1//===- FuzzerTracePC.cpp - PC tracing--------------------------------------===// 2// 3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4// See https://llvm.org/LICENSE.txt for license information. 5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6// 7//===----------------------------------------------------------------------===// 8// Trace PCs. 9// This module implements __sanitizer_cov_trace_pc_guard[_init], 10// the callback required for -fsanitize-coverage=trace-pc-guard instrumentation. 11// 12//===----------------------------------------------------------------------===// 13 14#include "FuzzerTracePC.h" 15#include "FuzzerBuiltins.h" 16#include "FuzzerBuiltinsMsvc.h" 17#include "FuzzerCorpus.h" 18#include "FuzzerDefs.h" 19#include "FuzzerDictionary.h" 20#include "FuzzerExtFunctions.h" 21#include "FuzzerIO.h" 22#include "FuzzerPlatform.h" 23#include "FuzzerUtil.h" 24#include "FuzzerValueBitMap.h" 25#include <set> 26 27// Used by -fsanitize-coverage=stack-depth to track stack depth 28ATTRIBUTES_INTERFACE_TLS_INITIAL_EXEC uintptr_t __sancov_lowest_stack; 29 30namespace fuzzer { 31 32TracePC TPC; 33 34size_t TracePC::GetTotalPCCoverage() { 35 return ObservedPCs.size(); 36} 37 38 39void TracePC::HandleInline8bitCountersInit(uint8_t *Start, uint8_t *Stop) { 40 if (Start == Stop) return; 41 if (NumModules && 42 Modules[NumModules - 1].Start() == Start) 43 return; 44 assert(NumModules < 45 sizeof(Modules) / sizeof(Modules[0])); 46 auto &M = Modules[NumModules++]; 47 uint8_t *AlignedStart = RoundUpByPage(Start); 48 uint8_t *AlignedStop = RoundDownByPage(Stop); 49 size_t NumFullPages = AlignedStop > AlignedStart ? 50 (AlignedStop - AlignedStart) / PageSize() : 0; 51 bool NeedFirst = Start < AlignedStart || !NumFullPages; 52 bool NeedLast = Stop > AlignedStop && AlignedStop >= AlignedStart; 53 M.NumRegions = NumFullPages + NeedFirst + NeedLast;; 54 assert(M.NumRegions > 0); 55 M.Regions = new Module::Region[M.NumRegions]; 56 assert(M.Regions); 57 size_t R = 0; 58 if (NeedFirst) 59 M.Regions[R++] = {Start, std::min(Stop, AlignedStart), true, false}; 60 for (uint8_t *P = AlignedStart; P < AlignedStop; P += PageSize()) 61 M.Regions[R++] = {P, P + PageSize(), true, true}; 62 if (NeedLast) 63 M.Regions[R++] = {AlignedStop, Stop, true, false}; 64 assert(R == M.NumRegions); 65 assert(M.Size() == (size_t)(Stop - Start)); 66 assert(M.Stop() == Stop); 67 assert(M.Start() == Start); 68 NumInline8bitCounters += M.Size(); 69} 70 71void TracePC::HandlePCsInit(const uintptr_t *Start, const uintptr_t *Stop) { 72 const PCTableEntry *B = reinterpret_cast<const PCTableEntry *>(Start); 73 const PCTableEntry *E = reinterpret_cast<const PCTableEntry *>(Stop); 74 if (NumPCTables && ModulePCTable[NumPCTables - 1].Start == B) return; 75 assert(NumPCTables < sizeof(ModulePCTable) / sizeof(ModulePCTable[0])); 76 ModulePCTable[NumPCTables++] = {B, E}; 77 NumPCsInPCTables += E - B; 78} 79 80void TracePC::PrintModuleInfo() { 81 if (NumModules) { 82 Printf("INFO: Loaded %zd modules (%zd inline 8-bit counters): ", 83 NumModules, NumInline8bitCounters); 84 for (size_t i = 0; i < NumModules; i++) 85 Printf("%zd [%p, %p), ", Modules[i].Size(), Modules[i].Start(), 86 Modules[i].Stop()); 87 Printf("\n"); 88 } 89 if (NumPCTables) { 90 Printf("INFO: Loaded %zd PC tables (%zd PCs): ", NumPCTables, 91 NumPCsInPCTables); 92 for (size_t i = 0; i < NumPCTables; i++) { 93 Printf("%zd [%p,%p), ", ModulePCTable[i].Stop - ModulePCTable[i].Start, 94 ModulePCTable[i].Start, ModulePCTable[i].Stop); 95 } 96 Printf("\n"); 97 98 if (NumInline8bitCounters && NumInline8bitCounters != NumPCsInPCTables) { 99 Printf("ERROR: The size of coverage PC tables does not match the\n" 100 "number of instrumented PCs. This might be a compiler bug,\n" 101 "please contact the libFuzzer developers.\n" 102 "Also check https://bugs.llvm.org/show_bug.cgi?id=34636\n" 103 "for possible workarounds (tl;dr: don't use the old GNU ld)\n"); 104 _Exit(1); 105 } 106 } 107 if (size_t NumExtraCounters = ExtraCountersEnd() - ExtraCountersBegin()) 108 Printf("INFO: %zd Extra Counters\n", NumExtraCounters); 109} 110 111ATTRIBUTE_NO_SANITIZE_ALL 112void TracePC::HandleCallerCallee(uintptr_t Caller, uintptr_t Callee) { 113 const uintptr_t kBits = 12; 114 const uintptr_t kMask = (1 << kBits) - 1; 115 uintptr_t Idx = (Caller & kMask) | ((Callee & kMask) << kBits); 116 ValueProfileMap.AddValueModPrime(Idx); 117} 118 119/// \return the address of the previous instruction. 120/// Note: the logic is copied from `sanitizer_common/sanitizer_stacktrace.h` 121inline ALWAYS_INLINE uintptr_t GetPreviousInstructionPc(uintptr_t PC) { 122#if defined(__arm__) 123 // T32 (Thumb) branch instructions might be 16 or 32 bit long, 124 // so we return (pc-2) in that case in order to be safe. 125 // For A32 mode we return (pc-4) because all instructions are 32 bit long. 126 return (PC - 3) & (~1); 127#elif defined(__powerpc__) || defined(__powerpc64__) || defined(__aarch64__) 128 // PCs are always 4 byte aligned. 129 return PC - 4; 130#elif defined(__sparc__) || defined(__mips__) 131 return PC - 8; 132#else 133 return PC - 1; 134#endif 135} 136 137/// \return the address of the next instruction. 138/// Note: the logic is copied from `sanitizer_common/sanitizer_stacktrace.cpp` 139ALWAYS_INLINE uintptr_t TracePC::GetNextInstructionPc(uintptr_t PC) { 140#if defined(__mips__) 141 return PC + 8; 142#elif defined(__powerpc__) || defined(__sparc__) || defined(__arm__) || \ 143 defined(__aarch64__) 144 return PC + 4; 145#else 146 return PC + 1; 147#endif 148} 149 150void TracePC::UpdateObservedPCs() { 151 Vector<uintptr_t> CoveredFuncs; 152 auto ObservePC = [&](const PCTableEntry *TE) { 153 if (ObservedPCs.insert(TE).second && DoPrintNewPCs) { 154 PrintPC("\tNEW_PC: %p %F %L", "\tNEW_PC: %p", 155 GetNextInstructionPc(TE->PC)); 156 Printf("\n"); 157 } 158 }; 159 160 auto Observe = [&](const PCTableEntry *TE) { 161 if (PcIsFuncEntry(TE)) 162 if (++ObservedFuncs[TE->PC] == 1 && NumPrintNewFuncs) 163 CoveredFuncs.push_back(TE->PC); 164 ObservePC(TE); 165 }; 166 167 if (NumPCsInPCTables) { 168 if (NumInline8bitCounters == NumPCsInPCTables) { 169 for (size_t i = 0; i < NumModules; i++) { 170 auto &M = Modules[i]; 171 assert(M.Size() == 172 (size_t)(ModulePCTable[i].Stop - ModulePCTable[i].Start)); 173 for (size_t r = 0; r < M.NumRegions; r++) { 174 auto &R = M.Regions[r]; 175 if (!R.Enabled) continue; 176 for (uint8_t *P = R.Start; P < R.Stop; P++) 177 if (*P) 178 Observe(&ModulePCTable[i].Start[M.Idx(P)]); 179 } 180 } 181 } 182 } 183 184 for (size_t i = 0, N = Min(CoveredFuncs.size(), NumPrintNewFuncs); i < N; 185 i++) { 186 Printf("\tNEW_FUNC[%zd/%zd]: ", i + 1, CoveredFuncs.size()); 187 PrintPC("%p %F %L", "%p", GetNextInstructionPc(CoveredFuncs[i])); 188 Printf("\n"); 189 } 190} 191 192uintptr_t TracePC::PCTableEntryIdx(const PCTableEntry *TE) { 193 size_t TotalTEs = 0; 194 for (size_t i = 0; i < NumPCTables; i++) { 195 auto &M = ModulePCTable[i]; 196 if (TE >= M.Start && TE < M.Stop) 197 return TotalTEs + TE - M.Start; 198 TotalTEs += M.Stop - M.Start; 199 } 200 assert(0); 201 return 0; 202} 203 204const TracePC::PCTableEntry *TracePC::PCTableEntryByIdx(uintptr_t Idx) { 205 for (size_t i = 0; i < NumPCTables; i++) { 206 auto &M = ModulePCTable[i]; 207 size_t Size = M.Stop - M.Start; 208 if (Idx < Size) return &M.Start[Idx]; 209 Idx -= Size; 210 } 211 return nullptr; 212} 213 214static std::string GetModuleName(uintptr_t PC) { 215 char ModulePathRaw[4096] = ""; // What's PATH_MAX in portable C++? 216 void *OffsetRaw = nullptr; 217 if (!EF->__sanitizer_get_module_and_offset_for_pc( 218 reinterpret_cast<void *>(PC), ModulePathRaw, 219 sizeof(ModulePathRaw), &OffsetRaw)) 220 return ""; 221 return ModulePathRaw; 222} 223 224template<class CallBack> 225void TracePC::IterateCoveredFunctions(CallBack CB) { 226 for (size_t i = 0; i < NumPCTables; i++) { 227 auto &M = ModulePCTable[i]; 228 assert(M.Start < M.Stop); 229 auto ModuleName = GetModuleName(M.Start->PC); 230 for (auto NextFE = M.Start; NextFE < M.Stop; ) { 231 auto FE = NextFE; 232 assert(PcIsFuncEntry(FE) && "Not a function entry point"); 233 do { 234 NextFE++; 235 } while (NextFE < M.Stop && !(PcIsFuncEntry(NextFE))); 236 CB(FE, NextFE, ObservedFuncs[FE->PC]); 237 } 238 } 239} 240 241void TracePC::SetFocusFunction(const std::string &FuncName) { 242 // This function should be called once. 243 assert(!FocusFunctionCounterPtr); 244 // "auto" is not a valid function name. If this function is called with "auto" 245 // that means the auto focus functionality failed. 246 if (FuncName.empty() || FuncName == "auto") 247 return; 248 for (size_t M = 0; M < NumModules; M++) { 249 auto &PCTE = ModulePCTable[M]; 250 size_t N = PCTE.Stop - PCTE.Start; 251 for (size_t I = 0; I < N; I++) { 252 if (!(PcIsFuncEntry(&PCTE.Start[I]))) continue; // not a function entry. 253 auto Name = DescribePC("%F", GetNextInstructionPc(PCTE.Start[I].PC)); 254 if (Name[0] == 'i' && Name[1] == 'n' && Name[2] == ' ') 255 Name = Name.substr(3, std::string::npos); 256 if (FuncName != Name) continue; 257 Printf("INFO: Focus function is set to '%s'\n", Name.c_str()); 258 FocusFunctionCounterPtr = Modules[M].Start() + I; 259 return; 260 } 261 } 262 263 Printf("ERROR: Failed to set focus function. Make sure the function name is " 264 "valid (%s) and symbolization is enabled.\n", FuncName.c_str()); 265 exit(1); 266} 267 268bool TracePC::ObservedFocusFunction() { 269 return FocusFunctionCounterPtr && *FocusFunctionCounterPtr; 270} 271 272void TracePC::PrintCoverage() { 273 if (!EF->__sanitizer_symbolize_pc || 274 !EF->__sanitizer_get_module_and_offset_for_pc) { 275 Printf("INFO: __sanitizer_symbolize_pc or " 276 "__sanitizer_get_module_and_offset_for_pc is not available," 277 " not printing coverage\n"); 278 return; 279 } 280 Printf("COVERAGE:\n"); 281 auto CoveredFunctionCallback = [&](const PCTableEntry *First, 282 const PCTableEntry *Last, 283 uintptr_t Counter) { 284 assert(First < Last); 285 auto VisualizePC = GetNextInstructionPc(First->PC); 286 std::string FileStr = DescribePC("%s", VisualizePC); 287 if (!IsInterestingCoverageFile(FileStr)) 288 return; 289 std::string FunctionStr = DescribePC("%F", VisualizePC); 290 if (FunctionStr.find("in ") == 0) 291 FunctionStr = FunctionStr.substr(3); 292 std::string LineStr = DescribePC("%l", VisualizePC); 293 size_t NumEdges = Last - First; 294 Vector<uintptr_t> UncoveredPCs; 295 for (auto TE = First; TE < Last; TE++) 296 if (!ObservedPCs.count(TE)) 297 UncoveredPCs.push_back(TE->PC); 298 Printf("%sCOVERED_FUNC: hits: %zd", Counter ? "" : "UN", Counter); 299 Printf(" edges: %zd/%zd", NumEdges - UncoveredPCs.size(), NumEdges); 300 Printf(" %s %s:%s\n", FunctionStr.c_str(), FileStr.c_str(), 301 LineStr.c_str()); 302 if (Counter) 303 for (auto PC : UncoveredPCs) 304 Printf(" UNCOVERED_PC: %s\n", 305 DescribePC("%s:%l", GetNextInstructionPc(PC)).c_str()); 306 }; 307 308 IterateCoveredFunctions(CoveredFunctionCallback); 309} 310 311// Value profile. 312// We keep track of various values that affect control flow. 313// These values are inserted into a bit-set-based hash map. 314// Every new bit in the map is treated as a new coverage. 315// 316// For memcmp/strcmp/etc the interesting value is the length of the common 317// prefix of the parameters. 318// For cmp instructions the interesting value is a XOR of the parameters. 319// The interesting value is mixed up with the PC and is then added to the map. 320 321ATTRIBUTE_NO_SANITIZE_ALL 322void TracePC::AddValueForMemcmp(void *caller_pc, const void *s1, const void *s2, 323 size_t n, bool StopAtZero) { 324 if (!n) return; 325 size_t Len = std::min(n, Word::GetMaxSize()); 326 const uint8_t *A1 = reinterpret_cast<const uint8_t *>(s1); 327 const uint8_t *A2 = reinterpret_cast<const uint8_t *>(s2); 328 uint8_t B1[Word::kMaxSize]; 329 uint8_t B2[Word::kMaxSize]; 330 // Copy the data into locals in this non-msan-instrumented function 331 // to avoid msan complaining further. 332 size_t Hash = 0; // Compute some simple hash of both strings. 333 for (size_t i = 0; i < Len; i++) { 334 B1[i] = A1[i]; 335 B2[i] = A2[i]; 336 size_t T = B1[i]; 337 Hash ^= (T << 8) | B2[i]; 338 } 339 size_t I = 0; 340 uint8_t HammingDistance = 0; 341 for (; I < Len; I++) { 342 if (B1[I] != B2[I] || (StopAtZero && B1[I] == 0)) { 343 HammingDistance = Popcountll(B1[I] ^ B2[I]); 344 break; 345 } 346 } 347 size_t PC = reinterpret_cast<size_t>(caller_pc); 348 size_t Idx = (PC & 4095) | (I << 12); 349 Idx += HammingDistance; 350 ValueProfileMap.AddValue(Idx); 351 TORCW.Insert(Idx ^ Hash, Word(B1, Len), Word(B2, Len)); 352} 353 354template <class T> 355ATTRIBUTE_TARGET_POPCNT ALWAYS_INLINE 356ATTRIBUTE_NO_SANITIZE_ALL 357void TracePC::HandleCmp(uintptr_t PC, T Arg1, T Arg2) { 358 uint64_t ArgXor = Arg1 ^ Arg2; 359 if (sizeof(T) == 4) 360 TORC4.Insert(ArgXor, Arg1, Arg2); 361 else if (sizeof(T) == 8) 362 TORC8.Insert(ArgXor, Arg1, Arg2); 363 uint64_t HammingDistance = Popcountll(ArgXor); // [0,64] 364 uint64_t AbsoluteDistance = (Arg1 == Arg2 ? 0 : Clzll(Arg1 - Arg2) + 1); 365 ValueProfileMap.AddValue(PC * 128 + HammingDistance); 366 ValueProfileMap.AddValue(PC * 128 + 64 + AbsoluteDistance); 367} 368 369static size_t InternalStrnlen(const char *S, size_t MaxLen) { 370 size_t Len = 0; 371 for (; Len < MaxLen && S[Len]; Len++) {} 372 return Len; 373} 374 375// Finds min of (strlen(S1), strlen(S2)). 376// Needed bacause one of these strings may actually be non-zero terminated. 377static size_t InternalStrnlen2(const char *S1, const char *S2) { 378 size_t Len = 0; 379 for (; S1[Len] && S2[Len]; Len++) {} 380 return Len; 381} 382 383void TracePC::ClearInlineCounters() { 384 IterateCounterRegions([](const Module::Region &R){ 385 if (R.Enabled) 386 memset(R.Start, 0, R.Stop - R.Start); 387 }); 388} 389 390ATTRIBUTE_NO_SANITIZE_ALL 391void TracePC::RecordInitialStack() { 392 int stack; 393 __sancov_lowest_stack = InitialStack = reinterpret_cast<uintptr_t>(&stack); 394} 395 396uintptr_t TracePC::GetMaxStackOffset() const { 397 return InitialStack - __sancov_lowest_stack; // Stack grows down 398} 399 400void WarnAboutDeprecatedInstrumentation(const char *flag) { 401 // Use RawPrint because Printf cannot be used on Windows before OutputFile is 402 // initialized. 403 RawPrint(flag); 404 RawPrint( 405 " is no longer supported by libFuzzer.\n" 406 "Please either migrate to a compiler that supports -fsanitize=fuzzer\n" 407 "or use an older version of libFuzzer\n"); 408 exit(1); 409} 410 411} // namespace fuzzer 412 413extern "C" { 414ATTRIBUTE_INTERFACE 415ATTRIBUTE_NO_SANITIZE_ALL 416void __sanitizer_cov_trace_pc_guard(uint32_t *Guard) { 417 fuzzer::WarnAboutDeprecatedInstrumentation( 418 "-fsanitize-coverage=trace-pc-guard"); 419} 420 421// Best-effort support for -fsanitize-coverage=trace-pc, which is available 422// in both Clang and GCC. 423ATTRIBUTE_INTERFACE 424ATTRIBUTE_NO_SANITIZE_ALL 425void __sanitizer_cov_trace_pc() { 426 fuzzer::WarnAboutDeprecatedInstrumentation("-fsanitize-coverage=trace-pc"); 427} 428 429ATTRIBUTE_INTERFACE 430void __sanitizer_cov_trace_pc_guard_init(uint32_t *Start, uint32_t *Stop) { 431 fuzzer::WarnAboutDeprecatedInstrumentation( 432 "-fsanitize-coverage=trace-pc-guard"); 433} 434 435ATTRIBUTE_INTERFACE 436void __sanitizer_cov_8bit_counters_init(uint8_t *Start, uint8_t *Stop) { 437 fuzzer::TPC.HandleInline8bitCountersInit(Start, Stop); 438} 439 440ATTRIBUTE_INTERFACE 441void __sanitizer_cov_pcs_init(const uintptr_t *pcs_beg, 442 const uintptr_t *pcs_end) { 443 fuzzer::TPC.HandlePCsInit(pcs_beg, pcs_end); 444} 445 446ATTRIBUTE_INTERFACE 447ATTRIBUTE_NO_SANITIZE_ALL 448void __sanitizer_cov_trace_pc_indir(uintptr_t Callee) { 449 uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC()); 450 fuzzer::TPC.HandleCallerCallee(PC, Callee); 451} 452 453ATTRIBUTE_INTERFACE 454ATTRIBUTE_NO_SANITIZE_ALL 455ATTRIBUTE_TARGET_POPCNT 456void __sanitizer_cov_trace_cmp8(uint64_t Arg1, uint64_t Arg2) { 457 uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC()); 458 fuzzer::TPC.HandleCmp(PC, Arg1, Arg2); 459} 460 461ATTRIBUTE_INTERFACE 462ATTRIBUTE_NO_SANITIZE_ALL 463ATTRIBUTE_TARGET_POPCNT 464// Now the __sanitizer_cov_trace_const_cmp[1248] callbacks just mimic 465// the behaviour of __sanitizer_cov_trace_cmp[1248] ones. This, however, 466// should be changed later to make full use of instrumentation. 467void __sanitizer_cov_trace_const_cmp8(uint64_t Arg1, uint64_t Arg2) { 468 uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC()); 469 fuzzer::TPC.HandleCmp(PC, Arg1, Arg2); 470} 471 472ATTRIBUTE_INTERFACE 473ATTRIBUTE_NO_SANITIZE_ALL 474ATTRIBUTE_TARGET_POPCNT 475void __sanitizer_cov_trace_cmp4(uint32_t Arg1, uint32_t Arg2) { 476 uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC()); 477 fuzzer::TPC.HandleCmp(PC, Arg1, Arg2); 478} 479 480ATTRIBUTE_INTERFACE 481ATTRIBUTE_NO_SANITIZE_ALL 482ATTRIBUTE_TARGET_POPCNT 483void __sanitizer_cov_trace_const_cmp4(uint32_t Arg1, uint32_t Arg2) { 484 uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC()); 485 fuzzer::TPC.HandleCmp(PC, Arg1, Arg2); 486} 487 488ATTRIBUTE_INTERFACE 489ATTRIBUTE_NO_SANITIZE_ALL 490ATTRIBUTE_TARGET_POPCNT 491void __sanitizer_cov_trace_cmp2(uint16_t Arg1, uint16_t Arg2) { 492 uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC()); 493 fuzzer::TPC.HandleCmp(PC, Arg1, Arg2); 494} 495 496ATTRIBUTE_INTERFACE 497ATTRIBUTE_NO_SANITIZE_ALL 498ATTRIBUTE_TARGET_POPCNT 499void __sanitizer_cov_trace_const_cmp2(uint16_t Arg1, uint16_t Arg2) { 500 uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC()); 501 fuzzer::TPC.HandleCmp(PC, Arg1, Arg2); 502} 503 504ATTRIBUTE_INTERFACE 505ATTRIBUTE_NO_SANITIZE_ALL 506ATTRIBUTE_TARGET_POPCNT 507void __sanitizer_cov_trace_cmp1(uint8_t Arg1, uint8_t Arg2) { 508 uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC()); 509 fuzzer::TPC.HandleCmp(PC, Arg1, Arg2); 510} 511 512ATTRIBUTE_INTERFACE 513ATTRIBUTE_NO_SANITIZE_ALL 514ATTRIBUTE_TARGET_POPCNT 515void __sanitizer_cov_trace_const_cmp1(uint8_t Arg1, uint8_t Arg2) { 516 uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC()); 517 fuzzer::TPC.HandleCmp(PC, Arg1, Arg2); 518} 519 520ATTRIBUTE_INTERFACE 521ATTRIBUTE_NO_SANITIZE_ALL 522ATTRIBUTE_TARGET_POPCNT 523void __sanitizer_cov_trace_switch(uint64_t Val, uint64_t *Cases) { 524 uint64_t N = Cases[0]; 525 uint64_t ValSizeInBits = Cases[1]; 526 uint64_t *Vals = Cases + 2; 527 // Skip the most common and the most boring case: all switch values are small. 528 // We may want to skip this at compile-time, but it will make the 529 // instrumentation less general. 530 if (Vals[N - 1] < 256) 531 return; 532 // Also skip small inputs values, they won't give good signal. 533 if (Val < 256) 534 return; 535 uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC()); 536 size_t i; 537 uint64_t Smaller = 0; 538 uint64_t Larger = ~(uint64_t)0; 539 // Find two switch values such that Smaller < Val < Larger. 540 // Use 0 and 0xfff..f as the defaults. 541 for (i = 0; i < N; i++) { 542 if (Val < Vals[i]) { 543 Larger = Vals[i]; 544 break; 545 } 546 if (Val > Vals[i]) Smaller = Vals[i]; 547 } 548 549 // Apply HandleCmp to {Val,Smaller} and {Val, Larger}, 550 // use i as the PC modifier for HandleCmp. 551 if (ValSizeInBits == 16) { 552 fuzzer::TPC.HandleCmp(PC + 2 * i, static_cast<uint16_t>(Val), 553 (uint16_t)(Smaller)); 554 fuzzer::TPC.HandleCmp(PC + 2 * i + 1, static_cast<uint16_t>(Val), 555 (uint16_t)(Larger)); 556 } else if (ValSizeInBits == 32) { 557 fuzzer::TPC.HandleCmp(PC + 2 * i, static_cast<uint32_t>(Val), 558 (uint32_t)(Smaller)); 559 fuzzer::TPC.HandleCmp(PC + 2 * i + 1, static_cast<uint32_t>(Val), 560 (uint32_t)(Larger)); 561 } else { 562 fuzzer::TPC.HandleCmp(PC + 2*i, Val, Smaller); 563 fuzzer::TPC.HandleCmp(PC + 2*i + 1, Val, Larger); 564 } 565} 566 567ATTRIBUTE_INTERFACE 568ATTRIBUTE_NO_SANITIZE_ALL 569ATTRIBUTE_TARGET_POPCNT 570void __sanitizer_cov_trace_div4(uint32_t Val) { 571 uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC()); 572 fuzzer::TPC.HandleCmp(PC, Val, (uint32_t)0); 573} 574 575ATTRIBUTE_INTERFACE 576ATTRIBUTE_NO_SANITIZE_ALL 577ATTRIBUTE_TARGET_POPCNT 578void __sanitizer_cov_trace_div8(uint64_t Val) { 579 uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC()); 580 fuzzer::TPC.HandleCmp(PC, Val, (uint64_t)0); 581} 582 583ATTRIBUTE_INTERFACE 584ATTRIBUTE_NO_SANITIZE_ALL 585ATTRIBUTE_TARGET_POPCNT 586void __sanitizer_cov_trace_gep(uintptr_t Idx) { 587 uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC()); 588 fuzzer::TPC.HandleCmp(PC, Idx, (uintptr_t)0); 589} 590 591ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY 592void __sanitizer_weak_hook_memcmp(void *caller_pc, const void *s1, 593 const void *s2, size_t n, int result) { 594 if (!fuzzer::RunningUserCallback) return; 595 if (result == 0) return; // No reason to mutate. 596 if (n <= 1) return; // Not interesting. 597 fuzzer::TPC.AddValueForMemcmp(caller_pc, s1, s2, n, /*StopAtZero*/false); 598} 599 600ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY 601void __sanitizer_weak_hook_strncmp(void *caller_pc, const char *s1, 602 const char *s2, size_t n, int result) { 603 if (!fuzzer::RunningUserCallback) return; 604 if (result == 0) return; // No reason to mutate. 605 size_t Len1 = fuzzer::InternalStrnlen(s1, n); 606 size_t Len2 = fuzzer::InternalStrnlen(s2, n); 607 n = std::min(n, Len1); 608 n = std::min(n, Len2); 609 if (n <= 1) return; // Not interesting. 610 fuzzer::TPC.AddValueForMemcmp(caller_pc, s1, s2, n, /*StopAtZero*/true); 611} 612 613ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY 614void __sanitizer_weak_hook_strcmp(void *caller_pc, const char *s1, 615 const char *s2, int result) { 616 if (!fuzzer::RunningUserCallback) return; 617 if (result == 0) return; // No reason to mutate. 618 size_t N = fuzzer::InternalStrnlen2(s1, s2); 619 if (N <= 1) return; // Not interesting. 620 fuzzer::TPC.AddValueForMemcmp(caller_pc, s1, s2, N, /*StopAtZero*/true); 621} 622 623ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY 624void __sanitizer_weak_hook_strncasecmp(void *called_pc, const char *s1, 625 const char *s2, size_t n, int result) { 626 if (!fuzzer::RunningUserCallback) return; 627 return __sanitizer_weak_hook_strncmp(called_pc, s1, s2, n, result); 628} 629 630ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY 631void __sanitizer_weak_hook_strcasecmp(void *called_pc, const char *s1, 632 const char *s2, int result) { 633 if (!fuzzer::RunningUserCallback) return; 634 return __sanitizer_weak_hook_strcmp(called_pc, s1, s2, result); 635} 636 637ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY 638void __sanitizer_weak_hook_strstr(void *called_pc, const char *s1, 639 const char *s2, char *result) { 640 if (!fuzzer::RunningUserCallback) return; 641 fuzzer::TPC.MMT.Add(reinterpret_cast<const uint8_t *>(s2), strlen(s2)); 642} 643 644ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY 645void __sanitizer_weak_hook_strcasestr(void *called_pc, const char *s1, 646 const char *s2, char *result) { 647 if (!fuzzer::RunningUserCallback) return; 648 fuzzer::TPC.MMT.Add(reinterpret_cast<const uint8_t *>(s2), strlen(s2)); 649} 650 651ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY 652void __sanitizer_weak_hook_memmem(void *called_pc, const void *s1, size_t len1, 653 const void *s2, size_t len2, void *result) { 654 if (!fuzzer::RunningUserCallback) return; 655 fuzzer::TPC.MMT.Add(reinterpret_cast<const uint8_t *>(s2), len2); 656} 657} // extern "C" 658