| /* |
| * Copyright (C) 2016 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 |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include "vdex_file.h" |
| |
| #include <sys/mman.h> // For the PROT_* and MAP_* constants. |
| |
| #include <memory> |
| |
| #include <android-base/logging.h> |
| |
| #include "base/bit_utils.h" |
| #include "base/stl_util.h" |
| #include "base/unix_file/fd_file.h" |
| #include "dex_file.h" |
| #include "dex_file_loader.h" |
| #include "dex_to_dex_decompiler.h" |
| |
| namespace art { |
| |
| constexpr uint8_t VdexFile::Header::kVdexInvalidMagic[4]; |
| constexpr uint8_t VdexFile::Header::kVdexMagic[4]; |
| constexpr uint8_t VdexFile::Header::kVdexVersion[4]; |
| |
| bool VdexFile::Header::IsMagicValid() const { |
| return (memcmp(magic_, kVdexMagic, sizeof(kVdexMagic)) == 0); |
| } |
| |
| bool VdexFile::Header::IsVersionValid() const { |
| return (memcmp(version_, kVdexVersion, sizeof(kVdexVersion)) == 0); |
| } |
| |
| VdexFile::Header::Header(uint32_t number_of_dex_files, |
| uint32_t dex_size, |
| uint32_t verifier_deps_size, |
| uint32_t quickening_info_size) |
| : number_of_dex_files_(number_of_dex_files), |
| dex_size_(dex_size), |
| verifier_deps_size_(verifier_deps_size), |
| quickening_info_size_(quickening_info_size) { |
| memcpy(magic_, kVdexMagic, sizeof(kVdexMagic)); |
| memcpy(version_, kVdexVersion, sizeof(kVdexVersion)); |
| DCHECK(IsMagicValid()); |
| DCHECK(IsVersionValid()); |
| } |
| |
| std::unique_ptr<VdexFile> VdexFile::Open(const std::string& vdex_filename, |
| bool writable, |
| bool low_4gb, |
| bool unquicken, |
| std::string* error_msg) { |
| if (!OS::FileExists(vdex_filename.c_str())) { |
| *error_msg = "File " + vdex_filename + " does not exist."; |
| return nullptr; |
| } |
| |
| std::unique_ptr<File> vdex_file; |
| if (writable) { |
| vdex_file.reset(OS::OpenFileReadWrite(vdex_filename.c_str())); |
| } else { |
| vdex_file.reset(OS::OpenFileForReading(vdex_filename.c_str())); |
| } |
| if (vdex_file == nullptr) { |
| *error_msg = "Could not open file " + vdex_filename + |
| (writable ? " for read/write" : "for reading"); |
| return nullptr; |
| } |
| |
| int64_t vdex_length = vdex_file->GetLength(); |
| if (vdex_length == -1) { |
| *error_msg = "Could not read the length of file " + vdex_filename; |
| return nullptr; |
| } |
| |
| return Open(vdex_file->Fd(), vdex_length, vdex_filename, writable, low_4gb, unquicken, error_msg); |
| } |
| |
| std::unique_ptr<VdexFile> VdexFile::Open(int file_fd, |
| size_t vdex_length, |
| const std::string& vdex_filename, |
| bool writable, |
| bool low_4gb, |
| bool unquicken, |
| std::string* error_msg) { |
| std::unique_ptr<MemMap> mmap(MemMap::MapFile( |
| vdex_length, |
| (writable || unquicken) ? PROT_READ | PROT_WRITE : PROT_READ, |
| unquicken ? MAP_PRIVATE : MAP_SHARED, |
| file_fd, |
| 0 /* start offset */, |
| low_4gb, |
| vdex_filename.c_str(), |
| error_msg)); |
| if (mmap == nullptr) { |
| *error_msg = "Failed to mmap file " + vdex_filename + " : " + *error_msg; |
| return nullptr; |
| } |
| |
| std::unique_ptr<VdexFile> vdex(new VdexFile(mmap.release())); |
| if (!vdex->IsValid()) { |
| *error_msg = "Vdex file is not valid"; |
| return nullptr; |
| } |
| |
| if (unquicken) { |
| std::vector<std::unique_ptr<const DexFile>> unique_ptr_dex_files; |
| if (!vdex->OpenAllDexFiles(&unique_ptr_dex_files, error_msg)) { |
| return nullptr; |
| } |
| Unquicken(MakeNonOwningPointerVector(unique_ptr_dex_files), |
| vdex->GetQuickeningInfo(), |
| /* decompile_return_instruction */ false); |
| // Update the quickening info size to pretend there isn't any. |
| reinterpret_cast<Header*>(vdex->mmap_->Begin())->quickening_info_size_ = 0; |
| } |
| |
| *error_msg = "Success"; |
| return vdex; |
| } |
| |
| const uint8_t* VdexFile::GetNextDexFileData(const uint8_t* cursor) const { |
| DCHECK(cursor == nullptr || (cursor > Begin() && cursor <= End())); |
| if (cursor == nullptr) { |
| // Beginning of the iteration, return the first dex file if there is one. |
| return HasDexSection() ? DexBegin() : nullptr; |
| } else { |
| // Fetch the next dex file. Return null if there is none. |
| const uint8_t* data = cursor + reinterpret_cast<const DexFile::Header*>(cursor)->file_size_; |
| // Dex files are required to be 4 byte aligned. the OatWriter makes sure they are, see |
| // OatWriter::SeekToDexFiles. |
| data = AlignUp(data, 4); |
| return (data == DexEnd()) ? nullptr : data; |
| } |
| } |
| |
| bool VdexFile::OpenAllDexFiles(std::vector<std::unique_ptr<const DexFile>>* dex_files, |
| std::string* error_msg) { |
| size_t i = 0; |
| for (const uint8_t* dex_file_start = GetNextDexFileData(nullptr); |
| dex_file_start != nullptr; |
| dex_file_start = GetNextDexFileData(dex_file_start), ++i) { |
| size_t size = reinterpret_cast<const DexFile::Header*>(dex_file_start)->file_size_; |
| // TODO: Supply the location information for a vdex file. |
| static constexpr char kVdexLocation[] = ""; |
| std::string location = DexFileLoader::GetMultiDexLocation(i, kVdexLocation); |
| std::unique_ptr<const DexFile> dex(DexFileLoader::Open(dex_file_start, |
| size, |
| location, |
| GetLocationChecksum(i), |
| nullptr /*oat_dex_file*/, |
| false /*verify*/, |
| false /*verify_checksum*/, |
| error_msg)); |
| if (dex == nullptr) { |
| return false; |
| } |
| dex_files->push_back(std::move(dex)); |
| } |
| return true; |
| } |
| |
| void VdexFile::Unquicken(const std::vector<const DexFile*>& dex_files, |
| ArrayRef<const uint8_t> quickening_info, |
| bool decompile_return_instruction) { |
| if (quickening_info.size() == 0 && !decompile_return_instruction) { |
| // Bail early if there is no quickening info and no need to decompile |
| // RETURN_VOID_NO_BARRIER instructions to RETURN_VOID instructions. |
| return; |
| } |
| |
| for (uint32_t i = 0; i < dex_files.size(); ++i) { |
| UnquickenDexFile(*dex_files[i], quickening_info, decompile_return_instruction); |
| } |
| } |
| |
| typedef __attribute__((__aligned__(1))) uint32_t unaligned_uint32_t; |
| |
| static uint32_t GetDebugInfoOffsetInternal(const DexFile& dex_file, |
| uint32_t offset_in_code_item, |
| const ArrayRef<const uint8_t>& quickening_info) { |
| if (quickening_info.size() == 0) { |
| // No quickening info: offset is the right one, return it. |
| return offset_in_code_item; |
| } |
| uint32_t quickening_offset = offset_in_code_item - dex_file.Size(); |
| return *reinterpret_cast<const unaligned_uint32_t*>(quickening_info.data() + quickening_offset); |
| } |
| |
| static uint32_t GetQuickeningInfoOffsetFrom(const DexFile& dex_file, |
| uint32_t offset_in_code_item, |
| const ArrayRef<const uint8_t>& quickening_info) { |
| if (offset_in_code_item < dex_file.Size()) { |
| return VdexFile::kNoQuickeningInfoOffset; |
| } |
| if (quickening_info.size() == 0) { |
| // No quickening info. |
| return VdexFile::kNoQuickeningInfoOffset; |
| } |
| uint32_t quickening_offset = offset_in_code_item - dex_file.Size(); |
| |
| // Add 2 * sizeof(uint32_t) for the debug info offset and the data offset. |
| CHECK_LE(quickening_offset + 2 * sizeof(uint32_t), quickening_info.size()); |
| return *reinterpret_cast<const unaligned_uint32_t*>( |
| quickening_info.data() + quickening_offset + sizeof(uint32_t)); |
| } |
| |
| static ArrayRef<const uint8_t> GetQuickeningInfoAt(const ArrayRef<const uint8_t>& quickening_info, |
| uint32_t quickening_offset) { |
| return (quickening_offset == VdexFile::kNoQuickeningInfoOffset) |
| ? ArrayRef<const uint8_t>(nullptr, 0) |
| : quickening_info.SubArray( |
| quickening_offset + sizeof(uint32_t), |
| *reinterpret_cast<const unaligned_uint32_t*>( |
| quickening_info.data() + quickening_offset)); |
| } |
| |
| void VdexFile::UnquickenDexFile(const DexFile& target_dex_file, |
| ArrayRef<const uint8_t> quickening_info, |
| bool decompile_return_instruction) { |
| if (quickening_info.size() == 0 && !decompile_return_instruction) { |
| // Bail early if there is no quickening info and no need to decompile |
| // RETURN_VOID_NO_BARRIER instructions to RETURN_VOID instructions. |
| return; |
| } |
| for (uint32_t i = 0; i < target_dex_file.NumClassDefs(); ++i) { |
| const DexFile::ClassDef& class_def = target_dex_file.GetClassDef(i); |
| const uint8_t* class_data = target_dex_file.GetClassData(class_def); |
| if (class_data != nullptr) { |
| for (ClassDataItemIterator class_it(target_dex_file, class_data); |
| class_it.HasNext(); |
| class_it.Next()) { |
| if (class_it.IsAtMethod() && class_it.GetMethodCodeItem() != nullptr) { |
| const DexFile::CodeItem* code_item = class_it.GetMethodCodeItem(); |
| uint32_t quickening_offset = GetQuickeningInfoOffsetFrom( |
| target_dex_file, code_item->debug_info_off_, quickening_info); |
| if (quickening_offset != VdexFile::kNoQuickeningInfoOffset) { |
| // If we have quickening data, put back the original debug_info_off. |
| const_cast<DexFile::CodeItem*>(code_item)->SetDebugInfoOffset( |
| GetDebugInfoOffsetInternal(target_dex_file, |
| code_item->debug_info_off_, |
| quickening_info)); |
| } |
| optimizer::ArtDecompileDEX( |
| *code_item, |
| GetQuickeningInfoAt(quickening_info, quickening_offset), |
| decompile_return_instruction); |
| } |
| } |
| } |
| } |
| } |
| |
| uint32_t VdexFile::GetDebugInfoOffset(const DexFile& dex_file, uint32_t offset_in_code_item) const { |
| return GetDebugInfoOffsetInternal(dex_file, offset_in_code_item, GetQuickeningInfo()); |
| } |
| |
| const uint8_t* VdexFile::GetQuickenedInfoOf(const DexFile& dex_file, |
| uint32_t code_item_offset) const { |
| ArrayRef<const uint8_t> quickening_info = GetQuickeningInfo(); |
| uint32_t quickening_offset = GetQuickeningInfoOffsetFrom( |
| dex_file, dex_file.GetCodeItem(code_item_offset)->debug_info_off_, quickening_info); |
| |
| return GetQuickeningInfoAt(quickening_info, quickening_offset).data(); |
| } |
| |
| bool VdexFile::CanEncodeQuickenedData(const DexFile& dex_file) { |
| // We are going to use the debug_info_off_ to signal there is |
| // quickened data, by putting a value greater than dex_file.Size(). So |
| // make sure we have some room in the offset by checking that we have at least |
| // half of the range of a uint32_t. |
| return dex_file.Size() <= (std::numeric_limits<uint32_t>::max() >> 1); |
| } |
| |
| } // namespace art |
