llvm/lib/Fuzzer/FuzzerDriver.cpp

538 lines
17 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 "FuzzerCorpus.h"
#include "FuzzerInterface.h"
#include "FuzzerInternal.h"
#include "FuzzerMutate.h"
#include "FuzzerRandom.h"
#include <algorithm>
#include <atomic>
#include <chrono>
#include <cstring>
#include <mutex>
#include <string>
#include <thread>
#include <unistd.h>
// This function should be present in the libFuzzer so that the client
// binary can test for its existence.
extern "C" __attribute__((used)) void __libfuzzer_is_present() {}
namespace fuzzer {
// Program arguments.
struct FlagDescription {
const char *Name;
const char *Description;
int Default;
int *IntFlag;
const char **StrFlag;
unsigned int *UIntFlag;
};
struct {
#define FUZZER_DEPRECATED_FLAG(Name)
#define FUZZER_FLAG_INT(Name, Default, Description) int Name;
#define FUZZER_FLAG_UNSIGNED(Name, Default, Description) unsigned int Name;
#define FUZZER_FLAG_STRING(Name, Description) const char *Name;
#include "FuzzerFlags.def"
#undef FUZZER_DEPRECATED_FLAG
#undef FUZZER_FLAG_INT
#undef FUZZER_FLAG_UNSIGNED
#undef FUZZER_FLAG_STRING
} Flags;
static const FlagDescription FlagDescriptions [] {
#define FUZZER_DEPRECATED_FLAG(Name) \
{#Name, "Deprecated; don't use", 0, nullptr, nullptr, nullptr},
#define FUZZER_FLAG_INT(Name, Default, Description) \
{#Name, Description, Default, &Flags.Name, nullptr, nullptr},
#define FUZZER_FLAG_UNSIGNED(Name, Default, Description) \
{#Name, Description, static_cast<int>(Default), \
nullptr, nullptr, &Flags.Name},
#define FUZZER_FLAG_STRING(Name, Description) \
{#Name, Description, 0, nullptr, &Flags.Name, nullptr},
#include "FuzzerFlags.def"
#undef FUZZER_DEPRECATED_FLAG
#undef FUZZER_FLAG_INT
#undef FUZZER_FLAG_UNSIGNED
#undef FUZZER_FLAG_STRING
};
static const size_t kNumFlags =
sizeof(FlagDescriptions) / sizeof(FlagDescriptions[0]);
static std::vector<std::string> *Inputs;
static std::string *ProgName;
static void PrintHelp() {
Printf("Usage:\n");
auto Prog = ProgName->c_str();
Printf("\nTo run fuzzing pass 0 or more directories.\n");
Printf("%s [-flag1=val1 [-flag2=val2 ...] ] [dir1 [dir2 ...] ]\n", Prog);
Printf("\nTo run individual tests without fuzzing pass 1 or more files:\n");
Printf("%s [-flag1=val1 [-flag2=val2 ...] ] file1 [file2 ...]\n", Prog);
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];
if (strstr(D.Description, "internal flag") == D.Description) continue;
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;
}
// Avoid calling stol as it triggers a bug in clang/glibc build.
static long MyStol(const char *Str) {
long Res = 0;
long Sign = 1;
if (*Str == '-') {
Str++;
Sign = -1;
}
for (size_t i = 0; Str[i]; i++) {
char Ch = Str[i];
if (Ch < '0' || Ch > '9')
return Res;
Res = Res * 10 + (Ch - '0');
}
return Res * Sign;
}
static bool ParseOneFlag(const char *Param) {
if (Param[0] != '-') return false;
if (Param[1] == '-') {
static bool PrintedWarning = false;
if (!PrintedWarning) {
PrintedWarning = true;
Printf("INFO: libFuzzer ignores flags that start with '--'\n");
}
for (size_t F = 0; F < kNumFlags; F++)
if (FlagValue(Param + 1, FlagDescriptions[F].Name))
Printf("WARNING: did you mean '%s' (single dash)?\n", Param + 1);
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 = MyStol(Str);
*FlagDescriptions[F].IntFlag = Val;
if (Flags.verbosity >= 2)
Printf("Flag: %s %d\n", Name, Val);;
return true;
} else if (FlagDescriptions[F].UIntFlag) {
unsigned int Val = std::stoul(Str);
*FlagDescriptions[F].UIntFlag = Val;
if (Flags.verbosity >= 2)
Printf("Flag: %s %u\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;
} else { // Deprecated flag.
Printf("Flag: %s: deprecated, don't use\n", Name);
return true;
}
}
}
Printf("\n\nWARNING: unrecognized flag '%s'; "
"use -help=1 to list all flags\n\n", Param);
return true;
}
// We don't use any library to minimize dependencies.
static void ParseFlags(const std::vector<std::string> &Args) {
for (size_t F = 0; F < kNumFlags; F++) {
if (FlagDescriptions[F].IntFlag)
*FlagDescriptions[F].IntFlag = FlagDescriptions[F].Default;
if (FlagDescriptions[F].UIntFlag)
*FlagDescriptions[F].UIntFlag =
static_cast<unsigned int>(FlagDescriptions[F].Default);
if (FlagDescriptions[F].StrFlag)
*FlagDescriptions[F].StrFlag = nullptr;
}
Inputs = new std::vector<std::string>;
for (size_t A = 1; A < Args.size(); A++) {
if (ParseOneFlag(Args[A].c_str())) continue;
Inputs->push_back(Args[A]);
}
}
static std::mutex Mu;
static void PulseThread() {
while (true) {
SleepSeconds(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 = ExecuteCommand(ToRun);
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 std::string CloneArgsWithoutX(const std::vector<std::string> &Args,
const char *X1, const char *X2) {
std::string Cmd;
for (auto &S : Args) {
if (FlagValue(S.c_str(), X1) || FlagValue(S.c_str(), X2))
continue;
Cmd += S + " ";
}
return Cmd;
}
static std::string CloneArgsWithoutX(const std::vector<std::string> &Args,
const char *X) {
return CloneArgsWithoutX(Args, X, X);
}
static int RunInMultipleProcesses(const std::vector<std::string> &Args,
int NumWorkers, int NumJobs) {
std::atomic<int> Counter(0);
std::atomic<bool> HasErrors(false);
std::string Cmd = CloneArgsWithoutX(Args, "jobs", "workers");
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;
}
static void RssThread(Fuzzer *F, size_t RssLimitMb) {
while (true) {
SleepSeconds(1);
size_t Peak = GetPeakRSSMb();
if (Peak > RssLimitMb)
F->RssLimitCallback();
}
}
static void StartRssThread(Fuzzer *F, size_t RssLimitMb) {
if (!RssLimitMb) return;
std::thread T(RssThread, F, RssLimitMb);
T.detach();
}
int RunOneTest(Fuzzer *F, const char *InputFilePath, size_t MaxLen) {
Unit U = FileToVector(InputFilePath);
if (MaxLen && MaxLen < U.size())
U.resize(MaxLen);
F->RunOne(U.data(), U.size());
F->TryDetectingAMemoryLeak(U.data(), U.size(), true);
return 0;
}
static bool AllInputsAreFiles() {
if (Inputs->empty()) return false;
for (auto &Path : *Inputs)
if (!IsFile(Path))
return false;
return true;
}
int MinimizeCrashInput(const std::vector<std::string> &Args) {
if (Inputs->size() != 1) {
Printf("ERROR: -minimize_crash should be given one input file\n");
exit(1);
}
if (Flags.runs <= 0 && Flags.max_total_time == 0) {
Printf("ERROR: you need to use -runs=N or "
"-max_total_time=N with -minimize_crash=1\n" );
exit(1);
}
std::string InputFilePath = Inputs->at(0);
std::string BaseCmd = CloneArgsWithoutX(Args, "minimize_crash");
auto InputPos = BaseCmd.find(" " + InputFilePath + " ");
assert(InputPos != std::string::npos);
BaseCmd.erase(InputPos, InputFilePath.size() + 1);
// BaseCmd += " > /dev/null 2>&1 ";
std::string CurrentFilePath = InputFilePath;
while (true) {
Unit U = FileToVector(CurrentFilePath);
if (U.size() < 2) {
Printf("CRASH_MIN: '%s' is small enough\n", CurrentFilePath.c_str());
return 0;
}
Printf("CRASH_MIN: minimizing crash input: '%s' (%zd bytes)\n",
CurrentFilePath.c_str(), U.size());
auto Cmd = BaseCmd + " " + CurrentFilePath;
Printf("CRASH_MIN: executing: %s\n", Cmd.c_str());
int ExitCode = ExecuteCommand(Cmd);
if (ExitCode == 0) {
Printf("ERROR: the input %s did not crash\n", CurrentFilePath.c_str());
exit(1);
}
Printf("CRASH_MIN: '%s' (%zd bytes) caused a crash. Will try to minimize "
"it further\n",
CurrentFilePath.c_str(), U.size());
std::string ArtifactPath = "minimized-from-" + Hash(U);
Cmd += " -minimize_crash_internal_step=1 -exact_artifact_path=" +
ArtifactPath;
Printf("CRASH_MIN: executing: %s\n", Cmd.c_str());
ExitCode = ExecuteCommand(Cmd);
if (ExitCode == 0) {
Printf("CRASH_MIN: failed to minimize beyond %s (%d bytes), exiting\n",
CurrentFilePath.c_str(), U.size());
return 0;
}
CurrentFilePath = ArtifactPath;
Printf("\n\n\n\n\n\n*********************************\n");
}
return 0;
}
int MinimizeCrashInputInternalStep(Fuzzer *F, InputCorpus *Corpus) {
assert(Inputs->size() == 1);
std::string InputFilePath = Inputs->at(0);
Unit U = FileToVector(InputFilePath);
assert(U.size() > 2);
Printf("INFO: Starting MinimizeCrashInputInternalStep: %zd\n", U.size());
Corpus->AddToCorpus(U, 0);
F->SetMaxInputLen(U.size());
F->SetMaxMutationLen(U.size() - 1);
F->MinimizeCrashLoop(U);
Printf("INFO: Done MinimizeCrashInputInternalStep, no crashes found\n");
exit(0);
return 0;
}
int FuzzerDriver(int *argc, char ***argv, UserCallback Callback) {
using namespace fuzzer;
assert(argc && argv && "Argument pointers cannot be nullptr");
EF = new ExternalFunctions();
if (EF->LLVMFuzzerInitialize)
EF->LLVMFuzzerInitialize(argc, argv);
const std::vector<std::string> Args(*argv, *argv + *argc);
assert(!Args.empty());
ProgName = new std::string(Args[0]);
ParseFlags(Args);
if (Flags.help) {
PrintHelp();
return 0;
}
if (Flags.minimize_crash)
return MinimizeCrashInput(Args);
if (Flags.close_fd_mask & 2)
DupAndCloseStderr();
if (Flags.close_fd_mask & 1)
CloseStdout();
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(Args, Flags.workers, Flags.jobs);
const size_t kMaxSaneLen = 1 << 20;
const size_t kMinDefaultLen = 64;
FuzzingOptions Options;
Options.Verbosity = Flags.verbosity;
Options.MaxLen = Flags.max_len;
Options.UnitTimeoutSec = Flags.timeout;
Options.TimeoutExitCode = Flags.timeout_exitcode;
Options.MaxTotalTimeSec = Flags.max_total_time;
Options.DoCrossOver = Flags.cross_over;
Options.MutateDepth = Flags.mutate_depth;
Options.UseCounters = Flags.use_counters;
Options.UseIndirCalls = Flags.use_indir_calls;
Options.UseMemcmp = Flags.use_memcmp;
Options.UseMemmem = Flags.use_memmem;
Options.UseCmp = Flags.use_cmp;
Options.UseValueProfile = Flags.use_value_profile;
Options.Shrink = Flags.shrink;
Options.ShuffleAtStartUp = Flags.shuffle;
Options.PreferSmall = Flags.prefer_small;
Options.ReloadIntervalSec = Flags.reload;
Options.OnlyASCII = Flags.only_ascii;
Options.OutputCSV = Flags.output_csv;
Options.DetectLeaks = Flags.detect_leaks;
Options.TraceMalloc = Flags.trace_malloc;
Options.RssLimitMb = Flags.rss_limit_mb;
if (Flags.runs >= 0)
Options.MaxNumberOfRuns = Flags.runs;
if (!Inputs->empty() && !Flags.minimize_crash_internal_step)
Options.OutputCorpus = (*Inputs)[0];
Options.ReportSlowUnits = Flags.report_slow_units;
if (Flags.artifact_prefix)
Options.ArtifactPrefix = Flags.artifact_prefix;
if (Flags.exact_artifact_path)
Options.ExactArtifactPath = Flags.exact_artifact_path;
std::vector<Unit> Dictionary;
if (Flags.dict)
if (!ParseDictionaryFile(FileToString(Flags.dict), &Dictionary))
return 1;
if (Flags.verbosity > 0 && !Dictionary.empty())
Printf("Dictionary: %zd entries\n", Dictionary.size());
bool DoPlainRun = AllInputsAreFiles();
Options.SaveArtifacts =
!DoPlainRun || Flags.minimize_crash_internal_step;
Options.PrintNewCovPcs = Flags.print_pcs;
Options.PrintFinalStats = Flags.print_final_stats;
Options.PrintCorpusStats = Flags.print_corpus_stats;
Options.PrintCoverage = Flags.print_coverage;
if (Flags.exit_on_src_pos)
Options.ExitOnSrcPos = Flags.exit_on_src_pos;
if (Flags.exit_on_item)
Options.ExitOnItem = Flags.exit_on_item;
unsigned Seed = Flags.seed;
// Initialize Seed.
if (Seed == 0)
Seed = (std::chrono::system_clock::now().time_since_epoch().count() << 10) +
getpid();
if (Flags.verbosity)
Printf("INFO: Seed: %u\n", Seed);
Random Rand(Seed);
MutationDispatcher MD(Rand, Options);
InputCorpus Corpus(Options.OutputCorpus);
Fuzzer F(Callback, Corpus, MD, Options);
for (auto &U: Dictionary)
if (U.size() <= Word::GetMaxSize())
MD.AddWordToManualDictionary(Word(U.data(), U.size()));
StartRssThread(&F, Flags.rss_limit_mb);
// Timer
if (Flags.timeout > 0)
SetTimer(Flags.timeout / 2 + 1);
if (Flags.handle_segv) SetSigSegvHandler();
if (Flags.handle_bus) SetSigBusHandler();
if (Flags.handle_abrt) SetSigAbrtHandler();
if (Flags.handle_ill) SetSigIllHandler();
if (Flags.handle_fpe) SetSigFpeHandler();
if (Flags.handle_int) SetSigIntHandler();
if (Flags.handle_term) SetSigTermHandler();
if (Flags.minimize_crash_internal_step)
return MinimizeCrashInputInternalStep(&F, &Corpus);
if (DoPlainRun) {
Options.SaveArtifacts = false;
int Runs = std::max(1, Flags.runs);
Printf("%s: Running %zd inputs %d time(s) each.\n", ProgName->c_str(),
Inputs->size(), Runs);
for (auto &Path : *Inputs) {
auto StartTime = system_clock::now();
Printf("Running: %s\n", Path.c_str());
for (int Iter = 0; Iter < Runs; Iter++)
RunOneTest(&F, Path.c_str(), Options.MaxLen);
auto StopTime = system_clock::now();
auto MS = duration_cast<milliseconds>(StopTime - StartTime).count();
Printf("Executed %s in %zd ms\n", Path.c_str(), (long)MS);
}
Printf("***\n"
"*** NOTE: fuzzing was not performed, you have only\n"
"*** executed the target code on a fixed set of inputs.\n"
"***\n");
F.PrintFinalStats();
exit(0);
}
if (Flags.merge) {
if (Options.MaxLen == 0)
F.SetMaxInputLen(kMaxSaneLen);
F.Merge(*Inputs);
exit(0);
}
size_t TemporaryMaxLen = Options.MaxLen ? Options.MaxLen : kMaxSaneLen;
UnitVector InitialCorpus;
for (auto &Inp : *Inputs) {
Printf("Loading corpus dir: %s\n", Inp.c_str());
ReadDirToVectorOfUnits(Inp.c_str(), &InitialCorpus, nullptr,
TemporaryMaxLen, /*ExitOnError=*/false);
}
if (Options.MaxLen == 0) {
size_t MaxLen = 0;
for (auto &U : InitialCorpus)
MaxLen = std::max(U.size(), MaxLen);
F.SetMaxInputLen(std::min(std::max(kMinDefaultLen, MaxLen), kMaxSaneLen));
}
if (InitialCorpus.empty()) {
InitialCorpus.push_back(Unit({0}));
if (Options.Verbosity)
Printf("INFO: A corpus is not provided, starting from an empty corpus\n");
}
F.ShuffleAndMinimize(&InitialCorpus);
InitialCorpus.clear(); // Don't need this memory any more.
F.Loop();
if (Flags.verbosity)
Printf("Done %d runs in %zd second(s)\n", F.getTotalNumberOfRuns(),
F.secondsSinceProcessStartUp());
F.PrintFinalStats();
exit(0); // Don't let F destroy itself.
}
// Storage for global ExternalFunctions object.
ExternalFunctions *EF = nullptr;
} // namespace fuzzer