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LeafOS / LeafOS-Project / android_art / 56de89aaf2a224de8c436291e3c23a1a61315437 / . / runtime / verifier / method_verifier.cc
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/*
* Copyright (C) 2011 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 "method_verifier-inl.h"
#include <iostream>
#include "android-base/stringprintf.h"
#include "art_field-inl.h"
#include "art_method-inl.h"
#include "base/aborting.h"
#include "base/enums.h"
#include "base/leb128.h"
#include "base/indenter.h"
#include "base/logging.h" // For VLOG.
#include "base/mutex-inl.h"
#include "base/stl_util.h"
#include "base/systrace.h"
#include "base/time_utils.h"
#include "base/utils.h"
#include "class_linker.h"
#include "class_root.h"
#include "compiler_callbacks.h"
#include "dex/class_accessor-inl.h"
#include "dex/descriptors_names.h"
#include "dex/dex_file-inl.h"
#include "dex/dex_file_exception_helpers.h"
#include "dex/dex_instruction-inl.h"
#include "dex/dex_instruction_utils.h"
#include "experimental_flags.h"
#include "gc/accounting/card_table-inl.h"
#include "handle_scope-inl.h"
#include "intern_table.h"
#include "mirror/class-inl.h"
#include "mirror/class.h"
#include "mirror/dex_cache-inl.h"
#include "mirror/method_handle_impl.h"
#include "mirror/method_type.h"
#include "mirror/object-inl.h"
#include "mirror/object_array-inl.h"
#include "mirror/var_handle.h"
#include "reg_type-inl.h"
#include "register_line-inl.h"
#include "runtime.h"
#include "scoped_thread_state_change-inl.h"
#include "stack.h"
#include "vdex_file.h"
#include "verifier_compiler_binding.h"
#include "verifier_deps.h"
namespace art {
namespace verifier {
using android::base::StringPrintf;
static constexpr bool kTimeVerifyMethod = !kIsDebugBuild;
// On VLOG(verifier), should we dump the whole state when we run into a hard failure?
static constexpr bool kDumpRegLinesOnHardFailureIfVLOG = true;
// We print a warning blurb about "dx --no-optimize" when we find monitor-locking issues. Make
// sure we only print this once.
static bool gPrintedDxMonitorText = false;
PcToRegisterLineTable::PcToRegisterLineTable(ScopedArenaAllocator& allocator)
: register_lines_(allocator.Adapter(kArenaAllocVerifier)) {}
void PcToRegisterLineTable::Init(RegisterTrackingMode mode, InstructionFlags* flags,
uint32_t insns_size, uint16_t registers_size,
MethodVerifier* verifier) {
DCHECK_GT(insns_size, 0U);
register_lines_.resize(insns_size);
for (uint32_t i = 0; i < insns_size; i++) {
bool interesting = false;
switch (mode) {
case kTrackRegsAll:
interesting = flags[i].IsOpcode();
break;
case kTrackCompilerInterestPoints:
interesting = flags[i].IsCompileTimeInfoPoint() || flags[i].IsBranchTarget();
break;
case kTrackRegsBranches:
interesting = flags[i].IsBranchTarget();
break;
default:
break;
}
if (interesting) {
register_lines_[i].reset(RegisterLine::Create(registers_size, verifier));
}
}
}
PcToRegisterLineTable::~PcToRegisterLineTable() {}
// Note: returns true on failure.
inline bool MethodVerifier::FailOrAbort(bool condition,
const char* error_msg,
uint32_t work_insn_idx) {
if (kIsDebugBuild) {
// In a debug build, abort if the error condition is wrong. Only warn if
// we are already aborting (as this verification is likely run to print
// lock information).
if (LIKELY(gAborting == 0)) {
DCHECK(condition) << error_msg << work_insn_idx << " "
<< dex_file_->PrettyMethod(dex_method_idx_);
} else {
if (!condition) {
LOG(ERROR) << error_msg << work_insn_idx;
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << error_msg << work_insn_idx;
return true;
}
}
} else {
// In a non-debug build, just fail the class.
if (!condition) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << error_msg << work_insn_idx;
return true;
}
}
return false;
}
static void SafelyMarkAllRegistersAsConflicts(MethodVerifier* verifier, RegisterLine* reg_line) {
if (verifier->IsInstanceConstructor()) {
// Before we mark all regs as conflicts, check that we don't have an uninitialized this.
reg_line->CheckConstructorReturn(verifier);
}
reg_line->MarkAllRegistersAsConflicts(verifier);
}
FailureKind MethodVerifier::VerifyClass(Thread* self,
ObjPtr<mirror::Class> klass,
CompilerCallbacks* callbacks,
bool allow_soft_failures,
HardFailLogMode log_level,
uint32_t api_level,
std::string* error) {
if (klass->IsVerified()) {
return FailureKind::kNoFailure;
}
bool early_failure = false;
std::string failure_message;
const DexFile& dex_file = klass->GetDexFile();
const DexFile::ClassDef* class_def = klass->GetClassDef();
ObjPtr<mirror::Class> super = klass->GetSuperClass();
std::string temp;
if (super == nullptr && strcmp("Ljava/lang/Object;", klass->GetDescriptor(&temp)) != 0) {
early_failure = true;
failure_message = " that has no super class";
} else if (super != nullptr && super->IsFinal()) {
early_failure = true;
failure_message = " that attempts to sub-class final class " + super->PrettyDescriptor();
} else if (class_def == nullptr) {
early_failure = true;
failure_message = " that isn't present in dex file " + dex_file.GetLocation();
}
if (early_failure) {
*error = "Verifier rejected class " + klass->PrettyDescriptor() + failure_message;
if (callbacks != nullptr) {
ClassReference ref(&dex_file, klass->GetDexClassDefIndex());
callbacks->ClassRejected(ref);
}
return FailureKind::kHardFailure;
}
StackHandleScope<2> hs(self);
Handle<mirror::DexCache> dex_cache(hs.NewHandle(klass->GetDexCache()));
Handle<mirror::ClassLoader> class_loader(hs.NewHandle(klass->GetClassLoader()));
return VerifyClass(self,
&dex_file,
dex_cache,
class_loader,
*class_def,
callbacks,
allow_soft_failures,
log_level,
api_level,
error);
}
static FailureKind FailureKindMax(FailureKind fk1, FailureKind fk2) {
static_assert(FailureKind::kNoFailure < FailureKind::kSoftFailure
&& FailureKind::kSoftFailure < FailureKind::kHardFailure,
"Unexpected FailureKind order");
return std::max(fk1, fk2);
}
void MethodVerifier::FailureData::Merge(const MethodVerifier::FailureData& fd) {
kind = FailureKindMax(kind, fd.kind);
types |= fd.types;
}
FailureKind MethodVerifier::VerifyClass(Thread* self,
const DexFile* dex_file,
Handle<mirror::DexCache> dex_cache,
Handle<mirror::ClassLoader> class_loader,
const DexFile::ClassDef& class_def,
CompilerCallbacks* callbacks,
bool allow_soft_failures,
HardFailLogMode log_level,
uint32_t api_level,
std::string* error) {
// A class must not be abstract and final.
if ((class_def.access_flags_ & (kAccAbstract | kAccFinal)) == (kAccAbstract | kAccFinal)) {
*error = "Verifier rejected class ";
*error += PrettyDescriptor(dex_file->GetClassDescriptor(class_def));
*error += ": class is abstract and final.";
return FailureKind::kHardFailure;
}
ClassAccessor accessor(*dex_file, class_def);
SCOPED_TRACE << "VerifyClass " << PrettyDescriptor(accessor.GetDescriptor());
int64_t previous_method_idx[2] = { -1, -1 };
MethodVerifier::FailureData failure_data;
ClassLinker* const linker = Runtime::Current()->GetClassLinker();
for (const ClassAccessor::Method& method : accessor.GetMethods()) {
int64_t* previous_idx = &previous_method_idx[method.IsStaticOrDirect() ? 0u : 1u];
self->AllowThreadSuspension();
const uint32_t method_idx = method.GetIndex();
if (method_idx == *previous_idx) {
// smali can create dex files with two encoded_methods sharing the same method_idx
// http://code.google.com/p/smali/issues/detail?id=119
continue;
}
*previous_idx = method_idx;
const InvokeType type = method.GetInvokeType(class_def.access_flags_);
ArtMethod* resolved_method = linker->ResolveMethod<ClassLinker::ResolveMode::kNoChecks>(
method_idx, dex_cache, class_loader, /* referrer */ nullptr, type);
if (resolved_method == nullptr) {
DCHECK(self->IsExceptionPending());
// We couldn't resolve the method, but continue regardless.
self->ClearException();
} else {
DCHECK(resolved_method->GetDeclaringClassUnchecked() != nullptr) << type;
}
std::string hard_failure_msg;
MethodVerifier::FailureData result = VerifyMethod(self,
method_idx,
dex_file,
dex_cache,
class_loader,
class_def,
method.GetCodeItem(),
resolved_method,
method.GetAccessFlags(),
callbacks,
allow_soft_failures,
log_level,
/*need_precise_constants*/ false,
api_level,
&hard_failure_msg);
if (result.kind == FailureKind::kHardFailure) {
if (failure_data.kind == FailureKind::kHardFailure) {
// If we logged an error before, we need a newline.
*error += "\n";
} else {
// If we didn't log a hard failure before, print the header of the message.
*error += "Verifier rejected class ";
*error += PrettyDescriptor(dex_file->GetClassDescriptor(class_def));
*error += ":";
}
*error += " ";
*error += hard_failure_msg;
}
failure_data.Merge(result);
}
if (failure_data.kind == FailureKind::kNoFailure) {
return FailureKind::kNoFailure;
} else {
if ((failure_data.types & VERIFY_ERROR_LOCKING) != 0) {
// Print a warning about expected slow-down. Use a string temporary to print one contiguous
// warning.
std::string tmp =
StringPrintf("Class %s failed lock verification and will run slower.",
PrettyDescriptor(accessor.GetDescriptor()).c_str());
if (!gPrintedDxMonitorText) {
tmp = tmp + "\nCommon causes for lock verification issues are non-optimized dex code\n"
"and incorrect proguard optimizations.";
gPrintedDxMonitorText = true;
}
LOG(WARNING) << tmp;
}
return failure_data.kind;
}
}
static bool IsLargeMethod(const CodeItemDataAccessor& accessor) {
if (!accessor.HasCodeItem()) {
return false;
}
uint16_t registers_size = accessor.RegistersSize();
uint32_t insns_size = accessor.InsnsSizeInCodeUnits();
return registers_size * insns_size > 4*1024*1024;
}
MethodVerifier::FailureData MethodVerifier::VerifyMethod(Thread* self,
uint32_t method_idx,
const DexFile* dex_file,
Handle<mirror::DexCache> dex_cache,
Handle<mirror::ClassLoader> class_loader,
const DexFile::ClassDef& class_def,
const DexFile::CodeItem* code_item,
ArtMethod* method,
uint32_t method_access_flags,
CompilerCallbacks* callbacks,
bool allow_soft_failures,
HardFailLogMode log_level,
bool need_precise_constants,
uint32_t api_level,
std::string* hard_failure_msg) {
MethodVerifier::FailureData result;
uint64_t start_ns = kTimeVerifyMethod ? NanoTime() : 0;
MethodVerifier verifier(self,
dex_file,
dex_cache,
class_loader,
class_def,
code_item,
method_idx,
method,
method_access_flags,
true /* can_load_classes */,
allow_soft_failures,
need_precise_constants,
false /* verify to dump */,
true /* allow_thread_suspension */,
api_level);
if (verifier.Verify()) {
// Verification completed, however failures may be pending that didn't cause the verification
// to hard fail.
CHECK(!verifier.have_pending_hard_failure_);
if (code_item != nullptr && callbacks != nullptr) {
// Let the interested party know that the method was verified.
callbacks->MethodVerified(&verifier);
}
if (verifier.failures_.size() != 0) {
if (VLOG_IS_ON(verifier)) {
verifier.DumpFailures(VLOG_STREAM(verifier) << "Soft verification failures in "
<< dex_file->PrettyMethod(method_idx) << "\n");
}
if (VLOG_IS_ON(verifier_debug)) {
std::cout << "\n" << verifier.info_messages_.str();
verifier.Dump(std::cout);
}
result.kind = FailureKind::kSoftFailure;
if (method != nullptr &&
!CanCompilerHandleVerificationFailure(verifier.encountered_failure_types_)) {
method->SetDontCompile();
}
}
if (method != nullptr) {
if (verifier.HasInstructionThatWillThrow()) {
method->SetDontCompile();
if (Runtime::Current()->IsAotCompiler() &&
(callbacks != nullptr) && !callbacks->IsBootImage()) {
// When compiling apps, make HasInstructionThatWillThrow a soft error to trigger
// re-verification at runtime.
// The dead code after the throw is not verified and might be invalid. This may cause
// the JIT compiler to crash since it assumes that all the code is valid.
//
// There's a strong assumption that the entire boot image is verified and all its dex
// code is valid (even the dead and unverified one). As such this is done only for apps.
// (CompilerDriver DCHECKs in VerifyClassVisitor that methods from boot image are
// fully verified).
result.kind = FailureKind::kSoftFailure;
}
}
if ((verifier.encountered_failure_types_ & VerifyError::VERIFY_ERROR_LOCKING) != 0) {
method->SetMustCountLocks();
}
}
} else {
// Bad method data.
CHECK_NE(verifier.failures_.size(), 0U);
if (UNLIKELY(verifier.have_pending_experimental_failure_)) {
// Failed due to being forced into interpreter. This is ok because
// we just want to skip verification.
result.kind = FailureKind::kSoftFailure;
} else {
CHECK(verifier.have_pending_hard_failure_);
if (VLOG_IS_ON(verifier)) {
log_level = std::max(HardFailLogMode::kLogVerbose, log_level);
}
if (log_level >= HardFailLogMode::kLogVerbose) {
LogSeverity severity;
switch (log_level) {
case HardFailLogMode::kLogVerbose:
severity = LogSeverity::VERBOSE;
break;
case HardFailLogMode::kLogWarning:
severity = LogSeverity::WARNING;
break;
case HardFailLogMode::kLogInternalFatal:
severity = LogSeverity::FATAL_WITHOUT_ABORT;
break;
default:
LOG(FATAL) << "Unsupported log-level " << static_cast<uint32_t>(log_level);
UNREACHABLE();
}
verifier.DumpFailures(LOG_STREAM(severity) << "Verification error in "
<< dex_file->PrettyMethod(method_idx)
<< "\n");
}
if (hard_failure_msg != nullptr) {
CHECK(!verifier.failure_messages_.empty());
*hard_failure_msg =
verifier.failure_messages_[verifier.failure_messages_.size() - 1]->str();
}
result.kind = FailureKind::kHardFailure;
if (callbacks != nullptr) {
// Let the interested party know that we failed the class.
ClassReference ref(dex_file, dex_file->GetIndexForClassDef(class_def));
callbacks->ClassRejected(ref);
}
}
if (VLOG_IS_ON(verifier) || VLOG_IS_ON(verifier_debug)) {
std::cout << "\n" << verifier.info_messages_.str();
verifier.Dump(std::cout);
}
}
if (kTimeVerifyMethod) {
uint64_t duration_ns = NanoTime() - start_ns;
if (duration_ns > MsToNs(Runtime::Current()->GetVerifierLoggingThresholdMs())) {
LOG(WARNING) << "Verification of " << dex_file->PrettyMethod(method_idx)
<< " took " << PrettyDuration(duration_ns)
<< (IsLargeMethod(verifier.CodeItem()) ? " (large method)" : "");
}
}
result.types = verifier.encountered_failure_types_;
return result;
}
MethodVerifier* MethodVerifier::VerifyMethodAndDump(Thread* self,
VariableIndentationOutputStream* vios,
uint32_t dex_method_idx,
const DexFile* dex_file,
Handle<mirror::DexCache> dex_cache,
Handle<mirror::ClassLoader> class_loader,
const DexFile::ClassDef& class_def,
const DexFile::CodeItem* code_item,
ArtMethod* method,
uint32_t method_access_flags,
uint32_t api_level) {
MethodVerifier* verifier = new MethodVerifier(self,
dex_file,
dex_cache,
class_loader,
class_def,
code_item,
dex_method_idx,
method,
method_access_flags,
true /* can_load_classes */,
true /* allow_soft_failures */,
true /* need_precise_constants */,
true /* verify_to_dump */,
true /* allow_thread_suspension */,
api_level);
verifier->Verify();
verifier->DumpFailures(vios->Stream());
vios->Stream() << verifier->info_messages_.str();
// Only dump and return if no hard failures. Otherwise the verifier may be not fully initialized
// and querying any info is dangerous/can abort.
if (verifier->have_pending_hard_failure_) {
delete verifier;
return nullptr;
} else {
verifier->Dump(vios);
return verifier;
}
}
MethodVerifier::MethodVerifier(Thread* self,
const DexFile* dex_file,
Handle<mirror::DexCache> dex_cache,
Handle<mirror::ClassLoader> class_loader,
const DexFile::ClassDef& class_def,
const DexFile::CodeItem* code_item,
uint32_t dex_method_idx,
ArtMethod* method,
uint32_t method_access_flags,
bool can_load_classes,
bool allow_soft_failures,
bool need_precise_constants,
bool verify_to_dump,
bool allow_thread_suspension,
uint32_t api_level)
: self_(self),
arena_stack_(Runtime::Current()->GetArenaPool()),
allocator_(&arena_stack_),
reg_types_(can_load_classes, allocator_, allow_thread_suspension),
reg_table_(allocator_),
work_insn_idx_(dex::kDexNoIndex),
dex_method_idx_(dex_method_idx),
method_being_verified_(method),
method_access_flags_(method_access_flags),
return_type_(nullptr),
dex_file_(dex_file),
dex_cache_(dex_cache),
class_loader_(class_loader),
class_def_(class_def),
code_item_accessor_(*dex_file, code_item),
declaring_class_(nullptr),
interesting_dex_pc_(-1),
monitor_enter_dex_pcs_(nullptr),
have_pending_hard_failure_(false),
have_pending_runtime_throw_failure_(false),
have_pending_experimental_failure_(false),
have_any_pending_runtime_throw_failure_(false),
new_instance_count_(0),
monitor_enter_count_(0),
encountered_failure_types_(0),
can_load_classes_(can_load_classes),
allow_soft_failures_(allow_soft_failures),
need_precise_constants_(need_precise_constants),
has_check_casts_(false),
has_virtual_or_interface_invokes_(false),
verify_to_dump_(verify_to_dump),
allow_thread_suspension_(allow_thread_suspension),
is_constructor_(false),
link_(nullptr),
api_level_(api_level == 0 ? std::numeric_limits<uint32_t>::max() : api_level) {
self->PushVerifier(this);
}
MethodVerifier::~MethodVerifier() {
Thread::Current()->PopVerifier(this);
STLDeleteElements(&failure_messages_);
}
void MethodVerifier::FindLocksAtDexPc(
ArtMethod* m,
uint32_t dex_pc,
std::vector<MethodVerifier::DexLockInfo>* monitor_enter_dex_pcs,
uint32_t api_level) {
StackHandleScope<2> hs(Thread::Current());
Handle<mirror::DexCache> dex_cache(hs.NewHandle(m->GetDexCache()));
Handle<mirror::ClassLoader> class_loader(hs.NewHandle(m->GetClassLoader()));
MethodVerifier verifier(hs.Self(),
m->GetDexFile(),
dex_cache,
class_loader,
m->GetClassDef(),
m->GetCodeItem(),
m->GetDexMethodIndex(),
m,
m->GetAccessFlags(),
false /* can_load_classes */,
true /* allow_soft_failures */,
false /* need_precise_constants */,
false /* verify_to_dump */,
false /* allow_thread_suspension */,
api_level);
verifier.interesting_dex_pc_ = dex_pc;
verifier.monitor_enter_dex_pcs_ = monitor_enter_dex_pcs;
verifier.FindLocksAtDexPc();
}
void MethodVerifier::FindLocksAtDexPc() {
CHECK(monitor_enter_dex_pcs_ != nullptr);
CHECK(code_item_accessor_.HasCodeItem()); // This only makes sense for methods with code.
// Quick check whether there are any monitor_enter instructions before verifying.
for (const DexInstructionPcPair& inst : code_item_accessor_) {
if (inst->Opcode() == Instruction::MONITOR_ENTER) {
// Strictly speaking, we ought to be able to get away with doing a subset of the full method
// verification. In practice, the phase we want relies on data structures set up by all the
// earlier passes, so we just run the full method verification and bail out early when we've
// got what we wanted.
Verify();
return;
}
}
}
bool MethodVerifier::Verify() {
// Some older code doesn't correctly mark constructors as such. Test for this case by looking at
// the name.
const DexFile::MethodId& method_id = dex_file_->GetMethodId(dex_method_idx_);
const char* method_name = dex_file_->StringDataByIdx(method_id.name_idx_);
bool instance_constructor_by_name = strcmp("<init>", method_name) == 0;
bool static_constructor_by_name = strcmp("<clinit>", method_name) == 0;
bool constructor_by_name = instance_constructor_by_name || static_constructor_by_name;
// Check that only constructors are tagged, and check for bad code that doesn't tag constructors.
if ((method_access_flags_ & kAccConstructor) != 0) {
if (!constructor_by_name) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD)
<< "method is marked as constructor, but not named accordingly";
return false;
}
is_constructor_ = true;
} else if (constructor_by_name) {
LOG(WARNING) << "Method " << dex_file_->PrettyMethod(dex_method_idx_)
<< " not marked as constructor.";
is_constructor_ = true;
}
// If it's a constructor, check whether IsStatic() matches the name.
// This should have been rejected by the dex file verifier. Only do in debug build.
if (kIsDebugBuild) {
if (IsConstructor()) {
if (IsStatic() ^ static_constructor_by_name) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD)
<< "constructor name doesn't match static flag";
return false;
}
}
}
// Methods may only have one of public/protected/private.
// This should have been rejected by the dex file verifier. Only do in debug build.
if (kIsDebugBuild) {
size_t access_mod_count =
(((method_access_flags_ & kAccPublic) == 0) ? 0 : 1) +
(((method_access_flags_ & kAccProtected) == 0) ? 0 : 1) +
(((method_access_flags_ & kAccPrivate) == 0) ? 0 : 1);
if (access_mod_count > 1) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "method has more than one of public/protected/private";
return false;
}
}
// If there aren't any instructions, make sure that's expected, then exit successfully.
if (!code_item_accessor_.HasCodeItem()) {
// Only native or abstract methods may not have code.
if ((method_access_flags_ & (kAccNative | kAccAbstract)) == 0) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "zero-length code in concrete non-native method";
return false;
}
// This should have been rejected by the dex file verifier. Only do in debug build.
// Note: the above will also be rejected in the dex file verifier, starting in dex version 37.
if (kIsDebugBuild) {
if ((method_access_flags_ & kAccAbstract) != 0) {
// Abstract methods are not allowed to have the following flags.
static constexpr uint32_t kForbidden =
kAccPrivate |
kAccStatic |
kAccFinal |
kAccNative |
kAccStrict |
kAccSynchronized;
if ((method_access_flags_ & kForbidden) != 0) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD)
<< "method can't be abstract and private/static/final/native/strict/synchronized";
return false;
}
}
if ((class_def_.GetJavaAccessFlags() & kAccInterface) != 0) {
// Interface methods must be public and abstract (if default methods are disabled).
uint32_t kRequired = kAccPublic;
if ((method_access_flags_ & kRequired) != kRequired) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "interface methods must be public";
return false;
}
// In addition to the above, interface methods must not be protected.
static constexpr uint32_t kForbidden = kAccProtected;
if ((method_access_flags_ & kForbidden) != 0) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "interface methods can't be protected";
return false;
}
}
// We also don't allow constructors to be abstract or native.
if (IsConstructor()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "constructors can't be abstract or native";
return false;
}
}
return true;
}
// This should have been rejected by the dex file verifier. Only do in debug build.
if (kIsDebugBuild) {
// When there's code, the method must not be native or abstract.
if ((method_access_flags_ & (kAccNative | kAccAbstract)) != 0) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "non-zero-length code in abstract or native method";
return false;
}
if ((class_def_.GetJavaAccessFlags() & kAccInterface) != 0) {
// Interfaces may always have static initializers for their fields. If we are running with
// default methods enabled we also allow other public, static, non-final methods to have code.
// Otherwise that is the only type of method allowed.
if (!(IsConstructor() && IsStatic())) {
if (IsInstanceConstructor()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "interfaces may not have non-static constructor";
return false;
} else if (method_access_flags_ & kAccFinal) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "interfaces may not have final methods";
return false;
} else {
uint32_t access_flag_options = kAccPublic;
if (dex_file_->SupportsDefaultMethods()) {
access_flag_options |= kAccPrivate;
}
if (!(method_access_flags_ & access_flag_options)) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD)
<< "interfaces may not have protected or package-private members";
return false;
}
}
}
}
// Instance constructors must not be synchronized.
if (IsInstanceConstructor()) {
static constexpr uint32_t kForbidden = kAccSynchronized;
if ((method_access_flags_ & kForbidden) != 0) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "constructors can't be synchronized";
return false;
}
}
}
// Sanity-check the register counts. ins + locals = registers, so make sure that ins <= registers.
if (code_item_accessor_.InsSize() > code_item_accessor_.RegistersSize()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "bad register counts (ins="
<< code_item_accessor_.InsSize()
<< " regs=" << code_item_accessor_.RegistersSize();
return false;
}
// Allocate and initialize an array to hold instruction data.
insn_flags_.reset(allocator_.AllocArray<InstructionFlags>(
code_item_accessor_.InsnsSizeInCodeUnits()));
DCHECK(insn_flags_ != nullptr);
std::uninitialized_fill_n(insn_flags_.get(),
code_item_accessor_.InsnsSizeInCodeUnits(),
InstructionFlags());
// Run through the instructions and see if the width checks out.
bool result = ComputeWidthsAndCountOps();
bool allow_runtime_only_instructions = !Runtime::Current()->IsAotCompiler() || verify_to_dump_;
// Flag instructions guarded by a "try" block and check exception handlers.
result = result && ScanTryCatchBlocks();
// Perform static instruction verification.
result = result && (allow_runtime_only_instructions
? VerifyInstructions<true>()
: VerifyInstructions<false>());
// Perform code-flow analysis and return.
result = result && VerifyCodeFlow();
return result;
}
std::ostream& MethodVerifier::Fail(VerifyError error) {
// Mark the error type as encountered.
encountered_failure_types_ |= static_cast<uint32_t>(error);
switch (error) {
case VERIFY_ERROR_NO_CLASS:
case VERIFY_ERROR_NO_FIELD:
case VERIFY_ERROR_NO_METHOD:
case VERIFY_ERROR_ACCESS_CLASS:
case VERIFY_ERROR_ACCESS_FIELD:
case VERIFY_ERROR_ACCESS_METHOD:
case VERIFY_ERROR_INSTANTIATION:
case VERIFY_ERROR_CLASS_CHANGE:
case VERIFY_ERROR_FORCE_INTERPRETER:
case VERIFY_ERROR_LOCKING:
if (Runtime::Current()->IsAotCompiler() || !can_load_classes_) {
// If we're optimistically running verification at compile time, turn NO_xxx, ACCESS_xxx,
// class change and instantiation errors into soft verification errors so that we re-verify
// at runtime. We may fail to find or to agree on access because of not yet available class
// loaders, or class loaders that will differ at runtime. In these cases, we don't want to
// affect the soundness of the code being compiled. Instead, the generated code runs "slow
// paths" that dynamically perform the verification and cause the behavior to be that akin
// to an interpreter.
error = VERIFY_ERROR_BAD_CLASS_SOFT;
} else {
// If we fail again at runtime, mark that this instruction would throw and force this
// method to be executed using the interpreter with checks.
have_pending_runtime_throw_failure_ = true;
// We need to save the work_line if the instruction wasn't throwing before. Otherwise we'll
// try to merge garbage.
// Note: this assumes that Fail is called before we do any work_line modifications.
// Note: this can fail before we touch any instruction, for the signature of a method. So
// add a check.
if (work_insn_idx_ < dex::kDexNoIndex) {
const Instruction& inst = code_item_accessor_.InstructionAt(work_insn_idx_);
int opcode_flags = Instruction::FlagsOf(inst.Opcode());
if ((opcode_flags & Instruction::kThrow) == 0 && CurrentInsnFlags()->IsInTry()) {
saved_line_->CopyFromLine(work_line_.get());
}
}
}
break;
// Indication that verification should be retried at runtime.
case VERIFY_ERROR_BAD_CLASS_SOFT:
if (!allow_soft_failures_) {
have_pending_hard_failure_ = true;
}
break;
// Hard verification failures at compile time will still fail at runtime, so the class is
// marked as rejected to prevent it from being compiled.
case VERIFY_ERROR_BAD_CLASS_HARD: {
have_pending_hard_failure_ = true;
if (VLOG_IS_ON(verifier) && kDumpRegLinesOnHardFailureIfVLOG) {
ScopedObjectAccess soa(Thread::Current());
std::ostringstream oss;
Dump(oss);
LOG(ERROR) << oss.str();
}
break;
}
}
failures_.push_back(error);
std::string location(StringPrintf("%s: [0x%X] ", dex_file_->PrettyMethod(dex_method_idx_).c_str(),
work_insn_idx_));
std::ostringstream* failure_message = new std::ostringstream(location, std::ostringstream::ate);
failure_messages_.push_back(failure_message);
return *failure_message;
}
std::ostream& MethodVerifier::LogVerifyInfo() {
return info_messages_ << "VFY: " << dex_file_->PrettyMethod(dex_method_idx_)
<< '[' << reinterpret_cast<void*>(work_insn_idx_) << "] : ";
}
void MethodVerifier::PrependToLastFailMessage(std::string prepend) {
size_t failure_num = failure_messages_.size();
DCHECK_NE(failure_num, 0U);
std::ostringstream* last_fail_message = failure_messages_[failure_num - 1];
prepend += last_fail_message->str();
failure_messages_[failure_num - 1] = new std::ostringstream(prepend, std::ostringstream::ate);
delete last_fail_message;
}
void MethodVerifier::AppendToLastFailMessage(const std::string& append) {
size_t failure_num = failure_messages_.size();
DCHECK_NE(failure_num, 0U);
std::ostringstream* last_fail_message = failure_messages_[failure_num - 1];
(*last_fail_message) << append;
}
bool MethodVerifier::ComputeWidthsAndCountOps() {
size_t new_instance_count = 0;
size_t monitor_enter_count = 0;
// We can't assume the instruction is well formed, handle the case where calculating the size
// goes past the end of the code item.
SafeDexInstructionIterator it(code_item_accessor_.begin(), code_item_accessor_.end());
for ( ; !it.IsErrorState() && it < code_item_accessor_.end(); ++it) {
// In case the instruction goes past the end of the code item, make sure to not process it.
SafeDexInstructionIterator next = it;
++next;
if (next.IsErrorState()) {
break;
}
Instruction::Code opcode = it->Opcode();
switch (opcode) {
case Instruction::APUT_OBJECT:
case Instruction::CHECK_CAST:
has_check_casts_ = true;
break;
case Instruction::INVOKE_VIRTUAL:
case Instruction::INVOKE_VIRTUAL_RANGE:
case Instruction::INVOKE_INTERFACE:
case Instruction::INVOKE_INTERFACE_RANGE:
has_virtual_or_interface_invokes_ = true;
break;
case Instruction::MONITOR_ENTER:
monitor_enter_count++;
break;
case Instruction::NEW_INSTANCE:
new_instance_count++;
break;
default:
break;
}
GetInstructionFlags(it.DexPc()).SetIsOpcode();
}
if (it != code_item_accessor_.end()) {
const size_t insns_size = code_item_accessor_.InsnsSizeInCodeUnits();
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "code did not end where expected ("
<< it.DexPc() << " vs. " << insns_size << ")";
return false;
}
new_instance_count_ = new_instance_count;
monitor_enter_count_ = monitor_enter_count;
return true;
}
bool MethodVerifier::ScanTryCatchBlocks() {
const uint32_t tries_size = code_item_accessor_.TriesSize();
if (tries_size == 0) {
return true;
}
const uint32_t insns_size = code_item_accessor_.InsnsSizeInCodeUnits();
for (const DexFile::TryItem& try_item : code_item_accessor_.TryItems()) {
const uint32_t start = try_item.start_addr_;
const uint32_t end = start + try_item.insn_count_;
if ((start >= end) || (start >= insns_size) || (end > insns_size)) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "bad exception entry: startAddr=" << start
<< " endAddr=" << end << " (size=" << insns_size << ")";
return false;
}
if (!GetInstructionFlags(start).IsOpcode()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD)
<< "'try' block starts inside an instruction (" << start << ")";
return false;
}
DexInstructionIterator end_it(code_item_accessor_.Insns(), end);
for (DexInstructionIterator it(code_item_accessor_.Insns(), start); it < end_it; ++it) {
GetInstructionFlags(it.DexPc()).SetInTry();
}
}
// Iterate over each of the handlers to verify target addresses.
const uint8_t* handlers_ptr = code_item_accessor_.GetCatchHandlerData();
const uint32_t handlers_size = DecodeUnsignedLeb128(&handlers_ptr);
ClassLinker* linker = Runtime::Current()->GetClassLinker();
for (uint32_t idx = 0; idx < handlers_size; idx++) {
CatchHandlerIterator iterator(handlers_ptr);
for (; iterator.HasNext(); iterator.Next()) {
uint32_t dex_pc = iterator.GetHandlerAddress();
if (!GetInstructionFlags(dex_pc).IsOpcode()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD)
<< "exception handler starts at bad address (" << dex_pc << ")";
return false;
}
if (!CheckNotMoveResult(code_item_accessor_.Insns(), dex_pc)) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD)
<< "exception handler begins with move-result* (" << dex_pc << ")";
return false;
}
GetInstructionFlags(dex_pc).SetBranchTarget();
// Ensure exception types are resolved so that they don't need resolution to be delivered,
// unresolved exception types will be ignored by exception delivery
if (iterator.GetHandlerTypeIndex().IsValid()) {
ObjPtr<mirror::Class> exception_type =
linker->ResolveType(iterator.GetHandlerTypeIndex(), dex_cache_, class_loader_);
if (exception_type == nullptr) {
DCHECK(self_->IsExceptionPending());
self_->ClearException();
}
}
}
handlers_ptr = iterator.EndDataPointer();
}
return true;
}
template <bool kAllowRuntimeOnlyInstructions>
bool MethodVerifier::VerifyInstructions() {
/* Flag the start of the method as a branch target, and a GC point due to stack overflow errors */
GetInstructionFlags(0).SetBranchTarget();
GetInstructionFlags(0).SetCompileTimeInfoPoint();
for (const DexInstructionPcPair& inst : code_item_accessor_) {
const uint32_t dex_pc = inst.DexPc();
if (!VerifyInstruction<kAllowRuntimeOnlyInstructions>(&inst.Inst(), dex_pc)) {
DCHECK_NE(failures_.size(), 0U);
return false;
}
/* Flag instructions that are garbage collection points */
// All invoke points are marked as "Throw" points already.
// We are relying on this to also count all the invokes as interesting.
if (inst->IsBranch()) {
GetInstructionFlags(dex_pc).SetCompileTimeInfoPoint();
// The compiler also needs safepoints for fall-through to loop heads.
// Such a loop head must be a target of a branch.
int32_t offset = 0;
bool cond, self_ok;
bool target_ok = GetBranchOffset(dex_pc, &offset, &cond, &self_ok);
DCHECK(target_ok);
GetInstructionFlags(dex_pc + offset).SetCompileTimeInfoPoint();
} else if (inst->IsSwitch() || inst->IsThrow()) {
GetInstructionFlags(dex_pc).SetCompileTimeInfoPoint();
} else if (inst->IsReturn()) {
GetInstructionFlags(dex_pc).SetCompileTimeInfoPointAndReturn();
}
}
return true;
}
template <bool kAllowRuntimeOnlyInstructions>
bool MethodVerifier::VerifyInstruction(const Instruction* inst, uint32_t code_offset) {
if (Instruction::kHaveExperimentalInstructions && UNLIKELY(inst->IsExperimental())) {
// Experimental instructions don't yet have verifier support implementation.
// While it is possible to use them by themselves, when we try to use stable instructions
// with a virtual register that was created by an experimental instruction,
// the data flow analysis will fail.
Fail(VERIFY_ERROR_FORCE_INTERPRETER)
<< "experimental instruction is not supported by verifier; skipping verification";
have_pending_experimental_failure_ = true;
return false;
}
bool result = true;
switch (inst->GetVerifyTypeArgumentA()) {
case Instruction::kVerifyRegA:
result = result && CheckRegisterIndex(inst->VRegA());
break;
case Instruction::kVerifyRegAWide:
result = result && CheckWideRegisterIndex(inst->VRegA());
break;
}
switch (inst->GetVerifyTypeArgumentB()) {
case Instruction::kVerifyRegB:
result = result && CheckRegisterIndex(inst->VRegB());
break;
case Instruction::kVerifyRegBField:
result = result && CheckFieldIndex(inst->VRegB());
break;
case Instruction::kVerifyRegBMethod:
result = result && CheckMethodIndex(inst->VRegB());
break;
case Instruction::kVerifyRegBNewInstance:
result = result && CheckNewInstance(dex::TypeIndex(inst->VRegB()));
break;
case Instruction::kVerifyRegBString:
result = result && CheckStringIndex(inst->VRegB());
break;
case Instruction::kVerifyRegBType:
result = result && CheckTypeIndex(dex::TypeIndex(inst->VRegB()));
break;
case Instruction::kVerifyRegBWide:
result = result && CheckWideRegisterIndex(inst->VRegB());
break;
case Instruction::kVerifyRegBCallSite:
result = result && CheckCallSiteIndex(inst->VRegB());
break;
case Instruction::kVerifyRegBMethodHandle:
result = result && CheckMethodHandleIndex(inst->VRegB());
break;
case Instruction::kVerifyRegBPrototype:
result = result && CheckPrototypeIndex(inst->VRegB());
break;
}
switch (inst->GetVerifyTypeArgumentC()) {
case Instruction::kVerifyRegC:
result = result && CheckRegisterIndex(inst->VRegC());
break;
case Instruction::kVerifyRegCField:
result = result && CheckFieldIndex(inst->VRegC());
break;
case Instruction::kVerifyRegCNewArray:
result = result && CheckNewArray(dex::TypeIndex(inst->VRegC()));
break;
case Instruction::kVerifyRegCType:
result = result && CheckTypeIndex(dex::TypeIndex(inst->VRegC()));
break;
case Instruction::kVerifyRegCWide:
result = result && CheckWideRegisterIndex(inst->VRegC());
break;
}
switch (inst->GetVerifyTypeArgumentH()) {
case Instruction::kVerifyRegHPrototype:
result = result && CheckPrototypeIndex(inst->VRegH());
break;
}
switch (inst->GetVerifyExtraFlags()) {
case Instruction::kVerifyArrayData:
result = result && CheckArrayData(code_offset);
break;
case Instruction::kVerifyBranchTarget:
result = result && CheckBranchTarget(code_offset);
break;
case Instruction::kVerifySwitchTargets:
result = result && CheckSwitchTargets(code_offset);
break;
case Instruction::kVerifyVarArgNonZero:
// Fall-through.
case Instruction::kVerifyVarArg: {
// Instructions that can actually return a negative value shouldn't have this flag.
uint32_t v_a = dchecked_integral_cast<uint32_t>(inst->VRegA());
if ((inst->GetVerifyExtraFlags() == Instruction::kVerifyVarArgNonZero && v_a == 0) ||
v_a > Instruction::kMaxVarArgRegs) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid arg count (" << v_a << ") in "
"non-range invoke";
return false;
}
uint32_t args[Instruction::kMaxVarArgRegs];
inst->GetVarArgs(args);
result = result && CheckVarArgRegs(v_a, args);
break;
}
case Instruction::kVerifyVarArgRangeNonZero:
// Fall-through.
case Instruction::kVerifyVarArgRange:
if (inst->GetVerifyExtraFlags() == Instruction::kVerifyVarArgRangeNonZero &&
inst->VRegA() <= 0) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid arg count (" << inst->VRegA() << ") in "
"range invoke";
return false;
}
result = result && CheckVarArgRangeRegs(inst->VRegA(), inst->VRegC());
break;
case Instruction::kVerifyError:
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "unexpected opcode " << inst->Name();
result = false;
break;
}
if (!kAllowRuntimeOnlyInstructions && inst->GetVerifyIsRuntimeOnly()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "opcode only expected at runtime " << inst->Name();
result = false;
}
return result;
}
inline bool MethodVerifier::CheckRegisterIndex(uint32_t idx) {
if (UNLIKELY(idx >= code_item_accessor_.RegistersSize())) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "register index out of range (" << idx << " >= "
<< code_item_accessor_.RegistersSize() << ")";
return false;
}
return true;
}
inline bool MethodVerifier::CheckWideRegisterIndex(uint32_t idx) {
if (UNLIKELY(idx + 1 >= code_item_accessor_.RegistersSize())) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "wide register index out of range (" << idx
<< "+1 >= " << code_item_accessor_.RegistersSize() << ")";
return false;
}
return true;
}
inline bool MethodVerifier::CheckCallSiteIndex(uint32_t idx) {
uint32_t limit = dex_file_->NumCallSiteIds();
if (UNLIKELY(idx >= limit)) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "bad call site index " << idx << " (max "
<< limit << ")";
return false;
}
return true;
}
inline bool MethodVerifier::CheckFieldIndex(uint32_t idx) {
if (UNLIKELY(idx >= dex_file_->GetHeader().field_ids_size_)) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "bad field index " << idx << " (max "
<< dex_file_->GetHeader().field_ids_size_ << ")";
return false;
}
return true;
}
inline bool MethodVerifier::CheckMethodIndex(uint32_t idx) {
if (UNLIKELY(idx >= dex_file_->GetHeader().method_ids_size_)) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "bad method index " << idx << " (max "
<< dex_file_->GetHeader().method_ids_size_ << ")";
return false;
}
return true;
}
inline bool MethodVerifier::CheckMethodHandleIndex(uint32_t idx) {
uint32_t limit = dex_file_->NumMethodHandles();
if (UNLIKELY(idx >= limit)) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "bad method handle index " << idx << " (max "
<< limit << ")";
return false;
}
return true;
}
inline bool MethodVerifier::CheckNewInstance(dex::TypeIndex idx) {
if (UNLIKELY(idx.index_ >= dex_file_->GetHeader().type_ids_size_)) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "bad type index " << idx.index_ << " (max "
<< dex_file_->GetHeader().type_ids_size_ << ")";
return false;
}
// We don't need the actual class, just a pointer to the class name.
const char* descriptor = dex_file_->StringByTypeIdx(idx);
if (UNLIKELY(descriptor[0] != 'L')) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "can't call new-instance on type '" << descriptor << "'";
return false;
} else if (UNLIKELY(strcmp(descriptor, "Ljava/lang/Class;") == 0)) {
// An unlikely new instance on Class is not allowed. Fall back to interpreter to ensure an
// exception is thrown when this statement is executed (compiled code would not do that).
Fail(VERIFY_ERROR_INSTANTIATION);
}
return true;
}
inline bool MethodVerifier::CheckPrototypeIndex(uint32_t idx) {
if (UNLIKELY(idx >= dex_file_->GetHeader().proto_ids_size_)) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "bad prototype index " << idx << " (max "
<< dex_file_->GetHeader().proto_ids_size_ << ")";
return false;
}
return true;
}
inline bool MethodVerifier::CheckStringIndex(uint32_t idx) {
if (UNLIKELY(idx >= dex_file_->GetHeader().string_ids_size_)) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "bad string index " << idx << " (max "
<< dex_file_->GetHeader().string_ids_size_ << ")";
return false;
}
return true;
}
inline bool MethodVerifier::CheckTypeIndex(dex::TypeIndex idx) {
if (UNLIKELY(idx.index_ >= dex_file_->GetHeader().type_ids_size_)) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "bad type index " << idx.index_ << " (max "
<< dex_file_->GetHeader().type_ids_size_ << ")";
return false;
}
return true;
}
bool MethodVerifier::CheckNewArray(dex::TypeIndex idx) {
if (UNLIKELY(idx.index_ >= dex_file_->GetHeader().type_ids_size_)) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "bad type index " << idx.index_ << " (max "
<< dex_file_->GetHeader().type_ids_size_ << ")";
return false;
}
int bracket_count = 0;
const char* descriptor = dex_file_->StringByTypeIdx(idx);
const char* cp = descriptor;
while (*cp++ == '[') {
bracket_count++;
}
if (UNLIKELY(bracket_count == 0)) {
/* The given class must be an array type. */
Fail(VERIFY_ERROR_BAD_CLASS_HARD)
<< "can't new-array class '" << descriptor << "' (not an array)";
return false;
} else if (UNLIKELY(bracket_count > 255)) {
/* It is illegal to create an array of more than 255 dimensions. */
Fail(VERIFY_ERROR_BAD_CLASS_HARD)
<< "can't new-array class '" << descriptor << "' (exceeds limit)";
return false;
}
return true;
}
bool MethodVerifier::CheckArrayData(uint32_t cur_offset) {
const uint32_t insn_count = code_item_accessor_.InsnsSizeInCodeUnits();
const uint16_t* insns = code_item_accessor_.Insns() + cur_offset;
const uint16_t* array_data;
int32_t array_data_offset;
DCHECK_LT(cur_offset, insn_count);
/* make sure the start of the array data table is in range */
array_data_offset = insns[1] | (static_cast<int32_t>(insns[2]) << 16);
if (UNLIKELY(static_cast<int32_t>(cur_offset) + array_data_offset < 0 ||
cur_offset + array_data_offset + 2 >= insn_count)) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid array data start: at " << cur_offset
<< ", data offset " << array_data_offset
<< ", count " << insn_count;
return false;
}
/* offset to array data table is a relative branch-style offset */
array_data = insns + array_data_offset;
// Make sure the table is at an even dex pc, that is, 32-bit aligned.
if (UNLIKELY(!IsAligned<4>(array_data))) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "unaligned array data table: at " << cur_offset
<< ", data offset " << array_data_offset;
return false;
}
// Make sure the array-data is marked as an opcode. This ensures that it was reached when
// traversing the code item linearly. It is an approximation for a by-spec padding value.
if (UNLIKELY(!GetInstructionFlags(cur_offset + array_data_offset).IsOpcode())) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "array data table at " << cur_offset
<< ", data offset " << array_data_offset
<< " not correctly visited, probably bad padding.";
return false;
}
uint32_t value_width = array_data[1];
uint32_t value_count = *reinterpret_cast<const uint32_t*>(&array_data[2]);
uint32_t table_size = 4 + (value_width * value_count + 1) / 2;
/* make sure the end of the switch is in range */
if (UNLIKELY(cur_offset + array_data_offset + table_size > insn_count)) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid array data end: at " << cur_offset
<< ", data offset " << array_data_offset << ", end "
<< cur_offset + array_data_offset + table_size
<< ", count " << insn_count;
return false;
}
return true;
}
bool MethodVerifier::CheckBranchTarget(uint32_t cur_offset) {
int32_t offset;
bool isConditional, selfOkay;
if (!GetBranchOffset(cur_offset, &offset, &isConditional, &selfOkay)) {
return false;
}
if (UNLIKELY(!selfOkay && offset == 0)) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "branch offset of zero not allowed at"
<< reinterpret_cast<void*>(cur_offset);
return false;
}
// Check for 32-bit overflow. This isn't strictly necessary if we can depend on the runtime
// to have identical "wrap-around" behavior, but it's unwise to depend on that.
if (UNLIKELY(((int64_t) cur_offset + (int64_t) offset) != (int64_t) (cur_offset + offset))) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "branch target overflow "
<< reinterpret_cast<void*>(cur_offset) << " +" << offset;
return false;
}
int32_t abs_offset = cur_offset + offset;
if (UNLIKELY(abs_offset < 0 ||
(uint32_t) abs_offset >= code_item_accessor_.InsnsSizeInCodeUnits() ||
!GetInstructionFlags(abs_offset).IsOpcode())) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid branch target " << offset << " (-> "
<< reinterpret_cast<void*>(abs_offset) << ") at "
<< reinterpret_cast<void*>(cur_offset);
return false;
}
GetInstructionFlags(abs_offset).SetBranchTarget();
return true;
}
bool MethodVerifier::GetBranchOffset(uint32_t cur_offset, int32_t* pOffset, bool* pConditional,
bool* selfOkay) {
const uint16_t* insns = code_item_accessor_.Insns() + cur_offset;
*pConditional = false;
*selfOkay = false;
switch (*insns & 0xff) {
case Instruction::GOTO:
*pOffset = ((int16_t) *insns) >> 8;
break;
case Instruction::GOTO_32:
*pOffset = insns[1] | (((uint32_t) insns[2]) << 16);
*selfOkay = true;
break;
case Instruction::GOTO_16:
*pOffset = (int16_t) insns[1];
break;
case Instruction::IF_EQ:
case Instruction::IF_NE:
case Instruction::IF_LT:
case Instruction::IF_GE:
case Instruction::IF_GT:
case Instruction::IF_LE:
case Instruction::IF_EQZ:
case Instruction::IF_NEZ:
case Instruction::IF_LTZ:
case Instruction::IF_GEZ:
case Instruction::IF_GTZ:
case Instruction::IF_LEZ:
*pOffset = (int16_t) insns[1];
*pConditional = true;
break;
default:
return false;
}
return true;
}
bool MethodVerifier::CheckSwitchTargets(uint32_t cur_offset) {
const uint32_t insn_count = code_item_accessor_.InsnsSizeInCodeUnits();
DCHECK_LT(cur_offset, insn_count);
const uint16_t* insns = code_item_accessor_.Insns() + cur_offset;
/* make sure the start of the switch is in range */
int32_t switch_offset = insns[1] | (static_cast<int32_t>(insns[2]) << 16);
if (UNLIKELY(static_cast<int32_t>(cur_offset) + switch_offset < 0 ||
cur_offset + switch_offset + 2 > insn_count)) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid switch start: at " << cur_offset
<< ", switch offset " << switch_offset
<< ", count " << insn_count;
return false;
}
/* offset to switch table is a relative branch-style offset */
const uint16_t* switch_insns = insns + switch_offset;
// Make sure the table is at an even dex pc, that is, 32-bit aligned.
if (UNLIKELY(!IsAligned<4>(switch_insns))) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "unaligned switch table: at " << cur_offset
<< ", switch offset " << switch_offset;
return false;
}
// Make sure the switch data is marked as an opcode. This ensures that it was reached when
// traversing the code item linearly. It is an approximation for a by-spec padding value.
if (UNLIKELY(!GetInstructionFlags(cur_offset + switch_offset).IsOpcode())) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "switch table at " << cur_offset
<< ", switch offset " << switch_offset
<< " not correctly visited, probably bad padding.";
return false;
}
bool is_packed_switch = (*insns & 0xff) == Instruction::PACKED_SWITCH;
uint32_t switch_count = switch_insns[1];
int32_t targets_offset;
uint16_t expected_signature;
if (is_packed_switch) {
/* 0=sig, 1=count, 2/3=firstKey */
targets_offset = 4;
expected_signature = Instruction::kPackedSwitchSignature;
} else {
/* 0=sig, 1=count, 2..count*2 = keys */
targets_offset = 2 + 2 * switch_count;
expected_signature = Instruction::kSparseSwitchSignature;
}
uint32_t table_size = targets_offset + switch_count * 2;
if (UNLIKELY(switch_insns[0] != expected_signature)) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD)
<< StringPrintf("wrong signature for switch table (%x, wanted %x)",
switch_insns[0], expected_signature);
return false;
}
/* make sure the end of the switch is in range */
if (UNLIKELY(cur_offset + switch_offset + table_size > (uint32_t) insn_count)) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid switch end: at " << cur_offset
<< ", switch offset " << switch_offset
<< ", end " << (cur_offset + switch_offset + table_size)
<< ", count " << insn_count;
return false;
}
constexpr int32_t keys_offset = 2;
if (switch_count > 1) {
if (is_packed_switch) {
/* for a packed switch, verify that keys do not overflow int32 */
int32_t first_key = switch_insns[keys_offset] | (switch_insns[keys_offset + 1] << 16);
int32_t max_first_key =
std::numeric_limits<int32_t>::max() - (static_cast<int32_t>(switch_count) - 1);
if (UNLIKELY(first_key > max_first_key)) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid packed switch: first_key=" << first_key
<< ", switch_count=" << switch_count;
return false;
}
} else {
/* for a sparse switch, verify the keys are in ascending order */
int32_t last_key = switch_insns[keys_offset] | (switch_insns[keys_offset + 1] << 16);
for (uint32_t targ = 1; targ < switch_count; targ++) {
int32_t key =
static_cast<int32_t>(switch_insns[keys_offset + targ * 2]) |
static_cast<int32_t>(switch_insns[keys_offset + targ * 2 + 1] << 16);
if (UNLIKELY(key <= last_key)) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid sparse switch: last key=" << last_key
<< ", this=" << key;
return false;
}
last_key = key;
}
}
}
/* verify each switch target */
for (uint32_t targ = 0; targ < switch_count; targ++) {
int32_t offset = static_cast<int32_t>(switch_insns[targets_offset + targ * 2]) |
static_cast<int32_t>(switch_insns[targets_offset + targ * 2 + 1] << 16);
int32_t abs_offset = cur_offset + offset;
if (UNLIKELY(abs_offset < 0 ||
abs_offset >= static_cast<int32_t>(insn_count) ||
!GetInstructionFlags(abs_offset).IsOpcode())) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid switch target " << offset
<< " (-> " << reinterpret_cast<void*>(abs_offset) << ") at "
<< reinterpret_cast<void*>(cur_offset)
<< "[" << targ << "]";
return false;
}
GetInstructionFlags(abs_offset).SetBranchTarget();
}
return true;
}
bool MethodVerifier::CheckVarArgRegs(uint32_t vA, uint32_t arg[]) {
uint16_t registers_size = code_item_accessor_.RegistersSize();
for (uint32_t idx = 0; idx < vA; idx++) {
if (UNLIKELY(arg[idx] >= registers_size)) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid reg index (" << arg[idx]
<< ") in non-range invoke (>= " << registers_size << ")";
return false;
}
}
return true;
}
bool MethodVerifier::CheckVarArgRangeRegs(uint32_t vA, uint32_t vC) {
uint16_t registers_size = code_item_accessor_.RegistersSize();
// vA/vC are unsigned 8-bit/16-bit quantities for /range instructions, so there's no risk of
// integer overflow when adding them here.
if (UNLIKELY(vA + vC > registers_size)) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid reg index " << vA << "+" << vC
<< " in range invoke (> " << registers_size << ")";
return false;
}
return true;
}
bool MethodVerifier::VerifyCodeFlow() {
const uint16_t registers_size = code_item_accessor_.RegistersSize();
/* Create and initialize table holding register status */
reg_table_.Init(kTrackCompilerInterestPoints,
insn_flags_.get(),
code_item_accessor_.InsnsSizeInCodeUnits(),
registers_size,
this);
work_line_.reset(RegisterLine::Create(registers_size, this));
saved_line_.reset(RegisterLine::Create(registers_size, this));
/* Initialize register types of method arguments. */
if (!SetTypesFromSignature()) {
DCHECK_NE(failures_.size(), 0U);
std::string prepend("Bad signature in ");
prepend += dex_file_->PrettyMethod(dex_method_idx_);
PrependToLastFailMessage(prepend);
return false;
}
// We may have a runtime failure here, clear.
have_pending_runtime_throw_failure_ = false;
/* Perform code flow verification. */
if (!CodeFlowVerifyMethod()) {
DCHECK_NE(failures_.size(), 0U);
return false;
}
return true;
}
std::ostream& MethodVerifier::DumpFailures(std::ostream& os) {
DCHECK_EQ(failures_.size(), failure_messages_.size());
for (size_t i = 0; i < failures_.size(); ++i) {
os << failure_messages_[i]->str() << "\n";
}
return os;
}
void MethodVerifier::Dump(std::ostream& os) {
VariableIndentationOutputStream vios(&os);
Dump(&vios);
}
void MethodVerifier::Dump(VariableIndentationOutputStream* vios) {
if (!code_item_accessor_.HasCodeItem()) {
vios->Stream() << "Native method\n";
return;
}
{
vios->Stream() << "Register Types:\n";
ScopedIndentation indent1(vios);
reg_types_.Dump(vios->Stream());
}
vios->Stream() << "Dumping instructions and register lines:\n";
ScopedIndentation indent1(vios);
for (const DexInstructionPcPair& inst : code_item_accessor_) {
const size_t dex_pc = inst.DexPc();
// Might be asked to dump before the table is initialized.
if (reg_table_.IsInitialized()) {
RegisterLine* reg_line = reg_table_.GetLine(dex_pc);
if (reg_line != nullptr) {
vios->Stream() << reg_line->Dump(this) << "\n";
}
}
vios->Stream()
<< StringPrintf("0x%04zx", dex_pc) << ": " << GetInstructionFlags(dex_pc).ToString() << " ";
const bool kDumpHexOfInstruction = false;
if (kDumpHexOfInstruction) {
vios->Stream() << inst->DumpHex(5) << " ";
}
vios->Stream() << inst->DumpString(dex_file_) << "\n";
}
}
static bool IsPrimitiveDescriptor(char descriptor) {
switch (descriptor) {
case 'I':
case 'C':
case 'S':
case 'B':
case 'Z':
case 'F':
case 'D':
case 'J':
return true;
default:
return false;
}
}
bool MethodVerifier::SetTypesFromSignature() {
RegisterLine* reg_line = reg_table_.GetLine(0);
// Should have been verified earlier.
DCHECK_GE(code_item_accessor_.RegistersSize(), code_item_accessor_.InsSize());
uint32_t arg_start = code_item_accessor_.RegistersSize() - code_item_accessor_.InsSize();
size_t expected_args = code_item_accessor_.InsSize(); /* long/double count as two */
// Include the "this" pointer.
size_t cur_arg = 0;
if (!IsStatic()) {
if (expected_args == 0) {
// Expect at least a receiver.
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "expected 0 args, but method is not static";
return false;
}
// If this is a constructor for a class other than java.lang.Object, mark the first ("this")
// argument as uninitialized. This restricts field access until the superclass constructor is
// called.
const RegType& declaring_class = GetDeclaringClass();
if (IsConstructor()) {
if (declaring_class.IsJavaLangObject()) {
// "this" is implicitly initialized.
reg_line->SetThisInitialized();
reg_line->SetRegisterType<LockOp::kClear>(this, arg_start + cur_arg, declaring_class);
} else {
reg_line->SetRegisterType<LockOp::kClear>(
this,
arg_start + cur_arg,
reg_types_.UninitializedThisArgument(declaring_class));
}
} else {
reg_line->SetRegisterType<LockOp::kClear>(this, arg_start + cur_arg, declaring_class);
}
cur_arg++;
}
const DexFile::ProtoId& proto_id =
dex_file_->GetMethodPrototype(dex_file_->GetMethodId(dex_method_idx_));
DexFileParameterIterator iterator(*dex_file_, proto_id);
for (; iterator.HasNext(); iterator.Next()) {
const char* descriptor = iterator.GetDescriptor();
if (descriptor == nullptr) {
LOG(FATAL) << "Null descriptor";
}
if (cur_arg >= expected_args) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "expected " << expected_args
<< " args, found more (" << descriptor << ")";
return false;
}
switch (descriptor[0]) {
case 'L':
case '[':
// We assume that reference arguments are initialized. The only way it could be otherwise
// (assuming the caller was verified) is if the current method is <init>, but in that case
// it's effectively considered initialized the instant we reach here (in the sense that we
// can return without doing anything or call virtual methods).
{
// Note: don't check access. No error would be thrown for declaring or passing an
// inaccessible class. Only actual accesses to fields or methods will.
const RegType& reg_type = ResolveClass<CheckAccess::kNo>(iterator.GetTypeIdx());
if (!reg_type.IsNonZeroReferenceTypes()) {
DCHECK(HasFailures());
return false;
}
reg_line->SetRegisterType<LockOp::kClear>(this, arg_start + cur_arg, reg_type);
}
break;
case 'Z':
reg_line->SetRegisterType<LockOp::kClear>(this, arg_start + cur_arg, reg_types_.Boolean());
break;
case 'C':
reg_line->SetRegisterType<LockOp::kClear>(this, arg_start + cur_arg, reg_types_.Char());
break;
case 'B':
reg_line->SetRegisterType<LockOp::kClear>(this, arg_start + cur_arg, reg_types_.Byte());
break;
case 'I':
reg_line->SetRegisterType<LockOp::kClear>(this, arg_start + cur_arg, reg_types_.Integer());
break;
case 'S':
reg_line->SetRegisterType<LockOp::kClear>(this, arg_start + cur_arg, reg_types_.Short());
break;
case 'F':
reg_line->SetRegisterType<LockOp::kClear>(this, arg_start + cur_arg, reg_types_.Float());
break;
case 'J':
case 'D': {
if (cur_arg + 1 >= expected_args) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "expected " << expected_args
<< " args, found more (" << descriptor << ")";
return false;
}
const RegType* lo_half;
const RegType* hi_half;
if (descriptor[0] == 'J') {
lo_half = &reg_types_.LongLo();
hi_half = &reg_types_.LongHi();
} else {
lo_half = &reg_types_.DoubleLo();
hi_half = &reg_types_.DoubleHi();
}
reg_line->SetRegisterTypeWide(this, arg_start + cur_arg, *lo_half, *hi_half);
cur_arg++;
break;
}
default:
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "unexpected signature type char '"
<< descriptor << "'";
return false;
}
cur_arg++;
}
if (cur_arg != expected_args) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "expected " << expected_args
<< " arguments, found " << cur_arg;
return false;
}
const char* descriptor = dex_file_->GetReturnTypeDescriptor(proto_id);
// Validate return type. We don't do the type lookup; just want to make sure that it has the right
// format. Only major difference from the method argument format is that 'V' is supported.
bool result;
if (IsPrimitiveDescriptor(descriptor[0]) || descriptor[0] == 'V') {
result = descriptor[1] == '\0';
} else if (descriptor[0] == '[') { // single/multi-dimensional array of object/primitive
size_t i = 0;
do {
i++;
} while (descriptor[i] == '['); // process leading [
if (descriptor[i] == 'L') { // object array
do {
i++; // find closing ;
} while (descriptor[i] != ';' && descriptor[i] != '\0');
result = descriptor[i] == ';';
} else { // primitive array
result = IsPrimitiveDescriptor(descriptor[i]) && descriptor[i + 1] == '\0';
}
} else if (descriptor[0] == 'L') {
// could be more thorough here, but shouldn't be required
size_t i = 0;
do {
i++;
} while (descriptor[i] != ';' && descriptor[i] != '\0');
result = descriptor[i] == ';';
} else {
result = false;
}
if (!result) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "unexpected char in return type descriptor '"
<< descriptor << "'";
}
return result;
}
bool MethodVerifier::CodeFlowVerifyMethod() {
const uint16_t* insns = code_item_accessor_.Insns();
const uint32_t insns_size = code_item_accessor_.InsnsSizeInCodeUnits();
/* Begin by marking the first instruction as "changed". */
GetInstructionFlags(0).SetChanged();
uint32_t start_guess = 0;
/* Continue until no instructions are marked "changed". */
while (true) {
if (allow_thread_suspension_) {
self_->AllowThreadSuspension();
}
// Find the first marked one. Use "start_guess" as a way to find one quickly.
uint32_t insn_idx = start_guess;
for (; insn_idx < insns_size; insn_idx++) {
if (GetInstructionFlags(insn_idx).IsChanged())
break;
}
if (insn_idx == insns_size) {
if (start_guess != 0) {
/* try again, starting from the top */
start_guess = 0;
continue;
} else {
/* all flags are clear */
break;
}
}
// We carry the working set of registers from instruction to instruction. If this address can
// be the target of a branch (or throw) instruction, or if we're skipping around chasing
// "changed" flags, we need to load the set of registers from the table.
// Because we always prefer to continue on to the next instruction, we should never have a
// situation where we have a stray "changed" flag set on an instruction that isn't a branch
// target.
work_insn_idx_ = insn_idx;
if (GetInstructionFlags(insn_idx).IsBranchTarget()) {
work_line_->CopyFromLine(reg_table_.GetLine(insn_idx));
} else if (kIsDebugBuild) {
/*
* Sanity check: retrieve the stored register line (assuming
* a full table) and make sure it actually matches.
*/
RegisterLine* register_line = reg_table_.GetLine(insn_idx);
if (register_line != nullptr) {
if (work_line_->CompareLine(register_line) != 0) {
Dump(std::cout);
std::cout << info_messages_.str();
LOG(FATAL) << "work_line diverged in " << dex_file_->PrettyMethod(dex_method_idx_)
<< "@" << reinterpret_cast<void*>(work_insn_idx_) << "\n"
<< " work_line=" << work_line_->Dump(this) << "\n"
<< " expected=" << register_line->Dump(this);
}
}
}
if (!CodeFlowVerifyInstruction(&start_guess)) {
std::string prepend(dex_file_->PrettyMethod(dex_method_idx_));
prepend += " failed to verify: ";
PrependToLastFailMessage(prepend);
return false;
}
/* Clear "changed" and mark as visited. */
GetInstructionFlags(insn_idx).SetVisited();
GetInstructionFlags(insn_idx).ClearChanged();
}
if (UNLIKELY(VLOG_IS_ON(verifier_debug))) {
/*
* Scan for dead code. There's nothing "evil" about dead code
* (besides the wasted space), but it indicates a flaw somewhere
* down the line, possibly in the verifier.
*
* If we've substituted "always throw" instructions into the stream,
* we are almost certainly going to have some dead code.
*/
int dead_start = -1;
for (const DexInstructionPcPair& inst : code_item_accessor_) {
const uint32_t insn_idx = inst.DexPc();
/*
* Switch-statement data doesn't get "visited" by scanner. It
* may or may not be preceded by a padding NOP (for alignment).
*/
if (insns[insn_idx] == Instruction::kPackedSwitchSignature ||
insns[insn_idx] == Instruction::kSparseSwitchSignature ||
insns[insn_idx] == Instruction::kArrayDataSignature ||
(insns[insn_idx] == Instruction::NOP && (insn_idx + 1 < insns_size) &&
(insns[insn_idx + 1] == Instruction::kPackedSwitchSignature ||
insns[insn_idx + 1] == Instruction::kSparseSwitchSignature ||
insns[insn_idx + 1] == Instruction::kArrayDataSignature))) {
GetInstructionFlags(insn_idx).SetVisited();
}
if (!GetInstructionFlags(insn_idx).IsVisited()) {
if (dead_start < 0) {
dead_start = insn_idx;
}
} else if (dead_start >= 0) {
LogVerifyInfo() << "dead code " << reinterpret_cast<void*>(dead_start)
<< "-" << reinterpret_cast<void*>(insn_idx - 1);
dead_start = -1;
}
}
if (dead_start >= 0) {
LogVerifyInfo()
<< "dead code " << reinterpret_cast<void*>(dead_start)
<< "-" << reinterpret_cast<void*>(code_item_accessor_.InsnsSizeInCodeUnits() - 1);
}
// To dump the state of the verify after a method, do something like:
// if (dex_file_->PrettyMethod(dex_method_idx_) ==
// "boolean java.lang.String.equals(java.lang.Object)") {
// LOG(INFO) << info_messages_.str();
// }
}
return true;
}
// Returns the index of the first final instance field of the given class, or kDexNoIndex if there
// is no such field.
static uint32_t GetFirstFinalInstanceFieldIndex(const DexFile& dex_file, dex::TypeIndex type_idx) {
const DexFile::ClassDef* class_def = dex_file.FindClassDef(type_idx);
DCHECK(class_def != nullptr);
ClassAccessor accessor(dex_file, *class_def);
for (const ClassAccessor::Field& field : accessor.GetInstanceFields()) {
if (field.IsFinal()) {
return field.GetIndex();
}
}
return dex::kDexNoIndex;
}
// Setup a register line for the given return instruction.
static void AdjustReturnLine(MethodVerifier* verifier,
const Instruction* ret_inst,
RegisterLine* line) {
Instruction::Code opcode = ret_inst->Opcode();
switch (opcode) {
case Instruction::RETURN_VOID:
case Instruction::RETURN_VOID_NO_BARRIER:
SafelyMarkAllRegistersAsConflicts(verifier, line);
break;
case Instruction::RETURN:
case Instruction::RETURN_OBJECT:
line->MarkAllRegistersAsConflictsExcept(verifier, ret_inst->VRegA_11x());
break;
case Instruction::RETURN_WIDE:
line->MarkAllRegistersAsConflictsExceptWide(verifier, ret_inst->VRegA_11x());
break;
default:
LOG(FATAL) << "Unknown return opcode " << opcode;
UNREACHABLE();
}
}
bool MethodVerifier::CodeFlowVerifyInstruction(uint32_t* start_guess) {
// If we're doing FindLocksAtDexPc, check whether we're at the dex pc we care about.
// We want the state _before_ the instruction, for the case where the dex pc we're
// interested in is itself a monitor-enter instruction (which is a likely place
// for a thread to be suspended).
if (monitor_enter_dex_pcs_ != nullptr && work_insn_idx_ == interesting_dex_pc_) {
monitor_enter_dex_pcs_->clear(); // The new work line is more accurate than the previous one.
std::map<uint32_t, DexLockInfo> depth_to_lock_info;
auto collector = [&](uint32_t dex_reg, uint32_t depth) {
auto insert_pair = depth_to_lock_info.emplace(depth, DexLockInfo(depth));
auto it = insert_pair.first;
auto set_insert_pair = it->second.dex_registers.insert(dex_reg);
DCHECK(set_insert_pair.second);
};
work_line_->IterateRegToLockDepths(collector);
for (auto& pair : depth_to_lock_info) {
monitor_enter_dex_pcs_->push_back(pair.second);
// Map depth to dex PC.
(*monitor_enter_dex_pcs_)[monitor_enter_dex_pcs_->size() - 1].dex_pc =
work_line_->GetMonitorEnterDexPc(pair.second.dex_pc);
}
}
/*
* Once we finish decoding the instruction, we need to figure out where
* we can go from here. There are three possible ways to transfer
* control to another statement:
*
* (1) Continue to the next instruction. Applies to all but
* unconditional branches, method returns, and exception throws.
* (2) Branch to one or more possible locations. Applies to branches
* and switch statements.
* (3) Exception handlers. Applies to any instruction that can
* throw an exception that is handled by an encompassing "try"
* block.
*
* We can also return, in which case there is no successor instruction
* from this point.
*
* The behavior can be determined from the opcode flags.
*/
const uint16_t* insns = code_item_accessor_.Insns() + work_insn_idx_;
const Instruction* inst = Instruction::At(insns);
int opcode_flags = Instruction::FlagsOf(inst->Opcode());
int32_t branch_target = 0;
bool just_set_result = false;
if (UNLIKELY(VLOG_IS_ON(verifier_debug))) {
// Generate processing back trace to debug verifier
LogVerifyInfo() << "Processing " << inst->DumpString(dex_file_) << "\n"
<< work_line_->Dump(this) << "\n";
}
/*
* Make a copy of the previous register state. If the instruction
* can throw an exception, we will copy/merge this into the "catch"
* address rather than work_line, because we don't want the result
* from the "successful" code path (e.g. a check-cast that "improves"
* a type) to be visible to the exception handler.
*/
if ((opcode_flags & Instruction::kThrow) != 0 && CurrentInsnFlags()->IsInTry()) {
saved_line_->CopyFromLine(work_line_.get());
} else if (kIsDebugBuild) {
saved_line_->FillWithGarbage();
}
DCHECK(!have_pending_runtime_throw_failure_); // Per-instruction flag, should not be set here.
// We need to ensure the work line is consistent while performing validation. When we spot a
// peephole pattern we compute a new line for either the fallthrough instruction or the
// branch target.
RegisterLineArenaUniquePtr branch_line;
RegisterLineArenaUniquePtr fallthrough_line;
switch (inst->Opcode()) {
case Instruction::NOP:
/*
* A "pure" NOP has no effect on anything. Data tables start with
* a signature that looks like a NOP; if we see one of these in
* the course of executing code then we have a problem.
*/
if (inst->VRegA_10x() != 0) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "encountered data table in instruction stream";
}
break;
case Instruction::MOVE:
work_line_->CopyRegister1(this, inst->VRegA_12x(), inst->VRegB_12x(), kTypeCategory1nr);
break;
case Instruction::MOVE_FROM16:
work_line_->CopyRegister1(this, inst->VRegA_22x(), inst->VRegB_22x(), kTypeCategory1nr);
break;
case Instruction::MOVE_16:
work_line_->CopyRegister1(this, inst->VRegA_32x(), inst->VRegB_32x(), kTypeCategory1nr);
break;
case Instruction::MOVE_WIDE:
work_line_->CopyRegister2(this, inst->VRegA_12x(), inst->VRegB_12x());
break;
case Instruction::MOVE_WIDE_FROM16:
work_line_->CopyRegister2(this, inst->VRegA_22x(), inst->VRegB_22x());
break;
case Instruction::MOVE_WIDE_16:
work_line_->CopyRegister2(this, inst->VRegA_32x(), inst->VRegB_32x());
break;
case Instruction::MOVE_OBJECT:
work_line_->CopyRegister1(this, inst->VRegA_12x(), inst->VRegB_12x(), kTypeCategoryRef);
break;
case Instruction::MOVE_OBJECT_FROM16:
work_line_->CopyRegister1(this, inst->VRegA_22x(), inst->VRegB_22x(), kTypeCategoryRef);
break;
case Instruction::MOVE_OBJECT_16:
work_line_->CopyRegister1(this, inst->VRegA_32x(), inst->VRegB_32x(), kTypeCategoryRef);
break;
/*
* The move-result instructions copy data out of a "pseudo-register"
* with the results from the last method invocation. In practice we
* might want to hold the result in an actual CPU register, so the
* Dalvik spec requires that these only appear immediately after an
* invoke or filled-new-array.
*
* These calls invalidate the "result" register. (This is now
* redundant with the reset done below, but it can make the debug info
* easier to read in some cases.)
*/
case Instruction::MOVE_RESULT:
work_line_->CopyResultRegister1(this, inst->VRegA_11x(), false);
break;
case Instruction::MOVE_RESULT_WIDE:
work_line_->CopyResultRegister2(this, inst->VRegA_11x());
break;
case Instruction::MOVE_RESULT_OBJECT:
work_line_->CopyResultRegister1(this, inst->VRegA_11x(), true);
break;
case Instruction::MOVE_EXCEPTION: {
// We do not allow MOVE_EXCEPTION as the first instruction in a method. This is a simple case
// where one entrypoint to the catch block is not actually an exception path.
if (work_insn_idx_ == 0) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "move-exception at pc 0x0";
break;
}
/*
* This statement can only appear as the first instruction in an exception handler. We verify
* that as part of extracting the exception type from the catch block list.
*/
const RegType& res_type = GetCaughtExceptionType();
work_line_->SetRegisterType<LockOp::kClear>(this, inst->VRegA_11x(), res_type);
break;
}
case Instruction::RETURN_VOID:
if (!IsInstanceConstructor() || work_line_->CheckConstructorReturn(this)) {
if (!GetMethodReturnType().IsConflict()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "return-void not expected";
}
}
break;
case Instruction::RETURN:
if (!IsInstanceConstructor() || work_line_->CheckConstructorReturn(this)) {
/* check the method signature */
const RegType& return_type = GetMethodReturnType();
if (!return_type.IsCategory1Types()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "unexpected non-category 1 return type "
<< return_type;
} else {
// Compilers may generate synthetic functions that write byte values into boolean fields.
// Also, it may use integer values for boolean, byte, short, and character return types.
const uint32_t vregA = inst->VRegA_11x();
const RegType& src_type = work_line_->GetRegisterType(this, vregA);
bool use_src = ((return_type.IsBoolean() && src_type.IsByte()) ||
((return_type.IsBoolean() || return_type.IsByte() ||
return_type.IsShort() || return_type.IsChar()) &&
src_type.IsInteger()));
/* check the register contents */
bool success =
work_line_->VerifyRegisterType(this, vregA, use_src ? src_type : return_type);
if (!success) {
AppendToLastFailMessage(StringPrintf(" return-1nr on invalid register v%d", vregA));
}
}
}
break;
case Instruction::RETURN_WIDE:
if (!IsInstanceConstructor() || work_line_->CheckConstructorReturn(this)) {
/* check the method signature */
const RegType& return_type = GetMethodReturnType();
if (!return_type.IsCategory2Types()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "return-wide not expected";
} else {
/* check the register contents */
const uint32_t vregA = inst->VRegA_11x();
bool success = work_line_->VerifyRegisterType(this, vregA, return_type);
if (!success) {
AppendToLastFailMessage(StringPrintf(" return-wide on invalid register v%d", vregA));
}
}
}
break;
case Instruction::RETURN_OBJECT:
if (!IsInstanceConstructor() || work_line_->CheckConstructorReturn(this)) {
const RegType& return_type = GetMethodReturnType();
if (!return_type.IsReferenceTypes()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "return-object not expected";
} else {
/* return_type is the *expected* return type, not register value */
DCHECK(!return_type.IsZeroOrNull());
DCHECK(!return_type.IsUninitializedReference());
const uint32_t vregA = inst->VRegA_11x();
const RegType& reg_type = work_line_->GetRegisterType(this, vregA);
// Disallow returning undefined, conflict & uninitialized values and verify that the
// reference in vAA is an instance of the "return_type."
if (reg_type.IsUndefined()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "returning undefined register";
} else if (reg_type.IsConflict()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "returning register with conflict";
} else if (reg_type.IsUninitializedTypes()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "returning uninitialized object '"
<< reg_type << "'";
} else if (!reg_type.IsReferenceTypes()) {
// We really do expect a reference here.
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "return-object returns a non-reference type "
<< reg_type;
} else if (!return_type.IsAssignableFrom(reg_type, this)) {
if (reg_type.IsUnresolvedTypes() || return_type.IsUnresolvedTypes()) {
Fail(VERIFY_ERROR_NO_CLASS) << " can't resolve returned type '" << return_type
<< "' or '" << reg_type << "'";
} else {
bool soft_error = false;
// Check whether arrays are involved. They will show a valid class status, even
// if their components are erroneous.
if (reg_type.IsArrayTypes() && return_type.IsArrayTypes()) {
return_type.CanAssignArray(reg_type, reg_types_, class_loader_, this, &soft_error);
if (soft_error) {
Fail(VERIFY_ERROR_BAD_CLASS_SOFT) << "array with erroneous component type: "
<< reg_type << " vs " << return_type;
}
}
if (!soft_error) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "returning '" << reg_type
<< "', but expected from declaration '" << return_type << "'";
}
}
}
}
}
break;
/* could be boolean, int, float, or a null reference */
case Instruction::CONST_4: {
int32_t val = static_cast<int32_t>(inst->VRegB_11n() << 28) >> 28;
work_line_->SetRegisterType<LockOp::kClear>(
this, inst->VRegA_11n(), DetermineCat1Constant(val, need_precise_constants_));
break;
}
case Instruction::CONST_16: {
int16_t val = static_cast<int16_t>(inst->VRegB_21s());
work_line_->SetRegisterType<LockOp::kClear>(
this, inst->VRegA_21s(), DetermineCat1Constant(val, need_precise_constants_));
break;
}
case Instruction::CONST: {
int32_t val = inst->VRegB_31i();
work_line_->SetRegisterType<LockOp::kClear>(
this, inst->VRegA_31i(), DetermineCat1Constant(val, need_precise_constants_));
break;
}
case Instruction::CONST_HIGH16: {
int32_t val = static_cast<int32_t>(inst->VRegB_21h() << 16);
work_line_->SetRegisterType<LockOp::kClear>(
this, inst->VRegA_21h(), DetermineCat1Constant(val, need_precise_constants_));
break;
}
/* could be long or double; resolved upon use */
case Instruction::CONST_WIDE_16: {
int64_t val = static_cast<int16_t>(inst->VRegB_21s());
const RegType& lo = reg_types_.FromCat2ConstLo(static_cast<int32_t>(val), true);
const RegType& hi = reg_types_.FromCat2ConstHi(static_cast<int32_t>(val >> 32), true);
work_line_->SetRegisterTypeWide(this, inst->VRegA_21s(), lo, hi);
break;
}
case Instruction::CONST_WIDE_32: {
int64_t val = static_cast<int32_t>(inst->VRegB_31i());
const RegType& lo = reg_types_.FromCat2ConstLo(static_cast<int32_t>(val), true);
const RegType& hi = reg_types_.FromCat2ConstHi(static_cast<int32_t>(val >> 32), true);
work_line_->SetRegisterTypeWide(this, inst->VRegA_31i(), lo, hi);
break;
}
case Instruction::CONST_WIDE: {
int64_t val = inst->VRegB_51l();
const RegType& lo = reg_types_.FromCat2ConstLo(static_cast<int32_t>(val), true);
const RegType& hi = reg_types_.FromCat2ConstHi(static_cast<int32_t>(val >> 32), true);
work_line_->SetRegisterTypeWide(this, inst->VRegA_51l(), lo, hi);
break;
}
case Instruction::CONST_WIDE_HIGH16: {
int64_t val = static_cast<uint64_t>(inst->VRegB_21h()) << 48;
const RegType& lo = reg_types_.FromCat2ConstLo(static_cast<int32_t>(val), true);
const RegType& hi = reg_types_.FromCat2ConstHi(static_cast<int32_t>(val >> 32), true);
work_line_->SetRegisterTypeWide(this, inst->VRegA_21h(), lo, hi);
break;
}
case Instruction::CONST_STRING:
work_line_->SetRegisterType<LockOp::kClear>(
this, inst->VRegA_21c(), reg_types_.JavaLangString());
break;
case Instruction::CONST_STRING_JUMBO:
work_line_->SetRegisterType<LockOp::kClear>(
this, inst->VRegA_31c(), reg_types_.JavaLangString());
break;
case Instruction::CONST_CLASS: {
// Get type from instruction if unresolved then we need an access check
// TODO: check Compiler::CanAccessTypeWithoutChecks returns false when res_type is unresolved
const RegType& res_type = ResolveClass<CheckAccess::kYes>(dex::TypeIndex(inst->VRegB_21c()));
// Register holds class, ie its type is class, on error it will hold Conflict.
work_line_->SetRegisterType<LockOp::kClear>(
this, inst->VRegA_21c(), res_type.IsConflict() ? res_type
: reg_types_.JavaLangClass());
break;
}
case Instruction::CONST_METHOD_HANDLE:
work_line_->SetRegisterType<LockOp::kClear>(
this, inst->VRegA_21c(), reg_types_.JavaLangInvokeMethodHandle());
break;
case Instruction::CONST_METHOD_TYPE:
work_line_->SetRegisterType<LockOp::kClear>(
this, inst->VRegA_21c(), reg_types_.JavaLangInvokeMethodType());
break;
case Instruction::MONITOR_ENTER:
work_line_->PushMonitor(this, inst->VRegA_11x(), work_insn_idx_);
// Check whether the previous instruction is a move-object with vAA as a source, creating
// untracked lock aliasing.
if (0 != work_insn_idx_ && !GetInstructionFlags(work_insn_idx_).IsBranchTarget()) {
uint32_t prev_idx = work_insn_idx_ - 1;
while (0 != prev_idx && !GetInstructionFlags(prev_idx).IsOpcode()) {
prev_idx--;
}
const Instruction& prev_inst = code_item_accessor_.InstructionAt(prev_idx);
switch (prev_inst.Opcode()) {
case Instruction::MOVE_OBJECT:
case Instruction::MOVE_OBJECT_16:
case Instruction::MOVE_OBJECT_FROM16:
if (prev_inst.VRegB() == inst->VRegA_11x()) {
// Redo the copy. This won't change the register types, but update the lock status
// for the aliased register.
work_line_->CopyRegister1(this,
prev_inst.VRegA(),
prev_inst.VRegB(),
kTypeCategoryRef);
}
break;
// Catch a case of register aliasing when two registers are linked to the same
// java.lang.Class object via two consequent const-class instructions immediately
// preceding monitor-enter called on one of those registers.
case Instruction::CONST_CLASS: {
// Get the second previous instruction.
if (prev_idx == 0 || GetInstructionFlags(prev_idx).IsBranchTarget()) {
break;
}
prev_idx--;
while (0 != prev_idx && !GetInstructionFlags(prev_idx).IsOpcode()) {
prev_idx--;
}
const Instruction& prev2_inst = code_item_accessor_.InstructionAt(prev_idx);
// Match the pattern "const-class; const-class; monitor-enter;"
if (prev2_inst.Opcode() != Instruction::CONST_CLASS) {
break;
}
// Ensure both const-classes are called for the same type_idx.
if (prev_inst.VRegB_21c() != prev2_inst.VRegB_21c()) {
break;
}
// Update the lock status for the aliased register.
if (prev_inst.VRegA() == inst->VRegA_11x()) {
work_line_->CopyRegister1(this,
prev2_inst.VRegA(),
inst->VRegA_11x(),
kTypeCategoryRef);
} else if (prev2_inst.VRegA() == inst->VRegA_11x()) {
work_line_->CopyRegister1(this,
prev_inst.VRegA(),
inst->VRegA_11x(),
kTypeCategoryRef);
}
break;
}
default: // Other instruction types ignored.
break;
}
}
break;
case Instruction::MONITOR_EXIT:
/*
* monitor-exit instructions are odd. They can throw exceptions,
* but when they do they act as if they succeeded and the PC is
* pointing to the following instruction. (This behavior goes back
* to the need to handle asynchronous exceptions, a now-deprecated
* feature that Dalvik doesn't support.)
*
* In practice we don't need to worry about this. The only
* exceptions that can be thrown from monitor-exit are for a
* null reference and -exit without a matching -enter. If the
* structured locking checks are working, the former would have
* failed on the -enter instruction, and the latter is impossible.
*
* This is fortunate, because issue 3221411 prevents us from
* chasing the "can throw" path when monitor verification is
* enabled. If we can fully verify the locking we can ignore
* some catch blocks (which will show up as "dead" code when
* we skip them here); if we can't, then the code path could be
* "live" so we still need to check it.
*/
opcode_flags &= ~Instruction::kThrow;
work_line_->PopMonitor(this, inst->VRegA_11x());
break;
case Instruction::CHECK_CAST:
case Instruction::INSTANCE_OF: {
/*
* If this instruction succeeds, we will "downcast" register vA to the type in vB. (This
* could be a "upcast" -- not expected, so we don't try to address it.)
*
* If it fails, an exception is thrown, which we deal with later by ignoring the update to
* dec_insn.vA when branching to a handler.
*/
const bool is_checkcast = (inst->Opcode() == Instruction::CHECK_CAST);
const dex::TypeIndex type_idx((is_checkcast) ? inst->VRegB_21c() : inst->VRegC_22c());
const RegType& res_type = ResolveClass<CheckAccess::kYes>(type_idx);
if (res_type.IsConflict()) {
// If this is a primitive type, fail HARD.
ObjPtr<mirror::Class> klass = Runtime::Current()->GetClassLinker()->LookupResolvedType(
type_idx, dex_cache_.Get(), class_loader_.Get());
if (klass != nullptr && klass->IsPrimitive()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "using primitive type "
<< dex_file_->StringByTypeIdx(type_idx) << " in instanceof in "
<< GetDeclaringClass();
break;
}
DCHECK_NE(failures_.size(), 0U);
if (!is_checkcast) {
work_line_->SetRegisterType<LockOp::kClear>(this,
inst->VRegA_22c(),
reg_types_.Boolean());
}
break; // bad class
}
// TODO: check Compiler::CanAccessTypeWithoutChecks returns false when res_type is unresolved
uint32_t orig_type_reg = (is_checkcast) ? inst->VRegA_21c() : inst->VRegB_22c();
const RegType& orig_type = work_line_->GetRegisterType(this, orig_type_reg);
if (!res_type.IsNonZeroReferenceTypes()) {
if (is_checkcast) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "check-cast on unexpected class " << res_type;
} else {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "instance-of on unexpected class " << res_type;
}
} else if (!orig_type.IsReferenceTypes()) {
if (is_checkcast) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "check-cast on non-reference in v" << orig_type_reg;
} else {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "instance-of on non-reference in v" << orig_type_reg;
}
} else if (orig_type.IsUninitializedTypes()) {
if (is_checkcast) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "check-cast on uninitialized reference in v"
<< orig_type_reg;
} else {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "instance-of on uninitialized reference in v"
<< orig_type_reg;
}
} else {
if (is_checkcast) {
work_line_->SetRegisterType<LockOp::kKeep>(this, inst->VRegA_21c(), res_type);
} else {
work_line_->SetRegisterType<LockOp::kClear>(this,
inst->VRegA_22c(),
reg_types_.Boolean());
}
}
break;
}
case Instruction::ARRAY_LENGTH: {
const RegType& res_type = work_line_->GetRegisterType(this, inst->VRegB_12x());
if (res_type.IsReferenceTypes()) {
if (!res_type.IsArrayTypes() && !res_type.IsZeroOrNull()) {
// ie not an array or null
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "array-length on non-array " << res_type;
} else {
work_line_->SetRegisterType<LockOp::kClear>(this,
inst->VRegA_12x(),
reg_types_.Integer());
}
} else {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "array-length on non-array " << res_type;
}
break;
}
case Instruction::NEW_INSTANCE: {
const RegType& res_type = ResolveClass<CheckAccess::kYes>(dex::TypeIndex(inst->VRegB_21c()));
if (res_type.IsConflict()) {
DCHECK_NE(failures_.size(), 0U);
break; // bad class
}
// TODO: check Compiler::CanAccessTypeWithoutChecks returns false when res_type is unresolved
// can't create an instance of an interface or abstract class */
if (!res_type.IsInstantiableTypes()) {
Fail(VERIFY_ERROR_INSTANTIATION)
<< "new-instance on primitive, interface or abstract class" << res_type;
// Soft failure so carry on to set register type.
}
const RegType& uninit_type = reg_types_.Uninitialized(res_type, work_insn_idx_);
// Any registers holding previous allocations from this address that have not yet been
// initialized must be marked invalid.
work_line_->MarkUninitRefsAsInvalid(this, uninit_type);
// add the new uninitialized reference to the register state
work_line_->SetRegisterType<LockOp::kClear>(this, inst->VRegA_21c(), uninit_type);
break;
}
case Instruction::NEW_ARRAY:
VerifyNewArray(inst, false, false);
break;
case Instruction::FILLED_NEW_ARRAY:
VerifyNewArray(inst, true, false);
just_set_result = true; // Filled new array sets result register
break;
case Instruction::FILLED_NEW_ARRAY_RANGE:
VerifyNewArray(inst, true, true);
just_set_result = true; // Filled new array range sets result register
break;
case Instruction::CMPL_FLOAT:
case Instruction::CMPG_FLOAT:
if (!work_line_->VerifyRegisterType(this, inst->VRegB_23x(), reg_types_.Float())) {
break;
}
if (!work_line_->VerifyRegisterType(this, inst->VRegC_23x(), reg_types_.Float())) {
break;
}
work_line_->SetRegisterType<LockOp::kClear>(this, inst->VRegA_23x(), reg_types_.Integer());
break;
case Instruction::CMPL_DOUBLE:
case Instruction::CMPG_DOUBLE:
if (!work_line_->VerifyRegisterTypeWide(this, inst->VRegB_23x(), reg_types_.DoubleLo(),
reg_types_.DoubleHi())) {
break;
}
if (!work_line_->VerifyRegisterTypeWide(this, inst->VRegC_23x(), reg_types_.DoubleLo(),
reg_types_.DoubleHi())) {
break;
}
work_line_->SetRegisterType<LockOp::kClear>(this, inst->VRegA_23x(), reg_types_.Integer());
break;
case Instruction::CMP_LONG:
if (!work_line_->VerifyRegisterTypeWide(this, inst->VRegB_23x(), reg_types_.LongLo(),
reg_types_.LongHi())) {
break;
}
if (!work_line_->VerifyRegisterTypeWide(this, inst->VRegC_23x(), reg_types_.LongLo(),
reg_types_.LongHi())) {
break;
}
work_line_->SetRegisterType<LockOp::kClear>(this, inst->VRegA_23x(), reg_types_.Integer());
break;
case Instruction::THROW: {
const RegType& res_type = work_line_->GetRegisterType(this, inst->VRegA_11x());
if (!reg_types_.JavaLangThrowable(false).IsAssignableFrom(res_type, this)) {
if (res_type.IsUninitializedTypes()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "thrown exception not initialized";
} else if (!res_type.IsReferenceTypes()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "thrown value of non-reference type " << res_type;
} else {
Fail(res_type.IsUnresolvedTypes() ? VERIFY_ERROR_NO_CLASS : VERIFY_ERROR_BAD_CLASS_SOFT)
<< "thrown class " << res_type << " not instanceof Throwable";
}
}
break;
}
case Instruction::GOTO:
case Instruction::GOTO_16:
case Instruction::GOTO_32:
/* no effect on or use of registers */
break;
case Instruction::PACKED_SWITCH:
case Instruction::SPARSE_SWITCH:
/* verify that vAA is an integer, or can be converted to one */
work_line_->VerifyRegisterType(this, inst->VRegA_31t(), reg_types_.Integer());
break;
case Instruction::FILL_ARRAY_DATA: {
/* Similar to the verification done for APUT */
const RegType& array_type = work_line_->GetRegisterType(this, inst->VRegA_31t());
/* array_type can be null if the reg type is Zero */
if (!array_type.IsZeroOrNull()) {
if (!array_type.IsArrayTypes()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid fill-array-data with array type "
<< array_type;
} else if (array_type.IsUnresolvedTypes()) {
// If it's an unresolved array type, it must be non-primitive.
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid fill-array-data for array of type "
<< array_type;
} else {
const RegType& component_type = reg_types_.GetComponentType(array_type, GetClassLoader());
DCHECK(!component_type.IsConflict());
if (component_type.IsNonZeroReferenceTypes()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid fill-array-data with component type "
<< component_type;
} else {
// Now verify if the element width in the table matches the element width declared in
// the array
const uint16_t* array_data =
insns + (insns[1] | (static_cast<int32_t>(insns[2]) << 16));
if (array_data[0] != Instruction::kArrayDataSignature) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid magic for array-data";
} else {
size_t elem_width = Primitive::ComponentSize(component_type.GetPrimitiveType());
// Since we don't compress the data in Dex, expect to see equal width of data stored
// in the table and expected from the array class.
if (array_data[1] != elem_width) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "array-data size mismatch (" << array_data[1]
<< " vs " << elem_width << ")";
}
}
}
}
}
break;
}
case Instruction::IF_EQ:
case Instruction::IF_NE: {
const RegType& reg_type1 = work_line_->GetRegisterType(this, inst->VRegA_22t());
const RegType& reg_type2 = work_line_->GetRegisterType(this, inst->VRegB_22t());
bool mismatch = false;
if (reg_type1.IsZeroOrNull()) { // zero then integral or reference expected
mismatch = !reg_type2.IsReferenceTypes() && !reg_type2.IsIntegralTypes();
} else if (reg_type1.IsReferenceTypes()) { // both references?
mismatch = !reg_type2.IsReferenceTypes();
} else { // both integral?
mismatch = !reg_type1.IsIntegralTypes() || !reg_type2.IsIntegralTypes();
}
if (mismatch) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "args to if-eq/if-ne (" << reg_type1 << ","
<< reg_type2 << ") must both be references or integral";
}
break;
}
case Instruction::IF_LT:
case Instruction::IF_GE:
case Instruction::IF_GT:
case Instruction::IF_LE: {
const RegType& reg_type1 = work_line_->GetRegisterType(this, inst->VRegA_22t());
const RegType& reg_type2 = work_line_->GetRegisterType(this, inst->VRegB_22t());
if (!reg_type1.IsIntegralTypes() || !reg_type2.IsIntegralTypes()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "args to 'if' (" << reg_type1 << ","
<< reg_type2 << ") must be integral";
}
break;
}
case Instruction::IF_EQZ:
case Instruction::IF_NEZ: {
const RegType& reg_type = work_line_->GetRegisterType(this, inst->VRegA_21t());
if (!reg_type.IsReferenceTypes() && !reg_type.IsIntegralTypes()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "type " << reg_type
<< " unexpected as arg to if-eqz/if-nez";
}
// Find previous instruction - its existence is a precondition to peephole optimization.
uint32_t instance_of_idx = 0;
if (0 != work_insn_idx_) {
instance_of_idx = work_insn_idx_ - 1;
while (0 != instance_of_idx && !GetInstructionFlags(instance_of_idx).IsOpcode()) {
instance_of_idx--;
}
if (FailOrAbort(GetInstructionFlags(instance_of_idx).IsOpcode(),
"Unable to get previous instruction of if-eqz/if-nez for work index ",
work_insn_idx_)) {
break;
}
} else {
break;
}
const Instruction& instance_of_inst = code_item_accessor_.InstructionAt(instance_of_idx);
/* Check for peep-hole pattern of:
* ...;
* instance-of vX, vY, T;
* ifXXX vX, label ;
* ...;
* label:
* ...;
* and sharpen the type of vY to be type T.
* Note, this pattern can't be if:
* - if there are other branches to this branch,
* - when vX == vY.
*/
if (!CurrentInsnFlags()->IsBranchTarget() &&
(Instruction::INSTANCE_OF == instance_of_inst.Opcode()) &&
(inst->VRegA_21t() == instance_of_inst.VRegA_22c()) &&
(instance_of_inst.VRegA_22c() != instance_of_inst.VRegB_22c())) {
// Check the type of the instance-of is different than that of registers type, as if they
// are the same there is no work to be done here. Check that the conversion is not to or
// from an unresolved type as type information is imprecise. If the instance-of is to an
// interface then ignore the type information as interfaces can only be treated as Objects
// and we don't want to disallow field and other operations on the object. If the value
// being instance-of checked against is known null (zero) then allow the optimization as
// we didn't have type information. If the merge of the instance-of type with the original
// type is assignable to the original then allow optimization. This check is performed to
// ensure that subsequent merges don't lose type information - such as becoming an
// interface from a class that would lose information relevant to field checks.
const RegType& orig_type = work_line_->GetRegisterType(this, instance_of_inst.VRegB_22c());
const RegType& cast_type = ResolveClass<CheckAccess::kYes>(
dex::TypeIndex(instance_of_inst.VRegC_22c()));
if (!orig_type.Equals(cast_type) &&
!cast_type.IsUnresolvedTypes() && !orig_type.IsUnresolvedTypes() &&
cast_type.HasClass() && // Could be conflict type, make sure it has a class.
!cast_type.GetClass()->IsInterface() &&
(orig_type.IsZeroOrNull() ||
orig_type.IsStrictlyAssignableFrom(
cast_type.Merge(orig_type, &reg_types_, this), this))) {
RegisterLine* update_line = RegisterLine::Create(code_item_accessor_.RegistersSize(),
this);
if (inst->Opcode() == Instruction::IF_EQZ) {
fallthrough_line.reset(update_line);
} else {
branch_line.reset(update_line);
}
update_line->CopyFromLine(work_line_.get());
update_line->SetRegisterType<LockOp::kKeep>(this,
instance_of_inst.VRegB_22c(),
cast_type);
if (!GetInstructionFlags(instance_of_idx).IsBranchTarget() && 0 != instance_of_idx) {
// See if instance-of was preceded by a move-object operation, common due to the small
// register encoding space of instance-of, and propagate type information to the source
// of the move-object.
uint32_t move_idx = instance_of_idx - 1;
while (0 != move_idx && !GetInstructionFlags(move_idx).IsOpcode()) {
move_idx--;
}
if (FailOrAbort(GetInstructionFlags(move_idx).IsOpcode(),
"Unable to get previous instruction of if-eqz/if-nez for work index ",
work_insn_idx_)) {
break;
}
const Instruction& move_inst = code_item_accessor_.InstructionAt(move_idx);
switch (move_inst.Opcode()) {
case Instruction::MOVE_OBJECT:
if (move_inst.VRegA_12x() == instance_of_inst.VRegB_22c()) {
update_line->SetRegisterType<LockOp::kKeep>(this,
move_inst.VRegB_12x(),
cast_type);
}
break;
case Instruction::MOVE_OBJECT_FROM16:
if (move_inst.VRegA_22x() == instance_of_inst.VRegB_22c()) {
update_line->SetRegisterType<LockOp::kKeep>(this,
move_inst.VRegB_22x(),
cast_type);
}
break;
case Instruction::MOVE_OBJECT_16:
if (move_inst.VRegA_32x() == instance_of_inst.VRegB_22c()) {
update_line->SetRegisterType<LockOp::kKeep>(this,
move_inst.VRegB_32x(),
cast_type);
}
break;
default:
break;
}
}
}
}
break;
}
case Instruction::IF_LTZ:
case Instruction::IF_GEZ:
case Instruction::IF_GTZ:
case Instruction::IF_LEZ: {
const RegType& reg_type = work_line_->GetRegisterType(this, inst->VRegA_21t());
if (!reg_type.IsIntegralTypes()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "type " << reg_type
<< " unexpected as arg to if-ltz/if-gez/if-gtz/if-lez";
}
break;
}
case Instruction::AGET_BOOLEAN:
VerifyAGet(inst, reg_types_.Boolean(), true);
break;
case Instruction::AGET_BYTE:
VerifyAGet(inst, reg_types_.Byte(), true);
break;
case Instruction::AGET_CHAR:
VerifyAGet(inst, reg_types_.Char(), true);
break;
case Instruction::AGET_SHORT:
VerifyAGet(inst, reg_types_.Short(), true);
break;
case Instruction::AGET:
VerifyAGet(inst, reg_types_.Integer(), true);
break;
case Instruction::AGET_WIDE:
VerifyAGet(inst, reg_types_.LongLo(), true);
break;
case Instruction::AGET_OBJECT:
VerifyAGet(inst, reg_types_.JavaLangObject(false), false);
break;
case Instruction::APUT_BOOLEAN:
VerifyAPut(inst, reg_types_.Boolean(), true);
break;
case Instruction::APUT_BYTE:
VerifyAPut(inst, reg_types_.Byte(), true);
break;
case Instruction::APUT_CHAR:
VerifyAPut(inst, reg_types_.Char(), true);
break;
case Instruction::APUT_SHORT:
VerifyAPut(inst, reg_types_.Short(), true);
break;
case Instruction::APUT:
VerifyAPut(inst, reg_types_.Integer(), true);
break;
case Instruction::APUT_WIDE:
VerifyAPut(inst, reg_types_.LongLo(), true);
break;
case Instruction::APUT_OBJECT:
VerifyAPut(inst, reg_types_.JavaLangObject(false), false);
break;
case Instruction::IGET_BOOLEAN:
case Instruction::IGET_BOOLEAN_QUICK:
VerifyISFieldAccess<FieldAccessType::kAccGet>(inst, reg_types_.Boolean(), true, false);
break;
case Instruction::IGET_BYTE:
case Instruction::IGET_BYTE_QUICK:
VerifyISFieldAccess<FieldAccessType::kAccGet>(inst, reg_types_.Byte(), true, false);
break;
case Instruction::IGET_CHAR:
case Instruction::IGET_CHAR_QUICK:
VerifyISFieldAccess<FieldAccessType::kAccGet>(inst, reg_types_.Char(), true, false);
break;
case Instruction::IGET_SHORT:
case Instruction::IGET_SHORT_QUICK:
VerifyISFieldAccess<FieldAccessType::kAccGet>(inst, reg_types_.Short(), true, false);
break;
case Instruction::IGET:
case Instruction::IGET_QUICK:
VerifyISFieldAccess<FieldAccessType::kAccGet>(inst, reg_types_.Integer(), true, false);
break;
case Instruction::IGET_WIDE:
case Instruction::IGET_WIDE_QUICK:
VerifyISFieldAccess<FieldAccessType::kAccGet>(inst, reg_types_.LongLo(), true, false);
break;
case Instruction::IGET_OBJECT:
case Instruction::IGET_OBJECT_QUICK:
VerifyISFieldAccess<FieldAccessType::kAccGet>(inst, reg_types_.JavaLangObject(false), false,
false);
break;
case Instruction::IPUT_BOOLEAN:
case Instruction::IPUT_BOOLEAN_QUICK:
VerifyISFieldAccess<FieldAccessType::kAccPut>(inst, reg_types_.Boolean(), true, false);
break;
case Instruction::IPUT_BYTE:
case Instruction::IPUT_BYTE_QUICK:
VerifyISFieldAccess<FieldAccessType::kAccPut>(inst, reg_types_.Byte(), true, false);
break;
case Instruction::IPUT_CHAR:
case Instruction::IPUT_CHAR_QUICK:
VerifyISFieldAccess<FieldAccessType::kAccPut>(inst, reg_types_.Char(), true, false);
break;
case Instruction::IPUT_SHORT:
case Instruction::IPUT_SHORT_QUICK:
VerifyISFieldAccess<FieldAccessType::kAccPut>(inst, reg_types_.Short(), true, false);
break;
case Instruction::IPUT:
case Instruction::IPUT_QUICK:
VerifyISFieldAccess<FieldAccessType::kAccPut>(inst, reg_types_.Integer(), true, false);
break;
case Instruction::IPUT_WIDE:
case Instruction::IPUT_WIDE_QUICK:
VerifyISFieldAccess<FieldAccessType::kAccPut>(inst, reg_types_.LongLo(), true, false);
break;
case Instruction::IPUT_OBJECT:
case Instruction::IPUT_OBJECT_QUICK:
VerifyISFieldAccess<FieldAccessType::kAccPut>(inst, reg_types_.JavaLangObject(false), false,
false);
break;
case Instruction::SGET_BOOLEAN:
VerifyISFieldAccess<FieldAccessType::kAccGet>(inst, reg_types_.Boolean(), true, true);
break;
case Instruction::SGET_BYTE:
VerifyISFieldAccess<FieldAccessType::kAccGet>(inst, reg_types_.Byte(), true, true);
break;
case Instruction::SGET_CHAR:
VerifyISFieldAccess<FieldAccessType::kAccGet>(inst, reg_types_.Char(), true, true);
break;
case Instruction::SGET_SHORT:
VerifyISFieldAccess<FieldAccessType::kAccGet>(inst, reg_types_.Short(), true, true);
break;
case Instruction::SGET:
VerifyISFieldAccess<FieldAccessType::kAccGet>(inst, reg_types_.Integer(), true, true);
break;
case Instruction::SGET_WIDE:
VerifyISFieldAccess<FieldAccessType::kAccGet>(inst, reg_types_.LongLo(), true, true);
break;
case Instruction::SGET_OBJECT:
VerifyISFieldAccess<FieldAccessType::kAccGet>(inst, reg_types_.JavaLangObject(false), false,
true);
break;
case Instruction::SPUT_BOOLEAN:
VerifyISFieldAccess<FieldAccessType::kAccPut>(inst, reg_types_.Boolean(), true, true);
break;
case Instruction::SPUT_BYTE:
VerifyISFieldAccess<FieldAccessType::kAccPut>(inst, reg_types_.Byte(), true, true);
break;
case Instruction::SPUT_CHAR:
VerifyISFieldAccess<FieldAccessType::kAccPut>(inst, reg_types_.Char(), true, true);
break;
case Instruction::SPUT_SHORT:
VerifyISFieldAccess<FieldAccessType::kAccPut>(inst, reg_types_.Short(), true, true);
break;
case Instruction::SPUT:
VerifyISFieldAccess<FieldAccessType::kAccPut>(inst, reg_types_.Integer(), true, true);
break;
case Instruction::SPUT_WIDE:
VerifyISFieldAccess<FieldAccessType::kAccPut>(inst, reg_types_.LongLo(), true, true);
break;
case Instruction::SPUT_OBJECT:
VerifyISFieldAccess<FieldAccessType::kAccPut>(inst, reg_types_.JavaLangObject(false), false,
true);
break;
case Instruction::INVOKE_VIRTUAL:
case Instruction::INVOKE_VIRTUAL_RANGE:
case Instruction::INVOKE_SUPER:
case Instruction::INVOKE_SUPER_RANGE:
case Instruction::INVOKE_VIRTUAL_QUICK:
case Instruction::INVOKE_VIRTUAL_RANGE_QUICK: {
bool is_range = (inst->Opcode() == Instruction::INVOKE_VIRTUAL_RANGE ||
inst->Opcode() == Instruction::INVOKE_SUPER_RANGE ||
inst->Opcode() == Instruction::INVOKE_VIRTUAL_RANGE_QUICK);
bool is_super = (inst->Opcode() == Instruction::INVOKE_SUPER ||
inst->Opcode() == Instruction::INVOKE_SUPER_RANGE);
MethodType type = is_super ? METHOD_SUPER : METHOD_VIRTUAL;
ArtMethod* called_method = VerifyInvocationArgs(inst, type, is_range);
const RegType* return_type = nullptr;
if (called_method != nullptr) {
ObjPtr<mirror::Class> return_type_class = can_load_classes_
? called_method->ResolveReturnType()
: called_method->LookupResolvedReturnType();
if (return_type_class != nullptr) {
return_type = &FromClass(called_method->GetReturnTypeDescriptor(),
return_type_class.Ptr(),
return_type_class->CannotBeAssignedFromOtherTypes());
} else {
DCHECK(!can_load_classes_ || self_->IsExceptionPending());
self_->ClearException();
}
}
if (return_type == nullptr) {
uint32_t method_idx = GetMethodIdxOfInvoke(inst);
const DexFile::MethodId& method_id = dex_file_->GetMethodId(method_idx);
dex::TypeIndex return_type_idx =
dex_file_->GetProtoId(method_id.proto_idx_).return_type_idx_;
const char* descriptor = dex_file_->StringByTypeIdx(return_type_idx);
return_type = &reg_types_.FromDescriptor(GetClassLoader(), descriptor, false);
}
if (!return_type->IsLowHalf()) {
work_line_->SetResultRegisterType(this, *return_type);
} else {
work_line_->SetResultRegisterTypeWide(*return_type, return_type->HighHalf(&reg_types_));
}
just_set_result = true;
break;
}
case Instruction::INVOKE_DIRECT:
case Instruction::INVOKE_DIRECT_RANGE: {
bool is_range = (inst->Opcode() == Instruction::INVOKE_DIRECT_RANGE);
ArtMethod* called_method = VerifyInvocationArgs(inst, METHOD_DIRECT, is_range);
const char* return_type_descriptor;
bool is_constructor;
const RegType* return_type = nullptr;
if (called_method == nullptr) {
uint32_t method_idx = (is_range) ? inst->VRegB_3rc() : inst->VRegB_35c();
const DexFile::MethodId& method_id = dex_file_->GetMethodId(method_idx);
is_constructor = strcmp("<init>", dex_file_->StringDataByIdx(method_id.name_idx_)) == 0;
dex::TypeIndex return_type_idx =
dex_file_->GetProtoId(method_id.proto_idx_).return_type_idx_;
return_type_descriptor = dex_file_->StringByTypeIdx(return_type_idx);
} else {
is_constructor = called_method->IsConstructor();
return_type_descriptor = called_method->GetReturnTypeDescriptor();
ObjPtr<mirror::Class> return_type_class = can_load_classes_
? called_method->ResolveReturnType()
: called_method->LookupResolvedReturnType();
if (return_type_class != nullptr) {
return_type = &FromClass(return_type_descriptor,
return_type_class,
return_type_class->CannotBeAssignedFromOtherTypes());
} else {
DCHECK(!can_load_classes_ || self_->IsExceptionPending());
self_->ClearException();
}
}
if (is_constructor) {
/*
* Some additional checks when calling a constructor. We know from the invocation arg check
* that the "this" argument is an instance of called_method->klass. Now we further restrict
* that to require that called_method->klass is the same as this->klass or this->super,
* allowing the latter only if the "this" argument is the same as the "this" argument to
* this method (which implies that we're in a constructor ourselves).
*/
const RegType& this_type = work_line_->GetInvocationThis(this, inst);
if (this_type.IsConflict()) // failure.
break;
/* no null refs allowed (?) */
if (this_type.IsZeroOrNull()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "unable to initialize null ref";
break;
}
/* must be in same class or in superclass */
// const RegType& this_super_klass = this_type.GetSuperClass(&reg_types_);
// TODO: re-enable constructor type verification
// if (this_super_klass.IsConflict()) {
// Unknown super class, fail so we re-check at runtime.
// Fail(VERIFY_ERROR_BAD_CLASS_SOFT) << "super class unknown for '" << this_type << "'";
// break;
// }
/* arg must be an uninitialized reference */
if (!this_type.IsUninitializedTypes()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Expected initialization on uninitialized reference "
<< this_type;
break;
}
/*
* Replace the uninitialized reference with an initialized one. We need to do this for all
* registers that have the same object instance in them, not just the "this" register.
*/
work_line_->MarkRefsAsInitialized(this, this_type);
}
if (return_type == nullptr) {
return_type = &reg_types_.FromDescriptor(GetClassLoader(), return_type_descriptor, false);
}
if (!return_type->IsLowHalf()) {
work_line_->SetResultRegisterType(this, *return_type);
} else {
work_line_->SetResultRegisterTypeWide(*return_type, return_type->HighHalf(&reg_types_));
}
just_set_result = true;
break;
}
case Instruction::INVOKE_STATIC:
case Instruction::INVOKE_STATIC_RANGE: {
bool is_range = (inst->Opcode() == Instruction::INVOKE_STATIC_RANGE);
ArtMethod* called_method = VerifyInvocationArgs(inst, METHOD_STATIC, is_range);
const char* descriptor;
if (called_method == nullptr) {
uint32_t method_idx = (is_range) ? inst->VRegB_3rc() : inst->VRegB_35c();
const DexFile::MethodId& method_id = dex_file_->GetMethodId(method_idx);
dex::TypeIndex return_type_idx =
dex_file_->GetProtoId(method_id.proto_idx_).return_type_idx_;
descriptor = dex_file_->StringByTypeIdx(return_type_idx);
} else {
descriptor = called_method->GetReturnTypeDescriptor();
}
const RegType& return_type = reg_types_.FromDescriptor(GetClassLoader(), descriptor, false);
if (!return_type.IsLowHalf()) {
work_line_->SetResultRegisterType(this, return_type);
} else {
work_line_->SetResultRegisterTypeWide(return_type, return_type.HighHalf(&reg_types_));
}
just_set_result = true;
}
break;
case Instruction::INVOKE_INTERFACE:
case Instruction::INVOKE_INTERFACE_RANGE: {
bool is_range = (inst->Opcode() == Instruction::INVOKE_INTERFACE_RANGE);
ArtMethod* abs_method = VerifyInvocationArgs(inst, METHOD_INTERFACE, is_range);
if (abs_method != nullptr) {
ObjPtr<mirror::Class> called_interface = abs_method->GetDeclaringClass();
if (!called_interface->IsInterface() && !called_interface->IsObjectClass()) {
Fail(VERIFY_ERROR_CLASS_CHANGE) << "expected interface class in invoke-interface '"
<< abs_method->PrettyMethod() << "'";
break;
}
}
/* Get the type of the "this" arg, which should either be a sub-interface of called
* interface or Object (see comments in RegType::JoinClass).
*/
const RegType& this_type = work_line_->GetInvocationThis(this, inst);
if (this_type.IsZeroOrNull()) {
/* null pointer always passes (and always fails at runtime) */
} else {
if (this_type.IsUninitializedTypes()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "interface call on uninitialized object "
<< this_type;
break;
}
// In the past we have tried to assert that "called_interface" is assignable
// from "this_type.GetClass()", however, as we do an imprecise Join
// (RegType::JoinClass) we don't have full information on what interfaces are
// implemented by "this_type". For example, two classes may implement the same
// interfaces and have a common parent that doesn't implement the interface. The
// join will set "this_type" to the parent class and a test that this implements
// the interface will incorrectly fail.
}
/*
* We don't have an object instance, so we can't find the concrete method. However, all of
* the type information is in the abstract method, so we're good.
*/
const char* descriptor;
if (abs_method == nullptr) {
uint32_t method_idx = (is_range) ? inst->VRegB_3rc() : inst->VRegB_35c();
const DexFile::MethodId& method_id = dex_file_->GetMethodId(method_idx);
dex::TypeIndex return_type_idx =
dex_file_->GetProtoId(method_id.proto_idx_).return_type_idx_;
descriptor = dex_file_->StringByTypeIdx(return_type_idx);
} else {
descriptor = abs_method->GetReturnTypeDescriptor();
}
const RegType& return_type = reg_types_.FromDescriptor(GetClassLoader(), descriptor, false);
if (!return_type.IsLowHalf()) {
work_line_->SetResultRegisterType(this, return_type);
} else {
work_line_->SetResultRegisterTypeWide(return_type, return_type.HighHalf(&reg_types_));
}
just_set_result = true;
break;
}
case Instruction::INVOKE_POLYMORPHIC:
case Instruction::INVOKE_POLYMORPHIC_RANGE: {
bool is_range = (inst->Opcode() == Instruction::INVOKE_POLYMORPHIC_RANGE);
ArtMethod* called_method = VerifyInvocationArgs(inst, METHOD_POLYMORPHIC, is_range);
if (called_method == nullptr) {
// Convert potential soft failures in VerifyInvocationArgs() to hard errors.
if (failure_messages_.size() > 0) {
std::string message = failure_messages_.back()->str();
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << message;
} else {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invoke-polymorphic verification failure.";
}
break;
}
if (!CheckSignaturePolymorphicMethod(called_method) ||
!CheckSignaturePolymorphicReceiver(inst)) {
DCHECK(HasFailures());
break;
}
const uint16_t vRegH = (is_range) ? inst->VRegH_4rcc() : inst->VRegH_45cc();
const dex::ProtoIndex proto_idx(vRegH);
const char* return_descriptor =
dex_file_->GetReturnTypeDescriptor(dex_file_->GetProtoId(proto_idx));
const RegType& return_type =
reg_types_.FromDescriptor(GetClassLoader(), return_descriptor, false);
if (!return_type.IsLowHalf()) {
work_line_->SetResultRegisterType(this, return_type);
} else {
work_line_->SetResultRegisterTypeWide(return_type, return_type.HighHalf(&reg_types_));
}
just_set_result = true;
break;
}
case Instruction::INVOKE_CUSTOM:
case Instruction::INVOKE_CUSTOM_RANGE: {
// Verify registers based on method_type in the call site.
bool is_range = (inst->Opcode() == Instruction::INVOKE_CUSTOM_RANGE);
// Step 1. Check the call site that produces the method handle for invocation
const uint32_t call_site_idx = is_range ? inst->VRegB_3rc() : inst->VRegB_35c();
if (!CheckCallSite(call_site_idx)) {
DCHECK(HasFailures());
break;
}
// Step 2. Check the register arguments correspond to the expected arguments for the
// method handle produced by step 1. The dex file verifier has checked ranges for
// the first three arguments and CheckCallSite has checked the method handle type.
const dex::ProtoIndex proto_idx = dex_file_->GetProtoIndexForCallSite(call_site_idx);
const DexFile::ProtoId& proto_id = dex_file_->GetProtoId(proto_idx);
DexFileParameterIterator param_it(*dex_file_, proto_id);
// Treat method as static as it has yet to be determined.
VerifyInvocationArgsFromIterator(&param_it, inst, METHOD_STATIC, is_range, nullptr);
const char* return_descriptor = dex_file_->GetReturnTypeDescriptor(proto_id);
// Step 3. Propagate return type information
const RegType& return_type =
reg_types_.FromDescriptor(GetClassLoader(), return_descriptor, false);
if (!return_type.IsLowHalf()) {
work_line_->SetResultRegisterType(this, return_type);
} else {
work_line_->SetResultRegisterTypeWide(return_type, return_type.HighHalf(&reg_types_));
}
just_set_result = true;
break;
}
case Instruction::NEG_INT:
case Instruction::NOT_INT:
work_line_->CheckUnaryOp(this, inst, reg_types_.Integer(), reg_types_.Integer());
break;
case Instruction::NEG_LONG:
case Instruction::NOT_LONG:
work_line_->CheckUnaryOpWide(this, inst, reg_types_.LongLo(), reg_types_.LongHi(),
reg_types_.LongLo(), reg_types_.LongHi());
break;
case Instruction::NEG_FLOAT:
work_line_->CheckUnaryOp(this, inst, reg_types_.Float(), reg_types_.Float());
break;
case Instruction::NEG_DOUBLE:
work_line_->CheckUnaryOpWide(this, inst, reg_types_.DoubleLo(), reg_types_.DoubleHi(),
reg_types_.DoubleLo(), reg_types_.DoubleHi());
break;
case Instruction::INT_TO_LONG:
work_line_->CheckUnaryOpToWide(this, inst, reg_types_.LongLo(), reg_types_.LongHi(),
reg_types_.Integer());
break;
case Instruction::INT_TO_FLOAT:
work_line_->CheckUnaryOp(this, inst, reg_types_.Float(), reg_types_.Integer());
break;
case Instruction::INT_TO_DOUBLE:
work_line_->CheckUnaryOpToWide(this, inst, reg_types_.DoubleLo(), reg_types_.DoubleHi(),
reg_types_.Integer());
break;
case Instruction::LONG_TO_INT:
work_line_->CheckUnaryOpFromWide(this, inst, reg_types_.Integer(),
reg_types_.LongLo(), reg_types_.LongHi());
break;
case Instruction::LONG_TO_FLOAT:
work_line_->CheckUnaryOpFromWide(this, inst, reg_types_.Float(),
reg_types_.LongLo(), reg_types_.LongHi());
break;
case Instruction::LONG_TO_DOUBLE:
work_line_->CheckUnaryOpWide(this, inst, reg_types_.DoubleLo(), reg_types_.DoubleHi(),
reg_types_.LongLo(), reg_types_.LongHi());
break;
case Instruction::FLOAT_TO_INT:
work_line_->CheckUnaryOp(this, inst, reg_types_.Integer(), reg_types_.Float());
break;
case Instruction::FLOAT_TO_LONG:
work_line_->CheckUnaryOpToWide(this, inst, reg_types_.LongLo(), reg_types_.LongHi(),
reg_types_.Float());
break;
case Instruction::FLOAT_TO_DOUBLE:
work_line_->CheckUnaryOpToWide(this, inst, reg_types_.DoubleLo(), reg_types_.DoubleHi(),
reg_types_.Float());
break;
case Instruction::DOUBLE_TO_INT:
work_line_->CheckUnaryOpFromWide(this, inst, reg_types_.Integer(),
reg_types_.DoubleLo(), reg_types_.DoubleHi());
break;
case Instruction::DOUBLE_TO_LONG:
work_line_->CheckUnaryOpWide(this, inst, reg_types_.LongLo(), reg_types_.LongHi(),
reg_types_.DoubleLo(), reg_types_.DoubleHi());
break;
case Instruction::DOUBLE_TO_FLOAT:
work_line_->CheckUnaryOpFromWide(this, inst, reg_types_.Float(),
reg_types_.DoubleLo(), reg_types_.DoubleHi());
break;
case Instruction::INT_TO_BYTE:
work_line_->CheckUnaryOp(this, inst, reg_types_.Byte(), reg_types_.Integer());
break;
case Instruction::INT_TO_CHAR:
work_line_->CheckUnaryOp(this, inst, reg_types_.Char(), reg_types_.Integer());
break;
case Instruction::INT_TO_SHORT:
work_line_->CheckUnaryOp(this, inst, reg_types_.Short(), reg_types_.Integer());
break;
case Instruction::ADD_INT:
case Instruction::SUB_INT:
case Instruction::MUL_INT:
case Instruction::REM_INT:
case Instruction::DIV_INT:
case Instruction::SHL_INT:
case Instruction::SHR_INT:
case Instruction::USHR_INT:
work_line_->CheckBinaryOp(this, inst, reg_types_.Integer(), reg_types_.Integer(),
reg_types_.Integer(), false);
break;
case Instruction::AND_INT:
case Instruction::OR_INT:
case Instruction::XOR_INT:
work_line_->CheckBinaryOp(this, inst, reg_types_.Integer(), reg_types_.Integer(),
reg_types_.Integer(), true);
break;
case Instruction::ADD_LONG:
case Instruction::SUB_LONG:
case Instruction::MUL_LONG:
case Instruction::DIV_LONG:
case Instruction::REM_LONG:
case Instruction::AND_LONG:
case Instruction::OR_LONG:
case Instruction::XOR_LONG:
work_line_->CheckBinaryOpWide(this, inst, reg_types_.LongLo(), reg_types_.LongHi(),
reg_types_.LongLo(), reg_types_.LongHi(),
reg_types_.LongLo(), reg_types_.LongHi());
break;
case Instruction::SHL_LONG:
case Instruction::SHR_LONG:
case Instruction::USHR_LONG:
/* shift distance is Int, making these different from other binary operations */
work_line_->CheckBinaryOpWideShift(this, inst, reg_types_.LongLo(), reg_types_.LongHi(),
reg_types_.Integer());
break;
case Instruction::ADD_FLOAT:
case Instruction::SUB_FLOAT:
case Instruction::MUL_FLOAT:
case Instruction::DIV_FLOAT:
case Instruction::REM_FLOAT:
work_line_->CheckBinaryOp(this, inst, reg_types_.Float(), reg_types_.Float(),
reg_types_.Float(), false);
break;
case Instruction::ADD_DOUBLE:
case Instruction::SUB_DOUBLE:
case Instruction::MUL_DOUBLE:
case Instruction::DIV_DOUBLE:
case Instruction::REM_DOUBLE:
work_line_->CheckBinaryOpWide(this, inst, reg_types_.DoubleLo(), reg_types_.DoubleHi(),
reg_types_.DoubleLo(), reg_types_.DoubleHi(),
reg_types_.DoubleLo(), reg_types_.DoubleHi());
break;
case Instruction::ADD_INT_2ADDR:
case Instruction::SUB_INT_2ADDR:
case Instruction::MUL_INT_2ADDR:
case Instruction::REM_INT_2ADDR:
case Instruction::SHL_INT_2ADDR:
case Instruction::SHR_INT_2ADDR:
case Instruction::USHR_INT_2ADDR:
work_line_->CheckBinaryOp2addr(this, inst, reg_types_.Integer(), reg_types_.Integer(),
reg_types_.Integer(), false);
break;
case Instruction::AND_INT_2ADDR:
case Instruction::OR_INT_2ADDR:
case Instruction::XOR_INT_2ADDR:
work_line_->CheckBinaryOp2addr(this, inst, reg_types_.Integer(), reg_types_.Integer(),
reg_types_.Integer(), true);
break;
case Instruction::DIV_INT_2ADDR:
work_line_->CheckBinaryOp2addr(this, inst, reg_types_.Integer(), reg_types_.Integer(),
reg_types_.Integer(), false);
break;
case Instruction::ADD_LONG_2ADDR:
case Instruction::SUB_LONG_2ADDR:
case Instruction::MUL_LONG_2ADDR:
case Instruction::DIV_LONG_2ADDR:
case Instruction::REM_LONG_2ADDR:
case Instruction::AND_LONG_2ADDR:
case Instruction::OR_LONG_2ADDR:
case Instruction::XOR_LONG_2ADDR:
work_line_->CheckBinaryOp2addrWide(this, inst, reg_types_.LongLo(), reg_types_.LongHi(),
reg_types_.LongLo(), reg_types_.LongHi(),
reg_types_.LongLo(), reg_types_.LongHi());
break;
case Instruction::SHL_LONG_2ADDR:
case Instruction::SHR_LONG_2ADDR:
case Instruction::USHR_LONG_2ADDR:
work_line_->CheckBinaryOp2addrWideShift(this, inst, reg_types_.LongLo(), reg_types_.LongHi(),
reg_types_.Integer());
break;
case Instruction::ADD_FLOAT_2ADDR:
case Instruction::SUB_FLOAT_2ADDR:
case Instruction::MUL_FLOAT_2ADDR:
case Instruction::DIV_FLOAT_2ADDR:
case Instruction::REM_FLOAT_2ADDR:
work_line_->CheckBinaryOp2addr(this, inst, reg_types_.Float(), reg_types_.Float(),
reg_types_.Float(), false);
break;
case Instruction::ADD_DOUBLE_2ADDR:
case Instruction::SUB_DOUBLE_2ADDR:
case Instruction::MUL_DOUBLE_2ADDR:
case Instruction::DIV_DOUBLE_2ADDR:
case Instruction::REM_DOUBLE_2ADDR:
work_line_->CheckBinaryOp2addrWide(this, inst, reg_types_.DoubleLo(), reg_types_.DoubleHi(),
reg_types_.DoubleLo(), reg_types_.DoubleHi(),
reg_types_.DoubleLo(), reg_types_.DoubleHi());
break;
case Instruction::ADD_INT_LIT16:
case Instruction::RSUB_INT_LIT16:
case Instruction::MUL_INT_LIT16:
case Instruction::DIV_INT_LIT16:
case Instruction::REM_INT_LIT16:
work_line_->CheckLiteralOp(this, inst, reg_types_.Integer(), reg_types_.Integer(), false,
true);
break;
case Instruction::AND_INT_LIT16:
case Instruction::OR_INT_LIT16:
case Instruction::XOR_INT_LIT16:
work_line_->CheckLiteralOp(this, inst, reg_types_.Integer(), reg_types_.Integer(), true,
true);
break;
case Instruction::ADD_INT_LIT8:
case Instruction::RSUB_INT_LIT8:
case Instruction::MUL_INT_LIT8:
case Instruction::DIV_INT_LIT8:
case Instruction::REM_INT_LIT8:
case Instruction::SHL_INT_LIT8:
case Instruction::SHR_INT_LIT8:
case Instruction::USHR_INT_LIT8:
work_line_->CheckLiteralOp(this, inst, reg_types_.Integer(), reg_types_.Integer(), false,
false);
break;
case Instruction::AND_INT_LIT8:
case Instruction::OR_INT_LIT8:
case Instruction::XOR_INT_LIT8:
work_line_->CheckLiteralOp(this, inst, reg_types_.Integer(), reg_types_.Integer(), true,
false);
break;
// Special instructions.
case Instruction::RETURN_VOID_NO_BARRIER:
if (IsConstructor() && !IsStatic()) {
const RegType& declaring_class = GetDeclaringClass();
if (declaring_class.IsUnresolvedReference()) {
// We must iterate over the fields, even if we cannot use mirror classes to do so. Do it
// manually over the underlying dex file.
uint32_t first_index = GetFirstFinalInstanceFieldIndex(*dex_file_,
dex_file_->GetMethodId(dex_method_idx_).class_idx_);
if (first_index != dex::kDexNoIndex) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "return-void-no-barrier not expected for field "
<< first_index;
}
break;
}
ObjPtr<mirror::Class> klass = declaring_class.GetClass();
for (uint32_t i = 0, num_fields = klass->NumInstanceFields(); i < num_fields; ++i) {
if (klass->GetInstanceField(i)->IsFinal()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "return-void-no-barrier not expected for "
<< klass->GetInstanceField(i)->PrettyField();
break;
}
}
}
// Handle this like a RETURN_VOID now. Code is duplicated to separate standard from
// quickened opcodes (otherwise this could be a fall-through).
if (!IsConstructor()) {
if (!GetMethodReturnType().IsConflict()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "return-void not expected";
}
}
break;
/* These should never appear during verification. */
case Instruction::UNUSED_3E ... Instruction::UNUSED_43:
case Instruction::UNUSED_F3 ... Instruction::UNUSED_F9:
case Instruction::UNUSED_79:
case Instruction::UNUSED_7A:
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Unexpected opcode " << inst->DumpString(dex_file_);
break;
/*
* DO NOT add a "default" clause here. Without it the compiler will
* complain if an instruction is missing (which is desirable).
*/
} // end - switch (dec_insn.opcode)
if (have_pending_hard_failure_) {
if (Runtime::Current()->IsAotCompiler()) {
/* When AOT compiling, check that the last failure is a hard failure */
if (failures_[failures_.size() - 1] != VERIFY_ERROR_BAD_CLASS_HARD) {
LOG(ERROR) << "Pending failures:";
for (auto& error : failures_) {
LOG(ERROR) << error;
}
for (auto& error_msg : failure_messages_) {
LOG(ERROR) << error_msg->str();
}
LOG(FATAL) << "Pending hard failure, but last failure not hard.";
}
}
/* immediate failure, reject class */
info_messages_ << "Rejecting opcode " << inst->DumpString(dex_file_);
return false;
} else if (have_pending_runtime_throw_failure_) {
/* checking interpreter will throw, mark following code as unreachable */
opcode_flags = Instruction::kThrow;
// Note: the flag must be reset as it is only global to decouple Fail and is semantically per
// instruction. However, RETURN checking may throw LOCKING errors, so we clear at the
// very end.
}
/*
* If we didn't just set the result register, clear it out. This ensures that you can only use
* "move-result" immediately after the result is set. (We could check this statically, but it's
* not expensive and it makes our debugging output cleaner.)
*/
if (!just_set_result) {
work_line_->SetResultTypeToUnknown(this);
}
/*
* Handle "branch". Tag the branch target.
*
* NOTE: instructions like Instruction::EQZ provide information about the
* state of the register when the branch is taken or not taken. For example,
* somebody could get a reference field, check it for zero, and if the
* branch is taken immediately store that register in a boolean field
* since the value is known to be zero. We do not currently account for
* that, and will reject the code.
*
* TODO: avoid re-fetching the branch target
*/
if ((opcode_flags & Instruction::kBranch) != 0) {
bool isConditional, selfOkay;
if (!GetBranchOffset(work_insn_idx_, &branch_target, &isConditional, &selfOkay)) {
/* should never happen after static verification */
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "bad branch";
return false;
}
DCHECK_EQ(isConditional, (opcode_flags & Instruction::kContinue) != 0);
if (!CheckNotMoveExceptionOrMoveResult(code_item_accessor_.Insns(),
work_insn_idx_ + branch_target)) {
return false;
}
/* update branch target, set "changed" if appropriate */
if (nullptr != branch_line) {
if (!UpdateRegisters(work_insn_idx_ + branch_target, branch_line.get(), false)) {
return false;
}
} else {
if (!UpdateRegisters(work_insn_idx_ + branch_target, work_line_.get(), false)) {
return false;
}
}
}
/*
* Handle "switch". Tag all possible branch targets.
*
* We've already verified that the table is structurally sound, so we
* just need to walk through and tag the targets.
*/
if ((opcode_flags & Instruction::kSwitch) != 0) {
int offset_to_switch = insns[1] | (static_cast<int32_t>(insns[2]) << 16);
const uint16_t* switch_insns = insns + offset_to_switch;
int switch_count = switch_insns[1];
int offset_to_targets, targ;
if ((*insns & 0xff) == Instruction::PACKED_SWITCH) {
/* 0 = sig, 1 = count, 2/3 = first key */
offset_to_targets = 4;
} else {
/* 0 = sig, 1 = count, 2..count * 2 = keys */
DCHECK((*insns & 0xff) == Instruction::SPARSE_SWITCH);
offset_to_targets = 2 + 2 * switch_count;
}
/* verify each switch target */
for (targ = 0; targ < switch_count; targ++) {
int offset;
uint32_t abs_offset;
/* offsets are 32-bit, and only partly endian-swapped */
offset = switch_insns[offset_to_targets + targ * 2] |
(static_cast<int32_t>(switch_insns[offset_to_targets + targ * 2 + 1]) << 16);
abs_offset = work_insn_idx_ + offset;
DCHECK_LT(abs_offset, code_item_accessor_.InsnsSizeInCodeUnits());
if (!CheckNotMoveExceptionOrMoveResult(code_item_accessor_.Insns(), abs_offset)) {
return false;
}
if (!UpdateRegisters(abs_offset, work_line_.get(), false)) {
return false;
}
}
}
/*
* Handle instructions that can throw and that are sitting in a "try" block. (If they're not in a
* "try" block when they throw, control transfers out of the method.)
*/
if ((opcode_flags & Instruction::kThrow) != 0 && GetInstructionFlags(work_insn_idx_).IsInTry()) {
bool has_catch_all_handler = false;
const DexFile::TryItem* try_item = code_item_accessor_.FindTryItem(work_insn_idx_);
CHECK(try_item != nullptr);
CatchHandlerIterator iterator(code_item_accessor_, *try_item);
// Need the linker to try and resolve the handled class to check if it's Throwable.
ClassLinker* linker = Runtime::Current()->GetClassLinker();
for (; iterator.HasNext(); iterator.Next()) {
dex::TypeIndex handler_type_idx = iterator.GetHandlerTypeIndex();
if (!handler_type_idx.IsValid()) {
has_catch_all_handler = true;
} else {
// It is also a catch-all if it is java.lang.Throwable.
ObjPtr<mirror::Class> klass =
linker->ResolveType(handler_type_idx, dex_cache_, class_loader_);
if (klass != nullptr) {
if (klass == GetClassRoot<mirror::Throwable>()) {
has_catch_all_handler = true;
}
} else {
// Clear exception.
DCHECK(self_->IsExceptionPending());
self_->ClearException();
}
}
/*
* Merge registers into the "catch" block. We want to use the "savedRegs" rather than
* "work_regs", because at runtime the exception will be thrown before the instruction
* modifies any registers.
*/
if (!UpdateRegisters(iterator.GetHandlerAddress(), saved_line_.get(), false)) {
return false;
}
}
/*
* If the monitor stack depth is nonzero, there must be a "catch all" handler for this
* instruction. This does apply to monitor-exit because of async exception handling.
*/
if (work_line_->MonitorStackDepth() > 0 && !has_catch_all_handler) {
/*
* The state in work_line reflects the post-execution state. If the current instruction is a
* monitor-enter and the monitor stack was empty, we don't need a catch-all (if it throws,
* it will do so before grabbing the lock).
*/
if (inst->Opcode() != Instruction::MONITOR_ENTER || work_line_->MonitorStackDepth() != 1) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD)
<< "expected to be within a catch-all for an instruction where a monitor is held";
return false;
}
}
}
/* Handle "continue". Tag the next consecutive instruction.
* Note: Keep the code handling "continue" case below the "branch" and "switch" cases,
* because it changes work_line_ when performing peephole optimization
* and this change should not be used in those cases.
*/
if ((opcode_flags & Instruction::kContinue) != 0) {
DCHECK_EQ(&code_item_accessor_.InstructionAt(work_insn_idx_), inst);
uint32_t next_insn_idx = work_insn_idx_ + inst->SizeInCodeUnits();
if (next_insn_idx >= code_item_accessor_.InsnsSizeInCodeUnits()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Execution can walk off end of code area";
return false;
}
// The only way to get to a move-exception instruction is to get thrown there. Make sure the
// next instruction isn't one.
if (!CheckNotMoveException(code_item_accessor_.Insns(), next_insn_idx)) {
return false;
}
if (nullptr != fallthrough_line) {
// Make workline consistent with fallthrough computed from peephole optimization.
work_line_->CopyFromLine(fallthrough_line.get());
}
if (GetInstructionFlags(next_insn_idx).IsReturn()) {
// For returns we only care about the operand to the return, all other registers are dead.
const Instruction* ret_inst = &code_item_accessor_.InstructionAt(next_insn_idx);
AdjustReturnLine(this, ret_inst, work_line_.get());
}
RegisterLine* next_line = reg_table_.GetLine(next_insn_idx);
if (next_line != nullptr) {
// Merge registers into what we have for the next instruction, and set the "changed" flag if
// needed. If the merge changes the state of the registers then the work line will be
// updated.
if (!UpdateRegisters(next_insn_idx, work_line_.get(), true)) {
return false;
}
} else {
/*
* We're not recording register data for the next instruction, so we don't know what the
* prior state was. We have to assume that something has changed and re-evaluate it.
*/
GetInstructionFlags(next_insn_idx).SetChanged();
}
}
/* If we're returning from the method, make sure monitor stack is empty. */
if ((opcode_flags & Instruction::kReturn) != 0) {
work_line_->VerifyMonitorStackEmpty(this);
}
/*
* Update start_guess. Advance to the next instruction of that's
* possible, otherwise use the branch target if one was found. If
* neither of those exists we're in a return or throw; leave start_guess
* alone and let the caller sort it out.
*/
if ((opcode_flags & Instruction::kContinue) != 0) {
DCHECK_EQ(&code_item_accessor_.InstructionAt(work_insn_idx_), inst);
*start_guess = work_insn_idx_ + inst->SizeInCodeUnits();
} else if ((opcode_flags & Instruction::kBranch) != 0) {
/* we're still okay if branch_target is zero */
*start_guess = work_insn_idx_ + branch_target;
}
DCHECK_LT(*start_guess, code_item_accessor_.InsnsSizeInCodeUnits());
DCHECK(GetInstructionFlags(*start_guess).IsOpcode());
if (have_pending_runtime_throw_failure_) {
have_any_pending_runtime_throw_failure_ = true;
// Reset the pending_runtime_throw flag now.
have_pending_runtime_throw_failure_ = false;
}
return true;
} // NOLINT(readability/fn_size)
void MethodVerifier::UninstantiableError(const char* descriptor) {
Fail(VerifyError::VERIFY_ERROR_NO_CLASS) << "Could not create precise reference for "
<< "non-instantiable klass " << descriptor;
}
inline bool MethodVerifier::IsInstantiableOrPrimitive(ObjPtr<mirror::Class> klass) {
return klass->IsInstantiable() || klass->IsPrimitive();
}
template <MethodVerifier::CheckAccess C>
const RegType& MethodVerifier::ResolveClass(dex::TypeIndex class_idx) {
ClassLinker* linker = Runtime::Current()->GetClassLinker();
ObjPtr<mirror::Class> klass = can_load_classes_
? linker->ResolveType(class_idx, dex_cache_, class_loader_)
: linker->LookupResolvedType(class_idx, dex_cache_.Get(), class_loader_.Get());
if (can_load_classes_ && klass == nullptr) {
DCHECK(self_->IsExceptionPending());
self_->ClearException();
}
const RegType* result = nullptr;
if (klass != nullptr) {
bool precise = klass->CannotBeAssignedFromOtherTypes();
if (precise && !IsInstantiableOrPrimitive(klass)) {
const char* descriptor = dex_file_->StringByTypeIdx(class_idx);
UninstantiableError(descriptor);
precise = false;
}
result = reg_types_.FindClass(klass, precise);
if (result == nullptr) {
const char* descriptor = dex_file_->StringByTypeIdx(class_idx);
result = reg_types_.InsertClass(descriptor, klass, precise);
}
} else {
const char* descriptor = dex_file_->StringByTypeIdx(class_idx);
result = &reg_types_.FromDescriptor(GetClassLoader(), descriptor, false);
}
DCHECK(result != nullptr);
if (result->IsConflict()) {
const char* descriptor = dex_file_->StringByTypeIdx(class_idx);
Fail(VERIFY_ERROR_BAD_CLASS_SOFT) << "accessing broken descriptor '" << descriptor
<< "' in " << GetDeclaringClass();
return *result;
}
// Record result of class resolution attempt.
VerifierDeps::MaybeRecordClassResolution(*dex_file_, class_idx, klass);
// If requested, check if access is allowed. Unresolved types are included in this check, as the
// interpreter only tests whether access is allowed when a class is not pre-verified and runs in
// the access-checks interpreter. If result is primitive, skip the access check.
//
// Note: we do this for unresolved classes to trigger re-verification at runtime.
if (C == CheckAccess::kYes &&
result->IsNonZeroReferenceTypes() &&
(api_level_ >= 28u || !result->IsUnresolvedTypes())) {
const RegType& referrer = GetDeclaringClass();
if ((api_level_ >= 28u || !referrer.IsUnresolvedTypes()) && !referrer.CanAccess(*result)) {
Fail(VERIFY_ERROR_ACCESS_CLASS) << "(possibly) illegal class access: '"
<< referrer << "' -> '" << *result << "'";
}
}
return *result;
}
// Instantiate ResolveClass variants. This is required as the -inl file has a function with a call
// to ResolveClass, and compilers may decide to inline, requiring a symbol.
template const RegType& MethodVerifier::ResolveClass<MethodVerifier::CheckAccess::kNo>(
dex::TypeIndex class_idx);
template const RegType& MethodVerifier::ResolveClass<MethodVerifier::CheckAccess::kYes>(
dex::TypeIndex class_idx);
const RegType& MethodVerifier::GetCaughtExceptionType() {
const RegType* common_super = nullptr;
if (code_item_accessor_.TriesSize() != 0) {
const uint8_t* handlers_ptr = code_item_accessor_.GetCatchHandlerData();
uint32_t handlers_size = DecodeUnsignedLeb128(&handlers_ptr);
for (uint32_t i = 0; i < handlers_size; i++) {
CatchHandlerIterator iterator(handlers_ptr);
for (; iterator.HasNext(); iterator.Next()) {
if (iterator.GetHandlerAddress() == (uint32_t) work_insn_idx_) {
if (!iterator.GetHandlerTypeIndex().IsValid()) {
common_super = &reg_types_.JavaLangThrowable(false);
} else {
const RegType& exception =
ResolveClass<CheckAccess::kYes>(iterator.GetHandlerTypeIndex());
if (!reg_types_.JavaLangThrowable(false).IsAssignableFrom(exception, this)) {
DCHECK(!exception.IsUninitializedTypes()); // Comes from dex, shouldn't be uninit.
if (exception.IsUnresolvedTypes()) {
// We don't know enough about the type. Fail here and let runtime handle it.
Fail(VERIFY_ERROR_NO_CLASS) << "unresolved exception class " << exception;
return exception;
} else {
Fail(VERIFY_ERROR_BAD_CLASS_SOFT) << "unexpected non-exception class " << exception;
return reg_types_.Conflict();
}
} else if (common_super == nullptr) {
common_super = &exception;
} else if (common_super->Equals(exception)) {
// odd case, but nothing to do
} else {
common_super = &common_super->Merge(exception, &reg_types_, this);
if (FailOrAbort(reg_types_.JavaLangThrowable(false).IsAssignableFrom(
*common_super, this),
"java.lang.Throwable is not assignable-from common_super at ",
work_insn_idx_)) {
break;
}
}
}
}
}
handlers_ptr = iterator.EndDataPointer();
}
}
if (common_super == nullptr) {
/* no catch blocks, or no catches with classes we can find */
Fail(VERIFY_ERROR_BAD_CLASS_SOFT) << "unable to find exception handler";
return reg_types_.Conflict();
}
return *common_super;
}
ArtMethod* MethodVerifier::ResolveMethodAndCheckAccess(
uint32_t dex_method_idx, MethodType method_type) {
const DexFile::MethodId& method_id = dex_file_->GetMethodId(dex_method_idx);
const RegType& klass_type = ResolveClass<CheckAccess::kYes>(method_id.class_idx_);
if (klass_type.IsConflict()) {
std::string append(" in attempt to access method ");
append += dex_file_->GetMethodName(method_id);
AppendToLastFailMessage(append);
return nullptr;
}
if (klass_type.IsUnresolvedTypes()) {
return nullptr; // Can't resolve Class so no more to do here
}
ObjPtr<mirror::Class> klass = klass_type.GetClass();
const RegType& referrer = GetDeclaringClass();
ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
PointerSize pointer_size = class_linker->GetImagePointerSize();
ArtMethod* res_method = dex_cache_->GetResolvedMethod(dex_method_idx, pointer_size);
if (res_method == nullptr) {
res_method = class_linker->FindResolvedMethod(
klass, dex_cache_.Get(), class_loader_.Get(), dex_method_idx);
}
// Record result of method resolution attempt. The klass resolution has recorded whether
// the class is an interface or not and therefore the type of the lookup performed above.
// TODO: Maybe we should not record dependency if the invoke type does not match the lookup type.
VerifierDeps::MaybeRecordMethodResolution(*dex_file_, dex_method_idx, res_method);
bool must_fail = false;
// This is traditional and helps with screwy bytecode. It will tell you that, yes, a method
// exists, but that it's called incorrectly. This significantly helps debugging, as locally it's
// hard to see the differences.
// If we don't have res_method here we must fail. Just use this bool to make sure of that with a
// DCHECK.
if (res_method == nullptr) {
must_fail = true;
// Try to find the method also with the other type for better error reporting below
// but do not store such bogus lookup result in the DexCache or VerifierDeps.
res_method = class_linker->FindIncompatibleMethod(
klass, dex_cache_.Get(), class_loader_.Get(), dex_method_idx);
}
if (res_method == nullptr) {
Fail(VERIFY_ERROR_NO_METHOD) << "couldn't find method "
<< klass->PrettyDescriptor() << "."
<< dex_file_->GetMethodName(method_id) << " "
<< dex_file_->GetMethodSignature(method_id);
return nullptr;
}
// Make sure calls to constructors are "direct". There are additional restrictions but we don't
// enforce them here.
if (res_method->IsConstructor() && method_type != METHOD_DIRECT) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "rejecting non-direct call to constructor "
<< res_method->PrettyMethod();
return nullptr;
}
// Disallow any calls to class initializers.
if (res_method->IsClassInitializer()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "rejecting call to class initializer "
<< res_method->PrettyMethod();
return nullptr;
}
// Check that interface methods are static or match interface classes.
// We only allow statics if we don't have default methods enabled.
//
// Note: this check must be after the initializer check, as those are required to fail a class,
// while this check implies an IncompatibleClassChangeError.
if (klass->IsInterface()) {
// methods called on interfaces should be invoke-interface, invoke-super, invoke-direct (if
// default methods are supported for the dex file), or invoke-static.
if (method_type != METHOD_INTERFACE &&
method_type != METHOD_STATIC &&
(!dex_file_->SupportsDefaultMethods() ||
method_type != METHOD_DIRECT) &&
method_type != METHOD_SUPER) {
Fail(VERIFY_ERROR_CLASS_CHANGE)
<< "non-interface method " << dex_file_->PrettyMethod(dex_method_idx)
<< " is in an interface class " << klass->PrettyClass();
return nullptr;
}
} else {
if (method_type == METHOD_INTERFACE) {
Fail(VERIFY_ERROR_CLASS_CHANGE)
<< "interface method " << dex_file_->PrettyMethod(dex_method_idx)
<< " is in a non-interface class " << klass->PrettyClass();
return nullptr;
}
}
// Check specifically for non-public object methods being provided for interface dispatch. This
// can occur if we failed to find a method with FindInterfaceMethod but later find one with
// FindClassMethod for error message use.
if (method_type == METHOD_INTERFACE &&
res_method->GetDeclaringClass()->IsObjectClass() &&
!res_method->IsPublic()) {
Fail(VERIFY_ERROR_NO_METHOD) << "invoke-interface " << klass->PrettyDescriptor() << "."
<< dex_file_->GetMethodName(method_id) << " "
<< dex_file_->GetMethodSignature(method_id) << " resolved to "
<< "non-public object method " << res_method->PrettyMethod() << " "
<< "but non-public Object methods are excluded from interface "
<< "method resolution.";
return nullptr;
}
// Check if access is allowed.
if (!referrer.CanAccessMember(res_method->GetDeclaringClass(), res_method->GetAccessFlags())) {
Fail(VERIFY_ERROR_ACCESS_METHOD) << "illegal method access (call "
<< res_method->PrettyMethod()
<< " from " << referrer << ")";
return res_method;
}
// Check that invoke-virtual and invoke-super are not used on private methods of the same class.
if (res_method->IsPrivate() && (method_type == METHOD_VIRTUAL || method_type == METHOD_SUPER)) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invoke-super/virtual can't be used on private method "
<< res_method->PrettyMethod();
return nullptr;
}
// See if the method type implied by the invoke instruction matches the access flags for the
// target method. The flags for METHOD_POLYMORPHIC are based on there being precisely two
// signature polymorphic methods supported by the run-time which are native methods with variable
// arguments.
if ((method_type == METHOD_DIRECT && (!res_method->IsDirect() || res_method->IsStatic())) ||
(method_type == METHOD_STATIC && !res_method->IsStatic()) ||
((method_type == METHOD_SUPER ||
method_type == METHOD_VIRTUAL ||
method_type == METHOD_INTERFACE) && res_method->IsDirect()) ||
((method_type == METHOD_POLYMORPHIC) &&
(!res_method->IsNative() || !res_method->IsVarargs()))) {
Fail(VERIFY_ERROR_CLASS_CHANGE) << "invoke type (" << method_type << ") does not match method "
"type of " << res_method->PrettyMethod();
return nullptr;
}
// Make sure we weren't expecting to fail.
DCHECK(!must_fail) << "invoke type (" << method_type << ")"
<< klass->PrettyDescriptor() << "."
<< dex_file_->GetMethodName(method_id) << " "
<< dex_file_->GetMethodSignature(method_id) << " unexpectedly resolved to "
<< res_method->PrettyMethod() << " without error. Initially this method was "
<< "not found so we were expecting to fail for some reason.";
return res_method;
}
template <class T>
ArtMethod* MethodVerifier::VerifyInvocationArgsFromIterator(
T* it, const Instruction* inst, MethodType method_type, bool is_range, ArtMethod* res_method) {
DCHECK_EQ(!is_range, inst->HasVarArgs());
// We use vAA as our expected arg count, rather than res_method->insSize, because we need to
// match the call to the signature. Also, we might be calling through an abstract method
// definition (which doesn't have register count values).
const size_t expected_args = inst->VRegA();
/* caught by static verifier */
DCHECK(is_range || expected_args <= 5);
if (expected_args > code_item_accessor_.OutsSize()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid argument count (" << expected_args
<< ") exceeds outsSize ("
<< code_item_accessor_.OutsSize() << ")";
return nullptr;
}
/*
* Check the "this" argument, which must be an instance of the class that declared the method.
* For an interface class, we don't do the full interface merge (see JoinClass), so we can't do a
* rigorous check here (which is okay since we have to do it at runtime).
*/
if (method_type != METHOD_STATIC) {
const RegType& actual_arg_type = work_line_->GetInvocationThis(this, inst);
if (actual_arg_type.IsConflict()) { // GetInvocationThis failed.
CHECK(have_pending_hard_failure_);
return nullptr;
}
bool is_init = false;
if (actual_arg_type.IsUninitializedTypes()) {
if (res_method) {
if (!res_method->IsConstructor()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "'this' arg must be initialized";
return nullptr;
}
} else {
// Check whether the name of the called method is "<init>"
const uint32_t method_idx = GetMethodIdxOfInvoke(inst);
if (strcmp(dex_file_->GetMethodName(dex_file_->GetMethodId(method_idx)), "<init>") != 0) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "'this' arg must be initialized";
return nullptr;
}
}
is_init = true;
}
const RegType& adjusted_type = is_init
? GetRegTypeCache()->FromUninitialized(actual_arg_type)
: actual_arg_type;
if (method_type != METHOD_INTERFACE && !adjusted_type.IsZeroOrNull()) {
const RegType* res_method_class;
// Miranda methods have the declaring interface as their declaring class, not the abstract
// class. It would be wrong to use this for the type check (interface type checks are
// postponed to runtime).
if (res_method != nullptr && !res_method->IsMiranda()) {
ObjPtr<mirror::Class> klass = res_method->GetDeclaringClass();
std::string temp;
res_method_class = &FromClass(klass->GetDescriptor(&temp), klass,
klass->CannotBeAssignedFromOtherTypes());
} else {
const uint32_t method_idx = GetMethodIdxOfInvoke(inst);
const dex::TypeIndex class_idx = dex_file_->GetMethodId(method_idx).class_idx_;
res_method_class = &reg_types_.FromDescriptor(
GetClassLoader(),
dex_file_->StringByTypeIdx(class_idx),
false);
}
if (!res_method_class->IsAssignableFrom(adjusted_type, this)) {
Fail(adjusted_type.IsUnresolvedTypes()
? VERIFY_ERROR_NO_CLASS
: VERIFY_ERROR_BAD_CLASS_SOFT)
<< "'this' argument '" << actual_arg_type << "' not instance of '"
<< *res_method_class << "'";
// Continue on soft failures. We need to find possible hard failures to avoid problems in
// the compiler.
if (have_pending_hard_failure_) {
return nullptr;
}
}
}
}
uint32_t arg[5];
if (!is_range) {
inst->GetVarArgs(arg);
}
uint32_t sig_registers = (method_type == METHOD_STATIC) ? 0 : 1;
for ( ; it->HasNext(); it->Next()) {
if (sig_registers >= expected_args) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Rejecting invocation, expected " << inst->VRegA() <<
" argument registers, method signature has " << sig_registers + 1 << " or more";
return nullptr;
}
const char* param_descriptor = it->GetDescriptor();
if (param_descriptor == nullptr) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Rejecting invocation because of missing signature "
"component";
return nullptr;
}
const RegType& reg_type = reg_types_.FromDescriptor(GetClassLoader(), param_descriptor, false);
uint32_t get_reg = is_range ? inst->VRegC() + static_cast<uint32_t>(sig_registers) :
arg[sig_registers];
if (reg_type.IsIntegralTypes()) {
const RegType& src_type = work_line_->GetRegisterType(this, get_reg);
if (!src_type.IsIntegralTypes()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "register v" << get_reg << " has type " << src_type
<< " but expected " << reg_type;
return nullptr;
}
} else {
if (!work_line_->VerifyRegisterType(this, get_reg, reg_type)) {
// Continue on soft failures. We need to find possible hard failures to avoid problems in
// the compiler.
if (have_pending_hard_failure_) {
return nullptr;
}
} else if (reg_type.IsLongOrDoubleTypes()) {
// Check that registers are consecutive (for non-range invokes). Invokes are the only
// instructions not specifying register pairs by the first component, but require them
// nonetheless. Only check when there's an actual register in the parameters. If there's
// none, this will fail below.
if (!is_range && sig_registers + 1 < expected_args) {
uint32_t second_reg = arg[sig_registers + 1];
if (second_reg != get_reg + 1) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Rejecting invocation, long or double parameter "
"at index " << sig_registers << " is not a pair: " << get_reg << " + "
<< second_reg << ".";
return nullptr;
}
}
}
}
sig_registers += reg_type.IsLongOrDoubleTypes() ? 2 : 1;
}
if (expected_args != sig_registers) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Rejecting invocation, expected " << expected_args <<
" argument registers, method signature has " << sig_registers;
return nullptr;
}
return res_method;
}
void MethodVerifier::VerifyInvocationArgsUnresolvedMethod(const Instruction* inst,
MethodType method_type,
bool is_range) {
// As the method may not have been resolved, make this static check against what we expect.
// The main reason for this code block is to fail hard when we find an illegal use, e.g.,
// wrong number of arguments or wrong primitive types, even if the method could not be resolved.
const uint32_t method_idx = GetMethodIdxOfInvoke(inst);
DexFileParameterIterator it(*dex_file_,
dex_file_->GetProtoId(dex_file_->GetMethodId(method_idx).proto_idx_));
VerifyInvocationArgsFromIterator(&it, inst, method_type, is_range, nullptr);
}
bool MethodVerifier::CheckCallSite(uint32_t call_site_idx) {
if (call_site_idx >= dex_file_->NumCallSiteIds()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Bad call site id #" << call_site_idx
<< " >= " << dex_file_->NumCallSiteIds();
return false;
}
CallSiteArrayValueIterator it(*dex_file_, dex_file_->GetCallSiteId(call_site_idx));
// Check essential arguments are provided. The dex file verifier has verified indicies of the
// main values (method handle, name, method_type).
static const size_t kRequiredArguments = 3;
if (it.Size() < kRequiredArguments) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Call site #" << call_site_idx
<< " has too few arguments: "
<< it.Size() << " < " << kRequiredArguments;
return false;
}
std::pair<const EncodedArrayValueIterator::ValueType, size_t> type_and_max[kRequiredArguments] =
{ { EncodedArrayValueIterator::ValueType::kMethodHandle, dex_file_->NumMethodHandles() },
{ EncodedArrayValueIterator::ValueType::kString, dex_file_->NumStringIds() },
{ EncodedArrayValueIterator::ValueType::kMethodType, dex_file_->NumProtoIds() }
};
uint32_t index[kRequiredArguments];
// Check arguments have expected types and are within permitted ranges.
for (size_t i = 0; i < kRequiredArguments; ++i) {
if (it.GetValueType() != type_and_max[i].first) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Call site id #" << call_site_idx
<< " argument " << i << " has wrong type "
<< it.GetValueType() << "!=" << type_and_max[i].first;
return false;
}
index[i] = static_cast<uint32_t>(it.GetJavaValue().i);
if (index[i] >= type_and_max[i].second) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Call site id #" << call_site_idx
<< " argument " << i << " bad index "
<< index[i] << " >= " << type_and_max[i].second;
return false;
}
it.Next();
}
// Check method handle kind is valid.
const DexFile::MethodHandleItem& mh = dex_file_->GetMethodHandle(index[0]);
if (mh.method_handle_type_ != static_cast<uint16_t>(DexFile::MethodHandleType::kInvokeStatic)) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Call site #" << call_site_idx
<< " argument 0 method handle type is not InvokeStatic: "
<< mh.method_handle_type_;
return false;
}
return true;
}
class MethodParamListDescriptorIterator {
public:
explicit MethodParamListDescriptorIterator(ArtMethod* res_method) :
res_method_(res_method), pos_(0), params_(res_method->GetParameterTypeList()),
params_size_(params_ == nullptr ? 0 : params_->Size()) {
}
bool HasNext() {
return pos_ < params_size_;
}
void Next() {
++pos_;
}
const char* GetDescriptor() REQUIRES_SHARED(Locks::mutator_lock_) {
return res_method_->GetTypeDescriptorFromTypeIdx(params_->GetTypeItem(pos_).type_idx_);
}
private:
ArtMethod* res_method_;
size_t pos_;
const DexFile::TypeList* params_;
const size_t params_size_;
};
ArtMethod* MethodVerifier::VerifyInvocationArgs(
const Instruction* inst, MethodType method_type, bool is_range) {
// Resolve the method. This could be an abstract or concrete method depending on what sort of call
// we're making.
const uint32_t method_idx = GetMethodIdxOfInvoke(inst);
ArtMethod* res_method = ResolveMethodAndCheckAccess(method_idx, method_type);
if (res_method == nullptr) { // error or class is unresolved
// Check what we can statically.
if (!have_pending_hard_failure_) {
VerifyInvocationArgsUnresolvedMethod(inst, method_type, is_range);
}
return nullptr;
}
// If we're using invoke-super(method), make sure that the executing method's class' superclass
// has a vtable entry for the target method. Or the target is on a interface.
if (method_type == METHOD_SUPER) {
dex::TypeIndex class_idx = dex_file_->GetMethodId(method_idx).class_idx_;
const RegType& reference_type = reg_types_.FromDescriptor(
GetClassLoader(),
dex_file_->StringByTypeIdx(class_idx),
false);
if (reference_type.IsUnresolvedTypes()) {
Fail(VERIFY_ERROR_BAD_CLASS_SOFT) << "Unable to find referenced class from invoke-super";
return nullptr;
}
if (reference_type.GetClass()->IsInterface()) {
// TODO Can we verify anything else.
if (class_idx == class_def_.class_idx_) {
Fail(VERIFY_ERROR_CLASS_CHANGE) << "Cannot invoke-super on self as interface";
return nullptr;
}
// TODO Revisit whether we want to allow invoke-super on direct interfaces only like the JLS
// does.
if (!GetDeclaringClass().HasClass()) {
Fail(VERIFY_ERROR_NO_CLASS) << "Unable to resolve the full class of 'this' used in an"
<< "interface invoke-super";
return nullptr;
} else if (!reference_type.IsStrictlyAssignableFrom(GetDeclaringClass(), this)) {
Fail(VERIFY_ERROR_CLASS_CHANGE)
<< "invoke-super in " << mirror::Class::PrettyClass(GetDeclaringClass().GetClass())
<< " in method "
<< dex_file_->PrettyMethod(dex_method_idx_) << " to method "
<< dex_file_->PrettyMethod(method_idx) << " references "
<< "non-super-interface type " << mirror::Class::PrettyClass(reference_type.GetClass());
return nullptr;
}
} else {
const RegType& super = GetDeclaringClass().GetSuperClass(&reg_types_);
if (super.IsUnresolvedTypes()) {
Fail(VERIFY_ERROR_NO_METHOD) << "unknown super class in invoke-super from "
<< dex_file_->PrettyMethod(dex_method_idx_)
<< " to super " << res_method->PrettyMethod();
return nullptr;
}
if (!reference_type.IsStrictlyAssignableFrom(GetDeclaringClass(), this) ||
(res_method->GetMethodIndex() >= super.GetClass()->GetVTableLength())) {
Fail(VERIFY_ERROR_NO_METHOD) << "invalid invoke-super from "
<< dex_file_->PrettyMethod(dex_method_idx_)
<< " to super " << super
<< "." << res_method->GetName()
<< res_method->GetSignature();
return nullptr;
}
}
}
if (UNLIKELY(method_type == METHOD_POLYMORPHIC)) {
// Process the signature of the calling site that is invoking the method handle.
dex::ProtoIndex proto_idx(inst->VRegH());
DexFileParameterIterator it(*dex_file_, dex_file_->GetProtoId(proto_idx));
return VerifyInvocationArgsFromIterator(&it, inst, method_type, is_range, res_method);
} else {
// Process the target method's signature.
MethodParamListDescriptorIterator it(res_method);
return VerifyInvocationArgsFromIterator(&it, inst, method_type, is_range, res_method);
}
}
bool MethodVerifier::CheckSignaturePolymorphicMethod(ArtMethod* method) {
ObjPtr<mirror::Class> klass = method->GetDeclaringClass();
const char* method_name = method->GetName();
const char* expected_return_descriptor;
ObjPtr<mirror::ObjectArray<mirror::Class>> class_roots =
Runtime::Current()->GetClassLinker()->GetClassRoots();
if (klass == GetClassRoot<mirror::MethodHandle>(class_roots)) {
expected_return_descriptor = mirror::MethodHandle::GetReturnTypeDescriptor(method_name);
} else if (klass == GetClassRoot<mirror::VarHandle>(class_roots)) {
expected_return_descriptor = mirror::VarHandle::GetReturnTypeDescriptor(method_name);
} else {
Fail(VERIFY_ERROR_BAD_CLASS_HARD)
<< "Signature polymorphic method in unsuppported class: " << klass->PrettyDescriptor();
return false;
}
if (expected_return_descriptor == nullptr) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD)
<< "Signature polymorphic method name invalid: " << method_name;
return false;
}
const DexFile::TypeList* types = method->GetParameterTypeList();
if (types->Size() != 1) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD)
<< "Signature polymorphic method has too many arguments " << types->Size() << " != 1";
return false;
}
const dex::TypeIndex argument_type_index = types->GetTypeItem(0).type_idx_;
const char* argument_descriptor = method->GetTypeDescriptorFromTypeIdx(argument_type_index);
if (strcmp(argument_descriptor, "[Ljava/lang/Object;") != 0) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD)
<< "Signature polymorphic method has unexpected argument type: " << argument_descriptor;
return false;
}
const char* return_descriptor = method->GetReturnTypeDescriptor();
if (strcmp(return_descriptor, expected_return_descriptor) != 0) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD)
<< "Signature polymorphic method has unexpected return type: " << return_descriptor
<< " != " << expected_return_descriptor;
return false;
}
return true;
}
bool MethodVerifier::CheckSignaturePolymorphicReceiver(const Instruction* inst) {
const RegType& this_type = work_line_->GetInvocationThis(this, inst);
if (this_type.IsZeroOrNull()) {
/* null pointer always passes (and always fails at run time) */
return true;
} else if (!this_type.IsNonZeroReferenceTypes()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD)
<< "invoke-polymorphic receiver is not a reference: "
<< this_type;
return false;
} else if (this_type.IsUninitializedReference()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD)
<< "invoke-polymorphic receiver is uninitialized: "
<< this_type;
return false;
} else if (!this_type.HasClass()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD)
<< "invoke-polymorphic receiver has no class: "
<< this_type;
return false;
} else {
ObjPtr<mirror::ObjectArray<mirror::Class>> class_roots =
Runtime::Current()->GetClassLinker()->GetClassRoots();
if (!this_type.GetClass()->IsSubClass(GetClassRoot<mirror::MethodHandle>(class_roots)) &&
!this_type.GetClass()->IsSubClass(GetClassRoot<mirror::VarHandle>(class_roots))) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD)
<< "invoke-polymorphic receiver is not a subclass of MethodHandle or VarHandle: "
<< this_type;
return false;
}
}
return true;
}
uint16_t MethodVerifier::GetMethodIdxOfInvoke(const Instruction* inst) {
switch (inst->Opcode()) {
case Instruction::INVOKE_VIRTUAL_RANGE_QUICK:
case Instruction::INVOKE_VIRTUAL_QUICK: {
DCHECK(Runtime::Current()->IsStarted() || verify_to_dump_)
<< dex_file_->PrettyMethod(dex_method_idx_, true) << "@" << work_insn_idx_;
DCHECK(method_being_verified_ != nullptr);
uint16_t method_idx = method_being_verified_->GetIndexFromQuickening(work_insn_idx_);
CHECK_NE(method_idx, DexFile::kDexNoIndex16);
return method_idx;
}
default: {
return inst->VRegB();
}
}
}
uint16_t MethodVerifier::GetFieldIdxOfFieldAccess(const Instruction* inst, bool is_static) {
if (is_static) {
return inst->VRegB_21c();
} else if (inst->IsQuickened()) {
DCHECK(Runtime::Current()->IsStarted() || verify_to_dump_);
DCHECK(method_being_verified_ != nullptr);
uint16_t field_idx = method_being_verified_->GetIndexFromQuickening(work_insn_idx_);
CHECK_NE(field_idx, DexFile::kDexNoIndex16);
return field_idx;
} else {
return inst->VRegC_22c();
}
}
void MethodVerifier::VerifyNewArray(const Instruction* inst, bool is_filled, bool is_range) {
dex::TypeIndex type_idx;
if (!is_filled) {
DCHECK_EQ(inst->Opcode(), Instruction::NEW_ARRAY);
type_idx = dex::TypeIndex(inst->VRegC_22c());
} else if (!is_range) {
DCHECK_EQ(inst->Opcode(), Instruction::FILLED_NEW_ARRAY);
type_idx = dex::TypeIndex(inst->VRegB_35c());
} else {
DCHECK_EQ(inst->Opcode(), Instruction::FILLED_NEW_ARRAY_RANGE);
type_idx = dex::TypeIndex(inst->VRegB_3rc());
}
const RegType& res_type = ResolveClass<CheckAccess::kYes>(type_idx);
if (res_type.IsConflict()) { // bad class
DCHECK_NE(failures_.size(), 0U);
} else {
// TODO: check Compiler::CanAccessTypeWithoutChecks returns false when res_type is unresolved
if (!res_type.IsArrayTypes()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "new-array on non-array class " << res_type;
} else if (!is_filled) {
/* make sure "size" register is valid type */
work_line_->VerifyRegisterType(this, inst->VRegB_22c(), reg_types_.Integer());
/* set register type to array class */
const RegType& precise_type = reg_types_.FromUninitialized(res_type);
work_line_->SetRegisterType<LockOp::kClear>(this, inst->VRegA_22c(), precise_type);
} else {
DCHECK(!res_type.IsUnresolvedMergedReference());
// Verify each register. If "arg_count" is bad, VerifyRegisterType() will run off the end of
// the list and fail. It's legal, if silly, for arg_count to be zero.
const RegType& expected_type = reg_types_.GetComponentType(res_type, GetClassLoader());
uint32_t arg_count = (is_range) ? inst->VRegA_3rc() : inst->VRegA_35c();
uint32_t arg[5];
if (!is_range) {
inst->GetVarArgs(arg);
}
for (size_t ui = 0; ui < arg_count; ui++) {
uint32_t get_reg = is_range ? inst->VRegC_3rc() + ui : arg[ui];
if (!work_line_->VerifyRegisterType(this, get_reg, expected_type)) {
work_line_->SetResultRegisterType(this, reg_types_.Conflict());
return;
}
}
// filled-array result goes into "result" register
const RegType& precise_type = reg_types_.FromUninitialized(res_type);
work_line_->SetResultRegisterType(this, precise_type);
}
}
}
void MethodVerifier::VerifyAGet(const Instruction* inst,
const RegType& insn_type, bool is_primitive) {
const RegType& index_type = work_line_->GetRegisterType(this, inst->VRegC_23x());
if (!index_type.IsArrayIndexTypes()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Invalid reg type for array index (" << index_type << ")";
} else {
const RegType& array_type = work_line_->GetRegisterType(this, inst->VRegB_23x());
if (array_type.IsZeroOrNull()) {
// Null array class; this code path will fail at runtime. Infer a merge-able type from the
// instruction type.
if (!is_primitive) {
work_line_->SetRegisterType<LockOp::kClear>(this, inst->VRegA_23x(), reg_types_.Null());
} else if (insn_type.IsInteger()) {
// Pick a non-zero constant (to distinguish with null) that can fit in any primitive.
// We cannot use 'insn_type' as it could be a float array or an int array.
work_line_->SetRegisterType<LockOp::kClear>(
this, inst->VRegA_23x(), DetermineCat1Constant(1, need_precise_constants_));
} else if (insn_type.IsCategory1Types()) {
// Category 1
// The 'insn_type' is exactly the type we need.
work_line_->SetRegisterType<LockOp::kClear>(this, inst->VRegA_23x(), insn_type);
} else {
// Category 2
work_line_->SetRegisterTypeWide(this, inst->VRegA_23x(),
reg_types_.FromCat2ConstLo(0, false),
reg_types_.FromCat2ConstHi(0, false));
}
} else if (!array_type.IsArrayTypes()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "not array type " << array_type << " with aget";
} else if (array_type.IsUnresolvedMergedReference()) {
// Unresolved array types must be reference array types.
if (is_primitive) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "reference array type " << array_type
<< " source for category 1 aget";
} else {
Fail(VERIFY_ERROR_NO_CLASS) << "cannot verify aget for " << array_type
<< " because of missing class";
// Approximate with java.lang.Object[].
work_line_->SetRegisterType<LockOp::kClear>(this,
inst->VRegA_23x(),
reg_types_.JavaLangObject(false));
}
} else {
/* verify the class */
const RegType& component_type = reg_types_.GetComponentType(array_type, GetClassLoader());
if (!component_type.IsReferenceTypes() && !is_primitive) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "primitive array type " << array_type
<< " source for aget-object";
} else if (component_type.IsNonZeroReferenceTypes() && is_primitive) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "reference array type " << array_type
<< " source for category 1 aget";
} else if (is_primitive && !insn_type.Equals(component_type) &&
!((insn_type.IsInteger() && component_type.IsFloat()) ||
(insn_type.IsLong() && component_type.IsDouble()))) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "array type " << array_type
<< " incompatible with aget of type " << insn_type;
} else {
// Use knowledge of the field type which is stronger than the type inferred from the
// instruction, which can't differentiate object types and ints from floats, longs from
// doubles.
if (!component_type.IsLowHalf()) {
work_line_->SetRegisterType<LockOp::kClear>(this, inst->VRegA_23x(), component_type);
} else {
work_line_->SetRegisterTypeWide(this, inst->VRegA_23x(), component_type,
component_type.HighHalf(&reg_types_));
}
}
}
}
}
void MethodVerifier::VerifyPrimitivePut(const RegType& target_type, const RegType& insn_type,
const uint32_t vregA) {
// Primitive assignability rules are weaker than regular assignability rules.
bool instruction_compatible;
bool value_compatible;
const RegType& value_type = work_line_->GetRegisterType(this, vregA);
if (target_type.IsIntegralTypes()) {
instruction_compatible = target_type.Equals(insn_type);
value_compatible = value_type.IsIntegralTypes();
} else if (target_type.IsFloat()) {
instruction_compatible = insn_type.IsInteger(); // no put-float, so expect put-int
value_compatible = value_type.IsFloatTypes();
} else if (target_type.IsLong()) {
instruction_compatible = insn_type.IsLong();
// Additional register check: this is not checked statically (as part of VerifyInstructions),
// as target_type depends on the resolved type of the field.
if (instruction_compatible && work_line_->NumRegs() > vregA + 1) {
const RegType& value_type_hi = work_line_->GetRegisterType(this, vregA + 1);
value_compatible = value_type.IsLongTypes() && value_type.CheckWidePair(value_type_hi);
} else {
value_compatible = false;
}
} else if (target_type.IsDouble()) {
instruction_compatible = insn_type.IsLong(); // no put-double, so expect put-long
// Additional register check: this is not checked statically (as part of VerifyInstructions),
// as target_type depends on the resolved type of the field.
if (instruction_compatible && work_line_->NumRegs() > vregA + 1) {
const RegType& value_type_hi = work_line_->GetRegisterType(this, vregA + 1);
value_compatible = value_type.IsDoubleTypes() && value_type.CheckWidePair(value_type_hi);
} else {
value_compatible = false;
}
} else {
instruction_compatible = false; // reference with primitive store
value_compatible = false; // unused
}
if (!instruction_compatible) {
// This is a global failure rather than a class change failure as the instructions and
// the descriptors for the type should have been consistent within the same file at
// compile time.
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "put insn has type '" << insn_type
<< "' but expected type '" << target_type << "'";
return;
}
if (!value_compatible) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "unexpected value in v" << vregA
<< " of type " << value_type << " but expected " << target_type << " for put";
return;
}
}
void MethodVerifier::VerifyAPut(const Instruction* inst,
const RegType& insn_type, bool is_primitive) {
const RegType& index_type = work_line_->GetRegisterType(this, inst->VRegC_23x());
if (!index_type.IsArrayIndexTypes()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Invalid reg type for array index (" << index_type << ")";
} else {
const RegType& array_type = work_line_->GetRegisterType(this, inst->VRegB_23x());
if (array_type.IsZeroOrNull()) {
// Null array type; this code path will fail at runtime.
// Still check that the given value matches the instruction's type.
// Note: this is, as usual, complicated by the fact the the instruction isn't fully typed
// and fits multiple register types.
const RegType* modified_reg_type = &insn_type;
if ((modified_reg_type == &reg_types_.Integer()) ||
(modified_reg_type == &reg_types_.LongLo())) {
// May be integer or float | long or double. Overwrite insn_type accordingly.
const RegType& value_type = work_line_->GetRegisterType(this, inst->VRegA_23x());
if (modified_reg_type == &reg_types_.Integer()) {
if (&value_type == &reg_types_.Float()) {
modified_reg_type = &value_type;
}
} else {
if (&value_type == &reg_types_.DoubleLo()) {
modified_reg_type = &value_type;
}
}
}
work_line_->VerifyRegisterType(this, inst->VRegA_23x(), *modified_reg_type);
} else if (!array_type.IsArrayTypes()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "not array type " << array_type << " with aput";
} else if (array_type.IsUnresolvedMergedReference()) {
// Unresolved array types must be reference array types.
if (is_primitive) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "put insn has type '" << insn_type
<< "' but unresolved type '" << array_type << "'";
} else {
Fail(VERIFY_ERROR_NO_CLASS) << "cannot verify aput for " << array_type
<< " because of missing class";
}
} else {
const RegType& component_type = reg_types_.GetComponentType(array_type, GetClassLoader());
const uint32_t vregA = inst->VRegA_23x();
if (is_primitive) {
VerifyPrimitivePut(component_type, insn_type, vregA);
} else {
if (!component_type.IsReferenceTypes()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "primitive array type " << array_type
<< " source for aput-object";
} else {
// The instruction agrees with the type of array, confirm the value to be stored does too
// Note: we use the instruction type (rather than the component type) for aput-object as
// incompatible classes will be caught at runtime as an array store exception
work_line_->VerifyRegisterType(this, vregA, insn_type);
}
}
}
}
}
ArtField* MethodVerifier::GetStaticField(int field_idx) {
const DexFile::FieldId& field_id = dex_file_->GetFieldId(field_idx);
// Check access to class
const RegType& klass_type = ResolveClass<CheckAccess::kYes>(field_id.class_idx_);
if (klass_type.IsConflict()) { // bad class
AppendToLastFailMessage(StringPrintf(" in attempt to access static field %d (%s) in %s",
field_idx, dex_file_->GetFieldName(field_id),
dex_file_->GetFieldDeclaringClassDescriptor(field_id)));
return nullptr;
}
if (klass_type.IsUnresolvedTypes()) {
// Accessibility checks depend on resolved fields.
DCHECK(klass_type.Equals(GetDeclaringClass()) || !failures_.empty() || api_level_ < 28u);
return nullptr; // Can't resolve Class so no more to do here, will do checking at runtime.
}
ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
ArtField* field = class_linker->ResolveFieldJLS(field_idx, dex_cache_, class_loader_);
// Record result of the field resolution attempt.
VerifierDeps::MaybeRecordFieldResolution(*dex_file_, field_idx, field);
if (field == nullptr) {
VLOG(verifier) << "Unable to resolve static field " << field_idx << " ("
<< dex_file_->GetFieldName(field_id) << ") in "
<< dex_file_->GetFieldDeclaringClassDescriptor(field_id);
DCHECK(self_->IsExceptionPending());
self_->ClearException();
return nullptr;
} else if (!GetDeclaringClass().CanAccessMember(field->GetDeclaringClass(),
field->GetAccessFlags())) {
Fail(VERIFY_ERROR_ACCESS_FIELD) << "cannot access static field " << field->PrettyField()
<< " from " << GetDeclaringClass();
return nullptr;
} else if (!field->IsStatic()) {
Fail(VERIFY_ERROR_CLASS_CHANGE) << "expected field " << field->PrettyField() << " to be static";
return nullptr;
}
return field;
}
ArtField* MethodVerifier::GetInstanceField(const RegType& obj_type, int field_idx) {
const DexFile::FieldId& field_id = dex_file_->GetFieldId(field_idx);
// Check access to class.
const RegType& klass_type = ResolveClass<CheckAccess::kYes>(field_id.class_idx_);
if (klass_type.IsConflict()) {
AppendToLastFailMessage(StringPrintf(" in attempt to access instance field %d (%s) in %s",
field_idx, dex_file_->GetFieldName(field_id),
dex_file_->GetFieldDeclaringClassDescriptor(field_id)));
return nullptr;
}
if (klass_type.IsUnresolvedTypes()) {
// Accessibility checks depend on resolved fields.
DCHECK(klass_type.Equals(GetDeclaringClass()) || !failures_.empty() || api_level_ < 28u);
return nullptr; // Can't resolve Class so no more to do here
}
ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
ArtField* field = class_linker->ResolveFieldJLS(field_idx, dex_cache_, class_loader_);
// Record result of the field resolution attempt.
VerifierDeps::MaybeRecordFieldResolution(*dex_file_, field_idx, field);
if (field == nullptr) {
VLOG(verifier) << "Unable to resolve instance field " << field_idx << " ("
<< dex_file_->GetFieldName(field_id) << ") in "
<< dex_file_->GetFieldDeclaringClassDescriptor(field_id);
DCHECK(self_->IsExceptionPending());
self_->ClearException();
return nullptr;
} else if (obj_type.IsZeroOrNull()) {
// Cannot infer and check type, however, access will cause null pointer exception.
// Fall through into a few last soft failure checks below.
} else if (!obj_type.IsReferenceTypes()) {
// Trying to read a field from something that isn't a reference.
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "instance field access on object that has "
<< "non-reference type " << obj_type;
return nullptr;
} else {
std::string temp;
ObjPtr<mirror::Class> klass = field->GetDeclaringClass();
const RegType& field_klass =
FromClass(klass->GetDescriptor(&temp), klass, klass->CannotBeAssignedFromOtherTypes());
if (obj_type.IsUninitializedTypes()) {
// Field accesses through uninitialized references are only allowable for constructors where
// the field is declared in this class.
// Note: this IsConstructor check is technically redundant, as UninitializedThis should only
// appear in constructors.
if (!obj_type.IsUninitializedThisReference() ||
!IsConstructor() ||
!field_klass.Equals(GetDeclaringClass())) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "cannot access instance field " << field->PrettyField()
<< " of a not fully initialized object within the context"
<< " of " << dex_file_->PrettyMethod(dex_method_idx_);
return nullptr;
}
} else if (!field_klass.IsAssignableFrom(obj_type, this)) {
// Trying to access C1.field1 using reference of type C2, which is neither C1 or a sub-class
// of C1. For resolution to occur the declared class of the field must be compatible with
// obj_type, we've discovered this wasn't so, so report the field didn't exist.
VerifyError type;
bool is_aot = Runtime::Current()->IsAotCompiler();
if (is_aot && (field_klass.IsUnresolvedTypes() || obj_type.IsUnresolvedTypes())) {
// Compiler & unresolved types involved, retry at runtime.
type = VerifyError::VERIFY_ERROR_NO_CLASS;
} else {
// Classes known (resolved; and thus assignability check is precise), or we are at runtime
// and still missing classes. This is a hard failure.
type = VerifyError::VERIFY_ERROR_BAD_CLASS_HARD;
}
Fail(type) << "cannot access instance field " << field->PrettyField()
<< " from object of type " << obj_type;
return nullptr;
}
}
// Few last soft failure checks.
if (!GetDeclaringClass().CanAccessMember(field->GetDeclaringClass(),
field->GetAccessFlags())) {
Fail(VERIFY_ERROR_ACCESS_FIELD) << "cannot access instance field " << field->PrettyField()
<< " from " << GetDeclaringClass();
return nullptr;
} else if (field->IsStatic()) {
Fail(VERIFY_ERROR_CLASS_CHANGE) << "expected field " << field->PrettyField()
<< " to not be static";
return nullptr;
}
return field;
}
template <MethodVerifier::FieldAccessType kAccType>
void MethodVerifier::VerifyISFieldAccess(const Instruction* inst, const RegType& insn_type,
bool is_primitive, bool is_static) {
uint32_t field_idx = GetFieldIdxOfFieldAccess(inst, is_static);
ArtField* field;
if (is_static) {
field = GetStaticField(field_idx);
} else {
const RegType& object_type = work_line_->GetRegisterType(this, inst->VRegB_22c());
// One is not allowed to access fields on uninitialized references, except to write to
// fields in the constructor (before calling another constructor).
// GetInstanceField does an assignability check which will fail for uninitialized types.
// We thus modify the type if the uninitialized reference is a "this" reference (this also
// checks at the same time that we're verifying a constructor).
bool should_adjust = (kAccType == FieldAccessType::kAccPut) &&
object_type.IsUninitializedThisReference();
const RegType& adjusted_type = should_adjust
? GetRegTypeCache()->FromUninitialized(object_type)
: object_type;
field = GetInstanceField(adjusted_type, field_idx);
if (UNLIKELY(have_pending_hard_failure_)) {
return;
}
if (should_adjust) {
if (field == nullptr) {
Fail(VERIFY_ERROR_BAD_CLASS_SOFT) << "Might be accessing a superclass instance field prior "
<< "to the superclass being initialized in "
<< dex_file_->PrettyMethod(dex_method_idx_);
} else if (field->GetDeclaringClass() != GetDeclaringClass().GetClass()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "cannot access superclass instance field "
<< field->PrettyField() << " of a not fully initialized "
<< "object within the context of "
<< dex_file_->PrettyMethod(dex_method_idx_);
return;
}
}
}
const RegType* field_type = nullptr;
if (field != nullptr) {
if (kAccType == FieldAccessType::kAccPut) {
if (field->IsFinal() && field->GetDeclaringClass() != GetDeclaringClass().GetClass()) {
Fail(VERIFY_ERROR_ACCESS_FIELD) << "cannot modify final field " << field->PrettyField()
<< " from other class " << GetDeclaringClass();
// Keep hunting for possible hard fails.
}
}
ObjPtr<mirror::Class> field_type_class =
can_load_classes_ ? field->ResolveType() : field->LookupResolvedType();
if (field_type_class != nullptr) {
field_type = &FromClass(field->GetTypeDescriptor(),
field_type_class,
field_type_class->CannotBeAssignedFromOtherTypes());
} else {
DCHECK(!can_load_classes_ || self_->IsExceptionPending());
self_->ClearException();
}
} else if (api_level_ >= 28u) {
// If we don't have the field (it seems we failed resolution) and this is a PUT, we need to
// redo verification at runtime as the field may be final, unless the field id shows it's in
// the same class.
//
// For simplicity, it is OK to not distinguish compile-time vs runtime, and post this an
// ACCESS_FIELD failure at runtime. This has the same effect as NO_FIELD - punting the class
// to the access-checks interpreter.
//
// Note: see b/34966607. This and above may be changed in the future.
if (kAccType == FieldAccessType::kAccPut) {
const DexFile::FieldId& field_id = dex_file_->GetFieldId(field_idx);
const char* field_class_descriptor = dex_file_->GetFieldDeclaringClassDescriptor(field_id);
const RegType* field_class_type = &reg_types_.FromDescriptor(GetClassLoader(),
field_class_descriptor,
false);
if (!field_class_type->Equals(GetDeclaringClass())) {
Fail(VERIFY_ERROR_ACCESS_FIELD) << "could not check field put for final field modify of "
<< field_class_descriptor
<< "."
<< dex_file_->GetFieldName(field_id)
<< " from other class "
<< GetDeclaringClass();
}
}
}
if (field_type == nullptr) {
const DexFile::FieldId& field_id = dex_file_->GetFieldId(field_idx);
const char* descriptor = dex_file_->GetFieldTypeDescriptor(field_id);
field_type = &reg_types_.FromDescriptor(GetClassLoader(), descriptor, false);
}
DCHECK(field_type != nullptr);
const uint32_t vregA = (is_static) ? inst->VRegA_21c() : inst->VRegA_22c();
static_assert(kAccType == FieldAccessType::kAccPut || kAccType == FieldAccessType::kAccGet,
"Unexpected third access type");
if (kAccType == FieldAccessType::kAccPut) {
// sput or iput.
if (is_primitive) {
VerifyPrimitivePut(*field_type, insn_type, vregA);
} else {
if (!insn_type.IsAssignableFrom(*field_type, this)) {
// If the field type is not a reference, this is a global failure rather than
// a class change failure as the instructions and the descriptors for the type
// should have been consistent within the same file at compile time.
VerifyError error = field_type->IsReferenceTypes() ? VERIFY_ERROR_BAD_CLASS_SOFT
: VERIFY_ERROR_BAD_CLASS_HARD;
Fail(error) << "expected field " << ArtField::PrettyField(field)
<< " to be compatible with type '" << insn_type
<< "' but found type '" << *field_type
<< "' in put-object";
return;
}
work_line_->VerifyRegisterType(this, vregA, *field_type);
}
} else if (kAccType == FieldAccessType::kAccGet) {
// sget or iget.
if (is_primitive) {
if (field_type->Equals(insn_type) ||
(field_type->IsFloat() && insn_type.IsInteger()) ||
(field_type->IsDouble() && insn_type.IsLong())) {
// expected that read is of the correct primitive type or that int reads are reading
// floats or long reads are reading doubles
} else {
// This is a global failure rather than a class change failure as the instructions and
// the descriptors for the type should have been consistent within the same file at
// compile time
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "expected field " << ArtField::PrettyField(field)
<< " to be of type '" << insn_type
<< "' but found type '" << *field_type << "' in get";
return;
}
} else {
if (!insn_type.IsAssignableFrom(*field_type, this)) {
// If the field type is not a reference, this is a global failure rather than
// a class change failure as the instructions and the descriptors for the type
// should have been consistent within the same file at compile time.
VerifyError error = field_type->IsReferenceTypes() ? VERIFY_ERROR_BAD_CLASS_SOFT
: VERIFY_ERROR_BAD_CLASS_HARD;
Fail(error) << "expected field " << ArtField::PrettyField(field)
<< " to be compatible with type '" << insn_type
<< "' but found type '" << *field_type
<< "' in get-object";
if (error != VERIFY_ERROR_BAD_CLASS_HARD) {
work_line_->SetRegisterType<LockOp::kClear>(this, vregA, reg_types_.Conflict());
}
return;
}
}
if (!field_type->IsLowHalf()) {
work_line_->SetRegisterType<LockOp::kClear>(this, vregA, *field_type);
} else {
work_line_->SetRegisterTypeWide(this, vregA, *field_type, field_type->HighHalf(&reg_types_));
}
} else {
LOG(FATAL) << "Unexpected case.";
}
}
bool MethodVerifier::CheckNotMoveException(const uint16_t* insns, int insn_idx) {
if ((insns[insn_idx] & 0xff) == Instruction::MOVE_EXCEPTION) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid use of move-exception";
return false;
}
return true;
}
bool MethodVerifier::CheckNotMoveResult(const uint16_t* insns, int insn_idx) {
if (((insns[insn_idx] & 0xff) >= Instruction::MOVE_RESULT) &&
((insns[insn_idx] & 0xff) <= Instruction::MOVE_RESULT_OBJECT)) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid use of move-result*";
return false;
}
return true;
}
bool MethodVerifier::CheckNotMoveExceptionOrMoveResult(const uint16_t* insns, int insn_idx) {
return (CheckNotMoveException(insns, insn_idx) && CheckNotMoveResult(insns, insn_idx));
}
bool MethodVerifier::UpdateRegisters(uint32_t next_insn, RegisterLine* merge_line,
bool update_merge_line) {
bool changed = true;
RegisterLine* target_line = reg_table_.GetLine(next_insn);
if (!GetInstructionFlags(next_insn).IsVisitedOrChanged()) {
/*
* We haven't processed this instruction before, and we haven't touched the registers here, so
* there's nothing to "merge". Copy the registers over and mark it as changed. (This is the
* only way a register can transition out of "unknown", so this is not just an optimization.)
*/
target_line->CopyFromLine(merge_line);
if (GetInstructionFlags(next_insn).IsReturn()) {
// Verify that the monitor stack is empty on return.
merge_line->VerifyMonitorStackEmpty(this);
// For returns we only care about the operand to the return, all other registers are dead.
// Initialize them as conflicts so they don't add to GC and deoptimization information.
const Instruction* ret_inst = &code_item_accessor_.InstructionAt(next_insn);
AdjustReturnLine(this, ret_inst, target_line);
// Directly bail if a hard failure was found.
if (have_pending_hard_failure_) {
return false;
}
}
} else {
RegisterLineArenaUniquePtr copy;
if (UNLIKELY(VLOG_IS_ON(verifier_debug))) {
copy.reset(RegisterLine::Create(target_line->NumRegs(), this));
copy->CopyFromLine(target_line);
}
changed = target_line->MergeRegisters(this, merge_line);
if (have_pending_hard_failure_) {
return false;
}
if (UNLIKELY(VLOG_IS_ON(verifier_debug)) && changed) {
LogVerifyInfo() << "Merging at [" << reinterpret_cast<void*>(work_insn_idx_) << "]"
<< " to [" << reinterpret_cast<void*>(next_insn) << "]: " << "\n"
<< copy->Dump(this) << " MERGE\n"
<< merge_line->Dump(this) << " ==\n"
<< target_line->Dump(this) << "\n";
}
if (update_merge_line && changed) {
merge_line->CopyFromLine(target_line);
}
}
if (changed) {
GetInstructionFlags(next_insn).SetChanged();
}
return true;
}
InstructionFlags* MethodVerifier::CurrentInsnFlags() {
return &GetInstructionFlags(work_insn_idx_);
}
const RegType& MethodVerifier::GetMethodReturnType() {
if (return_type_ == nullptr) {
if (method_being_verified_ != nullptr) {
ObjPtr<mirror::Class> return_type_class = can_load_classes_
? method_being_verified_->ResolveReturnType()
: method_being_verified_->LookupResolvedReturnType();
if (return_type_class != nullptr) {
return_type_ = &FromClass(method_being_verified_->GetReturnTypeDescriptor(),
return_type_class,
return_type_class->CannotBeAssignedFromOtherTypes());
} else {
DCHECK(!can_load_classes_ || self_->IsExceptionPending());
self_->ClearException();
}
}
if (return_type_ == nullptr) {
const DexFile::MethodId& method_id = dex_file_->GetMethodId(dex_method_idx_);
const DexFile::ProtoId& proto_id = dex_file_->GetMethodPrototype(method_id);
dex::TypeIndex return_type_idx = proto_id.return_type_idx_;
const char* descriptor = dex_file_->GetTypeDescriptor(dex_file_->GetTypeId(return_type_idx));
return_type_ = &reg_types_.FromDescriptor(GetClassLoader(), descriptor, false);
}
}
return *return_type_;
}
const RegType& MethodVerifier::GetDeclaringClass() {
if (declaring_class_ == nullptr) {
const DexFile::MethodId& method_id = dex_file_->GetMethodId(dex_method_idx_);
const char* descriptor
= dex_file_->GetTypeDescriptor(dex_file_->GetTypeId(method_id.class_idx_));
if (method_being_verified_ != nullptr) {
ObjPtr<mirror::Class> klass = method_being_verified_->GetDeclaringClass();
declaring_class_ = &FromClass(descriptor, klass, klass->CannotBeAssignedFromOtherTypes());
} else {
declaring_class_ = &reg_types_.FromDescriptor(GetClassLoader(), descriptor, false);
}
}
return *declaring_class_;
}
std::vector<int32_t> MethodVerifier::DescribeVRegs(uint32_t dex_pc) {
RegisterLine* line = reg_table_.GetLine(dex_pc);
DCHECK(line != nullptr) << "No register line at DEX pc " << StringPrintf("0x%x", dex_pc);
std::vector<int32_t> result;
for (size_t i = 0; i < line->NumRegs(); ++i) {
const RegType& type = line->GetRegisterType(this, i);
if (type.IsConstant()) {
result.push_back(type.IsPreciseConstant() ? kConstant : kImpreciseConstant);
const ConstantType* const_val = down_cast<const ConstantType*>(&type);
result.push_back(const_val->ConstantValue());
} else if (type.IsConstantLo()) {
result.push_back(type.IsPreciseConstantLo() ? kConstant : kImpreciseConstant);
const ConstantType* const_val = down_cast<const ConstantType*>(&type);
result.push_back(const_val->ConstantValueLo());
} else if (type.IsConstantHi()) {
result.push_back(type.IsPreciseConstantHi() ? kConstant : kImpreciseConstant);
const ConstantType* const_val = down_cast<const ConstantType*>(&type);
result.push_back(const_val->ConstantValueHi());
} else if (type.IsIntegralTypes()) {
result.push_back(kIntVReg);
result.push_back(0);
} else if (type.IsFloat()) {
result.push_back(kFloatVReg);
result.push_back(0);
} else if (type.IsLong()) {
result.push_back(kLongLoVReg);
result.push_back(0);
result.push_back(kLongHiVReg);
result.push_back(0);
++i;
} else if (type.IsDouble()) {
result.push_back(kDoubleLoVReg);
result.push_back(0);
result.push_back(kDoubleHiVReg);
result.push_back(0);
++i;
} else if (type.IsUndefined() || type.IsConflict() || type.IsHighHalf()) {
result.push_back(kUndefined);
result.push_back(0);
} else {
CHECK(type.IsNonZeroReferenceTypes());
result.push_back(kReferenceVReg);
result.push_back(0);
}
}
return result;
}
const RegType& MethodVerifier::DetermineCat1Constant(int32_t value, bool precise) {
if (precise) {
// Precise constant type.
return reg_types_.FromCat1Const(value, true);
} else {
// Imprecise constant type.
if (value < -32768) {
return reg_types_.IntConstant();
} else if (value < -128) {
return reg_types_.ShortConstant();
} else if (value < 0) {
return reg_types_.ByteConstant();
} else if (value == 0) {
return reg_types_.Zero();
} else if (value == 1) {
return reg_types_.One();
} else if (value < 128) {
return reg_types_.PosByteConstant();
} else if (value < 32768) {
return reg_types_.PosShortConstant();
} else if (value < 65536) {
return reg_types_.CharConstant();
} else {
return reg_types_.IntConstant();
}
}
}
void MethodVerifier::Init() {
art::verifier::RegTypeCache::Init();
}
void MethodVerifier::Shutdown() {
verifier::RegTypeCache::ShutDown();
}
void MethodVerifier::VisitStaticRoots(RootVisitor* visitor) {
RegTypeCache::VisitStaticRoots(visitor);
}
void MethodVerifier::VisitRoots(RootVisitor* visitor, const RootInfo& root_info) {
reg_types_.VisitRoots(visitor, root_info);
}
const RegType& MethodVerifier::FromClass(const char* descriptor,
ObjPtr<mirror::Class> klass,
bool precise) {
DCHECK(klass != nullptr);
if (precise && !klass->IsInstantiable() && !klass->IsPrimitive()) {
Fail(VerifyError::VERIFY_ERROR_NO_CLASS) << "Could not create precise reference for "
<< "non-instantiable klass " << descriptor;
precise = false;
}
return reg_types_.FromClass(descriptor, klass, precise);
}
} // namespace verifier
} // namespace art