| /* |
| * Copyright (C) 2018 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 <stdint.h> |
| #include <sys/mman.h> |
| #include <sys/stat.h> |
| #include <sys/types.h> |
| #include <unistd.h> |
| |
| #include <memory> |
| |
| #include <android-base/unique_fd.h> |
| #include <art_api/dex_file_support.h> |
| |
| #include <unwindstack/Log.h> |
| #include <unwindstack/MapInfo.h> |
| #include <unwindstack/Memory.h> |
| |
| #include "DexFile.h" |
| #include "MemoryBuffer.h" |
| |
| namespace unwindstack { |
| |
| static bool CheckDexSupport() { |
| if (std::string err_msg; !art_api::dex::TryLoadLibdexfile(&err_msg)) { |
| Log::Error("Failed to initialize DEX file support: %s", err_msg.c_str()); |
| return false; |
| } |
| return true; |
| } |
| |
| std::shared_ptr<DexFile> DexFile::CreateFromDisk(uint64_t addr, uint64_t size, MapInfo* map) { |
| static auto& mapped_dex_files = *new std::map<MappedFileKey, std::weak_ptr<DexFileApi>>; |
| static auto& lock = *new std::mutex; // Guards the static cache above. |
| |
| if (map == nullptr || map->name().empty()) { |
| return nullptr; // MapInfo not backed by file. |
| } |
| if (!(map->start() <= addr && addr < map->end())) { |
| return nullptr; // addr is not in MapInfo range. |
| } |
| if (size > (map->end() - addr)) { |
| return nullptr; // size is past the MapInfo end. |
| } |
| uint64_t offset_in_file = (addr - map->start()) + map->offset(); |
| |
| // Fast-path: Check if the dex file was already mapped from disk. |
| std::lock_guard<std::mutex> guard(lock); |
| MappedFileKey cache_key(map->name(), offset_in_file, size); |
| std::weak_ptr<DexFileApi>& cache_entry = mapped_dex_files[cache_key]; |
| std::shared_ptr<DexFileApi> dex_api = cache_entry.lock(); |
| if (dex_api != nullptr) { |
| return std::shared_ptr<DexFile>(new DexFile(addr, size, std::move(dex_api))); |
| } |
| |
| // Load the file from disk and cache it. |
| std::unique_ptr<Memory> memory = Memory::CreateFileMemory(map->name(), offset_in_file, size); |
| if (memory == nullptr) { |
| return nullptr; // failed to map the file. |
| } |
| std::unique_ptr<art_api::dex::DexFile> dex; |
| art_api::dex::DexFile::Create(memory->GetPtr(), size, nullptr, map->name().c_str(), &dex); |
| if (dex == nullptr) { |
| return nullptr; // invalid DEX file. |
| } |
| dex_api.reset(new DexFileApi{std::move(dex), std::move(memory), std::mutex()}); |
| cache_entry = dex_api; |
| return std::shared_ptr<DexFile>(new DexFile(addr, size, std::move(dex_api))); |
| } |
| |
| std::shared_ptr<DexFile> DexFile::Create(uint64_t base_addr, uint64_t file_size, Memory* memory, |
| MapInfo* info) { |
| static bool has_dex_support = CheckDexSupport(); |
| if (!has_dex_support || file_size == 0) { |
| return nullptr; |
| } |
| |
| // Do not try to open the DEX file if the file name ends with "(deleted)". It does not exist. |
| // This happens when an app is background-optimized by ART and all of its files are replaced. |
| // Furthermore, do NOT try to fallback to in-memory copy. It would work, but all apps tend to |
| // be background-optimized at the same time, so it would lead to excessive memory use during |
| // system-wide profiling (essentially copying all dex files for all apps: hundreds of MBs). |
| // This will cause missing symbols in the backtrace, however, that outcome is inevitable |
| // anyway, since we can not obtain mini-debug-info for the deleted .oat files. |
| const std::string_view filename(info != nullptr ? info->name() : ""); |
| const std::string_view kDeleted("(deleted)"); |
| if (filename.size() >= kDeleted.size() && |
| filename.substr(filename.size() - kDeleted.size()) == kDeleted) { |
| return nullptr; |
| } |
| |
| std::shared_ptr<DexFile> dex_file = CreateFromDisk(base_addr, file_size, info); |
| if (dex_file != nullptr) { |
| return dex_file; |
| } |
| |
| // Fallback: make copy in local buffer. |
| std::unique_ptr<MemoryBuffer> copy(new MemoryBuffer); |
| if (!copy->Resize(file_size)) { |
| return nullptr; |
| } |
| if (!memory->ReadFully(base_addr, copy->GetPtr(0), file_size)) { |
| return nullptr; |
| } |
| std::unique_ptr<art_api::dex::DexFile> dex; |
| art_api::dex::DexFile::Create(copy->GetPtr(0), file_size, nullptr, "", &dex); |
| if (dex == nullptr) { |
| return nullptr; |
| } |
| std::shared_ptr<DexFileApi> api(new DexFileApi{std::move(dex), std::move(copy), std::mutex()}); |
| return std::shared_ptr<DexFile>(new DexFile(base_addr, file_size, std::move(api))); |
| } |
| |
| bool DexFile::GetFunctionName(uint64_t dex_pc, SharedString* method_name, uint64_t* method_offset) { |
| uint64_t dex_offset = dex_pc - base_addr_; // Convert absolute PC to file-relative offset. |
| |
| // Lookup the function in the cache. |
| std::lock_guard<std::mutex> guard(dex_api_->lock_); // Protect both the symbols and the C API. |
| auto it = symbols_.upper_bound(dex_offset); |
| if (it == symbols_.end() || dex_offset < it->second.offset) { |
| // Lookup the function in the underlying dex file. |
| size_t found = dex_api_->dex_->FindMethodAtOffset(dex_offset, [&](const auto& method) { |
| size_t code_size, name_size; |
| uint32_t offset = method.GetCodeOffset(&code_size); |
| const char* name = method.GetQualifiedName(/*with_params=*/false, &name_size); |
| it = symbols_.emplace(offset + code_size, Info{offset, std::string(name, name_size)}).first; |
| }); |
| if (found == 0) { |
| return false; |
| } |
| } |
| |
| // Return the found function. |
| *method_offset = dex_offset - it->second.offset; |
| *method_name = it->second.name; |
| return true; |
| } |
| |
| } // namespace unwindstack |