llvm-project/llvm/lib/Fuzzer/FuzzerDriver.cpp

297 lines
8.7 KiB
C++

//===- FuzzerDriver.cpp - FuzzerDriver function and flags -----------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// FuzzerDriver and flag parsing.
//===----------------------------------------------------------------------===//
#include "FuzzerInterface.h"
#include "FuzzerInternal.h"
#include <cstring>
#include <chrono>
#include <unistd.h>
#include <thread>
#include <atomic>
#include <mutex>
#include <string>
#include <sstream>
#include <algorithm>
#include <iterator>
namespace fuzzer {
// Program arguments.
struct FlagDescription {
const char *Name;
const char *Description;
int Default;
int *IntFlag;
const char **StrFlag;
};
struct {
#define FUZZER_FLAG_INT(Name, Default, Description) int Name;
#define FUZZER_FLAG_STRING(Name, Description) const char *Name;
#include "FuzzerFlags.def"
#undef FUZZER_FLAG_INT
#undef FUZZER_FLAG_STRING
} Flags;
static FlagDescription FlagDescriptions [] {
#define FUZZER_FLAG_INT(Name, Default, Description) \
{ #Name, Description, Default, &Flags.Name, nullptr},
#define FUZZER_FLAG_STRING(Name, Description) \
{ #Name, Description, 0, nullptr, &Flags.Name },
#include "FuzzerFlags.def"
#undef FUZZER_FLAG_INT
#undef FUZZER_FLAG_STRING
};
static const size_t kNumFlags =
sizeof(FlagDescriptions) / sizeof(FlagDescriptions[0]);
static std::vector<std::string> inputs;
static const char *ProgName;
static void PrintHelp() {
Printf("Usage: %s [-flag1=val1 [-flag2=val2 ...] ] [dir1 [dir2 ...] ]\n",
ProgName);
Printf("\nFlags: (strictly in form -flag=value)\n");
size_t MaxFlagLen = 0;
for (size_t F = 0; F < kNumFlags; F++)
MaxFlagLen = std::max(strlen(FlagDescriptions[F].Name), MaxFlagLen);
for (size_t F = 0; F < kNumFlags; F++) {
const auto &D = FlagDescriptions[F];
Printf(" %s", D.Name);
for (size_t i = 0, n = MaxFlagLen - strlen(D.Name); i < n; i++)
Printf(" ");
Printf("\t");
Printf("%d\t%s\n", D.Default, D.Description);
}
Printf("\nFlags starting with '--' will be ignored and "
"will be passed verbatim to subprocesses.\n");
}
static const char *FlagValue(const char *Param, const char *Name) {
size_t Len = strlen(Name);
if (Param[0] == '-' && strstr(Param + 1, Name) == Param + 1 &&
Param[Len + 1] == '=')
return &Param[Len + 2];
return nullptr;
}
static bool ParseOneFlag(const char *Param) {
if (Param[0] != '-') return false;
if (Param[1] == '-') {
static bool PrintedWarning = false;
if (!PrintedWarning) {
PrintedWarning = true;
Printf("WARNING: libFuzzer ignores flags that start with '--'\n");
}
return true;
}
for (size_t F = 0; F < kNumFlags; F++) {
const char *Name = FlagDescriptions[F].Name;
const char *Str = FlagValue(Param, Name);
if (Str) {
if (FlagDescriptions[F].IntFlag) {
int Val = std::stol(Str);
*FlagDescriptions[F].IntFlag = Val;
if (Flags.verbosity >= 2)
Printf("Flag: %s %d\n", Name, Val);;
return true;
} else if (FlagDescriptions[F].StrFlag) {
*FlagDescriptions[F].StrFlag = Str;
if (Flags.verbosity >= 2)
Printf("Flag: %s %s\n", Name, Str);
return true;
}
}
}
PrintHelp();
exit(1);
}
// We don't use any library to minimize dependencies.
static void ParseFlags(int argc, char **argv) {
for (size_t F = 0; F < kNumFlags; F++) {
if (FlagDescriptions[F].IntFlag)
*FlagDescriptions[F].IntFlag = FlagDescriptions[F].Default;
if (FlagDescriptions[F].StrFlag)
*FlagDescriptions[F].StrFlag = nullptr;
}
for (int A = 1; A < argc; A++) {
if (ParseOneFlag(argv[A])) continue;
inputs.push_back(argv[A]);
}
}
static std::mutex Mu;
static void PulseThread() {
while (true) {
std::this_thread::sleep_for(std::chrono::seconds(600));
std::lock_guard<std::mutex> Lock(Mu);
Printf("pulse...\n");
}
}
static void WorkerThread(const std::string &Cmd, std::atomic<int> *Counter,
int NumJobs, std::atomic<bool> *HasErrors) {
while (true) {
int C = (*Counter)++;
if (C >= NumJobs) break;
std::string Log = "fuzz-" + std::to_string(C) + ".log";
std::string ToRun = Cmd + " > " + Log + " 2>&1\n";
if (Flags.verbosity)
Printf("%s", ToRun.c_str());
int ExitCode = system(ToRun.c_str());
if (ExitCode != 0)
*HasErrors = true;
std::lock_guard<std::mutex> Lock(Mu);
Printf("================== Job %d exited with exit code %d ============\n",
C, ExitCode);
fuzzer::CopyFileToErr(Log);
}
}
static int RunInMultipleProcesses(int argc, char **argv, int NumWorkers,
int NumJobs) {
std::atomic<int> Counter(0);
std::atomic<bool> HasErrors(false);
std::string Cmd;
for (int i = 0; i < argc; i++) {
if (FlagValue(argv[i], "jobs") || FlagValue(argv[i], "workers")) continue;
Cmd += argv[i];
Cmd += " ";
}
std::vector<std::thread> V;
std::thread Pulse(PulseThread);
Pulse.detach();
for (int i = 0; i < NumWorkers; i++)
V.push_back(std::thread(WorkerThread, Cmd, &Counter, NumJobs, &HasErrors));
for (auto &T : V)
T.join();
return HasErrors ? 1 : 0;
}
std::vector<std::string> ReadTokensFile(const char *TokensFilePath) {
if (!TokensFilePath) return {};
std::string TokensFileContents = FileToString(TokensFilePath);
std::istringstream ISS(TokensFileContents);
std::vector<std::string> Res = {std::istream_iterator<std::string>{ISS},
std::istream_iterator<std::string>{}};
Res.push_back(" ");
Res.push_back("\t");
Res.push_back("\n");
return Res;
}
int ApplyTokens(const Fuzzer &F, const char *InputFilePath) {
Unit U = FileToVector(InputFilePath);
auto T = F.SubstituteTokens(U);
T.push_back(0);
Printf("%s", T.data());
return 0;
}
int FuzzerDriver(int argc, char **argv, UserCallback Callback) {
FuzzerRandomLibc Rand(0);
SimpleUserSuppliedFuzzer SUSF(&Rand, Callback);
return FuzzerDriver(argc, argv, SUSF);
}
int FuzzerDriver(int argc, char **argv, UserSuppliedFuzzer &USF) {
using namespace fuzzer;
ProgName = argv[0];
ParseFlags(argc, argv);
if (Flags.help) {
PrintHelp();
return 0;
}
if (Flags.jobs > 0 && Flags.workers == 0) {
Flags.workers = std::min(NumberOfCpuCores() / 2, Flags.jobs);
if (Flags.workers > 1)
Printf("Running %d workers\n", Flags.workers);
}
if (Flags.workers > 0 && Flags.jobs > 0)
return RunInMultipleProcesses(argc, argv, Flags.workers, Flags.jobs);
Fuzzer::FuzzingOptions Options;
Options.Verbosity = Flags.verbosity;
Options.MaxLen = Flags.max_len;
Options.UnitTimeoutSec = Flags.timeout;
Options.DoCrossOver = Flags.cross_over;
Options.MutateDepth = Flags.mutate_depth;
Options.ExitOnFirst = Flags.exit_on_first;
Options.UseCounters = Flags.use_counters;
Options.UseTraces = Flags.use_traces;
Options.UseFullCoverageSet = Flags.use_full_coverage_set;
Options.PreferSmallDuringInitialShuffle =
Flags.prefer_small_during_initial_shuffle;
Options.Tokens = ReadTokensFile(Flags.tokens);
Options.Reload = Flags.reload;
Options.OnlyASCII = Flags.only_ascii;
Options.TBMDepth = Flags.tbm_depth;
Options.TBMWidth = Flags.tbm_width;
if (Flags.runs >= 0)
Options.MaxNumberOfRuns = Flags.runs;
if (!inputs.empty())
Options.OutputCorpus = inputs[0];
if (Flags.sync_command)
Options.SyncCommand = Flags.sync_command;
Options.SyncTimeout = Flags.sync_timeout;
Options.ReportSlowUnits = Flags.report_slow_units;
Fuzzer F(USF, Options);
if (Flags.apply_tokens)
return ApplyTokens(F, Flags.apply_tokens);
unsigned Seed = Flags.seed;
// Initialize Seed.
if (Seed == 0)
Seed = time(0) * 10000 + getpid();
if (Flags.verbosity)
Printf("Seed: %u\n", Seed);
USF.GetRand().ResetSeed(Seed);
// Timer
if (Flags.timeout > 0)
SetTimer(Flags.timeout / 2 + 1);
if (Flags.verbosity >= 2) {
Printf("Tokens: {");
for (auto &T : Options.Tokens)
Printf("%s,", T.c_str());
Printf("}\n");
}
F.RereadOutputCorpus();
for (auto &inp : inputs)
if (inp != Options.OutputCorpus)
F.ReadDir(inp, nullptr);
if (F.CorpusSize() == 0)
F.AddToCorpus(Unit()); // Can't fuzz empty corpus, so add an empty input.
F.ShuffleAndMinimize();
if (Flags.save_minimized_corpus)
F.SaveCorpus();
F.Loop(Flags.iterations < 0 ? INT_MAX : Flags.iterations);
if (Flags.verbosity)
Printf("Done %d runs in %zd second(s)\n", F.getTotalNumberOfRuns(),
F.secondsSinceProcessStartUp());
return 0;
}
} // namespace fuzzer