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| author | 2016-09-03 22:46:54 +0000 | |
|---|---|---|
| committer | 2016-09-03 22:46:54 +0000 | |
| commit | b5500b9ca0102f1ccaf32f0e77e96d0739aded9b (patch) | |
| tree | e1b7ebb5a0231f9e6d8d3f6f719582cebd64dc98 /gnu/llvm/lib/Fuzzer/FuzzerLoop.cpp | |
| parent | clarify purpose of src/gnu/ directory. (diff) | |
| download | wireguard-openbsd-b5500b9ca0102f1ccaf32f0e77e96d0739aded9b.tar.xz wireguard-openbsd-b5500b9ca0102f1ccaf32f0e77e96d0739aded9b.zip | |
Use the space freed up by sparc and zaurus to import LLVM.
ok hackroom@
Diffstat (limited to 'gnu/llvm/lib/Fuzzer/FuzzerLoop.cpp')
| -rw-r--r-- | gnu/llvm/lib/Fuzzer/FuzzerLoop.cpp | 512 |
1 files changed, 512 insertions, 0 deletions
diff --git a/gnu/llvm/lib/Fuzzer/FuzzerLoop.cpp b/gnu/llvm/lib/Fuzzer/FuzzerLoop.cpp new file mode 100644 index 00000000000..5237682ff24 --- /dev/null +++ b/gnu/llvm/lib/Fuzzer/FuzzerLoop.cpp @@ -0,0 +1,512 @@ +//===- FuzzerLoop.cpp - Fuzzer's main loop --------------------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// Fuzzer's main loop. +//===----------------------------------------------------------------------===// + +#include "FuzzerInternal.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 = 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; + +Fuzzer::Fuzzer(UserSuppliedFuzzer &USF, FuzzingOptions Options) + : USF(USF), Options(Options) { + SetDeathCallback(); + InitializeTraceState(); + assert(!F); + F = this; +} + +void Fuzzer::SetDeathCallback() { + CHECK_WEAK_API_FUNCTION(__sanitizer_set_death_callback); + __sanitizer_set_death_callback(StaticDeathCallback); +} + +void Fuzzer::PrintUnitInASCII(const Unit &U, const char *PrintAfter) { + PrintASCII(U, PrintAfter); +} + +void Fuzzer::StaticDeathCallback() { + assert(F); + F->DeathCallback(); +} + +void Fuzzer::DeathCallback() { + Printf("DEATH:\n"); + if (CurrentUnit.size() <= kMaxUnitSizeToPrint) { + Print(CurrentUnit, "\n"); + PrintUnitInASCII(CurrentUnit, "\n"); + } + WriteUnitToFileWithPrefix(CurrentUnit, "crash-"); +} + +void Fuzzer::StaticAlarmCallback() { + assert(F); + F->AlarmCallback(); +} + +void Fuzzer::AlarmCallback() { + assert(Options.UnitTimeoutSec > 0); + size_t Seconds = + duration_cast<seconds>(system_clock::now() - UnitStartTime).count(); + if (Seconds == 0) return; + if (Options.Verbosity >= 2) + Printf("AlarmCallback %zd\n", Seconds); + if (Seconds >= (size_t)Options.UnitTimeoutSec) { + 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) { + Print(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, const char *End) { + size_t Seconds = secondsSinceProcessStartUp(); + size_t ExecPerSec = (Seconds ? TotalNumberOfRuns / Seconds : 0); + + 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); +} + +void Fuzzer::RereadOutputCorpus() { + if (Options.OutputCorpus.empty()) return; + std::vector<Unit> AdditionalCorpus; + ReadDirToVectorOfUnits(Options.OutputCorpus.c_str(), &AdditionalCorpus, + &EpochOfLastReadOfOutputCorpus); + if (Corpus.empty()) { + Corpus = AdditionalCorpus; + return; + } + if (!Options.Reload) return; + if (Options.Verbosity >= 2) + Printf("Reload: read %zd new units.\n", AdditionalCorpus.size()); + for (auto &X : AdditionalCorpus) { + if (X.size() > (size_t)Options.MaxLen) + X.resize(Options.MaxLen); + if (UnitHashesAddedToCorpus.insert(Hash(X)).second) { + CurrentUnit.clear(); + CurrentUnit.insert(CurrentUnit.begin(), X.begin(), X.end()); + if (RunOne(CurrentUnit)) { + Corpus.push_back(X); + PrintStats("RELOAD"); + } + } + } +} + +void Fuzzer::ShuffleAndMinimize() { + bool PreferSmall = (Options.PreferSmallDuringInitialShuffle == 1 || + (Options.PreferSmallDuringInitialShuffle == -1 && + USF.GetRand().RandBool())); + if (Options.Verbosity) + Printf("PreferSmall: %d\n", PreferSmall); + PrintStats("READ "); + std::vector<Unit> NewCorpus; + 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.clear(); + size_t Last = std::min(First + Options.MaxLen, C.size()); + U.insert(U.begin(), C.begin() + First, C.begin() + Last); + if (Options.OnlyASCII) + ToASCII(U); + if (RunOne(U)) { + NewCorpus.push_back(U); + if (Options.Verbosity >= 2) + Printf("NEW0: %zd L %zd\n", LastRecordedBlockCoverage, U.size()); + } + } + } + Corpus = NewCorpus; + for (auto &X : Corpus) + UnitHashesAddedToCorpus.insert(Hash(X)); + PrintStats("INITED"); +} + +bool Fuzzer::RunOne(const Unit &U) { + UnitStartTime = system_clock::now(); + TotalNumberOfRuns++; + + 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); + WriteUnitToFileWithPrefix(U, "slow-unit-"); + } + return Res; +} + +void Fuzzer::RunOneAndUpdateCorpus(Unit &U) { + if (TotalNumberOfRuns >= Options.MaxNumberOfRuns) + return; + if (Options.OnlyASCII) + ToASCII(U); + if (RunOne(U)) + ReportNewCoverage(U); +} + +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); +} + +size_t Fuzzer::RecordBlockCoverage() { + CHECK_WEAK_API_FUNCTION(__sanitizer_get_total_unique_coverage); + uintptr_t PrevCoverage = LastRecordedBlockCoverage; + LastRecordedBlockCoverage = __sanitizer_get_total_unique_coverage(); + + 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; +} + +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(); +} + +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); + } + 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()); + return NewCoverage > OldCoverage || + NewCallerCalleeCoverage > OldCallerCalleeCoverage || NumNewBits; +} + +void Fuzzer::WriteToOutputCorpus(const Unit &U) { + if (Options.OutputCorpus.empty()) return; + std::string Path = DirPlusFile(Options.OutputCorpus, Hash(U)); + WriteToFile(U, Path); + if (Options.Verbosity >= 2) + Printf("Written to %s\n", Path.c_str()); + assert(!Options.OnlyASCII || IsASCII(U)); +} + +void Fuzzer::WriteUnitToFileWithPrefix(const Unit &U, const char *Prefix) { + 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("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() { + if (Options.OutputCorpus.empty()) return; + for (const auto &U : Corpus) + WriteToFile(U, DirPlusFile(Options.OutputCorpus, Hash(U))); + if (Options.Verbosity) + Printf("Written corpus of %zd files to %s\n", Corpus.size(), + Options.OutputCorpus.c_str()); +} + +void Fuzzer::PrintStatusForNewUnit(const Unit &U) { + if (!Options.PrintNEW) + return; + PrintStats("NEW ", ""); + if (Options.Verbosity) { + 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::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++) { + 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); + 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() { + system_clock::time_point LastCorpusReload = system_clock::now(); + if (Options.DoCrossOver) + USF.SetCorpus(&Corpus); + while (true) { + SyncCorpus(); + auto Now = system_clock::now(); + if (duration_cast<seconds>(Now - LastCorpusReload).count()) { + RereadOutputCorpus(); + 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() { + if (Options.SyncCommand.empty() || Options.OutputCorpus.empty()) return; + auto Now = system_clock::now(); + if (duration_cast<seconds>(Now - LastExternalSync).count() < + Options.SyncTimeout) + return; + LastExternalSync = Now; + ExecuteCommand(Options.SyncCommand + " " + Options.OutputCorpus); +} + +} // namespace fuzzer |
