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 
43   size_t secondsSinceProcessStartUp() {
44     return duration_cast<seconds>(system_clock::now() - ProcessStartTime)
45         .count();
46   }
47 
48   bool TimedOut() {
49     return Options.MaxTotalTimeSec > 0 &&
50            secondsSinceProcessStartUp() >
51                static_cast<size_t>(Options.MaxTotalTimeSec);
52   }
53 
54   size_t execPerSec() {
55     size_t Seconds = secondsSinceProcessStartUp();
56     return Seconds ? TotalNumberOfRuns / Seconds : 0;
57   }
58 
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 *FoundUniqFeatures = nullptr);
71 
72   // Merge Corpora[1:] into Corpora[0].
73   void Merge(const Vector<std::string> &Corpora);
74   void CrashResistantMergeInternalStep(const std::string &ControlFilePath);
75   MutationDispatcher &GetMD() { return MD; }
76   void PrintFinalStats();
77   void SetMaxInputLen(size_t MaxInputLen);
78   void SetMaxMutationLen(size_t MaxMutationLen);
79   void RssLimitCallback();
80 
81   bool InFuzzingThread() const { return IsMyThread; }
82   size_t GetCurrentUnitInFuzzingThead(const uint8_t **Data) const;
83   void TryDetectingAMemoryLeak(const uint8_t *Data, size_t Size,
84                                bool DuringInitialCorpusExecution);
85 
86   void HandleMalloc(size_t Size);
87   static void MaybeExitGracefully();
88   std::string WriteToOutputCorpus(const Unit &U);
89 
90 private:
91   void AlarmCallback();
92   void CrashCallback();
93   void ExitCallback();
94   void CrashOnOverwrittenData();
95   void InterruptCallback();
96   void MutateAndTestOne();
97   void PurgeAllocator();
98   void ReportNewCoverage(InputInfo *II, const Unit &U);
99   void PrintPulseAndReportSlowInput(const uint8_t *Data, size_t Size);
100   void WriteUnitToFileWithPrefix(const Unit &U, const char *Prefix);
101   void PrintStats(const char *Where, const char *End = "\n", size_t Units = 0,
102                   size_t Features = 0);
103   void PrintStatusForNewUnit(const Unit &U, const char *Text);
104   void CheckExitOnSrcPosOrItem();
105 
106   static void StaticDeathCallback();
107   void DumpCurrentUnit(const char *Prefix);
108   void DeathCallback();
109 
110   void AllocateCurrentUnitData();
111   uint8_t *CurrentUnitData = nullptr;
112   std::atomic<size_t> CurrentUnitSize;
113   uint8_t BaseSha1[kSHA1NumBytes];  // Checksum of the base unit.
114 
115   bool GracefulExitRequested = false;
116 
117   size_t TotalNumberOfRuns = 0;
118   size_t NumberOfNewUnitsAdded = 0;
119 
120   size_t LastCorpusUpdateRun = 0;
121 
122   bool HasMoreMallocsThanFrees = false;
123   size_t NumberOfLeakDetectionAttempts = 0;
124 
125   system_clock::time_point LastAllocatorPurgeAttemptTime = system_clock::now();
126 
127   UserCallback CB;
128   InputCorpus &Corpus;
129   MutationDispatcher &MD;
130   FuzzingOptions Options;
131   DataFlowTrace DFT;
132 
133   system_clock::time_point ProcessStartTime = system_clock::now();
134   system_clock::time_point UnitStartTime, UnitStopTime;
135   long TimeOfLongestUnitInSeconds = 0;
136   long EpochOfLastReadOfOutputCorpus = 0;
137 
138   size_t MaxInputLen = 0;
139   size_t MaxMutationLen = 0;
140   size_t TmpMaxMutationLen = 0;
141 
142   Vector<uint32_t> UniqFeatureSetTmp;
143 
144   // Need to know our own thread.
145   static thread_local bool IsMyThread;
146 };
147 
148 struct ScopedEnableMsanInterceptorChecks {
149   ScopedEnableMsanInterceptorChecks() {
150     if (EF->__msan_scoped_enable_interceptor_checks)
151       EF->__msan_scoped_enable_interceptor_checks();
152   }
153   ~ScopedEnableMsanInterceptorChecks() {
154     if (EF->__msan_scoped_disable_interceptor_checks)
155       EF->__msan_scoped_disable_interceptor_checks();
156   }
157 };
158 
159 struct ScopedDisableMsanInterceptorChecks {
160   ScopedDisableMsanInterceptorChecks() {
161     if (EF->__msan_scoped_disable_interceptor_checks)
162       EF->__msan_scoped_disable_interceptor_checks();
163   }
164   ~ScopedDisableMsanInterceptorChecks() {
165     if (EF->__msan_scoped_enable_interceptor_checks)
166       EF->__msan_scoped_enable_interceptor_checks();
167   }
168 };
169 
170 } // namespace fuzzer
171 
172 #endif // LLVM_FUZZER_INTERNAL_H
173