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() {
63 assert(Options.UnitTimeoutSec > 0);
65 duration_cast<seconds>(system_clock::now() - UnitStartTime).count();
66 if (Seconds == 0) return;
67 if (Options.Verbosity >= 2)
68 std::cerr << "AlarmCallback " << Seconds << "\n";
69 if (Seconds >= (size_t)Options.UnitTimeoutSec) {
70 std::cerr << "ALARM: working on the last Unit for " << Seconds << " seconds"
72 Print(CurrentUnit, "\n");
73 PrintUnitInASCIIOrTokens(CurrentUnit, "\n");
74 WriteToCrash(CurrentUnit, "timeout-");
79 void Fuzzer::PrintStats(const char *Where, size_t Cov, const char *End) {
80 if (!Options.Verbosity) return;
81 size_t Seconds = secondsSinceProcessStartUp();
82 size_t ExecPerSec = (Seconds ? TotalNumberOfRuns / Seconds : 0);
84 << "#" << TotalNumberOfRuns
87 << " bits " << TotalBits()
88 << " units " << Corpus.size()
89 << " exec/s " << ExecPerSec
93 void Fuzzer::RereadOutputCorpus() {
94 if (Options.OutputCorpus.empty()) return;
95 std::vector<Unit> AdditionalCorpus;
96 ReadDirToVectorOfUnits(Options.OutputCorpus.c_str(), &AdditionalCorpus,
97 &EpochOfLastReadOfOutputCorpus);
99 Corpus = AdditionalCorpus;
102 if (!Options.Reload) return;
103 if (Options.Verbosity >= 2)
104 std::cerr << "Reload: read " << AdditionalCorpus.size() << " new units.\n";
105 for (auto &X : AdditionalCorpus) {
106 if (X.size() > (size_t)Options.MaxLen)
107 X.resize(Options.MaxLen);
108 if (UnitHashesAddedToCorpus.insert(Hash(X)).second) {
110 CurrentUnit.insert(CurrentUnit.begin(), X.begin(), X.end());
111 size_t NewCoverage = RunOne(CurrentUnit);
114 if (Options.Verbosity >= 1)
115 PrintStats("RELOAD", NewCoverage);
121 void Fuzzer::ShuffleAndMinimize() {
124 (Options.PreferSmallDuringInitialShuffle == 1 ||
125 (Options.PreferSmallDuringInitialShuffle == -1 && rand() % 2));
126 if (Options.Verbosity)
127 std::cerr << "PreferSmall: " << PreferSmall << "\n";
128 PrintStats("READ ", 0);
129 std::vector<Unit> NewCorpus;
130 std::random_shuffle(Corpus.begin(), Corpus.end());
133 Corpus.begin(), Corpus.end(),
134 [](const Unit &A, const Unit &B) { return A.size() < B.size(); });
135 Unit &U = CurrentUnit;
136 for (const auto &C : Corpus) {
137 for (size_t First = 0; First < 1; First++) {
139 size_t Last = std::min(First + Options.MaxLen, C.size());
140 U.insert(U.begin(), C.begin() + First, C.begin() + Last);
141 size_t NewCoverage = RunOne(U);
143 MaxCov = NewCoverage;
144 NewCorpus.push_back(U);
145 if (Options.Verbosity >= 2)
146 std::cerr << "NEW0: " << NewCoverage
153 for (auto &X : Corpus)
154 UnitHashesAddedToCorpus.insert(Hash(X));
155 PrintStats("INITED", MaxCov);
158 size_t Fuzzer::RunOne(const Unit &U) {
159 UnitStartTime = system_clock::now();
162 if (Options.UseFullCoverageSet)
163 Res = RunOneMaximizeFullCoverageSet(U);
164 else if (Options.UseCoveragePairs)
165 Res = RunOneMaximizeCoveragePairs(U);
167 Res = RunOneMaximizeTotalCoverage(U);
168 auto UnitStopTime = system_clock::now();
170 duration_cast<seconds>(UnitStopTime - UnitStartTime).count();
171 if (TimeOfUnit > TimeOfLongestUnitInSeconds) {
172 TimeOfLongestUnitInSeconds = TimeOfUnit;
173 std::cerr << "Longest unit: " << TimeOfLongestUnitInSeconds
180 void Fuzzer::RunOneAndUpdateCorpus(const Unit &U) {
181 if (TotalNumberOfRuns >= Options.MaxNumberOfRuns)
183 ReportNewCoverage(RunOne(U), U);
186 static uintptr_t HashOfArrayOfPCs(uintptr_t *PCs, uintptr_t NumPCs) {
188 for (uintptr_t i = 0; i < NumPCs; i++) {
189 Res = (Res + PCs[i]) * 7;
194 Unit Fuzzer::SubstituteTokens(const Unit &U) const {
197 if (Idx < Options.Tokens.size()) {
198 std::string Token = Options.Tokens[Idx];
199 Res.insert(Res.end(), Token.begin(), Token.end());
204 // FIXME: Apply DFSan labels.
208 void Fuzzer::ExecuteCallback(const Unit &U) {
209 if (Options.Tokens.empty()) {
210 Callback(U.data(), U.size());
212 auto T = SubstituteTokens(U);
213 Callback(T.data(), T.size());
217 // Experimental. Does not yet scale.
218 // Fuly reset the current coverage state, run a single unit,
219 // collect all coverage pairs and return non-zero if a new pair is observed.
220 size_t Fuzzer::RunOneMaximizeCoveragePairs(const Unit &U) {
221 __sanitizer_reset_coverage();
224 uintptr_t NumPCs = __sanitizer_get_coverage_guards(&PCs);
225 bool HasNewPairs = false;
226 for (uintptr_t i = 0; i < NumPCs; i++) {
227 if (!PCs[i]) continue;
228 for (uintptr_t j = 0; j < NumPCs; j++) {
229 if (!PCs[j]) continue;
230 uint64_t Pair = (i << 32) | j;
231 HasNewPairs |= CoveragePairs.insert(Pair).second;
235 return CoveragePairs.size();
240 // Fuly reset the current coverage state, run a single unit,
241 // compute a hash function from the full coverage set,
242 // return non-zero if the hash value is new.
243 // This produces tons of new units and as is it's only suitable for small tests,
244 // e.g. test/FullCoverageSetTest.cpp. FIXME: make it scale.
245 size_t Fuzzer::RunOneMaximizeFullCoverageSet(const Unit &U) {
246 __sanitizer_reset_coverage();
249 uintptr_t NumPCs =__sanitizer_get_coverage_guards(&PCs);
250 if (FullCoverageSets.insert(HashOfArrayOfPCs(PCs, NumPCs)).second)
251 return FullCoverageSets.size();
255 size_t Fuzzer::RunOneMaximizeTotalCoverage(const Unit &U) {
256 size_t NumCounters = __sanitizer_get_number_of_counters();
257 if (Options.UseCounters) {
258 CounterBitmap.resize(NumCounters);
259 __sanitizer_update_counter_bitset_and_clear_counters(0);
261 size_t OldCoverage = __sanitizer_get_total_unique_coverage();
263 size_t NewCoverage = __sanitizer_get_total_unique_coverage();
264 size_t NumNewBits = 0;
265 if (Options.UseCounters)
266 NumNewBits = __sanitizer_update_counter_bitset_and_clear_counters(
267 CounterBitmap.data());
269 if (!(TotalNumberOfRuns & (TotalNumberOfRuns - 1)) && Options.Verbosity)
270 PrintStats("pulse ", NewCoverage);
272 if (NewCoverage > OldCoverage || NumNewBits)
277 void Fuzzer::WriteToOutputCorpus(const Unit &U) {
278 if (Options.OutputCorpus.empty()) return;
279 std::string Path = DirPlusFile(Options.OutputCorpus, Hash(U));
280 WriteToFile(U, Path);
281 if (Options.Verbosity >= 2)
282 std::cerr << "Written to " << Path << std::endl;
285 void Fuzzer::WriteToCrash(const Unit &U, const char *Prefix) {
286 std::string Path = Prefix + Hash(U);
287 WriteToFile(U, Path);
288 std::cerr << "CRASHED; file written to " << Path << std::endl;
289 std::cerr << "Base64: ";
290 PrintFileAsBase64(Path);
293 void Fuzzer::SaveCorpus() {
294 if (Options.OutputCorpus.empty()) return;
295 for (const auto &U : Corpus)
296 WriteToFile(U, DirPlusFile(Options.OutputCorpus, Hash(U)));
297 if (Options.Verbosity)
298 std::cerr << "Written corpus of " << Corpus.size() << " files to "
299 << Options.OutputCorpus << "\n";
302 void Fuzzer::ReportNewCoverage(size_t NewCoverage, const Unit &U) {
303 if (!NewCoverage) return;
305 UnitHashesAddedToCorpus.insert(Hash(U));
306 PrintStats("NEW ", NewCoverage, "");
307 if (Options.Verbosity) {
308 std::cerr << " L: " << U.size();
311 PrintUnitInASCIIOrTokens(U, "\t");
316 WriteToOutputCorpus(U);
317 if (Options.ExitOnFirst)
321 void Fuzzer::MutateAndTestOne(Unit *U) {
322 for (int i = 0; i < Options.MutateDepth; i++) {
323 StartTraceRecording();
324 Mutate(U, Options.MaxLen);
325 RunOneAndUpdateCorpus(*U);
326 size_t NumTraceBasedMutations = StopTraceRecording();
327 for (size_t j = 0; j < NumTraceBasedMutations; j++) {
328 ApplyTraceBasedMutation(j, U);
329 RunOneAndUpdateCorpus(*U);
334 void Fuzzer::Loop(size_t NumIterations) {
335 for (size_t i = 1; i <= NumIterations; i++) {
336 for (size_t J1 = 0; J1 < Corpus.size(); J1++) {
338 RereadOutputCorpus();
339 if (TotalNumberOfRuns >= Options.MaxNumberOfRuns)
341 // First, simply mutate the unit w/o doing crosses.
342 CurrentUnit = Corpus[J1];
343 MutateAndTestOne(&CurrentUnit);
344 // Now, cross with others.
345 if (Options.DoCrossOver) {
346 for (size_t J2 = 0; J2 < Corpus.size(); J2++) {
348 CrossOver(Corpus[J1], Corpus[J2], &CurrentUnit, Options.MaxLen);
349 MutateAndTestOne(&CurrentUnit);
356 void Fuzzer::SyncCorpus() {
357 if (Options.SyncCommand.empty() || Options.OutputCorpus.empty()) return;
358 auto Now = system_clock::now();
359 if (duration_cast<seconds>(Now - LastExternalSync).count() <
362 LastExternalSync = Now;
363 ExecuteCommand(Options.SyncCommand + " " + Options.OutputCorpus);
366 } // namespace fuzzer