lib/Fuzzer/FuzzerLoop.cpp - platform/external/llvm - Git at Google

 //===- 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 <sanitizer/coverage_interface.h>
 #include <algorithm>
 #include <iostream>

 namespace fuzzer {

 // Only one Fuzzer per process.
 static Fuzzer *F;

 Fuzzer::Fuzzer(UserCallback Callback, FuzzingOptions Options)
     : Callback(Callback), Options(Options) {
   SetDeathCallback();
   InitializeDFSan();
   assert(!F);
   F = this;
 }

 void Fuzzer::SetDeathCallback() {
   __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);
     std::cerr << T.data();
     std::cerr << PrintAfter;
   }
 }

 void Fuzzer::StaticDeathCallback() {
   assert(F);
   F->DeathCallback();
 }

 void Fuzzer::DeathCallback() {
   std::cerr << "DEATH: " <<  std::endl;
   Print(CurrentUnit, "\n");
   PrintUnitInASCIIOrTokens(CurrentUnit, "\n");
   WriteToCrash(CurrentUnit, "crash-");
 }

 void Fuzzer::StaticAlarmCallback() {
   assert(F);
   F->AlarmCallback();
 }

 void Fuzzer::AlarmCallback() {
   size_t Seconds =
       duration_cast<seconds>(system_clock::now() - UnitStartTime).count();
   std::cerr << "ALARM: working on the last Unit for " << Seconds << " seconds"
             << std::endl;
   if (Seconds >= 3) {
     Print(CurrentUnit, "\n");
     PrintUnitInASCIIOrTokens(CurrentUnit, "\n");
     WriteToCrash(CurrentUnit, "timeout-");
   }
   exit(1);
 }

 void Fuzzer::PrintStats(const char *Where, size_t Cov, const char *End) {
   if (!Options.Verbosity) return;
   size_t Seconds = secondsSinceProcessStartUp();
   size_t ExecPerSec = (Seconds ? TotalNumberOfRuns / Seconds : 0);
   std::cerr
       << "#" << TotalNumberOfRuns
       << "\t" << Where
       << " cov " << Cov
       << " bits " << TotalBits()
       << " units " << Corpus.size()
       << " exec/s " << ExecPerSec
       << End;
 }

 void Fuzzer::ShuffleAndMinimize() {
   size_t MaxCov = 0;
   bool PreferSmall =
       (Options.PreferSmallDuringInitialShuffle == 1 ||
        (Options.PreferSmallDuringInitialShuffle == -1 && rand() % 2));
   if (Options.Verbosity)
     std::cerr << "PreferSmall: " << PreferSmall << "\n";
   PrintStats("READ  ", 0);
   std::vector<Unit> NewCorpus;
   std::random_shuffle(Corpus.begin(), Corpus.end());
   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);
       size_t NewCoverage = RunOne(U);
       if (NewCoverage) {
         MaxCov = NewCoverage;
         NewCorpus.push_back(U);
         if (Options.Verbosity >= 2)
           std::cerr << "NEW0: " << NewCoverage
                     << " L " << U.size()
                     << "\n";
       }
     }
   }
   Corpus = NewCorpus;
   PrintStats("INITED", MaxCov);
 }

 size_t Fuzzer::RunOne(const Unit &U) {
   UnitStartTime = system_clock::now();
   TotalNumberOfRuns++;
   size_t Res = 0;
   if (Options.UseFullCoverageSet)
     Res = RunOneMaximizeFullCoverageSet(U);
   else if (Options.UseCoveragePairs)
     Res = RunOneMaximizeCoveragePairs(U);
   else
     Res = RunOneMaximizeTotalCoverage(U);
   auto UnitStopTime = system_clock::now();
   auto TimeOfUnit =
       duration_cast<seconds>(UnitStopTime - UnitStartTime).count();
   if (TimeOfUnit > TimeOfLongestUnitInSeconds) {
     TimeOfLongestUnitInSeconds = TimeOfUnit;
     std::cerr << "Longest unit: " << TimeOfLongestUnitInSeconds
               << " s:\n";
     Print(U, "\n");
   }
   return Res;
 }

 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;
 }

 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;
 }

 void Fuzzer::ExecuteCallback(const Unit &U) {
   if (Options.Tokens.empty()) {
     Callback(U.data(), U.size());
   } else {
     auto T = SubstituteTokens(U);
     Callback(T.data(), T.size());
   }
 }

 // Experimental. Does not yet scale.
 // Fuly reset the current coverage state, run a single unit,
 // collect all coverage pairs and return non-zero if a new pair is observed.
 size_t Fuzzer::RunOneMaximizeCoveragePairs(const Unit &U) {
   __sanitizer_reset_coverage();
   ExecuteCallback(U);
   uintptr_t *PCs;
   uintptr_t NumPCs = __sanitizer_get_coverage_guards(&PCs);
   bool HasNewPairs = false;
   for (uintptr_t i = 0; i < NumPCs; i++) {
     if (!PCs[i]) continue;
     for (uintptr_t j = 0; j < NumPCs; j++) {
       if (!PCs[j]) continue;
       uint64_t Pair = (i << 32) | j;
       HasNewPairs |= CoveragePairs.insert(Pair).second;
     }
   }
   if (HasNewPairs)
     return CoveragePairs.size();
   return 0;
 }

 // 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::RunOneMaximizeTotalCoverage(const Unit &U) {
   size_t NumCounters = __sanitizer_get_number_of_counters();
   if (Options.UseCounters) {
     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();
   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;
 }

 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)
     std::cerr << "Written to " << Path << std::endl;
 }

 void Fuzzer::WriteToCrash(const Unit &U, const char *Prefix) {
   std::string Path = Prefix + Hash(U);
   WriteToFile(U, Path);
   std::cerr << "CRASHED; file written to " << Path << std::endl;
 }

 void Fuzzer::SaveCorpus() {
   if (Options.OutputCorpus.empty()) return;
   for (const auto &U : Corpus)
     WriteToFile(U, DirPlusFile(Options.OutputCorpus, Hash(U)));
   if (Options.Verbosity)
     std::cerr << "Written corpus of " << Corpus.size() << " files to "
               << Options.OutputCorpus << "\n";
 }

 size_t Fuzzer::MutateAndTestOne(Unit *U) {
   size_t NewUnits = 0;
   for (int i = 0; i < Options.MutateDepth; i++) {
     if (TotalNumberOfRuns >= Options.MaxNumberOfRuns)
       return NewUnits;
     MutateWithDFSan(U);
     Mutate(U, Options.MaxLen);
     size_t NewCoverage = RunOne(*U);
     if (NewCoverage) {
       Corpus.push_back(*U);
       NewUnits++;
       PrintStats("NEW   ", NewCoverage, "");
       if (Options.Verbosity) {
         std::cerr << " L: " << U->size();
         if (U->size() < 30) {
           std::cerr << " ";
           PrintUnitInASCIIOrTokens(*U, "\t");
           Print(*U);
         }
         std::cerr << "\n";
       }
       WriteToOutputCorpus(*U);
       if (Options.ExitOnFirst)
         exit(0);
     }
   }
   return NewUnits;
 }

 size_t Fuzzer::Loop(size_t NumIterations) {
   size_t NewUnits = 0;
   for (size_t i = 1; i <= NumIterations; i++) {
     for (size_t J1 = 0; J1 < Corpus.size(); J1++) {
       if (TotalNumberOfRuns >= Options.MaxNumberOfRuns)
         return NewUnits;
       // First, simply mutate the unit w/o doing crosses.
       CurrentUnit = Corpus[J1];
       NewUnits += MutateAndTestOne(&CurrentUnit);
       // Now, cross with others.
       if (Options.DoCrossOver) {
         for (size_t J2 = 0; J2 < Corpus.size(); J2++) {
           CurrentUnit.clear();
           CrossOver(Corpus[J1], Corpus[J2], &CurrentUnit, Options.MaxLen);
           NewUnits += MutateAndTestOne(&CurrentUnit);
         }
       }
     }
   }
   return NewUnits;
 }

 }  // namespace fuzzer
	//===- 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 <sanitizer/coverage_interface.h>
	#include <algorithm>
	#include <iostream>

	namespace fuzzer {

	// Only one Fuzzer per process.
	static Fuzzer *F;

	Fuzzer::Fuzzer(UserCallback Callback, FuzzingOptions Options)
	: Callback(Callback), Options(Options) {
	SetDeathCallback();
	InitializeDFSan();
	assert(!F);
	F = this;
	}

	void Fuzzer::SetDeathCallback() {
	__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);
	std::cerr << T.data();
	std::cerr << PrintAfter;
	}
	}

	void Fuzzer::StaticDeathCallback() {
	assert(F);
	F->DeathCallback();
	}

	void Fuzzer::DeathCallback() {
	std::cerr << "DEATH: " << std::endl;
	Print(CurrentUnit, "\n");
	PrintUnitInASCIIOrTokens(CurrentUnit, "\n");
	WriteToCrash(CurrentUnit, "crash-");
	}

	void Fuzzer::StaticAlarmCallback() {
	assert(F);
	F->AlarmCallback();
	}

	void Fuzzer::AlarmCallback() {
	size_t Seconds =
	duration_cast<seconds>(system_clock::now() - UnitStartTime).count();
	std::cerr << "ALARM: working on the last Unit for " << Seconds << " seconds"
	<< std::endl;
	if (Seconds >= 3) {
	Print(CurrentUnit, "\n");
	PrintUnitInASCIIOrTokens(CurrentUnit, "\n");
	WriteToCrash(CurrentUnit, "timeout-");
	}
	exit(1);
	}

	void Fuzzer::PrintStats(const char Where, size_t Cov, const char End) {
	if (!Options.Verbosity) return;
	size_t Seconds = secondsSinceProcessStartUp();
	size_t ExecPerSec = (Seconds ? TotalNumberOfRuns / Seconds : 0);
	std::cerr
	<< "#" << TotalNumberOfRuns
	<< "\t" << Where
	<< " cov " << Cov
	<< " bits " << TotalBits()
	<< " units " << Corpus.size()
	<< " exec/s " << ExecPerSec
	<< End;
	}

	void Fuzzer::ShuffleAndMinimize() {
	size_t MaxCov = 0;
	bool PreferSmall =
	(Options.PreferSmallDuringInitialShuffle == 1 \|\|
	(Options.PreferSmallDuringInitialShuffle == -1 && rand() % 2));
	if (Options.Verbosity)
	std::cerr << "PreferSmall: " << PreferSmall << "\n";
	PrintStats("READ ", 0);
	std::vector<Unit> NewCorpus;
	std::random_shuffle(Corpus.begin(), Corpus.end());
	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);
	size_t NewCoverage = RunOne(U);
	if (NewCoverage) {
	MaxCov = NewCoverage;
	NewCorpus.push_back(U);
	if (Options.Verbosity >= 2)
	std::cerr << "NEW0: " << NewCoverage
	<< " L " << U.size()
	<< "\n";
	}
	}
	}
	Corpus = NewCorpus;
	PrintStats("INITED", MaxCov);
	}

	size_t Fuzzer::RunOne(const Unit &U) {
	UnitStartTime = system_clock::now();
	TotalNumberOfRuns++;
	size_t Res = 0;
	if (Options.UseFullCoverageSet)
	Res = RunOneMaximizeFullCoverageSet(U);
	else if (Options.UseCoveragePairs)
	Res = RunOneMaximizeCoveragePairs(U);
	else
	Res = RunOneMaximizeTotalCoverage(U);
	auto UnitStopTime = system_clock::now();
	auto TimeOfUnit =
	duration_cast<seconds>(UnitStopTime - UnitStartTime).count();
	if (TimeOfUnit > TimeOfLongestUnitInSeconds) {
	TimeOfLongestUnitInSeconds = TimeOfUnit;
	std::cerr << "Longest unit: " << TimeOfLongestUnitInSeconds
	<< " s:\n";
	Print(U, "\n");
	}
	return Res;
	}

	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;
	}

	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;
	}

	void Fuzzer::ExecuteCallback(const Unit &U) {
	if (Options.Tokens.empty()) {
	Callback(U.data(), U.size());
	} else {
	auto T = SubstituteTokens(U);
	Callback(T.data(), T.size());
	}
	}

	// Experimental. Does not yet scale.
	// Fuly reset the current coverage state, run a single unit,
	// collect all coverage pairs and return non-zero if a new pair is observed.
	size_t Fuzzer::RunOneMaximizeCoveragePairs(const Unit &U) {
	__sanitizer_reset_coverage();
	ExecuteCallback(U);
	uintptr_t *PCs;
	uintptr_t NumPCs = __sanitizer_get_coverage_guards(&PCs);
	bool HasNewPairs = false;
	for (uintptr_t i = 0; i < NumPCs; i++) {
	if (!PCs[i]) continue;
	for (uintptr_t j = 0; j < NumPCs; j++) {
	if (!PCs[j]) continue;
	uint64_t Pair = (i << 32) \| j;
	HasNewPairs \|= CoveragePairs.insert(Pair).second;
	}
	}
	if (HasNewPairs)
	return CoveragePairs.size();
	return 0;
	}

	// 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::RunOneMaximizeTotalCoverage(const Unit &U) {
	size_t NumCounters = __sanitizer_get_number_of_counters();
	if (Options.UseCounters) {
	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();
	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;
	}

	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)
	std::cerr << "Written to " << Path << std::endl;
	}

	void Fuzzer::WriteToCrash(const Unit &U, const char *Prefix) {
	std::string Path = Prefix + Hash(U);
	WriteToFile(U, Path);
	std::cerr << "CRASHED; file written to " << Path << std::endl;
	}

	void Fuzzer::SaveCorpus() {
	if (Options.OutputCorpus.empty()) return;
	for (const auto &U : Corpus)
	WriteToFile(U, DirPlusFile(Options.OutputCorpus, Hash(U)));
	if (Options.Verbosity)
	std::cerr << "Written corpus of " << Corpus.size() << " files to "
	<< Options.OutputCorpus << "\n";
	}

	size_t Fuzzer::MutateAndTestOne(Unit *U) {
	size_t NewUnits = 0;
	for (int i = 0; i < Options.MutateDepth; i++) {
	if (TotalNumberOfRuns >= Options.MaxNumberOfRuns)
	return NewUnits;
	MutateWithDFSan(U);
	Mutate(U, Options.MaxLen);
	size_t NewCoverage = RunOne(*U);
	if (NewCoverage) {
	Corpus.push_back(*U);
	NewUnits++;
	PrintStats("NEW ", NewCoverage, "");
	if (Options.Verbosity) {
	std::cerr << " L: " << U->size();
	if (U->size() < 30) {
	std::cerr << " ";
	PrintUnitInASCIIOrTokens(*U, "\t");
	Print(*U);
	}
	std::cerr << "\n";
	}
	WriteToOutputCorpus(*U);
	if (Options.ExitOnFirst)
	exit(0);
	}
	}
	return NewUnits;
	}

	size_t Fuzzer::Loop(size_t NumIterations) {
	size_t NewUnits = 0;
	for (size_t i = 1; i <= NumIterations; i++) {
	for (size_t J1 = 0; J1 < Corpus.size(); J1++) {
	if (TotalNumberOfRuns >= Options.MaxNumberOfRuns)
	return NewUnits;
	// First, simply mutate the unit w/o doing crosses.
	CurrentUnit = Corpus[J1];
	NewUnits += MutateAndTestOne(&CurrentUnit);
	// Now, cross with others.
	if (Options.DoCrossOver) {
	for (size_t J2 = 0; J2 < Corpus.size(); J2++) {
	CurrentUnit.clear();
	CrossOver(Corpus[J1], Corpus[J2], &CurrentUnit, Options.MaxLen);
	NewUnits += MutateAndTestOne(&CurrentUnit);
	}
	}
	}
	}
	return NewUnits;
	}

	} // namespace fuzzer