1 //===- FuzzerDriver.cpp - FuzzerDriver function and flags -----------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 // FuzzerDriver and flag parsing.
10 //===----------------------------------------------------------------------===//
11
12 #include "FuzzerInterface.h"
13 #include "FuzzerInternal.h"
14
15 #include <cstring>
16 #include <chrono>
17 #include <unistd.h>
18 #include <thread>
19 #include <atomic>
20 #include <mutex>
21 #include <string>
22 #include <sstream>
23 #include <algorithm>
24 #include <iterator>
25
26 namespace fuzzer {
27
28 // Program arguments.
29 struct FlagDescription {
30 const char *Name;
31 const char *Description;
32 int Default;
33 int *IntFlag;
34 const char **StrFlag;
35 unsigned int *UIntFlag;
36 };
37
38 struct {
39 #define FUZZER_FLAG_INT(Name, Default, Description) int Name;
40 #define FUZZER_FLAG_UNSIGNED(Name, Default, Description) unsigned int Name;
41 #define FUZZER_FLAG_STRING(Name, Description) const char *Name;
42 #include "FuzzerFlags.def"
43 #undef FUZZER_FLAG_INT
44 #undef FUZZER_FLAG_UNSIGNED
45 #undef FUZZER_FLAG_STRING
46 } Flags;
47
48 static const FlagDescription FlagDescriptions [] {
49 #define FUZZER_FLAG_INT(Name, Default, Description) \
50 {#Name, Description, Default, &Flags.Name, nullptr, nullptr},
51 #define FUZZER_FLAG_UNSIGNED(Name, Default, Description) \
52 {#Name, Description, static_cast<int>(Default), \
53 nullptr, nullptr, &Flags.Name},
54 #define FUZZER_FLAG_STRING(Name, Description) \
55 {#Name, Description, 0, nullptr, &Flags.Name, nullptr},
56 #include "FuzzerFlags.def"
57 #undef FUZZER_FLAG_INT
58 #undef FUZZER_FLAG_UNSIGNED
59 #undef FUZZER_FLAG_STRING
60 };
61
62 static const size_t kNumFlags =
63 sizeof(FlagDescriptions) / sizeof(FlagDescriptions[0]);
64
65 static std::vector<std::string> *Inputs;
66 static std::string *ProgName;
67
PrintHelp()68 static void PrintHelp() {
69 Printf("Usage: %s [-flag1=val1 [-flag2=val2 ...] ] [dir1 [dir2 ...] ]\n",
70 ProgName->c_str());
71 Printf("\nFlags: (strictly in form -flag=value)\n");
72 size_t MaxFlagLen = 0;
73 for (size_t F = 0; F < kNumFlags; F++)
74 MaxFlagLen = std::max(strlen(FlagDescriptions[F].Name), MaxFlagLen);
75
76 for (size_t F = 0; F < kNumFlags; F++) {
77 const auto &D = FlagDescriptions[F];
78 Printf(" %s", D.Name);
79 for (size_t i = 0, n = MaxFlagLen - strlen(D.Name); i < n; i++)
80 Printf(" ");
81 Printf("\t");
82 Printf("%d\t%s\n", D.Default, D.Description);
83 }
84 Printf("\nFlags starting with '--' will be ignored and "
85 "will be passed verbatim to subprocesses.\n");
86 }
87
FlagValue(const char * Param,const char * Name)88 static const char *FlagValue(const char *Param, const char *Name) {
89 size_t Len = strlen(Name);
90 if (Param[0] == '-' && strstr(Param + 1, Name) == Param + 1 &&
91 Param[Len + 1] == '=')
92 return &Param[Len + 2];
93 return nullptr;
94 }
95
ParseOneFlag(const char * Param)96 static bool ParseOneFlag(const char *Param) {
97 if (Param[0] != '-') return false;
98 if (Param[1] == '-') {
99 static bool PrintedWarning = false;
100 if (!PrintedWarning) {
101 PrintedWarning = true;
102 Printf("WARNING: libFuzzer ignores flags that start with '--'\n");
103 }
104 return true;
105 }
106 for (size_t F = 0; F < kNumFlags; F++) {
107 const char *Name = FlagDescriptions[F].Name;
108 const char *Str = FlagValue(Param, Name);
109 if (Str) {
110 if (FlagDescriptions[F].IntFlag) {
111 int Val = std::stol(Str);
112 *FlagDescriptions[F].IntFlag = Val;
113 if (Flags.verbosity >= 2)
114 Printf("Flag: %s %d\n", Name, Val);;
115 return true;
116 } else if (FlagDescriptions[F].UIntFlag) {
117 unsigned int Val = std::stoul(Str);
118 *FlagDescriptions[F].UIntFlag = Val;
119 if (Flags.verbosity >= 2)
120 Printf("Flag: %s %u\n", Name, Val);
121 return true;
122 } else if (FlagDescriptions[F].StrFlag) {
123 *FlagDescriptions[F].StrFlag = Str;
124 if (Flags.verbosity >= 2)
125 Printf("Flag: %s %s\n", Name, Str);
126 return true;
127 }
128 }
129 }
130 PrintHelp();
131 exit(1);
132 }
133
134 // We don't use any library to minimize dependencies.
ParseFlags(const std::vector<std::string> & Args)135 static void ParseFlags(const std::vector<std::string> &Args) {
136 for (size_t F = 0; F < kNumFlags; F++) {
137 if (FlagDescriptions[F].IntFlag)
138 *FlagDescriptions[F].IntFlag = FlagDescriptions[F].Default;
139 if (FlagDescriptions[F].UIntFlag)
140 *FlagDescriptions[F].UIntFlag =
141 static_cast<unsigned int>(FlagDescriptions[F].Default);
142 if (FlagDescriptions[F].StrFlag)
143 *FlagDescriptions[F].StrFlag = nullptr;
144 }
145 Inputs = new std::vector<std::string>;
146 for (size_t A = 1; A < Args.size(); A++) {
147 if (ParseOneFlag(Args[A].c_str())) continue;
148 Inputs->push_back(Args[A]);
149 }
150 }
151
152 static std::mutex Mu;
153
PulseThread()154 static void PulseThread() {
155 while (true) {
156 std::this_thread::sleep_for(std::chrono::seconds(600));
157 std::lock_guard<std::mutex> Lock(Mu);
158 Printf("pulse...\n");
159 }
160 }
161
WorkerThread(const std::string & Cmd,std::atomic<int> * Counter,int NumJobs,std::atomic<bool> * HasErrors)162 static void WorkerThread(const std::string &Cmd, std::atomic<int> *Counter,
163 int NumJobs, std::atomic<bool> *HasErrors) {
164 while (true) {
165 int C = (*Counter)++;
166 if (C >= NumJobs) break;
167 std::string Log = "fuzz-" + std::to_string(C) + ".log";
168 std::string ToRun = Cmd + " > " + Log + " 2>&1\n";
169 if (Flags.verbosity)
170 Printf("%s", ToRun.c_str());
171 int ExitCode = ExecuteCommand(ToRun.c_str());
172 if (ExitCode != 0)
173 *HasErrors = true;
174 std::lock_guard<std::mutex> Lock(Mu);
175 Printf("================== Job %d exited with exit code %d ============\n",
176 C, ExitCode);
177 fuzzer::CopyFileToErr(Log);
178 }
179 }
180
RunInMultipleProcesses(const std::vector<std::string> & Args,int NumWorkers,int NumJobs)181 static int RunInMultipleProcesses(const std::vector<std::string> &Args,
182 int NumWorkers, int NumJobs) {
183 std::atomic<int> Counter(0);
184 std::atomic<bool> HasErrors(false);
185 std::string Cmd;
186 for (auto &S : Args) {
187 if (FlagValue(S.c_str(), "jobs") || FlagValue(S.c_str(), "workers"))
188 continue;
189 Cmd += S + " ";
190 }
191 std::vector<std::thread> V;
192 std::thread Pulse(PulseThread);
193 Pulse.detach();
194 for (int i = 0; i < NumWorkers; i++)
195 V.push_back(std::thread(WorkerThread, Cmd, &Counter, NumJobs, &HasErrors));
196 for (auto &T : V)
197 T.join();
198 return HasErrors ? 1 : 0;
199 }
200
RunOneTest(Fuzzer * F,const char * InputFilePath)201 int RunOneTest(Fuzzer *F, const char *InputFilePath) {
202 Unit U = FileToVector(InputFilePath);
203 Unit PreciseSizedU(U);
204 assert(PreciseSizedU.size() == PreciseSizedU.capacity());
205 F->ExecuteCallback(PreciseSizedU);
206 return 0;
207 }
208
FuzzerDriver(int argc,char ** argv,UserCallback Callback)209 int FuzzerDriver(int argc, char **argv, UserCallback Callback) {
210 FuzzerRandomLibc Rand(0);
211 SimpleUserSuppliedFuzzer SUSF(&Rand, Callback);
212 return FuzzerDriver(argc, argv, SUSF);
213 }
214
FuzzerDriver(int argc,char ** argv,UserSuppliedFuzzer & USF)215 int FuzzerDriver(int argc, char **argv, UserSuppliedFuzzer &USF) {
216 std::vector<std::string> Args(argv, argv + argc);
217 return FuzzerDriver(Args, USF);
218 }
219
FuzzerDriver(const std::vector<std::string> & Args,UserCallback Callback)220 int FuzzerDriver(const std::vector<std::string> &Args, UserCallback Callback) {
221 FuzzerRandomLibc Rand(0);
222 SimpleUserSuppliedFuzzer SUSF(&Rand, Callback);
223 return FuzzerDriver(Args, SUSF);
224 }
225
FuzzerDriver(const std::vector<std::string> & Args,UserSuppliedFuzzer & USF)226 int FuzzerDriver(const std::vector<std::string> &Args,
227 UserSuppliedFuzzer &USF) {
228 using namespace fuzzer;
229 assert(!Args.empty());
230 ProgName = new std::string(Args[0]);
231 ParseFlags(Args);
232 if (Flags.help) {
233 PrintHelp();
234 return 0;
235 }
236
237 if (Flags.jobs > 0 && Flags.workers == 0) {
238 Flags.workers = std::min(NumberOfCpuCores() / 2, Flags.jobs);
239 if (Flags.workers > 1)
240 Printf("Running %d workers\n", Flags.workers);
241 }
242
243 if (Flags.workers > 0 && Flags.jobs > 0)
244 return RunInMultipleProcesses(Args, Flags.workers, Flags.jobs);
245
246 Fuzzer::FuzzingOptions Options;
247 Options.Verbosity = Flags.verbosity;
248 Options.MaxLen = Flags.max_len;
249 Options.UnitTimeoutSec = Flags.timeout;
250 Options.MaxTotalTimeSec = Flags.max_total_time;
251 Options.DoCrossOver = Flags.cross_over;
252 Options.MutateDepth = Flags.mutate_depth;
253 Options.ExitOnFirst = Flags.exit_on_first;
254 Options.UseCounters = Flags.use_counters;
255 Options.UseIndirCalls = Flags.use_indir_calls;
256 Options.UseTraces = Flags.use_traces;
257 Options.ShuffleAtStartUp = Flags.shuffle;
258 Options.PreferSmallDuringInitialShuffle =
259 Flags.prefer_small_during_initial_shuffle;
260 Options.Reload = Flags.reload;
261 Options.OnlyASCII = Flags.only_ascii;
262 Options.TBMDepth = Flags.tbm_depth;
263 Options.TBMWidth = Flags.tbm_width;
264 Options.OutputCSV = Flags.output_csv;
265 if (Flags.runs >= 0)
266 Options.MaxNumberOfRuns = Flags.runs;
267 if (!Inputs->empty())
268 Options.OutputCorpus = (*Inputs)[0];
269 if (Flags.sync_command)
270 Options.SyncCommand = Flags.sync_command;
271 Options.SyncTimeout = Flags.sync_timeout;
272 Options.ReportSlowUnits = Flags.report_slow_units;
273 if (Flags.artifact_prefix)
274 Options.ArtifactPrefix = Flags.artifact_prefix;
275 if (Flags.exact_artifact_path)
276 Options.ExactArtifactPath = Flags.exact_artifact_path;
277 std::vector<Unit> Dictionary;
278 if (Flags.dict)
279 if (!ParseDictionaryFile(FileToString(Flags.dict), &Dictionary))
280 return 1;
281 if (Flags.verbosity > 0 && !Dictionary.empty())
282 Printf("Dictionary: %zd entries\n", Dictionary.size());
283 Options.SaveArtifacts = !Flags.test_single_input;
284
285 Fuzzer F(USF, Options);
286
287 for (auto &U: Dictionary)
288 USF.GetMD().AddWordToDictionary(U.data(), U.size());
289
290 // Timer
291 if (Flags.timeout > 0)
292 SetTimer(Flags.timeout / 2 + 1);
293
294 if (Flags.test_single_input) {
295 RunOneTest(&F, Flags.test_single_input);
296 exit(0);
297 }
298
299 if (Flags.save_minimized_corpus) {
300 Printf("The flag -save_minimized_corpus is deprecated; use -merge=1\n");
301 exit(1);
302 }
303
304 if (Flags.merge) {
305 F.Merge(*Inputs);
306 exit(0);
307 }
308
309 unsigned Seed = Flags.seed;
310 // Initialize Seed.
311 if (Seed == 0)
312 Seed = time(0) * 10000 + getpid();
313 if (Flags.verbosity)
314 Printf("Seed: %u\n", Seed);
315 USF.GetRand().ResetSeed(Seed);
316
317 F.RereadOutputCorpus();
318 for (auto &inp : *Inputs)
319 if (inp != Options.OutputCorpus)
320 F.ReadDir(inp, nullptr);
321
322 if (F.CorpusSize() == 0)
323 F.AddToCorpus(Unit()); // Can't fuzz empty corpus, so add an empty input.
324 F.ShuffleAndMinimize();
325 if (Flags.drill)
326 F.Drill();
327 else
328 F.Loop();
329
330 if (Flags.verbosity)
331 Printf("Done %d runs in %zd second(s)\n", F.getTotalNumberOfRuns(),
332 F.secondsSinceProcessStartUp());
333
334 exit(0); // Don't let F destroy itself.
335 }
336
337 } // namespace fuzzer
338