method_verifier.h revision dc3761719fb5e2d1ced5708e3c73b965f9ef0c73
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 <set> 22#include <vector> 23 24#include "base/casts.h" 25#include "base/macros.h" 26#include "base/stl_util.h" 27#include "class_reference.h" 28#include "dex_file.h" 29#include "dex_instruction.h" 30#include "handle.h" 31#include "instruction_flags.h" 32#include "method_reference.h" 33#include "reg_type.h" 34#include "reg_type_cache.h" 35#include "register_line.h" 36#include "safe_map.h" 37 38namespace art { 39 40struct ReferenceMap2Visitor; 41template<class T> class Handle; 42 43namespace verifier { 44 45class MethodVerifier; 46class DexPcToReferenceMap; 47 48/* 49 * "Direct" and "virtual" methods are stored independently. The type of call used to invoke the 50 * method determines which list we search, and whether we travel up into superclasses. 51 * 52 * (<clinit>, <init>, and methods declared "private" or "static" are stored in the "direct" list. 53 * All others are stored in the "virtual" list.) 54 */ 55enum MethodType { 56 METHOD_UNKNOWN = 0, 57 METHOD_DIRECT, // <init>, private 58 METHOD_STATIC, // static 59 METHOD_VIRTUAL, // virtual, super 60 METHOD_INTERFACE // interface 61}; 62std::ostream& operator<<(std::ostream& os, const MethodType& rhs); 63 64/* 65 * An enumeration of problems that can turn up during verification. 66 * Both VERIFY_ERROR_BAD_CLASS_SOFT and VERIFY_ERROR_BAD_CLASS_HARD denote failures that cause 67 * the entire class to be rejected. However, VERIFY_ERROR_BAD_CLASS_SOFT denotes a soft failure 68 * that can potentially be corrected, and the verifier will try again at runtime. 69 * VERIFY_ERROR_BAD_CLASS_HARD denotes a hard failure that can't be corrected, and will cause 70 * the class to remain uncompiled. Other errors denote verification errors that cause bytecode 71 * to be rewritten to fail at runtime. 72 */ 73enum VerifyError { 74 VERIFY_ERROR_BAD_CLASS_HARD, // VerifyError; hard error that skips compilation. 75 VERIFY_ERROR_BAD_CLASS_SOFT, // VerifyError; soft error that verifies again at runtime. 76 77 VERIFY_ERROR_NO_CLASS, // NoClassDefFoundError. 78 VERIFY_ERROR_NO_FIELD, // NoSuchFieldError. 79 VERIFY_ERROR_NO_METHOD, // NoSuchMethodError. 80 VERIFY_ERROR_ACCESS_CLASS, // IllegalAccessError. 81 VERIFY_ERROR_ACCESS_FIELD, // IllegalAccessError. 82 VERIFY_ERROR_ACCESS_METHOD, // IllegalAccessError. 83 VERIFY_ERROR_CLASS_CHANGE, // IncompatibleClassChangeError. 84 VERIFY_ERROR_INSTANTIATION, // InstantiationError. 85}; 86std::ostream& operator<<(std::ostream& os, const VerifyError& rhs); 87 88/* 89 * Identifies the type of reference in the instruction that generated the verify error 90 * (e.g. VERIFY_ERROR_ACCESS_CLASS could come from a method, field, or class reference). 91 * 92 * This must fit in two bits. 93 */ 94enum VerifyErrorRefType { 95 VERIFY_ERROR_REF_CLASS = 0, 96 VERIFY_ERROR_REF_FIELD = 1, 97 VERIFY_ERROR_REF_METHOD = 2, 98}; 99const int kVerifyErrorRefTypeShift = 6; 100 101// We don't need to store the register data for many instructions, because we either only need 102// it at branch points (for verification) or GC points and branches (for verification + 103// type-precise register analysis). 104enum RegisterTrackingMode { 105 kTrackRegsBranches, 106 kTrackCompilerInterestPoints, 107 kTrackRegsAll, 108}; 109 110// A mapping from a dex pc to the register line statuses as they are immediately prior to the 111// execution of that instruction. 112class PcToRegisterLineTable { 113 public: 114 PcToRegisterLineTable() : size_(0) {} 115 ~PcToRegisterLineTable(); 116 117 // Initialize the RegisterTable. Every instruction address can have a different set of information 118 // about what's in which register, but for verification purposes we only need to store it at 119 // branch target addresses (because we merge into that). 120 void Init(RegisterTrackingMode mode, InstructionFlags* flags, uint32_t insns_size, 121 uint16_t registers_size, MethodVerifier* verifier); 122 123 RegisterLine* GetLine(size_t idx) { 124 DCHECK_LT(idx, size_); 125 return register_lines_[idx]; 126 } 127 128 private: 129 std::unique_ptr<RegisterLine*[]> register_lines_; 130 size_t size_; 131}; 132 133// The verifier 134class MethodVerifier { 135 public: 136 enum FailureKind { 137 kNoFailure, 138 kSoftFailure, 139 kHardFailure, 140 }; 141 142 /* Verify a class. Returns "kNoFailure" on success. */ 143 static FailureKind VerifyClass(mirror::Class* klass, bool allow_soft_failures, std::string* error) 144 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 145 static FailureKind VerifyClass(const DexFile* dex_file, Handle<mirror::DexCache> dex_cache, 146 Handle<mirror::ClassLoader> class_loader, 147 const DexFile::ClassDef* class_def, 148 bool allow_soft_failures, std::string* error) 149 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 150 151 static void VerifyMethodAndDump(std::ostream& os, uint32_t method_idx, 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, uint32_t method_access_flags) 157 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 158 159 uint8_t EncodePcToReferenceMapData() const; 160 161 uint32_t DexFileVersion() const { 162 return dex_file_->GetVersion(); 163 } 164 165 RegTypeCache* GetRegTypeCache() { 166 return ®_types_; 167 } 168 169 // Log a verification failure. 170 std::ostream& Fail(VerifyError error); 171 172 // Log for verification information. 173 std::ostream& LogVerifyInfo(); 174 175 // Dump the failures encountered by the verifier. 176 std::ostream& DumpFailures(std::ostream& os); 177 178 // Dump the state of the verifier, namely each instruction, what flags are set on it, register 179 // information 180 void Dump(std::ostream& os) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 181 182 // Fills 'monitor_enter_dex_pcs' with the dex pcs of the monitor-enter instructions corresponding 183 // to the locks held at 'dex_pc' in method 'm'. 184 static void FindLocksAtDexPc(mirror::ArtMethod* m, uint32_t dex_pc, 185 std::vector<uint32_t>* monitor_enter_dex_pcs) 186 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 187 188 // Returns the accessed field corresponding to the quick instruction's field 189 // offset at 'dex_pc' in method 'm'. 190 static mirror::ArtField* FindAccessedFieldAtDexPc(mirror::ArtMethod* m, uint32_t dex_pc) 191 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 192 193 // Returns the invoked method corresponding to the quick instruction's vtable 194 // index at 'dex_pc' in method 'm'. 195 static mirror::ArtMethod* FindInvokedMethodAtDexPc(mirror::ArtMethod* m, uint32_t dex_pc) 196 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 197 198 static void Init() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 199 static void Shutdown(); 200 201 bool CanLoadClasses() const { 202 return can_load_classes_; 203 } 204 205 MethodVerifier(const DexFile* dex_file, Handle<mirror::DexCache>* dex_cache, 206 Handle<mirror::ClassLoader>* class_loader, const DexFile::ClassDef* class_def, 207 const DexFile::CodeItem* code_item, uint32_t method_idx, Handle<mirror::ArtMethod> method, 208 uint32_t access_flags, bool can_load_classes, bool allow_soft_failures, 209 bool need_precise_constants) 210 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 211 212 ~MethodVerifier(); 213 214 // Run verification on the method. Returns true if verification completes and false if the input 215 // has an irrecoverable corruption. 216 bool Verify() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 217 218 // Describe VRegs at the given dex pc. 219 std::vector<int32_t> DescribeVRegs(uint32_t dex_pc); 220 221 void VisitRoots(RootCallback* callback, void* arg) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 222 223 // Accessors used by the compiler via CompilerCallback 224 const DexFile::CodeItem* CodeItem() const; 225 RegisterLine* GetRegLine(uint32_t dex_pc); 226 const InstructionFlags& GetInstructionFlags(size_t index) const; 227 mirror::ClassLoader* GetClassLoader() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 228 mirror::DexCache* GetDexCache() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 229 MethodReference GetMethodReference() const; 230 uint32_t GetAccessFlags() const; 231 bool HasCheckCasts() const; 232 bool HasVirtualOrInterfaceInvokes() const; 233 bool HasFailures() const; 234 RegType& ResolveCheckedClass(uint32_t class_idx) 235 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 236 237 private: 238 // Adds the given string to the beginning of the last failure message. 239 void PrependToLastFailMessage(std::string); 240 241 // Adds the given string to the end of the last failure message. 242 void AppendToLastFailMessage(std::string); 243 244 /* 245 * Perform verification on a single method. 246 * 247 * We do this in three passes: 248 * (1) Walk through all code units, determining instruction locations, 249 * widths, and other characteristics. 250 * (2) Walk through all code units, performing static checks on 251 * operands. 252 * (3) Iterate through the method, checking type safety and looking 253 * for code flow problems. 254 */ 255 static FailureKind VerifyMethod(uint32_t method_idx, const DexFile* dex_file, 256 Handle<mirror::DexCache> dex_cache, 257 Handle<mirror::ClassLoader> class_loader, 258 const DexFile::ClassDef* class_def_idx, 259 const DexFile::CodeItem* code_item, 260 Handle<mirror::ArtMethod> method, uint32_t method_access_flags, 261 bool allow_soft_failures, bool need_precise_constants) 262 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 263 264 void FindLocksAtDexPc() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 265 266 mirror::ArtField* FindAccessedFieldAtDexPc(uint32_t dex_pc) 267 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 268 269 mirror::ArtMethod* FindInvokedMethodAtDexPc(uint32_t dex_pc) 270 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 271 272 /* 273 * Compute the width of the instruction at each address in the instruction stream, and store it in 274 * insn_flags_. Addresses that are in the middle of an instruction, or that are part of switch 275 * table data, are not touched (so the caller should probably initialize "insn_flags" to zero). 276 * 277 * The "new_instance_count_" and "monitor_enter_count_" fields in vdata are also set. 278 * 279 * Performs some static checks, notably: 280 * - opcode of first instruction begins at index 0 281 * - only documented instructions may appear 282 * - each instruction follows the last 283 * - last byte of last instruction is at (code_length-1) 284 * 285 * Logs an error and returns "false" on failure. 286 */ 287 bool ComputeWidthsAndCountOps(); 288 289 /* 290 * Set the "in try" flags for all instructions protected by "try" statements. Also sets the 291 * "branch target" flags for exception handlers. 292 * 293 * Call this after widths have been set in "insn_flags". 294 * 295 * Returns "false" if something in the exception table looks fishy, but we're expecting the 296 * exception table to be somewhat sane. 297 */ 298 bool ScanTryCatchBlocks() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 299 300 /* 301 * Perform static verification on all instructions in a method. 302 * 303 * Walks through instructions in a method calling VerifyInstruction on each. 304 */ 305 bool VerifyInstructions(); 306 307 /* 308 * Perform static verification on an instruction. 309 * 310 * As a side effect, this sets the "branch target" flags in InsnFlags. 311 * 312 * "(CF)" items are handled during code-flow analysis. 313 * 314 * v3 4.10.1 315 * - target of each jump and branch instruction must be valid 316 * - targets of switch statements must be valid 317 * - operands referencing constant pool entries must be valid 318 * - (CF) operands of getfield, putfield, getstatic, putstatic must be valid 319 * - (CF) operands of method invocation instructions must be valid 320 * - (CF) only invoke-direct can call a method starting with '<' 321 * - (CF) <clinit> must never be called explicitly 322 * - operands of instanceof, checkcast, new (and variants) must be valid 323 * - new-array[-type] limited to 255 dimensions 324 * - can't use "new" on an array class 325 * - (?) limit dimensions in multi-array creation 326 * - local variable load/store register values must be in valid range 327 * 328 * v3 4.11.1.2 329 * - branches must be within the bounds of the code array 330 * - targets of all control-flow instructions are the start of an instruction 331 * - register accesses fall within range of allocated registers 332 * - (N/A) access to constant pool must be of appropriate type 333 * - code does not end in the middle of an instruction 334 * - execution cannot fall off the end of the code 335 * - (earlier) for each exception handler, the "try" area must begin and 336 * end at the start of an instruction (end can be at the end of the code) 337 * - (earlier) for each exception handler, the handler must start at a valid 338 * instruction 339 */ 340 bool VerifyInstruction(const Instruction* inst, uint32_t code_offset); 341 342 /* Ensure that the register index is valid for this code item. */ 343 bool CheckRegisterIndex(uint32_t idx); 344 345 /* Ensure that the wide register index is valid for this code item. */ 346 bool CheckWideRegisterIndex(uint32_t idx); 347 348 // Perform static checks on a field Get or set instruction. All we do here is ensure that the 349 // field index is in the valid range. 350 bool CheckFieldIndex(uint32_t idx); 351 352 // Perform static checks on a method invocation instruction. All we do here is ensure that the 353 // method index is in the valid range. 354 bool CheckMethodIndex(uint32_t idx); 355 356 // Perform static checks on a "new-instance" instruction. Specifically, make sure the class 357 // reference isn't for an array class. 358 bool CheckNewInstance(uint32_t idx); 359 360 /* Ensure that the string index is in the valid range. */ 361 bool CheckStringIndex(uint32_t idx); 362 363 // Perform static checks on an instruction that takes a class constant. Ensure that the class 364 // index is in the valid range. 365 bool CheckTypeIndex(uint32_t idx); 366 367 // Perform static checks on a "new-array" instruction. Specifically, make sure they aren't 368 // creating an array of arrays that causes the number of dimensions to exceed 255. 369 bool CheckNewArray(uint32_t idx); 370 371 // Verify an array data table. "cur_offset" is the offset of the fill-array-data instruction. 372 bool CheckArrayData(uint32_t cur_offset); 373 374 // Verify that the target of a branch instruction is valid. We don't expect code to jump directly 375 // into an exception handler, but it's valid to do so as long as the target isn't a 376 // "move-exception" instruction. We verify that in a later stage. 377 // The dex format forbids certain instructions from branching to themselves. 378 // Updates "insn_flags_", setting the "branch target" flag. 379 bool CheckBranchTarget(uint32_t cur_offset); 380 381 // Verify a switch table. "cur_offset" is the offset of the switch instruction. 382 // Updates "insn_flags_", setting the "branch target" flag. 383 bool CheckSwitchTargets(uint32_t cur_offset); 384 385 // Check the register indices used in a "vararg" instruction, such as invoke-virtual or 386 // filled-new-array. 387 // - vA holds word count (0-5), args[] have values. 388 // There are some tests we don't do here, e.g. we don't try to verify that invoking a method that 389 // takes a double is done with consecutive registers. This requires parsing the target method 390 // signature, which we will be doing later on during the code flow analysis. 391 bool CheckVarArgRegs(uint32_t vA, uint32_t arg[]); 392 393 // Check the register indices used in a "vararg/range" instruction, such as invoke-virtual/range 394 // or filled-new-array/range. 395 // - vA holds word count, vC holds index of first reg. 396 bool CheckVarArgRangeRegs(uint32_t vA, uint32_t vC); 397 398 // Extract the relative offset from a branch instruction. 399 // Returns "false" on failure (e.g. this isn't a branch instruction). 400 bool GetBranchOffset(uint32_t cur_offset, int32_t* pOffset, bool* pConditional, 401 bool* selfOkay); 402 403 /* Perform detailed code-flow analysis on a single method. */ 404 bool VerifyCodeFlow() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 405 406 // Set the register types for the first instruction in the method based on the method signature. 407 // This has the side-effect of validating the signature. 408 bool SetTypesFromSignature() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 409 410 /* 411 * Perform code flow on a method. 412 * 413 * The basic strategy is as outlined in v3 4.11.1.2: set the "changed" bit on the first 414 * instruction, process it (setting additional "changed" bits), and repeat until there are no 415 * more. 416 * 417 * v3 4.11.1.1 418 * - (N/A) operand stack is always the same size 419 * - operand stack [registers] contain the correct types of values 420 * - local variables [registers] contain the correct types of values 421 * - methods are invoked with the appropriate arguments 422 * - fields are assigned using values of appropriate types 423 * - opcodes have the correct type values in operand registers 424 * - there is never an uninitialized class instance in a local variable in code protected by an 425 * exception handler (operand stack is okay, because the operand stack is discarded when an 426 * exception is thrown) [can't know what's a local var w/o the debug info -- should fall out of 427 * register typing] 428 * 429 * v3 4.11.1.2 430 * - execution cannot fall off the end of the code 431 * 432 * (We also do many of the items described in the "static checks" sections, because it's easier to 433 * do them here.) 434 * 435 * We need an array of RegType values, one per register, for every instruction. If the method uses 436 * monitor-enter, we need extra data for every register, and a stack for every "interesting" 437 * instruction. In theory this could become quite large -- up to several megabytes for a monster 438 * function. 439 * 440 * NOTE: 441 * The spec forbids backward branches when there's an uninitialized reference in a register. The 442 * idea is to prevent something like this: 443 * loop: 444 * move r1, r0 445 * new-instance r0, MyClass 446 * ... 447 * if-eq rN, loop // once 448 * initialize r0 449 * 450 * This leaves us with two different instances, both allocated by the same instruction, but only 451 * one is initialized. The scheme outlined in v3 4.11.1.4 wouldn't catch this, so they work around 452 * it by preventing backward branches. We achieve identical results without restricting code 453 * reordering by specifying that you can't execute the new-instance instruction if a register 454 * contains an uninitialized instance created by that same instruction. 455 */ 456 bool CodeFlowVerifyMethod() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 457 458 /* 459 * Perform verification for a single instruction. 460 * 461 * This requires fully decoding the instruction to determine the effect it has on registers. 462 * 463 * Finds zero or more following instructions and sets the "changed" flag if execution at that 464 * point needs to be (re-)evaluated. Register changes are merged into "reg_types_" at the target 465 * addresses. Does not set or clear any other flags in "insn_flags_". 466 */ 467 bool CodeFlowVerifyInstruction(uint32_t* start_guess) 468 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 469 470 // Perform verification of a new array instruction 471 void VerifyNewArray(const Instruction* inst, bool is_filled, bool is_range) 472 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 473 474 // Helper to perform verification on puts of primitive type. 475 void VerifyPrimitivePut(RegType& target_type, RegType& insn_type, 476 const uint32_t vregA) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 477 478 // Perform verification of an aget instruction. The destination register's type will be set to 479 // be that of component type of the array unless the array type is unknown, in which case a 480 // bottom type inferred from the type of instruction is used. is_primitive is false for an 481 // aget-object. 482 void VerifyAGet(const Instruction* inst, RegType& insn_type, 483 bool is_primitive) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 484 485 // Perform verification of an aput instruction. 486 void VerifyAPut(const Instruction* inst, RegType& insn_type, 487 bool is_primitive) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 488 489 // Lookup instance field and fail for resolution violations 490 mirror::ArtField* GetInstanceField(RegType& obj_type, int field_idx) 491 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 492 493 // Lookup static field and fail for resolution violations 494 mirror::ArtField* GetStaticField(int field_idx) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 495 496 // Perform verification of an iget or sget instruction. 497 void VerifyISGet(const Instruction* inst, RegType& insn_type, 498 bool is_primitive, bool is_static) 499 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 500 501 // Perform verification of an iput or sput instruction. 502 void VerifyISPut(const Instruction* inst, RegType& insn_type, 503 bool is_primitive, bool is_static) 504 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 505 506 // Returns the access field of a quick field access (iget/iput-quick) or NULL 507 // if it cannot be found. 508 mirror::ArtField* GetQuickFieldAccess(const Instruction* inst, RegisterLine* reg_line) 509 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 510 511 // Perform verification of an iget-quick instruction. 512 void VerifyIGetQuick(const Instruction* inst, RegType& insn_type, 513 bool is_primitive) 514 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 515 516 // Perform verification of an iput-quick instruction. 517 void VerifyIPutQuick(const Instruction* inst, RegType& insn_type, 518 bool is_primitive) 519 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 520 521 // Resolves a class based on an index and performs access checks to ensure the referrer can 522 // access the resolved class. 523 RegType& ResolveClassAndCheckAccess(uint32_t class_idx) 524 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 525 526 /* 527 * For the "move-exception" instruction at "work_insn_idx_", which must be at an exception handler 528 * address, determine the Join of all exceptions that can land here. Fails if no matching 529 * exception handler can be found or if the Join of exception types fails. 530 */ 531 RegType& GetCaughtExceptionType() 532 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 533 534 /* 535 * Resolves a method based on an index and performs access checks to ensure 536 * the referrer can access the resolved method. 537 * Does not throw exceptions. 538 */ 539 mirror::ArtMethod* ResolveMethodAndCheckAccess(uint32_t method_idx, MethodType method_type) 540 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 541 542 /* 543 * Verify the arguments to a method. We're executing in "method", making 544 * a call to the method reference in vB. 545 * 546 * If this is a "direct" invoke, we allow calls to <init>. For calls to 547 * <init>, the first argument may be an uninitialized reference. Otherwise, 548 * calls to anything starting with '<' will be rejected, as will any 549 * uninitialized reference arguments. 550 * 551 * For non-static method calls, this will verify that the method call is 552 * appropriate for the "this" argument. 553 * 554 * The method reference is in vBBBB. The "is_range" parameter determines 555 * whether we use 0-4 "args" values or a range of registers defined by 556 * vAA and vCCCC. 557 * 558 * Widening conversions on integers and references are allowed, but 559 * narrowing conversions are not. 560 * 561 * Returns the resolved method on success, NULL on failure (with *failure 562 * set appropriately). 563 */ 564 mirror::ArtMethod* VerifyInvocationArgs(const Instruction* inst, 565 MethodType method_type, 566 bool is_range, bool is_super) 567 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 568 569 // Similar checks to the above, but on the proto. Will be used when the method cannot be 570 // resolved. 571 void VerifyInvocationArgsUnresolvedMethod(const Instruction* inst, MethodType method_type, 572 bool is_range) 573 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 574 575 template <class T> 576 mirror::ArtMethod* VerifyInvocationArgsFromIterator(T* it, const Instruction* inst, 577 MethodType method_type, bool is_range, 578 mirror::ArtMethod* res_method) 579 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 580 581 mirror::ArtMethod* GetQuickInvokedMethod(const Instruction* inst, 582 RegisterLine* reg_line, 583 bool is_range) 584 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 585 586 mirror::ArtMethod* VerifyInvokeVirtualQuickArgs(const Instruction* inst, bool is_range) 587 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 588 589 /* 590 * Verify that the target instruction is not "move-exception". It's important that the only way 591 * to execute a move-exception is as the first instruction of an exception handler. 592 * Returns "true" if all is well, "false" if the target instruction is move-exception. 593 */ 594 bool CheckNotMoveException(const uint16_t* insns, int insn_idx); 595 596 /* 597 * Control can transfer to "next_insn". Merge the registers from merge_line into the table at 598 * next_insn, and set the changed flag on the target address if any of the registers were changed. 599 * In the case of fall-through, update the merge line on a change as its the working line for the 600 * next instruction. 601 * Returns "false" if an error is encountered. 602 */ 603 bool UpdateRegisters(uint32_t next_insn, RegisterLine* merge_line, bool update_merge_line) 604 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 605 606 // Is the method being verified a constructor? 607 bool IsConstructor() const { 608 return (method_access_flags_ & kAccConstructor) != 0; 609 } 610 611 // Is the method verified static? 612 bool IsStatic() const { 613 return (method_access_flags_ & kAccStatic) != 0; 614 } 615 616 // Return the register type for the method. 617 RegType& GetMethodReturnType() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 618 619 // Get a type representing the declaring class of the method. 620 RegType& GetDeclaringClass() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 621 622 InstructionFlags* CurrentInsnFlags(); 623 624 RegType& DetermineCat1Constant(int32_t value, bool precise) 625 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 626 627 RegTypeCache reg_types_; 628 629 PcToRegisterLineTable reg_table_; 630 631 // Storage for the register status we're currently working on. 632 std::unique_ptr<RegisterLine> work_line_; 633 634 // The address of the instruction we're currently working on, note that this is in 2 byte 635 // quantities 636 uint32_t work_insn_idx_; 637 638 // Storage for the register status we're saving for later. 639 std::unique_ptr<RegisterLine> saved_line_; 640 641 const uint32_t dex_method_idx_; // The method we're working on. 642 // Its object representation if known. 643 Handle<mirror::ArtMethod> mirror_method_ GUARDED_BY(Locks::mutator_lock_); 644 const uint32_t method_access_flags_; // Method's access flags. 645 RegType* return_type_; // Lazily computed return type of the method. 646 const DexFile* const dex_file_; // The dex file containing the method. 647 // The dex_cache for the declaring class of the method. 648 Handle<mirror::DexCache>* dex_cache_ GUARDED_BY(Locks::mutator_lock_); 649 // The class loader for the declaring class of the method. 650 Handle<mirror::ClassLoader>* class_loader_ GUARDED_BY(Locks::mutator_lock_); 651 const DexFile::ClassDef* const class_def_; // The class def of the declaring class of the method. 652 const DexFile::CodeItem* const code_item_; // The code item containing the code for the method. 653 RegType* declaring_class_; // Lazily computed reg type of the method's declaring class. 654 // Instruction widths and flags, one entry per code unit. 655 std::unique_ptr<InstructionFlags[]> insn_flags_; 656 // The dex PC of a FindLocksAtDexPc request, -1 otherwise. 657 uint32_t interesting_dex_pc_; 658 // The container into which FindLocksAtDexPc should write the registers containing held locks, 659 // NULL if we're not doing FindLocksAtDexPc. 660 std::vector<uint32_t>* monitor_enter_dex_pcs_; 661 662 // The types of any error that occurs. 663 std::vector<VerifyError> failures_; 664 // Error messages associated with failures. 665 std::vector<std::ostringstream*> failure_messages_; 666 // Is there a pending hard failure? 667 bool have_pending_hard_failure_; 668 // Is there a pending runtime throw failure? A runtime throw failure is when an instruction 669 // would fail at runtime throwing an exception. Such an instruction causes the following code 670 // to be unreachable. This is set by Fail and used to ensure we don't process unreachable 671 // instructions that would hard fail the verification. 672 bool have_pending_runtime_throw_failure_; 673 674 // Info message log use primarily for verifier diagnostics. 675 std::ostringstream info_messages_; 676 677 // The number of occurrences of specific opcodes. 678 size_t new_instance_count_; 679 size_t monitor_enter_count_; 680 681 const bool can_load_classes_; 682 683 // Converts soft failures to hard failures when false. Only false when the compiler isn't 684 // running and the verifier is called from the class linker. 685 const bool allow_soft_failures_; 686 687 // An optimization where instead of generating unique RegTypes for constants we use imprecise 688 // constants that cover a range of constants. This isn't good enough for deoptimization that 689 // avoids loading from registers in the case of a constant as the dex instruction set lost the 690 // notion of whether a value should be in a floating point or general purpose register file. 691 const bool need_precise_constants_; 692 693 // Indicates the method being verified contains at least one check-cast or aput-object 694 // instruction. Aput-object operations implicitly check for array-store exceptions, similar to 695 // check-cast. 696 bool has_check_casts_; 697 698 // Indicates the method being verified contains at least one invoke-virtual/range 699 // or invoke-interface/range. 700 bool has_virtual_or_interface_invokes_; 701}; 702std::ostream& operator<<(std::ostream& os, const MethodVerifier::FailureKind& rhs); 703 704} // namespace verifier 705} // namespace art 706 707#endif // ART_RUNTIME_VERIFIER_METHOD_VERIFIER_H_ 708