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refactored whitelist and blacklist in llvm_mode

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This commit is contained in:
van Hauser
2020-04-25 17:53:38 +02:00
parent 07db922024
commit 0c3d06c41e
13 changed files with 305 additions and 1138 deletions
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208
llvm_mode/afl-llvm-pass.so.cc
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@ -61,6 +61,7 @@ typedef long double max_align_t;
#include "llvm/Support/CFG.h"
#endif
#include "afl-llvm-common.h"
#include "llvm-ngram-coverage.h"
using namespace llvm;
@ -73,58 +74,17 @@ class AFLCoverage : public ModulePass {
static char ID;
AFLCoverage() : ModulePass(ID) {
char *instWhiteListFilename = getenv("AFL_LLVM_WHITELIST");
if (instWhiteListFilename) {
std::string line;
std::ifstream fileStream;
fileStream.open(instWhiteListFilename);
if (!fileStream) report_fatal_error("Unable to open AFL_LLVM_WHITELIST");
getline(fileStream, line);
while (fileStream) {
myWhitelist.push_back(line);
getline(fileStream, line);
}
}
}
// ripped from aflgo
static bool isBlacklisted(const Function *F) {
static const char *Blacklist[] = {
"asan.", "llvm.", "sancov.", "__ubsan_handle_", "ign.", "__afl_",
"_fini", "__libc_csu", "__asan", "__msan", "msan."
};
for (auto const &BlacklistFunc : Blacklist) {
if (F->getName().startswith(BlacklistFunc)) { return true; }
}
return false;
initWhitelist();
}
bool runOnModule(Module &M) override;
// StringRef getPassName() const override {
// return "American Fuzzy Lop Instrumentation";
// }
protected:
std::list<std::string> myWhitelist;
uint32_t ngram_size = 0;
uint32_t debug = 0;
uint32_t map_size = MAP_SIZE;
char * ctx_str = NULL;
uint32_t ngram_size = 0;
uint32_t debug = 0;
uint32_t map_size = MAP_SIZE;
char * ctx_str = NULL;
};
@ -334,9 +294,7 @@ bool AFLCoverage::runOnModule(Module &M) {
fprintf(stderr, "FUNCTION: %s (%zu)\n", F.getName().str().c_str(),
F.size());
if (isBlacklisted(&F)) continue;
// AllocaInst *CallingContext = nullptr;
if (!isInWhitelist(&F)) continue;
if (ctx_str && F.size() > 1) { // Context sensitive coverage
// load the context ID of the previous function and write to to a local
@ -391,115 +349,6 @@ bool AFLCoverage::runOnModule(Module &M) {
BasicBlock::iterator IP = BB.getFirstInsertionPt();
IRBuilder<> IRB(&(*IP));
if (!myWhitelist.empty()) {
bool instrumentBlock = false;
/* Get the current location using debug information.
* For now, just instrument the block if we are not able
* to determine our location. */
DebugLoc Loc = IP->getDebugLoc();
#if LLVM_VERSION_MAJOR >= 4 || \
(LLVM_VERSION_MAJOR == 3 && LLVM_VERSION_MINOR >= 7)
if (Loc) {
DILocation *cDILoc = dyn_cast<DILocation>(Loc.getAsMDNode());
unsigned int instLine = cDILoc->getLine();
StringRef instFilename = cDILoc->getFilename();
if (instFilename.str().empty()) {
/* If the original location is empty, try using the inlined location
*/
DILocation *oDILoc = cDILoc->getInlinedAt();
if (oDILoc) {
instFilename = oDILoc->getFilename();
instLine = oDILoc->getLine();
}
}
(void)instLine;
/* Continue only if we know where we actually are */
if (!instFilename.str().empty()) {
for (std::list<std::string>::iterator it = myWhitelist.begin();
it != myWhitelist.end(); ++it) {
/* We don't check for filename equality here because
* filenames might actually be full paths. Instead we
* check that the actual filename ends in the filename
* specified in the list. */
if (instFilename.str().length() >= it->length()) {
if (instFilename.str().compare(
instFilename.str().length() - it->length(),
it->length(), *it) == 0) {
instrumentBlock = true;
break;
}
}
}
}
}
#else
if (!Loc.isUnknown()) {
DILocation cDILoc(Loc.getAsMDNode(C));
unsigned int instLine = cDILoc.getLineNumber();
StringRef instFilename = cDILoc.getFilename();
(void)instLine;
/* Continue only if we know where we actually are */
if (!instFilename.str().empty()) {
for (std::list<std::string>::iterator it = myWhitelist.begin();
it != myWhitelist.end(); ++it) {
/* We don't check for filename equality here because
* filenames might actually be full paths. Instead we
* check that the actual filename ends in the filename
* specified in the list. */
if (instFilename.str().length() >= it->length()) {
if (instFilename.str().compare(
instFilename.str().length() - it->length(),
it->length(), *it) == 0) {
instrumentBlock = true;
break;
}
}
}
}
}
#endif
/* Either we couldn't figure out our location or the location is
* not whitelisted, so we skip instrumentation. */
if (!instrumentBlock) continue;
}
// in CTX mode we have to restore the original context for the caller -
// she might be calling other functions which need the correct CTX
if (ctx_str && has_calls) {
@ -628,54 +477,11 @@ bool AFLCoverage::runOnModule(Module &M) {
* Counter + 1 -> {Counter, OverflowFlag}
* Counter + OverflowFlag -> Counter
*/
/* // we keep the old solutions just in case
// Solution #1
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
} else if (neverZero_counters_str[0] == '2') {
auto cf = IRB.CreateICmpEQ(Counter,
ConstantInt::get(Int8Ty, 255)); Value *HowMuch =
IRB.CreateAdd(ConstantInt::get(Int8Ty, 1), cf); Incr =
IRB.CreateAdd(Counter, HowMuch);
// Solution #3
} else if (neverZero_counters_str[0] == '3') {
*/
// this is the solution we choose because llvm9 should do the right
// thing here
auto cf = IRB.CreateICmpEQ(Incr, Zero);
auto carry = IRB.CreateZExt(cf, Int8Ty);
Incr = IRB.CreateAdd(Incr, carry);
/*
// Solution #4
} else if (neverZero_counters_str[0] == '4') {
auto cf = IRB.CreateICmpULT(Incr, ConstantInt::get(Int8Ty, 1));
auto carry = IRB.CreateZExt(cf, Int8Ty);
Incr = IRB.CreateAdd(Incr, carry);
} else {
fprintf(stderr, "Error: unknown value for AFL_NZERO_COUNTS: %s
(valid is 1-4)\n", neverZero_counters_str); exit(-1);
}
*/
#if LLVM_VERSION_MAJOR < 9
}