From 864056fcaaeea0e156e650b7a0f6182e81db566a Mon Sep 17 00:00:00 2001 From: van Hauser Date: Sat, 13 Jul 2019 11:08:13 +0200 Subject: initial commit --- llvm_mode/LLVMInsTrim.so.cc | 197 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 197 insertions(+) create mode 100644 llvm_mode/LLVMInsTrim.so.cc (limited to 'llvm_mode/LLVMInsTrim.so.cc') diff --git a/llvm_mode/LLVMInsTrim.so.cc b/llvm_mode/LLVMInsTrim.so.cc new file mode 100644 index 00000000..2a13981d --- /dev/null +++ b/llvm_mode/LLVMInsTrim.so.cc @@ -0,0 +1,197 @@ +#include "llvm/ADT/DenseMap.h" +#include "llvm/ADT/DenseSet.h" +#include "llvm/IR/CFG.h" +#include "llvm/IR/Dominators.h" +#include "llvm/IR/IRBuilder.h" +#include "llvm/IR/Instructions.h" +#include "llvm/IR/LegacyPassManager.h" +#include "llvm/IR/Module.h" +#include "llvm/Pass.h" +#include "llvm/Support/raw_ostream.h" +#include "llvm/Transforms/IPO/PassManagerBuilder.h" +#include "llvm/Transforms/Utils/BasicBlockUtils.h" +#include +#include + +#include "MarkNodes.h" + +using namespace llvm; + +static cl::opt MarkSetOpt("markset", cl::desc("MarkSet"), + cl::init(false)); +static cl::opt LoopHeadOpt("loophead", cl::desc("LoopHead"), + cl::init(false)); + +namespace { + struct InsTrim : public ModulePass { + private: + std::mt19937 generator; + int total_instr = 0; + + unsigned genLabel() { + return generator() % 65536; + } + + public: + static char ID; + InsTrim() : ModulePass(ID), generator(0) {} + + void getAnalysisUsage(AnalysisUsage &AU) const override { + AU.addRequired(); + } + + StringRef getPassName() const override { + return "InstTrim Instrumentation"; + } + + bool runOnModule(Module &M) override { + if (getenv("LOOPHEAD")) { + LoopHeadOpt = true; + MarkSetOpt = true; + } else if (getenv("MARKSET")) { + MarkSetOpt = true; + } + + LLVMContext &C = M.getContext(); + IntegerType *Int8Ty = IntegerType::getInt8Ty(C); + IntegerType *Int32Ty = IntegerType::getInt32Ty(C); + + GlobalVariable *CovMapPtr = new GlobalVariable( + M, PointerType::getUnqual(Int8Ty), false, GlobalValue::ExternalLinkage, + nullptr, "__afl_area_ptr"); + + GlobalVariable *OldPrev = new GlobalVariable( + M, Int32Ty, false, GlobalValue::ExternalLinkage, 0, "__afl_prev_loc", + 0, GlobalVariable::GeneralDynamicTLSModel, 0, false); + + unsigned total_rs = 0; + unsigned total_hs = 0; + + for (Function &F : M) { + if (!F.size()) { + continue; + } + + std::unordered_set MS; + if (!MarkSetOpt) { + for (auto &BB : F) { + MS.insert(&BB); + } + total_rs += F.size(); + } else { + auto Result = markNodes(&F); + auto RS = Result.first; + auto HS = Result.second; + + MS.insert(RS.begin(), RS.end()); + if (!LoopHeadOpt) { + MS.insert(HS.begin(), HS.end()); + total_rs += MS.size(); + } else { + DenseSet> EdgeSet; + DominatorTreeWrapperPass *DTWP = + &getAnalysis(F); + auto DT = &DTWP->getDomTree(); + + total_rs += RS.size(); + total_hs += HS.size(); + + for (BasicBlock *BB : HS) { + bool Inserted = false; + for (auto BI = pred_begin(BB), BE = pred_end(BB); + BI != BE; ++BI + ) { + auto Edge = BasicBlockEdge(*BI, BB); + if (Edge.isSingleEdge() && DT->dominates(Edge, BB)) { + EdgeSet.insert({*BI, BB}); + Inserted = true; + break; + } + } + if (!Inserted) { + MS.insert(BB); + total_rs += 1; + total_hs -= 1; + } + } + for (auto I = EdgeSet.begin(), E = EdgeSet.end(); I != E; ++I) { + auto PredBB = I->first; + auto SuccBB = I->second; + auto NewBB = SplitBlockPredecessors(SuccBB, {PredBB}, ".split", + DT, nullptr, false); + MS.insert(NewBB); + } + } + + auto *EBB = &F.getEntryBlock(); + if (succ_begin(EBB) == succ_end(EBB)) { + MS.insert(EBB); + total_rs += 1; + } + + for (BasicBlock &BB : F) { + if (MS.find(&BB) == MS.end()) { + continue; + } + IRBuilder<> IRB(&*BB.getFirstInsertionPt()); + IRB.CreateStore(ConstantInt::get(Int32Ty, genLabel()), OldPrev); + } + } + + for (BasicBlock &BB : F) { + auto PI = pred_begin(&BB); + auto PE = pred_end(&BB); + if (MarkSetOpt && MS.find(&BB) == MS.end()) { + continue; + } + + IRBuilder<> IRB(&*BB.getFirstInsertionPt()); + Value *L = NULL; + if (PI == PE) { + L = ConstantInt::get(Int32Ty, genLabel()); + } else { + auto *PN = PHINode::Create(Int32Ty, 0, "", &*BB.begin()); + DenseMap PredMap; + for (auto PI = pred_begin(&BB), PE = pred_end(&BB); + PI != PE; ++PI + ) { + BasicBlock *PBB = *PI; + auto It = PredMap.insert({PBB, genLabel()}); + unsigned Label = It.first->second; + PN->addIncoming(ConstantInt::get(Int32Ty, Label), PBB); + } + L = PN; + } + + LoadInst *PrevLoc = IRB.CreateLoad(OldPrev); + Value *PrevLocCasted = IRB.CreateZExt(PrevLoc, IRB.getInt32Ty()); + + LoadInst *MapPtr = IRB.CreateLoad(CovMapPtr); + Value *MapPtrIdx = IRB.CreateGEP(MapPtr, + IRB.CreateXor(PrevLocCasted, L)); + + LoadInst *Counter = IRB.CreateLoad(MapPtrIdx); + Value *Incr = IRB.CreateAdd(Counter, ConstantInt::get(Int8Ty, 1)); + IRB.CreateStore(Incr, MapPtrIdx); + total_instr++; + } + } + + errs() << total_instr << " locations instrumented ("<< total_rs << "," << total_hs << ")\n"; + return false; + } + }; // end of struct InsTrim +} // end of anonymous namespace + +char InsTrim::ID = 0; + +static void registerAFLPass(const PassManagerBuilder &, + legacy::PassManagerBase &PM) { + PM.add(new InsTrim()); +} + +static RegisterStandardPasses RegisterAFLPass( + PassManagerBuilder::EP_OptimizerLast, registerAFLPass); + +static RegisterStandardPasses RegisterAFLPass0( + PassManagerBuilder::EP_EnabledOnOptLevel0, registerAFLPass); -- cgit 1.4.1 From 0f1313761686a61983a4deb2646a8265f8acc214 Mon Sep 17 00:00:00 2001 From: Heiko Eißfeldt Date: Sat, 13 Jul 2019 23:40:34 +0200 Subject: compiles now with LLVM 8.0 --- llvm_mode/LLVMInsTrim.so.cc | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'llvm_mode/LLVMInsTrim.so.cc') diff --git a/llvm_mode/LLVMInsTrim.so.cc b/llvm_mode/LLVMInsTrim.so.cc index 2a13981d..bba0b86c 100644 --- a/llvm_mode/LLVMInsTrim.so.cc +++ b/llvm_mode/LLVMInsTrim.so.cc @@ -118,7 +118,7 @@ namespace { auto PredBB = I->first; auto SuccBB = I->second; auto NewBB = SplitBlockPredecessors(SuccBB, {PredBB}, ".split", - DT, nullptr, false); + DT); MS.insert(NewBB); } } -- cgit 1.4.1 From c204efaaab59551bb325af64620626be40aae993 Mon Sep 17 00:00:00 2001 From: Heiko Eißfeldt Date: Sat, 13 Jul 2019 23:12:36 +0200 Subject: Compile fix for LLVM 3.8.0 --- llvm_mode/LLVMInsTrim.so.cc | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'llvm_mode/LLVMInsTrim.so.cc') diff --git a/llvm_mode/LLVMInsTrim.so.cc b/llvm_mode/LLVMInsTrim.so.cc index bba0b86c..0c75eb4e 100644 --- a/llvm_mode/LLVMInsTrim.so.cc +++ b/llvm_mode/LLVMInsTrim.so.cc @@ -40,7 +40,12 @@ namespace { AU.addRequired(); } - StringRef getPassName() const override { +#if LLVM_VERSION_MAJOR < 4 + const char * +#else + StringRef +#endif + getPassName() const override { return "InstTrim Instrumentation"; } -- cgit 1.4.1 From 495f3b9a681af527018a92d3d0e3240568ac7997 Mon Sep 17 00:00:00 2001 From: van Hauser Date: Sun, 14 Jul 2019 10:23:54 +0200 Subject: notZero added and first attempt at whitelist --- llvm_mode/LLVMInsTrim.so.cc | 159 ++++++++++++++++++++++++++++++--- llvm_mode/compare-transform-pass.so.cc | 3 +- llvm_mode/split-compares-pass.so.cc | 3 +- llvm_mode/split-switches-pass.so.cc | 6 +- 4 files changed, 157 insertions(+), 14 deletions(-) (limited to 'llvm_mode/LLVMInsTrim.so.cc') diff --git a/llvm_mode/LLVMInsTrim.so.cc b/llvm_mode/LLVMInsTrim.so.cc index 0c75eb4e..62977e97 100644 --- a/llvm_mode/LLVMInsTrim.so.cc +++ b/llvm_mode/LLVMInsTrim.so.cc @@ -1,3 +1,5 @@ +#include + #include "llvm/ADT/DenseMap.h" #include "llvm/ADT/DenseSet.h" #include "llvm/IR/CFG.h" @@ -10,8 +12,17 @@ #include "llvm/Support/raw_ostream.h" #include "llvm/Transforms/IPO/PassManagerBuilder.h" #include "llvm/Transforms/Utils/BasicBlockUtils.h" +#include "llvm/IR/DebugInfo.h" +#include "llvm/IR/BasicBlock.h" +#include "llvm/IR/CFG.h" #include #include +#include +#include +#include + +#include "../config.h" +#include "../debug.h" #include "MarkNodes.h" @@ -24,6 +35,10 @@ static cl::opt LoopHeadOpt("loophead", cl::desc("LoopHead"), namespace { struct InsTrim : public ModulePass { + + protected: + std::list myWhitelist; + private: std::mt19937 generator; int total_instr = 0; @@ -34,7 +49,23 @@ namespace { public: static char ID; - InsTrim() : ModulePass(ID), generator(0) {} + InsTrim() : ModulePass(ID), generator(0) {//} + +// 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); + } + } + } void getAnalysisUsage(AnalysisUsage &AU) const override { AU.addRequired(); @@ -50,12 +81,33 @@ namespace { } bool runOnModule(Module &M) override { + char be_quiet = 0; + + if (isatty(2) && !getenv("AFL_QUIET")) { + SAYF(cCYA "LLVMInsTrim" VERSION cRST " by csienslab\n"); + } else be_quiet = 1; + +#if LLVM_VERSION_MAJOR < 9 + char* neverZero_counters_str; + if ((neverZero_counters_str = getenv("AFL_LLVM_NOT_ZERO")) != NULL) + OKF("LLVM neverZero activated (by hexcoder)\n"); +#endif + if (getenv("LOOPHEAD")) { LoopHeadOpt = true; MarkSetOpt = true; } else if (getenv("MARKSET")) { MarkSetOpt = true; } + +/* // I dont think this makes sense to port into LLVMInsTrim + char* inst_ratio_str = getenv("AFL_INST_RATIO"); + unsigned int inst_ratio = 100; + if (inst_ratio_str) { + if (sscanf(inst_ratio_str, "%u", &inst_ratio) != 1 || !inst_ratio || inst_ratio > 100) + FATAL("Bad value of AFL_INST_RATIO (must be between 1 and 100)"); + } +*/ LLVMContext &C = M.getContext(); IntegerType *Int8Ty = IntegerType::getInt8Ty(C); @@ -69,14 +121,59 @@ namespace { M, Int32Ty, false, GlobalValue::ExternalLinkage, 0, "__afl_prev_loc", 0, GlobalVariable::GeneralDynamicTLSModel, 0, false); - unsigned total_rs = 0; - unsigned total_hs = 0; + u64 total_rs = 0; + u64 total_hs = 0; for (Function &F : M) { if (!F.size()) { continue; } + if (!myWhitelist.empty()) { + bool instrumentBlock = false; + BasicBlock &BB = F.getEntryBlock(); + BasicBlock::iterator IP = BB.getFirstInsertionPt(); + IRBuilder<> IRB(&(*IP)); + DebugLoc Loc = IP->getDebugLoc(); + StringRef instFilename; + + if ( Loc ) { + DILocation *cDILoc = dyn_cast(Loc.getAsMDNode()); + + unsigned int instLine = cDILoc->getLine(); + 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(); + } + } + + /* Continue only if we know where we actually are */ + if (!instFilename.str().empty()) { + for (std::list::iterator it = myWhitelist.begin(); it != myWhitelist.end(); ++it) { + if (instFilename.str().length() >= it->length()) { + if (instFilename.str().compare(instFilename.str().length() - it->length(), it->length(), *it) == 0) { + instrumentBlock = true; + break; + } + } + } + } + } + + /* Either we couldn't figure out our location or the location is + * not whitelisted, so we skip instrumentation. */ + if (!instrumentBlock) { + if (!instFilename.str().empty()) + SAYF( "Not in whitelist, skipping %s ...\n", instFilename.str().c_str()); + continue; + } + } + std::unordered_set MS; if (!MarkSetOpt) { for (auto &BB : F) { @@ -94,8 +191,7 @@ namespace { total_rs += MS.size(); } else { DenseSet> EdgeSet; - DominatorTreeWrapperPass *DTWP = - &getAnalysis(F); + DominatorTreeWrapperPass *DTWP = &getAnalysis(F); auto DT = &DTWP->getDomTree(); total_rs += RS.size(); @@ -123,7 +219,11 @@ namespace { auto PredBB = I->first; auto SuccBB = I->second; auto NewBB = SplitBlockPredecessors(SuccBB, {PredBB}, ".split", - DT); + DT, nullptr, +#if LLVM_VERSION_MAJOR >= 8 + nullptr, +#endif + false); MS.insert(NewBB); } } @@ -168,21 +268,60 @@ namespace { L = PN; } + /* Load prev_loc */ LoadInst *PrevLoc = IRB.CreateLoad(OldPrev); + PrevLoc->setMetadata(M.getMDKindID("nosanitize"), MDNode::get(C, None)); Value *PrevLocCasted = IRB.CreateZExt(PrevLoc, IRB.getInt32Ty()); + /* Load SHM pointer */ LoadInst *MapPtr = IRB.CreateLoad(CovMapPtr); - Value *MapPtrIdx = IRB.CreateGEP(MapPtr, - IRB.CreateXor(PrevLocCasted, L)); + MapPtr->setMetadata(M.getMDKindID("nosanitize"), MDNode::get(C, None)); + Value *MapPtrIdx = IRB.CreateGEP(MapPtr, IRB.CreateXor(PrevLocCasted, L)); + /* Update bitmap */ LoadInst *Counter = IRB.CreateLoad(MapPtrIdx); + Counter->setMetadata(M.getMDKindID("nosanitize"), MDNode::get(C, None)); + Value *Incr = IRB.CreateAdd(Counter, ConstantInt::get(Int8Ty, 1)); - IRB.CreateStore(Incr, MapPtrIdx); + +#if LLVM_VERSION_MAJOR < 9 + if (neverZero_counters_str != NULL) { // with llvm 9 we make this the default as the bug in llvm is then fixed +#else + #warning "neverZero implementation needs to be reviewed!" +#endif + /* hexcoder: Realize a counter that skips zero during overflow. + * Once this counter reaches its maximum value, it next increments to 1 + * + * Instead of + * Counter + 1 -> Counter + * we inject now this + * Counter + 1 -> {Counter, OverflowFlag} + * Counter + OverflowFlag -> Counter + */ + auto cf = IRB.CreateICmpEQ(Incr, ConstantInt::get(Int8Ty, 0)); + auto carry = IRB.CreateZExt(cf, Int8Ty); + Incr = IRB.CreateAdd(Incr, carry); +#if LLVM_VERSION_MAJOR < 9 + } +#endif + + IRB.CreateStore(Incr, MapPtrIdx)->setMetadata(M.getMDKindID("nosanitize"), MDNode::get(C, None)); + + /* Set prev_loc to cur_loc >> 1 */ + /* + StoreInst *Store = IRB.CreateStore(ConstantInt::get(Int32Ty, cur_loc >> 1), AFLPrevLoc); + Store->setMetadata(M.getMDKindID("nosanitize"), MDNode::get(C, None)); + */ + total_instr++; } } - errs() << total_instr << " locations instrumented ("<< total_rs << "," << total_hs << ")\n"; + OKF("Instrumented %u locations (%llu, %llu) (%s mode)\n"/*", ratio %u%%)."*/, + total_instr, total_rs, total_hs, + getenv("AFL_HARDEN") ? "hardened" : + ((getenv("AFL_USE_ASAN") || getenv("AFL_USE_MSAN")) ? + "ASAN/MSAN" : "non-hardened")/*, inst_ratio*/); return false; } }; // end of struct InsTrim diff --git a/llvm_mode/compare-transform-pass.so.cc b/llvm_mode/compare-transform-pass.so.cc index d9a1f945..95435db7 100644 --- a/llvm_mode/compare-transform-pass.so.cc +++ b/llvm_mode/compare-transform-pass.so.cc @@ -304,7 +304,8 @@ bool CompareTransform::transformCmps(Module &M, const bool processStrcmp, const bool CompareTransform::runOnModule(Module &M) { - llvm::errs() << "Running compare-transform-pass by laf.intel@gmail.com, extended by heiko@hexco.de\n"; + if (getenv("AFL_QUIET") == NULL) + llvm::errs() << "Running compare-transform-pass by laf.intel@gmail.com, extended by heiko@hexco.de\n"; transformCmps(M, true, true, true, true, true); verifyModule(M); diff --git a/llvm_mode/split-compares-pass.so.cc b/llvm_mode/split-compares-pass.so.cc index 2ea73aaa..c025628f 100644 --- a/llvm_mode/split-compares-pass.so.cc +++ b/llvm_mode/split-compares-pass.so.cc @@ -487,7 +487,8 @@ bool SplitComparesTransform::runOnModule(Module &M) { simplifySignedness(M); - errs() << "Split-compare-pass by laf.intel@gmail.com\n"; + if (getenv("AFL_QUIET") == NULL) + errs() << "Split-compare-pass by laf.intel@gmail.com\n"; switch (bitw) { case 64: diff --git a/llvm_mode/split-switches-pass.so.cc b/llvm_mode/split-switches-pass.so.cc index 4c28f34c..1ace3185 100644 --- a/llvm_mode/split-switches-pass.so.cc +++ b/llvm_mode/split-switches-pass.so.cc @@ -244,7 +244,8 @@ bool SplitSwitchesTransform::splitSwitches(Module &M) { /* If there is only the default destination or the condition checks 8 bit or less, don't bother with the code below. */ if (!SI->getNumCases() || bitw <= 8) { - errs() << "skip trivial switch..\n"; + if (getenv("AFL_QUIET") == NULL) + errs() << "skip trivial switch..\n"; continue; } @@ -302,7 +303,8 @@ bool SplitSwitchesTransform::splitSwitches(Module &M) { bool SplitSwitchesTransform::runOnModule(Module &M) { - llvm::errs() << "Running split-switches-pass by laf.intel@gmail.com\n"; + if (getenv("AFL_QUIET") == NULL) + llvm::errs() << "Running split-switches-pass by laf.intel@gmail.com\n"; splitSwitches(M); verifyModule(M); -- cgit 1.4.1 From e66402485342088e6fcaecfe2abbba291a48bda5 Mon Sep 17 00:00:00 2001 From: van Hauser Date: Sun, 14 Jul 2019 10:50:13 +0200 Subject: whitelist features works now --- docs/PATCHES | 1 + docs/README | 6 +++++- llvm_mode/LLVMInsTrim.so.cc | 19 ++++++++++++++----- llvm_mode/README.llvm | 10 ++++++---- 4 files changed, 26 insertions(+), 10 deletions(-) (limited to 'llvm_mode/LLVMInsTrim.so.cc') diff --git a/docs/PATCHES b/docs/PATCHES index 06da053e..f6ca9284 100644 --- a/docs/PATCHES +++ b/docs/PATCHES @@ -17,6 +17,7 @@ afl-qemu-optimize-entrypoint.diff by mh(at)mh-sec(dot)de afl-qemu-speed.diff by abiondo on github afl-qemu-optimize-map.diff by mh(at)mh-sec(dot)de ++ instrim (https://github.com/csienslab/instrim) was integrated + MOpt (github.com/puppet-meteor/MOpt-AFL) was imported + AFLfast additions (github.com/mboehme/aflfast) were incorporated. + Qemu 3.1 upgrade with enhancement patches (github.com/andreafioraldi/afl) diff --git a/docs/README b/docs/README index 3f19d328..54e3e4a4 100644 --- a/docs/README +++ b/docs/README @@ -19,9 +19,13 @@ american fuzzy lop plus plus C. Hollers afl-fuzz Python mutator module and llvm_mode whitelist support was added too (https://github.com/choller/afl) - The newest additions is the excellent MOpt mutator from + New is the excellent MOpt mutator from https://github.com/puppet-meteor/MOpt-AFL + Also newly integrated is instrim, a very effective CFG llvm_mode + instrumentation implementation which replaced the original afl one and is + from https://github.com/csienslab/instrim + A more thorough list is available in the PATCHES file. So all in all this is the best-of AFL that is currently out there :-) diff --git a/llvm_mode/LLVMInsTrim.so.cc b/llvm_mode/LLVMInsTrim.so.cc index 62977e97..51640870 100644 --- a/llvm_mode/LLVMInsTrim.so.cc +++ b/llvm_mode/LLVMInsTrim.so.cc @@ -1,3 +1,6 @@ +#include +#include +#include #include #include "llvm/ADT/DenseMap.h" @@ -131,12 +134,16 @@ namespace { if (!myWhitelist.empty()) { bool instrumentBlock = false; - BasicBlock &BB = F.getEntryBlock(); - BasicBlock::iterator IP = BB.getFirstInsertionPt(); - IRBuilder<> IRB(&(*IP)); - DebugLoc Loc = IP->getDebugLoc(); + DebugLoc Loc; StringRef instFilename; + for (auto &BB : F) { + BasicBlock::iterator IP = BB.getFirstInsertionPt(); + IRBuilder<> IRB(&(*IP)); + if (!Loc) + Loc = IP->getDebugLoc(); + } + if ( Loc ) { DILocation *cDILoc = dyn_cast(Loc.getAsMDNode()); @@ -169,7 +176,9 @@ namespace { * not whitelisted, so we skip instrumentation. */ if (!instrumentBlock) { if (!instFilename.str().empty()) - SAYF( "Not in whitelist, skipping %s ...\n", instFilename.str().c_str()); + SAYF(cYEL "[!] " cBRI "Not in whitelist, skipping %s ...\n", instFilename.str().c_str()); + else + SAYF(cYEL "[!] " cBRI "No filename information found, skipping it"); continue; } } diff --git a/llvm_mode/README.llvm b/llvm_mode/README.llvm index dc860e97..b4e05a7a 100644 --- a/llvm_mode/README.llvm +++ b/llvm_mode/README.llvm @@ -38,8 +38,8 @@ co-exists with the original code. The idea and much of the implementation comes from Laszlo Szekeres. -2) How to use -------------- +2) How to use this +------------------ In order to leverage this mechanism, you need to have clang installed on your system. You should also make sure that the llvm-config tool is in your path @@ -69,8 +69,10 @@ operating mode of AFL, e.g.: Be sure to also include CXX set to afl-clang-fast++ for C++ code. The tool honors roughly the same environmental variables as afl-gcc (see -../docs/env_variables.txt). This includes AFL_INST_RATIO, AFL_USE_ASAN, -AFL_HARDEN, and AFL_DONT_OPTIMIZE. +../docs/env_variables.txt). This includes AFL_USE_ASAN, +AFL_HARDEN, and AFL_DONT_OPTIMIZE. However AFL_INST_RATIO is not honored +as it does not serve a good purpose with the more effective instrim CFG +analysis. Note: if you want the LLVM helper to be installed on your system for all users, you need to build it before issuing 'make install' in the parent -- cgit 1.4.1 From 013a1731d590eaa1f3e4c58c69985f89b7a3d2f9 Mon Sep 17 00:00:00 2001 From: van Hauser Date: Sun, 14 Jul 2019 19:48:28 +0200 Subject: set instrim as default and updated documentation --- docs/env_variables.txt | 13 ++++++++----- llvm_mode/LLVMInsTrim.so.cc | 6 +++--- llvm_mode/README.llvm | 27 +++++++++++++++++++++++---- 3 files changed, 34 insertions(+), 12 deletions(-) (limited to 'llvm_mode/LLVMInsTrim.so.cc') diff --git a/docs/env_variables.txt b/docs/env_variables.txt index d854ea8d..8e2723d7 100644 --- a/docs/env_variables.txt +++ b/docs/env_variables.txt @@ -82,6 +82,9 @@ discussed in section #1, with the exception of: - TMPDIR and AFL_KEEP_ASSEMBLY, since no temporary assembly files are created. + - AFL_INST_RATIO, as we switched for instrim instrumentation which + is more effective but makes not much sense together with this option. + Then there are a few specific features that are only available in llvm_mode: LAF-INTEL @@ -108,16 +111,16 @@ Then there are a few specific features that are only available in llvm_mode: OTHER ===== - - Setting export AFL_LLVM_NOT_ZERO=1 during compilation will use counters + - Setting LOOPHEAD=1 optimized loops. afl-fuzz will only be able to + see the path the loop took, but not how many times it was called + (unless its a complex loop). + + - Setting AFL_LLVM_NOT_ZERO=1 during compilation will use counters that skip zero on overflow. This is the default for llvm >= 9, however for llvm versions below that this will increase an unnecessary slowdown due a performance issue that is only fixed in llvm 9+. This feature increases path discovery by a little bit. -Note that AFL_INST_RATIO will behave a bit differently than for afl-gcc, -because functions are *not* instrumented unconditionally - so low values -will have a more striking effect. For this tool, 0 is not a valid choice. - 3) Settings for afl-fuzz ------------------------ diff --git a/llvm_mode/LLVMInsTrim.so.cc b/llvm_mode/LLVMInsTrim.so.cc index 51640870..8e9f7667 100644 --- a/llvm_mode/LLVMInsTrim.so.cc +++ b/llvm_mode/LLVMInsTrim.so.cc @@ -98,10 +98,10 @@ namespace { if (getenv("LOOPHEAD")) { LoopHeadOpt = true; - MarkSetOpt = true; - } else if (getenv("MARKSET")) { - MarkSetOpt = true; } + + // this is our default + MarkSetOpt = true; /* // I dont think this makes sense to port into LLVMInsTrim char* inst_ratio_str = getenv("AFL_INST_RATIO"); diff --git a/llvm_mode/README.llvm b/llvm_mode/README.llvm index b4e05a7a..77c406f8 100644 --- a/llvm_mode/README.llvm +++ b/llvm_mode/README.llvm @@ -78,13 +78,32 @@ Note: if you want the LLVM helper to be installed on your system for all users, you need to build it before issuing 'make install' in the parent directory. -3) Gotchas, feedback, bugs +3) Options + +Several options are present to make llvm_mode faster or help it rearrange +the code to make afl-fuzz path discovery easier. + +If you need just to instrument specific parts of the code, you can whitelist +which C/C++ files to actually intrument. See README.whitelist + +For splitting memcmp, strncmp, etc. please see README.laf-intel + +As the original afl llvm_mode implementation has been replaced with +then much more effective instrim (https://github.com/csienslab/instrim/) +there is an option for optimizing loops. This optimization shows which +part of the loop has been selected, but not how many time a loop has been +called in a row (unless its a complex loop and a block inside was +instrumented). If you want to enable this set the environment variable +LOOPHEAD=1 + + +4) Gotchas, feedback, bugs -------------------------- This is an early-stage mechanism, so field reports are welcome. You can send bug reports to . -4) Bonus feature #1: deferred instrumentation +5) Bonus feature #1: deferred instrumentation --------------------------------------------- AFL tries to optimize performance by executing the targeted binary just once, @@ -131,7 +150,7 @@ will keep working normally when compiled with a tool other than afl-clang-fast. Finally, recompile the program with afl-clang-fast (afl-gcc or afl-clang will *not* generate a deferred-initialization binary) - and you should be all set! -5) Bonus feature #2: persistent mode +6) Bonus feature #2: persistent mode ------------------------------------ Some libraries provide APIs that are stateless, or whose state can be reset in @@ -171,7 +190,7 @@ PS. Because there are task switches still involved, the mode isn't as fast as faster than the normal fork() model, and compared to in-process fuzzing, should be a lot more robust. -6) Bonus feature #3: new 'trace-pc-guard' mode +8) Bonus feature #3: new 'trace-pc-guard' mode ---------------------------------------------- Recent versions of LLVM are shipping with a built-in execution tracing feature -- cgit 1.4.1 From 32525238238e96ec0ce64a36f70558f76bc90ff5 Mon Sep 17 00:00:00 2001 From: van Hauser Date: Mon, 15 Jul 2019 11:22:54 +0200 Subject: fixing commit fuckup --- Makefile | 2 +- docs/ChangeLog | 8 +++----- docs/README | 3 +-- docs/env_variables.txt | 22 +++++++++++++++++----- llvm_mode/LLVMInsTrim.so.cc | 2 +- llvm_mode/Makefile | 13 ++++++++----- llvm_mode/README.llvm | 19 ++++++++++++------- llvm_mode/afl-clang-fast.c | 16 +++++++++------- 8 files changed, 52 insertions(+), 33 deletions(-) (limited to 'llvm_mode/LLVMInsTrim.so.cc') diff --git a/Makefile b/Makefile index 60dfde18..6b580381 100644 --- a/Makefile +++ b/Makefile @@ -194,7 +194,7 @@ install: all rm -f $${DESTDIR}$(BIN_PATH)/afl-as if [ -f afl-qemu-trace ]; then install -m 755 afl-qemu-trace $${DESTDIR}$(BIN_PATH); fi ifndef AFL_TRACE_PC - if [ -f afl-clang-fast -a -f libLLVMInsTrim.so -a -f afl-llvm-rt.o ]; then set -e; install -m 755 afl-clang-fast $${DESTDIR}$(BIN_PATH); ln -sf afl-clang-fast $${DESTDIR}$(BIN_PATH)/afl-clang-fast++; install -m 755 libLLVMInsTrim.so afl-llvm-rt.o $${DESTDIR}$(HELPER_PATH); fi + if [ -f afl-clang-fast -a -f libLLVMInsTrim.so -a -f afl-llvm-rt.o ]; then set -e; install -m 755 afl-clang-fast $${DESTDIR}$(BIN_PATH); ln -sf afl-clang-fast $${DESTDIR}$(BIN_PATH)/afl-clang-fast++; install -m 755 libLLVMInsTrim.so afl-llvm-pass.so afl-llvm-rt.o $${DESTDIR}$(HELPER_PATH); fi else if [ -f afl-clang-fast -a -f afl-llvm-rt.o ]; then set -e; install -m 755 afl-clang-fast $${DESTDIR}$(BIN_PATH); ln -sf afl-clang-fast $${DESTDIR}$(BIN_PATH)/afl-clang-fast++; install -m 755 afl-llvm-rt.o $${DESTDIR}$(HELPER_PATH); fi endif diff --git a/docs/ChangeLog b/docs/ChangeLog index 9cdca49b..116029ea 100644 --- a/docs/ChangeLog +++ b/docs/ChangeLog @@ -17,9 +17,9 @@ sending a mail to . Version ++2.52d (tbd): ----------------------------- - - added instrim a much better llvm_mode instrumentation - (https://github.com/csienslab/instrim) - - added MOpt (github.com/puppet-meteor/MOpt-AFL) mode + - added instrim, a much faster llvm_mode instrumentation at the cost of + path discovery. See llvm_mode/README.instrim (https://github.com/csienslab/instrim) + - added MOpt (github.com/puppet-meteor/MOpt-AFL) mode, see docs/README.MOpt - added code to make it more portable to other platforms than Intel Linux - added never zero counters for afl-gcc and optional (because of an optimization issue in llvm < 9) for llvm_mode (AFL_LLVM_NEVER_ZERO=1) @@ -41,8 +41,6 @@ Version ++2.52d (tbd): tests as the random numbers are deterministic then - llvm_mode LAF_... env variables can now be specified as AFL_LLVM_LAF_... that is longer but in line with other llvm specific env vars - - ... your idea or patch? - ----------------------------- diff --git a/docs/README b/docs/README index 54e3e4a4..3a6c2921 100644 --- a/docs/README +++ b/docs/README @@ -23,8 +23,7 @@ american fuzzy lop plus plus https://github.com/puppet-meteor/MOpt-AFL Also newly integrated is instrim, a very effective CFG llvm_mode - instrumentation implementation which replaced the original afl one and is - from https://github.com/csienslab/instrim + instrumentation implementation from https://github.com/csienslab/instrim A more thorough list is available in the PATCHES file. diff --git a/docs/env_variables.txt b/docs/env_variables.txt index 8e2723d7..e58327b4 100644 --- a/docs/env_variables.txt +++ b/docs/env_variables.txt @@ -109,11 +109,21 @@ Then there are a few specific features that are only available in llvm_mode: See llvm_mode/README.whitelist for more information. - OTHER - ===== - - Setting LOOPHEAD=1 optimized loops. afl-fuzz will only be able to - see the path the loop took, but not how many times it was called - (unless its a complex loop). + INSTRIM + ======= + This feature increases the speed by whopping 20% but at the cost of a + lower path discovery and thefore coverage. + + - Setting AFL_LLVM_INSTRIM activates this mode + + - Setting AFL_LLVM_INSTRIM LOOPHEAD=1 expands on INSTRIM to optimize loops. + afl-fuzz will only be able to see the path the loop took, but not how + many times it was called (unless its a complex loop). + + See llvm_mode/README.instrim + + NOT_ZERO + ======== - Setting AFL_LLVM_NOT_ZERO=1 during compilation will use counters that skip zero on overflow. This is the default for llvm >= 9, @@ -121,6 +131,8 @@ Then there are a few specific features that are only available in llvm_mode: slowdown due a performance issue that is only fixed in llvm 9+. This feature increases path discovery by a little bit. + See llvm_mode/README.neverzero + 3) Settings for afl-fuzz ------------------------ diff --git a/llvm_mode/LLVMInsTrim.so.cc b/llvm_mode/LLVMInsTrim.so.cc index 8e9f7667..81cf98c4 100644 --- a/llvm_mode/LLVMInsTrim.so.cc +++ b/llvm_mode/LLVMInsTrim.so.cc @@ -96,7 +96,7 @@ namespace { OKF("LLVM neverZero activated (by hexcoder)\n"); #endif - if (getenv("LOOPHEAD")) { + if (getenv("AFL_LLVM_INSTRIM_LOOPHEAD") != NULL || getenv("LOOPHEAD") != NULL) { LoopHeadOpt = true; } diff --git a/llvm_mode/Makefile b/llvm_mode/Makefile index d0d4b690..2b685ddc 100644 --- a/llvm_mode/Makefile +++ b/llvm_mode/Makefile @@ -94,7 +94,7 @@ endif ifndef AFL_TRACE_PC - PROGS = ../afl-clang-fast ../libLLVMInsTrim.so ../afl-llvm-rt.o ../afl-llvm-rt-32.o ../afl-llvm-rt-64.o ../compare-transform-pass.so ../split-compares-pass.so ../split-switches-pass.so + PROGS = ../afl-clang-fast ../afl-llvm-pass.so ../libLLVMInsTrim.so ../afl-llvm-rt.o ../afl-llvm-rt-32.o ../afl-llvm-rt-64.o ../compare-transform-pass.so ../split-compares-pass.so ../split-switches-pass.so else PROGS = ../afl-clang-fast ../afl-llvm-rt.o ../afl-llvm-rt-32.o ../afl-llvm-rt-64.o ../compare-transform-pass.so ../split-compares-pass.so ../split-switches-pass.so endif @@ -104,7 +104,7 @@ ifneq "$(CLANGVER)" "$(LLVMVER)" CXX = $(shell llvm-config --bindir)/clang++ endif -all: test_deps test_shm $(PROGS) test_build all_done +all: test_shm test_deps $(PROGS) test_build all_done ifeq "$(SHMAT_OK)" "1" @@ -132,10 +132,10 @@ endif @which $(CC) >/dev/null 2>&1 || ( echo "[-] Oops, can't find '$(CC)'. Make sure that it's in your \$$PATH (or set \$$CC and \$$CXX)."; exit 1 ) @echo "[*] Checking for matching versions of '$(CC)' and '$(LLVM_CONFIG)'" ifneq "$(CLANGVER)" "$(LLVMVER)" - @echo "WARNING: we have llvm-config version $(LLVMVER) and a clang version $(CLANGVER)" - @echo "Retrying with the clang compiler from llvm: CC=`llvm-config --bindir`/clang" + @echo "[!] WARNING: we have llvm-config version $(LLVMVER) and a clang version $(CLANGVER)" + @echo "[!] Retrying with the clang compiler from llvm: CC=`llvm-config --bindir`/clang" else - @echo "we have llvm-config version $(LLVMVER) with a clang version $(CLANGVER), good." + @echo "[*] We have llvm-config version $(LLVMVER) with a clang version $(CLANGVER), good." endif @echo "[*] Checking for '../afl-showmap'..." @test -f ../afl-showmap || ( echo "[-] Oops, can't find '../afl-showmap'. Be sure to compile AFL first."; exit 1 ) @@ -148,6 +148,9 @@ endif ../libLLVMInsTrim.so: LLVMInsTrim.so.cc MarkNodes.cc | test_deps $(CXX) $(CLANG_CFL) -DLLVMInsTrim_EXPORTS -fno-rtti -fPIC -std=gnu++11 -shared $< MarkNodes.cc -o $@ $(CLANG_LFL) +../afl-llvm-pass.so: afl-llvm-pass.so.cc | test_deps + $(CXX) $(CLANG_CFL) -DLLVMInsTrim_EXPORTS -fno-rtti -fPIC -std=gnu++11 -shared $< -o $@ $(CLANG_LFL) + # laf ../split-switches-pass.so: split-switches-pass.so.cc | test_deps $(CXX) $(CLANG_CFL) -shared $< -o $@ $(CLANG_LFL) diff --git a/llvm_mode/README.llvm b/llvm_mode/README.llvm index 77c406f8..779ff47c 100644 --- a/llvm_mode/README.llvm +++ b/llvm_mode/README.llvm @@ -88,13 +88,18 @@ which C/C++ files to actually intrument. See README.whitelist For splitting memcmp, strncmp, etc. please see README.laf-intel -As the original afl llvm_mode implementation has been replaced with -then much more effective instrim (https://github.com/csienslab/instrim/) -there is an option for optimizing loops. This optimization shows which -part of the loop has been selected, but not how many time a loop has been -called in a row (unless its a complex loop and a block inside was -instrumented). If you want to enable this set the environment variable -LOOPHEAD=1 +Then there is an optimized instrumentation strategy that uses CFGs and +markers to just instrument what is needed. This increases speed by 20-25% +however has a lower path discovery. +If you want to use this, set AFL_LLVM_INSTRIM=1 +See README.instrim + +Finally if your llvm version is 8 or lower, you can activate a mode that +prevents that a counter overflow result in a 0 value. This is good for +path discovery, but the llvm implementation for intel for this functionality +is not optimal and was only fixed in llvm 9. +You can set this with AFL_LLVM_NOT_ZERO=1 +See README.neverzero 4) Gotchas, feedback, bugs diff --git a/llvm_mode/afl-clang-fast.c b/llvm_mode/afl-clang-fast.c index 249eea7d..19bad86c 100644 --- a/llvm_mode/afl-clang-fast.c +++ b/llvm_mode/afl-clang-fast.c @@ -88,7 +88,7 @@ static void find_obj(u8* argv0) { return; } - FATAL("Unable to find 'afl-llvm-rt.o' or 'libLLVMInsTrim.so'. Please set AFL_PATH"); + FATAL("Unable to find 'afl-llvm-rt.o' or 'afl-llvm-pass.so.cc'. Please set AFL_PATH"); } @@ -113,11 +113,11 @@ static void edit_params(u32 argc, char** argv) { cc_params[0] = alt_cc ? alt_cc : (u8*)"clang"; } - /* There are two ways to compile afl-clang-fast. In the traditional mode, we - use libLLVMInsTrim.so to inject instrumentation. In the experimental + /* There are three ways to compile with afl-clang-fast. In the traditional + mode, we use afl-llvm-pass.so, then there is libLLVMInsTrim.so which is + much faster but has less coverage. Finally tere is the experimental 'trace-pc-guard' mode, we use native LLVM instrumentation callbacks - instead. The latter is a very recent addition - see: - + instead. For trace-pc-guard see: http://clang.llvm.org/docs/SanitizerCoverage.html#tracing-pcs-with-guards */ // laf @@ -151,8 +151,10 @@ static void edit_params(u32 argc, char** argv) { cc_params[cc_par_cnt++] = "-Xclang"; cc_params[cc_par_cnt++] = "-load"; cc_params[cc_par_cnt++] = "-Xclang"; - cc_params[cc_par_cnt++] = alloc_printf("%s/libLLVMInsTrim.so", obj_path); -// cc_params[cc_par_cnt++] = alloc_printf("%s/afl-llvm-pass.so", obj_path); + if (getenv("AFL_LLVM_INSTRIM") != NULL || getenv("INSTRIM_LIB") != NULL) + cc_params[cc_par_cnt++] = alloc_printf("%s/libLLVMInsTrim.so", obj_path); + else + cc_params[cc_par_cnt++] = alloc_printf("%s/afl-llvm-pass.so", obj_path); #endif /* ^USE_TRACE_PC */ cc_params[cc_par_cnt++] = "-Qunused-arguments"; -- cgit 1.4.1