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gerrit-public.fairphone.software / platform / art / 307f650806e55ea54e7562a25a20b4b79f65271b / . / 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 "base/logging.h"
#include "base/mutex-inl.h"
#include "class_linker.h"
#include "compiler_callbacks.h"
#include "dex_file-inl.h"
#include "dex_instruction-inl.h"
#include "dex_instruction_visitor.h"
#include "field_helper.h"
#include "gc/accounting/card_table-inl.h"
#include "indenter.h"
#include "intern_table.h"
#include "leb128.h"
#include "method_helper-inl.h"
#include "mirror/art_field-inl.h"
#include "mirror/art_method-inl.h"
#include "mirror/class.h"
#include "mirror/class-inl.h"
#include "mirror/dex_cache-inl.h"
#include "mirror/object-inl.h"
#include "mirror/object_array-inl.h"
#include "register_line-inl.h"
#include "runtime.h"
#include "scoped_thread_state_change.h"
#include "handle_scope-inl.h"
#include "verifier/dex_gc_map.h"
namespace art {
namespace verifier {
static constexpr bool gDebugVerify = false;
// TODO: Add a constant to method_verifier to turn on verbose logging?
void PcToRegisterLineTable::Init(RegisterTrackingMode mode, InstructionFlags* flags,
uint32_t insns_size, uint16_t registers_size,
MethodVerifier* verifier) {
DCHECK_GT(insns_size, 0U);
register_lines_.reset(new RegisterLine*[insns_size]());
size_ = 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] = RegisterLine::Create(registers_size, verifier);
}
}
}
PcToRegisterLineTable::~PcToRegisterLineTable() {
for (size_t i = 0; i < size_; i++) {
delete register_lines_[i];
if (kIsDebugBuild) {
register_lines_[i] = nullptr;
}
}
}
MethodVerifier::FailureKind MethodVerifier::VerifyClass(mirror::Class* klass,
bool allow_soft_failures,
std::string* error) {
if (klass->IsVerified()) {
return kNoFailure;
}
bool early_failure = false;
std::string failure_message;
const DexFile& dex_file = klass->GetDexFile();
const DexFile::ClassDef* class_def = klass->GetClassDef();
mirror::Class* super = klass->GetSuperClass();
if (super == NULL && "Ljava/lang/Object;" != klass->GetDescriptor()) {
early_failure = true;
failure_message = " that has no super class";
} else if (super != NULL && super->IsFinal()) {
early_failure = true;
failure_message = " that attempts to sub-class final class " + PrettyDescriptor(super);
} else if (class_def == NULL) {
early_failure = true;
failure_message = " that isn't present in dex file " + dex_file.GetLocation();
}
if (early_failure) {
*error = "Verifier rejected class " + PrettyDescriptor(klass) + failure_message;
if (Runtime::Current()->IsCompiler()) {
ClassReference ref(&dex_file, klass->GetDexClassDefIndex());
Runtime::Current()->GetCompilerCallbacks()->ClassRejected(ref);
}
return kHardFailure;
}
StackHandleScope<2> hs(Thread::Current());
Handle<mirror::DexCache> dex_cache(hs.NewHandle(klass->GetDexCache()));
Handle<mirror::ClassLoader> class_loader(hs.NewHandle(klass->GetClassLoader()));
return VerifyClass(&dex_file, dex_cache, class_loader, class_def, allow_soft_failures, error);
}
MethodVerifier::FailureKind MethodVerifier::VerifyClass(const DexFile* dex_file,
Handle<mirror::DexCache> dex_cache,
Handle<mirror::ClassLoader> class_loader,
const DexFile::ClassDef* class_def,
bool allow_soft_failures,
std::string* error) {
DCHECK(class_def != nullptr);
const byte* class_data = dex_file->GetClassData(*class_def);
if (class_data == NULL) {
// empty class, probably a marker interface
return kNoFailure;
}
ClassDataItemIterator it(*dex_file, class_data);
while (it.HasNextStaticField() || it.HasNextInstanceField()) {
it.Next();
}
size_t error_count = 0;
bool hard_fail = false;
ClassLinker* linker = Runtime::Current()->GetClassLinker();
int64_t previous_direct_method_idx = -1;
while (it.HasNextDirectMethod()) {
uint32_t method_idx = it.GetMemberIndex();
if (method_idx == previous_direct_method_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
it.Next();
continue;
}
previous_direct_method_idx = method_idx;
InvokeType type = it.GetMethodInvokeType(*class_def);
mirror::ArtMethod* method =
linker->ResolveMethod(*dex_file, method_idx, dex_cache, class_loader,
NullHandle<mirror::ArtMethod>(), type);
if (method == NULL) {
DCHECK(Thread::Current()->IsExceptionPending());
// We couldn't resolve the method, but continue regardless.
Thread::Current()->ClearException();
}
MethodVerifier::FailureKind result = VerifyMethod(method_idx,
dex_file,
dex_cache,
class_loader,
class_def,
it.GetMethodCodeItem(),
method,
it.GetMemberAccessFlags(),
allow_soft_failures,
false);
if (result != kNoFailure) {
if (result == kHardFailure) {
hard_fail = true;
if (error_count > 0) {
*error += "\n";
}
*error = "Verifier rejected class ";
*error += PrettyDescriptor(dex_file->GetClassDescriptor(*class_def));
*error += " due to bad method ";
*error += PrettyMethod(method_idx, *dex_file);
}
++error_count;
}
it.Next();
}
int64_t previous_virtual_method_idx = -1;
while (it.HasNextVirtualMethod()) {
uint32_t method_idx = it.GetMemberIndex();
if (method_idx == previous_virtual_method_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
it.Next();
continue;
}
previous_virtual_method_idx = method_idx;
InvokeType type = it.GetMethodInvokeType(*class_def);
mirror::ArtMethod* method =
linker->ResolveMethod(*dex_file, method_idx, dex_cache, class_loader,
NullHandle<mirror::ArtMethod>(), type);
if (method == NULL) {
DCHECK(Thread::Current()->IsExceptionPending());
// We couldn't resolve the method, but continue regardless.
Thread::Current()->ClearException();
}
MethodVerifier::FailureKind result = VerifyMethod(method_idx,
dex_file,
dex_cache,
class_loader,
class_def,
it.GetMethodCodeItem(),
method,
it.GetMemberAccessFlags(),
allow_soft_failures,
false);
if (result != kNoFailure) {
if (result == kHardFailure) {
hard_fail = true;
if (error_count > 0) {
*error += "\n";
}
*error = "Verifier rejected class ";
*error += PrettyDescriptor(dex_file->GetClassDescriptor(*class_def));
*error += " due to bad method ";
*error += PrettyMethod(method_idx, *dex_file);
}
++error_count;
}
it.Next();
}
if (error_count == 0) {
return kNoFailure;
} else {
return hard_fail ? kHardFailure : kSoftFailure;
}
}
MethodVerifier::FailureKind MethodVerifier::VerifyMethod(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,
mirror::ArtMethod* method,
uint32_t method_access_flags,
bool allow_soft_failures,
bool need_precise_constants) {
MethodVerifier::FailureKind result = kNoFailure;
uint64_t start_ns = NanoTime();
MethodVerifier verifier(dex_file, &dex_cache, &class_loader, class_def, code_item,
method_idx, method, method_access_flags, true, allow_soft_failures,
need_precise_constants);
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 (verifier.failures_.size() != 0) {
if (VLOG_IS_ON(verifier)) {
verifier.DumpFailures(VLOG_STREAM(verifier) << "Soft verification failures in "
<< PrettyMethod(method_idx, *dex_file) << "\n");
}
result = kSoftFailure;
}
} else {
// Bad method data.
CHECK_NE(verifier.failures_.size(), 0U);
CHECK(verifier.have_pending_hard_failure_);
verifier.DumpFailures(LOG(INFO) << "Verification error in "
<< PrettyMethod(method_idx, *dex_file) << "\n");
if (gDebugVerify) {
std::cout << "\n" << verifier.info_messages_.str();
verifier.Dump(std::cout);
}
result = kHardFailure;
}
uint64_t duration_ns = NanoTime() - start_ns;
if (duration_ns > MsToNs(100) && !kIsDebugBuild) {
LOG(WARNING) << "Verification of " << PrettyMethod(method_idx, *dex_file)
<< " took " << PrettyDuration(duration_ns);
}
return result;
}
void MethodVerifier::VerifyMethodAndDump(std::ostream& os, 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,
mirror::ArtMethod* method,
uint32_t method_access_flags) {
MethodVerifier verifier(dex_file, &dex_cache, &class_loader, class_def, code_item,
dex_method_idx, method, method_access_flags, true, true, true);
verifier.Verify();
verifier.DumpFailures(os);
os << verifier.info_messages_.str();
verifier.Dump(os);
}
MethodVerifier::MethodVerifier(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,
mirror::ArtMethod* method, uint32_t method_access_flags,
bool can_load_classes, bool allow_soft_failures,
bool need_precise_constants)
: reg_types_(can_load_classes),
work_insn_idx_(-1),
dex_method_idx_(dex_method_idx),
mirror_method_(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_(code_item),
declaring_class_(NULL),
interesting_dex_pc_(-1),
monitor_enter_dex_pcs_(nullptr),
have_pending_hard_failure_(false),
have_pending_runtime_throw_failure_(false),
new_instance_count_(0),
monitor_enter_count_(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) {
Runtime::Current()->AddMethodVerifier(this);
DCHECK(class_def != nullptr);
}
MethodVerifier::~MethodVerifier() {
Runtime::Current()->RemoveMethodVerifier(this);
STLDeleteElements(&failure_messages_);
}
void MethodVerifier::FindLocksAtDexPc(mirror::ArtMethod* m, uint32_t dex_pc,
std::vector<uint32_t>* monitor_enter_dex_pcs) {
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(m->GetDexFile(), &dex_cache, &class_loader, &m->GetClassDef(),
m->GetCodeItem(), m->GetDexMethodIndex(), m, m->GetAccessFlags(), false,
true, false);
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_ != NULL);
CHECK(code_item_ != NULL); // This only makes sense for methods with code.
// 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();
}
mirror::ArtField* MethodVerifier::FindAccessedFieldAtDexPc(mirror::ArtMethod* m,
uint32_t dex_pc) {
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(m->GetDexFile(), &dex_cache, &class_loader, &m->GetClassDef(),
m->GetCodeItem(), m->GetDexMethodIndex(), m, m->GetAccessFlags(), true,
true, false);
return verifier.FindAccessedFieldAtDexPc(dex_pc);
}
mirror::ArtField* MethodVerifier::FindAccessedFieldAtDexPc(uint32_t dex_pc) {
CHECK(code_item_ != NULL); // This only makes sense for methods with code.
// 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.
bool success = Verify();
if (!success) {
return nullptr;
}
RegisterLine* register_line = reg_table_.GetLine(dex_pc);
if (register_line == NULL) {
return nullptr;
}
const Instruction* inst = Instruction::At(code_item_->insns_ + dex_pc);
return GetQuickFieldAccess(inst, register_line);
}
mirror::ArtMethod* MethodVerifier::FindInvokedMethodAtDexPc(mirror::ArtMethod* m,
uint32_t dex_pc) {
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(m->GetDexFile(), &dex_cache, &class_loader, &m->GetClassDef(),
m->GetCodeItem(), m->GetDexMethodIndex(), m, m->GetAccessFlags(), true,
true, false);
return verifier.FindInvokedMethodAtDexPc(dex_pc);
}
mirror::ArtMethod* MethodVerifier::FindInvokedMethodAtDexPc(uint32_t dex_pc) {
CHECK(code_item_ != NULL); // This only makes sense for methods with code.
// 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.
bool success = Verify();
if (!success) {
return NULL;
}
RegisterLine* register_line = reg_table_.GetLine(dex_pc);
if (register_line == NULL) {
return NULL;
}
const Instruction* inst = Instruction::At(code_item_->insns_ + dex_pc);
const bool is_range = (inst->Opcode() == Instruction::INVOKE_VIRTUAL_RANGE_QUICK);
return GetQuickInvokedMethod(inst, register_line, is_range);
}
bool MethodVerifier::Verify() {
// If there aren't any instructions, make sure that's expected, then exit successfully.
if (code_item_ == NULL) {
if ((method_access_flags_ & (kAccNative | kAccAbstract)) == 0) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "zero-length code in concrete non-native method";
return false;
} else {
return true;
}
}
// Sanity-check the register counts. ins + locals = registers, so make sure that ins <= registers.
if (code_item_->ins_size_ > code_item_->registers_size_) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "bad register counts (ins=" << code_item_->ins_size_
<< " regs=" << code_item_->registers_size_;
return false;
}
// Allocate and initialize an array to hold instruction data.
insn_flags_.reset(new InstructionFlags[code_item_->insns_size_in_code_units_]());
// Run through the instructions and see if the width checks out.
bool result = ComputeWidthsAndCountOps();
// Flag instructions guarded by a "try" block and check exception handlers.
result = result && ScanTryCatchBlocks();
// Perform static instruction verification.
result = result && VerifyInstructions();
// Perform code-flow analysis and return.
result = result && VerifyCodeFlow();
// Compute information for compiler.
if (result && Runtime::Current()->IsCompiler()) {
result = Runtime::Current()->GetCompilerCallbacks()->MethodVerified(this);
}
return result;
}
std::ostream& MethodVerifier::Fail(VerifyError 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:
if (Runtime::Current()->IsCompiler() || !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;
}
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: {
if (Runtime::Current()->IsCompiler()) {
ClassReference ref(dex_file_, dex_file_->GetIndexForClassDef(*class_def_));
Runtime::Current()->GetCompilerCallbacks()->ClassRejected(ref);
}
have_pending_hard_failure_ = true;
break;
}
}
failures_.push_back(error);
std::string location(StringPrintf("%s: [0x%X]", PrettyMethod(dex_method_idx_, *dex_file_).c_str(),
work_insn_idx_));
std::ostringstream* failure_message = new std::ostringstream(location);
failure_messages_.push_back(failure_message);
return *failure_message;
}
std::ostream& MethodVerifier::LogVerifyInfo() {
return info_messages_ << "VFY: " << PrettyMethod(dex_method_idx_, *dex_file_)
<< '[' << 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);
delete last_fail_message;
}
void MethodVerifier::AppendToLastFailMessage(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() {
const uint16_t* insns = code_item_->insns_;
size_t insns_size = code_item_->insns_size_in_code_units_;
const Instruction* inst = Instruction::At(insns);
size_t new_instance_count = 0;
size_t monitor_enter_count = 0;
size_t dex_pc = 0;
while (dex_pc < insns_size) {
Instruction::Code opcode = inst->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;
}
size_t inst_size = inst->SizeInCodeUnits();
insn_flags_[dex_pc].SetLengthInCodeUnits(inst_size);
dex_pc += inst_size;
inst = inst->Next();
}
if (dex_pc != insns_size) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "code did not end where expected ("
<< dex_pc << " vs. " << insns_size << ")";
return false;
}
new_instance_count_ = new_instance_count;
monitor_enter_count_ = monitor_enter_count;
return true;
}
bool MethodVerifier::ScanTryCatchBlocks() {
uint32_t tries_size = code_item_->tries_size_;
if (tries_size == 0) {
return true;
}
uint32_t insns_size = code_item_->insns_size_in_code_units_;
const DexFile::TryItem* tries = DexFile::GetTryItems(*code_item_, 0);
for (uint32_t idx = 0; idx < tries_size; idx++) {
const DexFile::TryItem* try_item = &tries[idx];
uint32_t start = try_item->start_addr_;
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 (!insn_flags_[start].IsOpcode()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD)
<< "'try' block starts inside an instruction (" << start << ")";
return false;
}
for (uint32_t dex_pc = start; dex_pc < end;
dex_pc += insn_flags_[dex_pc].GetLengthInCodeUnits()) {
insn_flags_[dex_pc].SetInTry();
}
}
// Iterate over each of the handlers to verify target addresses.
const byte* handlers_ptr = DexFile::GetCatchHandlerData(*code_item_, 0);
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 (!insn_flags_[dex_pc].IsOpcode()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD)
<< "exception handler starts at bad address (" << dex_pc << ")";
return false;
}
insn_flags_[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() != DexFile::kDexNoIndex16) {
mirror::Class* exception_type = linker->ResolveType(*dex_file_,
iterator.GetHandlerTypeIndex(),
*dex_cache_, *class_loader_);
if (exception_type == NULL) {
DCHECK(Thread::Current()->IsExceptionPending());
Thread::Current()->ClearException();
}
}
}
handlers_ptr = iterator.EndDataPointer();
}
return true;
}
bool MethodVerifier::VerifyInstructions() {
const Instruction* inst = Instruction::At(code_item_->insns_);
/* Flag the start of the method as a branch target, and a GC point due to stack overflow errors */
insn_flags_[0].SetBranchTarget();
insn_flags_[0].SetCompileTimeInfoPoint();
uint32_t insns_size = code_item_->insns_size_in_code_units_;
for (uint32_t dex_pc = 0; dex_pc < insns_size;) {
if (!VerifyInstruction(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() || inst->IsSwitch() || inst->IsThrow()) {
insn_flags_[dex_pc].SetCompileTimeInfoPoint();
} else if (inst->IsReturn()) {
insn_flags_[dex_pc].SetCompileTimeInfoPointAndReturn();
}
dex_pc += inst->SizeInCodeUnits();
inst = inst->Next();
}
return true;
}
bool MethodVerifier::VerifyInstruction(const Instruction* inst, uint32_t code_offset) {
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(inst->VRegB());
break;
case Instruction::kVerifyRegBString:
result = result && CheckStringIndex(inst->VRegB());
break;
case Instruction::kVerifyRegBType:
result = result && CheckTypeIndex(inst->VRegB());
break;
case Instruction::kVerifyRegBWide:
result = result && CheckWideRegisterIndex(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(inst->VRegC());
break;
case Instruction::kVerifyRegCType:
result = result && CheckTypeIndex(inst->VRegC());
break;
case Instruction::kVerifyRegCWide:
result = result && CheckWideRegisterIndex(inst->VRegC());
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: {
if (inst->GetVerifyExtraFlags() == Instruction::kVerifyVarArgNonZero && inst->VRegA() <= 0) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid arg count (" << inst->VRegA() << ") in "
"non-range invoke";
return false;
}
uint32_t args[Instruction::kMaxVarArgRegs];
inst->GetVarArgs(args);
result = result && CheckVarArgRegs(inst->VRegA(), 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 (inst->GetVerifyIsRuntimeOnly() && Runtime::Current()->IsCompiler()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "opcode only expected at runtime " << inst->Name();
result = false;
}
return result;
}
bool MethodVerifier::CheckRegisterIndex(uint32_t idx) {
if (idx >= code_item_->registers_size_) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "register index out of range (" << idx << " >= "
<< code_item_->registers_size_ << ")";
return false;
}
return true;
}
bool MethodVerifier::CheckWideRegisterIndex(uint32_t idx) {
if (idx + 1 >= code_item_->registers_size_) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "wide register index out of range (" << idx
<< "+1 >= " << code_item_->registers_size_ << ")";
return false;
}
return true;
}
bool MethodVerifier::CheckFieldIndex(uint32_t idx) {
if (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;
}
bool MethodVerifier::CheckMethodIndex(uint32_t idx) {
if (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;
}
bool MethodVerifier::CheckNewInstance(uint32_t idx) {
if (idx >= dex_file_->GetHeader().type_ids_size_) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "bad type index " << idx << " (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 (descriptor[0] != 'L') {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "can't call new-instance on type '" << descriptor << "'";
return false;
}
return true;
}
bool MethodVerifier::CheckStringIndex(uint32_t idx) {
if (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;
}
bool MethodVerifier::CheckTypeIndex(uint32_t idx) {
if (idx >= dex_file_->GetHeader().type_ids_size_) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "bad type index " << idx << " (max "
<< dex_file_->GetHeader().type_ids_size_ << ")";
return false;
}
return true;
}
bool MethodVerifier::CheckNewArray(uint32_t idx) {
if (idx >= dex_file_->GetHeader().type_ids_size_) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "bad type index " << idx << " (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 (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 (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_->insns_size_in_code_units_;
const uint16_t* insns = code_item_->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] | (((int32_t) insns[2]) << 16);
if ((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 32-bit aligned */
if ((reinterpret_cast<uintptr_t>(array_data) & 0x03) != 0) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "unaligned array data table: at " << cur_offset
<< ", data offset " << array_data_offset;
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 (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 (!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 (((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;
}
const uint32_t insn_count = code_item_->insns_size_in_code_units_;
int32_t abs_offset = cur_offset + offset;
if (abs_offset < 0 ||
(uint32_t) abs_offset >= insn_count ||
!insn_flags_[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;
}
insn_flags_[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_->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;
break;
}
return true;
}
bool MethodVerifier::CheckSwitchTargets(uint32_t cur_offset) {
const uint32_t insn_count = code_item_->insns_size_in_code_units_;
DCHECK_LT(cur_offset, insn_count);
const uint16_t* insns = code_item_->insns_ + cur_offset;
/* make sure the start of the switch is in range */
int32_t switch_offset = insns[1] | ((int32_t) insns[2]) << 16;
if ((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 32-bit aligned */
if ((reinterpret_cast<uintptr_t>(switch_insns) & 0x03) != 0) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "unaligned switch table: at " << cur_offset
<< ", switch offset " << switch_offset;
return false;
}
uint32_t switch_count = switch_insns[1];
int32_t keys_offset, targets_offset;
uint16_t expected_signature;
if ((*insns & 0xff) == Instruction::PACKED_SWITCH) {
/* 0=sig, 1=count, 2/3=firstKey */
targets_offset = 4;
keys_offset = -1;
expected_signature = Instruction::kPackedSwitchSignature;
} else {
/* 0=sig, 1=count, 2..count*2 = keys */
keys_offset = 2;
targets_offset = 2 + 2 * switch_count;
expected_signature = Instruction::kSparseSwitchSignature;
}
uint32_t table_size = targets_offset + switch_count * 2;
if (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 (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;
}
/* for a sparse switch, verify the keys are in ascending order */
if (keys_offset > 0 && switch_count > 1) {
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 = (int32_t) switch_insns[keys_offset + targ * 2] |
(int32_t) (switch_insns[keys_offset + targ * 2 + 1] << 16);
if (key <= last_key) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid packed 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 = (int32_t) switch_insns[targets_offset + targ * 2] |
(int32_t) (switch_insns[targets_offset + targ * 2 + 1] << 16);
int32_t abs_offset = cur_offset + offset;
if (abs_offset < 0 ||
abs_offset >= (int32_t) insn_count ||
!insn_flags_[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;
}
insn_flags_[abs_offset].SetBranchTarget();
}
return true;
}
bool MethodVerifier::CheckVarArgRegs(uint32_t vA, uint32_t arg[]) {
if (vA > Instruction::kMaxVarArgRegs) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid arg count (" << vA << ") in non-range invoke)";
return false;
}
uint16_t registers_size = code_item_->registers_size_;
for (uint32_t idx = 0; idx < vA; idx++) {
if (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_->registers_size_;
// 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 (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() {
uint16_t registers_size = code_item_->registers_size_;
uint32_t insns_size = code_item_->insns_size_in_code_units_;
if (registers_size * insns_size > 4*1024*1024) {
LOG(WARNING) << "warning: method is huge (regs=" << registers_size
<< " insns_size=" << insns_size << ")";
}
/* Create and initialize table holding register status */
reg_table_.Init(kTrackCompilerInterestPoints,
insn_flags_.get(),
insns_size,
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 += PrettyMethod(dex_method_idx_, *dex_file_);
PrependToLastFailMessage(prepend);
return 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;
}
extern "C" void MethodVerifierGdbDump(MethodVerifier* v)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
v->Dump(std::cerr);
}
void MethodVerifier::Dump(std::ostream& os) {
if (code_item_ == NULL) {
os << "Native method\n";
return;
}
{
os << "Register Types:\n";
Indenter indent_filter(os.rdbuf(), kIndentChar, kIndentBy1Count);
std::ostream indent_os(&indent_filter);
reg_types_.Dump(indent_os);
}
os << "Dumping instructions and register lines:\n";
Indenter indent_filter(os.rdbuf(), kIndentChar, kIndentBy1Count);
std::ostream indent_os(&indent_filter);
const Instruction* inst = Instruction::At(code_item_->insns_);
for (size_t dex_pc = 0; dex_pc < code_item_->insns_size_in_code_units_;
dex_pc += insn_flags_[dex_pc].GetLengthInCodeUnits()) {
RegisterLine* reg_line = reg_table_.GetLine(dex_pc);
if (reg_line != NULL) {
indent_os << reg_line->Dump() << "\n";
}
indent_os << StringPrintf("0x%04zx", dex_pc) << ": " << insn_flags_[dex_pc].ToString() << " ";
const bool kDumpHexOfInstruction = false;
if (kDumpHexOfInstruction) {
indent_os << inst->DumpHex(5) << " ";
}
indent_os << inst->DumpString(dex_file_) << "\n";
inst = inst->Next();
}
}
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);
int arg_start = code_item_->registers_size_ - code_item_->ins_size_;
size_t expected_args = code_item_->ins_size_; /* long/double count as two */
DCHECK_GE(arg_start, 0); /* should have been verified earlier */
// Include the "this" pointer.
size_t cur_arg = 0;
if (!IsStatic()) {
// 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() && !declaring_class.IsJavaLangObject()) {
reg_line->SetRegisterType(arg_start + cur_arg,
reg_types_.UninitializedThisArgument(declaring_class));
} else {
reg_line->SetRegisterType(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 == NULL) {
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).
{
const RegType& reg_type = ResolveClassAndCheckAccess(iterator.GetTypeIdx());
if (!reg_type.IsNonZeroReferenceTypes()) {
DCHECK(HasFailures());
return false;
}
reg_line->SetRegisterType(arg_start + cur_arg, reg_type);
}
break;
case 'Z':
reg_line->SetRegisterType(arg_start + cur_arg, reg_types_.Boolean());
break;
case 'C':
reg_line->SetRegisterType(arg_start + cur_arg, reg_types_.Char());
break;
case 'B':
reg_line->SetRegisterType(arg_start + cur_arg, reg_types_.Byte());
break;
case 'I':
reg_line->SetRegisterType(arg_start + cur_arg, reg_types_.Integer());
break;
case 'S':
reg_line->SetRegisterType(arg_start + cur_arg, reg_types_.Short());
break;
case 'F':
reg_line->SetRegisterType(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 = descriptor[0] == 'J' ? reg_types_.LongLo() : reg_types_.DoubleLo();
const RegType& hi_half = descriptor[0] == 'J' ? reg_types_.LongHi() : reg_types_.DoubleHi();
reg_line->SetRegisterTypeWide(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_->insns_;
const uint32_t insns_size = code_item_->insns_size_in_code_units_;
/* Begin by marking the first instruction as "changed". */
insn_flags_[0].SetChanged();
uint32_t start_guess = 0;
/* Continue until no instructions are marked "changed". */
while (true) {
// 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 (insn_flags_[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 (insn_flags_[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 != NULL) {
if (work_line_->CompareLine(register_line) != 0) {
Dump(std::cout);
std::cout << info_messages_.str();
LOG(FATAL) << "work_line diverged in " << PrettyMethod(dex_method_idx_, *dex_file_)
<< "@" << reinterpret_cast<void*>(work_insn_idx_) << "\n"
<< " work_line=" << *work_line_ << "\n"
<< " expected=" << *register_line;
}
}
}
if (!CodeFlowVerifyInstruction(&start_guess)) {
std::string prepend(PrettyMethod(dex_method_idx_, *dex_file_));
prepend += " failed to verify: ";
PrependToLastFailMessage(prepend);
return false;
}
/* Clear "changed" and mark as visited. */
insn_flags_[insn_idx].SetVisited();
insn_flags_[insn_idx].ClearChanged();
}
if (gDebugVerify) {
/*
* 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;
uint32_t insn_idx = 0;
for (; insn_idx < insns_size; insn_idx += insn_flags_[insn_idx].GetLengthInCodeUnits()) {
/*
* 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))) {
insn_flags_[insn_idx].SetVisited();
}
if (!insn_flags_[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*>(insn_idx - 1);
}
// To dump the state of the verify after a method, do something like:
// if (PrettyMethod(dex_method_idx_, *dex_file_) ==
// "boolean java.lang.String.equals(java.lang.Object)") {
// LOG(INFO) << info_messages_.str();
// }
}
return true;
}
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_ != NULL && work_insn_idx_ == interesting_dex_pc_) {
monitor_enter_dex_pcs_->clear(); // The new work line is more accurate than the previous one.
for (size_t i = 0; i < work_line_->GetMonitorEnterCount(); ++i) {
monitor_enter_dex_pcs_->push_back(work_line_->GetMonitorEnterDexPc(i));
}
}
/*
* 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_->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 (gDebugVerify) {
// Generate processing back trace to debug verifier
LogVerifyInfo() << "Processing " << inst->DumpString(dex_file_) << "\n"
<< *work_line_.get() << "\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 {
#ifndef NDEBUG
saved_line_->FillWithGarbage();
#endif
}
// 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.
std::unique_ptr<RegisterLine> branch_line;
std::unique_ptr<RegisterLine> 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(inst->VRegA_12x(), inst->VRegB_12x(), kTypeCategory1nr);
break;
case Instruction::MOVE_FROM16:
work_line_->CopyRegister1(inst->VRegA_22x(), inst->VRegB_22x(), kTypeCategory1nr);
break;
case Instruction::MOVE_16:
work_line_->CopyRegister1(inst->VRegA_32x(), inst->VRegB_32x(), kTypeCategory1nr);
break;
case Instruction::MOVE_WIDE:
work_line_->CopyRegister2(inst->VRegA_12x(), inst->VRegB_12x());
break;
case Instruction::MOVE_WIDE_FROM16:
work_line_->CopyRegister2(inst->VRegA_22x(), inst->VRegB_22x());
break;
case Instruction::MOVE_WIDE_16:
work_line_->CopyRegister2(inst->VRegA_32x(), inst->VRegB_32x());
break;
case Instruction::MOVE_OBJECT:
work_line_->CopyRegister1(inst->VRegA_12x(), inst->VRegB_12x(), kTypeCategoryRef);
break;
case Instruction::MOVE_OBJECT_FROM16:
work_line_->CopyRegister1(inst->VRegA_22x(), inst->VRegB_22x(), kTypeCategoryRef);
break;
case Instruction::MOVE_OBJECT_16:
work_line_->CopyRegister1(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(inst->VRegA_11x(), false);
break;
case Instruction::MOVE_RESULT_WIDE:
work_line_->CopyResultRegister2(inst->VRegA_11x());
break;
case Instruction::MOVE_RESULT_OBJECT:
work_line_->CopyResultRegister1(inst->VRegA_11x(), true);
break;
case Instruction::MOVE_EXCEPTION: {
/*
* 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(inst->VRegA_11x(), res_type);
break;
}
case Instruction::RETURN_VOID:
if (!IsConstructor() || work_line_->CheckConstructorReturn()) {
if (!GetMethodReturnType().IsConflict()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "return-void not expected";
}
}
break;
case Instruction::RETURN:
if (!IsConstructor() || work_line_->CheckConstructorReturn()) {
/* 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(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(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 (!IsConstructor() || work_line_->CheckConstructorReturn()) {
/* 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(vregA, return_type);
if (!success) {
AppendToLastFailMessage(StringPrintf(" return-wide on invalid register v%d", vregA));
}
}
}
break;
case Instruction::RETURN_OBJECT:
if (!IsConstructor() || work_line_->CheckConstructorReturn()) {
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.IsZero());
DCHECK(!return_type.IsUninitializedReference());
const uint32_t vregA = inst->VRegA_11x();
const RegType& reg_type = work_line_->GetRegisterType(vregA);
// Disallow returning uninitialized values and verify that the reference in vAA is an
// instance of the "return_type"
if (reg_type.IsUninitializedTypes()) {
Fail(VERIFY_ERROR_BAD_CLASS_SOFT) << "returning uninitialized object '"
<< reg_type << "'";
} else if (!return_type.IsAssignableFrom(reg_type)) {
if (reg_type.IsUnresolvedTypes() || return_type.IsUnresolvedTypes()) {
Fail(VERIFY_ERROR_NO_CLASS) << " can't resolve returned type '" << return_type
<< "' or '" << reg_type << "'";
} else {
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(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(inst->VRegA_21s(),
DetermineCat1Constant(val, need_precise_constants_));
break;
}
case Instruction::CONST: {
int32_t val = inst->VRegB_31i();
work_line_->SetRegisterType(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(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(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(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(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(inst->VRegA_21h(), lo, hi);
break;
}
case Instruction::CONST_STRING:
work_line_->SetRegisterType(inst->VRegA_21c(), reg_types_.JavaLangString());
break;
case Instruction::CONST_STRING_JUMBO:
work_line_->SetRegisterType(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 = ResolveClassAndCheckAccess(inst->VRegB_21c());
// Register holds class, ie its type is class, on error it will hold Conflict.
work_line_->SetRegisterType(inst->VRegA_21c(),
res_type.IsConflict() ? res_type
: reg_types_.JavaLangClass(true));
break;
}
case Instruction::MONITOR_ENTER:
work_line_->PushMonitor(inst->VRegA_11x(), work_insn_idx_);
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(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 uint32_t type_idx = (is_checkcast) ? inst->VRegB_21c() : inst->VRegC_22c();
const RegType& res_type = ResolveClassAndCheckAccess(type_idx);
if (res_type.IsConflict()) {
// If this is a primitive type, fail HARD.
mirror::Class* klass = (*dex_cache_)->GetResolvedType(type_idx);
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(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(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 (is_checkcast) {
work_line_->SetRegisterType(inst->VRegA_21c(), res_type);
} else {
work_line_->SetRegisterType(inst->VRegA_22c(), reg_types_.Boolean());
}
}
break;
}
case Instruction::ARRAY_LENGTH: {
const RegType& res_type = work_line_->GetRegisterType(inst->VRegB_12x());
if (res_type.IsReferenceTypes()) {
if (!res_type.IsArrayTypes() && !res_type.IsZero()) { // ie not an array or null
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "array-length on non-array " << res_type;
} else {
work_line_->SetRegisterType(inst->VRegA_12x(), reg_types_.Integer());
}
}
break;
}
case Instruction::NEW_INSTANCE: {
const RegType& res_type = ResolveClassAndCheckAccess(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(uninit_type);
// add the new uninitialized reference to the register state
work_line_->SetRegisterType(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(inst->VRegB_23x(), reg_types_.Float())) {
break;
}
if (!work_line_->VerifyRegisterType(inst->VRegC_23x(), reg_types_.Float())) {
break;
}
work_line_->SetRegisterType(inst->VRegA_23x(), reg_types_.Integer());
break;
case Instruction::CMPL_DOUBLE:
case Instruction::CMPG_DOUBLE:
if (!work_line_->VerifyRegisterTypeWide(inst->VRegB_23x(), reg_types_.DoubleLo(),
reg_types_.DoubleHi())) {
break;
}
if (!work_line_->VerifyRegisterTypeWide(inst->VRegC_23x(), reg_types_.DoubleLo(),
reg_types_.DoubleHi())) {
break;
}
work_line_->SetRegisterType(inst->VRegA_23x(), reg_types_.Integer());
break;
case Instruction::CMP_LONG:
if (!work_line_->VerifyRegisterTypeWide(inst->VRegB_23x(), reg_types_.LongLo(),
reg_types_.LongHi())) {
break;
}
if (!work_line_->VerifyRegisterTypeWide(inst->VRegC_23x(), reg_types_.LongLo(),
reg_types_.LongHi())) {
break;
}
work_line_->SetRegisterType(inst->VRegA_23x(), reg_types_.Integer());
break;
case Instruction::THROW: {
const RegType& res_type = work_line_->GetRegisterType(inst->VRegA_11x());
if (!reg_types_.JavaLangThrowable(false).IsAssignableFrom(res_type)) {
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(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(inst->VRegA_31t());
/* array_type can be null if the reg type is Zero */
if (!array_type.IsZero()) {
if (!array_type.IsArrayTypes()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid fill-array-data with array type "
<< array_type;
} else {
const RegType& component_type = reg_types_.GetComponentType(array_type,
class_loader_->Get());
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] | (((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(inst->VRegA_22t());
const RegType& reg_type2 = work_line_->GetRegisterType(inst->VRegB_22t());
bool mismatch = false;
if (reg_type1.IsZero()) { // 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(inst->VRegA_22t());
const RegType& reg_type2 = work_line_->GetRegisterType(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(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 && !insn_flags_[instance_of_idx].IsOpcode()) {
instance_of_idx--;
}
CHECK(insn_flags_[instance_of_idx].IsOpcode());
} else {
break;
}
const Instruction* instance_of_inst = Instruction::At(code_item_->insns_ + 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(instance_of_inst->VRegB_22c());
const RegType& cast_type = ResolveClassAndCheckAccess(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.IsZero() ||
orig_type.IsStrictlyAssignableFrom(cast_type.Merge(orig_type, &reg_types_)))) {
RegisterLine* update_line = RegisterLine::Create(code_item_->registers_size_, 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(instance_of_inst->VRegB_22c(), cast_type);
if (!insn_flags_[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 && !insn_flags_[move_idx].IsOpcode()) {
move_idx--;
}
CHECK(insn_flags_[move_idx].IsOpcode());
const Instruction* move_inst = Instruction::At(code_item_->insns_ + move_idx);
switch (move_inst->Opcode()) {
case Instruction::MOVE_OBJECT:
if (move_inst->VRegA_12x() == instance_of_inst->VRegB_22c()) {
update_line->SetRegisterType(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(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(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(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:
VerifyISGet(inst, reg_types_.Boolean(), true, false);
break;
case Instruction::IGET_BYTE:
VerifyISGet(inst, reg_types_.Byte(), true, false);
break;
case Instruction::IGET_CHAR:
VerifyISGet(inst, reg_types_.Char(), true, false);
break;
case Instruction::IGET_SHORT:
VerifyISGet(inst, reg_types_.Short(), true, false);
break;
case Instruction::IGET:
VerifyISGet(inst, reg_types_.Integer(), true, false);
break;
case Instruction::IGET_WIDE:
VerifyISGet(inst, reg_types_.LongLo(), true, false);
break;
case Instruction::IGET_OBJECT:
VerifyISGet(inst, reg_types_.JavaLangObject(false), false, false);
break;
case Instruction::IPUT_BOOLEAN:
VerifyISPut(inst, reg_types_.Boolean(), true, false);
break;
case Instruction::IPUT_BYTE:
VerifyISPut(inst, reg_types_.Byte(), true, false);
break;
case Instruction::IPUT_CHAR:
VerifyISPut(inst, reg_types_.Char(), true, false);
break;
case Instruction::IPUT_SHORT:
VerifyISPut(inst, reg_types_.Short(), true, false);
break;
case Instruction::IPUT:
VerifyISPut(inst, reg_types_.Integer(), true, false);
break;
case Instruction::IPUT_WIDE:
VerifyISPut(inst, reg_types_.LongLo(), true, false);
break;
case Instruction::IPUT_OBJECT:
VerifyISPut(inst, reg_types_.JavaLangObject(false), false, false);
break;
case Instruction::SGET_BOOLEAN:
VerifyISGet(inst, reg_types_.Boolean(), true, true);
break;
case Instruction::SGET_BYTE:
VerifyISGet(inst, reg_types_.Byte(), true, true);
break;
case Instruction::SGET_CHAR:
VerifyISGet(inst, reg_types_.Char(), true, true);
break;
case Instruction::SGET_SHORT:
VerifyISGet(inst, reg_types_.Short(), true, true);
break;
case Instruction::SGET:
VerifyISGet(inst, reg_types_.Integer(), true, true);
break;
case Instruction::SGET_WIDE:
VerifyISGet(inst, reg_types_.LongLo(), true, true);
break;
case Instruction::SGET_OBJECT:
VerifyISGet(inst, reg_types_.JavaLangObject(false), false, true);
break;
case Instruction::SPUT_BOOLEAN:
VerifyISPut(inst, reg_types_.Boolean(), true, true);
break;
case Instruction::SPUT_BYTE:
VerifyISPut(inst, reg_types_.Byte(), true, true);
break;
case Instruction::SPUT_CHAR:
VerifyISPut(inst, reg_types_.Char(), true, true);
break;
case Instruction::SPUT_SHORT:
VerifyISPut(inst, reg_types_.Short(), true, true);
break;
case Instruction::SPUT:
VerifyISPut(inst, reg_types_.Integer(), true, true);
break;
case Instruction::SPUT_WIDE:
VerifyISPut(inst, reg_types_.LongLo(), true, true);
break;
case Instruction::SPUT_OBJECT:
VerifyISPut(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: {
bool is_range = (inst->Opcode() == Instruction::INVOKE_VIRTUAL_RANGE ||
inst->Opcode() == Instruction::INVOKE_SUPER_RANGE);
bool is_super = (inst->Opcode() == Instruction::INVOKE_SUPER ||
inst->Opcode() == Instruction::INVOKE_SUPER_RANGE);
mirror::ArtMethod* called_method = VerifyInvocationArgs(inst, METHOD_VIRTUAL, is_range,
is_super);
const RegType* return_type = nullptr;
if (called_method != nullptr) {
Thread* self = Thread::Current();
StackHandleScope<1> hs(self);
Handle<mirror::ArtMethod> h_called_method(hs.NewHandle(called_method));
MethodHelper mh(h_called_method);
mirror::Class* return_type_class = mh.GetReturnType(can_load_classes_);
if (return_type_class != nullptr) {
return_type = &reg_types_.FromClass(h_called_method->GetReturnTypeDescriptor(),
return_type_class,
return_type_class->CannotBeAssignedFromOtherTypes());
} else {
DCHECK(!can_load_classes_ || self->IsExceptionPending());
self->ClearException();
}
}
if (return_type == nullptr) {
uint32_t method_idx = (is_range) ? inst->VRegB_3rc() : inst->VRegB_35c();
const DexFile::MethodId& method_id = dex_file_->GetMethodId(method_idx);
uint32_t 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(class_loader_->Get(), descriptor, false);
}
if (!return_type->IsLowHalf()) {
work_line_->SetResultRegisterType(*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);
mirror::ArtMethod* called_method = VerifyInvocationArgs(inst, METHOD_DIRECT,
is_range, false);
const char* return_type_descriptor;
bool is_constructor;
if (called_method == NULL) {
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;
uint32_t 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();
}
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(inst, is_range);
if (this_type.IsConflict()) // failure.
break;
/* no null refs allowed (?) */
if (this_type.IsZero()) {
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_type);
}
const RegType& return_type = reg_types_.FromDescriptor(class_loader_->Get(),
return_type_descriptor, false);
if (!return_type.IsLowHalf()) {
work_line_->SetResultRegisterType(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);
mirror::ArtMethod* called_method = VerifyInvocationArgs(inst,
METHOD_STATIC,
is_range,
false);
const char* descriptor;
if (called_method == NULL) {
uint32_t method_idx = (is_range) ? inst->VRegB_3rc() : inst->VRegB_35c();
const DexFile::MethodId& method_id = dex_file_->GetMethodId(method_idx);
uint32_t 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(class_loader_->Get(), descriptor,
false);
if (!return_type.IsLowHalf()) {
work_line_->SetResultRegisterType(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);
mirror::ArtMethod* abs_method = VerifyInvocationArgs(inst,
METHOD_INTERFACE,
is_range,
false);
if (abs_method != NULL) {
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 '"
<< PrettyMethod(abs_method) << "'";
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(inst, is_range);
if (this_type.IsZero()) {
/* 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 == NULL) {
uint32_t method_idx = (is_range) ? inst->VRegB_3rc() : inst->VRegB_35c();
const DexFile::MethodId& method_id = dex_file_->GetMethodId(method_idx);
uint32_t 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(class_loader_->Get(), descriptor,
false);
if (!return_type.IsLowHalf()) {
work_line_->SetResultRegisterType(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(inst, reg_types_.Integer(), reg_types_.Integer());
break;
case Instruction::NEG_LONG:
case Instruction::NOT_LONG:
work_line_->CheckUnaryOpWide(inst, reg_types_.LongLo(), reg_types_.LongHi(),
reg_types_.LongLo(), reg_types_.LongHi());
break;
case Instruction::NEG_FLOAT:
work_line_->CheckUnaryOp(inst, reg_types_.Float(), reg_types_.Float());
break;
case Instruction::NEG_DOUBLE:
work_line_->CheckUnaryOpWide(inst, reg_types_.DoubleLo(), reg_types_.DoubleHi(),
reg_types_.DoubleLo(), reg_types_.DoubleHi());
break;
case Instruction::INT_TO_LONG:
work_line_->CheckUnaryOpToWide(inst, reg_types_.LongLo(), reg_types_.LongHi(),
reg_types_.Integer());
break;
case Instruction::INT_TO_FLOAT:
work_line_->CheckUnaryOp(inst, reg_types_.Float(), reg_types_.Integer());
break;
case Instruction::INT_TO_DOUBLE:
work_line_->CheckUnaryOpToWide(inst, reg_types_.DoubleLo(), reg_types_.DoubleHi(),
reg_types_.Integer());
break;
case Instruction::LONG_TO_INT:
work_line_->CheckUnaryOpFromWide(inst, reg_types_.Integer(),
reg_types_.LongLo(), reg_types_.LongHi());
break;
case Instruction::LONG_TO_FLOAT:
work_line_->CheckUnaryOpFromWide(inst, reg_types_.Float(),
reg_types_.LongLo(), reg_types_.LongHi());
break;
case Instruction::LONG_TO_DOUBLE:
work_line_->CheckUnaryOpWide(inst, reg_types_.DoubleLo(), reg_types_.DoubleHi(),
reg_types_.LongLo(), reg_types_.LongHi());
break;
case Instruction::FLOAT_TO_INT:
work_line_->CheckUnaryOp(inst, reg_types_.Integer(), reg_types_.Float());
break;
case Instruction::FLOAT_TO_LONG:
work_line_->CheckUnaryOpToWide(inst, reg_types_.LongLo(), reg_types_.LongHi(),
reg_types_.Float());
break;
case Instruction::FLOAT_TO_DOUBLE:
work_line_->CheckUnaryOpToWide(inst, reg_types_.DoubleLo(), reg_types_.DoubleHi(),
reg_types_.Float());
break;
case Instruction::DOUBLE_TO_INT:
work_line_->CheckUnaryOpFromWide(inst, reg_types_.Integer(),
reg_types_.DoubleLo(), reg_types_.DoubleHi());
break;
case Instruction::DOUBLE_TO_LONG:
work_line_->CheckUnaryOpWide(inst, reg_types_.LongLo(), reg_types_.LongHi(),
reg_types_.DoubleLo(), reg_types_.DoubleHi());
break;
case Instruction::DOUBLE_TO_FLOAT:
work_line_->CheckUnaryOpFromWide(inst, reg_types_.Float(),
reg_types_.DoubleLo(), reg_types_.DoubleHi());
break;
case Instruction::INT_TO_BYTE:
work_line_->CheckUnaryOp(inst, reg_types_.Byte(), reg_types_.Integer());
break;
case Instruction::INT_TO_CHAR:
work_line_->CheckUnaryOp(inst, reg_types_.Char(), reg_types_.Integer());
break;
case Instruction::INT_TO_SHORT:
work_line_->CheckUnaryOp(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(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(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(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(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(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(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(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(inst,
reg_types_.Integer(),
reg_types_.Integer(),
reg_types_.Integer(),
true);
break;
case Instruction::DIV_INT_2ADDR:
work_line_->CheckBinaryOp2addr(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(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(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(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(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:
case Instruction::MUL_INT_LIT16:
case Instruction::DIV_INT_LIT16:
case Instruction::REM_INT_LIT16:
work_line_->CheckLiteralOp(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(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(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(inst, reg_types_.Integer(), reg_types_.Integer(), true, false);
break;
// Special instructions.
case Instruction::RETURN_VOID_BARRIER:
if (!IsConstructor() || IsStatic()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "return-void-barrier not expected";
}
break;
// Note: the following instructions encode offsets derived from class linking.
// As such they use Class*/Field*/AbstractMethod* as these offsets only have
// meaning if the class linking and resolution were successful.
case Instruction::IGET_QUICK:
VerifyIGetQuick(inst, reg_types_.Integer(), true);
break;
case Instruction::IGET_WIDE_QUICK:
VerifyIGetQuick(inst, reg_types_.LongLo(), true);
break;
case Instruction::IGET_OBJECT_QUICK:
VerifyIGetQuick(inst, reg_types_.JavaLangObject(false), false);
break;
case Instruction::IPUT_QUICK:
VerifyIPutQuick(inst, reg_types_.Integer(), true);
break;
case Instruction::IPUT_WIDE_QUICK:
VerifyIPutQuick(inst, reg_types_.LongLo(), true);
break;
case Instruction::IPUT_OBJECT_QUICK:
VerifyIPutQuick(inst, reg_types_.JavaLangObject(false), false);
break;
case Instruction::INVOKE_VIRTUAL_QUICK:
case Instruction::INVOKE_VIRTUAL_RANGE_QUICK: {
bool is_range = (inst->Opcode() == Instruction::INVOKE_VIRTUAL_RANGE_QUICK);
mirror::ArtMethod* called_method = VerifyInvokeVirtualQuickArgs(inst, is_range);
if (called_method != NULL) {
const char* descriptor = called_method->GetReturnTypeDescriptor();
const RegType& return_type = reg_types_.FromDescriptor(class_loader_->Get(), descriptor,
false);
if (!return_type.IsLowHalf()) {
work_line_->SetResultRegisterType(return_type);
} else {
work_line_->SetResultRegisterTypeWide(return_type, return_type.HighHalf(&reg_types_));
}
just_set_result = true;
}
break;
}
/* These should never appear during verification. */
case Instruction::UNUSED_3E:
case Instruction::UNUSED_3F:
case Instruction::UNUSED_40:
case Instruction::UNUSED_41:
case Instruction::UNUSED_42:
case Instruction::UNUSED_43:
case Instruction::UNUSED_79:
case Instruction::UNUSED_7A:
case Instruction::UNUSED_EB:
case Instruction::UNUSED_EC:
case Instruction::UNUSED_ED:
case Instruction::UNUSED_EE:
case Instruction::UNUSED_EF:
case Instruction::UNUSED_F0:
case Instruction::UNUSED_F1:
case Instruction::UNUSED_F2:
case Instruction::UNUSED_F3:
case Instruction::UNUSED_F4:
case Instruction::UNUSED_F5:
case Instruction::UNUSED_F6:
case Instruction::UNUSED_F7:
case Instruction::UNUSED_F8:
case Instruction::UNUSED_F9:
case Instruction::UNUSED_FA:
case Instruction::UNUSED_FB:
case Instruction::UNUSED_FC:
case Instruction::UNUSED_FD:
case Instruction::UNUSED_FE:
case Instruction::UNUSED_FF:
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()->IsCompiler()) {
/* When compiling, check that the last failure is a hard failure */
CHECK_EQ(failures_[failures_.size() - 1], VERIFY_ERROR_BAD_CLASS_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;
}
/*
* 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();
}
/*
* 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 (!CheckNotMoveException(code_item_->insns_, work_insn_idx_ + branch_target)) {
return false;
}
/* update branch target, set "changed" if appropriate */
if (NULL != branch_line.get()) {
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] | (((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] |
(((int32_t) switch_insns[offset_to_targets + targ * 2 + 1]) << 16);
abs_offset = work_insn_idx_ + offset;
DCHECK_LT(abs_offset, code_item_->insns_size_in_code_units_);
if (!CheckNotMoveException(code_item_->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 && insn_flags_[work_insn_idx_].IsInTry()) {
bool has_catch_all_handler = false;
CatchHandlerIterator iterator(*code_item_, work_insn_idx_);
// 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()) {
uint16_t handler_type_idx = iterator.GetHandlerTypeIndex();
if (handler_type_idx == DexFile::kDexNoIndex16) {
has_catch_all_handler = true;
} else {
// It is also a catch-all if it is java.lang.Throwable.
mirror::Class* klass = linker->ResolveType(*dex_file_, handler_type_idx, *dex_cache_,
*class_loader_);
if (klass != nullptr) {
if (klass == mirror::Throwable::GetJavaLangThrowable()) {
has_catch_all_handler = true;
}
} else {
// Clear exception.
Thread* self = Thread::Current();
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) {
uint32_t next_insn_idx = work_insn_idx_ + CurrentInsnFlags()->GetLengthInCodeUnits();
if (next_insn_idx >= code_item_->insns_size_in_code_units_) {
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_->insns_, next_insn_idx)) {
return false;
}
if (NULL != fallthrough_line.get()) {
// Make workline consistent with fallthrough computed from peephole optimization.
work_line_->CopyFromLine(fallthrough_line.get());
}
if (insn_flags_[next_insn_idx].IsReturn()) {
// For returns we only care about the operand to the return, all other registers are dead.
const Instruction* ret_inst = Instruction::At(code_item_->insns_ + next_insn_idx);
Instruction::Code opcode = ret_inst->Opcode();
if ((opcode == Instruction::RETURN_VOID) || (opcode == Instruction::RETURN_VOID_BARRIER)) {
work_line_->MarkAllRegistersAsConflicts();
} else {
if (opcode == Instruction::RETURN_WIDE) {
work_line_->MarkAllRegistersAsConflictsExceptWide(ret_inst->VRegA_11x());
} else {
work_line_->MarkAllRegistersAsConflictsExcept(ret_inst->VRegA_11x());
}
}
}
RegisterLine* next_line = reg_table_.GetLine(next_insn_idx);
if (next_line != NULL) {
// 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.
*/
insn_flags_[next_insn_idx].SetChanged();
}
}
/* If we're returning from the method, make sure monitor stack is empty. */
if ((opcode_flags & Instruction::kReturn) != 0) {
if (!work_line_->VerifyMonitorStackEmpty()) {
return false;
}
}
/*
* 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) {
*start_guess = work_insn_idx_ + insn_flags_[work_insn_idx_].GetLengthInCodeUnits();
} 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_->insns_size_in_code_units_);
DCHECK(insn_flags_[*start_guess].IsOpcode());
return true;
} // NOLINT(readability/fn_size)
const RegType& MethodVerifier::ResolveClassAndCheckAccess(uint32_t class_idx) {
const char* descriptor = dex_file_->StringByTypeIdx(class_idx);
const RegType& referrer = GetDeclaringClass();
mirror::Class* klass = (*dex_cache_)->GetResolvedType(class_idx);
const RegType& result =
klass != NULL ? reg_types_.FromClass(descriptor, klass,
klass->CannotBeAssignedFromOtherTypes())
: reg_types_.FromDescriptor(class_loader_->Get(), descriptor, false);
if (result.IsConflict()) {
Fail(VERIFY_ERROR_BAD_CLASS_SOFT) << "accessing broken descriptor '" << descriptor
<< "' in " << referrer;
return result;
}
if (klass == NULL && !result.IsUnresolvedTypes()) {
(*dex_cache_)->SetResolvedType(class_idx, result.GetClass());
}
// Check if access is allowed. Unresolved types use xxxWithAccessCheck to
// check at runtime if access is allowed and so pass here. If result is
// primitive, skip the access check.
if (result.IsNonZeroReferenceTypes() && !result.IsUnresolvedTypes() &&
!referrer.IsUnresolvedTypes() && !referrer.CanAccess(result)) {
Fail(VERIFY_ERROR_ACCESS_CLASS) << "illegal class access: '"
<< referrer << "' -> '" << result << "'";
}
return result;
}
const RegType& MethodVerifier::GetCaughtExceptionType() {
const RegType* common_super = NULL;
if (code_item_->tries_size_ != 0) {
const byte* handlers_ptr = DexFile::GetCatchHandlerData(*code_item_, 0);
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() == DexFile::kDexNoIndex16) {
common_super = &reg_types_.JavaLangThrowable(false);
} else {
const RegType& exception = ResolveClassAndCheckAccess(iterator.GetHandlerTypeIndex());
if (!reg_types_.JavaLangThrowable(false).IsAssignableFrom(exception)) {
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_);
CHECK(reg_types_.JavaLangThrowable(false).IsAssignableFrom(*common_super));
}
}
}
}
handlers_ptr = iterator.EndDataPointer();
}
}
if (common_super == NULL) {
/* 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;
}
mirror::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 = ResolveClassAndCheckAccess(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 NULL;
}
if (klass_type.IsUnresolvedTypes()) {
return NULL; // Can't resolve Class so no more to do here
}
mirror::Class* klass = klass_type.GetClass();
const RegType& referrer = GetDeclaringClass();
mirror::ArtMethod* res_method = (*dex_cache_)->GetResolvedMethod(dex_method_idx);
if (res_method == NULL) {
const char* name = dex_file_->GetMethodName(method_id);
const Signature signature = dex_file_->GetMethodSignature(method_id);
if (method_type == METHOD_DIRECT || method_type == METHOD_STATIC) {
res_method = klass->FindDirectMethod(name, signature);
} else if (method_type == METHOD_INTERFACE) {
res_method = klass->FindInterfaceMethod(name, signature);
} else {
res_method = klass->FindVirtualMethod(name, signature);
}
if (res_method != NULL) {
(*dex_cache_)->SetResolvedMethod(dex_method_idx, res_method);
} else {
// If a virtual or interface method wasn't found with the expected type, look in
// the direct methods. This can happen when the wrong invoke type is used or when
// a class has changed, and will be flagged as an error in later checks.
if (method_type == METHOD_INTERFACE || method_type == METHOD_VIRTUAL) {
res_method = klass->FindDirectMethod(name, signature);
}
if (res_method == NULL) {
Fail(VERIFY_ERROR_NO_METHOD) << "couldn't find method "
<< PrettyDescriptor(klass) << "." << name
<< " " << signature;
return NULL;
}
}
}
// 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 "
<< PrettyMethod(res_method);
return NULL;
}
// Disallow any calls to class initializers.
if (res_method->IsClassInitializer()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "rejecting call to class initializer "
<< PrettyMethod(res_method);
return NULL;
}
// Check if access is allowed.
if (!referrer.CanAccessMember(res_method->GetDeclaringClass(), res_method->GetAccessFlags())) {
Fail(VERIFY_ERROR_ACCESS_METHOD) << "illegal method access (call " << PrettyMethod(res_method)
<< " 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) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invoke-super/virtual can't be used on private method "
<< PrettyMethod(res_method);
return NULL;
}
// Check that interface methods match interface classes.
if (klass->IsInterface() && method_type != METHOD_INTERFACE) {
Fail(VERIFY_ERROR_CLASS_CHANGE) << "non-interface method " << PrettyMethod(res_method)
<< " is in an interface class " << PrettyClass(klass);
return NULL;
} else if (!klass->IsInterface() && method_type == METHOD_INTERFACE) {
Fail(VERIFY_ERROR_CLASS_CHANGE) << "interface method " << PrettyMethod(res_method)
<< " is in a non-interface class " << PrettyClass(klass);
return NULL;
}
// See if the method type implied by the invoke instruction matches the access flags for the
// target method.
if ((method_type == METHOD_DIRECT && !res_method->IsDirect()) ||
(method_type == METHOD_STATIC && !res_method->IsStatic()) ||
((method_type == METHOD_VIRTUAL || method_type == METHOD_INTERFACE) && res_method->IsDirect())
) {
Fail(VERIFY_ERROR_CLASS_CHANGE) << "invoke type (" << method_type << ") does not match method "
" type of " << PrettyMethod(res_method);
return NULL;
}
return res_method;
}
template <class T>
mirror::ArtMethod* MethodVerifier::VerifyInvocationArgsFromIterator(T* it, const Instruction* inst,
MethodType method_type,
bool is_range,
mirror::ArtMethod* res_method) {
// 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 = (is_range) ? inst->VRegA_3rc() : inst->VRegA_35c();
/* caught by static verifier */
DCHECK(is_range || expected_args <= 5);
if (expected_args > code_item_->outs_size_) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid argument count (" << expected_args
<< ") exceeds outsSize (" << code_item_->outs_size_ << ")";
return nullptr;
}
uint32_t arg[5];
if (!is_range) {
inst->GetVarArgs(arg);
}
uint32_t sig_registers = 0;
/*
* 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(inst, is_range);
if (actual_arg_type.IsConflict()) { // GetInvocationThis failed.
CHECK(have_pending_hard_failure_);
return nullptr;
}
if (actual_arg_type.IsUninitializedReference()) {
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 = (is_range) ? inst->VRegB_3rc() : inst->VRegB_35c();
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;
}
}
}
if (method_type != METHOD_INTERFACE && !actual_arg_type.IsZero()) {
const RegType* res_method_class;
if (res_method != nullptr) {
mirror::Class* klass = res_method->GetDeclaringClass();
res_method_class = &reg_types_.FromClass(klass->GetDescriptor().c_str(), klass,
klass->CannotBeAssignedFromOtherTypes());
} else {
const uint32_t method_idx = (is_range) ? inst->VRegB_3rc() : inst->VRegB_35c();
const uint16_t class_idx = dex_file_->GetMethodId(method_idx).class_idx_;
res_method_class = &reg_types_.FromDescriptor(class_loader_->Get(),
dex_file_->StringByTypeIdx(class_idx),
false);
}
if (!res_method_class->IsAssignableFrom(actual_arg_type)) {
Fail(actual_arg_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;
}
}
}
sig_registers = 1;
}
for ( ; it->HasNext(); it->Next()) {
if (sig_registers >= expected_args) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Rejecting invocation, expected " << inst->VRegA() <<
" arguments, found " << sig_registers << " 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(class_loader_->Get(), param_descriptor,
false);
uint32_t get_reg = is_range ? inst->VRegC_3rc() + static_cast<uint32_t>(sig_registers) :
arg[sig_registers];
if (reg_type.IsIntegralTypes()) {
const RegType& src_type = work_line_->GetRegisterType(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 res_method;
}
} else if (!work_line_->VerifyRegisterType(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 res_method;
}
}
sig_registers += reg_type.IsLongOrDoubleTypes() ? 2 : 1;
}
if (expected_args != sig_registers) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Rejecting invocation, expected " << expected_args <<
" arguments, found " << 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 = (is_range) ? inst->VRegB_3rc() : inst->VRegB_35c();
DexFileParameterIterator it(*dex_file_,
dex_file_->GetProtoId(dex_file_->GetMethodId(method_idx).proto_idx_));
VerifyInvocationArgsFromIterator<DexFileParameterIterator>(&it, inst, method_type, is_range,
nullptr);
}
class MethodParamListDescriptorIterator {
public:
explicit MethodParamListDescriptorIterator(mirror::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() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
return res_method_->GetTypeDescriptorFromTypeIdx(params_->GetTypeItem(pos_).type_idx_);
}
private:
mirror::ArtMethod* res_method_;
size_t pos_;
const DexFile::TypeList* params_;
const size_t params_size_;
};
mirror::ArtMethod* MethodVerifier::VerifyInvocationArgs(const Instruction* inst,
MethodType method_type,
bool is_range,
bool is_super) {
// 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 = (is_range) ? inst->VRegB_3rc() : inst->VRegB_35c();
mirror::ArtMethod* res_method = ResolveMethodAndCheckAccess(method_idx, method_type);
if (res_method == NULL) { // 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.
if (is_super) {
DCHECK(method_type == METHOD_VIRTUAL);
const RegType& super = GetDeclaringClass().GetSuperClass(&reg_types_);
if (super.IsUnresolvedTypes()) {
Fail(VERIFY_ERROR_NO_METHOD) << "unknown super class in invoke-super from "
<< PrettyMethod(dex_method_idx_, *dex_file_)
<< " to super " << PrettyMethod(res_method);
return nullptr;
}
mirror::Class* super_klass = super.GetClass();
if (res_method->GetMethodIndex() >= super_klass->GetVTableLength()) {
Fail(VERIFY_ERROR_NO_METHOD) << "invalid invoke-super from "
<< PrettyMethod(dex_method_idx_, *dex_file_)
<< " to super " << super
<< "." << res_method->GetName()
<< res_method->GetSignature();
return nullptr;
}
}
// Process the target method's signature. This signature may or may not
MethodParamListDescriptorIterator it(res_method);
return VerifyInvocationArgsFromIterator<MethodParamListDescriptorIterator>(&it, inst, method_type,
is_range, res_method);
}
mirror::ArtMethod* MethodVerifier::GetQuickInvokedMethod(const Instruction* inst,
RegisterLine* reg_line, bool is_range) {
DCHECK(inst->Opcode() == Instruction::INVOKE_VIRTUAL_QUICK ||
inst->Opcode() == Instruction::INVOKE_VIRTUAL_RANGE_QUICK);
const RegType& actual_arg_type = reg_line->GetInvocationThis(inst, is_range);
if (!actual_arg_type.HasClass()) {
VLOG(verifier) << "Failed to get mirror::Class* from '" << actual_arg_type << "'";
return nullptr;
}
mirror::Class* klass = actual_arg_type.GetClass();
mirror::Class* dispatch_class;
if (klass->IsInterface()) {
// Derive Object.class from Class.class.getSuperclass().
mirror::Class* object_klass = klass->GetClass()->GetSuperClass();
CHECK(object_klass->IsObjectClass());
dispatch_class = object_klass;
} else {
dispatch_class = klass;
}
CHECK(dispatch_class->HasVTable()) << PrettyDescriptor(dispatch_class);
uint16_t vtable_index = is_range ? inst->VRegB_3rc() : inst->VRegB_35c();
CHECK_LT(static_cast<int32_t>(vtable_index), dispatch_class->GetVTableLength())
<< PrettyDescriptor(klass);
mirror::ArtMethod* res_method = dispatch_class->GetVTableEntry(vtable_index);
CHECK(!Thread::Current()->IsExceptionPending());
return res_method;
}
mirror::ArtMethod* MethodVerifier::VerifyInvokeVirtualQuickArgs(const Instruction* inst,
bool is_range) {
DCHECK(Runtime::Current()->IsStarted());
mirror::ArtMethod* res_method = GetQuickInvokedMethod(inst, work_line_.get(),
is_range);
if (res_method == NULL) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Cannot infer method from " << inst->Name();
return NULL;
}
CHECK(!res_method->IsDirect() && !res_method->IsStatic());
// 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 RegType& actual_arg_type = work_line_->GetInvocationThis(inst, is_range);
if (actual_arg_type.IsConflict()) { // GetInvocationThis failed.
return NULL;
}
const size_t expected_args = (is_range) ? inst->VRegA_3rc() : inst->VRegA_35c();
/* caught by static verifier */
DCHECK(is_range || expected_args <= 5);
if (expected_args > code_item_->outs_size_) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid argument count (" << expected_args
<< ") exceeds outsSize (" << code_item_->outs_size_ << ")";
return NULL;
}
/*
* 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 (actual_arg_type.IsUninitializedReference() && !res_method->IsConstructor()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "'this' arg must be initialized";
return NULL;
}
if (!actual_arg_type.IsZero()) {
mirror::Class* klass = res_method->GetDeclaringClass();
const RegType& res_method_class =
reg_types_.FromClass(klass->GetDescriptor().c_str(), klass,
klass->CannotBeAssignedFromOtherTypes());
if (!res_method_class.IsAssignableFrom(actual_arg_type)) {
Fail(actual_arg_type.IsUnresolvedTypes() ? VERIFY_ERROR_NO_CLASS :
VERIFY_ERROR_BAD_CLASS_SOFT) << "'this' argument '" << actual_arg_type
<< "' not instance of '" << res_method_class << "'";
return NULL;
}
}
/*
* Process the target method's signature. This signature may or may not
* have been verified, so we can't assume it's properly formed.
*/
const DexFile::TypeList* params = res_method->GetParameterTypeList();
size_t params_size = params == NULL ? 0 : params->Size();
uint32_t arg[5];
if (!is_range) {
inst->GetVarArgs(arg);
}
size_t actual_args = 1;
for (size_t param_index = 0; param_index < params_size; param_index++) {
if (actual_args >= expected_args) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Rejecting invalid call to '" << PrettyMethod(res_method)
<< "'. Expected " << expected_args
<< " arguments, processing argument " << actual_args
<< " (where longs/doubles count twice).";
return NULL;
}
const char* descriptor =
res_method->GetTypeDescriptorFromTypeIdx(params->GetTypeItem(param_index).type_idx_);
if (descriptor == NULL) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Rejecting invocation of " << PrettyMethod(res_method)
<< " missing signature component";
return NULL;
}
const RegType& reg_type = reg_types_.FromDescriptor(class_loader_->Get(), descriptor, false);
uint32_t get_reg = is_range ? inst->VRegC_3rc() + actual_args : arg[actual_args];
if (!work_line_->VerifyRegisterType(get_reg, reg_type)) {
return res_method;
}
actual_args = reg_type.IsLongOrDoubleTypes() ? actual_args + 2 : actual_args + 1;
}
if (actual_args != expected_args) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Rejecting invocation of " << PrettyMethod(res_method)
<< " expected " << expected_args << " arguments, found " << actual_args;
return NULL;
} else {
return res_method;
}
}
void MethodVerifier::VerifyNewArray(const Instruction* inst, bool is_filled, bool is_range) {
uint32_t type_idx;
if (!is_filled) {
DCHECK_EQ(inst->Opcode(), Instruction::NEW_ARRAY);
type_idx = inst->VRegC_22c();
} else if (!is_range) {
DCHECK_EQ(inst->Opcode(), Instruction::FILLED_NEW_ARRAY);
type_idx = inst->VRegB_35c();
} else {
DCHECK_EQ(inst->Opcode(), Instruction::FILLED_NEW_ARRAY_RANGE);
type_idx = inst->VRegB_3rc();
}
const RegType& res_type = ResolveClassAndCheckAccess(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(inst->VRegB_22c(), reg_types_.Integer());
/* set register type to array class */
const RegType& precise_type = reg_types_.FromUninitialized(res_type);
work_line_->SetRegisterType(inst->VRegA_22c(), precise_type);
} else {
// 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, class_loader_->Get());
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(get_reg, expected_type)) {
work_line_->SetResultRegisterType(reg_types_.Conflict());
return;
}
}
// filled-array result goes into "result" register
const RegType& precise_type = reg_types_.FromUninitialized(res_type);
work_line_->SetResultRegisterType(precise_type);
}
}
}
void MethodVerifier::VerifyAGet(const Instruction* inst,
const RegType& insn_type, bool is_primitive) {
const RegType& index_type = work_line_->GetRegisterType(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(inst->VRegB_23x());
if (array_type.IsZero()) {
// Null array class; this code path will fail at runtime. Infer a merge-able type from the
// instruction type. TODO: have a proper notion of bottom here.
if (!is_primitive || insn_type.IsCategory1Types()) {
// Reference or category 1
work_line_->SetRegisterType(inst->VRegA_23x(), reg_types_.Zero());
} else {
// Category 2
work_line_->SetRegisterTypeWide(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 {
/* verify the class */
const RegType& component_type = reg_types_.GetComponentType(array_type, class_loader_->Get());
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(inst->VRegA_23x(), component_type);
} else {
work_line_->SetRegisterTypeWide(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(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();
const RegType& value_type_hi = work_line_->GetRegisterType(vregA + 1);
value_compatible = value_type.IsLongTypes() && value_type.CheckWidePair(value_type_hi);
} else if (target_type.IsDouble()) {
instruction_compatible = insn_type.IsLong(); // no put-double, so expect put-long
const RegType& value_type_hi = work_line_->GetRegisterType(vregA + 1);
value_compatible = value_type.IsDoubleTypes() && value_type.CheckWidePair(value_type_hi);
} 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(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(inst->VRegB_23x());
if (array_type.IsZero()) {
// Null array type; this code path will fail at runtime. Infer a merge-able type from the
// instruction type.
} else if (!array_type.IsArrayTypes()) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "not array type " << array_type << " with aput";
} else {
const RegType& component_type = reg_types_.GetComponentType(array_type, class_loader_->Get());
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(vregA, insn_type);
}
}
}
}
}
mirror::ArtField* MethodVerifier::GetStaticField(int field_idx) {
const DexFile::FieldId& field_id = dex_file_->GetFieldId(field_idx);
// Check access to class
const RegType& klass_type = ResolveClassAndCheckAccess(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 NULL;
}
if (klass_type.IsUnresolvedTypes()) {
return NULL; // Can't resolve Class so no more to do here, will do checking at runtime.
}
ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
mirror::ArtField* field = class_linker->ResolveFieldJLS(*dex_file_, field_idx, *dex_cache_,
*class_loader_);
if (field == NULL) {
VLOG(verifier) << "Unable to resolve static field " << field_idx << " ("
<< dex_file_->GetFieldName(field_id) << ") in "
<< dex_file_->GetFieldDeclaringClassDescriptor(field_id);
DCHECK(Thread::Current()->IsExceptionPending());
Thread::Current()->ClearException();
return NULL;
} else if (!GetDeclaringClass().CanAccessMember(field->GetDeclaringClass(),
field->GetAccessFlags())) {
Fail(VERIFY_ERROR_ACCESS_FIELD) << "cannot access static field " << PrettyField(field)
<< " from " << GetDeclaringClass();
return NULL;
} else if (!field->IsStatic()) {
Fail(VERIFY_ERROR_CLASS_CHANGE) << "expected field " << PrettyField(field) << " to be static";
return NULL;
}
return field;
}
mirror::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 = ResolveClassAndCheckAccess(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 NULL;
}
if (klass_type.IsUnresolvedTypes()) {
return NULL; // Can't resolve Class so no more to do here
}
ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
mirror::ArtField* field = class_linker->ResolveFieldJLS(*dex_file_, field_idx, *dex_cache_,
*class_loader_);
if (field == NULL) {
VLOG(verifier) << "Unable to resolve instance field " << field_idx << " ("
<< dex_file_->GetFieldName(field_id) << ") in "
<< dex_file_->GetFieldDeclaringClassDescriptor(field_id);
DCHECK(Thread::Current()->IsExceptionPending());
Thread::Current()->ClearException();
return NULL;
} else if (!GetDeclaringClass().CanAccessMember(field->GetDeclaringClass(),
field->GetAccessFlags())) {
Fail(VERIFY_ERROR_ACCESS_FIELD) << "cannot access instance field " << PrettyField(field)
<< " from " << GetDeclaringClass();
return NULL;
} else if (field->IsStatic()) {
Fail(VERIFY_ERROR_CLASS_CHANGE) << "expected field " << PrettyField(field)
<< " to not be static";
return NULL;
} else if (obj_type.IsZero()) {
// Cannot infer and check type, however, access will cause null pointer exception
return field;
} else {
mirror::Class* klass = field->GetDeclaringClass();
const RegType& field_klass =
reg_types_.FromClass(dex_file_->GetFieldDeclaringClassDescriptor(field_id),
klass, klass->CannotBeAssignedFromOtherTypes());
if (obj_type.IsUninitializedTypes() &&
(!IsConstructor() || GetDeclaringClass().Equals(obj_type) ||
!field_klass.Equals(GetDeclaringClass()))) {
// Field accesses through uninitialized references are only allowable for constructors where
// the field is declared in this class
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "cannot access instance field " << PrettyField(field)
<< " of a not fully initialized object within the context"
<< " of " << PrettyMethod(dex_method_idx_, *dex_file_);
return NULL;
} else if (!field_klass.IsAssignableFrom(obj_type)) {
// 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.
Fail(VERIFY_ERROR_NO_FIELD) << "cannot access instance field " << PrettyField(field)
<< " from object of type " << obj_type;
return NULL;
} else {
return field;
}
}
}
void MethodVerifier::VerifyISGet(const Instruction* inst, const RegType& insn_type,
bool is_primitive, bool is_static) {
uint32_t field_idx = is_static ? inst->VRegB_21c() : inst->VRegC_22c();
mirror::ArtField* field;
if (is_static) {
field = GetStaticField(field_idx);
} else {
const RegType& object_type = work_line_->GetRegisterType(inst->VRegB_22c());
field = GetInstanceField(object_type, field_idx);
}
const RegType* field_type = nullptr;
if (field != NULL) {
Thread* self = Thread::Current();
mirror::Class* field_type_class;
{
StackHandleScope<1> hs(self);
HandleWrapper<mirror::ArtField> h_field(hs.NewHandleWrapper(&field));
field_type_class = FieldHelper(h_field).GetType(can_load_classes_);
}
if (field_type_class != nullptr) {
field_type = &reg_types_.FromClass(field->GetTypeDescriptor(), field_type_class,
field_type_class->CannotBeAssignedFromOtherTypes());
} else {
DCHECK(!can_load_classes_ || self->IsExceptionPending());
self->ClearException();
}
}
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(class_loader_->Get(), descriptor, false);
}
DCHECK(field_type != nullptr);
const uint32_t vregA = (is_static) ? inst->VRegA_21c() : inst->VRegA_22c();
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 " << PrettyField(field)
<< " to be of type '" << insn_type
<< "' but found type '" << *field_type << "' in get";
return;
}
} else {
if (!insn_type.IsAssignableFrom(*field_type)) {
Fail(VERIFY_ERROR_BAD_CLASS_SOFT) << "expected field " << PrettyField(field)
<< " to be compatible with type '" << insn_type
<< "' but found type '" << *field_type
<< "' in Get-object";
work_line_->SetRegisterType(vregA, reg_types_.Conflict());
return;
}
}
if (!field_type->IsLowHalf()) {
work_line_->SetRegisterType(vregA, *field_type);
} else {
work_line_->SetRegisterTypeWide(vregA, *field_type, field_type->HighHalf(&reg_types_));
}
}
void MethodVerifier::VerifyISPut(const Instruction* inst, const RegType& insn_type,
bool is_primitive, bool is_static) {
uint32_t field_idx = is_static ? inst->VRegB_21c() : inst->VRegC_22c();
mirror::ArtField* field;
if (is_static) {
field = GetStaticField(field_idx);
} else {
const RegType& object_type = work_line_->GetRegisterType(inst->VRegB_22c());
field = GetInstanceField(object_type, field_idx);
}
const RegType* field_type = nullptr;
if (field != NULL) {
if (field->IsFinal() && field->GetDeclaringClass() != GetDeclaringClass().GetClass()) {
Fail(VERIFY_ERROR_ACCESS_FIELD) << "cannot modify final field " << PrettyField(field)
<< " from other class " << GetDeclaringClass();
return;
}
mirror::Class* field_type_class;
{
StackHandleScope<1> hs(Thread::Current());
HandleWrapper<mirror::ArtField> h_field(hs.NewHandleWrapper(&field));
FieldHelper fh(h_field);
field_type_class = fh.GetType(can_load_classes_);
}
if (field_type_class != nullptr) {
field_type = &reg_types_.FromClass(field->GetTypeDescriptor(), field_type_class,
field_type_class->CannotBeAssignedFromOtherTypes());
} else {
Thread* self = Thread::Current();
DCHECK(!can_load_classes_ || self->IsExceptionPending());
self->ClearException();
}
}
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(class_loader_->Get(), descriptor, false);
}
DCHECK(field_type != nullptr);
const uint32_t vregA = (is_static) ? inst->VRegA_21c() : inst->VRegA_22c();
if (is_primitive) {
VerifyPrimitivePut(*field_type, insn_type, vregA);
} else {
if (!insn_type.IsAssignableFrom(*field_type)) {
Fail(VERIFY_ERROR_BAD_CLASS_SOFT) << "expected field " << PrettyField(field)
<< " to be compatible with type '" << insn_type
<< "' but found type '" << *field_type
<< "' in put-object";
return;
}
work_line_->VerifyRegisterType(vregA, *field_type);
}
}
mirror::ArtField* MethodVerifier::GetQuickFieldAccess(const Instruction* inst,
RegisterLine* reg_line) {
DCHECK(inst->Opcode() == Instruction::IGET_QUICK ||
inst->Opcode() == Instruction::IGET_WIDE_QUICK ||
inst->Opcode() == Instruction::IGET_OBJECT_QUICK ||
inst->Opcode() == Instruction::IPUT_QUICK ||
inst->Opcode() == Instruction::IPUT_WIDE_QUICK ||
inst->Opcode() == Instruction::IPUT_OBJECT_QUICK);
const RegType& object_type = reg_line->GetRegisterType(inst->VRegB_22c());
if (!object_type.HasClass()) {
VLOG(verifier) << "Failed to get mirror::Class* from '" << object_type << "'";
return nullptr;
}
uint32_t field_offset = static_cast<uint32_t>(inst->VRegC_22c());
mirror::ArtField* f = mirror::ArtField::FindInstanceFieldWithOffset(object_type.GetClass(),
field_offset);
if (f == nullptr) {
VLOG(verifier) << "Failed to find instance field at offset '" << field_offset
<< "' from '" << PrettyDescriptor(object_type.GetClass()) << "'";
}
return f;
}
void MethodVerifier::VerifyIGetQuick(const Instruction* inst, const RegType& insn_type,
bool is_primitive) {
DCHECK(Runtime::Current()->IsStarted());
mirror::ArtField* field = GetQuickFieldAccess(inst, work_line_.get());
if (field == NULL) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Cannot infer field from " << inst->Name();
return;
}
mirror::Class* field_type_class;
{
StackHandleScope<1> hs(Thread::Current());
HandleWrapper<mirror::ArtField> h_field(hs.NewHandleWrapper(&field));
FieldHelper fh(h_field);
field_type_class = fh.GetType(can_load_classes_);
}
const RegType* field_type;
if (field_type_class != nullptr) {
field_type = &reg_types_.FromClass(field->GetTypeDescriptor(), field_type_class,
field_type_class->CannotBeAssignedFromOtherTypes());
} else {
Thread* self = Thread::Current();
DCHECK(!can_load_classes_ || self->IsExceptionPending());
self->ClearException();
field_type = &reg_types_.FromDescriptor(field->GetDeclaringClass()->GetClassLoader(),
field->GetTypeDescriptor(), false);
}
DCHECK(field_type != nullptr);
const uint32_t vregA = inst->VRegA_22c();
if (is_primitive) {
if (field_type->Equals(insn_type) ||
(field_type->IsFloat() && insn_type.IsIntegralTypes()) ||
(field_type->IsDouble() && insn_type.IsLongTypes())) {
// 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 " << PrettyField(field)
<< " to be of type '" << insn_type
<< "' but found type '" << *field_type << "' in Get";
return;
}
} else {
if (!insn_type.IsAssignableFrom(*field_type)) {
Fail(VERIFY_ERROR_BAD_CLASS_SOFT) << "expected field " << PrettyField(field)
<< " to be compatible with type '" << insn_type
<< "' but found type '" << *field_type
<< "' in get-object";
work_line_->SetRegisterType(vregA, reg_types_.Conflict());
return;
}
}
if (!field_type->IsLowHalf()) {
work_line_->SetRegisterType(vregA, *field_type);
} else {
work_line_->SetRegisterTypeWide(vregA, *field_type, field_type->HighHalf(&reg_types_));
}
}
void MethodVerifier::VerifyIPutQuick(const Instruction* inst, const RegType& insn_type,
bool is_primitive) {
DCHECK(Runtime::Current()->IsStarted());
mirror::ArtField* field = GetQuickFieldAccess(inst, work_line_.get());
if (field == NULL) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Cannot infer field from " << inst->Name();
return;
}
const char* descriptor = field->GetTypeDescriptor();
mirror::ClassLoader* loader = field->GetDeclaringClass()->GetClassLoader();
const RegType& field_type = reg_types_.FromDescriptor(loader, descriptor, false);
if (field != NULL) {
if (field->IsFinal() && field->GetDeclaringClass() != GetDeclaringClass().GetClass()) {
Fail(VERIFY_ERROR_ACCESS_FIELD) << "cannot modify final field " << PrettyField(field)
<< " from other class " << GetDeclaringClass();
return;
}
}
const uint32_t vregA = inst->VRegA_22c();
if (is_primitive) {
// Primitive field assignability rules are weaker than regular assignability rules
bool instruction_compatible;
bool value_compatible;
const RegType& value_type = work_line_->GetRegisterType(vregA);
if (field_type.IsIntegralTypes()) {
instruction_compatible = insn_type.IsIntegralTypes();
value_compatible = value_type.IsIntegralTypes();
} else if (field_type.IsFloat()) {
instruction_compatible = insn_type.IsInteger(); // no [is]put-float, so expect [is]put-int
value_compatible = value_type.IsFloatTypes();
} else if (field_type.IsLong()) {
instruction_compatible = insn_type.IsLong();
value_compatible = value_type.IsLongTypes();
} else if (field_type.IsDouble()) {
instruction_compatible = insn_type.IsLong(); // no [is]put-double, so expect [is]put-long
value_compatible = value_type.IsDoubleTypes();
} else {
instruction_compatible = false; // reference field 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) << "expected field " << PrettyField(field)
<< " to be of type '" << insn_type
<< "' but found type '" << field_type
<< "' in put";
return;
}
if (!value_compatible) {
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "unexpected value in v" << vregA
<< " of type " << value_type
<< " but expected " << field_type
<< " for store to " << PrettyField(field) << " in put";
return;
}
} else {
if (!insn_type.IsAssignableFrom(field_type)) {
Fail(VERIFY_ERROR_BAD_CLASS_SOFT) << "expected field " << PrettyField(field)
<< " to be compatible with type '" << insn_type
<< "' but found type '" << field_type
<< "' in put-object";
return;
}
work_line_->VerifyRegisterType(vregA, field_type);
}
}
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::UpdateRegisters(uint32_t next_insn, RegisterLine* merge_line,
bool update_merge_line) {
bool changed = true;
RegisterLine* target_line = reg_table_.GetLine(next_insn);
if (!insn_flags_[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.)
*/
if (!insn_flags_[next_insn].IsReturn()) {
target_line->CopyFromLine(merge_line);
} else {
// Verify that the monitor stack is empty on return.
if (!merge_line->VerifyMonitorStackEmpty()) {
return false;
}
// 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 = Instruction::At(code_item_->insns_ + next_insn);
Instruction::Code opcode = ret_inst->Opcode();
if ((opcode == Instruction::RETURN_VOID) || (opcode == Instruction::RETURN_VOID_BARRIER)) {
target_line->MarkAllRegistersAsConflicts();
} else {
target_line->CopyFromLine(merge_line);
if (opcode == Instruction::RETURN_WIDE) {
target_line->MarkAllRegistersAsConflictsExceptWide(ret_inst->VRegA_11x());
} else {
target_line->MarkAllRegistersAsConflictsExcept(ret_inst->VRegA_11x());
}
}
}
} else {
std::unique_ptr<RegisterLine> copy(gDebugVerify ?
RegisterLine::Create(target_line->NumRegs(), this) :
NULL);
if (gDebugVerify) {
copy->CopyFromLine(target_line);
}
changed = target_line->MergeRegisters(merge_line);
if (have_pending_hard_failure_) {
return false;
}
if (gDebugVerify && changed) {
LogVerifyInfo() << "Merging at [" << reinterpret_cast<void*>(work_insn_idx_) << "]"
<< " to [" << reinterpret_cast<void*>(next_insn) << "]: " << "\n"
<< *copy.get() << " MERGE\n"
<< *merge_line << " ==\n"
<< *target_line << "\n";
}
if (update_merge_line && changed) {
merge_line->CopyFromLine(target_line);
}
}
if (changed) {
insn_flags_[next_insn].SetChanged();
}
return true;
}
InstructionFlags* MethodVerifier::CurrentInsnFlags() {
return &insn_flags_[work_insn_idx_];
}
const RegType& MethodVerifier::GetMethodReturnType() {
if (return_type_ == nullptr) {
if (mirror_method_ != NULL) {
Thread* self = Thread::Current();
StackHandleScope<1> hs(self);
mirror::Class* return_type_class;
{
HandleWrapper<mirror::ArtMethod> h_mirror_method(hs.NewHandleWrapper(&mirror_method_));
return_type_class = MethodHelper(h_mirror_method).GetReturnType(can_load_classes_);
}
if (return_type_class != nullptr) {
return_type_ = &reg_types_.FromClass(mirror_method_->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);
uint16_t 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(class_loader_->Get(), descriptor, false);
}
}
return *return_type_;
}
const RegType& MethodVerifier::GetDeclaringClass() {
if (declaring_class_ == NULL) {
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 (mirror_method_ != NULL) {
mirror::Class* klass = mirror_method_->GetDeclaringClass();
declaring_class_ = &reg_types_.FromClass(descriptor, klass,
klass->CannotBeAssignedFromOtherTypes());
} else {
declaring_class_ = &reg_types_.FromDescriptor(class_loader_->Get(), 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(i);
if (type.IsConstant()) {
result.push_back(type.IsPreciseConstant() ? kConstant : kImpreciseConstant);
result.push_back(type.ConstantValue());
} else if (type.IsConstantLo()) {
result.push_back(type.IsPreciseConstantLo() ? kConstant : kImpreciseConstant);
result.push_back(type.ConstantValueLo());
} else if (type.IsConstantHi()) {
result.push_back(type.IsPreciseConstantHi() ? kConstant : kImpreciseConstant);
result.push_back(type.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::VisitRoots(RootCallback* callback, void* arg) {
reg_types_.VisitRoots(callback, arg);
}
} // namespace verifier
} // namespace art