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1//===- FuzzerDriver.cpp - FuzzerDriver function and flags -----------------===//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-exception6//7//===----------------------------------------------------------------------===//8// FuzzerDriver and flag parsing.9//===----------------------------------------------------------------------===//10 11#include "FuzzerCommand.h"12#include "FuzzerCorpus.h"13#include "FuzzerFork.h"14#include "FuzzerIO.h"15#include "FuzzerInterface.h"16#include "FuzzerInternal.h"17#include "FuzzerMerge.h"18#include "FuzzerMutate.h"19#include "FuzzerPlatform.h"20#include "FuzzerRandom.h"21#include "FuzzerTracePC.h"22#include <algorithm>23#include <atomic>24#include <chrono>25#include <cstdlib>26#include <cstring>27#include <fstream>28#include <functional>29#include <mutex>30#include <string>31#include <thread>32 33// This function should be present in the libFuzzer so that the client34// binary can test for its existence.35#if LIBFUZZER_MSVC36extern "C" void __libfuzzer_is_present() {}37#if defined(_M_IX86) || defined(__i386__)38#pragma comment(linker, "/include:___libfuzzer_is_present")39#else40#pragma comment(linker, "/include:__libfuzzer_is_present")41#endif42#else43extern "C" __attribute__((used)) void __libfuzzer_is_present() {}44#endif  // LIBFUZZER_MSVC45 46namespace fuzzer {47 48// Program arguments.49struct FlagDescription {50  const char *Name;51  const char *Description;52  int   Default;53  int   *IntFlag;54  const char **StrFlag;55  unsigned int *UIntFlag;56};57 58struct {59#define FUZZER_DEPRECATED_FLAG(Name)60#define FUZZER_FLAG_INT(Name, Default, Description) int Name;61#define FUZZER_FLAG_UNSIGNED(Name, Default, Description) unsigned int Name;62#define FUZZER_FLAG_STRING(Name, Description) const char *Name;63#include "FuzzerFlags.def"64#undef FUZZER_DEPRECATED_FLAG65#undef FUZZER_FLAG_INT66#undef FUZZER_FLAG_UNSIGNED67#undef FUZZER_FLAG_STRING68} Flags;69 70static const FlagDescription FlagDescriptions [] {71#define FUZZER_DEPRECATED_FLAG(Name)                                           \72  {#Name, "Deprecated; don't use", 0, nullptr, nullptr, nullptr},73#define FUZZER_FLAG_INT(Name, Default, Description)                            \74  {#Name, Description, Default, &Flags.Name, nullptr, nullptr},75#define FUZZER_FLAG_UNSIGNED(Name, Default, Description)                       \76  {#Name,   Description, static_cast<int>(Default),                            \77   nullptr, nullptr, &Flags.Name},78#define FUZZER_FLAG_STRING(Name, Description)                                  \79  {#Name, Description, 0, nullptr, &Flags.Name, nullptr},80#include "FuzzerFlags.def"81#undef FUZZER_DEPRECATED_FLAG82#undef FUZZER_FLAG_INT83#undef FUZZER_FLAG_UNSIGNED84#undef FUZZER_FLAG_STRING85};86 87static const size_t kNumFlags =88    sizeof(FlagDescriptions) / sizeof(FlagDescriptions[0]);89 90static std::vector<std::string> *Inputs;91static std::string *ProgName;92 93static void PrintHelp() {94  Printf("Usage:\n");95  auto Prog = ProgName->c_str();96  Printf("\nTo run fuzzing pass 0 or more directories.\n");97  Printf("%s [-flag1=val1 [-flag2=val2 ...] ] [dir1 [dir2 ...] ]\n", Prog);98 99  Printf("\nTo run individual tests without fuzzing pass 1 or more files:\n");100  Printf("%s [-flag1=val1 [-flag2=val2 ...] ] file1 [file2 ...]\n", Prog);101 102  Printf("\nFlags: (strictly in form -flag=value)\n");103  size_t MaxFlagLen = 0;104  for (size_t F = 0; F < kNumFlags; F++)105    MaxFlagLen = std::max(strlen(FlagDescriptions[F].Name), MaxFlagLen);106 107  for (size_t F = 0; F < kNumFlags; F++) {108    const auto &D = FlagDescriptions[F];109    if (strstr(D.Description, "internal flag") == D.Description) continue;110    Printf(" %s", D.Name);111    for (size_t i = 0, n = MaxFlagLen - strlen(D.Name); i < n; i++)112      Printf(" ");113    Printf("\t");114    Printf("%d\t%s\n", D.Default, D.Description);115  }116  Printf("\nFlags starting with '--' will be ignored and "117            "will be passed verbatim to subprocesses.\n");118}119 120static const char *FlagValue(const char *Param, const char *Name) {121  size_t Len = strlen(Name);122  if (Param[0] == '-' && strstr(Param + 1, Name) == Param + 1 &&123      Param[Len + 1] == '=')124      return &Param[Len + 2];125  return nullptr;126}127 128// Avoid calling stol as it triggers a bug in clang/glibc build.129static long MyStol(const char *Str) {130  long Res = 0;131  long Sign = 1;132  if (*Str == '-') {133    Str++;134    Sign = -1;135  }136  for (size_t i = 0; Str[i]; i++) {137    char Ch = Str[i];138    if (Ch < '0' || Ch > '9')139      return Res;140    Res = Res * 10 + (Ch - '0');141  }142  return Res * Sign;143}144 145static bool ParseOneFlag(const char *Param) {146  if (Param[0] != '-') return false;147  if (Param[1] == '-') {148    static bool PrintedWarning = false;149    if (!PrintedWarning) {150      PrintedWarning = true;151      Printf("INFO: libFuzzer ignores flags that start with '--'\n");152    }153    for (size_t F = 0; F < kNumFlags; F++)154      if (FlagValue(Param + 1, FlagDescriptions[F].Name))155        Printf("WARNING: did you mean '%s' (single dash)?\n", Param + 1);156    return true;157  }158  for (size_t F = 0; F < kNumFlags; F++) {159    const char *Name = FlagDescriptions[F].Name;160    const char *Str = FlagValue(Param, Name);161    if (Str)  {162      if (FlagDescriptions[F].IntFlag) {163        auto Val = MyStol(Str);164        *FlagDescriptions[F].IntFlag = static_cast<int>(Val);165        if (Flags.verbosity >= 2)166          Printf("Flag: %s %d\n", Name, (int)Val);167        return true;168      } else if (FlagDescriptions[F].UIntFlag) {169        auto Val = std::stoul(Str);170        *FlagDescriptions[F].UIntFlag = static_cast<unsigned int>(Val);171        if (Flags.verbosity >= 2)172          Printf("Flag: %s %u\n", Name, (uint32_t)Val);173        return true;174      } else if (FlagDescriptions[F].StrFlag) {175        *FlagDescriptions[F].StrFlag = Str;176        if (Flags.verbosity >= 2)177          Printf("Flag: %s %s\n", Name, Str);178        return true;179      } else {  // Deprecated flag.180        Printf("Flag: %s: deprecated, don't use\n", Name);181        return true;182      }183    }184  }185  Printf("\n\nWARNING: unrecognized flag '%s'; "186         "use -help=1 to list all flags\n\n", Param);187  return true;188}189 190// We don't use any library to minimize dependencies.191static void ParseFlags(const std::vector<std::string> &Args,192                       const ExternalFunctions *EF) {193  for (size_t F = 0; F < kNumFlags; F++) {194    if (FlagDescriptions[F].IntFlag)195      *FlagDescriptions[F].IntFlag = FlagDescriptions[F].Default;196    if (FlagDescriptions[F].UIntFlag)197      *FlagDescriptions[F].UIntFlag =198          static_cast<unsigned int>(FlagDescriptions[F].Default);199    if (FlagDescriptions[F].StrFlag)200      *FlagDescriptions[F].StrFlag = nullptr;201  }202 203  // Disable len_control by default, if LLVMFuzzerCustomMutator is used.204  if (EF->LLVMFuzzerCustomMutator) {205    Flags.len_control = 0;206    Printf("INFO: found LLVMFuzzerCustomMutator (%p). "207           "Disabling -len_control by default.\n", EF->LLVMFuzzerCustomMutator);208  }209 210  Inputs = new std::vector<std::string>;211  for (size_t A = 1; A < Args.size(); A++) {212    if (ParseOneFlag(Args[A].c_str())) {213      if (Flags.ignore_remaining_args)214        break;215      continue;216    }217    Inputs->push_back(Args[A]);218  }219}220 221static std::mutex Mu;222 223static void PulseThread() {224  while (true) {225    SleepSeconds(600);226    std::lock_guard<std::mutex> Lock(Mu);227    Printf("pulse...\n");228  }229}230 231static void WorkerThread(const Command &BaseCmd, std::atomic<unsigned> *Counter,232                         unsigned NumJobs, std::atomic<bool> *HasErrors) {233  ScopedDisableMsanInterceptorChecks S;234  while (true) {235    unsigned C = (*Counter)++;236    if (C >= NumJobs) break;237    std::string Log = "fuzz-" + std::to_string(C) + ".log";238    Command Cmd(BaseCmd);239    Cmd.setOutputFile(Log);240    Cmd.combineOutAndErr();241    if (Flags.verbosity) {242      std::string CommandLine = Cmd.toString();243      Printf("%s\n", CommandLine.c_str());244    }245    int ExitCode = ExecuteCommand(Cmd);246    if (ExitCode != 0)247      *HasErrors = true;248    std::lock_guard<std::mutex> Lock(Mu);249    Printf("================== Job %u exited with exit code %d ============\n",250           C, ExitCode);251    fuzzer::CopyFileToErr(Log);252  }253}254 255static void ValidateDirectoryExists(const std::string &Path,256                                    bool CreateDirectory) {257  if (Path.empty()) {258    Printf("ERROR: Provided directory path is an empty string\n");259    exit(1);260  }261 262  if (IsDirectory(Path))263    return;264 265  if (CreateDirectory) {266    if (!MkDirRecursive(Path)) {267      Printf("ERROR: Failed to create directory \"%s\"\n", Path.c_str());268      exit(1);269    }270    return;271  }272 273  Printf("ERROR: The required directory \"%s\" does not exist\n", Path.c_str());274  exit(1);275}276 277std::string CloneArgsWithoutX(const std::vector<std::string> &Args,278                              const char *X1, const char *X2) {279  std::string Cmd;280  for (auto &S : Args) {281    if (FlagValue(S.c_str(), X1) || FlagValue(S.c_str(), X2))282      continue;283    Cmd += S + " ";284  }285  return Cmd;286}287 288static int RunInMultipleProcesses(const std::vector<std::string> &Args,289                                  unsigned NumWorkers, unsigned NumJobs) {290  std::atomic<unsigned> Counter(0);291  std::atomic<bool> HasErrors(false);292  Command Cmd(Args);293  Cmd.removeFlag("jobs");294  Cmd.removeFlag("workers");295  std::vector<std::thread> V;296  std::thread Pulse(PulseThread);297  Pulse.detach();298  V.resize(NumWorkers);299  for (unsigned i = 0; i < NumWorkers; i++) {300    V[i] = std::thread(WorkerThread, std::ref(Cmd), &Counter, NumJobs,301                            &HasErrors);302    SetThreadName(V[i], "FuzzerWorker");303  }304  for (auto &T : V)305    T.join();306  return HasErrors ? 1 : 0;307}308 309void StartRssThread(Fuzzer *F, size_t RssLimitMb);310 311// Fuchsia needs to do some book checking before starting the RssThread,312// so it has its own implementation.313#if !LIBFUZZER_FUCHSIA314static void RssThread(Fuzzer *F, size_t RssLimitMb) {315  while (true) {316    SleepSeconds(1);317    size_t Peak = GetPeakRSSMb();318    if (Peak > RssLimitMb)319      F->RssLimitCallback();320  }321}322 323void StartRssThread(Fuzzer *F, size_t RssLimitMb) {324  if (!RssLimitMb)325    return;326  std::thread T(RssThread, F, RssLimitMb);327  T.detach();328}329#endif330 331int RunOneTest(Fuzzer *F, const char *InputFilePath, size_t MaxLen) {332  Unit U = FileToVector(InputFilePath);333  if (MaxLen && MaxLen < U.size())334    U.resize(MaxLen);335  F->ExecuteCallback(U.data(), U.size());336  if (Flags.print_full_coverage) {337    // Leak detection is not needed when collecting full coverage data.338    F->TPCUpdateObservedPCs();339  } else {340    F->TryDetectingAMemoryLeak(U.data(), U.size(), true);341  }342  return 0;343}344 345static bool AllInputsAreFiles() {346  if (Inputs->empty()) return false;347  for (auto &Path : *Inputs)348    if (!IsFile(Path))349      return false;350  return true;351}352 353static std::string GetDedupTokenFromCmdOutput(const std::string &S) {354  auto Beg = S.find("DEDUP_TOKEN:");355  if (Beg == std::string::npos)356    return "";357  auto End = S.find('\n', Beg);358  if (End == std::string::npos)359    return "";360  return S.substr(Beg, End - Beg);361}362 363int CleanseCrashInput(const std::vector<std::string> &Args,364                      const FuzzingOptions &Options) {365  if (Inputs->size() != 1 || !Flags.exact_artifact_path) {366    Printf("ERROR: -cleanse_crash should be given one input file and"367          " -exact_artifact_path\n");368    exit(1);369  }370  std::string InputFilePath = Inputs->at(0);371  std::string OutputFilePath = Flags.exact_artifact_path;372  Command Cmd(Args);373  Cmd.removeFlag("cleanse_crash");374 375  assert(Cmd.hasArgument(InputFilePath));376  Cmd.removeArgument(InputFilePath);377 378  auto TmpFilePath = TempPath("CleanseCrashInput", ".repro");379  Cmd.addArgument(TmpFilePath);380  Cmd.setOutputFile(getDevNull());381  Cmd.combineOutAndErr();382 383  std::string CurrentFilePath = InputFilePath;384  auto U = FileToVector(CurrentFilePath);385  size_t Size = U.size();386 387  const std::vector<uint8_t> ReplacementBytes = {' ', 0xff};388  for (int NumAttempts = 0; NumAttempts < 5; NumAttempts++) {389    bool Changed = false;390    for (size_t Idx = 0; Idx < Size; Idx++) {391      Printf("CLEANSE[%d]: Trying to replace byte %zd of %zd\n", NumAttempts,392             Idx, Size);393      uint8_t OriginalByte = U[Idx];394      if (ReplacementBytes.end() != std::find(ReplacementBytes.begin(),395                                              ReplacementBytes.end(),396                                              OriginalByte))397        continue;398      for (auto NewByte : ReplacementBytes) {399        U[Idx] = NewByte;400        WriteToFile(U, TmpFilePath);401        auto ExitCode = ExecuteCommand(Cmd);402        RemoveFile(TmpFilePath);403        if (!ExitCode) {404          U[Idx] = OriginalByte;405        } else {406          Changed = true;407          Printf("CLEANSE: Replaced byte %zd with 0x%x\n", Idx, NewByte);408          WriteToFile(U, OutputFilePath);409          break;410        }411      }412    }413    if (!Changed) break;414  }415  return 0;416}417 418int MinimizeCrashInput(const std::vector<std::string> &Args,419                       const FuzzingOptions &Options) {420  if (Inputs->size() != 1) {421    Printf("ERROR: -minimize_crash should be given one input file\n");422    exit(1);423  }424  std::string InputFilePath = Inputs->at(0);425  Command BaseCmd(Args);426  BaseCmd.removeFlag("minimize_crash");427  BaseCmd.removeFlag("exact_artifact_path");428  assert(BaseCmd.hasArgument(InputFilePath));429  BaseCmd.removeArgument(InputFilePath);430  if (Flags.runs <= 0 && Flags.max_total_time == 0) {431    Printf("INFO: you need to specify -runs=N or "432           "-max_total_time=N with -minimize_crash=1\n"433           "INFO: defaulting to -max_total_time=600\n");434    BaseCmd.addFlag("max_total_time", "600");435  }436 437  BaseCmd.combineOutAndErr();438 439  std::string CurrentFilePath = InputFilePath;440  while (true) {441    Unit U = FileToVector(CurrentFilePath);442    Printf("CRASH_MIN: minimizing crash input: '%s' (%zd bytes)\n",443           CurrentFilePath.c_str(), U.size());444 445    Command Cmd(BaseCmd);446    Cmd.addArgument(CurrentFilePath);447 448    Printf("CRASH_MIN: executing: %s\n", Cmd.toString().c_str());449    std::string CmdOutput;450    bool Success = ExecuteCommand(Cmd, &CmdOutput);451    if (Success) {452      Printf("ERROR: the input %s did not crash\n", CurrentFilePath.c_str());453      exit(1);454    }455    Printf("CRASH_MIN: '%s' (%zd bytes) caused a crash. Will try to minimize "456           "it further\n",457           CurrentFilePath.c_str(), U.size());458    auto DedupToken1 = GetDedupTokenFromCmdOutput(CmdOutput);459    if (!DedupToken1.empty())460      Printf("CRASH_MIN: DedupToken1: %s\n", DedupToken1.c_str());461 462    std::string ArtifactPath =463        Flags.exact_artifact_path464            ? Flags.exact_artifact_path465            : Options.ArtifactPrefix + "minimized-from-" + Hash(U);466    Cmd.addFlag("minimize_crash_internal_step", "1");467    Cmd.addFlag("exact_artifact_path", ArtifactPath);468    Printf("CRASH_MIN: executing: %s\n", Cmd.toString().c_str());469    CmdOutput.clear();470    Success = ExecuteCommand(Cmd, &CmdOutput);471    Printf("%s", CmdOutput.c_str());472    if (Success) {473      if (Flags.exact_artifact_path) {474        CurrentFilePath = Flags.exact_artifact_path;475        WriteToFile(U, CurrentFilePath);476      }477      Printf("CRASH_MIN: failed to minimize beyond %s (%zu bytes), exiting\n",478             CurrentFilePath.c_str(), U.size());479      break;480    }481    auto DedupToken2 = GetDedupTokenFromCmdOutput(CmdOutput);482    if (!DedupToken2.empty())483      Printf("CRASH_MIN: DedupToken2: %s\n", DedupToken2.c_str());484 485    if (DedupToken1 != DedupToken2) {486      if (Flags.exact_artifact_path) {487        CurrentFilePath = Flags.exact_artifact_path;488        WriteToFile(U, CurrentFilePath);489      }490      Printf("CRASH_MIN: mismatch in dedup tokens"491             " (looks like a different bug). Won't minimize further\n");492      break;493    }494 495    CurrentFilePath = ArtifactPath;496    Printf("*********************************\n");497  }498  return 0;499}500 501int MinimizeCrashInputInternalStep(Fuzzer *F, InputCorpus *Corpus) {502  assert(Inputs->size() == 1);503  std::string InputFilePath = Inputs->at(0);504  Unit U = FileToVector(InputFilePath);505  Printf("INFO: Starting MinimizeCrashInputInternalStep: %zd\n", U.size());506  if (U.size() < 2) {507    Printf("INFO: The input is small enough, exiting\n");508    exit(0);509  }510  F->SetMaxInputLen(U.size());511  F->SetMaxMutationLen(U.size() - 1);512  F->MinimizeCrashLoop(U);513  Printf("INFO: Done MinimizeCrashInputInternalStep, no crashes found\n");514  exit(0);515}516 517void Merge(Fuzzer *F, FuzzingOptions &Options,518           const std::vector<std::string> &Args,519           const std::vector<std::string> &Corpora, const char *CFPathOrNull) {520  if (Corpora.size() < 2) {521    Printf("INFO: Merge requires two or more corpus dirs\n");522    exit(0);523  }524 525  std::vector<SizedFile> OldCorpus, NewCorpus;526  GetSizedFilesFromDir(Corpora[0], &OldCorpus);527  for (size_t i = 1; i < Corpora.size(); i++)528    GetSizedFilesFromDir(Corpora[i], &NewCorpus);529  std::sort(OldCorpus.begin(), OldCorpus.end());530  std::sort(NewCorpus.begin(), NewCorpus.end());531 532  std::string CFPath = CFPathOrNull ? CFPathOrNull : TempPath("Merge", ".txt");533  std::vector<std::string> NewFiles;534  std::set<uint32_t> NewFeatures, NewCov;535  CrashResistantMerge(Args, OldCorpus, NewCorpus, &NewFiles, {}, &NewFeatures,536                      {}, &NewCov, CFPath, true, Flags.set_cover_merge);537  for (auto &Path : NewFiles)538    F->WriteToOutputCorpus(FileToVector(Path, Options.MaxLen));539  // We are done, delete the control file if it was a temporary one.540  if (!Flags.merge_control_file)541    RemoveFile(CFPath);542 543  exit(0);544}545 546int AnalyzeDictionary(Fuzzer *F, const std::vector<Unit> &Dict,547                      UnitVector &Corpus) {548  Printf("Started dictionary minimization (up to %zu tests)\n",549         Dict.size() * Corpus.size() * 2);550 551  // Scores and usage count for each dictionary unit.552  std::vector<int> Scores(Dict.size());553  std::vector<int> Usages(Dict.size());554 555  std::vector<size_t> InitialFeatures;556  std::vector<size_t> ModifiedFeatures;557  for (auto &C : Corpus) {558    // Get coverage for the testcase without modifications.559    F->ExecuteCallback(C.data(), C.size());560    InitialFeatures.clear();561    TPC.CollectFeatures([&](size_t Feature) {562      InitialFeatures.push_back(Feature);563    });564 565    for (size_t i = 0; i < Dict.size(); ++i) {566      std::vector<uint8_t> Data = C;567      auto StartPos = std::search(Data.begin(), Data.end(),568                                  Dict[i].begin(), Dict[i].end());569      // Skip dictionary unit, if the testcase does not contain it.570      if (StartPos == Data.end())571        continue;572 573      ++Usages[i];574      while (StartPos != Data.end()) {575        // Replace all occurrences of dictionary unit in the testcase.576        auto EndPos = StartPos + Dict[i].size();577        for (auto It = StartPos; It != EndPos; ++It)578          *It ^= 0xFF;579 580        StartPos = std::search(EndPos, Data.end(),581                               Dict[i].begin(), Dict[i].end());582      }583 584      // Get coverage for testcase with masked occurrences of dictionary unit.585      F->ExecuteCallback(Data.data(), Data.size());586      ModifiedFeatures.clear();587      TPC.CollectFeatures([&](size_t Feature) {588        ModifiedFeatures.push_back(Feature);589      });590 591      if (InitialFeatures == ModifiedFeatures)592        --Scores[i];593      else594        Scores[i] += 2;595    }596  }597 598  Printf("###### Useless dictionary elements. ######\n");599  for (size_t i = 0; i < Dict.size(); ++i) {600    // Dictionary units with positive score are treated as useful ones.601    if (Scores[i] > 0)602       continue;603 604    Printf("\"");605    PrintASCII(Dict[i].data(), Dict[i].size(), "\"");606    Printf(" # Score: %d, Used: %d\n", Scores[i], Usages[i]);607  }608  Printf("###### End of useless dictionary elements. ######\n");609  return 0;610}611 612std::vector<std::string> ParseSeedInputs(const char *seed_inputs) {613  // Parse -seed_inputs=file1,file2,... or -seed_inputs=@seed_inputs_file614  std::vector<std::string> Files;615  if (!seed_inputs) return Files;616  std::string SeedInputs;617  if (Flags.seed_inputs[0] == '@')618    SeedInputs = FileToString(Flags.seed_inputs + 1); // File contains list.619  else620    SeedInputs = Flags.seed_inputs; // seed_inputs contains the list.621  if (SeedInputs.empty()) {622    Printf("seed_inputs is empty or @file does not exist.\n");623    exit(1);624  }625  // Parse SeedInputs.626  size_t comma_pos = 0;627  while ((comma_pos = SeedInputs.find_last_of(',')) != std::string::npos) {628    Files.push_back(SeedInputs.substr(comma_pos + 1));629    SeedInputs = SeedInputs.substr(0, comma_pos);630  }631  Files.push_back(SeedInputs);632  return Files;633}634 635static std::vector<SizedFile>636ReadCorpora(const std::vector<std::string> &CorpusDirs,637            const std::vector<std::string> &ExtraSeedFiles) {638  std::vector<SizedFile> SizedFiles;639  size_t LastNumFiles = 0;640  for (auto &Dir : CorpusDirs) {641    GetSizedFilesFromDir(Dir, &SizedFiles);642    Printf("INFO: % 8zd files found in %s\n", SizedFiles.size() - LastNumFiles,643           Dir.c_str());644    LastNumFiles = SizedFiles.size();645  }646  for (auto &File : ExtraSeedFiles)647    if (auto Size = FileSize(File))648      SizedFiles.push_back({File, Size});649  return SizedFiles;650}651 652int FuzzerDriver(int *argc, char ***argv, UserCallback Callback) {653  using namespace fuzzer;654  assert(argc && argv && "Argument pointers cannot be nullptr");655  std::string Argv0((*argv)[0]);656  EF = new ExternalFunctions();657  if (EF->LLVMFuzzerInitialize)658    EF->LLVMFuzzerInitialize(argc, argv);659  if (EF->__msan_scoped_disable_interceptor_checks)660    EF->__msan_scoped_disable_interceptor_checks();661  const std::vector<std::string> Args(*argv, *argv + *argc);662  assert(!Args.empty());663  ProgName = new std::string(Args[0]);664  if (Argv0 != *ProgName) {665    Printf("ERROR: argv[0] has been modified in LLVMFuzzerInitialize\n");666    exit(1);667  }668  ParseFlags(Args, EF);669  if (Flags.help) {670    PrintHelp();671    return 0;672  }673 674  if (Flags.close_fd_mask & 2)675    DupAndCloseStderr();676  if (Flags.close_fd_mask & 1)677    CloseStdout();678 679  if (Flags.jobs > 0 && Flags.workers == 0) {680    Flags.workers = std::min(NumberOfCpuCores() / 2, Flags.jobs);681    if (Flags.workers > 1)682      Printf("Running %u workers\n", Flags.workers);683  }684 685  if (Flags.workers > 0 && Flags.jobs > 0)686    return RunInMultipleProcesses(Args, Flags.workers, Flags.jobs);687 688  FuzzingOptions Options;689  Options.Verbosity = Flags.verbosity;690  Options.MaxLen = Flags.max_len;691  Options.LenControl = Flags.len_control;692  Options.KeepSeed = Flags.keep_seed;693  Options.UnitTimeoutSec = Flags.timeout;694  Options.ErrorExitCode = Flags.error_exitcode;695  Options.TimeoutExitCode = Flags.timeout_exitcode;696  Options.IgnoreTimeouts = Flags.ignore_timeouts;697  Options.IgnoreOOMs = Flags.ignore_ooms;698  Options.IgnoreCrashes = Flags.ignore_crashes;699  Options.MaxTotalTimeSec = Flags.max_total_time;700  Options.DoCrossOver = Flags.cross_over;701  Options.CrossOverUniformDist = Flags.cross_over_uniform_dist;702  Options.MutateDepth = Flags.mutate_depth;703  Options.ReduceDepth = Flags.reduce_depth;704  Options.UseCounters = Flags.use_counters;705  Options.UseMemmem = Flags.use_memmem;706  Options.UseCmp = Flags.use_cmp;707  Options.UseValueProfile = Flags.use_value_profile;708  Options.Shrink = Flags.shrink;709  Options.ReduceInputs = Flags.reduce_inputs;710  Options.ShuffleAtStartUp = Flags.shuffle;711  Options.PreferSmall = Flags.prefer_small;712  Options.ReloadIntervalSec = Flags.reload;713  Options.OnlyASCII = Flags.only_ascii;714  Options.DetectLeaks = Flags.detect_leaks;715  Options.PurgeAllocatorIntervalSec = Flags.purge_allocator_interval;716  Options.TraceMalloc = Flags.trace_malloc;717  Options.RssLimitMb = Flags.rss_limit_mb;718  Options.MallocLimitMb = Flags.malloc_limit_mb;719  if (!Options.MallocLimitMb)720    Options.MallocLimitMb = Options.RssLimitMb;721  if (Flags.runs >= 0)722    Options.MaxNumberOfRuns = Flags.runs;723  if (!Inputs->empty() && !Flags.minimize_crash_internal_step) {724    // Ensure output corpus assumed to be the first arbitrary argument input725    // is not a path to an existing file.726    std::string OutputCorpusDir = (*Inputs)[0];727    if (!IsFile(OutputCorpusDir)) {728      Options.OutputCorpus = OutputCorpusDir;729      ValidateDirectoryExists(Options.OutputCorpus, Flags.create_missing_dirs);730    }731  }732  Options.ReportSlowUnits = Flags.report_slow_units;733  if (Flags.artifact_prefix) {734    Options.ArtifactPrefix = Flags.artifact_prefix;735 736    // Since the prefix could be a full path to a file name prefix, assume737    // that if the path ends with the platform's separator that a directory738    // is desired739    std::string ArtifactPathDir = Options.ArtifactPrefix;740    if (!IsSeparator(ArtifactPathDir[ArtifactPathDir.length() - 1])) {741      ArtifactPathDir = DirName(ArtifactPathDir);742    }743    ValidateDirectoryExists(ArtifactPathDir, Flags.create_missing_dirs);744  }745  if (Flags.exact_artifact_path) {746    Options.ExactArtifactPath = Flags.exact_artifact_path;747    ValidateDirectoryExists(DirName(Options.ExactArtifactPath),748                            Flags.create_missing_dirs);749  }750  std::vector<Unit> Dictionary;751  if (Flags.dict)752    if (!ParseDictionaryFile(FileToString(Flags.dict), &Dictionary))753      return 1;754  if (Flags.verbosity > 0 && !Dictionary.empty())755    Printf("Dictionary: %zd entries\n", Dictionary.size());756  bool RunIndividualFiles = AllInputsAreFiles();757  Options.SaveArtifacts =758      !RunIndividualFiles || Flags.minimize_crash_internal_step;759  Options.PrintNewCovPcs = Flags.print_pcs;760  Options.PrintNewCovFuncs = Flags.print_funcs;761  Options.PrintFinalStats = Flags.print_final_stats;762  Options.PrintCorpusStats = Flags.print_corpus_stats;763  Options.PrintCoverage = Flags.print_coverage;764  Options.PrintFullCoverage = Flags.print_full_coverage;765  if (Flags.exit_on_src_pos)766    Options.ExitOnSrcPos = Flags.exit_on_src_pos;767  if (Flags.exit_on_item)768    Options.ExitOnItem = Flags.exit_on_item;769  if (Flags.focus_function)770    Options.FocusFunction = Flags.focus_function;771  if (Flags.data_flow_trace)772    Options.DataFlowTrace = Flags.data_flow_trace;773  if (Flags.features_dir) {774    Options.FeaturesDir = Flags.features_dir;775    ValidateDirectoryExists(Options.FeaturesDir, Flags.create_missing_dirs);776  }777  if (Flags.mutation_graph_file)778    Options.MutationGraphFile = Flags.mutation_graph_file;779  if (Flags.collect_data_flow)780    Options.CollectDataFlow = Flags.collect_data_flow;781  if (Flags.stop_file)782    Options.StopFile = Flags.stop_file;783  Options.Entropic = Flags.entropic;784  Options.EntropicFeatureFrequencyThreshold =785      (size_t)Flags.entropic_feature_frequency_threshold;786  Options.EntropicNumberOfRarestFeatures =787      (size_t)Flags.entropic_number_of_rarest_features;788  Options.EntropicScalePerExecTime = Flags.entropic_scale_per_exec_time;789  if (!Options.FocusFunction.empty())790    Options.Entropic = false; // FocusFunction overrides entropic scheduling.791  if (Options.Entropic)792    Printf("INFO: Running with entropic power schedule (0x%zX, %zu).\n",793           Options.EntropicFeatureFrequencyThreshold,794           Options.EntropicNumberOfRarestFeatures);795  struct EntropicOptions Entropic;796  Entropic.Enabled = Options.Entropic;797  Entropic.FeatureFrequencyThreshold =798      Options.EntropicFeatureFrequencyThreshold;799  Entropic.NumberOfRarestFeatures = Options.EntropicNumberOfRarestFeatures;800  Entropic.ScalePerExecTime = Options.EntropicScalePerExecTime;801 802  unsigned Seed = Flags.seed;803  // Initialize Seed.804  if (Seed == 0)805    Seed = static_cast<unsigned>(806        std::chrono::system_clock::now().time_since_epoch().count() + GetPid());807  if (Flags.verbosity)808    Printf("INFO: Seed: %u\n", Seed);809 810  if (Flags.collect_data_flow && Flags.data_flow_trace && !Flags.fork &&811      !(Flags.merge || Flags.set_cover_merge)) {812    if (RunIndividualFiles)813      return CollectDataFlow(Flags.collect_data_flow, Flags.data_flow_trace,814                        ReadCorpora({}, *Inputs));815    else816      return CollectDataFlow(Flags.collect_data_flow, Flags.data_flow_trace,817                        ReadCorpora(*Inputs, {}));818  }819 820  Random Rand(Seed);821  auto *MD = new MutationDispatcher(Rand, Options);822  auto *Corpus = new InputCorpus(Options.OutputCorpus, Entropic);823  auto *F = new Fuzzer(Callback, *Corpus, *MD, Options);824 825  for (auto &U: Dictionary)826    if (U.size() <= Word::GetMaxSize())827      MD->AddWordToManualDictionary(Word(U.data(), U.size()));828 829      // Threads are only supported by Chrome. Don't use them with emscripten830      // for now.831#if !LIBFUZZER_EMSCRIPTEN832  StartRssThread(F, Flags.rss_limit_mb);833#endif // LIBFUZZER_EMSCRIPTEN834 835  Options.HandleAbrt = Flags.handle_abrt;836  Options.HandleAlrm = !Flags.minimize_crash;837  Options.HandleBus = Flags.handle_bus;838  Options.HandleFpe = Flags.handle_fpe;839  Options.HandleIll = Flags.handle_ill;840  Options.HandleInt = Flags.handle_int;841  Options.HandleSegv = Flags.handle_segv;842  Options.HandleTerm = Flags.handle_term;843  Options.HandleTrap = Flags.handle_trap;844  Options.HandleXfsz = Flags.handle_xfsz;845  Options.HandleUsr1 = Flags.handle_usr1;846  Options.HandleUsr2 = Flags.handle_usr2;847  Options.HandleWinExcept = Flags.handle_winexcept;848 849  SetSignalHandler(Options);850 851  std::atexit(Fuzzer::StaticExitCallback);852 853  if (Flags.minimize_crash)854    return MinimizeCrashInput(Args, Options);855 856  if (Flags.minimize_crash_internal_step)857    return MinimizeCrashInputInternalStep(F, Corpus);858 859  if (Flags.cleanse_crash)860    return CleanseCrashInput(Args, Options);861 862  if (RunIndividualFiles) {863    Options.SaveArtifacts = false;864    int Runs = std::max(1, Flags.runs);865    Printf("%s: Running %zd inputs %d time(s) each.\n", ProgName->c_str(),866           Inputs->size(), Runs);867    for (auto &Path : *Inputs) {868      auto StartTime = system_clock::now();869      Printf("Running: %s\n", Path.c_str());870      for (int Iter = 0; Iter < Runs; Iter++)871        RunOneTest(F, Path.c_str(), Options.MaxLen);872      auto StopTime = system_clock::now();873      auto MS = duration_cast<milliseconds>(StopTime - StartTime).count();874      Printf("Executed %s in %ld ms\n", Path.c_str(), (long)MS);875    }876    Printf("***\n"877           "*** NOTE: fuzzing was not performed, you have only\n"878           "***       executed the target code on a fixed set of inputs.\n"879           "***\n");880    F->PrintFinalStats();881    exit(0);882  }883 884  Options.ForkCorpusGroups = Flags.fork_corpus_groups;885  if (Flags.fork)886    FuzzWithFork(F->GetMD().GetRand(), Options, Args, *Inputs, Flags.fork);887 888  if (Flags.merge || Flags.set_cover_merge)889    Merge(F, Options, Args, *Inputs, Flags.merge_control_file);890 891  if (Flags.merge_inner) {892    const size_t kDefaultMaxMergeLen = 1 << 20;893    if (Options.MaxLen == 0)894      F->SetMaxInputLen(kDefaultMaxMergeLen);895    assert(Flags.merge_control_file);896    F->CrashResistantMergeInternalStep(Flags.merge_control_file,897                                       !strncmp(Flags.merge_inner, "2", 1));898    exit(0);899  }900 901  if (Flags.analyze_dict) {902    size_t MaxLen = INT_MAX;  // Large max length.903    UnitVector InitialCorpus;904    for (auto &Inp : *Inputs) {905      Printf("Loading corpus dir: %s\n", Inp.c_str());906      ReadDirToVectorOfUnits(Inp.c_str(), &InitialCorpus, nullptr,907                             MaxLen, /*ExitOnError=*/false);908    }909 910    if (Dictionary.empty() || Inputs->empty()) {911      Printf("ERROR: can't analyze dict without dict and corpus provided\n");912      return 1;913    }914    if (AnalyzeDictionary(F, Dictionary, InitialCorpus)) {915      Printf("Dictionary analysis failed\n");916      exit(1);917    }918    Printf("Dictionary analysis succeeded\n");919    exit(0);920  }921 922  auto CorporaFiles = ReadCorpora(*Inputs, ParseSeedInputs(Flags.seed_inputs));923  F->Loop(CorporaFiles);924 925  if (Flags.verbosity)926    Printf("Done %zd runs in %zd second(s)\n", F->getTotalNumberOfRuns(),927           F->secondsSinceProcessStartUp());928  F->PrintFinalStats();929 930  exit(0);  // Don't let F destroy itself.931}932 933extern "C" ATTRIBUTE_INTERFACE int934LLVMFuzzerRunDriver(int *argc, char ***argv,935                    int (*UserCb)(const uint8_t *Data, size_t Size)) {936  return FuzzerDriver(argc, argv, UserCb);937}938 939// Storage for global ExternalFunctions object.940ExternalFunctions *EF = nullptr;941 942}  // namespace fuzzer943