1 //===- FuzzerInternal.h - Internal header for the Fuzzer --------*- C++ -* ===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 // Define the main class fuzzer::Fuzzer and most functions.
9 //===----------------------------------------------------------------------===//
10 
11 #ifndef LLVM_FUZZER_INTERNAL_H
12 #define LLVM_FUZZER_INTERNAL_H
13 
14 #include "FuzzerDataFlowTrace.h"
15 #include "FuzzerDefs.h"
16 #include "FuzzerExtFunctions.h"
17 #include "FuzzerInterface.h"
18 #include "FuzzerOptions.h"
19 #include "FuzzerSHA1.h"
20 #include "FuzzerValueBitMap.h"
21 #include <algorithm>
22 #include <atomic>
23 #include <chrono>
24 #include <climits>
25 #include <cstdlib>
26 #include <string.h>
27 
28 namespace fuzzer {
29 
30 using namespace std::chrono;
31 
32 class Fuzzer {
33 public:
34 
35   Fuzzer(UserCallback CB, InputCorpus &Corpus, MutationDispatcher &MD,
36          FuzzingOptions Options);
37   ~Fuzzer();
38   void Loop(Vector<SizedFile> &CorporaFiles);
39   void ReadAndExecuteSeedCorpora(Vector<SizedFile> &CorporaFiles);
40   void MinimizeCrashLoop(const Unit &U);
41   void RereadOutputCorpus(size_t MaxSize);
42 
secondsSinceProcessStartUp()43   size_t secondsSinceProcessStartUp() {
44     return duration_cast<seconds>(system_clock::now() - ProcessStartTime)
45         .count();
46   }
47 
TimedOut()48   bool TimedOut() {
49     return Options.MaxTotalTimeSec > 0 &&
50            secondsSinceProcessStartUp() >
51                static_cast<size_t>(Options.MaxTotalTimeSec);
52   }
53 
execPerSec()54   size_t execPerSec() {
55     size_t Seconds = secondsSinceProcessStartUp();
56     return Seconds ? TotalNumberOfRuns / Seconds : 0;
57   }
58 
getTotalNumberOfRuns()59   size_t getTotalNumberOfRuns() { return TotalNumberOfRuns; }
60 
61   static void StaticAlarmCallback();
62   static void StaticCrashSignalCallback();
63   static void StaticExitCallback();
64   static void StaticInterruptCallback();
65   static void StaticFileSizeExceedCallback();
66   static void StaticGracefulExitCallback();
67 
68   void ExecuteCallback(const uint8_t *Data, size_t Size);
69   bool RunOne(const uint8_t *Data, size_t Size, bool MayDeleteFile = false,
70               InputInfo *II = nullptr, bool ForceAddToCorpus = false,
71               bool *FoundUniqFeatures = nullptr);
72   void TPCUpdateObservedPCs();
73 
74   // Merge Corpora[1:] into Corpora[0].
75   void Merge(const Vector<std::string> &Corpora);
76   void CrashResistantMergeInternalStep(const std::string &ControlFilePath);
GetMD()77   MutationDispatcher &GetMD() { return MD; }
78   void PrintFinalStats();
79   void SetMaxInputLen(size_t MaxInputLen);
80   void SetMaxMutationLen(size_t MaxMutationLen);
81   void RssLimitCallback();
82 
InFuzzingThread()83   bool InFuzzingThread() const { return IsMyThread; }
84   size_t GetCurrentUnitInFuzzingThead(const uint8_t **Data) const;
85   void TryDetectingAMemoryLeak(const uint8_t *Data, size_t Size,
86                                bool DuringInitialCorpusExecution);
87 
88   void HandleMalloc(size_t Size);
89   static void MaybeExitGracefully();
90   std::string WriteToOutputCorpus(const Unit &U);
91 
92 private:
93   void AlarmCallback();
94   void CrashCallback();
95   void ExitCallback();
96   void CrashOnOverwrittenData();
97   void InterruptCallback();
98   void MutateAndTestOne();
99   void PurgeAllocator();
100   void ReportNewCoverage(InputInfo *II, const Unit &U);
101   void PrintPulseAndReportSlowInput(const uint8_t *Data, size_t Size);
102   void WriteUnitToFileWithPrefix(const Unit &U, const char *Prefix);
103   void PrintStats(const char *Where, const char *End = "\n", size_t Units = 0,
104                   size_t Features = 0);
105   void PrintStatusForNewUnit(const Unit &U, const char *Text);
106   void CheckExitOnSrcPosOrItem();
107 
108   static void StaticDeathCallback();
109   void DumpCurrentUnit(const char *Prefix);
110   void DeathCallback();
111 
112   void AllocateCurrentUnitData();
113   uint8_t *CurrentUnitData = nullptr;
114   std::atomic<size_t> CurrentUnitSize;
115   uint8_t BaseSha1[kSHA1NumBytes];  // Checksum of the base unit.
116 
117   bool GracefulExitRequested = false;
118 
119   size_t TotalNumberOfRuns = 0;
120   size_t NumberOfNewUnitsAdded = 0;
121 
122   size_t LastCorpusUpdateRun = 0;
123 
124   bool HasMoreMallocsThanFrees = false;
125   size_t NumberOfLeakDetectionAttempts = 0;
126 
127   system_clock::time_point LastAllocatorPurgeAttemptTime = system_clock::now();
128 
129   UserCallback CB;
130   InputCorpus &Corpus;
131   MutationDispatcher &MD;
132   FuzzingOptions Options;
133   DataFlowTrace DFT;
134 
135   system_clock::time_point ProcessStartTime = system_clock::now();
136   system_clock::time_point UnitStartTime, UnitStopTime;
137   long TimeOfLongestUnitInSeconds = 0;
138   long EpochOfLastReadOfOutputCorpus = 0;
139 
140   size_t MaxInputLen = 0;
141   size_t MaxMutationLen = 0;
142   size_t TmpMaxMutationLen = 0;
143 
144   Vector<uint32_t> UniqFeatureSetTmp;
145 
146   // Need to know our own thread.
147   static thread_local bool IsMyThread;
148 };
149 
150 struct ScopedEnableMsanInterceptorChecks {
ScopedEnableMsanInterceptorChecksScopedEnableMsanInterceptorChecks151   ScopedEnableMsanInterceptorChecks() {
152     if (EF->__msan_scoped_enable_interceptor_checks)
153       EF->__msan_scoped_enable_interceptor_checks();
154   }
~ScopedEnableMsanInterceptorChecksScopedEnableMsanInterceptorChecks155   ~ScopedEnableMsanInterceptorChecks() {
156     if (EF->__msan_scoped_disable_interceptor_checks)
157       EF->__msan_scoped_disable_interceptor_checks();
158   }
159 };
160 
161 struct ScopedDisableMsanInterceptorChecks {
ScopedDisableMsanInterceptorChecksScopedDisableMsanInterceptorChecks162   ScopedDisableMsanInterceptorChecks() {
163     if (EF->__msan_scoped_disable_interceptor_checks)
164       EF->__msan_scoped_disable_interceptor_checks();
165   }
~ScopedDisableMsanInterceptorChecksScopedDisableMsanInterceptorChecks166   ~ScopedDisableMsanInterceptorChecks() {
167     if (EF->__msan_scoped_enable_interceptor_checks)
168       EF->__msan_scoped_enable_interceptor_checks();
169   }
170 };
171 
172 } // namespace fuzzer
173 
174 #endif // LLVM_FUZZER_INTERNAL_H
175