AddressSanitizer, first commit (compiler module only)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144758 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 967 insertions, 0 deletions

diff --git a/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
new file mode 100644
index 0000000000..e858bccdfb
--- /dev/null
+++ b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -0,0 +1,965 @@
+//===-- AddressSanitizer.cpp - memory error detector ------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of AddressSanitizer, an address sanity checker.
+// Details of the algorithm:
+//  http://code.google.com/p/address-sanitizer/wiki/AddressSanitizerAlgorithm
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "asan"
+
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/OwningPtr.h"
+#include "llvm/ADT/SmallSet.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringExtras.h"
+#include "llvm/Function.h"
+#include "llvm/InlineAsm.h"
+#include "llvm/IntrinsicInst.h"
+#include "llvm/LLVMContext.h"
+#include "llvm/Module.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/DataTypes.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/IRBuilder.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/Regex.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/system_error.h"
+#include "llvm/Target/TargetData.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Transforms/Instrumentation.h"
+#include "llvm/Transforms/Utils/BasicBlockUtils.h"
+#include "llvm/Transforms/Utils/ModuleUtils.h"
+#include "llvm/Type.h"
+
+#include <string>
+#include <algorithm>
+
+using namespace llvm;
+
+static const uint64_t kDefaultShadowScale = 3;
+static const uint64_t kDefaultShadowOffset32 = 1ULL << 29;
+static const uint64_t kDefaultShadowOffset64 = 1ULL << 44;
+
+static const size_t kMaxStackMallocSize = 1 << 16;  // 64K
+static const uintptr_t kCurrentStackFrameMagic = 0x41B58AB3;
+static const uintptr_t kRetiredStackFrameMagic = 0x45E0360E;
+
+static const char *kAsanModuleCtorName = "asan.module_ctor";
+static const char *kAsanReportErrorTemplate = "__asan_report_";
+static const char *kAsanRegisterGlobalsName = "__asan_register_globals";
+static const char *kAsanInitName = "__asan_init";
+static const char *kAsanMappingOffsetName = "__asan_mapping_offset";
+static const char *kAsanMappingScaleName = "__asan_mapping_scale";
+static const char *kAsanStackMallocName = "__asan_stack_malloc";
+static const char *kAsanStackFreeName = "__asan_stack_free";
+
+static const int kAsanStackLeftRedzoneMagic = 0xf1;
+static const int kAsanStackMidRedzoneMagic = 0xf2;
+static const int kAsanStackRightRedzoneMagic = 0xf3;
+static const int kAsanStackPartialRedzoneMagic = 0xf4;
+
+// Command-line flags.
+
+// This flag may need to be replaced with -f[no-]asan-reads.
+static cl::opt<bool> ClInstrumentReads("asan-instrument-reads",
+       cl::desc("instrument read instructions"), cl::Hidden, cl::init(true));
+static cl::opt<bool> ClInstrumentWrites("asan-instrument-writes",
+       cl::desc("instrument write instructions"), cl::Hidden, cl::init(true));
+// This flag may need to be replaced with -f[no]asan-stack.
+static cl::opt<bool> ClStack("asan-stack",
+       cl::desc("Handle stack memory"), cl::Hidden, cl::init(true));
+// This flag may need to be replaced with -f[no]asan-use-after-return.
+static cl::opt<bool> ClUseAfterReturn("asan-use-after-return",
+       cl::desc("Check return-after-free"), cl::Hidden, cl::init(false));
+// This flag may need to be replaced with -f[no]asan-globals.
+static cl::opt<bool> ClGlobals("asan-globals",
+       cl::desc("Handle global objects"), cl::Hidden, cl::init(true));
+static cl::opt<bool> ClMemIntrin("asan-memintrin",
+       cl::desc("Handle memset/memcpy/memmove"), cl::Hidden, cl::init(true));
+// This flag may need to be replaced with -fasan-blacklist.
+static cl::opt<std::string>  ClBlackListFile("asan-blacklist",
+       cl::desc("File containing the list of functions to ignore "
+                "during instrumentation"), cl::Hidden);
+static cl::opt<bool> ClUseCall("asan-use-call",
+       cl::desc("Use function call to generate a crash"), cl::Hidden,
+       cl::init(true));
+
+// These flags allow to change the shadow mapping.
+// The shadow mapping looks like
+//    Shadow = (Mem >> scale) + (1 << offset_log)
+static cl::opt<int> ClMappingScale("asan-mapping-scale",
+       cl::desc("scale of asan shadow mapping"), cl::Hidden, cl::init(0));
+static cl::opt<int> ClMappingOffsetLog("asan-mapping-offset-log",
+       cl::desc("offset of asan shadow mapping"), cl::Hidden, cl::init(-1));
+
+// Optimization flags. Not user visible, used mostly for testing
+// and benchmarking the tool.
+static cl::opt<bool> ClOpt("asan-opt",
+       cl::desc("Optimize instrumentation"), cl::Hidden, cl::init(true));
+static cl::opt<bool> ClOptSameTemp("asan-opt-same-temp",
+       cl::desc("Instrument the same temp just once"), cl::Hidden,
+       cl::init(true));
+static cl::opt<bool> ClOptGlobals("asan-opt-globals",
+       cl::desc("Don't instrument scalar globals"), cl::Hidden, cl::init(true));
+
+// Debug flags.
+static cl::opt<int> ClDebug("asan-debug", cl::desc("debug"), cl::Hidden,
+                            cl::init(0));
+static cl::opt<int> ClDebugStack("asan-debug-stack", cl::desc("debug stack"),
+                                 cl::Hidden, cl::init(0));
+static cl::opt<std::string> ClDebugFunc("asan-debug-func",
+                                        cl::Hidden, cl::desc("Debug func"));
+static cl::opt<int> ClDebugMin("asan-debug-min", cl::desc("Debug min inst"),
+                               cl::Hidden, cl::init(-1));
+static cl::opt<int> ClDebugMax("asan-debug-max", cl::desc("Debug man inst"),
+                               cl::Hidden, cl::init(-1));
+
+namespace {
+
+// Blacklisted functions are not instrumented.
+// The blacklist file contains one or more lines like this:
+// ---
+// fun:FunctionWildCard
+// ---
+// This is similar to the "ignore" feature of ThreadSanitizer.
+// http://code.google.com/p/data-race-test/wiki/ThreadSanitizerIgnores
+class BlackList {
+ public:
+  BlackList(const std::string &Path);
+  bool isIn(const Function &F);
+ private:
+  Regex *Functions;
+};
+
+/// AddressSanitizer: instrument the code in module to find memory bugs.
+struct AddressSanitizer : public ModulePass {
+  AddressSanitizer();
+  void instrumentMop(Instruction *I);
+  void instrumentAddress(Instruction *OrigIns, IRBuilder<> &IRB,
+                         Value *Addr, uint32_t TypeSize, bool IsWrite);
+  Instruction *generateCrashCode(IRBuilder<> &IRB, Value *Addr,
+                                 bool IsWrite, uint32_t TypeSize);
+  bool instrumentMemIntrinsic(MemIntrinsic *MI);
+  void instrumentMemIntrinsicParam(Instruction *OrigIns, Value *Addr,
+                                  Value *Size,
+                                   Instruction *InsertBefore, bool IsWrite);
+  Value *memToShadow(Value *Shadow, IRBuilder<> &IRB);
+  bool handleFunction(Module &M, Function &F);
+  bool poisonStackInFunction(Module &M, Function &F);
+  virtual bool runOnModule(Module &M);
+  bool insertGlobalRedzones(Module &M);
+  BranchInst *splitBlockAndInsertIfThen(Instruction *SplitBefore, Value *Cmp);
+  static char ID;  // Pass identification, replacement for typeid
+
+ private:
+
+  uint64_t getAllocaSizeInBytes(AllocaInst *AI) {
+    Type *Ty = AI->getAllocatedType();
+    uint64_t SizeInBytes = TD->getTypeStoreSizeInBits(Ty) / 8;
+    return SizeInBytes;
+  }
+  uint64_t getAlignedSize(uint64_t SizeInBytes) {
+    return ((SizeInBytes + RedzoneSize - 1)
+            / RedzoneSize) * RedzoneSize;
+  }
+  uint64_t getAlignedAllocaSize(AllocaInst *AI) {
+    uint64_t SizeInBytes = getAllocaSizeInBytes(AI);
+    return getAlignedSize(SizeInBytes);
+  }
+
+  void PoisonStack(const ArrayRef<AllocaInst*> &AllocaVec, IRBuilder<> IRB,
+                   Value *ShadowBase, bool DoPoison);
+
+  Module      *CurrentModule;
+  LLVMContext *C;
+  TargetData *TD;
+  uint64_t MappingOffset;
+  int MappingScale;
+  size_t RedzoneSize;
+  int LongSize;
+  Type *IntptrTy;
+  Type *IntptrPtrTy;
+  Function *AsanCtorFunction;
+  Function *AsanInitFunction;
+  Instruction *CtorInsertBefore;
+  OwningPtr<BlackList> BL;
+};
+}  // namespace
+
+char AddressSanitizer::ID = 0;
+INITIALIZE_PASS(AddressSanitizer, "asan",
+    "AddressSanitizer: detects use-after-free and out-of-bounds bugs.",
+    false, false)
+AddressSanitizer::AddressSanitizer() : ModulePass(ID) { }
+ModulePass *llvm::createAddressSanitizerPass() {
+  return new AddressSanitizer();
+}
+
+// Create a constant for Str so that we can pass it to the run-time lib.
+static GlobalVariable *createPrivateGlobalForString(Module &M, StringRef Str) {
+  Constant *StrConst = ConstantArray::get(M.getContext(), Str);
+  return new GlobalVariable(M, StrConst->getType(), true,
+                            GlobalValue::PrivateLinkage, StrConst, "");
+}
+
+// Split the basic block and insert an if-then code.
+// Before:
+//   Head
+//   SplitBefore
+//   Tail
+// After:
+//   Head
+//   if (Cmp)
+//     NewBasicBlock
+//   SplitBefore
+//   Tail
+//
+// Returns the NewBasicBlock's terminator.
+BranchInst *AddressSanitizer::splitBlockAndInsertIfThen(
+    Instruction *SplitBefore, Value *Cmp) {
+  BasicBlock *Head = SplitBefore->getParent();
+  BasicBlock *Tail = Head->splitBasicBlock(SplitBefore);
+  TerminatorInst *HeadOldTerm = Head->getTerminator();
+  BasicBlock *NewBasicBlock =
+      BasicBlock::Create(*C, "", Head->getParent());
+  BranchInst *HeadNewTerm = BranchInst::Create(/*ifTrue*/NewBasicBlock,
+                                               /*ifFalse*/Tail,
+                                               Cmp);
+  ReplaceInstWithInst(HeadOldTerm, HeadNewTerm);
+
+  BranchInst *CheckTerm = BranchInst::Create(Tail, NewBasicBlock);
+  return CheckTerm;
+}
+
+Value *AddressSanitizer::memToShadow(Value *Shadow, IRBuilder<> &IRB) {
+  // Shadow >> scale
+  Shadow = IRB.CreateLShr(Shadow, MappingScale);
+  if (MappingOffset == 0)
+    return Shadow;
+  // (Shadow >> scale) | offset
+  return IRB.CreateOr(Shadow, ConstantInt::get(IntptrTy,
+                                               MappingOffset));
+}
+
+void AddressSanitizer::instrumentMemIntrinsicParam(Instruction *OrigIns,
+    Value *Addr, Value *Size, Instruction *InsertBefore, bool IsWrite) {
+  // Check the first byte.
+  {
+    IRBuilder<> IRB(InsertBefore);
+    instrumentAddress(OrigIns, IRB, Addr, 8, IsWrite);
+  }
+  // Check the last byte.
+  {
+    IRBuilder<> IRB(InsertBefore);
+    Value *SizeMinusOne = IRB.CreateSub(
+        Size, ConstantInt::get(Size->getType(), 1));
+    SizeMinusOne = IRB.CreateIntCast(SizeMinusOne, IntptrTy, false);
+    Value *AddrLong = IRB.CreatePointerCast(Addr, IntptrTy);
+    Value *AddrPlusSizeMinisOne = IRB.CreateAdd(AddrLong, SizeMinusOne);
+    instrumentAddress(OrigIns, IRB, AddrPlusSizeMinisOne, 8, IsWrite);
+  }
+}
+
+// Instrument memset/memmove/memcpy
+bool AddressSanitizer::instrumentMemIntrinsic(MemIntrinsic *MI) {
+  Value *Dst = MI->getDest();
+  MemTransferInst *MemTran = dyn_cast<MemTransferInst>(MI);
+  Value *Src = MemTran ? MemTran->getSource() : NULL;
+  Value *Length = MI->getLength();
+
+  Constant *ConstLength = dyn_cast<Constant>(Length);
+  Instruction *InsertBefore = MI;
+  if (ConstLength) {
+    if (ConstLength->isNullValue()) return false;
+  } else {
+    // The size is not a constant so it could be zero -- check at run-time.
+    IRBuilder<> IRB(InsertBefore);
+
+    Value *Cmp = IRB.CreateICmpNE(Length,
+                                   Constant::getNullValue(Length->getType()));
+    InsertBefore = splitBlockAndInsertIfThen(InsertBefore, Cmp);
+  }
+
+  instrumentMemIntrinsicParam(MI, Dst, Length, InsertBefore, true);
+  if (Src)
+    instrumentMemIntrinsicParam(MI, Src, Length, InsertBefore, false);
+  return true;
+}
+
+static Value *getLDSTOperand(Instruction *I) {
+  if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
+    return LI->getPointerOperand();
+  }
+  return cast<StoreInst>(*I).getPointerOperand();
+}
+
+void AddressSanitizer::instrumentMop(Instruction *I) {
+  int IsWrite = isa<StoreInst>(*I);
+  Value *Addr = getLDSTOperand(I);
+  if (ClOpt && ClOptGlobals && isa<GlobalVariable>(Addr)) {
+    // We are accessing a global scalar variable. Nothing to catch here.
+    return;
+  }
+  Type *OrigPtrTy = Addr->getType();
+  Type *OrigTy = cast<PointerType>(OrigPtrTy)->getElementType();
+
+  assert(OrigTy->isSized());
+  uint32_t TypeSize = TD->getTypeStoreSizeInBits(OrigTy);
+
+  if (TypeSize != 8  && TypeSize != 16 &&
+      TypeSize != 32 && TypeSize != 64 && TypeSize != 128) {
+    // Ignore all unusual sizes.
+    return;
+  }
+
+  IRBuilder<> IRB(I);
+  instrumentAddress(I, IRB, Addr, TypeSize, IsWrite);
+}
+
+Instruction *AddressSanitizer::generateCrashCode(
+    IRBuilder<> &IRB, Value *Addr, bool IsWrite, uint32_t TypeSize) {
+
+  if (ClUseCall) {
+    // Here we use a call instead of arch-specific asm to report an error.
+    // This is almost always slower (because the codegen needs to generate
+    // prologue/epilogue for otherwise leaf functions) and generates more code.
+    // This mode could be useful if we can not use SIGILL for some reason.
+    //
+    // IsWrite and TypeSize are encoded in the function name.
+    std::string FunctionName = std::string(kAsanReportErrorTemplate) +
+        (IsWrite ? "store" : "load") + itostr(TypeSize / 8);
+    Value *ReportWarningFunc = CurrentModule->getOrInsertFunction(
+        FunctionName, IRB.getVoidTy(), IntptrTy, NULL);
+    CallInst *Call = IRB.CreateCall(ReportWarningFunc, Addr);
+    Call->setDoesNotReturn();
+    return Call;
+  }
+
+  uint32_t LogOfSizeInBytes = CountTrailingZeros_32(TypeSize / 8);
+  assert(8U * (1 << LogOfSizeInBytes) == TypeSize);
+  uint8_t TelltaleValue = IsWrite * 8 + LogOfSizeInBytes;
+  assert(TelltaleValue < 16);
+
+  // Move the failing address to %rax/%eax
+  FunctionType *Fn1Ty = FunctionType::get(
+      IRB.getVoidTy(), ArrayRef<Type*>(IntptrTy), false);
+  const char *MovStr = LongSize == 32
+      ? "mov $0, %eax" : "mov $0, %rax";
+  Value *AsmMov = InlineAsm::get(
+      Fn1Ty, StringRef(MovStr), StringRef("r"), true);
+  IRB.CreateCall(AsmMov, Addr);
+
+  // crash with ud2; could use int3, but it is less friendly to gdb.
+  // after ud2 put a 1-byte instruction that encodes the access type and size.
+
+  const char *TelltaleInsns[16] = {
+    "push   %eax",  // 0x50
+    "push   %ecx",  // 0x51
+    "push   %edx",  // 0x52
+    "push   %ebx",  // 0x53
+    "push   %esp",  // 0x54
+    "push   %ebp",  // 0x55
+    "push   %esi",  // 0x56
+    "push   %edi",  // 0x57
+    "pop    %eax",  // 0x58
+    "pop    %ecx",  // 0x59
+    "pop    %edx",  // 0x5a
+    "pop    %ebx",  // 0x5b
+    "pop    %esp",  // 0x5c
+    "pop    %ebp",  // 0x5d
+    "pop    %esi",  // 0x5e
+    "pop    %edi"   // 0x5f
+  };
+
+  std::string AsmStr = "ud2;";
+  AsmStr += TelltaleInsns[TelltaleValue];
+  Value *MyAsm = InlineAsm::get(FunctionType::get(Type::getVoidTy(*C), false),
+                                StringRef(AsmStr), StringRef(""), true);
+  CallInst *AsmCall = IRB.CreateCall(MyAsm);
+
+  // This saves us one jump, but triggers a bug in RA (or somewhere else):
+  // while building 483.xalancbmk the compiler goes into infinite loop in
+  // llvm::SpillPlacement::iterate() / RAGreedy::growRegion
+  // AsmCall->setDoesNotReturn();
+  return AsmCall;
+}
+
+void AddressSanitizer::instrumentAddress(Instruction *OrigIns,
+                                         IRBuilder<> &IRB, Value *Addr,
+                                         uint32_t TypeSize, bool IsWrite) {
+  Value *AddrLong = IRB.CreatePointerCast(Addr, IntptrTy);
+
+  Type *ShadowTy  = IntegerType::get(
+      *C, std::max(8U, TypeSize >> MappingScale));
+  Type *ShadowPtrTy = PointerType::get(ShadowTy, 0);
+  Value *ShadowPtr = memToShadow(AddrLong, IRB);
+  Value *CmpVal = Constant::getNullValue(ShadowTy);
+  Value *ShadowValue = IRB.CreateLoad(
+      IRB.CreateIntToPtr(ShadowPtr, ShadowPtrTy));
+
+  Value *Cmp = IRB.CreateICmpNE(ShadowValue, CmpVal);
+
+  Instruction *CheckTerm = splitBlockAndInsertIfThen(
+      cast<Instruction>(Cmp)->getNextNode(), Cmp);
+  IRBuilder<> IRB2(CheckTerm);
+
+  size_t Granularity = 1 << MappingScale;
+  if (TypeSize < 8 * Granularity) {
+    // Addr & (Granularity - 1)
+    Value *Lower3Bits = IRB2.CreateAnd(
+        AddrLong, ConstantInt::get(IntptrTy, Granularity - 1));
+    // (Addr & (Granularity - 1)) + size - 1
+    Value *LastAccessedByte = IRB2.CreateAdd(
+        Lower3Bits, ConstantInt::get(IntptrTy, TypeSize / 8 - 1));
+    // (uint8_t) ((Addr & (Granularity-1)) + size - 1)
+    LastAccessedByte = IRB2.CreateIntCast(
+        LastAccessedByte, IRB.getInt8Ty(), false);
+    // ((uint8_t) ((Addr & (Granularity-1)) + size - 1)) >= ShadowValue
+    Value *Cmp2 = IRB2.CreateICmpSGE(LastAccessedByte, ShadowValue);
+
+    CheckTerm = splitBlockAndInsertIfThen(CheckTerm, Cmp2);
+  }
+
+  IRBuilder<> IRB1(CheckTerm);
+  Instruction *Crash = generateCrashCode(IRB1, AddrLong, IsWrite, TypeSize);
+  Crash->setDebugLoc(OrigIns->getDebugLoc());
+}
+
+// This function replaces all global variables with new variables that have
+// trailing redzones. It also creates a function that poisons
+// redzones and inserts this function into llvm.global_ctors.
+bool AddressSanitizer::insertGlobalRedzones(Module &M) {
+  SmallVector<GlobalVariable *, 16> GlobalsToChange;
+
+  for (Module::GlobalListType::iterator G = M.getGlobalList().begin(),
+       E = M.getGlobalList().end(); G != E; ++G) {
+    Type *Ty = cast<PointerType>(G->getType())->getElementType();
+    DEBUG(dbgs() << "GLOBAL: " << *G);
+
+    if (!Ty->isSized()) continue;
+    if (!G->hasInitializer()) continue;
+    if (GlobalVariable::mayBeOverridden(G->getLinkage()) ||
+        G->getLinkage() == GlobalVariable::AppendingLinkage)
+      continue;
+    // For now, just ignore this Alloca if the alignment is large.
+    if (G->getAlignment() > RedzoneSize) continue;
+
+    // Ignore all the globals with the names starting with "\01L_OBJC_".
+    // Many of those are put into the .cstring section. The linker compresses
+    // that section by removing the spare \0s after the string terminator, so
+    // our redzones get broken.
+    if ((G->getName().find("\01L_OBJC_") == 0) ||
+        (G->getName().find("\01l_OBJC_") == 0)) {
+      DEBUG(dbgs() << "Ignoring \\01L_OBJC_* global: " << *G);
+      continue;
+    }
+
+    // Ignore the globals from the __OBJC section. The ObjC runtime assumes
+    // those conform to /usr/lib/objc/runtime.h, so we can't add redzones to
+    // them.
+    if (G->hasSection()) {
+      StringRef Section(G->getSection());
+      if ((Section.find("__OBJC,") == 0) ||
+          (Section.find("__DATA, __objc_") == 0)) {
+        DEBUG(dbgs() << "Ignoring ObjC runtime global: " << *G);
+        continue;
+      }
+    }
+
+    GlobalsToChange.push_back(G);
+  }
+
+  size_t n = GlobalsToChange.size();
+  if (n == 0) return false;
+
+  // A global is described by a structure
+  //   size_t beg;
+  //   size_t size;
+  //   size_t size_with_redzone;
+  //   const char *name;
+  // We initialize an array of such structures and pass it to a run-time call.
+  StructType *GlobalStructTy = StructType::get(IntptrTy, IntptrTy,
+                                               IntptrTy, IntptrTy, NULL);
+  SmallVector<Constant *, 16> Initializers(n);
+
+  IRBuilder<> IRB(CtorInsertBefore);
+
+  for (size_t i = 0; i < n; i++) {
+    GlobalVariable *G = GlobalsToChange[i];
+    PointerType *PtrTy = cast<PointerType>(G->getType());
+    Type *Ty = PtrTy->getElementType();
+    uint64_t SizeInBytes = TD->getTypeStoreSizeInBits(Ty) / 8;
+    uint64_t RightRedzoneSize = RedzoneSize +
+        (RedzoneSize - (SizeInBytes % RedzoneSize));
+    Type *RightRedZoneTy = ArrayType::get(IRB.getInt8Ty(), RightRedzoneSize);
+
+    StructType *NewTy = StructType::get(Ty, RightRedZoneTy, NULL);
+    Constant *NewInitializer = ConstantStruct::get(
+        NewTy, G->getInitializer(),
+        Constant::getNullValue(RightRedZoneTy), NULL);
+
+    GlobalVariable *Name = createPrivateGlobalForString(M, G->getName());
+
+    // Create a new global variable with enough space for a redzone.
+    GlobalVariable *NewGlobal = new GlobalVariable(
+        M, NewTy, G->isConstant(), G->getLinkage(),
+        NewInitializer, "", G, G->isThreadLocal());
+    NewGlobal->copyAttributesFrom(G);
+    NewGlobal->setAlignment(RedzoneSize);
+
+    Value *Indices2[2];
+    Indices2[0] = IRB.getInt32(0);
+    Indices2[1] = IRB.getInt32(0);
+
+    G->replaceAllUsesWith(
+        ConstantExpr::getGetElementPtr(NewGlobal, Indices2, 2));
+    NewGlobal->takeName(G);
+    G->eraseFromParent();
+
+    Initializers[i] = ConstantStruct::get(
+        GlobalStructTy,
+        ConstantExpr::getPointerCast(NewGlobal, IntptrTy),
+        ConstantInt::get(IntptrTy, SizeInBytes),
+        ConstantInt::get(IntptrTy, SizeInBytes + RightRedzoneSize),
+        ConstantExpr::getPointerCast(Name, IntptrTy),
+        NULL);
+    DEBUG(dbgs() << "NEW GLOBAL:\n" << *NewGlobal);
+  }
+
+  ArrayType *ArrayOfGlobalStructTy = ArrayType::get(GlobalStructTy, n);
+  GlobalVariable *AllGlobals = new GlobalVariable(
+      M, ArrayOfGlobalStructTy, false, GlobalVariable::PrivateLinkage,
+      ConstantArray::get(ArrayOfGlobalStructTy, Initializers), "");
+
+  Function *AsanRegisterGlobals = cast<Function>(M.getOrInsertFunction(
+      kAsanRegisterGlobalsName, IRB.getVoidTy(), IntptrTy, IntptrTy, NULL));
+  AsanRegisterGlobals->setLinkage(Function::ExternalLinkage);
+
+  IRB.CreateCall2(AsanRegisterGlobals,
+                  IRB.CreatePointerCast(AllGlobals, IntptrTy),
+                  ConstantInt::get(IntptrTy, n));
+
+  DEBUG(dbgs() << M);
+  return true;
+}
+
+// virtual
+bool AddressSanitizer::runOnModule(Module &M) {
+  // Initialize the private fields. No one has accessed them before.
+  TD = getAnalysisIfAvailable<TargetData>();
+  if (!TD)
+    return false;
+  BL.reset(new BlackList(ClBlackListFile));
+
+  CurrentModule = &M;
+  C = &(M.getContext());
+  LongSize = TD->getPointerSizeInBits();
+  IntptrTy = Type::getIntNTy(*C, LongSize);
+  IntptrPtrTy = PointerType::get(IntptrTy, 0);
+
+  AsanCtorFunction = Function::Create(
+      FunctionType::get(Type::getVoidTy(*C), false),
+      GlobalValue::InternalLinkage, kAsanModuleCtorName, &M);
+  BasicBlock *AsanCtorBB = BasicBlock::Create(*C, "", AsanCtorFunction);
+  CtorInsertBefore = ReturnInst::Create(*C, AsanCtorBB);
+
+  // call __asan_init in the module ctor.
+  IRBuilder<> IRB(CtorInsertBefore);
+  AsanInitFunction = cast<Function>(
+      M.getOrInsertFunction(kAsanInitName, IRB.getVoidTy(), NULL));
+  AsanInitFunction->setLinkage(Function::ExternalLinkage);
+  IRB.CreateCall(AsanInitFunction);
+
+  MappingOffset = LongSize == 32
+      ? kDefaultShadowOffset32 : kDefaultShadowOffset64;
+  if (ClMappingOffsetLog >= 0) {
+    if (ClMappingOffsetLog == 0) {
+      // special case
+      MappingOffset = 0;
+    } else {
+      MappingOffset = 1ULL << ClMappingOffsetLog;
+    }
+  }
+  MappingScale = kDefaultShadowScale;
+  if (ClMappingScale) {
+    MappingScale = ClMappingScale;
+  }
+  // Redzone used for stack and globals is at least 32 bytes.
+  // For scales 6 and 7, the redzone has to be 64 and 128 bytes respectively.
+  RedzoneSize = std::max(32, (int)(1 << MappingScale));
+
+  bool Res = false;
+
+  if (ClGlobals)
+    Res |= insertGlobalRedzones(M);
+
+  // Tell the run-time the current values of mapping offset and scale.
+  GlobalValue *asan_mapping_offset =
+      new GlobalVariable(M, IntptrTy, true, GlobalValue::LinkOnceODRLinkage,
+                     ConstantInt::get(IntptrTy, MappingOffset),
+                     kAsanMappingOffsetName);
+  GlobalValue *asan_mapping_scale =
+      new GlobalVariable(M, IntptrTy, true, GlobalValue::LinkOnceODRLinkage,
+                         ConstantInt::get(IntptrTy, MappingScale),
+                         kAsanMappingScaleName);
+  // Read these globals, otherwise they may be optimized away.
+  IRB.CreateLoad(asan_mapping_scale, true);
+  IRB.CreateLoad(asan_mapping_offset, true);
+
+
+  for (Module::iterator F = M.begin(), E = M.end(); F != E; ++F) {
+    if (F->isDeclaration()) continue;
+    Res |= handleFunction(M, *F);
+  }
+
+  appendToGlobalCtors(M, AsanCtorFunction, 1 /*high priority*/);
+
+  return Res;
+}
+
+bool AddressSanitizer::handleFunction(Module &M, Function &F) {
+  if (BL->isIn(F)) return false;
+  if (&F == AsanCtorFunction) return false;
+
+  if (!ClDebugFunc.empty() && ClDebugFunc != F.getName())
+    return false;
+  // We want to instrument every address only once per basic block
+  // (unless there are calls between uses).
+  SmallSet<Value*, 16> TempsToInstrument;
+  SmallVector<Instruction*, 16> ToInstrument;
+
+  // Fill the set of memory operations to instrument.
+  for (Function::iterator FI = F.begin(), FE = F.end();
+       FI != FE; ++FI) {
+    TempsToInstrument.clear();
+    for (BasicBlock::iterator BI = FI->begin(), BE = FI->end();
+         BI != BE; ++BI) {
+      if ((isa<LoadInst>(BI) && ClInstrumentReads) ||
+          (isa<StoreInst>(BI) && ClInstrumentWrites)) {
+        Value *Addr = getLDSTOperand(BI);
+        if (ClOpt && ClOptSameTemp) {
+          if (!TempsToInstrument.insert(Addr))
+            continue;  // We've seen this temp in the current BB.
+        }
+      } else if (isa<MemIntrinsic>(BI) && ClMemIntrin) {
+        // ok, take it.
+      } else {
+        if (isa<CallInst>(BI)) {
+          // A call inside BB.
+          TempsToInstrument.clear();
+        }
+        continue;
+      }
+      ToInstrument.push_back(BI);
+    }
+  }
+
+  // Instrument.
+  int NumInstrumented = 0;
+  for (size_t i = 0, n = ToInstrument.size(); i != n; i++) {
+    Instruction *Inst = ToInstrument[i];
+    if (ClDebugMin < 0 || ClDebugMax < 0 ||
+        (NumInstrumented >= ClDebugMin && NumInstrumented <= ClDebugMax)) {
+      if (isa<StoreInst>(Inst) || isa<LoadInst>(Inst))
+        instrumentMop(Inst);
+      else
+        instrumentMemIntrinsic(cast<MemIntrinsic>(Inst));
+    }
+    NumInstrumented++;
+  }
+
+  DEBUG(dbgs() << F);
+
+  bool ChangedStack = poisonStackInFunction(M, F);
+
+  // For each NSObject descendant having a +load method, this method is invoked
+  // by the ObjC runtime before any of the static constructors is called.
+  // Therefore we need to instrument such methods with a call to __asan_init
+  // at the beginning in order to initialize our runtime before any access to
+  // the shadow memory.
+  // We cannot just ignore these methods, because they may call other
+  // instrumented functions.
+  if (F.getName().find(" load]") != std::string::npos) {
+    IRBuilder<> IRB(F.begin()->begin());
+    IRB.CreateCall(AsanInitFunction);
+  }
+
+  return NumInstrumented > 0 || ChangedStack;
+}
+
+static uint64_t ValueForPoison(uint64_t PoisonByte, size_t ShadowRedzoneSize) {
+  if (ShadowRedzoneSize == 1) return PoisonByte;
+  if (ShadowRedzoneSize == 2) return (PoisonByte << 8) + PoisonByte;
+  if (ShadowRedzoneSize == 4)
+    return (PoisonByte << 24) + (PoisonByte << 16) +
+        (PoisonByte << 8) + (PoisonByte);
+  assert(0 && "ShadowRedzoneSize is either 1, 2 or 4");
+  return 0;
+}
+
+static void PoisonShadowPartialRightRedzone(uint8_t *Shadow,
+                                            size_t Size,
+                                            size_t RedzoneSize,
+                                            size_t ShadowGranularity,
+                                            uint8_t Magic) {
+  for (size_t i = 0; i < RedzoneSize;
+       i+= ShadowGranularity, Shadow++) {
+    if (i + ShadowGranularity <= Size) {
+      *Shadow = 0;  // fully addressable
+    } else if (i >= Size) {
+      *Shadow = Magic;  // unaddressable
+    } else {
+      *Shadow = Size - i;  // first Size-i bytes are addressable
+    }
+  }
+}
+
+void AddressSanitizer::PoisonStack(const ArrayRef<AllocaInst*> &AllocaVec,
+                                   IRBuilder<> IRB,
+                                   Value *ShadowBase, bool DoPoison) {
+  size_t ShadowRZSize = RedzoneSize >> MappingScale;
+  assert(ShadowRZSize >= 1 && ShadowRZSize <= 4);
+  Type *RZTy = Type::getIntNTy(*C, ShadowRZSize * 8);
+  Type *RZPtrTy = PointerType::get(RZTy, 0);
+
+  Value *PoisonLeft  = ConstantInt::get(RZTy,
+    ValueForPoison(DoPoison ? kAsanStackLeftRedzoneMagic : 0LL, ShadowRZSize));
+  Value *PoisonMid   = ConstantInt::get(RZTy,
+    ValueForPoison(DoPoison ? kAsanStackMidRedzoneMagic : 0LL, ShadowRZSize));
+  Value *PoisonRight = ConstantInt::get(RZTy,
+    ValueForPoison(DoPoison ? kAsanStackRightRedzoneMagic : 0LL, ShadowRZSize));
+
+  // poison the first red zone.
+  IRB.CreateStore(PoisonLeft, IRB.CreateIntToPtr(ShadowBase, RZPtrTy));
+
+  // poison all other red zones.
+  uint64_t Pos = RedzoneSize;
+  for (size_t i = 0, n = AllocaVec.size(); i < n; i++) {
+    AllocaInst *AI = AllocaVec[i];
+    uint64_t SizeInBytes = getAllocaSizeInBytes(AI);
+    uint64_t AlignedSize = getAlignedAllocaSize(AI);
+    assert(AlignedSize - SizeInBytes < RedzoneSize);
+    Value *Ptr = NULL;
+
+    Pos += AlignedSize;
+
+    assert(ShadowBase->getType() == IntptrTy);
+    if (SizeInBytes < AlignedSize) {
+      // Poison the partial redzone at right
+      Ptr = IRB.CreateAdd(
+          ShadowBase, ConstantInt::get(IntptrTy,
+                                       (Pos >> MappingScale) - ShadowRZSize));
+      size_t AddressableBytes = RedzoneSize - (AlignedSize - SizeInBytes);
+      uint32_t Poison = 0;
+      if (DoPoison) {
+        PoisonShadowPartialRightRedzone((uint8_t*)&Poison, AddressableBytes,
+                                        RedzoneSize,
+                                        1ULL << MappingScale,
+                                        kAsanStackPartialRedzoneMagic);
+      }
+      Value *PartialPoison = ConstantInt::get(RZTy, Poison);
+      IRB.CreateStore(PartialPoison, IRB.CreateIntToPtr(Ptr, RZPtrTy));
+    }
+
+    // Poison the full redzone at right.
+    Ptr = IRB.CreateAdd(ShadowBase,
+                        ConstantInt::get(IntptrTy, Pos >> MappingScale));
+    Value *Poison = i == AllocaVec.size() - 1 ? PoisonRight : PoisonMid;
+    IRB.CreateStore(Poison, IRB.CreateIntToPtr(Ptr, RZPtrTy));
+
+    Pos += RedzoneSize;
+  }
+}
+
+// Find all static Alloca instructions and put
+// poisoned red zones around all of them.
+// Then unpoison everything back before the function returns.
+//
+// Stack poisoning does not play well with exception handling.
+// When an exception is thrown, we essentially bypass the code
+// that unpoisones the stack. This is why the run-time library has
+// to intercept __cxa_throw (as well as longjmp, etc) and unpoison the entire
+// stack in the interceptor. This however does not work inside the
+// actual function which catches the exception. Most likely because the
+// compiler hoists the load of the shadow value somewhere too high.
+// This causes asan to report a non-existing bug on 453.povray.
+// It sounds like an LLVM bug.
+bool AddressSanitizer::poisonStackInFunction(Module &M, Function &F) {
+  if (!ClStack) return false;
+  SmallVector<AllocaInst*, 16> AllocaVec;
+  SmallVector<Instruction*, 8> RetVec;
+  uint64_t TotalSize = 0;
+
+  // Filter out Alloca instructions we want (and can) handle.
+  // Collect Ret instructions.
+  for (Function::iterator FI = F.begin(), FE = F.end();
+       FI != FE; ++FI) {
+    BasicBlock &BB = *FI;
+    for (BasicBlock::iterator BI = BB.begin(), BE = BB.end();
+         BI != BE; ++BI) {
+      if (isa<ReturnInst>(BI)) {
+          RetVec.push_back(BI);
+          continue;
+      }
+
+      AllocaInst *AI = dyn_cast<AllocaInst>(BI);
+      if (!AI) continue;
+      if (AI->isArrayAllocation()) continue;
+      if (!AI->isStaticAlloca()) continue;
+      if (!AI->getAllocatedType()->isSized()) continue;
+      if (AI->getAlignment() > RedzoneSize) continue;
+      AllocaVec.push_back(AI);
+      uint64_t AlignedSize =  getAlignedAllocaSize(AI);
+      TotalSize += AlignedSize;
+    }
+  }
+
+  if (AllocaVec.empty()) return false;
+
+  uint64_t LocalStackSize = TotalSize + (AllocaVec.size() + 1) * RedzoneSize;
+
+  bool DoStackMalloc = ClUseAfterReturn
+      && LocalStackSize <= kMaxStackMallocSize;
+
+  Instruction *InsBefore = AllocaVec[0];
+  IRBuilder<> IRB(InsBefore);
+
+
+  Type *ByteArrayTy = ArrayType::get(IRB.getInt8Ty(), LocalStackSize);
+  AllocaInst *MyAlloca =
+      new AllocaInst(ByteArrayTy, "MyAlloca", InsBefore);
+  MyAlloca->setAlignment(RedzoneSize);
+  assert(MyAlloca->isStaticAlloca());
+  Value *OrigStackBase = IRB.CreatePointerCast(MyAlloca, IntptrTy);
+  Value *LocalStackBase = OrigStackBase;
+
+  if (DoStackMalloc) {
+    Value *AsanStackMallocFunc = M.getOrInsertFunction(
+        kAsanStackMallocName, IntptrTy, IntptrTy, IntptrTy, NULL);
+    LocalStackBase = IRB.CreateCall2(AsanStackMallocFunc,
+        ConstantInt::get(IntptrTy, LocalStackSize), OrigStackBase);
+  }
+
+  // This string will be parsed by the run-time (DescribeStackAddress).
+  SmallString<2048> StackDescriptionStorage;
+  raw_svector_ostream StackDescription(StackDescriptionStorage);
+  StackDescription << F.getName() << " " << AllocaVec.size() << " ";
+
+  uint64_t Pos = RedzoneSize;
+  // Replace Alloca instructions with base+offset.
+  for (size_t i = 0, n = AllocaVec.size(); i < n; i++) {
+    AllocaInst *AI = AllocaVec[i];
+    uint64_t SizeInBytes = getAllocaSizeInBytes(AI);
+    StringRef Name = AI->getName();
+    StackDescription << Pos << " " << SizeInBytes << " "
+                     << Name.size() << " " << Name << " ";
+    uint64_t AlignedSize = getAlignedAllocaSize(AI);
+    assert((AlignedSize % RedzoneSize) == 0);
+    AI->replaceAllUsesWith(
+        IRB.CreateIntToPtr(
+            IRB.CreateAdd(LocalStackBase, ConstantInt::get(IntptrTy, Pos)),
+            AI->getType()));
+    Pos += AlignedSize + RedzoneSize;
+  }
+  assert(Pos == LocalStackSize);
+
+  // Write the Magic value and the frame description constant to the redzone.
+  Value *BasePlus0 = IRB.CreateIntToPtr(LocalStackBase, IntptrPtrTy);
+  IRB.CreateStore(ConstantInt::get(IntptrTy, kCurrentStackFrameMagic),
+                  BasePlus0);
+  Value *BasePlus1 = IRB.CreateAdd(LocalStackBase,
+                                   ConstantInt::get(IntptrTy, LongSize/8));
+  BasePlus1 = IRB.CreateIntToPtr(BasePlus1, IntptrPtrTy);
+  Value *Description = IRB.CreatePointerCast(
+      createPrivateGlobalForString(M, StackDescription.str()),
+      IntptrTy);
+  IRB.CreateStore(Description, BasePlus1);
+
+  // Poison the stack redzones at the entry.
+  Value *ShadowBase = memToShadow(LocalStackBase, IRB);
+  PoisonStack(ArrayRef<AllocaInst*>(AllocaVec), IRB, ShadowBase, true);
+
+  Value *AsanStackFreeFunc = NULL;
+  if (DoStackMalloc) {
+    AsanStackFreeFunc = M.getOrInsertFunction(
+        kAsanStackFreeName, IRB.getVoidTy(),
+        IntptrTy, IntptrTy, IntptrTy, NULL);
+  }
+
+  // Unpoison the stack before all ret instructions.
+  for (size_t i = 0, n = RetVec.size(); i < n; i++) {
+    Instruction *Ret = RetVec[i];
+    IRBuilder<> IRBRet(Ret);
+
+    // Mark the current frame as retired.
+    IRBRet.CreateStore(ConstantInt::get(IntptrTy, kRetiredStackFrameMagic),
+                       BasePlus0);
+    // Unpoison the stack.
+    PoisonStack(ArrayRef<AllocaInst*>(AllocaVec), IRBRet, ShadowBase, false);
+
+    if (DoStackMalloc) {
+      IRBRet.CreateCall3(AsanStackFreeFunc, LocalStackBase,
+                         ConstantInt::get(IntptrTy, LocalStackSize),
+                         OrigStackBase);
+    }
+  }
+
+  if (ClDebugStack) {
+    DEBUG(dbgs() << F);
+  }
+
+  return true;
+}
+
+BlackList::BlackList(const std::string &Path) {
+  Functions = NULL;
+  const char *kFunPrefix = "fun:";
+  if (!ClBlackListFile.size()) return;
+  std::string Fun;
+
+  OwningPtr<MemoryBuffer> File;
+  if (error_code EC = MemoryBuffer::getFile(ClBlackListFile.c_str(), File)) {
+    errs() << EC.message();
+    exit(1);
+  }
+  MemoryBuffer *Buff = File.take();
+  const char *Data = Buff->getBufferStart();
+  size_t DataLen = Buff->getBufferSize();
+  SmallVector<StringRef, 16> Lines;
+  SplitString(StringRef(Data, DataLen), Lines, "\n\r");
+  for (size_t i = 0, numLines = Lines.size(); i < numLines; i++) {
+    if (Lines[i].startswith(kFunPrefix)) {
+      std::string ThisFunc = Lines[i].substr(strlen(kFunPrefix));
+      if (Fun.size()) {
+        Fun += "|";
+      }
+      // add ThisFunc replacing * with .*
+      for (size_t j = 0, n = ThisFunc.size(); j < n; j++) {
+        if (ThisFunc[j] == '*')
+          Fun += '.';
+        Fun += ThisFunc[j];
+      }
+    }
+  }
+  if (Fun.size()) {
+    Functions = new Regex(Fun);
+  }
+}
+
+bool BlackList::isIn(const Function &F) {
+  if (Functions) {
+    bool Res = Functions->match(F.getName());
+    return Res;
+  }
+  return false;
+}
diff --git a/lib/Transforms/Instrumentation/CMakeLists.txt b/lib/Transforms/Instrumentation/CMakeLists.txt
index 7b3a927a4e..929b7cd394 100644
--- a/lib/Transforms/Instrumentation/CMakeLists.txt
+++ b/lib/Transforms/Instrumentation/CMakeLists.txt
@@ -1,4 +1,5 @@
 add_llvm_library(LLVMInstrumentation
+  AddressSanitizer.cpp
   EdgeProfiling.cpp
   GCOVProfiling.cpp
   Instrumentation.cpp
diff --git a/lib/Transforms/Instrumentation/Instrumentation.cpp b/lib/Transforms/Instrumentation/Instrumentation.cpp
index 71adc1ec6d..6d6e0ae34b 100644
--- a/lib/Transforms/Instrumentation/Instrumentation.cpp
+++ b/lib/Transforms/Instrumentation/Instrumentation.cpp
@@ -24,6 +24,7 @@ void llvm::initializeInstrumentation(PassRegistry &Registry) {
   initializeOptimalEdgeProfilerPass(Registry);
   initializePathProfilerPass(Registry);
   initializeGCOVProfilerPass(Registry);
+  initializeAddressSanitizerPass(Registry);
 }
 
 /// LLVMInitializeInstrumentation - C binding for