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 "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 <mutex>
28#include <string>
29#include <thread>
30#include <fstream>
31
32// This function should be present in the libFuzzer so that the client
33// binary can test for its existence.
34#if LIBFUZZER_MSVC
35extern "C" void __libfuzzer_is_present() {}
36#if defined(_M_IX86) || defined(__i386__)
37#pragma comment(linker, "/include:___libfuzzer_is_present")
38#else
39#pragma comment(linker, "/include:__libfuzzer_is_present")
40#endif
41#else
42extern "C" __attribute__((used)) void __libfuzzer_is_present() {}
43#endif // LIBFUZZER_MSVC
44
45namespace fuzzer {
46
47// Program arguments.
48struct FlagDescription {
49 const char *Name;
50 const char *Description;
51 int Default;
52 int *IntFlag;
53 const char **StrFlag;
54 unsigned int *UIntFlag;
55};
56
57struct {
58#define FUZZER_DEPRECATED_FLAG(Name)
59#define FUZZER_FLAG_INT(Name, Default, Description) int Name;
60#define FUZZER_FLAG_UNSIGNED(Name, Default, Description) unsigned int Name;
61#define FUZZER_FLAG_STRING(Name, Description) const char *Name;
62#include "FuzzerFlags.def"
63#undef FUZZER_DEPRECATED_FLAG
64#undef FUZZER_FLAG_INT
65#undef FUZZER_FLAG_UNSIGNED
66#undef FUZZER_FLAG_STRING
67} Flags;
68
69static const FlagDescription FlagDescriptions [] {
70#define FUZZER_DEPRECATED_FLAG(Name) \
71 {#Name, "Deprecated; don't use", 0, nullptr, nullptr, nullptr},
72#define FUZZER_FLAG_INT(Name, Default, Description) \
73 {#Name, Description, Default, &Flags.Name, nullptr, nullptr},
74#define FUZZER_FLAG_UNSIGNED(Name, Default, Description) \
75 {#Name, Description, static_cast<int>(Default), \
76 nullptr, nullptr, &Flags.Name},
77#define FUZZER_FLAG_STRING(Name, Description) \
78 {#Name, Description, 0, nullptr, &Flags.Name, nullptr},
79#include "FuzzerFlags.def"
80#undef FUZZER_DEPRECATED_FLAG
81#undef FUZZER_FLAG_INT
82#undef FUZZER_FLAG_UNSIGNED
83#undef FUZZER_FLAG_STRING
84};
85
86static const size_t kNumFlags =
87 sizeof(FlagDescriptions) / sizeof(FlagDescriptions[0]);
88
89static std::vector<std::string> *Inputs;
90static std::string *ProgName;
91
92static void PrintHelp() {
93 Printf(Fmt: "Usage:\n");
94 auto Prog = ProgName->c_str();
95 Printf(Fmt: "\nTo run fuzzing pass 0 or more directories.\n");
96 Printf(Fmt: "%s [-flag1=val1 [-flag2=val2 ...] ] [dir1 [dir2 ...] ]\n", Prog);
97
98 Printf(Fmt: "\nTo run individual tests without fuzzing pass 1 or more files:\n");
99 Printf(Fmt: "%s [-flag1=val1 [-flag2=val2 ...] ] file1 [file2 ...]\n", Prog);
100
101 Printf(Fmt: "\nFlags: (strictly in form -flag=value)\n");
102 size_t MaxFlagLen = 0;
103 for (size_t F = 0; F < kNumFlags; F++)
104 MaxFlagLen = std::max(a: strlen(s: FlagDescriptions[F].Name), b: MaxFlagLen);
105
106 for (size_t F = 0; F < kNumFlags; F++) {
107 const auto &D = FlagDescriptions[F];
108 if (strstr(haystack: D.Description, needle: "internal flag") == D.Description) continue;
109 Printf(Fmt: " %s", D.Name);
110 for (size_t i = 0, n = MaxFlagLen - strlen(s: D.Name); i < n; i++)
111 Printf(Fmt: " ");
112 Printf(Fmt: "\t");
113 Printf(Fmt: "%d\t%s\n", D.Default, D.Description);
114 }
115 Printf(Fmt: "\nFlags starting with '--' will be ignored and "
116 "will be passed verbatim to subprocesses.\n");
117}
118
119static const char *FlagValue(const char *Param, const char *Name) {
120 size_t Len = strlen(s: Name);
121 if (Param[0] == '-' && strstr(haystack: Param + 1, needle: Name) == Param + 1 &&
122 Param[Len + 1] == '=')
123 return &Param[Len + 2];
124 return nullptr;
125}
126
127// Avoid calling stol as it triggers a bug in clang/glibc build.
128static long MyStol(const char *Str) {
129 long Res = 0;
130 long Sign = 1;
131 if (*Str == '-') {
132 Str++;
133 Sign = -1;
134 }
135 for (size_t i = 0; Str[i]; i++) {
136 char Ch = Str[i];
137 if (Ch < '0' || Ch > '9')
138 return Res;
139 Res = Res * 10 + (Ch - '0');
140 }
141 return Res * Sign;
142}
143
144static bool ParseOneFlag(const char *Param) {
145 if (Param[0] != '-') return false;
146 if (Param[1] == '-') {
147 static bool PrintedWarning = false;
148 if (!PrintedWarning) {
149 PrintedWarning = true;
150 Printf(Fmt: "INFO: libFuzzer ignores flags that start with '--'\n");
151 }
152 for (size_t F = 0; F < kNumFlags; F++)
153 if (FlagValue(Param: Param + 1, Name: FlagDescriptions[F].Name))
154 Printf(Fmt: "WARNING: did you mean '%s' (single dash)?\n", Param + 1);
155 return true;
156 }
157 for (size_t F = 0; F < kNumFlags; F++) {
158 const char *Name = FlagDescriptions[F].Name;
159 const char *Str = FlagValue(Param, Name);
160 if (Str) {
161 if (FlagDescriptions[F].IntFlag) {
162 auto Val = MyStol(Str);
163 *FlagDescriptions[F].IntFlag = static_cast<int>(Val);
164 if (Flags.verbosity >= 2)
165 Printf(Fmt: "Flag: %s %d\n", Name, Val);
166 return true;
167 } else if (FlagDescriptions[F].UIntFlag) {
168 auto Val = std::stoul(str: Str);
169 *FlagDescriptions[F].UIntFlag = static_cast<unsigned int>(Val);
170 if (Flags.verbosity >= 2)
171 Printf(Fmt: "Flag: %s %u\n", Name, Val);
172 return true;
173 } else if (FlagDescriptions[F].StrFlag) {
174 *FlagDescriptions[F].StrFlag = Str;
175 if (Flags.verbosity >= 2)
176 Printf(Fmt: "Flag: %s %s\n", Name, Str);
177 return true;
178 } else { // Deprecated flag.
179 Printf(Fmt: "Flag: %s: deprecated, don't use\n", Name);
180 return true;
181 }
182 }
183 }
184 Printf(Fmt: "\n\nWARNING: unrecognized flag '%s'; "
185 "use -help=1 to list all flags\n\n", Param);
186 return true;
187}
188
189// We don't use any library to minimize dependencies.
190static void ParseFlags(const std::vector<std::string> &Args,
191 const ExternalFunctions *EF) {
192 for (size_t F = 0; F < kNumFlags; F++) {
193 if (FlagDescriptions[F].IntFlag)
194 *FlagDescriptions[F].IntFlag = FlagDescriptions[F].Default;
195 if (FlagDescriptions[F].UIntFlag)
196 *FlagDescriptions[F].UIntFlag =
197 static_cast<unsigned int>(FlagDescriptions[F].Default);
198 if (FlagDescriptions[F].StrFlag)
199 *FlagDescriptions[F].StrFlag = nullptr;
200 }
201
202 // Disable len_control by default, if LLVMFuzzerCustomMutator is used.
203 if (EF->LLVMFuzzerCustomMutator) {
204 Flags.len_control = 0;
205 Printf(Fmt: "INFO: found LLVMFuzzerCustomMutator (%p). "
206 "Disabling -len_control by default.\n", EF->LLVMFuzzerCustomMutator);
207 }
208
209 Inputs = new std::vector<std::string>;
210 for (size_t A = 1; A < Args.size(); A++) {
211 if (ParseOneFlag(Param: Args[A].c_str())) {
212 if (Flags.ignore_remaining_args)
213 break;
214 continue;
215 }
216 Inputs->push_back(x: Args[A]);
217 }
218}
219
220static std::mutex Mu;
221
222static void PulseThread() {
223 while (true) {
224 SleepSeconds(Seconds: 600);
225 std::lock_guard<std::mutex> Lock(Mu);
226 Printf(Fmt: "pulse...\n");
227 }
228}
229
230static void WorkerThread(const Command &BaseCmd, std::atomic<unsigned> *Counter,
231 unsigned NumJobs, std::atomic<bool> *HasErrors) {
232 while (true) {
233 unsigned C = (*Counter)++;
234 if (C >= NumJobs) break;
235 std::string Log = "fuzz-" + std::to_string(val: C) + ".log";
236 Command Cmd(BaseCmd);
237 Cmd.setOutputFile(Log);
238 Cmd.combineOutAndErr();
239 if (Flags.verbosity) {
240 std::string CommandLine = Cmd.toString();
241 Printf(Fmt: "%s\n", CommandLine.c_str());
242 }
243 int ExitCode = ExecuteCommand(Cmd);
244 if (ExitCode != 0)
245 *HasErrors = true;
246 std::lock_guard<std::mutex> Lock(Mu);
247 Printf(Fmt: "================== Job %u exited with exit code %d ============\n",
248 C, ExitCode);
249 fuzzer::CopyFileToErr(Path: Log);
250 }
251}
252
253static void ValidateDirectoryExists(const std::string &Path,
254 bool CreateDirectory) {
255 if (Path.empty()) {
256 Printf(Fmt: "ERROR: Provided directory path is an empty string\n");
257 exit(status: 1);
258 }
259
260 if (IsDirectory(Path))
261 return;
262
263 if (CreateDirectory) {
264 if (!MkDirRecursive(Dir: Path)) {
265 Printf(Fmt: "ERROR: Failed to create directory \"%s\"\n", Path.c_str());
266 exit(status: 1);
267 }
268 return;
269 }
270
271 Printf(Fmt: "ERROR: The required directory \"%s\" does not exist\n", Path.c_str());
272 exit(status: 1);
273}
274
275std::string CloneArgsWithoutX(const std::vector<std::string> &Args,
276 const char *X1, const char *X2) {
277 std::string Cmd;
278 for (auto &S : Args) {
279 if (FlagValue(Param: S.c_str(), Name: X1) || FlagValue(Param: S.c_str(), Name: X2))
280 continue;
281 Cmd += S + " ";
282 }
283 return Cmd;
284}
285
286static int RunInMultipleProcesses(const std::vector<std::string> &Args,
287 unsigned NumWorkers, unsigned NumJobs) {
288 std::atomic<unsigned> Counter(0);
289 std::atomic<bool> HasErrors(false);
290 Command Cmd(Args);
291 Cmd.removeFlag(Flag: "jobs");
292 Cmd.removeFlag(Flag: "workers");
293 std::vector<std::thread> V;
294 std::thread Pulse(PulseThread);
295 Pulse.detach();
296 V.resize(new_size: NumWorkers);
297 for (unsigned i = 0; i < NumWorkers; i++) {
298 V[i] = std::thread(WorkerThread, std::ref(t&: Cmd), &Counter, NumJobs,
299 &HasErrors);
300 SetThreadName(thread&: V[i], name: "FuzzerWorker");
301 }
302 for (auto &T : V)
303 T.join();
304 return HasErrors ? 1 : 0;
305}
306
307static void RssThread(Fuzzer *F, size_t RssLimitMb) {
308 while (true) {
309 SleepSeconds(Seconds: 1);
310 size_t Peak = GetPeakRSSMb();
311 if (Peak > RssLimitMb)
312 F->RssLimitCallback();
313 }
314}
315
316static void StartRssThread(Fuzzer *F, size_t RssLimitMb) {
317 if (!RssLimitMb)
318 return;
319 std::thread T(RssThread, F, RssLimitMb);
320 T.detach();
321}
322
323int RunOneTest(Fuzzer *F, const char *InputFilePath, size_t MaxLen) {
324 Unit U = FileToVector(Path: InputFilePath);
325 if (MaxLen && MaxLen < U.size())
326 U.resize(new_size: MaxLen);
327 F->ExecuteCallback(Data: U.data(), Size: U.size());
328 if (Flags.print_full_coverage) {
329 // Leak detection is not needed when collecting full coverage data.
330 F->TPCUpdateObservedPCs();
331 } else {
332 F->TryDetectingAMemoryLeak(Data: U.data(), Size: U.size(), DuringInitialCorpusExecution: true);
333 }
334 return 0;
335}
336
337static bool AllInputsAreFiles() {
338 if (Inputs->empty()) return false;
339 for (auto &Path : *Inputs)
340 if (!IsFile(Path))
341 return false;
342 return true;
343}
344
345static std::string GetDedupTokenFromCmdOutput(const std::string &S) {
346 auto Beg = S.find(s: "DEDUP_TOKEN:");
347 if (Beg == std::string::npos)
348 return "";
349 auto End = S.find(c: '\n', pos: Beg);
350 if (End == std::string::npos)
351 return "";
352 return S.substr(pos: Beg, n: End - Beg);
353}
354
355int CleanseCrashInput(const std::vector<std::string> &Args,
356 const FuzzingOptions &Options) {
357 if (Inputs->size() != 1 || !Flags.exact_artifact_path) {
358 Printf(Fmt: "ERROR: -cleanse_crash should be given one input file and"
359 " -exact_artifact_path\n");
360 exit(status: 1);
361 }
362 std::string InputFilePath = Inputs->at(n: 0);
363 std::string OutputFilePath = Flags.exact_artifact_path;
364 Command Cmd(Args);
365 Cmd.removeFlag(Flag: "cleanse_crash");
366
367 assert(Cmd.hasArgument(InputFilePath));
368 Cmd.removeArgument(Arg: InputFilePath);
369
370 auto TmpFilePath = TempPath(Prefix: "CleanseCrashInput", Extension: ".repro");
371 Cmd.addArgument(Arg: TmpFilePath);
372 Cmd.setOutputFile(getDevNull());
373 Cmd.combineOutAndErr();
374
375 std::string CurrentFilePath = InputFilePath;
376 auto U = FileToVector(Path: CurrentFilePath);
377 size_t Size = U.size();
378
379 const std::vector<uint8_t> ReplacementBytes = {' ', 0xff};
380 for (int NumAttempts = 0; NumAttempts < 5; NumAttempts++) {
381 bool Changed = false;
382 for (size_t Idx = 0; Idx < Size; Idx++) {
383 Printf(Fmt: "CLEANSE[%d]: Trying to replace byte %zd of %zd\n", NumAttempts,
384 Idx, Size);
385 uint8_t OriginalByte = U[Idx];
386 if (ReplacementBytes.end() != std::find(first: ReplacementBytes.begin(),
387 last: ReplacementBytes.end(),
388 val: OriginalByte))
389 continue;
390 for (auto NewByte : ReplacementBytes) {
391 U[Idx] = NewByte;
392 WriteToFile(U, Path: TmpFilePath);
393 auto ExitCode = ExecuteCommand(Cmd);
394 RemoveFile(Path: TmpFilePath);
395 if (!ExitCode) {
396 U[Idx] = OriginalByte;
397 } else {
398 Changed = true;
399 Printf(Fmt: "CLEANSE: Replaced byte %zd with 0x%x\n", Idx, NewByte);
400 WriteToFile(U, Path: OutputFilePath);
401 break;
402 }
403 }
404 }
405 if (!Changed) break;
406 }
407 return 0;
408}
409
410int MinimizeCrashInput(const std::vector<std::string> &Args,
411 const FuzzingOptions &Options) {
412 if (Inputs->size() != 1) {
413 Printf(Fmt: "ERROR: -minimize_crash should be given one input file\n");
414 exit(status: 1);
415 }
416 std::string InputFilePath = Inputs->at(n: 0);
417 Command BaseCmd(Args);
418 BaseCmd.removeFlag(Flag: "minimize_crash");
419 BaseCmd.removeFlag(Flag: "exact_artifact_path");
420 assert(BaseCmd.hasArgument(InputFilePath));
421 BaseCmd.removeArgument(Arg: InputFilePath);
422 if (Flags.runs <= 0 && Flags.max_total_time == 0) {
423 Printf(Fmt: "INFO: you need to specify -runs=N or "
424 "-max_total_time=N with -minimize_crash=1\n"
425 "INFO: defaulting to -max_total_time=600\n");
426 BaseCmd.addFlag(Flag: "max_total_time", Value: "600");
427 }
428
429 BaseCmd.combineOutAndErr();
430
431 std::string CurrentFilePath = InputFilePath;
432 while (true) {
433 Unit U = FileToVector(Path: CurrentFilePath);
434 Printf(Fmt: "CRASH_MIN: minimizing crash input: '%s' (%zd bytes)\n",
435 CurrentFilePath.c_str(), U.size());
436
437 Command Cmd(BaseCmd);
438 Cmd.addArgument(Arg: CurrentFilePath);
439
440 Printf(Fmt: "CRASH_MIN: executing: %s\n", Cmd.toString().c_str());
441 std::string CmdOutput;
442 bool Success = ExecuteCommand(Cmd, CmdOutput: &CmdOutput);
443 if (Success) {
444 Printf(Fmt: "ERROR: the input %s did not crash\n", CurrentFilePath.c_str());
445 exit(status: 1);
446 }
447 Printf(Fmt: "CRASH_MIN: '%s' (%zd bytes) caused a crash. Will try to minimize "
448 "it further\n",
449 CurrentFilePath.c_str(), U.size());
450 auto DedupToken1 = GetDedupTokenFromCmdOutput(S: CmdOutput);
451 if (!DedupToken1.empty())
452 Printf(Fmt: "CRASH_MIN: DedupToken1: %s\n", DedupToken1.c_str());
453
454 std::string ArtifactPath =
455 Flags.exact_artifact_path
456 ? Flags.exact_artifact_path
457 : Options.ArtifactPrefix + "minimized-from-" + Hash(U);
458 Cmd.addFlag(Flag: "minimize_crash_internal_step", Value: "1");
459 Cmd.addFlag(Flag: "exact_artifact_path", Value: ArtifactPath);
460 Printf(Fmt: "CRASH_MIN: executing: %s\n", Cmd.toString().c_str());
461 CmdOutput.clear();
462 Success = ExecuteCommand(Cmd, CmdOutput: &CmdOutput);
463 Printf(Fmt: "%s", CmdOutput.c_str());
464 if (Success) {
465 if (Flags.exact_artifact_path) {
466 CurrentFilePath = Flags.exact_artifact_path;
467 WriteToFile(U, Path: CurrentFilePath);
468 }
469 Printf(Fmt: "CRASH_MIN: failed to minimize beyond %s (%zu bytes), exiting\n",
470 CurrentFilePath.c_str(), U.size());
471 break;
472 }
473 auto DedupToken2 = GetDedupTokenFromCmdOutput(S: CmdOutput);
474 if (!DedupToken2.empty())
475 Printf(Fmt: "CRASH_MIN: DedupToken2: %s\n", DedupToken2.c_str());
476
477 if (DedupToken1 != DedupToken2) {
478 if (Flags.exact_artifact_path) {
479 CurrentFilePath = Flags.exact_artifact_path;
480 WriteToFile(U, Path: CurrentFilePath);
481 }
482 Printf(Fmt: "CRASH_MIN: mismatch in dedup tokens"
483 " (looks like a different bug). Won't minimize further\n");
484 break;
485 }
486
487 CurrentFilePath = ArtifactPath;
488 Printf(Fmt: "*********************************\n");
489 }
490 return 0;
491}
492
493int MinimizeCrashInputInternalStep(Fuzzer *F, InputCorpus *Corpus) {
494 assert(Inputs->size() == 1);
495 std::string InputFilePath = Inputs->at(n: 0);
496 Unit U = FileToVector(Path: InputFilePath);
497 Printf(Fmt: "INFO: Starting MinimizeCrashInputInternalStep: %zd\n", U.size());
498 if (U.size() < 2) {
499 Printf(Fmt: "INFO: The input is small enough, exiting\n");
500 exit(status: 0);
501 }
502 F->SetMaxInputLen(U.size());
503 F->SetMaxMutationLen(U.size() - 1);
504 F->MinimizeCrashLoop(U);
505 Printf(Fmt: "INFO: Done MinimizeCrashInputInternalStep, no crashes found\n");
506 exit(status: 0);
507}
508
509void Merge(Fuzzer *F, FuzzingOptions &Options,
510 const std::vector<std::string> &Args,
511 const std::vector<std::string> &Corpora, const char *CFPathOrNull) {
512 if (Corpora.size() < 2) {
513 Printf(Fmt: "INFO: Merge requires two or more corpus dirs\n");
514 exit(status: 0);
515 }
516
517 std::vector<SizedFile> OldCorpus, NewCorpus;
518 GetSizedFilesFromDir(Dir: Corpora[0], V: &OldCorpus);
519 for (size_t i = 1; i < Corpora.size(); i++)
520 GetSizedFilesFromDir(Dir: Corpora[i], V: &NewCorpus);
521 std::sort(first: OldCorpus.begin(), last: OldCorpus.end());
522 std::sort(first: NewCorpus.begin(), last: NewCorpus.end());
523
524 std::string CFPath = CFPathOrNull ? CFPathOrNull : TempPath(Prefix: "Merge", Extension: ".txt");
525 std::vector<std::string> NewFiles;
526 std::set<uint32_t> NewFeatures, NewCov;
527 CrashResistantMerge(Args, OldCorpus, NewCorpus, NewFiles: &NewFiles, InitialFeatures: {}, NewFeatures: &NewFeatures,
528 InitialCov: {}, NewCov: &NewCov, CFPath, Verbose: true, IsSetCoverMerge: Flags.set_cover_merge);
529 for (auto &Path : NewFiles)
530 F->WriteToOutputCorpus(U: FileToVector(Path, MaxSize: Options.MaxLen));
531 // We are done, delete the control file if it was a temporary one.
532 if (!Flags.merge_control_file)
533 RemoveFile(Path: CFPath);
534
535 exit(status: 0);
536}
537
538int AnalyzeDictionary(Fuzzer *F, const std::vector<Unit> &Dict,
539 UnitVector &Corpus) {
540 Printf(Fmt: "Started dictionary minimization (up to %zu tests)\n",
541 Dict.size() * Corpus.size() * 2);
542
543 // Scores and usage count for each dictionary unit.
544 std::vector<int> Scores(Dict.size());
545 std::vector<int> Usages(Dict.size());
546
547 std::vector<size_t> InitialFeatures;
548 std::vector<size_t> ModifiedFeatures;
549 for (auto &C : Corpus) {
550 // Get coverage for the testcase without modifications.
551 F->ExecuteCallback(Data: C.data(), Size: C.size());
552 InitialFeatures.clear();
553 TPC.CollectFeatures(HandleFeature: [&](size_t Feature) {
554 InitialFeatures.push_back(x: Feature);
555 });
556
557 for (size_t i = 0; i < Dict.size(); ++i) {
558 std::vector<uint8_t> Data = C;
559 auto StartPos = std::search(first1: Data.begin(), last1: Data.end(),
560 first2: Dict[i].begin(), last2: Dict[i].end());
561 // Skip dictionary unit, if the testcase does not contain it.
562 if (StartPos == Data.end())
563 continue;
564
565 ++Usages[i];
566 while (StartPos != Data.end()) {
567 // Replace all occurrences of dictionary unit in the testcase.
568 auto EndPos = StartPos + Dict[i].size();
569 for (auto It = StartPos; It != EndPos; ++It)
570 *It ^= 0xFF;
571
572 StartPos = std::search(first1: EndPos, last1: Data.end(),
573 first2: Dict[i].begin(), last2: Dict[i].end());
574 }
575
576 // Get coverage for testcase with masked occurrences of dictionary unit.
577 F->ExecuteCallback(Data: Data.data(), Size: Data.size());
578 ModifiedFeatures.clear();
579 TPC.CollectFeatures(HandleFeature: [&](size_t Feature) {
580 ModifiedFeatures.push_back(x: Feature);
581 });
582
583 if (InitialFeatures == ModifiedFeatures)
584 --Scores[i];
585 else
586 Scores[i] += 2;
587 }
588 }
589
590 Printf(Fmt: "###### Useless dictionary elements. ######\n");
591 for (size_t i = 0; i < Dict.size(); ++i) {
592 // Dictionary units with positive score are treated as useful ones.
593 if (Scores[i] > 0)
594 continue;
595
596 Printf(Fmt: "\"");
597 PrintASCII(Data: Dict[i].data(), Size: Dict[i].size(), PrintAfter: "\"");
598 Printf(Fmt: " # Score: %d, Used: %d\n", Scores[i], Usages[i]);
599 }
600 Printf(Fmt: "###### End of useless dictionary elements. ######\n");
601 return 0;
602}
603
604std::vector<std::string> ParseSeedInuts(const char *seed_inputs) {
605 // Parse -seed_inputs=file1,file2,... or -seed_inputs=@seed_inputs_file
606 std::vector<std::string> Files;
607 if (!seed_inputs) return Files;
608 std::string SeedInputs;
609 if (Flags.seed_inputs[0] == '@')
610 SeedInputs = FileToString(Path: Flags.seed_inputs + 1); // File contains list.
611 else
612 SeedInputs = Flags.seed_inputs; // seed_inputs contains the list.
613 if (SeedInputs.empty()) {
614 Printf(Fmt: "seed_inputs is empty or @file does not exist.\n");
615 exit(status: 1);
616 }
617 // Parse SeedInputs.
618 size_t comma_pos = 0;
619 while ((comma_pos = SeedInputs.find_last_of(c: ',')) != std::string::npos) {
620 Files.push_back(x: SeedInputs.substr(pos: comma_pos + 1));
621 SeedInputs = SeedInputs.substr(pos: 0, n: comma_pos);
622 }
623 Files.push_back(x: SeedInputs);
624 return Files;
625}
626
627static std::vector<SizedFile>
628ReadCorpora(const std::vector<std::string> &CorpusDirs,
629 const std::vector<std::string> &ExtraSeedFiles) {
630 std::vector<SizedFile> SizedFiles;
631 size_t LastNumFiles = 0;
632 for (auto &Dir : CorpusDirs) {
633 GetSizedFilesFromDir(Dir, V: &SizedFiles);
634 Printf(Fmt: "INFO: % 8zd files found in %s\n", SizedFiles.size() - LastNumFiles,
635 Dir.c_str());
636 LastNumFiles = SizedFiles.size();
637 }
638 for (auto &File : ExtraSeedFiles)
639 if (auto Size = FileSize(Path: File))
640 SizedFiles.push_back(x: {.File: File, .Size: Size});
641 return SizedFiles;
642}
643
644int FuzzerDriver(int *argc, char ***argv, UserCallback Callback) {
645 using namespace fuzzer;
646 assert(argc && argv && "Argument pointers cannot be nullptr");
647 std::string Argv0((*argv)[0]);
648 EF = new ExternalFunctions();
649 if (EF->LLVMFuzzerInitialize)
650 EF->LLVMFuzzerInitialize(argc, argv);
651 if (EF->__msan_scoped_disable_interceptor_checks)
652 EF->__msan_scoped_disable_interceptor_checks();
653 const std::vector<std::string> Args(*argv, *argv + *argc);
654 assert(!Args.empty());
655 ProgName = new std::string(Args[0]);
656 if (Argv0 != *ProgName) {
657 Printf(Fmt: "ERROR: argv[0] has been modified in LLVMFuzzerInitialize\n");
658 exit(status: 1);
659 }
660 ParseFlags(Args, EF);
661 if (Flags.help) {
662 PrintHelp();
663 return 0;
664 }
665
666 if (Flags.close_fd_mask & 2)
667 DupAndCloseStderr();
668 if (Flags.close_fd_mask & 1)
669 CloseStdout();
670
671 if (Flags.jobs > 0 && Flags.workers == 0) {
672 Flags.workers = std::min(a: NumberOfCpuCores() / 2, b: Flags.jobs);
673 if (Flags.workers > 1)
674 Printf(Fmt: "Running %u workers\n", Flags.workers);
675 }
676
677 if (Flags.workers > 0 && Flags.jobs > 0)
678 return RunInMultipleProcesses(Args, NumWorkers: Flags.workers, NumJobs: Flags.jobs);
679
680 FuzzingOptions Options;
681 Options.Verbosity = Flags.verbosity;
682 Options.MaxLen = Flags.max_len;
683 Options.LenControl = Flags.len_control;
684 Options.KeepSeed = Flags.keep_seed;
685 Options.UnitTimeoutSec = Flags.timeout;
686 Options.ErrorExitCode = Flags.error_exitcode;
687 Options.TimeoutExitCode = Flags.timeout_exitcode;
688 Options.IgnoreTimeouts = Flags.ignore_timeouts;
689 Options.IgnoreOOMs = Flags.ignore_ooms;
690 Options.IgnoreCrashes = Flags.ignore_crashes;
691 Options.MaxTotalTimeSec = Flags.max_total_time;
692 Options.DoCrossOver = Flags.cross_over;
693 Options.CrossOverUniformDist = Flags.cross_over_uniform_dist;
694 Options.MutateDepth = Flags.mutate_depth;
695 Options.ReduceDepth = Flags.reduce_depth;
696 Options.UseCounters = Flags.use_counters;
697 Options.UseMemmem = Flags.use_memmem;
698 Options.UseCmp = Flags.use_cmp;
699 Options.UseValueProfile = Flags.use_value_profile;
700 Options.Shrink = Flags.shrink;
701 Options.ReduceInputs = Flags.reduce_inputs;
702 Options.ShuffleAtStartUp = Flags.shuffle;
703 Options.PreferSmall = Flags.prefer_small;
704 Options.ReloadIntervalSec = Flags.reload;
705 Options.OnlyASCII = Flags.only_ascii;
706 Options.DetectLeaks = Flags.detect_leaks;
707 Options.PurgeAllocatorIntervalSec = Flags.purge_allocator_interval;
708 Options.TraceMalloc = Flags.trace_malloc;
709 Options.RssLimitMb = Flags.rss_limit_mb;
710 Options.MallocLimitMb = Flags.malloc_limit_mb;
711 if (!Options.MallocLimitMb)
712 Options.MallocLimitMb = Options.RssLimitMb;
713 if (Flags.runs >= 0)
714 Options.MaxNumberOfRuns = Flags.runs;
715 if (!Inputs->empty() && !Flags.minimize_crash_internal_step) {
716 // Ensure output corpus assumed to be the first arbitrary argument input
717 // is not a path to an existing file.
718 std::string OutputCorpusDir = (*Inputs)[0];
719 if (!IsFile(Path: OutputCorpusDir)) {
720 Options.OutputCorpus = OutputCorpusDir;
721 ValidateDirectoryExists(Path: Options.OutputCorpus, CreateDirectory: Flags.create_missing_dirs);
722 }
723 }
724 Options.ReportSlowUnits = Flags.report_slow_units;
725 if (Flags.artifact_prefix) {
726 Options.ArtifactPrefix = Flags.artifact_prefix;
727
728 // Since the prefix could be a full path to a file name prefix, assume
729 // that if the path ends with the platform's separator that a directory
730 // is desired
731 std::string ArtifactPathDir = Options.ArtifactPrefix;
732 if (!IsSeparator(C: ArtifactPathDir[ArtifactPathDir.length() - 1])) {
733 ArtifactPathDir = DirName(FileName: ArtifactPathDir);
734 }
735 ValidateDirectoryExists(Path: ArtifactPathDir, CreateDirectory: Flags.create_missing_dirs);
736 }
737 if (Flags.exact_artifact_path) {
738 Options.ExactArtifactPath = Flags.exact_artifact_path;
739 ValidateDirectoryExists(Path: DirName(FileName: Options.ExactArtifactPath),
740 CreateDirectory: Flags.create_missing_dirs);
741 }
742 std::vector<Unit> Dictionary;
743 if (Flags.dict)
744 if (!ParseDictionaryFile(Text: FileToString(Path: Flags.dict), Units: &Dictionary))
745 return 1;
746 if (Flags.verbosity > 0 && !Dictionary.empty())
747 Printf(Fmt: "Dictionary: %zd entries\n", Dictionary.size());
748 bool RunIndividualFiles = AllInputsAreFiles();
749 Options.SaveArtifacts =
750 !RunIndividualFiles || Flags.minimize_crash_internal_step;
751 Options.PrintNewCovPcs = Flags.print_pcs;
752 Options.PrintNewCovFuncs = Flags.print_funcs;
753 Options.PrintFinalStats = Flags.print_final_stats;
754 Options.PrintCorpusStats = Flags.print_corpus_stats;
755 Options.PrintCoverage = Flags.print_coverage;
756 Options.PrintFullCoverage = Flags.print_full_coverage;
757 if (Flags.exit_on_src_pos)
758 Options.ExitOnSrcPos = Flags.exit_on_src_pos;
759 if (Flags.exit_on_item)
760 Options.ExitOnItem = Flags.exit_on_item;
761 if (Flags.focus_function)
762 Options.FocusFunction = Flags.focus_function;
763 if (Flags.data_flow_trace)
764 Options.DataFlowTrace = Flags.data_flow_trace;
765 if (Flags.features_dir) {
766 Options.FeaturesDir = Flags.features_dir;
767 ValidateDirectoryExists(Path: Options.FeaturesDir, CreateDirectory: Flags.create_missing_dirs);
768 }
769 if (Flags.mutation_graph_file)
770 Options.MutationGraphFile = Flags.mutation_graph_file;
771 if (Flags.collect_data_flow)
772 Options.CollectDataFlow = Flags.collect_data_flow;
773 if (Flags.stop_file)
774 Options.StopFile = Flags.stop_file;
775 Options.Entropic = Flags.entropic;
776 Options.EntropicFeatureFrequencyThreshold =
777 (size_t)Flags.entropic_feature_frequency_threshold;
778 Options.EntropicNumberOfRarestFeatures =
779 (size_t)Flags.entropic_number_of_rarest_features;
780 Options.EntropicScalePerExecTime = Flags.entropic_scale_per_exec_time;
781 if (!Options.FocusFunction.empty())
782 Options.Entropic = false; // FocusFunction overrides entropic scheduling.
783 if (Options.Entropic)
784 Printf(Fmt: "INFO: Running with entropic power schedule (0x%zX, %zu).\n",
785 Options.EntropicFeatureFrequencyThreshold,
786 Options.EntropicNumberOfRarestFeatures);
787 struct EntropicOptions Entropic;
788 Entropic.Enabled = Options.Entropic;
789 Entropic.FeatureFrequencyThreshold =
790 Options.EntropicFeatureFrequencyThreshold;
791 Entropic.NumberOfRarestFeatures = Options.EntropicNumberOfRarestFeatures;
792 Entropic.ScalePerExecTime = Options.EntropicScalePerExecTime;
793
794 unsigned Seed = Flags.seed;
795 // Initialize Seed.
796 if (Seed == 0)
797 Seed = static_cast<unsigned>(
798 std::chrono::system_clock::now().time_since_epoch().count() + GetPid());
799 if (Flags.verbosity)
800 Printf(Fmt: "INFO: Seed: %u\n", Seed);
801
802 if (Flags.collect_data_flow && Flags.data_flow_trace && !Flags.fork &&
803 !(Flags.merge || Flags.set_cover_merge)) {
804 if (RunIndividualFiles)
805 return CollectDataFlow(DFTBinary: Flags.collect_data_flow, DirPath: Flags.data_flow_trace,
806 CorporaFiles: ReadCorpora(CorpusDirs: {}, ExtraSeedFiles: *Inputs));
807 else
808 return CollectDataFlow(DFTBinary: Flags.collect_data_flow, DirPath: Flags.data_flow_trace,
809 CorporaFiles: ReadCorpora(CorpusDirs: *Inputs, ExtraSeedFiles: {}));
810 }
811
812 Random Rand(Seed);
813 auto *MD = new MutationDispatcher(Rand, Options);
814 auto *Corpus = new InputCorpus(Options.OutputCorpus, Entropic);
815 auto *F = new Fuzzer(Callback, *Corpus, *MD, Options);
816
817 for (auto &U: Dictionary)
818 if (U.size() <= Word::GetMaxSize())
819 MD->AddWordToManualDictionary(W: Word(U.data(), U.size()));
820
821 // Threads are only supported by Chrome. Don't use them with emscripten
822 // for now.
823#if !LIBFUZZER_EMSCRIPTEN
824 StartRssThread(F, RssLimitMb: Flags.rss_limit_mb);
825#endif // LIBFUZZER_EMSCRIPTEN
826
827 Options.HandleAbrt = Flags.handle_abrt;
828 Options.HandleAlrm = !Flags.minimize_crash;
829 Options.HandleBus = Flags.handle_bus;
830 Options.HandleFpe = Flags.handle_fpe;
831 Options.HandleIll = Flags.handle_ill;
832 Options.HandleInt = Flags.handle_int;
833 Options.HandleSegv = Flags.handle_segv;
834 Options.HandleTerm = Flags.handle_term;
835 Options.HandleXfsz = Flags.handle_xfsz;
836 Options.HandleUsr1 = Flags.handle_usr1;
837 Options.HandleUsr2 = Flags.handle_usr2;
838 Options.HandleWinExcept = Flags.handle_winexcept;
839
840 SetSignalHandler(Options);
841
842 std::atexit(func: Fuzzer::StaticExitCallback);
843
844 if (Flags.minimize_crash)
845 return MinimizeCrashInput(Args, Options);
846
847 if (Flags.minimize_crash_internal_step)
848 return MinimizeCrashInputInternalStep(F, Corpus);
849
850 if (Flags.cleanse_crash)
851 return CleanseCrashInput(Args, Options);
852
853 if (RunIndividualFiles) {
854 Options.SaveArtifacts = false;
855 int Runs = std::max(a: 1, b: Flags.runs);
856 Printf(Fmt: "%s: Running %zd inputs %d time(s) each.\n", ProgName->c_str(),
857 Inputs->size(), Runs);
858 for (auto &Path : *Inputs) {
859 auto StartTime = system_clock::now();
860 Printf(Fmt: "Running: %s\n", Path.c_str());
861 for (int Iter = 0; Iter < Runs; Iter++)
862 RunOneTest(F, InputFilePath: Path.c_str(), MaxLen: Options.MaxLen);
863 auto StopTime = system_clock::now();
864 auto MS = duration_cast<milliseconds>(d: StopTime - StartTime).count();
865 Printf(Fmt: "Executed %s in %ld ms\n", Path.c_str(), (long)MS);
866 }
867 Printf(Fmt: "***\n"
868 "*** NOTE: fuzzing was not performed, you have only\n"
869 "*** executed the target code on a fixed set of inputs.\n"
870 "***\n");
871 F->PrintFinalStats();
872 exit(status: 0);
873 }
874
875 Options.ForkCorpusGroups = Flags.fork_corpus_groups;
876 if (Flags.fork)
877 FuzzWithFork(Rand&: F->GetMD().GetRand(), Options, Args, CorpusDirs: *Inputs, NumJobs: Flags.fork);
878
879 if (Flags.merge || Flags.set_cover_merge)
880 Merge(F, Options, Args, Corpora: *Inputs, CFPathOrNull: Flags.merge_control_file);
881
882 if (Flags.merge_inner) {
883 const size_t kDefaultMaxMergeLen = 1 << 20;
884 if (Options.MaxLen == 0)
885 F->SetMaxInputLen(kDefaultMaxMergeLen);
886 assert(Flags.merge_control_file);
887 F->CrashResistantMergeInternalStep(ControlFilePath: Flags.merge_control_file,
888 IsSetCoverMerge: !strncmp(s1: Flags.merge_inner, s2: "2", n: 1));
889 exit(status: 0);
890 }
891
892 if (Flags.analyze_dict) {
893 size_t MaxLen = INT_MAX; // Large max length.
894 UnitVector InitialCorpus;
895 for (auto &Inp : *Inputs) {
896 Printf(Fmt: "Loading corpus dir: %s\n", Inp.c_str());
897 ReadDirToVectorOfUnits(Path: Inp.c_str(), V: &InitialCorpus, Epoch: nullptr,
898 MaxSize: MaxLen, /*ExitOnError=*/false);
899 }
900
901 if (Dictionary.empty() || Inputs->empty()) {
902 Printf(Fmt: "ERROR: can't analyze dict without dict and corpus provided\n");
903 return 1;
904 }
905 if (AnalyzeDictionary(F, Dict: Dictionary, Corpus&: InitialCorpus)) {
906 Printf(Fmt: "Dictionary analysis failed\n");
907 exit(status: 1);
908 }
909 Printf(Fmt: "Dictionary analysis succeeded\n");
910 exit(status: 0);
911 }
912
913 auto CorporaFiles = ReadCorpora(CorpusDirs: *Inputs, ExtraSeedFiles: ParseSeedInuts(seed_inputs: Flags.seed_inputs));
914 F->Loop(CorporaFiles);
915
916 if (Flags.verbosity)
917 Printf(Fmt: "Done %zd runs in %zd second(s)\n", F->getTotalNumberOfRuns(),
918 F->secondsSinceProcessStartUp());
919 F->PrintFinalStats();
920
921 exit(status: 0); // Don't let F destroy itself.
922}
923
924extern "C" ATTRIBUTE_INTERFACE int
925LLVMFuzzerRunDriver(int *argc, char ***argv,
926 int (*UserCb)(const uint8_t *Data, size_t Size)) {
927 return FuzzerDriver(argc, argv, Callback: UserCb);
928}
929
930// Storage for global ExternalFunctions object.
931ExternalFunctions *EF = nullptr;
932
933} // namespace fuzzer
934

source code of compiler-rt/lib/fuzzer/FuzzerDriver.cpp