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* Copyright (C) 2014 The Android Open Source Project
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* See the License for the specific language governing permissions and
* limitations under the License.
#include "arch/instruction_set.h"
#include "base/macros.h"
#include "base/mutex.h"
#include "elf_file.h"
#include "elf_utils.h"
#include "gc/accounting/space_bitmap.h"
#include "gc/space/image_space.h"
#include "gc/heap.h"
#include "os.h"
#include "runtime.h"
namespace art {
class ArtMethod;
class ImageHeader;
class OatHeader;
namespace mirror {
class Object;
class PointerArray;
class Reference;
class Class;
} // namespace mirror
class PatchOat {
// Patch only the oat file
static bool Patch(File* oat_in, off_t delta, File* oat_out, TimingLogger* timings,
bool output_oat_opened_from_fd, // Was this using --oatput-oat-fd ?
bool new_oat_out); // Output oat was a new file created by us?
// Patch only the image (art file)
static bool Patch(const std::string& art_location, off_t delta, File* art_out, InstructionSet isa,
TimingLogger* timings);
// Patch both the image and the oat file
static bool Patch(const std::string& art_location,
off_t delta,
const std::string& output_directory,
InstructionSet isa,
TimingLogger* timings);
~PatchOat() {}
PatchOat(PatchOat&&) = default;
// Takes ownership only of the ElfFile. All other pointers are only borrowed.
PatchOat(ElfFile* oat_file, off_t delta, TimingLogger* timings)
: oat_file_(oat_file), image_(nullptr), bitmap_(nullptr), heap_(nullptr), delta_(delta),
isa_(kNone), space_map_(nullptr), timings_(timings) {}
PatchOat(InstructionSet isa, MemMap* image, gc::accounting::ContinuousSpaceBitmap* bitmap,
MemMap* heap, off_t delta, TimingLogger* timings)
: image_(image), bitmap_(bitmap), heap_(heap),
delta_(delta), isa_(isa), space_map_(nullptr), timings_(timings) {}
PatchOat(InstructionSet isa, ElfFile* oat_file, MemMap* image,
gc::accounting::ContinuousSpaceBitmap* bitmap, MemMap* heap, off_t delta,
std::map<gc::space::ImageSpace*, std::unique_ptr<MemMap>>* map, TimingLogger* timings)
: oat_file_(oat_file), image_(image), bitmap_(bitmap), heap_(heap),
delta_(delta), isa_(isa), space_map_(map), timings_(timings) {}
// Was the .art image at image_path made with --compile-pic ?
static bool IsImagePic(const ImageHeader& image_header, const std::string& image_path);
enum MaybePic {
NOT_PIC, // Code not pic. Patch as usual.
PIC, // Code was pic. Create symlink; skip OAT patching.
ERROR_OAT_FILE, // Failed to symlink oat file
// Was the .oat image at oat_in made with --compile-pic ?
static MaybePic IsOatPic(const ElfFile* oat_in);
// Attempt to replace the file with a symlink
// Returns false if it fails
static bool ReplaceOatFileWithSymlink(const std::string& input_oat_filename,
const std::string& output_oat_filename,
bool output_oat_opened_from_fd,
bool new_oat_out); // Output oat was newly created?
static void BitmapCallback(mirror::Object* obj, void* arg)
SHARED_REQUIRES(Locks::mutator_lock_) {
void VisitObject(mirror::Object* obj)
void FixupMethod(ArtMethod* object, ArtMethod* copy)
// Patches oat in place, modifying the oat_file given to the constructor.
bool PatchElf();
template <typename ElfFileImpl>
bool PatchElf(ElfFileImpl* oat_file);
template <typename ElfFileImpl>
bool PatchOatHeader(ElfFileImpl* oat_file);
bool PatchImage(bool primary_image) SHARED_REQUIRES(Locks::mutator_lock_);
void PatchArtFields(const ImageHeader* image_header) SHARED_REQUIRES(Locks::mutator_lock_);
void PatchArtMethods(const ImageHeader* image_header) SHARED_REQUIRES(Locks::mutator_lock_);
void PatchImtConflictTables(const ImageHeader* image_header)
void PatchInternedStrings(const ImageHeader* image_header)
void PatchClassTable(const ImageHeader* image_header)
void PatchDexFileArrays(mirror::ObjectArray<mirror::Object>* img_roots)
bool WriteElf(File* out);
bool WriteImage(File* out);
template <typename T>
T* RelocatedCopyOf(T* obj) const {
if (obj == nullptr) {
return nullptr;
DCHECK_GT(reinterpret_cast<uintptr_t>(obj), reinterpret_cast<uintptr_t>(heap_->Begin()));
DCHECK_LT(reinterpret_cast<uintptr_t>(obj), reinterpret_cast<uintptr_t>(heap_->End()));
uintptr_t heap_off =
reinterpret_cast<uintptr_t>(obj) - reinterpret_cast<uintptr_t>(heap_->Begin());
DCHECK_LT(heap_off, image_->Size());
return reinterpret_cast<T*>(image_->Begin() + heap_off);
template <typename T>
T* RelocatedCopyOfFollowImages(T* obj) const {
if (obj == nullptr) {
return nullptr;
// Find ImageSpace this belongs to.
auto image_spaces = Runtime::Current()->GetHeap()->GetBootImageSpaces();
for (gc::space::ImageSpace* image_space : image_spaces) {
if (image_space->Contains(obj)) {
uintptr_t heap_off = reinterpret_cast<uintptr_t>(obj) -
return reinterpret_cast<T*>(space_map_->find(image_space)->second->Begin() + heap_off);
LOG(FATAL) << "Did not find object in boot image space " << obj;
template <typename T>
T* RelocatedAddressOfPointer(T* obj) const {
if (obj == nullptr) {
return obj;
auto ret = reinterpret_cast<uintptr_t>(obj) + delta_;
// Trim off high bits in case negative relocation with 64 bit patchoat.
if (InstructionSetPointerSize(isa_) == sizeof(uint32_t)) {
ret = static_cast<uintptr_t>(static_cast<uint32_t>(ret));
return reinterpret_cast<T*>(ret);
template <typename T>
T RelocatedAddressOfIntPointer(T obj) const {
if (obj == 0) {
return obj;
T ret = obj + delta_;
// Trim off high bits in case negative relocation with 64 bit patchoat.
if (InstructionSetPointerSize(isa_) == 4) {
ret = static_cast<T>(static_cast<uint32_t>(ret));
return ret;
// Walks through the old image and patches the mmap'd copy of it to the new offset. It does not
// change the heap.
class PatchVisitor {
PatchVisitor(PatchOat* patcher, mirror::Object* copy) : patcher_(patcher), copy_(copy) {}
~PatchVisitor() {}
void operator() (mirror::Object* obj, MemberOffset off, bool b) const
REQUIRES(Locks::mutator_lock_, Locks::heap_bitmap_lock_);
// For reference classes.
void operator() (mirror::Class* cls, mirror::Reference* ref) const
REQUIRES(Locks::mutator_lock_, Locks::heap_bitmap_lock_);
// TODO: Consider using these for updating native class roots?
void VisitRootIfNonNull(mirror::CompressedReference<mirror::Object>* root ATTRIBUTE_UNUSED)
const {}
void VisitRoot(mirror::CompressedReference<mirror::Object>* root ATTRIBUTE_UNUSED) const {}
PatchOat* const patcher_;
mirror::Object* const copy_;
// The elf file we are patching.
std::unique_ptr<ElfFile> oat_file_;
// A mmap of the image we are patching. This is modified.
const MemMap* const image_;
// The bitmap over the image within the heap we are patching. This is not modified.
gc::accounting::ContinuousSpaceBitmap* const bitmap_;
// The heap we are patching. This is not modified.
const MemMap* const heap_;
// The amount we are changing the offset by.
const off_t delta_;
// Active instruction set, used to know the entrypoint size.
const InstructionSet isa_;
const std::map<gc::space::ImageSpace*, std::unique_ptr<MemMap>>* space_map_;
TimingLogger* timings_;
friend class FixupRootVisitor;
friend class RelocatedPointerVisitor;
friend class PatchOatArtFieldVisitor;
friend class PatchOatArtMethodVisitor;
} // namespace art