1 //===- FuzzerMerge.h - merging corpa ----------------------------*- 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 // Merging Corpora. 9 // 10 // The task: 11 // Take the existing corpus (possibly empty) and merge new inputs into 12 // it so that only inputs with new coverage ('features') are added. 13 // The process should tolerate the crashes, OOMs, leaks, etc. 14 // 15 // Algorithm: 16 // The outer process collects the set of files and writes their names 17 // into a temporary "control" file, then repeatedly launches the inner 18 // process until all inputs are processed. 19 // The outer process does not actually execute the target code. 20 // 21 // The inner process reads the control file and sees a) list of all the inputs 22 // and b) the last processed input. Then it starts processing the inputs one 23 // by one. Before processing every input it writes one line to control file: 24 // STARTED INPUT_ID INPUT_SIZE 25 // After processing an input it writes the following lines: 26 // FT INPUT_ID Feature1 Feature2 Feature3 ... 27 // COV INPUT_ID Coverage1 Coverage2 Coverage3 ... 28 // If a crash happens while processing an input the last line in the control 29 // file will be "STARTED INPUT_ID" and so the next process will know 30 // where to resume. 31 // 32 // Once all inputs are processed by the inner process(es) the outer process 33 // reads the control files and does the merge based entirely on the contents 34 // of control file. 35 // It uses a single pass greedy algorithm choosing first the smallest inputs 36 // within the same size the inputs that have more new features. 37 // 38 //===----------------------------------------------------------------------===// 39 40 #ifndef LLVM_FUZZER_MERGE_H 41 #define LLVM_FUZZER_MERGE_H 42 43 #include "FuzzerDefs.h" 44 45 #include <istream> 46 #include <ostream> 47 #include <set> 48 #include <vector> 49 50 namespace fuzzer { 51 52 struct MergeFileInfo { 53 std::string Name; 54 size_t Size = 0; 55 Vector<uint32_t> Features, Cov; 56 }; 57 58 struct Merger { 59 Vector<MergeFileInfo> Files; 60 size_t NumFilesInFirstCorpus = 0; 61 size_t FirstNotProcessedFile = 0; 62 std::string LastFailure; 63 64 bool Parse(std::istream &IS, bool ParseCoverage); 65 bool Parse(const std::string &Str, bool ParseCoverage); 66 void ParseOrExit(std::istream &IS, bool ParseCoverage); 67 size_t Merge(const Set<uint32_t> &InitialFeatures, Set<uint32_t> *NewFeatures, 68 const Set<uint32_t> &InitialCov, Set<uint32_t> *NewCov, 69 Vector<std::string> *NewFiles); 70 size_t ApproximateMemoryConsumption() const; 71 Set<uint32_t> AllFeatures() const; 72 }; 73 74 void CrashResistantMerge(const Vector<std::string> &Args, 75 const Vector<SizedFile> &OldCorpus, 76 const Vector<SizedFile> &NewCorpus, 77 Vector<std::string> *NewFiles, 78 const Set<uint32_t> &InitialFeatures, 79 Set<uint32_t> *NewFeatures, 80 const Set<uint32_t> &InitialCov, 81 Set<uint32_t> *NewCov, 82 const std::string &CFPath, 83 bool Verbose); 84 85 } // namespace fuzzer 86 87 #endif // LLVM_FUZZER_MERGE_H 88