llvm-project/llvm/lib/Fuzzer/FuzzerTracePC.h

123 lines
3.5 KiB
C++

//===- FuzzerTracePC.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::TracePC
//===----------------------------------------------------------------------===//
#ifndef LLVM_FUZZER_TRACE_PC
#define LLVM_FUZZER_TRACE_PC
#include <set>
#include "FuzzerDefs.h"
#include "FuzzerValueBitMap.h"
namespace fuzzer {
// TableOfRecentCompares (TORC) remembers the most recently performed
// comparisons of type T.
// We record the arguments of CMP instructions in this table unconditionally
// because it seems cheaper this way than to compute some expensive
// conditions inside __sanitizer_cov_trace_cmp*.
// After the unit has been executed we may decide to use the contents of
// this table to populate a Dictionary.
template<class T, size_t kSizeT>
struct TableOfRecentCompares {
static const size_t kSize = kSizeT;
struct Pair {
T A, B;
};
void Insert(size_t Idx, T Arg1, T Arg2) {
Idx = Idx % kSize;
Table[Idx].A = Arg1;
Table[Idx].B = Arg2;
}
Pair Get(size_t I) { return Table[I % kSize]; }
Pair Table[kSize];
};
class TracePC {
public:
static const size_t kFeatureSetSize = ValueBitMap::kNumberOfItems;
void HandleTrace(uint32_t *guard, uintptr_t PC);
void HandleInit(uint32_t *start, uint32_t *stop);
void HandleCallerCallee(uintptr_t Caller, uintptr_t Callee);
void HandleValueProfile(size_t Value) { ValueProfileMap.AddValue(Value); }
template <class T> void HandleCmp(void *PC, T Arg1, T Arg2);
size_t GetTotalPCCoverage();
void SetUseCounters(bool UC) { UseCounters = UC; }
void SetUseValueProfile(bool VP) { UseValueProfile = VP; }
void SetPrintNewPCs(bool P) { DoPrintNewPCs = P; }
size_t FinalizeTrace(InputCorpus *C, size_t InputSize, bool Shrink);
bool UpdateValueProfileMap(ValueBitMap *MaxValueProfileMap) {
return UseValueProfile && MaxValueProfileMap->MergeFrom(ValueProfileMap);
}
void ResetMaps() {
ValueProfileMap.Reset();
memset(Counters, 0, sizeof(Counters));
}
void UpdateFeatureSet(size_t CurrentElementIdx, size_t CurrentElementSize);
void PrintFeatureSet();
void PrintModuleInfo();
void PrintCoverage();
void AddValueForMemcmp(void *caller_pc, const void *s1, const void *s2,
size_t n);
void AddValueForStrcmp(void *caller_pc, const char *s1, const char *s2,
size_t n);
bool UsingTracePcGuard() const {return NumModules; }
static const size_t kTORCSize = 1 << 5;
TableOfRecentCompares<uint32_t, kTORCSize> TORC4;
TableOfRecentCompares<uint64_t, kTORCSize> TORC8;
void PrintNewPCs();
size_t GetNumPCs() const { return Min(kNumPCs, NumGuards + 1); }
uintptr_t GetPC(size_t Idx) {
assert(Idx < GetNumPCs());
return PCs[Idx];
}
private:
bool UseCounters = false;
bool UseValueProfile = false;
bool DoPrintNewPCs = false;
struct Module {
uint32_t *Start, *Stop;
};
Module Modules[4096];
size_t NumModules; // linker-initialized.
size_t NumGuards; // linker-initialized.
static const size_t kNumCounters = 1 << 14;
alignas(8) uint8_t Counters[kNumCounters];
static const size_t kNumPCs = 1 << 24;
uintptr_t PCs[kNumPCs];
std::set<uintptr_t> *PrintedPCs;
ValueBitMap ValueProfileMap;
};
extern TracePC TPC;
} // namespace fuzzer
#endif // LLVM_FUZZER_TRACE_PC