/* * 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 "art_field-inl.h" #include "base/dchecked_vector.h" #include "base/stl_util.h" #include "class_linker.h" #include "class_loader_utils.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_internal.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 kClassLoaderOpeningMark = '['; static constexpr char kClassLoaderClosingMark = ']'; static constexpr char kClassLoaderSeparator = ';'; static constexpr char kClasspathSeparator = ':'; static constexpr char kDexFileChecksumSeparator = '*'; 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) {} ClassLoaderContext::~ClassLoaderContext() { if (!owns_the_dex_files_) { // If the context does not own the dex/oat files release the unique pointers to // make sure we do not de-allocate them. for (ClassLoaderInfo& info : class_loader_chain_) { for (std::unique_ptr<OatFile>& oat_file : info.opened_oat_files) { oat_file.release(); } for (std::unique_ptr<const DexFile>& dex_file : info.opened_dex_files) { dex_file.release(); } } } } 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; } } // The expected format is: "ClassLoaderType1[ClasspathElem1*Checksum1:ClasspathElem2*Checksum2...]". // The checksum part of the format is expected only if parse_cheksums is true. bool ClassLoaderContext::ParseClassLoaderSpec(const std::string& class_loader_spec, ClassLoaderType class_loader_type, bool parse_checksums) { 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 false; } if (class_loader_spec[class_loader_spec.length() - 1] != kClassLoaderClosingMark) { return false; } // 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, class_loader_spec.length() - type_str_size - 2); class_loader_chain_.push_back(ClassLoaderInfo(class_loader_type)); if (!parse_checksums) { Split(classpath, kClasspathSeparator, &class_loader_chain_.back().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 false; } uint32_t checksum = 0; if (!ParseInt(dex_file_with_checksum[1].c_str(), &checksum)) { return false; } class_loader_chain_.back().classpath.push_back(dex_file_with_checksum[0]); class_loader_chain_.back().checksums.push_back(checksum); } } return true; } // 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}; 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_.push_back(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; } std::vector<std::string> class_loaders; Split(spec, kClassLoaderSeparator, &class_loaders); for (const std::string& class_loader : class_loaders) { ClassLoaderType type = ExtractClassLoaderType(class_loader); if (type == kInvalidClassLoader) { LOG(ERROR) << "Invalid class loader type: " << class_loader; return false; } if (!ParseClassLoaderSpec(class_loader, type, parse_checksums)) { LOG(ERROR) << "Invalid class loader spec: " << class_loader; return false; } } return true; } // 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) { 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; for (ClassLoaderInfo& info : class_loader_chain_) { 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; } 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 (!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; } } } // 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()); } } 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"; std::set<std::string> canonical_locations; for (const std::string& location : locations) { canonical_locations.insert(DexFileLoader::GetDexCanonicalLocation(location.c_str())); } bool removed_locations = false; for (ClassLoaderInfo& info : class_loader_chain_) { 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; } } 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(class_loader_chain_.size(), stored_context->class_loader_chain_.size()); } std::ostringstream out; if (class_loader_chain_.empty()) { // 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(); } for (size_t i = 0; i < class_loader_chain_.size(); i++) { const ClassLoaderInfo& info = class_loader_chain_[i]; if (i > 0) { out << kClassLoaderSeparator; } out << GetClassLoaderTypeName(info.type); out << kClassLoaderOpeningMark; std::set<std::string> seen_locations; SafeMap<std::string, std::string> remap; if (stored_context != nullptr) { DCHECK_EQ(info.original_classpath.size(), stored_context->class_loader_chain_[i].classpath.size()); 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_context->class_loader_chain_[i].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; } // Find paths that were relative and convert them back from absolute. if (!base_dir.empty() && location.substr(0, base_dir.length()) == base_dir) { 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; } return out.str(); } 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_.empty()) { return class_linker->CreatePathClassLoader(self, compilation_sources); } // Create the class loaders starting from the top most parent (the one on the last position // in the chain) but omit the first class loader which will contain the compilation_sources and // needs special handling. jobject current_parent = nullptr; // the starting parent is the BootClassLoader. for (size_t i = class_loader_chain_.size() - 1; i > 0; i--) { std::vector<const DexFile*> class_path_files = MakeNonOwningPointerVector( class_loader_chain_[i].opened_dex_files); current_parent = class_linker->CreateWellKnownClassLoader( self, class_path_files, GetClassLoaderClass(class_loader_chain_[i].type), current_parent); } // We set up all the parents. Move on to create 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. std::vector<const DexFile*> first_class_loader_classpath = MakeNonOwningPointerVector( class_loader_chain_[0].opened_dex_files); first_class_loader_classpath.insert(first_class_loader_classpath.end(), compilation_sources.begin(), compilation_sources.end()); return class_linker->CreateWellKnownClassLoader( self, first_class_loader_classpath, GetClassLoaderClass(class_loader_chain_[0].type), current_parent); } std::vector<const DexFile*> ClassLoaderContext::FlattenOpenedDexFiles() const { CheckDexFilesOpened("FlattenOpenedDexFiles"); std::vector<const DexFile*> result; for (const ClassLoaderInfo& info : class_loader_chain_) { for (const std::unique_ptr<const DexFile>& dex_file : info.opened_dex_files) { result.push_back(dex_file.get()); } } return result; } const char* ClassLoaderContext::GetClassLoaderTypeName(ClassLoaderType type) { switch (type) { case kPathClassLoader: return kPathClassLoaderString; case kDelegateLastClassLoader: return kDelegateLastClassLoaderString; 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. 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_cast<const DexFile*>(static_cast<uintptr_t>( 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)); // 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) { 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); ObjPtr<mirror::Class> const element_class = soa.Decode<mirror::Class>( WellKnownClasses::dalvik_system_DexPathList__Element); ObjPtr<mirror::Class> const dexfile_class = soa.Decode<mirror::Class>( WellKnownClasses::dalvik_system_DexFile); for (int32_t i = 0; i < dex_elements->GetLength(); ++i) { 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::AddInfoToContextFromClassLoader( ScopedObjectAccessAlreadyRunnable& soa, Handle<mirror::ClassLoader> class_loader, Handle<mirror::ObjectArray<mirror::Object>> dex_elements) 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 { 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); } class_loader_chain_.push_back(ClassLoaderContext::ClassLoaderInfo(type)); ClassLoaderInfo& info = class_loader_chain_.back(); for (const DexFile* dex_file : dex_files_loaded) { info.classpath.push_back(dex_file->GetLocation()); info.checksums.push_back(dex_file->GetLocationChecksum()); info.opened_dex_files.emplace_back(dex_file); } // We created the ClassLoaderInfo for the current loader. Move on to its parent. StackHandleScope<1> hs(Thread::Current()); Handle<mirror::ClassLoader> parent = hs.NewHandle(class_loader->GetParent()); // 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; return AddInfoToContextFromClassLoader(soa, parent, null_dex_elements); } 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->AddInfoToContextFromClassLoader(soa, h_class_loader, h_dex_elements)) { return result; } else { return nullptr; } } static bool IsAbsoluteLocation(const std::string& location) { return !location.empty() && location[0] == '/'; } bool 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 false; } // 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 (special_shared_library_ || expected_context.special_shared_library_) { return true; } if (expected_context.class_loader_chain_.size() != class_loader_chain_.size()) { LOG(WARNING) << "ClassLoaderContext size mismatch. expected=" << expected_context.class_loader_chain_.size() << ", actual=" << class_loader_chain_.size() << " (" << context_spec << " | " << EncodeContextForOatFile("") << ")"; return false; } for (size_t i = 0; i < class_loader_chain_.size(); i++) { const ClassLoaderInfo& info = class_loader_chain_[i]; const ClassLoaderInfo& expected_info = expected_context.class_loader_chain_[i]; if (info.type != expected_info.type) { LOG(WARNING) << "ClassLoaderContext type mismatch for position " << i << ". 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 for position " << i << ". 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) { continue; } 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]; expected_dex_name = OatFile::ResolveRelativeEncodedDexLocation( info.classpath[k].c_str(), expected_info.classpath[k]); } 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...). dex_name = OatFile::ResolveRelativeEncodedDexLocation( expected_info.classpath[k].c_str(), info.classpath[k]); 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 for position " << i << ". 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 for position " << i << ". expected=" << expected_info.checksums[k] << ", found=" << info.checksums[k] << " (" << context_spec << " | " << EncodeContextForOatFile("") << ")"; return false; } } } return true; } jclass ClassLoaderContext::GetClassLoaderClass(ClassLoaderType type) { switch (type) { case kPathClassLoader: return WellKnownClasses::dalvik_system_PathClassLoader; case kDelegateLastClassLoader: return WellKnownClasses::dalvik_system_DelegateLastClassLoader; case kInvalidClassLoader: break; // will fail after the switch. } LOG(FATAL) << "Invalid class loader type " << type; UNREACHABLE(); } } // namespace art