/*
* 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