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 ScopedDisableMsanInterceptorChecks S;
233 while (true) {
234 unsigned C = (*Counter)++;
235 if (C >= NumJobs) break;
236 std::string Log = "fuzz-" + std::to_string(val: C) + ".log";
237 Command Cmd(BaseCmd);
238 Cmd.setOutputFile(Log);
239 Cmd.combineOutAndErr();
240 if (Flags.verbosity) {
241 std::string CommandLine = Cmd.toString();
242 Printf(Fmt: "%s\n", CommandLine.c_str());
243 }
244 int ExitCode = ExecuteCommand(Cmd);
245 if (ExitCode != 0)
246 *HasErrors = true;
247 std::lock_guard<std::mutex> Lock(Mu);
248 Printf(Fmt: "================== Job %u exited with exit code %d ============\n",
249 C, ExitCode);
250 fuzzer::CopyFileToErr(Path: Log);
251 }
252}
253
254static void ValidateDirectoryExists(const std::string &Path,
255 bool CreateDirectory) {
256 if (Path.empty()) {
257 Printf(Fmt: "ERROR: Provided directory path is an empty string\n");
258 exit(status: 1);
259 }
260
261 if (IsDirectory(Path))
262 return;
263
264 if (CreateDirectory) {
265 if (!MkDirRecursive(Dir: Path)) {
266 Printf(Fmt: "ERROR: Failed to create directory \"%s\"\n", Path.c_str());
267 exit(status: 1);
268 }
269 return;
270 }
271
272 Printf(Fmt: "ERROR: The required directory \"%s\" does not exist\n", Path.c_str());
273 exit(status: 1);
274}
275
276std::string CloneArgsWithoutX(const std::vector<std::string> &Args,
277 const char *X1, const char *X2) {
278 std::string Cmd;
279 for (auto &S : Args) {
280 if (FlagValue(Param: S.c_str(), Name: X1) || FlagValue(Param: S.c_str(), Name: X2))
281 continue;
282 Cmd += S + " ";
283 }
284 return Cmd;
285}
286
287static int RunInMultipleProcesses(const std::vector<std::string> &Args,
288 unsigned NumWorkers, unsigned NumJobs) {
289 std::atomic<unsigned> Counter(0);
290 std::atomic<bool> HasErrors(false);
291 Command Cmd(Args);
292 Cmd.removeFlag(Flag: "jobs");
293 Cmd.removeFlag(Flag: "workers");
294 std::vector<std::thread> V;
295 std::thread Pulse(PulseThread);
296 Pulse.detach();
297 V.resize(sz: NumWorkers);
298 for (unsigned i = 0; i < NumWorkers; i++) {
299 V[i] = std::thread(WorkerThread, std::ref(t&: Cmd), &Counter, NumJobs,
300 &HasErrors);
301 SetThreadName(thread&: V[i], name: "FuzzerWorker");
302 }
303 for (auto &T : V)
304 T.join();
305 return HasErrors ? 1 : 0;
306}
307
308static void RssThread(Fuzzer *F, size_t RssLimitMb) {
309 while (true) {
310 SleepSeconds(Seconds: 1);
311 size_t Peak = GetPeakRSSMb();
312 if (Peak > RssLimitMb)
313 F->RssLimitCallback();
314 }
315}
316
317static void StartRssThread(Fuzzer *F, size_t RssLimitMb) {
318 if (!RssLimitMb)
319 return;
320 std::thread T(RssThread, F, RssLimitMb);
321 T.detach();
322}
323
324int RunOneTest(Fuzzer *F, const char *InputFilePath, size_t MaxLen) {
325 Unit U = FileToVector(Path: InputFilePath);
326 if (MaxLen && MaxLen < U.size())
327 U.resize(sz: MaxLen);
328 F->ExecuteCallback(Data: U.data(), Size: U.size());
329 if (Flags.print_full_coverage) {
330 // Leak detection is not needed when collecting full coverage data.
331 F->TPCUpdateObservedPCs();
332 } else {
333 F->TryDetectingAMemoryLeak(Data: U.data(), Size: U.size(), DuringInitialCorpusExecution: true);
334 }
335 return 0;
336}
337
338static bool AllInputsAreFiles() {
339 if (Inputs->empty()) return false;
340 for (auto &Path : *Inputs)
341 if (!IsFile(Path))
342 return false;
343 return true;
344}
345
346static std::string GetDedupTokenFromCmdOutput(const std::string &S) {
347 auto Beg = S.find(s: "DEDUP_TOKEN:");
348 if (Beg == std::string::npos)
349 return "";
350 auto End = S.find(c: '\n', pos: Beg);
351 if (End == std::string::npos)
352 return "";
353 return S.substr(pos: Beg, n: End - Beg);
354}
355
356int CleanseCrashInput(const std::vector<std::string> &Args,
357 const FuzzingOptions &Options) {
358 if (Inputs->size() != 1 || !Flags.exact_artifact_path) {
359 Printf(Fmt: "ERROR: -cleanse_crash should be given one input file and"
360 " -exact_artifact_path\n");
361 exit(status: 1);
362 }
363 std::string InputFilePath = Inputs->at(n: 0);
364 std::string OutputFilePath = Flags.exact_artifact_path;
365 Command Cmd(Args);
366 Cmd.removeFlag(Flag: "cleanse_crash");
367
368 assert(Cmd.hasArgument(InputFilePath));
369 Cmd.removeArgument(Arg: InputFilePath);
370
371 auto TmpFilePath = TempPath(Prefix: "CleanseCrashInput", Extension: ".repro");
372 Cmd.addArgument(Arg: TmpFilePath);
373 Cmd.setOutputFile(getDevNull());
374 Cmd.combineOutAndErr();
375
376 std::string CurrentFilePath = InputFilePath;
377 auto U = FileToVector(Path: CurrentFilePath);
378 size_t Size = U.size();
379
380 const std::vector<uint8_t> ReplacementBytes = {' ', 0xff};
381 for (int NumAttempts = 0; NumAttempts < 5; NumAttempts++) {
382 bool Changed = false;
383 for (size_t Idx = 0; Idx < Size; Idx++) {
384 Printf(Fmt: "CLEANSE[%d]: Trying to replace byte %zd of %zd\n", NumAttempts,
385 Idx, Size);
386 uint8_t OriginalByte = U[Idx];
387 if (ReplacementBytes.end() != std::find(first: ReplacementBytes.begin(),
388 last: ReplacementBytes.end(),
389 value: OriginalByte))
390 continue;
391 for (auto NewByte : ReplacementBytes) {
392 U[Idx] = NewByte;
393 WriteToFile(U, Path: TmpFilePath);
394 auto ExitCode = ExecuteCommand(Cmd);
395 RemoveFile(Path: TmpFilePath);
396 if (!ExitCode) {
397 U[Idx] = OriginalByte;
398 } else {
399 Changed = true;
400 Printf(Fmt: "CLEANSE: Replaced byte %zd with 0x%x\n", Idx, NewByte);
401 WriteToFile(U, Path: OutputFilePath);
402 break;
403 }
404 }
405 }
406 if (!Changed) break;
407 }
408 return 0;
409}
410
411int MinimizeCrashInput(const std::vector<std::string> &Args,
412 const FuzzingOptions &Options) {
413 if (Inputs->size() != 1) {
414 Printf(Fmt: "ERROR: -minimize_crash should be given one input file\n");
415 exit(status: 1);
416 }
417 std::string InputFilePath = Inputs->at(n: 0);
418 Command BaseCmd(Args);
419 BaseCmd.removeFlag(Flag: "minimize_crash");
420 BaseCmd.removeFlag(Flag: "exact_artifact_path");
421 assert(BaseCmd.hasArgument(InputFilePath));
422 BaseCmd.removeArgument(Arg: InputFilePath);
423 if (Flags.runs <= 0 && Flags.max_total_time == 0) {
424 Printf(Fmt: "INFO: you need to specify -runs=N or "
425 "-max_total_time=N with -minimize_crash=1\n"
426 "INFO: defaulting to -max_total_time=600\n");
427 BaseCmd.addFlag(Flag: "max_total_time", Value: "600");
428 }
429
430 BaseCmd.combineOutAndErr();
431
432 std::string CurrentFilePath = InputFilePath;
433 while (true) {
434 Unit U = FileToVector(Path: CurrentFilePath);
435 Printf(Fmt: "CRASH_MIN: minimizing crash input: '%s' (%zd bytes)\n",
436 CurrentFilePath.c_str(), U.size());
437
438 Command Cmd(BaseCmd);
439 Cmd.addArgument(Arg: CurrentFilePath);
440
441 Printf(Fmt: "CRASH_MIN: executing: %s\n", Cmd.toString().c_str());
442 std::string CmdOutput;
443 bool Success = ExecuteCommand(Cmd, CmdOutput: &CmdOutput);
444 if (Success) {
445 Printf(Fmt: "ERROR: the input %s did not crash\n", CurrentFilePath.c_str());
446 exit(status: 1);
447 }
448 Printf(Fmt: "CRASH_MIN: '%s' (%zd bytes) caused a crash. Will try to minimize "
449 "it further\n",
450 CurrentFilePath.c_str(), U.size());
451 auto DedupToken1 = GetDedupTokenFromCmdOutput(S: CmdOutput);
452 if (!DedupToken1.empty())
453 Printf(Fmt: "CRASH_MIN: DedupToken1: %s\n", DedupToken1.c_str());
454
455 std::string ArtifactPath =
456 Flags.exact_artifact_path
457 ? Flags.exact_artifact_path
458 : Options.ArtifactPrefix + "minimized-from-" + Hash(U);
459 Cmd.addFlag(Flag: "minimize_crash_internal_step", Value: "1");
460 Cmd.addFlag(Flag: "exact_artifact_path", Value: ArtifactPath);
461 Printf(Fmt: "CRASH_MIN: executing: %s\n", Cmd.toString().c_str());
462 CmdOutput.clear();
463 Success = ExecuteCommand(Cmd, CmdOutput: &CmdOutput);
464 Printf(Fmt: "%s", CmdOutput.c_str());
465 if (Success) {
466 if (Flags.exact_artifact_path) {
467 CurrentFilePath = Flags.exact_artifact_path;
468 WriteToFile(U, Path: CurrentFilePath);
469 }
470 Printf(Fmt: "CRASH_MIN: failed to minimize beyond %s (%zu bytes), exiting\n",
471 CurrentFilePath.c_str(), U.size());
472 break;
473 }
474 auto DedupToken2 = GetDedupTokenFromCmdOutput(S: CmdOutput);
475 if (!DedupToken2.empty())
476 Printf(Fmt: "CRASH_MIN: DedupToken2: %s\n", DedupToken2.c_str());
477
478 if (DedupToken1 != DedupToken2) {
479 if (Flags.exact_artifact_path) {
480 CurrentFilePath = Flags.exact_artifact_path;
481 WriteToFile(U, Path: CurrentFilePath);
482 }
483 Printf(Fmt: "CRASH_MIN: mismatch in dedup tokens"
484 " (looks like a different bug). Won't minimize further\n");
485 break;
486 }
487
488 CurrentFilePath = ArtifactPath;
489 Printf(Fmt: "*********************************\n");
490 }
491 return 0;
492}
493
494int MinimizeCrashInputInternalStep(Fuzzer *F, InputCorpus *Corpus) {
495 assert(Inputs->size() == 1);
496 std::string InputFilePath = Inputs->at(n: 0);
497 Unit U = FileToVector(Path: InputFilePath);
498 Printf(Fmt: "INFO: Starting MinimizeCrashInputInternalStep: %zd\n", U.size());
499 if (U.size() < 2) {
500 Printf(Fmt: "INFO: The input is small enough, exiting\n");
501 exit(status: 0);
502 }
503 F->SetMaxInputLen(U.size());
504 F->SetMaxMutationLen(U.size() - 1);
505 F->MinimizeCrashLoop(U);
506 Printf(Fmt: "INFO: Done MinimizeCrashInputInternalStep, no crashes found\n");
507 exit(status: 0);
508}
509
510void Merge(Fuzzer *F, FuzzingOptions &Options,
511 const std::vector<std::string> &Args,
512 const std::vector<std::string> &Corpora, const char *CFPathOrNull) {
513 if (Corpora.size() < 2) {
514 Printf(Fmt: "INFO: Merge requires two or more corpus dirs\n");
515 exit(status: 0);
516 }
517
518 std::vector<SizedFile> OldCorpus, NewCorpus;
519 GetSizedFilesFromDir(Dir: Corpora[0], V: &OldCorpus);
520 for (size_t i = 1; i < Corpora.size(); i++)
521 GetSizedFilesFromDir(Dir: Corpora[i], V: &NewCorpus);
522 std::sort(first: OldCorpus.begin(), last: OldCorpus.end());
523 std::sort(first: NewCorpus.begin(), last: NewCorpus.end());
524
525 std::string CFPath = CFPathOrNull ? CFPathOrNull : TempPath(Prefix: "Merge", Extension: ".txt");
526 std::vector<std::string> NewFiles;
527 std::set<uint32_t> NewFeatures, NewCov;
528 CrashResistantMerge(Args, OldCorpus, NewCorpus, NewFiles: &NewFiles, InitialFeatures: {}, NewFeatures: &NewFeatures,
529 InitialCov: {}, NewCov: &NewCov, CFPath, Verbose: true, IsSetCoverMerge: Flags.set_cover_merge);
530 for (auto &Path : NewFiles)
531 F->WriteToOutputCorpus(U: FileToVector(Path, MaxSize: Options.MaxLen));
532 // We are done, delete the control file if it was a temporary one.
533 if (!Flags.merge_control_file)
534 RemoveFile(Path: CFPath);
535
536 exit(status: 0);
537}
538
539int AnalyzeDictionary(Fuzzer *F, const std::vector<Unit> &Dict,
540 UnitVector &Corpus) {
541 Printf(Fmt: "Started dictionary minimization (up to %zu tests)\n",
542 Dict.size() * Corpus.size() * 2);
543
544 // Scores and usage count for each dictionary unit.
545 std::vector<int> Scores(Dict.size());
546 std::vector<int> Usages(Dict.size());
547
548 std::vector<size_t> InitialFeatures;
549 std::vector<size_t> ModifiedFeatures;
550 for (auto &C : Corpus) {
551 // Get coverage for the testcase without modifications.
552 F->ExecuteCallback(Data: C.data(), Size: C.size());
553 InitialFeatures.clear();
554 TPC.CollectFeatures(HandleFeature: [&](size_t Feature) {
555 InitialFeatures.push_back(x: Feature);
556 });
557
558 for (size_t i = 0; i < Dict.size(); ++i) {
559 std::vector<uint8_t> Data = C;
560 auto StartPos = std::search(first1: Data.begin(), last1: Data.end(),
561 first2: Dict[i].begin(), last2: Dict[i].end());
562 // Skip dictionary unit, if the testcase does not contain it.
563 if (StartPos == Data.end())
564 continue;
565
566 ++Usages[i];
567 while (StartPos != Data.end()) {
568 // Replace all occurrences of dictionary unit in the testcase.
569 auto EndPos = StartPos + Dict[i].size();
570 for (auto It = StartPos; It != EndPos; ++It)
571 *It ^= 0xFF;
572
573 StartPos = std::search(first1: EndPos, last1: Data.end(),
574 first2: Dict[i].begin(), last2: Dict[i].end());
575 }
576
577 // Get coverage for testcase with masked occurrences of dictionary unit.
578 F->ExecuteCallback(Data: Data.data(), Size: Data.size());
579 ModifiedFeatures.clear();
580 TPC.CollectFeatures(HandleFeature: [&](size_t Feature) {
581 ModifiedFeatures.push_back(x: Feature);
582 });
583
584 if (InitialFeatures == ModifiedFeatures)
585 --Scores[i];
586 else
587 Scores[i] += 2;
588 }
589 }
590
591 Printf(Fmt: "###### Useless dictionary elements. ######\n");
592 for (size_t i = 0; i < Dict.size(); ++i) {
593 // Dictionary units with positive score are treated as useful ones.
594 if (Scores[i] > 0)
595 continue;
596
597 Printf(Fmt: "\"");
598 PrintASCII(Data: Dict[i].data(), Size: Dict[i].size(), PrintAfter: "\"");
599 Printf(Fmt: " # Score: %d, Used: %d\n", Scores[i], Usages[i]);
600 }
601 Printf(Fmt: "###### End of useless dictionary elements. ######\n");
602 return 0;
603}
604
605std::vector<std::string> ParseSeedInuts(const char *seed_inputs) {
606 // Parse -seed_inputs=file1,file2,... or -seed_inputs=@seed_inputs_file
607 std::vector<std::string> Files;
608 if (!seed_inputs) return Files;
609 std::string SeedInputs;
610 if (Flags.seed_inputs[0] == '@')
611 SeedInputs = FileToString(Path: Flags.seed_inputs + 1); // File contains list.
612 else
613 SeedInputs = Flags.seed_inputs; // seed_inputs contains the list.
614 if (SeedInputs.empty()) {
615 Printf(Fmt: "seed_inputs is empty or @file does not exist.\n");
616 exit(status: 1);
617 }
618 // Parse SeedInputs.
619 size_t comma_pos = 0;
620 while ((comma_pos = SeedInputs.find_last_of(c: ',')) != std::string::npos) {
621 Files.push_back(x: SeedInputs.substr(pos: comma_pos + 1));
622 SeedInputs = SeedInputs.substr(pos: 0, n: comma_pos);
623 }
624 Files.push_back(x: SeedInputs);
625 return Files;
626}
627
628static std::vector<SizedFile>
629ReadCorpora(const std::vector<std::string> &CorpusDirs,
630 const std::vector<std::string> &ExtraSeedFiles) {
631 std::vector<SizedFile> SizedFiles;
632 size_t LastNumFiles = 0;
633 for (auto &Dir : CorpusDirs) {
634 GetSizedFilesFromDir(Dir, V: &SizedFiles);
635 Printf(Fmt: "INFO: % 8zd files found in %s\n", SizedFiles.size() - LastNumFiles,
636 Dir.c_str());
637 LastNumFiles = SizedFiles.size();
638 }
639 for (auto &File : ExtraSeedFiles)
640 if (auto Size = FileSize(Path: File))
641 SizedFiles.push_back(x: {.File: File, .Size: Size});
642 return SizedFiles;
643}
644
645int FuzzerDriver(int *argc, char ***argv, UserCallback Callback) {
646 using namespace fuzzer;
647 assert(argc && argv && "Argument pointers cannot be nullptr");
648 std::string Argv0((*argv)[0]);
649 EF = new ExternalFunctions();
650 if (EF->LLVMFuzzerInitialize)
651 EF->LLVMFuzzerInitialize(argc, argv);
652 if (EF->__msan_scoped_disable_interceptor_checks)
653 EF->__msan_scoped_disable_interceptor_checks();
654 const std::vector<std::string> Args(*argv, *argv + *argc);
655 assert(!Args.empty());
656 ProgName = new std::string(Args[0]);
657 if (Argv0 != *ProgName) {
658 Printf(Fmt: "ERROR: argv[0] has been modified in LLVMFuzzerInitialize\n");
659 exit(status: 1);
660 }
661 ParseFlags(Args, EF);
662 if (Flags.help) {
663 PrintHelp();
664 return 0;
665 }
666
667 if (Flags.close_fd_mask & 2)
668 DupAndCloseStderr();
669 if (Flags.close_fd_mask & 1)
670 CloseStdout();
671
672 if (Flags.jobs > 0 && Flags.workers == 0) {
673 Flags.workers = std::min(a: NumberOfCpuCores() / 2, b: Flags.jobs);
674 if (Flags.workers > 1)
675 Printf(Fmt: "Running %u workers\n", Flags.workers);
676 }
677
678 if (Flags.workers > 0 && Flags.jobs > 0)
679 return RunInMultipleProcesses(Args, NumWorkers: Flags.workers, NumJobs: Flags.jobs);
680
681 FuzzingOptions Options;
682 Options.Verbosity = Flags.verbosity;
683 Options.MaxLen = Flags.max_len;
684 Options.LenControl = Flags.len_control;
685 Options.KeepSeed = Flags.keep_seed;
686 Options.UnitTimeoutSec = Flags.timeout;
687 Options.ErrorExitCode = Flags.error_exitcode;
688 Options.TimeoutExitCode = Flags.timeout_exitcode;
689 Options.IgnoreTimeouts = Flags.ignore_timeouts;
690 Options.IgnoreOOMs = Flags.ignore_ooms;
691 Options.IgnoreCrashes = Flags.ignore_crashes;
692 Options.MaxTotalTimeSec = Flags.max_total_time;
693 Options.DoCrossOver = Flags.cross_over;
694 Options.CrossOverUniformDist = Flags.cross_over_uniform_dist;
695 Options.MutateDepth = Flags.mutate_depth;
696 Options.ReduceDepth = Flags.reduce_depth;
697 Options.UseCounters = Flags.use_counters;
698 Options.UseMemmem = Flags.use_memmem;
699 Options.UseCmp = Flags.use_cmp;
700 Options.UseValueProfile = Flags.use_value_profile;
701 Options.Shrink = Flags.shrink;
702 Options.ReduceInputs = Flags.reduce_inputs;
703 Options.ShuffleAtStartUp = Flags.shuffle;
704 Options.PreferSmall = Flags.prefer_small;
705 Options.ReloadIntervalSec = Flags.reload;
706 Options.OnlyASCII = Flags.only_ascii;
707 Options.DetectLeaks = Flags.detect_leaks;
708 Options.PurgeAllocatorIntervalSec = Flags.purge_allocator_interval;
709 Options.TraceMalloc = Flags.trace_malloc;
710 Options.RssLimitMb = Flags.rss_limit_mb;
711 Options.MallocLimitMb = Flags.malloc_limit_mb;
712 if (!Options.MallocLimitMb)
713 Options.MallocLimitMb = Options.RssLimitMb;
714 if (Flags.runs >= 0)
715 Options.MaxNumberOfRuns = Flags.runs;
716 if (!Inputs->empty() && !Flags.minimize_crash_internal_step) {
717 // Ensure output corpus assumed to be the first arbitrary argument input
718 // is not a path to an existing file.
719 std::string OutputCorpusDir = (*Inputs)[0];
720 if (!IsFile(Path: OutputCorpusDir)) {
721 Options.OutputCorpus = OutputCorpusDir;
722 ValidateDirectoryExists(Path: Options.OutputCorpus, CreateDirectory: Flags.create_missing_dirs);
723 }
724 }
725 Options.ReportSlowUnits = Flags.report_slow_units;
726 if (Flags.artifact_prefix) {
727 Options.ArtifactPrefix = Flags.artifact_prefix;
728
729 // Since the prefix could be a full path to a file name prefix, assume
730 // that if the path ends with the platform's separator that a directory
731 // is desired
732 std::string ArtifactPathDir = Options.ArtifactPrefix;
733 if (!IsSeparator(C: ArtifactPathDir[ArtifactPathDir.length() - 1])) {
734 ArtifactPathDir = DirName(FileName: ArtifactPathDir);
735 }
736 ValidateDirectoryExists(Path: ArtifactPathDir, CreateDirectory: Flags.create_missing_dirs);
737 }
738 if (Flags.exact_artifact_path) {
739 Options.ExactArtifactPath = Flags.exact_artifact_path;
740 ValidateDirectoryExists(Path: DirName(FileName: Options.ExactArtifactPath),
741 CreateDirectory: Flags.create_missing_dirs);
742 }
743 std::vector<Unit> Dictionary;
744 if (Flags.dict)
745 if (!ParseDictionaryFile(Text: FileToString(Path: Flags.dict), Units: &Dictionary))
746 return 1;
747 if (Flags.verbosity > 0 && !Dictionary.empty())
748 Printf(Fmt: "Dictionary: %zd entries\n", Dictionary.size());
749 bool RunIndividualFiles = AllInputsAreFiles();
750 Options.SaveArtifacts =
751 !RunIndividualFiles || Flags.minimize_crash_internal_step;
752 Options.PrintNewCovPcs = Flags.print_pcs;
753 Options.PrintNewCovFuncs = Flags.print_funcs;
754 Options.PrintFinalStats = Flags.print_final_stats;
755 Options.PrintCorpusStats = Flags.print_corpus_stats;
756 Options.PrintCoverage = Flags.print_coverage;
757 Options.PrintFullCoverage = Flags.print_full_coverage;
758 if (Flags.exit_on_src_pos)
759 Options.ExitOnSrcPos = Flags.exit_on_src_pos;
760 if (Flags.exit_on_item)
761 Options.ExitOnItem = Flags.exit_on_item;
762 if (Flags.focus_function)
763 Options.FocusFunction = Flags.focus_function;
764 if (Flags.data_flow_trace)
765 Options.DataFlowTrace = Flags.data_flow_trace;
766 if (Flags.features_dir) {
767 Options.FeaturesDir = Flags.features_dir;
768 ValidateDirectoryExists(Path: Options.FeaturesDir, CreateDirectory: Flags.create_missing_dirs);
769 }
770 if (Flags.mutation_graph_file)
771 Options.MutationGraphFile = Flags.mutation_graph_file;
772 if (Flags.collect_data_flow)
773 Options.CollectDataFlow = Flags.collect_data_flow;
774 if (Flags.stop_file)
775 Options.StopFile = Flags.stop_file;
776 Options.Entropic = Flags.entropic;
777 Options.EntropicFeatureFrequencyThreshold =
778 (size_t)Flags.entropic_feature_frequency_threshold;
779 Options.EntropicNumberOfRarestFeatures =
780 (size_t)Flags.entropic_number_of_rarest_features;
781 Options.EntropicScalePerExecTime = Flags.entropic_scale_per_exec_time;
782 if (!Options.FocusFunction.empty())
783 Options.Entropic = false; // FocusFunction overrides entropic scheduling.
784 if (Options.Entropic)
785 Printf(Fmt: "INFO: Running with entropic power schedule (0x%zX, %zu).\n",
786 Options.EntropicFeatureFrequencyThreshold,
787 Options.EntropicNumberOfRarestFeatures);
788 struct EntropicOptions Entropic;
789 Entropic.Enabled = Options.Entropic;
790 Entropic.FeatureFrequencyThreshold =
791 Options.EntropicFeatureFrequencyThreshold;
792 Entropic.NumberOfRarestFeatures = Options.EntropicNumberOfRarestFeatures;
793 Entropic.ScalePerExecTime = Options.EntropicScalePerExecTime;
794
795 unsigned Seed = Flags.seed;
796 // Initialize Seed.
797 if (Seed == 0)
798 Seed = static_cast<unsigned>(
799 std::chrono::system_clock::now().time_since_epoch().count() + GetPid());
800 if (Flags.verbosity)
801 Printf(Fmt: "INFO: Seed: %u\n", Seed);
802
803 if (Flags.collect_data_flow && Flags.data_flow_trace && !Flags.fork &&
804 !(Flags.merge || Flags.set_cover_merge)) {
805 if (RunIndividualFiles)
806 return CollectDataFlow(DFTBinary: Flags.collect_data_flow, DirPath: Flags.data_flow_trace,
807 CorporaFiles: ReadCorpora(CorpusDirs: {}, ExtraSeedFiles: *Inputs));
808 else
809 return CollectDataFlow(DFTBinary: Flags.collect_data_flow, DirPath: Flags.data_flow_trace,
810 CorporaFiles: ReadCorpora(CorpusDirs: *Inputs, ExtraSeedFiles: {}));
811 }
812
813 Random Rand(Seed);
814 auto *MD = new MutationDispatcher(Rand, Options);
815 auto *Corpus = new InputCorpus(Options.OutputCorpus, Entropic);
816 auto *F = new Fuzzer(Callback, *Corpus, *MD, Options);
817
818 for (auto &U: Dictionary)
819 if (U.size() <= Word::GetMaxSize())
820 MD->AddWordToManualDictionary(W: Word(U.data(), U.size()));
821
822 // Threads are only supported by Chrome. Don't use them with emscripten
823 // for now.
824#if !LIBFUZZER_EMSCRIPTEN
825 StartRssThread(F, RssLimitMb: Flags.rss_limit_mb);
826#endif // LIBFUZZER_EMSCRIPTEN
827
828 Options.HandleAbrt = Flags.handle_abrt;
829 Options.HandleAlrm = !Flags.minimize_crash;
830 Options.HandleBus = Flags.handle_bus;
831 Options.HandleFpe = Flags.handle_fpe;
832 Options.HandleIll = Flags.handle_ill;
833 Options.HandleInt = Flags.handle_int;
834 Options.HandleSegv = Flags.handle_segv;
835 Options.HandleTerm = Flags.handle_term;
836 Options.HandleXfsz = Flags.handle_xfsz;
837 Options.HandleUsr1 = Flags.handle_usr1;
838 Options.HandleUsr2 = Flags.handle_usr2;
839 Options.HandleWinExcept = Flags.handle_winexcept;
840
841 SetSignalHandler(Options);
842
843 std::atexit(func: Fuzzer::StaticExitCallback);
844
845 if (Flags.minimize_crash)
846 return MinimizeCrashInput(Args, Options);
847
848 if (Flags.minimize_crash_internal_step)
849 return MinimizeCrashInputInternalStep(F, Corpus);
850
851 if (Flags.cleanse_crash)
852 return CleanseCrashInput(Args, Options);
853
854 if (RunIndividualFiles) {
855 Options.SaveArtifacts = false;
856 int Runs = std::max(a: 1, b: Flags.runs);
857 Printf(Fmt: "%s: Running %zd inputs %d time(s) each.\n", ProgName->c_str(),
858 Inputs->size(), Runs);
859 for (auto &Path : *Inputs) {
860 auto StartTime = system_clock::now();
861 Printf(Fmt: "Running: %s\n", Path.c_str());
862 for (int Iter = 0; Iter < Runs; Iter++)
863 RunOneTest(F, InputFilePath: Path.c_str(), MaxLen: Options.MaxLen);
864 auto StopTime = system_clock::now();
865 auto MS = duration_cast<milliseconds>(fd: StopTime - StartTime).count();
866 Printf(Fmt: "Executed %s in %ld ms\n", Path.c_str(), (long)MS);
867 }
868 Printf(Fmt: "***\n"
869 "*** NOTE: fuzzing was not performed, you have only\n"
870 "*** executed the target code on a fixed set of inputs.\n"
871 "***\n");
872 F->PrintFinalStats();
873 exit(status: 0);
874 }
875
876 Options.ForkCorpusGroups = Flags.fork_corpus_groups;
877 if (Flags.fork)
878 FuzzWithFork(Rand&: F->GetMD().GetRand(), Options, Args, CorpusDirs: *Inputs, NumJobs: Flags.fork);
879
880 if (Flags.merge || Flags.set_cover_merge)
881 Merge(F, Options, Args, Corpora: *Inputs, CFPathOrNull: Flags.merge_control_file);
882
883 if (Flags.merge_inner) {
884 const size_t kDefaultMaxMergeLen = 1 << 20;
885 if (Options.MaxLen == 0)
886 F->SetMaxInputLen(kDefaultMaxMergeLen);
887 assert(Flags.merge_control_file);
888 F->CrashResistantMergeInternalStep(ControlFilePath: Flags.merge_control_file,
889 IsSetCoverMerge: !strncmp(s1: Flags.merge_inner, s2: "2", n: 1));
890 exit(status: 0);
891 }
892
893 if (Flags.analyze_dict) {
894 size_t MaxLen = INT_MAX; // Large max length.
895 UnitVector InitialCorpus;
896 for (auto &Inp : *Inputs) {
897 Printf(Fmt: "Loading corpus dir: %s\n", Inp.c_str());
898 ReadDirToVectorOfUnits(Path: Inp.c_str(), V: &InitialCorpus, Epoch: nullptr,
899 MaxSize: MaxLen, /*ExitOnError=*/false);
900 }
901
902 if (Dictionary.empty() || Inputs->empty()) {
903 Printf(Fmt: "ERROR: can't analyze dict without dict and corpus provided\n");
904 return 1;
905 }
906 if (AnalyzeDictionary(F, Dict: Dictionary, Corpus&: InitialCorpus)) {
907 Printf(Fmt: "Dictionary analysis failed\n");
908 exit(status: 1);
909 }
910 Printf(Fmt: "Dictionary analysis succeeded\n");
911 exit(status: 0);
912 }
913
914 auto CorporaFiles = ReadCorpora(CorpusDirs: *Inputs, ExtraSeedFiles: ParseSeedInuts(seed_inputs: Flags.seed_inputs));
915 F->Loop(CorporaFiles);
916
917 if (Flags.verbosity)
918 Printf(Fmt: "Done %zd runs in %zd second(s)\n", F->getTotalNumberOfRuns(),
919 F->secondsSinceProcessStartUp());
920 F->PrintFinalStats();
921
922 exit(status: 0); // Don't let F destroy itself.
923}
924
925extern "C" ATTRIBUTE_INTERFACE int
926LLVMFuzzerRunDriver(int *argc, char ***argv,
927 int (*UserCb)(const uint8_t *Data, size_t Size)) {
928 return FuzzerDriver(argc, argv, Callback: UserCb);
929}
930
931// Storage for global ExternalFunctions object.
932ExternalFunctions *EF = nullptr;
933
934} // namespace fuzzer
935