//===----------------------------------------------------------------------===//
#include "FuzzerInternal.h"
-#include <sanitizer/coverage_interface.h>
#include <algorithm>
+#if defined(__has_include)
+# if __has_include(<sanitizer/coverage_interface.h>)
+# include <sanitizer/coverage_interface.h>
+# endif
+#endif
+
+extern "C" {
+// Re-declare some of the sanitizer functions as "weak" so that
+// libFuzzer can be linked w/o the sanitizers and sanitizer-coverage
+// (in which case it will complain at start-up time).
+__attribute__((weak)) void __sanitizer_print_stack_trace();
+__attribute__((weak)) void __sanitizer_reset_coverage();
+__attribute__((weak)) size_t __sanitizer_get_total_unique_caller_callee_pairs();
+__attribute__((weak)) size_t __sanitizer_get_total_unique_coverage();
+__attribute__((weak))
+void __sanitizer_set_death_callback(void (*callback)(void));
+__attribute__((weak)) size_t __sanitizer_get_number_of_counters();
+__attribute__((weak))
+uintptr_t __sanitizer_update_counter_bitset_and_clear_counters(uint8_t *bitset);
+__attribute__((weak)) uintptr_t
+__sanitizer_get_coverage_pc_buffer(uintptr_t **data);
+}
+
namespace fuzzer {
-static const size_t kMaxUnitSizeToPrint = 4096;
+static const size_t kMaxUnitSizeToPrint = 256;
+
+static void MissingWeakApiFunction(const char *FnName) {
+ Printf("ERROR: %s is not defined. Exiting.\n"
+ "Did you use -fsanitize-coverage=... to build your code?\n", FnName);
+ exit(1);
+}
+
+#define CHECK_WEAK_API_FUNCTION(fn) \
+ do { \
+ if (!fn) \
+ MissingWeakApiFunction(#fn); \
+ } while (false)
// Only one Fuzzer per process.
static Fuzzer *F;
}
void Fuzzer::SetDeathCallback() {
+ CHECK_WEAK_API_FUNCTION(__sanitizer_set_death_callback);
__sanitizer_set_death_callback(StaticDeathCallback);
}
-void Fuzzer::PrintUnitInASCIIOrTokens(const Unit &U, const char *PrintAfter) {
- if (Options.Tokens.empty()) {
- PrintASCII(U, PrintAfter);
- } else {
- auto T = SubstituteTokens(U);
- T.push_back(0);
- Printf("%s%s", T.data(), PrintAfter);
- }
+void Fuzzer::PrintUnitInASCII(const Unit &U, const char *PrintAfter) {
+ PrintASCII(U, PrintAfter);
}
void Fuzzer::StaticDeathCallback() {
void Fuzzer::DeathCallback() {
Printf("DEATH:\n");
- Print(CurrentUnit, "\n");
- PrintUnitInASCIIOrTokens(CurrentUnit, "\n");
+ if (CurrentUnit.size() <= kMaxUnitSizeToPrint) {
+ Print(CurrentUnit, "\n");
+ PrintUnitInASCII(CurrentUnit, "\n");
+ }
WriteUnitToFileWithPrefix(CurrentUnit, "crash-");
}
Printf("ALARM: working on the last Unit for %zd seconds\n", Seconds);
Printf(" and the timeout value is %d (use -timeout=N to change)\n",
Options.UnitTimeoutSec);
- if (CurrentUnit.size() <= kMaxUnitSizeToPrint)
+ if (CurrentUnit.size() <= kMaxUnitSizeToPrint) {
Print(CurrentUnit, "\n");
- PrintUnitInASCIIOrTokens(CurrentUnit, "\n");
+ PrintUnitInASCII(CurrentUnit, "\n");
+ }
WriteUnitToFileWithPrefix(CurrentUnit, "timeout-");
+ Printf("==%d== ERROR: libFuzzer: timeout after %d seconds\n", GetPid(),
+ Seconds);
+ if (__sanitizer_print_stack_trace)
+ __sanitizer_print_stack_trace();
+ Printf("SUMMARY: libFuzzer: timeout\n");
exit(1);
}
}
-void Fuzzer::PrintStats(const char *Where, size_t Cov, const char *End) {
- if (!Options.Verbosity) return;
+void Fuzzer::PrintStats(const char *Where, const char *End) {
size_t Seconds = secondsSinceProcessStartUp();
size_t ExecPerSec = (Seconds ? TotalNumberOfRuns / Seconds : 0);
- Printf("#%zd\t%s cov: %zd bits: %zd units: %zd exec/s: %zd",
- TotalNumberOfRuns, Where, Cov, TotalBits(), Corpus.size(), ExecPerSec);
+
+ if (Options.OutputCSV) {
+ static bool csvHeaderPrinted = false;
+ if (!csvHeaderPrinted) {
+ csvHeaderPrinted = true;
+ Printf("runs,block_cov,bits,cc_cov,corpus,execs_per_sec,tbms,reason\n");
+ }
+ Printf("%zd,%zd,%zd,%zd,%zd,%zd,%zd,%s\n", TotalNumberOfRuns,
+ LastRecordedBlockCoverage, TotalBits(),
+ LastRecordedCallerCalleeCoverage, Corpus.size(), ExecPerSec,
+ TotalNumberOfExecutedTraceBasedMutations, Where);
+ }
+
+ if (!Options.Verbosity)
+ return;
+ Printf("#%zd\t%s", TotalNumberOfRuns, Where);
+ if (LastRecordedBlockCoverage)
+ Printf(" cov: %zd", LastRecordedBlockCoverage);
+ if (auto TB = TotalBits())
+ Printf(" bits: %zd", TB);
+ if (LastRecordedCallerCalleeCoverage)
+ Printf(" indir: %zd", LastRecordedCallerCalleeCoverage);
+ Printf(" units: %zd exec/s: %zd", Corpus.size(), ExecPerSec);
if (TotalNumberOfExecutedTraceBasedMutations)
Printf(" tbm: %zd", TotalNumberOfExecutedTraceBasedMutations);
Printf("%s", End);
if (UnitHashesAddedToCorpus.insert(Hash(X)).second) {
CurrentUnit.clear();
CurrentUnit.insert(CurrentUnit.begin(), X.begin(), X.end());
- size_t NewCoverage = RunOne(CurrentUnit);
- if (NewCoverage) {
+ if (RunOne(CurrentUnit)) {
Corpus.push_back(X);
- if (Options.Verbosity >= 1)
- PrintStats("RELOAD", NewCoverage);
+ PrintStats("RELOAD");
}
}
}
}
void Fuzzer::ShuffleAndMinimize() {
- size_t MaxCov = 0;
bool PreferSmall = (Options.PreferSmallDuringInitialShuffle == 1 ||
(Options.PreferSmallDuringInitialShuffle == -1 &&
USF.GetRand().RandBool()));
if (Options.Verbosity)
Printf("PreferSmall: %d\n", PreferSmall);
- PrintStats("READ ", 0);
+ PrintStats("READ ");
std::vector<Unit> NewCorpus;
- std::random_shuffle(Corpus.begin(), Corpus.end(), USF.GetRand());
- if (PreferSmall)
- std::stable_sort(
- Corpus.begin(), Corpus.end(),
- [](const Unit &A, const Unit &B) { return A.size() < B.size(); });
+ if (Options.ShuffleAtStartUp) {
+ std::random_shuffle(Corpus.begin(), Corpus.end(), USF.GetRand());
+ if (PreferSmall)
+ std::stable_sort(
+ Corpus.begin(), Corpus.end(),
+ [](const Unit &A, const Unit &B) { return A.size() < B.size(); });
+ }
Unit &U = CurrentUnit;
for (const auto &C : Corpus) {
for (size_t First = 0; First < 1; First++) {
U.insert(U.begin(), C.begin() + First, C.begin() + Last);
if (Options.OnlyASCII)
ToASCII(U);
- size_t NewCoverage = RunOne(U);
- if (NewCoverage) {
- MaxCov = NewCoverage;
+ if (RunOne(U)) {
NewCorpus.push_back(U);
if (Options.Verbosity >= 2)
- Printf("NEW0: %zd L %zd\n", NewCoverage, U.size());
+ Printf("NEW0: %zd L %zd\n", LastRecordedBlockCoverage, U.size());
}
}
}
Corpus = NewCorpus;
for (auto &X : Corpus)
UnitHashesAddedToCorpus.insert(Hash(X));
- PrintStats("INITED", MaxCov);
+ PrintStats("INITED");
}
-size_t Fuzzer::RunOne(const Unit &U) {
+bool Fuzzer::RunOne(const Unit &U) {
UnitStartTime = system_clock::now();
TotalNumberOfRuns++;
- size_t Res = 0;
- if (Options.UseFullCoverageSet)
- Res = RunOneMaximizeFullCoverageSet(U);
- else
- Res = RunOneMaximizeTotalCoverage(U);
+
+ PrepareCoverageBeforeRun();
+ ExecuteCallback(U);
+ bool Res = CheckCoverageAfterRun();
+
auto UnitStopTime = system_clock::now();
auto TimeOfUnit =
duration_cast<seconds>(UnitStopTime - UnitStartTime).count();
+ if (!(TotalNumberOfRuns & (TotalNumberOfRuns - 1)) &&
+ secondsSinceProcessStartUp() >= 2)
+ PrintStats("pulse ");
if (TimeOfUnit > TimeOfLongestUnitInSeconds &&
TimeOfUnit >= Options.ReportSlowUnits) {
TimeOfLongestUnitInSeconds = TimeOfUnit;
Printf("Slowest unit: %zd s:\n", TimeOfLongestUnitInSeconds);
- if (U.size() <= kMaxUnitSizeToPrint)
- Print(U, "\n");
WriteUnitToFileWithPrefix(U, "slow-unit-");
}
return Res;
return;
if (Options.OnlyASCII)
ToASCII(U);
- ReportNewCoverage(RunOne(U), U);
+ if (RunOne(U))
+ ReportNewCoverage(U);
}
-static uintptr_t HashOfArrayOfPCs(uintptr_t *PCs, uintptr_t NumPCs) {
- uintptr_t Res = 0;
- for (uintptr_t i = 0; i < NumPCs; i++) {
- Res = (Res + PCs[i]) * 7;
- }
- return Res;
+void Fuzzer::ExecuteCallback(const Unit &U) {
+ const uint8_t *Data = U.data();
+ uint8_t EmptyData;
+ if (!Data)
+ Data = &EmptyData;
+ int Res = USF.TargetFunction(Data, U.size());
+ (void)Res;
+ assert(Res == 0);
}
-Unit Fuzzer::SubstituteTokens(const Unit &U) const {
- Unit Res;
- for (auto Idx : U) {
- if (Idx < Options.Tokens.size()) {
- std::string Token = Options.Tokens[Idx];
- Res.insert(Res.end(), Token.begin(), Token.end());
- } else {
- Res.push_back(' ');
- }
- }
- // FIXME: Apply DFSan labels.
- return Res;
-}
+size_t Fuzzer::RecordBlockCoverage() {
+ CHECK_WEAK_API_FUNCTION(__sanitizer_get_total_unique_coverage);
+ uintptr_t PrevCoverage = LastRecordedBlockCoverage;
+ LastRecordedBlockCoverage = __sanitizer_get_total_unique_coverage();
-void Fuzzer::ExecuteCallback(const Unit &U) {
- if (Options.Tokens.empty()) {
- USF.TargetFunction(U.data(), U.size());
- } else {
- auto T = SubstituteTokens(U);
- USF.TargetFunction(T.data(), T.size());
+ if (PrevCoverage == LastRecordedBlockCoverage || !Options.PrintNewCovPcs)
+ return LastRecordedBlockCoverage;
+
+ uintptr_t PrevBufferLen = LastCoveragePcBufferLen;
+ uintptr_t *CoverageBuf;
+ LastCoveragePcBufferLen = __sanitizer_get_coverage_pc_buffer(&CoverageBuf);
+ assert(CoverageBuf);
+ for (size_t i = PrevBufferLen; i < LastCoveragePcBufferLen; ++i) {
+ Printf("0x%x\n", CoverageBuf[i]);
}
+
+ return LastRecordedBlockCoverage;
}
-// Experimental.
-// Fuly reset the current coverage state, run a single unit,
-// compute a hash function from the full coverage set,
-// return non-zero if the hash value is new.
-// This produces tons of new units and as is it's only suitable for small tests,
-// e.g. test/FullCoverageSetTest.cpp. FIXME: make it scale.
-size_t Fuzzer::RunOneMaximizeFullCoverageSet(const Unit &U) {
- __sanitizer_reset_coverage();
- ExecuteCallback(U);
- uintptr_t *PCs;
- uintptr_t NumPCs =__sanitizer_get_coverage_guards(&PCs);
- if (FullCoverageSets.insert(HashOfArrayOfPCs(PCs, NumPCs)).second)
- return FullCoverageSets.size();
- return 0;
+size_t Fuzzer::RecordCallerCalleeCoverage() {
+ if (!Options.UseIndirCalls)
+ return 0;
+ if (!__sanitizer_get_total_unique_caller_callee_pairs)
+ return 0;
+ return LastRecordedCallerCalleeCoverage =
+ __sanitizer_get_total_unique_caller_callee_pairs();
}
-size_t Fuzzer::RunOneMaximizeTotalCoverage(const Unit &U) {
- size_t NumCounters = __sanitizer_get_number_of_counters();
+void Fuzzer::PrepareCoverageBeforeRun() {
if (Options.UseCounters) {
+ size_t NumCounters = __sanitizer_get_number_of_counters();
CounterBitmap.resize(NumCounters);
__sanitizer_update_counter_bitset_and_clear_counters(0);
}
- size_t OldCoverage = __sanitizer_get_total_unique_coverage();
- ExecuteCallback(U);
- size_t NewCoverage = __sanitizer_get_total_unique_coverage();
+ RecordBlockCoverage();
+ RecordCallerCalleeCoverage();
+}
+
+bool Fuzzer::CheckCoverageAfterRun() {
+ size_t OldCoverage = LastRecordedBlockCoverage;
+ size_t NewCoverage = RecordBlockCoverage();
+ size_t OldCallerCalleeCoverage = LastRecordedCallerCalleeCoverage;
+ size_t NewCallerCalleeCoverage = RecordCallerCalleeCoverage();
size_t NumNewBits = 0;
if (Options.UseCounters)
NumNewBits = __sanitizer_update_counter_bitset_and_clear_counters(
CounterBitmap.data());
-
- if (!(TotalNumberOfRuns & (TotalNumberOfRuns - 1)) && Options.Verbosity)
- PrintStats("pulse ", NewCoverage);
-
- if (NewCoverage > OldCoverage || NumNewBits)
- return NewCoverage;
- return 0;
+ return NewCoverage > OldCoverage ||
+ NewCallerCalleeCoverage > OldCallerCalleeCoverage || NumNewBits;
}
void Fuzzer::WriteToOutputCorpus(const Unit &U) {
}
void Fuzzer::WriteUnitToFileWithPrefix(const Unit &U, const char *Prefix) {
- std::string Path = Prefix + Hash(U);
+ if (!Options.SaveArtifacts)
+ return;
+ std::string Path = Options.ArtifactPrefix + Prefix + Hash(U);
+ if (!Options.ExactArtifactPath.empty())
+ Path = Options.ExactArtifactPath; // Overrides ArtifactPrefix.
WriteToFile(U, Path);
- Printf("Test unit written to %s\n", Path.c_str());
- if (U.size() <= kMaxUnitSizeToPrint) {
- Printf("Base64: ");
- PrintFileAsBase64(Path);
- }
+ Printf("artifact_prefix='%s'; Test unit written to %s\n",
+ Options.ArtifactPrefix.c_str(), Path.c_str());
+ if (U.size() <= kMaxUnitSizeToPrint)
+ Printf("Base64: %s\n", Base64(U).c_str());
}
void Fuzzer::SaveCorpus() {
Options.OutputCorpus.c_str());
}
-void Fuzzer::ReportNewCoverage(size_t NewCoverage, const Unit &U) {
- if (!NewCoverage) return;
- Corpus.push_back(U);
- UnitHashesAddedToCorpus.insert(Hash(U));
- PrintStats("NEW ", NewCoverage, "");
+void Fuzzer::PrintStatusForNewUnit(const Unit &U) {
+ if (!Options.PrintNEW)
+ return;
+ PrintStats("NEW ", "");
if (Options.Verbosity) {
- Printf(" L: %zd", U.size());
- if (U.size() < 30) {
- Printf(" ");
- PrintUnitInASCIIOrTokens(U, "\t");
- Print(U);
- }
+ Printf(" L: %zd ", U.size());
+ USF.PrintMutationSequence();
Printf("\n");
}
+}
+
+void Fuzzer::ReportNewCoverage(const Unit &U) {
+ Corpus.push_back(U);
+ UnitHashesAddedToCorpus.insert(Hash(U));
+ PrintStatusForNewUnit(U);
WriteToOutputCorpus(U);
if (Options.ExitOnFirst)
exit(0);
}
-void Fuzzer::MutateAndTestOne(Unit *U) {
+void Fuzzer::Merge(const std::vector<std::string> &Corpora) {
+ if (Corpora.size() <= 1) {
+ Printf("Merge requires two or more corpus dirs\n");
+ return;
+ }
+ auto InitialCorpusDir = Corpora[0];
+ ReadDir(InitialCorpusDir, nullptr);
+ Printf("Merge: running the initial corpus '%s' of %d units\n",
+ InitialCorpusDir.c_str(), Corpus.size());
+ for (auto &U : Corpus)
+ RunOne(U);
+
+ std::vector<std::string> ExtraCorpora(Corpora.begin() + 1, Corpora.end());
+
+ size_t NumTried = 0;
+ size_t NumMerged = 0;
+ for (auto &C : ExtraCorpora) {
+ Corpus.clear();
+ ReadDir(C, nullptr);
+ Printf("Merge: merging the extra corpus '%s' of %zd units\n", C.c_str(),
+ Corpus.size());
+ for (auto &U : Corpus) {
+ NumTried++;
+ if (RunOne(U)) {
+ WriteToOutputCorpus(U);
+ NumMerged++;
+ }
+ }
+ }
+ Printf("Merge: written %zd out of %zd units\n", NumMerged, NumTried);
+}
+
+void Fuzzer::MutateAndTestOne() {
+ auto &U = CurrentUnit;
+ USF.StartMutationSequence();
+
+ U = ChooseUnitToMutate();
+
for (int i = 0; i < Options.MutateDepth; i++) {
- StartTraceRecording();
- size_t Size = U->size();
- U->resize(Options.MaxLen);
- size_t NewSize = USF.Mutate(U->data(), Size, U->size());
+ size_t Size = U.size();
+ U.resize(Options.MaxLen);
+ size_t NewSize = USF.Mutate(U.data(), Size, U.size());
assert(NewSize > 0 && "Mutator returned empty unit");
assert(NewSize <= (size_t)Options.MaxLen &&
"Mutator return overisized unit");
- U->resize(NewSize);
- RunOneAndUpdateCorpus(*U);
- size_t NumTraceBasedMutations = StopTraceRecording();
- size_t TBMWidth =
- std::min((size_t)Options.TBMWidth, NumTraceBasedMutations);
- size_t TBMDepth =
- std::min((size_t)Options.TBMDepth, NumTraceBasedMutations);
- Unit BackUp = *U;
- for (size_t w = 0; w < TBMWidth; w++) {
- *U = BackUp;
- for (size_t d = 0; d < TBMDepth; d++) {
- TotalNumberOfExecutedTraceBasedMutations++;
- ApplyTraceBasedMutation(USF.GetRand()(NumTraceBasedMutations), U);
- RunOneAndUpdateCorpus(*U);
- }
+ U.resize(NewSize);
+ if (i == 0)
+ StartTraceRecording();
+ RunOneAndUpdateCorpus(U);
+ StopTraceRecording();
+ }
+}
+
+// Returns an index of random unit from the corpus to mutate.
+// Hypothesis: units added to the corpus last are more likely to be interesting.
+// This function gives more wieght to the more recent units.
+size_t Fuzzer::ChooseUnitIdxToMutate() {
+ size_t N = Corpus.size();
+ size_t Total = (N + 1) * N / 2;
+ size_t R = USF.GetRand()(Total);
+ size_t IdxBeg = 0, IdxEnd = N;
+ // Binary search.
+ while (IdxEnd - IdxBeg >= 2) {
+ size_t Idx = IdxBeg + (IdxEnd - IdxBeg) / 2;
+ if (R > (Idx + 1) * Idx / 2)
+ IdxBeg = Idx;
+ else
+ IdxEnd = Idx;
+ }
+ assert(IdxBeg < N);
+ return IdxBeg;
+}
+
+// Experimental search heuristic: drilling.
+// - Read, shuffle, execute and minimize the corpus.
+// - Choose one random unit.
+// - Reset the coverage.
+// - Start fuzzing as if the chosen unit was the only element of the corpus.
+// - When done, reset the coverage again.
+// - Merge the newly created corpus into the original one.
+void Fuzzer::Drill() {
+ // The corpus is already read, shuffled, and minimized.
+ assert(!Corpus.empty());
+ Options.PrintNEW = false; // Don't print NEW status lines when drilling.
+
+ Unit U = ChooseUnitToMutate();
+
+ CHECK_WEAK_API_FUNCTION(__sanitizer_reset_coverage);
+ __sanitizer_reset_coverage();
+
+ std::vector<Unit> SavedCorpus;
+ SavedCorpus.swap(Corpus);
+ Corpus.push_back(U);
+ assert(Corpus.size() == 1);
+ RunOne(U);
+ PrintStats("DRILL ");
+ std::string SavedOutputCorpusPath; // Don't write new units while drilling.
+ SavedOutputCorpusPath.swap(Options.OutputCorpus);
+ Loop();
+
+ __sanitizer_reset_coverage();
+
+ PrintStats("REINIT");
+ SavedOutputCorpusPath.swap(Options.OutputCorpus);
+ for (auto &U : SavedCorpus) {
+ CurrentUnit = U;
+ RunOne(U);
+ }
+ PrintStats("MERGE ");
+ Options.PrintNEW = true;
+ size_t NumMerged = 0;
+ for (auto &U : Corpus) {
+ CurrentUnit = U;
+ if (RunOne(U)) {
+ PrintStatusForNewUnit(U);
+ NumMerged++;
+ WriteToOutputCorpus(U);
}
}
+ PrintStats("MERGED");
+ if (NumMerged && Options.Verbosity)
+ Printf("Drilling discovered %zd new units\n", NumMerged);
}
void Fuzzer::Loop() {
- for (auto &U: Options.Dictionary)
- USF.GetMD().AddWordToDictionary(U.data(), U.size());
-
+ system_clock::time_point LastCorpusReload = system_clock::now();
+ if (Options.DoCrossOver)
+ USF.SetCorpus(&Corpus);
while (true) {
- for (size_t J1 = 0; J1 < Corpus.size(); J1++) {
- SyncCorpus();
+ SyncCorpus();
+ auto Now = system_clock::now();
+ if (duration_cast<seconds>(Now - LastCorpusReload).count()) {
RereadOutputCorpus();
- if (TotalNumberOfRuns >= Options.MaxNumberOfRuns)
- return;
- // First, simply mutate the unit w/o doing crosses.
- CurrentUnit = Corpus[J1];
- MutateAndTestOne(&CurrentUnit);
- // Now, cross with others.
- if (Options.DoCrossOver && !Corpus[J1].empty()) {
- for (size_t J2 = 0; J2 < Corpus.size(); J2++) {
- CurrentUnit.resize(Options.MaxLen);
- size_t NewSize = USF.CrossOver(
- Corpus[J1].data(), Corpus[J1].size(), Corpus[J2].data(),
- Corpus[J2].size(), CurrentUnit.data(), CurrentUnit.size());
- assert(NewSize > 0 && "CrossOver returned empty unit");
- assert(NewSize <= (size_t)Options.MaxLen &&
- "CrossOver return overisized unit");
- CurrentUnit.resize(NewSize);
- MutateAndTestOne(&CurrentUnit);
- }
- }
+ LastCorpusReload = Now;
}
+ if (TotalNumberOfRuns >= Options.MaxNumberOfRuns)
+ break;
+ if (Options.MaxTotalTimeSec > 0 &&
+ secondsSinceProcessStartUp() >
+ static_cast<size_t>(Options.MaxTotalTimeSec))
+ break;
+ // Perform several mutations and runs.
+ MutateAndTestOne();
}
+
+ PrintStats("DONE ", "\n");
}
void Fuzzer::SyncCorpus() {