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 Print(CurrentUnit, "\n");
70 PrintUnitInASCIIOrTokens(CurrentUnit, "\n");
71 WriteToCrash(CurrentUnit, "timeout-");
76 void Fuzzer::PrintStats(const char *Where, size_t Cov, const char *End) {
77 if (!Options.Verbosity) return;
78 size_t Seconds = secondsSinceProcessStartUp();
79 size_t ExecPerSec = (Seconds ? TotalNumberOfRuns / Seconds : 0);
80 Printf("#%zd\t%s cov %zd bits %zd units %zd exec/s %zd %s", TotalNumberOfRuns,
81 Where, Cov, TotalBits(), Corpus.size(), ExecPerSec, End);
84 void Fuzzer::RereadOutputCorpus() {
85 if (Options.OutputCorpus.empty()) return;
86 std::vector<Unit> AdditionalCorpus;
87 ReadDirToVectorOfUnits(Options.OutputCorpus.c_str(), &AdditionalCorpus,
88 &EpochOfLastReadOfOutputCorpus);
90 Corpus = AdditionalCorpus;
93 if (!Options.Reload) return;
94 if (Options.Verbosity >= 2)
95 Printf("Reload: read %zd new units.\n", AdditionalCorpus.size());
96 for (auto &X : AdditionalCorpus) {
97 if (X.size() > (size_t)Options.MaxLen)
98 X.resize(Options.MaxLen);
99 if (UnitHashesAddedToCorpus.insert(Hash(X)).second) {
101 CurrentUnit.insert(CurrentUnit.begin(), X.begin(), X.end());
102 size_t NewCoverage = RunOne(CurrentUnit);
105 if (Options.Verbosity >= 1)
106 PrintStats("RELOAD", NewCoverage);
112 void Fuzzer::ShuffleAndMinimize() {
115 (Options.PreferSmallDuringInitialShuffle == 1 ||
116 (Options.PreferSmallDuringInitialShuffle == -1 && rand() % 2));
117 if (Options.Verbosity)
118 Printf("PreferSmall: %d\n", PreferSmall);
119 PrintStats("READ ", 0);
120 std::vector<Unit> NewCorpus;
121 std::random_shuffle(Corpus.begin(), Corpus.end());
124 Corpus.begin(), Corpus.end(),
125 [](const Unit &A, const Unit &B) { return A.size() < B.size(); });
126 Unit &U = CurrentUnit;
127 for (const auto &C : Corpus) {
128 for (size_t First = 0; First < 1; First++) {
130 size_t Last = std::min(First + Options.MaxLen, C.size());
131 U.insert(U.begin(), C.begin() + First, C.begin() + Last);
132 size_t NewCoverage = RunOne(U);
134 MaxCov = NewCoverage;
135 NewCorpus.push_back(U);
136 if (Options.Verbosity >= 2)
137 Printf("NEW0: %zd L %zd\n", NewCoverage, U.size());
142 for (auto &X : Corpus)
143 UnitHashesAddedToCorpus.insert(Hash(X));
144 PrintStats("INITED", MaxCov);
147 size_t Fuzzer::RunOne(const Unit &U) {
148 UnitStartTime = system_clock::now();
151 if (Options.UseFullCoverageSet)
152 Res = RunOneMaximizeFullCoverageSet(U);
154 Res = RunOneMaximizeTotalCoverage(U);
155 auto UnitStopTime = system_clock::now();
157 duration_cast<seconds>(UnitStopTime - UnitStartTime).count();
158 if (TimeOfUnit > TimeOfLongestUnitInSeconds) {
159 TimeOfLongestUnitInSeconds = TimeOfUnit;
160 Printf("Longest unit: %zd s:\n", TimeOfLongestUnitInSeconds);
166 void Fuzzer::RunOneAndUpdateCorpus(const Unit &U) {
167 if (TotalNumberOfRuns >= Options.MaxNumberOfRuns)
169 ReportNewCoverage(RunOne(U), U);
172 static uintptr_t HashOfArrayOfPCs(uintptr_t *PCs, uintptr_t NumPCs) {
174 for (uintptr_t i = 0; i < NumPCs; i++) {
175 Res = (Res + PCs[i]) * 7;
180 Unit Fuzzer::SubstituteTokens(const Unit &U) const {
183 if (Idx < Options.Tokens.size()) {
184 std::string Token = Options.Tokens[Idx];
185 Res.insert(Res.end(), Token.begin(), Token.end());
190 // FIXME: Apply DFSan labels.
194 void Fuzzer::ExecuteCallback(const Unit &U) {
195 if (Options.Tokens.empty()) {
196 USF.TargetFunction(U.data(), U.size());
198 auto T = SubstituteTokens(U);
199 USF.TargetFunction(T.data(), T.size());
204 // Fuly reset the current coverage state, run a single unit,
205 // compute a hash function from the full coverage set,
206 // return non-zero if the hash value is new.
207 // This produces tons of new units and as is it's only suitable for small tests,
208 // e.g. test/FullCoverageSetTest.cpp. FIXME: make it scale.
209 size_t Fuzzer::RunOneMaximizeFullCoverageSet(const Unit &U) {
210 __sanitizer_reset_coverage();
213 uintptr_t NumPCs =__sanitizer_get_coverage_guards(&PCs);
214 if (FullCoverageSets.insert(HashOfArrayOfPCs(PCs, NumPCs)).second)
215 return FullCoverageSets.size();
219 size_t Fuzzer::RunOneMaximizeTotalCoverage(const Unit &U) {
220 size_t NumCounters = __sanitizer_get_number_of_counters();
221 if (Options.UseCounters) {
222 CounterBitmap.resize(NumCounters);
223 __sanitizer_update_counter_bitset_and_clear_counters(0);
225 size_t OldCoverage = __sanitizer_get_total_unique_coverage();
227 size_t NewCoverage = __sanitizer_get_total_unique_coverage();
228 size_t NumNewBits = 0;
229 if (Options.UseCounters)
230 NumNewBits = __sanitizer_update_counter_bitset_and_clear_counters(
231 CounterBitmap.data());
233 if (!(TotalNumberOfRuns & (TotalNumberOfRuns - 1)) && Options.Verbosity)
234 PrintStats("pulse ", NewCoverage);
236 if (NewCoverage > OldCoverage || NumNewBits)
241 void Fuzzer::WriteToOutputCorpus(const Unit &U) {
242 if (Options.OutputCorpus.empty()) return;
243 std::string Path = DirPlusFile(Options.OutputCorpus, Hash(U));
244 WriteToFile(U, Path);
245 if (Options.Verbosity >= 2)
246 Printf("Written to %s\n", Path.c_str());
249 void Fuzzer::WriteToCrash(const Unit &U, const char *Prefix) {
250 std::string Path = Prefix + Hash(U);
251 WriteToFile(U, Path);
252 Printf("CRASHED; file written to %s\nBase64: ", Path.c_str());
253 PrintFileAsBase64(Path);
256 void Fuzzer::SaveCorpus() {
257 if (Options.OutputCorpus.empty()) return;
258 for (const auto &U : Corpus)
259 WriteToFile(U, DirPlusFile(Options.OutputCorpus, Hash(U)));
260 if (Options.Verbosity)
261 Printf("Written corpus of %zd files to %s\n", Corpus.size(),
262 Options.OutputCorpus.c_str());
265 void Fuzzer::ReportNewCoverage(size_t NewCoverage, const Unit &U) {
266 if (!NewCoverage) return;
268 UnitHashesAddedToCorpus.insert(Hash(U));
269 PrintStats("NEW ", NewCoverage, "");
270 if (Options.Verbosity) {
271 Printf(" L: %zd", U.size());
274 PrintUnitInASCIIOrTokens(U, "\t");
279 WriteToOutputCorpus(U);
280 if (Options.ExitOnFirst)
284 void Fuzzer::MutateAndTestOne(Unit *U) {
285 for (int i = 0; i < Options.MutateDepth; i++) {
286 StartTraceRecording();
287 size_t Size = U->size();
288 U->resize(Options.MaxLen);
289 size_t NewSize = USF.Mutate(U->data(), Size, U->size());
290 assert(NewSize > 0 && NewSize <= (size_t)Options.MaxLen);
292 RunOneAndUpdateCorpus(*U);
293 size_t NumTraceBasedMutations = StopTraceRecording();
294 for (size_t j = 0; j < NumTraceBasedMutations; j++) {
295 ApplyTraceBasedMutation(j, U);
296 RunOneAndUpdateCorpus(*U);
301 void Fuzzer::Loop(size_t NumIterations) {
302 for (size_t i = 1; i <= NumIterations; i++) {
303 for (size_t J1 = 0; J1 < Corpus.size(); J1++) {
305 RereadOutputCorpus();
306 if (TotalNumberOfRuns >= Options.MaxNumberOfRuns)
308 // First, simply mutate the unit w/o doing crosses.
309 CurrentUnit = Corpus[J1];
310 MutateAndTestOne(&CurrentUnit);
311 // Now, cross with others.
312 if (Options.DoCrossOver && !Corpus[J1].empty()) {
313 for (size_t J2 = 0; J2 < Corpus.size(); J2++) {
314 CurrentUnit.resize(Options.MaxLen);
315 size_t NewSize = USF.CrossOver(
316 Corpus[J1].data(), Corpus[J1].size(), Corpus[J2].data(),
317 Corpus[J2].size(), CurrentUnit.data(), CurrentUnit.size());
318 assert(NewSize > 0 && NewSize <= (size_t)Options.MaxLen);
319 CurrentUnit.resize(NewSize);
320 MutateAndTestOne(&CurrentUnit);
327 void Fuzzer::SyncCorpus() {
328 if (Options.SyncCommand.empty() || Options.OutputCorpus.empty()) return;
329 auto Now = system_clock::now();
330 if (duration_cast<seconds>(Now - LastExternalSync).count() <
333 LastExternalSync = Now;
334 ExecuteCommand(Options.SyncCommand + " " + Options.OutputCorpus);
337 } // namespace fuzzer