/*
* Copyright (C) 2016 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 "verifier_deps.h"
#include <cstring>
#include <sstream>
#include "art_field-inl.h"
#include "art_method-inl.h"
#include "base/indenter.h"
#include "base/leb128.h"
#include "base/mutex-inl.h"
#include "compiler_callbacks.h"
#include "dex/class_accessor-inl.h"
#include "dex/dex_file-inl.h"
#include "mirror/class-inl.h"
#include "mirror/class_loader.h"
#include "oat_file.h"
#include "obj_ptr-inl.h"
#include "runtime.h"
namespace art {
namespace verifier {
VerifierDeps::VerifierDeps(const std::vector<const DexFile*>& dex_files, bool output_only)
: output_only_(output_only) {
for (const DexFile* dex_file : dex_files) {
DCHECK(GetDexFileDeps(*dex_file) == nullptr);
std::unique_ptr<DexFileDeps> deps(new DexFileDeps(dex_file->NumClassDefs()));
dex_deps_.emplace(dex_file, std::move(deps));
}
}
VerifierDeps::VerifierDeps(const std::vector<const DexFile*>& dex_files)
: VerifierDeps(dex_files, /*output_only=*/ true) {}
// Perform logical OR on two bit vectors and assign back to LHS, i.e. `to_update |= other`.
// Size of the two vectors must be equal.
// Size of `other` must be equal to size of `to_update`.
static inline void BitVectorOr(std::vector<bool>& to_update, const std::vector<bool>& other) {
DCHECK_EQ(to_update.size(), other.size());
std::transform(other.begin(),
other.end(),
to_update.begin(),
to_update.begin(),
std::logical_or<bool>());
}
void VerifierDeps::MergeWith(std::unique_ptr<VerifierDeps> other,
const std::vector<const DexFile*>& dex_files) {
DCHECK(other != nullptr);
DCHECK_EQ(dex_deps_.size(), other->dex_deps_.size());
for (const DexFile* dex_file : dex_files) {
DexFileDeps* my_deps = GetDexFileDeps(*dex_file);
DexFileDeps& other_deps = *other->GetDexFileDeps(*dex_file);
// We currently collect extra strings only on the main `VerifierDeps`,
// which should be the one passed as `this` in this method.
DCHECK(other_deps.strings_.empty());
my_deps->assignable_types_.merge(other_deps.assignable_types_);
my_deps->unassignable_types_.merge(other_deps.unassignable_types_);
my_deps->classes_.merge(other_deps.classes_);
my_deps->fields_.merge(other_deps.fields_);
my_deps->methods_.merge(other_deps.methods_);
BitVectorOr(my_deps->verified_classes_, other_deps.verified_classes_);
BitVectorOr(my_deps->redefined_classes_, other_deps.redefined_classes_);
}
}
VerifierDeps::DexFileDeps* VerifierDeps::GetDexFileDeps(const DexFile& dex_file) {
auto it = dex_deps_.find(&dex_file);
return (it == dex_deps_.end()) ? nullptr : it->second.get();
}
const VerifierDeps::DexFileDeps* VerifierDeps::GetDexFileDeps(const DexFile& dex_file) const {
auto it = dex_deps_.find(&dex_file);
return (it == dex_deps_.end()) ? nullptr : it->second.get();
}
// Access flags that impact vdex verification.
static constexpr uint32_t kAccVdexAccessFlags =
kAccPublic | kAccPrivate | kAccProtected | kAccStatic | kAccInterface;
template <typename Ptr>
uint16_t VerifierDeps::GetAccessFlags(Ptr element) {
static_assert(kAccJavaFlagsMask == 0xFFFF, "Unexpected value of a constant");
if (element == nullptr) {
return VerifierDeps::kUnresolvedMarker;
} else {
uint16_t access_flags = Low16Bits(element->GetAccessFlags()) & kAccVdexAccessFlags;
CHECK_NE(access_flags, VerifierDeps::kUnresolvedMarker);
return access_flags;
}
}
dex::StringIndex VerifierDeps::GetClassDescriptorStringId(const DexFile& dex_file,
ObjPtr<mirror::Class> klass) {
DCHECK(klass != nullptr);
ObjPtr<mirror::DexCache> dex_cache = klass->GetDexCache();
// Array and proxy classes do not have a dex cache.
if (!klass->IsArrayClass() && !klass->IsProxyClass()) {
DCHECK(dex_cache != nullptr) << klass->PrettyClass();
if (dex_cache->GetDexFile() == &dex_file) {
// FindStringId is slow, try to go through the class def if we have one.
const dex::ClassDef* class_def = klass->GetClassDef();
DCHECK(class_def != nullptr) << klass->PrettyClass();
const dex::TypeId& type_id = dex_file.GetTypeId(class_def->class_idx_);
if (kIsDebugBuild) {
std::string temp;
CHECK_EQ(GetIdFromString(dex_file, klass->GetDescriptor(&temp)), type_id.descriptor_idx_);
}
return type_id.descriptor_idx_;
}
}
std::string temp;
return GetIdFromString(dex_file, klass->GetDescriptor(&temp));
}
// Try to find the string descriptor of the class. type_idx is a best guess of a matching string id.
static dex::StringIndex TryGetClassDescriptorStringId(const DexFile& dex_file,
dex::TypeIndex type_idx,
ObjPtr<mirror::Class> klass)
REQUIRES_SHARED(Locks::mutator_lock_) {
if (!klass->IsArrayClass()) {
const dex::TypeId& type_id = dex_file.GetTypeId(type_idx);
const DexFile& klass_dex = klass->GetDexFile();
const dex::TypeId& klass_type_id = klass_dex.GetTypeId(klass->GetClassDef()->class_idx_);
if (strcmp(dex_file.GetTypeDescriptor(type_id),
klass_dex.GetTypeDescriptor(klass_type_id)) == 0) {
return type_id.descriptor_idx_;
}
}
return dex::StringIndex::Invalid();
}
dex::StringIndex VerifierDeps::GetMethodDeclaringClassStringId(const DexFile& dex_file,
uint32_t dex_method_index,
ArtMethod* method) {
static_assert(kAccJavaFlagsMask == 0xFFFF, "Unexpected value of a constant");
if (method == nullptr) {
return dex::StringIndex(VerifierDeps::kUnresolvedMarker);
}
const dex::StringIndex string_id = TryGetClassDescriptorStringId(
dex_file,
dex_file.GetMethodId(dex_method_index).class_idx_,
method->GetDeclaringClass());
if (string_id.IsValid()) {
// Got lucky using the original dex file, return based on the input dex file.
DCHECK_EQ(GetClassDescriptorStringId(dex_file, method->GetDeclaringClass()), string_id);
return string_id;
}
return GetClassDescriptorStringId(dex_file, method->GetDeclaringClass());
}
dex::StringIndex VerifierDeps::GetFieldDeclaringClassStringId(const DexFile& dex_file,
uint32_t dex_field_idx,
ArtField* field) {
static_assert(kAccJavaFlagsMask == 0xFFFF, "Unexpected value of a constant");
if (field == nullptr) {
return dex::StringIndex(VerifierDeps::kUnresolvedMarker);
}
const dex::StringIndex string_id = TryGetClassDescriptorStringId(
dex_file,
dex_file.GetFieldId(dex_field_idx).class_idx_,
field->GetDeclaringClass());
if (string_id.IsValid()) {
// Got lucky using the original dex file, return based on the input dex file.
DCHECK_EQ(GetClassDescriptorStringId(dex_file, field->GetDeclaringClass()), string_id);
return string_id;
}
return GetClassDescriptorStringId(dex_file, field->GetDeclaringClass());
}
static inline VerifierDeps* GetMainVerifierDeps() {
// The main VerifierDeps is the one set in the compiler callbacks, which at the
// end of verification will have all the per-thread VerifierDeps merged into it.
CompilerCallbacks* callbacks = Runtime::Current()->GetCompilerCallbacks();
if (callbacks == nullptr) {
return nullptr;
}
return callbacks->GetVerifierDeps();
}
static inline VerifierDeps* GetThreadLocalVerifierDeps() {
// During AOT, each thread has its own VerifierDeps, to avoid lock contention. At the end
// of full verification, these VerifierDeps will be merged into the main one.
if (!Runtime::Current()->IsAotCompiler()) {
return nullptr;
}
return Thread::Current()->GetVerifierDeps();
}
static bool FindExistingStringId(const std::vector<std::string>& strings,
const std::string& str,
uint32_t* found_id) {
uint32_t num_extra_ids = strings.size();
for (size_t i = 0; i < num_extra_ids; ++i) {
if (strings[i] == str) {
*found_id = i;
return true;
}
}
return false;
}
dex::StringIndex VerifierDeps::GetIdFromString(const DexFile& dex_file, const std::string& str) {
const dex::StringId* string_id = dex_file.FindStringId(str.c_str());
if (string_id != nullptr) {
// String is in the DEX file. Return its ID.
return dex_file.GetIndexForStringId(*string_id);
}
// String is not in the DEX file. Assign a new ID to it which is higher than
// the number of strings in the DEX file.
// We use the main `VerifierDeps` for adding new strings to simplify
// synchronization/merging of these entries between threads.
VerifierDeps* singleton = GetMainVerifierDeps();
DexFileDeps* deps = singleton->GetDexFileDeps(dex_file);
DCHECK(deps != nullptr);
uint32_t num_ids_in_dex = dex_file.NumStringIds();
uint32_t found_id;
{
ReaderMutexLock mu(Thread::Current(), *Locks::verifier_deps_lock_);
if (FindExistingStringId(deps->strings_, str, &found_id)) {
return dex::StringIndex(num_ids_in_dex + found_id);
}
}
{
WriterMutexLock mu(Thread::Current(), *Locks::verifier_deps_lock_);
if (FindExistingStringId(deps->strings_, str, &found_id)) {
return dex::StringIndex(num_ids_in_dex + found_id);
}
deps->strings_.push_back(str);
dex::StringIndex new_id(num_ids_in_dex + deps->strings_.size() - 1);
CHECK_GE(new_id.index_, num_ids_in_dex); // check for overflows
DCHECK_EQ(str, singleton->GetStringFromId(dex_file, new_id));
return new_id;
}
}
std::string VerifierDeps::GetStringFromId(const DexFile& dex_file, dex::StringIndex string_id)
const {
uint32_t num_ids_in_dex = dex_file.NumStringIds();
if (string_id.index_ < num_ids_in_dex) {
return std::string(dex_file.StringDataByIdx(string_id));
} else {
const DexFileDeps* deps = GetDexFileDeps(dex_file);
DCHECK(deps != nullptr);
string_id.index_ -= num_ids_in_dex;
CHECK_LT(string_id.index_, deps->strings_.size());
return deps->strings_[string_id.index_];
}
}
bool VerifierDeps::IsInClassPath(ObjPtr<mirror::Class> klass) const {
DCHECK(klass != nullptr);
// For array types, we return whether the non-array component type
// is in the classpath.
while (klass->IsArrayClass()) {
klass = klass->GetComponentType();
}
if (klass->IsPrimitive()) {
return true;
}
ObjPtr<mirror::DexCache> dex_cache = klass->GetDexCache();
DCHECK(dex_cache != nullptr);
const DexFile* dex_file = dex_cache->GetDexFile();
DCHECK(dex_file != nullptr);
// Test if the `dex_deps_` contains an entry for `dex_file`. If not, the dex
// file was not registered as being compiled and we assume `klass` is in the
// classpath.
return (GetDexFileDeps(*dex_file) == nullptr);
}
void VerifierDeps::AddClassResolution(const DexFile& dex_file,
dex::TypeIndex type_idx,
ObjPtr<mirror::Class> klass) {
DexFileDeps* dex_deps = GetDexFileDeps(dex_file);
if (dex_deps == nullptr) {
// This invocation is from verification of a dex file which is not being compiled.
return;
}
if (klass != nullptr && !IsInClassPath(klass)) {
// Class resolved into one of the DEX files which are being compiled.
// This is not a classpath dependency.
return;
}
dex_deps->classes_.emplace(ClassResolution(type_idx, GetAccessFlags(klass)));
}
void VerifierDeps::AddFieldResolution(const DexFile& dex_file,
uint32_t field_idx,
ArtField* field) {
DexFileDeps* dex_deps = GetDexFileDeps(dex_file);
if (dex_deps == nullptr) {
// This invocation is from verification of a dex file which is not being compiled.
return;
}
if (field != nullptr && !IsInClassPath(field->GetDeclaringClass())) {
// Field resolved into one of the DEX files which are being compiled.
// This is not a classpath dependency.
return;
}
dex_deps->fields_.emplace(FieldResolution(field_idx,
GetAccessFlags(field),
GetFieldDeclaringClassStringId(dex_file,
field_idx,
field)));
}
void VerifierDeps::AddMethodResolution(const DexFile& dex_file,
uint32_t method_idx,
ArtMethod* method) {
DexFileDeps* dex_deps = GetDexFileDeps(dex_file);
if (dex_deps == nullptr) {
// This invocation is from verification of a dex file which is not being compiled.
return;
}
if (method != nullptr && !IsInClassPath(method->GetDeclaringClass())) {
// Method resolved into one of the DEX files which are being compiled.
// This is not a classpath dependency.
return;
}
MethodResolution method_tuple(method_idx,
GetAccessFlags(method),
GetMethodDeclaringClassStringId(dex_file, method_idx, method));
dex_deps->methods_.insert(method_tuple);
}
ObjPtr<mirror::Class> VerifierDeps::FindOneClassPathBoundaryForInterface(
ObjPtr<mirror::Class> destination,
ObjPtr<mirror::Class> source) const {
DCHECK(destination->IsInterface());
DCHECK(IsInClassPath(destination));
Thread* thread = Thread::Current();
ObjPtr<mirror::Class> current = source;
// Record the classes that are at the boundary between the compiled DEX files and
// the classpath. We will check those classes later to find one class that inherits
// `destination`.
std::vector<ObjPtr<mirror::Class>> boundaries;
// If the destination is a direct interface of a class defined in the DEX files being
// compiled, no need to record it.
while (!IsInClassPath(current)) {
for (size_t i = 0; i < current->NumDirectInterfaces(); ++i) {
ObjPtr<mirror::Class> direct = mirror::Class::GetDirectInterface(thread, current, i);
if (direct == destination) {
return nullptr;
} else if (IsInClassPath(direct)) {
boundaries.push_back(direct);
}
}
current = current->GetSuperClass();
}
DCHECK(current != nullptr);
boundaries.push_back(current);
// Check if we have an interface defined in the DEX files being compiled, direclty
// inheriting `destination`.
int32_t iftable_count = source->GetIfTableCount();
ObjPtr<mirror::IfTable> iftable = source->GetIfTable();
for (int32_t i = 0; i < iftable_count; ++i) {
ObjPtr<mirror::Class> itf = iftable->GetInterface(i);
if (!IsInClassPath(itf)) {
for (size_t j = 0; j < itf->NumDirectInterfaces(); ++j) {
ObjPtr<mirror::Class> direct = mirror::Class::GetDirectInterface(thread, itf, j);
if (direct == destination) {
return nullptr;
} else if (IsInClassPath(direct)) {
boundaries.push_back(direct);
}
}
}
}
// Find a boundary making `source` inherit from `destination`. We must find one.
for (const ObjPtr<mirror::Class>& boundary : boundaries) {
if (destination->IsAssignableFrom(boundary)) {
return boundary;
}
}
LOG(FATAL) << "Should have found a classpath boundary";
UNREACHABLE();
}
void VerifierDeps::AddAssignability(const DexFile& dex_file,
ObjPtr<mirror::Class> destination,
ObjPtr<mirror::Class> source,
bool is_strict,
bool is_assignable) {
// Test that the method is only called on reference types.
// Note that concurrent verification of `destination` and `source` may have
// set their status to erroneous. However, the tests performed below rely
// merely on no issues with linking (valid access flags, superclass and
// implemented interfaces). If the class at any point reached the IsResolved
// status, the requirement holds. This is guaranteed by RegTypeCache::ResolveClass.
DCHECK(destination != nullptr);
DCHECK(source != nullptr);
if (destination->IsPrimitive() || source->IsPrimitive()) {
// Primitive types are trivially non-assignable to anything else.
// We do not need to record trivial assignability, as it will
// not change across releases.
return;
}
if (source->IsObjectClass() && !is_assignable) {
// j.l.Object is trivially non-assignable to other types, don't
// record it.
return;
}
if (destination == source ||
destination->IsObjectClass() ||
(!is_strict && destination->IsInterface())) {
// Cases when `destination` is trivially assignable from `source`.
DCHECK(is_assignable);
return;
}
if (destination->IsArrayClass() && source->IsArrayClass()) {
// Both types are arrays. Break down to component types and add recursively.
// This helps filter out destinations from compiled DEX files (see below)
// and deduplicate entries with the same canonical component type.
ObjPtr<mirror::Class> destination_component = destination->GetComponentType();
ObjPtr<mirror::Class> source_component = source->GetComponentType();
// Only perform the optimization if both types are resolved which guarantees
// that they linked successfully, as required at the top of this method.
if (destination_component->IsResolved() && source_component->IsResolved()) {
AddAssignability(dex_file,
destination_component,
source_component,
/* is_strict= */ true,
is_assignable);
return;
}
} else {
// We only do this check for non-array types, as arrays might have erroneous
// component types which makes the IsAssignableFrom check unreliable.
DCHECK_EQ(is_assignable, destination->IsAssignableFrom(source));
}
DexFileDeps* dex_deps = GetDexFileDeps(dex_file);
if (dex_deps == nullptr) {
// This invocation is from verification of a DEX file which is not being compiled.
return;
}
if (!IsInClassPath(destination) && !IsInClassPath(source)) {
// Both `destination` and `source` are defined in the compiled DEX files.
// No need to record a dependency.
return;
}
if (!IsInClassPath(source)) {
if (!destination->IsInterface() && !source->IsInterface()) {
// Find the super class at the classpath boundary. Only that class
// can change the assignability.
do {
source = source->GetSuperClass();
} while (!IsInClassPath(source));
// If that class is the actual destination, no need to record it.
if (source == destination) {
return;
}
} else if (is_assignable) {
source = FindOneClassPathBoundaryForInterface(destination, source);
if (source == nullptr) {
// There was no classpath boundary, no need to record.
return;
}
DCHECK(IsInClassPath(source));
}
}
// Get string IDs for both descriptors and store in the appropriate set.
dex::StringIndex destination_id = GetClassDescriptorStringId(dex_file, destination);
dex::StringIndex source_id = GetClassDescriptorStringId(dex_file, source);
if (is_assignable) {
dex_deps->assignable_types_.emplace(TypeAssignability(destination_id, source_id));
} else {
dex_deps->unassignable_types_.emplace(TypeAssignability(destination_id, source_id));
}
}
void VerifierDeps::MaybeRecordClassRedefinition(const DexFile& dex_file,
const dex::ClassDef& class_def) {
VerifierDeps* thread_deps = GetThreadLocalVerifierDeps();
if (thread_deps != nullptr) {
DexFileDeps* dex_deps = thread_deps->GetDexFileDeps(dex_file);
DCHECK_EQ(dex_deps->redefined_classes_.size(), dex_file.NumClassDefs());
dex_deps->redefined_classes_[dex_file.GetIndexForClassDef(class_def)] = true;
}
}
void VerifierDeps::MaybeRecordVerificationStatus(const DexFile& dex_file,
const dex::ClassDef& class_def,
FailureKind failure_kind) {
// The `verified_classes_` bit vector is initialized to `false`.
// Only continue if we are about to write `true`.
if (failure_kind == FailureKind::kNoFailure) {
VerifierDeps* thread_deps = GetThreadLocalVerifierDeps();
if (thread_deps != nullptr) {
thread_deps->RecordClassVerified(dex_file, class_def);
}
}
}
void VerifierDeps::RecordClassVerified(const DexFile& dex_file, const dex::ClassDef& class_def) {
DexFileDeps* dex_deps = GetDexFileDeps(dex_file);
DCHECK_EQ(dex_deps->verified_classes_.size(), dex_file.NumClassDefs());
dex_deps->verified_classes_[dex_file.GetIndexForClassDef(class_def)] = true;
}
void VerifierDeps::MaybeRecordClassResolution(const DexFile& dex_file,
dex::TypeIndex type_idx,
ObjPtr<mirror::Class> klass) {
VerifierDeps* thread_deps = GetThreadLocalVerifierDeps();
if (thread_deps != nullptr) {
thread_deps->AddClassResolution(dex_file, type_idx, klass);
}
}
void VerifierDeps::MaybeRecordFieldResolution(const DexFile& dex_file,
uint32_t field_idx,
ArtField* field) {
VerifierDeps* thread_deps = GetThreadLocalVerifierDeps();
if (thread_deps != nullptr) {
thread_deps->AddFieldResolution(dex_file, field_idx, field);
}
}
void VerifierDeps::MaybeRecordMethodResolution(const DexFile& dex_file,
uint32_t method_idx,
ArtMethod* method) {
VerifierDeps* thread_deps = GetThreadLocalVerifierDeps();
if (thread_deps != nullptr) {
thread_deps->AddMethodResolution(dex_file, method_idx, method);
}
}
void VerifierDeps::MaybeRecordAssignability(const DexFile& dex_file,
ObjPtr<mirror::Class> destination,
ObjPtr<mirror::Class> source,
bool is_strict,
bool is_assignable) {
VerifierDeps* thread_deps = GetThreadLocalVerifierDeps();
if (thread_deps != nullptr) {
thread_deps->AddAssignability(dex_file, destination, source, is_strict, is_assignable);
}
}
namespace {
static inline uint32_t DecodeUint32WithOverflowCheck(const uint8_t** in, const uint8_t* end) {
CHECK_LT(*in, end);
return DecodeUnsignedLeb128(in);
}
template<typename T> inline uint32_t Encode(T in);
template<> inline uint32_t Encode<uint16_t>(uint16_t in) {
return in;
}
template<> inline uint32_t Encode<uint32_t>(uint32_t in) {
return in;
}
template<> inline uint32_t Encode<dex::TypeIndex>(dex::TypeIndex in) {
return in.index_;
}
template<> inline uint32_t Encode<dex::StringIndex>(dex::StringIndex in) {
return in.index_;
}
template<typename T> inline T Decode(uint32_t in);
template<> inline uint16_t Decode<uint16_t>(uint32_t in) {
return dchecked_integral_cast<uint16_t>(in);
}
template<> inline uint32_t Decode<uint32_t>(uint32_t in) {
return in;
}
template<> inline dex::TypeIndex Decode<dex::TypeIndex>(uint32_t in) {
return dex::TypeIndex(in);
}
template<> inline dex::StringIndex Decode<dex::StringIndex>(uint32_t in) {
return dex::StringIndex(in);
}
template<typename T1, typename T2>
static inline void EncodeTuple(std::vector<uint8_t>* out, const std::tuple<T1, T2>& t) {
EncodeUnsignedLeb128(out, Encode(std::get<0>(t)));
EncodeUnsignedLeb128(out, Encode(std::get<1>(t)));
}
template<typename T1, typename T2>
static inline void DecodeTuple(const uint8_t** in, const uint8_t* end, std::tuple<T1, T2>* t) {
T1 v1 = Decode<T1>(DecodeUint32WithOverflowCheck(in, end));
T2 v2 = Decode<T2>(DecodeUint32WithOverflowCheck(in, end));
*t = std::make_tuple(v1, v2);
}
template<typename T1, typename T2, typename T3>
static inline void EncodeTuple(std::vector<uint8_t>* out, const std::tuple<T1, T2, T3>& t) {
EncodeUnsignedLeb128(out, Encode(std::get<0>(t)));
EncodeUnsignedLeb128(out, Encode(std::get<1>(t)));
EncodeUnsignedLeb128(out, Encode(std::get<2>(t)));
}
template<typename T1, typename T2, typename T3>
static inline void DecodeTuple(const uint8_t** in, const uint8_t* end, std::tuple<T1, T2, T3>* t) {
T1 v1 = Decode<T1>(DecodeUint32WithOverflowCheck(in, end));
T2 v2 = Decode<T2>(DecodeUint32WithOverflowCheck(in, end));
T3 v3 = Decode<T3>(DecodeUint32WithOverflowCheck(in, end));
*t = std::make_tuple(v1, v2, v3);
}
template<typename T>
static inline void EncodeSet(std::vector<uint8_t>* out, const std::set<T>& set) {
EncodeUnsignedLeb128(out, set.size());
for (const T& entry : set) {
EncodeTuple(out, entry);
}
}
template<typename T>
static inline void DecodeSet(const uint8_t** in, const uint8_t* end, std::set<T>* set) {
DCHECK(set->empty());
size_t num_entries = DecodeUint32WithOverflowCheck(in, end);
for (size_t i = 0; i < num_entries; ++i) {
T tuple;
DecodeTuple(in, end, &tuple);
set->emplace(tuple);
}
}
static inline void EncodeUint16SparseBitVector(std::vector<uint8_t>* out,
const std::vector<bool>& vector,
bool sparse_value) {
DCHECK(IsUint<16>(vector.size()));
EncodeUnsignedLeb128(out, std::count(vector.begin(), vector.end(), sparse_value));
for (uint16_t idx = 0; idx < vector.size(); ++idx) {
if (vector[idx] == sparse_value) {
EncodeUnsignedLeb128(out, Encode(idx));
}
}
}
static inline void DecodeUint16SparseBitVector(const uint8_t** in,
const uint8_t* end,
std::vector<bool>* vector,
bool sparse_value) {
DCHECK(IsUint<16>(vector->size()));
std::fill(vector->begin(), vector->end(), !sparse_value);
size_t num_entries = DecodeUint32WithOverflowCheck(in, end);
for (size_t i = 0; i < num_entries; ++i) {
uint16_t idx = Decode<uint16_t>(DecodeUint32WithOverflowCheck(in, end));
DCHECK_LT(idx, vector->size());
(*vector)[idx] = sparse_value;
}
}
static inline void EncodeStringVector(std::vector<uint8_t>* out,
const std::vector<std::string>& strings) {
EncodeUnsignedLeb128(out, strings.size());
for (const std::string& str : strings) {
const uint8_t* data = reinterpret_cast<const uint8_t*>(str.c_str());
size_t length = str.length() + 1;
out->insert(out->end(), data, data + length);
DCHECK_EQ(0u, out->back());
}
}
static inline void DecodeStringVector(const uint8_t** in,
const uint8_t* end,
std::vector<std::string>* strings) {
DCHECK(strings->empty());
size_t num_strings = DecodeUint32WithOverflowCheck(in, end);
strings->reserve(num_strings);
for (size_t i = 0; i < num_strings; ++i) {
CHECK_LT(*in, end);
const char* string_start = reinterpret_cast<const char*>(*in);
strings->emplace_back(std::string(string_start));
*in += strings->back().length() + 1;
}
}
static inline std::string ToHex(uint32_t value) {
std::stringstream ss;
ss << std::hex << value << std::dec;
return ss.str();
}
} // namespace
void VerifierDeps::Encode(const std::vector<const DexFile*>& dex_files,
std::vector<uint8_t>* buffer) const {
for (const DexFile* dex_file : dex_files) {
const DexFileDeps& deps = *GetDexFileDeps(*dex_file);
EncodeStringVector(buffer, deps.strings_);
EncodeSet(buffer, deps.assignable_types_);
EncodeSet(buffer, deps.unassignable_types_);
EncodeSet(buffer, deps.classes_);
EncodeSet(buffer, deps.fields_);
EncodeSet(buffer, deps.methods_);
EncodeUint16SparseBitVector(buffer, deps.verified_classes_, /* sparse_value= */ false);
EncodeUint16SparseBitVector(buffer, deps.redefined_classes_, /* sparse_value= */ true);
}
}
void VerifierDeps::DecodeDexFileDeps(DexFileDeps& deps,
const uint8_t** data_start,
const uint8_t* data_end) {
DecodeStringVector(data_start, data_end, &deps.strings_);
DecodeSet(data_start, data_end, &deps.assignable_types_);
DecodeSet(data_start, data_end, &deps.unassignable_types_);
DecodeSet(data_start, data_end, &deps.classes_);
DecodeSet(data_start, data_end, &deps.fields_);
DecodeSet(data_start, data_end, &deps.methods_);
DecodeUint16SparseBitVector(data_start,
data_end,
&deps.verified_classes_,
/* sparse_value= */ false);
DecodeUint16SparseBitVector(data_start,
data_end,
&deps.redefined_classes_,
/* sparse_value= */ true);
}
VerifierDeps::VerifierDeps(const std::vector<const DexFile*>& dex_files,
ArrayRef<const uint8_t> data)
: VerifierDeps(dex_files, /*output_only=*/ false) {
if (data.empty()) {
// Return eagerly, as the first thing we expect from VerifierDeps data is
// the number of created strings, even if there is no dependency.
// Currently, only the boot image does not have any VerifierDeps data.
return;
}
const uint8_t* data_start = data.data();
const uint8_t* data_end = data_start + data.size();
for (const DexFile* dex_file : dex_files) {
DexFileDeps* deps = GetDexFileDeps(*dex_file);
DecodeDexFileDeps(*deps, &data_start, data_end);
}
CHECK_LE(data_start, data_end);
}
std::vector<std::vector<bool>> VerifierDeps::ParseVerifiedClasses(
const std::vector<const DexFile*>& dex_files,
ArrayRef<const uint8_t> data) {
DCHECK(!data.empty());
DCHECK(!dex_files.empty());
std::vector<std::vector<bool>> verified_classes_per_dex;
verified_classes_per_dex.reserve(dex_files.size());
const uint8_t* data_start = data.data();
const uint8_t* data_end = data_start + data.size();
for (const DexFile* dex_file : dex_files) {
DexFileDeps deps(dex_file->NumClassDefs());
DecodeDexFileDeps(deps, &data_start, data_end);
verified_classes_per_dex.push_back(std::move(deps.verified_classes_));
}
return verified_classes_per_dex;
}
bool VerifierDeps::Equals(const VerifierDeps& rhs) const {
if (dex_deps_.size() != rhs.dex_deps_.size()) {
return false;
}
auto lhs_it = dex_deps_.begin();
auto rhs_it = rhs.dex_deps_.begin();
for (; (lhs_it != dex_deps_.end()) && (rhs_it != rhs.dex_deps_.end()); lhs_it++, rhs_it++) {
const DexFile* lhs_dex_file = lhs_it->first;
const DexFile* rhs_dex_file = rhs_it->first;
if (lhs_dex_file != rhs_dex_file) {
return false;
}
DexFileDeps* lhs_deps = lhs_it->second.get();
DexFileDeps* rhs_deps = rhs_it->second.get();
if (!lhs_deps->Equals(*rhs_deps)) {
return false;
}
}
DCHECK((lhs_it == dex_deps_.end()) && (rhs_it == rhs.dex_deps_.end()));
return true;
}
bool VerifierDeps::DexFileDeps::Equals(const VerifierDeps::DexFileDeps& rhs) const {
return (strings_ == rhs.strings_) &&
(assignable_types_ == rhs.assignable_types_) &&
(unassignable_types_ == rhs.unassignable_types_) &&
(classes_ == rhs.classes_) &&
(fields_ == rhs.fields_) &&
(methods_ == rhs.methods_) &&
(verified_classes_ == rhs.verified_classes_);
}
void VerifierDeps::Dump(VariableIndentationOutputStream* vios) const {
for (const auto& dep : dex_deps_) {
const DexFile& dex_file = *dep.first;
vios->Stream()
<< "Dependencies of "
<< dex_file.GetLocation()
<< ":\n";
ScopedIndentation indent(vios);
for (const std::string& str : dep.second->strings_) {
vios->Stream() << "Extra string: " << str << "\n";
}
for (const TypeAssignability& entry : dep.second->assignable_types_) {
vios->Stream()
<< GetStringFromId(dex_file, entry.GetSource())
<< " must be assignable to "
<< GetStringFromId(dex_file, entry.GetDestination())
<< "\n";
}
for (const TypeAssignability& entry : dep.second->unassignable_types_) {
vios->Stream()
<< GetStringFromId(dex_file, entry.GetSource())
<< " must not be assignable to "
<< GetStringFromId(dex_file, entry.GetDestination())
<< "\n";
}
for (const ClassResolution& entry : dep.second->classes_) {
vios->Stream()
<< dex_file.StringByTypeIdx(entry.GetDexTypeIndex())
<< (entry.IsResolved() ? " must be resolved " : "must not be resolved ")
<< " with access flags " << std::hex << entry.GetAccessFlags() << std::dec
<< "\n";
}
for (const FieldResolution& entry : dep.second->fields_) {
const dex::FieldId& field_id = dex_file.GetFieldId(entry.GetDexFieldIndex());
vios->Stream()
<< dex_file.GetFieldDeclaringClassDescriptor(field_id) << "->"
<< dex_file.GetFieldName(field_id) << ":"
<< dex_file.GetFieldTypeDescriptor(field_id)
<< " is expected to be ";
if (!entry.IsResolved()) {
vios->Stream() << "unresolved\n";
} else {
vios->Stream()
<< "in class "
<< GetStringFromId(dex_file, entry.GetDeclaringClassIndex())
<< ", and have the access flags " << std::hex << entry.GetAccessFlags() << std::dec
<< "\n";
}
}
for (const MethodResolution& method : dep.second->methods_) {
const dex::MethodId& method_id = dex_file.GetMethodId(method.GetDexMethodIndex());
vios->Stream()
<< dex_file.GetMethodDeclaringClassDescriptor(method_id) << "->"
<< dex_file.GetMethodName(method_id)
<< dex_file.GetMethodSignature(method_id).ToString()
<< " is expected to be ";
if (!method.IsResolved()) {
vios->Stream() << "unresolved\n";
} else {
vios->Stream()
<< "in class "
<< GetStringFromId(dex_file, method.GetDeclaringClassIndex())
<< ", have the access flags " << std::hex << method.GetAccessFlags() << std::dec
<< "\n";
}
}
for (size_t idx = 0; idx < dep.second->verified_classes_.size(); idx++) {
if (!dep.second->verified_classes_[idx]) {
vios->Stream()
<< dex_file.GetClassDescriptor(dex_file.GetClassDef(idx))
<< " will be verified at runtime\n";
}
}
}
}
bool VerifierDeps::ValidateDependencies(Thread* self,
Handle<mirror::ClassLoader> class_loader,
const std::vector<const DexFile*>& classpath,
/* out */ std::string* error_msg) const {
for (const auto& entry : dex_deps_) {
if (!VerifyDexFile(class_loader, *entry.first, *entry.second, classpath, self, error_msg)) {
return false;
}
}
return true;
}
// TODO: share that helper with other parts of the compiler that have
// the same lookup pattern.
static ObjPtr<mirror::Class> FindClassAndClearException(ClassLinker* class_linker,
Thread* self,
const std::string& name,
Handle<mirror::ClassLoader> class_loader)
REQUIRES_SHARED(Locks::mutator_lock_) {
ObjPtr<mirror::Class> result = class_linker->FindClass(self, name.c_str(), class_loader);
if (result == nullptr) {
DCHECK(self->IsExceptionPending());
self->ClearException();
}
return result;
}
bool VerifierDeps::VerifyAssignability(Handle<mirror::ClassLoader> class_loader,
const DexFile& dex_file,
const std::set<TypeAssignability>& assignables,
bool expected_assignability,
Thread* self,
/* out */ std::string* error_msg) const {
StackHandleScope<2> hs(self);
ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
MutableHandle<mirror::Class> source(hs.NewHandle<mirror::Class>(nullptr));
MutableHandle<mirror::Class> destination(hs.NewHandle<mirror::Class>(nullptr));
for (const auto& entry : assignables) {
const std::string& destination_desc = GetStringFromId(dex_file, entry.GetDestination());
destination.Assign(
FindClassAndClearException(class_linker, self, destination_desc.c_str(), class_loader));
const std::string& source_desc = GetStringFromId(dex_file, entry.GetSource());
source.Assign(
FindClassAndClearException(class_linker, self, source_desc.c_str(), class_loader));
if (destination == nullptr) {
*error_msg = "Could not resolve class " + destination_desc;
return false;
}
if (source == nullptr) {
*error_msg = "Could not resolve class " + source_desc;
return false;
}
DCHECK(destination->IsResolved() && source->IsResolved());
if (destination->IsAssignableFrom(source.Get()) != expected_assignability) {
*error_msg = "Class " + destination_desc + (expected_assignability ? " not " : " ") +
"assignable from " + source_desc;
return false;
}
}
return true;
}
bool VerifierDeps::VerifyClasses(Handle<mirror::ClassLoader> class_loader,
const DexFile& dex_file,
const std::set<ClassResolution>& classes,
Thread* self,
/* out */ std::string* error_msg) const {
StackHandleScope<1> hs(self);
ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
MutableHandle<mirror::Class> cls(hs.NewHandle<mirror::Class>(nullptr));
for (const auto& entry : classes) {
std::string descriptor = dex_file.StringByTypeIdx(entry.GetDexTypeIndex());
cls.Assign(FindClassAndClearException(class_linker, self, descriptor, class_loader));
if (entry.IsResolved()) {
if (cls == nullptr) {
*error_msg = "Could not resolve class " + descriptor;
return false;
} else if (entry.GetAccessFlags() != GetAccessFlags(cls.Get())) {
*error_msg = "Unexpected access flags on class " + descriptor
+ " (expected=" + ToHex(entry.GetAccessFlags())
+ ", actual=" + ToHex(GetAccessFlags(cls.Get())) + ")";
return false;
}
} else if (cls != nullptr) {
*error_msg = "Unexpected successful resolution of class " + descriptor;
return false;
}
}
return true;
}
static std::string GetFieldDescription(const DexFile& dex_file, uint32_t index) {
const dex::FieldId& field_id = dex_file.GetFieldId(index);
return std::string(dex_file.GetFieldDeclaringClassDescriptor(field_id))
+ "->"
+ dex_file.GetFieldName(field_id)
+ ":"
+ dex_file.GetFieldTypeDescriptor(field_id);
}
bool VerifierDeps::VerifyFields(Handle<mirror::ClassLoader> class_loader,
const DexFile& dex_file,
const std::set<FieldResolution>& fields,
Thread* self,
/* out */ std::string* error_msg) const {
// Check recorded fields are resolved the same way, have the same recorded class,
// and have the same recorded flags.
ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
for (const auto& entry : fields) {
const dex::FieldId& field_id = dex_file.GetFieldId(entry.GetDexFieldIndex());
std::string_view name(dex_file.StringDataByIdx(field_id.name_idx_));
std::string_view type(
dex_file.StringDataByIdx(dex_file.GetTypeId(field_id.type_idx_).descriptor_idx_));
// Only use field_id.class_idx_ when the entry is unresolved, which is rare.
// Otherwise, we might end up resolving an application class, which is expensive.
std::string expected_decl_klass = entry.IsResolved()
? GetStringFromId(dex_file, entry.GetDeclaringClassIndex())
: dex_file.StringByTypeIdx(field_id.class_idx_);
ObjPtr<mirror::Class> cls = FindClassAndClearException(
class_linker, self, expected_decl_klass.c_str(), class_loader);
if (cls == nullptr) {
*error_msg = "Could not resolve class " + expected_decl_klass;
return false;
}
DCHECK(cls->IsResolved());
ArtField* field = mirror::Class::FindField(self, cls, name, type);
if (entry.IsResolved()) {
std::string temp;
if (field == nullptr) {
*error_msg = "Could not resolve field " +
GetFieldDescription(dex_file, entry.GetDexFieldIndex());
return false;
} else if (expected_decl_klass != field->GetDeclaringClass()->GetDescriptor(&temp)) {
*error_msg = "Unexpected declaring class for field resolution "
+ GetFieldDescription(dex_file, entry.GetDexFieldIndex())
+ " (expected=" + expected_decl_klass
+ ", actual=" + field->GetDeclaringClass()->GetDescriptor(&temp) + ")";
return false;
} else if (entry.GetAccessFlags() != GetAccessFlags(field)) {
*error_msg = "Unexpected access flags for resolved field "
+ GetFieldDescription(dex_file, entry.GetDexFieldIndex())
+ " (expected=" + ToHex(entry.GetAccessFlags())
+ ", actual=" + ToHex(GetAccessFlags(field)) + ")";
return false;
}
} else if (field != nullptr) {
*error_msg = "Unexpected successful resolution of field "
+ GetFieldDescription(dex_file, entry.GetDexFieldIndex());
return false;
}
}
return true;
}
static std::string GetMethodDescription(const DexFile& dex_file, uint32_t index) {
const dex::MethodId& method_id = dex_file.GetMethodId(index);
return std::string(dex_file.GetMethodDeclaringClassDescriptor(method_id))
+ "->"
+ dex_file.GetMethodName(method_id)
+ dex_file.GetMethodSignature(method_id).ToString();
}
bool VerifierDeps::VerifyMethods(Handle<mirror::ClassLoader> class_loader,
const DexFile& dex_file,
const std::set<MethodResolution>& methods,
Thread* self,
/* out */ std::string* error_msg) const {
ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
PointerSize pointer_size = class_linker->GetImagePointerSize();
for (const auto& entry : methods) {
const dex::MethodId& method_id = dex_file.GetMethodId(entry.GetDexMethodIndex());
const char* name = dex_file.GetMethodName(method_id);
const Signature signature = dex_file.GetMethodSignature(method_id);
// Only use method_id.class_idx_ when the entry is unresolved, which is rare.
// Otherwise, we might end up resolving an application class, which is expensive.
std::string expected_decl_klass = entry.IsResolved()
? GetStringFromId(dex_file, entry.GetDeclaringClassIndex())
: dex_file.StringByTypeIdx(method_id.class_idx_);
ObjPtr<mirror::Class> cls = FindClassAndClearException(
class_linker, self, expected_decl_klass.c_str(), class_loader);
if (cls == nullptr) {
*error_msg = "Could not resolve class " + expected_decl_klass;
return false;
}
DCHECK(cls->IsResolved());
ArtMethod* method = nullptr;
if (cls->IsInterface()) {
method = cls->FindInterfaceMethod(name, signature, pointer_size);
} else {
method = cls->FindClassMethod(name, signature, pointer_size);
}
if (entry.IsResolved()) {
std::string temp;
if (method == nullptr) {
*error_msg = "Could not resolve method "
+ GetMethodDescription(dex_file, entry.GetDexMethodIndex());
return false;
} else if (expected_decl_klass != method->GetDeclaringClass()->GetDescriptor(&temp)) {
*error_msg = "Unexpected declaring class for method resolution "
+ GetMethodDescription(dex_file, entry.GetDexMethodIndex())
+ " (expected=" + expected_decl_klass
+ ", actual=" + method->GetDeclaringClass()->GetDescriptor(&temp) + ")";
return false;
} else if (entry.GetAccessFlags() != GetAccessFlags(method)) {
*error_msg = "Unexpected access flags for resolved method resolution "
+ GetMethodDescription(dex_file, entry.GetDexMethodIndex())
+ " (expected=" + ToHex(entry.GetAccessFlags())
+ ", actual=" + ToHex(GetAccessFlags(method)) + ")";
return false;
}
} else if (method != nullptr) {
*error_msg = "Unexpected successful resolution of method "
+ GetMethodDescription(dex_file, entry.GetDexMethodIndex());
return false;
}
}
return true;
}
bool VerifierDeps::IsInDexFiles(const char* descriptor,
size_t hash,
const std::vector<const DexFile*>& dex_files,
/* out */ const DexFile** out_dex_file) const {
for (const DexFile* dex_file : dex_files) {
if (OatDexFile::FindClassDef(*dex_file, descriptor, hash) != nullptr) {
*out_dex_file = dex_file;
return true;
}
}
return false;
}
bool VerifierDeps::VerifyInternalClasses(const DexFile& dex_file,
const std::vector<const DexFile*>& classpath,
const std::vector<bool>& verified_classes,
const std::vector<bool>& redefined_classes,
/* out */ std::string* error_msg) const {
const std::vector<const DexFile*>& boot_classpath =
Runtime::Current()->GetClassLinker()->GetBootClassPath();
for (ClassAccessor accessor : dex_file.GetClasses()) {
const char* descriptor = accessor.GetDescriptor();
const uint16_t class_def_index = accessor.GetClassDefIndex();
if (redefined_classes[class_def_index]) {
if (verified_classes[class_def_index]) {
*error_msg = std::string("Class ") + descriptor + " marked both verified and redefined";
return false;
}
// Class was not verified under these dependencies. No need to check it further.
continue;
}
// Check that the class resolved into the same dex file. Otherwise there is
// a different class with the same descriptor somewhere in one of the parent
// class loaders.
const size_t hash = ComputeModifiedUtf8Hash(descriptor);
const DexFile* cp_dex_file = nullptr;
if (IsInDexFiles(descriptor, hash, boot_classpath, &cp_dex_file) ||
IsInDexFiles(descriptor, hash, classpath, &cp_dex_file)) {
*error_msg = std::string("Class ") + descriptor
+ " redefines a class in the classpath "
+ "(dexFile expected=" + dex_file.GetLocation()
+ ", actual=" + cp_dex_file->GetLocation() + ")";
return false;
}
}
return true;
}
bool VerifierDeps::VerifyDexFile(Handle<mirror::ClassLoader> class_loader,
const DexFile& dex_file,
const DexFileDeps& deps,
const std::vector<const DexFile*>& classpath,
Thread* self,
/* out */ std::string* error_msg) const {
return VerifyInternalClasses(dex_file,
classpath,
deps.verified_classes_,
deps.redefined_classes_,
error_msg) &&
VerifyAssignability(class_loader,
dex_file,
deps.assignable_types_,
/* expected_assignability= */ true,
self,
error_msg) &&
VerifyAssignability(class_loader,
dex_file,
deps.unassignable_types_,
/* expected_assignability= */ false,
self,
error_msg) &&
VerifyClasses(class_loader, dex_file, deps.classes_, self, error_msg) &&
VerifyFields(class_loader, dex_file, deps.fields_, self, error_msg) &&
VerifyMethods(class_loader, dex_file, deps.methods_, self, error_msg);
}
} // namespace verifier
} // namespace art