llvm-project/compiler-rt/test/fuzzer/MsanCustomMutator.cpp

48 lines
1.3 KiB
C++

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// Triggers the bug described here:
// https://github.com/google/oss-fuzz/issues/4605
//
// Tests that custom mutators do not cause MSan false positives. We are careful
// to use every parameter to ensure none cause false positives.
#include <algorithm>
#include <cstddef>
#include <cstdint>
#include <cstdio>
#include <cstring>
extern "C" {
int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) { return 0; }
size_t LLVMFuzzerCustomMutator(uint8_t *Data, size_t Size, size_t MaxSize,
unsigned int Seed) {
if (Seed == 7)
return 0;
if (MaxSize == 0)
return 0;
for (size_t I = 0; I < Size; ++I) {
if (Data[I] == 42) {
printf("BINGO\n");
}
}
return Size;
}
size_t LLVMFuzzerCustomCrossOver(
const uint8_t *Data1, size_t Size1, const uint8_t *Data2, size_t Size2,
uint8_t *Out, size_t MaxOutSize, unsigned int Seed) {
if (Seed == 7)
return 0;
size_t I = 0;
for (; I < Size1 && I < Size2 && I < MaxOutSize; ++I) {
Out[I] = std::min(Data1[I], Data2[I]);
}
return I;
}
} // extern "C"