/* * Copyright (C) 2011 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 "oat_file.h" #include #include #include #include #include #ifndef __APPLE__ #include // for dl_iterate_phdr. #endif #include // dlopen_ext support from bionic. #ifdef __ANDROID__ #include "android/dlext.h" #endif #include "art_method-inl.h" #include "base/bit_vector.h" #include "base/stl_util.h" #include "base/systrace.h" #include "base/unix_file/fd_file.h" #include "elf_file.h" #include "elf_utils.h" #include "oat.h" #include "mem_map.h" #include "mirror/class.h" #include "mirror/object-inl.h" #include "oat_file-inl.h" #include "oat_file_manager.h" #include "os.h" #include "runtime.h" #include "type_lookup_table.h" #include "utils.h" #include "utils/dex_cache_arrays_layout-inl.h" namespace art { // Whether OatFile::Open will try dlopen. Fallback is our own ELF loader. static constexpr bool kUseDlopen = true; // Whether OatFile::Open will try dlopen on the host. On the host we're not linking against // bionic, so cannot take advantage of the support for changed semantics (loading the same soname // multiple times). However, if/when we switch the above, we likely want to switch this, too, // to get test coverage of the code paths. static constexpr bool kUseDlopenOnHost = true; // For debugging, Open will print DlOpen error message if set to true. static constexpr bool kPrintDlOpenErrorMessage = false; // Note for OatFileBase and descendents: // // These are used in OatFile::Open to try all our loaders. // // The process is simple: // // 1) Allocate an instance through the standard constructor (location, executable) // 2) Load() to try to open the file. // 3) ComputeFields() to populate the OatFile fields like begin_, using FindDynamicSymbolAddress. // 4) PreSetup() for any steps that should be done before the final setup. // 5) Setup() to complete the procedure. class OatFileBase : public OatFile { public: virtual ~OatFileBase() {} template static OatFileBase* OpenOatFile(const std::string& elf_filename, const std::string& location, uint8_t* requested_base, uint8_t* oat_file_begin, bool writable, bool executable, bool low_4gb, const char* abs_dex_location, std::string* error_msg); protected: OatFileBase(const std::string& filename, bool executable) : OatFile(filename, executable) {} virtual const uint8_t* FindDynamicSymbolAddress(const std::string& symbol_name, std::string* error_msg) const = 0; virtual void PreLoad() = 0; virtual bool Load(const std::string& elf_filename, uint8_t* oat_file_begin, bool writable, bool executable, bool low_4gb, std::string* error_msg) = 0; bool ComputeFields(uint8_t* requested_base, const std::string& file_path, std::string* error_msg); virtual void PreSetup(const std::string& elf_filename) = 0; bool Setup(const char* abs_dex_location, std::string* error_msg); // Setters exposed for ElfOatFile. void SetBegin(const uint8_t* begin) { begin_ = begin; } void SetEnd(const uint8_t* end) { end_ = end; } private: DISALLOW_COPY_AND_ASSIGN(OatFileBase); }; template OatFileBase* OatFileBase::OpenOatFile(const std::string& elf_filename, const std::string& location, uint8_t* requested_base, uint8_t* oat_file_begin, bool writable, bool executable, bool low_4gb, const char* abs_dex_location, std::string* error_msg) { std::unique_ptr ret(new kOatFileBaseSubType(location, executable)); ret->PreLoad(); if (!ret->Load(elf_filename, oat_file_begin, writable, executable, low_4gb, error_msg)) { return nullptr; } if (!ret->ComputeFields(requested_base, elf_filename, error_msg)) { return nullptr; } ret->PreSetup(elf_filename); if (!ret->Setup(abs_dex_location, error_msg)) { return nullptr; } return ret.release(); } bool OatFileBase::ComputeFields(uint8_t* requested_base, const std::string& file_path, std::string* error_msg) { std::string symbol_error_msg; begin_ = FindDynamicSymbolAddress("oatdata", &symbol_error_msg); if (begin_ == nullptr) { *error_msg = StringPrintf("Failed to find oatdata symbol in '%s' %s", file_path.c_str(), symbol_error_msg.c_str()); return false; } if (requested_base != nullptr && begin_ != requested_base) { // Host can fail this check. Do not dump there to avoid polluting the output. if (kIsTargetBuild && (kIsDebugBuild || VLOG_IS_ON(oat))) { PrintFileToLog("/proc/self/maps", LogSeverity::WARNING); } *error_msg = StringPrintf("Failed to find oatdata symbol at expected address: " "oatdata=%p != expected=%p. See process maps in the log.", begin_, requested_base); return false; } end_ = FindDynamicSymbolAddress("oatlastword", &symbol_error_msg); if (end_ == nullptr) { *error_msg = StringPrintf("Failed to find oatlastword symbol in '%s' %s", file_path.c_str(), symbol_error_msg.c_str()); return false; } // Readjust to be non-inclusive upper bound. end_ += sizeof(uint32_t); bss_begin_ = const_cast(FindDynamicSymbolAddress("oatbss", &symbol_error_msg)); if (bss_begin_ == nullptr) { // No .bss section. bss_end_ = nullptr; } else { bss_end_ = const_cast(FindDynamicSymbolAddress("oatbsslastword", &symbol_error_msg)); if (bss_end_ == nullptr) { *error_msg = StringPrintf("Failed to find oatbasslastword symbol in '%s'", file_path.c_str()); return false; } // Readjust to be non-inclusive upper bound. bss_end_ += sizeof(uint32_t); } return true; } // Read an unaligned entry from the OatDexFile data in OatFile and advance the read // position by the number of bytes read, i.e. sizeof(T). // Return true on success, false if the read would go beyond the end of the OatFile. template inline static bool ReadOatDexFileData(const OatFile& oat_file, /*inout*/const uint8_t** oat, /*out*/T* value) { DCHECK(oat != nullptr); DCHECK(value != nullptr); DCHECK_LE(*oat, oat_file.End()); if (UNLIKELY(static_cast(oat_file.End() - *oat) < sizeof(T))) { return false; } static_assert(std::is_trivial::value, "T must be a trivial type"); typedef __attribute__((__aligned__(1))) T unaligned_type; *value = *reinterpret_cast(*oat); *oat += sizeof(T); return true; } bool OatFileBase::Setup(const char* abs_dex_location, std::string* error_msg) { if (!GetOatHeader().IsValid()) { std::string cause = GetOatHeader().GetValidationErrorMessage(); *error_msg = StringPrintf("Invalid oat header for '%s': %s", GetLocation().c_str(), cause.c_str()); return false; } const uint8_t* oat = Begin(); oat += sizeof(OatHeader); if (oat > End()) { *error_msg = StringPrintf("In oat file '%s' found truncated OatHeader", GetLocation().c_str()); return false; } oat += GetOatHeader().GetKeyValueStoreSize(); if (oat > End()) { *error_msg = StringPrintf("In oat file '%s' found truncated variable-size data: " "%p + %zu + %u <= %p", GetLocation().c_str(), Begin(), sizeof(OatHeader), GetOatHeader().GetKeyValueStoreSize(), End()); return false; } size_t pointer_size = GetInstructionSetPointerSize(GetOatHeader().GetInstructionSet()); uint8_t* dex_cache_arrays = bss_begin_; uint32_t dex_file_count = GetOatHeader().GetDexFileCount(); oat_dex_files_storage_.reserve(dex_file_count); for (size_t i = 0; i < dex_file_count; i++) { uint32_t dex_file_location_size; if (UNLIKELY(!ReadOatDexFileData(*this, &oat, &dex_file_location_size))) { *error_msg = StringPrintf("In oat file '%s' found OatDexFile #%zu truncated after dex file " "location size", GetLocation().c_str(), i); return false; } if (UNLIKELY(dex_file_location_size == 0U)) { *error_msg = StringPrintf("In oat file '%s' found OatDexFile #%zu with empty location name", GetLocation().c_str(), i); return false; } if (UNLIKELY(static_cast(End() - oat) < dex_file_location_size)) { *error_msg = StringPrintf("In oat file '%s' found OatDexFile #%zu with truncated dex file " "location", GetLocation().c_str(), i); return false; } const char* dex_file_location_data = reinterpret_cast(oat); oat += dex_file_location_size; std::string dex_file_location = ResolveRelativeEncodedDexLocation( abs_dex_location, std::string(dex_file_location_data, dex_file_location_size)); uint32_t dex_file_checksum; if (UNLIKELY(!ReadOatDexFileData(*this, &oat, &dex_file_checksum))) { *error_msg = StringPrintf("In oat file '%s' found OatDexFile #%zu for '%s' truncated after " "dex file checksum", GetLocation().c_str(), i, dex_file_location.c_str()); return false; } uint32_t dex_file_offset; if (UNLIKELY(!ReadOatDexFileData(*this, &oat, &dex_file_offset))) { *error_msg = StringPrintf("In oat file '%s' found OatDexFile #%zu for '%s' truncated " "after dex file offsets", GetLocation().c_str(), i, dex_file_location.c_str()); return false; } if (UNLIKELY(dex_file_offset == 0U)) { *error_msg = StringPrintf("In oat file '%s' found OatDexFile #%zu for '%s' with zero dex " "file offset", GetLocation().c_str(), i, dex_file_location.c_str()); return false; } if (UNLIKELY(dex_file_offset > Size())) { *error_msg = StringPrintf("In oat file '%s' found OatDexFile #%zu for '%s' with dex file " "offset %u > %zu", GetLocation().c_str(), i, dex_file_location.c_str(), dex_file_offset, Size()); return false; } if (UNLIKELY(Size() - dex_file_offset < sizeof(DexFile::Header))) { *error_msg = StringPrintf("In oat file '%s' found OatDexFile #%zu for '%s' with dex file " "offset %u of %zu but the size of dex file header is %zu", GetLocation().c_str(), i, dex_file_location.c_str(), dex_file_offset, Size(), sizeof(DexFile::Header)); return false; } const uint8_t* dex_file_pointer = Begin() + dex_file_offset; if (UNLIKELY(!DexFile::IsMagicValid(dex_file_pointer))) { *error_msg = StringPrintf("In oat file '%s' found OatDexFile #%zu for '%s' with invalid " "dex file magic '%s'", GetLocation().c_str(), i, dex_file_location.c_str(), dex_file_pointer); return false; } if (UNLIKELY(!DexFile::IsVersionValid(dex_file_pointer))) { *error_msg = StringPrintf("In oat file '%s' found OatDexFile #%zu for '%s' with invalid " "dex file version '%s'", GetLocation().c_str(), i, dex_file_location.c_str(), dex_file_pointer); return false; } const DexFile::Header* header = reinterpret_cast(dex_file_pointer); if (Size() - dex_file_offset < header->file_size_) { *error_msg = StringPrintf("In oat file '%s' found OatDexFile #%zu for '%s' with dex file " "offset %u and size %u truncated at %zu", GetLocation().c_str(), i, dex_file_location.c_str(), dex_file_offset, header->file_size_, Size()); return false; } uint32_t class_offsets_offset; if (UNLIKELY(!ReadOatDexFileData(*this, &oat, &class_offsets_offset))) { *error_msg = StringPrintf("In oat file '%s' found OatDexFile #%zu for '%s' truncated " "after class offsets offset", GetLocation().c_str(), i, dex_file_location.c_str()); return false; } if (UNLIKELY(class_offsets_offset > Size()) || UNLIKELY((Size() - class_offsets_offset) / sizeof(uint32_t) < header->class_defs_size_)) { *error_msg = StringPrintf("In oat file '%s' found OatDexFile #%zu for '%s' with truncated " "class offsets, offset %u of %zu, class defs %u", GetLocation().c_str(), i, dex_file_location.c_str(), class_offsets_offset, Size(), header->class_defs_size_); return false; } if (UNLIKELY(!IsAligned(class_offsets_offset))) { *error_msg = StringPrintf("In oat file '%s' found OatDexFile #%zu for '%s' with unaligned " "class offsets, offset %u", GetLocation().c_str(), i, dex_file_location.c_str(), class_offsets_offset); return false; } const uint32_t* class_offsets_pointer = reinterpret_cast(Begin() + class_offsets_offset); uint32_t lookup_table_offset; if (UNLIKELY(!ReadOatDexFileData(*this, &oat, &lookup_table_offset))) { *error_msg = StringPrintf("In oat file '%s' found OatDexFile #%zd for '%s' truncated " "after lookup table offset", GetLocation().c_str(), i, dex_file_location.c_str()); return false; } const uint8_t* lookup_table_data = lookup_table_offset != 0u ? Begin() + lookup_table_offset : nullptr; if (lookup_table_offset != 0u && (UNLIKELY(lookup_table_offset > Size()) || UNLIKELY(Size() - lookup_table_offset < TypeLookupTable::RawDataLength(header->class_defs_size_)))) { *error_msg = StringPrintf("In oat file '%s' found OatDexFile #%zu for '%s' with truncated " "type lookup table, offset %u of %zu, class defs %u", GetLocation().c_str(), i, dex_file_location.c_str(), lookup_table_offset, Size(), header->class_defs_size_); return false; } uint8_t* current_dex_cache_arrays = nullptr; if (dex_cache_arrays != nullptr) { DexCacheArraysLayout layout(pointer_size, *header); if (layout.Size() != 0u) { if (static_cast(bss_end_ - dex_cache_arrays) < layout.Size()) { *error_msg = StringPrintf("In oat file '%s' found OatDexFile #%zu for '%s' with " "truncated dex cache arrays, %zu < %zu.", GetLocation().c_str(), i, dex_file_location.c_str(), static_cast(bss_end_ - dex_cache_arrays), layout.Size()); return false; } current_dex_cache_arrays = dex_cache_arrays; dex_cache_arrays += layout.Size(); } } std::string canonical_location = DexFile::GetDexCanonicalLocation(dex_file_location.c_str()); // Create the OatDexFile and add it to the owning container. OatDexFile* oat_dex_file = new OatDexFile(this, dex_file_location, canonical_location, dex_file_checksum, dex_file_pointer, lookup_table_data, class_offsets_pointer, current_dex_cache_arrays); oat_dex_files_storage_.push_back(oat_dex_file); // Add the location and canonical location (if different) to the oat_dex_files_ table. StringPiece key(oat_dex_file->GetDexFileLocation()); oat_dex_files_.Put(key, oat_dex_file); if (canonical_location != dex_file_location) { StringPiece canonical_key(oat_dex_file->GetCanonicalDexFileLocation()); oat_dex_files_.Put(canonical_key, oat_dex_file); } } if (dex_cache_arrays != bss_end_) { // We expect the bss section to be either empty (dex_cache_arrays and bss_end_ // both null) or contain just the dex cache arrays and nothing else. *error_msg = StringPrintf("In oat file '%s' found unexpected bss size bigger by %zu bytes.", GetLocation().c_str(), static_cast(bss_end_ - dex_cache_arrays)); return false; } return true; } //////////////////////// // OatFile via dlopen // //////////////////////// class DlOpenOatFile FINAL : public OatFileBase { public: DlOpenOatFile(const std::string& filename, bool executable) : OatFileBase(filename, executable), dlopen_handle_(nullptr), shared_objects_before_(0) { } ~DlOpenOatFile() { if (dlopen_handle_ != nullptr) { if (!kIsTargetBuild) { MutexLock mu(Thread::Current(), *Locks::host_dlopen_handles_lock_); host_dlopen_handles_.erase(dlopen_handle_); dlclose(dlopen_handle_); } else { dlclose(dlopen_handle_); } } } protected: const uint8_t* FindDynamicSymbolAddress(const std::string& symbol_name, std::string* error_msg) const OVERRIDE { const uint8_t* ptr = reinterpret_cast(dlsym(dlopen_handle_, symbol_name.c_str())); if (ptr == nullptr) { *error_msg = dlerror(); } return ptr; } void PreLoad() OVERRIDE; bool Load(const std::string& elf_filename, uint8_t* oat_file_begin, bool writable, bool executable, bool low_4gb, std::string* error_msg) OVERRIDE; // Ask the linker where it mmaped the file and notify our mmap wrapper of the regions. void PreSetup(const std::string& elf_filename) OVERRIDE; private: bool Dlopen(const std::string& elf_filename, uint8_t* oat_file_begin, std::string* error_msg); // On the host, if the same library is loaded again with dlopen the same // file handle is returned. This differs from the behavior of dlopen on the // target, where dlopen reloads the library at a different address every // time you load it. The runtime relies on the target behavior to ensure // each instance of the loaded library has a unique dex cache. To avoid // problems, we fall back to our own linker in the case when the same // library is opened multiple times on host. dlopen_handles_ is used to // detect that case. // Guarded by host_dlopen_handles_lock_; static std::unordered_set host_dlopen_handles_; // dlopen handle during runtime. void* dlopen_handle_; // TODO: Unique_ptr with custom deleter. // Dummy memory map objects corresponding to the regions mapped by dlopen. std::vector> dlopen_mmaps_; // The number of shared objects the linker told us about before loading. Used to // (optimistically) optimize the PreSetup stage (see comment there). size_t shared_objects_before_; DISALLOW_COPY_AND_ASSIGN(DlOpenOatFile); }; std::unordered_set DlOpenOatFile::host_dlopen_handles_; void DlOpenOatFile::PreLoad() { #ifdef __APPLE__ UNUSED(shared_objects_before_); LOG(FATAL) << "Should not reach here."; UNREACHABLE(); #else // Count the entries in dl_iterate_phdr we get at this point in time. struct dl_iterate_context { static int callback(struct dl_phdr_info *info ATTRIBUTE_UNUSED, size_t size ATTRIBUTE_UNUSED, void *data) { reinterpret_cast(data)->count++; return 0; // Continue iteration. } size_t count = 0; } context; dl_iterate_phdr(dl_iterate_context::callback, &context); shared_objects_before_ = context.count; #endif } bool DlOpenOatFile::Load(const std::string& elf_filename, uint8_t* oat_file_begin, bool writable, bool executable, bool low_4gb, std::string* error_msg) { // Use dlopen only when flagged to do so, and when it's OK to load things executable. // TODO: Also try when not executable? The issue here could be re-mapping as writable (as // !executable is a sign that we may want to patch), which may not be allowed for // various reasons. if (!kUseDlopen) { *error_msg = "DlOpen is disabled."; return false; } if (low_4gb) { *error_msg = "DlOpen does not support low 4gb loading."; return false; } if (writable) { *error_msg = "DlOpen does not support writable loading."; return false; } if (!executable) { *error_msg = "DlOpen does not support non-executable loading."; return false; } // dlopen always returns the same library if it is already opened on the host. For this reason // we only use dlopen if we are the target or we do not already have the dex file opened. Having // the same library loaded multiple times at different addresses is required for class unloading // and for having dex caches arrays in the .bss section. if (!kIsTargetBuild) { if (!kUseDlopenOnHost) { *error_msg = "DlOpen disabled for host."; return false; } } bool success = Dlopen(elf_filename, oat_file_begin, error_msg); DCHECK(dlopen_handle_ != nullptr || !success); return success; } bool DlOpenOatFile::Dlopen(const std::string& elf_filename, uint8_t* oat_file_begin, std::string* error_msg) { #ifdef __APPLE__ // The dl_iterate_phdr syscall is missing. There is similar API on OSX, // but let's fallback to the custom loading code for the time being. UNUSED(elf_filename, oat_file_begin); *error_msg = "Dlopen unsupported on Mac."; return false; #else { UniqueCPtr absolute_path(realpath(elf_filename.c_str(), nullptr)); if (absolute_path == nullptr) { *error_msg = StringPrintf("Failed to find absolute path for '%s'", elf_filename.c_str()); return false; } #ifdef __ANDROID__ android_dlextinfo extinfo; extinfo.flags = ANDROID_DLEXT_FORCE_LOAD | // Force-load, don't reuse handle // (open oat files multiple // times). ANDROID_DLEXT_FORCE_FIXED_VADDR; // Take a non-zero vaddr as absolute // (non-pic boot image). if (oat_file_begin != nullptr) { // extinfo.flags |= ANDROID_DLEXT_LOAD_AT_FIXED_ADDRESS; // Use the requested addr if extinfo.reserved_addr = oat_file_begin; // vaddr = 0. } // (pic boot image). dlopen_handle_ = android_dlopen_ext(absolute_path.get(), RTLD_NOW, &extinfo); #else UNUSED(oat_file_begin); static_assert(!kIsTargetBuild, "host_dlopen_handles_ will leak handles"); MutexLock mu(Thread::Current(), *Locks::host_dlopen_handles_lock_); dlopen_handle_ = dlopen(absolute_path.get(), RTLD_NOW); if (dlopen_handle_ != nullptr) { if (!host_dlopen_handles_.insert(dlopen_handle_).second) { dlclose(dlopen_handle_); dlopen_handle_ = nullptr; *error_msg = StringPrintf("host dlopen re-opened '%s'", elf_filename.c_str()); return false; } } #endif } if (dlopen_handle_ == nullptr) { *error_msg = StringPrintf("Failed to dlopen '%s': %s", elf_filename.c_str(), dlerror()); return false; } return true; #endif } void DlOpenOatFile::PreSetup(const std::string& elf_filename) { #ifdef __APPLE__ UNUSED(elf_filename); LOG(FATAL) << "Should not reach here."; UNREACHABLE(); #else struct dl_iterate_context { static int callback(struct dl_phdr_info *info, size_t /* size */, void *data) { auto* context = reinterpret_cast(data); context->shared_objects_seen++; if (context->shared_objects_seen < context->shared_objects_before) { // We haven't been called yet for anything we haven't seen before. Just continue. // Note: this is aggressively optimistic. If another thread was unloading a library, // we may miss out here. However, this does not happen often in practice. return 0; } // See whether this callback corresponds to the file which we have just loaded. bool contains_begin = false; for (int i = 0; i < info->dlpi_phnum; i++) { if (info->dlpi_phdr[i].p_type == PT_LOAD) { uint8_t* vaddr = reinterpret_cast(info->dlpi_addr + info->dlpi_phdr[i].p_vaddr); size_t memsz = info->dlpi_phdr[i].p_memsz; if (vaddr <= context->begin_ && context->begin_ < vaddr + memsz) { contains_begin = true; break; } } } // Add dummy mmaps for this file. if (contains_begin) { for (int i = 0; i < info->dlpi_phnum; i++) { if (info->dlpi_phdr[i].p_type == PT_LOAD) { uint8_t* vaddr = reinterpret_cast(info->dlpi_addr + info->dlpi_phdr[i].p_vaddr); size_t memsz = info->dlpi_phdr[i].p_memsz; MemMap* mmap = MemMap::MapDummy(info->dlpi_name, vaddr, memsz); context->dlopen_mmaps_->push_back(std::unique_ptr(mmap)); } } return 1; // Stop iteration and return 1 from dl_iterate_phdr. } return 0; // Continue iteration and return 0 from dl_iterate_phdr when finished. } const uint8_t* const begin_; std::vector>* const dlopen_mmaps_; const size_t shared_objects_before; size_t shared_objects_seen; }; dl_iterate_context context = { Begin(), &dlopen_mmaps_, shared_objects_before_, 0}; if (dl_iterate_phdr(dl_iterate_context::callback, &context) == 0) { // Hm. Maybe our optimization went wrong. Try another time with shared_objects_before == 0 // before giving up. This should be unusual. VLOG(oat) << "Need a second run in PreSetup, didn't find with shared_objects_before=" << shared_objects_before_; dl_iterate_context context0 = { Begin(), &dlopen_mmaps_, 0, 0}; if (dl_iterate_phdr(dl_iterate_context::callback, &context0) == 0) { // OK, give up and print an error. PrintFileToLog("/proc/self/maps", LogSeverity::WARNING); LOG(ERROR) << "File " << elf_filename << " loaded with dlopen but cannot find its mmaps."; } } #endif } //////////////////////////////////////////////// // OatFile via our own ElfFile implementation // //////////////////////////////////////////////// class ElfOatFile FINAL : public OatFileBase { public: ElfOatFile(const std::string& filename, bool executable) : OatFileBase(filename, executable) {} static ElfOatFile* OpenElfFile(File* file, const std::string& location, uint8_t* requested_base, uint8_t* oat_file_begin, // Override base if not null bool writable, bool executable, bool low_4gb, const char* abs_dex_location, std::string* error_msg); bool InitializeFromElfFile(ElfFile* elf_file, const char* abs_dex_location, std::string* error_msg); protected: const uint8_t* FindDynamicSymbolAddress(const std::string& symbol_name, std::string* error_msg) const OVERRIDE { const uint8_t* ptr = elf_file_->FindDynamicSymbolAddress(symbol_name); if (ptr == nullptr) { *error_msg = "(Internal implementation could not find symbol)"; } return ptr; } void PreLoad() OVERRIDE { } bool Load(const std::string& elf_filename, uint8_t* oat_file_begin, // Override where the file is loaded to if not null bool writable, bool executable, bool low_4gb, std::string* error_msg) OVERRIDE; void PreSetup(const std::string& elf_filename ATTRIBUTE_UNUSED) OVERRIDE { } private: bool ElfFileOpen(File* file, uint8_t* oat_file_begin, // Override where the file is loaded to if not null bool writable, bool executable, bool low_4gb, std::string* error_msg); private: // Backing memory map for oat file during cross compilation. std::unique_ptr elf_file_; DISALLOW_COPY_AND_ASSIGN(ElfOatFile); }; ElfOatFile* ElfOatFile::OpenElfFile(File* file, const std::string& location, uint8_t* requested_base, uint8_t* oat_file_begin, // Override base if not null bool writable, bool executable, bool low_4gb, const char* abs_dex_location, std::string* error_msg) { ScopedTrace trace("Open elf file " + location); std::unique_ptr oat_file(new ElfOatFile(location, executable)); bool success = oat_file->ElfFileOpen(file, oat_file_begin, writable, low_4gb, executable, error_msg); if (!success) { CHECK(!error_msg->empty()); return nullptr; } // Complete the setup. if (!oat_file->ComputeFields(requested_base, file->GetPath(), error_msg)) { return nullptr; } if (!oat_file->Setup(abs_dex_location, error_msg)) { return nullptr; } return oat_file.release(); } bool ElfOatFile::InitializeFromElfFile(ElfFile* elf_file, const char* abs_dex_location, std::string* error_msg) { ScopedTrace trace(__PRETTY_FUNCTION__); if (IsExecutable()) { *error_msg = "Cannot initialize from elf file in executable mode."; return false; } elf_file_.reset(elf_file); uint64_t offset, size; bool has_section = elf_file->GetSectionOffsetAndSize(".rodata", &offset, &size); CHECK(has_section); SetBegin(elf_file->Begin() + offset); SetEnd(elf_file->Begin() + size + offset); // Ignore the optional .bss section when opening non-executable. return Setup(abs_dex_location, error_msg); } bool ElfOatFile::Load(const std::string& elf_filename, uint8_t* oat_file_begin, // Override where the file is loaded to if not null bool writable, bool executable, bool low_4gb, std::string* error_msg) { ScopedTrace trace(__PRETTY_FUNCTION__); std::unique_ptr file(OS::OpenFileForReading(elf_filename.c_str())); if (file == nullptr) { *error_msg = StringPrintf("Failed to open oat filename for reading: %s", strerror(errno)); return false; } return ElfOatFile::ElfFileOpen(file.get(), oat_file_begin, writable, executable, low_4gb, error_msg); } bool ElfOatFile::ElfFileOpen(File* file, uint8_t* oat_file_begin, bool writable, bool executable, bool low_4gb, std::string* error_msg) { ScopedTrace trace(__PRETTY_FUNCTION__); // TODO: rename requested_base to oat_data_begin elf_file_.reset(ElfFile::Open(file, writable, /*program_header_only*/true, low_4gb, error_msg, oat_file_begin)); if (elf_file_ == nullptr) { DCHECK(!error_msg->empty()); return false; } bool loaded = elf_file_->Load(file, executable, low_4gb, error_msg); DCHECK(loaded || !error_msg->empty()); return loaded; } ////////////////////////// // General OatFile code // ////////////////////////// std::string OatFile::ResolveRelativeEncodedDexLocation( const char* abs_dex_location, const std::string& rel_dex_location) { if (abs_dex_location != nullptr && rel_dex_location[0] != '/') { // Strip :classes.dex used for secondary multidex files. std::string base = DexFile::GetBaseLocation(rel_dex_location); std::string multidex_suffix = DexFile::GetMultiDexSuffix(rel_dex_location); // Check if the base is a suffix of the provided abs_dex_location. std::string target_suffix = "/" + base; std::string abs_location(abs_dex_location); if (abs_location.size() > target_suffix.size()) { size_t pos = abs_location.size() - target_suffix.size(); if (abs_location.compare(pos, std::string::npos, target_suffix) == 0) { return abs_location + multidex_suffix; } } } return rel_dex_location; } static void CheckLocation(const std::string& location) { CHECK(!location.empty()); } OatFile* OatFile::OpenWithElfFile(ElfFile* elf_file, const std::string& location, const char* abs_dex_location, std::string* error_msg) { std::unique_ptr oat_file(new ElfOatFile(location, false /* executable */)); return oat_file->InitializeFromElfFile(elf_file, abs_dex_location, error_msg) ? oat_file.release() : nullptr; } OatFile* OatFile::Open(const std::string& filename, const std::string& location, uint8_t* requested_base, uint8_t* oat_file_begin, bool executable, bool low_4gb, const char* abs_dex_location, std::string* error_msg) { ScopedTrace trace("Open oat file " + location); CHECK(!filename.empty()) << location; CheckLocation(location); // Check that the file even exists, fast-fail. if (!OS::FileExists(filename.c_str())) { *error_msg = StringPrintf("File %s does not exist.", filename.c_str()); return nullptr; } // Try dlopen first, as it is required for native debuggability. This will fail fast if dlopen is // disabled. OatFile* with_dlopen = OatFileBase::OpenOatFile(filename, location, requested_base, oat_file_begin, false, executable, low_4gb, abs_dex_location, error_msg); if (with_dlopen != nullptr) { return with_dlopen; } if (kPrintDlOpenErrorMessage) { LOG(ERROR) << "Failed to dlopen: " << filename << " with error " << *error_msg; } // If we aren't trying to execute, we just use our own ElfFile loader for a couple reasons: // // On target, dlopen may fail when compiling due to selinux restrictions on installd. // // We use our own ELF loader for Quick to deal with legacy apps that // open a generated dex file by name, remove the file, then open // another generated dex file with the same name. http://b/10614658 // // On host, dlopen is expected to fail when cross compiling, so fall back to OpenElfFile. // // // Another independent reason is the absolute placement of boot.oat. dlopen on the host usually // does honor the virtual address encoded in the ELF file only for ET_EXEC files, not ET_DYN. OatFile* with_internal = OatFileBase::OpenOatFile(filename, location, requested_base, oat_file_begin, false, executable, low_4gb, abs_dex_location, error_msg); return with_internal; } OatFile* OatFile::OpenWritable(File* file, const std::string& location, const char* abs_dex_location, std::string* error_msg) { CheckLocation(location); return ElfOatFile::OpenElfFile(file, location, nullptr, nullptr, true, false, /*low_4gb*/false, abs_dex_location, error_msg); } OatFile* OatFile::OpenReadable(File* file, const std::string& location, const char* abs_dex_location, std::string* error_msg) { CheckLocation(location); return ElfOatFile::OpenElfFile(file, location, nullptr, nullptr, false, false, /*low_4gb*/false, abs_dex_location, error_msg); } OatFile::OatFile(const std::string& location, bool is_executable) : location_(location), begin_(nullptr), end_(nullptr), bss_begin_(nullptr), bss_end_(nullptr), is_executable_(is_executable), secondary_lookup_lock_("OatFile secondary lookup lock", kOatFileSecondaryLookupLock) { CHECK(!location_.empty()); } OatFile::~OatFile() { STLDeleteElements(&oat_dex_files_storage_); } const OatHeader& OatFile::GetOatHeader() const { return *reinterpret_cast(Begin()); } const uint8_t* OatFile::Begin() const { CHECK(begin_ != nullptr); return begin_; } const uint8_t* OatFile::End() const { CHECK(end_ != nullptr); return end_; } const uint8_t* OatFile::BssBegin() const { return bss_begin_; } const uint8_t* OatFile::BssEnd() const { return bss_end_; } const OatFile::OatDexFile* OatFile::GetOatDexFile(const char* dex_location, const uint32_t* dex_location_checksum, bool warn_if_not_found) const { // NOTE: We assume here that the canonical location for a given dex_location never // changes. If it does (i.e. some symlink used by the filename changes) we may return // an incorrect OatDexFile. As long as we have a checksum to check, we shall return // an identical file or fail; otherwise we may see some unpredictable failures. // TODO: Additional analysis of usage patterns to see if this can be simplified // without any performance loss, for example by not doing the first lock-free lookup. const OatFile::OatDexFile* oat_dex_file = nullptr; StringPiece key(dex_location); // Try to find the key cheaply in the oat_dex_files_ map which holds dex locations // directly mentioned in the oat file and doesn't require locking. auto primary_it = oat_dex_files_.find(key); if (primary_it != oat_dex_files_.end()) { oat_dex_file = primary_it->second; DCHECK(oat_dex_file != nullptr); } else { // This dex_location is not one of the dex locations directly mentioned in the // oat file. The correct lookup is via the canonical location but first see in // the secondary_oat_dex_files_ whether we've looked up this location before. MutexLock mu(Thread::Current(), secondary_lookup_lock_); auto secondary_lb = secondary_oat_dex_files_.lower_bound(key); if (secondary_lb != secondary_oat_dex_files_.end() && key == secondary_lb->first) { oat_dex_file = secondary_lb->second; // May be null. } else { // We haven't seen this dex_location before, we must check the canonical location. std::string dex_canonical_location = DexFile::GetDexCanonicalLocation(dex_location); if (dex_canonical_location != dex_location) { StringPiece canonical_key(dex_canonical_location); auto canonical_it = oat_dex_files_.find(canonical_key); if (canonical_it != oat_dex_files_.end()) { oat_dex_file = canonical_it->second; } // else keep null. } // else keep null. // Copy the key to the string_cache_ and store the result in secondary map. string_cache_.emplace_back(key.data(), key.length()); StringPiece key_copy(string_cache_.back()); secondary_oat_dex_files_.PutBefore(secondary_lb, key_copy, oat_dex_file); } } if (oat_dex_file != nullptr && (dex_location_checksum == nullptr || oat_dex_file->GetDexFileLocationChecksum() == *dex_location_checksum)) { return oat_dex_file; } if (warn_if_not_found) { std::string dex_canonical_location = DexFile::GetDexCanonicalLocation(dex_location); std::string checksum(""); if (dex_location_checksum != nullptr) { checksum = StringPrintf("0x%08x", *dex_location_checksum); } LOG(WARNING) << "Failed to find OatDexFile for DexFile " << dex_location << " ( canonical path " << dex_canonical_location << ")" << " with checksum " << checksum << " in OatFile " << GetLocation(); if (kIsDebugBuild) { for (const OatDexFile* odf : oat_dex_files_storage_) { LOG(WARNING) << "OatFile " << GetLocation() << " contains OatDexFile " << odf->GetDexFileLocation() << " (canonical path " << odf->GetCanonicalDexFileLocation() << ")" << " with checksum 0x" << std::hex << odf->GetDexFileLocationChecksum(); } } } return nullptr; } OatFile::OatDexFile::OatDexFile(const OatFile* oat_file, const std::string& dex_file_location, const std::string& canonical_dex_file_location, uint32_t dex_file_location_checksum, const uint8_t* dex_file_pointer, const uint8_t* lookup_table_data, const uint32_t* oat_class_offsets_pointer, uint8_t* dex_cache_arrays) : oat_file_(oat_file), dex_file_location_(dex_file_location), canonical_dex_file_location_(canonical_dex_file_location), dex_file_location_checksum_(dex_file_location_checksum), dex_file_pointer_(dex_file_pointer), lookup_table_data_(lookup_table_data), oat_class_offsets_pointer_(oat_class_offsets_pointer), dex_cache_arrays_(dex_cache_arrays) {} OatFile::OatDexFile::~OatDexFile() {} size_t OatFile::OatDexFile::FileSize() const { return reinterpret_cast(dex_file_pointer_)->file_size_; } std::unique_ptr OatFile::OatDexFile::OpenDexFile(std::string* error_msg) const { ScopedTrace trace(__PRETTY_FUNCTION__); return DexFile::Open(dex_file_pointer_, FileSize(), dex_file_location_, dex_file_location_checksum_, this, false /* verify */, error_msg); } uint32_t OatFile::OatDexFile::GetOatClassOffset(uint16_t class_def_index) const { return oat_class_offsets_pointer_[class_def_index]; } OatFile::OatClass OatFile::OatDexFile::GetOatClass(uint16_t class_def_index) const { uint32_t oat_class_offset = GetOatClassOffset(class_def_index); const uint8_t* oat_class_pointer = oat_file_->Begin() + oat_class_offset; CHECK_LT(oat_class_pointer, oat_file_->End()) << oat_file_->GetLocation(); const uint8_t* status_pointer = oat_class_pointer; CHECK_LT(status_pointer, oat_file_->End()) << oat_file_->GetLocation(); mirror::Class::Status status = static_cast(*reinterpret_cast(status_pointer)); CHECK_LT(status, mirror::Class::kStatusMax); const uint8_t* type_pointer = status_pointer + sizeof(uint16_t); CHECK_LT(type_pointer, oat_file_->End()) << oat_file_->GetLocation(); OatClassType type = static_cast(*reinterpret_cast(type_pointer)); CHECK_LT(type, kOatClassMax); const uint8_t* after_type_pointer = type_pointer + sizeof(int16_t); CHECK_LE(after_type_pointer, oat_file_->End()) << oat_file_->GetLocation(); uint32_t bitmap_size = 0; const uint8_t* bitmap_pointer = nullptr; const uint8_t* methods_pointer = nullptr; if (type != kOatClassNoneCompiled) { if (type == kOatClassSomeCompiled) { bitmap_size = static_cast(*reinterpret_cast(after_type_pointer)); bitmap_pointer = after_type_pointer + sizeof(bitmap_size); CHECK_LE(bitmap_pointer, oat_file_->End()) << oat_file_->GetLocation(); methods_pointer = bitmap_pointer + bitmap_size; } else { methods_pointer = after_type_pointer; } CHECK_LE(methods_pointer, oat_file_->End()) << oat_file_->GetLocation(); } return OatFile::OatClass(oat_file_, status, type, bitmap_size, reinterpret_cast(bitmap_pointer), reinterpret_cast(methods_pointer)); } OatFile::OatClass::OatClass(const OatFile* oat_file, mirror::Class::Status status, OatClassType type, uint32_t bitmap_size, const uint32_t* bitmap_pointer, const OatMethodOffsets* methods_pointer) : oat_file_(oat_file), status_(status), type_(type), bitmap_(bitmap_pointer), methods_pointer_(methods_pointer) { switch (type_) { case kOatClassAllCompiled: { CHECK_EQ(0U, bitmap_size); CHECK(bitmap_pointer == nullptr); CHECK(methods_pointer != nullptr); break; } case kOatClassSomeCompiled: { CHECK_NE(0U, bitmap_size); CHECK(bitmap_pointer != nullptr); CHECK(methods_pointer != nullptr); break; } case kOatClassNoneCompiled: { CHECK_EQ(0U, bitmap_size); CHECK(bitmap_pointer == nullptr); CHECK(methods_pointer_ == nullptr); break; } case kOatClassMax: { LOG(FATAL) << "Invalid OatClassType " << type_; break; } } } uint32_t OatFile::OatClass::GetOatMethodOffsetsOffset(uint32_t method_index) const { const OatMethodOffsets* oat_method_offsets = GetOatMethodOffsets(method_index); if (oat_method_offsets == nullptr) { return 0u; } return reinterpret_cast(oat_method_offsets) - oat_file_->Begin(); } const OatMethodOffsets* OatFile::OatClass::GetOatMethodOffsets(uint32_t method_index) const { // NOTE: We don't keep the number of methods and cannot do a bounds check for method_index. if (methods_pointer_ == nullptr) { CHECK_EQ(kOatClassNoneCompiled, type_); return nullptr; } size_t methods_pointer_index; if (bitmap_ == nullptr) { CHECK_EQ(kOatClassAllCompiled, type_); methods_pointer_index = method_index; } else { CHECK_EQ(kOatClassSomeCompiled, type_); if (!BitVector::IsBitSet(bitmap_, method_index)) { return nullptr; } size_t num_set_bits = BitVector::NumSetBits(bitmap_, method_index); methods_pointer_index = num_set_bits; } const OatMethodOffsets& oat_method_offsets = methods_pointer_[methods_pointer_index]; return &oat_method_offsets; } const OatFile::OatMethod OatFile::OatClass::GetOatMethod(uint32_t method_index) const { const OatMethodOffsets* oat_method_offsets = GetOatMethodOffsets(method_index); if (oat_method_offsets == nullptr) { return OatMethod(nullptr, 0); } if (oat_file_->IsExecutable() || Runtime::Current() == nullptr || // This case applies for oatdump. Runtime::Current()->IsAotCompiler()) { return OatMethod(oat_file_->Begin(), oat_method_offsets->code_offset_); } // We aren't allowed to use the compiled code. We just force it down the interpreted / jit // version. return OatMethod(oat_file_->Begin(), 0); } void OatFile::OatMethod::LinkMethod(ArtMethod* method) const { CHECK(method != nullptr); method->SetEntryPointFromQuickCompiledCode(GetQuickCode()); } bool OatFile::HasPatchInfo() const { return GetOatHeader().HasPatchInfo(); } bool OatFile::IsPic() const { return GetOatHeader().IsPic(); // TODO: Check against oat_patches. b/18144996 } bool OatFile::IsDebuggable() const { return GetOatHeader().IsDebuggable(); } CompilerFilter::Filter OatFile::GetCompilerFilter() const { return GetOatHeader().GetCompilerFilter(); } static constexpr char kDexClassPathEncodingSeparator = '*'; std::string OatFile::EncodeDexFileDependencies(const std::vector& dex_files) { std::ostringstream out; for (const DexFile* dex_file : dex_files) { out << dex_file->GetLocation().c_str(); out << kDexClassPathEncodingSeparator; out << dex_file->GetLocationChecksum(); out << kDexClassPathEncodingSeparator; } return out.str(); } bool OatFile::CheckStaticDexFileDependencies(const char* dex_dependencies, std::string* msg) { if (dex_dependencies == nullptr || dex_dependencies[0] == 0) { // No dependencies. return true; } // Assumption: this is not performance-critical. So it's OK to do this with a std::string and // Split() instead of manual parsing of the combined char*. std::vector split; Split(dex_dependencies, kDexClassPathEncodingSeparator, &split); if (split.size() % 2 != 0) { // Expected pairs of location and checksum. *msg = StringPrintf("Odd number of elements in dependency list %s", dex_dependencies); return false; } for (auto it = split.begin(), end = split.end(); it != end; it += 2) { std::string& location = *it; std::string& checksum = *(it + 1); int64_t converted = strtoll(checksum.c_str(), nullptr, 10); if (converted == 0) { // Conversion error. *msg = StringPrintf("Conversion error for %s", checksum.c_str()); return false; } uint32_t dex_checksum; std::string error_msg; if (DexFile::GetChecksum(DexFile::GetDexCanonicalLocation(location.c_str()).c_str(), &dex_checksum, &error_msg)) { if (converted != dex_checksum) { *msg = StringPrintf("Checksums don't match for %s: %" PRId64 " vs %u", location.c_str(), converted, dex_checksum); return false; } } else { // Problem retrieving checksum. // TODO: odex files? *msg = StringPrintf("Could not retrieve checksum for %s: %s", location.c_str(), error_msg.c_str()); return false; } } return true; } bool OatFile::GetDexLocationsFromDependencies(const char* dex_dependencies, std::vector* locations) { DCHECK(locations != nullptr); if (dex_dependencies == nullptr || dex_dependencies[0] == 0) { return true; } // Assumption: this is not performance-critical. So it's OK to do this with a std::string and // Split() instead of manual parsing of the combined char*. std::vector split; Split(dex_dependencies, kDexClassPathEncodingSeparator, &split); if (split.size() % 2 != 0) { // Expected pairs of location and checksum. return false; } for (auto it = split.begin(), end = split.end(); it != end; it += 2) { locations->push_back(*it); } return true; } } // namespace art