned string that was forward referenced and already assigned
383    if (IsImageOffsetAssigned(obj)) {
384      DCHECK_EQ(obj, obj->AsString()->Intern());
385      return;
386    }
387    mirror::String* const interned = obj->AsString()->Intern();
388    if (obj != interned) {
389      if (!IsImageOffsetAssigned(interned)) {
390        // interned obj is after us, allocate its location early
391        AssignImageOffset(interned);
392      }
393      // point those looking for this object to the interned version.
394      SetImageOffset(obj, GetImageOffset(interned));
395      return;
396    }
397    // else (obj == interned), nothing to do but fall through to the normal case
398  }
399
400  AssignImageOffset(obj);
401}
402
403ObjectArray<Object>* ImageWriter::CreateImageRoots() const {
404  Runtime* runtime = Runtime::Current();
405  ClassLinker* class_linker = runtime->GetClassLinker();
406  Thread* self = Thread::Current();
407  StackHandleScope<3> hs(self);
408  Handle<Class> object_array_class(hs.NewHandle(
409      class_linker->FindSystemClass(self, "[Ljava/lang/Object;")));
410
411  // build an Object[] of all the DexCaches used in the source_space_
412  Handle<ObjectArray<Object>> dex_caches(
413      hs.NewHandle(ObjectArray<Object>::Alloc(self, object_array_class.Get(),
414                                              class_linker->GetDexCaches().size())));
415  int i = 0;
416  for (DexCache* dex_cache : class_linker->GetDexCaches()) {
417    dex_caches->Set<false>(i++, dex_cache);
418  }
419
420  // build an Object[] of the roots needed to restore the runtime
421  Handle<ObjectArray<Object>> image_roots(hs.NewHandle(
422      ObjectArray<Object>::Alloc(self, object_array_class.Get(), ImageHeader::kImageRootsMax)));
423  image_roots->Set<false>(ImageHeader::kResolutionMethod, runtime->GetResolutionMethod());
424  image_roots->Set<false>(ImageHeader::kImtConflictMethod, runtime->GetImtConflictMethod());
425  image_roots->Set<false>(ImageHeader::kDefaultImt, runtime->GetDefaultImt());
426  image_roots->Set<false>(ImageHeader::kCalleeSaveMethod,
427                          runtime->GetCalleeSaveMethod(Runtime::kSaveAll));
428  image_roots->Set<false>(ImageHeader::kRefsOnlySaveMethod,
429                          runtime->GetCalleeSaveMethod(Runtime::kRefsOnly));
430  image_roots->Set<false>(ImageHeader::kRefsAndArgsSaveMethod,
431                          runtime->GetCalleeSaveMethod(Runtime::kRefsAndArgs));
432  image_roots->Set<false>(ImageHeader::kDexCaches, dex_caches.Get());
433  image_roots->Set<false>(ImageHeader::kClassRoots, class_linker->GetClassRoots());
434  for (int i = 0; i < ImageHeader::kImageRootsMax; i++) {
435    CHECK(image_roots->Get(i) != NULL);
436  }
437  return image_roots.Get();
438}
439
440// Walk instance fields of the given Class. Separate function to allow recursion on the super
441// class.
442void ImageWriter::WalkInstanceFields(mirror::Object* obj, mirror::Class* klass) {
443  // Visit fields of parent classes first.
444  StackHandleScope<1> hs(Thread::Current());
445  Handle<mirror::Class> h_class(hs.NewHandle(klass));
446  mirror::Class* super = h_class->GetSuperClass();
447  if (super != nullptr) {
448    WalkInstanceFields(obj, super);
449  }
450  //
451  size_t num_reference_fields = h_class->NumReferenceInstanceFields();
452  for (size_t i = 0; i < num_reference_fields; ++i) {
453    mirror::ArtField* field = h_class->GetInstanceField(i);
454    MemberOffset field_offset = field->GetOffset();
455    mirror::Object* value = obj->GetFieldObject<mirror::Object>(field_offset);
456    if (value != nullptr) {
457      WalkFieldsInOrder(value);
458    }
459  }
460}
461
462// For an unvisited object, visit it then all its children found via fields.
463void ImageWriter::WalkFieldsInOrder(mirror::Object* obj) {
464  if (!IsImageOffsetAssigned(obj)) {
465    // Walk instance fields of all objects
466    StackHandleScope<2> hs(Thread::Current());
467    Handle<mirror::Object> h_obj(hs.NewHandle(obj));
468    Handle<mirror::Class> klass(hs.NewHandle(obj->GetClass()));
469    // visit the object itself.
470    CalculateObjectOffsets(h_obj.Get());
471    WalkInstanceFields(h_obj.Get(), klass.Get());
472    // Walk static fields of a Class.
473    if (h_obj->IsClass()) {
474      size_t num_static_fields = klass->NumReferenceStaticFields();
475      for (size_t i = 0; i < num_static_fields; ++i) {
476        mirror::ArtField* field = klass->GetStaticField(i);
477        MemberOffset field_offset = field->GetOffset();
478        mirror::Object* value = h_obj->GetFieldObject<mirror::Object>(field_offset);
479        if (value != nullptr) {
480          WalkFieldsInOrder(value);
481        }
482      }
483    } else if (h_obj->IsObjectArray()) {
484      // Walk elements of an object array.
485      int32_t length = h_obj->AsObjectArray<mirror::Object>()->GetLength();
486      for (int32_t i = 0; i < length; i++) {
487        mirror::ObjectArray<mirror::Object>* obj_array = h_obj->AsObjectArray<mirror::Object>();
488        mirror::Object* value = obj_array->Get(i);
489        if (value != nullptr) {
490          WalkFieldsInOrder(value);
491        }
492      }
493    }
494  }
495}
496
497void ImageWriter::WalkFieldsCallback(mirror::Object* obj, void* arg) {
498  ImageWriter* writer = reinterpret_cast<ImageWriter*>(arg);
499  DCHECK(writer != nullptr);
500  writer->WalkFieldsInOrder(obj);
501}
502
503void ImageWriter::CalculateNewObjectOffsets(size_t oat_loaded_size, size_t oat_data_offset) {
504  CHECK_NE(0U, oat_loaded_size);
505  Thread* self = Thread::Current();
506  StackHandleScope<1> hs(self);
507  Handle<ObjectArray<Object>> image_roots(hs.NewHandle(CreateImageRoots()));
508
509  gc::Heap* heap = Runtime::Current()->GetHeap();
510  DCHECK_EQ(0U, image_end_);
511
512  // Leave space for the header, but do not write it yet, we need to
513  // know where image_roots is going to end up
514  image_end_ += RoundUp(sizeof(ImageHeader), 8);  // 64-bit-alignment
515
516  {
517    WriterMutexLock mu(self, *Locks::heap_bitmap_lock_);
518    // TODO: Image spaces only?
519    const char* old = self->StartAssertNoThreadSuspension("ImageWriter");
520    DCHECK_LT(image_end_, image_->Size());
521    // Clear any pre-existing monitors which may have been in the monitor words.
522    heap->VisitObjects(WalkFieldsCallback, this);
523    self->EndAssertNoThreadSuspension(old);
524  }
525
526  const byte* oat_file_begin = image_begin_ + RoundUp(image_end_, kPageSize);
527  const byte* oat_file_end = oat_file_begin + oat_loaded_size;
528  oat_data_begin_ = oat_file_begin + oat_data_offset;
529  const byte* oat_data_end = oat_data_begin_ + oat_file_->Size();
530
531  // Return to write header at start of image with future location of image_roots. At this point,
532  // image_end_ is the size of the image (excluding bitmaps).
533  const size_t heap_bytes_per_bitmap_byte = kBitsPerByte * kObjectAlignment;
534  const size_t bitmap_bytes = RoundUp(image_end_, heap_bytes_per_bitmap_byte) /
535      heap_bytes_per_bitmap_byte;
536  ImageHeader image_header(PointerToLowMemUInt32(image_begin_),
537                           static_cast<uint32_t>(image_end_),
538                           RoundUp(image_end_, kPageSize),
539                           RoundUp(bitmap_bytes, kPageSize),
540                           PointerToLowMemUInt32(GetImageAddress(image_roots.Get())),
541                           oat_file_->GetOatHeader().GetChecksum(),
542                           PointerToLowMemUInt32(oat_file_begin),
543                           PointerToLowMemUInt32(oat_data_begin_),
544                           PointerToLowMemUInt32(oat_data_end),
545                           PointerToLowMemUInt32(oat_file_end));
546  memcpy(image_->Begin(), &image_header, sizeof(image_header));
547
548  // Note that image_end_ is left at end of used space
549}
550
551void ImageWriter::CopyAndFixupObjects()
552    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
553  Thread* self = Thread::Current();
554  const char* old_cause = self->StartAssertNoThreadSuspension("ImageWriter");
555  gc::Heap* heap = Runtime::Current()->GetHeap();
556  // TODO: heap validation can't handle this fix up pass
557  heap->DisableObjectValidation();
558  // TODO: Image spaces only?
559  WriterMutexLock mu(self, *Locks::heap_bitmap_lock_);
560  heap->VisitObjects(CopyAndFixupObjectsCallback, this);
561  // Fix up the object previously had hash codes.
562  for (const std::pair<mirror::Object*, uint32_t>& hash_pair : saved_hashes_) {
563    hash_pair.first->SetLockWord(LockWord::FromHashCode(hash_pair.second), false);
564  }
565  saved_hashes_.clear();
566  self->EndAssertNoThreadSuspension(old_cause);
567}
568
569void ImageWriter::CopyAndFixupObjectsCallback(Object* obj, void* arg) {
570  DCHECK(obj != nullptr);
571  DCHECK(arg != nullptr);
572  ImageWriter* image_writer = reinterpret_cast<ImageWriter*>(arg);
573  // see GetLocalAddress for similar computation
574  size_t offset = image_writer->GetImageOffset(obj);
575  byte* dst = image_writer->image_->Begin() + offset;
576  const byte* src = reinterpret_cast<const byte*>(obj);
577  size_t n = obj->SizeOf();
578  DCHECK_LT(offset + n, image_writer->image_->Size());
579  memcpy(dst, src, n);
580  Object* copy = reinterpret_cast<Object*>(dst);
581  // Write in a hash code of objects which have inflated monitors or a hash code in their monitor
582  // word.
583  copy->SetLockWord(LockWord(), false);
584  image_writer->FixupObject(obj, copy);
585}
586
587class FixupVisitor {
588 public:
589  FixupVisitor(ImageWriter* image_writer, Object* copy) : image_writer_(image_writer), copy_(copy) {
590  }
591
592  void operator()(Object* obj, MemberOffset offset, bool /*is_static*/) const
593      EXCLUSIVE_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) {
594    Object* ref = obj->GetFieldObject<Object, kVerifyNone>(offset);
595    // Use SetFieldObjectWithoutWriteBarrier to avoid card marking since we are writing to the
596    // image.
597    copy_->SetFieldObjectWithoutWriteBarrier<false, true, kVerifyNone>(
598        offset, image_writer_->GetImageAddress(ref));
599  }
600
601  // java.lang.ref.Reference visitor.
602  void operator()(mirror::Class* /*klass*/, mirror::Reference* ref) const
603      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_)
604      EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_) {
605    copy_->SetFieldObjectWithoutWriteBarrier<false, true, kVerifyNone>(
606        mirror::Reference::ReferentOffset(), image_writer_->GetImageAddress(ref->GetReferent()));
607  }
608
609 private:
610  ImageWriter* const image_writer_;
611  mirror::Object* const copy_;
612};
613
614void ImageWriter::FixupObject(Object* orig, Object* copy) {
615  DCHECK(orig != nullptr);
616  DCHECK(copy != nullptr);
617  if (kUseBakerOrBrooksReadBarrier) {
618    orig->AssertReadBarrierPointer();
619    if (kUseBrooksReadBarrier) {
620      // Note the address 'copy' isn't the same as the image address of 'orig'.
621      copy->SetReadBarrierPointer(GetImageAddress(orig));
622      DCHECK_EQ(copy->GetReadBarrierPointer(), GetImageAddress(orig));
623    }
624  }
625  FixupVisitor visitor(this, copy);
626  orig->VisitReferences<true /*visit class*/>(visitor, visitor);
627  if (orig->IsArtMethod<kVerifyNone>()) {
628    FixupMethod(orig->AsArtMethod<kVerifyNone>(), down_cast<ArtMethod*>(copy));
629  }
630}
631
632void ImageWriter::FixupMethod(ArtMethod* orig, ArtMethod* copy) {
633  // OatWriter replaces the code_ with an offset value. Here we re-adjust to a pointer relative to
634  // oat_begin_
635
636  // The resolution method has a special trampoline to call.
637  if (UNLIKELY(orig == Runtime::Current()->GetResolutionMethod())) {
638    copy->SetEntryPointFromPortableCompiledCode<kVerifyNone>(GetOatAddress(portable_resolution_trampoline_offset_));
639    copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(GetOatAddress(quick_resolution_trampoline_offset_));
640  } else if (UNLIKELY(orig == Runtime::Current()->GetImtConflictMethod())) {
641    copy->SetEntryPointFromPortableCompiledCode<kVerifyNone>(GetOatAddress(portable_imt_conflict_trampoline_offset_));
642    copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(GetOatAddress(quick_imt_conflict_trampoline_offset_));
643  } else {
644    // We assume all methods have code. If they don't currently then we set them to the use the
645    // resolution trampoline. Abstract methods never have code and so we need to make sure their
646    // use results in an AbstractMethodError. We use the interpreter to achieve this.
647    if (UNLIKELY(orig->IsAbstract())) {
648      copy->SetEntryPointFromPortableCompiledCode<kVerifyNone>(GetOatAddress(portable_to_interpreter_bridge_offset_));
649      copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(GetOatAddress(quick_to_interpreter_bridge_offset_));
650      copy->SetEntryPointFromInterpreter<kVerifyNone>(reinterpret_cast<EntryPointFromInterpreter*>
651          (const_cast<byte*>(GetOatAddress(interpreter_to_interpreter_bridge_offset_))));
652    } else {
653      copy->SetEntryPointFromInterpreter<kVerifyNone>(reinterpret_cast<EntryPointFromInterpreter*>
654          (const_cast<byte*>(GetOatAddress(interpreter_to_compiled_code_bridge_offset_))));
655      // Use original code if it exists. Otherwise, set the code pointer to the resolution
656      // trampoline.
657      const byte* quick_code = GetOatAddress(orig->GetQuickOatCodeOffset());
658      if (quick_code != nullptr &&
659          (!orig->IsStatic() || orig->IsConstructor() || orig->GetDeclaringClass()->IsInitialized())) {
660        // We have code for a non-static or initialized method, just use the code.
661        copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(quick_code);
662      } else if (quick_code == nullptr && orig->IsNative() &&
663          (!orig->IsStatic() || orig->GetDeclaringClass()->IsInitialized())) {
664        // Non-static or initialized native method missing compiled code, use generic JNI version.
665        copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(GetOatAddress(quick_generic_jni_trampoline_offset_));
666      } else if (quick_code == nullptr && !orig->IsNative()) {
667        // We don't have code at all for a non-native method, use the interpreter.
668        copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(GetOatAddress(quick_to_interpreter_bridge_offset_));
669      } else {
670        CHECK(!orig->GetDeclaringClass()->IsInitialized());
671        // We have code for a static method, but need to go through the resolution stub for class
672        // initialization.
673        copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(GetOatAddress(quick_resolution_trampoline_offset_));
674      }
675      const byte* portable_code = GetOatAddress(orig->GetPortableOatCodeOffset());
676      if (portable_code != nullptr) {
677        copy->SetEntryPointFromPortableCompiledCode<kVerifyNone>(portable_code);
678      } else {
679        copy->SetEntryPointFromPortableCompiledCode<kVerifyNone>(GetOatAddress(portable_resolution_trampoline_offset_));
680      }
681      if (orig->IsNative()) {
682        // The native method's pointer is set to a stub to lookup via dlsym.
683        // Note this is not the code_ pointer, that is handled above.
684        copy->SetNativeMethod<kVerifyNone>(GetOatAddress(jni_dlsym_lookup_offset_));
685      } else {
686        // Normal (non-abstract non-native) methods have various tables to relocate.
687        uint32_t native_gc_map_offset = orig->GetOatNativeGcMapOffset();
688        const byte* native_gc_map = GetOatAddress(native_gc_map_offset);
689        copy->SetNativeGcMap<kVerifyNone>(reinterpret_cast<const uint8_t*>(native_gc_map));
690      }
691    }
692  }
693}
694
695static ArtMethod* GetTargetMethod(const CompilerDriver::CallPatchInformation* patch)
696    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
697  ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
698  StackHandleScope<1> hs(Thread::Current());
699  Handle<mirror::DexCache> dex_cache(
700      hs.NewHandle(class_linker->FindDexCache(*patch->GetTargetDexFile())));
701  ArtMethod* method = class_linker->ResolveMethod(*patch->GetTargetDexFile(),
702                                                  patch->GetTargetMethodIdx(),
703                                                  dex_cache,
704                                                  NullHandle<mirror::ClassLoader>(),
705                                                  NullHandle<mirror::ArtMethod>(),
706                                                  patch->GetTargetInvokeType());
707  CHECK(method != NULL)
708    << patch->GetTargetDexFile()->GetLocation() << " " << patch->GetTargetMethodIdx();
709  CHECK(!method->IsRuntimeMethod())
710    << patch->GetTargetDexFile()->GetLocation() << " " << patch->GetTargetMethodIdx();
711  CHECK(dex_cache->GetResolvedMethods()->Get(patch->GetTargetMethodIdx()) == method)
712    << patch->GetTargetDexFile()->GetLocation() << " " << patch->GetReferrerMethodIdx() << " "
713    << PrettyMethod(dex_cache->GetResolvedMethods()->Get(patch->GetTargetMethodIdx())) << " "
714    << PrettyMethod(method);
715  return method;
716}
717
718static Class* GetTargetType(const CompilerDriver::TypePatchInformation* patch)
719    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
720  ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
721  StackHandleScope<2> hs(Thread::Current());
722  Handle<mirror::DexCache> dex_cache(hs.NewHandle(class_linker->FindDexCache(patch->GetDexFile())));
723  Class* klass = class_linker->ResolveType(patch->GetDexFile(), patch->GetTargetTypeIdx(),
724                                           dex_cache, NullHandle<mirror::ClassLoader>());
725  CHECK(klass != NULL)
726    << patch->GetDexFile().GetLocation() << " " << patch->GetTargetTypeIdx();
727  CHECK(dex_cache->GetResolvedTypes()->Get(patch->GetTargetTypeIdx()) == klass)
728    << patch->GetDexFile().GetLocation() << " " << patch->GetReferrerMethodIdx() << " "
729    << PrettyClass(dex_cache->GetResolvedTypes()->Get(patch->GetTargetTypeIdx())) << " "
730    << PrettyClass(klass);
731  return klass;
732}
733
734void ImageWriter::PatchOatCodeAndMethods() {
735  Thread* self = Thread::Current();
736  ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
737  const char* old_cause = self->StartAssertNoThreadSuspension("ImageWriter");
738
739  typedef std::vector<const CompilerDriver::CallPatchInformation*> CallPatches;
740  const CallPatches& code_to_patch = compiler_driver_.GetCodeToPatch();
741  for (size_t i = 0; i < code_to_patch.size(); i++) {
742    const CompilerDriver::CallPatchInformation* patch = code_to_patch[i];
743    ArtMethod* target = GetTargetMethod(patch);
744    uintptr_t quick_code = reinterpret_cast<uintptr_t>(class_linker->GetQuickOatCodeFor(target));
745    DCHECK_NE(quick_code, 0U) << PrettyMethod(target);
746    uintptr_t code_base = reinterpret_cast<uintptr_t>(&oat_file_->GetOatHeader());
747    uintptr_t code_offset = quick_code - code_base;
748    bool is_quick_offset = false;
749    if (quick_code == reinterpret_cast<uintptr_t>(GetQuickToInterpreterBridge())) {
750      is_quick_offset = true;
751      code_offset = PointerToLowMemUInt32(GetOatAddress(quick_to_interpreter_bridge_offset_));
752    } else if (quick_code ==
753        reinterpret_cast<uintptr_t>(class_linker->GetQuickGenericJniTrampoline())) {
754      CHECK(target->IsNative());
755      is_quick_offset = true;
756      code_offset = PointerToLowMemUInt32(GetOatAddress(quick_generic_jni_trampoline_offset_));
757    }
758    uintptr_t value;
759    if (patch->IsRelative()) {
760      // value to patch is relative to the location being patched
761      const void* quick_oat_code =
762        class_linker->GetQuickOatCodeFor(patch->GetDexFile(),
763                                         patch->GetReferrerClassDefIdx(),
764                                         patch->GetReferrerMethodIdx());
765      if (is_quick_offset) {
766        quick_code = code_offset;
767        // If its a quick offset it means that we are doing a relative patch from the class linker
768        // oat_file to the image writer oat_file so we need to adjust the quick oat code to be the
769        // one in the image writer oat_file.
770        quick_oat_code =
771            reinterpret_cast<const void*>(reinterpret_cast<uintptr_t>(quick_oat_code) +
772                reinterpret_cast<uintptr_t>(oat_data_begin_) - code_base);
773      }
774      uintptr_t base = reinterpret_cast<uintptr_t>(quick_oat_code);
775      uintptr_t patch_location = base + patch->GetLiteralOffset();
776      value = quick_code - patch_location + patch->RelativeOffset();
777    } else {
778      value = code_offset;
779    }
780    SetPatchLocation(patch, value);
781  }
782
783  const CallPatches& methods_to_patch = compiler_driver_.GetMethodsToPatch();
784  for (size_t i = 0; i < methods_to_patch.size(); i++) {
785    const CompilerDriver::CallPatchInformation* patch = methods_to_patch[i];
786    ArtMethod* target = GetTargetMethod(patch);
787    SetPatchLocation(patch, PointerToLowMemUInt32(GetImageAddress(target)));
788  }
789
790  const std::vector<const CompilerDriver::TypePatchInformation*>& classes_to_patch =
791      compiler_driver_.GetClassesToPatch();
792  for (size_t i = 0; i < classes_to_patch.size(); i++) {
793    const CompilerDriver::TypePatchInformation* patch = classes_to_patch[i];
794    Class* target = GetTargetType(patch);
795    SetPatchLocation(patch, PointerToLowMemUInt32(GetImageAddress(target)));
796  }
797
798  // Update the image header with the new checksum after patching
799  ImageHeader* image_header = reinterpret_cast<ImageHeader*>(image_->Begin());
800  image_header->SetOatChecksum(oat_file_->GetOatHeader().GetChecksum());
801  self->EndAssertNoThreadSuspension(old_cause);
802}
803
804void ImageWriter::SetPatchLocation(const CompilerDriver::PatchInformation* patch, uint32_t value) {
805  ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
806  const void* quick_oat_code = class_linker->GetQuickOatCodeFor(patch->GetDexFile(),
807                                                                patch->GetReferrerClassDefIdx(),
808                                                                patch->GetReferrerMethodIdx());
809  OatHeader& oat_header = const_cast<OatHeader&>(oat_file_->GetOatHeader());
810  // TODO: make this Thumb2 specific
811  uint8_t* base = reinterpret_cast<uint8_t*>(reinterpret_cast<uintptr_t>(quick_oat_code) & ~0x1);
812  uint32_t* patch_location = reinterpret_cast<uint32_t*>(base + patch->GetLiteralOffset());
813  if (kIsDebugBuild) {
814    if (patch->IsCall()) {
815      const CompilerDriver::CallPatchInformation* cpatch = patch->AsCall();
816      const DexFile::MethodId& id = cpatch->GetTargetDexFile()->GetMethodId(cpatch->GetTargetMethodIdx());
817      uint32_t expected = reinterpret_cast<uintptr_t>(&id) & 0xFFFFFFFF;
818      uint32_t actual = *patch_location;
819      CHECK(actual == expected || actual == value) << std::hex
820          << "actual=" << actual
821          << "expected=" << expected
822          << "value=" << value;
823    }
824    if (patch->IsType()) {
825      const CompilerDriver::TypePatchInformation* tpatch = patch->AsType();
826      const DexFile::TypeId& id = tpatch->GetDexFile().GetTypeId(tpatch->GetTargetTypeIdx());
827      uint32_t expected = reinterpret_cast<uintptr_t>(&id) & 0xFFFFFFFF;
828      uint32_t actual = *patch_location;
829      CHECK(actual == expected || actual == value) << std::hex
830          << "actual=" << actual
831          << "expected=" << expected
832          << "value=" << value;
833    }
834  }
835  *patch_location = value;
836  oat_header.UpdateChecksum(patch_location, sizeof(value));
837}
838
839}  // namespace art
840