diff options
Diffstat (limited to 'custom_mutators/libfuzzer/FuzzerFork.cpp')
| -rw-r--r-- | custom_mutators/libfuzzer/FuzzerFork.cpp | 501 |
1 files changed, 501 insertions, 0 deletions
diff --git a/custom_mutators/libfuzzer/FuzzerFork.cpp b/custom_mutators/libfuzzer/FuzzerFork.cpp new file mode 100644 index 00000000..d6ffed74 --- /dev/null +++ b/custom_mutators/libfuzzer/FuzzerFork.cpp @@ -0,0 +1,501 @@ +//===- FuzzerFork.cpp - run fuzzing in separate subprocesses --------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// Spawn and orchestrate separate fuzzing processes. +//===----------------------------------------------------------------------===// + +#include "FuzzerCommand.h" +#include "FuzzerFork.h" +#include "FuzzerIO.h" +#include "FuzzerInternal.h" +#include "FuzzerMerge.h" +#include "FuzzerSHA1.h" +#include "FuzzerTracePC.h" +#include "FuzzerUtil.h" + +#include <atomic> +#include <chrono> +#include <condition_variable> +#include <fstream> +#include <memory> +#include <mutex> +#include <queue> +#include <sstream> +#include <thread> + +namespace fuzzer { + +struct Stats { + + size_t number_of_executed_units = 0; + size_t peak_rss_mb = 0; + size_t average_exec_per_sec = 0; + +}; + +static Stats ParseFinalStatsFromLog(const std::string &LogPath) { + + std::ifstream In(LogPath); + std::string Line; + Stats Res; + struct { + + const char *Name; + size_t * Var; + + } NameVarPairs[] = { + + {"stat::number_of_executed_units:", &Res.number_of_executed_units}, + {"stat::peak_rss_mb:", &Res.peak_rss_mb}, + {"stat::average_exec_per_sec:", &Res.average_exec_per_sec}, + {nullptr, nullptr}, + + }; + + while (std::getline(In, Line, '\n')) { + + if (Line.find("stat::") != 0) continue; + std::istringstream ISS(Line); + std::string Name; + size_t Val; + ISS >> Name >> Val; + for (size_t i = 0; NameVarPairs[i].Name; i++) + if (Name == NameVarPairs[i].Name) *NameVarPairs[i].Var = Val; + + } + + return Res; + +} + +struct FuzzJob { + + // Inputs. + Command Cmd; + std::string CorpusDir; + std::string FeaturesDir; + std::string LogPath; + std::string SeedListPath; + std::string CFPath; + size_t JobId; + + int DftTimeInSeconds = 0; + + // Fuzzing Outputs. + int ExitCode; + + ~FuzzJob() { + + RemoveFile(CFPath); + RemoveFile(LogPath); + RemoveFile(SeedListPath); + RmDirRecursive(CorpusDir); + RmDirRecursive(FeaturesDir); + + } + +}; + +struct GlobalEnv { + + Vector<std::string> Args; + Vector<std::string> CorpusDirs; + std::string MainCorpusDir; + std::string TempDir; + std::string DFTDir; + std::string DataFlowBinary; + Set<uint32_t> Features, Cov; + Set<std::string> FilesWithDFT; + Vector<std::string> Files; + Random * Rand; + std::chrono::system_clock::time_point ProcessStartTime; + int Verbosity = 0; + + size_t NumTimeouts = 0; + size_t NumOOMs = 0; + size_t NumCrashes = 0; + + size_t NumRuns = 0; + + std::string StopFile() { + + return DirPlusFile(TempDir, "STOP"); + + } + + size_t secondsSinceProcessStartUp() const { + + return std::chrono::duration_cast<std::chrono::seconds>( + std::chrono::system_clock::now() - ProcessStartTime) + .count(); + + } + + FuzzJob *CreateNewJob(size_t JobId) { + + Command Cmd(Args); + Cmd.removeFlag("fork"); + Cmd.removeFlag("runs"); + Cmd.removeFlag("collect_data_flow"); + for (auto &C : CorpusDirs) // Remove all corpora from the args. + Cmd.removeArgument(C); + Cmd.addFlag("reload", "0"); // working in an isolated dir, no reload. + Cmd.addFlag("print_final_stats", "1"); + Cmd.addFlag("print_funcs", "0"); // no need to spend time symbolizing. + Cmd.addFlag("max_total_time", std::to_string(std::min((size_t)300, JobId))); + Cmd.addFlag("stop_file", StopFile()); + if (!DataFlowBinary.empty()) { + + Cmd.addFlag("data_flow_trace", DFTDir); + if (!Cmd.hasFlag("focus_function")) Cmd.addFlag("focus_function", "auto"); + + } + + auto Job = new FuzzJob; + std::string Seeds; + if (size_t CorpusSubsetSize = + std::min(Files.size(), (size_t)sqrt(Files.size() + 2))) { + + auto Time1 = std::chrono::system_clock::now(); + for (size_t i = 0; i < CorpusSubsetSize; i++) { + + auto &SF = Files[Rand->SkewTowardsLast(Files.size())]; + Seeds += (Seeds.empty() ? "" : ",") + SF; + CollectDFT(SF); + + } + + auto Time2 = std::chrono::system_clock::now(); + Job->DftTimeInSeconds = duration_cast<seconds>(Time2 - Time1).count(); + + } + + if (!Seeds.empty()) { + + Job->SeedListPath = + DirPlusFile(TempDir, std::to_string(JobId) + ".seeds"); + WriteToFile(Seeds, Job->SeedListPath); + Cmd.addFlag("seed_inputs", "@" + Job->SeedListPath); + + } + + Job->LogPath = DirPlusFile(TempDir, std::to_string(JobId) + ".log"); + Job->CorpusDir = DirPlusFile(TempDir, "C" + std::to_string(JobId)); + Job->FeaturesDir = DirPlusFile(TempDir, "F" + std::to_string(JobId)); + Job->CFPath = DirPlusFile(TempDir, std::to_string(JobId) + ".merge"); + Job->JobId = JobId; + + Cmd.addArgument(Job->CorpusDir); + Cmd.addFlag("features_dir", Job->FeaturesDir); + + for (auto &D : {Job->CorpusDir, Job->FeaturesDir}) { + + RmDirRecursive(D); + MkDir(D); + + } + + Cmd.setOutputFile(Job->LogPath); + Cmd.combineOutAndErr(); + + Job->Cmd = Cmd; + + if (Verbosity >= 2) + Printf("Job %zd/%p Created: %s\n", JobId, Job, + Job->Cmd.toString().c_str()); + // Start from very short runs and gradually increase them. + return Job; + + } + + void RunOneMergeJob(FuzzJob *Job) { + + auto Stats = ParseFinalStatsFromLog(Job->LogPath); + NumRuns += Stats.number_of_executed_units; + + Vector<SizedFile> TempFiles, MergeCandidates; + // Read all newly created inputs and their feature sets. + // Choose only those inputs that have new features. + GetSizedFilesFromDir(Job->CorpusDir, &TempFiles); + std::sort(TempFiles.begin(), TempFiles.end()); + for (auto &F : TempFiles) { + + auto FeatureFile = F.File; + FeatureFile.replace(0, Job->CorpusDir.size(), Job->FeaturesDir); + auto FeatureBytes = FileToVector(FeatureFile, 0, false); + assert((FeatureBytes.size() % sizeof(uint32_t)) == 0); + Vector<uint32_t> NewFeatures(FeatureBytes.size() / sizeof(uint32_t)); + memcpy(NewFeatures.data(), FeatureBytes.data(), FeatureBytes.size()); + for (auto Ft : NewFeatures) { + + if (!Features.count(Ft)) { + + MergeCandidates.push_back(F); + break; + + } + + } + + } + + // if (!FilesToAdd.empty() || Job->ExitCode != 0) + Printf( + "#%zd: cov: %zd ft: %zd corp: %zd exec/s %zd " + "oom/timeout/crash: %zd/%zd/%zd time: %zds job: %zd dft_time: %d\n", + NumRuns, Cov.size(), Features.size(), Files.size(), + Stats.average_exec_per_sec, NumOOMs, NumTimeouts, NumCrashes, + secondsSinceProcessStartUp(), Job->JobId, Job->DftTimeInSeconds); + + if (MergeCandidates.empty()) return; + + Vector<std::string> FilesToAdd; + Set<uint32_t> NewFeatures, NewCov; + CrashResistantMerge(Args, {}, MergeCandidates, &FilesToAdd, Features, + &NewFeatures, Cov, &NewCov, Job->CFPath, false); + for (auto &Path : FilesToAdd) { + + auto U = FileToVector(Path); + auto NewPath = DirPlusFile(MainCorpusDir, Hash(U)); + WriteToFile(U, NewPath); + Files.push_back(NewPath); + + } + + Features.insert(NewFeatures.begin(), NewFeatures.end()); + Cov.insert(NewCov.begin(), NewCov.end()); + for (auto Idx : NewCov) + if (auto *TE = TPC.PCTableEntryByIdx(Idx)) + if (TPC.PcIsFuncEntry(TE)) + PrintPC(" NEW_FUNC: %p %F %L\n", "", + TPC.GetNextInstructionPc(TE->PC)); + + } + + void CollectDFT(const std::string &InputPath) { + + if (DataFlowBinary.empty()) return; + if (!FilesWithDFT.insert(InputPath).second) return; + Command Cmd(Args); + Cmd.removeFlag("fork"); + Cmd.removeFlag("runs"); + Cmd.addFlag("data_flow_trace", DFTDir); + Cmd.addArgument(InputPath); + for (auto &C : CorpusDirs) // Remove all corpora from the args. + Cmd.removeArgument(C); + Cmd.setOutputFile(DirPlusFile(TempDir, "dft.log")); + Cmd.combineOutAndErr(); + // Printf("CollectDFT: %s\n", Cmd.toString().c_str()); + ExecuteCommand(Cmd); + + } + +}; + +struct JobQueue { + + std::queue<FuzzJob *> Qu; + std::mutex Mu; + std::condition_variable Cv; + + void Push(FuzzJob *Job) { + + { + + std::lock_guard<std::mutex> Lock(Mu); + Qu.push(Job); + + } + + Cv.notify_one(); + + } + + FuzzJob *Pop() { + + std::unique_lock<std::mutex> Lk(Mu); + // std::lock_guard<std::mutex> Lock(Mu); + Cv.wait(Lk, [&] { return !Qu.empty(); }); + assert(!Qu.empty()); + auto Job = Qu.front(); + Qu.pop(); + return Job; + + } + +}; + +void WorkerThread(JobQueue *FuzzQ, JobQueue *MergeQ) { + + while (auto Job = FuzzQ->Pop()) { + + // Printf("WorkerThread: job %p\n", Job); + Job->ExitCode = ExecuteCommand(Job->Cmd); + MergeQ->Push(Job); + + } + +} + +// This is just a skeleton of an experimental -fork=1 feature. +void FuzzWithFork(Random &Rand, const FuzzingOptions &Options, + const Vector<std::string> &Args, + const Vector<std::string> &CorpusDirs, int NumJobs) { + + Printf("INFO: -fork=%d: fuzzing in separate process(s)\n", NumJobs); + + GlobalEnv Env; + Env.Args = Args; + Env.CorpusDirs = CorpusDirs; + Env.Rand = &Rand; + Env.Verbosity = Options.Verbosity; + Env.ProcessStartTime = std::chrono::system_clock::now(); + Env.DataFlowBinary = Options.CollectDataFlow; + + Vector<SizedFile> SeedFiles; + for (auto &Dir : CorpusDirs) + GetSizedFilesFromDir(Dir, &SeedFiles); + std::sort(SeedFiles.begin(), SeedFiles.end()); + Env.TempDir = TempPath("FuzzWithFork", ".dir"); + Env.DFTDir = DirPlusFile(Env.TempDir, "DFT"); + RmDirRecursive(Env.TempDir); // in case there is a leftover from old runs. + MkDir(Env.TempDir); + MkDir(Env.DFTDir); + + if (CorpusDirs.empty()) + MkDir(Env.MainCorpusDir = DirPlusFile(Env.TempDir, "C")); + else + Env.MainCorpusDir = CorpusDirs[0]; + + if (Options.KeepSeed) { + + for (auto &File : SeedFiles) + Env.Files.push_back(File.File); + + } else { + + auto CFPath = DirPlusFile(Env.TempDir, "merge.txt"); + CrashResistantMerge(Env.Args, {}, SeedFiles, &Env.Files, {}, &Env.Features, + {}, &Env.Cov, CFPath, false); + RemoveFile(CFPath); + + } + + Printf("INFO: -fork=%d: %zd seed inputs, starting to fuzz in %s\n", NumJobs, + Env.Files.size(), Env.TempDir.c_str()); + + int ExitCode = 0; + + JobQueue FuzzQ, MergeQ; + + auto StopJobs = [&]() { + + for (int i = 0; i < NumJobs; i++) + FuzzQ.Push(nullptr); + MergeQ.Push(nullptr); + WriteToFile(Unit({1}), Env.StopFile()); + + }; + + size_t JobId = 1; + Vector<std::thread> Threads; + for (int t = 0; t < NumJobs; t++) { + + Threads.push_back(std::thread(WorkerThread, &FuzzQ, &MergeQ)); + FuzzQ.Push(Env.CreateNewJob(JobId++)); + + } + + while (true) { + + std::unique_ptr<FuzzJob> Job(MergeQ.Pop()); + if (!Job) break; + ExitCode = Job->ExitCode; + if (ExitCode == Options.InterruptExitCode) { + + Printf("==%lu== libFuzzer: a child was interrupted; exiting\n", GetPid()); + StopJobs(); + break; + + } + + Fuzzer::MaybeExitGracefully(); + + Env.RunOneMergeJob(Job.get()); + + // Continue if our crash is one of the ignorred ones. + if (Options.IgnoreTimeouts && ExitCode == Options.TimeoutExitCode) + Env.NumTimeouts++; + else if (Options.IgnoreOOMs && ExitCode == Options.OOMExitCode) + Env.NumOOMs++; + else if (ExitCode != 0) { + + Env.NumCrashes++; + if (Options.IgnoreCrashes) { + + std::ifstream In(Job->LogPath); + std::string Line; + while (std::getline(In, Line, '\n')) + if (Line.find("ERROR:") != Line.npos || + Line.find("runtime error:") != Line.npos) + Printf("%s\n", Line.c_str()); + + } else { + + // And exit if we don't ignore this crash. + Printf("INFO: log from the inner process:\n%s", + FileToString(Job->LogPath).c_str()); + StopJobs(); + break; + + } + + } + + // Stop if we are over the time budget. + // This is not precise, since other threads are still running + // and we will wait while joining them. + // We also don't stop instantly: other jobs need to finish. + if (Options.MaxTotalTimeSec > 0 && + Env.secondsSinceProcessStartUp() >= (size_t)Options.MaxTotalTimeSec) { + + Printf("INFO: fuzzed for %zd seconds, wrapping up soon\n", + Env.secondsSinceProcessStartUp()); + StopJobs(); + break; + + } + + if (Env.NumRuns >= Options.MaxNumberOfRuns) { + + Printf("INFO: fuzzed for %zd iterations, wrapping up soon\n", + Env.NumRuns); + StopJobs(); + break; + + } + + FuzzQ.Push(Env.CreateNewJob(JobId++)); + + } + + for (auto &T : Threads) + T.join(); + + // The workers have terminated. Don't try to remove the directory before they + // terminate to avoid a race condition preventing cleanup on Windows. + RmDirRecursive(Env.TempDir); + + // Use the exit code from the last child process. + Printf("INFO: exiting: %d time: %zds\n", ExitCode, + Env.secondsSinceProcessStartUp()); + exit(ExitCode); + +} + +} // namespace fuzzer + |