FuzzerDriver.cpp revision 360784 
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-exception
6//
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 "FuzzerRandom.h"
20#include "FuzzerTracePC.h"
21#include <algorithm>
22#include <atomic>
23#include <chrono>
24#include <cstdlib>
25#include <cstring>
26#include <mutex>
27#include <string>
28#include <thread>
29#include <fstream>
30
31// This function should be present in the libFuzzer so that the client
32// binary can test for its existence.
33#if LIBFUZZER_MSVC
34extern "C" void __libfuzzer_is_present() {}
35#pragma comment(linker, "/include:__libfuzzer_is_present")
36#else
37extern "C" __attribute__((used)) void __libfuzzer_is_present() {}
38#endif  // LIBFUZZER_MSVC
39
40namespace fuzzer {
41
42// Program arguments.
43struct FlagDescription {
44  const char *Name;
45  const char *Description;
46  int   Default;
47  int   *IntFlag;
48  const char **StrFlag;
49  unsigned int *UIntFlag;
50};
51
52struct {
53#define FUZZER_DEPRECATED_FLAG(Name)
54#define FUZZER_FLAG_INT(Name, Default, Description) int Name;
55#define FUZZER_FLAG_UNSIGNED(Name, Default, Description) unsigned int Name;
56#define FUZZER_FLAG_STRING(Name, Description) const char *Name;
57#include "FuzzerFlags.def"
58#undef FUZZER_DEPRECATED_FLAG
59#undef FUZZER_FLAG_INT
60#undef FUZZER_FLAG_UNSIGNED
61#undef FUZZER_FLAG_STRING
62} Flags;
63
64static const FlagDescription FlagDescriptions [] {
65#define FUZZER_DEPRECATED_FLAG(Name)                                           \
66  {#Name, "Deprecated; don't use", 0, nullptr, nullptr, nullptr},
67#define FUZZER_FLAG_INT(Name, Default, Description)                            \
68  {#Name, Description, Default, &Flags.Name, nullptr, nullptr},
69#define FUZZER_FLAG_UNSIGNED(Name, Default, Description)                       \
70  {#Name,   Description, static_cast<int>(Default),                            \
71   nullptr, nullptr, &Flags.Name},
72#define FUZZER_FLAG_STRING(Name, Description)                                  \
73  {#Name, Description, 0, nullptr, &Flags.Name, nullptr},
74#include "FuzzerFlags.def"
75#undef FUZZER_DEPRECATED_FLAG
76#undef FUZZER_FLAG_INT
77#undef FUZZER_FLAG_UNSIGNED
78#undef FUZZER_FLAG_STRING
79};
80
81static const size_t kNumFlags =
82    sizeof(FlagDescriptions) / sizeof(FlagDescriptions[0]);
83
84static Vector<std::string> *Inputs;
85static std::string *ProgName;
86
87static void PrintHelp() {
88  Printf("Usage:\n");
89  auto Prog = ProgName->c_str();
90  Printf("\nTo run fuzzing pass 0 or more directories.\n");
91  Printf("%s [-flag1=val1 [-flag2=val2 ...] ] [dir1 [dir2 ...] ]\n", Prog);
92
93  Printf("\nTo run individual tests without fuzzing pass 1 or more files:\n");
94  Printf("%s [-flag1=val1 [-flag2=val2 ...] ] file1 [file2 ...]\n", Prog);
95
96  Printf("\nFlags: (strictly in form -flag=value)\n");
97  size_t MaxFlagLen = 0;
98  for (size_t F = 0; F < kNumFlags; F++)
99    MaxFlagLen = std::max(strlen(FlagDescriptions[F].Name), MaxFlagLen);
100
101  for (size_t F = 0; F < kNumFlags; F++) {
102    const auto &D = FlagDescriptions[F];
103    if (strstr(D.Description, "internal flag") == D.Description) continue;
104    Printf(" %s", D.Name);
105    for (size_t i = 0, n = MaxFlagLen - strlen(D.Name); i < n; i++)
106      Printf(" ");
107    Printf("\t");
108    Printf("%d\t%s\n", D.Default, D.Description);
109  }
110  Printf("\nFlags starting with '--' will be ignored and "
111            "will be passed verbatim to subprocesses.\n");
112}
113
114static const char *FlagValue(const char *Param, const char *Name) {
115  size_t Len = strlen(Name);
116  if (Param[0] == '-' && strstr(Param + 1, Name) == Param + 1 &&
117      Param[Len + 1] == '=')
118      return &Param[Len + 2];
119  return nullptr;
120}
121
122// Avoid calling stol as it triggers a bug in clang/glibc build.
123static long MyStol(const char *Str) {
124  long Res = 0;
125  long Sign = 1;
126  if (*Str == '-') {
127    Str++;
128    Sign = -1;
129  }
130  for (size_t i = 0; Str[i]; i++) {
131    char Ch = Str[i];
132    if (Ch < '0' || Ch > '9')
133      return Res;
134    Res = Res * 10 + (Ch - '0');
135  }
136  return Res * Sign;
137}
138
139static bool ParseOneFlag(const char *Param) {
140  if (Param[0] != '-') return false;
141  if (Param[1] == '-') {
142    static bool PrintedWarning = false;
143    if (!PrintedWarning) {
144      PrintedWarning = true;
145      Printf("INFO: libFuzzer ignores flags that start with '--'\n");
146    }
147    for (size_t F = 0; F < kNumFlags; F++)
148      if (FlagValue(Param + 1, FlagDescriptions[F].Name))
149        Printf("WARNING: did you mean '%s' (single dash)?\n", Param + 1);
150    return true;
151  }
152  for (size_t F = 0; F < kNumFlags; F++) {
153    const char *Name = FlagDescriptions[F].Name;
154    const char *Str = FlagValue(Param, Name);
155    if (Str)  {
156      if (FlagDescriptions[F].IntFlag) {
157        int Val = MyStol(Str);
158        *FlagDescriptions[F].IntFlag = Val;
159        if (Flags.verbosity >= 2)
160          Printf("Flag: %s %d\n", Name, Val);
161        return true;
162      } else if (FlagDescriptions[F].UIntFlag) {
163        unsigned int Val = std::stoul(Str);
164        *FlagDescriptions[F].UIntFlag = Val;
165        if (Flags.verbosity >= 2)
166          Printf("Flag: %s %u\n", Name, Val);
167        return true;
168      } else if (FlagDescriptions[F].StrFlag) {
169        *FlagDescriptions[F].StrFlag = Str;
170        if (Flags.verbosity >= 2)
171          Printf("Flag: %s %s\n", Name, Str);
172        return true;
173      } else {  // Deprecated flag.
174        Printf("Flag: %s: deprecated, don't use\n", Name);
175        return true;
176      }
177    }
178  }
179  Printf("\n\nWARNING: unrecognized flag '%s'; "
180         "use -help=1 to list all flags\n\n", Param);
181  return true;
182}
183
184// We don't use any library to minimize dependencies.
185static void ParseFlags(const Vector<std::string> &Args,
186                       const ExternalFunctions *EF) {
187  for (size_t F = 0; F < kNumFlags; F++) {
188    if (FlagDescriptions[F].IntFlag)
189      *FlagDescriptions[F].IntFlag = FlagDescriptions[F].Default;
190    if (FlagDescriptions[F].UIntFlag)
191      *FlagDescriptions[F].UIntFlag =
192          static_cast<unsigned int>(FlagDescriptions[F].Default);
193    if (FlagDescriptions[F].StrFlag)
194      *FlagDescriptions[F].StrFlag = nullptr;
195  }
196
197  // Disable len_control by default, if LLVMFuzzerCustomMutator is used.
198  if (EF->LLVMFuzzerCustomMutator)
199    Flags.len_control = 0;
200
201  Inputs = new Vector<std::string>;
202  for (size_t A = 1; A < Args.size(); A++) {
203    if (ParseOneFlag(Args[A].c_str())) {
204      if (Flags.ignore_remaining_args)
205        break;
206      continue;
207    }
208    Inputs->push_back(Args[A]);
209  }
210}
211
212static std::mutex Mu;
213
214static void PulseThread() {
215  while (true) {
216    SleepSeconds(600);
217    std::lock_guard<std::mutex> Lock(Mu);
218    Printf("pulse...\n");
219  }
220}
221
222static void WorkerThread(const Command &BaseCmd, std::atomic<unsigned> *Counter,
223                         unsigned NumJobs, std::atomic<bool> *HasErrors) {
224  while (true) {
225    unsigned C = (*Counter)++;
226    if (C >= NumJobs) break;
227    std::string Log = "fuzz-" + std::to_string(C) + ".log";
228    Command Cmd(BaseCmd);
229    Cmd.setOutputFile(Log);
230    Cmd.combineOutAndErr();
231    if (Flags.verbosity) {
232      std::string CommandLine = Cmd.toString();
233      Printf("%s\n", CommandLine.c_str());
234    }
235    int ExitCode = ExecuteCommand(Cmd);
236    if (ExitCode != 0)
237      *HasErrors = true;
238    std::lock_guard<std::mutex> Lock(Mu);
239    Printf("================== Job %u exited with exit code %d ============\n",
240           C, ExitCode);
241    fuzzer::CopyFileToErr(Log);
242  }
243}
244
245std::string CloneArgsWithoutX(const Vector<std::string> &Args,
246                              const char *X1, const char *X2) {
247  std::string Cmd;
248  for (auto &S : Args) {
249    if (FlagValue(S.c_str(), X1) || FlagValue(S.c_str(), X2))
250      continue;
251    Cmd += S + " ";
252  }
253  return Cmd;
254}
255
256static int RunInMultipleProcesses(const Vector<std::string> &Args,
257                                  unsigned NumWorkers, unsigned NumJobs) {
258  std::atomic<unsigned> Counter(0);
259  std::atomic<bool> HasErrors(false);
260  Command Cmd(Args);
261  Cmd.removeFlag("jobs");
262  Cmd.removeFlag("workers");
263  Vector<std::thread> V;
264  std::thread Pulse(PulseThread);
265  Pulse.detach();
266  for (unsigned i = 0; i < NumWorkers; i++)
267    V.push_back(std::thread(WorkerThread, std::ref(Cmd), &Counter, NumJobs, &HasErrors));
268  for (auto &T : V)
269    T.join();
270  return HasErrors ? 1 : 0;
271}
272
273static void RssThread(Fuzzer *F, size_t RssLimitMb) {
274  while (true) {
275    SleepSeconds(1);
276    size_t Peak = GetPeakRSSMb();
277    if (Peak > RssLimitMb)
278      F->RssLimitCallback();
279  }
280}
281
282static void StartRssThread(Fuzzer *F, size_t RssLimitMb) {
283  if (!RssLimitMb)
284    return;
285  std::thread T(RssThread, F, RssLimitMb);
286  T.detach();
287}
288
289int RunOneTest(Fuzzer *F, const char *InputFilePath, size_t MaxLen) {
290  Unit U = FileToVector(InputFilePath);
291  if (MaxLen && MaxLen < U.size())
292    U.resize(MaxLen);
293  F->ExecuteCallback(U.data(), U.size());
294  F->TryDetectingAMemoryLeak(U.data(), U.size(), true);
295  return 0;
296}
297
298static bool AllInputsAreFiles() {
299  if (Inputs->empty()) return false;
300  for (auto &Path : *Inputs)
301    if (!IsFile(Path))
302      return false;
303  return true;
304}
305
306static std::string GetDedupTokenFromFile(const std::string &Path) {
307  auto S = FileToString(Path);
308  auto Beg = S.find("DEDUP_TOKEN:");
309  if (Beg == std::string::npos)
310    return "";
311  auto End = S.find('\n', Beg);
312  if (End == std::string::npos)
313    return "";
314  return S.substr(Beg, End - Beg);
315}
316
317int CleanseCrashInput(const Vector<std::string> &Args,
318                       const FuzzingOptions &Options) {
319  if (Inputs->size() != 1 || !Flags.exact_artifact_path) {
320    Printf("ERROR: -cleanse_crash should be given one input file and"
321          " -exact_artifact_path\n");
322    exit(1);
323  }
324  std::string InputFilePath = Inputs->at(0);
325  std::string OutputFilePath = Flags.exact_artifact_path;
326  Command Cmd(Args);
327  Cmd.removeFlag("cleanse_crash");
328
329  assert(Cmd.hasArgument(InputFilePath));
330  Cmd.removeArgument(InputFilePath);
331
332  auto LogFilePath = TempPath(".txt");
333  auto TmpFilePath = TempPath(".repro");
334  Cmd.addArgument(TmpFilePath);
335  Cmd.setOutputFile(LogFilePath);
336  Cmd.combineOutAndErr();
337
338  std::string CurrentFilePath = InputFilePath;
339  auto U = FileToVector(CurrentFilePath);
340  size_t Size = U.size();
341
342  const Vector<uint8_t> ReplacementBytes = {' ', 0xff};
343  for (int NumAttempts = 0; NumAttempts < 5; NumAttempts++) {
344    bool Changed = false;
345    for (size_t Idx = 0; Idx < Size; Idx++) {
346      Printf("CLEANSE[%d]: Trying to replace byte %zd of %zd\n", NumAttempts,
347             Idx, Size);
348      uint8_t OriginalByte = U[Idx];
349      if (ReplacementBytes.end() != std::find(ReplacementBytes.begin(),
350                                              ReplacementBytes.end(),
351                                              OriginalByte))
352        continue;
353      for (auto NewByte : ReplacementBytes) {
354        U[Idx] = NewByte;
355        WriteToFile(U, TmpFilePath);
356        auto ExitCode = ExecuteCommand(Cmd);
357        RemoveFile(TmpFilePath);
358        if (!ExitCode) {
359          U[Idx] = OriginalByte;
360        } else {
361          Changed = true;
362          Printf("CLEANSE: Replaced byte %zd with 0x%x\n", Idx, NewByte);
363          WriteToFile(U, OutputFilePath);
364          break;
365        }
366      }
367    }
368    if (!Changed) break;
369  }
370  RemoveFile(LogFilePath);
371  return 0;
372}
373
374int MinimizeCrashInput(const Vector<std::string> &Args,
375                       const FuzzingOptions &Options) {
376  if (Inputs->size() != 1) {
377    Printf("ERROR: -minimize_crash should be given one input file\n");
378    exit(1);
379  }
380  std::string InputFilePath = Inputs->at(0);
381  Command BaseCmd(Args);
382  BaseCmd.removeFlag("minimize_crash");
383  BaseCmd.removeFlag("exact_artifact_path");
384  assert(BaseCmd.hasArgument(InputFilePath));
385  BaseCmd.removeArgument(InputFilePath);
386  if (Flags.runs <= 0 && Flags.max_total_time == 0) {
387    Printf("INFO: you need to specify -runs=N or "
388           "-max_total_time=N with -minimize_crash=1\n"
389           "INFO: defaulting to -max_total_time=600\n");
390    BaseCmd.addFlag("max_total_time", "600");
391  }
392
393  auto LogFilePath = TempPath(".txt");
394  BaseCmd.setOutputFile(LogFilePath);
395  BaseCmd.combineOutAndErr();
396
397  std::string CurrentFilePath = InputFilePath;
398  while (true) {
399    Unit U = FileToVector(CurrentFilePath);
400    Printf("CRASH_MIN: minimizing crash input: '%s' (%zd bytes)\n",
401           CurrentFilePath.c_str(), U.size());
402
403    Command Cmd(BaseCmd);
404    Cmd.addArgument(CurrentFilePath);
405
406    std::string CommandLine = Cmd.toString();
407    Printf("CRASH_MIN: executing: %s\n", CommandLine.c_str());
408    int ExitCode = ExecuteCommand(Cmd);
409    if (ExitCode == 0) {
410      Printf("ERROR: the input %s did not crash\n", CurrentFilePath.c_str());
411      exit(1);
412    }
413    Printf("CRASH_MIN: '%s' (%zd bytes) caused a crash. Will try to minimize "
414           "it further\n",
415           CurrentFilePath.c_str(), U.size());
416    auto DedupToken1 = GetDedupTokenFromFile(LogFilePath);
417    if (!DedupToken1.empty())
418      Printf("CRASH_MIN: DedupToken1: %s\n", DedupToken1.c_str());
419
420    std::string ArtifactPath =
421        Flags.exact_artifact_path
422            ? Flags.exact_artifact_path
423            : Options.ArtifactPrefix + "minimized-from-" + Hash(U);
424    Cmd.addFlag("minimize_crash_internal_step", "1");
425    Cmd.addFlag("exact_artifact_path", ArtifactPath);
426    CommandLine = Cmd.toString();
427    Printf("CRASH_MIN: executing: %s\n", CommandLine.c_str());
428    ExitCode = ExecuteCommand(Cmd);
429    CopyFileToErr(LogFilePath);
430    if (ExitCode == 0) {
431      if (Flags.exact_artifact_path) {
432        CurrentFilePath = Flags.exact_artifact_path;
433        WriteToFile(U, CurrentFilePath);
434      }
435      Printf("CRASH_MIN: failed to minimize beyond %s (%d bytes), exiting\n",
436             CurrentFilePath.c_str(), U.size());
437      break;
438    }
439    auto DedupToken2 = GetDedupTokenFromFile(LogFilePath);
440    if (!DedupToken2.empty())
441      Printf("CRASH_MIN: DedupToken2: %s\n", DedupToken2.c_str());
442
443    if (DedupToken1 != DedupToken2) {
444      if (Flags.exact_artifact_path) {
445        CurrentFilePath = Flags.exact_artifact_path;
446        WriteToFile(U, CurrentFilePath);
447      }
448      Printf("CRASH_MIN: mismatch in dedup tokens"
449             " (looks like a different bug). Won't minimize further\n");
450      break;
451    }
452
453    CurrentFilePath = ArtifactPath;
454    Printf("*********************************\n");
455  }
456  RemoveFile(LogFilePath);
457  return 0;
458}
459
460int MinimizeCrashInputInternalStep(Fuzzer *F, InputCorpus *Corpus) {
461  assert(Inputs->size() == 1);
462  std::string InputFilePath = Inputs->at(0);
463  Unit U = FileToVector(InputFilePath);
464  Printf("INFO: Starting MinimizeCrashInputInternalStep: %zd\n", U.size());
465  if (U.size() < 2) {
466    Printf("INFO: The input is small enough, exiting\n");
467    exit(0);
468  }
469  F->SetMaxInputLen(U.size());
470  F->SetMaxMutationLen(U.size() - 1);
471  F->MinimizeCrashLoop(U);
472  Printf("INFO: Done MinimizeCrashInputInternalStep, no crashes found\n");
473  exit(0);
474  return 0;
475}
476
477void Merge(Fuzzer *F, FuzzingOptions &Options, const Vector<std::string> &Args,
478           const Vector<std::string> &Corpora, const char *CFPathOrNull) {
479  if (Corpora.size() < 2) {
480    Printf("INFO: Merge requires two or more corpus dirs\n");
481    exit(0);
482  }
483
484  Vector<SizedFile> OldCorpus, NewCorpus;
485  GetSizedFilesFromDir(Corpora[0], &OldCorpus);
486  for (size_t i = 1; i < Corpora.size(); i++)
487    GetSizedFilesFromDir(Corpora[i], &NewCorpus);
488  std::sort(OldCorpus.begin(), OldCorpus.end());
489  std::sort(NewCorpus.begin(), NewCorpus.end());
490
491  std::string CFPath = CFPathOrNull ? CFPathOrNull : TempPath(".txt");
492  Vector<std::string> NewFiles;
493  Set<uint32_t> NewFeatures, NewCov;
494  CrashResistantMerge(Args, OldCorpus, NewCorpus, &NewFiles, {}, &NewFeatures,
495                      {}, &NewCov, CFPath, true);
496  for (auto &Path : NewFiles)
497    F->WriteToOutputCorpus(FileToVector(Path, Options.MaxLen));
498  // We are done, delete the control file if it was a temporary one.
499  if (!Flags.merge_control_file)
500    RemoveFile(CFPath);
501
502  exit(0);
503}
504
505int AnalyzeDictionary(Fuzzer *F, const Vector<Unit>& Dict,
506                      UnitVector& Corpus) {
507  Printf("Started dictionary minimization (up to %d tests)\n",
508         Dict.size() * Corpus.size() * 2);
509
510  // Scores and usage count for each dictionary unit.
511  Vector<int> Scores(Dict.size());
512  Vector<int> Usages(Dict.size());
513
514  Vector<size_t> InitialFeatures;
515  Vector<size_t> ModifiedFeatures;
516  for (auto &C : Corpus) {
517    // Get coverage for the testcase without modifications.
518    F->ExecuteCallback(C.data(), C.size());
519    InitialFeatures.clear();
520    TPC.CollectFeatures([&](size_t Feature) {
521      InitialFeatures.push_back(Feature);
522    });
523
524    for (size_t i = 0; i < Dict.size(); ++i) {
525      Vector<uint8_t> Data = C;
526      auto StartPos = std::search(Data.begin(), Data.end(),
527                                  Dict[i].begin(), Dict[i].end());
528      // Skip dictionary unit, if the testcase does not contain it.
529      if (StartPos == Data.end())
530        continue;
531
532      ++Usages[i];
533      while (StartPos != Data.end()) {
534        // Replace all occurrences of dictionary unit in the testcase.
535        auto EndPos = StartPos + Dict[i].size();
536        for (auto It = StartPos; It != EndPos; ++It)
537          *It ^= 0xFF;
538
539        StartPos = std::search(EndPos, Data.end(),
540                               Dict[i].begin(), Dict[i].end());
541      }
542
543      // Get coverage for testcase with masked occurrences of dictionary unit.
544      F->ExecuteCallback(Data.data(), Data.size());
545      ModifiedFeatures.clear();
546      TPC.CollectFeatures([&](size_t Feature) {
547        ModifiedFeatures.push_back(Feature);
548      });
549
550      if (InitialFeatures == ModifiedFeatures)
551        --Scores[i];
552      else
553        Scores[i] += 2;
554    }
555  }
556
557  Printf("###### Useless dictionary elements. ######\n");
558  for (size_t i = 0; i < Dict.size(); ++i) {
559    // Dictionary units with positive score are treated as useful ones.
560    if (Scores[i] > 0)
561       continue;
562
563    Printf("\"");
564    PrintASCII(Dict[i].data(), Dict[i].size(), "\"");
565    Printf(" # Score: %d, Used: %d\n", Scores[i], Usages[i]);
566  }
567  Printf("###### End of useless dictionary elements. ######\n");
568  return 0;
569}
570
571Vector<std::string> ParseSeedInuts(const char *seed_inputs) {
572  // Parse -seed_inputs=file1,file2,... or -seed_inputs=@seed_inputs_file
573  Vector<std::string> Files;
574  if (!seed_inputs) return Files;
575  std::string SeedInputs;
576  if (Flags.seed_inputs[0] == '@')
577    SeedInputs = FileToString(Flags.seed_inputs + 1); // File contains list.
578  else
579    SeedInputs = Flags.seed_inputs; // seed_inputs contains the list.
580  if (SeedInputs.empty()) {
581    Printf("seed_inputs is empty or @file does not exist.\n");
582    exit(1);
583  }
584  // Parse SeedInputs.
585  size_t comma_pos = 0;
586  while ((comma_pos = SeedInputs.find_last_of(',')) != std::string::npos) {
587    Files.push_back(SeedInputs.substr(comma_pos + 1));
588    SeedInputs = SeedInputs.substr(0, comma_pos);
589  }
590  Files.push_back(SeedInputs);
591  return Files;
592}
593
594static Vector<SizedFile> ReadCorpora(const Vector<std::string> &CorpusDirs,
595    const Vector<std::string> &ExtraSeedFiles) {
596  Vector<SizedFile> SizedFiles;
597  size_t LastNumFiles = 0;
598  for (auto &Dir : CorpusDirs) {
599    GetSizedFilesFromDir(Dir, &SizedFiles);
600    Printf("INFO: % 8zd files found in %s\n", SizedFiles.size() - LastNumFiles,
601           Dir.c_str());
602    LastNumFiles = SizedFiles.size();
603  }
604  for (auto &File : ExtraSeedFiles)
605    if (auto Size = FileSize(File))
606      SizedFiles.push_back({File, Size});
607  return SizedFiles;
608}
609
610int FuzzerDriver(int *argc, char ***argv, UserCallback Callback) {
611  using namespace fuzzer;
612  assert(argc && argv && "Argument pointers cannot be nullptr");
613  std::string Argv0((*argv)[0]);
614  EF = new ExternalFunctions();
615  if (EF->LLVMFuzzerInitialize)
616    EF->LLVMFuzzerInitialize(argc, argv);
617  if (EF->__msan_scoped_disable_interceptor_checks)
618    EF->__msan_scoped_disable_interceptor_checks();
619  const Vector<std::string> Args(*argv, *argv + *argc);
620  assert(!Args.empty());
621  ProgName = new std::string(Args[0]);
622  if (Argv0 != *ProgName) {
623    Printf("ERROR: argv[0] has been modified in LLVMFuzzerInitialize\n");
624    exit(1);
625  }
626  ParseFlags(Args, EF);
627  if (Flags.help) {
628    PrintHelp();
629    return 0;
630  }
631
632  if (Flags.close_fd_mask & 2)
633    DupAndCloseStderr();
634  if (Flags.close_fd_mask & 1)
635    CloseStdout();
636
637  if (Flags.jobs > 0 && Flags.workers == 0) {
638    Flags.workers = std::min(NumberOfCpuCores() / 2, Flags.jobs);
639    if (Flags.workers > 1)
640      Printf("Running %u workers\n", Flags.workers);
641  }
642
643  if (Flags.workers > 0 && Flags.jobs > 0)
644    return RunInMultipleProcesses(Args, Flags.workers, Flags.jobs);
645
646  FuzzingOptions Options;
647  Options.Verbosity = Flags.verbosity;
648  Options.MaxLen = Flags.max_len;
649  Options.LenControl = Flags.len_control;
650  Options.UnitTimeoutSec = Flags.timeout;
651  Options.ErrorExitCode = Flags.error_exitcode;
652  Options.TimeoutExitCode = Flags.timeout_exitcode;
653  Options.IgnoreTimeouts = Flags.ignore_timeouts;
654  Options.IgnoreOOMs = Flags.ignore_ooms;
655  Options.IgnoreCrashes = Flags.ignore_crashes;
656  Options.MaxTotalTimeSec = Flags.max_total_time;
657  Options.DoCrossOver = Flags.cross_over;
658  Options.MutateDepth = Flags.mutate_depth;
659  Options.ReduceDepth = Flags.reduce_depth;
660  Options.UseCounters = Flags.use_counters;
661  Options.UseMemmem = Flags.use_memmem;
662  Options.UseCmp = Flags.use_cmp;
663  Options.UseValueProfile = Flags.use_value_profile;
664  Options.Shrink = Flags.shrink;
665  Options.ReduceInputs = Flags.reduce_inputs;
666  Options.ShuffleAtStartUp = Flags.shuffle;
667  Options.PreferSmall = Flags.prefer_small;
668  Options.ReloadIntervalSec = Flags.reload;
669  Options.OnlyASCII = Flags.only_ascii;
670  Options.DetectLeaks = Flags.detect_leaks;
671  Options.PurgeAllocatorIntervalSec = Flags.purge_allocator_interval;
672  Options.TraceMalloc = Flags.trace_malloc;
673  Options.RssLimitMb = Flags.rss_limit_mb;
674  Options.MallocLimitMb = Flags.malloc_limit_mb;
675  if (!Options.MallocLimitMb)
676    Options.MallocLimitMb = Options.RssLimitMb;
677  if (Flags.runs >= 0)
678    Options.MaxNumberOfRuns = Flags.runs;
679  if (!Inputs->empty() && !Flags.minimize_crash_internal_step)
680    Options.OutputCorpus = (*Inputs)[0];
681  Options.ReportSlowUnits = Flags.report_slow_units;
682  if (Flags.artifact_prefix)
683    Options.ArtifactPrefix = Flags.artifact_prefix;
684  if (Flags.exact_artifact_path)
685    Options.ExactArtifactPath = Flags.exact_artifact_path;
686  Vector<Unit> Dictionary;
687  if (Flags.dict)
688    if (!ParseDictionaryFile(FileToString(Flags.dict), &Dictionary))
689      return 1;
690  if (Flags.verbosity > 0 && !Dictionary.empty())
691    Printf("Dictionary: %zd entries\n", Dictionary.size());
692  bool RunIndividualFiles = AllInputsAreFiles();
693  Options.SaveArtifacts =
694      !RunIndividualFiles || Flags.minimize_crash_internal_step;
695  Options.PrintNewCovPcs = Flags.print_pcs;
696  Options.PrintNewCovFuncs = Flags.print_funcs;
697  Options.PrintFinalStats = Flags.print_final_stats;
698  Options.PrintCorpusStats = Flags.print_corpus_stats;
699  Options.PrintCoverage = Flags.print_coverage;
700  if (Flags.exit_on_src_pos)
701    Options.ExitOnSrcPos = Flags.exit_on_src_pos;
702  if (Flags.exit_on_item)
703    Options.ExitOnItem = Flags.exit_on_item;
704  if (Flags.focus_function)
705    Options.FocusFunction = Flags.focus_function;
706  if (Flags.data_flow_trace)
707    Options.DataFlowTrace = Flags.data_flow_trace;
708  if (Flags.features_dir)
709    Options.FeaturesDir = Flags.features_dir;
710  if (Flags.collect_data_flow)
711    Options.CollectDataFlow = Flags.collect_data_flow;
712  if (Flags.stop_file)
713    Options.StopFile = Flags.stop_file;
714
715  unsigned Seed = Flags.seed;
716  // Initialize Seed.
717  if (Seed == 0)
718    Seed =
719        std::chrono::system_clock::now().time_since_epoch().count() + GetPid();
720  if (Flags.verbosity)
721    Printf("INFO: Seed: %u\n", Seed);
722
723  if (Flags.collect_data_flow && !Flags.fork && !Flags.merge) {
724    if (RunIndividualFiles)
725      return CollectDataFlow(Flags.collect_data_flow, Flags.data_flow_trace,
726                        ReadCorpora({}, *Inputs));
727    else
728      return CollectDataFlow(Flags.collect_data_flow, Flags.data_flow_trace,
729                        ReadCorpora(*Inputs, {}));
730  }
731
732  Random Rand(Seed);
733  auto *MD = new MutationDispatcher(Rand, Options);
734  auto *Corpus = new InputCorpus(Options.OutputCorpus);
735  auto *F = new Fuzzer(Callback, *Corpus, *MD, Options);
736
737  for (auto &U: Dictionary)
738    if (U.size() <= Word::GetMaxSize())
739      MD->AddWordToManualDictionary(Word(U.data(), U.size()));
740
741      // Threads are only supported by Chrome. Don't use them with emscripten
742      // for now.
743#if !LIBFUZZER_EMSCRIPTEN
744  StartRssThread(F, Flags.rss_limit_mb);
745#endif // LIBFUZZER_EMSCRIPTEN
746
747  Options.HandleAbrt = Flags.handle_abrt;
748  Options.HandleBus = Flags.handle_bus;
749  Options.HandleFpe = Flags.handle_fpe;
750  Options.HandleIll = Flags.handle_ill;
751  Options.HandleInt = Flags.handle_int;
752  Options.HandleSegv = Flags.handle_segv;
753  Options.HandleTerm = Flags.handle_term;
754  Options.HandleXfsz = Flags.handle_xfsz;
755  Options.HandleUsr1 = Flags.handle_usr1;
756  Options.HandleUsr2 = Flags.handle_usr2;
757  SetSignalHandler(Options);
758
759  std::atexit(Fuzzer::StaticExitCallback);
760
761  if (Flags.minimize_crash)
762    return MinimizeCrashInput(Args, Options);
763
764  if (Flags.minimize_crash_internal_step)
765    return MinimizeCrashInputInternalStep(F, Corpus);
766
767  if (Flags.cleanse_crash)
768    return CleanseCrashInput(Args, Options);
769
770  if (RunIndividualFiles) {
771    Options.SaveArtifacts = false;
772    int Runs = std::max(1, Flags.runs);
773    Printf("%s: Running %zd inputs %d time(s) each.\n", ProgName->c_str(),
774           Inputs->size(), Runs);
775    for (auto &Path : *Inputs) {
776      auto StartTime = system_clock::now();
777      Printf("Running: %s\n", Path.c_str());
778      for (int Iter = 0; Iter < Runs; Iter++)
779        RunOneTest(F, Path.c_str(), Options.MaxLen);
780      auto StopTime = system_clock::now();
781      auto MS = duration_cast<milliseconds>(StopTime - StartTime).count();
782      Printf("Executed %s in %zd ms\n", Path.c_str(), (long)MS);
783    }
784    Printf("***\n"
785           "*** NOTE: fuzzing was not performed, you have only\n"
786           "***       executed the target code on a fixed set of inputs.\n"
787           "***\n");
788    F->PrintFinalStats();
789    exit(0);
790  }
791
792  if (Flags.fork)
793    FuzzWithFork(F->GetMD().GetRand(), Options, Args, *Inputs, Flags.fork);
794
795  if (Flags.merge)
796    Merge(F, Options, Args, *Inputs, Flags.merge_control_file);
797
798  if (Flags.merge_inner) {
799    const size_t kDefaultMaxMergeLen = 1 << 20;
800    if (Options.MaxLen == 0)
801      F->SetMaxInputLen(kDefaultMaxMergeLen);
802    assert(Flags.merge_control_file);
803    F->CrashResistantMergeInternalStep(Flags.merge_control_file);
804    exit(0);
805  }
806
807  if (Flags.analyze_dict) {
808    size_t MaxLen = INT_MAX;  // Large max length.
809    UnitVector InitialCorpus;
810    for (auto &Inp : *Inputs) {
811      Printf("Loading corpus dir: %s\n", Inp.c_str());
812      ReadDirToVectorOfUnits(Inp.c_str(), &InitialCorpus, nullptr,
813                             MaxLen, /*ExitOnError=*/false);
814    }
815
816    if (Dictionary.empty() || Inputs->empty()) {
817      Printf("ERROR: can't analyze dict without dict and corpus provided\n");
818      return 1;
819    }
820    if (AnalyzeDictionary(F, Dictionary, InitialCorpus)) {
821      Printf("Dictionary analysis failed\n");
822      exit(1);
823    }
824    Printf("Dictionary analysis succeeded\n");
825    exit(0);
826  }
827
828  auto CorporaFiles = ReadCorpora(*Inputs, ParseSeedInuts(Flags.seed_inputs));
829  F->Loop(CorporaFiles);
830
831  if (Flags.verbosity)
832    Printf("Done %zd runs in %zd second(s)\n", F->getTotalNumberOfRuns(),
833           F->secondsSinceProcessStartUp());
834  F->PrintFinalStats();
835
836  exit(0);  // Don't let F destroy itself.
837}
838
839// Storage for global ExternalFunctions object.
840ExternalFunctions *EF = nullptr;
841
842}  // namespace fuzzer
843