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[libFuzzer] mutation: insert the size of the input in bytes as one of the ways to mutate a binary integer 

llvm-svn: 284909
This commit is contained in:
Kostya Serebryany 2016-10-22 03:48:53 +00:00
parent 9e2afa8bd7
commit 65f102d4d2
2 changed files with 21 additions and 11 deletions
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24
llvm/lib/Fuzzer/FuzzerMutate.cpp
View File

@ -299,15 +299,21 @@ size_t ChangeBinaryInteger(uint8_t *Data, size_t Size, Random &Rand) {
size_t Off = Rand(Size - sizeof(T) + 1);
assert(Off + sizeof(T) <= Size);
T Val;
memcpy(&Val, Data + Off, sizeof(Val));
T Add = Rand(21);
Add -= 10;
if (Rand.RandBool())
Val = Bswap(T(Bswap(Val) + Add)); // Add assuming different endiannes.
else
Val = Val + Add; // Add assuming current endiannes.
if (Add == 0 || Rand.RandBool()) // Maybe negate.
Val = -Val;
if (Off < 64 && !Rand(4)) {
Val = Size;
if (Rand.RandBool())
Val = Bswap(Val);
} else {
memcpy(&Val, Data + Off, sizeof(Val));
T Add = Rand(21);
Add -= 10;
if (Rand.RandBool())
Val = Bswap(T(Bswap(Val) + Add)); // Add assuming different endiannes.
else
Val = Val + Add; // Add assuming current endiannes.
if (Add == 0 || Rand.RandBool()) // Maybe negate.
Val = -Val;
}
memcpy(Data + Off, &Val, sizeof(Val));
return Size;
}

8
llvm/lib/Fuzzer/test/FuzzerUnittest.cpp
View File

@ -491,6 +491,8 @@ void TestChangeBinaryInteger(Mutator M, int NumIter) {
uint8_t CH3[8] = {0x00, 0x11, 0x2a, 0x33, 0x44, 0x55, 0x66, 0x77};
uint8_t CH4[8] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x4f, 0x66, 0x77};
uint8_t CH5[8] = {0xff, 0xee, 0xdd, 0xcc, 0xbb, 0xaa, 0x99, 0x88};
uint8_t CH6[8] = {0x00, 0x11, 0x22, 0x00, 0x00, 0x00, 0x08, 0x77}; // Size
uint8_t CH7[8] = {0x00, 0x08, 0x00, 0x33, 0x44, 0x55, 0x66, 0x77}; // Sw(Size)
int FoundMask = 0;
for (int i = 0; i < NumIter; i++) {
@ -502,8 +504,10 @@ void TestChangeBinaryInteger(Mutator M, int NumIter) {
else if (NewSize == 8 && !memcmp(CH3, T, 8)) FoundMask |= 1 << 3;
else if (NewSize == 8 && !memcmp(CH4, T, 8)) FoundMask |= 1 << 4;
else if (NewSize == 8 && !memcmp(CH5, T, 8)) FoundMask |= 1 << 5;
else if (NewSize == 8 && !memcmp(CH6, T, 8)) FoundMask |= 1 << 6;
else if (NewSize == 8 && !memcmp(CH7, T, 8)) FoundMask |= 1 << 7;
}
EXPECT_EQ(FoundMask, 63);
EXPECT_EQ(FoundMask, 255);
}
TEST(FuzzerMutate, ChangeBinaryInteger1) {
@ -581,7 +585,7 @@ TEST(Corpus, Distribution) {
Random Rand(0);
InputCorpus C("");
size_t N = 10;
size_t TriesPerUnit = 1<<20;
size_t TriesPerUnit = 1<<16;
for (size_t i = 0; i < N; i++)
C.AddToCorpus(Unit{ static_cast<uint8_t>(i) }, 0);