/*
* Copyright (C) 2015 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "oat_file_manager.h"
#include <memory>
#include <queue>
#include <vector>
#include "android-base/stringprintf.h"
#include "android-base/strings.h"
#include "art_field-inl.h"
#include "base/bit_vector-inl.h"
#include "base/file_utils.h"
#include "base/logging.h" // For VLOG.
#include "base/stl_util.h"
#include "base/systrace.h"
#include "class_linker.h"
#include "class_loader_context.h"
#include "dex/art_dex_file_loader.h"
#include "dex/dex_file-inl.h"
#include "dex/dex_file_loader.h"
#include "dex/dex_file_tracking_registrar.h"
#include "gc/scoped_gc_critical_section.h"
#include "gc/space/image_space.h"
#include "handle_scope-inl.h"
#include "jni_internal.h"
#include "mirror/class_loader.h"
#include "mirror/object-inl.h"
#include "oat_file.h"
#include "oat_file_assistant.h"
#include "obj_ptr-inl.h"
#include "scoped_thread_state_change-inl.h"
#include "thread-current-inl.h"
#include "thread_list.h"
#include "well_known_classes.h"
namespace art {
using android::base::StringPrintf;
// If true, we attempt to load the application image if it exists.
static constexpr bool kEnableAppImage = true;
const OatFile* OatFileManager::RegisterOatFile(std::unique_ptr<const OatFile> oat_file) {
WriterMutexLock mu(Thread::Current(), *Locks::oat_file_manager_lock_);
CHECK(!only_use_system_oat_files_ ||
LocationIsOnSystem(oat_file->GetLocation().c_str()) ||
!oat_file->IsExecutable())
<< "Registering a non /system oat file: " << oat_file->GetLocation();
DCHECK(oat_file != nullptr);
if (kIsDebugBuild) {
CHECK(oat_files_.find(oat_file) == oat_files_.end());
for (const std::unique_ptr<const OatFile>& existing : oat_files_) {
CHECK_NE(oat_file.get(), existing.get()) << oat_file->GetLocation();
// Check that we don't have an oat file with the same address. Copies of the same oat file
// should be loaded at different addresses.
CHECK_NE(oat_file->Begin(), existing->Begin()) << "Oat file already mapped at that location";
}
}
have_non_pic_oat_file_ = have_non_pic_oat_file_ || !oat_file->IsPic();
const OatFile* ret = oat_file.get();
oat_files_.insert(std::move(oat_file));
return ret;
}
void OatFileManager::UnRegisterAndDeleteOatFile(const OatFile* oat_file) {
WriterMutexLock mu(Thread::Current(), *Locks::oat_file_manager_lock_);
DCHECK(oat_file != nullptr);
std::unique_ptr<const OatFile> compare(oat_file);
auto it = oat_files_.find(compare);
CHECK(it != oat_files_.end());
oat_files_.erase(it);
compare.release();
}
const OatFile* OatFileManager::FindOpenedOatFileFromDexLocation(
const std::string& dex_base_location) const {
ReaderMutexLock mu(Thread::Current(), *Locks::oat_file_manager_lock_);
for (const std::unique_ptr<const OatFile>& oat_file : oat_files_) {
const std::vector<const OatDexFile*>& oat_dex_files = oat_file->GetOatDexFiles();
for (const OatDexFile* oat_dex_file : oat_dex_files) {
if (DexFileLoader::GetBaseLocation(oat_dex_file->GetDexFileLocation()) == dex_base_location) {
return oat_file.get();
}
}
}
return nullptr;
}
const OatFile* OatFileManager::FindOpenedOatFileFromOatLocation(const std::string& oat_location)
const {
ReaderMutexLock mu(Thread::Current(), *Locks::oat_file_manager_lock_);
return FindOpenedOatFileFromOatLocationLocked(oat_location);
}
const OatFile* OatFileManager::FindOpenedOatFileFromOatLocationLocked(
const std::string& oat_location) const {
for (const std::unique_ptr<const OatFile>& oat_file : oat_files_) {
if (oat_file->GetLocation() == oat_location) {
return oat_file.get();
}
}
return nullptr;
}
std::vector<const OatFile*> OatFileManager::GetBootOatFiles() const {
std::vector<const OatFile*> oat_files;
std::vector<gc::space::ImageSpace*> image_spaces =
Runtime::Current()->GetHeap()->GetBootImageSpaces();
for (gc::space::ImageSpace* image_space : image_spaces) {
oat_files.push_back(image_space->GetOatFile());
}
return oat_files;
}
const OatFile* OatFileManager::GetPrimaryOatFile() const {
ReaderMutexLock mu(Thread::Current(), *Locks::oat_file_manager_lock_);
std::vector<const OatFile*> boot_oat_files = GetBootOatFiles();
if (!boot_oat_files.empty()) {
for (const std::unique_ptr<const OatFile>& oat_file : oat_files_) {
if (std::find(boot_oat_files.begin(), boot_oat_files.end(), oat_file.get()) ==
boot_oat_files.end()) {
return oat_file.get();
}
}
}
return nullptr;
}
OatFileManager::OatFileManager()
: have_non_pic_oat_file_(false), only_use_system_oat_files_(false) {}
OatFileManager::~OatFileManager() {
// Explicitly clear oat_files_ since the OatFile destructor calls back into OatFileManager for
// UnRegisterOatFileLocation.
oat_files_.clear();
}
std::vector<const OatFile*> OatFileManager::RegisterImageOatFiles(
std::vector<gc::space::ImageSpace*> spaces) {
std::vector<const OatFile*> oat_files;
for (gc::space::ImageSpace* space : spaces) {
oat_files.push_back(RegisterOatFile(space->ReleaseOatFile()));
}
return oat_files;
}
class TypeIndexInfo {
public:
explicit TypeIndexInfo(const DexFile* dex_file)
: type_indexes_(GenerateTypeIndexes(dex_file)),
iter_(type_indexes_.Indexes().begin()),
end_(type_indexes_.Indexes().end()) { }
BitVector& GetTypeIndexes() {
return type_indexes_;
}
BitVector::IndexIterator& GetIterator() {
return iter_;
}
BitVector::IndexIterator& GetIteratorEnd() {
return end_;
}
void AdvanceIterator() {
iter_++;
}
private:
static BitVector GenerateTypeIndexes(const DexFile* dex_file) {
BitVector type_indexes(/*start_bits*/0, /*expandable*/true, Allocator::GetMallocAllocator());
for (uint16_t i = 0; i < dex_file->NumClassDefs(); ++i) {
const DexFile::ClassDef& class_def = dex_file->GetClassDef(i);
uint16_t type_idx = class_def.class_idx_.index_;
type_indexes.SetBit(type_idx);
}
return type_indexes;
}
// BitVector with bits set for the type indexes of all classes in the input dex file.
BitVector type_indexes_;
BitVector::IndexIterator iter_;
BitVector::IndexIterator end_;
};
class DexFileAndClassPair : ValueObject {
public:
DexFileAndClassPair(const DexFile* dex_file, TypeIndexInfo* type_info, bool from_loaded_oat)
: type_info_(type_info),
dex_file_(dex_file),
cached_descriptor_(dex_file_->StringByTypeIdx(dex::TypeIndex(*type_info->GetIterator()))),
from_loaded_oat_(from_loaded_oat) {
type_info_->AdvanceIterator();
}
DexFileAndClassPair(const DexFileAndClassPair& rhs) = default;
DexFileAndClassPair& operator=(const DexFileAndClassPair& rhs) = default;
const char* GetCachedDescriptor() const {
return cached_descriptor_;
}
bool operator<(const DexFileAndClassPair& rhs) const {
const int cmp = strcmp(cached_descriptor_, rhs.cached_descriptor_);
if (cmp != 0) {
// Note that the order must be reversed. We want to iterate over the classes in dex files.
// They are sorted lexicographically. Thus, the priority-queue must be a min-queue.
return cmp > 0;
}
return dex_file_ < rhs.dex_file_;
}
bool DexFileHasMoreClasses() const {
return type_info_->GetIterator() != type_info_->GetIteratorEnd();
}
void Next() {
cached_descriptor_ = dex_file_->StringByTypeIdx(dex::TypeIndex(*type_info_->GetIterator()));
type_info_->AdvanceIterator();
}
bool FromLoadedOat() const {
return from_loaded_oat_;
}
const DexFile* GetDexFile() const {
return dex_file_;
}
private:
TypeIndexInfo* type_info_;
const DexFile* dex_file_;
const char* cached_descriptor_;
bool from_loaded_oat_; // We only need to compare mismatches between what we load now
// and what was loaded before. Any old duplicates must have been
// OK, and any new "internal" duplicates are as well (they must
// be from multidex, which resolves correctly).
};
static void AddDexFilesFromOat(
const OatFile* oat_file,
/*out*/std::vector<const DexFile*>* dex_files,
std::vector<std::unique_ptr<const DexFile>>* opened_dex_files) {
for (const OatDexFile* oat_dex_file : oat_file->GetOatDexFiles()) {
std::string error;
std::unique_ptr<const DexFile> dex_file = oat_dex_file->OpenDexFile(&error);
if (dex_file == nullptr) {
LOG(WARNING) << "Could not create dex file from oat file: " << error;
} else if (dex_file->NumClassDefs() > 0U) {
dex_files->push_back(dex_file.get());
opened_dex_files->push_back(std::move(dex_file));
}
}
}
static void AddNext(/*inout*/DexFileAndClassPair& original,
/*inout*/std::priority_queue<DexFileAndClassPair>& heap) {
if (original.DexFileHasMoreClasses()) {
original.Next();
heap.push(std::move(original));
}
}
static bool CollisionCheck(std::vector<const DexFile*>& dex_files_loaded,
std::vector<const DexFile*>& dex_files_unloaded,
std::string* error_msg /*out*/) {
// Generate type index information for each dex file.
std::vector<TypeIndexInfo> loaded_types;
for (const DexFile* dex_file : dex_files_loaded) {
loaded_types.push_back(TypeIndexInfo(dex_file));
}
std::vector<TypeIndexInfo> unloaded_types;
for (const DexFile* dex_file : dex_files_unloaded) {
unloaded_types.push_back(TypeIndexInfo(dex_file));
}
// Populate the queue of dex file and class pairs with the loaded and unloaded dex files.
std::priority_queue<DexFileAndClassPair> queue;
for (size_t i = 0; i < dex_files_loaded.size(); ++i) {
if (loaded_types[i].GetIterator() != loaded_types[i].GetIteratorEnd()) {
queue.emplace(dex_files_loaded[i], &loaded_types[i], /*from_loaded_oat*/true);
}
}
for (size_t i = 0; i < dex_files_unloaded.size(); ++i) {
if (unloaded_types[i].GetIterator() != unloaded_types[i].GetIteratorEnd()) {
queue.emplace(dex_files_unloaded[i], &unloaded_types[i], /*from_loaded_oat*/false);
}
}
// Now drain the queue.
bool has_duplicates = false;
error_msg->clear();
while (!queue.empty()) {
// Modifying the top element is only safe if we pop right after.
DexFileAndClassPair compare_pop(queue.top());
queue.pop();
// Compare against the following elements.
while (!queue.empty()) {
DexFileAndClassPair top(queue.top());
if (strcmp(compare_pop.GetCachedDescriptor(), top.GetCachedDescriptor()) == 0) {
// Same descriptor. Check whether it's crossing old-oat-files to new-oat-files.
if (compare_pop.FromLoadedOat() != top.FromLoadedOat()) {
error_msg->append(
StringPrintf("Found duplicated class when checking oat files: '%s' in %s and %s\n",
compare_pop.GetCachedDescriptor(),
compare_pop.GetDexFile()->GetLocation().c_str(),
top.GetDexFile()->GetLocation().c_str()));
if (!VLOG_IS_ON(oat)) {
return true;
}
has_duplicates = true;
}
queue.pop();
AddNext(top, queue);
} else {
// Something else. Done here.
break;
}
}
AddNext(compare_pop, queue);
}
return has_duplicates;
}
// Check for class-def collisions in dex files.
//
// This first walks the class loader chain present in the given context, getting all the dex files
// from the class loader.
//
// If the context is null (which means the initial class loader was null or unsupported)
// this returns false. b/37777332.
//
// This first checks whether all class loaders in the context have the same type and
// classpath. If so, we exit early. Otherwise, we do the collision check.
//
// The collision check works by maintaining a heap with one class from each dex file, sorted by the
// class descriptor. Then a dex-file/class pair is continually removed from the heap and compared
// against the following top element. If the descriptor is the same, it is now checked whether
// the two elements agree on whether their dex file was from an already-loaded oat-file or the
// new oat file. Any disagreement indicates a collision.
bool OatFileManager::HasCollisions(const OatFile* oat_file,
const ClassLoaderContext* context,
std::string* error_msg /*out*/) const {
DCHECK(oat_file != nullptr);
DCHECK(error_msg != nullptr);
// The context might be null if there are unrecognized class loaders in the chain or they
// don't meet sensible sanity conditions. In this case we assume that the app knows what it's
// doing and accept the oat file.
// Note that this has correctness implications as we cannot guarantee that the class resolution
// used during compilation is OK (b/37777332).
if (context == nullptr) {
LOG(WARNING) << "Skipping duplicate class check due to unsupported classloader";
return false;
}
// If the pat file loading context matches the context used during compilation then we accept
// the oat file without addition checks
if (context->VerifyClassLoaderContextMatch(oat_file->GetClassLoaderContext())) {
return false;
}
// The class loader context does not match. Perform a full duplicate classes check.
std::vector<const DexFile*> dex_files_loaded = context->FlattenOpenedDexFiles();
// Vector that holds the newly opened dex files live, this is done to prevent leaks.
std::vector<std::unique_ptr<const DexFile>> opened_dex_files;
ScopedTrace st("Collision check");
// Add dex files from the oat file to check.
std::vector<const DexFile*> dex_files_unloaded;
AddDexFilesFromOat(oat_file, &dex_files_unloaded, &opened_dex_files);
return CollisionCheck(dex_files_loaded, dex_files_unloaded, error_msg);
}
std::vector<std::unique_ptr<const DexFile>> OatFileManager::OpenDexFilesFromOat(
const char* dex_location,
jobject class_loader,
jobjectArray dex_elements,
const OatFile** out_oat_file,
std::vector<std::string>* error_msgs) {
ScopedTrace trace(__FUNCTION__);
CHECK(dex_location != nullptr);
CHECK(error_msgs != nullptr);
// Verify we aren't holding the mutator lock, which could starve GC if we
// have to generate or relocate an oat file.
Thread* const self = Thread::Current();
Locks::mutator_lock_->AssertNotHeld(self);
Runtime* const runtime = Runtime::Current();
std::unique_ptr<ClassLoaderContext> context;
// If the class_loader is null there's not much we can do. This happens if a dex files is loaded
// directly with DexFile APIs instead of using class loaders.
if (class_loader == nullptr) {
LOG(WARNING) << "Opening an oat file without a class loader. "
<< "Are you using the deprecated DexFile APIs?";
context = nullptr;
} else {
context = ClassLoaderContext::CreateContextForClassLoader(class_loader, dex_elements);
}
OatFileAssistant oat_file_assistant(dex_location,
kRuntimeISA,
!runtime->IsAotCompiler(),
only_use_system_oat_files_);
// Lock the target oat location to avoid races generating and loading the
// oat file.
std::string error_msg;
if (!oat_file_assistant.Lock(/*out*/&error_msg)) {
// Don't worry too much if this fails. If it does fail, it's unlikely we
// can generate an oat file anyway.
VLOG(class_linker) << "OatFileAssistant::Lock: " << error_msg;
}
const OatFile* source_oat_file = nullptr;
if (!oat_file_assistant.IsUpToDate()) {
// Update the oat file on disk if we can, based on the --compiler-filter
// option derived from the current runtime options.
// This may fail, but that's okay. Best effort is all that matters here.
// TODO(calin): b/64530081 b/66984396. Pass a null context to verify and compile
// secondary dex files in isolation (and avoid to extract/verify the main apk
// if it's in the class path). Note this trades correctness for performance
// since the resulting slow down is unacceptable in some cases until b/64530081
// is fixed.
// We still pass the class loader context when the classpath string of the runtime
// is not empty, which is the situation when ART is invoked standalone.
ClassLoaderContext* actual_context = Runtime::Current()->GetClassPathString().empty()
? nullptr
: context.get();
switch (oat_file_assistant.MakeUpToDate(/*profile_changed*/ false,
actual_context,
/*out*/ &error_msg)) {
case OatFileAssistant::kUpdateFailed:
LOG(WARNING) << error_msg;
break;
case OatFileAssistant::kUpdateNotAttempted:
// Avoid spamming the logs if we decided not to attempt making the oat
// file up to date.
VLOG(oat) << error_msg;
break;
case OatFileAssistant::kUpdateSucceeded:
// Nothing to do.
break;
}
}
// Get the oat file on disk.
std::unique_ptr<const OatFile> oat_file(oat_file_assistant.GetBestOatFile().release());
VLOG(oat) << "OatFileAssistant(" << dex_location << ").GetBestOatFile()="
<< reinterpret_cast<uintptr_t>(oat_file.get())
<< " (executable=" << (oat_file != nullptr ? oat_file->IsExecutable() : false) << ")";
if ((class_loader != nullptr || dex_elements != nullptr) && oat_file != nullptr) {
// Prevent oat files from being loaded if no class_loader or dex_elements are provided.
// This can happen when the deprecated DexFile.<init>(String) is called directly, and it
// could load oat files without checking the classpath, which would be incorrect.
// Take the file only if it has no collisions, or we must take it because of preopting.
bool accept_oat_file =
!HasCollisions(oat_file.get(), context.get(), /*out*/ &error_msg);
if (!accept_oat_file) {
// Failed the collision check. Print warning.
if (Runtime::Current()->IsDexFileFallbackEnabled()) {
if (!oat_file_assistant.HasOriginalDexFiles()) {
// We need to fallback but don't have original dex files. We have to
// fallback to opening the existing oat file. This is potentially
// unsafe so we warn about it.
accept_oat_file = true;
LOG(WARNING) << "Dex location " << dex_location << " does not seem to include dex file. "
<< "Allow oat file use. This is potentially dangerous.";
} else {
// We have to fallback and found original dex files - extract them from an APK.
// Also warn about this operation because it's potentially wasteful.
LOG(WARNING) << "Found duplicate classes, falling back to extracting from APK : "
<< dex_location;
LOG(WARNING) << "NOTE: This wastes RAM and hurts startup performance.";
}
} else {
// TODO: We should remove this. The fact that we're here implies -Xno-dex-file-fallback
// was set, which means that we should never fallback. If we don't have original dex
// files, we should just fail resolution as the flag intended.
if (!oat_file_assistant.HasOriginalDexFiles()) {
accept_oat_file = true;
}
LOG(WARNING) << "Found duplicate classes, dex-file-fallback disabled, will be failing to "
" load classes for " << dex_location;
}
LOG(WARNING) << error_msg;
}
if (accept_oat_file) {
VLOG(class_linker) << "Registering " << oat_file->GetLocation();
source_oat_file = RegisterOatFile(std::move(oat_file));
*out_oat_file = source_oat_file;
}
}
std::vector<std::unique_ptr<const DexFile>> dex_files;
// Load the dex files from the oat file.
if (source_oat_file != nullptr) {
bool added_image_space = false;
if (source_oat_file->IsExecutable()) {
// We need to throw away the image space if we are debuggable but the oat-file source of the
// image is not otherwise we might get classes with inlined methods or other such things.
std::unique_ptr<gc::space::ImageSpace> image_space;
if (kEnableAppImage && (!runtime->IsJavaDebuggable() || source_oat_file->IsDebuggable())) {
image_space = oat_file_assistant.OpenImageSpace(source_oat_file);
} else {
image_space = nullptr;
}
if (image_space != nullptr) {
ScopedObjectAccess soa(self);
StackHandleScope<1> hs(self);
Handle<mirror::ClassLoader> h_loader(
hs.NewHandle(soa.Decode<mirror::ClassLoader>(class_loader)));
// Can not load app image without class loader.
if (h_loader != nullptr) {
std::string temp_error_msg;
// Add image space has a race condition since other threads could be reading from the
// spaces array.
{
ScopedThreadSuspension sts(self, kSuspended);
gc::ScopedGCCriticalSection gcs(self,
gc::kGcCauseAddRemoveAppImageSpace,
gc::kCollectorTypeAddRemoveAppImageSpace);
ScopedSuspendAll ssa("Add image space");
runtime->GetHeap()->AddSpace(image_space.get());
}
{
ScopedTrace trace2(StringPrintf("Adding image space for location %s", dex_location));
added_image_space = runtime->GetClassLinker()->AddImageSpace(image_space.get(),
h_loader,
dex_elements,
dex_location,
/*out*/&dex_files,
/*out*/&temp_error_msg);
}
if (added_image_space) {
// Successfully added image space to heap, release the map so that it does not get
// freed.
image_space.release();
// Register for tracking.
for (const auto& dex_file : dex_files) {
dex::tracking::RegisterDexFile(dex_file.get());
}
} else {
LOG(INFO) << "Failed to add image file " << temp_error_msg;
dex_files.clear();
{
ScopedThreadSuspension sts(self, kSuspended);
gc::ScopedGCCriticalSection gcs(self,
gc::kGcCauseAddRemoveAppImageSpace,
gc::kCollectorTypeAddRemoveAppImageSpace);
ScopedSuspendAll ssa("Remove image space");
runtime->GetHeap()->RemoveSpace(image_space.get());
}
// Non-fatal, don't update error_msg.
}
}
}
}
if (!added_image_space) {
DCHECK(dex_files.empty());
dex_files = oat_file_assistant.LoadDexFiles(*source_oat_file, dex_location);
// Register for tracking.
for (const auto& dex_file : dex_files) {
dex::tracking::RegisterDexFile(dex_file.get());
}
}
if (dex_files.empty()) {
error_msgs->push_back("Failed to open dex files from " + source_oat_file->GetLocation());
} else {
// Opened dex files from an oat file, madvise them to their loaded state.
for (const std::unique_ptr<const DexFile>& dex_file : dex_files) {
OatDexFile::MadviseDexFile(*dex_file, MadviseState::kMadviseStateAtLoad);
}
}
}
// Fall back to running out of the original dex file if we couldn't load any
// dex_files from the oat file.
if (dex_files.empty()) {
if (oat_file_assistant.HasOriginalDexFiles()) {
if (Runtime::Current()->IsDexFileFallbackEnabled()) {
static constexpr bool kVerifyChecksum = true;
const ArtDexFileLoader dex_file_loader;
if (!dex_file_loader.Open(dex_location,
dex_location,
Runtime::Current()->IsVerificationEnabled(),
kVerifyChecksum,
/*out*/ &error_msg,
&dex_files)) {
LOG(WARNING) << error_msg;
error_msgs->push_back("Failed to open dex files from " + std::string(dex_location)
+ " because: " + error_msg);
}
} else {
error_msgs->push_back("Fallback mode disabled, skipping dex files.");
}
} else {
error_msgs->push_back("No original dex files found for dex location "
+ std::string(dex_location));
}
}
return dex_files;
}
void OatFileManager::SetOnlyUseSystemOatFiles() {
ReaderMutexLock mu(Thread::Current(), *Locks::oat_file_manager_lock_);
CHECK_EQ(oat_files_.size(), GetBootOatFiles().size());
only_use_system_oat_files_ = true;
}
void OatFileManager::DumpForSigQuit(std::ostream& os) {
ReaderMutexLock mu(Thread::Current(), *Locks::oat_file_manager_lock_);
std::vector<const OatFile*> boot_oat_files = GetBootOatFiles();
for (const std::unique_ptr<const OatFile>& oat_file : oat_files_) {
if (ContainsElement(boot_oat_files, oat_file.get())) {
continue;
}
os << oat_file->GetLocation() << ": " << oat_file->GetCompilerFilter() << "\n";
}
}
} // namespace art