method_verifier.h revision 590fee9e8972f872301c2d16a575d579ee564bee
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 <set> 21#include <vector> 22 23#include "base/casts.h" 24#include "base/macros.h" 25#include "base/stl_util.h" 26#include "class_reference.h" 27#include "dex_file.h" 28#include "dex_instruction.h" 29#include "instruction_flags.h" 30#include "method_reference.h" 31#include "mirror/object.h" 32#include "reg_type.h" 33#include "reg_type_cache-inl.h" 34#include "register_line.h" 35#include "safe_map.h" 36#include "sirt_ref.h" 37#include "UniquePtr.h" 38 39namespace art { 40 41struct ReferenceMap2Visitor; 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 UniquePtr<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(const mirror::Class* klass, bool allow_soft_failures, 144 std::string* error) 145 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 146 static FailureKind VerifyClass(const DexFile* dex_file, SirtRef<mirror::DexCache>& dex_cache, 147 SirtRef<mirror::ClassLoader>& class_loader, 148 const DexFile::ClassDef* class_def, 149 bool allow_soft_failures, std::string* error) 150 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 151 152 static void VerifyMethodAndDump(std::ostream& os, uint32_t method_idx, const DexFile* dex_file, 153 SirtRef<mirror::DexCache>& dex_cache, 154 SirtRef<mirror::ClassLoader>& class_loader, 155 const DexFile::ClassDef* class_def, 156 const DexFile::CodeItem* code_item, 157 mirror::ArtMethod* method, uint32_t method_access_flags) 158 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 159 160 uint8_t EncodePcToReferenceMapData() const; 161 162 uint32_t DexFileVersion() const { 163 return dex_file_->GetVersion(); 164 } 165 166 RegTypeCache* GetRegTypeCache() { 167 return ®_types_; 168 } 169 170 // Log a verification failure. 171 std::ostream& Fail(VerifyError error); 172 173 // Log for verification information. 174 std::ostream& LogVerifyInfo() { 175 return info_messages_ << "VFY: " << PrettyMethod(dex_method_idx_, *dex_file_) 176 << '[' << reinterpret_cast<void*>(work_insn_idx_) << "] : "; 177 } 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 static const std::vector<uint8_t>* GetDexGcMap(MethodReference ref) 187 LOCKS_EXCLUDED(dex_gc_maps_lock_); 188 189 static const MethodReference* GetDevirtMap(const MethodReference& ref, uint32_t dex_pc) 190 LOCKS_EXCLUDED(devirt_maps_lock_); 191 192 // Returns true if the cast can statically be verified to be redundant 193 // by using the check-cast elision peephole optimization in the verifier 194 static bool IsSafeCast(MethodReference ref, uint32_t pc) LOCKS_EXCLUDED(safecast_map_lock_); 195 196 // Fills 'monitor_enter_dex_pcs' with the dex pcs of the monitor-enter instructions corresponding 197 // to the locks held at 'dex_pc' in method 'm'. 198 static void FindLocksAtDexPc(mirror::ArtMethod* m, uint32_t dex_pc, 199 std::vector<uint32_t>& monitor_enter_dex_pcs) 200 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 201 202 // Returns the accessed field corresponding to the quick instruction's field 203 // offset at 'dex_pc' in method 'm'. 204 static mirror::ArtField* FindAccessedFieldAtDexPc(mirror::ArtMethod* m, uint32_t dex_pc) 205 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 206 207 // Returns the invoked method corresponding to the quick instruction's vtable 208 // index at 'dex_pc' in method 'm'. 209 static mirror::ArtMethod* FindInvokedMethodAtDexPc(mirror::ArtMethod* m, uint32_t dex_pc) 210 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 211 212 static void Init() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 213 static void Shutdown(); 214 215 static bool IsClassRejected(ClassReference ref) 216 LOCKS_EXCLUDED(rejected_classes_lock_); 217 218 bool CanLoadClasses() const { 219 return can_load_classes_; 220 } 221 222 MethodVerifier(const DexFile* dex_file, SirtRef<mirror::DexCache>* dex_cache, 223 SirtRef<mirror::ClassLoader>* class_loader, const DexFile::ClassDef* class_def, 224 const DexFile::CodeItem* code_item, uint32_t method_idx, mirror::ArtMethod* method, 225 uint32_t access_flags, bool can_load_classes, bool allow_soft_failures) 226 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 227 228 ~MethodVerifier(); 229 230 // Run verification on the method. Returns true if verification completes and false if the input 231 // has an irrecoverable corruption. 232 bool Verify() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 233 234 // Describe VRegs at the given dex pc. 235 std::vector<int32_t> DescribeVRegs(uint32_t dex_pc); 236 237 static bool IsCandidateForCompilation(MethodReference& method_ref, 238 const uint32_t access_flags); 239 240 private: 241 // Adds the given string to the beginning of the last failure message. 242 void PrependToLastFailMessage(std::string); 243 244 // Adds the given string to the end of the last failure message. 245 void AppendToLastFailMessage(std::string); 246 247 /* 248 * Perform verification on a single method. 249 * 250 * We do this in three passes: 251 * (1) Walk through all code units, determining instruction locations, 252 * widths, and other characteristics. 253 * (2) Walk through all code units, performing static checks on 254 * operands. 255 * (3) Iterate through the method, checking type safety and looking 256 * for code flow problems. 257 */ 258 static FailureKind VerifyMethod(uint32_t method_idx, const DexFile* dex_file, 259 SirtRef<mirror::DexCache>& dex_cache, 260 SirtRef<mirror::ClassLoader>& class_loader, 261 const DexFile::ClassDef* class_def_idx, 262 const DexFile::CodeItem* code_item, 263 mirror::ArtMethod* method, uint32_t method_access_flags, 264 bool allow_soft_failures) 265 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 266 267 void FindLocksAtDexPc() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 268 269 mirror::ArtField* FindAccessedFieldAtDexPc(uint32_t dex_pc) 270 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 271 272 mirror::ArtMethod* FindInvokedMethodAtDexPc(uint32_t dex_pc) 273 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 274 275 /* 276 * Compute the width of the instruction at each address in the instruction stream, and store it in 277 * insn_flags_. Addresses that are in the middle of an instruction, or that are part of switch 278 * table data, are not touched (so the caller should probably initialize "insn_flags" to zero). 279 * 280 * The "new_instance_count_" and "monitor_enter_count_" fields in vdata are also set. 281 * 282 * Performs some static checks, notably: 283 * - opcode of first instruction begins at index 0 284 * - only documented instructions may appear 285 * - each instruction follows the last 286 * - last byte of last instruction is at (code_length-1) 287 * 288 * Logs an error and returns "false" on failure. 289 */ 290 bool ComputeWidthsAndCountOps(); 291 292 /* 293 * Set the "in try" flags for all instructions protected by "try" statements. Also sets the 294 * "branch target" flags for exception handlers. 295 * 296 * Call this after widths have been set in "insn_flags". 297 * 298 * Returns "false" if something in the exception table looks fishy, but we're expecting the 299 * exception table to be somewhat sane. 300 */ 301 bool ScanTryCatchBlocks() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 302 303 /* 304 * Perform static verification on all instructions in a method. 305 * 306 * Walks through instructions in a method calling VerifyInstruction on each. 307 */ 308 bool VerifyInstructions(); 309 310 /* 311 * Perform static verification on an instruction. 312 * 313 * As a side effect, this sets the "branch target" flags in InsnFlags. 314 * 315 * "(CF)" items are handled during code-flow analysis. 316 * 317 * v3 4.10.1 318 * - target of each jump and branch instruction must be valid 319 * - targets of switch statements must be valid 320 * - operands referencing constant pool entries must be valid 321 * - (CF) operands of getfield, putfield, getstatic, putstatic must be valid 322 * - (CF) operands of method invocation instructions must be valid 323 * - (CF) only invoke-direct can call a method starting with '<' 324 * - (CF) <clinit> must never be called explicitly 325 * - operands of instanceof, checkcast, new (and variants) must be valid 326 * - new-array[-type] limited to 255 dimensions 327 * - can't use "new" on an array class 328 * - (?) limit dimensions in multi-array creation 329 * - local variable load/store register values must be in valid range 330 * 331 * v3 4.11.1.2 332 * - branches must be within the bounds of the code array 333 * - targets of all control-flow instructions are the start of an instruction 334 * - register accesses fall within range of allocated registers 335 * - (N/A) access to constant pool must be of appropriate type 336 * - code does not end in the middle of an instruction 337 * - execution cannot fall off the end of the code 338 * - (earlier) for each exception handler, the "try" area must begin and 339 * end at the start of an instruction (end can be at the end of the code) 340 * - (earlier) for each exception handler, the handler must start at a valid 341 * instruction 342 */ 343 bool VerifyInstruction(const Instruction* inst, uint32_t code_offset); 344 345 /* Ensure that the register index is valid for this code item. */ 346 bool CheckRegisterIndex(uint32_t idx); 347 348 /* Ensure that the wide register index is valid for this code item. */ 349 bool CheckWideRegisterIndex(uint32_t idx); 350 351 // Perform static checks on a field get or set instruction. All we do here is ensure that the 352 // field index is in the valid range. 353 bool CheckFieldIndex(uint32_t idx); 354 355 // Perform static checks on a method invocation instruction. All we do here is ensure that the 356 // method index is in the valid range. 357 bool CheckMethodIndex(uint32_t idx); 358 359 // Perform static checks on a "new-instance" instruction. Specifically, make sure the class 360 // reference isn't for an array class. 361 bool CheckNewInstance(uint32_t idx); 362 363 /* Ensure that the string index is in the valid range. */ 364 bool CheckStringIndex(uint32_t idx); 365 366 // Perform static checks on an instruction that takes a class constant. Ensure that the class 367 // index is in the valid range. 368 bool CheckTypeIndex(uint32_t idx); 369 370 // Perform static checks on a "new-array" instruction. Specifically, make sure they aren't 371 // creating an array of arrays that causes the number of dimensions to exceed 255. 372 bool CheckNewArray(uint32_t idx); 373 374 // Verify an array data table. "cur_offset" is the offset of the fill-array-data instruction. 375 bool CheckArrayData(uint32_t cur_offset); 376 377 // Verify that the target of a branch instruction is valid. We don't expect code to jump directly 378 // into an exception handler, but it's valid to do so as long as the target isn't a 379 // "move-exception" instruction. We verify that in a later stage. 380 // The dex format forbids certain instructions from branching to themselves. 381 // Updates "insn_flags_", setting the "branch target" flag. 382 bool CheckBranchTarget(uint32_t cur_offset); 383 384 // Verify a switch table. "cur_offset" is the offset of the switch instruction. 385 // Updates "insn_flags_", setting the "branch target" flag. 386 bool CheckSwitchTargets(uint32_t cur_offset); 387 388 // Check the register indices used in a "vararg" instruction, such as invoke-virtual or 389 // filled-new-array. 390 // - vA holds word count (0-5), args[] have values. 391 // There are some tests we don't do here, e.g. we don't try to verify that invoking a method that 392 // takes a double is done with consecutive registers. This requires parsing the target method 393 // signature, which we will be doing later on during the code flow analysis. 394 bool CheckVarArgRegs(uint32_t vA, uint32_t arg[]); 395 396 // Check the register indices used in a "vararg/range" instruction, such as invoke-virtual/range 397 // or filled-new-array/range. 398 // - vA holds word count, vC holds index of first reg. 399 bool CheckVarArgRangeRegs(uint32_t vA, uint32_t vC); 400 401 // Extract the relative offset from a branch instruction. 402 // Returns "false" on failure (e.g. this isn't a branch instruction). 403 bool GetBranchOffset(uint32_t cur_offset, int32_t* pOffset, bool* pConditional, 404 bool* selfOkay); 405 406 /* Perform detailed code-flow analysis on a single method. */ 407 bool VerifyCodeFlow() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 408 409 // Set the register types for the first instruction in the method based on the method signature. 410 // This has the side-effect of validating the signature. 411 bool SetTypesFromSignature() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 412 413 /* 414 * Perform code flow on a method. 415 * 416 * The basic strategy is as outlined in v3 4.11.1.2: set the "changed" bit on the first 417 * instruction, process it (setting additional "changed" bits), and repeat until there are no 418 * more. 419 * 420 * v3 4.11.1.1 421 * - (N/A) operand stack is always the same size 422 * - operand stack [registers] contain the correct types of values 423 * - local variables [registers] contain the correct types of values 424 * - methods are invoked with the appropriate arguments 425 * - fields are assigned using values of appropriate types 426 * - opcodes have the correct type values in operand registers 427 * - there is never an uninitialized class instance in a local variable in code protected by an 428 * exception handler (operand stack is okay, because the operand stack is discarded when an 429 * exception is thrown) [can't know what's a local var w/o the debug info -- should fall out of 430 * register typing] 431 * 432 * v3 4.11.1.2 433 * - execution cannot fall off the end of the code 434 * 435 * (We also do many of the items described in the "static checks" sections, because it's easier to 436 * do them here.) 437 * 438 * We need an array of RegType values, one per register, for every instruction. If the method uses 439 * monitor-enter, we need extra data for every register, and a stack for every "interesting" 440 * instruction. In theory this could become quite large -- up to several megabytes for a monster 441 * function. 442 * 443 * NOTE: 444 * The spec forbids backward branches when there's an uninitialized reference in a register. The 445 * idea is to prevent something like this: 446 * loop: 447 * move r1, r0 448 * new-instance r0, MyClass 449 * ... 450 * if-eq rN, loop // once 451 * initialize r0 452 * 453 * This leaves us with two different instances, both allocated by the same instruction, but only 454 * one is initialized. The scheme outlined in v3 4.11.1.4 wouldn't catch this, so they work around 455 * it by preventing backward branches. We achieve identical results without restricting code 456 * reordering by specifying that you can't execute the new-instance instruction if a register 457 * contains an uninitialized instance created by that same instruction. 458 */ 459 bool CodeFlowVerifyMethod() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 460 461 /* 462 * Perform verification for a single instruction. 463 * 464 * This requires fully decoding the instruction to determine the effect it has on registers. 465 * 466 * Finds zero or more following instructions and sets the "changed" flag if execution at that 467 * point needs to be (re-)evaluated. Register changes are merged into "reg_types_" at the target 468 * addresses. Does not set or clear any other flags in "insn_flags_". 469 */ 470 bool CodeFlowVerifyInstruction(uint32_t* start_guess) 471 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 472 473 // Perform verification of a new array instruction 474 void VerifyNewArray(const Instruction* inst, bool is_filled, bool is_range) 475 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 476 477 // Helper to perform verification on puts of primitive type. 478 void VerifyPrimitivePut(const RegType& target_type, const RegType& insn_type, 479 const uint32_t vregA) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 480 481 // Perform verification of an aget instruction. The destination register's type will be set to 482 // be that of component type of the array unless the array type is unknown, in which case a 483 // bottom type inferred from the type of instruction is used. is_primitive is false for an 484 // aget-object. 485 void VerifyAGet(const Instruction* inst, const RegType& insn_type, 486 bool is_primitive) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 487 488 // Perform verification of an aput instruction. 489 void VerifyAPut(const Instruction* inst, const RegType& insn_type, 490 bool is_primitive) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 491 492 // Lookup instance field and fail for resolution violations 493 mirror::ArtField* GetInstanceField(const RegType& obj_type, int field_idx) 494 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 495 496 // Lookup static field and fail for resolution violations 497 mirror::ArtField* GetStaticField(int field_idx) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 498 499 // Perform verification of an iget or sget instruction. 500 void VerifyISGet(const Instruction* inst, const RegType& insn_type, 501 bool is_primitive, bool is_static) 502 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 503 504 // Perform verification of an iput or sput instruction. 505 void VerifyISPut(const Instruction* inst, const RegType& insn_type, 506 bool is_primitive, bool is_static) 507 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 508 509 // Returns the access field of a quick field access (iget/iput-quick) or NULL 510 // if it cannot be found. 511 mirror::ArtField* GetQuickFieldAccess(const Instruction* inst, RegisterLine* reg_line) 512 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 513 514 // Perform verification of an iget-quick instruction. 515 void VerifyIGetQuick(const Instruction* inst, const RegType& insn_type, 516 bool is_primitive) 517 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 518 519 // Perform verification of an iput-quick instruction. 520 void VerifyIPutQuick(const Instruction* inst, const RegType& insn_type, 521 bool is_primitive) 522 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 523 524 // Resolves a class based on an index and performs access checks to ensure the referrer can 525 // access the resolved class. 526 const RegType& ResolveClassAndCheckAccess(uint32_t class_idx) 527 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 528 529 /* 530 * For the "move-exception" instruction at "work_insn_idx_", which must be at an exception handler 531 * address, determine the Join of all exceptions that can land here. Fails if no matching 532 * exception handler can be found or if the Join of exception types fails. 533 */ 534 const RegType& GetCaughtExceptionType() 535 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 536 537 /* 538 * Resolves a method based on an index and performs access checks to ensure 539 * the referrer can access the resolved method. 540 * Does not throw exceptions. 541 */ 542 mirror::ArtMethod* ResolveMethodAndCheckAccess(uint32_t method_idx, MethodType method_type) 543 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 544 545 /* 546 * Verify the arguments to a method. We're executing in "method", making 547 * a call to the method reference in vB. 548 * 549 * If this is a "direct" invoke, we allow calls to <init>. For calls to 550 * <init>, the first argument may be an uninitialized reference. Otherwise, 551 * calls to anything starting with '<' will be rejected, as will any 552 * uninitialized reference arguments. 553 * 554 * For non-static method calls, this will verify that the method call is 555 * appropriate for the "this" argument. 556 * 557 * The method reference is in vBBBB. The "is_range" parameter determines 558 * whether we use 0-4 "args" values or a range of registers defined by 559 * vAA and vCCCC. 560 * 561 * Widening conversions on integers and references are allowed, but 562 * narrowing conversions are not. 563 * 564 * Returns the resolved method on success, NULL on failure (with *failure 565 * set appropriately). 566 */ 567 mirror::ArtMethod* VerifyInvocationArgs(const Instruction* inst, 568 MethodType method_type, 569 bool is_range, bool is_super) 570 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 571 572 mirror::ArtMethod* GetQuickInvokedMethod(const Instruction* inst, 573 RegisterLine* reg_line, 574 bool is_range) 575 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 576 577 mirror::ArtMethod* VerifyInvokeVirtualQuickArgs(const Instruction* inst, bool is_range) 578 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 579 580 /* 581 * Verify that the target instruction is not "move-exception". It's important that the only way 582 * to execute a move-exception is as the first instruction of an exception handler. 583 * Returns "true" if all is well, "false" if the target instruction is move-exception. 584 */ 585 bool CheckNotMoveException(const uint16_t* insns, int insn_idx); 586 587 /* 588 * Control can transfer to "next_insn". Merge the registers from merge_line into the table at 589 * next_insn, and set the changed flag on the target address if any of the registers were changed. 590 * Returns "false" if an error is encountered. 591 */ 592 bool UpdateRegisters(uint32_t next_insn, const RegisterLine* merge_line) 593 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 594 595 // Is the method being verified a constructor? 596 bool IsConstructor() const { 597 return (method_access_flags_ & kAccConstructor) != 0; 598 } 599 600 // Is the method verified static? 601 bool IsStatic() const { 602 return (method_access_flags_ & kAccStatic) != 0; 603 } 604 605 // Return the register type for the method. 606 const RegType& GetMethodReturnType() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 607 608 // Get a type representing the declaring class of the method. 609 const RegType& GetDeclaringClass() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 610 611 /* 612 * Generate the GC map for a method that has just been verified (i.e. we're doing this as part of 613 * verification). For type-precise determination we have all the data we need, so we just need to 614 * encode it in some clever fashion. 615 * Returns a pointer to a newly-allocated RegisterMap, or NULL on failure. 616 */ 617 const std::vector<uint8_t>* GenerateGcMap(); 618 619 // Verify that the GC map associated with method_ is well formed 620 void VerifyGcMap(const std::vector<uint8_t>& data); 621 622 // Compute sizes for GC map data 623 void ComputeGcMapSizes(size_t* gc_points, size_t* ref_bitmap_bits, size_t* log2_max_gc_pc); 624 625 InstructionFlags* CurrentInsnFlags(); 626 627 // All the GC maps that the verifier has created 628 typedef SafeMap<const MethodReference, const std::vector<uint8_t>*, 629 MethodReferenceComparator> DexGcMapTable; 630 static ReaderWriterMutex* dex_gc_maps_lock_ DEFAULT_MUTEX_ACQUIRED_AFTER; 631 static DexGcMapTable* dex_gc_maps_ GUARDED_BY(dex_gc_maps_lock_); 632 static void SetDexGcMap(MethodReference ref, const std::vector<uint8_t>& dex_gc_map) 633 LOCKS_EXCLUDED(dex_gc_maps_lock_); 634 635 636 // Cast elision types. 637 typedef std::set<uint32_t> MethodSafeCastSet; 638 typedef SafeMap<const MethodReference, const MethodSafeCastSet*, 639 MethodReferenceComparator> SafeCastMap; 640 MethodVerifier::MethodSafeCastSet* GenerateSafeCastSet() 641 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 642 static void SetSafeCastMap(MethodReference ref, const MethodSafeCastSet* mscs); 643 LOCKS_EXCLUDED(safecast_map_lock_); 644 static ReaderWriterMutex* safecast_map_lock_ DEFAULT_MUTEX_ACQUIRED_AFTER; 645 static SafeCastMap* safecast_map_ GUARDED_BY(safecast_map_lock_); 646 647 // Devirtualization map. 648 typedef SafeMap<const uint32_t, MethodReference> PcToConcreteMethodMap; 649 typedef SafeMap<const MethodReference, const PcToConcreteMethodMap*, 650 MethodReferenceComparator> DevirtualizationMapTable; 651 MethodVerifier::PcToConcreteMethodMap* GenerateDevirtMap() 652 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 653 654 static ReaderWriterMutex* devirt_maps_lock_ DEFAULT_MUTEX_ACQUIRED_AFTER; 655 static DevirtualizationMapTable* devirt_maps_ GUARDED_BY(devirt_maps_lock_); 656 static void SetDevirtMap(MethodReference ref, 657 const PcToConcreteMethodMap* pc_method_map) 658 LOCKS_EXCLUDED(devirt_maps_lock_); 659 typedef std::set<ClassReference> RejectedClassesTable; 660 static ReaderWriterMutex* rejected_classes_lock_ DEFAULT_MUTEX_ACQUIRED_AFTER; 661 static RejectedClassesTable* rejected_classes_ GUARDED_BY(rejected_classes_lock_); 662 663 static void AddRejectedClass(ClassReference ref) 664 LOCKS_EXCLUDED(rejected_classes_lock_); 665 666 RegTypeCache reg_types_; 667 668 PcToRegisterLineTable reg_table_; 669 670 // Storage for the register status we're currently working on. 671 UniquePtr<RegisterLine> work_line_; 672 673 // The address of the instruction we're currently working on, note that this is in 2 byte 674 // quantities 675 uint32_t work_insn_idx_; 676 677 // Storage for the register status we're saving for later. 678 UniquePtr<RegisterLine> saved_line_; 679 680 const uint32_t dex_method_idx_; // The method we're working on. 681 // Its object representation if known. 682 mirror::ArtMethod* mirror_method_ GUARDED_BY(Locks::mutator_lock_); 683 const uint32_t method_access_flags_; // Method's access flags. 684 const RegType* return_type_; // Lazily computed return type of the method. 685 const DexFile* const dex_file_; // The dex file containing the method. 686 // The dex_cache for the declaring class of the method. 687 SirtRef<mirror::DexCache>* dex_cache_ GUARDED_BY(Locks::mutator_lock_); 688 // The class loader for the declaring class of the method. 689 SirtRef<mirror::ClassLoader>* class_loader_ GUARDED_BY(Locks::mutator_lock_); 690 const DexFile::ClassDef* const class_def_; // The class def of the declaring class of the method. 691 const DexFile::CodeItem* const code_item_; // The code item containing the code for the method. 692 const RegType* declaring_class_; // Lazily computed reg type of the method's declaring class. 693 // Instruction widths and flags, one entry per code unit. 694 UniquePtr<InstructionFlags[]> insn_flags_; 695 // The dex PC of a FindLocksAtDexPc request, -1 otherwise. 696 uint32_t interesting_dex_pc_; 697 // The container into which FindLocksAtDexPc should write the registers containing held locks, 698 // NULL if we're not doing FindLocksAtDexPc. 699 std::vector<uint32_t>* monitor_enter_dex_pcs_; 700 701 // The types of any error that occurs. 702 std::vector<VerifyError> failures_; 703 // Error messages associated with failures. 704 std::vector<std::ostringstream*> failure_messages_; 705 // Is there a pending hard failure? 706 bool have_pending_hard_failure_; 707 // Is there a pending runtime throw failure? A runtime throw failure is when an instruction 708 // would fail at runtime throwing an exception. Such an instruction causes the following code 709 // to be unreachable. This is set by Fail and used to ensure we don't process unreachable 710 // instructions that would hard fail the verification. 711 bool have_pending_runtime_throw_failure_; 712 713 // Info message log use primarily for verifier diagnostics. 714 std::ostringstream info_messages_; 715 716 // The number of occurrences of specific opcodes. 717 size_t new_instance_count_; 718 size_t monitor_enter_count_; 719 720 const bool can_load_classes_; 721 722 // Converts soft failures to hard failures when false. Only false when the compiler isn't 723 // running and the verifier is called from the class linker. 724 const bool allow_soft_failures_; 725 726 // Indicates the method being verified contains at least one check-cast or aput-object 727 // instruction. Aput-object operations implicitly check for array-store exceptions, similar to 728 // check-cast. 729 bool has_check_casts_; 730 731 // Indicates the method being verified contains at least one invoke-virtual/range 732 // or invoke-interface/range. 733 bool has_virtual_or_interface_invokes_; 734}; 735std::ostream& operator<<(std::ostream& os, const MethodVerifier::FailureKind& rhs); 736 737} // namespace verifier 738} // namespace art 739 740#endif // ART_RUNTIME_VERIFIER_METHOD_VERIFIER_H_ 741