1 files changed, 414 insertions, 0 deletions
diff --git a/instrumentation/cmplog-switches-pass.cc b/instrumentation/cmplog-switches-pass.cc
new file mode 100644
index 00000000..c42d44fe
--- /dev/null
+++ b/instrumentation/cmplog-switches-pass.cc
@@ -0,0 +1,414 @@
+/*
+   american fuzzy lop++ - LLVM CmpLog instrumentation
+   --------------------------------------------------
+
+   Written by Andrea Fioraldi <andreafioraldi@gmail.com>
+
+   Copyright 2015, 2016 Google Inc. All rights reserved.
+   Copyright 2019-2020 AFLplusplus Project. All rights reserved.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at:
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include <iostream>
+#include <list>
+#include <string>
+#include <fstream>
+#include <sys/time.h>
+
+#include "llvm/Config/llvm-config.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/LegacyPassManager.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Transforms/IPO/PassManagerBuilder.h"
+#include "llvm/Transforms/Utils/BasicBlockUtils.h"
+#include "llvm/Pass.h"
+#include "llvm/Analysis/ValueTracking.h"
+
+#if LLVM_VERSION_MAJOR > 3 || \
+    (LLVM_VERSION_MAJOR == 3 && LLVM_VERSION_MINOR > 4)
+  #include "llvm/IR/Verifier.h"
+  #include "llvm/IR/DebugInfo.h"
+#else
+  #include "llvm/Analysis/Verifier.h"
+  #include "llvm/DebugInfo.h"
+  #define nullptr 0
+#endif
+
+#include <set>
+#include "afl-llvm-common.h"
+
+using namespace llvm;
+
+namespace {
+
+class CmpLogInstructions : public ModulePass {
+
+ public:
+  static char ID;
+  CmpLogInstructions() : ModulePass(ID) {
+
+    initInstrumentList();
+
+  }
+
+  bool runOnModule(Module &M) override;
+
+#if LLVM_VERSION_MAJOR < 4
+  const char *getPassName() const override {
+
+#else
+  StringRef getPassName() const override {
+
+#endif
+    return "cmplog instructions";
+
+  }
+
+ private:
+  bool hookInstrs(Module &M);
+
+};
+
+}  // namespace
+
+char CmpLogInstructions::ID = 0;
+
+template <class Iterator>
+Iterator Unique(Iterator first, Iterator last) {
+
+  while (first != last) {
+
+    Iterator next(first);
+    last = std::remove(++next, last, *first);
+    first = next;
+
+  }
+
+  return last;
+
+}
+
+bool CmpLogInstructions::hookInstrs(Module &M) {
+
+  std::vector<SwitchInst *> switches;
+  LLVMContext &             C = M.getContext();
+
+  Type *       VoidTy = Type::getVoidTy(C);
+  IntegerType *Int8Ty = IntegerType::getInt8Ty(C);
+  IntegerType *Int16Ty = IntegerType::getInt16Ty(C);
+  IntegerType *Int32Ty = IntegerType::getInt32Ty(C);
+  IntegerType *Int64Ty = IntegerType::getInt64Ty(C);
+
+#if LLVM_VERSION_MAJOR < 9
+  Constant *
+#else
+  FunctionCallee
+#endif
+      c1 = M.getOrInsertFunction("__cmplog_ins_hook1", VoidTy, Int8Ty, Int8Ty,
+                                 Int8Ty
+#if LLVM_VERSION_MAJOR < 5
+                                 ,
+                                 NULL
+#endif
+      );
+#if LLVM_VERSION_MAJOR < 9
+  Function *cmplogHookIns1 = cast<Function>(c1);
+#else
+  FunctionCallee cmplogHookIns1 = c1;
+#endif
+
+#if LLVM_VERSION_MAJOR < 9
+  Constant *
+#else
+  FunctionCallee
+#endif
+      c2 = M.getOrInsertFunction("__cmplog_ins_hook2", VoidTy, Int16Ty, Int16Ty,
+                                 Int8Ty
+#if LLVM_VERSION_MAJOR < 5
+                                 ,
+                                 NULL
+#endif
+      );
+#if LLVM_VERSION_MAJOR < 9
+  Function *cmplogHookIns2 = cast<Function>(c2);
+#else
+  FunctionCallee cmplogHookIns2 = c2;
+#endif
+
+#if LLVM_VERSION_MAJOR < 9
+  Constant *
+#else
+  FunctionCallee
+#endif
+      c4 = M.getOrInsertFunction("__cmplog_ins_hook4", VoidTy, Int32Ty, Int32Ty,
+                                 Int8Ty
+#if LLVM_VERSION_MAJOR < 5
+                                 ,
+                                 NULL
+#endif
+      );
+#if LLVM_VERSION_MAJOR < 9
+  Function *cmplogHookIns4 = cast<Function>(c4);
+#else
+  FunctionCallee cmplogHookIns4 = c4;
+#endif
+
+#if LLVM_VERSION_MAJOR < 9
+  Constant *
+#else
+  FunctionCallee
+#endif
+      c8 = M.getOrInsertFunction("__cmplog_ins_hook8", VoidTy, Int64Ty, Int64Ty,
+                                 Int8Ty
+#if LLVM_VERSION_MAJOR < 5
+                                 ,
+                                 NULL
+#endif
+      );
+#if LLVM_VERSION_MAJOR < 9
+  Function *cmplogHookIns8 = cast<Function>(c8);
+#else
+  FunctionCallee cmplogHookIns8 = c8;
+#endif
+
+  GlobalVariable *AFLCmplogPtr = M.getNamedGlobal("__afl_cmp_map");
+
+  if (!AFLCmplogPtr) {
+
+    AFLCmplogPtr = new GlobalVariable(M, PointerType::get(Int8Ty, 0), false,
+                                      GlobalValue::ExternalWeakLinkage, 0,
+                                      "__afl_cmp_map");
+
+  }
+
+  Constant *Null = Constant::getNullValue(PointerType::get(Int8Ty, 0));
+
+  /* iterate over all functions, bbs and instruction and add suitable calls */
+  for (auto &F : M) {
+
+    if (!isInInstrumentList(&F)) continue;
+
+    for (auto &BB : F) {
+
+      SwitchInst *switchInst = nullptr;
+      if ((switchInst = dyn_cast<SwitchInst>(BB.getTerminator()))) {
+
+        if (switchInst->getNumCases() > 1) { switches.push_back(switchInst); }
+
+      }
+
+    }
+
+  }
+
+  // unique the collected switches
+  switches.erase(Unique(switches.begin(), switches.end()), switches.end());
+
+  // Instrument switch values for cmplog
+  if (switches.size()) {
+
+    if (!be_quiet)
+      errs() << "Hooking " << switches.size() << " switch instructions\n";
+
+    for (auto &SI : switches) {
+
+      Value *       Val = SI->getCondition();
+      unsigned int  max_size = Val->getType()->getIntegerBitWidth(), cast_size;
+      unsigned char do_cast = 0;
+
+      if (!SI->getNumCases() || max_size < 16) {
+
+        // if (!be_quiet) errs() << "skip trivial switch..\n";
+        continue;
+
+      }
+
+      if (max_size % 8) {
+
+        max_size = (((max_size / 8) + 1) * 8);
+        do_cast = 1;
+
+      }
+
+      IRBuilder<> IRB2(SI->getParent());
+      IRB2.SetInsertPoint(SI);
+
+      LoadInst *CmpPtr = IRB2.CreateLoad(AFLCmplogPtr);
+      CmpPtr->setMetadata(M.getMDKindID("nosanitize"), MDNode::get(C, None));
+      auto is_not_null = IRB2.CreateICmpNE(CmpPtr, Null);
+      auto ThenTerm = SplitBlockAndInsertIfThen(is_not_null, SI, false);
+
+      IRBuilder<> IRB(ThenTerm);
+
+      if (max_size > 128) {
+
+        if (!be_quiet) {
+
+          fprintf(stderr,
+                  "Cannot handle this switch bit size: %u (truncating)\n",
+                  max_size);
+
+        }
+
+        max_size = 128;
+        do_cast = 1;
+
+      }
+
+      // do we need to cast?
+      switch (max_size) {
+
+        case 8:
+        case 16:
+        case 32:
+        case 64:
+        case 128:
+          cast_size = max_size;
+          break;
+        default:
+          cast_size = 128;
+          do_cast = 1;
+
+      }
+
+      Value *CompareTo = Val;
+
+      if (do_cast) {
+
+        CompareTo =
+            IRB.CreateIntCast(CompareTo, IntegerType::get(C, cast_size), false);
+
+      }
+
+      for (SwitchInst::CaseIt i = SI->case_begin(), e = SI->case_end(); i != e;
+           ++i) {
+
+#if LLVM_VERSION_MAJOR < 5
+        ConstantInt *cint = i.getCaseValue();
+#else
+        ConstantInt *cint = i->getCaseValue();
+#endif
+
+        if (cint) {
+
+          std::vector<Value *> args;
+          args.push_back(CompareTo);
+
+          Value *new_param = cint;
+
+          if (do_cast) {
+
+            new_param =
+                IRB.CreateIntCast(cint, IntegerType::get(C, cast_size), false);
+
+          }
+
+          if (new_param) {
+
+            args.push_back(new_param);
+            ConstantInt *attribute = ConstantInt::get(Int8Ty, 1);
+            args.push_back(attribute);
+            if (cast_size != max_size) {
+
+              ConstantInt *bitsize =
+                  ConstantInt::get(Int8Ty, (max_size / 8) - 1);
+              args.push_back(bitsize);
+
+            }
+
+            switch (cast_size) {
+
+              case 8:
+                IRB.CreateCall(cmplogHookIns1, args);
+                break;
+              case 16:
+                IRB.CreateCall(cmplogHookIns2, args);
+                break;
+              case 32:
+                IRB.CreateCall(cmplogHookIns4, args);
+                break;
+              case 64:
+                IRB.CreateCall(cmplogHookIns8, args);
+                break;
+              case 128:
+#ifdef WORD_SIZE_64
+                if (max_size == 128) {
+
+                  IRB.CreateCall(cmplogHookIns16, args);
+
+                } else {
+
+                  IRB.CreateCall(cmplogHookInsN, args);
+
+                }
+
+#endif
+                break;
+              default:
+                break;
+
+            }
+
+          }
+
+        }
+
+      }
+
+    }
+
+  }
+
+  if (switches.size())
+    return true;
+  else
+    return false;
+
+}
+
+bool CmpLogInstructions::runOnModule(Module &M) {
+
+  if (getenv("AFL_QUIET") == NULL)
+    printf("Running cmplog-switches-pass by andreafioraldi@gmail.com\n");
+  else
+    be_quiet = 1;
+  hookInstrs(M);
+  verifyModule(M);
+
+  return true;
+
+}
+
+static void registerCmpLogInstructionsPass(const PassManagerBuilder &,
+                                           legacy::PassManagerBase &PM) {
+
+  auto p = new CmpLogInstructions();
+  PM.add(p);
+
+}
+
+static RegisterStandardPasses RegisterCmpLogInstructionsPass(
+    PassManagerBuilder::EP_OptimizerLast, registerCmpLogInstructionsPass);
+
+static RegisterStandardPasses RegisterCmpLogInstructionsPass0(
+    PassManagerBuilder::EP_EnabledOnOptLevel0, registerCmpLogInstructionsPass);
+
+#if LLVM_VERSION_MAJOR >= 11
+static RegisterStandardPasses RegisterCmpLogInstructionsPassLTO(
+    PassManagerBuilder::EP_FullLinkTimeOptimizationLast,
+    registerCmpLogInstructionsPass);
+#endif
+