/* * Copyright (C) 2017 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 "class_loader_context.h" #include <android-base/parseint.h> #include <android-base/strings.h> #include "art_field-inl.h" #include "base/casts.h" #include "base/dchecked_vector.h" #include "base/stl_util.h" #include "class_linker.h" #include "class_loader_utils.h" #include "class_root.h" #include "dex/art_dex_file_loader.h" #include "dex/dex_file.h" #include "dex/dex_file_loader.h" #include "handle_scope-inl.h" #include "jni/jni_internal.h" #include "mirror/class_loader-inl.h" #include "mirror/object_array-alloc-inl.h" #include "nativehelper/scoped_local_ref.h" #include "oat_file_assistant.h" #include "obj_ptr-inl.h" #include "runtime.h" #include "scoped_thread_state_change-inl.h" #include "thread.h" #include "well_known_classes.h" namespace art { static constexpr char kPathClassLoaderString[] = "PCL"; static constexpr char kDelegateLastClassLoaderString[] = "DLC"; static constexpr char kInMemoryDexClassLoaderString[] = "IMC"; static constexpr char kClassLoaderOpeningMark = '['; static constexpr char kClassLoaderClosingMark = ']'; static constexpr char kClassLoaderSharedLibraryOpeningMark = '{'; static constexpr char kClassLoaderSharedLibraryClosingMark = '}'; static constexpr char kClassLoaderSharedLibrarySeparator = '#'; static constexpr char kClassLoaderSeparator = ';'; static constexpr char kClasspathSeparator = ':'; static constexpr char kDexFileChecksumSeparator = '*'; static constexpr char kInMemoryDexClassLoaderDexLocationMagic[] = "<unknown>"; ClassLoaderContext::ClassLoaderContext() : special_shared_library_(false), dex_files_open_attempted_(false), dex_files_open_result_(false), owns_the_dex_files_(true) {} ClassLoaderContext::ClassLoaderContext(bool owns_the_dex_files) : special_shared_library_(false), dex_files_open_attempted_(true), dex_files_open_result_(true), owns_the_dex_files_(owns_the_dex_files) {} // Utility method to add parent and shared libraries of `info` into // the `work_list`. static void AddToWorkList( ClassLoaderContext::ClassLoaderInfo* info, std::vector<ClassLoaderContext::ClassLoaderInfo*>& work_list) { if (info->parent != nullptr) { work_list.push_back(info->parent.get()); } for (size_t i = 0; i < info->shared_libraries.size(); ++i) { work_list.push_back(info->shared_libraries[i].get()); } } ClassLoaderContext::~ClassLoaderContext() { if (!owns_the_dex_files_ && class_loader_chain_ != nullptr) { // If the context does not own the dex/oat files release the unique pointers to // make sure we do not de-allocate them. std::vector<ClassLoaderInfo*> work_list; work_list.push_back(class_loader_chain_.get()); while (!work_list.empty()) { ClassLoaderInfo* info = work_list.back(); work_list.pop_back(); for (std::unique_ptr<OatFile>& oat_file : info->opened_oat_files) { oat_file.release(); // NOLINT b/117926937 } for (std::unique_ptr<const DexFile>& dex_file : info->opened_dex_files) { dex_file.release(); // NOLINT b/117926937 } AddToWorkList(info, work_list); } } } std::unique_ptr<ClassLoaderContext> ClassLoaderContext::Default() { return Create(""); } std::unique_ptr<ClassLoaderContext> ClassLoaderContext::Create(const std::string& spec) { std::unique_ptr<ClassLoaderContext> result(new ClassLoaderContext()); if (result->Parse(spec)) { return result; } else { return nullptr; } } static size_t FindMatchingSharedLibraryCloseMarker(const std::string& spec, size_t shared_library_open_index) { // Counter of opened shared library marker we've encountered so far. uint32_t counter = 1; // The index at which we're operating in the loop. uint32_t string_index = shared_library_open_index + 1; size_t shared_library_close = std::string::npos; while (counter != 0) { shared_library_close = spec.find_first_of(kClassLoaderSharedLibraryClosingMark, string_index); size_t shared_library_open = spec.find_first_of(kClassLoaderSharedLibraryOpeningMark, string_index); if (shared_library_close == std::string::npos) { // No matching closing marker. Return an error. break; } if ((shared_library_open == std::string::npos) || (shared_library_close < shared_library_open)) { // We have seen a closing marker. Decrement the counter. --counter; // Move the search index forward. string_index = shared_library_close + 1; } else { // New nested opening marker. Increment the counter and move the search // index after the marker. ++counter; string_index = shared_library_open + 1; } } return shared_library_close; } // The expected format is: // "ClassLoaderType1[ClasspathElem1*Checksum1:ClasspathElem2*Checksum2...]{ClassLoaderType2[...]}". // The checksum part of the format is expected only if parse_cheksums is true. std::unique_ptr<ClassLoaderContext::ClassLoaderInfo> ClassLoaderContext::ParseClassLoaderSpec( const std::string& class_loader_spec, bool parse_checksums) { ClassLoaderType class_loader_type = ExtractClassLoaderType(class_loader_spec); if (class_loader_type == kInvalidClassLoader) { return nullptr; } // InMemoryDexClassLoader's dex location is always bogus. Special-case it. if (class_loader_type == kInMemoryDexClassLoader) { if (parse_checksums) { // Make sure that OpenDexFiles() will never be attempted on this context // because the dex locations of IMC do not correspond to real files. CHECK(!dex_files_open_attempted_ || !dex_files_open_result_) << "Parsing spec not supported when context created from a ClassLoader object"; dex_files_open_attempted_ = true; dex_files_open_result_ = false; } else { // Checksums are not provided and dex locations themselves have no meaning // (although we keep them in the spec to simplify parsing). Treat this as // an unknown class loader. // We can hit this case if dex2oat is invoked with a spec containing IMC. // Because the dex file data is only available at runtime, we cannot proceed. return nullptr; } } const char* class_loader_type_str = GetClassLoaderTypeName(class_loader_type); size_t type_str_size = strlen(class_loader_type_str); CHECK_EQ(0, class_loader_spec.compare(0, type_str_size, class_loader_type_str)); // Check the opening and closing markers. if (class_loader_spec[type_str_size] != kClassLoaderOpeningMark) { return nullptr; } if ((class_loader_spec[class_loader_spec.length() - 1] != kClassLoaderClosingMark) && (class_loader_spec[class_loader_spec.length() - 1] != kClassLoaderSharedLibraryClosingMark)) { return nullptr; } size_t closing_index = class_loader_spec.find_first_of(kClassLoaderClosingMark); // At this point we know the format is ok; continue and extract the classpath. // Note that class loaders with an empty class path are allowed. std::string classpath = class_loader_spec.substr(type_str_size + 1, closing_index - type_str_size - 1); std::unique_ptr<ClassLoaderInfo> info(new ClassLoaderInfo(class_loader_type)); if (!parse_checksums) { DCHECK(class_loader_type != kInMemoryDexClassLoader); Split(classpath, kClasspathSeparator, &info->classpath); } else { std::vector<std::string> classpath_elements; Split(classpath, kClasspathSeparator, &classpath_elements); for (const std::string& element : classpath_elements) { std::vector<std::string> dex_file_with_checksum; Split(element, kDexFileChecksumSeparator, &dex_file_with_checksum); if (dex_file_with_checksum.size() != 2) { return nullptr; } uint32_t checksum = 0; if (!android::base::ParseUint(dex_file_with_checksum[1].c_str(), &checksum)) { return nullptr; } if ((class_loader_type == kInMemoryDexClassLoader) && (dex_file_with_checksum[0] != kInMemoryDexClassLoaderDexLocationMagic)) { return nullptr; } info->classpath.push_back(dex_file_with_checksum[0]); info->checksums.push_back(checksum); } } if ((class_loader_spec[class_loader_spec.length() - 1] == kClassLoaderSharedLibraryClosingMark) && (class_loader_spec[class_loader_spec.length() - 2] != kClassLoaderSharedLibraryOpeningMark)) { // Non-empty list of shared libraries. size_t start_index = class_loader_spec.find_first_of(kClassLoaderSharedLibraryOpeningMark); if (start_index == std::string::npos) { return nullptr; } std::string shared_libraries_spec = class_loader_spec.substr(start_index + 1, class_loader_spec.length() - start_index - 2); std::vector<std::string> shared_libraries; size_t cursor = 0; while (cursor != shared_libraries_spec.length()) { size_t shared_library_separator = shared_libraries_spec.find_first_of(kClassLoaderSharedLibrarySeparator, cursor); size_t shared_library_open = shared_libraries_spec.find_first_of(kClassLoaderSharedLibraryOpeningMark, cursor); std::string shared_library_spec; if (shared_library_separator == std::string::npos) { // Only one shared library, for example: // PCL[...] shared_library_spec = shared_libraries_spec.substr(cursor, shared_libraries_spec.length() - cursor); cursor = shared_libraries_spec.length(); } else if ((shared_library_open == std::string::npos) || (shared_library_open > shared_library_separator)) { // We found a shared library without nested shared libraries, for example: // PCL[...]#PCL[...]{...} shared_library_spec = shared_libraries_spec.substr(cursor, shared_library_separator - cursor); cursor = shared_library_separator + 1; } else { // The shared library contains nested shared libraries. Find the matching closing shared // marker for it. size_t closing_marker = FindMatchingSharedLibraryCloseMarker(shared_libraries_spec, shared_library_open); if (closing_marker == std::string::npos) { // No matching closing marker, return an error. return nullptr; } shared_library_spec = shared_libraries_spec.substr(cursor, closing_marker + 1 - cursor); cursor = closing_marker + 1; if (cursor != shared_libraries_spec.length() && shared_libraries_spec[cursor] == kClassLoaderSharedLibrarySeparator) { // Pass the shared library separator marker. ++cursor; } } std::unique_ptr<ClassLoaderInfo> shared_library( ParseInternal(shared_library_spec, parse_checksums)); if (shared_library == nullptr) { return nullptr; } info->shared_libraries.push_back(std::move(shared_library)); } } return info; } // Extracts the class loader type from the given spec. // Return ClassLoaderContext::kInvalidClassLoader if the class loader type is not // recognized. ClassLoaderContext::ClassLoaderType ClassLoaderContext::ExtractClassLoaderType(const std::string& class_loader_spec) { const ClassLoaderType kValidTypes[] = { kPathClassLoader, kDelegateLastClassLoader, kInMemoryDexClassLoader }; for (const ClassLoaderType& type : kValidTypes) { const char* type_str = GetClassLoaderTypeName(type); if (class_loader_spec.compare(0, strlen(type_str), type_str) == 0) { return type; } } return kInvalidClassLoader; } // The format: ClassLoaderType1[ClasspathElem1:ClasspathElem2...];ClassLoaderType2[...]... // ClassLoaderType is either "PCL" (PathClassLoader) or "DLC" (DelegateLastClassLoader). // ClasspathElem is the path of dex/jar/apk file. bool ClassLoaderContext::Parse(const std::string& spec, bool parse_checksums) { if (spec.empty()) { // By default we load the dex files in a PathClassLoader. // So an empty spec is equivalent to an empty PathClassLoader (this happens when running // tests) class_loader_chain_.reset(new ClassLoaderInfo(kPathClassLoader)); return true; } // Stop early if we detect the special shared library, which may be passed as the classpath // for dex2oat when we want to skip the shared libraries check. if (spec == OatFile::kSpecialSharedLibrary) { LOG(INFO) << "The ClassLoaderContext is a special shared library."; special_shared_library_ = true; return true; } CHECK(class_loader_chain_ == nullptr); class_loader_chain_.reset(ParseInternal(spec, parse_checksums)); return class_loader_chain_ != nullptr; } ClassLoaderContext::ClassLoaderInfo* ClassLoaderContext::ParseInternal( const std::string& spec, bool parse_checksums) { CHECK(!spec.empty()); CHECK_NE(spec, OatFile::kSpecialSharedLibrary); std::string remaining = spec; std::unique_ptr<ClassLoaderInfo> first(nullptr); ClassLoaderInfo* previous_iteration = nullptr; while (!remaining.empty()) { std::string class_loader_spec; size_t first_class_loader_separator = remaining.find_first_of(kClassLoaderSeparator); size_t first_shared_library_open = remaining.find_first_of(kClassLoaderSharedLibraryOpeningMark); if (first_class_loader_separator == std::string::npos) { // Only one class loader, for example: // PCL[...] class_loader_spec = remaining; remaining = ""; } else if ((first_shared_library_open == std::string::npos) || (first_shared_library_open > first_class_loader_separator)) { // We found a class loader spec without shared libraries, for example: // PCL[...];PCL[...]{...} class_loader_spec = remaining.substr(0, first_class_loader_separator); remaining = remaining.substr(first_class_loader_separator + 1, remaining.size() - first_class_loader_separator - 1); } else { // The class loader spec contains shared libraries. Find the matching closing // shared library marker for it. uint32_t shared_library_close = FindMatchingSharedLibraryCloseMarker(remaining, first_shared_library_open); if (shared_library_close == std::string::npos) { LOG(ERROR) << "Invalid class loader spec: " << class_loader_spec; return nullptr; } class_loader_spec = remaining.substr(0, shared_library_close + 1); // Compute the remaining string to analyze. if (remaining.size() == shared_library_close + 1) { remaining = ""; } else if ((remaining.size() == shared_library_close + 2) || (remaining.at(shared_library_close + 1) != kClassLoaderSeparator)) { LOG(ERROR) << "Invalid class loader spec: " << class_loader_spec; return nullptr; } else { remaining = remaining.substr(shared_library_close + 2, remaining.size() - shared_library_close - 2); } } std::unique_ptr<ClassLoaderInfo> info = ParseClassLoaderSpec(class_loader_spec, parse_checksums); if (info == nullptr) { LOG(ERROR) << "Invalid class loader spec: " << class_loader_spec; return nullptr; } if (first == nullptr) { first = std::move(info); previous_iteration = first.get(); } else { CHECK(previous_iteration != nullptr); previous_iteration->parent = std::move(info); previous_iteration = previous_iteration->parent.get(); } } return first.release(); } // Opens requested class path files and appends them to opened_dex_files. If the dex files have // been stripped, this opens them from their oat files (which get added to opened_oat_files). bool ClassLoaderContext::OpenDexFiles(InstructionSet isa, const std::string& classpath_dir, const std::vector<int>& fds) { if (dex_files_open_attempted_) { // Do not attempt to re-open the files if we already tried. return dex_files_open_result_; } dex_files_open_attempted_ = true; // Assume we can open all dex files. If not, we will set this to false as we go. dex_files_open_result_ = true; if (special_shared_library_) { // Nothing to open if the context is a special shared library. return true; } // Note that we try to open all dex files even if some fail. // We may get resource-only apks which we cannot load. // TODO(calin): Refine the dex opening interface to be able to tell if an archive contains // no dex files. So that we can distinguish the real failures... const ArtDexFileLoader dex_file_loader; std::vector<ClassLoaderInfo*> work_list; CHECK(class_loader_chain_ != nullptr); work_list.push_back(class_loader_chain_.get()); size_t dex_file_index = 0; while (!work_list.empty()) { ClassLoaderInfo* info = work_list.back(); work_list.pop_back(); DCHECK(info->type != kInMemoryDexClassLoader) << __FUNCTION__ << " not supported for IMC"; size_t opened_dex_files_index = info->opened_dex_files.size(); for (const std::string& cp_elem : info->classpath) { // If path is relative, append it to the provided base directory. std::string location = cp_elem; if (location[0] != '/' && !classpath_dir.empty()) { location = classpath_dir + (classpath_dir.back() == '/' ? "" : "/") + location; } // If file descriptors were provided for the class loader context dex paths, // get the descriptor which correponds to this dex path. We assume the `fds` // vector follows the same order as a flattened class loader context. int fd = -1; if (!fds.empty()) { if (dex_file_index >= fds.size()) { LOG(WARNING) << "Number of FDs is smaller than number of dex files in the context"; dex_files_open_result_ = false; return false; } fd = fds[dex_file_index++]; DCHECK_GE(fd, 0); } std::string error_msg; // When opening the dex files from the context we expect their checksum to match their // contents. So pass true to verify_checksum. if (fd < 0) { if (!dex_file_loader.Open(location.c_str(), location.c_str(), Runtime::Current()->IsVerificationEnabled(), /*verify_checksum=*/ true, &error_msg, &info->opened_dex_files)) { // If we fail to open the dex file because it's been stripped, try to // open the dex file from its corresponding oat file. // This could happen when we need to recompile a pre-build whose dex // code has been stripped (for example, if the pre-build is only // quicken and we want to re-compile it speed-profile). // TODO(calin): Use the vdex directly instead of going through the oat file. OatFileAssistant oat_file_assistant(location.c_str(), isa, false); std::unique_ptr<OatFile> oat_file(oat_file_assistant.GetBestOatFile()); std::vector<std::unique_ptr<const DexFile>> oat_dex_files; if (oat_file != nullptr && OatFileAssistant::LoadDexFiles(*oat_file, location, &oat_dex_files)) { info->opened_oat_files.push_back(std::move(oat_file)); info->opened_dex_files.insert(info->opened_dex_files.end(), std::make_move_iterator(oat_dex_files.begin()), std::make_move_iterator(oat_dex_files.end())); } else { LOG(WARNING) << "Could not open dex files from location: " << location; dex_files_open_result_ = false; } } } else if (!dex_file_loader.Open(fd, location.c_str(), Runtime::Current()->IsVerificationEnabled(), /*verify_checksum=*/ true, &error_msg, &info->opened_dex_files)) { LOG(WARNING) << "Could not open dex files from fd " << fd << " for location: " << location; dex_files_open_result_ = false; } } // We finished opening the dex files from the classpath. // Now update the classpath and the checksum with the locations of the dex files. // // We do this because initially the classpath contains the paths of the dex files; and // some of them might be multi-dexes. So in order to have a consistent view we replace all the // file paths with the actual dex locations being loaded. // This will allow the context to VerifyClassLoaderContextMatch which expects or multidex // location in the class paths. // Note that this will also remove the paths that could not be opened. info->original_classpath = std::move(info->classpath); info->classpath.clear(); info->checksums.clear(); for (size_t k = opened_dex_files_index; k < info->opened_dex_files.size(); k++) { std::unique_ptr<const DexFile>& dex = info->opened_dex_files[k]; info->classpath.push_back(dex->GetLocation()); info->checksums.push_back(dex->GetLocationChecksum()); } AddToWorkList(info, work_list); } // Check that if file descriptors were provided, there were exactly as many // as we have encountered while iterating over this class loader context. if (dex_file_index != fds.size()) { LOG(WARNING) << fds.size() << " FDs provided but only " << dex_file_index << " dex files are in the class loader context"; dex_files_open_result_ = false; } return dex_files_open_result_; } bool ClassLoaderContext::RemoveLocationsFromClassPaths( const dchecked_vector<std::string>& locations) { CHECK(!dex_files_open_attempted_) << "RemoveLocationsFromClasspaths cannot be call after OpenDexFiles"; if (class_loader_chain_ == nullptr) { return false; } std::set<std::string> canonical_locations; for (const std::string& location : locations) { canonical_locations.insert(DexFileLoader::GetDexCanonicalLocation(location.c_str())); } bool removed_locations = false; std::vector<ClassLoaderInfo*> work_list; work_list.push_back(class_loader_chain_.get()); while (!work_list.empty()) { ClassLoaderInfo* info = work_list.back(); work_list.pop_back(); size_t initial_size = info->classpath.size(); auto kept_it = std::remove_if( info->classpath.begin(), info->classpath.end(), [canonical_locations](const std::string& location) { return ContainsElement(canonical_locations, DexFileLoader::GetDexCanonicalLocation(location.c_str())); }); info->classpath.erase(kept_it, info->classpath.end()); if (initial_size != info->classpath.size()) { removed_locations = true; } AddToWorkList(info, work_list); } return removed_locations; } std::string ClassLoaderContext::EncodeContextForDex2oat(const std::string& base_dir) const { return EncodeContext(base_dir, /*for_dex2oat=*/ true, /*stored_context=*/ nullptr); } std::string ClassLoaderContext::EncodeContextForOatFile(const std::string& base_dir, ClassLoaderContext* stored_context) const { return EncodeContext(base_dir, /*for_dex2oat=*/ false, stored_context); } std::string ClassLoaderContext::EncodeContext(const std::string& base_dir, bool for_dex2oat, ClassLoaderContext* stored_context) const { CheckDexFilesOpened("EncodeContextForOatFile"); if (special_shared_library_) { return OatFile::kSpecialSharedLibrary; } if (stored_context != nullptr) { DCHECK_EQ(GetParentChainSize(), stored_context->GetParentChainSize()); } std::ostringstream out; if (class_loader_chain_ == nullptr) { // We can get in this situation if the context was created with a class path containing the // source dex files which were later removed (happens during run-tests). out << GetClassLoaderTypeName(kPathClassLoader) << kClassLoaderOpeningMark << kClassLoaderClosingMark; return out.str(); } EncodeContextInternal( *class_loader_chain_, base_dir, for_dex2oat, (stored_context == nullptr ? nullptr : stored_context->class_loader_chain_.get()), out); return out.str(); } void ClassLoaderContext::EncodeContextInternal(const ClassLoaderInfo& info, const std::string& base_dir, bool for_dex2oat, ClassLoaderInfo* stored_info, std::ostringstream& out) const { out << GetClassLoaderTypeName(info.type); out << kClassLoaderOpeningMark; std::set<std::string> seen_locations; SafeMap<std::string, std::string> remap; if (stored_info != nullptr) { for (size_t k = 0; k < info.original_classpath.size(); ++k) { // Note that we don't care if the same name appears twice. remap.Put(info.original_classpath[k], stored_info->classpath[k]); } } for (size_t k = 0; k < info.opened_dex_files.size(); k++) { const std::unique_ptr<const DexFile>& dex_file = info.opened_dex_files[k]; if (for_dex2oat) { // dex2oat only needs the base location. It cannot accept multidex locations. // So ensure we only add each file once. bool new_insert = seen_locations.insert( DexFileLoader::GetBaseLocation(dex_file->GetLocation())).second; if (!new_insert) { continue; } } std::string location = dex_file->GetLocation(); // If there is a stored class loader remap, fix up the multidex strings. if (!remap.empty()) { std::string base_dex_location = DexFileLoader::GetBaseLocation(location); auto it = remap.find(base_dex_location); CHECK(it != remap.end()) << base_dex_location; location = it->second + DexFileLoader::GetMultiDexSuffix(location); } if (k > 0) { out << kClasspathSeparator; } if (info.type == kInMemoryDexClassLoader) { out << kInMemoryDexClassLoaderDexLocationMagic; } else if (!base_dir.empty() && location.substr(0, base_dir.length()) == base_dir) { // Find paths that were relative and convert them back from absolute. out << location.substr(base_dir.length() + 1).c_str(); } else { out << location.c_str(); } // dex2oat does not need the checksums. if (!for_dex2oat) { out << kDexFileChecksumSeparator; out << dex_file->GetLocationChecksum(); } } out << kClassLoaderClosingMark; if (!info.shared_libraries.empty()) { out << kClassLoaderSharedLibraryOpeningMark; for (uint32_t i = 0; i < info.shared_libraries.size(); ++i) { if (i > 0) { out << kClassLoaderSharedLibrarySeparator; } EncodeContextInternal( *info.shared_libraries[i].get(), base_dir, for_dex2oat, (stored_info == nullptr ? nullptr : stored_info->shared_libraries[i].get()), out); } out << kClassLoaderSharedLibraryClosingMark; } if (info.parent != nullptr) { out << kClassLoaderSeparator; EncodeContextInternal( *info.parent.get(), base_dir, for_dex2oat, (stored_info == nullptr ? nullptr : stored_info->parent.get()), out); } } // Returns the WellKnownClass for the given class loader type. static jclass GetClassLoaderClass(ClassLoaderContext::ClassLoaderType type) { switch (type) { case ClassLoaderContext::kPathClassLoader: return WellKnownClasses::dalvik_system_PathClassLoader; case ClassLoaderContext::kDelegateLastClassLoader: return WellKnownClasses::dalvik_system_DelegateLastClassLoader; case ClassLoaderContext::kInMemoryDexClassLoader: return WellKnownClasses::dalvik_system_InMemoryDexClassLoader; case ClassLoaderContext::kInvalidClassLoader: break; // will fail after the switch. } LOG(FATAL) << "Invalid class loader type " << type; UNREACHABLE(); } static std::string FlattenClasspath(const std::vector<std::string>& classpath) { return android::base::Join(classpath, ':'); } static ObjPtr<mirror::ClassLoader> CreateClassLoaderInternal( Thread* self, ScopedObjectAccess& soa, const ClassLoaderContext::ClassLoaderInfo& info, bool for_shared_library, VariableSizedHandleScope& map_scope, std::map<std::string, Handle<mirror::ClassLoader>>& canonicalized_libraries, bool add_compilation_sources, const std::vector<const DexFile*>& compilation_sources) REQUIRES_SHARED(Locks::mutator_lock_) { if (for_shared_library) { // Check if the shared library has already been created. auto search = canonicalized_libraries.find(FlattenClasspath(info.classpath)); if (search != canonicalized_libraries.end()) { return search->second.Get(); } } StackHandleScope<3> hs(self); MutableHandle<mirror::ObjectArray<mirror::ClassLoader>> libraries( hs.NewHandle<mirror::ObjectArray<mirror::ClassLoader>>(nullptr)); if (!info.shared_libraries.empty()) { libraries.Assign(mirror::ObjectArray<mirror::ClassLoader>::Alloc( self, GetClassRoot<mirror::ObjectArray<mirror::ClassLoader>>(), info.shared_libraries.size())); for (uint32_t i = 0; i < info.shared_libraries.size(); ++i) { // We should only add the compilation sources to the first class loader. libraries->Set(i, CreateClassLoaderInternal( self, soa, *info.shared_libraries[i].get(), /* for_shared_library= */ true, map_scope, canonicalized_libraries, /* add_compilation_sources= */ false, compilation_sources)); } } MutableHandle<mirror::ClassLoader> parent = hs.NewHandle<mirror::ClassLoader>(nullptr); if (info.parent != nullptr) { // We should only add the compilation sources to the first class loader. parent.Assign(CreateClassLoaderInternal( self, soa, *info.parent.get(), /* for_shared_library= */ false, map_scope, canonicalized_libraries, /* add_compilation_sources= */ false, compilation_sources)); } std::vector<const DexFile*> class_path_files = MakeNonOwningPointerVector( info.opened_dex_files); if (add_compilation_sources) { // For the first class loader, its classpath comes first, followed by compilation sources. // This ensures that whenever we need to resolve classes from it the classpath elements // come first. class_path_files.insert(class_path_files.end(), compilation_sources.begin(), compilation_sources.end()); } Handle<mirror::Class> loader_class = hs.NewHandle<mirror::Class>( soa.Decode<mirror::Class>(GetClassLoaderClass(info.type))); ObjPtr<mirror::ClassLoader> loader = Runtime::Current()->GetClassLinker()->CreateWellKnownClassLoader( self, class_path_files, loader_class, parent, libraries); if (for_shared_library) { canonicalized_libraries[FlattenClasspath(info.classpath)] = map_scope.NewHandle<mirror::ClassLoader>(loader); } return loader; } jobject ClassLoaderContext::CreateClassLoader( const std::vector<const DexFile*>& compilation_sources) const { CheckDexFilesOpened("CreateClassLoader"); Thread* self = Thread::Current(); ScopedObjectAccess soa(self); ClassLinker* const class_linker = Runtime::Current()->GetClassLinker(); if (class_loader_chain_ == nullptr) { CHECK(special_shared_library_); return class_linker->CreatePathClassLoader(self, compilation_sources); } // Create a map of canonicalized shared libraries. As we're holding objects, // we're creating a variable size handle scope to put handles in the map. VariableSizedHandleScope map_scope(self); std::map<std::string, Handle<mirror::ClassLoader>> canonicalized_libraries; // Create the class loader. ObjPtr<mirror::ClassLoader> loader = CreateClassLoaderInternal(self, soa, *class_loader_chain_.get(), /* for_shared_library= */ false, map_scope, canonicalized_libraries, /* add_compilation_sources= */ true, compilation_sources); // Make it a global ref and return. ScopedLocalRef<jobject> local_ref( soa.Env(), soa.Env()->AddLocalReference<jobject>(loader)); return soa.Env()->NewGlobalRef(local_ref.get()); } std::vector<const DexFile*> ClassLoaderContext::FlattenOpenedDexFiles() const { CheckDexFilesOpened("FlattenOpenedDexFiles"); std::vector<const DexFile*> result; if (class_loader_chain_ == nullptr) { return result; } std::vector<ClassLoaderInfo*> work_list; work_list.push_back(class_loader_chain_.get()); while (!work_list.empty()) { ClassLoaderInfo* info = work_list.back(); work_list.pop_back(); for (const std::unique_ptr<const DexFile>& dex_file : info->opened_dex_files) { result.push_back(dex_file.get()); } AddToWorkList(info, work_list); } return result; } std::string ClassLoaderContext::FlattenDexPaths() const { if (class_loader_chain_ == nullptr) { return ""; } std::vector<std::string> result; std::vector<ClassLoaderInfo*> work_list; work_list.push_back(class_loader_chain_.get()); while (!work_list.empty()) { ClassLoaderInfo* info = work_list.back(); work_list.pop_back(); for (const std::string& dex_path : info->classpath) { result.push_back(dex_path); } AddToWorkList(info, work_list); } return FlattenClasspath(result); } const char* ClassLoaderContext::GetClassLoaderTypeName(ClassLoaderType type) { switch (type) { case kPathClassLoader: return kPathClassLoaderString; case kDelegateLastClassLoader: return kDelegateLastClassLoaderString; case kInMemoryDexClassLoader: return kInMemoryDexClassLoaderString; default: LOG(FATAL) << "Invalid class loader type " << type; UNREACHABLE(); } } void ClassLoaderContext::CheckDexFilesOpened(const std::string& calling_method) const { CHECK(dex_files_open_attempted_) << "Dex files were not successfully opened before the call to " << calling_method << "attempt=" << dex_files_open_attempted_ << ", result=" << dex_files_open_result_; } // Collects the dex files from the give Java dex_file object. Only the dex files with // at least 1 class are collected. If a null java_dex_file is passed this method does nothing. static bool CollectDexFilesFromJavaDexFile(ObjPtr<mirror::Object> java_dex_file, ArtField* const cookie_field, std::vector<const DexFile*>* out_dex_files) REQUIRES_SHARED(Locks::mutator_lock_) { if (java_dex_file == nullptr) { return true; } // On the Java side, the dex files are stored in the cookie field. ObjPtr<mirror::LongArray> long_array = cookie_field->GetObject(java_dex_file)->AsLongArray(); if (long_array == nullptr) { // This should never happen so log a warning. LOG(ERROR) << "Unexpected null cookie"; return false; } int32_t long_array_size = long_array->GetLength(); // Index 0 from the long array stores the oat file. The dex files start at index 1. for (int32_t j = 1; j < long_array_size; ++j) { const DexFile* cp_dex_file = reinterpret_cast64<const DexFile*>(long_array->GetWithoutChecks(j)); if (cp_dex_file != nullptr && cp_dex_file->NumClassDefs() > 0) { // TODO(calin): It's unclear why the dex files with no classes are skipped here and when // cp_dex_file can be null. out_dex_files->push_back(cp_dex_file); } } return true; } // Collects all the dex files loaded by the given class loader. // Returns true for success or false if an unexpected state is discovered (e.g. a null dex cookie, // a null list of dex elements or a null dex element). static bool CollectDexFilesFromSupportedClassLoader(ScopedObjectAccessAlreadyRunnable& soa, Handle<mirror::ClassLoader> class_loader, std::vector<const DexFile*>* out_dex_files) REQUIRES_SHARED(Locks::mutator_lock_) { CHECK(IsPathOrDexClassLoader(soa, class_loader) || IsDelegateLastClassLoader(soa, class_loader) || IsInMemoryDexClassLoader(soa, class_loader)); // All supported class loaders inherit from BaseDexClassLoader. // We need to get the DexPathList and loop through it. ArtField* const cookie_field = jni::DecodeArtField(WellKnownClasses::dalvik_system_DexFile_cookie); ArtField* const dex_file_field = jni::DecodeArtField(WellKnownClasses::dalvik_system_DexPathList__Element_dexFile); ObjPtr<mirror::Object> dex_path_list = jni::DecodeArtField(WellKnownClasses::dalvik_system_BaseDexClassLoader_pathList)-> GetObject(class_loader.Get()); CHECK(cookie_field != nullptr); CHECK(dex_file_field != nullptr); if (dex_path_list == nullptr) { // This may be null if the current class loader is under construction and it does not // have its fields setup yet. return true; } // DexPathList has an array dexElements of Elements[] which each contain a dex file. ObjPtr<mirror::Object> dex_elements_obj = jni::DecodeArtField(WellKnownClasses::dalvik_system_DexPathList_dexElements)-> GetObject(dex_path_list); // Loop through each dalvik.system.DexPathList$Element's dalvik.system.DexFile and look // at the mCookie which is a DexFile vector. if (dex_elements_obj == nullptr) { // TODO(calin): It's unclear if we should just assert here. For now be prepared for the worse // and assume we have no elements. return true; } else { StackHandleScope<1> hs(soa.Self()); Handle<mirror::ObjectArray<mirror::Object>> dex_elements( hs.NewHandle(dex_elements_obj->AsObjectArray<mirror::Object>())); for (int32_t i = 0; i < dex_elements->GetLength(); ++i) { ObjPtr<mirror::Object> element = dex_elements->GetWithoutChecks(i); if (element == nullptr) { // Should never happen, log an error and break. // TODO(calin): It's unclear if we should just assert here. // This code was propagated to oat_file_manager from the class linker where it would // throw a NPE. For now, return false which will mark this class loader as unsupported. LOG(ERROR) << "Unexpected null in the dex element list"; return false; } ObjPtr<mirror::Object> dex_file = dex_file_field->GetObject(element); if (!CollectDexFilesFromJavaDexFile(dex_file, cookie_field, out_dex_files)) { return false; } } } return true; } static bool GetDexFilesFromDexElementsArray( ScopedObjectAccessAlreadyRunnable& soa, Handle<mirror::ObjectArray<mirror::Object>> dex_elements, std::vector<const DexFile*>* out_dex_files) REQUIRES_SHARED(Locks::mutator_lock_) { DCHECK(dex_elements != nullptr); ArtField* const cookie_field = jni::DecodeArtField(WellKnownClasses::dalvik_system_DexFile_cookie); ArtField* const dex_file_field = jni::DecodeArtField(WellKnownClasses::dalvik_system_DexPathList__Element_dexFile); const ObjPtr<mirror::Class> element_class = soa.Decode<mirror::Class>( WellKnownClasses::dalvik_system_DexPathList__Element); const ObjPtr<mirror::Class> dexfile_class = soa.Decode<mirror::Class>( WellKnownClasses::dalvik_system_DexFile); for (int32_t i = 0; i < dex_elements->GetLength(); ++i) { ObjPtr<mirror::Object> element = dex_elements->GetWithoutChecks(i); // We can hit a null element here because this is invoked with a partially filled dex_elements // array from DexPathList. DexPathList will open each dex sequentially, each time passing the // list of dex files which were opened before. if (element == nullptr) { continue; } // We support this being dalvik.system.DexPathList$Element and dalvik.system.DexFile. // TODO(calin): Code caried over oat_file_manager: supporting both classes seem to be // a historical glitch. All the java code opens dex files using an array of Elements. ObjPtr<mirror::Object> dex_file; if (element_class == element->GetClass()) { dex_file = dex_file_field->GetObject(element); } else if (dexfile_class == element->GetClass()) { dex_file = element; } else { LOG(ERROR) << "Unsupported element in dex_elements: " << mirror::Class::PrettyClass(element->GetClass()); return false; } if (!CollectDexFilesFromJavaDexFile(dex_file, cookie_field, out_dex_files)) { return false; } } return true; } // Adds the `class_loader` info to the `context`. // The dex file present in `dex_elements` array (if not null) will be added at the end of // the classpath. // This method is recursive (w.r.t. the class loader parent) and will stop once it reaches the // BootClassLoader. Note that the class loader chain is expected to be short. bool ClassLoaderContext::CreateInfoFromClassLoader( ScopedObjectAccessAlreadyRunnable& soa, Handle<mirror::ClassLoader> class_loader, Handle<mirror::ObjectArray<mirror::Object>> dex_elements, ClassLoaderInfo* child_info, bool is_shared_library) REQUIRES_SHARED(Locks::mutator_lock_) { if (ClassLinker::IsBootClassLoader(soa, class_loader.Get())) { // Nothing to do for the boot class loader as we don't add its dex files to the context. return true; } ClassLoaderContext::ClassLoaderType type; if (IsPathOrDexClassLoader(soa, class_loader)) { type = kPathClassLoader; } else if (IsDelegateLastClassLoader(soa, class_loader)) { type = kDelegateLastClassLoader; } else if (IsInMemoryDexClassLoader(soa, class_loader)) { type = kInMemoryDexClassLoader; } else { LOG(WARNING) << "Unsupported class loader"; return false; } // Inspect the class loader for its dex files. std::vector<const DexFile*> dex_files_loaded; CollectDexFilesFromSupportedClassLoader(soa, class_loader, &dex_files_loaded); // If we have a dex_elements array extract its dex elements now. // This is used in two situations: // 1) when a new ClassLoader is created DexPathList will open each dex file sequentially // passing the list of already open dex files each time. This ensures that we see the // correct context even if the ClassLoader under construction is not fully build. // 2) when apk splits are loaded on the fly, the framework will load their dex files by // appending them to the current class loader. When the new code paths are loaded in // BaseDexClassLoader, the paths already present in the class loader will be passed // in the dex_elements array. if (dex_elements != nullptr) { GetDexFilesFromDexElementsArray(soa, dex_elements, &dex_files_loaded); } ClassLoaderInfo* info = new ClassLoaderContext::ClassLoaderInfo(type); // Attach the `ClassLoaderInfo` now, before populating dex files, as only the // `ClassLoaderContext` knows whether these dex files should be deleted or not. if (child_info == nullptr) { class_loader_chain_.reset(info); } else if (is_shared_library) { child_info->shared_libraries.push_back(std::unique_ptr<ClassLoaderInfo>(info)); } else { child_info->parent.reset(info); } // Now that `info` is in the chain, populate dex files. for (const DexFile* dex_file : dex_files_loaded) { // Dex location of dex files loaded with InMemoryDexClassLoader is always bogus. // Use a magic value for the classpath instead. info->classpath.push_back((type == kInMemoryDexClassLoader) ? kInMemoryDexClassLoaderDexLocationMagic : dex_file->GetLocation()); info->checksums.push_back(dex_file->GetLocationChecksum()); info->opened_dex_files.emplace_back(dex_file); } // Note that dex_elements array is null here. The elements are considered to be part of the // current class loader and are not passed to the parents. ScopedNullHandle<mirror::ObjectArray<mirror::Object>> null_dex_elements; // Add the shared libraries. StackHandleScope<3> hs(Thread::Current()); ArtField* field = jni::DecodeArtField(WellKnownClasses::dalvik_system_BaseDexClassLoader_sharedLibraryLoaders); ObjPtr<mirror::Object> raw_shared_libraries = field->GetObject(class_loader.Get()); if (raw_shared_libraries != nullptr) { Handle<mirror::ObjectArray<mirror::ClassLoader>> shared_libraries = hs.NewHandle(raw_shared_libraries->AsObjectArray<mirror::ClassLoader>()); MutableHandle<mirror::ClassLoader> temp_loader = hs.NewHandle<mirror::ClassLoader>(nullptr); for (int32_t i = 0; i < shared_libraries->GetLength(); ++i) { temp_loader.Assign(shared_libraries->Get(i)); if (!CreateInfoFromClassLoader( soa, temp_loader, null_dex_elements, info, /*is_shared_library=*/ true)) { return false; } } } // We created the ClassLoaderInfo for the current loader. Move on to its parent. Handle<mirror::ClassLoader> parent = hs.NewHandle(class_loader->GetParent()); if (!CreateInfoFromClassLoader( soa, parent, null_dex_elements, info, /*is_shared_library=*/ false)) { return false; } return true; } std::unique_ptr<ClassLoaderContext> ClassLoaderContext::CreateContextForClassLoader( jobject class_loader, jobjectArray dex_elements) { CHECK(class_loader != nullptr); ScopedObjectAccess soa(Thread::Current()); StackHandleScope<2> hs(soa.Self()); Handle<mirror::ClassLoader> h_class_loader = hs.NewHandle(soa.Decode<mirror::ClassLoader>(class_loader)); Handle<mirror::ObjectArray<mirror::Object>> h_dex_elements = hs.NewHandle(soa.Decode<mirror::ObjectArray<mirror::Object>>(dex_elements)); std::unique_ptr<ClassLoaderContext> result(new ClassLoaderContext(/*owns_the_dex_files=*/ false)); if (!result->CreateInfoFromClassLoader( soa, h_class_loader, h_dex_elements, nullptr, /*is_shared_library=*/ false)) { return nullptr; } return result; } ClassLoaderContext::VerificationResult ClassLoaderContext::VerifyClassLoaderContextMatch( const std::string& context_spec, bool verify_names, bool verify_checksums) const { if (verify_names || verify_checksums) { DCHECK(dex_files_open_attempted_); DCHECK(dex_files_open_result_); } ClassLoaderContext expected_context; if (!expected_context.Parse(context_spec, verify_checksums)) { LOG(WARNING) << "Invalid class loader context: " << context_spec; return VerificationResult::kMismatch; } // Special shared library contexts always match. They essentially instruct the runtime // to ignore the class path check because the oat file is known to be loaded in different // contexts. OatFileManager will further verify if the oat file can be loaded based on the // collision check. if (expected_context.special_shared_library_) { // Special case where we are the only entry in the class path. if (class_loader_chain_ != nullptr && class_loader_chain_->parent == nullptr && class_loader_chain_->classpath.size() == 0) { return VerificationResult::kVerifies; } return VerificationResult::kForcedToSkipChecks; } else if (special_shared_library_) { return VerificationResult::kForcedToSkipChecks; } ClassLoaderInfo* info = class_loader_chain_.get(); ClassLoaderInfo* expected = expected_context.class_loader_chain_.get(); CHECK(info != nullptr); CHECK(expected != nullptr); if (!ClassLoaderInfoMatch(*info, *expected, context_spec, verify_names, verify_checksums)) { return VerificationResult::kMismatch; } return VerificationResult::kVerifies; } bool ClassLoaderContext::ClassLoaderInfoMatch( const ClassLoaderInfo& info, const ClassLoaderInfo& expected_info, const std::string& context_spec, bool verify_names, bool verify_checksums) const { if (info.type != expected_info.type) { LOG(WARNING) << "ClassLoaderContext type mismatch" << ". expected=" << GetClassLoaderTypeName(expected_info.type) << ", found=" << GetClassLoaderTypeName(info.type) << " (" << context_spec << " | " << EncodeContextForOatFile("") << ")"; return false; } if (info.classpath.size() != expected_info.classpath.size()) { LOG(WARNING) << "ClassLoaderContext classpath size mismatch" << ". expected=" << expected_info.classpath.size() << ", found=" << info.classpath.size() << " (" << context_spec << " | " << EncodeContextForOatFile("") << ")"; return false; } if (verify_checksums) { DCHECK_EQ(info.classpath.size(), info.checksums.size()); DCHECK_EQ(expected_info.classpath.size(), expected_info.checksums.size()); } if (verify_names) { for (size_t k = 0; k < info.classpath.size(); k++) { // Compute the dex location that must be compared. // We shouldn't do a naive comparison `info.classpath[k] == expected_info.classpath[k]` // because even if they refer to the same file, one could be encoded as a relative location // and the other as an absolute one. bool is_dex_name_absolute = IsAbsoluteLocation(info.classpath[k]); bool is_expected_dex_name_absolute = IsAbsoluteLocation(expected_info.classpath[k]); std::string dex_name; std::string expected_dex_name; if (is_dex_name_absolute == is_expected_dex_name_absolute) { // If both locations are absolute or relative then compare them as they are. // This is usually the case for: shared libraries and secondary dex files. dex_name = info.classpath[k]; expected_dex_name = expected_info.classpath[k]; } else if (is_dex_name_absolute) { // The runtime name is absolute but the compiled name (the expected one) is relative. // This is the case for split apks which depend on base or on other splits. dex_name = info.classpath[k]; OatFile::ResolveRelativeEncodedDexLocation(info.classpath[k].c_str(), expected_info.classpath[k], &expected_dex_name); } else if (is_expected_dex_name_absolute) { // The runtime name is relative but the compiled name is absolute. // There is no expected use case that would end up here as dex files are always loaded // with their absolute location. However, be tolerant and do the best effort (in case // there are unexpected new use case...). OatFile::ResolveRelativeEncodedDexLocation(expected_info.classpath[k].c_str(), info.classpath[k], &dex_name); expected_dex_name = expected_info.classpath[k]; } else { // Both locations are relative. In this case there's not much we can be sure about // except that the names are the same. The checksum will ensure that the files are // are same. This should not happen outside testing and manual invocations. dex_name = info.classpath[k]; expected_dex_name = expected_info.classpath[k]; } // Compare the locations. if (dex_name != expected_dex_name) { LOG(WARNING) << "ClassLoaderContext classpath element mismatch" << ". expected=" << expected_info.classpath[k] << ", found=" << info.classpath[k] << " (" << context_spec << " | " << EncodeContextForOatFile("") << ")"; return false; } // Compare the checksums. if (info.checksums[k] != expected_info.checksums[k]) { LOG(WARNING) << "ClassLoaderContext classpath element checksum mismatch" << ". expected=" << expected_info.checksums[k] << ", found=" << info.checksums[k] << " (" << context_spec << " | " << EncodeContextForOatFile("") << ")"; return false; } } } if (info.shared_libraries.size() != expected_info.shared_libraries.size()) { LOG(WARNING) << "ClassLoaderContext shared library size mismatch. " << "Expected=" << expected_info.shared_libraries.size() << ", found=" << info.shared_libraries.size() << " (" << context_spec << " | " << EncodeContextForOatFile("") << ")"; return false; } for (size_t i = 0; i < info.shared_libraries.size(); ++i) { if (!ClassLoaderInfoMatch(*info.shared_libraries[i].get(), *expected_info.shared_libraries[i].get(), context_spec, verify_names, verify_checksums)) { return false; } } if (info.parent.get() == nullptr) { if (expected_info.parent.get() != nullptr) { LOG(WARNING) << "ClassLoaderContext parent mismatch. " << " (" << context_spec << " | " << EncodeContextForOatFile("") << ")"; return false; } return true; } else if (expected_info.parent.get() == nullptr) { LOG(WARNING) << "ClassLoaderContext parent mismatch. " << " (" << context_spec << " | " << EncodeContextForOatFile("") << ")"; return false; } else { return ClassLoaderInfoMatch(*info.parent.get(), *expected_info.parent.get(), context_spec, verify_names, verify_checksums); } } } // namespace art