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1 /*
2  * Copyright (C) 2011 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include "method_verifier-inl.h"
18 
19 #include <iostream>
20 
21 #include "base/logging.h"
22 #include "base/mutex-inl.h"
23 #include "class_linker.h"
24 #include "compiler_callbacks.h"
25 #include "dex_file-inl.h"
26 #include "dex_instruction-inl.h"
27 #include "dex_instruction_visitor.h"
28 #include "field_helper.h"
29 #include "gc/accounting/card_table-inl.h"
30 #include "indenter.h"
31 #include "intern_table.h"
32 #include "leb128.h"
33 #include "method_helper-inl.h"
34 #include "mirror/art_field-inl.h"
35 #include "mirror/art_method-inl.h"
36 #include "mirror/class.h"
37 #include "mirror/class-inl.h"
38 #include "mirror/dex_cache-inl.h"
39 #include "mirror/object-inl.h"
40 #include "mirror/object_array-inl.h"
41 #include "register_line-inl.h"
42 #include "runtime.h"
43 #include "scoped_thread_state_change.h"
44 #include "handle_scope-inl.h"
45 #include "verifier/dex_gc_map.h"
46 
47 namespace art {
48 namespace verifier {
49 
50 static constexpr bool kTimeVerifyMethod = !kIsDebugBuild;
51 static constexpr bool gDebugVerify = false;
52 // TODO: Add a constant to method_verifier to turn on verbose logging?
53 
Init(RegisterTrackingMode mode,InstructionFlags * flags,uint32_t insns_size,uint16_t registers_size,MethodVerifier * verifier)54 void PcToRegisterLineTable::Init(RegisterTrackingMode mode, InstructionFlags* flags,
55                                  uint32_t insns_size, uint16_t registers_size,
56                                  MethodVerifier* verifier) {
57   DCHECK_GT(insns_size, 0U);
58   register_lines_.reset(new RegisterLine*[insns_size]());
59   size_ = insns_size;
60   for (uint32_t i = 0; i < insns_size; i++) {
61     bool interesting = false;
62     switch (mode) {
63       case kTrackRegsAll:
64         interesting = flags[i].IsOpcode();
65         break;
66       case kTrackCompilerInterestPoints:
67         interesting = flags[i].IsCompileTimeInfoPoint() || flags[i].IsBranchTarget();
68         break;
69       case kTrackRegsBranches:
70         interesting = flags[i].IsBranchTarget();
71         break;
72       default:
73         break;
74     }
75     if (interesting) {
76       register_lines_[i] = RegisterLine::Create(registers_size, verifier);
77     }
78   }
79 }
80 
~PcToRegisterLineTable()81 PcToRegisterLineTable::~PcToRegisterLineTable() {
82   for (size_t i = 0; i < size_; i++) {
83     delete register_lines_[i];
84     if (kIsDebugBuild) {
85       register_lines_[i] = nullptr;
86     }
87   }
88 }
89 
VerifyClass(mirror::Class * klass,bool allow_soft_failures,std::string * error)90 MethodVerifier::FailureKind MethodVerifier::VerifyClass(mirror::Class* klass,
91                                                         bool allow_soft_failures,
92                                                         std::string* error) {
93   if (klass->IsVerified()) {
94     return kNoFailure;
95   }
96   bool early_failure = false;
97   std::string failure_message;
98   const DexFile& dex_file = klass->GetDexFile();
99   const DexFile::ClassDef* class_def = klass->GetClassDef();
100   mirror::Class* super = klass->GetSuperClass();
101   std::string temp;
102   if (super == nullptr && strcmp("Ljava/lang/Object;", klass->GetDescriptor(&temp)) != 0) {
103     early_failure = true;
104     failure_message = " that has no super class";
105   } else if (super != nullptr && super->IsFinal()) {
106     early_failure = true;
107     failure_message = " that attempts to sub-class final class " + PrettyDescriptor(super);
108   } else if (class_def == nullptr) {
109     early_failure = true;
110     failure_message = " that isn't present in dex file " + dex_file.GetLocation();
111   }
112   if (early_failure) {
113     *error = "Verifier rejected class " + PrettyDescriptor(klass) + failure_message;
114     if (Runtime::Current()->IsCompiler()) {
115       ClassReference ref(&dex_file, klass->GetDexClassDefIndex());
116       Runtime::Current()->GetCompilerCallbacks()->ClassRejected(ref);
117     }
118     return kHardFailure;
119   }
120   StackHandleScope<2> hs(Thread::Current());
121   Handle<mirror::DexCache> dex_cache(hs.NewHandle(klass->GetDexCache()));
122   Handle<mirror::ClassLoader> class_loader(hs.NewHandle(klass->GetClassLoader()));
123   return VerifyClass(&dex_file, dex_cache, class_loader, class_def, allow_soft_failures, error);
124 }
125 
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)126 MethodVerifier::FailureKind MethodVerifier::VerifyClass(const DexFile* dex_file,
127                                                         Handle<mirror::DexCache> dex_cache,
128                                                         Handle<mirror::ClassLoader> class_loader,
129                                                         const DexFile::ClassDef* class_def,
130                                                         bool allow_soft_failures,
131                                                         std::string* error) {
132   DCHECK(class_def != nullptr);
133   const byte* class_data = dex_file->GetClassData(*class_def);
134   if (class_data == nullptr) {
135     // empty class, probably a marker interface
136     return kNoFailure;
137   }
138   ClassDataItemIterator it(*dex_file, class_data);
139   while (it.HasNextStaticField() || it.HasNextInstanceField()) {
140     it.Next();
141   }
142   size_t error_count = 0;
143   bool hard_fail = false;
144   ClassLinker* linker = Runtime::Current()->GetClassLinker();
145   int64_t previous_direct_method_idx = -1;
146   while (it.HasNextDirectMethod()) {
147     uint32_t method_idx = it.GetMemberIndex();
148     if (method_idx == previous_direct_method_idx) {
149       // smali can create dex files with two encoded_methods sharing the same method_idx
150       // http://code.google.com/p/smali/issues/detail?id=119
151       it.Next();
152       continue;
153     }
154     previous_direct_method_idx = method_idx;
155     InvokeType type = it.GetMethodInvokeType(*class_def);
156     mirror::ArtMethod* method =
157         linker->ResolveMethod(*dex_file, method_idx, dex_cache, class_loader,
158                               NullHandle<mirror::ArtMethod>(), type);
159     if (method == nullptr) {
160       DCHECK(Thread::Current()->IsExceptionPending());
161       // We couldn't resolve the method, but continue regardless.
162       Thread::Current()->ClearException();
163     }
164     MethodVerifier::FailureKind result = VerifyMethod(method_idx,
165                                                       dex_file,
166                                                       dex_cache,
167                                                       class_loader,
168                                                       class_def,
169                                                       it.GetMethodCodeItem(),
170                                                       method,
171                                                       it.GetMethodAccessFlags(),
172                                                       allow_soft_failures,
173                                                       false);
174     if (result != kNoFailure) {
175       if (result == kHardFailure) {
176         hard_fail = true;
177         if (error_count > 0) {
178           *error += "\n";
179         }
180         *error = "Verifier rejected class ";
181         *error += PrettyDescriptor(dex_file->GetClassDescriptor(*class_def));
182         *error += " due to bad method ";
183         *error += PrettyMethod(method_idx, *dex_file);
184       }
185       ++error_count;
186     }
187     it.Next();
188   }
189   int64_t previous_virtual_method_idx = -1;
190   while (it.HasNextVirtualMethod()) {
191     uint32_t method_idx = it.GetMemberIndex();
192     if (method_idx == previous_virtual_method_idx) {
193       // smali can create dex files with two encoded_methods sharing the same method_idx
194       // http://code.google.com/p/smali/issues/detail?id=119
195       it.Next();
196       continue;
197     }
198     previous_virtual_method_idx = method_idx;
199     InvokeType type = it.GetMethodInvokeType(*class_def);
200     mirror::ArtMethod* method =
201         linker->ResolveMethod(*dex_file, method_idx, dex_cache, class_loader,
202                               NullHandle<mirror::ArtMethod>(), type);
203     if (method == nullptr) {
204       DCHECK(Thread::Current()->IsExceptionPending());
205       // We couldn't resolve the method, but continue regardless.
206       Thread::Current()->ClearException();
207     }
208     MethodVerifier::FailureKind result = VerifyMethod(method_idx,
209                                                       dex_file,
210                                                       dex_cache,
211                                                       class_loader,
212                                                       class_def,
213                                                       it.GetMethodCodeItem(),
214                                                       method,
215                                                       it.GetMethodAccessFlags(),
216                                                       allow_soft_failures,
217                                                       false);
218     if (result != kNoFailure) {
219       if (result == kHardFailure) {
220         hard_fail = true;
221         if (error_count > 0) {
222           *error += "\n";
223         }
224         *error = "Verifier rejected class ";
225         *error += PrettyDescriptor(dex_file->GetClassDescriptor(*class_def));
226         *error += " due to bad method ";
227         *error += PrettyMethod(method_idx, *dex_file);
228       }
229       ++error_count;
230     }
231     it.Next();
232   }
233   if (error_count == 0) {
234     return kNoFailure;
235   } else {
236     return hard_fail ? kHardFailure : kSoftFailure;
237   }
238 }
239 
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)240 MethodVerifier::FailureKind MethodVerifier::VerifyMethod(uint32_t method_idx,
241                                                          const DexFile* dex_file,
242                                                          Handle<mirror::DexCache> dex_cache,
243                                                          Handle<mirror::ClassLoader> class_loader,
244                                                          const DexFile::ClassDef* class_def,
245                                                          const DexFile::CodeItem* code_item,
246                                                          mirror::ArtMethod* method,
247                                                          uint32_t method_access_flags,
248                                                          bool allow_soft_failures,
249                                                          bool need_precise_constants) {
250   MethodVerifier::FailureKind result = kNoFailure;
251   uint64_t start_ns = kTimeVerifyMethod ? NanoTime() : 0;
252 
253   MethodVerifier verifier(dex_file, &dex_cache, &class_loader, class_def, code_item,
254                            method_idx, method, method_access_flags, true, allow_soft_failures,
255                            need_precise_constants);
256   if (verifier.Verify()) {
257     // Verification completed, however failures may be pending that didn't cause the verification
258     // to hard fail.
259     CHECK(!verifier.have_pending_hard_failure_);
260     if (verifier.failures_.size() != 0) {
261       if (VLOG_IS_ON(verifier)) {
262           verifier.DumpFailures(VLOG_STREAM(verifier) << "Soft verification failures in "
263                                 << PrettyMethod(method_idx, *dex_file) << "\n");
264       }
265       result = kSoftFailure;
266     }
267   } else {
268     // Bad method data.
269     CHECK_NE(verifier.failures_.size(), 0U);
270     CHECK(verifier.have_pending_hard_failure_);
271     verifier.DumpFailures(LOG(INFO) << "Verification error in "
272                                     << PrettyMethod(method_idx, *dex_file) << "\n");
273     if (gDebugVerify) {
274       std::cout << "\n" << verifier.info_messages_.str();
275       verifier.Dump(std::cout);
276     }
277     result = kHardFailure;
278   }
279   if (kTimeVerifyMethod) {
280     uint64_t duration_ns = NanoTime() - start_ns;
281     if (duration_ns > MsToNs(100)) {
282       LOG(WARNING) << "Verification of " << PrettyMethod(method_idx, *dex_file)
283                    << " took " << PrettyDuration(duration_ns);
284     }
285   }
286   return result;
287 }
288 
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)289 MethodVerifier* MethodVerifier::VerifyMethodAndDump(std::ostream& os, uint32_t dex_method_idx,
290                                                     const DexFile* dex_file,
291                                                     Handle<mirror::DexCache> dex_cache,
292                                                     Handle<mirror::ClassLoader> class_loader,
293                                                     const DexFile::ClassDef* class_def,
294                                                     const DexFile::CodeItem* code_item,
295                                                     mirror::ArtMethod* method,
296                                                     uint32_t method_access_flags) {
297   MethodVerifier* verifier = new MethodVerifier(dex_file, &dex_cache, &class_loader, class_def,
298                                                 code_item, dex_method_idx, method,
299                                                 method_access_flags, true, true, true, true);
300   verifier->Verify();
301   verifier->DumpFailures(os);
302   os << verifier->info_messages_.str();
303   verifier->Dump(os);
304 
305   return verifier;
306 }
307 
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,bool verify_to_dump)308 MethodVerifier::MethodVerifier(const DexFile* dex_file, Handle<mirror::DexCache>* dex_cache,
309                                Handle<mirror::ClassLoader>* class_loader,
310                                const DexFile::ClassDef* class_def,
311                                const DexFile::CodeItem* code_item, uint32_t dex_method_idx,
312                                mirror::ArtMethod* method, uint32_t method_access_flags,
313                                bool can_load_classes, bool allow_soft_failures,
314                                bool need_precise_constants, bool verify_to_dump)
315     : reg_types_(can_load_classes),
316       work_insn_idx_(-1),
317       dex_method_idx_(dex_method_idx),
318       mirror_method_(method),
319       method_access_flags_(method_access_flags),
320       return_type_(nullptr),
321       dex_file_(dex_file),
322       dex_cache_(dex_cache),
323       class_loader_(class_loader),
324       class_def_(class_def),
325       code_item_(code_item),
326       declaring_class_(nullptr),
327       interesting_dex_pc_(-1),
328       monitor_enter_dex_pcs_(nullptr),
329       have_pending_hard_failure_(false),
330       have_pending_runtime_throw_failure_(false),
331       new_instance_count_(0),
332       monitor_enter_count_(0),
333       can_load_classes_(can_load_classes),
334       allow_soft_failures_(allow_soft_failures),
335       need_precise_constants_(need_precise_constants),
336       has_check_casts_(false),
337       has_virtual_or_interface_invokes_(false),
338       verify_to_dump_(verify_to_dump) {
339   Runtime::Current()->AddMethodVerifier(this);
340   DCHECK(class_def != nullptr);
341 }
342 
~MethodVerifier()343 MethodVerifier::~MethodVerifier() {
344   Runtime::Current()->RemoveMethodVerifier(this);
345   STLDeleteElements(&failure_messages_);
346 }
347 
FindLocksAtDexPc(mirror::ArtMethod * m,uint32_t dex_pc,std::vector<uint32_t> * monitor_enter_dex_pcs)348 void MethodVerifier::FindLocksAtDexPc(mirror::ArtMethod* m, uint32_t dex_pc,
349                                       std::vector<uint32_t>* monitor_enter_dex_pcs) {
350   StackHandleScope<2> hs(Thread::Current());
351   Handle<mirror::DexCache> dex_cache(hs.NewHandle(m->GetDexCache()));
352   Handle<mirror::ClassLoader> class_loader(hs.NewHandle(m->GetClassLoader()));
353   MethodVerifier verifier(m->GetDexFile(), &dex_cache, &class_loader, &m->GetClassDef(),
354                           m->GetCodeItem(), m->GetDexMethodIndex(), m, m->GetAccessFlags(), false,
355                           true, false);
356   verifier.interesting_dex_pc_ = dex_pc;
357   verifier.monitor_enter_dex_pcs_ = monitor_enter_dex_pcs;
358   verifier.FindLocksAtDexPc();
359 }
360 
FindLocksAtDexPc()361 void MethodVerifier::FindLocksAtDexPc() {
362   CHECK(monitor_enter_dex_pcs_ != nullptr);
363   CHECK(code_item_ != nullptr);  // This only makes sense for methods with code.
364 
365   // Strictly speaking, we ought to be able to get away with doing a subset of the full method
366   // verification. In practice, the phase we want relies on data structures set up by all the
367   // earlier passes, so we just run the full method verification and bail out early when we've
368   // got what we wanted.
369   Verify();
370 }
371 
FindAccessedFieldAtDexPc(mirror::ArtMethod * m,uint32_t dex_pc)372 mirror::ArtField* MethodVerifier::FindAccessedFieldAtDexPc(mirror::ArtMethod* m,
373                                                            uint32_t dex_pc) {
374   StackHandleScope<2> hs(Thread::Current());
375   Handle<mirror::DexCache> dex_cache(hs.NewHandle(m->GetDexCache()));
376   Handle<mirror::ClassLoader> class_loader(hs.NewHandle(m->GetClassLoader()));
377   MethodVerifier verifier(m->GetDexFile(), &dex_cache, &class_loader, &m->GetClassDef(),
378                           m->GetCodeItem(), m->GetDexMethodIndex(), m, m->GetAccessFlags(), true,
379                           true, false);
380   return verifier.FindAccessedFieldAtDexPc(dex_pc);
381 }
382 
FindAccessedFieldAtDexPc(uint32_t dex_pc)383 mirror::ArtField* MethodVerifier::FindAccessedFieldAtDexPc(uint32_t dex_pc) {
384   CHECK(code_item_ != nullptr);  // This only makes sense for methods with code.
385 
386   // Strictly speaking, we ought to be able to get away with doing a subset of the full method
387   // verification. In practice, the phase we want relies on data structures set up by all the
388   // earlier passes, so we just run the full method verification and bail out early when we've
389   // got what we wanted.
390   bool success = Verify();
391   if (!success) {
392     return nullptr;
393   }
394   RegisterLine* register_line = reg_table_.GetLine(dex_pc);
395   if (register_line == nullptr) {
396     return nullptr;
397   }
398   const Instruction* inst = Instruction::At(code_item_->insns_ + dex_pc);
399   return GetQuickFieldAccess(inst, register_line);
400 }
401 
FindInvokedMethodAtDexPc(mirror::ArtMethod * m,uint32_t dex_pc)402 mirror::ArtMethod* MethodVerifier::FindInvokedMethodAtDexPc(mirror::ArtMethod* m,
403                                                             uint32_t dex_pc) {
404   StackHandleScope<2> hs(Thread::Current());
405   Handle<mirror::DexCache> dex_cache(hs.NewHandle(m->GetDexCache()));
406   Handle<mirror::ClassLoader> class_loader(hs.NewHandle(m->GetClassLoader()));
407   MethodVerifier verifier(m->GetDexFile(), &dex_cache, &class_loader, &m->GetClassDef(),
408                           m->GetCodeItem(), m->GetDexMethodIndex(), m, m->GetAccessFlags(), true,
409                           true, false);
410   return verifier.FindInvokedMethodAtDexPc(dex_pc);
411 }
412 
FindInvokedMethodAtDexPc(uint32_t dex_pc)413 mirror::ArtMethod* MethodVerifier::FindInvokedMethodAtDexPc(uint32_t dex_pc) {
414   CHECK(code_item_ != nullptr);  // This only makes sense for methods with code.
415 
416   // Strictly speaking, we ought to be able to get away with doing a subset of the full method
417   // verification. In practice, the phase we want relies on data structures set up by all the
418   // earlier passes, so we just run the full method verification and bail out early when we've
419   // got what we wanted.
420   bool success = Verify();
421   if (!success) {
422     return nullptr;
423   }
424   RegisterLine* register_line = reg_table_.GetLine(dex_pc);
425   if (register_line == nullptr) {
426     return nullptr;
427   }
428   const Instruction* inst = Instruction::At(code_item_->insns_ + dex_pc);
429   const bool is_range = (inst->Opcode() == Instruction::INVOKE_VIRTUAL_RANGE_QUICK);
430   return GetQuickInvokedMethod(inst, register_line, is_range);
431 }
432 
Verify()433 bool MethodVerifier::Verify() {
434   // If there aren't any instructions, make sure that's expected, then exit successfully.
435   if (code_item_ == nullptr) {
436     if ((method_access_flags_ & (kAccNative | kAccAbstract)) == 0) {
437       Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "zero-length code in concrete non-native method";
438       return false;
439     } else {
440       return true;
441     }
442   }
443   // Sanity-check the register counts. ins + locals = registers, so make sure that ins <= registers.
444   if (code_item_->ins_size_ > code_item_->registers_size_) {
445     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "bad register counts (ins=" << code_item_->ins_size_
446                                       << " regs=" << code_item_->registers_size_;
447     return false;
448   }
449   // Allocate and initialize an array to hold instruction data.
450   insn_flags_.reset(new InstructionFlags[code_item_->insns_size_in_code_units_]());
451   // Run through the instructions and see if the width checks out.
452   bool result = ComputeWidthsAndCountOps();
453   // Flag instructions guarded by a "try" block and check exception handlers.
454   result = result && ScanTryCatchBlocks();
455   // Perform static instruction verification.
456   result = result && VerifyInstructions();
457   // Perform code-flow analysis and return.
458   result = result && VerifyCodeFlow();
459   // Compute information for compiler.
460   if (result && Runtime::Current()->IsCompiler()) {
461     result = Runtime::Current()->GetCompilerCallbacks()->MethodVerified(this);
462   }
463   return result;
464 }
465 
Fail(VerifyError error)466 std::ostream& MethodVerifier::Fail(VerifyError error) {
467   switch (error) {
468     case VERIFY_ERROR_NO_CLASS:
469     case VERIFY_ERROR_NO_FIELD:
470     case VERIFY_ERROR_NO_METHOD:
471     case VERIFY_ERROR_ACCESS_CLASS:
472     case VERIFY_ERROR_ACCESS_FIELD:
473     case VERIFY_ERROR_ACCESS_METHOD:
474     case VERIFY_ERROR_INSTANTIATION:
475     case VERIFY_ERROR_CLASS_CHANGE:
476       if (Runtime::Current()->IsCompiler() || !can_load_classes_) {
477         // If we're optimistically running verification at compile time, turn NO_xxx, ACCESS_xxx,
478         // class change and instantiation errors into soft verification errors so that we re-verify
479         // at runtime. We may fail to find or to agree on access because of not yet available class
480         // loaders, or class loaders that will differ at runtime. In these cases, we don't want to
481         // affect the soundness of the code being compiled. Instead, the generated code runs "slow
482         // paths" that dynamically perform the verification and cause the behavior to be that akin
483         // to an interpreter.
484         error = VERIFY_ERROR_BAD_CLASS_SOFT;
485       } else {
486         // If we fail again at runtime, mark that this instruction would throw and force this
487         // method to be executed using the interpreter with checks.
488         have_pending_runtime_throw_failure_ = true;
489       }
490       break;
491       // Indication that verification should be retried at runtime.
492     case VERIFY_ERROR_BAD_CLASS_SOFT:
493       if (!allow_soft_failures_) {
494         have_pending_hard_failure_ = true;
495       }
496       break;
497       // Hard verification failures at compile time will still fail at runtime, so the class is
498       // marked as rejected to prevent it from being compiled.
499     case VERIFY_ERROR_BAD_CLASS_HARD: {
500       if (Runtime::Current()->IsCompiler()) {
501         ClassReference ref(dex_file_, dex_file_->GetIndexForClassDef(*class_def_));
502         Runtime::Current()->GetCompilerCallbacks()->ClassRejected(ref);
503       }
504       have_pending_hard_failure_ = true;
505       break;
506     }
507   }
508   failures_.push_back(error);
509   std::string location(StringPrintf("%s: [0x%X]", PrettyMethod(dex_method_idx_, *dex_file_).c_str(),
510                                     work_insn_idx_));
511   std::ostringstream* failure_message = new std::ostringstream(location);
512   failure_messages_.push_back(failure_message);
513   return *failure_message;
514 }
515 
LogVerifyInfo()516 std::ostream& MethodVerifier::LogVerifyInfo() {
517   return info_messages_ << "VFY: " << PrettyMethod(dex_method_idx_, *dex_file_)
518                         << '[' << reinterpret_cast<void*>(work_insn_idx_) << "] : ";
519 }
520 
PrependToLastFailMessage(std::string prepend)521 void MethodVerifier::PrependToLastFailMessage(std::string prepend) {
522   size_t failure_num = failure_messages_.size();
523   DCHECK_NE(failure_num, 0U);
524   std::ostringstream* last_fail_message = failure_messages_[failure_num - 1];
525   prepend += last_fail_message->str();
526   failure_messages_[failure_num - 1] = new std::ostringstream(prepend);
527   delete last_fail_message;
528 }
529 
AppendToLastFailMessage(std::string append)530 void MethodVerifier::AppendToLastFailMessage(std::string append) {
531   size_t failure_num = failure_messages_.size();
532   DCHECK_NE(failure_num, 0U);
533   std::ostringstream* last_fail_message = failure_messages_[failure_num - 1];
534   (*last_fail_message) << append;
535 }
536 
ComputeWidthsAndCountOps()537 bool MethodVerifier::ComputeWidthsAndCountOps() {
538   const uint16_t* insns = code_item_->insns_;
539   size_t insns_size = code_item_->insns_size_in_code_units_;
540   const Instruction* inst = Instruction::At(insns);
541   size_t new_instance_count = 0;
542   size_t monitor_enter_count = 0;
543   size_t dex_pc = 0;
544 
545   while (dex_pc < insns_size) {
546     Instruction::Code opcode = inst->Opcode();
547     switch (opcode) {
548       case Instruction::APUT_OBJECT:
549       case Instruction::CHECK_CAST:
550         has_check_casts_ = true;
551         break;
552       case Instruction::INVOKE_VIRTUAL:
553       case Instruction::INVOKE_VIRTUAL_RANGE:
554       case Instruction::INVOKE_INTERFACE:
555       case Instruction::INVOKE_INTERFACE_RANGE:
556         has_virtual_or_interface_invokes_ = true;
557         break;
558       case Instruction::MONITOR_ENTER:
559         monitor_enter_count++;
560         break;
561       case Instruction::NEW_INSTANCE:
562         new_instance_count++;
563         break;
564       default:
565         break;
566     }
567     size_t inst_size = inst->SizeInCodeUnits();
568     insn_flags_[dex_pc].SetLengthInCodeUnits(inst_size);
569     dex_pc += inst_size;
570     inst = inst->Next();
571   }
572 
573   if (dex_pc != insns_size) {
574     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "code did not end where expected ("
575                                       << dex_pc << " vs. " << insns_size << ")";
576     return false;
577   }
578 
579   new_instance_count_ = new_instance_count;
580   monitor_enter_count_ = monitor_enter_count;
581   return true;
582 }
583 
ScanTryCatchBlocks()584 bool MethodVerifier::ScanTryCatchBlocks() {
585   uint32_t tries_size = code_item_->tries_size_;
586   if (tries_size == 0) {
587     return true;
588   }
589   uint32_t insns_size = code_item_->insns_size_in_code_units_;
590   const DexFile::TryItem* tries = DexFile::GetTryItems(*code_item_, 0);
591 
592   for (uint32_t idx = 0; idx < tries_size; idx++) {
593     const DexFile::TryItem* try_item = &tries[idx];
594     uint32_t start = try_item->start_addr_;
595     uint32_t end = start + try_item->insn_count_;
596     if ((start >= end) || (start >= insns_size) || (end > insns_size)) {
597       Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "bad exception entry: startAddr=" << start
598                                         << " endAddr=" << end << " (size=" << insns_size << ")";
599       return false;
600     }
601     if (!insn_flags_[start].IsOpcode()) {
602       Fail(VERIFY_ERROR_BAD_CLASS_HARD)
603           << "'try' block starts inside an instruction (" << start << ")";
604       return false;
605     }
606     for (uint32_t dex_pc = start; dex_pc < end;
607         dex_pc += insn_flags_[dex_pc].GetLengthInCodeUnits()) {
608       insn_flags_[dex_pc].SetInTry();
609     }
610   }
611   // Iterate over each of the handlers to verify target addresses.
612   const byte* handlers_ptr = DexFile::GetCatchHandlerData(*code_item_, 0);
613   uint32_t handlers_size = DecodeUnsignedLeb128(&handlers_ptr);
614   ClassLinker* linker = Runtime::Current()->GetClassLinker();
615   for (uint32_t idx = 0; idx < handlers_size; idx++) {
616     CatchHandlerIterator iterator(handlers_ptr);
617     for (; iterator.HasNext(); iterator.Next()) {
618       uint32_t dex_pc= iterator.GetHandlerAddress();
619       if (!insn_flags_[dex_pc].IsOpcode()) {
620         Fail(VERIFY_ERROR_BAD_CLASS_HARD)
621             << "exception handler starts at bad address (" << dex_pc << ")";
622         return false;
623       }
624       insn_flags_[dex_pc].SetBranchTarget();
625       // Ensure exception types are resolved so that they don't need resolution to be delivered,
626       // unresolved exception types will be ignored by exception delivery
627       if (iterator.GetHandlerTypeIndex() != DexFile::kDexNoIndex16) {
628         mirror::Class* exception_type = linker->ResolveType(*dex_file_,
629                                                             iterator.GetHandlerTypeIndex(),
630                                                             *dex_cache_, *class_loader_);
631         if (exception_type == nullptr) {
632           DCHECK(Thread::Current()->IsExceptionPending());
633           Thread::Current()->ClearException();
634         }
635       }
636     }
637     handlers_ptr = iterator.EndDataPointer();
638   }
639   return true;
640 }
641 
VerifyInstructions()642 bool MethodVerifier::VerifyInstructions() {
643   const Instruction* inst = Instruction::At(code_item_->insns_);
644 
645   /* Flag the start of the method as a branch target, and a GC point due to stack overflow errors */
646   insn_flags_[0].SetBranchTarget();
647   insn_flags_[0].SetCompileTimeInfoPoint();
648 
649   uint32_t insns_size = code_item_->insns_size_in_code_units_;
650   for (uint32_t dex_pc = 0; dex_pc < insns_size;) {
651     if (!VerifyInstruction(inst, dex_pc)) {
652       DCHECK_NE(failures_.size(), 0U);
653       return false;
654     }
655     /* Flag instructions that are garbage collection points */
656     // All invoke points are marked as "Throw" points already.
657     // We are relying on this to also count all the invokes as interesting.
658     if (inst->IsBranch() || inst->IsSwitch() || inst->IsThrow()) {
659       insn_flags_[dex_pc].SetCompileTimeInfoPoint();
660     } else if (inst->IsReturn()) {
661       insn_flags_[dex_pc].SetCompileTimeInfoPointAndReturn();
662     }
663     dex_pc += inst->SizeInCodeUnits();
664     inst = inst->Next();
665   }
666   return true;
667 }
668 
VerifyInstruction(const Instruction * inst,uint32_t code_offset)669 bool MethodVerifier::VerifyInstruction(const Instruction* inst, uint32_t code_offset) {
670   bool result = true;
671   switch (inst->GetVerifyTypeArgumentA()) {
672     case Instruction::kVerifyRegA:
673       result = result && CheckRegisterIndex(inst->VRegA());
674       break;
675     case Instruction::kVerifyRegAWide:
676       result = result && CheckWideRegisterIndex(inst->VRegA());
677       break;
678   }
679   switch (inst->GetVerifyTypeArgumentB()) {
680     case Instruction::kVerifyRegB:
681       result = result && CheckRegisterIndex(inst->VRegB());
682       break;
683     case Instruction::kVerifyRegBField:
684       result = result && CheckFieldIndex(inst->VRegB());
685       break;
686     case Instruction::kVerifyRegBMethod:
687       result = result && CheckMethodIndex(inst->VRegB());
688       break;
689     case Instruction::kVerifyRegBNewInstance:
690       result = result && CheckNewInstance(inst->VRegB());
691       break;
692     case Instruction::kVerifyRegBString:
693       result = result && CheckStringIndex(inst->VRegB());
694       break;
695     case Instruction::kVerifyRegBType:
696       result = result && CheckTypeIndex(inst->VRegB());
697       break;
698     case Instruction::kVerifyRegBWide:
699       result = result && CheckWideRegisterIndex(inst->VRegB());
700       break;
701   }
702   switch (inst->GetVerifyTypeArgumentC()) {
703     case Instruction::kVerifyRegC:
704       result = result && CheckRegisterIndex(inst->VRegC());
705       break;
706     case Instruction::kVerifyRegCField:
707       result = result && CheckFieldIndex(inst->VRegC());
708       break;
709     case Instruction::kVerifyRegCNewArray:
710       result = result && CheckNewArray(inst->VRegC());
711       break;
712     case Instruction::kVerifyRegCType:
713       result = result && CheckTypeIndex(inst->VRegC());
714       break;
715     case Instruction::kVerifyRegCWide:
716       result = result && CheckWideRegisterIndex(inst->VRegC());
717       break;
718   }
719   switch (inst->GetVerifyExtraFlags()) {
720     case Instruction::kVerifyArrayData:
721       result = result && CheckArrayData(code_offset);
722       break;
723     case Instruction::kVerifyBranchTarget:
724       result = result && CheckBranchTarget(code_offset);
725       break;
726     case Instruction::kVerifySwitchTargets:
727       result = result && CheckSwitchTargets(code_offset);
728       break;
729     case Instruction::kVerifyVarArgNonZero:
730       // Fall-through.
731     case Instruction::kVerifyVarArg: {
732       if (inst->GetVerifyExtraFlags() == Instruction::kVerifyVarArgNonZero && inst->VRegA() <= 0) {
733         Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid arg count (" << inst->VRegA() << ") in "
734                                              "non-range invoke";
735         return false;
736       }
737       uint32_t args[Instruction::kMaxVarArgRegs];
738       inst->GetVarArgs(args);
739       result = result && CheckVarArgRegs(inst->VRegA(), args);
740       break;
741     }
742     case Instruction::kVerifyVarArgRangeNonZero:
743       // Fall-through.
744     case Instruction::kVerifyVarArgRange:
745       if (inst->GetVerifyExtraFlags() == Instruction::kVerifyVarArgRangeNonZero &&
746           inst->VRegA() <= 0) {
747         Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid arg count (" << inst->VRegA() << ") in "
748                                              "range invoke";
749         return false;
750       }
751       result = result && CheckVarArgRangeRegs(inst->VRegA(), inst->VRegC());
752       break;
753     case Instruction::kVerifyError:
754       Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "unexpected opcode " << inst->Name();
755       result = false;
756       break;
757   }
758   if (inst->GetVerifyIsRuntimeOnly() && Runtime::Current()->IsCompiler() && !verify_to_dump_) {
759     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "opcode only expected at runtime " << inst->Name();
760     result = false;
761   }
762   return result;
763 }
764 
CheckRegisterIndex(uint32_t idx)765 bool MethodVerifier::CheckRegisterIndex(uint32_t idx) {
766   if (idx >= code_item_->registers_size_) {
767     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "register index out of range (" << idx << " >= "
768                                       << code_item_->registers_size_ << ")";
769     return false;
770   }
771   return true;
772 }
773 
CheckWideRegisterIndex(uint32_t idx)774 bool MethodVerifier::CheckWideRegisterIndex(uint32_t idx) {
775   if (idx + 1 >= code_item_->registers_size_) {
776     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "wide register index out of range (" << idx
777                                       << "+1 >= " << code_item_->registers_size_ << ")";
778     return false;
779   }
780   return true;
781 }
782 
CheckFieldIndex(uint32_t idx)783 bool MethodVerifier::CheckFieldIndex(uint32_t idx) {
784   if (idx >= dex_file_->GetHeader().field_ids_size_) {
785     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "bad field index " << idx << " (max "
786                                       << dex_file_->GetHeader().field_ids_size_ << ")";
787     return false;
788   }
789   return true;
790 }
791 
CheckMethodIndex(uint32_t idx)792 bool MethodVerifier::CheckMethodIndex(uint32_t idx) {
793   if (idx >= dex_file_->GetHeader().method_ids_size_) {
794     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "bad method index " << idx << " (max "
795                                       << dex_file_->GetHeader().method_ids_size_ << ")";
796     return false;
797   }
798   return true;
799 }
800 
CheckNewInstance(uint32_t idx)801 bool MethodVerifier::CheckNewInstance(uint32_t idx) {
802   if (idx >= dex_file_->GetHeader().type_ids_size_) {
803     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "bad type index " << idx << " (max "
804                                       << dex_file_->GetHeader().type_ids_size_ << ")";
805     return false;
806   }
807   // We don't need the actual class, just a pointer to the class name.
808   const char* descriptor = dex_file_->StringByTypeIdx(idx);
809   if (descriptor[0] != 'L') {
810     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "can't call new-instance on type '" << descriptor << "'";
811     return false;
812   }
813   return true;
814 }
815 
CheckStringIndex(uint32_t idx)816 bool MethodVerifier::CheckStringIndex(uint32_t idx) {
817   if (idx >= dex_file_->GetHeader().string_ids_size_) {
818     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "bad string index " << idx << " (max "
819                                       << dex_file_->GetHeader().string_ids_size_ << ")";
820     return false;
821   }
822   return true;
823 }
824 
CheckTypeIndex(uint32_t idx)825 bool MethodVerifier::CheckTypeIndex(uint32_t idx) {
826   if (idx >= dex_file_->GetHeader().type_ids_size_) {
827     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "bad type index " << idx << " (max "
828                                       << dex_file_->GetHeader().type_ids_size_ << ")";
829     return false;
830   }
831   return true;
832 }
833 
CheckNewArray(uint32_t idx)834 bool MethodVerifier::CheckNewArray(uint32_t idx) {
835   if (idx >= dex_file_->GetHeader().type_ids_size_) {
836     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "bad type index " << idx << " (max "
837                                       << dex_file_->GetHeader().type_ids_size_ << ")";
838     return false;
839   }
840   int bracket_count = 0;
841   const char* descriptor = dex_file_->StringByTypeIdx(idx);
842   const char* cp = descriptor;
843   while (*cp++ == '[') {
844     bracket_count++;
845   }
846   if (bracket_count == 0) {
847     /* The given class must be an array type. */
848     Fail(VERIFY_ERROR_BAD_CLASS_HARD)
849         << "can't new-array class '" << descriptor << "' (not an array)";
850     return false;
851   } else if (bracket_count > 255) {
852     /* It is illegal to create an array of more than 255 dimensions. */
853     Fail(VERIFY_ERROR_BAD_CLASS_HARD)
854         << "can't new-array class '" << descriptor << "' (exceeds limit)";
855     return false;
856   }
857   return true;
858 }
859 
CheckArrayData(uint32_t cur_offset)860 bool MethodVerifier::CheckArrayData(uint32_t cur_offset) {
861   const uint32_t insn_count = code_item_->insns_size_in_code_units_;
862   const uint16_t* insns = code_item_->insns_ + cur_offset;
863   const uint16_t* array_data;
864   int32_t array_data_offset;
865 
866   DCHECK_LT(cur_offset, insn_count);
867   /* make sure the start of the array data table is in range */
868   array_data_offset = insns[1] | (((int32_t) insns[2]) << 16);
869   if ((int32_t) cur_offset + array_data_offset < 0 ||
870       cur_offset + array_data_offset + 2 >= insn_count) {
871     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid array data start: at " << cur_offset
872                                       << ", data offset " << array_data_offset
873                                       << ", count " << insn_count;
874     return false;
875   }
876   /* offset to array data table is a relative branch-style offset */
877   array_data = insns + array_data_offset;
878   /* make sure the table is 32-bit aligned */
879   if ((reinterpret_cast<uintptr_t>(array_data) & 0x03) != 0) {
880     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "unaligned array data table: at " << cur_offset
881                                       << ", data offset " << array_data_offset;
882     return false;
883   }
884   uint32_t value_width = array_data[1];
885   uint32_t value_count = *reinterpret_cast<const uint32_t*>(&array_data[2]);
886   uint32_t table_size = 4 + (value_width * value_count + 1) / 2;
887   /* make sure the end of the switch is in range */
888   if (cur_offset + array_data_offset + table_size > insn_count) {
889     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid array data end: at " << cur_offset
890                                       << ", data offset " << array_data_offset << ", end "
891                                       << cur_offset + array_data_offset + table_size
892                                       << ", count " << insn_count;
893     return false;
894   }
895   return true;
896 }
897 
CheckBranchTarget(uint32_t cur_offset)898 bool MethodVerifier::CheckBranchTarget(uint32_t cur_offset) {
899   int32_t offset;
900   bool isConditional, selfOkay;
901   if (!GetBranchOffset(cur_offset, &offset, &isConditional, &selfOkay)) {
902     return false;
903   }
904   if (!selfOkay && offset == 0) {
905     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "branch offset of zero not allowed at"
906                                       << reinterpret_cast<void*>(cur_offset);
907     return false;
908   }
909   // Check for 32-bit overflow. This isn't strictly necessary if we can depend on the runtime
910   // to have identical "wrap-around" behavior, but it's unwise to depend on that.
911   if (((int64_t) cur_offset + (int64_t) offset) != (int64_t) (cur_offset + offset)) {
912     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "branch target overflow "
913                                       << reinterpret_cast<void*>(cur_offset) << " +" << offset;
914     return false;
915   }
916   const uint32_t insn_count = code_item_->insns_size_in_code_units_;
917   int32_t abs_offset = cur_offset + offset;
918   if (abs_offset < 0 ||
919       (uint32_t) abs_offset >= insn_count ||
920       !insn_flags_[abs_offset].IsOpcode()) {
921     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid branch target " << offset << " (-> "
922                                       << reinterpret_cast<void*>(abs_offset) << ") at "
923                                       << reinterpret_cast<void*>(cur_offset);
924     return false;
925   }
926   insn_flags_[abs_offset].SetBranchTarget();
927   return true;
928 }
929 
GetBranchOffset(uint32_t cur_offset,int32_t * pOffset,bool * pConditional,bool * selfOkay)930 bool MethodVerifier::GetBranchOffset(uint32_t cur_offset, int32_t* pOffset, bool* pConditional,
931                                   bool* selfOkay) {
932   const uint16_t* insns = code_item_->insns_ + cur_offset;
933   *pConditional = false;
934   *selfOkay = false;
935   switch (*insns & 0xff) {
936     case Instruction::GOTO:
937       *pOffset = ((int16_t) *insns) >> 8;
938       break;
939     case Instruction::GOTO_32:
940       *pOffset = insns[1] | (((uint32_t) insns[2]) << 16);
941       *selfOkay = true;
942       break;
943     case Instruction::GOTO_16:
944       *pOffset = (int16_t) insns[1];
945       break;
946     case Instruction::IF_EQ:
947     case Instruction::IF_NE:
948     case Instruction::IF_LT:
949     case Instruction::IF_GE:
950     case Instruction::IF_GT:
951     case Instruction::IF_LE:
952     case Instruction::IF_EQZ:
953     case Instruction::IF_NEZ:
954     case Instruction::IF_LTZ:
955     case Instruction::IF_GEZ:
956     case Instruction::IF_GTZ:
957     case Instruction::IF_LEZ:
958       *pOffset = (int16_t) insns[1];
959       *pConditional = true;
960       break;
961     default:
962       return false;
963       break;
964   }
965   return true;
966 }
967 
CheckSwitchTargets(uint32_t cur_offset)968 bool MethodVerifier::CheckSwitchTargets(uint32_t cur_offset) {
969   const uint32_t insn_count = code_item_->insns_size_in_code_units_;
970   DCHECK_LT(cur_offset, insn_count);
971   const uint16_t* insns = code_item_->insns_ + cur_offset;
972   /* make sure the start of the switch is in range */
973   int32_t switch_offset = insns[1] | ((int32_t) insns[2]) << 16;
974   if ((int32_t) cur_offset + switch_offset < 0 || cur_offset + switch_offset + 2 >= insn_count) {
975     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid switch start: at " << cur_offset
976                                       << ", switch offset " << switch_offset
977                                       << ", count " << insn_count;
978     return false;
979   }
980   /* offset to switch table is a relative branch-style offset */
981   const uint16_t* switch_insns = insns + switch_offset;
982   /* make sure the table is 32-bit aligned */
983   if ((reinterpret_cast<uintptr_t>(switch_insns) & 0x03) != 0) {
984     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "unaligned switch table: at " << cur_offset
985                                       << ", switch offset " << switch_offset;
986     return false;
987   }
988   uint32_t switch_count = switch_insns[1];
989   int32_t keys_offset, targets_offset;
990   uint16_t expected_signature;
991   if ((*insns & 0xff) == Instruction::PACKED_SWITCH) {
992     /* 0=sig, 1=count, 2/3=firstKey */
993     targets_offset = 4;
994     keys_offset = -1;
995     expected_signature = Instruction::kPackedSwitchSignature;
996   } else {
997     /* 0=sig, 1=count, 2..count*2 = keys */
998     keys_offset = 2;
999     targets_offset = 2 + 2 * switch_count;
1000     expected_signature = Instruction::kSparseSwitchSignature;
1001   }
1002   uint32_t table_size = targets_offset + switch_count * 2;
1003   if (switch_insns[0] != expected_signature) {
1004     Fail(VERIFY_ERROR_BAD_CLASS_HARD)
1005         << StringPrintf("wrong signature for switch table (%x, wanted %x)",
1006                         switch_insns[0], expected_signature);
1007     return false;
1008   }
1009   /* make sure the end of the switch is in range */
1010   if (cur_offset + switch_offset + table_size > (uint32_t) insn_count) {
1011     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid switch end: at " << cur_offset
1012                                       << ", switch offset " << switch_offset
1013                                       << ", end " << (cur_offset + switch_offset + table_size)
1014                                       << ", count " << insn_count;
1015     return false;
1016   }
1017   /* for a sparse switch, verify the keys are in ascending order */
1018   if (keys_offset > 0 && switch_count > 1) {
1019     int32_t last_key = switch_insns[keys_offset] | (switch_insns[keys_offset + 1] << 16);
1020     for (uint32_t targ = 1; targ < switch_count; targ++) {
1021       int32_t key = (int32_t) switch_insns[keys_offset + targ * 2] |
1022                     (int32_t) (switch_insns[keys_offset + targ * 2 + 1] << 16);
1023       if (key <= last_key) {
1024         Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid packed switch: last key=" << last_key
1025                                           << ", this=" << key;
1026         return false;
1027       }
1028       last_key = key;
1029     }
1030   }
1031   /* verify each switch target */
1032   for (uint32_t targ = 0; targ < switch_count; targ++) {
1033     int32_t offset = (int32_t) switch_insns[targets_offset + targ * 2] |
1034                      (int32_t) (switch_insns[targets_offset + targ * 2 + 1] << 16);
1035     int32_t abs_offset = cur_offset + offset;
1036     if (abs_offset < 0 ||
1037         abs_offset >= (int32_t) insn_count ||
1038         !insn_flags_[abs_offset].IsOpcode()) {
1039       Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid switch target " << offset
1040                                         << " (-> " << reinterpret_cast<void*>(abs_offset) << ") at "
1041                                         << reinterpret_cast<void*>(cur_offset)
1042                                         << "[" << targ << "]";
1043       return false;
1044     }
1045     insn_flags_[abs_offset].SetBranchTarget();
1046   }
1047   return true;
1048 }
1049 
CheckVarArgRegs(uint32_t vA,uint32_t arg[])1050 bool MethodVerifier::CheckVarArgRegs(uint32_t vA, uint32_t arg[]) {
1051   if (vA > Instruction::kMaxVarArgRegs) {
1052     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid arg count (" << vA << ") in non-range invoke)";
1053     return false;
1054   }
1055   uint16_t registers_size = code_item_->registers_size_;
1056   for (uint32_t idx = 0; idx < vA; idx++) {
1057     if (arg[idx] >= registers_size) {
1058       Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid reg index (" << arg[idx]
1059                                         << ") in non-range invoke (>= " << registers_size << ")";
1060       return false;
1061     }
1062   }
1063 
1064   return true;
1065 }
1066 
CheckVarArgRangeRegs(uint32_t vA,uint32_t vC)1067 bool MethodVerifier::CheckVarArgRangeRegs(uint32_t vA, uint32_t vC) {
1068   uint16_t registers_size = code_item_->registers_size_;
1069   // vA/vC are unsigned 8-bit/16-bit quantities for /range instructions, so there's no risk of
1070   // integer overflow when adding them here.
1071   if (vA + vC > registers_size) {
1072     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid reg index " << vA << "+" << vC
1073                                       << " in range invoke (> " << registers_size << ")";
1074     return false;
1075   }
1076   return true;
1077 }
1078 
VerifyCodeFlow()1079 bool MethodVerifier::VerifyCodeFlow() {
1080   uint16_t registers_size = code_item_->registers_size_;
1081   uint32_t insns_size = code_item_->insns_size_in_code_units_;
1082 
1083   if (registers_size * insns_size > 4*1024*1024) {
1084     LOG(WARNING) << "warning: method is huge (regs=" << registers_size
1085                  << " insns_size=" << insns_size << ")";
1086   }
1087   /* Create and initialize table holding register status */
1088   reg_table_.Init(kTrackCompilerInterestPoints,
1089                   insn_flags_.get(),
1090                   insns_size,
1091                   registers_size,
1092                   this);
1093 
1094 
1095   work_line_.reset(RegisterLine::Create(registers_size, this));
1096   saved_line_.reset(RegisterLine::Create(registers_size, this));
1097 
1098   /* Initialize register types of method arguments. */
1099   if (!SetTypesFromSignature()) {
1100     DCHECK_NE(failures_.size(), 0U);
1101     std::string prepend("Bad signature in ");
1102     prepend += PrettyMethod(dex_method_idx_, *dex_file_);
1103     PrependToLastFailMessage(prepend);
1104     return false;
1105   }
1106   /* Perform code flow verification. */
1107   if (!CodeFlowVerifyMethod()) {
1108     DCHECK_NE(failures_.size(), 0U);
1109     return false;
1110   }
1111   return true;
1112 }
1113 
DumpFailures(std::ostream & os)1114 std::ostream& MethodVerifier::DumpFailures(std::ostream& os) {
1115   DCHECK_EQ(failures_.size(), failure_messages_.size());
1116   for (size_t i = 0; i < failures_.size(); ++i) {
1117       os << failure_messages_[i]->str() << "\n";
1118   }
1119   return os;
1120 }
1121 
MethodVerifierGdbDump(MethodVerifier * v)1122 extern "C" void MethodVerifierGdbDump(MethodVerifier* v)
1123     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
1124   v->Dump(std::cerr);
1125 }
1126 
Dump(std::ostream & os)1127 void MethodVerifier::Dump(std::ostream& os) {
1128   if (code_item_ == nullptr) {
1129     os << "Native method\n";
1130     return;
1131   }
1132   {
1133     os << "Register Types:\n";
1134     Indenter indent_filter(os.rdbuf(), kIndentChar, kIndentBy1Count);
1135     std::ostream indent_os(&indent_filter);
1136     reg_types_.Dump(indent_os);
1137   }
1138   os << "Dumping instructions and register lines:\n";
1139   Indenter indent_filter(os.rdbuf(), kIndentChar, kIndentBy1Count);
1140   std::ostream indent_os(&indent_filter);
1141   const Instruction* inst = Instruction::At(code_item_->insns_);
1142   for (size_t dex_pc = 0; dex_pc < code_item_->insns_size_in_code_units_;
1143       dex_pc += insn_flags_[dex_pc].GetLengthInCodeUnits()) {
1144     RegisterLine* reg_line = reg_table_.GetLine(dex_pc);
1145     if (reg_line != nullptr) {
1146       indent_os << reg_line->Dump() << "\n";
1147     }
1148     indent_os << StringPrintf("0x%04zx", dex_pc) << ": " << insn_flags_[dex_pc].ToString() << " ";
1149     const bool kDumpHexOfInstruction = false;
1150     if (kDumpHexOfInstruction) {
1151       indent_os << inst->DumpHex(5) << " ";
1152     }
1153     indent_os << inst->DumpString(dex_file_) << "\n";
1154     inst = inst->Next();
1155   }
1156 }
1157 
IsPrimitiveDescriptor(char descriptor)1158 static bool IsPrimitiveDescriptor(char descriptor) {
1159   switch (descriptor) {
1160     case 'I':
1161     case 'C':
1162     case 'S':
1163     case 'B':
1164     case 'Z':
1165     case 'F':
1166     case 'D':
1167     case 'J':
1168       return true;
1169     default:
1170       return false;
1171   }
1172 }
1173 
SetTypesFromSignature()1174 bool MethodVerifier::SetTypesFromSignature() {
1175   RegisterLine* reg_line = reg_table_.GetLine(0);
1176   int arg_start = code_item_->registers_size_ - code_item_->ins_size_;
1177   size_t expected_args = code_item_->ins_size_;   /* long/double count as two */
1178 
1179   DCHECK_GE(arg_start, 0);      /* should have been verified earlier */
1180   // Include the "this" pointer.
1181   size_t cur_arg = 0;
1182   if (!IsStatic()) {
1183     // If this is a constructor for a class other than java.lang.Object, mark the first ("this")
1184     // argument as uninitialized. This restricts field access until the superclass constructor is
1185     // called.
1186     RegType& declaring_class = GetDeclaringClass();
1187     if (IsConstructor() && !declaring_class.IsJavaLangObject()) {
1188       reg_line->SetRegisterType(arg_start + cur_arg,
1189                                 reg_types_.UninitializedThisArgument(declaring_class));
1190     } else {
1191       reg_line->SetRegisterType(arg_start + cur_arg, declaring_class);
1192     }
1193     cur_arg++;
1194   }
1195 
1196   const DexFile::ProtoId& proto_id =
1197       dex_file_->GetMethodPrototype(dex_file_->GetMethodId(dex_method_idx_));
1198   DexFileParameterIterator iterator(*dex_file_, proto_id);
1199 
1200   for (; iterator.HasNext(); iterator.Next()) {
1201     const char* descriptor = iterator.GetDescriptor();
1202     if (descriptor == nullptr) {
1203       LOG(FATAL) << "Null descriptor";
1204     }
1205     if (cur_arg >= expected_args) {
1206       Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "expected " << expected_args
1207                                         << " args, found more (" << descriptor << ")";
1208       return false;
1209     }
1210     switch (descriptor[0]) {
1211       case 'L':
1212       case '[':
1213         // We assume that reference arguments are initialized. The only way it could be otherwise
1214         // (assuming the caller was verified) is if the current method is <init>, but in that case
1215         // it's effectively considered initialized the instant we reach here (in the sense that we
1216         // can return without doing anything or call virtual methods).
1217         {
1218           RegType& reg_type = ResolveClassAndCheckAccess(iterator.GetTypeIdx());
1219           if (!reg_type.IsNonZeroReferenceTypes()) {
1220             DCHECK(HasFailures());
1221             return false;
1222           }
1223           reg_line->SetRegisterType(arg_start + cur_arg, reg_type);
1224         }
1225         break;
1226       case 'Z':
1227         reg_line->SetRegisterType(arg_start + cur_arg, reg_types_.Boolean());
1228         break;
1229       case 'C':
1230         reg_line->SetRegisterType(arg_start + cur_arg, reg_types_.Char());
1231         break;
1232       case 'B':
1233         reg_line->SetRegisterType(arg_start + cur_arg, reg_types_.Byte());
1234         break;
1235       case 'I':
1236         reg_line->SetRegisterType(arg_start + cur_arg, reg_types_.Integer());
1237         break;
1238       case 'S':
1239         reg_line->SetRegisterType(arg_start + cur_arg, reg_types_.Short());
1240         break;
1241       case 'F':
1242         reg_line->SetRegisterType(arg_start + cur_arg, reg_types_.Float());
1243         break;
1244       case 'J':
1245       case 'D': {
1246         if (cur_arg + 1 >= expected_args) {
1247           Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "expected " << expected_args
1248               << " args, found more (" << descriptor << ")";
1249           return false;
1250         }
1251 
1252         RegType& lo_half = descriptor[0] == 'J' ? reg_types_.LongLo() : reg_types_.DoubleLo();
1253         RegType& hi_half = descriptor[0] == 'J' ? reg_types_.LongHi() : reg_types_.DoubleHi();
1254         reg_line->SetRegisterTypeWide(arg_start + cur_arg, lo_half, hi_half);
1255         cur_arg++;
1256         break;
1257       }
1258       default:
1259         Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "unexpected signature type char '"
1260                                           << descriptor << "'";
1261         return false;
1262     }
1263     cur_arg++;
1264   }
1265   if (cur_arg != expected_args) {
1266     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "expected " << expected_args
1267                                       << " arguments, found " << cur_arg;
1268     return false;
1269   }
1270   const char* descriptor = dex_file_->GetReturnTypeDescriptor(proto_id);
1271   // Validate return type. We don't do the type lookup; just want to make sure that it has the right
1272   // format. Only major difference from the method argument format is that 'V' is supported.
1273   bool result;
1274   if (IsPrimitiveDescriptor(descriptor[0]) || descriptor[0] == 'V') {
1275     result = descriptor[1] == '\0';
1276   } else if (descriptor[0] == '[') {  // single/multi-dimensional array of object/primitive
1277     size_t i = 0;
1278     do {
1279       i++;
1280     } while (descriptor[i] == '[');  // process leading [
1281     if (descriptor[i] == 'L') {  // object array
1282       do {
1283         i++;  // find closing ;
1284       } while (descriptor[i] != ';' && descriptor[i] != '\0');
1285       result = descriptor[i] == ';';
1286     } else {  // primitive array
1287       result = IsPrimitiveDescriptor(descriptor[i]) && descriptor[i + 1] == '\0';
1288     }
1289   } else if (descriptor[0] == 'L') {
1290     // could be more thorough here, but shouldn't be required
1291     size_t i = 0;
1292     do {
1293       i++;
1294     } while (descriptor[i] != ';' && descriptor[i] != '\0');
1295     result = descriptor[i] == ';';
1296   } else {
1297     result = false;
1298   }
1299   if (!result) {
1300     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "unexpected char in return type descriptor '"
1301                                       << descriptor << "'";
1302   }
1303   return result;
1304 }
1305 
CodeFlowVerifyMethod()1306 bool MethodVerifier::CodeFlowVerifyMethod() {
1307   const uint16_t* insns = code_item_->insns_;
1308   const uint32_t insns_size = code_item_->insns_size_in_code_units_;
1309 
1310   /* Begin by marking the first instruction as "changed". */
1311   insn_flags_[0].SetChanged();
1312   uint32_t start_guess = 0;
1313 
1314   /* Continue until no instructions are marked "changed". */
1315   while (true) {
1316     // Find the first marked one. Use "start_guess" as a way to find one quickly.
1317     uint32_t insn_idx = start_guess;
1318     for (; insn_idx < insns_size; insn_idx++) {
1319       if (insn_flags_[insn_idx].IsChanged())
1320         break;
1321     }
1322     if (insn_idx == insns_size) {
1323       if (start_guess != 0) {
1324         /* try again, starting from the top */
1325         start_guess = 0;
1326         continue;
1327       } else {
1328         /* all flags are clear */
1329         break;
1330       }
1331     }
1332     // We carry the working set of registers from instruction to instruction. If this address can
1333     // be the target of a branch (or throw) instruction, or if we're skipping around chasing
1334     // "changed" flags, we need to load the set of registers from the table.
1335     // Because we always prefer to continue on to the next instruction, we should never have a
1336     // situation where we have a stray "changed" flag set on an instruction that isn't a branch
1337     // target.
1338     work_insn_idx_ = insn_idx;
1339     if (insn_flags_[insn_idx].IsBranchTarget()) {
1340       work_line_->CopyFromLine(reg_table_.GetLine(insn_idx));
1341     } else if (kIsDebugBuild) {
1342       /*
1343        * Sanity check: retrieve the stored register line (assuming
1344        * a full table) and make sure it actually matches.
1345        */
1346       RegisterLine* register_line = reg_table_.GetLine(insn_idx);
1347       if (register_line != nullptr) {
1348         if (work_line_->CompareLine(register_line) != 0) {
1349           Dump(std::cout);
1350           std::cout << info_messages_.str();
1351           LOG(FATAL) << "work_line diverged in " << PrettyMethod(dex_method_idx_, *dex_file_)
1352                      << "@" << reinterpret_cast<void*>(work_insn_idx_) << "\n"
1353                      << " work_line=" << *work_line_ << "\n"
1354                      << "  expected=" << *register_line;
1355         }
1356       }
1357     }
1358     if (!CodeFlowVerifyInstruction(&start_guess)) {
1359       std::string prepend(PrettyMethod(dex_method_idx_, *dex_file_));
1360       prepend += " failed to verify: ";
1361       PrependToLastFailMessage(prepend);
1362       return false;
1363     }
1364     /* Clear "changed" and mark as visited. */
1365     insn_flags_[insn_idx].SetVisited();
1366     insn_flags_[insn_idx].ClearChanged();
1367   }
1368 
1369   if (gDebugVerify) {
1370     /*
1371      * Scan for dead code. There's nothing "evil" about dead code
1372      * (besides the wasted space), but it indicates a flaw somewhere
1373      * down the line, possibly in the verifier.
1374      *
1375      * If we've substituted "always throw" instructions into the stream,
1376      * we are almost certainly going to have some dead code.
1377      */
1378     int dead_start = -1;
1379     uint32_t insn_idx = 0;
1380     for (; insn_idx < insns_size; insn_idx += insn_flags_[insn_idx].GetLengthInCodeUnits()) {
1381       /*
1382        * Switch-statement data doesn't get "visited" by scanner. It
1383        * may or may not be preceded by a padding NOP (for alignment).
1384        */
1385       if (insns[insn_idx] == Instruction::kPackedSwitchSignature ||
1386           insns[insn_idx] == Instruction::kSparseSwitchSignature ||
1387           insns[insn_idx] == Instruction::kArrayDataSignature ||
1388           (insns[insn_idx] == Instruction::NOP && (insn_idx + 1 < insns_size) &&
1389            (insns[insn_idx + 1] == Instruction::kPackedSwitchSignature ||
1390             insns[insn_idx + 1] == Instruction::kSparseSwitchSignature ||
1391             insns[insn_idx + 1] == Instruction::kArrayDataSignature))) {
1392         insn_flags_[insn_idx].SetVisited();
1393       }
1394 
1395       if (!insn_flags_[insn_idx].IsVisited()) {
1396         if (dead_start < 0)
1397           dead_start = insn_idx;
1398       } else if (dead_start >= 0) {
1399         LogVerifyInfo() << "dead code " << reinterpret_cast<void*>(dead_start)
1400                         << "-" << reinterpret_cast<void*>(insn_idx - 1);
1401         dead_start = -1;
1402       }
1403     }
1404     if (dead_start >= 0) {
1405       LogVerifyInfo() << "dead code " << reinterpret_cast<void*>(dead_start)
1406                       << "-" << reinterpret_cast<void*>(insn_idx - 1);
1407     }
1408     // To dump the state of the verify after a method, do something like:
1409     // if (PrettyMethod(dex_method_idx_, *dex_file_) ==
1410     //     "boolean java.lang.String.equals(java.lang.Object)") {
1411     //   LOG(INFO) << info_messages_.str();
1412     // }
1413   }
1414   return true;
1415 }
1416 
CodeFlowVerifyInstruction(uint32_t * start_guess)1417 bool MethodVerifier::CodeFlowVerifyInstruction(uint32_t* start_guess) {
1418   // If we're doing FindLocksAtDexPc, check whether we're at the dex pc we care about.
1419   // We want the state _before_ the instruction, for the case where the dex pc we're
1420   // interested in is itself a monitor-enter instruction (which is a likely place
1421   // for a thread to be suspended).
1422   if (monitor_enter_dex_pcs_ != nullptr && work_insn_idx_ == interesting_dex_pc_) {
1423     monitor_enter_dex_pcs_->clear();  // The new work line is more accurate than the previous one.
1424     for (size_t i = 0; i < work_line_->GetMonitorEnterCount(); ++i) {
1425       monitor_enter_dex_pcs_->push_back(work_line_->GetMonitorEnterDexPc(i));
1426     }
1427   }
1428 
1429   /*
1430    * Once we finish decoding the instruction, we need to figure out where
1431    * we can go from here. There are three possible ways to transfer
1432    * control to another statement:
1433    *
1434    * (1) Continue to the next instruction. Applies to all but
1435    *     unconditional branches, method returns, and exception throws.
1436    * (2) Branch to one or more possible locations. Applies to branches
1437    *     and switch statements.
1438    * (3) Exception handlers. Applies to any instruction that can
1439    *     throw an exception that is handled by an encompassing "try"
1440    *     block.
1441    *
1442    * We can also return, in which case there is no successor instruction
1443    * from this point.
1444    *
1445    * The behavior can be determined from the opcode flags.
1446    */
1447   const uint16_t* insns = code_item_->insns_ + work_insn_idx_;
1448   const Instruction* inst = Instruction::At(insns);
1449   int opcode_flags = Instruction::FlagsOf(inst->Opcode());
1450 
1451   int32_t branch_target = 0;
1452   bool just_set_result = false;
1453   if (gDebugVerify) {
1454     // Generate processing back trace to debug verifier
1455     LogVerifyInfo() << "Processing " << inst->DumpString(dex_file_) << "\n"
1456                     << *work_line_.get() << "\n";
1457   }
1458 
1459   /*
1460    * Make a copy of the previous register state. If the instruction
1461    * can throw an exception, we will copy/merge this into the "catch"
1462    * address rather than work_line, because we don't want the result
1463    * from the "successful" code path (e.g. a check-cast that "improves"
1464    * a type) to be visible to the exception handler.
1465    */
1466   if ((opcode_flags & Instruction::kThrow) != 0 && CurrentInsnFlags()->IsInTry()) {
1467     saved_line_->CopyFromLine(work_line_.get());
1468   } else if (kIsDebugBuild) {
1469     saved_line_->FillWithGarbage();
1470   }
1471 
1472 
1473   // We need to ensure the work line is consistent while performing validation. When we spot a
1474   // peephole pattern we compute a new line for either the fallthrough instruction or the
1475   // branch target.
1476   std::unique_ptr<RegisterLine> branch_line;
1477   std::unique_ptr<RegisterLine> fallthrough_line;
1478 
1479   switch (inst->Opcode()) {
1480     case Instruction::NOP:
1481       /*
1482        * A "pure" NOP has no effect on anything. Data tables start with
1483        * a signature that looks like a NOP; if we see one of these in
1484        * the course of executing code then we have a problem.
1485        */
1486       if (inst->VRegA_10x() != 0) {
1487         Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "encountered data table in instruction stream";
1488       }
1489       break;
1490 
1491     case Instruction::MOVE:
1492       work_line_->CopyRegister1(inst->VRegA_12x(), inst->VRegB_12x(), kTypeCategory1nr);
1493       break;
1494     case Instruction::MOVE_FROM16:
1495       work_line_->CopyRegister1(inst->VRegA_22x(), inst->VRegB_22x(), kTypeCategory1nr);
1496       break;
1497     case Instruction::MOVE_16:
1498       work_line_->CopyRegister1(inst->VRegA_32x(), inst->VRegB_32x(), kTypeCategory1nr);
1499       break;
1500     case Instruction::MOVE_WIDE:
1501       work_line_->CopyRegister2(inst->VRegA_12x(), inst->VRegB_12x());
1502       break;
1503     case Instruction::MOVE_WIDE_FROM16:
1504       work_line_->CopyRegister2(inst->VRegA_22x(), inst->VRegB_22x());
1505       break;
1506     case Instruction::MOVE_WIDE_16:
1507       work_line_->CopyRegister2(inst->VRegA_32x(), inst->VRegB_32x());
1508       break;
1509     case Instruction::MOVE_OBJECT:
1510       work_line_->CopyRegister1(inst->VRegA_12x(), inst->VRegB_12x(), kTypeCategoryRef);
1511       break;
1512     case Instruction::MOVE_OBJECT_FROM16:
1513       work_line_->CopyRegister1(inst->VRegA_22x(), inst->VRegB_22x(), kTypeCategoryRef);
1514       break;
1515     case Instruction::MOVE_OBJECT_16:
1516       work_line_->CopyRegister1(inst->VRegA_32x(), inst->VRegB_32x(), kTypeCategoryRef);
1517       break;
1518 
1519     /*
1520      * The move-result instructions copy data out of a "pseudo-register"
1521      * with the results from the last method invocation. In practice we
1522      * might want to hold the result in an actual CPU register, so the
1523      * Dalvik spec requires that these only appear immediately after an
1524      * invoke or filled-new-array.
1525      *
1526      * These calls invalidate the "result" register. (This is now
1527      * redundant with the reset done below, but it can make the debug info
1528      * easier to read in some cases.)
1529      */
1530     case Instruction::MOVE_RESULT:
1531       work_line_->CopyResultRegister1(inst->VRegA_11x(), false);
1532       break;
1533     case Instruction::MOVE_RESULT_WIDE:
1534       work_line_->CopyResultRegister2(inst->VRegA_11x());
1535       break;
1536     case Instruction::MOVE_RESULT_OBJECT:
1537       work_line_->CopyResultRegister1(inst->VRegA_11x(), true);
1538       break;
1539 
1540     case Instruction::MOVE_EXCEPTION: {
1541       /*
1542        * This statement can only appear as the first instruction in an exception handler. We verify
1543        * that as part of extracting the exception type from the catch block list.
1544        */
1545       RegType& res_type = GetCaughtExceptionType();
1546       work_line_->SetRegisterType(inst->VRegA_11x(), res_type);
1547       break;
1548     }
1549     case Instruction::RETURN_VOID:
1550       if (!IsConstructor() || work_line_->CheckConstructorReturn()) {
1551         if (!GetMethodReturnType().IsConflict()) {
1552           Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "return-void not expected";
1553         }
1554       }
1555       break;
1556     case Instruction::RETURN:
1557       if (!IsConstructor() || work_line_->CheckConstructorReturn()) {
1558         /* check the method signature */
1559         RegType& return_type = GetMethodReturnType();
1560         if (!return_type.IsCategory1Types()) {
1561           Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "unexpected non-category 1 return type "
1562                                             << return_type;
1563         } else {
1564           // Compilers may generate synthetic functions that write byte values into boolean fields.
1565           // Also, it may use integer values for boolean, byte, short, and character return types.
1566           const uint32_t vregA = inst->VRegA_11x();
1567           RegType& src_type = work_line_->GetRegisterType(vregA);
1568           bool use_src = ((return_type.IsBoolean() && src_type.IsByte()) ||
1569                           ((return_type.IsBoolean() || return_type.IsByte() ||
1570                            return_type.IsShort() || return_type.IsChar()) &&
1571                            src_type.IsInteger()));
1572           /* check the register contents */
1573           bool success =
1574               work_line_->VerifyRegisterType(vregA, use_src ? src_type : return_type);
1575           if (!success) {
1576             AppendToLastFailMessage(StringPrintf(" return-1nr on invalid register v%d", vregA));
1577           }
1578         }
1579       }
1580       break;
1581     case Instruction::RETURN_WIDE:
1582       if (!IsConstructor() || work_line_->CheckConstructorReturn()) {
1583         /* check the method signature */
1584         RegType& return_type = GetMethodReturnType();
1585         if (!return_type.IsCategory2Types()) {
1586           Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "return-wide not expected";
1587         } else {
1588           /* check the register contents */
1589           const uint32_t vregA = inst->VRegA_11x();
1590           bool success = work_line_->VerifyRegisterType(vregA, return_type);
1591           if (!success) {
1592             AppendToLastFailMessage(StringPrintf(" return-wide on invalid register v%d", vregA));
1593           }
1594         }
1595       }
1596       break;
1597     case Instruction::RETURN_OBJECT:
1598       if (!IsConstructor() || work_line_->CheckConstructorReturn()) {
1599         RegType& return_type = GetMethodReturnType();
1600         if (!return_type.IsReferenceTypes()) {
1601           Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "return-object not expected";
1602         } else {
1603           /* return_type is the *expected* return type, not register value */
1604           DCHECK(!return_type.IsZero());
1605           DCHECK(!return_type.IsUninitializedReference());
1606           const uint32_t vregA = inst->VRegA_11x();
1607           RegType& reg_type = work_line_->GetRegisterType(vregA);
1608           // Disallow returning uninitialized values and verify that the reference in vAA is an
1609           // instance of the "return_type"
1610           if (reg_type.IsUninitializedTypes()) {
1611             Fail(VERIFY_ERROR_BAD_CLASS_SOFT) << "returning uninitialized object '"
1612                                               << reg_type << "'";
1613           } else if (!return_type.IsAssignableFrom(reg_type)) {
1614             if (reg_type.IsUnresolvedTypes() || return_type.IsUnresolvedTypes()) {
1615               Fail(VERIFY_ERROR_NO_CLASS) << " can't resolve returned type '" << return_type
1616                   << "' or '" << reg_type << "'";
1617             } else {
1618               Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "returning '" << reg_type
1619                   << "', but expected from declaration '" << return_type << "'";
1620             }
1621           }
1622         }
1623       }
1624       break;
1625 
1626       /* could be boolean, int, float, or a null reference */
1627     case Instruction::CONST_4: {
1628       int32_t val = static_cast<int32_t>(inst->VRegB_11n() << 28) >> 28;
1629       work_line_->SetRegisterType(inst->VRegA_11n(),
1630                                   DetermineCat1Constant(val, need_precise_constants_));
1631       break;
1632     }
1633     case Instruction::CONST_16: {
1634       int16_t val = static_cast<int16_t>(inst->VRegB_21s());
1635       work_line_->SetRegisterType(inst->VRegA_21s(),
1636                                   DetermineCat1Constant(val, need_precise_constants_));
1637       break;
1638     }
1639     case Instruction::CONST: {
1640       int32_t val = inst->VRegB_31i();
1641       work_line_->SetRegisterType(inst->VRegA_31i(),
1642                                   DetermineCat1Constant(val, need_precise_constants_));
1643       break;
1644     }
1645     case Instruction::CONST_HIGH16: {
1646       int32_t val = static_cast<int32_t>(inst->VRegB_21h() << 16);
1647       work_line_->SetRegisterType(inst->VRegA_21h(),
1648                                   DetermineCat1Constant(val, need_precise_constants_));
1649       break;
1650     }
1651       /* could be long or double; resolved upon use */
1652     case Instruction::CONST_WIDE_16: {
1653       int64_t val = static_cast<int16_t>(inst->VRegB_21s());
1654       RegType& lo = reg_types_.FromCat2ConstLo(static_cast<int32_t>(val), true);
1655       RegType& hi = reg_types_.FromCat2ConstHi(static_cast<int32_t>(val >> 32), true);
1656       work_line_->SetRegisterTypeWide(inst->VRegA_21s(), lo, hi);
1657       break;
1658     }
1659     case Instruction::CONST_WIDE_32: {
1660       int64_t val = static_cast<int32_t>(inst->VRegB_31i());
1661       RegType& lo = reg_types_.FromCat2ConstLo(static_cast<int32_t>(val), true);
1662       RegType& hi = reg_types_.FromCat2ConstHi(static_cast<int32_t>(val >> 32), true);
1663       work_line_->SetRegisterTypeWide(inst->VRegA_31i(), lo, hi);
1664       break;
1665     }
1666     case Instruction::CONST_WIDE: {
1667       int64_t val = inst->VRegB_51l();
1668       RegType& lo = reg_types_.FromCat2ConstLo(static_cast<int32_t>(val), true);
1669       RegType& hi = reg_types_.FromCat2ConstHi(static_cast<int32_t>(val >> 32), true);
1670       work_line_->SetRegisterTypeWide(inst->VRegA_51l(), lo, hi);
1671       break;
1672     }
1673     case Instruction::CONST_WIDE_HIGH16: {
1674       int64_t val = static_cast<uint64_t>(inst->VRegB_21h()) << 48;
1675       RegType& lo = reg_types_.FromCat2ConstLo(static_cast<int32_t>(val), true);
1676       RegType& hi = reg_types_.FromCat2ConstHi(static_cast<int32_t>(val >> 32), true);
1677       work_line_->SetRegisterTypeWide(inst->VRegA_21h(), lo, hi);
1678       break;
1679     }
1680     case Instruction::CONST_STRING:
1681       work_line_->SetRegisterType(inst->VRegA_21c(), reg_types_.JavaLangString());
1682       break;
1683     case Instruction::CONST_STRING_JUMBO:
1684       work_line_->SetRegisterType(inst->VRegA_31c(), reg_types_.JavaLangString());
1685       break;
1686     case Instruction::CONST_CLASS: {
1687       // Get type from instruction if unresolved then we need an access check
1688       // TODO: check Compiler::CanAccessTypeWithoutChecks returns false when res_type is unresolved
1689       RegType& res_type = ResolveClassAndCheckAccess(inst->VRegB_21c());
1690       // Register holds class, ie its type is class, on error it will hold Conflict.
1691       work_line_->SetRegisterType(inst->VRegA_21c(),
1692                                   res_type.IsConflict() ? res_type
1693                                                         : reg_types_.JavaLangClass(true));
1694       break;
1695     }
1696     case Instruction::MONITOR_ENTER:
1697       work_line_->PushMonitor(inst->VRegA_11x(), work_insn_idx_);
1698       break;
1699     case Instruction::MONITOR_EXIT:
1700       /*
1701        * monitor-exit instructions are odd. They can throw exceptions,
1702        * but when they do they act as if they succeeded and the PC is
1703        * pointing to the following instruction. (This behavior goes back
1704        * to the need to handle asynchronous exceptions, a now-deprecated
1705        * feature that Dalvik doesn't support.)
1706        *
1707        * In practice we don't need to worry about this. The only
1708        * exceptions that can be thrown from monitor-exit are for a
1709        * null reference and -exit without a matching -enter. If the
1710        * structured locking checks are working, the former would have
1711        * failed on the -enter instruction, and the latter is impossible.
1712        *
1713        * This is fortunate, because issue 3221411 prevents us from
1714        * chasing the "can throw" path when monitor verification is
1715        * enabled. If we can fully verify the locking we can ignore
1716        * some catch blocks (which will show up as "dead" code when
1717        * we skip them here); if we can't, then the code path could be
1718        * "live" so we still need to check it.
1719        */
1720       opcode_flags &= ~Instruction::kThrow;
1721       work_line_->PopMonitor(inst->VRegA_11x());
1722       break;
1723 
1724     case Instruction::CHECK_CAST:
1725     case Instruction::INSTANCE_OF: {
1726       /*
1727        * If this instruction succeeds, we will "downcast" register vA to the type in vB. (This
1728        * could be a "upcast" -- not expected, so we don't try to address it.)
1729        *
1730        * If it fails, an exception is thrown, which we deal with later by ignoring the update to
1731        * dec_insn.vA when branching to a handler.
1732        */
1733       const bool is_checkcast = (inst->Opcode() == Instruction::CHECK_CAST);
1734       const uint32_t type_idx = (is_checkcast) ? inst->VRegB_21c() : inst->VRegC_22c();
1735       RegType& res_type = ResolveClassAndCheckAccess(type_idx);
1736       if (res_type.IsConflict()) {
1737         // If this is a primitive type, fail HARD.
1738         mirror::Class* klass = (*dex_cache_)->GetResolvedType(type_idx);
1739         if (klass != nullptr && klass->IsPrimitive()) {
1740           Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "using primitive type "
1741               << dex_file_->StringByTypeIdx(type_idx) << " in instanceof in "
1742               << GetDeclaringClass();
1743           break;
1744         }
1745 
1746         DCHECK_NE(failures_.size(), 0U);
1747         if (!is_checkcast) {
1748           work_line_->SetRegisterType(inst->VRegA_22c(), reg_types_.Boolean());
1749         }
1750         break;  // bad class
1751       }
1752       // TODO: check Compiler::CanAccessTypeWithoutChecks returns false when res_type is unresolved
1753       uint32_t orig_type_reg = (is_checkcast) ? inst->VRegA_21c() : inst->VRegB_22c();
1754       RegType& orig_type = work_line_->GetRegisterType(orig_type_reg);
1755       if (!res_type.IsNonZeroReferenceTypes()) {
1756         if (is_checkcast) {
1757           Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "check-cast on unexpected class " << res_type;
1758         } else {
1759           Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "instance-of on unexpected class " << res_type;
1760         }
1761       } else if (!orig_type.IsReferenceTypes()) {
1762         if (is_checkcast) {
1763           Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "check-cast on non-reference in v" << orig_type_reg;
1764         } else {
1765           Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "instance-of on non-reference in v" << orig_type_reg;
1766         }
1767       } else {
1768         if (is_checkcast) {
1769           work_line_->SetRegisterType(inst->VRegA_21c(), res_type);
1770         } else {
1771           work_line_->SetRegisterType(inst->VRegA_22c(), reg_types_.Boolean());
1772         }
1773       }
1774       break;
1775     }
1776     case Instruction::ARRAY_LENGTH: {
1777       RegType& res_type = work_line_->GetRegisterType(inst->VRegB_12x());
1778       if (res_type.IsReferenceTypes()) {
1779         if (!res_type.IsArrayTypes() && !res_type.IsZero()) {  // ie not an array or null
1780           Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "array-length on non-array " << res_type;
1781         } else {
1782           work_line_->SetRegisterType(inst->VRegA_12x(), reg_types_.Integer());
1783         }
1784       } else {
1785         Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "array-length on non-array " << res_type;
1786       }
1787       break;
1788     }
1789     case Instruction::NEW_INSTANCE: {
1790       RegType& res_type = ResolveClassAndCheckAccess(inst->VRegB_21c());
1791       if (res_type.IsConflict()) {
1792         DCHECK_NE(failures_.size(), 0U);
1793         break;  // bad class
1794       }
1795       // TODO: check Compiler::CanAccessTypeWithoutChecks returns false when res_type is unresolved
1796       // can't create an instance of an interface or abstract class */
1797       if (!res_type.IsInstantiableTypes()) {
1798         Fail(VERIFY_ERROR_INSTANTIATION)
1799             << "new-instance on primitive, interface or abstract class" << res_type;
1800         // Soft failure so carry on to set register type.
1801       }
1802       RegType& uninit_type = reg_types_.Uninitialized(res_type, work_insn_idx_);
1803       // Any registers holding previous allocations from this address that have not yet been
1804       // initialized must be marked invalid.
1805       work_line_->MarkUninitRefsAsInvalid(uninit_type);
1806       // add the new uninitialized reference to the register state
1807       work_line_->SetRegisterType(inst->VRegA_21c(), uninit_type);
1808       break;
1809     }
1810     case Instruction::NEW_ARRAY:
1811       VerifyNewArray(inst, false, false);
1812       break;
1813     case Instruction::FILLED_NEW_ARRAY:
1814       VerifyNewArray(inst, true, false);
1815       just_set_result = true;  // Filled new array sets result register
1816       break;
1817     case Instruction::FILLED_NEW_ARRAY_RANGE:
1818       VerifyNewArray(inst, true, true);
1819       just_set_result = true;  // Filled new array range sets result register
1820       break;
1821     case Instruction::CMPL_FLOAT:
1822     case Instruction::CMPG_FLOAT:
1823       if (!work_line_->VerifyRegisterType(inst->VRegB_23x(), reg_types_.Float())) {
1824         break;
1825       }
1826       if (!work_line_->VerifyRegisterType(inst->VRegC_23x(), reg_types_.Float())) {
1827         break;
1828       }
1829       work_line_->SetRegisterType(inst->VRegA_23x(), reg_types_.Integer());
1830       break;
1831     case Instruction::CMPL_DOUBLE:
1832     case Instruction::CMPG_DOUBLE:
1833       if (!work_line_->VerifyRegisterTypeWide(inst->VRegB_23x(), reg_types_.DoubleLo(),
1834                                               reg_types_.DoubleHi())) {
1835         break;
1836       }
1837       if (!work_line_->VerifyRegisterTypeWide(inst->VRegC_23x(), reg_types_.DoubleLo(),
1838                                               reg_types_.DoubleHi())) {
1839         break;
1840       }
1841       work_line_->SetRegisterType(inst->VRegA_23x(), reg_types_.Integer());
1842       break;
1843     case Instruction::CMP_LONG:
1844       if (!work_line_->VerifyRegisterTypeWide(inst->VRegB_23x(), reg_types_.LongLo(),
1845                                               reg_types_.LongHi())) {
1846         break;
1847       }
1848       if (!work_line_->VerifyRegisterTypeWide(inst->VRegC_23x(), reg_types_.LongLo(),
1849                                               reg_types_.LongHi())) {
1850         break;
1851       }
1852       work_line_->SetRegisterType(inst->VRegA_23x(), reg_types_.Integer());
1853       break;
1854     case Instruction::THROW: {
1855       RegType& res_type = work_line_->GetRegisterType(inst->VRegA_11x());
1856       if (!reg_types_.JavaLangThrowable(false).IsAssignableFrom(res_type)) {
1857         Fail(res_type.IsUnresolvedTypes() ? VERIFY_ERROR_NO_CLASS : VERIFY_ERROR_BAD_CLASS_SOFT)
1858             << "thrown class " << res_type << " not instanceof Throwable";
1859       }
1860       break;
1861     }
1862     case Instruction::GOTO:
1863     case Instruction::GOTO_16:
1864     case Instruction::GOTO_32:
1865       /* no effect on or use of registers */
1866       break;
1867 
1868     case Instruction::PACKED_SWITCH:
1869     case Instruction::SPARSE_SWITCH:
1870       /* verify that vAA is an integer, or can be converted to one */
1871       work_line_->VerifyRegisterType(inst->VRegA_31t(), reg_types_.Integer());
1872       break;
1873 
1874     case Instruction::FILL_ARRAY_DATA: {
1875       /* Similar to the verification done for APUT */
1876       RegType& array_type = work_line_->GetRegisterType(inst->VRegA_31t());
1877       /* array_type can be null if the reg type is Zero */
1878       if (!array_type.IsZero()) {
1879         if (!array_type.IsArrayTypes()) {
1880           Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid fill-array-data with array type "
1881                                             << array_type;
1882         } else {
1883           RegType& component_type = reg_types_.GetComponentType(array_type,
1884                                                                       class_loader_->Get());
1885           DCHECK(!component_type.IsConflict());
1886           if (component_type.IsNonZeroReferenceTypes()) {
1887             Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid fill-array-data with component type "
1888                                               << component_type;
1889           } else {
1890             // Now verify if the element width in the table matches the element width declared in
1891             // the array
1892             const uint16_t* array_data = insns + (insns[1] | (((int32_t) insns[2]) << 16));
1893             if (array_data[0] != Instruction::kArrayDataSignature) {
1894               Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid magic for array-data";
1895             } else {
1896               size_t elem_width = Primitive::ComponentSize(component_type.GetPrimitiveType());
1897               // Since we don't compress the data in Dex, expect to see equal width of data stored
1898               // in the table and expected from the array class.
1899               if (array_data[1] != elem_width) {
1900                 Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "array-data size mismatch (" << array_data[1]
1901                                                   << " vs " << elem_width << ")";
1902               }
1903             }
1904           }
1905         }
1906       }
1907       break;
1908     }
1909     case Instruction::IF_EQ:
1910     case Instruction::IF_NE: {
1911       RegType& reg_type1 = work_line_->GetRegisterType(inst->VRegA_22t());
1912       RegType& reg_type2 = work_line_->GetRegisterType(inst->VRegB_22t());
1913       bool mismatch = false;
1914       if (reg_type1.IsZero()) {  // zero then integral or reference expected
1915         mismatch = !reg_type2.IsReferenceTypes() && !reg_type2.IsIntegralTypes();
1916       } else if (reg_type1.IsReferenceTypes()) {  // both references?
1917         mismatch = !reg_type2.IsReferenceTypes();
1918       } else {  // both integral?
1919         mismatch = !reg_type1.IsIntegralTypes() || !reg_type2.IsIntegralTypes();
1920       }
1921       if (mismatch) {
1922         Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "args to if-eq/if-ne (" << reg_type1 << ","
1923                                           << reg_type2 << ") must both be references or integral";
1924       }
1925       break;
1926     }
1927     case Instruction::IF_LT:
1928     case Instruction::IF_GE:
1929     case Instruction::IF_GT:
1930     case Instruction::IF_LE: {
1931       RegType& reg_type1 = work_line_->GetRegisterType(inst->VRegA_22t());
1932       RegType& reg_type2 = work_line_->GetRegisterType(inst->VRegB_22t());
1933       if (!reg_type1.IsIntegralTypes() || !reg_type2.IsIntegralTypes()) {
1934         Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "args to 'if' (" << reg_type1 << ","
1935                                           << reg_type2 << ") must be integral";
1936       }
1937       break;
1938     }
1939     case Instruction::IF_EQZ:
1940     case Instruction::IF_NEZ: {
1941       RegType& reg_type = work_line_->GetRegisterType(inst->VRegA_21t());
1942       if (!reg_type.IsReferenceTypes() && !reg_type.IsIntegralTypes()) {
1943         Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "type " << reg_type
1944                                           << " unexpected as arg to if-eqz/if-nez";
1945       }
1946 
1947       // Find previous instruction - its existence is a precondition to peephole optimization.
1948       uint32_t instance_of_idx = 0;
1949       if (0 != work_insn_idx_) {
1950         instance_of_idx = work_insn_idx_ - 1;
1951         while (0 != instance_of_idx && !insn_flags_[instance_of_idx].IsOpcode()) {
1952           instance_of_idx--;
1953         }
1954         CHECK(insn_flags_[instance_of_idx].IsOpcode());
1955       } else {
1956         break;
1957       }
1958 
1959       const Instruction* instance_of_inst = Instruction::At(code_item_->insns_ + instance_of_idx);
1960 
1961       /* Check for peep-hole pattern of:
1962        *    ...;
1963        *    instance-of vX, vY, T;
1964        *    ifXXX vX, label ;
1965        *    ...;
1966        * label:
1967        *    ...;
1968        * and sharpen the type of vY to be type T.
1969        * Note, this pattern can't be if:
1970        *  - if there are other branches to this branch,
1971        *  - when vX == vY.
1972        */
1973       if (!CurrentInsnFlags()->IsBranchTarget() &&
1974           (Instruction::INSTANCE_OF == instance_of_inst->Opcode()) &&
1975           (inst->VRegA_21t() == instance_of_inst->VRegA_22c()) &&
1976           (instance_of_inst->VRegA_22c() != instance_of_inst->VRegB_22c())) {
1977         // Check the type of the instance-of is different than that of registers type, as if they
1978         // are the same there is no work to be done here. Check that the conversion is not to or
1979         // from an unresolved type as type information is imprecise. If the instance-of is to an
1980         // interface then ignore the type information as interfaces can only be treated as Objects
1981         // and we don't want to disallow field and other operations on the object. If the value
1982         // being instance-of checked against is known null (zero) then allow the optimization as
1983         // we didn't have type information. If the merge of the instance-of type with the original
1984         // type is assignable to the original then allow optimization. This check is performed to
1985         // ensure that subsequent merges don't lose type information - such as becoming an
1986         // interface from a class that would lose information relevant to field checks.
1987         RegType& orig_type = work_line_->GetRegisterType(instance_of_inst->VRegB_22c());
1988         RegType& cast_type = ResolveClassAndCheckAccess(instance_of_inst->VRegC_22c());
1989 
1990         if (!orig_type.Equals(cast_type) &&
1991             !cast_type.IsUnresolvedTypes() && !orig_type.IsUnresolvedTypes() &&
1992             cast_type.HasClass() &&             // Could be conflict type, make sure it has a class.
1993             !cast_type.GetClass()->IsInterface() &&
1994             (orig_type.IsZero() ||
1995                 orig_type.IsStrictlyAssignableFrom(cast_type.Merge(orig_type, &reg_types_)))) {
1996           RegisterLine* update_line = RegisterLine::Create(code_item_->registers_size_, this);
1997           if (inst->Opcode() == Instruction::IF_EQZ) {
1998             fallthrough_line.reset(update_line);
1999           } else {
2000             branch_line.reset(update_line);
2001           }
2002           update_line->CopyFromLine(work_line_.get());
2003           update_line->SetRegisterType(instance_of_inst->VRegB_22c(), cast_type);
2004           if (!insn_flags_[instance_of_idx].IsBranchTarget() && 0 != instance_of_idx) {
2005             // See if instance-of was preceded by a move-object operation, common due to the small
2006             // register encoding space of instance-of, and propagate type information to the source
2007             // of the move-object.
2008             uint32_t move_idx = instance_of_idx - 1;
2009             while (0 != move_idx && !insn_flags_[move_idx].IsOpcode()) {
2010               move_idx--;
2011             }
2012             CHECK(insn_flags_[move_idx].IsOpcode());
2013             const Instruction* move_inst = Instruction::At(code_item_->insns_ + move_idx);
2014             switch (move_inst->Opcode()) {
2015               case Instruction::MOVE_OBJECT:
2016                 if (move_inst->VRegA_12x() == instance_of_inst->VRegB_22c()) {
2017                   update_line->SetRegisterType(move_inst->VRegB_12x(), cast_type);
2018                 }
2019                 break;
2020               case Instruction::MOVE_OBJECT_FROM16:
2021                 if (move_inst->VRegA_22x() == instance_of_inst->VRegB_22c()) {
2022                   update_line->SetRegisterType(move_inst->VRegB_22x(), cast_type);
2023                 }
2024                 break;
2025               case Instruction::MOVE_OBJECT_16:
2026                 if (move_inst->VRegA_32x() == instance_of_inst->VRegB_22c()) {
2027                   update_line->SetRegisterType(move_inst->VRegB_32x(), cast_type);
2028                 }
2029                 break;
2030               default:
2031                 break;
2032             }
2033           }
2034         }
2035       }
2036 
2037       break;
2038     }
2039     case Instruction::IF_LTZ:
2040     case Instruction::IF_GEZ:
2041     case Instruction::IF_GTZ:
2042     case Instruction::IF_LEZ: {
2043       RegType& reg_type = work_line_->GetRegisterType(inst->VRegA_21t());
2044       if (!reg_type.IsIntegralTypes()) {
2045         Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "type " << reg_type
2046                                           << " unexpected as arg to if-ltz/if-gez/if-gtz/if-lez";
2047       }
2048       break;
2049     }
2050     case Instruction::AGET_BOOLEAN:
2051       VerifyAGet(inst, reg_types_.Boolean(), true);
2052       break;
2053     case Instruction::AGET_BYTE:
2054       VerifyAGet(inst, reg_types_.Byte(), true);
2055       break;
2056     case Instruction::AGET_CHAR:
2057       VerifyAGet(inst, reg_types_.Char(), true);
2058       break;
2059     case Instruction::AGET_SHORT:
2060       VerifyAGet(inst, reg_types_.Short(), true);
2061       break;
2062     case Instruction::AGET:
2063       VerifyAGet(inst, reg_types_.Integer(), true);
2064       break;
2065     case Instruction::AGET_WIDE:
2066       VerifyAGet(inst, reg_types_.LongLo(), true);
2067       break;
2068     case Instruction::AGET_OBJECT:
2069       VerifyAGet(inst, reg_types_.JavaLangObject(false), false);
2070       break;
2071 
2072     case Instruction::APUT_BOOLEAN:
2073       VerifyAPut(inst, reg_types_.Boolean(), true);
2074       break;
2075     case Instruction::APUT_BYTE:
2076       VerifyAPut(inst, reg_types_.Byte(), true);
2077       break;
2078     case Instruction::APUT_CHAR:
2079       VerifyAPut(inst, reg_types_.Char(), true);
2080       break;
2081     case Instruction::APUT_SHORT:
2082       VerifyAPut(inst, reg_types_.Short(), true);
2083       break;
2084     case Instruction::APUT:
2085       VerifyAPut(inst, reg_types_.Integer(), true);
2086       break;
2087     case Instruction::APUT_WIDE:
2088       VerifyAPut(inst, reg_types_.LongLo(), true);
2089       break;
2090     case Instruction::APUT_OBJECT:
2091       VerifyAPut(inst, reg_types_.JavaLangObject(false), false);
2092       break;
2093 
2094     case Instruction::IGET_BOOLEAN:
2095       VerifyISGet(inst, reg_types_.Boolean(), true, false);
2096       break;
2097     case Instruction::IGET_BYTE:
2098       VerifyISGet(inst, reg_types_.Byte(), true, false);
2099       break;
2100     case Instruction::IGET_CHAR:
2101       VerifyISGet(inst, reg_types_.Char(), true, false);
2102       break;
2103     case Instruction::IGET_SHORT:
2104       VerifyISGet(inst, reg_types_.Short(), true, false);
2105       break;
2106     case Instruction::IGET:
2107       VerifyISGet(inst, reg_types_.Integer(), true, false);
2108       break;
2109     case Instruction::IGET_WIDE:
2110       VerifyISGet(inst, reg_types_.LongLo(), true, false);
2111       break;
2112     case Instruction::IGET_OBJECT:
2113       VerifyISGet(inst, reg_types_.JavaLangObject(false), false, false);
2114       break;
2115 
2116     case Instruction::IPUT_BOOLEAN:
2117       VerifyISPut(inst, reg_types_.Boolean(), true, false);
2118       break;
2119     case Instruction::IPUT_BYTE:
2120       VerifyISPut(inst, reg_types_.Byte(), true, false);
2121       break;
2122     case Instruction::IPUT_CHAR:
2123       VerifyISPut(inst, reg_types_.Char(), true, false);
2124       break;
2125     case Instruction::IPUT_SHORT:
2126       VerifyISPut(inst, reg_types_.Short(), true, false);
2127       break;
2128     case Instruction::IPUT:
2129       VerifyISPut(inst, reg_types_.Integer(), true, false);
2130       break;
2131     case Instruction::IPUT_WIDE:
2132       VerifyISPut(inst, reg_types_.LongLo(), true, false);
2133       break;
2134     case Instruction::IPUT_OBJECT:
2135       VerifyISPut(inst, reg_types_.JavaLangObject(false), false, false);
2136       break;
2137 
2138     case Instruction::SGET_BOOLEAN:
2139       VerifyISGet(inst, reg_types_.Boolean(), true, true);
2140       break;
2141     case Instruction::SGET_BYTE:
2142       VerifyISGet(inst, reg_types_.Byte(), true, true);
2143       break;
2144     case Instruction::SGET_CHAR:
2145       VerifyISGet(inst, reg_types_.Char(), true, true);
2146       break;
2147     case Instruction::SGET_SHORT:
2148       VerifyISGet(inst, reg_types_.Short(), true, true);
2149       break;
2150     case Instruction::SGET:
2151       VerifyISGet(inst, reg_types_.Integer(), true, true);
2152       break;
2153     case Instruction::SGET_WIDE:
2154       VerifyISGet(inst, reg_types_.LongLo(), true, true);
2155       break;
2156     case Instruction::SGET_OBJECT:
2157       VerifyISGet(inst, reg_types_.JavaLangObject(false), false, true);
2158       break;
2159 
2160     case Instruction::SPUT_BOOLEAN:
2161       VerifyISPut(inst, reg_types_.Boolean(), true, true);
2162       break;
2163     case Instruction::SPUT_BYTE:
2164       VerifyISPut(inst, reg_types_.Byte(), true, true);
2165       break;
2166     case Instruction::SPUT_CHAR:
2167       VerifyISPut(inst, reg_types_.Char(), true, true);
2168       break;
2169     case Instruction::SPUT_SHORT:
2170       VerifyISPut(inst, reg_types_.Short(), true, true);
2171       break;
2172     case Instruction::SPUT:
2173       VerifyISPut(inst, reg_types_.Integer(), true, true);
2174       break;
2175     case Instruction::SPUT_WIDE:
2176       VerifyISPut(inst, reg_types_.LongLo(), true, true);
2177       break;
2178     case Instruction::SPUT_OBJECT:
2179       VerifyISPut(inst, reg_types_.JavaLangObject(false), false, true);
2180       break;
2181 
2182     case Instruction::INVOKE_VIRTUAL:
2183     case Instruction::INVOKE_VIRTUAL_RANGE:
2184     case Instruction::INVOKE_SUPER:
2185     case Instruction::INVOKE_SUPER_RANGE: {
2186       bool is_range = (inst->Opcode() == Instruction::INVOKE_VIRTUAL_RANGE ||
2187                        inst->Opcode() == Instruction::INVOKE_SUPER_RANGE);
2188       bool is_super = (inst->Opcode() == Instruction::INVOKE_SUPER ||
2189                        inst->Opcode() == Instruction::INVOKE_SUPER_RANGE);
2190       mirror::ArtMethod* called_method = VerifyInvocationArgs(inst, METHOD_VIRTUAL, is_range,
2191                                                               is_super);
2192       RegType* return_type = nullptr;
2193       if (called_method != nullptr) {
2194         Thread* self = Thread::Current();
2195         StackHandleScope<1> hs(self);
2196         Handle<mirror::ArtMethod> h_called_method(hs.NewHandle(called_method));
2197         MethodHelper mh(h_called_method);
2198         mirror::Class* return_type_class = mh.GetReturnType(can_load_classes_);
2199         if (return_type_class != nullptr) {
2200           return_type = &reg_types_.FromClass(h_called_method->GetReturnTypeDescriptor(),
2201                                               return_type_class,
2202                                               return_type_class->CannotBeAssignedFromOtherTypes());
2203         } else {
2204           DCHECK(!can_load_classes_ || self->IsExceptionPending());
2205           self->ClearException();
2206         }
2207       }
2208       if (return_type == nullptr) {
2209         uint32_t method_idx = (is_range) ? inst->VRegB_3rc() : inst->VRegB_35c();
2210         const DexFile::MethodId& method_id = dex_file_->GetMethodId(method_idx);
2211         uint32_t return_type_idx = dex_file_->GetProtoId(method_id.proto_idx_).return_type_idx_;
2212         const char* descriptor = dex_file_->StringByTypeIdx(return_type_idx);
2213         return_type = &reg_types_.FromDescriptor(class_loader_->Get(), descriptor, false);
2214       }
2215       if (!return_type->IsLowHalf()) {
2216         work_line_->SetResultRegisterType(*return_type);
2217       } else {
2218         work_line_->SetResultRegisterTypeWide(*return_type, return_type->HighHalf(&reg_types_));
2219       }
2220       just_set_result = true;
2221       break;
2222     }
2223     case Instruction::INVOKE_DIRECT:
2224     case Instruction::INVOKE_DIRECT_RANGE: {
2225       bool is_range = (inst->Opcode() == Instruction::INVOKE_DIRECT_RANGE);
2226       mirror::ArtMethod* called_method = VerifyInvocationArgs(inst, METHOD_DIRECT,
2227                                                                    is_range, false);
2228       const char* return_type_descriptor;
2229       bool is_constructor;
2230       RegType* return_type = nullptr;
2231       if (called_method == nullptr) {
2232         uint32_t method_idx = (is_range) ? inst->VRegB_3rc() : inst->VRegB_35c();
2233         const DexFile::MethodId& method_id = dex_file_->GetMethodId(method_idx);
2234         is_constructor = strcmp("<init>", dex_file_->StringDataByIdx(method_id.name_idx_)) == 0;
2235         uint32_t return_type_idx = dex_file_->GetProtoId(method_id.proto_idx_).return_type_idx_;
2236         return_type_descriptor =  dex_file_->StringByTypeIdx(return_type_idx);
2237       } else {
2238         is_constructor = called_method->IsConstructor();
2239         return_type_descriptor = called_method->GetReturnTypeDescriptor();
2240         Thread* self = Thread::Current();
2241         StackHandleScope<1> hs(self);
2242         Handle<mirror::ArtMethod> h_called_method(hs.NewHandle(called_method));
2243         MethodHelper mh(h_called_method);
2244         mirror::Class* return_type_class = mh.GetReturnType(can_load_classes_);
2245         if (return_type_class != nullptr) {
2246           return_type = &reg_types_.FromClass(return_type_descriptor,
2247                                               return_type_class,
2248                                               return_type_class->CannotBeAssignedFromOtherTypes());
2249         } else {
2250           DCHECK(!can_load_classes_ || self->IsExceptionPending());
2251           self->ClearException();
2252         }
2253       }
2254       if (is_constructor) {
2255         /*
2256          * Some additional checks when calling a constructor. We know from the invocation arg check
2257          * that the "this" argument is an instance of called_method->klass. Now we further restrict
2258          * that to require that called_method->klass is the same as this->klass or this->super,
2259          * allowing the latter only if the "this" argument is the same as the "this" argument to
2260          * this method (which implies that we're in a constructor ourselves).
2261          */
2262         RegType& this_type = work_line_->GetInvocationThis(inst, is_range);
2263         if (this_type.IsConflict())  // failure.
2264           break;
2265 
2266         /* no null refs allowed (?) */
2267         if (this_type.IsZero()) {
2268           Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "unable to initialize null ref";
2269           break;
2270         }
2271 
2272         /* must be in same class or in superclass */
2273         // RegType& this_super_klass = this_type.GetSuperClass(&reg_types_);
2274         // TODO: re-enable constructor type verification
2275         // if (this_super_klass.IsConflict()) {
2276           // Unknown super class, fail so we re-check at runtime.
2277           // Fail(VERIFY_ERROR_BAD_CLASS_SOFT) << "super class unknown for '" << this_type << "'";
2278           // break;
2279         // }
2280 
2281         /* arg must be an uninitialized reference */
2282         if (!this_type.IsUninitializedTypes()) {
2283           Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Expected initialization on uninitialized reference "
2284               << this_type;
2285           break;
2286         }
2287 
2288         /*
2289          * Replace the uninitialized reference with an initialized one. We need to do this for all
2290          * registers that have the same object instance in them, not just the "this" register.
2291          */
2292         work_line_->MarkRefsAsInitialized(this_type);
2293       }
2294       if (return_type == nullptr) {
2295         return_type = &reg_types_.FromDescriptor(class_loader_->Get(),
2296                                                  return_type_descriptor, false);
2297       }
2298       if (!return_type->IsLowHalf()) {
2299         work_line_->SetResultRegisterType(*return_type);
2300       } else {
2301         work_line_->SetResultRegisterTypeWide(*return_type, return_type->HighHalf(&reg_types_));
2302       }
2303       just_set_result = true;
2304       break;
2305     }
2306     case Instruction::INVOKE_STATIC:
2307     case Instruction::INVOKE_STATIC_RANGE: {
2308         bool is_range = (inst->Opcode() == Instruction::INVOKE_STATIC_RANGE);
2309         mirror::ArtMethod* called_method = VerifyInvocationArgs(inst,
2310                                                                      METHOD_STATIC,
2311                                                                      is_range,
2312                                                                      false);
2313         const char* descriptor;
2314         if (called_method == nullptr) {
2315           uint32_t method_idx = (is_range) ? inst->VRegB_3rc() : inst->VRegB_35c();
2316           const DexFile::MethodId& method_id = dex_file_->GetMethodId(method_idx);
2317           uint32_t return_type_idx = dex_file_->GetProtoId(method_id.proto_idx_).return_type_idx_;
2318           descriptor = dex_file_->StringByTypeIdx(return_type_idx);
2319         } else {
2320           descriptor = called_method->GetReturnTypeDescriptor();
2321         }
2322         RegType& return_type = reg_types_.FromDescriptor(class_loader_->Get(), descriptor,
2323                                                                false);
2324         if (!return_type.IsLowHalf()) {
2325           work_line_->SetResultRegisterType(return_type);
2326         } else {
2327           work_line_->SetResultRegisterTypeWide(return_type, return_type.HighHalf(&reg_types_));
2328         }
2329         just_set_result = true;
2330       }
2331       break;
2332     case Instruction::INVOKE_INTERFACE:
2333     case Instruction::INVOKE_INTERFACE_RANGE: {
2334       bool is_range =  (inst->Opcode() == Instruction::INVOKE_INTERFACE_RANGE);
2335       mirror::ArtMethod* abs_method = VerifyInvocationArgs(inst,
2336                                                                 METHOD_INTERFACE,
2337                                                                 is_range,
2338                                                                 false);
2339       if (abs_method != nullptr) {
2340         mirror::Class* called_interface = abs_method->GetDeclaringClass();
2341         if (!called_interface->IsInterface() && !called_interface->IsObjectClass()) {
2342           Fail(VERIFY_ERROR_CLASS_CHANGE) << "expected interface class in invoke-interface '"
2343               << PrettyMethod(abs_method) << "'";
2344           break;
2345         }
2346       }
2347       /* Get the type of the "this" arg, which should either be a sub-interface of called
2348        * interface or Object (see comments in RegType::JoinClass).
2349        */
2350       RegType& this_type = work_line_->GetInvocationThis(inst, is_range);
2351       if (this_type.IsZero()) {
2352         /* null pointer always passes (and always fails at runtime) */
2353       } else {
2354         if (this_type.IsUninitializedTypes()) {
2355           Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "interface call on uninitialized object "
2356               << this_type;
2357           break;
2358         }
2359         // In the past we have tried to assert that "called_interface" is assignable
2360         // from "this_type.GetClass()", however, as we do an imprecise Join
2361         // (RegType::JoinClass) we don't have full information on what interfaces are
2362         // implemented by "this_type". For example, two classes may implement the same
2363         // interfaces and have a common parent that doesn't implement the interface. The
2364         // join will set "this_type" to the parent class and a test that this implements
2365         // the interface will incorrectly fail.
2366       }
2367       /*
2368        * We don't have an object instance, so we can't find the concrete method. However, all of
2369        * the type information is in the abstract method, so we're good.
2370        */
2371       const char* descriptor;
2372       if (abs_method == nullptr) {
2373         uint32_t method_idx = (is_range) ? inst->VRegB_3rc() : inst->VRegB_35c();
2374         const DexFile::MethodId& method_id = dex_file_->GetMethodId(method_idx);
2375         uint32_t return_type_idx = dex_file_->GetProtoId(method_id.proto_idx_).return_type_idx_;
2376         descriptor =  dex_file_->StringByTypeIdx(return_type_idx);
2377       } else {
2378         descriptor = abs_method->GetReturnTypeDescriptor();
2379       }
2380       RegType& return_type = reg_types_.FromDescriptor(class_loader_->Get(), descriptor,
2381                                                              false);
2382       if (!return_type.IsLowHalf()) {
2383         work_line_->SetResultRegisterType(return_type);
2384       } else {
2385         work_line_->SetResultRegisterTypeWide(return_type, return_type.HighHalf(&reg_types_));
2386       }
2387       just_set_result = true;
2388       break;
2389     }
2390     case Instruction::NEG_INT:
2391     case Instruction::NOT_INT:
2392       work_line_->CheckUnaryOp(inst, reg_types_.Integer(), reg_types_.Integer());
2393       break;
2394     case Instruction::NEG_LONG:
2395     case Instruction::NOT_LONG:
2396       work_line_->CheckUnaryOpWide(inst, reg_types_.LongLo(), reg_types_.LongHi(),
2397                                    reg_types_.LongLo(), reg_types_.LongHi());
2398       break;
2399     case Instruction::NEG_FLOAT:
2400       work_line_->CheckUnaryOp(inst, reg_types_.Float(), reg_types_.Float());
2401       break;
2402     case Instruction::NEG_DOUBLE:
2403       work_line_->CheckUnaryOpWide(inst, reg_types_.DoubleLo(), reg_types_.DoubleHi(),
2404                                    reg_types_.DoubleLo(), reg_types_.DoubleHi());
2405       break;
2406     case Instruction::INT_TO_LONG:
2407       work_line_->CheckUnaryOpToWide(inst, reg_types_.LongLo(), reg_types_.LongHi(),
2408                                      reg_types_.Integer());
2409       break;
2410     case Instruction::INT_TO_FLOAT:
2411       work_line_->CheckUnaryOp(inst, reg_types_.Float(), reg_types_.Integer());
2412       break;
2413     case Instruction::INT_TO_DOUBLE:
2414       work_line_->CheckUnaryOpToWide(inst, reg_types_.DoubleLo(), reg_types_.DoubleHi(),
2415                                      reg_types_.Integer());
2416       break;
2417     case Instruction::LONG_TO_INT:
2418       work_line_->CheckUnaryOpFromWide(inst, reg_types_.Integer(),
2419                                        reg_types_.LongLo(), reg_types_.LongHi());
2420       break;
2421     case Instruction::LONG_TO_FLOAT:
2422       work_line_->CheckUnaryOpFromWide(inst, reg_types_.Float(),
2423                                        reg_types_.LongLo(), reg_types_.LongHi());
2424       break;
2425     case Instruction::LONG_TO_DOUBLE:
2426       work_line_->CheckUnaryOpWide(inst, reg_types_.DoubleLo(), reg_types_.DoubleHi(),
2427                                    reg_types_.LongLo(), reg_types_.LongHi());
2428       break;
2429     case Instruction::FLOAT_TO_INT:
2430       work_line_->CheckUnaryOp(inst, reg_types_.Integer(), reg_types_.Float());
2431       break;
2432     case Instruction::FLOAT_TO_LONG:
2433       work_line_->CheckUnaryOpToWide(inst, reg_types_.LongLo(), reg_types_.LongHi(),
2434                                      reg_types_.Float());
2435       break;
2436     case Instruction::FLOAT_TO_DOUBLE:
2437       work_line_->CheckUnaryOpToWide(inst, reg_types_.DoubleLo(), reg_types_.DoubleHi(),
2438                                      reg_types_.Float());
2439       break;
2440     case Instruction::DOUBLE_TO_INT:
2441       work_line_->CheckUnaryOpFromWide(inst, reg_types_.Integer(),
2442                                        reg_types_.DoubleLo(), reg_types_.DoubleHi());
2443       break;
2444     case Instruction::DOUBLE_TO_LONG:
2445       work_line_->CheckUnaryOpWide(inst, reg_types_.LongLo(), reg_types_.LongHi(),
2446                                    reg_types_.DoubleLo(), reg_types_.DoubleHi());
2447       break;
2448     case Instruction::DOUBLE_TO_FLOAT:
2449       work_line_->CheckUnaryOpFromWide(inst, reg_types_.Float(),
2450                                        reg_types_.DoubleLo(), reg_types_.DoubleHi());
2451       break;
2452     case Instruction::INT_TO_BYTE:
2453       work_line_->CheckUnaryOp(inst, reg_types_.Byte(), reg_types_.Integer());
2454       break;
2455     case Instruction::INT_TO_CHAR:
2456       work_line_->CheckUnaryOp(inst, reg_types_.Char(), reg_types_.Integer());
2457       break;
2458     case Instruction::INT_TO_SHORT:
2459       work_line_->CheckUnaryOp(inst, reg_types_.Short(), reg_types_.Integer());
2460       break;
2461 
2462     case Instruction::ADD_INT:
2463     case Instruction::SUB_INT:
2464     case Instruction::MUL_INT:
2465     case Instruction::REM_INT:
2466     case Instruction::DIV_INT:
2467     case Instruction::SHL_INT:
2468     case Instruction::SHR_INT:
2469     case Instruction::USHR_INT:
2470       work_line_->CheckBinaryOp(inst, reg_types_.Integer(), reg_types_.Integer(),
2471                                 reg_types_.Integer(), false);
2472       break;
2473     case Instruction::AND_INT:
2474     case Instruction::OR_INT:
2475     case Instruction::XOR_INT:
2476       work_line_->CheckBinaryOp(inst, reg_types_.Integer(), reg_types_.Integer(),
2477                                 reg_types_.Integer(), true);
2478       break;
2479     case Instruction::ADD_LONG:
2480     case Instruction::SUB_LONG:
2481     case Instruction::MUL_LONG:
2482     case Instruction::DIV_LONG:
2483     case Instruction::REM_LONG:
2484     case Instruction::AND_LONG:
2485     case Instruction::OR_LONG:
2486     case Instruction::XOR_LONG:
2487       work_line_->CheckBinaryOpWide(inst, reg_types_.LongLo(), reg_types_.LongHi(),
2488                                     reg_types_.LongLo(), reg_types_.LongHi(),
2489                                     reg_types_.LongLo(), reg_types_.LongHi());
2490       break;
2491     case Instruction::SHL_LONG:
2492     case Instruction::SHR_LONG:
2493     case Instruction::USHR_LONG:
2494       /* shift distance is Int, making these different from other binary operations */
2495       work_line_->CheckBinaryOpWideShift(inst, reg_types_.LongLo(), reg_types_.LongHi(),
2496                                          reg_types_.Integer());
2497       break;
2498     case Instruction::ADD_FLOAT:
2499     case Instruction::SUB_FLOAT:
2500     case Instruction::MUL_FLOAT:
2501     case Instruction::DIV_FLOAT:
2502     case Instruction::REM_FLOAT:
2503       work_line_->CheckBinaryOp(inst,
2504                                 reg_types_.Float(),
2505                                 reg_types_.Float(),
2506                                 reg_types_.Float(),
2507                                 false);
2508       break;
2509     case Instruction::ADD_DOUBLE:
2510     case Instruction::SUB_DOUBLE:
2511     case Instruction::MUL_DOUBLE:
2512     case Instruction::DIV_DOUBLE:
2513     case Instruction::REM_DOUBLE:
2514       work_line_->CheckBinaryOpWide(inst, reg_types_.DoubleLo(), reg_types_.DoubleHi(),
2515                                     reg_types_.DoubleLo(), reg_types_.DoubleHi(),
2516                                     reg_types_.DoubleLo(), reg_types_.DoubleHi());
2517       break;
2518     case Instruction::ADD_INT_2ADDR:
2519     case Instruction::SUB_INT_2ADDR:
2520     case Instruction::MUL_INT_2ADDR:
2521     case Instruction::REM_INT_2ADDR:
2522     case Instruction::SHL_INT_2ADDR:
2523     case Instruction::SHR_INT_2ADDR:
2524     case Instruction::USHR_INT_2ADDR:
2525       work_line_->CheckBinaryOp2addr(inst,
2526                                      reg_types_.Integer(),
2527                                      reg_types_.Integer(),
2528                                      reg_types_.Integer(),
2529                                      false);
2530       break;
2531     case Instruction::AND_INT_2ADDR:
2532     case Instruction::OR_INT_2ADDR:
2533     case Instruction::XOR_INT_2ADDR:
2534       work_line_->CheckBinaryOp2addr(inst,
2535                                      reg_types_.Integer(),
2536                                      reg_types_.Integer(),
2537                                      reg_types_.Integer(),
2538                                      true);
2539       break;
2540     case Instruction::DIV_INT_2ADDR:
2541       work_line_->CheckBinaryOp2addr(inst,
2542                                      reg_types_.Integer(),
2543                                      reg_types_.Integer(),
2544                                      reg_types_.Integer(),
2545                                      false);
2546       break;
2547     case Instruction::ADD_LONG_2ADDR:
2548     case Instruction::SUB_LONG_2ADDR:
2549     case Instruction::MUL_LONG_2ADDR:
2550     case Instruction::DIV_LONG_2ADDR:
2551     case Instruction::REM_LONG_2ADDR:
2552     case Instruction::AND_LONG_2ADDR:
2553     case Instruction::OR_LONG_2ADDR:
2554     case Instruction::XOR_LONG_2ADDR:
2555       work_line_->CheckBinaryOp2addrWide(inst, reg_types_.LongLo(), reg_types_.LongHi(),
2556                                          reg_types_.LongLo(), reg_types_.LongHi(),
2557                                          reg_types_.LongLo(), reg_types_.LongHi());
2558       break;
2559     case Instruction::SHL_LONG_2ADDR:
2560     case Instruction::SHR_LONG_2ADDR:
2561     case Instruction::USHR_LONG_2ADDR:
2562       work_line_->CheckBinaryOp2addrWideShift(inst, reg_types_.LongLo(), reg_types_.LongHi(),
2563                                               reg_types_.Integer());
2564       break;
2565     case Instruction::ADD_FLOAT_2ADDR:
2566     case Instruction::SUB_FLOAT_2ADDR:
2567     case Instruction::MUL_FLOAT_2ADDR:
2568     case Instruction::DIV_FLOAT_2ADDR:
2569     case Instruction::REM_FLOAT_2ADDR:
2570       work_line_->CheckBinaryOp2addr(inst,
2571                                      reg_types_.Float(),
2572                                      reg_types_.Float(),
2573                                      reg_types_.Float(),
2574                                      false);
2575       break;
2576     case Instruction::ADD_DOUBLE_2ADDR:
2577     case Instruction::SUB_DOUBLE_2ADDR:
2578     case Instruction::MUL_DOUBLE_2ADDR:
2579     case Instruction::DIV_DOUBLE_2ADDR:
2580     case Instruction::REM_DOUBLE_2ADDR:
2581       work_line_->CheckBinaryOp2addrWide(inst, reg_types_.DoubleLo(), reg_types_.DoubleHi(),
2582                                          reg_types_.DoubleLo(),  reg_types_.DoubleHi(),
2583                                          reg_types_.DoubleLo(), reg_types_.DoubleHi());
2584       break;
2585     case Instruction::ADD_INT_LIT16:
2586     case Instruction::RSUB_INT:
2587     case Instruction::MUL_INT_LIT16:
2588     case Instruction::DIV_INT_LIT16:
2589     case Instruction::REM_INT_LIT16:
2590       work_line_->CheckLiteralOp(inst, reg_types_.Integer(), reg_types_.Integer(), false, true);
2591       break;
2592     case Instruction::AND_INT_LIT16:
2593     case Instruction::OR_INT_LIT16:
2594     case Instruction::XOR_INT_LIT16:
2595       work_line_->CheckLiteralOp(inst, reg_types_.Integer(), reg_types_.Integer(), true, true);
2596       break;
2597     case Instruction::ADD_INT_LIT8:
2598     case Instruction::RSUB_INT_LIT8:
2599     case Instruction::MUL_INT_LIT8:
2600     case Instruction::DIV_INT_LIT8:
2601     case Instruction::REM_INT_LIT8:
2602     case Instruction::SHL_INT_LIT8:
2603     case Instruction::SHR_INT_LIT8:
2604     case Instruction::USHR_INT_LIT8:
2605       work_line_->CheckLiteralOp(inst, reg_types_.Integer(), reg_types_.Integer(), false, false);
2606       break;
2607     case Instruction::AND_INT_LIT8:
2608     case Instruction::OR_INT_LIT8:
2609     case Instruction::XOR_INT_LIT8:
2610       work_line_->CheckLiteralOp(inst, reg_types_.Integer(), reg_types_.Integer(), true, false);
2611       break;
2612 
2613     // Special instructions.
2614     case Instruction::RETURN_VOID_BARRIER:
2615       if (!IsConstructor() || IsStatic()) {
2616           Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "return-void-barrier not expected";
2617       }
2618       break;
2619     // Note: the following instructions encode offsets derived from class linking.
2620     // As such they use Class*/Field*/AbstractMethod* as these offsets only have
2621     // meaning if the class linking and resolution were successful.
2622     case Instruction::IGET_QUICK:
2623       VerifyIGetQuick(inst, reg_types_.Integer(), true);
2624       break;
2625     case Instruction::IGET_WIDE_QUICK:
2626       VerifyIGetQuick(inst, reg_types_.LongLo(), true);
2627       break;
2628     case Instruction::IGET_OBJECT_QUICK:
2629       VerifyIGetQuick(inst, reg_types_.JavaLangObject(false), false);
2630       break;
2631     case Instruction::IPUT_QUICK:
2632       VerifyIPutQuick(inst, reg_types_.Integer(), true);
2633       break;
2634     case Instruction::IPUT_WIDE_QUICK:
2635       VerifyIPutQuick(inst, reg_types_.LongLo(), true);
2636       break;
2637     case Instruction::IPUT_OBJECT_QUICK:
2638       VerifyIPutQuick(inst, reg_types_.JavaLangObject(false), false);
2639       break;
2640     case Instruction::INVOKE_VIRTUAL_QUICK:
2641     case Instruction::INVOKE_VIRTUAL_RANGE_QUICK: {
2642       bool is_range = (inst->Opcode() == Instruction::INVOKE_VIRTUAL_RANGE_QUICK);
2643       mirror::ArtMethod* called_method = VerifyInvokeVirtualQuickArgs(inst, is_range);
2644       if (called_method != nullptr) {
2645         const char* descriptor = called_method->GetReturnTypeDescriptor();
2646         RegType& return_type = reg_types_.FromDescriptor(class_loader_->Get(), descriptor,
2647                                                                false);
2648         if (!return_type.IsLowHalf()) {
2649           work_line_->SetResultRegisterType(return_type);
2650         } else {
2651           work_line_->SetResultRegisterTypeWide(return_type, return_type.HighHalf(&reg_types_));
2652         }
2653         just_set_result = true;
2654       }
2655       break;
2656     }
2657 
2658     /* These should never appear during verification. */
2659     case Instruction::UNUSED_3E:
2660     case Instruction::UNUSED_3F:
2661     case Instruction::UNUSED_40:
2662     case Instruction::UNUSED_41:
2663     case Instruction::UNUSED_42:
2664     case Instruction::UNUSED_43:
2665     case Instruction::UNUSED_79:
2666     case Instruction::UNUSED_7A:
2667     case Instruction::UNUSED_EB:
2668     case Instruction::UNUSED_EC:
2669     case Instruction::UNUSED_ED:
2670     case Instruction::UNUSED_EE:
2671     case Instruction::UNUSED_EF:
2672     case Instruction::UNUSED_F0:
2673     case Instruction::UNUSED_F1:
2674     case Instruction::UNUSED_F2:
2675     case Instruction::UNUSED_F3:
2676     case Instruction::UNUSED_F4:
2677     case Instruction::UNUSED_F5:
2678     case Instruction::UNUSED_F6:
2679     case Instruction::UNUSED_F7:
2680     case Instruction::UNUSED_F8:
2681     case Instruction::UNUSED_F9:
2682     case Instruction::UNUSED_FA:
2683     case Instruction::UNUSED_FB:
2684     case Instruction::UNUSED_FC:
2685     case Instruction::UNUSED_FD:
2686     case Instruction::UNUSED_FE:
2687     case Instruction::UNUSED_FF:
2688       Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Unexpected opcode " << inst->DumpString(dex_file_);
2689       break;
2690 
2691     /*
2692      * DO NOT add a "default" clause here. Without it the compiler will
2693      * complain if an instruction is missing (which is desirable).
2694      */
2695   }  // end - switch (dec_insn.opcode)
2696 
2697   if (have_pending_hard_failure_) {
2698     if (Runtime::Current()->IsCompiler()) {
2699       /* When compiling, check that the last failure is a hard failure */
2700       CHECK_EQ(failures_[failures_.size() - 1], VERIFY_ERROR_BAD_CLASS_HARD);
2701     }
2702     /* immediate failure, reject class */
2703     info_messages_ << "Rejecting opcode " << inst->DumpString(dex_file_);
2704     return false;
2705   } else if (have_pending_runtime_throw_failure_) {
2706     /* checking interpreter will throw, mark following code as unreachable */
2707     opcode_flags = Instruction::kThrow;
2708   }
2709   /*
2710    * If we didn't just set the result register, clear it out. This ensures that you can only use
2711    * "move-result" immediately after the result is set. (We could check this statically, but it's
2712    * not expensive and it makes our debugging output cleaner.)
2713    */
2714   if (!just_set_result) {
2715     work_line_->SetResultTypeToUnknown();
2716   }
2717 
2718 
2719 
2720   /*
2721    * Handle "branch". Tag the branch target.
2722    *
2723    * NOTE: instructions like Instruction::EQZ provide information about the
2724    * state of the register when the branch is taken or not taken. For example,
2725    * somebody could get a reference field, check it for zero, and if the
2726    * branch is taken immediately store that register in a boolean field
2727    * since the value is known to be zero. We do not currently account for
2728    * that, and will reject the code.
2729    *
2730    * TODO: avoid re-fetching the branch target
2731    */
2732   if ((opcode_flags & Instruction::kBranch) != 0) {
2733     bool isConditional, selfOkay;
2734     if (!GetBranchOffset(work_insn_idx_, &branch_target, &isConditional, &selfOkay)) {
2735       /* should never happen after static verification */
2736       Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "bad branch";
2737       return false;
2738     }
2739     DCHECK_EQ(isConditional, (opcode_flags & Instruction::kContinue) != 0);
2740     if (!CheckNotMoveException(code_item_->insns_, work_insn_idx_ + branch_target)) {
2741       return false;
2742     }
2743     /* update branch target, set "changed" if appropriate */
2744     if (nullptr != branch_line.get()) {
2745       if (!UpdateRegisters(work_insn_idx_ + branch_target, branch_line.get(), false)) {
2746         return false;
2747       }
2748     } else {
2749       if (!UpdateRegisters(work_insn_idx_ + branch_target, work_line_.get(), false)) {
2750         return false;
2751       }
2752     }
2753   }
2754 
2755   /*
2756    * Handle "switch". Tag all possible branch targets.
2757    *
2758    * We've already verified that the table is structurally sound, so we
2759    * just need to walk through and tag the targets.
2760    */
2761   if ((opcode_flags & Instruction::kSwitch) != 0) {
2762     int offset_to_switch = insns[1] | (((int32_t) insns[2]) << 16);
2763     const uint16_t* switch_insns = insns + offset_to_switch;
2764     int switch_count = switch_insns[1];
2765     int offset_to_targets, targ;
2766 
2767     if ((*insns & 0xff) == Instruction::PACKED_SWITCH) {
2768       /* 0 = sig, 1 = count, 2/3 = first key */
2769       offset_to_targets = 4;
2770     } else {
2771       /* 0 = sig, 1 = count, 2..count * 2 = keys */
2772       DCHECK((*insns & 0xff) == Instruction::SPARSE_SWITCH);
2773       offset_to_targets = 2 + 2 * switch_count;
2774     }
2775 
2776     /* verify each switch target */
2777     for (targ = 0; targ < switch_count; targ++) {
2778       int offset;
2779       uint32_t abs_offset;
2780 
2781       /* offsets are 32-bit, and only partly endian-swapped */
2782       offset = switch_insns[offset_to_targets + targ * 2] |
2783          (((int32_t) switch_insns[offset_to_targets + targ * 2 + 1]) << 16);
2784       abs_offset = work_insn_idx_ + offset;
2785       DCHECK_LT(abs_offset, code_item_->insns_size_in_code_units_);
2786       if (!CheckNotMoveException(code_item_->insns_, abs_offset)) {
2787         return false;
2788       }
2789       if (!UpdateRegisters(abs_offset, work_line_.get(), false)) {
2790         return false;
2791       }
2792     }
2793   }
2794 
2795   /*
2796    * Handle instructions that can throw and that are sitting in a "try" block. (If they're not in a
2797    * "try" block when they throw, control transfers out of the method.)
2798    */
2799   if ((opcode_flags & Instruction::kThrow) != 0 && insn_flags_[work_insn_idx_].IsInTry()) {
2800     bool has_catch_all_handler = false;
2801     CatchHandlerIterator iterator(*code_item_, work_insn_idx_);
2802 
2803     // Need the linker to try and resolve the handled class to check if it's Throwable.
2804     ClassLinker* linker = Runtime::Current()->GetClassLinker();
2805 
2806     for (; iterator.HasNext(); iterator.Next()) {
2807       uint16_t handler_type_idx = iterator.GetHandlerTypeIndex();
2808       if (handler_type_idx == DexFile::kDexNoIndex16) {
2809         has_catch_all_handler = true;
2810       } else {
2811         // It is also a catch-all if it is java.lang.Throwable.
2812         mirror::Class* klass = linker->ResolveType(*dex_file_, handler_type_idx, *dex_cache_,
2813                                                    *class_loader_);
2814         if (klass != nullptr) {
2815           if (klass == mirror::Throwable::GetJavaLangThrowable()) {
2816             has_catch_all_handler = true;
2817           }
2818         } else {
2819           // Clear exception.
2820           Thread* self = Thread::Current();
2821           DCHECK(self->IsExceptionPending());
2822           self->ClearException();
2823         }
2824       }
2825       /*
2826        * Merge registers into the "catch" block. We want to use the "savedRegs" rather than
2827        * "work_regs", because at runtime the exception will be thrown before the instruction
2828        * modifies any registers.
2829        */
2830       if (!UpdateRegisters(iterator.GetHandlerAddress(), saved_line_.get(), false)) {
2831         return false;
2832       }
2833     }
2834 
2835     /*
2836      * If the monitor stack depth is nonzero, there must be a "catch all" handler for this
2837      * instruction. This does apply to monitor-exit because of async exception handling.
2838      */
2839     if (work_line_->MonitorStackDepth() > 0 && !has_catch_all_handler) {
2840       /*
2841        * The state in work_line reflects the post-execution state. If the current instruction is a
2842        * monitor-enter and the monitor stack was empty, we don't need a catch-all (if it throws,
2843        * it will do so before grabbing the lock).
2844        */
2845       if (inst->Opcode() != Instruction::MONITOR_ENTER || work_line_->MonitorStackDepth() != 1) {
2846         Fail(VERIFY_ERROR_BAD_CLASS_HARD)
2847             << "expected to be within a catch-all for an instruction where a monitor is held";
2848         return false;
2849       }
2850     }
2851   }
2852 
2853   /* Handle "continue". Tag the next consecutive instruction.
2854    *  Note: Keep the code handling "continue" case below the "branch" and "switch" cases,
2855    *        because it changes work_line_ when performing peephole optimization
2856    *        and this change should not be used in those cases.
2857    */
2858   if ((opcode_flags & Instruction::kContinue) != 0) {
2859     uint32_t next_insn_idx = work_insn_idx_ + CurrentInsnFlags()->GetLengthInCodeUnits();
2860     if (next_insn_idx >= code_item_->insns_size_in_code_units_) {
2861       Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Execution can walk off end of code area";
2862       return false;
2863     }
2864     // The only way to get to a move-exception instruction is to get thrown there. Make sure the
2865     // next instruction isn't one.
2866     if (!CheckNotMoveException(code_item_->insns_, next_insn_idx)) {
2867       return false;
2868     }
2869     if (nullptr != fallthrough_line.get()) {
2870       // Make workline consistent with fallthrough computed from peephole optimization.
2871       work_line_->CopyFromLine(fallthrough_line.get());
2872     }
2873     if (insn_flags_[next_insn_idx].IsReturn()) {
2874       // For returns we only care about the operand to the return, all other registers are dead.
2875       const Instruction* ret_inst = Instruction::At(code_item_->insns_ + next_insn_idx);
2876       Instruction::Code opcode = ret_inst->Opcode();
2877       if ((opcode == Instruction::RETURN_VOID) || (opcode == Instruction::RETURN_VOID_BARRIER)) {
2878         work_line_->MarkAllRegistersAsConflicts();
2879       } else {
2880         if (opcode == Instruction::RETURN_WIDE) {
2881           work_line_->MarkAllRegistersAsConflictsExceptWide(ret_inst->VRegA_11x());
2882         } else {
2883           work_line_->MarkAllRegistersAsConflictsExcept(ret_inst->VRegA_11x());
2884         }
2885       }
2886     }
2887     RegisterLine* next_line = reg_table_.GetLine(next_insn_idx);
2888     if (next_line != nullptr) {
2889       // Merge registers into what we have for the next instruction, and set the "changed" flag if
2890       // needed. If the merge changes the state of the registers then the work line will be
2891       // updated.
2892       if (!UpdateRegisters(next_insn_idx, work_line_.get(), true)) {
2893         return false;
2894       }
2895     } else {
2896       /*
2897        * We're not recording register data for the next instruction, so we don't know what the
2898        * prior state was. We have to assume that something has changed and re-evaluate it.
2899        */
2900       insn_flags_[next_insn_idx].SetChanged();
2901     }
2902   }
2903 
2904   /* If we're returning from the method, make sure monitor stack is empty. */
2905   if ((opcode_flags & Instruction::kReturn) != 0) {
2906     if (!work_line_->VerifyMonitorStackEmpty()) {
2907       return false;
2908     }
2909   }
2910 
2911   /*
2912    * Update start_guess. Advance to the next instruction of that's
2913    * possible, otherwise use the branch target if one was found. If
2914    * neither of those exists we're in a return or throw; leave start_guess
2915    * alone and let the caller sort it out.
2916    */
2917   if ((opcode_flags & Instruction::kContinue) != 0) {
2918     *start_guess = work_insn_idx_ + insn_flags_[work_insn_idx_].GetLengthInCodeUnits();
2919   } else if ((opcode_flags & Instruction::kBranch) != 0) {
2920     /* we're still okay if branch_target is zero */
2921     *start_guess = work_insn_idx_ + branch_target;
2922   }
2923 
2924   DCHECK_LT(*start_guess, code_item_->insns_size_in_code_units_);
2925   DCHECK(insn_flags_[*start_guess].IsOpcode());
2926 
2927   return true;
2928 }  // NOLINT(readability/fn_size)
2929 
ResolveClassAndCheckAccess(uint32_t class_idx)2930 RegType& MethodVerifier::ResolveClassAndCheckAccess(uint32_t class_idx) {
2931   const char* descriptor = dex_file_->StringByTypeIdx(class_idx);
2932   RegType& referrer = GetDeclaringClass();
2933   mirror::Class* klass = (*dex_cache_)->GetResolvedType(class_idx);
2934   RegType& result =
2935       klass != nullptr ? reg_types_.FromClass(descriptor, klass,
2936                                            klass->CannotBeAssignedFromOtherTypes())
2937                     : reg_types_.FromDescriptor(class_loader_->Get(), descriptor, false);
2938   if (result.IsConflict()) {
2939     Fail(VERIFY_ERROR_BAD_CLASS_SOFT) << "accessing broken descriptor '" << descriptor
2940         << "' in " << referrer;
2941     return result;
2942   }
2943   if (klass == nullptr && !result.IsUnresolvedTypes()) {
2944     (*dex_cache_)->SetResolvedType(class_idx, result.GetClass());
2945   }
2946   // Check if access is allowed. Unresolved types use xxxWithAccessCheck to
2947   // check at runtime if access is allowed and so pass here. If result is
2948   // primitive, skip the access check.
2949   if (result.IsNonZeroReferenceTypes() && !result.IsUnresolvedTypes() &&
2950       !referrer.IsUnresolvedTypes() && !referrer.CanAccess(result)) {
2951     Fail(VERIFY_ERROR_ACCESS_CLASS) << "illegal class access: '"
2952                                     << referrer << "' -> '" << result << "'";
2953   }
2954   return result;
2955 }
2956 
GetCaughtExceptionType()2957 RegType& MethodVerifier::GetCaughtExceptionType() {
2958   RegType* common_super = nullptr;
2959   if (code_item_->tries_size_ != 0) {
2960     const byte* handlers_ptr = DexFile::GetCatchHandlerData(*code_item_, 0);
2961     uint32_t handlers_size = DecodeUnsignedLeb128(&handlers_ptr);
2962     for (uint32_t i = 0; i < handlers_size; i++) {
2963       CatchHandlerIterator iterator(handlers_ptr);
2964       for (; iterator.HasNext(); iterator.Next()) {
2965         if (iterator.GetHandlerAddress() == (uint32_t) work_insn_idx_) {
2966           if (iterator.GetHandlerTypeIndex() == DexFile::kDexNoIndex16) {
2967             common_super = &reg_types_.JavaLangThrowable(false);
2968           } else {
2969             RegType& exception = ResolveClassAndCheckAccess(iterator.GetHandlerTypeIndex());
2970             if (!reg_types_.JavaLangThrowable(false).IsAssignableFrom(exception)) {
2971               if (exception.IsUnresolvedTypes()) {
2972                 // We don't know enough about the type. Fail here and let runtime handle it.
2973                 Fail(VERIFY_ERROR_NO_CLASS) << "unresolved exception class " << exception;
2974                 return exception;
2975               } else {
2976                 Fail(VERIFY_ERROR_BAD_CLASS_SOFT) << "unexpected non-exception class " << exception;
2977                 return reg_types_.Conflict();
2978               }
2979             } else if (common_super == nullptr) {
2980               common_super = &exception;
2981             } else if (common_super->Equals(exception)) {
2982               // odd case, but nothing to do
2983             } else {
2984               common_super = &common_super->Merge(exception, &reg_types_);
2985               CHECK(reg_types_.JavaLangThrowable(false).IsAssignableFrom(*common_super));
2986             }
2987           }
2988         }
2989       }
2990       handlers_ptr = iterator.EndDataPointer();
2991     }
2992   }
2993   if (common_super == nullptr) {
2994     /* no catch blocks, or no catches with classes we can find */
2995     Fail(VERIFY_ERROR_BAD_CLASS_SOFT) << "unable to find exception handler";
2996     return reg_types_.Conflict();
2997   }
2998   return *common_super;
2999 }
3000 
ResolveMethodAndCheckAccess(uint32_t dex_method_idx,MethodType method_type)3001 mirror::ArtMethod* MethodVerifier::ResolveMethodAndCheckAccess(uint32_t dex_method_idx,
3002                                                                MethodType method_type) {
3003   const DexFile::MethodId& method_id = dex_file_->GetMethodId(dex_method_idx);
3004   RegType& klass_type = ResolveClassAndCheckAccess(method_id.class_idx_);
3005   if (klass_type.IsConflict()) {
3006     std::string append(" in attempt to access method ");
3007     append += dex_file_->GetMethodName(method_id);
3008     AppendToLastFailMessage(append);
3009     return nullptr;
3010   }
3011   if (klass_type.IsUnresolvedTypes()) {
3012     return nullptr;  // Can't resolve Class so no more to do here
3013   }
3014   mirror::Class* klass = klass_type.GetClass();
3015   RegType& referrer = GetDeclaringClass();
3016   mirror::ArtMethod* res_method = (*dex_cache_)->GetResolvedMethod(dex_method_idx);
3017   if (res_method == nullptr) {
3018     const char* name = dex_file_->GetMethodName(method_id);
3019     const Signature signature = dex_file_->GetMethodSignature(method_id);
3020 
3021     if (method_type == METHOD_DIRECT || method_type == METHOD_STATIC) {
3022       res_method = klass->FindDirectMethod(name, signature);
3023     } else if (method_type == METHOD_INTERFACE) {
3024       res_method = klass->FindInterfaceMethod(name, signature);
3025     } else {
3026       res_method = klass->FindVirtualMethod(name, signature);
3027     }
3028     if (res_method != nullptr) {
3029       (*dex_cache_)->SetResolvedMethod(dex_method_idx, res_method);
3030     } else {
3031       // If a virtual or interface method wasn't found with the expected type, look in
3032       // the direct methods. This can happen when the wrong invoke type is used or when
3033       // a class has changed, and will be flagged as an error in later checks.
3034       if (method_type == METHOD_INTERFACE || method_type == METHOD_VIRTUAL) {
3035         res_method = klass->FindDirectMethod(name, signature);
3036       }
3037       if (res_method == nullptr) {
3038         Fail(VERIFY_ERROR_NO_METHOD) << "couldn't find method "
3039                                      << PrettyDescriptor(klass) << "." << name
3040                                      << " " << signature;
3041         return nullptr;
3042       }
3043     }
3044   }
3045   // Make sure calls to constructors are "direct". There are additional restrictions but we don't
3046   // enforce them here.
3047   if (res_method->IsConstructor() && method_type != METHOD_DIRECT) {
3048     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "rejecting non-direct call to constructor "
3049                                       << PrettyMethod(res_method);
3050     return nullptr;
3051   }
3052   // Disallow any calls to class initializers.
3053   if (res_method->IsClassInitializer()) {
3054     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "rejecting call to class initializer "
3055                                       << PrettyMethod(res_method);
3056     return nullptr;
3057   }
3058   // Check if access is allowed.
3059   if (!referrer.CanAccessMember(res_method->GetDeclaringClass(), res_method->GetAccessFlags())) {
3060     Fail(VERIFY_ERROR_ACCESS_METHOD) << "illegal method access (call " << PrettyMethod(res_method)
3061                                      << " from " << referrer << ")";
3062     return res_method;
3063   }
3064   // Check that invoke-virtual and invoke-super are not used on private methods of the same class.
3065   if (res_method->IsPrivate() && method_type == METHOD_VIRTUAL) {
3066     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invoke-super/virtual can't be used on private method "
3067                                       << PrettyMethod(res_method);
3068     return nullptr;
3069   }
3070   // Check that interface methods match interface classes.
3071   if (klass->IsInterface() && method_type != METHOD_INTERFACE) {
3072     Fail(VERIFY_ERROR_CLASS_CHANGE) << "non-interface method " << PrettyMethod(res_method)
3073                                     << " is in an interface class " << PrettyClass(klass);
3074     return nullptr;
3075   } else if (!klass->IsInterface() && method_type == METHOD_INTERFACE) {
3076     Fail(VERIFY_ERROR_CLASS_CHANGE) << "interface method " << PrettyMethod(res_method)
3077                                     << " is in a non-interface class " << PrettyClass(klass);
3078     return nullptr;
3079   }
3080   // See if the method type implied by the invoke instruction matches the access flags for the
3081   // target method.
3082   if ((method_type == METHOD_DIRECT && !res_method->IsDirect()) ||
3083       (method_type == METHOD_STATIC && !res_method->IsStatic()) ||
3084       ((method_type == METHOD_VIRTUAL || method_type == METHOD_INTERFACE) && res_method->IsDirect())
3085       ) {
3086     Fail(VERIFY_ERROR_CLASS_CHANGE) << "invoke type (" << method_type << ") does not match method "
3087                                        " type of " << PrettyMethod(res_method);
3088     return nullptr;
3089   }
3090   return res_method;
3091 }
3092 
3093 template <class T>
VerifyInvocationArgsFromIterator(T * it,const Instruction * inst,MethodType method_type,bool is_range,mirror::ArtMethod * res_method)3094 mirror::ArtMethod* MethodVerifier::VerifyInvocationArgsFromIterator(T* it, const Instruction* inst,
3095                                                                     MethodType method_type,
3096                                                                     bool is_range,
3097                                                                     mirror::ArtMethod* res_method) {
3098   // We use vAA as our expected arg count, rather than res_method->insSize, because we need to
3099   // match the call to the signature. Also, we might be calling through an abstract method
3100   // definition (which doesn't have register count values).
3101   const size_t expected_args = (is_range) ? inst->VRegA_3rc() : inst->VRegA_35c();
3102   /* caught by static verifier */
3103   DCHECK(is_range || expected_args <= 5);
3104   if (expected_args > code_item_->outs_size_) {
3105     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid argument count (" << expected_args
3106         << ") exceeds outsSize (" << code_item_->outs_size_ << ")";
3107     return nullptr;
3108   }
3109 
3110   uint32_t arg[5];
3111   if (!is_range) {
3112     inst->GetVarArgs(arg);
3113   }
3114   uint32_t sig_registers = 0;
3115 
3116   /*
3117    * Check the "this" argument, which must be an instance of the class that declared the method.
3118    * For an interface class, we don't do the full interface merge (see JoinClass), so we can't do a
3119    * rigorous check here (which is okay since we have to do it at runtime).
3120    */
3121   if (method_type != METHOD_STATIC) {
3122     RegType& actual_arg_type = work_line_->GetInvocationThis(inst, is_range);
3123     if (actual_arg_type.IsConflict()) {  // GetInvocationThis failed.
3124       CHECK(have_pending_hard_failure_);
3125       return nullptr;
3126     }
3127     if (actual_arg_type.IsUninitializedReference()) {
3128       if (res_method) {
3129         if (!res_method->IsConstructor()) {
3130           Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "'this' arg must be initialized";
3131           return nullptr;
3132         }
3133       } else {
3134         // Check whether the name of the called method is "<init>"
3135         const uint32_t method_idx = (is_range) ? inst->VRegB_3rc() : inst->VRegB_35c();
3136         if (strcmp(dex_file_->GetMethodName(dex_file_->GetMethodId(method_idx)), "<init>") != 0) {
3137           Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "'this' arg must be initialized";
3138           return nullptr;
3139         }
3140       }
3141     }
3142     if (method_type != METHOD_INTERFACE && !actual_arg_type.IsZero()) {
3143       RegType* res_method_class;
3144       if (res_method != nullptr) {
3145         mirror::Class* klass = res_method->GetDeclaringClass();
3146         std::string temp;
3147         res_method_class = &reg_types_.FromClass(klass->GetDescriptor(&temp), klass,
3148                                                  klass->CannotBeAssignedFromOtherTypes());
3149       } else {
3150         const uint32_t method_idx = (is_range) ? inst->VRegB_3rc() : inst->VRegB_35c();
3151         const uint16_t class_idx = dex_file_->GetMethodId(method_idx).class_idx_;
3152         res_method_class = &reg_types_.FromDescriptor(class_loader_->Get(),
3153                                                       dex_file_->StringByTypeIdx(class_idx),
3154                                                       false);
3155       }
3156       if (!res_method_class->IsAssignableFrom(actual_arg_type)) {
3157         Fail(actual_arg_type.IsUnresolvedTypes() ? VERIFY_ERROR_NO_CLASS:
3158             VERIFY_ERROR_BAD_CLASS_SOFT) << "'this' argument '" << actual_arg_type
3159                 << "' not instance of '" << *res_method_class << "'";
3160         // Continue on soft failures. We need to find possible hard failures to avoid problems in
3161         // the compiler.
3162         if (have_pending_hard_failure_) {
3163           return nullptr;
3164         }
3165       }
3166     }
3167     sig_registers = 1;
3168   }
3169 
3170   for ( ; it->HasNext(); it->Next()) {
3171     if (sig_registers >= expected_args) {
3172       Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Rejecting invocation, expected " << inst->VRegA() <<
3173           " arguments, found " << sig_registers << " or more.";
3174       return nullptr;
3175     }
3176 
3177     const char* param_descriptor = it->GetDescriptor();
3178 
3179     if (param_descriptor == nullptr) {
3180       Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Rejecting invocation because of missing signature "
3181           "component";
3182       return nullptr;
3183     }
3184 
3185     RegType& reg_type = reg_types_.FromDescriptor(class_loader_->Get(), param_descriptor,
3186                                                         false);
3187     uint32_t get_reg = is_range ? inst->VRegC_3rc() + static_cast<uint32_t>(sig_registers) :
3188         arg[sig_registers];
3189     if (reg_type.IsIntegralTypes()) {
3190       RegType& src_type = work_line_->GetRegisterType(get_reg);
3191       if (!src_type.IsIntegralTypes()) {
3192         Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "register v" << get_reg << " has type " << src_type
3193             << " but expected " << reg_type;
3194         return res_method;
3195       }
3196     } else if (!work_line_->VerifyRegisterType(get_reg, reg_type)) {
3197       // Continue on soft failures. We need to find possible hard failures to avoid problems in the
3198       // compiler.
3199       if (have_pending_hard_failure_) {
3200         return res_method;
3201       }
3202     }
3203     sig_registers += reg_type.IsLongOrDoubleTypes() ?  2 : 1;
3204   }
3205   if (expected_args != sig_registers) {
3206     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Rejecting invocation, expected " << expected_args <<
3207         " arguments, found " << sig_registers;
3208     return nullptr;
3209   }
3210   return res_method;
3211 }
3212 
VerifyInvocationArgsUnresolvedMethod(const Instruction * inst,MethodType method_type,bool is_range)3213 void MethodVerifier::VerifyInvocationArgsUnresolvedMethod(const Instruction* inst,
3214                                                           MethodType method_type,
3215                                                           bool is_range) {
3216   // As the method may not have been resolved, make this static check against what we expect.
3217   // The main reason for this code block is to fail hard when we find an illegal use, e.g.,
3218   // wrong number of arguments or wrong primitive types, even if the method could not be resolved.
3219   const uint32_t method_idx = (is_range) ? inst->VRegB_3rc() : inst->VRegB_35c();
3220   DexFileParameterIterator it(*dex_file_,
3221                               dex_file_->GetProtoId(dex_file_->GetMethodId(method_idx).proto_idx_));
3222   VerifyInvocationArgsFromIterator<DexFileParameterIterator>(&it, inst, method_type, is_range,
3223                                                              nullptr);
3224 }
3225 
3226 class MethodParamListDescriptorIterator {
3227  public:
MethodParamListDescriptorIterator(mirror::ArtMethod * res_method)3228   explicit MethodParamListDescriptorIterator(mirror::ArtMethod* res_method) :
3229       res_method_(res_method), pos_(0), params_(res_method->GetParameterTypeList()),
3230       params_size_(params_ == nullptr ? 0 : params_->Size()) {
3231   }
3232 
HasNext()3233   bool HasNext() {
3234     return pos_ < params_size_;
3235   }
3236 
Next()3237   void Next() {
3238     ++pos_;
3239   }
3240 
GetDescriptor()3241   const char* GetDescriptor() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
3242     return res_method_->GetTypeDescriptorFromTypeIdx(params_->GetTypeItem(pos_).type_idx_);
3243   }
3244 
3245  private:
3246   mirror::ArtMethod* res_method_;
3247   size_t pos_;
3248   const DexFile::TypeList* params_;
3249   const size_t params_size_;
3250 };
3251 
VerifyInvocationArgs(const Instruction * inst,MethodType method_type,bool is_range,bool is_super)3252 mirror::ArtMethod* MethodVerifier::VerifyInvocationArgs(const Instruction* inst,
3253                                                              MethodType method_type,
3254                                                              bool is_range,
3255                                                              bool is_super) {
3256   // Resolve the method. This could be an abstract or concrete method depending on what sort of call
3257   // we're making.
3258   const uint32_t method_idx = (is_range) ? inst->VRegB_3rc() : inst->VRegB_35c();
3259 
3260   mirror::ArtMethod* res_method = ResolveMethodAndCheckAccess(method_idx, method_type);
3261   if (res_method == nullptr) {  // error or class is unresolved
3262     // Check what we can statically.
3263     if (!have_pending_hard_failure_) {
3264       VerifyInvocationArgsUnresolvedMethod(inst, method_type, is_range);
3265     }
3266     return nullptr;
3267   }
3268 
3269   // If we're using invoke-super(method), make sure that the executing method's class' superclass
3270   // has a vtable entry for the target method.
3271   if (is_super) {
3272     DCHECK(method_type == METHOD_VIRTUAL);
3273     RegType& super = GetDeclaringClass().GetSuperClass(&reg_types_);
3274     if (super.IsUnresolvedTypes()) {
3275       Fail(VERIFY_ERROR_NO_METHOD) << "unknown super class in invoke-super from "
3276                                    << PrettyMethod(dex_method_idx_, *dex_file_)
3277                                    << " to super " << PrettyMethod(res_method);
3278       return nullptr;
3279     }
3280     mirror::Class* super_klass = super.GetClass();
3281     if (res_method->GetMethodIndex() >= super_klass->GetVTableLength()) {
3282       Fail(VERIFY_ERROR_NO_METHOD) << "invalid invoke-super from "
3283                                    << PrettyMethod(dex_method_idx_, *dex_file_)
3284                                    << " to super " << super
3285                                    << "." << res_method->GetName()
3286                                    << res_method->GetSignature();
3287       return nullptr;
3288     }
3289   }
3290 
3291   // Process the target method's signature. This signature may or may not
3292   MethodParamListDescriptorIterator it(res_method);
3293   return VerifyInvocationArgsFromIterator<MethodParamListDescriptorIterator>(&it, inst, method_type,
3294                                                                              is_range, res_method);
3295 }
3296 
GetQuickInvokedMethod(const Instruction * inst,RegisterLine * reg_line,bool is_range)3297 mirror::ArtMethod* MethodVerifier::GetQuickInvokedMethod(const Instruction* inst,
3298                                                          RegisterLine* reg_line, bool is_range) {
3299   DCHECK(inst->Opcode() == Instruction::INVOKE_VIRTUAL_QUICK ||
3300          inst->Opcode() == Instruction::INVOKE_VIRTUAL_RANGE_QUICK);
3301   RegType& actual_arg_type = reg_line->GetInvocationThis(inst, is_range);
3302   if (!actual_arg_type.HasClass()) {
3303     VLOG(verifier) << "Failed to get mirror::Class* from '" << actual_arg_type << "'";
3304     return nullptr;
3305   }
3306   mirror::Class* klass = actual_arg_type.GetClass();
3307   mirror::Class* dispatch_class;
3308   if (klass->IsInterface()) {
3309     // Derive Object.class from Class.class.getSuperclass().
3310     mirror::Class* object_klass = klass->GetClass()->GetSuperClass();
3311     CHECK(object_klass->IsObjectClass());
3312     dispatch_class = object_klass;
3313   } else {
3314     dispatch_class = klass;
3315   }
3316   CHECK(dispatch_class->HasVTable()) << PrettyDescriptor(dispatch_class);
3317   uint16_t vtable_index = is_range ? inst->VRegB_3rc() : inst->VRegB_35c();
3318   CHECK_LT(static_cast<int32_t>(vtable_index), dispatch_class->GetVTableLength())
3319       << PrettyDescriptor(klass);
3320   mirror::ArtMethod* res_method = dispatch_class->GetVTableEntry(vtable_index);
3321   CHECK(!Thread::Current()->IsExceptionPending());
3322   return res_method;
3323 }
3324 
VerifyInvokeVirtualQuickArgs(const Instruction * inst,bool is_range)3325 mirror::ArtMethod* MethodVerifier::VerifyInvokeVirtualQuickArgs(const Instruction* inst,
3326                                                                 bool is_range) {
3327   DCHECK(Runtime::Current()->IsStarted() || verify_to_dump_);
3328   mirror::ArtMethod* res_method = GetQuickInvokedMethod(inst, work_line_.get(),
3329                                                              is_range);
3330   if (res_method == nullptr) {
3331     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Cannot infer method from " << inst->Name();
3332     return nullptr;
3333   }
3334   CHECK(!res_method->IsDirect() && !res_method->IsStatic());
3335 
3336   // We use vAA as our expected arg count, rather than res_method->insSize, because we need to
3337   // match the call to the signature. Also, we might be calling through an abstract method
3338   // definition (which doesn't have register count values).
3339   RegType& actual_arg_type = work_line_->GetInvocationThis(inst, is_range);
3340   if (actual_arg_type.IsConflict()) {  // GetInvocationThis failed.
3341     return nullptr;
3342   }
3343   const size_t expected_args = (is_range) ? inst->VRegA_3rc() : inst->VRegA_35c();
3344   /* caught by static verifier */
3345   DCHECK(is_range || expected_args <= 5);
3346   if (expected_args > code_item_->outs_size_) {
3347     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid argument count (" << expected_args
3348         << ") exceeds outsSize (" << code_item_->outs_size_ << ")";
3349     return nullptr;
3350   }
3351 
3352   /*
3353    * Check the "this" argument, which must be an instance of the class that declared the method.
3354    * For an interface class, we don't do the full interface merge (see JoinClass), so we can't do a
3355    * rigorous check here (which is okay since we have to do it at runtime).
3356    */
3357   if (actual_arg_type.IsUninitializedReference() && !res_method->IsConstructor()) {
3358     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "'this' arg must be initialized";
3359     return nullptr;
3360   }
3361   if (!actual_arg_type.IsZero()) {
3362     mirror::Class* klass = res_method->GetDeclaringClass();
3363     std::string temp;
3364     RegType& res_method_class =
3365         reg_types_.FromClass(klass->GetDescriptor(&temp), klass,
3366                              klass->CannotBeAssignedFromOtherTypes());
3367     if (!res_method_class.IsAssignableFrom(actual_arg_type)) {
3368       Fail(actual_arg_type.IsUnresolvedTypes() ? VERIFY_ERROR_NO_CLASS :
3369           VERIFY_ERROR_BAD_CLASS_SOFT) << "'this' argument '" << actual_arg_type
3370           << "' not instance of '" << res_method_class << "'";
3371       return nullptr;
3372     }
3373   }
3374   /*
3375    * Process the target method's signature. This signature may or may not
3376    * have been verified, so we can't assume it's properly formed.
3377    */
3378   const DexFile::TypeList* params = res_method->GetParameterTypeList();
3379   size_t params_size = params == nullptr ? 0 : params->Size();
3380   uint32_t arg[5];
3381   if (!is_range) {
3382     inst->GetVarArgs(arg);
3383   }
3384   size_t actual_args = 1;
3385   for (size_t param_index = 0; param_index < params_size; param_index++) {
3386     if (actual_args >= expected_args) {
3387       Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Rejecting invalid call to '" << PrettyMethod(res_method)
3388                                         << "'. Expected " << expected_args
3389                                          << " arguments, processing argument " << actual_args
3390                                         << " (where longs/doubles count twice).";
3391       return nullptr;
3392     }
3393     const char* descriptor =
3394         res_method->GetTypeDescriptorFromTypeIdx(params->GetTypeItem(param_index).type_idx_);
3395     if (descriptor == nullptr) {
3396       Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Rejecting invocation of " << PrettyMethod(res_method)
3397                                         << " missing signature component";
3398       return nullptr;
3399     }
3400     RegType& reg_type = reg_types_.FromDescriptor(class_loader_->Get(), descriptor, false);
3401     uint32_t get_reg = is_range ? inst->VRegC_3rc() + actual_args : arg[actual_args];
3402     if (!work_line_->VerifyRegisterType(get_reg, reg_type)) {
3403       return res_method;
3404     }
3405     actual_args = reg_type.IsLongOrDoubleTypes() ? actual_args + 2 : actual_args + 1;
3406   }
3407   if (actual_args != expected_args) {
3408     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Rejecting invocation of " << PrettyMethod(res_method)
3409               << " expected " << expected_args << " arguments, found " << actual_args;
3410     return nullptr;
3411   } else {
3412     return res_method;
3413   }
3414 }
3415 
VerifyNewArray(const Instruction * inst,bool is_filled,bool is_range)3416 void MethodVerifier::VerifyNewArray(const Instruction* inst, bool is_filled, bool is_range) {
3417   uint32_t type_idx;
3418   if (!is_filled) {
3419     DCHECK_EQ(inst->Opcode(), Instruction::NEW_ARRAY);
3420     type_idx = inst->VRegC_22c();
3421   } else if (!is_range) {
3422     DCHECK_EQ(inst->Opcode(), Instruction::FILLED_NEW_ARRAY);
3423     type_idx = inst->VRegB_35c();
3424   } else {
3425     DCHECK_EQ(inst->Opcode(), Instruction::FILLED_NEW_ARRAY_RANGE);
3426     type_idx = inst->VRegB_3rc();
3427   }
3428   RegType& res_type = ResolveClassAndCheckAccess(type_idx);
3429   if (res_type.IsConflict()) {  // bad class
3430     DCHECK_NE(failures_.size(), 0U);
3431   } else {
3432     // TODO: check Compiler::CanAccessTypeWithoutChecks returns false when res_type is unresolved
3433     if (!res_type.IsArrayTypes()) {
3434       Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "new-array on non-array class " << res_type;
3435     } else if (!is_filled) {
3436       /* make sure "size" register is valid type */
3437       work_line_->VerifyRegisterType(inst->VRegB_22c(), reg_types_.Integer());
3438       /* set register type to array class */
3439       RegType& precise_type = reg_types_.FromUninitialized(res_type);
3440       work_line_->SetRegisterType(inst->VRegA_22c(), precise_type);
3441     } else {
3442       // Verify each register. If "arg_count" is bad, VerifyRegisterType() will run off the end of
3443       // the list and fail. It's legal, if silly, for arg_count to be zero.
3444       RegType& expected_type = reg_types_.GetComponentType(res_type, class_loader_->Get());
3445       uint32_t arg_count = (is_range) ? inst->VRegA_3rc() : inst->VRegA_35c();
3446       uint32_t arg[5];
3447       if (!is_range) {
3448         inst->GetVarArgs(arg);
3449       }
3450       for (size_t ui = 0; ui < arg_count; ui++) {
3451         uint32_t get_reg = is_range ? inst->VRegC_3rc() + ui : arg[ui];
3452         if (!work_line_->VerifyRegisterType(get_reg, expected_type)) {
3453           work_line_->SetResultRegisterType(reg_types_.Conflict());
3454           return;
3455         }
3456       }
3457       // filled-array result goes into "result" register
3458       RegType& precise_type = reg_types_.FromUninitialized(res_type);
3459       work_line_->SetResultRegisterType(precise_type);
3460     }
3461   }
3462 }
3463 
VerifyAGet(const Instruction * inst,RegType & insn_type,bool is_primitive)3464 void MethodVerifier::VerifyAGet(const Instruction* inst,
3465                                 RegType& insn_type, bool is_primitive) {
3466   RegType& index_type = work_line_->GetRegisterType(inst->VRegC_23x());
3467   if (!index_type.IsArrayIndexTypes()) {
3468     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Invalid reg type for array index (" << index_type << ")";
3469   } else {
3470     RegType& array_type = work_line_->GetRegisterType(inst->VRegB_23x());
3471     if (array_type.IsZero()) {
3472       // Null array class; this code path will fail at runtime. Infer a merge-able type from the
3473       // instruction type. TODO: have a proper notion of bottom here.
3474       if (!is_primitive || insn_type.IsCategory1Types()) {
3475         // Reference or category 1
3476         work_line_->SetRegisterType(inst->VRegA_23x(), reg_types_.Zero());
3477       } else {
3478         // Category 2
3479         work_line_->SetRegisterTypeWide(inst->VRegA_23x(), reg_types_.FromCat2ConstLo(0, false),
3480                                         reg_types_.FromCat2ConstHi(0, false));
3481       }
3482     } else if (!array_type.IsArrayTypes()) {
3483       Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "not array type " << array_type << " with aget";
3484     } else {
3485       /* verify the class */
3486       RegType& component_type = reg_types_.GetComponentType(array_type, class_loader_->Get());
3487       if (!component_type.IsReferenceTypes() && !is_primitive) {
3488         Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "primitive array type " << array_type
3489             << " source for aget-object";
3490       } else if (component_type.IsNonZeroReferenceTypes() && is_primitive) {
3491         Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "reference array type " << array_type
3492             << " source for category 1 aget";
3493       } else if (is_primitive && !insn_type.Equals(component_type) &&
3494                  !((insn_type.IsInteger() && component_type.IsFloat()) ||
3495                  (insn_type.IsLong() && component_type.IsDouble()))) {
3496         Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "array type " << array_type
3497             << " incompatible with aget of type " << insn_type;
3498       } else {
3499         // Use knowledge of the field type which is stronger than the type inferred from the
3500         // instruction, which can't differentiate object types and ints from floats, longs from
3501         // doubles.
3502         if (!component_type.IsLowHalf()) {
3503           work_line_->SetRegisterType(inst->VRegA_23x(), component_type);
3504         } else {
3505           work_line_->SetRegisterTypeWide(inst->VRegA_23x(), component_type,
3506                                           component_type.HighHalf(&reg_types_));
3507         }
3508       }
3509     }
3510   }
3511 }
3512 
VerifyPrimitivePut(RegType & target_type,RegType & insn_type,const uint32_t vregA)3513 void MethodVerifier::VerifyPrimitivePut(RegType& target_type, RegType& insn_type,
3514                                         const uint32_t vregA) {
3515   // Primitive assignability rules are weaker than regular assignability rules.
3516   bool instruction_compatible;
3517   bool value_compatible;
3518   RegType& value_type = work_line_->GetRegisterType(vregA);
3519   if (target_type.IsIntegralTypes()) {
3520     instruction_compatible = target_type.Equals(insn_type);
3521     value_compatible = value_type.IsIntegralTypes();
3522   } else if (target_type.IsFloat()) {
3523     instruction_compatible = insn_type.IsInteger();  // no put-float, so expect put-int
3524     value_compatible = value_type.IsFloatTypes();
3525   } else if (target_type.IsLong()) {
3526     instruction_compatible = insn_type.IsLong();
3527     // Additional register check: this is not checked statically (as part of VerifyInstructions),
3528     // as target_type depends on the resolved type of the field.
3529     if (instruction_compatible && work_line_->NumRegs() > vregA + 1) {
3530       RegType& value_type_hi = work_line_->GetRegisterType(vregA + 1);
3531       value_compatible = value_type.IsLongTypes() && value_type.CheckWidePair(value_type_hi);
3532     } else {
3533       value_compatible = false;
3534     }
3535   } else if (target_type.IsDouble()) {
3536     instruction_compatible = insn_type.IsLong();  // no put-double, so expect put-long
3537     // Additional register check: this is not checked statically (as part of VerifyInstructions),
3538     // as target_type depends on the resolved type of the field.
3539     if (instruction_compatible && work_line_->NumRegs() > vregA + 1) {
3540       RegType& value_type_hi = work_line_->GetRegisterType(vregA + 1);
3541       value_compatible = value_type.IsDoubleTypes() && value_type.CheckWidePair(value_type_hi);
3542     } else {
3543       value_compatible = false;
3544     }
3545   } else {
3546     instruction_compatible = false;  // reference with primitive store
3547     value_compatible = false;  // unused
3548   }
3549   if (!instruction_compatible) {
3550     // This is a global failure rather than a class change failure as the instructions and
3551     // the descriptors for the type should have been consistent within the same file at
3552     // compile time.
3553     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "put insn has type '" << insn_type
3554         << "' but expected type '" << target_type << "'";
3555     return;
3556   }
3557   if (!value_compatible) {
3558     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "unexpected value in v" << vregA
3559         << " of type " << value_type << " but expected " << target_type << " for put";
3560     return;
3561   }
3562 }
3563 
VerifyAPut(const Instruction * inst,RegType & insn_type,bool is_primitive)3564 void MethodVerifier::VerifyAPut(const Instruction* inst,
3565                                 RegType& insn_type, bool is_primitive) {
3566   RegType& index_type = work_line_->GetRegisterType(inst->VRegC_23x());
3567   if (!index_type.IsArrayIndexTypes()) {
3568     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Invalid reg type for array index (" << index_type << ")";
3569   } else {
3570     RegType& array_type = work_line_->GetRegisterType(inst->VRegB_23x());
3571     if (array_type.IsZero()) {
3572       // Null array type; this code path will fail at runtime. Infer a merge-able type from the
3573       // instruction type.
3574     } else if (!array_type.IsArrayTypes()) {
3575       Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "not array type " << array_type << " with aput";
3576     } else {
3577       RegType& component_type = reg_types_.GetComponentType(array_type, class_loader_->Get());
3578       const uint32_t vregA = inst->VRegA_23x();
3579       if (is_primitive) {
3580         VerifyPrimitivePut(component_type, insn_type, vregA);
3581       } else {
3582         if (!component_type.IsReferenceTypes()) {
3583           Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "primitive array type " << array_type
3584               << " source for aput-object";
3585         } else {
3586           // The instruction agrees with the type of array, confirm the value to be stored does too
3587           // Note: we use the instruction type (rather than the component type) for aput-object as
3588           // incompatible classes will be caught at runtime as an array store exception
3589           work_line_->VerifyRegisterType(vregA, insn_type);
3590         }
3591       }
3592     }
3593   }
3594 }
3595 
GetStaticField(int field_idx)3596 mirror::ArtField* MethodVerifier::GetStaticField(int field_idx) {
3597   const DexFile::FieldId& field_id = dex_file_->GetFieldId(field_idx);
3598   // Check access to class
3599   RegType& klass_type = ResolveClassAndCheckAccess(field_id.class_idx_);
3600   if (klass_type.IsConflict()) {  // bad class
3601     AppendToLastFailMessage(StringPrintf(" in attempt to access static field %d (%s) in %s",
3602                                          field_idx, dex_file_->GetFieldName(field_id),
3603                                          dex_file_->GetFieldDeclaringClassDescriptor(field_id)));
3604     return nullptr;
3605   }
3606   if (klass_type.IsUnresolvedTypes()) {
3607     return nullptr;  // Can't resolve Class so no more to do here, will do checking at runtime.
3608   }
3609   ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
3610   mirror::ArtField* field = class_linker->ResolveFieldJLS(*dex_file_, field_idx, *dex_cache_,
3611                                                           *class_loader_);
3612   if (field == nullptr) {
3613     VLOG(verifier) << "Unable to resolve static field " << field_idx << " ("
3614               << dex_file_->GetFieldName(field_id) << ") in "
3615               << dex_file_->GetFieldDeclaringClassDescriptor(field_id);
3616     DCHECK(Thread::Current()->IsExceptionPending());
3617     Thread::Current()->ClearException();
3618     return nullptr;
3619   } else if (!GetDeclaringClass().CanAccessMember(field->GetDeclaringClass(),
3620                                                   field->GetAccessFlags())) {
3621     Fail(VERIFY_ERROR_ACCESS_FIELD) << "cannot access static field " << PrettyField(field)
3622                                     << " from " << GetDeclaringClass();
3623     return nullptr;
3624   } else if (!field->IsStatic()) {
3625     Fail(VERIFY_ERROR_CLASS_CHANGE) << "expected field " << PrettyField(field) << " to be static";
3626     return nullptr;
3627   }
3628   return field;
3629 }
3630 
GetInstanceField(RegType & obj_type,int field_idx)3631 mirror::ArtField* MethodVerifier::GetInstanceField(RegType& obj_type, int field_idx) {
3632   const DexFile::FieldId& field_id = dex_file_->GetFieldId(field_idx);
3633   // Check access to class
3634   RegType& klass_type = ResolveClassAndCheckAccess(field_id.class_idx_);
3635   if (klass_type.IsConflict()) {
3636     AppendToLastFailMessage(StringPrintf(" in attempt to access instance field %d (%s) in %s",
3637                                          field_idx, dex_file_->GetFieldName(field_id),
3638                                          dex_file_->GetFieldDeclaringClassDescriptor(field_id)));
3639     return nullptr;
3640   }
3641   if (klass_type.IsUnresolvedTypes()) {
3642     return nullptr;  // Can't resolve Class so no more to do here
3643   }
3644   ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
3645   mirror::ArtField* field = class_linker->ResolveFieldJLS(*dex_file_, field_idx, *dex_cache_,
3646                                                           *class_loader_);
3647   if (field == nullptr) {
3648     VLOG(verifier) << "Unable to resolve instance field " << field_idx << " ("
3649               << dex_file_->GetFieldName(field_id) << ") in "
3650               << dex_file_->GetFieldDeclaringClassDescriptor(field_id);
3651     DCHECK(Thread::Current()->IsExceptionPending());
3652     Thread::Current()->ClearException();
3653     return nullptr;
3654   } else if (!GetDeclaringClass().CanAccessMember(field->GetDeclaringClass(),
3655                                                   field->GetAccessFlags())) {
3656     Fail(VERIFY_ERROR_ACCESS_FIELD) << "cannot access instance field " << PrettyField(field)
3657                                     << " from " << GetDeclaringClass();
3658     return nullptr;
3659   } else if (field->IsStatic()) {
3660     Fail(VERIFY_ERROR_CLASS_CHANGE) << "expected field " << PrettyField(field)
3661                                     << " to not be static";
3662     return nullptr;
3663   } else if (obj_type.IsZero()) {
3664     // Cannot infer and check type, however, access will cause null pointer exception
3665     return field;
3666   } else if (!obj_type.IsReferenceTypes()) {
3667     // Trying to read a field from something that isn't a reference
3668     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "instance field access on object that has "
3669                                       << "non-reference type " << obj_type;
3670     return nullptr;
3671   } else {
3672     mirror::Class* klass = field->GetDeclaringClass();
3673     RegType& field_klass =
3674         reg_types_.FromClass(dex_file_->GetFieldDeclaringClassDescriptor(field_id),
3675                              klass, klass->CannotBeAssignedFromOtherTypes());
3676     if (obj_type.IsUninitializedTypes() &&
3677         (!IsConstructor() || GetDeclaringClass().Equals(obj_type) ||
3678             !field_klass.Equals(GetDeclaringClass()))) {
3679       // Field accesses through uninitialized references are only allowable for constructors where
3680       // the field is declared in this class
3681       Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "cannot access instance field " << PrettyField(field)
3682                                         << " of a not fully initialized object within the context"
3683                                         << " of " << PrettyMethod(dex_method_idx_, *dex_file_);
3684       return nullptr;
3685     } else if (!field_klass.IsAssignableFrom(obj_type)) {
3686       // Trying to access C1.field1 using reference of type C2, which is neither C1 or a sub-class
3687       // of C1. For resolution to occur the declared class of the field must be compatible with
3688       // obj_type, we've discovered this wasn't so, so report the field didn't exist.
3689       Fail(VERIFY_ERROR_NO_FIELD) << "cannot access instance field " << PrettyField(field)
3690                                   << " from object of type " << obj_type;
3691       return nullptr;
3692     } else {
3693       return field;
3694     }
3695   }
3696 }
3697 
VerifyISGet(const Instruction * inst,RegType & insn_type,bool is_primitive,bool is_static)3698 void MethodVerifier::VerifyISGet(const Instruction* inst, RegType& insn_type,
3699                                  bool is_primitive, bool is_static) {
3700   uint32_t field_idx = is_static ? inst->VRegB_21c() : inst->VRegC_22c();
3701   mirror::ArtField* field;
3702   if (is_static) {
3703     field = GetStaticField(field_idx);
3704   } else {
3705     RegType& object_type = work_line_->GetRegisterType(inst->VRegB_22c());
3706     field = GetInstanceField(object_type, field_idx);
3707   }
3708   RegType* field_type = nullptr;
3709   if (field != nullptr) {
3710     Thread* self = Thread::Current();
3711     mirror::Class* field_type_class;
3712     {
3713       StackHandleScope<1> hs(self);
3714       HandleWrapper<mirror::ArtField> h_field(hs.NewHandleWrapper(&field));
3715       field_type_class = FieldHelper(h_field).GetType(can_load_classes_);
3716     }
3717     if (field_type_class != nullptr) {
3718       field_type = &reg_types_.FromClass(field->GetTypeDescriptor(), field_type_class,
3719                                          field_type_class->CannotBeAssignedFromOtherTypes());
3720     } else {
3721       DCHECK(!can_load_classes_ || self->IsExceptionPending());
3722       self->ClearException();
3723     }
3724   }
3725   if (field_type == nullptr) {
3726     const DexFile::FieldId& field_id = dex_file_->GetFieldId(field_idx);
3727     const char* descriptor = dex_file_->GetFieldTypeDescriptor(field_id);
3728     field_type = &reg_types_.FromDescriptor(class_loader_->Get(), descriptor, false);
3729   }
3730   DCHECK(field_type != nullptr);
3731   const uint32_t vregA = (is_static) ? inst->VRegA_21c() : inst->VRegA_22c();
3732   if (is_primitive) {
3733     if (field_type->Equals(insn_type) ||
3734         (field_type->IsFloat() && insn_type.IsInteger()) ||
3735         (field_type->IsDouble() && insn_type.IsLong())) {
3736       // expected that read is of the correct primitive type or that int reads are reading
3737       // floats or long reads are reading doubles
3738     } else {
3739       // This is a global failure rather than a class change failure as the instructions and
3740       // the descriptors for the type should have been consistent within the same file at
3741       // compile time
3742       Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "expected field " << PrettyField(field)
3743                                         << " to be of type '" << insn_type
3744                                         << "' but found type '" << *field_type << "' in get";
3745       return;
3746     }
3747   } else {
3748     if (!insn_type.IsAssignableFrom(*field_type)) {
3749       Fail(VERIFY_ERROR_BAD_CLASS_SOFT) << "expected field " << PrettyField(field)
3750                                         << " to be compatible with type '" << insn_type
3751                                         << "' but found type '" << *field_type
3752                                         << "' in Get-object";
3753       work_line_->SetRegisterType(vregA, reg_types_.Conflict());
3754       return;
3755     }
3756   }
3757   if (!field_type->IsLowHalf()) {
3758     work_line_->SetRegisterType(vregA, *field_type);
3759   } else {
3760     work_line_->SetRegisterTypeWide(vregA, *field_type, field_type->HighHalf(&reg_types_));
3761   }
3762 }
3763 
VerifyISPut(const Instruction * inst,RegType & insn_type,bool is_primitive,bool is_static)3764 void MethodVerifier::VerifyISPut(const Instruction* inst, RegType& insn_type,
3765                                  bool is_primitive, bool is_static) {
3766   uint32_t field_idx = is_static ? inst->VRegB_21c() : inst->VRegC_22c();
3767   mirror::ArtField* field;
3768   if (is_static) {
3769     field = GetStaticField(field_idx);
3770   } else {
3771     RegType& object_type = work_line_->GetRegisterType(inst->VRegB_22c());
3772     field = GetInstanceField(object_type, field_idx);
3773   }
3774   RegType* field_type = nullptr;
3775   if (field != nullptr) {
3776     if (field->IsFinal() && field->GetDeclaringClass() != GetDeclaringClass().GetClass()) {
3777       Fail(VERIFY_ERROR_ACCESS_FIELD) << "cannot modify final field " << PrettyField(field)
3778                                       << " from other class " << GetDeclaringClass();
3779       return;
3780     }
3781     mirror::Class* field_type_class;
3782     {
3783       StackHandleScope<1> hs(Thread::Current());
3784       HandleWrapper<mirror::ArtField> h_field(hs.NewHandleWrapper(&field));
3785       FieldHelper fh(h_field);
3786       field_type_class = fh.GetType(can_load_classes_);
3787     }
3788     if (field_type_class != nullptr) {
3789       field_type = &reg_types_.FromClass(field->GetTypeDescriptor(), field_type_class,
3790                                          field_type_class->CannotBeAssignedFromOtherTypes());
3791     } else {
3792       Thread* self = Thread::Current();
3793       DCHECK(!can_load_classes_ || self->IsExceptionPending());
3794       self->ClearException();
3795     }
3796   }
3797   if (field_type == nullptr) {
3798     const DexFile::FieldId& field_id = dex_file_->GetFieldId(field_idx);
3799     const char* descriptor = dex_file_->GetFieldTypeDescriptor(field_id);
3800     field_type = &reg_types_.FromDescriptor(class_loader_->Get(), descriptor, false);
3801   }
3802   DCHECK(field_type != nullptr);
3803   const uint32_t vregA = (is_static) ? inst->VRegA_21c() : inst->VRegA_22c();
3804   if (is_primitive) {
3805     VerifyPrimitivePut(*field_type, insn_type, vregA);
3806   } else {
3807     if (!insn_type.IsAssignableFrom(*field_type)) {
3808       Fail(VERIFY_ERROR_BAD_CLASS_SOFT) << "expected field " << PrettyField(field)
3809                                         << " to be compatible with type '" << insn_type
3810                                         << "' but found type '" << *field_type
3811                                         << "' in put-object";
3812       return;
3813     }
3814     work_line_->VerifyRegisterType(vregA, *field_type);
3815   }
3816 }
3817 
GetQuickFieldAccess(const Instruction * inst,RegisterLine * reg_line)3818 mirror::ArtField* MethodVerifier::GetQuickFieldAccess(const Instruction* inst,
3819                                                       RegisterLine* reg_line) {
3820   DCHECK(inst->Opcode() == Instruction::IGET_QUICK ||
3821          inst->Opcode() == Instruction::IGET_WIDE_QUICK ||
3822          inst->Opcode() == Instruction::IGET_OBJECT_QUICK ||
3823          inst->Opcode() == Instruction::IPUT_QUICK ||
3824          inst->Opcode() == Instruction::IPUT_WIDE_QUICK ||
3825          inst->Opcode() == Instruction::IPUT_OBJECT_QUICK);
3826   RegType& object_type = reg_line->GetRegisterType(inst->VRegB_22c());
3827   if (!object_type.HasClass()) {
3828     VLOG(verifier) << "Failed to get mirror::Class* from '" << object_type << "'";
3829     return nullptr;
3830   }
3831   uint32_t field_offset = static_cast<uint32_t>(inst->VRegC_22c());
3832   mirror::ArtField* f = mirror::ArtField::FindInstanceFieldWithOffset(object_type.GetClass(),
3833                                                                       field_offset);
3834   if (f == nullptr) {
3835     VLOG(verifier) << "Failed to find instance field at offset '" << field_offset
3836                    << "' from '" << PrettyDescriptor(object_type.GetClass()) << "'";
3837   }
3838   return f;
3839 }
3840 
VerifyIGetQuick(const Instruction * inst,RegType & insn_type,bool is_primitive)3841 void MethodVerifier::VerifyIGetQuick(const Instruction* inst, RegType& insn_type,
3842                                      bool is_primitive) {
3843   DCHECK(Runtime::Current()->IsStarted() || verify_to_dump_);
3844   mirror::ArtField* field = GetQuickFieldAccess(inst, work_line_.get());
3845   if (field == nullptr) {
3846     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Cannot infer field from " << inst->Name();
3847     return;
3848   }
3849   mirror::Class* field_type_class;
3850   {
3851     StackHandleScope<1> hs(Thread::Current());
3852     HandleWrapper<mirror::ArtField> h_field(hs.NewHandleWrapper(&field));
3853     FieldHelper fh(h_field);
3854     field_type_class = fh.GetType(can_load_classes_);
3855   }
3856   RegType* field_type;
3857   if (field_type_class != nullptr) {
3858     field_type = &reg_types_.FromClass(field->GetTypeDescriptor(), field_type_class,
3859                                        field_type_class->CannotBeAssignedFromOtherTypes());
3860   } else {
3861     Thread* self = Thread::Current();
3862     DCHECK(!can_load_classes_ || self->IsExceptionPending());
3863     self->ClearException();
3864     field_type = &reg_types_.FromDescriptor(field->GetDeclaringClass()->GetClassLoader(),
3865                                             field->GetTypeDescriptor(), false);
3866   }
3867   DCHECK(field_type != nullptr);
3868   const uint32_t vregA = inst->VRegA_22c();
3869   if (is_primitive) {
3870     if (field_type->Equals(insn_type) ||
3871         (field_type->IsFloat() && insn_type.IsIntegralTypes()) ||
3872         (field_type->IsDouble() && insn_type.IsLongTypes())) {
3873       // expected that read is of the correct primitive type or that int reads are reading
3874       // floats or long reads are reading doubles
3875     } else {
3876       // This is a global failure rather than a class change failure as the instructions and
3877       // the descriptors for the type should have been consistent within the same file at
3878       // compile time
3879       Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "expected field " << PrettyField(field)
3880                                         << " to be of type '" << insn_type
3881                                         << "' but found type '" << *field_type << "' in Get";
3882       return;
3883     }
3884   } else {
3885     if (!insn_type.IsAssignableFrom(*field_type)) {
3886       Fail(VERIFY_ERROR_BAD_CLASS_SOFT) << "expected field " << PrettyField(field)
3887                                         << " to be compatible with type '" << insn_type
3888                                         << "' but found type '" << *field_type
3889                                         << "' in get-object";
3890       work_line_->SetRegisterType(vregA, reg_types_.Conflict());
3891       return;
3892     }
3893   }
3894   if (!field_type->IsLowHalf()) {
3895     work_line_->SetRegisterType(vregA, *field_type);
3896   } else {
3897     work_line_->SetRegisterTypeWide(vregA, *field_type, field_type->HighHalf(&reg_types_));
3898   }
3899 }
3900 
VerifyIPutQuick(const Instruction * inst,RegType & insn_type,bool is_primitive)3901 void MethodVerifier::VerifyIPutQuick(const Instruction* inst, RegType& insn_type,
3902                                      bool is_primitive) {
3903   DCHECK(Runtime::Current()->IsStarted() || verify_to_dump_);
3904   mirror::ArtField* field = GetQuickFieldAccess(inst, work_line_.get());
3905   if (field == nullptr) {
3906     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Cannot infer field from " << inst->Name();
3907     return;
3908   }
3909   const char* descriptor = field->GetTypeDescriptor();
3910   mirror::ClassLoader* loader = field->GetDeclaringClass()->GetClassLoader();
3911   RegType& field_type = reg_types_.FromDescriptor(loader, descriptor, false);
3912   if (field != nullptr) {
3913     if (field->IsFinal() && field->GetDeclaringClass() != GetDeclaringClass().GetClass()) {
3914       Fail(VERIFY_ERROR_ACCESS_FIELD) << "cannot modify final field " << PrettyField(field)
3915                                       << " from other class " << GetDeclaringClass();
3916       return;
3917     }
3918   }
3919   const uint32_t vregA = inst->VRegA_22c();
3920   if (is_primitive) {
3921     // Primitive field assignability rules are weaker than regular assignability rules
3922     bool instruction_compatible;
3923     bool value_compatible;
3924     RegType& value_type = work_line_->GetRegisterType(vregA);
3925     if (field_type.IsIntegralTypes()) {
3926       instruction_compatible = insn_type.IsIntegralTypes();
3927       value_compatible = value_type.IsIntegralTypes();
3928     } else if (field_type.IsFloat()) {
3929       instruction_compatible = insn_type.IsInteger();  // no [is]put-float, so expect [is]put-int
3930       value_compatible = value_type.IsFloatTypes();
3931     } else if (field_type.IsLong()) {
3932       instruction_compatible = insn_type.IsLong();
3933       value_compatible = value_type.IsLongTypes();
3934     } else if (field_type.IsDouble()) {
3935       instruction_compatible = insn_type.IsLong();  // no [is]put-double, so expect [is]put-long
3936       value_compatible = value_type.IsDoubleTypes();
3937     } else {
3938       instruction_compatible = false;  // reference field with primitive store
3939       value_compatible = false;  // unused
3940     }
3941     if (!instruction_compatible) {
3942       // This is a global failure rather than a class change failure as the instructions and
3943       // the descriptors for the type should have been consistent within the same file at
3944       // compile time
3945       Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "expected field " << PrettyField(field)
3946                                         << " to be of type '" << insn_type
3947                                         << "' but found type '" << field_type
3948                                         << "' in put";
3949       return;
3950     }
3951     if (!value_compatible) {
3952       Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "unexpected value in v" << vregA
3953           << " of type " << value_type
3954           << " but expected " << field_type
3955           << " for store to " << PrettyField(field) << " in put";
3956       return;
3957     }
3958   } else {
3959     if (!insn_type.IsAssignableFrom(field_type)) {
3960       Fail(VERIFY_ERROR_BAD_CLASS_SOFT) << "expected field " << PrettyField(field)
3961                                         << " to be compatible with type '" << insn_type
3962                                         << "' but found type '" << field_type
3963                                         << "' in put-object";
3964       return;
3965     }
3966     work_line_->VerifyRegisterType(vregA, field_type);
3967   }
3968 }
3969 
CheckNotMoveException(const uint16_t * insns,int insn_idx)3970 bool MethodVerifier::CheckNotMoveException(const uint16_t* insns, int insn_idx) {
3971   if ((insns[insn_idx] & 0xff) == Instruction::MOVE_EXCEPTION) {
3972     Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid use of move-exception";
3973     return false;
3974   }
3975   return true;
3976 }
3977 
UpdateRegisters(uint32_t next_insn,RegisterLine * merge_line,bool update_merge_line)3978 bool MethodVerifier::UpdateRegisters(uint32_t next_insn, RegisterLine* merge_line,
3979                                      bool update_merge_line) {
3980   bool changed = true;
3981   RegisterLine* target_line = reg_table_.GetLine(next_insn);
3982   if (!insn_flags_[next_insn].IsVisitedOrChanged()) {
3983     /*
3984      * We haven't processed this instruction before, and we haven't touched the registers here, so
3985      * there's nothing to "merge". Copy the registers over and mark it as changed. (This is the
3986      * only way a register can transition out of "unknown", so this is not just an optimization.)
3987      */
3988     if (!insn_flags_[next_insn].IsReturn()) {
3989       target_line->CopyFromLine(merge_line);
3990     } else {
3991       // Verify that the monitor stack is empty on return.
3992       if (!merge_line->VerifyMonitorStackEmpty()) {
3993         return false;
3994       }
3995       // For returns we only care about the operand to the return, all other registers are dead.
3996       // Initialize them as conflicts so they don't add to GC and deoptimization information.
3997       const Instruction* ret_inst = Instruction::At(code_item_->insns_ + next_insn);
3998       Instruction::Code opcode = ret_inst->Opcode();
3999       if ((opcode == Instruction::RETURN_VOID) || (opcode == Instruction::RETURN_VOID_BARRIER)) {
4000         target_line->MarkAllRegistersAsConflicts();
4001       } else {
4002         target_line->CopyFromLine(merge_line);
4003         if (opcode == Instruction::RETURN_WIDE) {
4004           target_line->MarkAllRegistersAsConflictsExceptWide(ret_inst->VRegA_11x());
4005         } else {
4006           target_line->MarkAllRegistersAsConflictsExcept(ret_inst->VRegA_11x());
4007         }
4008       }
4009     }
4010   } else {
4011     std::unique_ptr<RegisterLine> copy(gDebugVerify ?
4012                                            RegisterLine::Create(target_line->NumRegs(), this) :
4013                                            nullptr);
4014     if (gDebugVerify) {
4015       copy->CopyFromLine(target_line);
4016     }
4017     changed = target_line->MergeRegisters(merge_line);
4018     if (have_pending_hard_failure_) {
4019       return false;
4020     }
4021     if (gDebugVerify && changed) {
4022       LogVerifyInfo() << "Merging at [" << reinterpret_cast<void*>(work_insn_idx_) << "]"
4023                       << " to [" << reinterpret_cast<void*>(next_insn) << "]: " << "\n"
4024                       << *copy.get() << "  MERGE\n"
4025                       << *merge_line << "  ==\n"
4026                       << *target_line << "\n";
4027     }
4028     if (update_merge_line && changed) {
4029       merge_line->CopyFromLine(target_line);
4030     }
4031   }
4032   if (changed) {
4033     insn_flags_[next_insn].SetChanged();
4034   }
4035   return true;
4036 }
4037 
CurrentInsnFlags()4038 InstructionFlags* MethodVerifier::CurrentInsnFlags() {
4039   return &insn_flags_[work_insn_idx_];
4040 }
4041 
GetMethodReturnType()4042 RegType& MethodVerifier::GetMethodReturnType() {
4043   if (return_type_ == nullptr) {
4044     if (mirror_method_ != nullptr) {
4045       Thread* self = Thread::Current();
4046       StackHandleScope<1> hs(self);
4047       mirror::Class* return_type_class;
4048       {
4049         HandleWrapper<mirror::ArtMethod> h_mirror_method(hs.NewHandleWrapper(&mirror_method_));
4050         return_type_class = MethodHelper(h_mirror_method).GetReturnType(can_load_classes_);
4051       }
4052       if (return_type_class != nullptr) {
4053         return_type_ = &reg_types_.FromClass(mirror_method_->GetReturnTypeDescriptor(),
4054                                              return_type_class,
4055                                              return_type_class->CannotBeAssignedFromOtherTypes());
4056       } else {
4057         DCHECK(!can_load_classes_ || self->IsExceptionPending());
4058         self->ClearException();
4059       }
4060     }
4061     if (return_type_ == nullptr) {
4062       const DexFile::MethodId& method_id = dex_file_->GetMethodId(dex_method_idx_);
4063       const DexFile::ProtoId& proto_id = dex_file_->GetMethodPrototype(method_id);
4064       uint16_t return_type_idx = proto_id.return_type_idx_;
4065       const char* descriptor = dex_file_->GetTypeDescriptor(dex_file_->GetTypeId(return_type_idx));
4066       return_type_ = &reg_types_.FromDescriptor(class_loader_->Get(), descriptor, false);
4067     }
4068   }
4069   return *return_type_;
4070 }
4071 
GetDeclaringClass()4072 RegType& MethodVerifier::GetDeclaringClass() {
4073   if (declaring_class_ == nullptr) {
4074     const DexFile::MethodId& method_id = dex_file_->GetMethodId(dex_method_idx_);
4075     const char* descriptor
4076         = dex_file_->GetTypeDescriptor(dex_file_->GetTypeId(method_id.class_idx_));
4077     if (mirror_method_ != nullptr) {
4078       mirror::Class* klass = mirror_method_->GetDeclaringClass();
4079       declaring_class_ = &reg_types_.FromClass(descriptor, klass,
4080                                                klass->CannotBeAssignedFromOtherTypes());
4081     } else {
4082       declaring_class_ = &reg_types_.FromDescriptor(class_loader_->Get(), descriptor, false);
4083     }
4084   }
4085   return *declaring_class_;
4086 }
4087 
DescribeVRegs(uint32_t dex_pc)4088 std::vector<int32_t> MethodVerifier::DescribeVRegs(uint32_t dex_pc) {
4089   RegisterLine* line = reg_table_.GetLine(dex_pc);
4090   DCHECK(line != nullptr) << "No register line at DEX pc " << StringPrintf("0x%x", dex_pc);
4091   std::vector<int32_t> result;
4092   for (size_t i = 0; i < line->NumRegs(); ++i) {
4093     RegType& type = line->GetRegisterType(i);
4094     if (type.IsConstant()) {
4095       result.push_back(type.IsPreciseConstant() ? kConstant : kImpreciseConstant);
4096       result.push_back(type.ConstantValue());
4097     } else if (type.IsConstantLo()) {
4098       result.push_back(type.IsPreciseConstantLo() ? kConstant : kImpreciseConstant);
4099       result.push_back(type.ConstantValueLo());
4100     } else if (type.IsConstantHi()) {
4101       result.push_back(type.IsPreciseConstantHi() ? kConstant : kImpreciseConstant);
4102       result.push_back(type.ConstantValueHi());
4103     } else if (type.IsIntegralTypes()) {
4104       result.push_back(kIntVReg);
4105       result.push_back(0);
4106     } else if (type.IsFloat()) {
4107       result.push_back(kFloatVReg);
4108       result.push_back(0);
4109     } else if (type.IsLong()) {
4110       result.push_back(kLongLoVReg);
4111       result.push_back(0);
4112       result.push_back(kLongHiVReg);
4113       result.push_back(0);
4114       ++i;
4115     } else if (type.IsDouble()) {
4116       result.push_back(kDoubleLoVReg);
4117       result.push_back(0);
4118       result.push_back(kDoubleHiVReg);
4119       result.push_back(0);
4120       ++i;
4121     } else if (type.IsUndefined() || type.IsConflict() || type.IsHighHalf()) {
4122       result.push_back(kUndefined);
4123       result.push_back(0);
4124     } else {
4125       CHECK(type.IsNonZeroReferenceTypes());
4126       result.push_back(kReferenceVReg);
4127       result.push_back(0);
4128     }
4129   }
4130   return result;
4131 }
4132 
DetermineCat1Constant(int32_t value,bool precise)4133 RegType& MethodVerifier::DetermineCat1Constant(int32_t value, bool precise) {
4134   if (precise) {
4135     // Precise constant type.
4136     return reg_types_.FromCat1Const(value, true);
4137   } else {
4138     // Imprecise constant type.
4139     if (value < -32768) {
4140       return reg_types_.IntConstant();
4141     } else if (value < -128) {
4142       return reg_types_.ShortConstant();
4143     } else if (value < 0) {
4144       return reg_types_.ByteConstant();
4145     } else if (value == 0) {
4146       return reg_types_.Zero();
4147     } else if (value == 1) {
4148       return reg_types_.One();
4149     } else if (value < 128) {
4150       return reg_types_.PosByteConstant();
4151     } else if (value < 32768) {
4152       return reg_types_.PosShortConstant();
4153     } else if (value < 65536) {
4154       return reg_types_.CharConstant();
4155     } else {
4156       return reg_types_.IntConstant();
4157     }
4158   }
4159 }
4160 
Init()4161 void MethodVerifier::Init() {
4162   art::verifier::RegTypeCache::Init();
4163 }
4164 
Shutdown()4165 void MethodVerifier::Shutdown() {
4166   verifier::RegTypeCache::ShutDown();
4167 }
4168 
VisitStaticRoots(RootCallback * callback,void * arg)4169 void MethodVerifier::VisitStaticRoots(RootCallback* callback, void* arg) {
4170   RegTypeCache::VisitStaticRoots(callback, arg);
4171 }
4172 
VisitRoots(RootCallback * callback,void * arg)4173 void MethodVerifier::VisitRoots(RootCallback* callback, void* arg) {
4174   reg_types_.VisitRoots(callback, arg);
4175 }
4176 
4177 }  // namespace verifier
4178 }  // namespace art
4179