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(std::vector<SizedFile> &CorporaFiles);
39   void ReadAndExecuteSeedCorpora(std::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   // Executes the target callback on {Data, Size} once.
69   // Returns false if the input was rejected by the target (target returned -1),
70   // and true otherwise.
71   bool ExecuteCallback(const uint8_t *Data, size_t Size);
72   bool RunOne(const uint8_t *Data, size_t Size, bool MayDeleteFile = false,
73               InputInfo *II = nullptr, bool ForceAddToCorpus = false,
74               bool *FoundUniqFeatures = nullptr);
75   void TPCUpdateObservedPCs();
76 
77   // Merge Corpora[1:] into Corpora[0].
78   void Merge(const std::vector<std::string> &Corpora);
79   void CrashResistantMergeInternalStep(const std::string &ControlFilePath,
80                                        bool IsSetCoverMerge);
81   MutationDispatcher &GetMD() { return MD; }
82   void PrintFinalStats();
83   void SetMaxInputLen(size_t MaxInputLen);
84   void SetMaxMutationLen(size_t MaxMutationLen);
85   void RssLimitCallback();
86 
87   bool InFuzzingThread() const { return IsMyThread; }
88   size_t GetCurrentUnitInFuzzingThead(const uint8_t **Data) const;
89   void TryDetectingAMemoryLeak(const uint8_t *Data, size_t Size,
90                                bool DuringInitialCorpusExecution);
91 
92   void HandleMalloc(size_t Size);
93   static void MaybeExitGracefully();
94   std::string WriteToOutputCorpus(const Unit &U);
95 
96 private:
97   void AlarmCallback();
98   void CrashCallback();
99   void ExitCallback();
100   void CrashOnOverwrittenData();
101   void InterruptCallback();
102   void MutateAndTestOne();
103   void PurgeAllocator();
104   void ReportNewCoverage(InputInfo *II, const Unit &U);
105   void PrintPulseAndReportSlowInput(const uint8_t *Data, size_t Size);
106   void WriteUnitToFileWithPrefix(const Unit &U, const char *Prefix);
107   void PrintStats(const char *Where, const char *End = "\n", size_t Units = 0,
108                   size_t Features = 0);
109   void PrintStatusForNewUnit(const Unit &U, const char *Text);
110   void CheckExitOnSrcPosOrItem();
111 
112   static void StaticDeathCallback();
113   void DumpCurrentUnit(const char *Prefix);
114   void DeathCallback();
115 
116   void AllocateCurrentUnitData();
117   uint8_t *CurrentUnitData = nullptr;
118   std::atomic<size_t> CurrentUnitSize;
119   uint8_t BaseSha1[kSHA1NumBytes];  // Checksum of the base unit.
120 
121   bool GracefulExitRequested = false;
122 
123   size_t TotalNumberOfRuns = 0;
124   size_t NumberOfNewUnitsAdded = 0;
125 
126   size_t LastCorpusUpdateRun = 0;
127 
128   bool HasMoreMallocsThanFrees = false;
129   size_t NumberOfLeakDetectionAttempts = 0;
130 
131   system_clock::time_point LastAllocatorPurgeAttemptTime = system_clock::now();
132 
133   UserCallback CB;
134   InputCorpus &Corpus;
135   MutationDispatcher &MD;
136   FuzzingOptions Options;
137   DataFlowTrace DFT;
138 
139   system_clock::time_point ProcessStartTime = system_clock::now();
140   system_clock::time_point UnitStartTime, UnitStopTime;
141   long TimeOfLongestUnitInSeconds = 0;
142   long EpochOfLastReadOfOutputCorpus = 0;
143 
144   size_t MaxInputLen = 0;
145   size_t MaxMutationLen = 0;
146   size_t TmpMaxMutationLen = 0;
147 
148   std::vector<uint32_t> UniqFeatureSetTmp;
149 
150   // Need to know our own thread.
151   static thread_local bool IsMyThread;
152 };
153 
154 struct ScopedEnableMsanInterceptorChecks {
155   ScopedEnableMsanInterceptorChecks() {
156     if (EF->__msan_scoped_enable_interceptor_checks)
157       EF->__msan_scoped_enable_interceptor_checks();
158   }
159   ~ScopedEnableMsanInterceptorChecks() {
160     if (EF->__msan_scoped_disable_interceptor_checks)
161       EF->__msan_scoped_disable_interceptor_checks();
162   }
163 };
164 
165 struct ScopedDisableMsanInterceptorChecks {
166   ScopedDisableMsanInterceptorChecks() {
167     if (EF->__msan_scoped_disable_interceptor_checks)
168       EF->__msan_scoped_disable_interceptor_checks();
169   }
170   ~ScopedDisableMsanInterceptorChecks() {
171     if (EF->__msan_scoped_enable_interceptor_checks)
172       EF->__msan_scoped_enable_interceptor_checks();
173   }
174 };
175 
176 } // namespace fuzzer
177 
178 #endif // LLVM_FUZZER_INTERNAL_H
179