/*
* 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 <sys/stat.h>
#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/mutex-inl.h"
#include "base/sdk_version.h"
#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 "jit/jit.h"
#include "jni/java_vm_ext.h"
#include "jni/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 "thread_pool.h"
#include "vdex_file.h"
#include "verifier/verifier_deps.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";
}
}
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(); // NOLINT b/117926937
}
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<gc::space::ImageSpace*> image_spaces =
Runtime::Current()->GetHeap()->GetBootImageSpaces();
std::vector<const OatFile*> oat_files;
oat_files.reserve(image_spaces.size());
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()
: 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(
const std::vector<gc::space::ImageSpace*>& spaces) {
std::vector<const OatFile*> oat_files;
oat_files.reserve(spaces.size());
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 dex::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 CheckClassCollision(const OatFile* oat_file,
const ClassLoaderContext* context,
std::string* error_msg /*out*/) {
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);
// Generate type index information for each dex file.
std::vector<TypeIndexInfo> loaded_types;
loaded_types.reserve(dex_files_loaded.size());
for (const DexFile* dex_file : dex_files_loaded) {
loaded_types.push_back(TypeIndexInfo(dex_file));
}
std::vector<TypeIndexInfo> unloaded_types;
unloaded_types.reserve(dex_files_unloaded.size());
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.
OatFileManager::CheckCollisionResult OatFileManager::CheckCollision(
const OatFile* oat_file,
const ClassLoaderContext* context,
/*out*/ std::string* error_msg) 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 CheckCollisionResult::kSkippedUnsupportedClassLoader;
}
// If the oat file loading context matches the context used during compilation then we accept
// the oat file without addition checks
ClassLoaderContext::VerificationResult result = context->VerifyClassLoaderContextMatch(
oat_file->GetClassLoaderContext(),
/*verify_names=*/ true,
/*verify_checksums=*/ true);
switch (result) {
case ClassLoaderContext::VerificationResult::kForcedToSkipChecks:
return CheckCollisionResult::kSkippedClassLoaderContextSharedLibrary;
case ClassLoaderContext::VerificationResult::kMismatch:
// Mismatched context, do the actual collision check.
break;
case ClassLoaderContext::VerificationResult::kVerifies:
return CheckCollisionResult::kNoCollisions;
}
// The class loader context does not match. Perform a full duplicate classes check.
return CheckClassCollision(oat_file, context, error_msg)
? CheckCollisionResult::kPerformedHasCollisions : CheckCollisionResult::kNoCollisions;
}
bool OatFileManager::AcceptOatFile(CheckCollisionResult result) const {
// Take the file only if it has no collisions, or we must take it because of preopting.
// Also accept oat files for shared libraries and unsupported class loaders.
return result != CheckCollisionResult::kPerformedHasCollisions;
}
bool OatFileManager::ShouldLoadAppImage(CheckCollisionResult check_collision_result,
const OatFile* source_oat_file,
ClassLoaderContext* context,
std::string* error_msg) {
Runtime* const runtime = Runtime::Current();
if (kEnableAppImage && (!runtime->IsJavaDebuggable() || source_oat_file->IsDebuggable())) {
// If we verified the class loader context (skipping due to the special marker doesn't
// count), then also avoid the collision check.
bool load_image = check_collision_result == CheckCollisionResult::kNoCollisions;
// If we skipped the collision check, we need to reverify to be sure its OK to load the
// image.
if (!load_image &&
check_collision_result ==
CheckCollisionResult::kSkippedClassLoaderContextSharedLibrary) {
// We can load the app image only if there are no collisions. If we know the
// class loader but didn't do the full collision check in HasCollisions(),
// do it now. b/77342775
load_image = !CheckClassCollision(source_oat_file, context, error_msg);
}
return load_image;
}
return false;
}
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_);
// 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) << ")";
const OatFile* source_oat_file = nullptr;
CheckCollisionResult check_collision_result = CheckCollisionResult::kPerformedHasCollisions;
std::string error_msg;
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.
check_collision_result = CheckCollision(oat_file.get(), context.get(), /*out*/ &error_msg);
bool accept_oat_file = AcceptOatFile(check_collision_result);
if (!accept_oat_file) {
// Failed the collision check. Print warning.
if (runtime->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()) {
ScopedTrace app_image_timing("AppImage:Loading");
// 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 (ShouldLoadAppImage(check_collision_result,
source_oat_file,
context.get(),
&error_msg)) {
image_space = oat_file_assistant.OpenImageSpace(source_oat_file);
}
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(); // NOLINT b/117926937
// 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));
}
}
if (Runtime::Current()->GetJit() != nullptr) {
ScopedObjectAccess soa(self);
Runtime::Current()->GetJit()->RegisterDexFiles(
dex_files, soa.Decode<mirror::ClassLoader>(class_loader));
}
return dex_files;
}
static std::vector<const DexFile::Header*> GetDexFileHeaders(const std::vector<MemMap>& maps) {
std::vector<const DexFile::Header*> headers;
headers.reserve(maps.size());
for (const MemMap& map : maps) {
DCHECK(map.IsValid());
headers.push_back(reinterpret_cast<const DexFile::Header*>(map.Begin()));
}
return headers;
}
static std::vector<const DexFile::Header*> GetDexFileHeaders(
const std::vector<const DexFile*>& dex_files) {
std::vector<const DexFile::Header*> headers;
headers.reserve(dex_files.size());
for (const DexFile* dex_file : dex_files) {
headers.push_back(&dex_file->GetHeader());
}
return headers;
}
std::vector<std::unique_ptr<const DexFile>> OatFileManager::OpenDexFilesFromOat(
std::vector<MemMap>&& dex_mem_maps,
jobject class_loader,
jobjectArray dex_elements,
const OatFile** out_oat_file,
std::vector<std::string>* error_msgs) {
std::vector<std::unique_ptr<const DexFile>> dex_files = OpenDexFilesFromOat_Impl(
std::move(dex_mem_maps),
class_loader,
dex_elements,
out_oat_file,
error_msgs);
if (error_msgs->empty()) {
// Remove write permission from DexFile pages. We do this at the end because
// OatFile assigns OatDexFile pointer in the DexFile objects.
for (std::unique_ptr<const DexFile>& dex_file : dex_files) {
if (!dex_file->DisableWrite()) {
error_msgs->push_back("Failed to make dex file " + dex_file->GetLocation() + " read-only");
}
}
}
if (!error_msgs->empty()) {
return std::vector<std::unique_ptr<const DexFile>>();
}
return dex_files;
}
std::vector<std::unique_ptr<const DexFile>> OatFileManager::OpenDexFilesFromOat_Impl(
std::vector<MemMap>&& dex_mem_maps,
jobject class_loader,
jobjectArray dex_elements,
const OatFile** out_oat_file,
std::vector<std::string>* error_msgs) {
ScopedTrace trace(__FUNCTION__);
std::string error_msg;
DCHECK(error_msgs != nullptr);
// Extract dex file headers from `dex_mem_maps`.
const std::vector<const DexFile::Header*> dex_headers = GetDexFileHeaders(dex_mem_maps);
// Determine dex/vdex locations and the combined location checksum.
uint32_t location_checksum;
std::string dex_location;
std::string vdex_path;
bool has_vdex = OatFileAssistant::AnonymousDexVdexLocation(dex_headers,
kRuntimeISA,
&location_checksum,
&dex_location,
&vdex_path);
// Attempt to open an existing vdex and check dex file checksums match.
std::unique_ptr<VdexFile> vdex_file = nullptr;
if (has_vdex && OS::FileExists(vdex_path.c_str())) {
vdex_file = VdexFile::Open(vdex_path,
/* writable= */ false,
/* low_4gb= */ false,
/* unquicken= */ false,
&error_msg);
if (vdex_file == nullptr) {
LOG(WARNING) << "Failed to open vdex " << vdex_path << ": " << error_msg;
} else if (!vdex_file->MatchesDexFileChecksums(dex_headers)) {
LOG(WARNING) << "Failed to open vdex " << vdex_path << ": dex file checksum mismatch";
vdex_file.reset(nullptr);
}
}
// Load dex files. Skip structural dex file verification if vdex was found
// and dex checksums matched.
std::vector<std::unique_ptr<const DexFile>> dex_files;
for (size_t i = 0; i < dex_mem_maps.size(); ++i) {
static constexpr bool kVerifyChecksum = true;
const ArtDexFileLoader dex_file_loader;
std::unique_ptr<const DexFile> dex_file(dex_file_loader.Open(
DexFileLoader::GetMultiDexLocation(i, dex_location.c_str()),
location_checksum,
std::move(dex_mem_maps[i]),
/* verify= */ (vdex_file == nullptr) && Runtime::Current()->IsVerificationEnabled(),
kVerifyChecksum,
&error_msg));
if (dex_file != nullptr) {
dex::tracking::RegisterDexFile(dex_file.get()); // Register for tracking.
dex_files.push_back(std::move(dex_file));
} else {
error_msgs->push_back("Failed to open dex files from memory: " + error_msg);
}
}
// Check if we should proceed to creating an OatFile instance backed by the vdex.
// We need: (a) an existing vdex, (b) class loader (can be null if invoked via reflection),
// and (c) no errors during dex file loading.
if (vdex_file == nullptr || class_loader == nullptr || !error_msgs->empty()) {
return dex_files;
}
// Attempt to create a class loader context, check OpenDexFiles succeeds (prerequisite
// for using the context later).
std::unique_ptr<ClassLoaderContext> context = ClassLoaderContext::CreateContextForClassLoader(
class_loader,
dex_elements);
if (context == nullptr) {
LOG(ERROR) << "Could not create class loader context for " << vdex_path;
return dex_files;
}
DCHECK(context->OpenDexFiles(kRuntimeISA, ""))
<< "Context created from already opened dex files should not attempt to open again";
// Check that we can use the vdex against this boot class path and in this class loader context.
// Note 1: We do not need a class loader collision check because there is no compiled code.
// Note 2: If these checks fail, we cannot fast-verify because the vdex does not contain
// full VerifierDeps.
if (!vdex_file->MatchesBootClassPathChecksums() ||
!vdex_file->MatchesClassLoaderContext(*context.get())) {
return dex_files;
}
// Initialize an OatFile instance backed by the loaded vdex.
std::unique_ptr<OatFile> oat_file(OatFile::OpenFromVdex(MakeNonOwningPointerVector(dex_files),
std::move(vdex_file),
dex_location));
DCHECK(oat_file != nullptr);
VLOG(class_linker) << "Registering " << oat_file->GetLocation();
*out_oat_file = RegisterOatFile(std::move(oat_file));
return dex_files;
}
// Check how many vdex files exist in the same directory as the vdex file we are about
// to write. If more than or equal to kAnonymousVdexCacheSize, unlink the least
// recently used one(s) (according to stat-reported atime).
static bool UnlinkLeastRecentlyUsedVdexIfNeeded(const std::string& vdex_path_to_add,
std::string* error_msg) {
if (OS::FileExists(vdex_path_to_add.c_str())) {
// File already exists and will be overwritten.
// This will not change the number of entries in the cache.
return true;
}
auto last_slash = vdex_path_to_add.rfind('/');
CHECK(last_slash != std::string::npos);
std::string vdex_dir = vdex_path_to_add.substr(0, last_slash + 1);
if (!OS::DirectoryExists(vdex_dir.c_str())) {
// Folder does not exist yet. Cache has zero entries.
return true;
}
std::vector<std::pair<time_t, std::string>> cache;
DIR* c_dir = opendir(vdex_dir.c_str());
if (c_dir == nullptr) {
*error_msg = "Unable to open " + vdex_dir + " to delete unused vdex files";
return false;
}
for (struct dirent* de = readdir(c_dir); de != nullptr; de = readdir(c_dir)) {
if (de->d_type != DT_REG) {
continue;
}
std::string basename = de->d_name;
if (!OatFileAssistant::IsAnonymousVdexBasename(basename)) {
continue;
}
std::string fullname = vdex_dir + basename;
struct stat s;
int rc = TEMP_FAILURE_RETRY(stat(fullname.c_str(), &s));
if (rc == -1) {
*error_msg = "Failed to stat() anonymous vdex file " + fullname;
return false;
}
cache.push_back(std::make_pair(s.st_atime, fullname));
}
CHECK_EQ(0, closedir(c_dir)) << "Unable to close directory.";
if (cache.size() < OatFileManager::kAnonymousVdexCacheSize) {
return true;
}
std::sort(cache.begin(),
cache.end(),
[](const auto& a, const auto& b) { return a.first < b.first; });
for (size_t i = OatFileManager::kAnonymousVdexCacheSize - 1; i < cache.size(); ++i) {
if (unlink(cache[i].second.c_str()) != 0) {
*error_msg = "Could not unlink anonymous vdex file " + cache[i].second;
return false;
}
}
return true;
}
class BackgroundVerificationTask final : public Task {
public:
BackgroundVerificationTask(const std::vector<const DexFile*>& dex_files,
jobject class_loader,
const char* class_loader_context,
const std::string& vdex_path)
: dex_files_(dex_files),
class_loader_context_(class_loader_context),
vdex_path_(vdex_path) {
Thread* const self = Thread::Current();
ScopedObjectAccess soa(self);
// Create a global ref for `class_loader` because it will be accessed from a different thread.
class_loader_ = soa.Vm()->AddGlobalRef(self, soa.Decode<mirror::ClassLoader>(class_loader));
CHECK(class_loader_ != nullptr);
}
~BackgroundVerificationTask() {
Thread* const self = Thread::Current();
ScopedObjectAccess soa(self);
soa.Vm()->DeleteGlobalRef(self, class_loader_);
}
void Run(Thread* self) override {
std::string error_msg;
ClassLinker* const class_linker = Runtime::Current()->GetClassLinker();
verifier::VerifierDeps verifier_deps(dex_files_);
// Iterate over all classes and verify them.
for (const DexFile* dex_file : dex_files_) {
for (uint32_t cdef_idx = 0; cdef_idx < dex_file->NumClassDefs(); cdef_idx++) {
const dex::ClassDef& class_def = dex_file->GetClassDef(cdef_idx);
// Take handles inside the loop. The background verification is low priority
// and we want to minimize the risk of blocking anyone else.
ScopedObjectAccess soa(self);
StackHandleScope<2> hs(self);
Handle<mirror::ClassLoader> h_loader(hs.NewHandle(
soa.Decode<mirror::ClassLoader>(class_loader_)));
Handle<mirror::Class> h_class(hs.NewHandle<mirror::Class>(class_linker->FindClass(
self,
dex_file->GetClassDescriptor(class_def),
h_loader)));
if (h_class == nullptr) {
CHECK(self->IsExceptionPending());
self->ClearException();
continue;
}
if (&h_class->GetDexFile() != dex_file) {
// There is a different class in the class path or a parent class loader
// with the same descriptor. This `h_class` is not resolvable, skip it.
continue;
}
CHECK(h_class->IsResolved()) << h_class->PrettyDescriptor();
class_linker->VerifyClass(self, h_class);
if (h_class->IsErroneous()) {
// ClassLinker::VerifyClass throws, which isn't useful here.
CHECK(soa.Self()->IsExceptionPending());
soa.Self()->ClearException();
}
CHECK(h_class->IsVerified() || h_class->IsErroneous())
<< h_class->PrettyDescriptor() << ": state=" << h_class->GetStatus();
if (h_class->IsVerified()) {
verifier_deps.RecordClassVerified(*dex_file, class_def);
}
}
}
// Delete old vdex files if there are too many in the folder.
if (!UnlinkLeastRecentlyUsedVdexIfNeeded(vdex_path_, &error_msg)) {
LOG(ERROR) << "Could not unlink old vdex files " << vdex_path_ << ": " << error_msg;
return;
}
// Construct a vdex file and write `verifier_deps` into it.
if (!VdexFile::WriteToDisk(vdex_path_,
dex_files_,
verifier_deps,
class_loader_context_,
&error_msg)) {
LOG(ERROR) << "Could not write anonymous vdex " << vdex_path_ << ": " << error_msg;
return;
}
}
void Finalize() override {
delete this;
}
private:
const std::vector<const DexFile*> dex_files_;
jobject class_loader_;
const std::string class_loader_context_;
const std::string vdex_path_;
DISALLOW_COPY_AND_ASSIGN(BackgroundVerificationTask);
};
void OatFileManager::RunBackgroundVerification(const std::vector<const DexFile*>& dex_files,
jobject class_loader,
const char* class_loader_context) {
Runtime* const runtime = Runtime::Current();
Thread* const self = Thread::Current();
if (runtime->IsJavaDebuggable()) {
// Threads created by ThreadPool ("runtime threads") are not allowed to load
// classes when debuggable to match class-initialization semantics
// expectations. Do not verify in the background.
return;
}
if (!IsSdkVersionSetAndAtLeast(runtime->GetTargetSdkVersion(), SdkVersion::kQ)) {
// Do not run for legacy apps as they may depend on the previous class loader behaviour.
return;
}
if (runtime->IsShuttingDown(self)) {
// Not allowed to create new threads during runtime shutdown.
return;
}
uint32_t location_checksum;
std::string dex_location;
std::string vdex_path;
if (OatFileAssistant::AnonymousDexVdexLocation(GetDexFileHeaders(dex_files),
kRuntimeISA,
&location_checksum,
&dex_location,
&vdex_path)) {
if (verification_thread_pool_ == nullptr) {
verification_thread_pool_.reset(
new ThreadPool("Verification thread pool", /* num_threads= */ 1));
verification_thread_pool_->StartWorkers(self);
}
verification_thread_pool_->AddTask(self, new BackgroundVerificationTask(
dex_files,
class_loader,
class_loader_context,
vdex_path));
}
}
void OatFileManager::WaitForWorkersToBeCreated() {
DCHECK(!Runtime::Current()->IsShuttingDown(Thread::Current()))
<< "Cannot create new threads during runtime shutdown";
if (verification_thread_pool_ != nullptr) {
verification_thread_pool_->WaitForWorkersToBeCreated();
}
}
void OatFileManager::DeleteThreadPool() {
verification_thread_pool_.reset(nullptr);
}
void OatFileManager::WaitForBackgroundVerificationTasks() {
if (verification_thread_pool_ != nullptr) {
Thread* const self = Thread::Current();
verification_thread_pool_->WaitForWorkersToBeCreated();
verification_thread_pool_->Wait(self, /* do_work= */ true, /* may_hold_locks= */ false);
}
}
void OatFileManager::SetOnlyUseSystemOatFiles(bool enforce, bool assert_no_files_loaded) {
ReaderMutexLock mu(Thread::Current(), *Locks::oat_file_manager_lock_);
if (!only_use_system_oat_files_ && enforce && assert_no_files_loaded) {
// Make sure all files that were loaded up to this point are on /system. Skip the image
// files.
std::vector<const OatFile*> boot_vector = GetBootOatFiles();
std::unordered_set<const OatFile*> boot_set(boot_vector.begin(), boot_vector.end());
for (const std::unique_ptr<const OatFile>& oat_file : oat_files_) {
if (boot_set.find(oat_file.get()) == boot_set.end()) {
CHECK(LocationIsOnSystem(oat_file->GetLocation().c_str())) << oat_file->GetLocation();
}
}
}
only_use_system_oat_files_ = enforce;
}
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