notzero for afl-gcc
MODIFY
afl-as.h
afl-as.h
@@ -189,6 +189,7 @@ static const u8* main_payload_32 =
" orb $1, (%edx, %edi, 1)\n"
#else
" incb (%edx, %edi, 1)\n"
+ " adcb $0, (%edx, %edi, 1)\n"
#endif /* ^SKIP_COUNTS */
"\n"
"__afl_return:\n"
@@ -417,6 +418,7 @@ static const u8* main_payload_64 =
" orb $1, (%rdx, %rcx, 1)\n"
#else
" incb (%rdx, %rcx, 1)\n"
+ " adcb $0, (%rdx, %rcx, 1)\n"
#endif /* ^SKIP_COUNTS */
"\n"
"__afl_return:\n"

MODIFY
llvm_mode/afl-llvm-pass.so.cc
llvm_mode/afl-llvm-pass.so.cc
@@ -287,6 +287,16 @@ bool AFLCoverage::runOnModule(Module &M) {
Value *HowMuch = IRB.CreateAdd(ConstantInt::get(Int8Ty, 1), cf);
Incr = IRB.CreateAdd(Counter, HowMuch);
+ } else if (neverZero_counters_str[0] == '5') {
+ auto cf = IRB.CreateICmpEQ(Incr, ConstantInt::get(Int8Ty, 0));
+ auto carry = IRB.CreateZExt(cf, Int8Ty);
+ Incr = IRB.CreateAdd(Incr, carry);
+
+ } else if (neverZero_counters_str[0] == '6') {
+ auto cf = IRB.CreateICmpULT(Incr, ConstantInt::get(Int8Ty, 1));
+ auto carry = IRB.CreateZExt(cf, Int8Ty);
+ Incr = IRB.CreateAdd(Incr, carry);
+
// no other implementations yet
} else {
fprintf(stderr, "Error: unknown value for AFL_NZERO_COUNTS: %s (valid is 1-4)\n", neverZero_counters_str);

notzero for afl-gcc