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>
19 // Only one Fuzzer per process.
22 Fuzzer::Fuzzer(UserCallback Callback, FuzzingOptions Options)
23 : Callback(Callback), Options(Options) {
25 InitializeTraceState();
30 void Fuzzer::SetDeathCallback() {
31 __sanitizer_set_death_callback(StaticDeathCallback);
34 void Fuzzer::PrintUnitInASCIIOrTokens(const Unit &U, const char *PrintAfter) {
35 if (Options.Tokens.empty()) {
36 PrintASCII(U, PrintAfter);
38 auto T = SubstituteTokens(U);
40 std::cerr << T.data();
41 std::cerr << PrintAfter;
45 void Fuzzer::StaticDeathCallback() {
50 void Fuzzer::DeathCallback() {
51 std::cerr << "DEATH: " << std::endl;
52 Print(CurrentUnit, "\n");
53 PrintUnitInASCIIOrTokens(CurrentUnit, "\n");
54 WriteToCrash(CurrentUnit, "crash-");
57 void Fuzzer::StaticAlarmCallback() {
62 void Fuzzer::AlarmCallback() {
64 duration_cast<seconds>(system_clock::now() - UnitStartTime).count();
65 std::cerr << "ALARM: working on the last Unit for " << Seconds << " seconds"
68 Print(CurrentUnit, "\n");
69 PrintUnitInASCIIOrTokens(CurrentUnit, "\n");
70 WriteToCrash(CurrentUnit, "timeout-");
75 void Fuzzer::PrintStats(const char *Where, size_t Cov, const char *End) {
76 if (!Options.Verbosity) return;
77 size_t Seconds = secondsSinceProcessStartUp();
78 size_t ExecPerSec = (Seconds ? TotalNumberOfRuns / Seconds : 0);
80 << "#" << TotalNumberOfRuns
83 << " bits " << TotalBits()
84 << " units " << Corpus.size()
85 << " exec/s " << ExecPerSec
89 void Fuzzer::RereadOutputCorpus() {
90 if (Options.OutputCorpus.empty()) return;
91 std::vector<Unit> AdditionalCorpus;
92 ReadDirToVectorOfUnits(Options.OutputCorpus.c_str(), &AdditionalCorpus,
93 &EpochOfLastReadOfOutputCorpus);
95 Corpus = AdditionalCorpus;
98 if (!Options.Reload) return;
99 for (auto &X : AdditionalCorpus) {
100 if (X.size() > (size_t)Options.MaxLen)
101 X.resize(Options.MaxLen);
102 if (UnitHashesAddedToCorpus.insert(Hash(X)).second) {
104 CurrentUnit.insert(CurrentUnit.begin(), X.begin(), X.end());
105 size_t NewCoverage = RunOne(CurrentUnit);
108 if (Options.Verbosity >= 1)
109 PrintStats("RELOAD", NewCoverage);
115 void Fuzzer::ShuffleAndMinimize() {
118 (Options.PreferSmallDuringInitialShuffle == 1 ||
119 (Options.PreferSmallDuringInitialShuffle == -1 && rand() % 2));
120 if (Options.Verbosity)
121 std::cerr << "PreferSmall: " << PreferSmall << "\n";
122 PrintStats("READ ", 0);
123 std::vector<Unit> NewCorpus;
124 std::random_shuffle(Corpus.begin(), Corpus.end());
127 Corpus.begin(), Corpus.end(),
128 [](const Unit &A, const Unit &B) { return A.size() < B.size(); });
129 Unit &U = CurrentUnit;
130 for (const auto &C : Corpus) {
131 for (size_t First = 0; First < 1; First++) {
133 size_t Last = std::min(First + Options.MaxLen, C.size());
134 U.insert(U.begin(), C.begin() + First, C.begin() + Last);
135 size_t NewCoverage = RunOne(U);
137 MaxCov = NewCoverage;
138 NewCorpus.push_back(U);
139 if (Options.Verbosity >= 2)
140 std::cerr << "NEW0: " << NewCoverage
147 for (auto &X : Corpus)
148 UnitHashesAddedToCorpus.insert(Hash(X));
149 PrintStats("INITED", MaxCov);
152 size_t Fuzzer::RunOne(const Unit &U) {
153 UnitStartTime = system_clock::now();
156 if (Options.UseFullCoverageSet)
157 Res = RunOneMaximizeFullCoverageSet(U);
158 else if (Options.UseCoveragePairs)
159 Res = RunOneMaximizeCoveragePairs(U);
161 Res = RunOneMaximizeTotalCoverage(U);
162 auto UnitStopTime = system_clock::now();
164 duration_cast<seconds>(UnitStopTime - UnitStartTime).count();
165 if (TimeOfUnit > TimeOfLongestUnitInSeconds) {
166 TimeOfLongestUnitInSeconds = TimeOfUnit;
167 std::cerr << "Longest unit: " << TimeOfLongestUnitInSeconds
174 void Fuzzer::RunOneAndUpdateCorpus(const Unit &U) {
175 if (TotalNumberOfRuns >= Options.MaxNumberOfRuns)
177 ReportNewCoverage(RunOne(U), U);
180 static uintptr_t HashOfArrayOfPCs(uintptr_t *PCs, uintptr_t NumPCs) {
182 for (uintptr_t i = 0; i < NumPCs; i++) {
183 Res = (Res + PCs[i]) * 7;
188 Unit Fuzzer::SubstituteTokens(const Unit &U) const {
191 if (Idx < Options.Tokens.size()) {
192 std::string Token = Options.Tokens[Idx];
193 Res.insert(Res.end(), Token.begin(), Token.end());
198 // FIXME: Apply DFSan labels.
202 void Fuzzer::ExecuteCallback(const Unit &U) {
203 if (Options.Tokens.empty()) {
204 Callback(U.data(), U.size());
206 auto T = SubstituteTokens(U);
207 Callback(T.data(), T.size());
211 // Experimental. Does not yet scale.
212 // Fuly reset the current coverage state, run a single unit,
213 // collect all coverage pairs and return non-zero if a new pair is observed.
214 size_t Fuzzer::RunOneMaximizeCoveragePairs(const Unit &U) {
215 __sanitizer_reset_coverage();
218 uintptr_t NumPCs = __sanitizer_get_coverage_guards(&PCs);
219 bool HasNewPairs = false;
220 for (uintptr_t i = 0; i < NumPCs; i++) {
221 if (!PCs[i]) continue;
222 for (uintptr_t j = 0; j < NumPCs; j++) {
223 if (!PCs[j]) continue;
224 uint64_t Pair = (i << 32) | j;
225 HasNewPairs |= CoveragePairs.insert(Pair).second;
229 return CoveragePairs.size();
234 // Fuly reset the current coverage state, run a single unit,
235 // compute a hash function from the full coverage set,
236 // return non-zero if the hash value is new.
237 // This produces tons of new units and as is it's only suitable for small tests,
238 // e.g. test/FullCoverageSetTest.cpp. FIXME: make it scale.
239 size_t Fuzzer::RunOneMaximizeFullCoverageSet(const Unit &U) {
240 __sanitizer_reset_coverage();
243 uintptr_t NumPCs =__sanitizer_get_coverage_guards(&PCs);
244 if (FullCoverageSets.insert(HashOfArrayOfPCs(PCs, NumPCs)).second)
245 return FullCoverageSets.size();
249 size_t Fuzzer::RunOneMaximizeTotalCoverage(const Unit &U) {
250 size_t NumCounters = __sanitizer_get_number_of_counters();
251 if (Options.UseCounters) {
252 CounterBitmap.resize(NumCounters);
253 __sanitizer_update_counter_bitset_and_clear_counters(0);
255 size_t OldCoverage = __sanitizer_get_total_unique_coverage();
257 size_t NewCoverage = __sanitizer_get_total_unique_coverage();
258 size_t NumNewBits = 0;
259 if (Options.UseCounters)
260 NumNewBits = __sanitizer_update_counter_bitset_and_clear_counters(
261 CounterBitmap.data());
263 if (!(TotalNumberOfRuns & (TotalNumberOfRuns - 1)) && Options.Verbosity)
264 PrintStats("pulse ", NewCoverage);
266 if (NewCoverage > OldCoverage || NumNewBits)
271 void Fuzzer::WriteToOutputCorpus(const Unit &U) {
272 if (Options.OutputCorpus.empty()) return;
273 std::string Path = DirPlusFile(Options.OutputCorpus, Hash(U));
274 WriteToFile(U, Path);
275 if (Options.Verbosity >= 2)
276 std::cerr << "Written to " << Path << std::endl;
279 void Fuzzer::WriteToCrash(const Unit &U, const char *Prefix) {
280 std::string Path = Prefix + Hash(U);
281 WriteToFile(U, Path);
282 std::cerr << "CRASHED; file written to " << Path << std::endl;
283 std::cerr << "Base64: ";
284 PrintFileAsBase64(Path);
287 void Fuzzer::SaveCorpus() {
288 if (Options.OutputCorpus.empty()) return;
289 for (const auto &U : Corpus)
290 WriteToFile(U, DirPlusFile(Options.OutputCorpus, Hash(U)));
291 if (Options.Verbosity)
292 std::cerr << "Written corpus of " << Corpus.size() << " files to "
293 << Options.OutputCorpus << "\n";
296 void Fuzzer::ReportNewCoverage(size_t NewCoverage, const Unit &U) {
297 if (!NewCoverage) return;
299 UnitHashesAddedToCorpus.insert(Hash(U));
300 PrintStats("NEW ", NewCoverage, "");
301 if (Options.Verbosity) {
302 std::cerr << " L: " << U.size();
305 PrintUnitInASCIIOrTokens(U, "\t");
310 WriteToOutputCorpus(U);
311 if (Options.ExitOnFirst)
315 void Fuzzer::MutateAndTestOne(Unit *U) {
316 for (int i = 0; i < Options.MutateDepth; i++) {
317 StartTraceRecording();
318 Mutate(U, Options.MaxLen);
319 RunOneAndUpdateCorpus(*U);
320 size_t NumTraceBasedMutations = StopTraceRecording();
321 for (size_t j = 0; j < NumTraceBasedMutations; j++) {
322 ApplyTraceBasedMutation(j, U);
323 RunOneAndUpdateCorpus(*U);
328 void Fuzzer::Loop(size_t NumIterations) {
329 for (size_t i = 1; i <= NumIterations; i++) {
330 for (size_t J1 = 0; J1 < Corpus.size(); J1++) {
332 RereadOutputCorpus();
333 if (TotalNumberOfRuns >= Options.MaxNumberOfRuns)
335 // First, simply mutate the unit w/o doing crosses.
336 CurrentUnit = Corpus[J1];
337 MutateAndTestOne(&CurrentUnit);
338 // Now, cross with others.
339 if (Options.DoCrossOver) {
340 for (size_t J2 = 0; J2 < Corpus.size(); J2++) {
342 CrossOver(Corpus[J1], Corpus[J2], &CurrentUnit, Options.MaxLen);
343 MutateAndTestOne(&CurrentUnit);
350 void Fuzzer::SyncCorpus() {
351 if (Options.SyncCommand.empty() || Options.OutputCorpus.empty()) return;
352 auto Now = system_clock::now();
353 if (duration_cast<seconds>(Now - LastExternalSync).count() <
356 LastExternalSync = Now;
357 ExecuteCommand(Options.SyncCommand + " " + Options.OutputCorpus);
360 } // namespace fuzzer