ExternalVendorCode/AFLplusplus
1
0
Fork 0
mirror of https://github.com/AFLplusplus/AFLplusplus.git synced 2025-06-10 17:21:33 +00:00
Code Issues Packages Projects Releases Wiki Activity

select implementations

Browse Source
This commit is contained in:
van Hauser 2019-07-03 16:36:31 +02:00
parent aa4fc44a80
commit 00b22e37df
1 changed files with 34 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

54
llvm_mode/afl-llvm-pass.so.cc
View File

@ -236,7 +236,9 @@ bool AFLCoverage::runOnModule(Module &M) {
LoadInst *Counter = IRB.CreateLoad(MapPtrIdx);
Counter->setMetadata(M.getMDKindID("nosanitize"), MDNode::get(C, None));
Value *Incr = IRB.CreateAdd(Counter, ConstantInt::get(Int8Ty, 1));
Value *Incr;
if (neverZero_counters_str == NULL || neverZero_counters_str[0] != '4')
Incr = IRB.CreateAdd(Counter, ConstantInt::get(Int8Ty, 1));
if (neverZero_counters_str != NULL) {
/* hexcoder: Realize a counter that skips zero during overflow.
@ -250,34 +252,46 @@ bool AFLCoverage::runOnModule(Module &M) {
*/
// Solution #1 - creates
//mov dl,BYTE PTR [rsi+rdi*1]
//mov ecx,edx
//add cl,0x1
//adc dl,0x1
/*
CallInst *AddOv = IRB.CreateBinaryIntrinsic(Intrinsic::uadd_with_overflow, Counter, ConstantInt::get(Int8Ty, 1));
AddOv->setMetadata(M.getMDKindID("nosanitize"), MDNode::get(C, None));
Value *SumWithOverflowBit = AddOv;
Incr = IRB.CreateAdd(IRB.CreateExtractValue(SumWithOverflowBit, 0), // sum
IRB.CreateZExt( // convert from one bit type to 8 bits type
IRB.CreateExtractValue(SumWithOverflowBit, 1), // overflow
Int8Ty));
*/
if (neverZero_counters_str[0] == '1') {
CallInst *AddOv = IRB.CreateBinaryIntrinsic(Intrinsic::uadd_with_overflow, Counter, ConstantInt::get(Int8Ty, 1));
AddOv->setMetadata(M.getMDKindID("nosanitize"), MDNode::get(C, None));
Value *SumWithOverflowBit = AddOv;
Incr = IRB.CreateAdd(IRB.CreateExtractValue(SumWithOverflowBit, 0), // sum
IRB.CreateZExt( // convert from one bit type to 8 bits type
IRB.CreateExtractValue(SumWithOverflowBit, 1), // overflow
Int8Ty));
// Solution #2 - creates the same code as #1
///*
auto cf = IRB.CreateICmpULT(Incr, ConstantInt::get(Int8Ty, 1));
Incr = IRB.CreateAdd(Incr, cf);
//*/
} else if (neverZero_counters_str[0] == '2') {
auto cf = IRB.CreateICmpULT(Incr, ConstantInt::get(Int8Ty, 1));
Incr = IRB.CreateAdd(Incr, cf);
// Solution #3 - creates
//mov cl,BYTE PTR [rsi+rdx*1]
//add cl,0x1
//cmp cl,0x1
//adc cl,0x0
/*
auto cf = IRB.CreateICmpEQ(Incr, ConstantInt::get(Int8Ty, 0));
Incr = IRB.CreateAdd(Incr, cf);
*/
} else if (neverZero_counters_str[0] == '3') {
auto cf = IRB.CreateICmpEQ(Incr, ConstantInt::get(Int8Ty, 0));
Incr = IRB.CreateAdd(Incr, cf);
// Solution #4 - creates
// cmp dl, $0xff
// sete cl
// add dl,cl
// add dl,0x01
} else if (neverZero_counters_str[0] == '4') {
auto cf = IRB.CreateICmpEQ(Counter, ConstantInt::get(Int8Ty, 255));
Value *HowMuch = IRB.CreateAdd(ConstantInt::get(Int8Ty, 1), cf);
Incr = IRB.CreateAdd(Counter, HowMuch);
// no other implementations yet
} else {
fprintf(stderr, "Error: unknown value for AFL_NZERO_COUNTS: %s (valid is 1-4)\n", neverZero_counters_str);
exit(-1);
}
}
IRB.CreateStore(Incr, MapPtrIdx)->setMetadata(M.getMDKindID("nosanitize"), MDNode::get(C, None));