#define DEBUG_TYPE "asan"
#include "llvm/Transforms/Instrumentation.h"
-#include "BlackList.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/StringExtras.h"
#include "llvm/ADT/Triple.h"
-#include "llvm/DataLayout.h"
-#include "llvm/Function.h"
-#include "llvm/IRBuilder.h"
-#include "llvm/InlineAsm.h"
-#include "llvm/IntrinsicInst.h"
-#include "llvm/LLVMContext.h"
-#include "llvm/Module.h"
+#include "llvm/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/IntrinsicInst.h"
+#include "llvm/IR/LLVMContext.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/system_error.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
+#include "llvm/Transforms/Utils/BlackList.h"
+#include "llvm/Transforms/Utils/Local.h"
#include "llvm/Transforms/Utils/ModuleUtils.h"
-#include "llvm/Type.h"
#include <algorithm>
#include <string>
static const uint64_t kDefaultShadowScale = 3;
static const uint64_t kDefaultShadowOffset32 = 1ULL << 29;
static const uint64_t kDefaultShadowOffset64 = 1ULL << 44;
-static const uint64_t kDefaultShadowOffsetAndroid = 0;
+static const uint64_t kDefaultShort64bitShadowOffset = 0x7FFF8000; // < 2G.
+static const uint64_t kPPC64_ShadowOffset64 = 1ULL << 41;
static const size_t kMaxStackMallocSize = 1 << 16; // 64K
static const uintptr_t kCurrentStackFrameMagic = 0x41B58AB3;
static const char *kAsanModuleDtorName = "asan.module_dtor";
static const int kAsanCtorAndCtorPriority = 1;
static const char *kAsanReportErrorTemplate = "__asan_report_";
+static const char *kAsanReportLoadN = "__asan_report_load_n";
+static const char *kAsanReportStoreN = "__asan_report_store_n";
static const char *kAsanRegisterGlobalsName = "__asan_register_globals";
static const char *kAsanUnregisterGlobalsName = "__asan_unregister_globals";
static const char *kAsanPoisonGlobalsName = "__asan_before_dynamic_init";
static const char *kAsanUnpoisonGlobalsName = "__asan_after_dynamic_init";
-static const char *kAsanInitName = "__asan_init";
+static const char *kAsanInitName = "__asan_init_v2";
static const char *kAsanHandleNoReturnName = "__asan_handle_no_return";
static const char *kAsanMappingOffsetName = "__asan_mapping_offset";
static const char *kAsanMappingScaleName = "__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.
SmallSet<GlobalValue*, 32> DynInitGlobals;
};
-static int MappingScale() {
- return ClMappingScale ? ClMappingScale : kDefaultShadowScale;
+/// This struct defines the shadow mapping using the rule:
+/// shadow = (mem >> Scale) ADD-or-OR Offset.
+struct ShadowMapping {
+ int Scale;
+ uint64_t Offset;
+ bool OrShadowOffset;
+};
+
+static ShadowMapping getShadowMapping(const Module &M, int LongSize,
+ bool ZeroBaseShadow) {
+ llvm::Triple TargetTriple(M.getTargetTriple());
+ bool IsAndroid = TargetTriple.getEnvironment() == llvm::Triple::Android;
+ bool IsMacOSX = TargetTriple.getOS() == llvm::Triple::MacOSX;
+ bool IsPPC64 = TargetTriple.getArch() == llvm::Triple::ppc64;
+ 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 ? 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;
+ }
+
+ Mapping.Scale = kDefaultShadowScale;
+ if (ClMappingScale) {
+ Mapping.Scale = ClMappingScale;
+ }
+
+ return Mapping;
}
-static size_t RedzoneSize() {
+static size_t RedzoneSizeForScale(int MappingScale) {
// 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.
- return std::max(32U, 1U << MappingScale());
+ return std::max(32U, 1U << MappingScale);
}
/// AddressSanitizer: instrument the code in module to find memory bugs.
struct AddressSanitizer : public FunctionPass {
- AddressSanitizer(bool CheckInitOrder = false,
+ AddressSanitizer(bool CheckInitOrder = true,
bool CheckUseAfterReturn = false,
bool CheckLifetime = false,
- StringRef BlacklistFile = StringRef())
+ StringRef BlacklistFile = StringRef(),
+ bool ZeroBaseShadow = false)
: FunctionPass(ID),
CheckInitOrder(CheckInitOrder || ClInitializers),
CheckUseAfterReturn(CheckUseAfterReturn || ClUseAfterReturn),
CheckLifetime(CheckLifetime || ClCheckLifetime),
BlacklistFile(BlacklistFile.empty() ? ClBlacklistFile
- : BlacklistFile) {}
+ : BlacklistFile),
+ ZeroBaseShadow(ZeroBaseShadow) {}
virtual const char *getPassName() const {
return "AddressSanitizerFunctionPass";
}
void instrumentMop(Instruction *I);
- void instrumentAddress(Instruction *OrigIns, IRBuilder<> &IRB,
- Value *Addr, uint32_t TypeSize, bool IsWrite);
+ void instrumentAddress(Instruction *OrigIns, Instruction *InsertBefore,
+ Value *Addr, uint32_t TypeSize, bool IsWrite,
+ Value *SizeArgument);
Value *createSlowPathCmp(IRBuilder<> &IRB, Value *AddrLong,
Value *ShadowValue, uint32_t TypeSize);
Instruction *generateCrashCode(Instruction *InsertBefore, Value *Addr,
- bool IsWrite, size_t AccessSizeIndex);
+ bool IsWrite, size_t AccessSizeIndex,
+ Value *SizeArgument);
bool instrumentMemIntrinsic(MemIntrinsic *MI);
void instrumentMemIntrinsicParam(Instruction *OrigIns, Value *Addr,
Value *Size,
void createInitializerPoisonCalls(Module &M,
Value *FirstAddr, Value *LastAddr);
bool maybeInsertAsanInitAtFunctionEntry(Function &F);
- bool poisonStackInFunction(Function &F);
+ void emitShadowMapping(Module &M, IRBuilder<> &IRB) const;
virtual bool doInitialization(Module &M);
static char ID; // Pass identification, replacement for typeid
private:
void initializeCallbacks(Module &M);
- uint64_t getAllocaSizeInBytes(AllocaInst *AI) {
- Type *Ty = AI->getAllocatedType();
- uint64_t SizeInBytes = TD->getTypeAllocSize(Ty);
- return SizeInBytes;
- }
- uint64_t getAlignedSize(uint64_t SizeInBytes) {
- size_t RZ = RedzoneSize();
- return ((SizeInBytes + RZ - 1) / RZ) * RZ;
- }
- uint64_t getAlignedAllocaSize(AllocaInst *AI) {
- uint64_t SizeInBytes = getAllocaSizeInBytes(AI);
- return getAlignedSize(SizeInBytes);
- }
bool ShouldInstrumentGlobal(GlobalVariable *G);
- void PoisonStack(const ArrayRef<AllocaInst*> &AllocaVec, IRBuilder<> IRB,
- Value *ShadowBase, bool DoPoison);
bool LooksLikeCodeInBug11395(Instruction *I);
void FindDynamicInitializers(Module &M);
- /// Analyze lifetime intrinsics for given alloca. Use Value* instead of
- /// AllocaInst* here, as we call this method after we merge all allocas into a
- /// single one. Returns true if ASan added some instrumentation.
- bool handleAllocaLifetime(Value *Alloca);
- /// Analyze lifetime intrinsics for a specific value, casted from alloca.
- /// Returns true if if ASan added some instrumentation.
- bool handleValueLifetime(Value *V);
- void poisonAlloca(Value *V, uint64_t Size, IRBuilder<> IRB, bool DoPoison);
bool CheckInitOrder;
bool CheckUseAfterReturn;
bool CheckLifetime;
+ SmallString<64> BlacklistFile;
+ bool ZeroBaseShadow;
+
LLVMContext *C;
DataLayout *TD;
- uint64_t MappingOffset;
int LongSize;
Type *IntptrTy;
- Type *IntptrPtrTy;
+ ShadowMapping Mapping;
Function *AsanCtorFunction;
Function *AsanInitFunction;
- Function *AsanStackMallocFunc, *AsanStackFreeFunc;
- Function *AsanPoisonStackMemoryFunc, *AsanUnpoisonStackMemoryFunc;
Function *AsanHandleNoReturnFunc;
- SmallString<64> BlacklistFile;
OwningPtr<BlackList> BL;
// This array is indexed by AccessIsWrite and log2(AccessSize).
Function *AsanErrorCallback[2][kNumberOfAccessSizes];
+ // This array is indexed by AccessIsWrite.
+ Function *AsanErrorCallbackSized[2];
InlineAsm *EmptyAsm;
SetOfDynamicallyInitializedGlobals DynamicallyInitializedGlobals;
+
+ friend struct FunctionStackPoisoner;
};
class AddressSanitizerModule : public ModulePass {
public:
- AddressSanitizerModule(bool CheckInitOrder = false,
- StringRef BlacklistFile = StringRef())
+ AddressSanitizerModule(bool CheckInitOrder = true,
+ StringRef BlacklistFile = StringRef(),
+ bool ZeroBaseShadow = false)
: ModulePass(ID),
CheckInitOrder(CheckInitOrder || ClInitializers),
BlacklistFile(BlacklistFile.empty() ? ClBlacklistFile
- : BlacklistFile) {}
+ : BlacklistFile),
+ ZeroBaseShadow(ZeroBaseShadow) {}
bool runOnModule(Module &M);
static char ID; // Pass identification, replacement for typeid
virtual const char *getPassName() const {
}
private:
+ void initializeCallbacks(Module &M);
+
bool ShouldInstrumentGlobal(GlobalVariable *G);
void createInitializerPoisonCalls(Module &M, Value *FirstAddr,
Value *LastAddr);
+ size_t RedzoneSize() const {
+ return RedzoneSizeForScale(Mapping.Scale);
+ }
bool CheckInitOrder;
SmallString<64> BlacklistFile;
+ bool ZeroBaseShadow;
+
OwningPtr<BlackList> BL;
SetOfDynamicallyInitializedGlobals DynamicallyInitializedGlobals;
Type *IntptrTy;
LLVMContext *C;
DataLayout *TD;
+ ShadowMapping Mapping;
+ Function *AsanPoisonGlobals;
+ Function *AsanUnpoisonGlobals;
+ Function *AsanRegisterGlobals;
+ Function *AsanUnregisterGlobals;
+};
+
+// 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.
+struct FunctionStackPoisoner : public InstVisitor<FunctionStackPoisoner> {
+ Function &F;
+ AddressSanitizer &ASan;
+ DIBuilder DIB;
+ LLVMContext *C;
+ Type *IntptrTy;
+ Type *IntptrPtrTy;
+ ShadowMapping Mapping;
+
+ SmallVector<AllocaInst*, 16> AllocaVec;
+ SmallVector<Instruction*, 8> RetVec;
+ uint64_t TotalStackSize;
+ unsigned StackAlignment;
+
+ Function *AsanStackMallocFunc, *AsanStackFreeFunc;
+ Function *AsanPoisonStackMemoryFunc, *AsanUnpoisonStackMemoryFunc;
+
+ // Stores a place and arguments of poisoning/unpoisoning call for alloca.
+ struct AllocaPoisonCall {
+ IntrinsicInst *InsBefore;
+ uint64_t Size;
+ bool DoPoison;
+ };
+ SmallVector<AllocaPoisonCall, 8> AllocaPoisonCallVec;
+
+ // Maps Value to an AllocaInst from which the Value is originated.
+ typedef DenseMap<Value*, AllocaInst*> AllocaForValueMapTy;
+ AllocaForValueMapTy AllocaForValue;
+
+ FunctionStackPoisoner(Function &F, AddressSanitizer &ASan)
+ : 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) {}
+
+ 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;
+ visit(*BB);
+ }
+ if (AllocaVec.empty()) return false;
+
+ initializeCallbacks(*F.getParent());
+
+ poisonStack();
+
+ if (ClDebugStack) {
+ DEBUG(dbgs() << F);
+ }
+ return true;
+ }
+
+ // Finds all static Alloca instructions and puts
+ // poisoned red zones around all of them.
+ // Then unpoison everything back before the function returns.
+ void poisonStack();
+
+ // ----------------------- Visitors.
+ /// \brief Collect all Ret instructions.
+ void visitReturnInst(ReturnInst &RI) {
+ RetVec.push_back(&RI);
+ }
+
+ /// \brief Collect Alloca instructions we want (and can) handle.
+ void visitAllocaInst(AllocaInst &AI) {
+ if (!isInterestingAlloca(AI)) return;
+
+ 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
+ /// errors.
+ void visitIntrinsicInst(IntrinsicInst &II) {
+ if (!ASan.CheckLifetime) return;
+ Intrinsic::ID ID = II.getIntrinsicID();
+ if (ID != Intrinsic::lifetime_start &&
+ ID != Intrinsic::lifetime_end)
+ return;
+ // Found lifetime intrinsic, add ASan instrumentation if necessary.
+ ConstantInt *Size = dyn_cast<ConstantInt>(II.getArgOperand(0));
+ // If size argument is undefined, don't do anything.
+ if (Size->isMinusOne()) return;
+ // Check that size doesn't saturate uint64_t and can
+ // be stored in IntptrTy.
+ const uint64_t SizeValue = Size->getValue().getLimitedValue();
+ if (SizeValue == ~0ULL ||
+ !ConstantInt::isValueValidForType(IntptrTy, SizeValue))
+ return;
+ // Find alloca instruction that corresponds to llvm.lifetime argument.
+ AllocaInst *AI = findAllocaForValue(II.getArgOperand(1));
+ if (!AI) return;
+ bool DoPoison = (ID == Intrinsic::lifetime_end);
+ AllocaPoisonCall APC = {&II, SizeValue, DoPoison};
+ AllocaPoisonCallVec.push_back(APC);
+ }
+
+ // ---------------------- Helpers.
+ void initializeCallbacks(Module &M);
+
+ // Check if we want (and can) handle this alloca.
+ bool isInterestingAlloca(AllocaInst &AI) {
+ return (!AI.isArrayAllocation() &&
+ AI.isStaticAlloca() &&
+ AI.getAllocatedType()->isSized());
+ }
+
+ size_t RedzoneSize() const {
+ return RedzoneSizeForScale(Mapping.Scale);
+ }
+ uint64_t getAllocaSizeInBytes(AllocaInst *AI) {
+ Type *Ty = AI->getAllocatedType();
+ uint64_t SizeInBytes = ASan.TD->getTypeAllocSize(Ty);
+ return SizeInBytes;
+ }
+ uint64_t getAlignedSize(uint64_t SizeInBytes) {
+ size_t RZ = RedzoneSize();
+ return ((SizeInBytes + RZ - 1) / RZ) * RZ;
+ }
+ uint64_t getAlignedAllocaSize(AllocaInst *AI) {
+ 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,
+ Value *ShadowBase, bool DoPoison);
+ void poisonAlloca(Value *V, uint64_t Size, IRBuilder<> IRB, bool DoPoison);
};
} // namespace
false, false)
FunctionPass *llvm::createAddressSanitizerFunctionPass(
bool CheckInitOrder, bool CheckUseAfterReturn, bool CheckLifetime,
- StringRef BlacklistFile) {
+ StringRef BlacklistFile, bool ZeroBaseShadow) {
return new AddressSanitizer(CheckInitOrder, CheckUseAfterReturn,
- CheckLifetime, BlacklistFile);
+ CheckLifetime, BlacklistFile, ZeroBaseShadow);
}
char AddressSanitizerModule::ID = 0;
"AddressSanitizer: detects use-after-free and out-of-bounds bugs."
"ModulePass", false, false)
ModulePass *llvm::createAddressSanitizerModulePass(
- bool CheckInitOrder, StringRef BlacklistFile) {
- return new AddressSanitizerModule(CheckInitOrder, BlacklistFile);
+ bool CheckInitOrder, StringRef BlacklistFile, bool ZeroBaseShadow) {
+ return new AddressSanitizerModule(CheckInitOrder, BlacklistFile,
+ ZeroBaseShadow);
}
static size_t TypeSizeToSizeIndex(uint32_t TypeSize) {
// 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 = ConstantDataArray::getString(M.getContext(), Str);
- return new GlobalVariable(M, StrConst->getType(), true,
+ GlobalVariable *GV = new GlobalVariable(M, StrConst->getType(), true,
GlobalValue::PrivateLinkage, StrConst,
kAsanGenPrefix);
+ GV->setUnnamedAddr(true); // Ok to merge these.
+ GV->setAlignment(1); // Strings may not be merged w/o setting align 1.
+ return GV;
}
static bool GlobalWasGeneratedByAsan(GlobalVariable *G) {
Value *AddressSanitizer::memToShadow(Value *Shadow, IRBuilder<> &IRB) {
// Shadow >> scale
- Shadow = IRB.CreateLShr(Shadow, MappingScale());
- if (MappingOffset == 0)
+ Shadow = IRB.CreateLShr(Shadow, Mapping.Scale);
+ if (Mapping.Offset == 0)
return Shadow;
// (Shadow >> scale) | offset
- return IRB.CreateOr(Shadow, ConstantInt::get(IntptrTy,
- MappingOffset));
+ if (Mapping.OrShadowOffset)
+ return IRB.CreateOr(Shadow, ConstantInt::get(IntptrTy, Mapping.Offset));
+ else
+ 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.
- {
- IRBuilder<> IRB(InsertBefore);
- instrumentAddress(OrigIns, IRB, Addr, 8, IsWrite);
- }
+ instrumentAddress(OrigIns, InsertBefore, Addr, 8, IsWrite, Size);
// 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);
- }
+ 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
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;
- }
+ 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).
+ // 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);
- instrumentAddress(I, IRB, Addr, TypeSize, IsWrite);
+ 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);
}
// Validate the result of Module::getOrInsertFunction called for an interface
Instruction *AddressSanitizer::generateCrashCode(
Instruction *InsertBefore, Value *Addr,
- bool IsWrite, size_t AccessSizeIndex) {
+ bool IsWrite, size_t AccessSizeIndex, Value *SizeArgument) {
IRBuilder<> IRB(InsertBefore);
- CallInst *Call = IRB.CreateCall(AsanErrorCallback[IsWrite][AccessSizeIndex],
- Addr);
+ CallInst *Call = SizeArgument
+ ? IRB.CreateCall2(AsanErrorCallbackSized[IsWrite], Addr, SizeArgument)
+ : IRB.CreateCall(AsanErrorCallback[IsWrite][AccessSizeIndex], Addr);
+
// We don't do Call->setDoesNotReturn() because the BB already has
// UnreachableInst at the end.
// This EmptyAsm is required to avoid callback merge.
Value *AddressSanitizer::createSlowPathCmp(IRBuilder<> &IRB, Value *AddrLong,
Value *ShadowValue,
uint32_t TypeSize) {
- size_t Granularity = 1 << MappingScale();
+ size_t Granularity = 1 << Mapping.Scale;
// Addr & (Granularity - 1)
Value *LastAccessedByte = IRB.CreateAnd(
AddrLong, ConstantInt::get(IntptrTy, Granularity - 1));
}
void AddressSanitizer::instrumentAddress(Instruction *OrigIns,
- IRBuilder<> &IRB, Value *Addr,
- uint32_t TypeSize, bool IsWrite) {
+ Instruction *InsertBefore,
+ Value *Addr, uint32_t TypeSize,
+ bool IsWrite, Value *SizeArgument) {
+ IRBuilder<> IRB(InsertBefore);
Value *AddrLong = IRB.CreatePointerCast(Addr, IntptrTy);
Type *ShadowTy = IntegerType::get(
- *C, std::max(8U, TypeSize >> MappingScale()));
+ *C, std::max(8U, TypeSize >> Mapping.Scale));
Type *ShadowPtrTy = PointerType::get(ShadowTy, 0);
Value *ShadowPtr = memToShadow(AddrLong, IRB);
Value *CmpVal = Constant::getNullValue(ShadowTy);
Value *Cmp = IRB.CreateICmpNE(ShadowValue, CmpVal);
size_t AccessSizeIndex = TypeSizeToSizeIndex(TypeSize);
- size_t Granularity = 1 << MappingScale();
+ size_t Granularity = 1 << Mapping.Scale;
TerminatorInst *CrashTerm = 0;
if (ClAlwaysSlowPath || (TypeSize < 8 * Granularity)) {
CrashTerm = SplitBlockAndInsertIfThen(cast<Instruction>(Cmp), true);
}
- Instruction *Crash =
- generateCrashCode(CrashTerm, AddrLong, IsWrite, AccessSizeIndex);
+ Instruction *Crash = generateCrashCode(
+ CrashTerm, AddrLong, IsWrite, AccessSizeIndex, SizeArgument);
Crash->setDebugLoc(OrigIns->getDebugLoc());
}
// Set up the arguments to our poison/unpoison functions.
IRBuilder<> IRB(GlobalInit->begin()->getFirstInsertionPt());
- // Declare our poisoning and unpoisoning functions.
- Function *AsanPoisonGlobals = checkInterfaceFunction(M.getOrInsertFunction(
- kAsanPoisonGlobalsName, IRB.getVoidTy(), IntptrTy, IntptrTy, NULL));
- AsanPoisonGlobals->setLinkage(Function::ExternalLinkage);
- Function *AsanUnpoisonGlobals = checkInterfaceFunction(M.getOrInsertFunction(
- kAsanUnpoisonGlobalsName, IRB.getVoidTy(), NULL));
- AsanUnpoisonGlobals->setLinkage(Function::ExternalLinkage);
-
// Add a call to poison all external globals before the given function starts.
IRB.CreateCall2(AsanPoisonGlobals, FirstAddr, LastAddr);
return true;
}
+void AddressSanitizerModule::initializeCallbacks(Module &M) {
+ IRBuilder<> IRB(*C);
+ // Declare our poisoning and unpoisoning functions.
+ AsanPoisonGlobals = checkInterfaceFunction(M.getOrInsertFunction(
+ kAsanPoisonGlobalsName, IRB.getVoidTy(), IntptrTy, IntptrTy, NULL));
+ AsanPoisonGlobals->setLinkage(Function::ExternalLinkage);
+ AsanUnpoisonGlobals = checkInterfaceFunction(M.getOrInsertFunction(
+ kAsanUnpoisonGlobalsName, IRB.getVoidTy(), NULL));
+ AsanUnpoisonGlobals->setLinkage(Function::ExternalLinkage);
+ // Declare functions that register/unregister globals.
+ AsanRegisterGlobals = checkInterfaceFunction(M.getOrInsertFunction(
+ kAsanRegisterGlobalsName, IRB.getVoidTy(),
+ IntptrTy, IntptrTy, NULL));
+ AsanRegisterGlobals->setLinkage(Function::ExternalLinkage);
+ AsanUnregisterGlobals = checkInterfaceFunction(M.getOrInsertFunction(
+ kAsanUnregisterGlobalsName,
+ IRB.getVoidTy(), IntptrTy, IntptrTy, NULL));
+ AsanUnregisterGlobals->setLinkage(Function::ExternalLinkage);
+}
+
// 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.
return false;
BL.reset(new BlackList(BlacklistFile));
if (BL->isIn(M)) return false;
- DynamicallyInitializedGlobals.Init(M);
C = &(M.getContext());
- IntptrTy = Type::getIntNTy(*C, TD->getPointerSizeInBits());
+ int LongSize = TD->getPointerSizeInBits();
+ IntptrTy = Type::getIntNTy(*C, LongSize);
+ Mapping = getShadowMapping(M, LongSize, ZeroBaseShadow);
+ initializeCallbacks(M);
+ DynamicallyInitializedGlobals.Init(M);
SmallVector<GlobalVariable *, 16> GlobalsToChange;
// size_t size;
// size_t size_with_redzone;
// const char *name;
+ // const char *module_name;
// size_t has_dynamic_init;
// We initialize an array of such structures and pass it to a run-time call.
StructType *GlobalStructTy = StructType::get(IntptrTy, IntptrTy,
IntptrTy, IntptrTy,
- IntptrTy, NULL);
+ IntptrTy, IntptrTy, NULL);
SmallVector<Constant *, 16> Initializers(n), DynamicInit;
// this TU. Used in initialization order checking.
Value *FirstDynamic = 0, *LastDynamic = 0;
+ GlobalVariable *ModuleName = createPrivateGlobalForString(
+ M, M.getModuleIdentifier());
+
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);
- size_t RZ = RedzoneSize();
- uint64_t RightRedzoneSize = RZ + (RZ - (SizeInBytes % RZ));
+ uint64_t MinRZ = RedzoneSize();
+ // MinRZ <= RZ <= kMaxGlobalRedzone
+ // and trying to make RZ to be ~ 1/4 of SizeInBytes.
+ uint64_t RZ = std::max(MinRZ,
+ std::min(kMaxGlobalRedzone,
+ (SizeInBytes / MinRZ / 4) * MinRZ));
+ uint64_t RightRedzoneSize = RZ;
+ // Round up to MinRZ
+ if (SizeInBytes % MinRZ)
+ RightRedzoneSize += MinRZ - (SizeInBytes % MinRZ);
+ assert(((RightRedzoneSize + SizeInBytes) % MinRZ) == 0);
Type *RightRedZoneTy = ArrayType::get(IRB.getInt8Ty(), RightRedzoneSize);
// Determine whether this global should be poisoned in initialization.
bool GlobalHasDynamicInitializer =
NewTy, G->getInitializer(),
Constant::getNullValue(RightRedZoneTy), NULL);
- SmallString<2048> DescriptionOfGlobal = G->getName();
- DescriptionOfGlobal += " (";
- DescriptionOfGlobal += M.getModuleIdentifier();
- DescriptionOfGlobal += ")";
- GlobalVariable *Name = createPrivateGlobalForString(M, DescriptionOfGlobal);
+ 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->getThreadLocalMode());
NewGlobal->copyAttributesFrom(G);
- NewGlobal->setAlignment(RZ);
+ NewGlobal->setAlignment(MinRZ);
Value *Indices2[2];
Indices2[0] = IRB.getInt32(0);
ConstantInt::get(IntptrTy, SizeInBytes),
ConstantInt::get(IntptrTy, SizeInBytes + RightRedzoneSize),
ConstantExpr::getPointerCast(Name, IntptrTy),
+ ConstantExpr::getPointerCast(ModuleName, IntptrTy),
ConstantInt::get(IntptrTy, GlobalHasDynamicInitializer),
NULL);
// Create calls for poisoning before initializers run and unpoisoning after.
if (CheckInitOrder && FirstDynamic && LastDynamic)
createInitializerPoisonCalls(M, FirstDynamic, LastDynamic);
-
- Function *AsanRegisterGlobals = checkInterfaceFunction(M.getOrInsertFunction(
- kAsanRegisterGlobalsName, IRB.getVoidTy(),
- IntptrTy, IntptrTy, NULL));
- AsanRegisterGlobals->setLinkage(Function::ExternalLinkage);
-
IRB.CreateCall2(AsanRegisterGlobals,
IRB.CreatePointerCast(AllGlobals, IntptrTy),
ConstantInt::get(IntptrTy, n));
GlobalValue::InternalLinkage, kAsanModuleDtorName, &M);
BasicBlock *AsanDtorBB = BasicBlock::Create(*C, "", AsanDtorFunction);
IRBuilder<> IRB_Dtor(ReturnInst::Create(*C, AsanDtorBB));
- Function *AsanUnregisterGlobals =
- checkInterfaceFunction(M.getOrInsertFunction(
- kAsanUnregisterGlobalsName,
- IRB.getVoidTy(), IntptrTy, IntptrTy, NULL));
- AsanUnregisterGlobals->setLinkage(Function::ExternalLinkage);
-
IRB_Dtor.CreateCall2(AsanUnregisterGlobals,
IRB.CreatePointerCast(AllGlobals, IntptrTy),
ConstantInt::get(IntptrTy, n));
FunctionName, IRB.getVoidTy(), IntptrTy, NULL));
}
}
+ AsanErrorCallbackSized[0] = checkInterfaceFunction(M.getOrInsertFunction(
+ kAsanReportLoadN, IRB.getVoidTy(), IntptrTy, IntptrTy, NULL));
+ AsanErrorCallbackSized[1] = checkInterfaceFunction(M.getOrInsertFunction(
+ kAsanReportStoreN, IRB.getVoidTy(), IntptrTy, IntptrTy, NULL));
- AsanStackMallocFunc = checkInterfaceFunction(M.getOrInsertFunction(
- kAsanStackMallocName, IntptrTy, IntptrTy, IntptrTy, NULL));
- AsanStackFreeFunc = checkInterfaceFunction(M.getOrInsertFunction(
- kAsanStackFreeName, IRB.getVoidTy(),
- IntptrTy, IntptrTy, IntptrTy, NULL));
AsanHandleNoReturnFunc = checkInterfaceFunction(M.getOrInsertFunction(
kAsanHandleNoReturnName, IRB.getVoidTy(), NULL));
- AsanPoisonStackMemoryFunc = checkInterfaceFunction(M.getOrInsertFunction(
- kAsanPoisonStackMemoryName, IRB.getVoidTy(), IntptrTy, IntptrTy, NULL));
- AsanUnpoisonStackMemoryFunc = checkInterfaceFunction(M.getOrInsertFunction(
- kAsanUnpoisonStackMemoryName, 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.
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),
AsanInitFunction->setLinkage(Function::ExternalLinkage);
IRB.CreateCall(AsanInitFunction);
- llvm::Triple targetTriple(M.getTargetTriple());
- bool isAndroid = targetTriple.getEnvironment() == llvm::Triple::Android;
-
- MappingOffset = isAndroid ? kDefaultShadowOffsetAndroid :
- (LongSize == 32 ? kDefaultShadowOffset32 : kDefaultShadowOffset64);
- if (ClMappingOffsetLog >= 0) {
- if (ClMappingOffsetLog == 0) {
- // special case
- MappingOffset = 0;
- } else {
- MappingOffset = 1ULL << ClMappingOffsetLog;
- }
- }
-
-
- if (ClMappingOffsetLog >= 0) {
- // 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);
- // Read the global, otherwise it may be optimized away.
- IRB.CreateLoad(asan_mapping_offset, true);
- }
- if (ClMappingScale) {
- GlobalValue *asan_mapping_scale =
- new GlobalVariable(M, IntptrTy, true, GlobalValue::LinkOnceODRLinkage,
- ConstantInt::get(IntptrTy, MappingScale()),
- kAsanMappingScaleName);
- // Read the global, otherwise it may be optimized away.
- IRB.CreateLoad(asan_mapping_scale, true);
- }
+ Mapping = getShadowMapping(M, LongSize, ZeroBaseShadow);
+ emitShadowMapping(M, IRB);
appendToGlobalCtors(M, AsanCtorFunction, kAsanCtorAndCtorPriority);
-
return true;
}
bool AddressSanitizer::runOnFunction(Function &F) {
if (BL->isIn(F)) return false;
if (&F == AsanCtorFunction) return false;
+ if (F.getLinkage() == GlobalValue::AvailableExternallyLinkage) return false;
DEBUG(dbgs() << "ASAN instrumenting:\n" << F << "\n");
initializeCallbacks(*F.getParent());
- // If needed, insert __asan_init before checking for AddressSafety attr.
+ // If needed, insert __asan_init before checking for SanitizeAddress attr.
maybeInsertAsanInitAtFunctionEntry(F);
- if (!F.getFnAttributes().hasAttribute(Attributes::AddressSafety))
+ if (!F.getAttributes().hasAttribute(AttributeSet::FunctionIndex,
+ Attribute::SanitizeAddress))
return false;
if (!ClDebugFunc.empty() && ClDebugFunc != F.getName())
} else if (isa<MemIntrinsic>(BI) && ClMemIntrin) {
// ok, take it.
} else {
- if (CallInst *CI = dyn_cast<CallInst>(BI)) {
+ CallSite CS(BI);
+ if (CS) {
// A call inside BB.
TempsToInstrument.clear();
- if (CI->doesNotReturn()) {
- NoReturnCalls.push_back(CI);
- }
+ if (CS.doesNotReturn())
+ NoReturnCalls.push_back(CS.getInstruction());
}
continue;
}
NumInstrumented++;
}
- bool ChangedStack = poisonStackInFunction(F);
+ FunctionStackPoisoner FSP(F, *this);
+ bool ChangedStack = FSP.runOnFunction();
// We must unpoison the stack before every NoReturn call (throw, _exit, etc).
// See e.g. http://code.google.com/p/address-sanitizer/issues/detail?id=37
}
}
-void AddressSanitizer::PoisonStack(const ArrayRef<AllocaInst*> &AllocaVec,
- IRBuilder<> IRB,
- Value *ShadowBase, bool DoPoison) {
- size_t ShadowRZSize = RedzoneSize() >> MappingScale();
+// 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.
+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;
+ // We have inline assembly with quite a few arguments.
+ return true;
+}
+
+void FunctionStackPoisoner::initializeCallbacks(Module &M) {
+ IRBuilder<> IRB(*C);
+ AsanStackMallocFunc = checkInterfaceFunction(M.getOrInsertFunction(
+ kAsanStackMallocName, IntptrTy, IntptrTy, IntptrTy, NULL));
+ AsanStackFreeFunc = checkInterfaceFunction(M.getOrInsertFunction(
+ kAsanStackFreeName, IRB.getVoidTy(),
+ IntptrTy, IntptrTy, IntptrTy, NULL));
+ AsanPoisonStackMemoryFunc = checkInterfaceFunction(M.getOrInsertFunction(
+ kAsanPoisonStackMemoryName, IRB.getVoidTy(), IntptrTy, IntptrTy, NULL));
+ AsanUnpoisonStackMemoryFunc = checkInterfaceFunction(M.getOrInsertFunction(
+ 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);
// Poison the partial redzone at right
Ptr = IRB.CreateAdd(
ShadowBase, ConstantInt::get(IntptrTy,
- (Pos >> MappingScale()) - ShadowRZSize));
+ (Pos >> Mapping.Scale) - ShadowRZSize));
size_t AddressableBytes = RedzoneSize() - (AlignedSize - SizeInBytes);
uint32_t Poison = 0;
if (DoPoison) {
PoisonShadowPartialRightRedzone((uint8_t*)&Poison, AddressableBytes,
RedzoneSize(),
- 1ULL << MappingScale(),
+ 1ULL << Mapping.Scale,
kAsanStackPartialRedzoneMagic);
}
Value *PartialPoison = ConstantInt::get(RZTy, Poison);
// Poison the full redzone at right.
Ptr = IRB.CreateAdd(ShadowBase,
- ConstantInt::get(IntptrTy, Pos >> MappingScale()));
- Value *Poison = i == AllocaVec.size() - 1 ? PoisonRight : PoisonMid;
+ 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();
}
}
-// 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.
-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;
- // We have inline assembly with quite a few arguments.
- return true;
-}
-
-// Handling llvm.lifetime intrinsics for a given %alloca:
-// (1) collect all llvm.lifetime.xxx(%size, %value) describing the alloca.
-// (2) if %size is constant, poison memory for llvm.lifetime.end (to detect
-// invalid accesses) and unpoison it for llvm.lifetime.start (the memory
-// could be poisoned by previous llvm.lifetime.end instruction, as the
-// variable may go in and out of scope several times, e.g. in loops).
-// (3) if we poisoned at least one %alloca in a function,
-// unpoison the whole stack frame at function exit.
-bool AddressSanitizer::handleAllocaLifetime(Value *Alloca) {
- assert(CheckLifetime);
- Type *AllocaType = Alloca->getType();
- Type *Int8PtrTy = Type::getInt8PtrTy(AllocaType->getContext());
-
- bool Res = false;
- // Typical code looks like this:
- // %alloca = alloca <type>, <alignment>
- // ... some code ...
- // %val1 = bitcast <type>* %alloca to i8*
- // call void @llvm.lifetime.start(i64 <size>, i8* %val1)
- // ... more code ...
- // %val2 = bitcast <type>* %alloca to i8*
- // call void @llvm.lifetime.start(i64 <size>, i8* %val2)
- // That is, to handle %alloca we must find all its casts to
- // i8* values, and find lifetime instructions for these values.
- if (AllocaType == Int8PtrTy)
- Res |= handleValueLifetime(Alloca);
- for (Value::use_iterator UI = Alloca->use_begin(), UE = Alloca->use_end();
- UI != UE; ++UI) {
- if (UI->getType() != Int8PtrTy) continue;
- if (UI->stripPointerCasts() != Alloca) continue;
- Res |= handleValueLifetime(*UI);
- }
- return Res;
-}
-
-bool AddressSanitizer::handleValueLifetime(Value *V) {
- assert(CheckLifetime);
- bool Res = false;
- for (Value::use_iterator UI = V->use_begin(), UE = V->use_end(); UI != UE;
- ++UI) {
- IntrinsicInst *II = dyn_cast<IntrinsicInst>(*UI);
- if (!II) continue;
- Intrinsic::ID ID = II->getIntrinsicID();
- if (ID != Intrinsic::lifetime_start &&
- ID != Intrinsic::lifetime_end)
- continue;
- if (V != II->getArgOperand(1))
- continue;
- // Found lifetime intrinsic, add ASan instrumentation if necessary.
- ConstantInt *Size = dyn_cast<ConstantInt>(II->getArgOperand(0));
- // If size argument is undefined, don't do anything.
- if (Size->isMinusOne())
- continue;
- // Check that size doesn't saturate uint64_t and can
- // be stored in IntptrTy.
- const uint64_t SizeValue = Size->getValue().getLimitedValue();
- if (SizeValue == ~0ULL ||
- !ConstantInt::isValueValidForType(IntptrTy, SizeValue)) {
- continue;
- }
- IRBuilder<> IRB(II);
- bool DoPoison = (ID == Intrinsic::lifetime_end);
- poisonAlloca(V, SizeValue, IRB, DoPoison);
- Res = true;
- }
- return Res;
-}
-
-// 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(Function &F) {
- if (!ClStack) return false;
- SmallVector<AllocaInst*, 16> AllocaVec;
- SmallVector<Instruction*, 8> RetVec;
- uint64_t TotalSize = 0;
- bool HavePoisonedAllocas = false;
-
- // Filter out Alloca instructions we want (and can) handle.
- // Collect Ret instructions.
- unsigned ResultAlignment = 1 << MappingScale();
- 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;
- ResultAlignment = std::max(ResultAlignment, AI->getAlignment());
- AllocaVec.push_back(AI);
- uint64_t AlignedSize = getAlignedAllocaSize(AI);
- TotalSize += AlignedSize;
- }
- }
-
- if (AllocaVec.empty()) return false;
+void FunctionStackPoisoner::poisonStack() {
+ uint64_t LocalStackSize = TotalStackSize +
+ (AllocaVec.size() + 1) * RedzoneSize();
- uint64_t LocalStackSize = TotalSize + (AllocaVec.size() + 1) * RedzoneSize();
-
- bool DoStackMalloc = CheckUseAfterReturn
+ bool DoStackMalloc = ASan.CheckUseAfterReturn
&& LocalStackSize <= kMaxStackMallocSize;
+ assert(AllocaVec.size() > 0);
Instruction *InsBefore = AllocaVec[0];
IRBuilder<> IRB(InsBefore);
Type *ByteArrayTy = ArrayType::get(IRB.getInt8Ty(), LocalStackSize);
AllocaInst *MyAlloca =
new AllocaInst(ByteArrayTy, "MyAlloca", InsBefore);
- if (ClRealignStack && ResultAlignment < RedzoneSize())
- ResultAlignment = RedzoneSize();
- MyAlloca->setAlignment(ResultAlignment);
+ if (ClRealignStack && StackAlignment < RedzoneSize())
+ StackAlignment = RedzoneSize();
+ MyAlloca->setAlignment(StackAlignment);
assert(MyAlloca->isStaticAlloca());
Value *OrigStackBase = IRB.CreatePointerCast(MyAlloca, IntptrTy);
Value *LocalStackBase = OrigStackBase;
raw_svector_ostream StackDescription(StackDescriptionStorage);
StackDescription << F.getName() << " " << 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);
+ HavePoisonedAllocas |= APC.DoPoison;
+ }
+
uint64_t Pos = RedzoneSize();
// Replace Alloca instructions with base+offset.
for (size_t i = 0, n = AllocaVec.size(); i < n; i++) {
Value *NewAllocaPtr = IRB.CreateIntToPtr(
IRB.CreateAdd(LocalStackBase, ConstantInt::get(IntptrTy, Pos)),
AI->getType());
+ replaceDbgDeclareForAlloca(AI, NewAllocaPtr, DIB);
AI->replaceAllUsesWith(NewAllocaPtr);
- // Analyze lifetime intrinsics only for static allocas we handle.
- if (CheckLifetime)
- HavePoisonedAllocas |= handleAllocaLifetime(NewAllocaPtr);
Pos += AlignedSize + RedzoneSize();
}
assert(Pos == LocalStackSize);
IRB.CreateStore(ConstantInt::get(IntptrTy, kCurrentStackFrameMagic),
BasePlus0);
Value *BasePlus1 = IRB.CreateAdd(LocalStackBase,
- ConstantInt::get(IntptrTy, LongSize/8));
+ ConstantInt::get(IntptrTy,
+ ASan.LongSize/8));
BasePlus1 = IRB.CreateIntToPtr(BasePlus1, IntptrPtrTy);
GlobalVariable *StackDescriptionGlobal =
createPrivateGlobalForString(*F.getParent(), StackDescription.str());
- Value *Description = IRB.CreatePointerCast(StackDescriptionGlobal, IntptrTy);
+ Value *Description = IRB.CreatePointerCast(StackDescriptionGlobal,
+ 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 *ShadowBase = ASan.memToShadow(LocalStackBase, IRB);
+ poisonRedZones(AllocaVec, IRB, ShadowBase, true);
// 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);
-
+ poisonRedZones(AllocaVec, IRBRet, ShadowBase, false);
if (DoStackMalloc) {
// In use-after-return mode, mark the whole stack frame unaddressable.
IRBRet.CreateCall3(AsanStackFreeFunc, LocalStackBase,
// We are done. Remove the old unused alloca instructions.
for (size_t i = 0, n = AllocaVec.size(); i < n; i++)
AllocaVec[i]->eraseFromParent();
-
- if (ClDebugStack) {
- DEBUG(dbgs() << F);
- }
-
- return true;
}
-void AddressSanitizer::poisonAlloca(Value *V, uint64_t Size, IRBuilder<> IRB,
- bool DoPoison) {
+void FunctionStackPoisoner::poisonAlloca(Value *V, uint64_t Size,
+ IRBuilder<> IRB, bool DoPoison) {
// For now just insert the call to ASan runtime.
Value *AddrArg = IRB.CreatePointerCast(V, IntptrTy);
Value *SizeArg = ConstantInt::get(IntptrTy, Size);
: AsanUnpoisonStackMemoryFunc,
AddrArg, SizeArg);
}
+
+// Handling llvm.lifetime intrinsics for a given %alloca:
+// (1) collect all llvm.lifetime.xxx(%size, %value) describing the alloca.
+// (2) if %size is constant, poison memory for llvm.lifetime.end (to detect
+// invalid accesses) and unpoison it for llvm.lifetime.start (the memory
+// could be poisoned by previous llvm.lifetime.end instruction, as the
+// variable may go in and out of scope several times, e.g. in loops).
+// (3) if we poisoned at least one %alloca in a function,
+// unpoison the whole stack frame at function exit.
+
+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;
+ // See if we've already calculated (or started to calculate) alloca for a
+ // given value.
+ AllocaForValueMapTy::iterator I = AllocaForValue.find(V);
+ if (I != AllocaForValue.end())
+ 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;
+ if (CastInst *CI = dyn_cast<CastInst>(V))
+ Res = findAllocaForValue(CI->getOperand(0));
+ else if (PHINode *PN = dyn_cast<PHINode>(V)) {
+ for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
+ Value *IncValue = PN->getIncomingValue(i);
+ // Allow self-referencing phi-nodes.
+ 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;
+ Res = IncValueAI;
+ }
+ }
+ if (Res != 0)
+ AllocaForValue[V] = Res;
+ return Res;
+}
projects / oota-llvm.git / blobdiff