method_verifier.h revision c785344b87221f5e4e6473e5b762e4e61fe65dcf
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#ifndef ART_RUNTIME_VERIFIER_METHOD_VERIFIER_H_ 18#define ART_RUNTIME_VERIFIER_METHOD_VERIFIER_H_ 19 20#include <memory> 21#include <vector> 22 23#include "base/macros.h" 24#include "dex_file.h" 25#include "handle.h" 26#include "instruction_flags.h" 27#include "method_reference.h" 28#include "reg_type_cache.h" 29 30namespace art { 31 32class Instruction; 33struct ReferenceMap2Visitor; 34class Thread; 35 36namespace verifier { 37 38class DexPcToReferenceMap; 39class MethodVerifier; 40class RegisterLine; 41class RegType; 42 43/* 44 * "Direct" and "virtual" methods are stored independently. The type of call used to invoke the 45 * method determines which list we search, and whether we travel up into superclasses. 46 * 47 * (<clinit>, <init>, and methods declared "private" or "static" are stored in the "direct" list. 48 * All others are stored in the "virtual" list.) 49 */ 50enum MethodType { 51 METHOD_UNKNOWN = 0, 52 METHOD_DIRECT, // <init>, private 53 METHOD_STATIC, // static 54 METHOD_VIRTUAL, // virtual, super 55 METHOD_INTERFACE // interface 56}; 57std::ostream& operator<<(std::ostream& os, const MethodType& rhs); 58 59/* 60 * An enumeration of problems that can turn up during verification. 61 * Both VERIFY_ERROR_BAD_CLASS_SOFT and VERIFY_ERROR_BAD_CLASS_HARD denote failures that cause 62 * the entire class to be rejected. However, VERIFY_ERROR_BAD_CLASS_SOFT denotes a soft failure 63 * that can potentially be corrected, and the verifier will try again at runtime. 64 * VERIFY_ERROR_BAD_CLASS_HARD denotes a hard failure that can't be corrected, and will cause 65 * the class to remain uncompiled. Other errors denote verification errors that cause bytecode 66 * to be rewritten to fail at runtime. 67 */ 68enum VerifyError { 69 VERIFY_ERROR_BAD_CLASS_HARD, // VerifyError; hard error that skips compilation. 70 VERIFY_ERROR_BAD_CLASS_SOFT, // VerifyError; soft error that verifies again at runtime. 71 72 VERIFY_ERROR_NO_CLASS, // NoClassDefFoundError. 73 VERIFY_ERROR_NO_FIELD, // NoSuchFieldError. 74 VERIFY_ERROR_NO_METHOD, // NoSuchMethodError. 75 VERIFY_ERROR_ACCESS_CLASS, // IllegalAccessError. 76 VERIFY_ERROR_ACCESS_FIELD, // IllegalAccessError. 77 VERIFY_ERROR_ACCESS_METHOD, // IllegalAccessError. 78 VERIFY_ERROR_CLASS_CHANGE, // IncompatibleClassChangeError. 79 VERIFY_ERROR_INSTANTIATION, // InstantiationError. 80}; 81std::ostream& operator<<(std::ostream& os, const VerifyError& rhs); 82 83/* 84 * Identifies the type of reference in the instruction that generated the verify error 85 * (e.g. VERIFY_ERROR_ACCESS_CLASS could come from a method, field, or class reference). 86 * 87 * This must fit in two bits. 88 */ 89enum VerifyErrorRefType { 90 VERIFY_ERROR_REF_CLASS = 0, 91 VERIFY_ERROR_REF_FIELD = 1, 92 VERIFY_ERROR_REF_METHOD = 2, 93}; 94const int kVerifyErrorRefTypeShift = 6; 95 96// We don't need to store the register data for many instructions, because we either only need 97// it at branch points (for verification) or GC points and branches (for verification + 98// type-precise register analysis). 99enum RegisterTrackingMode { 100 kTrackRegsBranches, 101 kTrackCompilerInterestPoints, 102 kTrackRegsAll, 103}; 104 105// A mapping from a dex pc to the register line statuses as they are immediately prior to the 106// execution of that instruction. 107class PcToRegisterLineTable { 108 public: 109 PcToRegisterLineTable() : size_(0) {} 110 ~PcToRegisterLineTable(); 111 112 // Initialize the RegisterTable. Every instruction address can have a different set of information 113 // about what's in which register, but for verification purposes we only need to store it at 114 // branch target addresses (because we merge into that). 115 void Init(RegisterTrackingMode mode, InstructionFlags* flags, uint32_t insns_size, 116 uint16_t registers_size, MethodVerifier* verifier); 117 118 RegisterLine* GetLine(size_t idx) { 119 DCHECK_LT(idx, size_); 120 return register_lines_[idx]; 121 } 122 123 private: 124 std::unique_ptr<RegisterLine*[]> register_lines_; 125 size_t size_; 126 127 DISALLOW_COPY_AND_ASSIGN(PcToRegisterLineTable); 128}; 129 130// The verifier 131class MethodVerifier { 132 public: 133 enum FailureKind { 134 kNoFailure, 135 kSoftFailure, 136 kHardFailure, 137 }; 138 139 /* Verify a class. Returns "kNoFailure" on success. */ 140 static FailureKind VerifyClass(Thread* self, mirror::Class* klass, bool allow_soft_failures, 141 std::string* error) 142 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 143 static FailureKind VerifyClass(Thread* self, const DexFile* dex_file, 144 Handle<mirror::DexCache> dex_cache, 145 Handle<mirror::ClassLoader> class_loader, 146 const DexFile::ClassDef* class_def, 147 bool allow_soft_failures, std::string* error) 148 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 149 150 static MethodVerifier* VerifyMethodAndDump(Thread* self, std::ostream& os, uint32_t method_idx, 151 const DexFile* dex_file, 152 Handle<mirror::DexCache> dex_cache, 153 Handle<mirror::ClassLoader> class_loader, 154 const DexFile::ClassDef* class_def, 155 const DexFile::CodeItem* code_item, 156 Handle<mirror::ArtMethod> method, 157 uint32_t method_access_flags) 158 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 159 160 static FailureKind VerifyMethod(mirror::ArtMethod* method, bool allow_soft_failures, 161 std::string* error) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 162 163 uint8_t EncodePcToReferenceMapData() const; 164 165 uint32_t DexFileVersion() const { 166 return dex_file_->GetVersion(); 167 } 168 169 RegTypeCache* GetRegTypeCache() { 170 return ®_types_; 171 } 172 173 // Log a verification failure. 174 std::ostream& Fail(VerifyError error); 175 176 // Log for verification information. 177 std::ostream& LogVerifyInfo(); 178 179 // Dump the failures encountered by the verifier. 180 std::ostream& DumpFailures(std::ostream& os); 181 182 // Dump the state of the verifier, namely each instruction, what flags are set on it, register 183 // information 184 void Dump(std::ostream& os) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 185 186 // Fills 'monitor_enter_dex_pcs' with the dex pcs of the monitor-enter instructions corresponding 187 // to the locks held at 'dex_pc' in method 'm'. 188 static void FindLocksAtDexPc(mirror::ArtMethod* m, uint32_t dex_pc, 189 std::vector<uint32_t>* monitor_enter_dex_pcs) 190 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 191 192 // Returns the accessed field corresponding to the quick instruction's field 193 // offset at 'dex_pc' in method 'm'. 194 static ArtField* FindAccessedFieldAtDexPc(mirror::ArtMethod* m, uint32_t dex_pc) 195 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 196 197 // Returns the invoked method corresponding to the quick instruction's vtable 198 // index at 'dex_pc' in method 'm'. 199 static mirror::ArtMethod* FindInvokedMethodAtDexPc(mirror::ArtMethod* m, uint32_t dex_pc) 200 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 201 202 static void Init() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 203 static void Shutdown(); 204 205 bool CanLoadClasses() const { 206 return can_load_classes_; 207 } 208 209 MethodVerifier(Thread* self, const DexFile* dex_file, Handle<mirror::DexCache> dex_cache, 210 Handle<mirror::ClassLoader> class_loader, const DexFile::ClassDef* class_def, 211 const DexFile::CodeItem* code_item, uint32_t method_idx, 212 Handle<mirror::ArtMethod> method, 213 uint32_t access_flags, bool can_load_classes, bool allow_soft_failures, 214 bool need_precise_constants, bool allow_thread_suspension) 215 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 216 : MethodVerifier(self, dex_file, dex_cache, class_loader, class_def, code_item, method_idx, 217 method, access_flags, can_load_classes, allow_soft_failures, 218 need_precise_constants, false, allow_thread_suspension) {} 219 220 ~MethodVerifier(); 221 222 // Run verification on the method. Returns true if verification completes and false if the input 223 // has an irrecoverable corruption. 224 bool Verify() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 225 226 // Describe VRegs at the given dex pc. 227 std::vector<int32_t> DescribeVRegs(uint32_t dex_pc); 228 229 static void VisitStaticRoots(RootVisitor* visitor) 230 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 231 void VisitRoots(RootVisitor* visitor, const RootInfo& roots) 232 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 233 234 // Accessors used by the compiler via CompilerCallback 235 const DexFile::CodeItem* CodeItem() const; 236 RegisterLine* GetRegLine(uint32_t dex_pc); 237 const InstructionFlags& GetInstructionFlags(size_t index) const; 238 mirror::ClassLoader* GetClassLoader() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 239 mirror::DexCache* GetDexCache() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 240 MethodReference GetMethodReference() const; 241 uint32_t GetAccessFlags() const; 242 bool HasCheckCasts() const; 243 bool HasVirtualOrInterfaceInvokes() const; 244 bool HasFailures() const; 245 const RegType& ResolveCheckedClass(uint32_t class_idx) 246 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 247 // Returns the method of a quick invoke or nullptr if it cannot be found. 248 mirror::ArtMethod* GetQuickInvokedMethod(const Instruction* inst, RegisterLine* reg_line, 249 bool is_range, bool allow_failure) 250 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 251 // Returns the access field of a quick field access (iget/iput-quick) or nullptr 252 // if it cannot be found. 253 ArtField* GetQuickFieldAccess(const Instruction* inst, RegisterLine* reg_line) 254 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 255 256 // Is the method being verified a constructor? 257 bool IsConstructor() const { 258 return (method_access_flags_ & kAccConstructor) != 0; 259 } 260 261 // Is the method verified static? 262 bool IsStatic() const { 263 return (method_access_flags_ & kAccStatic) != 0; 264 } 265 266 private: 267 // Private constructor for dumping. 268 MethodVerifier(Thread* self, const DexFile* dex_file, Handle<mirror::DexCache> dex_cache, 269 Handle<mirror::ClassLoader> class_loader, const DexFile::ClassDef* class_def, 270 const DexFile::CodeItem* code_item, uint32_t method_idx, 271 Handle<mirror::ArtMethod> method, uint32_t access_flags, 272 bool can_load_classes, bool allow_soft_failures, bool need_precise_constants, 273 bool verify_to_dump, bool allow_thread_suspension) 274 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 275 276 // Adds the given string to the beginning of the last failure message. 277 void PrependToLastFailMessage(std::string); 278 279 // Adds the given string to the end of the last failure message. 280 void AppendToLastFailMessage(std::string); 281 282 /* 283 * Perform verification on a single method. 284 * 285 * We do this in three passes: 286 * (1) Walk through all code units, determining instruction locations, 287 * widths, and other characteristics. 288 * (2) Walk through all code units, performing static checks on 289 * operands. 290 * (3) Iterate through the method, checking type safety and looking 291 * for code flow problems. 292 */ 293 static FailureKind VerifyMethod(Thread* self, uint32_t method_idx, const DexFile* dex_file, 294 Handle<mirror::DexCache> dex_cache, 295 Handle<mirror::ClassLoader> class_loader, 296 const DexFile::ClassDef* class_def_idx, 297 const DexFile::CodeItem* code_item, 298 Handle<mirror::ArtMethod> method, uint32_t method_access_flags, 299 bool allow_soft_failures, bool need_precise_constants) 300 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 301 302 void FindLocksAtDexPc() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 303 304 ArtField* FindAccessedFieldAtDexPc(uint32_t dex_pc) 305 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 306 307 mirror::ArtMethod* FindInvokedMethodAtDexPc(uint32_t dex_pc) 308 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 309 310 /* 311 * Compute the width of the instruction at each address in the instruction stream, and store it in 312 * insn_flags_. Addresses that are in the middle of an instruction, or that are part of switch 313 * table data, are not touched (so the caller should probably initialize "insn_flags" to zero). 314 * 315 * The "new_instance_count_" and "monitor_enter_count_" fields in vdata are also set. 316 * 317 * Performs some static checks, notably: 318 * - opcode of first instruction begins at index 0 319 * - only documented instructions may appear 320 * - each instruction follows the last 321 * - last byte of last instruction is at (code_length-1) 322 * 323 * Logs an error and returns "false" on failure. 324 */ 325 bool ComputeWidthsAndCountOps(); 326 327 /* 328 * Set the "in try" flags for all instructions protected by "try" statements. Also sets the 329 * "branch target" flags for exception handlers. 330 * 331 * Call this after widths have been set in "insn_flags". 332 * 333 * Returns "false" if something in the exception table looks fishy, but we're expecting the 334 * exception table to be somewhat sane. 335 */ 336 bool ScanTryCatchBlocks() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 337 338 /* 339 * Perform static verification on all instructions in a method. 340 * 341 * Walks through instructions in a method calling VerifyInstruction on each. 342 */ 343 bool VerifyInstructions(); 344 345 /* 346 * Perform static verification on an instruction. 347 * 348 * As a side effect, this sets the "branch target" flags in InsnFlags. 349 * 350 * "(CF)" items are handled during code-flow analysis. 351 * 352 * v3 4.10.1 353 * - target of each jump and branch instruction must be valid 354 * - targets of switch statements must be valid 355 * - operands referencing constant pool entries must be valid 356 * - (CF) operands of getfield, putfield, getstatic, putstatic must be valid 357 * - (CF) operands of method invocation instructions must be valid 358 * - (CF) only invoke-direct can call a method starting with '<' 359 * - (CF) <clinit> must never be called explicitly 360 * - operands of instanceof, checkcast, new (and variants) must be valid 361 * - new-array[-type] limited to 255 dimensions 362 * - can't use "new" on an array class 363 * - (?) limit dimensions in multi-array creation 364 * - local variable load/store register values must be in valid range 365 * 366 * v3 4.11.1.2 367 * - branches must be within the bounds of the code array 368 * - targets of all control-flow instructions are the start of an instruction 369 * - register accesses fall within range of allocated registers 370 * - (N/A) access to constant pool must be of appropriate type 371 * - code does not end in the middle of an instruction 372 * - execution cannot fall off the end of the code 373 * - (earlier) for each exception handler, the "try" area must begin and 374 * end at the start of an instruction (end can be at the end of the code) 375 * - (earlier) for each exception handler, the handler must start at a valid 376 * instruction 377 */ 378 bool VerifyInstruction(const Instruction* inst, uint32_t code_offset); 379 380 /* Ensure that the register index is valid for this code item. */ 381 bool CheckRegisterIndex(uint32_t idx); 382 383 /* Ensure that the wide register index is valid for this code item. */ 384 bool CheckWideRegisterIndex(uint32_t idx); 385 386 // Perform static checks on a field Get or set instruction. All we do here is ensure that the 387 // field index is in the valid range. 388 bool CheckFieldIndex(uint32_t idx); 389 390 // Perform static checks on a method invocation instruction. All we do here is ensure that the 391 // method index is in the valid range. 392 bool CheckMethodIndex(uint32_t idx); 393 394 // Perform static checks on a "new-instance" instruction. Specifically, make sure the class 395 // reference isn't for an array class. 396 bool CheckNewInstance(uint32_t idx); 397 398 /* Ensure that the string index is in the valid range. */ 399 bool CheckStringIndex(uint32_t idx); 400 401 // Perform static checks on an instruction that takes a class constant. Ensure that the class 402 // index is in the valid range. 403 bool CheckTypeIndex(uint32_t idx); 404 405 // Perform static checks on a "new-array" instruction. Specifically, make sure they aren't 406 // creating an array of arrays that causes the number of dimensions to exceed 255. 407 bool CheckNewArray(uint32_t idx); 408 409 // Verify an array data table. "cur_offset" is the offset of the fill-array-data instruction. 410 bool CheckArrayData(uint32_t cur_offset); 411 412 // Verify that the target of a branch instruction is valid. We don't expect code to jump directly 413 // into an exception handler, but it's valid to do so as long as the target isn't a 414 // "move-exception" instruction. We verify that in a later stage. 415 // The dex format forbids certain instructions from branching to themselves. 416 // Updates "insn_flags_", setting the "branch target" flag. 417 bool CheckBranchTarget(uint32_t cur_offset); 418 419 // Verify a switch table. "cur_offset" is the offset of the switch instruction. 420 // Updates "insn_flags_", setting the "branch target" flag. 421 bool CheckSwitchTargets(uint32_t cur_offset); 422 423 // Check the register indices used in a "vararg" instruction, such as invoke-virtual or 424 // filled-new-array. 425 // - vA holds word count (0-5), args[] have values. 426 // There are some tests we don't do here, e.g. we don't try to verify that invoking a method that 427 // takes a double is done with consecutive registers. This requires parsing the target method 428 // signature, which we will be doing later on during the code flow analysis. 429 bool CheckVarArgRegs(uint32_t vA, uint32_t arg[]); 430 431 // Check the register indices used in a "vararg/range" instruction, such as invoke-virtual/range 432 // or filled-new-array/range. 433 // - vA holds word count, vC holds index of first reg. 434 bool CheckVarArgRangeRegs(uint32_t vA, uint32_t vC); 435 436 // Extract the relative offset from a branch instruction. 437 // Returns "false" on failure (e.g. this isn't a branch instruction). 438 bool GetBranchOffset(uint32_t cur_offset, int32_t* pOffset, bool* pConditional, 439 bool* selfOkay); 440 441 /* Perform detailed code-flow analysis on a single method. */ 442 bool VerifyCodeFlow() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 443 444 // Set the register types for the first instruction in the method based on the method signature. 445 // This has the side-effect of validating the signature. 446 bool SetTypesFromSignature() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 447 448 /* 449 * Perform code flow on a method. 450 * 451 * The basic strategy is as outlined in v3 4.11.1.2: set the "changed" bit on the first 452 * instruction, process it (setting additional "changed" bits), and repeat until there are no 453 * more. 454 * 455 * v3 4.11.1.1 456 * - (N/A) operand stack is always the same size 457 * - operand stack [registers] contain the correct types of values 458 * - local variables [registers] contain the correct types of values 459 * - methods are invoked with the appropriate arguments 460 * - fields are assigned using values of appropriate types 461 * - opcodes have the correct type values in operand registers 462 * - there is never an uninitialized class instance in a local variable in code protected by an 463 * exception handler (operand stack is okay, because the operand stack is discarded when an 464 * exception is thrown) [can't know what's a local var w/o the debug info -- should fall out of 465 * register typing] 466 * 467 * v3 4.11.1.2 468 * - execution cannot fall off the end of the code 469 * 470 * (We also do many of the items described in the "static checks" sections, because it's easier to 471 * do them here.) 472 * 473 * We need an array of RegType values, one per register, for every instruction. If the method uses 474 * monitor-enter, we need extra data for every register, and a stack for every "interesting" 475 * instruction. In theory this could become quite large -- up to several megabytes for a monster 476 * function. 477 * 478 * NOTE: 479 * The spec forbids backward branches when there's an uninitialized reference in a register. The 480 * idea is to prevent something like this: 481 * loop: 482 * move r1, r0 483 * new-instance r0, MyClass 484 * ... 485 * if-eq rN, loop // once 486 * initialize r0 487 * 488 * This leaves us with two different instances, both allocated by the same instruction, but only 489 * one is initialized. The scheme outlined in v3 4.11.1.4 wouldn't catch this, so they work around 490 * it by preventing backward branches. We achieve identical results without restricting code 491 * reordering by specifying that you can't execute the new-instance instruction if a register 492 * contains an uninitialized instance created by that same instruction. 493 */ 494 bool CodeFlowVerifyMethod() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 495 496 /* 497 * Perform verification for a single instruction. 498 * 499 * This requires fully decoding the instruction to determine the effect it has on registers. 500 * 501 * Finds zero or more following instructions and sets the "changed" flag if execution at that 502 * point needs to be (re-)evaluated. Register changes are merged into "reg_types_" at the target 503 * addresses. Does not set or clear any other flags in "insn_flags_". 504 */ 505 bool CodeFlowVerifyInstruction(uint32_t* start_guess) 506 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 507 508 // Perform verification of a new array instruction 509 void VerifyNewArray(const Instruction* inst, bool is_filled, bool is_range) 510 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 511 512 // Helper to perform verification on puts of primitive type. 513 void VerifyPrimitivePut(const RegType& target_type, const RegType& insn_type, 514 const uint32_t vregA) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 515 516 // Perform verification of an aget instruction. The destination register's type will be set to 517 // be that of component type of the array unless the array type is unknown, in which case a 518 // bottom type inferred from the type of instruction is used. is_primitive is false for an 519 // aget-object. 520 void VerifyAGet(const Instruction* inst, const RegType& insn_type, 521 bool is_primitive) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 522 523 // Perform verification of an aput instruction. 524 void VerifyAPut(const Instruction* inst, const RegType& insn_type, 525 bool is_primitive) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 526 527 // Lookup instance field and fail for resolution violations 528 ArtField* GetInstanceField(const RegType& obj_type, int field_idx) 529 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 530 531 // Lookup static field and fail for resolution violations 532 ArtField* GetStaticField(int field_idx) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 533 534 // Perform verification of an iget/sget/iput/sput instruction. 535 enum class FieldAccessType { // private 536 kAccGet, 537 kAccPut 538 }; 539 template <FieldAccessType kAccType> 540 void VerifyISFieldAccess(const Instruction* inst, const RegType& insn_type, 541 bool is_primitive, bool is_static) 542 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 543 544 template <FieldAccessType kAccType> 545 void VerifyQuickFieldAccess(const Instruction* inst, const RegType& insn_type, bool is_primitive) 546 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 547 548 // Resolves a class based on an index and performs access checks to ensure the referrer can 549 // access the resolved class. 550 const RegType& ResolveClassAndCheckAccess(uint32_t class_idx) 551 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 552 553 /* 554 * For the "move-exception" instruction at "work_insn_idx_", which must be at an exception handler 555 * address, determine the Join of all exceptions that can land here. Fails if no matching 556 * exception handler can be found or if the Join of exception types fails. 557 */ 558 const RegType& GetCaughtExceptionType() 559 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 560 561 /* 562 * Resolves a method based on an index and performs access checks to ensure 563 * the referrer can access the resolved method. 564 * Does not throw exceptions. 565 */ 566 mirror::ArtMethod* ResolveMethodAndCheckAccess(uint32_t method_idx, MethodType method_type) 567 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 568 569 /* 570 * Verify the arguments to a method. We're executing in "method", making 571 * a call to the method reference in vB. 572 * 573 * If this is a "direct" invoke, we allow calls to <init>. For calls to 574 * <init>, the first argument may be an uninitialized reference. Otherwise, 575 * calls to anything starting with '<' will be rejected, as will any 576 * uninitialized reference arguments. 577 * 578 * For non-static method calls, this will verify that the method call is 579 * appropriate for the "this" argument. 580 * 581 * The method reference is in vBBBB. The "is_range" parameter determines 582 * whether we use 0-4 "args" values or a range of registers defined by 583 * vAA and vCCCC. 584 * 585 * Widening conversions on integers and references are allowed, but 586 * narrowing conversions are not. 587 * 588 * Returns the resolved method on success, nullptr on failure (with *failure 589 * set appropriately). 590 */ 591 mirror::ArtMethod* VerifyInvocationArgs(const Instruction* inst, 592 MethodType method_type, 593 bool is_range, bool is_super) 594 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 595 596 // Similar checks to the above, but on the proto. Will be used when the method cannot be 597 // resolved. 598 void VerifyInvocationArgsUnresolvedMethod(const Instruction* inst, MethodType method_type, 599 bool is_range) 600 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 601 602 template <class T> 603 mirror::ArtMethod* VerifyInvocationArgsFromIterator(T* it, const Instruction* inst, 604 MethodType method_type, bool is_range, 605 mirror::ArtMethod* res_method) 606 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 607 608 mirror::ArtMethod* VerifyInvokeVirtualQuickArgs(const Instruction* inst, bool is_range) 609 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 610 611 /* 612 * Verify that the target instruction is not "move-exception". It's important that the only way 613 * to execute a move-exception is as the first instruction of an exception handler. 614 * Returns "true" if all is well, "false" if the target instruction is move-exception. 615 */ 616 bool CheckNotMoveException(const uint16_t* insns, int insn_idx); 617 618 /* 619 * Verify that the target instruction is not "move-result". It is important that we cannot 620 * branch to move-result instructions, but we have to make this a distinct check instead of 621 * adding it to CheckNotMoveException, because it is legal to continue into "move-result" 622 * instructions - as long as the previous instruction was an invoke, which is checked elsewhere. 623 */ 624 bool CheckNotMoveResult(const uint16_t* insns, int insn_idx); 625 626 /* 627 * Verify that the target instruction is not "move-result" or "move-exception". This is to 628 * be used when checking branch and switch instructions, but not instructions that can 629 * continue. 630 */ 631 bool CheckNotMoveExceptionOrMoveResult(const uint16_t* insns, int insn_idx); 632 633 /* 634 * Control can transfer to "next_insn". Merge the registers from merge_line into the table at 635 * next_insn, and set the changed flag on the target address if any of the registers were changed. 636 * In the case of fall-through, update the merge line on a change as its the working line for the 637 * next instruction. 638 * Returns "false" if an error is encountered. 639 */ 640 bool UpdateRegisters(uint32_t next_insn, RegisterLine* merge_line, bool update_merge_line) 641 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 642 643 // Return the register type for the method. 644 const RegType& GetMethodReturnType() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 645 646 // Get a type representing the declaring class of the method. 647 const RegType& GetDeclaringClass() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 648 649 InstructionFlags* CurrentInsnFlags(); 650 651 const RegType& DetermineCat1Constant(int32_t value, bool precise) 652 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 653 654 // The thread we're verifying on. 655 Thread* const self_; 656 657 RegTypeCache reg_types_; 658 659 PcToRegisterLineTable reg_table_; 660 661 // Storage for the register status we're currently working on. 662 std::unique_ptr<RegisterLine> work_line_; 663 664 // The address of the instruction we're currently working on, note that this is in 2 byte 665 // quantities 666 uint32_t work_insn_idx_; 667 668 // Storage for the register status we're saving for later. 669 std::unique_ptr<RegisterLine> saved_line_; 670 671 const uint32_t dex_method_idx_; // The method we're working on. 672 // Its object representation if known. 673 Handle<mirror::ArtMethod> mirror_method_ GUARDED_BY(Locks::mutator_lock_); 674 const uint32_t method_access_flags_; // Method's access flags. 675 const RegType* return_type_; // Lazily computed return type of the method. 676 const DexFile* const dex_file_; // The dex file containing the method. 677 // The dex_cache for the declaring class of the method. 678 Handle<mirror::DexCache> dex_cache_ GUARDED_BY(Locks::mutator_lock_); 679 // The class loader for the declaring class of the method. 680 Handle<mirror::ClassLoader> class_loader_ GUARDED_BY(Locks::mutator_lock_); 681 const DexFile::ClassDef* const class_def_; // The class def of the declaring class of the method. 682 const DexFile::CodeItem* const code_item_; // The code item containing the code for the method. 683 const RegType* declaring_class_; // Lazily computed reg type of the method's declaring class. 684 // Instruction widths and flags, one entry per code unit. 685 std::unique_ptr<InstructionFlags[]> insn_flags_; 686 // The dex PC of a FindLocksAtDexPc request, -1 otherwise. 687 uint32_t interesting_dex_pc_; 688 // The container into which FindLocksAtDexPc should write the registers containing held locks, 689 // nullptr if we're not doing FindLocksAtDexPc. 690 std::vector<uint32_t>* monitor_enter_dex_pcs_; 691 692 // The types of any error that occurs. 693 std::vector<VerifyError> failures_; 694 // Error messages associated with failures. 695 std::vector<std::ostringstream*> failure_messages_; 696 // Is there a pending hard failure? 697 bool have_pending_hard_failure_; 698 // Is there a pending runtime throw failure? A runtime throw failure is when an instruction 699 // would fail at runtime throwing an exception. Such an instruction causes the following code 700 // to be unreachable. This is set by Fail and used to ensure we don't process unreachable 701 // instructions that would hard fail the verification. 702 bool have_pending_runtime_throw_failure_; 703 704 // Info message log use primarily for verifier diagnostics. 705 std::ostringstream info_messages_; 706 707 // The number of occurrences of specific opcodes. 708 size_t new_instance_count_; 709 size_t monitor_enter_count_; 710 711 const bool can_load_classes_; 712 713 // Converts soft failures to hard failures when false. Only false when the compiler isn't 714 // running and the verifier is called from the class linker. 715 const bool allow_soft_failures_; 716 717 // An optimization where instead of generating unique RegTypes for constants we use imprecise 718 // constants that cover a range of constants. This isn't good enough for deoptimization that 719 // avoids loading from registers in the case of a constant as the dex instruction set lost the 720 // notion of whether a value should be in a floating point or general purpose register file. 721 const bool need_precise_constants_; 722 723 // Indicates the method being verified contains at least one check-cast or aput-object 724 // instruction. Aput-object operations implicitly check for array-store exceptions, similar to 725 // check-cast. 726 bool has_check_casts_; 727 728 // Indicates the method being verified contains at least one invoke-virtual/range 729 // or invoke-interface/range. 730 bool has_virtual_or_interface_invokes_; 731 732 // Indicates whether we verify to dump the info. In that case we accept quickened instructions 733 // even though we might detect to be a compiler. Should only be set when running 734 // VerifyMethodAndDump. 735 const bool verify_to_dump_; 736 737 // Whether or not we call AllowThreadSuspension periodically, we want a way to disable this for 738 // thread dumping checkpoints since we may get thread suspension at an inopportune time due to 739 // FindLocksAtDexPC, resulting in deadlocks. 740 const bool allow_thread_suspension_; 741 742 // Link, for the method verifier root linked list. 743 MethodVerifier* link_; 744 745 friend class art::Thread; 746 DISALLOW_COPY_AND_ASSIGN(MethodVerifier); 747}; 748std::ostream& operator<<(std::ostream& os, const MethodVerifier::FailureKind& rhs); 749 750} // namespace verifier 751} // namespace art 752 753#endif // ART_RUNTIME_VERIFIER_METHOD_VERIFIER_H_ 754