//
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "asan"
-
#include "llvm/Transforms/Instrumentation.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/DepthFirstIterator.h"
-#include "llvm/ADT/OwningPtr.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/Triple.h"
-#include "llvm/DIBuilder.h"
+#include "llvm/IR/CallSite.h"
+#include "llvm/IR/DIBuilder.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/InlineAsm.h"
+#include "llvm/IR/InstVisitor.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/MDBuilder.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Type.h"
-#include "llvm/InstVisitor.h"
-#include "llvm/Support/CallSite.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/DataTypes.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/Endian.h"
-#include "llvm/Support/raw_ostream.h"
#include "llvm/Support/system_error.h"
+#include "llvm/Transforms/Utils/ASanStackFrameLayout.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/Transforms/Utils/Cloning.h"
#include "llvm/Transforms/Utils/Local.h"
using namespace llvm;
+#define DEBUG_TYPE "asan"
+
static const uint64_t kDefaultShadowScale = 3;
static const uint64_t kDefaultShadowOffset32 = 1ULL << 29;
+static const uint64_t kIOSShadowOffset32 = 1ULL << 30;
static const uint64_t kDefaultShadowOffset64 = 1ULL << 44;
-static const uint64_t kDefaultShort64bitShadowOffset = 0x7FFF8000; // < 2G.
+static const uint64_t kSmallX86_64ShadowOffset = 0x7FFF8000; // < 2G.
static const uint64_t kPPC64_ShadowOffset64 = 1ULL << 41;
static const uint64_t kMIPS32_ShadowOffset32 = 0x0aaa8000;
+static const uint64_t kFreeBSD_ShadowOffset32 = 1ULL << 30;
+static const uint64_t kFreeBSD_ShadowOffset64 = 1ULL << 46;
static const size_t kMinStackMallocSize = 1 << 6; // 64B
static const size_t kMaxStackMallocSize = 1 << 16; // 64K
static const char *const kAsanPoisonGlobalsName = "__asan_before_dynamic_init";
static const char *const kAsanUnpoisonGlobalsName = "__asan_after_dynamic_init";
static const char *const kAsanInitName = "__asan_init_v3";
+static const char *const kAsanCovModuleInitName = "__sanitizer_cov_module_init";
+static const char *const kAsanCovName = "__sanitizer_cov";
+static const char *const kAsanPtrCmp = "__sanitizer_ptr_cmp";
+static const char *const kAsanPtrSub = "__sanitizer_ptr_sub";
static const char *const kAsanHandleNoReturnName = "__asan_handle_no_return";
-static const char *const kAsanMappingOffsetName = "__asan_mapping_offset";
-static const char *const kAsanMappingScaleName = "__asan_mapping_scale";
static const int kMaxAsanStackMallocSizeClass = 10;
static const char *const kAsanStackMallocNameTemplate = "__asan_stack_malloc_";
static const char *const kAsanStackFreeNameTemplate = "__asan_stack_free_";
static const char *const kAsanOptionDetectUAR =
"__asan_option_detect_stack_use_after_return";
-// These constants must match the definitions in the run-time library.
-static const int kAsanStackLeftRedzoneMagic = 0xf1;
-static const int kAsanStackMidRedzoneMagic = 0xf2;
-static const int kAsanStackRightRedzoneMagic = 0xf3;
-static const int kAsanStackPartialRedzoneMagic = 0xf4;
#ifndef NDEBUG
static const int kAsanStackAfterReturnMagic = 0xf5;
#endif
// 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<int> ClCoverage("asan-coverage",
+ cl::desc("ASan coverage. 0: none, 1: entry block, 2: all blocks"),
+ cl::Hidden, cl::init(false));
+static cl::opt<int> ClCoverageBlockThreshold("asan-coverage-block-threshold",
+ cl::desc("Add coverage instrumentation only to the entry block if there "
+ "are more than this number of blocks."),
+ cl::Hidden, cl::init(1500));
static cl::opt<bool> ClInitializers("asan-initialization-order",
cl::desc("Handle C++ initializer order"), cl::Hidden, cl::init(false));
-static cl::opt<bool> ClMemIntrin("asan-memintrin",
- cl::desc("Handle memset/memcpy/memmove"), cl::Hidden, cl::init(true));
-static cl::opt<bool> ClRealignStack("asan-realign-stack",
- cl::desc("Realign stack to 32"), cl::Hidden, cl::init(true));
+static cl::opt<bool> ClInvalidPointerPairs("asan-detect-invalid-pointer-pair",
+ cl::desc("Instrument <, <=, >, >=, - with pointer operands"),
+ cl::Hidden, cl::init(false));
+static cl::opt<unsigned> ClRealignStack("asan-realign-stack",
+ cl::desc("Realign stack to the value of this flag (power of two)"),
+ cl::Hidden, cl::init(32));
static cl::opt<std::string> ClBlacklistFile("asan-blacklist",
cl::desc("File containing the list of objects to ignore "
"during instrumentation"), cl::Hidden);
+static cl::opt<int> ClInstrumentationWithCallsThreshold(
+ "asan-instrumentation-with-call-threshold",
+ cl::desc("If the function being instrumented contains more than "
+ "this number of memory accesses, use callbacks instead of "
+ "inline checks (-1 means never use callbacks)."),
+ cl::Hidden, cl::init(7000));
+static cl::opt<std::string> ClMemoryAccessCallbackPrefix(
+ "asan-memory-access-callback-prefix",
+ cl::desc("Prefix for memory access callbacks"), cl::Hidden,
+ cl::init("__asan_"));
// This is an experimental feature that will allow to choose between
// instrumented and non-instrumented code at link-time.
// 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));
-static cl::opt<bool> ClShort64BitOffset("asan-short-64bit-mapping-offset",
- cl::desc("Use short immediate constant as the mapping offset for 64bit"),
- cl::Hidden, cl::init(true));
// Optimization flags. Not user visible, used mostly for testing
// and benchmarking the tool.
static cl::opt<int> ClDebugMax("asan-debug-max", cl::desc("Debug man inst"),
cl::Hidden, cl::init(-1));
+STATISTIC(NumInstrumentedReads, "Number of instrumented reads");
+STATISTIC(NumInstrumentedWrites, "Number of instrumented writes");
+STATISTIC(NumOptimizedAccessesToGlobalArray,
+ "Number of optimized accesses to global arrays");
+STATISTIC(NumOptimizedAccessesToGlobalVar,
+ "Number of optimized accesses to global vars");
+
namespace {
/// A set of dynamically initialized globals extracted from metadata.
class SetOfDynamicallyInitializedGlobals {
bool OrShadowOffset;
};
-static ShadowMapping getShadowMapping(const Module &M, int LongSize,
- bool ZeroBaseShadow) {
+static ShadowMapping getShadowMapping(const Module &M, int LongSize) {
llvm::Triple TargetTriple(M.getTargetTriple());
bool IsAndroid = TargetTriple.getEnvironment() == llvm::Triple::Android;
- bool IsMacOSX = TargetTriple.getOS() == llvm::Triple::MacOSX;
+ bool IsIOS = TargetTriple.getOS() == llvm::Triple::IOS;
+ bool IsFreeBSD = TargetTriple.getOS() == llvm::Triple::FreeBSD;
+ bool IsLinux = TargetTriple.getOS() == llvm::Triple::Linux;
bool IsPPC64 = TargetTriple.getArch() == llvm::Triple::ppc64 ||
TargetTriple.getArch() == llvm::Triple::ppc64le;
bool IsX86_64 = TargetTriple.getArch() == llvm::Triple::x86_64;
ShadowMapping Mapping;
- // OR-ing shadow offset if more efficient (at least on x86),
- // but on ppc64 we have to use add since the shadow offset is not neccesary
- // 1/8-th of the address space.
- Mapping.OrShadowOffset = !IsPPC64 && !ClShort64BitOffset;
-
- Mapping.Offset = (IsAndroid || ZeroBaseShadow) ? 0 :
- (LongSize == 32 ?
- (IsMIPS32 ? kMIPS32_ShadowOffset32 : kDefaultShadowOffset32) :
- IsPPC64 ? kPPC64_ShadowOffset64 : kDefaultShadowOffset64);
- if (!ZeroBaseShadow && ClShort64BitOffset && IsX86_64 && !IsMacOSX) {
- assert(LongSize == 64);
- Mapping.Offset = kDefaultShort64bitShadowOffset;
- }
- if (!ZeroBaseShadow && ClMappingOffsetLog >= 0) {
- // Zero offset log is the special case.
- Mapping.Offset = (ClMappingOffsetLog == 0) ? 0 : 1ULL << ClMappingOffsetLog;
+ if (LongSize == 32) {
+ if (IsAndroid)
+ Mapping.Offset = 0;
+ else if (IsMIPS32)
+ Mapping.Offset = kMIPS32_ShadowOffset32;
+ else if (IsFreeBSD)
+ Mapping.Offset = kFreeBSD_ShadowOffset32;
+ else if (IsIOS)
+ Mapping.Offset = kIOSShadowOffset32;
+ else
+ Mapping.Offset = kDefaultShadowOffset32;
+ } else { // LongSize == 64
+ if (IsPPC64)
+ Mapping.Offset = kPPC64_ShadowOffset64;
+ else if (IsFreeBSD)
+ Mapping.Offset = kFreeBSD_ShadowOffset64;
+ else if (IsLinux && IsX86_64)
+ Mapping.Offset = kSmallX86_64ShadowOffset;
+ else
+ Mapping.Offset = kDefaultShadowOffset64;
}
Mapping.Scale = kDefaultShadowScale;
Mapping.Scale = ClMappingScale;
}
+ // OR-ing shadow offset if more efficient (at least on x86) if the offset
+ // is a power of two, but on ppc64 we have to use add since the shadow
+ // offset is not necessary 1/8-th of the address space.
+ Mapping.OrShadowOffset = !IsPPC64 && !(Mapping.Offset & (Mapping.Offset - 1));
+
return Mapping;
}
AddressSanitizer(bool CheckInitOrder = true,
bool CheckUseAfterReturn = false,
bool CheckLifetime = false,
- StringRef BlacklistFile = StringRef(),
- bool ZeroBaseShadow = false)
+ StringRef BlacklistFile = StringRef())
: FunctionPass(ID),
CheckInitOrder(CheckInitOrder || ClInitializers),
CheckUseAfterReturn(CheckUseAfterReturn || ClUseAfterReturn),
CheckLifetime(CheckLifetime || ClCheckLifetime),
BlacklistFile(BlacklistFile.empty() ? ClBlacklistFile
- : BlacklistFile),
- ZeroBaseShadow(ZeroBaseShadow) {}
- virtual const char *getPassName() const {
+ : BlacklistFile) {}
+ const char *getPassName() const override {
return "AddressSanitizerFunctionPass";
}
- void instrumentMop(Instruction *I);
+ void instrumentMop(Instruction *I, bool UseCalls);
+ void instrumentPointerComparisonOrSubtraction(Instruction *I);
void instrumentAddress(Instruction *OrigIns, Instruction *InsertBefore,
Value *Addr, uint32_t TypeSize, bool IsWrite,
- Value *SizeArgument);
+ Value *SizeArgument, bool UseCalls);
Value *createSlowPathCmp(IRBuilder<> &IRB, Value *AddrLong,
Value *ShadowValue, uint32_t TypeSize);
Instruction *generateCrashCode(Instruction *InsertBefore, Value *Addr,
bool IsWrite, size_t AccessSizeIndex,
Value *SizeArgument);
- bool instrumentMemIntrinsic(MemIntrinsic *MI);
- void instrumentMemIntrinsicParam(Instruction *OrigIns, Value *Addr,
- Value *Size,
- Instruction *InsertBefore, bool IsWrite);
+ void instrumentMemIntrinsic(MemIntrinsic *MI);
Value *memToShadow(Value *Shadow, IRBuilder<> &IRB);
- bool runOnFunction(Function &F);
+ bool runOnFunction(Function &F) override;
bool maybeInsertAsanInitAtFunctionEntry(Function &F);
- void emitShadowMapping(Module &M, IRBuilder<> &IRB) const;
- virtual bool doInitialization(Module &M);
+ bool doInitialization(Module &M) override;
static char ID; // Pass identification, replacement for typeid
private:
void initializeCallbacks(Module &M);
- bool ShouldInstrumentGlobal(GlobalVariable *G);
bool LooksLikeCodeInBug11395(Instruction *I);
- void FindDynamicInitializers(Module &M);
+ bool GlobalIsLinkerInitialized(GlobalVariable *G);
+ bool InjectCoverage(Function &F, const ArrayRef<BasicBlock*> AllBlocks);
+ void InjectCoverageAtBlock(Function &F, BasicBlock &BB);
bool CheckInitOrder;
bool CheckUseAfterReturn;
bool CheckLifetime;
SmallString<64> BlacklistFile;
- bool ZeroBaseShadow;
LLVMContext *C;
- DataLayout *TD;
+ const DataLayout *DL;
int LongSize;
Type *IntptrTy;
ShadowMapping Mapping;
Function *AsanCtorFunction;
Function *AsanInitFunction;
Function *AsanHandleNoReturnFunc;
- OwningPtr<SpecialCaseList> BL;
+ Function *AsanCovFunction;
+ Function *AsanPtrCmpFunction, *AsanPtrSubFunction;
+ std::unique_ptr<SpecialCaseList> BL;
// This array is indexed by AccessIsWrite and log2(AccessSize).
Function *AsanErrorCallback[2][kNumberOfAccessSizes];
+ Function *AsanMemoryAccessCallback[2][kNumberOfAccessSizes];
// This array is indexed by AccessIsWrite.
- Function *AsanErrorCallbackSized[2];
+ Function *AsanErrorCallbackSized[2],
+ *AsanMemoryAccessCallbackSized[2];
+ Function *AsanMemmove, *AsanMemcpy, *AsanMemset;
InlineAsm *EmptyAsm;
SetOfDynamicallyInitializedGlobals DynamicallyInitializedGlobals;
class AddressSanitizerModule : public ModulePass {
public:
AddressSanitizerModule(bool CheckInitOrder = true,
- StringRef BlacklistFile = StringRef(),
- bool ZeroBaseShadow = false)
+ StringRef BlacklistFile = StringRef())
: ModulePass(ID),
CheckInitOrder(CheckInitOrder || ClInitializers),
BlacklistFile(BlacklistFile.empty() ? ClBlacklistFile
- : BlacklistFile),
- ZeroBaseShadow(ZeroBaseShadow) {}
- bool runOnModule(Module &M);
+ : BlacklistFile) {}
+ bool runOnModule(Module &M) override;
static char ID; // Pass identification, replacement for typeid
- virtual const char *getPassName() const {
+ const char *getPassName() const override {
return "AddressSanitizerModule";
}
bool ShouldInstrumentGlobal(GlobalVariable *G);
void createInitializerPoisonCalls(Module &M, GlobalValue *ModuleName);
- size_t RedzoneSize() const {
+ size_t MinRedzoneSizeForGlobal() const {
return RedzoneSizeForScale(Mapping.Scale);
}
bool CheckInitOrder;
SmallString<64> BlacklistFile;
- bool ZeroBaseShadow;
- OwningPtr<SpecialCaseList> BL;
+ std::unique_ptr<SpecialCaseList> BL;
SetOfDynamicallyInitializedGlobals DynamicallyInitializedGlobals;
Type *IntptrTy;
LLVMContext *C;
- DataLayout *TD;
+ const DataLayout *DL;
ShadowMapping Mapping;
Function *AsanPoisonGlobals;
Function *AsanUnpoisonGlobals;
Function *AsanRegisterGlobals;
Function *AsanUnregisterGlobals;
+ Function *AsanCovModuleInit;
};
// Stack poisoning does not play well with exception handling.
SmallVector<AllocaInst*, 16> AllocaVec;
SmallVector<Instruction*, 8> RetVec;
- uint64_t TotalStackSize;
unsigned StackAlignment;
Function *AsanStackMallocFunc[kMaxAsanStackMallocSizeClass + 1],
// Stores a place and arguments of poisoning/unpoisoning call for alloca.
struct AllocaPoisonCall {
IntrinsicInst *InsBefore;
+ AllocaInst *AI;
uint64_t Size;
bool DoPoison;
};
: F(F), ASan(ASan), DIB(*F.getParent()), C(ASan.C),
IntptrTy(ASan.IntptrTy), IntptrPtrTy(PointerType::get(IntptrTy, 0)),
Mapping(ASan.Mapping),
- TotalStackSize(0), StackAlignment(1 << Mapping.Scale) {}
+ StackAlignment(1 << Mapping.Scale) {}
bool runOnFunction() {
if (!ClStack) return false;
// Collect alloca, ret, lifetime instructions etc.
- for (df_iterator<BasicBlock*> DI = df_begin(&F.getEntryBlock()),
- DE = df_end(&F.getEntryBlock()); DI != DE; ++DI) {
- BasicBlock *BB = *DI;
+ for (BasicBlock *BB : depth_first(&F.getEntryBlock()))
visit(*BB);
- }
+
if (AllocaVec.empty()) return false;
initializeCallbacks(*F.getParent());
StackAlignment = std::max(StackAlignment, AI.getAlignment());
AllocaVec.push_back(&AI);
- uint64_t AlignedSize = getAlignedAllocaSize(&AI);
- TotalStackSize += AlignedSize;
}
/// \brief Collect lifetime intrinsic calls to check for use-after-scope
AllocaInst *AI = findAllocaForValue(II.getArgOperand(1));
if (!AI) return;
bool DoPoison = (ID == Intrinsic::lifetime_end);
- AllocaPoisonCall APC = {&II, SizeValue, DoPoison};
+ AllocaPoisonCall APC = {&II, AI, SizeValue, DoPoison};
AllocaPoisonCallVec.push_back(APC);
}
// Check if we want (and can) handle this alloca.
bool isInterestingAlloca(AllocaInst &AI) const {
- return (!AI.isArrayAllocation() &&
- AI.isStaticAlloca() &&
- AI.getAlignment() <= RedzoneSize() &&
- AI.getAllocatedType()->isSized());
+ return (!AI.isArrayAllocation() && AI.isStaticAlloca() &&
+ AI.getAllocatedType()->isSized() &&
+ // alloca() may be called with 0 size, ignore it.
+ getAllocaSizeInBytes(&AI) > 0);
}
- size_t RedzoneSize() const {
- return RedzoneSizeForScale(Mapping.Scale);
- }
uint64_t getAllocaSizeInBytes(AllocaInst *AI) const {
Type *Ty = AI->getAllocatedType();
- uint64_t SizeInBytes = ASan.TD->getTypeAllocSize(Ty);
+ uint64_t SizeInBytes = ASan.DL->getTypeAllocSize(Ty);
return SizeInBytes;
}
- uint64_t getAlignedSize(uint64_t SizeInBytes) const {
- size_t RZ = RedzoneSize();
- return ((SizeInBytes + RZ - 1) / RZ) * RZ;
- }
- uint64_t getAlignedAllocaSize(AllocaInst *AI) const {
- uint64_t SizeInBytes = getAllocaSizeInBytes(AI);
- return getAlignedSize(SizeInBytes);
- }
/// Finds alloca where the value comes from.
AllocaInst *findAllocaForValue(Value *V);
- void poisonRedZones(const ArrayRef<AllocaInst*> &AllocaVec, IRBuilder<> &IRB,
+ void poisonRedZones(const ArrayRef<uint8_t> ShadowBytes, IRBuilder<> &IRB,
Value *ShadowBase, bool DoPoison);
void poisonAlloca(Value *V, uint64_t Size, IRBuilder<> &IRB, bool DoPoison);
false, false)
FunctionPass *llvm::createAddressSanitizerFunctionPass(
bool CheckInitOrder, bool CheckUseAfterReturn, bool CheckLifetime,
- StringRef BlacklistFile, bool ZeroBaseShadow) {
+ StringRef BlacklistFile) {
return new AddressSanitizer(CheckInitOrder, CheckUseAfterReturn,
- CheckLifetime, BlacklistFile, ZeroBaseShadow);
+ CheckLifetime, BlacklistFile);
}
char AddressSanitizerModule::ID = 0;
"AddressSanitizer: detects use-after-free and out-of-bounds bugs."
"ModulePass", false, false)
ModulePass *llvm::createAddressSanitizerModulePass(
- bool CheckInitOrder, StringRef BlacklistFile, bool ZeroBaseShadow) {
- return new AddressSanitizerModule(CheckInitOrder, BlacklistFile,
- ZeroBaseShadow);
+ bool CheckInitOrder, StringRef BlacklistFile) {
+ return new AddressSanitizerModule(CheckInitOrder, BlacklistFile);
}
static size_t TypeSizeToSizeIndex(uint32_t TypeSize) {
}
// \brief Create a constant for Str so that we can pass it to the run-time lib.
-static GlobalVariable *createPrivateGlobalForString(Module &M, StringRef Str) {
+static GlobalVariable *createPrivateGlobalForString(
+ Module &M, StringRef Str, bool AllowMerging) {
Constant *StrConst = ConstantDataArray::getString(M.getContext(), Str);
- GlobalVariable *GV = new GlobalVariable(M, StrConst->getType(), true,
- GlobalValue::InternalLinkage, StrConst,
- kAsanGenPrefix);
- GV->setUnnamedAddr(true); // Ok to merge these.
+ // We use private linkage for module-local strings. If they can be merged
+ // with another one, we set the unnamed_addr attribute.
+ GlobalVariable *GV =
+ new GlobalVariable(M, StrConst->getType(), true,
+ GlobalValue::PrivateLinkage, StrConst, kAsanGenPrefix);
+ if (AllowMerging)
+ GV->setUnnamedAddr(true);
GV->setAlignment(1); // Strings may not be merged w/o setting align 1.
return GV;
}
return IRB.CreateAdd(Shadow, ConstantInt::get(IntptrTy, Mapping.Offset));
}
-void AddressSanitizer::instrumentMemIntrinsicParam(
- Instruction *OrigIns,
- Value *Addr, Value *Size, Instruction *InsertBefore, bool IsWrite) {
- IRBuilder<> IRB(InsertBefore);
- if (Size->getType() != IntptrTy)
- Size = IRB.CreateIntCast(Size, IntptrTy, false);
- // Check the first byte.
- instrumentAddress(OrigIns, InsertBefore, Addr, 8, IsWrite, Size);
- // Check the last byte.
- IRB.SetInsertPoint(InsertBefore);
- Value *SizeMinusOne = IRB.CreateSub(Size, ConstantInt::get(IntptrTy, 1));
- Value *AddrLong = IRB.CreatePointerCast(Addr, IntptrTy);
- Value *AddrLast = IRB.CreateAdd(AddrLong, SizeMinusOne);
- instrumentAddress(OrigIns, InsertBefore, AddrLast, 8, IsWrite, Size);
-}
-
// Instrument memset/memmove/memcpy
-bool AddressSanitizer::instrumentMemIntrinsic(MemIntrinsic *MI) {
- Value *Dst = MI->getDest();
- MemTransferInst *MemTran = dyn_cast<MemTransferInst>(MI);
- Value *Src = MemTran ? MemTran->getSource() : 0;
- 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(cast<Instruction>(Cmp), false);
+void AddressSanitizer::instrumentMemIntrinsic(MemIntrinsic *MI) {
+ IRBuilder<> IRB(MI);
+ if (isa<MemTransferInst>(MI)) {
+ IRB.CreateCall3(
+ isa<MemMoveInst>(MI) ? AsanMemmove : AsanMemcpy,
+ IRB.CreatePointerCast(MI->getOperand(0), IRB.getInt8PtrTy()),
+ IRB.CreatePointerCast(MI->getOperand(1), IRB.getInt8PtrTy()),
+ IRB.CreateIntCast(MI->getOperand(2), IntptrTy, false));
+ } else if (isa<MemSetInst>(MI)) {
+ IRB.CreateCall3(
+ AsanMemset,
+ IRB.CreatePointerCast(MI->getOperand(0), IRB.getInt8PtrTy()),
+ IRB.CreateIntCast(MI->getOperand(1), IRB.getInt32Ty(), false),
+ IRB.CreateIntCast(MI->getOperand(2), IntptrTy, false));
}
-
- instrumentMemIntrinsicParam(MI, Dst, Length, InsertBefore, true);
- if (Src)
- instrumentMemIntrinsicParam(MI, Src, Length, InsertBefore, false);
- return true;
+ MI->eraseFromParent();
}
// If I is an interesting memory access, return the PointerOperand
-// and set IsWrite. Otherwise return NULL.
-static Value *isInterestingMemoryAccess(Instruction *I, bool *IsWrite) {
+// and set IsWrite/Alignment. Otherwise return NULL.
+static Value *isInterestingMemoryAccess(Instruction *I, bool *IsWrite,
+ unsigned *Alignment) {
if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
- if (!ClInstrumentReads) return NULL;
+ if (!ClInstrumentReads) return nullptr;
*IsWrite = false;
+ *Alignment = LI->getAlignment();
return LI->getPointerOperand();
}
if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
- if (!ClInstrumentWrites) return NULL;
+ if (!ClInstrumentWrites) return nullptr;
*IsWrite = true;
+ *Alignment = SI->getAlignment();
return SI->getPointerOperand();
}
if (AtomicRMWInst *RMW = dyn_cast<AtomicRMWInst>(I)) {
- if (!ClInstrumentAtomics) return NULL;
+ if (!ClInstrumentAtomics) return nullptr;
*IsWrite = true;
+ *Alignment = 0;
return RMW->getPointerOperand();
}
if (AtomicCmpXchgInst *XCHG = dyn_cast<AtomicCmpXchgInst>(I)) {
- if (!ClInstrumentAtomics) return NULL;
+ if (!ClInstrumentAtomics) return nullptr;
*IsWrite = true;
+ *Alignment = 0;
return XCHG->getPointerOperand();
}
- return NULL;
+ return nullptr;
+}
+
+static bool isPointerOperand(Value *V) {
+ return V->getType()->isPointerTy() || isa<PtrToIntInst>(V);
+}
+
+// This is a rough heuristic; it may cause both false positives and
+// false negatives. The proper implementation requires cooperation with
+// the frontend.
+static bool isInterestingPointerComparisonOrSubtraction(Instruction *I) {
+ if (ICmpInst *Cmp = dyn_cast<ICmpInst>(I)) {
+ if (!Cmp->isRelational())
+ return false;
+ } else if (BinaryOperator *BO = dyn_cast<BinaryOperator>(I)) {
+ if (BO->getOpcode() != Instruction::Sub)
+ return false;
+ } else {
+ return false;
+ }
+ if (!isPointerOperand(I->getOperand(0)) ||
+ !isPointerOperand(I->getOperand(1)))
+ return false;
+ return true;
+}
+
+bool AddressSanitizer::GlobalIsLinkerInitialized(GlobalVariable *G) {
+ // If a global variable does not have dynamic initialization we don't
+ // have to instrument it. However, if a global does not have initializer
+ // at all, we assume it has dynamic initializer (in other TU).
+ return G->hasInitializer() && !DynamicallyInitializedGlobals.Contains(G);
}
-void AddressSanitizer::instrumentMop(Instruction *I) {
+void
+AddressSanitizer::instrumentPointerComparisonOrSubtraction(Instruction *I) {
+ IRBuilder<> IRB(I);
+ Function *F = isa<ICmpInst>(I) ? AsanPtrCmpFunction : AsanPtrSubFunction;
+ Value *Param[2] = {I->getOperand(0), I->getOperand(1)};
+ for (int i = 0; i < 2; i++) {
+ if (Param[i]->getType()->isPointerTy())
+ Param[i] = IRB.CreatePointerCast(Param[i], IntptrTy);
+ }
+ IRB.CreateCall2(F, Param[0], Param[1]);
+}
+
+void AddressSanitizer::instrumentMop(Instruction *I, bool UseCalls) {
bool IsWrite = false;
- Value *Addr = isInterestingMemoryAccess(I, &IsWrite);
+ unsigned Alignment = 0;
+ Value *Addr = isInterestingMemoryAccess(I, &IsWrite, &Alignment);
assert(Addr);
if (ClOpt && ClOptGlobals) {
if (GlobalVariable *G = dyn_cast<GlobalVariable>(Addr)) {
// If initialization order checking is disabled, a simple access to a
// dynamically initialized global is always valid.
- if (!CheckInitOrder)
- return;
- // If a global variable does not have dynamic initialization we don't
- // have to instrument it. However, if a global does not have initailizer
- // at all, we assume it has dynamic initializer (in other TU).
- if (G->hasInitializer() && !DynamicallyInitializedGlobals.Contains(G))
+ if (!CheckInitOrder || GlobalIsLinkerInitialized(G)) {
+ NumOptimizedAccessesToGlobalVar++;
return;
+ }
+ }
+ ConstantExpr *CE = dyn_cast<ConstantExpr>(Addr);
+ if (CE && CE->isGEPWithNoNotionalOverIndexing()) {
+ if (GlobalVariable *G = dyn_cast<GlobalVariable>(CE->getOperand(0))) {
+ if (CE->getOperand(1)->isNullValue() && GlobalIsLinkerInitialized(G)) {
+ NumOptimizedAccessesToGlobalArray++;
+ return;
+ }
+ }
}
}
Type *OrigTy = cast<PointerType>(OrigPtrTy)->getElementType();
assert(OrigTy->isSized());
- uint32_t TypeSize = TD->getTypeStoreSizeInBits(OrigTy);
+ uint32_t TypeSize = DL->getTypeStoreSizeInBits(OrigTy);
assert((TypeSize % 8) == 0);
- // Instrument a 1-, 2-, 4-, 8-, or 16- byte access with one check.
- if (TypeSize == 8 || TypeSize == 16 ||
- TypeSize == 32 || TypeSize == 64 || TypeSize == 128)
- return instrumentAddress(I, I, Addr, TypeSize, IsWrite, 0);
- // Instrument unusual size (but still multiple of 8).
+ if (IsWrite)
+ NumInstrumentedWrites++;
+ else
+ NumInstrumentedReads++;
+
+ unsigned Granularity = 1 << Mapping.Scale;
+ // Instrument a 1-, 2-, 4-, 8-, or 16- byte access with one check
+ // if the data is properly aligned.
+ if ((TypeSize == 8 || TypeSize == 16 || TypeSize == 32 || TypeSize == 64 ||
+ TypeSize == 128) &&
+ (Alignment >= Granularity || Alignment == 0 || Alignment >= TypeSize / 8))
+ return instrumentAddress(I, I, Addr, TypeSize, IsWrite, nullptr, UseCalls);
+ // Instrument unusual size or unusual alignment.
// We can not do it with a single check, so we do 1-byte check for the first
// and the last bytes. We call __asan_report_*_n(addr, real_size) to be able
// to report the actual access size.
IRBuilder<> IRB(I);
- Value *LastByte = IRB.CreateIntToPtr(
- IRB.CreateAdd(IRB.CreatePointerCast(Addr, IntptrTy),
- ConstantInt::get(IntptrTy, TypeSize / 8 - 1)),
- OrigPtrTy);
Value *Size = ConstantInt::get(IntptrTy, TypeSize / 8);
- instrumentAddress(I, I, Addr, 8, IsWrite, Size);
- instrumentAddress(I, I, LastByte, 8, IsWrite, Size);
+ Value *AddrLong = IRB.CreatePointerCast(Addr, IntptrTy);
+ if (UseCalls) {
+ IRB.CreateCall2(AsanMemoryAccessCallbackSized[IsWrite], AddrLong, Size);
+ } else {
+ Value *LastByte = IRB.CreateIntToPtr(
+ IRB.CreateAdd(AddrLong, ConstantInt::get(IntptrTy, TypeSize / 8 - 1)),
+ OrigPtrTy);
+ instrumentAddress(I, I, Addr, 8, IsWrite, Size, false);
+ instrumentAddress(I, I, LastByte, 8, IsWrite, Size, false);
+ }
}
// Validate the result of Module::getOrInsertFunction called for an interface
}
void AddressSanitizer::instrumentAddress(Instruction *OrigIns,
- Instruction *InsertBefore,
- Value *Addr, uint32_t TypeSize,
- bool IsWrite, Value *SizeArgument) {
+ Instruction *InsertBefore, Value *Addr,
+ uint32_t TypeSize, bool IsWrite,
+ Value *SizeArgument, bool UseCalls) {
IRBuilder<> IRB(InsertBefore);
Value *AddrLong = IRB.CreatePointerCast(Addr, IntptrTy);
+ size_t AccessSizeIndex = TypeSizeToSizeIndex(TypeSize);
+
+ if (UseCalls) {
+ IRB.CreateCall(AsanMemoryAccessCallback[IsWrite][AccessSizeIndex],
+ AddrLong);
+ return;
+ }
Type *ShadowTy = IntegerType::get(
*C, std::max(8U, TypeSize >> Mapping.Scale));
IRB.CreateIntToPtr(ShadowPtr, ShadowPtrTy));
Value *Cmp = IRB.CreateICmpNE(ShadowValue, CmpVal);
- size_t AccessSizeIndex = TypeSizeToSizeIndex(TypeSize);
size_t Granularity = 1 << Mapping.Scale;
- TerminatorInst *CrashTerm = 0;
+ TerminatorInst *CrashTerm = nullptr;
if (ClAlwaysSlowPath || (TypeSize < 8 * Granularity)) {
TerminatorInst *CheckTerm =
- SplitBlockAndInsertIfThen(cast<Instruction>(Cmp), false);
+ SplitBlockAndInsertIfThen(Cmp, InsertBefore, false);
assert(dyn_cast<BranchInst>(CheckTerm)->isUnconditional());
BasicBlock *NextBB = CheckTerm->getSuccessor(0);
IRB.SetInsertPoint(CheckTerm);
BranchInst *NewTerm = BranchInst::Create(CrashBlock, NextBB, Cmp2);
ReplaceInstWithInst(CheckTerm, NewTerm);
} else {
- CrashTerm = SplitBlockAndInsertIfThen(cast<Instruction>(Cmp), true);
+ CrashTerm = SplitBlockAndInsertIfThen(Cmp, InsertBefore, true);
}
Instruction *Crash = generateCrashCode(
void AddressSanitizerModule::createInitializerPoisonCalls(
Module &M, GlobalValue *ModuleName) {
- // We do all of our poisoning and unpoisoning within _GLOBAL__I_a.
- Function *GlobalInit = M.getFunction("_GLOBAL__I_a");
+ // We do all of our poisoning and unpoisoning within a global constructor.
+ // These are called _GLOBAL__(sub_)?I_.*.
+ // TODO: Consider looking through the functions in
+ // M.getGlobalVariable("llvm.global_ctors") instead of using this stringly
+ // typed approach.
+ Function *GlobalInit = nullptr;
+ for (auto &F : M.getFunctionList()) {
+ StringRef FName = F.getName();
+
+ const char kGlobalPrefix[] = "_GLOBAL__";
+ if (!FName.startswith(kGlobalPrefix))
+ continue;
+ FName = FName.substr(strlen(kGlobalPrefix));
+
+ const char kOptionalSub[] = "sub_";
+ if (FName.startswith(kOptionalSub))
+ FName = FName.substr(strlen(kOptionalSub));
+
+ if (FName.startswith("I_")) {
+ GlobalInit = &F;
+ break;
+ }
+ }
// If that function is not present, this TU contains no globals, or they have
// all been optimized away
if (!GlobalInit)
// Add calls to unpoison all globals before each return instruction.
for (Function::iterator I = GlobalInit->begin(), E = GlobalInit->end();
- I != E; ++I) {
+ I != E; ++I) {
if (ReturnInst *RI = dyn_cast<ReturnInst>(I->getTerminator())) {
CallInst::Create(AsanUnpoisonGlobals, "", RI);
}
// - Need to poison all copies, not just the main thread's one.
if (G->isThreadLocal())
return false;
- // For now, just ignore this Alloca if the alignment is large.
- if (G->getAlignment() > RedzoneSize()) return false;
+ // For now, just ignore this Global if the alignment is large.
+ if (G->getAlignment() > MinRedzoneSizeForGlobal()) return false;
// Ignore all the globals with the names starting with "\01L_OBJC_".
// Many of those are put into the .cstring section. The linker compresses
// our redzones get broken.
if ((G->getName().find("\01L_OBJC_") == 0) ||
(G->getName().find("\01l_OBJC_") == 0)) {
- DEBUG(dbgs() << "Ignoring \\01L_OBJC_* global: " << *G);
+ DEBUG(dbgs() << "Ignoring \\01L_OBJC_* global: " << *G << "\n");
return false;
}
// 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 ((Section.find("__OBJC,") == 0) ||
- (Section.find("__DATA, __objc_") == 0)) {
- DEBUG(dbgs() << "Ignoring ObjC runtime global: " << *G);
+ if (Section.startswith("__OBJC,") ||
+ Section.startswith("__DATA, __objc_")) {
+ DEBUG(dbgs() << "Ignoring ObjC runtime global: " << *G << "\n");
return false;
}
// See http://code.google.com/p/address-sanitizer/issues/detail?id=32
// is placed into __DATA,__cfstring
// Therefore there's no point in placing redzones into __DATA,__cfstring.
// Moreover, it causes the linker to crash on OS X 10.7
- if (Section.find("__DATA,__cfstring") == 0) {
- DEBUG(dbgs() << "Ignoring CFString: " << *G);
+ if (Section.startswith("__DATA,__cfstring")) {
+ DEBUG(dbgs() << "Ignoring CFString: " << *G << "\n");
+ return false;
+ }
+ // The linker merges the contents of cstring_literals and removes the
+ // trailing zeroes.
+ if (Section.startswith("__TEXT,__cstring,cstring_literals")) {
+ DEBUG(dbgs() << "Ignoring a cstring literal: " << *G << "\n");
return false;
}
+
+ // Callbacks put into the CRT initializer/terminator sections
+ // should not be instrumented.
+ // See https://code.google.com/p/address-sanitizer/issues/detail?id=305
+ // and http://msdn.microsoft.com/en-US/en-en/library/bb918180(v=vs.120).aspx
+ if (Section.startswith(".CRT")) {
+ DEBUG(dbgs() << "Ignoring a global initializer callback: " << *G << "\n");
+ return false;
+ }
+
+ // Globals from llvm.metadata aren't emitted, do not instrument them.
+ if (Section == "llvm.metadata") return false;
}
return true;
kAsanUnregisterGlobalsName,
IRB.getVoidTy(), IntptrTy, IntptrTy, NULL));
AsanUnregisterGlobals->setLinkage(Function::ExternalLinkage);
+ AsanCovModuleInit = checkInterfaceFunction(M.getOrInsertFunction(
+ kAsanCovModuleInitName,
+ IRB.getVoidTy(), IntptrTy, NULL));
+ AsanCovModuleInit->setLinkage(Function::ExternalLinkage);
}
// This function replaces all global variables with new variables that have
// redzones and inserts this function into llvm.global_ctors.
bool AddressSanitizerModule::runOnModule(Module &M) {
if (!ClGlobals) return false;
- TD = getAnalysisIfAvailable<DataLayout>();
- if (!TD)
+
+ DataLayoutPass *DLP = getAnalysisIfAvailable<DataLayoutPass>();
+ if (!DLP)
return false;
+ DL = &DLP->getDataLayout();
+
BL.reset(SpecialCaseList::createOrDie(BlacklistFile));
if (BL->isIn(M)) return false;
C = &(M.getContext());
- int LongSize = TD->getPointerSizeInBits();
+ int LongSize = DL->getPointerSizeInBits();
IntptrTy = Type::getIntNTy(*C, LongSize);
- Mapping = getShadowMapping(M, LongSize, ZeroBaseShadow);
+ Mapping = getShadowMapping(M, LongSize);
initializeCallbacks(M);
DynamicallyInitializedGlobals.Init(M);
GlobalsToChange.push_back(G);
}
+ Function *CtorFunc = M.getFunction(kAsanModuleCtorName);
+ assert(CtorFunc);
+ IRBuilder<> IRB(CtorFunc->getEntryBlock().getTerminator());
+
+ Function *CovFunc = M.getFunction(kAsanCovName);
+ int nCov = CovFunc ? CovFunc->getNumUses() : 0;
+ IRB.CreateCall(AsanCovModuleInit, ConstantInt::get(IntptrTy, nCov));
+
size_t n = GlobalsToChange.size();
if (n == 0) return false;
IntptrTy, IntptrTy, NULL);
SmallVector<Constant *, 16> Initializers(n);
- Function *CtorFunc = M.getFunction(kAsanModuleCtorName);
- assert(CtorFunc);
- IRBuilder<> IRB(CtorFunc->getEntryBlock().getTerminator());
-
bool HasDynamicallyInitializedGlobals = false;
- GlobalVariable *ModuleName = createPrivateGlobalForString(
- M, M.getModuleIdentifier());
// We shouldn't merge same module names, as this string serves as unique
// module ID in runtime.
- ModuleName->setUnnamedAddr(false);
+ GlobalVariable *ModuleName = createPrivateGlobalForString(
+ M, M.getModuleIdentifier(), /*AllowMerging*/false);
for (size_t i = 0; i < n; i++) {
static const uint64_t kMaxGlobalRedzone = 1 << 18;
GlobalVariable *G = GlobalsToChange[i];
PointerType *PtrTy = cast<PointerType>(G->getType());
Type *Ty = PtrTy->getElementType();
- uint64_t SizeInBytes = TD->getTypeAllocSize(Ty);
- uint64_t MinRZ = RedzoneSize();
+ uint64_t SizeInBytes = DL->getTypeAllocSize(Ty);
+ uint64_t MinRZ = MinRedzoneSizeForGlobal();
// MinRZ <= RZ <= kMaxGlobalRedzone
// and trying to make RZ to be ~ 1/4 of SizeInBytes.
uint64_t RZ = std::max(MinRZ,
NewTy, G->getInitializer(),
Constant::getNullValue(RightRedZoneTy), NULL);
- GlobalVariable *Name = createPrivateGlobalForString(M, G->getName());
+ GlobalVariable *Name =
+ createPrivateGlobalForString(M, G->getName(), /*AllowMerging*/true);
// Create a new global variable with enough space for a redzone.
GlobalValue::LinkageTypes Linkage = G->getLinkage();
for (size_t AccessSizeIndex = 0; AccessSizeIndex < kNumberOfAccessSizes;
AccessSizeIndex++) {
// IsWrite and TypeSize are encoded in the function name.
- std::string FunctionName = std::string(kAsanReportErrorTemplate) +
+ std::string Suffix =
(AccessIsWrite ? "store" : "load") + itostr(1 << AccessSizeIndex);
- // If we are merging crash callbacks, they have two parameters.
AsanErrorCallback[AccessIsWrite][AccessSizeIndex] =
- checkInterfaceFunction(M.getOrInsertFunction(
- FunctionName, IRB.getVoidTy(), IntptrTy, NULL));
+ checkInterfaceFunction(
+ M.getOrInsertFunction(kAsanReportErrorTemplate + Suffix,
+ IRB.getVoidTy(), IntptrTy, NULL));
+ AsanMemoryAccessCallback[AccessIsWrite][AccessSizeIndex] =
+ checkInterfaceFunction(
+ M.getOrInsertFunction(ClMemoryAccessCallbackPrefix + Suffix,
+ IRB.getVoidTy(), IntptrTy, NULL));
}
}
AsanErrorCallbackSized[0] = checkInterfaceFunction(M.getOrInsertFunction(
AsanErrorCallbackSized[1] = checkInterfaceFunction(M.getOrInsertFunction(
kAsanReportStoreN, IRB.getVoidTy(), IntptrTy, IntptrTy, NULL));
- AsanHandleNoReturnFunc = checkInterfaceFunction(M.getOrInsertFunction(
- kAsanHandleNoReturnName, IRB.getVoidTy(), NULL));
+ AsanMemoryAccessCallbackSized[0] = checkInterfaceFunction(
+ M.getOrInsertFunction(ClMemoryAccessCallbackPrefix + "loadN",
+ IRB.getVoidTy(), IntptrTy, IntptrTy, NULL));
+ AsanMemoryAccessCallbackSized[1] = checkInterfaceFunction(
+ M.getOrInsertFunction(ClMemoryAccessCallbackPrefix + "storeN",
+ IRB.getVoidTy(), IntptrTy, IntptrTy, NULL));
+
+ AsanMemmove = checkInterfaceFunction(M.getOrInsertFunction(
+ ClMemoryAccessCallbackPrefix + "memmove", IRB.getInt8PtrTy(),
+ IRB.getInt8PtrTy(), IRB.getInt8PtrTy(), IntptrTy, NULL));
+ AsanMemcpy = checkInterfaceFunction(M.getOrInsertFunction(
+ ClMemoryAccessCallbackPrefix + "memcpy", IRB.getInt8PtrTy(),
+ IRB.getInt8PtrTy(), IRB.getInt8PtrTy(), IntptrTy, NULL));
+ AsanMemset = checkInterfaceFunction(M.getOrInsertFunction(
+ ClMemoryAccessCallbackPrefix + "memset", IRB.getInt8PtrTy(),
+ IRB.getInt8PtrTy(), IRB.getInt32Ty(), IntptrTy, NULL));
+
+ AsanHandleNoReturnFunc = checkInterfaceFunction(
+ M.getOrInsertFunction(kAsanHandleNoReturnName, IRB.getVoidTy(), NULL));
+ AsanCovFunction = checkInterfaceFunction(M.getOrInsertFunction(
+ kAsanCovName, IRB.getVoidTy(), NULL));
+ AsanPtrCmpFunction = checkInterfaceFunction(M.getOrInsertFunction(
+ kAsanPtrCmp, IRB.getVoidTy(), IntptrTy, IntptrTy, NULL));
+ AsanPtrSubFunction = checkInterfaceFunction(M.getOrInsertFunction(
+ kAsanPtrSub, IRB.getVoidTy(), IntptrTy, IntptrTy, NULL));
// We insert an empty inline asm after __asan_report* to avoid callback merge.
EmptyAsm = InlineAsm::get(FunctionType::get(IRB.getVoidTy(), false),
StringRef(""), StringRef(""),
/*hasSideEffects=*/true);
}
-void AddressSanitizer::emitShadowMapping(Module &M, IRBuilder<> &IRB) const {
- // Tell the values of mapping offset and scale to the run-time.
- GlobalValue *asan_mapping_offset =
- new GlobalVariable(M, IntptrTy, true, GlobalValue::LinkOnceODRLinkage,
- ConstantInt::get(IntptrTy, Mapping.Offset),
- kAsanMappingOffsetName);
- // Read the global, otherwise it may be optimized away.
- IRB.CreateLoad(asan_mapping_offset, true);
-
- GlobalValue *asan_mapping_scale =
- new GlobalVariable(M, IntptrTy, true, GlobalValue::LinkOnceODRLinkage,
- ConstantInt::get(IntptrTy, Mapping.Scale),
- kAsanMappingScaleName);
- // Read the global, otherwise it may be optimized away.
- IRB.CreateLoad(asan_mapping_scale, true);
-}
-
// virtual
bool AddressSanitizer::doInitialization(Module &M) {
// Initialize the private fields. No one has accessed them before.
- TD = getAnalysisIfAvailable<DataLayout>();
+ DataLayoutPass *DLP = getAnalysisIfAvailable<DataLayoutPass>();
+ if (!DLP)
+ report_fatal_error("data layout missing");
+ DL = &DLP->getDataLayout();
- if (!TD)
- return false;
BL.reset(SpecialCaseList::createOrDie(BlacklistFile));
DynamicallyInitializedGlobals.Init(M);
C = &(M.getContext());
- LongSize = TD->getPointerSizeInBits();
+ LongSize = DL->getPointerSizeInBits();
IntptrTy = Type::getIntNTy(*C, LongSize);
AsanCtorFunction = Function::Create(
AsanInitFunction->setLinkage(Function::ExternalLinkage);
IRB.CreateCall(AsanInitFunction);
- Mapping = getShadowMapping(M, LongSize, ZeroBaseShadow);
- emitShadowMapping(M, IRB);
+ Mapping = getShadowMapping(M, LongSize);
appendToGlobalCtors(M, AsanCtorFunction, kAsanCtorAndCtorPriority);
return true;
return false;
}
+void AddressSanitizer::InjectCoverageAtBlock(Function &F, BasicBlock &BB) {
+ BasicBlock::iterator IP = BB.getFirstInsertionPt(), BE = BB.end();
+ // Skip static allocas at the top of the entry block so they don't become
+ // dynamic when we split the block. If we used our optimized stack layout,
+ // then there will only be one alloca and it will come first.
+ for (; IP != BE; ++IP) {
+ AllocaInst *AI = dyn_cast<AllocaInst>(IP);
+ if (!AI || !AI->isStaticAlloca())
+ break;
+ }
+
+ IRBuilder<> IRB(IP);
+ Type *Int8Ty = IRB.getInt8Ty();
+ GlobalVariable *Guard = new GlobalVariable(
+ *F.getParent(), Int8Ty, false, GlobalValue::PrivateLinkage,
+ Constant::getNullValue(Int8Ty), "__asan_gen_cov_" + F.getName());
+ LoadInst *Load = IRB.CreateLoad(Guard);
+ Load->setAtomic(Monotonic);
+ Load->setAlignment(1);
+ Value *Cmp = IRB.CreateICmpEQ(Constant::getNullValue(Int8Ty), Load);
+ Instruction *Ins = SplitBlockAndInsertIfThen(
+ Cmp, IP, false, MDBuilder(*C).createBranchWeights(1, 100000));
+ IRB.SetInsertPoint(Ins);
+ // We pass &F to __sanitizer_cov. We could avoid this and rely on
+ // GET_CALLER_PC, but having the PC of the first instruction is just nice.
+ Instruction *Call = IRB.CreateCall(AsanCovFunction);
+ Call->setDebugLoc(IP->getDebugLoc());
+ StoreInst *Store = IRB.CreateStore(ConstantInt::get(Int8Ty, 1), Guard);
+ Store->setAtomic(Monotonic);
+ Store->setAlignment(1);
+}
+
+// Poor man's coverage that works with ASan.
+// We create a Guard boolean variable with the same linkage
+// as the function and inject this code into the entry block (-asan-coverage=1)
+// or all blocks (-asan-coverage=2):
+// if (*Guard) {
+// __sanitizer_cov(&F);
+// *Guard = 1;
+// }
+// The accesses to Guard are atomic. The rest of the logic is
+// in __sanitizer_cov (it's fine to call it more than once).
+//
+// This coverage implementation provides very limited data:
+// it only tells if a given function (block) was ever executed.
+// No counters, no per-edge data.
+// But for many use cases this is what we need and the added slowdown
+// is negligible. This simple implementation will probably be obsoleted
+// by the upcoming Clang-based coverage implementation.
+// By having it here and now we hope to
+// a) get the functionality to users earlier and
+// b) collect usage statistics to help improve Clang coverage design.
+bool AddressSanitizer::InjectCoverage(Function &F,
+ const ArrayRef<BasicBlock *> AllBlocks) {
+ if (!ClCoverage) return false;
+
+ if (ClCoverage == 1 ||
+ (unsigned)ClCoverageBlockThreshold < AllBlocks.size()) {
+ InjectCoverageAtBlock(F, F.getEntryBlock());
+ } else {
+ for (size_t i = 0, n = AllBlocks.size(); i < n; i++)
+ InjectCoverageAtBlock(F, *AllBlocks[i]);
+ }
+ return true;
+}
+
bool AddressSanitizer::runOnFunction(Function &F) {
if (BL->isIn(F)) return false;
if (&F == AsanCtorFunction) return false;
SmallSet<Value*, 16> TempsToInstrument;
SmallVector<Instruction*, 16> ToInstrument;
SmallVector<Instruction*, 8> NoReturnCalls;
+ SmallVector<BasicBlock*, 16> AllBlocks;
+ SmallVector<Instruction*, 16> PointerComparisonsOrSubtracts;
int NumAllocas = 0;
bool IsWrite;
+ unsigned Alignment;
// Fill the set of memory operations to instrument.
for (Function::iterator FI = F.begin(), FE = F.end();
FI != FE; ++FI) {
+ AllBlocks.push_back(FI);
TempsToInstrument.clear();
int NumInsnsPerBB = 0;
for (BasicBlock::iterator BI = FI->begin(), BE = FI->end();
BI != BE; ++BI) {
if (LooksLikeCodeInBug11395(BI)) return false;
- if (Value *Addr = isInterestingMemoryAccess(BI, &IsWrite)) {
+ if (Value *Addr = isInterestingMemoryAccess(BI, &IsWrite, &Alignment)) {
if (ClOpt && ClOptSameTemp) {
if (!TempsToInstrument.insert(Addr))
continue; // We've seen this temp in the current BB.
}
- } else if (isa<MemIntrinsic>(BI) && ClMemIntrin) {
+ } else if (ClInvalidPointerPairs &&
+ isInterestingPointerComparisonOrSubtraction(BI)) {
+ PointerComparisonsOrSubtracts.push_back(BI);
+ continue;
+ } else if (isa<MemIntrinsic>(BI)) {
// ok, take it.
} else {
if (isa<AllocaInst>(BI))
}
}
- Function *UninstrumentedDuplicate = 0;
+ Function *UninstrumentedDuplicate = nullptr;
bool LikelyToInstrument =
!NoReturnCalls.empty() || !ToInstrument.empty() || (NumAllocas > 0);
if (ClKeepUninstrumented && LikelyToInstrument) {
F.getParent()->getFunctionList().push_back(UninstrumentedDuplicate);
}
+ bool UseCalls = false;
+ if (ClInstrumentationWithCallsThreshold >= 0 &&
+ ToInstrument.size() > (unsigned)ClInstrumentationWithCallsThreshold)
+ UseCalls = true;
+
// 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 (isInterestingMemoryAccess(Inst, &IsWrite))
- instrumentMop(Inst);
+ if (isInterestingMemoryAccess(Inst, &IsWrite, &Alignment))
+ instrumentMop(Inst, UseCalls);
else
instrumentMemIntrinsic(cast<MemIntrinsic>(Inst));
}
IRB.CreateCall(AsanHandleNoReturnFunc);
}
+ for (size_t i = 0, n = PointerComparisonsOrSubtracts.size(); i != n; i++) {
+ instrumentPointerComparisonOrSubtraction(PointerComparisonsOrSubtracts[i]);
+ NumInstrumented++;
+ }
+
bool res = NumInstrumented > 0 || ChangedStack || !NoReturnCalls.empty();
+
+ if (InjectCoverage(F, AllBlocks))
+ res = true;
+
DEBUG(dbgs() << "ASAN done instrumenting: " << res << " " << F << "\n");
if (ClKeepUninstrumented) {
return res;
}
-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 RZSize,
- size_t ShadowGranularity,
- uint8_t Magic) {
- for (size_t i = 0; i < RZSize;
- 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
- }
- }
-}
-
// Workaround for bug 11395: we don't want to instrument stack in functions
// with large assembly blobs (32-bit only), otherwise reg alloc may crash.
// FIXME: remove once the bug 11395 is fixed.
kAsanUnpoisonStackMemoryName, IRB.getVoidTy(), IntptrTy, IntptrTy, NULL));
}
-void FunctionStackPoisoner::poisonRedZones(
- const ArrayRef<AllocaInst*> &AllocaVec, IRBuilder<> &IRB, Value *ShadowBase,
- bool DoPoison) {
- size_t ShadowRZSize = RedzoneSize() >> Mapping.Scale;
- 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 >> Mapping.Scale) - ShadowRZSize));
- size_t AddressableBytes = RedzoneSize() - (AlignedSize - SizeInBytes);
- uint32_t Poison = 0;
- if (DoPoison) {
- PoisonShadowPartialRightRedzone((uint8_t*)&Poison, AddressableBytes,
- RedzoneSize(),
- 1ULL << Mapping.Scale,
- kAsanStackPartialRedzoneMagic);
- Poison =
- ASan.TD->isLittleEndian()
- ? support::endian::byte_swap<uint32_t, support::little>(Poison)
- : support::endian::byte_swap<uint32_t, support::big>(Poison);
+void
+FunctionStackPoisoner::poisonRedZones(const ArrayRef<uint8_t> ShadowBytes,
+ IRBuilder<> &IRB, Value *ShadowBase,
+ bool DoPoison) {
+ size_t n = ShadowBytes.size();
+ size_t i = 0;
+ // We need to (un)poison n bytes of stack shadow. Poison as many as we can
+ // using 64-bit stores (if we are on 64-bit arch), then poison the rest
+ // with 32-bit stores, then with 16-byte stores, then with 8-byte stores.
+ for (size_t LargeStoreSizeInBytes = ASan.LongSize / 8;
+ LargeStoreSizeInBytes != 0; LargeStoreSizeInBytes /= 2) {
+ for (; i + LargeStoreSizeInBytes - 1 < n; i += LargeStoreSizeInBytes) {
+ uint64_t Val = 0;
+ for (size_t j = 0; j < LargeStoreSizeInBytes; j++) {
+ if (ASan.DL->isLittleEndian())
+ Val |= (uint64_t)ShadowBytes[i + j] << (8 * j);
+ else
+ Val = (Val << 8) | ShadowBytes[i + j];
}
- Value *PartialPoison = ConstantInt::get(RZTy, Poison);
- IRB.CreateStore(PartialPoison, IRB.CreateIntToPtr(Ptr, RZPtrTy));
+ if (!Val) continue;
+ Value *Ptr = IRB.CreateAdd(ShadowBase, ConstantInt::get(IntptrTy, i));
+ Type *StoreTy = Type::getIntNTy(*C, LargeStoreSizeInBytes * 8);
+ Value *Poison = ConstantInt::get(StoreTy, DoPoison ? Val : 0);
+ IRB.CreateStore(Poison, IRB.CreateIntToPtr(Ptr, StoreTy->getPointerTo()));
}
-
- // Poison the full redzone at right.
- Ptr = IRB.CreateAdd(ShadowBase,
- ConstantInt::get(IntptrTy, Pos >> Mapping.Scale));
- bool LastAlloca = (i == AllocaVec.size() - 1);
- Value *Poison = LastAlloca ? PoisonRight : PoisonMid;
- IRB.CreateStore(Poison, IRB.CreateIntToPtr(Ptr, RZPtrTy));
-
- Pos += RedzoneSize();
}
}
}
}
-void FunctionStackPoisoner::poisonStack() {
- uint64_t LocalStackSize = TotalStackSize +
- (AllocaVec.size() + 1) * RedzoneSize();
+static DebugLoc getFunctionEntryDebugLocation(Function &F) {
+ BasicBlock::iterator I = F.getEntryBlock().begin(),
+ E = F.getEntryBlock().end();
+ for (; I != E; ++I)
+ if (!isa<AllocaInst>(I))
+ break;
+ return I->getDebugLoc();
+}
- bool DoStackMalloc = ASan.CheckUseAfterReturn
- && LocalStackSize <= kMaxStackMallocSize;
+void FunctionStackPoisoner::poisonStack() {
int StackMallocIdx = -1;
+ DebugLoc EntryDebugLocation = getFunctionEntryDebugLocation(F);
assert(AllocaVec.size() > 0);
Instruction *InsBefore = AllocaVec[0];
IRBuilder<> IRB(InsBefore);
+ IRB.SetCurrentDebugLocation(EntryDebugLocation);
+ SmallVector<ASanStackVariableDescription, 16> SVD;
+ SVD.reserve(AllocaVec.size());
+ for (size_t i = 0, n = AllocaVec.size(); i < n; i++) {
+ AllocaInst *AI = AllocaVec[i];
+ ASanStackVariableDescription D = { AI->getName().data(),
+ getAllocaSizeInBytes(AI),
+ AI->getAlignment(), AI, 0};
+ SVD.push_back(D);
+ }
+ // Minimal header size (left redzone) is 4 pointers,
+ // i.e. 32 bytes on 64-bit platforms and 16 bytes in 32-bit platforms.
+ size_t MinHeaderSize = ASan.LongSize / 2;
+ ASanStackFrameLayout L;
+ ComputeASanStackFrameLayout(SVD, 1UL << Mapping.Scale, MinHeaderSize, &L);
+ DEBUG(dbgs() << L.DescriptionString << " --- " << L.FrameSize << "\n");
+ uint64_t LocalStackSize = L.FrameSize;
+ bool DoStackMalloc =
+ ASan.CheckUseAfterReturn && LocalStackSize <= kMaxStackMallocSize;
Type *ByteArrayTy = ArrayType::get(IRB.getInt8Ty(), LocalStackSize);
AllocaInst *MyAlloca =
new AllocaInst(ByteArrayTy, "MyAlloca", InsBefore);
- if (ClRealignStack && StackAlignment < RedzoneSize())
- StackAlignment = RedzoneSize();
- MyAlloca->setAlignment(StackAlignment);
+ MyAlloca->setDebugLoc(EntryDebugLocation);
+ assert((ClRealignStack & (ClRealignStack - 1)) == 0);
+ size_t FrameAlignment = std::max(L.FrameAlignment, (size_t)ClRealignStack);
+ MyAlloca->setAlignment(FrameAlignment);
assert(MyAlloca->isStaticAlloca());
Value *OrigStackBase = IRB.CreatePointerCast(MyAlloca, IntptrTy);
Value *LocalStackBase = OrigStackBase;
kAsanOptionDetectUAR, IRB.getInt32Ty());
Value *Cmp = IRB.CreateICmpNE(IRB.CreateLoad(OptionDetectUAR),
Constant::getNullValue(IRB.getInt32Ty()));
- Instruction *Term =
- SplitBlockAndInsertIfThen(cast<Instruction>(Cmp), false);
+ Instruction *Term = SplitBlockAndInsertIfThen(Cmp, InsBefore, false);
BasicBlock *CmpBlock = cast<Instruction>(Cmp)->getParent();
IRBuilder<> IRBIf(Term);
+ IRBIf.SetCurrentDebugLocation(EntryDebugLocation);
LocalStackBase = IRBIf.CreateCall2(
AsanStackMallocFunc[StackMallocIdx],
ConstantInt::get(IntptrTy, LocalStackSize), OrigStackBase);
BasicBlock *SetBlock = cast<Instruction>(LocalStackBase)->getParent();
IRB.SetInsertPoint(InsBefore);
+ IRB.SetCurrentDebugLocation(EntryDebugLocation);
PHINode *Phi = IRB.CreatePHI(IntptrTy, 2);
Phi->addIncoming(OrigStackBase, CmpBlock);
Phi->addIncoming(LocalStackBase, SetBlock);
LocalStackBase = Phi;
}
- // This string will be parsed by the run-time (DescribeAddressIfStack).
- SmallString<2048> StackDescriptionStorage;
- raw_svector_ostream StackDescription(StackDescriptionStorage);
- StackDescription << AllocaVec.size() << " ";
-
// Insert poison calls for lifetime intrinsics for alloca.
bool HavePoisonedAllocas = false;
for (size_t i = 0, n = AllocaPoisonCallVec.size(); i < n; i++) {
const AllocaPoisonCall &APC = AllocaPoisonCallVec[i];
- IntrinsicInst *II = APC.InsBefore;
- AllocaInst *AI = findAllocaForValue(II->getArgOperand(1));
- assert(AI);
- IRBuilder<> IRB(II);
- poisonAlloca(AI, APC.Size, IRB, APC.DoPoison);
+ assert(APC.InsBefore);
+ assert(APC.AI);
+ IRBuilder<> IRB(APC.InsBefore);
+ poisonAlloca(APC.AI, APC.Size, IRB, APC.DoPoison);
HavePoisonedAllocas |= APC.DoPoison;
}
- 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);
+ for (size_t i = 0, n = SVD.size(); i < n; i++) {
+ AllocaInst *AI = SVD[i].AI;
Value *NewAllocaPtr = IRB.CreateIntToPtr(
- IRB.CreateAdd(LocalStackBase, ConstantInt::get(IntptrTy, Pos)),
- AI->getType());
+ IRB.CreateAdd(LocalStackBase,
+ ConstantInt::get(IntptrTy, SVD[i].Offset)),
+ AI->getType());
replaceDbgDeclareForAlloca(AI, NewAllocaPtr, DIB);
AI->replaceAllUsesWith(NewAllocaPtr);
- Pos += AlignedSize + RedzoneSize();
}
- assert(Pos == LocalStackSize);
// The left-most redzone has enough space for at least 4 pointers.
// Write the Magic value to redzone[0].
IRB.CreateAdd(LocalStackBase, ConstantInt::get(IntptrTy, ASan.LongSize/8)),
IntptrPtrTy);
GlobalVariable *StackDescriptionGlobal =
- createPrivateGlobalForString(*F.getParent(), StackDescription.str());
+ createPrivateGlobalForString(*F.getParent(), L.DescriptionString,
+ /*AllowMerging*/true);
Value *Description = IRB.CreatePointerCast(StackDescriptionGlobal,
IntptrTy);
IRB.CreateStore(Description, BasePlus1);
// Poison the stack redzones at the entry.
Value *ShadowBase = ASan.memToShadow(LocalStackBase, IRB);
- poisonRedZones(AllocaVec, IRB, ShadowBase, true);
+ poisonRedZones(L.ShadowBytes, IRB, ShadowBase, true);
- // Unpoison the stack before all ret instructions.
+ // (Un)poison 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.
- poisonRedZones(AllocaVec, IRBRet, ShadowBase, false);
if (DoStackMalloc) {
assert(StackMallocIdx >= 0);
- // In use-after-return mode, mark the whole stack frame unaddressable.
+ // if LocalStackBase != OrigStackBase:
+ // // In use-after-return mode, poison the whole stack frame.
+ // if StackMallocIdx <= 4
+ // // For small sizes inline the whole thing:
+ // memset(ShadowBase, kAsanStackAfterReturnMagic, ShadowSize);
+ // **SavedFlagPtr(LocalStackBase) = 0
+ // else
+ // __asan_stack_free_N(LocalStackBase, OrigStackBase)
+ // else
+ // <This is not a fake stack; unpoison the redzones>
+ Value *Cmp = IRBRet.CreateICmpNE(LocalStackBase, OrigStackBase);
+ TerminatorInst *ThenTerm, *ElseTerm;
+ SplitBlockAndInsertIfThenElse(Cmp, Ret, &ThenTerm, &ElseTerm);
+
+ IRBuilder<> IRBPoison(ThenTerm);
if (StackMallocIdx <= 4) {
- // For small sizes inline the whole thing:
- // if LocalStackBase != OrigStackBase:
- // memset(ShadowBase, kAsanStackAfterReturnMagic, ShadowSize);
- // **SavedFlagPtr(LocalStackBase) = 0
- // FIXME: if LocalStackBase != OrigStackBase don't call poisonRedZones.
- Value *Cmp = IRBRet.CreateICmpNE(LocalStackBase, OrigStackBase);
- TerminatorInst *PoisonTerm =
- SplitBlockAndInsertIfThen(cast<Instruction>(Cmp), false);
- IRBuilder<> IRBPoison(PoisonTerm);
int ClassSize = kMinStackMallocSize << StackMallocIdx;
SetShadowToStackAfterReturnInlined(IRBPoison, ShadowBase,
ClassSize >> Mapping.Scale);
IRBPoison.CreateIntToPtr(SavedFlagPtr, IRBPoison.getInt8PtrTy()));
} else {
// For larger frames call __asan_stack_free_*.
- IRBRet.CreateCall3(AsanStackFreeFunc[StackMallocIdx], LocalStackBase,
- ConstantInt::get(IntptrTy, LocalStackSize),
- OrigStackBase);
+ IRBPoison.CreateCall3(AsanStackFreeFunc[StackMallocIdx], LocalStackBase,
+ ConstantInt::get(IntptrTy, LocalStackSize),
+ OrigStackBase);
}
+
+ IRBuilder<> IRBElse(ElseTerm);
+ poisonRedZones(L.ShadowBytes, IRBElse, ShadowBase, false);
} else if (HavePoisonedAllocas) {
// If we poisoned some allocas in llvm.lifetime analysis,
// unpoison whole stack frame now.
assert(LocalStackBase == OrigStackBase);
poisonAlloca(LocalStackBase, LocalStackSize, IRBRet, false);
+ } else {
+ poisonRedZones(L.ShadowBytes, IRBRet, ShadowBase, false);
}
}
AllocaInst *FunctionStackPoisoner::findAllocaForValue(Value *V) {
if (AllocaInst *AI = dyn_cast<AllocaInst>(V))
// We're intested only in allocas we can handle.
- return isInterestingAlloca(*AI) ? AI : 0;
+ return isInterestingAlloca(*AI) ? AI : nullptr;
// See if we've already calculated (or started to calculate) alloca for a
// given value.
AllocaForValueMapTy::iterator I = AllocaForValue.find(V);
return I->second;
// Store 0 while we're calculating alloca for value V to avoid
// infinite recursion if the value references itself.
- AllocaForValue[V] = 0;
- AllocaInst *Res = 0;
+ AllocaForValue[V] = nullptr;
+ AllocaInst *Res = nullptr;
if (CastInst *CI = dyn_cast<CastInst>(V))
Res = findAllocaForValue(CI->getOperand(0));
else if (PHINode *PN = dyn_cast<PHINode>(V)) {
if (IncValue == PN) continue;
AllocaInst *IncValueAI = findAllocaForValue(IncValue);
// AI for incoming values should exist and should all be equal.
- if (IncValueAI == 0 || (Res != 0 && IncValueAI != Res))
- return 0;
+ if (IncValueAI == nullptr || (Res != nullptr && IncValueAI != Res))
+ return nullptr;
Res = IncValueAI;
}
}
- if (Res != 0)
+ if (Res)
AllocaForValue[V] = Res;
return Res;
}
projects / oota-llvm.git / blobdiff