1 //===- FuzzerLoop.cpp - Fuzzer's main loop --------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 //===----------------------------------------------------------------------===//
12 #include "FuzzerInternal.h"
13 #include <sanitizer/coverage_interface.h>
18 // Only one Fuzzer per process.
21 Fuzzer::Fuzzer(UserSuppliedFuzzer &USF, FuzzingOptions Options)
22 : USF(USF), Options(Options) {
24 InitializeTraceState();
29 void Fuzzer::SetDeathCallback() {
30 __sanitizer_set_death_callback(StaticDeathCallback);
33 void Fuzzer::PrintUnitInASCIIOrTokens(const Unit &U, const char *PrintAfter) {
34 if (Options.Tokens.empty()) {
35 PrintASCII(U, PrintAfter);
37 auto T = SubstituteTokens(U);
39 Printf("%s%s", T.data(), PrintAfter);
43 void Fuzzer::StaticDeathCallback() {
48 void Fuzzer::DeathCallback() {
50 Print(CurrentUnit, "\n");
51 PrintUnitInASCIIOrTokens(CurrentUnit, "\n");
52 WriteToCrash(CurrentUnit, "crash-");
55 void Fuzzer::StaticAlarmCallback() {
60 void Fuzzer::AlarmCallback() {
61 assert(Options.UnitTimeoutSec > 0);
63 duration_cast<seconds>(system_clock::now() - UnitStartTime).count();
64 if (Seconds == 0) return;
65 if (Options.Verbosity >= 2)
66 Printf("AlarmCallback %zd\n", Seconds);
67 if (Seconds >= (size_t)Options.UnitTimeoutSec) {
68 Printf("ALARM: working on the last Unit for %zd seconds\n", Seconds);
69 Printf(" and the timeout value is %d (use -timeout=N to change)\n",
70 Options.UnitTimeoutSec);
71 Print(CurrentUnit, "\n");
72 PrintUnitInASCIIOrTokens(CurrentUnit, "\n");
73 WriteToCrash(CurrentUnit, "timeout-");
78 void Fuzzer::PrintStats(const char *Where, size_t Cov, const char *End) {
79 if (!Options.Verbosity) return;
80 size_t Seconds = secondsSinceProcessStartUp();
81 size_t ExecPerSec = (Seconds ? TotalNumberOfRuns / Seconds : 0);
82 Printf("#%zd\t%s cov %zd bits %zd units %zd exec/s %zd %s", TotalNumberOfRuns,
83 Where, Cov, TotalBits(), Corpus.size(), ExecPerSec, End);
86 void Fuzzer::RereadOutputCorpus() {
87 if (Options.OutputCorpus.empty()) return;
88 std::vector<Unit> AdditionalCorpus;
89 ReadDirToVectorOfUnits(Options.OutputCorpus.c_str(), &AdditionalCorpus,
90 &EpochOfLastReadOfOutputCorpus);
92 Corpus = AdditionalCorpus;
95 if (!Options.Reload) return;
96 if (Options.Verbosity >= 2)
97 Printf("Reload: read %zd new units.\n", AdditionalCorpus.size());
98 for (auto &X : AdditionalCorpus) {
99 if (X.size() > (size_t)Options.MaxLen)
100 X.resize(Options.MaxLen);
101 if (UnitHashesAddedToCorpus.insert(Hash(X)).second) {
103 CurrentUnit.insert(CurrentUnit.begin(), X.begin(), X.end());
104 size_t NewCoverage = RunOne(CurrentUnit);
107 if (Options.Verbosity >= 1)
108 PrintStats("RELOAD", NewCoverage);
114 void Fuzzer::ShuffleAndMinimize() {
117 (Options.PreferSmallDuringInitialShuffle == 1 ||
118 (Options.PreferSmallDuringInitialShuffle == -1 && rand() % 2));
119 if (Options.Verbosity)
120 Printf("PreferSmall: %d\n", PreferSmall);
121 PrintStats("READ ", 0);
122 std::vector<Unit> NewCorpus;
123 std::random_shuffle(Corpus.begin(), Corpus.end());
126 Corpus.begin(), Corpus.end(),
127 [](const Unit &A, const Unit &B) { return A.size() < B.size(); });
128 Unit &U = CurrentUnit;
129 for (const auto &C : Corpus) {
130 for (size_t First = 0; First < 1; First++) {
132 size_t Last = std::min(First + Options.MaxLen, C.size());
133 U.insert(U.begin(), C.begin() + First, C.begin() + Last);
134 size_t NewCoverage = RunOne(U);
136 MaxCov = NewCoverage;
137 NewCorpus.push_back(U);
138 if (Options.Verbosity >= 2)
139 Printf("NEW0: %zd L %zd\n", NewCoverage, U.size());
144 for (auto &X : Corpus)
145 UnitHashesAddedToCorpus.insert(Hash(X));
146 PrintStats("INITED", MaxCov);
149 size_t Fuzzer::RunOne(const Unit &U) {
150 UnitStartTime = system_clock::now();
153 if (Options.UseFullCoverageSet)
154 Res = RunOneMaximizeFullCoverageSet(U);
156 Res = RunOneMaximizeTotalCoverage(U);
157 auto UnitStopTime = system_clock::now();
159 duration_cast<seconds>(UnitStopTime - UnitStartTime).count();
160 if (TimeOfUnit > TimeOfLongestUnitInSeconds) {
161 TimeOfLongestUnitInSeconds = TimeOfUnit;
162 Printf("Longest unit: %zd s:\n", TimeOfLongestUnitInSeconds);
168 void Fuzzer::RunOneAndUpdateCorpus(const Unit &U) {
169 if (TotalNumberOfRuns >= Options.MaxNumberOfRuns)
171 ReportNewCoverage(RunOne(U), U);
174 static uintptr_t HashOfArrayOfPCs(uintptr_t *PCs, uintptr_t NumPCs) {
176 for (uintptr_t i = 0; i < NumPCs; i++) {
177 Res = (Res + PCs[i]) * 7;
182 Unit Fuzzer::SubstituteTokens(const Unit &U) const {
185 if (Idx < Options.Tokens.size()) {
186 std::string Token = Options.Tokens[Idx];
187 Res.insert(Res.end(), Token.begin(), Token.end());
192 // FIXME: Apply DFSan labels.
196 void Fuzzer::ExecuteCallback(const Unit &U) {
197 if (Options.Tokens.empty()) {
198 USF.TargetFunction(U.data(), U.size());
200 auto T = SubstituteTokens(U);
201 USF.TargetFunction(T.data(), T.size());
206 // Fuly reset the current coverage state, run a single unit,
207 // compute a hash function from the full coverage set,
208 // return non-zero if the hash value is new.
209 // This produces tons of new units and as is it's only suitable for small tests,
210 // e.g. test/FullCoverageSetTest.cpp. FIXME: make it scale.
211 size_t Fuzzer::RunOneMaximizeFullCoverageSet(const Unit &U) {
212 __sanitizer_reset_coverage();
215 uintptr_t NumPCs =__sanitizer_get_coverage_guards(&PCs);
216 if (FullCoverageSets.insert(HashOfArrayOfPCs(PCs, NumPCs)).second)
217 return FullCoverageSets.size();
221 size_t Fuzzer::RunOneMaximizeTotalCoverage(const Unit &U) {
222 size_t NumCounters = __sanitizer_get_number_of_counters();
223 if (Options.UseCounters) {
224 CounterBitmap.resize(NumCounters);
225 __sanitizer_update_counter_bitset_and_clear_counters(0);
227 size_t OldCoverage = __sanitizer_get_total_unique_coverage();
229 size_t NewCoverage = __sanitizer_get_total_unique_coverage();
230 size_t NumNewBits = 0;
231 if (Options.UseCounters)
232 NumNewBits = __sanitizer_update_counter_bitset_and_clear_counters(
233 CounterBitmap.data());
235 if (!(TotalNumberOfRuns & (TotalNumberOfRuns - 1)) && Options.Verbosity)
236 PrintStats("pulse ", NewCoverage);
238 if (NewCoverage > OldCoverage || NumNewBits)
243 void Fuzzer::WriteToOutputCorpus(const Unit &U) {
244 if (Options.OutputCorpus.empty()) return;
245 std::string Path = DirPlusFile(Options.OutputCorpus, Hash(U));
246 WriteToFile(U, Path);
247 if (Options.Verbosity >= 2)
248 Printf("Written to %s\n", Path.c_str());
251 void Fuzzer::WriteToCrash(const Unit &U, const char *Prefix) {
252 std::string Path = Prefix + Hash(U);
253 WriteToFile(U, Path);
254 Printf("CRASHED; file written to %s\nBase64: ", Path.c_str());
255 PrintFileAsBase64(Path);
258 void Fuzzer::SaveCorpus() {
259 if (Options.OutputCorpus.empty()) return;
260 for (const auto &U : Corpus)
261 WriteToFile(U, DirPlusFile(Options.OutputCorpus, Hash(U)));
262 if (Options.Verbosity)
263 Printf("Written corpus of %zd files to %s\n", Corpus.size(),
264 Options.OutputCorpus.c_str());
267 void Fuzzer::ReportNewCoverage(size_t NewCoverage, const Unit &U) {
268 if (!NewCoverage) return;
270 UnitHashesAddedToCorpus.insert(Hash(U));
271 PrintStats("NEW ", NewCoverage, "");
272 if (Options.Verbosity) {
273 Printf(" L: %zd", U.size());
276 PrintUnitInASCIIOrTokens(U, "\t");
281 WriteToOutputCorpus(U);
282 if (Options.ExitOnFirst)
286 void Fuzzer::MutateAndTestOne(Unit *U) {
287 for (int i = 0; i < Options.MutateDepth; i++) {
288 StartTraceRecording();
289 size_t Size = U->size();
290 U->resize(Options.MaxLen);
291 size_t NewSize = USF.Mutate(U->data(), Size, U->size());
292 assert(NewSize > 0 && NewSize <= (size_t)Options.MaxLen);
294 RunOneAndUpdateCorpus(*U);
295 size_t NumTraceBasedMutations = StopTraceRecording();
296 for (size_t j = 0; j < NumTraceBasedMutations; j++) {
297 ApplyTraceBasedMutation(j, U);
298 RunOneAndUpdateCorpus(*U);
303 void Fuzzer::Loop(size_t NumIterations) {
304 for (size_t i = 1; i <= NumIterations; i++) {
305 for (size_t J1 = 0; J1 < Corpus.size(); J1++) {
307 RereadOutputCorpus();
308 if (TotalNumberOfRuns >= Options.MaxNumberOfRuns)
310 // First, simply mutate the unit w/o doing crosses.
311 CurrentUnit = Corpus[J1];
312 MutateAndTestOne(&CurrentUnit);
313 // Now, cross with others.
314 if (Options.DoCrossOver && !Corpus[J1].empty()) {
315 for (size_t J2 = 0; J2 < Corpus.size(); J2++) {
316 CurrentUnit.resize(Options.MaxLen);
317 size_t NewSize = USF.CrossOver(
318 Corpus[J1].data(), Corpus[J1].size(), Corpus[J2].data(),
319 Corpus[J2].size(), CurrentUnit.data(), CurrentUnit.size());
320 assert(NewSize > 0 && NewSize <= (size_t)Options.MaxLen);
321 CurrentUnit.resize(NewSize);
322 MutateAndTestOne(&CurrentUnit);
329 void Fuzzer::SyncCorpus() {
330 if (Options.SyncCommand.empty() || Options.OutputCorpus.empty()) return;
331 auto Now = system_clock::now();
332 if (duration_cast<seconds>(Now - LastExternalSync).count() <
335 LastExternalSync = Now;
336 ExecuteCommand(Options.SyncCommand + " " + Options.OutputCorpus);
339 } // namespace fuzzer