/* * 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 // For the PROT_* and MAP_* constants. #include #include "base/logging.h" #include "base/stl_util.h" #include "base/unix_file/fd_file.h" #include "dex_file.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::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 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::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 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 vdex(new VdexFile(mmap.release())); if (!vdex->IsValid()) { *error_msg = "Vdex file is not valid"; return nullptr; } if (unquicken) { std::vector> unique_ptr_dex_files; if (!vdex->OpenAllDexFiles(&unique_ptr_dex_files, error_msg)) { return nullptr; } Unquicken(MakeNonOwningPointerVector(unique_ptr_dex_files), vdex->GetQuickeningInfo()); // Update the quickening info size to pretend there isn't any. reinterpret_cast(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(cursor)->file_size_; return (data == DexEnd()) ? nullptr : data; } } bool VdexFile::OpenAllDexFiles(std::vector>* 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(dex_file_start)->file_size_; // TODO: Supply the location information for a vdex file. static constexpr char kVdexLocation[] = ""; std::string location = DexFile::GetMultiDexLocation(i, kVdexLocation); std::unique_ptr dex(DexFile::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& dex_files, const ArrayRef& quickening_info) { if (quickening_info.size() == 0) { // If there is no quickening info, we bail early, as the code below expects at // least the size of quickening data for each method that has a code item. return; } const uint8_t* quickening_info_ptr = quickening_info.data(); const uint8_t* const quickening_info_end = quickening_info.data() + quickening_info.size(); for (const DexFile* dex_file : dex_files) { for (uint32_t i = 0; i < dex_file->NumClassDefs(); ++i) { const DexFile::ClassDef& class_def = dex_file->GetClassDef(i); const uint8_t* class_data = dex_file->GetClassData(class_def); if (class_data == nullptr) { continue; } ClassDataItemIterator it(*dex_file, class_data); // Skip fields while (it.HasNextStaticField()) { it.Next(); } while (it.HasNextInstanceField()) { it.Next(); } while (it.HasNextDirectMethod()) { const DexFile::CodeItem* code_item = it.GetMethodCodeItem(); if (code_item != nullptr) { uint32_t quickening_size = *reinterpret_cast(quickening_info_ptr); quickening_info_ptr += sizeof(uint32_t); optimizer::ArtDecompileDEX(*code_item, ArrayRef(quickening_info_ptr, quickening_size), /* decompile_return_instruction */ false); quickening_info_ptr += quickening_size; } it.Next(); } while (it.HasNextVirtualMethod()) { const DexFile::CodeItem* code_item = it.GetMethodCodeItem(); if (code_item != nullptr) { uint32_t quickening_size = *reinterpret_cast(quickening_info_ptr); quickening_info_ptr += sizeof(uint32_t); optimizer::ArtDecompileDEX(*code_item, ArrayRef(quickening_info_ptr, quickening_size), /* decompile_return_instruction */ false); quickening_info_ptr += quickening_size; } it.Next(); } DCHECK(!it.HasNext()); } } if (quickening_info_ptr != quickening_info_end) { LOG(FATAL) << "Failed to use all quickening info"; } } } // namespace art