AddressSanitizer.cpp [plain text]
#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/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; static const uintptr_t kCurrentStackFrameMagic = 0x41B58AB3;
static const uintptr_t kRetiredStackFrameMagic = 0x45E0360E;
static const char *kAsanModuleCtorName = "asan.module_ctor";
static const char *kAsanModuleDtorName = "asan.module_dtor";
static const int kAsanCtorAndCtorPriority = 1;
static const char *kAsanReportErrorTemplate = "__asan_report_";
static const char *kAsanRegisterGlobalsName = "__asan_register_globals";
static const char *kAsanUnregisterGlobalsName = "__asan_unregister_globals";
static const char *kAsanInitName = "__asan_init";
static const char *kAsanHandleNoReturnName = "__asan_handle_no_return";
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;
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));
static cl::opt<bool> ClStack("asan-stack",
cl::desc("Handle stack memory"), cl::Hidden, cl::init(true));
static cl::opt<bool> ClUseAfterReturn("asan-use-after-return",
cl::desc("Check return-after-free"), cl::Hidden, cl::init(false));
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));
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<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));
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));
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 {
class BlackList {
public:
BlackList(const std::string &Path);
bool isIn(const Function &F);
private:
Regex *Functions;
};
struct AddressSanitizer : public ModulePass {
AddressSanitizer();
virtual const char *getPassName() const;
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 maybeInsertAsanInitAtFunctionEntry(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;
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);
bool LooksLikeCodeInBug11395(Instruction *I);
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;
};
}
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();
}
const char *AddressSanitizer::getPassName() const {
return "AddressSanitizer";
}
static GlobalVariable *createPrivateGlobalForString(Module &M, StringRef Str) {
Constant *StrConst = ConstantDataArray::getString(M.getContext(), Str);
return new GlobalVariable(M, StrConst->getType(), true,
GlobalValue::PrivateLinkage, StrConst, "");
}
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(NewBasicBlock,
Tail,
Cmp);
ReplaceInstWithInst(HeadOldTerm, HeadNewTerm);
BranchInst *CheckTerm = BranchInst::Create(Tail, NewBasicBlock);
return CheckTerm;
}
Value *AddressSanitizer::memToShadow(Value *Shadow, IRBuilder<> &IRB) {
Shadow = IRB.CreateLShr(Shadow, MappingScale);
if (MappingOffset == 0)
return Shadow;
return IRB.CreateOr(Shadow, ConstantInt::get(IntptrTy,
MappingOffset));
}
void AddressSanitizer::instrumentMemIntrinsicParam(Instruction *OrigIns,
Value *Addr, Value *Size, Instruction *InsertBefore, bool IsWrite) {
{
IRBuilder<> IRB(InsertBefore);
instrumentAddress(OrigIns, IRB, Addr, 8, IsWrite);
}
{
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);
}
}
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 {
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)) {
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) {
return;
}
IRBuilder<> IRB(I);
instrumentAddress(I, IRB, Addr, TypeSize, IsWrite);
}
Instruction *AddressSanitizer::generateCrashCode(
IRBuilder<> &IRB, Value *Addr, bool IsWrite, uint32_t TypeSize) {
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;
}
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) {
Value *Lower3Bits = IRB2.CreateAnd(
AddrLong, ConstantInt::get(IntptrTy, Granularity - 1));
Value *LastAccessedByte = IRB2.CreateAdd(
Lower3Bits, ConstantInt::get(IntptrTy, TypeSize / 8 - 1));
LastAccessedByte = IRB2.CreateIntCast(
LastAccessedByte, IRB.getInt8Ty(), false);
Value *Cmp2 = IRB2.CreateICmpSGE(LastAccessedByte, ShadowValue);
CheckTerm = splitBlockAndInsertIfThen(CheckTerm, Cmp2);
}
IRBuilder<> IRB1(CheckTerm);
Instruction *Crash = generateCrashCode(IRB1, AddrLong, IsWrite, TypeSize);
Crash->setDebugLoc(OrigIns->getDebugLoc());
ReplaceInstWithInst(CheckTerm, new UnreachableInst(*C));
}
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 (G->getLinkage() != GlobalVariable::ExternalLinkage &&
G->getLinkage() != GlobalVariable::PrivateLinkage &&
G->getLinkage() != GlobalVariable::InternalLinkage)
continue;
if (G->isThreadLocal())
continue;
if (G->getAlignment() > RedzoneSize) continue;
if ((G->getName().find("\01L_OBJC_") == 0) ||
(G->getName().find("\01l_OBJC_") == 0)) {
DEBUG(dbgs() << "Ignoring \\01L_OBJC_* global: " << *G);
continue;
}
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;
}
if (Section.find("__DATA,__cfstring") == 0) {
DEBUG(dbgs() << "Ignoring CFString: " << *G);
continue;
}
}
GlobalsToChange.push_back(G);
}
size_t n = GlobalsToChange.size();
if (n == 0) return false;
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);
SmallString<2048> DescriptionOfGlobal = G->getName();
DescriptionOfGlobal += " (";
DescriptionOfGlobal += M.getModuleIdentifier();
DescriptionOfGlobal += ")";
GlobalVariable *Name = createPrivateGlobalForString(M, DescriptionOfGlobal);
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, true));
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));
Function *AsanDtorFunction = Function::Create(
FunctionType::get(Type::getVoidTy(*C), false),
GlobalValue::InternalLinkage, kAsanModuleDtorName, &M);
BasicBlock *AsanDtorBB = BasicBlock::Create(*C, "", AsanDtorFunction);
IRBuilder<> IRB_Dtor(ReturnInst::Create(*C, AsanDtorBB));
Function *AsanUnregisterGlobals = cast<Function>(M.getOrInsertFunction(
kAsanUnregisterGlobalsName, IRB.getVoidTy(), IntptrTy, IntptrTy, NULL));
AsanUnregisterGlobals->setLinkage(Function::ExternalLinkage);
IRB_Dtor.CreateCall2(AsanUnregisterGlobals,
IRB.CreatePointerCast(AllGlobals, IntptrTy),
ConstantInt::get(IntptrTy, n));
appendToGlobalDtors(M, AsanDtorFunction, kAsanCtorAndCtorPriority);
DEBUG(dbgs() << M);
return true;
}
bool AddressSanitizer::runOnModule(Module &M) {
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);
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) {
MappingOffset = 0;
} else {
MappingOffset = 1ULL << ClMappingOffsetLog;
}
}
MappingScale = kDefaultShadowScale;
if (ClMappingScale) {
MappingScale = ClMappingScale;
}
RedzoneSize = std::max(32, (int)(1 << MappingScale));
bool Res = false;
if (ClGlobals)
Res |= insertGlobalRedzones(M);
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);
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, kAsanCtorAndCtorPriority);
return Res;
}
bool AddressSanitizer::maybeInsertAsanInitAtFunctionEntry(Function &F) {
if (F.getName().find(" load]") != std::string::npos) {
IRBuilder<> IRB(F.begin()->begin());
IRB.CreateCall(AsanInitFunction);
return true;
}
return false;
}
bool AddressSanitizer::handleFunction(Module &M, Function &F) {
if (BL->isIn(F)) return false;
if (&F == AsanCtorFunction) return false;
maybeInsertAsanInitAtFunctionEntry(F);
if (!F.hasFnAttr(Attribute::AddressSafety)) return false;
if (!ClDebugFunc.empty() && ClDebugFunc != F.getName())
return false;
SmallSet<Value*, 16> TempsToInstrument;
SmallVector<Instruction*, 16> ToInstrument;
SmallVector<Instruction*, 8> NoReturnCalls;
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 (LooksLikeCodeInBug11395(BI)) return false;
if ((isa<LoadInst>(BI) && ClInstrumentReads) ||
(isa<StoreInst>(BI) && ClInstrumentWrites)) {
Value *Addr = getLDSTOperand(BI);
if (ClOpt && ClOptSameTemp) {
if (!TempsToInstrument.insert(Addr))
continue; }
} else if (isa<MemIntrinsic>(BI) && ClMemIntrin) {
} else {
if (CallInst *CI = dyn_cast<CallInst>(BI)) {
TempsToInstrument.clear();
if (CI->doesNotReturn()) {
NoReturnCalls.push_back(CI);
}
}
continue;
}
ToInstrument.push_back(BI);
}
}
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 (size_t i = 0, n = NoReturnCalls.size(); i != n; i++) {
Instruction *CI = NoReturnCalls[i];
IRBuilder<> IRB(CI);
IRB.CreateCall(M.getOrInsertFunction(kAsanHandleNoReturnName,
IRB.getVoidTy(), NULL));
}
return NumInstrumented > 0 || ChangedStack || !NoReturnCalls.empty();
}
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);
llvm_unreachable("ShadowRedzoneSize is either 1, 2 or 4");
}
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; } else if (i >= Size) {
*Shadow = Magic; } else {
*Shadow = Size - i; }
}
}
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));
IRB.CreateStore(PoisonLeft, IRB.CreateIntToPtr(ShadowBase, RZPtrTy));
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) {
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));
}
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;
}
}
bool AddressSanitizer::LooksLikeCodeInBug11395(Instruction *I) {
if (LongSize != 32) return false;
CallInst *CI = dyn_cast<CallInst>(I);
if (!CI || !CI->isInlineAsm()) return false;
if (CI->getNumArgOperands() <= 5) return false;
return true;
}
bool AddressSanitizer::poisonStackInFunction(Module &M, Function &F) {
if (!ClStack) return false;
SmallVector<AllocaInst*, 16> AllocaVec;
SmallVector<Instruction*, 8> RetVec;
uint64_t TotalSize = 0;
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);
}
SmallString<2048> StackDescriptionStorage;
raw_svector_ostream StackDescription(StackDescriptionStorage);
StackDescription << F.getName() << " " << AllocaVec.size() << " ";
uint64_t Pos = RedzoneSize;
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);
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);
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);
}
for (size_t i = 0, n = RetVec.size(); i < n; i++) {
Instruction *Ret = RetVec[i];
IRBuilder<> IRBRet(Ret);
IRBRet.CreateStore(ConstantInt::get(IntptrTy, kRetiredStackFrameMagic),
BasePlus0);
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)) {
report_fatal_error("Can't open blacklist file " + ClBlackListFile + ": " +
EC.message());
}
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));
std::string ThisFuncRE;
for (size_t j = 0, n = ThisFunc.size(); j < n; j++) {
if (ThisFunc[j] == '*')
ThisFuncRE += '.';
ThisFuncRE += ThisFunc[j];
}
Regex CheckRE(ThisFuncRE);
std::string Error;
if (!CheckRE.isValid(Error))
report_fatal_error("malformed blacklist regex: " + ThisFunc +
": " + Error);
if (Fun.size())
Fun += "|";
Fun += ThisFuncRE;
}
}
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;
}