1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
|
//===- FuzzerCorpus.h - Internal header for the Fuzzer ----------*- C++ -* ===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// fuzzer::InputCorpus
//===----------------------------------------------------------------------===//
#ifndef LLVM_FUZZER_CORPUS
#define LLVM_FUZZER_CORPUS
#include <random>
#include <unordered_set>
#include "FuzzerDefs.h"
#include "FuzzerRandom.h"
#include "FuzzerTracePC.h"
namespace fuzzer {
struct InputInfo {
Unit U; // The actual input data.
uint8_t Sha1[kSHA1NumBytes]; // Checksum.
// Number of features that this input has and no smaller input has.
size_t NumFeatures = 0;
size_t Tmp = 0; // Used by ValidateFeatureSet.
// Stats.
size_t NumExecutedMutations = 0;
size_t NumSuccessfullMutations = 0;
};
class InputCorpus {
public:
InputCorpus() {
Inputs.reserve(1 << 14); // Avoid too many resizes.
memset(FeatureSet, 0, sizeof(FeatureSet));
}
size_t size() const { return Inputs.size(); }
bool empty() const { return Inputs.empty(); }
const Unit &operator[] (size_t Idx) const { return Inputs[Idx].U; }
void AddToCorpus(const Unit &U) {
uint8_t Hash[kSHA1NumBytes];
ComputeSHA1(U.data(), U.size(), Hash);
if (!Hashes.insert(Sha1ToString(Hash)).second) return;
Inputs.push_back(InputInfo());
InputInfo &II = Inputs.back();
II.U = U;
memcpy(II.Sha1, Hash, kSHA1NumBytes);
UpdateFeatureSet(Inputs.size() - 1);
UpdateCorpusDistribution();
}
typedef const std::vector<InputInfo>::const_iterator ConstIter;
ConstIter begin() const { return Inputs.begin(); }
ConstIter end() const { return Inputs.end(); }
bool HasUnit(const Unit &U) { return Hashes.count(Hash(U)); }
bool HasUnit(const std::string &H) { return Hashes.count(H); }
InputInfo &ChooseUnitToMutate(Random &Rand) {
return Inputs[ChooseUnitIdxToMutate(Rand)];
};
// Returns an index of random unit from the corpus to mutate.
// Hypothesis: units added to the corpus last are more likely to be
// interesting. This function gives more weight to the more recent units.
size_t ChooseUnitIdxToMutate(Random &Rand) {
size_t Idx = static_cast<size_t>(CorpusDistribution(Rand.Get_mt19937()));
assert(Idx < Inputs.size());
return Idx;
}
void PrintStats() {
for (size_t i = 0; i < Inputs.size(); i++) {
const auto &II = Inputs[i];
Printf(" [%zd %s]\tsz: %zd\truns: %zd\tsucc: %zd\n", i,
Sha1ToString(II.Sha1).c_str(), II.U.size(),
II.NumExecutedMutations, II.NumSuccessfullMutations);
}
}
void PrintFeatureSet() {
Printf("Features [id: idx sz] ");
for (size_t i = 0; i < kFeatureSetSize; i++) {
auto &Fe = FeatureSet[i];
if (!Fe.Count) continue;
Printf("[%zd: %zd %zd] ", i, Fe.SmallestElementIdx,
Fe.SmallestElementSize);
}
Printf("\n\t");
for (size_t i = 0; i < Inputs.size(); i++)
if (size_t N = Inputs[i].NumFeatures)
Printf(" %zd=>%zd ", i, N);
Printf("\n");
}
private:
static const bool FeatureDebug = false;
static const size_t kFeatureSetSize = TracePC::kFeatureSetSize;
void ValidateFeatureSet() {
for (size_t Idx = 0; Idx < kFeatureSetSize; Idx++) {
Feature &Fe = FeatureSet[Idx];
if(Fe.Count && Fe.SmallestElementSize)
Inputs[Fe.SmallestElementIdx].Tmp++;
}
for (auto &II: Inputs) {
assert(II.Tmp == II.NumFeatures);
II.Tmp = 0;
}
}
void UpdateFeatureSet(size_t CurrentElementIdx) {
auto &II = Inputs[CurrentElementIdx];
size_t Size = II.U.size();
if (!Size)
return;
bool Updated = false;
for (size_t Idx = 0; Idx < kFeatureSetSize; Idx++) {
if (!TPC.HasFeature(Idx))
continue;
Feature &Fe = FeatureSet[Idx];
Fe.Count++;
if (!Fe.SmallestElementSize ||
Fe.SmallestElementSize > Size) {
II.NumFeatures++;
if (Fe.SmallestElementSize > Size) {
auto &OlderII = Inputs[Fe.SmallestElementIdx];
assert(OlderII.NumFeatures > 0);
OlderII.NumFeatures--;
if (!OlderII.NumFeatures && FeatureDebug)
Printf("EVICTED %zd\n", Fe.SmallestElementIdx);
}
Fe.SmallestElementIdx = CurrentElementIdx;
Fe.SmallestElementSize = Size;
Updated = true;
}
}
if (Updated && FeatureDebug) PrintFeatureSet();
ValidateFeatureSet();
}
// Updates the probability distribution for the units in the corpus.
// Must be called whenever the corpus or unit weights are changed.
void UpdateCorpusDistribution() {
size_t N = Inputs.size();
std::vector<double> Intervals(N + 1);
std::vector<double> Weights(N);
std::iota(Intervals.begin(), Intervals.end(), 0);
std::iota(Weights.begin(), Weights.end(), 1);
CorpusDistribution = std::piecewise_constant_distribution<double>(
Intervals.begin(), Intervals.end(), Weights.begin());
}
std::piecewise_constant_distribution<double> CorpusDistribution;
std::unordered_set<std::string> Hashes;
std::vector<InputInfo> Inputs;
struct Feature {
size_t Count;
size_t SmallestElementIdx;
size_t SmallestElementSize;
};
Feature FeatureSet[kFeatureSetSize];
};
} // namespace fuzzer
#endif // LLVM_FUZZER_CORPUS
|
