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-rw-r--r--lib/Transforms/Instrumentation/AddressSanitizer.cpp474
1 files changed, 320 insertions, 154 deletions
diff --git a/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index 0c6a406203..f095cff33c 100644
--- a/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -15,14 +15,8 @@
#define DEBUG_TYPE "asan"
+#include "llvm/Transforms/Instrumentation.h"
#include "BlackList.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/Type.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/OwningPtr.h"
#include "llvm/ADT/SmallSet.h"
@@ -30,19 +24,24 @@
#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/Support/CommandLine.h"
#include "llvm/Support/DataTypes.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Support/system_error.h"
-#include "llvm/DataLayout.h"
#include "llvm/Target/TargetMachine.h"
-#include "llvm/Transforms/Instrumentation.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/Transforms/Utils/ModuleUtils.h"
-
-#include <string>
+#include "llvm/Type.h"
#include <algorithm>
+#include <string>
using namespace llvm;
@@ -69,6 +68,10 @@ static const char *kAsanMappingOffsetName = "__asan_mapping_offset";
static const char *kAsanMappingScaleName = "__asan_mapping_scale";
static const char *kAsanStackMallocName = "__asan_stack_malloc";
static const char *kAsanStackFreeName = "__asan_stack_free";
+static const char *kAsanGenPrefix = "__asan_gen_";
+static const char *kAsanPoisonStackMemoryName = "__asan_poison_stack_memory";
+static const char *kAsanUnpoisonStackMemoryName =
+ "__asan_unpoison_stack_memory";
static const int kAsanStackLeftRedzoneMagic = 0xf1;
static const int kAsanStackMidRedzoneMagic = 0xf2;
@@ -112,9 +115,10 @@ 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));
-// This flag may need to be replaced with -fasan-blacklist.
-static cl::opt<std::string> ClBlackListFile("asan-blacklist",
- cl::desc("File containing the list of functions to ignore "
+static cl::opt<bool> ClRealignStack("asan-realign-stack",
+ cl::desc("Realign stack to 32"), cl::Hidden, cl::init(true));
+static cl::opt<std::string> ClBlacklistFile("asan-blacklist",
+ cl::desc("File containing the list of objects to ignore "
"during instrumentation"), cl::Hidden);
// These flags allow to change the shadow mapping.
@@ -135,6 +139,10 @@ static cl::opt<bool> ClOptSameTemp("asan-opt-same-temp",
static cl::opt<bool> ClOptGlobals("asan-opt-globals",
cl::desc("Don't instrument scalar globals"), cl::Hidden, cl::init(true));
+static cl::opt<bool> ClCheckLifetime("asan-check-lifetime",
+ cl::desc("Use llvm.lifetime intrinsics to insert extra checks"),
+ cl::Hidden, cl::init(false));
+
// Debug flags.
static cl::opt<int> ClDebug("asan-debug", cl::desc("debug"), cl::Hidden,
cl::init(0));
@@ -148,10 +156,56 @@ static cl::opt<int> ClDebugMax("asan-debug-max", cl::desc("Debug man inst"),
cl::Hidden, cl::init(-1));
namespace {
+/// A set of dynamically initialized globals extracted from metadata.
+class SetOfDynamicallyInitializedGlobals {
+ public:
+ void Init(Module& M) {
+ // Clang generates metadata identifying all dynamically initialized globals.
+ NamedMDNode *DynamicGlobals =
+ M.getNamedMetadata("llvm.asan.dynamically_initialized_globals");
+ if (!DynamicGlobals)
+ return;
+ for (int i = 0, n = DynamicGlobals->getNumOperands(); i < n; ++i) {
+ MDNode *MDN = DynamicGlobals->getOperand(i);
+ assert(MDN->getNumOperands() == 1);
+ Value *VG = MDN->getOperand(0);
+ // The optimizer may optimize away a global entirely, in which case we
+ // cannot instrument access to it.
+ if (!VG)
+ continue;
+ DynInitGlobals.insert(cast<GlobalVariable>(VG));
+ }
+ }
+ bool Contains(GlobalVariable *G) { return DynInitGlobals.count(G) != 0; }
+ private:
+ SmallSet<GlobalValue*, 32> DynInitGlobals;
+};
+
+static int MappingScale() {
+ return ClMappingScale ? ClMappingScale : kDefaultShadowScale;
+}
+
+static size_t RedzoneSize() {
+ // 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());
+}
+
/// AddressSanitizer: instrument the code in module to find memory bugs.
struct AddressSanitizer : public FunctionPass {
- AddressSanitizer();
- virtual const char *getPassName() const;
+ AddressSanitizer(bool CheckInitOrder = false,
+ bool CheckUseAfterReturn = false,
+ bool CheckLifetime = false,
+ StringRef BlacklistFile = StringRef())
+ : FunctionPass(ID),
+ CheckInitOrder(CheckInitOrder || ClInitializers),
+ CheckUseAfterReturn(CheckUseAfterReturn || ClUseAfterReturn),
+ CheckLifetime(CheckLifetime || ClCheckLifetime),
+ BlacklistFile(BlacklistFile.empty() ? ClBlacklistFile
+ : BlacklistFile) {}
+ virtual const char *getPassName() const {
+ return "AddressSanitizerFunctionPass";
+ }
void instrumentMop(Instruction *I);
void instrumentAddress(Instruction *OrigIns, IRBuilder<> &IRB,
Value *Addr, uint32_t TypeSize, bool IsWrite);
@@ -170,52 +224,86 @@ struct AddressSanitizer : public FunctionPass {
bool maybeInsertAsanInitAtFunctionEntry(Function &F);
bool poisonStackInFunction(Function &F);
virtual bool doInitialization(Module &M);
- virtual bool doFinalization(Module &M);
- bool insertGlobalRedzones(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) {
- return ((SizeInBytes + RedzoneSize - 1)
- / RedzoneSize) * RedzoneSize;
+ size_t RZ = RedzoneSize();
+ return ((SizeInBytes + RZ - 1) / RZ) * RZ;
}
uint64_t getAlignedAllocaSize(AllocaInst *AI) {
uint64_t SizeInBytes = getAllocaSizeInBytes(AI);
return getAlignedSize(SizeInBytes);
}
- Function *checkInterfaceFunction(Constant *FuncOrBitcast);
bool ShouldInstrumentGlobal(GlobalVariable *G);
void PoisonStack(const ArrayRef<AllocaInst*> &AllocaVec, IRBuilder<> IRB,
Value *ShadowBase, bool DoPoison);
bool LooksLikeCodeInBug11395(Instruction *I);
void FindDynamicInitializers(Module &M);
- bool HasDynamicInitializer(GlobalVariable *G);
-
+ /// 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;
LLVMContext *C;
DataLayout *TD;
uint64_t MappingOffset;
- int MappingScale;
- size_t RedzoneSize;
int LongSize;
Type *IntptrTy;
Type *IntptrPtrTy;
Function *AsanCtorFunction;
Function *AsanInitFunction;
Function *AsanStackMallocFunc, *AsanStackFreeFunc;
+ Function *AsanPoisonStackMemoryFunc, *AsanUnpoisonStackMemoryFunc;
Function *AsanHandleNoReturnFunc;
- Instruction *CtorInsertBefore;
+ SmallString<64> BlacklistFile;
OwningPtr<BlackList> BL;
// This array is indexed by AccessIsWrite and log2(AccessSize).
Function *AsanErrorCallback[2][kNumberOfAccessSizes];
InlineAsm *EmptyAsm;
- SmallSet<GlobalValue*, 32> DynamicallyInitializedGlobals;
- SmallSet<GlobalValue*, 32> GlobalsCreatedByAsan;
+ SetOfDynamicallyInitializedGlobals DynamicallyInitializedGlobals;
+};
+
+class AddressSanitizerModule : public ModulePass {
+ public:
+ AddressSanitizerModule(bool CheckInitOrder = false,
+ StringRef BlacklistFile = StringRef())
+ : ModulePass(ID),
+ CheckInitOrder(CheckInitOrder || ClInitializers),
+ BlacklistFile(BlacklistFile.empty() ? ClBlacklistFile
+ : BlacklistFile) {}
+ bool runOnModule(Module &M);
+ static char ID; // Pass identification, replacement for typeid
+ virtual const char *getPassName() const {
+ return "AddressSanitizerModule";
+ }
+
+ private:
+ bool ShouldInstrumentGlobal(GlobalVariable *G);
+ void createInitializerPoisonCalls(Module &M, Value *FirstAddr,
+ Value *LastAddr);
+
+ bool CheckInitOrder;
+ SmallString<64> BlacklistFile;
+ OwningPtr<BlackList> BL;
+ SetOfDynamicallyInitializedGlobals DynamicallyInitializedGlobals;
+ Type *IntptrTy;
+ LLVMContext *C;
+ DataLayout *TD;
};
} // namespace
@@ -224,13 +312,20 @@ char AddressSanitizer::ID = 0;
INITIALIZE_PASS(AddressSanitizer, "asan",
"AddressSanitizer: detects use-after-free and out-of-bounds bugs.",
false, false)
-AddressSanitizer::AddressSanitizer() : FunctionPass(ID) { }
-FunctionPass *llvm::createAddressSanitizerPass() {
- return new AddressSanitizer();
+FunctionPass *llvm::createAddressSanitizerFunctionPass(
+ bool CheckInitOrder, bool CheckUseAfterReturn, bool CheckLifetime,
+ StringRef BlacklistFile) {
+ return new AddressSanitizer(CheckInitOrder, CheckUseAfterReturn,
+ CheckLifetime, BlacklistFile);
}
-const char *AddressSanitizer::getPassName() const {
- return "AddressSanitizer";
+char AddressSanitizerModule::ID = 0;
+INITIALIZE_PASS(AddressSanitizerModule, "asan-module",
+ "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);
}
static size_t TypeSizeToSizeIndex(uint32_t TypeSize) {
@@ -243,12 +338,17 @@ static size_t TypeSizeToSizeIndex(uint32_t TypeSize) {
static GlobalVariable *createPrivateGlobalForString(Module &M, StringRef Str) {
Constant *StrConst = ConstantDataArray::getString(M.getContext(), Str);
return new GlobalVariable(M, StrConst->getType(), true,
- GlobalValue::PrivateLinkage, StrConst, "");
+ GlobalValue::PrivateLinkage, StrConst,
+ kAsanGenPrefix);
+}
+
+static bool GlobalWasGeneratedByAsan(GlobalVariable *G) {
+ return G->getName().find(kAsanGenPrefix) == 0;
}
Value *AddressSanitizer::memToShadow(Value *Shadow, IRBuilder<> &IRB) {
// Shadow >> scale
- Shadow = IRB.CreateLShr(Shadow, MappingScale);
+ Shadow = IRB.CreateLShr(Shadow, MappingScale());
if (MappingOffset == 0)
return Shadow;
// (Shadow >> scale) | offset
@@ -328,30 +428,6 @@ static Value *isInterestingMemoryAccess(Instruction *I, bool *IsWrite) {
return NULL;
}
-void AddressSanitizer::FindDynamicInitializers(Module& M) {
- // Clang generates metadata identifying all dynamically initialized globals.
- NamedMDNode *DynamicGlobals =
- M.getNamedMetadata("llvm.asan.dynamically_initialized_globals");
- if (!DynamicGlobals)
- return;
- for (int i = 0, n = DynamicGlobals->getNumOperands(); i < n; ++i) {
- MDNode *MDN = DynamicGlobals->getOperand(i);
- assert(MDN->getNumOperands() == 1);
- Value *VG = MDN->getOperand(0);
- // The optimizer may optimize away a global entirely, in which case we
- // cannot instrument access to it.
- if (!VG)
- continue;
-
- GlobalVariable *G = cast<GlobalVariable>(VG);
- DynamicallyInitializedGlobals.insert(G);
- }
-}
-// Returns true if a global variable is initialized dynamically in this TU.
-bool AddressSanitizer::HasDynamicInitializer(GlobalVariable *G) {
- return DynamicallyInitializedGlobals.count(G);
-}
-
void AddressSanitizer::instrumentMop(Instruction *I) {
bool IsWrite = false;
Value *Addr = isInterestingMemoryAccess(I, &IsWrite);
@@ -360,14 +436,12 @@ void AddressSanitizer::instrumentMop(Instruction *I) {
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 (!ClInitializers)
+ if (!CheckInitOrder)
return;
// If a global variable does not have dynamic initialization we don't
- // have to instrument it. However, if a global has external linkage, we
- // assume it has dynamic initialization, as it may have an initializer
- // in a different TU.
- if (G->getLinkage() != GlobalVariable::ExternalLinkage &&
- !HasDynamicInitializer(G))
+ // 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))
return;
}
}
@@ -392,7 +466,7 @@ void AddressSanitizer::instrumentMop(Instruction *I) {
// function of AddressSanitizer. If the instrumented module defines a function
// with the same name, their prototypes must match, otherwise
// getOrInsertFunction returns a bitcast.
-Function *AddressSanitizer::checkInterfaceFunction(Constant *FuncOrBitcast) {
+static Function *checkInterfaceFunction(Constant *FuncOrBitcast) {
if (isa<Function>(FuncOrBitcast)) return cast<Function>(FuncOrBitcast);
FuncOrBitcast->dump();
report_fatal_error("trying to redefine an AddressSanitizer "
@@ -415,7 +489,7 @@ Instruction *AddressSanitizer::generateCrashCode(
Value *AddressSanitizer::createSlowPathCmp(IRBuilder<> &IRB, Value *AddrLong,
Value *ShadowValue,
uint32_t TypeSize) {
- size_t Granularity = 1 << MappingScale;
+ size_t Granularity = 1 << MappingScale();
// Addr & (Granularity - 1)
Value *LastAccessedByte = IRB.CreateAnd(
AddrLong, ConstantInt::get(IntptrTy, Granularity - 1));
@@ -436,7 +510,7 @@ void AddressSanitizer::instrumentAddress(Instruction *OrigIns,
Value *AddrLong = IRB.CreatePointerCast(Addr, IntptrTy);
Type *ShadowTy = IntegerType::get(
- *C, std::max(8U, TypeSize >> MappingScale));
+ *C, std::max(8U, TypeSize >> MappingScale()));
Type *ShadowPtrTy = PointerType::get(ShadowTy, 0);
Value *ShadowPtr = memToShadow(AddrLong, IRB);
Value *CmpVal = Constant::getNullValue(ShadowTy);
@@ -445,7 +519,7 @@ void AddressSanitizer::instrumentAddress(Instruction *OrigIns,
Value *Cmp = IRB.CreateICmpNE(ShadowValue, CmpVal);
size_t AccessSizeIndex = TypeSizeToSizeIndex(TypeSize);
- size_t Granularity = 1 << MappingScale;
+ size_t Granularity = 1 << MappingScale();
TerminatorInst *CrashTerm = 0;
if (ClAlwaysSlowPath || (TypeSize < 8 * Granularity)) {
@@ -469,9 +543,8 @@ void AddressSanitizer::instrumentAddress(Instruction *OrigIns,
Crash->setDebugLoc(OrigIns->getDebugLoc());
}
-void AddressSanitizer::createInitializerPoisonCalls(Module &M,
- Value *FirstAddr,
- Value *LastAddr) {
+void AddressSanitizerModule::createInitializerPoisonCalls(
+ Module &M, Value *FirstAddr, Value *LastAddr) {
// We do all of our poisoning and unpoisoning within _GLOBAL__I_a.
Function *GlobalInit = M.getFunction("_GLOBAL__I_a");
// If that function is not present, this TU contains no globals, or they have
@@ -502,14 +575,14 @@ void AddressSanitizer::createInitializerPoisonCalls(Module &M,
}
}
-bool AddressSanitizer::ShouldInstrumentGlobal(GlobalVariable *G) {
+bool AddressSanitizerModule::ShouldInstrumentGlobal(GlobalVariable *G) {
Type *Ty = cast<PointerType>(G->getType())->getElementType();
DEBUG(dbgs() << "GLOBAL: " << *G << "\n");
if (BL->isIn(*G)) return false;
if (!Ty->isSized()) return false;
if (!G->hasInitializer()) return false;
- if (GlobalsCreatedByAsan.count(G)) return false; // Our own global.
+ if (GlobalWasGeneratedByAsan(G)) return false; // Our own global.
// Touch only those globals that will not be defined in other modules.
// Don't handle ODR type linkages since other modules may be built w/o asan.
if (G->getLinkage() != GlobalVariable::ExternalLinkage &&
@@ -522,7 +595,7 @@ bool AddressSanitizer::ShouldInstrumentGlobal(GlobalVariable *G) {
if (G->isThreadLocal())
return false;
// For now, just ignore this Alloca if the alignment is large.
- if (G->getAlignment() > RedzoneSize) return false;
+ if (G->getAlignment() > RedzoneSize()) 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
@@ -564,7 +637,17 @@ bool AddressSanitizer::ShouldInstrumentGlobal(GlobalVariable *G) {
// This function replaces all global variables with new variables that have
// trailing redzones. It also creates a function that poisons
// redzones and inserts this function into llvm.global_ctors.
-bool AddressSanitizer::insertGlobalRedzones(Module &M) {
+bool AddressSanitizerModule::runOnModule(Module &M) {
+ if (!ClGlobals) return false;
+ TD = getAnalysisIfAvailable<DataLayout>();
+ if (!TD)
+ 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());
+
SmallVector<GlobalVariable *, 16> GlobalsToChange;
for (Module::GlobalListType::iterator G = M.global_begin(),
@@ -588,10 +671,10 @@ bool AddressSanitizer::insertGlobalRedzones(Module &M) {
IntptrTy, NULL);
SmallVector<Constant *, 16> Initializers(n), DynamicInit;
- IRBuilder<> IRB(CtorInsertBefore);
- if (ClInitializers)
- FindDynamicInitializers(M);
+ Function *CtorFunc = M.getFunction(kAsanModuleCtorName);
+ assert(CtorFunc);
+ IRBuilder<> IRB(CtorFunc->getEntryBlock().getTerminator());
// The addresses of the first and last dynamically initialized globals in
// this TU. Used in initialization order checking.
@@ -602,11 +685,12 @@ bool AddressSanitizer::insertGlobalRedzones(Module &M) {
PointerType *PtrTy = cast<PointerType>(G->getType());
Type *Ty = PtrTy->getElementType();
uint64_t SizeInBytes = TD->getTypeAllocSize(Ty);
- uint64_t RightRedzoneSize = RedzoneSize +
- (RedzoneSize - (SizeInBytes % RedzoneSize));
+ size_t RZ = RedzoneSize();
+ uint64_t RightRedzoneSize = RZ + (RZ - (SizeInBytes % RZ));
Type *RightRedZoneTy = ArrayType::get(IRB.getInt8Ty(), RightRedzoneSize);
// Determine whether this global should be poisoned in initialization.
- bool GlobalHasDynamicInitializer = HasDynamicInitializer(G);
+ bool GlobalHasDynamicInitializer =
+ DynamicallyInitializedGlobals.Contains(G);
// Don't check initialization order if this global is blacklisted.
GlobalHasDynamicInitializer &= !BL->isInInit(*G);
@@ -626,7 +710,7 @@ bool AddressSanitizer::insertGlobalRedzones(Module &M) {
M, NewTy, G->isConstant(), G->getLinkage(),
NewInitializer, "", G, G->getThreadLocalMode());
NewGlobal->copyAttributesFrom(G);
- NewGlobal->setAlignment(RedzoneSize);
+ NewGlobal->setAlignment(RZ);
Value *Indices2[2];
Indices2[0] = IRB.getInt32(0);
@@ -647,7 +731,7 @@ bool AddressSanitizer::insertGlobalRedzones(Module &M) {
NULL);
// Populate the first and last globals declared in this TU.
- if (ClInitializers && GlobalHasDynamicInitializer) {
+ if (CheckInitOrder && GlobalHasDynamicInitializer) {
LastDynamic = ConstantExpr::getPointerCast(NewGlobal, IntptrTy);
if (FirstDynamic == 0)
FirstDynamic = LastDynamic;
@@ -662,7 +746,7 @@ bool AddressSanitizer::insertGlobalRedzones(Module &M) {
ConstantArray::get(ArrayOfGlobalStructTy, Initializers), "");
// Create calls for poisoning before initializers run and unpoisoning after.
- if (ClInitializers && FirstDynamic && LastDynamic)
+ if (CheckInitOrder && FirstDynamic && LastDynamic)
createInitializerPoisonCalls(M, FirstDynamic, LastDynamic);
Function *AsanRegisterGlobals = checkInterfaceFunction(M.getOrInsertFunction(
@@ -696,33 +780,8 @@ bool AddressSanitizer::insertGlobalRedzones(Module &M) {
return true;
}
-// virtual
-bool AddressSanitizer::doInitialization(Module &M) {
- // Initialize the private fields. No one has accessed them before.
- TD = getAnalysisIfAvailable<DataLayout>();
-
- if (!TD)
- return false;
- BL.reset(new BlackList(ClBlackListFile));
-
- C = &(M.getContext());
- LongSize = TD->getPointerSizeInBits();
- IntptrTy = Type::getIntNTy(*C, LongSize);
- IntptrPtrTy = PointerType::get(IntptrTy, 0);
-
- AsanCtorFunction = Function::Create(
- FunctionType::get(Type::getVoidTy(*C), false),
- GlobalValue::InternalLinkage, kAsanModuleCtorName, &M);
- BasicBlock *AsanCtorBB = BasicBlock::Create(*C, "", AsanCtorFunction);
- CtorInsertBefore = ReturnInst::Create(*C, AsanCtorBB);
-
- // call __asan_init in the module ctor.
- IRBuilder<> IRB(CtorInsertBefore);
- AsanInitFunction = checkInterfaceFunction(
- M.getOrInsertFunction(kAsanInitName, IRB.getVoidTy(), NULL));
- AsanInitFunction->setLinkage(Function::ExternalLinkage);
- IRB.CreateCall(AsanInitFunction);
-
+void AddressSanitizer::initializeCallbacks(Module &M) {
+ IRBuilder<> IRB(*C);
// Create __asan_report* callbacks.
for (size_t AccessIsWrite = 0; AccessIsWrite <= 1; AccessIsWrite++) {
for (size_t AccessSizeIndex = 0; AccessSizeIndex < kNumberOfAccessSizes;
@@ -731,8 +790,9 @@ bool AddressSanitizer::doInitialization(Module &M) {
std::string FunctionName = std::string(kAsanReportErrorTemplate) +
(AccessIsWrite ? "store" : "load") + itostr(1 << AccessSizeIndex);
// If we are merging crash callbacks, they have two parameters.
- AsanErrorCallback[AccessIsWrite][AccessSizeIndex] = cast<Function>(
- M.getOrInsertFunction(FunctionName, IRB.getVoidTy(), IntptrTy, NULL));
+ AsanErrorCallback[AccessIsWrite][AccessSizeIndex] =
+ checkInterfaceFunction(M.getOrInsertFunction(
+ FunctionName, IRB.getVoidTy(), IntptrTy, NULL));
}
}
@@ -743,11 +803,42 @@ bool AddressSanitizer::doInitialization(Module &M) {
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);
+}
+
+// virtual
+bool AddressSanitizer::doInitialization(Module &M) {
+ // Initialize the private fields. No one has accessed them before.
+ TD = getAnalysisIfAvailable<DataLayout>();
+
+ if (!TD)
+ return false;
+ BL.reset(new BlackList(BlacklistFile));
+ DynamicallyInitializedGlobals.Init(M);
+
+ C = &(M.getContext());
+ LongSize = TD->getPointerSizeInBits();
+ IntptrTy = Type::getIntNTy(*C, LongSize);
+ IntptrPtrTy = PointerType::get(IntptrTy, 0);
+
+ AsanCtorFunction = Function::Create(
+ FunctionType::get(Type::getVoidTy(*C), false),
+ GlobalValue::InternalLinkage, kAsanModuleCtorName, &M);
+ BasicBlock *AsanCtorBB = BasicBlock::Create(*C, "", AsanCtorFunction);
+ // call __asan_init in the module ctor.
+ IRBuilder<> IRB(ReturnInst::Create(*C, AsanCtorBB));
+ AsanInitFunction = checkInterfaceFunction(
+ M.getOrInsertFunction(kAsanInitName, IRB.getVoidTy(), NULL));
+ AsanInitFunction->setLinkage(Function::ExternalLinkage);
+ IRB.CreateCall(AsanInitFunction);
llvm::Triple targetTriple(M.getTargetTriple());
bool isAndroid = targetTriple.getEnvironment() == llvm::Triple::Android;
@@ -762,13 +853,6 @@ bool AddressSanitizer::doInitialization(Module &M) {
MappingOffset = 1ULL << ClMappingOffsetLog;
}
}
- MappingScale = kDefaultShadowScale;
- if (ClMappingScale) {
- MappingScale = ClMappingScale;
- }
- // Redzone used for stack and globals is at least 32 bytes.
- // For scales 6 and 7, the redzone has to be 64 and 128 bytes respectively.
- RedzoneSize = std::max(32, (int)(1 << MappingScale));
if (ClMappingOffsetLog >= 0) {
@@ -783,7 +867,7 @@ bool AddressSanitizer::doInitialization(Module &M) {
if (ClMappingScale) {
GlobalValue *asan_mapping_scale =
new GlobalVariable(M, IntptrTy, true, GlobalValue::LinkOnceODRLinkage,
- ConstantInt::get(IntptrTy, MappingScale),
+ ConstantInt::get(IntptrTy, MappingScale()),
kAsanMappingScaleName);
// Read the global, otherwise it may be optimized away.
IRB.CreateLoad(asan_mapping_scale, true);
@@ -794,15 +878,6 @@ bool AddressSanitizer::doInitialization(Module &M) {
return true;
}
-bool AddressSanitizer::doFinalization(Module &M) {
- // We transform the globals at the very end so that the optimization analysis
- // works on the original globals.
- if (ClGlobals)
- return insertGlobalRedzones(M);
- return false;
-}
-
-
bool AddressSanitizer::maybeInsertAsanInitAtFunctionEntry(Function &F) {
// For each NSObject descendant having a +load method, this method is invoked
// by the ObjC runtime before any of the static constructors is called.
@@ -823,6 +898,7 @@ bool AddressSanitizer::runOnFunction(Function &F) {
if (BL->isIn(F)) return false;
if (&F == AsanCtorFunction) return false;
DEBUG(dbgs() << "ASAN instrumenting:\n" << F << "\n");
+ initializeCallbacks(*F.getParent());
// If needed, insert __asan_init before checking for AddressSafety attr.
maybeInsertAsanInitAtFunctionEntry(F);
@@ -911,10 +987,10 @@ static uint64_t ValueForPoison(uint64_t PoisonByte, size_t ShadowRedzoneSize) {
static void PoisonShadowPartialRightRedzone(uint8_t *Shadow,
size_t Size,
- size_t RedzoneSize,
+ size_t RZSize,
size_t ShadowGranularity,
uint8_t Magic) {
- for (size_t i = 0; i < RedzoneSize;
+ for (size_t i = 0; i < RZSize;
i+= ShadowGranularity, Shadow++) {
if (i + ShadowGranularity <= Size) {
*Shadow = 0; // fully addressable
@@ -929,7 +1005,7 @@ static void PoisonShadowPartialRightRedzone(uint8_t *Shadow,
void AddressSanitizer::PoisonStack(const ArrayRef<AllocaInst*> &AllocaVec,
IRBuilder<> IRB,
Value *ShadowBase, bool DoPoison) {
- size_t ShadowRZSize = RedzoneSize >> MappingScale;
+ size_t ShadowRZSize = RedzoneSize() >> MappingScale();
assert(ShadowRZSize >= 1 && ShadowRZSize <= 4);
Type *RZTy = Type::getIntNTy(*C, ShadowRZSize * 8);
Type *RZPtrTy = PointerType::get(RZTy, 0);
@@ -945,12 +1021,12 @@ void AddressSanitizer::PoisonStack(const ArrayRef<AllocaInst*> &AllocaVec,
IRB.CreateStore(PoisonLeft, IRB.CreateIntToPtr(ShadowBase, RZPtrTy));
// poison all other red zones.
- uint64_t Pos = RedzoneSize;
+ 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);
+ assert(AlignedSize - SizeInBytes < RedzoneSize());
Value *Ptr = NULL;
Pos += AlignedSize;
@@ -960,13 +1036,13 @@ void AddressSanitizer::PoisonStack(const ArrayRef<AllocaInst*> &AllocaVec,
// Poison the partial redzone at right
Ptr = IRB.CreateAdd(
ShadowBase, ConstantInt::get(IntptrTy,
- (Pos >> MappingScale) - ShadowRZSize));
- size_t AddressableBytes = RedzoneSize - (AlignedSize - SizeInBytes);
+ (Pos >> MappingScale()) - ShadowRZSize));
+ size_t AddressableBytes = RedzoneSize() - (AlignedSize - SizeInBytes);
uint32_t Poison = 0;
if (DoPoison) {
PoisonShadowPartialRightRedzone((uint8_t*)&Poison, AddressableBytes,
- RedzoneSize,
- 1ULL << MappingScale,
+ RedzoneSize(),
+ 1ULL << MappingScale(),
kAsanStackPartialRedzoneMagic);
}
Value *PartialPoison = ConstantInt::get(RZTy, Poison);
@@ -975,11 +1051,11 @@ void AddressSanitizer::PoisonStack(const ArrayRef<AllocaInst*> &AllocaVec,
// Poison the full redzone at right.
Ptr = IRB.CreateAdd(ShadowBase,
- ConstantInt::get(IntptrTy, Pos >> MappingScale));
+ ConstantInt::get(IntptrTy, Pos >> MappingScale()));
Value *Poison = i == AllocaVec.size() - 1 ? PoisonRight : PoisonMid;
IRB.CreateStore(Poison, IRB.CreateIntToPtr(Ptr, RZPtrTy));
- Pos += RedzoneSize;
+ Pos += RedzoneSize();
}
}
@@ -995,6 +1071,74 @@ bool AddressSanitizer::LooksLikeCodeInBug11395(Instruction *I) {
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.
@@ -1013,9 +1157,11 @@ bool AddressSanitizer::poisonStackInFunction(Function &F) {
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;
@@ -1031,7 +1177,7 @@ bool AddressSanitizer::poisonStackInFunction(Function &F) {
if (AI->isArrayAllocation()) continue;
if (!AI->isStaticAlloca()) continue;
if (!AI->getAllocatedType()->isSized()) continue;
- if (AI->getAlignment() > RedzoneSize) continue;
+ ResultAlignment = std::max(ResultAlignment, AI->getAlignment());
AllocaVec.push_back(AI);
uint64_t AlignedSize = getAlignedAllocaSize(AI);
TotalSize += AlignedSize;
@@ -1040,9 +1186,9 @@ bool AddressSanitizer::poisonStackInFunction(Function &F) {
if (AllocaVec.empty()) return false;
- uint64_t LocalStackSize = TotalSize + (AllocaVec.size() + 1) * RedzoneSize;
+ uint64_t LocalStackSize = TotalSize + (AllocaVec.size() + 1) * RedzoneSize();
- bool DoStackMalloc = ClUseAfterReturn
+ bool DoStackMalloc = CheckUseAfterReturn
&& LocalStackSize <= kMaxStackMallocSize;
Instruction *InsBefore = AllocaVec[0];
@@ -1052,7 +1198,9 @@ bool AddressSanitizer::poisonStackInFunction(Function &F) {
Type *ByteArrayTy = ArrayType::get(IRB.getInt8Ty(), LocalStackSize);
AllocaInst *MyAlloca =
new AllocaInst(ByteArrayTy, "MyAlloca", InsBefore);
- MyAlloca->setAlignment(RedzoneSize);
+ if (ClRealignStack && ResultAlignment < RedzoneSize())
+ ResultAlignment = RedzoneSize();
+ MyAlloca->setAlignment(ResultAlignment);
assert(MyAlloca->isStaticAlloca());
Value *OrigStackBase = IRB.CreatePointerCast(MyAlloca, IntptrTy);
Value *LocalStackBase = OrigStackBase;
@@ -1067,7 +1215,7 @@ bool AddressSanitizer::poisonStackInFunction(Function &F) {
raw_svector_ostream StackDescription(StackDescriptionStorage);
StackDescription << F.getName() << " " << AllocaVec.size() << " ";
- uint64_t Pos = RedzoneSize;
+ 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];
@@ -1076,12 +1224,15 @@ bool AddressSanitizer::poisonStackInFunction(Function &F) {
StackDescription << Pos << " " << SizeInBytes << " "
<< Name.size() << " " << Name << " ";
uint64_t AlignedSize = getAlignedAllocaSize(AI);
- assert((AlignedSize % RedzoneSize) == 0);
- AI->replaceAllUsesWith(
- IRB.CreateIntToPtr(
+ assert((AlignedSize % RedzoneSize()) == 0);
+ Value *NewAllocaPtr = IRB.CreateIntToPtr(
IRB.CreateAdd(LocalStackBase, ConstantInt::get(IntptrTy, Pos)),
- AI->getType()));
- Pos += AlignedSize + RedzoneSize;
+ AI->getType());
+ AI->replaceAllUsesWith(NewAllocaPtr);
+ // Analyze lifetime intrinsics only for static allocas we handle.
+ if (CheckLifetime)
+ HavePoisonedAllocas |= handleAllocaLifetime(NewAllocaPtr);
+ Pos += AlignedSize + RedzoneSize();
}
assert(Pos == LocalStackSize);
@@ -1092,9 +1243,8 @@ bool AddressSanitizer::poisonStackInFunction(Function &F) {
Value *BasePlus1 = IRB.CreateAdd(LocalStackBase,
ConstantInt::get(IntptrTy, LongSize/8));
BasePlus1 = IRB.CreateIntToPtr(BasePlus1, IntptrPtrTy);
- GlobalVariable *StackDescriptionGlobal =
+ GlobalVariable *StackDescriptionGlobal =
createPrivateGlobalForString(*F.getParent(), StackDescription.str());
- GlobalsCreatedByAsan.insert(StackDescriptionGlobal);
Value *Description = IRB.CreatePointerCast(StackDescriptionGlobal, IntptrTy);
IRB.CreateStore(Description, BasePlus1);
@@ -1114,9 +1264,15 @@ bool AddressSanitizer::poisonStackInFunction(Function &F) {
PoisonStack(ArrayRef<AllocaInst*>(AllocaVec), IRBRet, ShadowBase, false);
if (DoStackMalloc) {
+ // In use-after-return mode, mark the whole stack frame unaddressable.
IRBRet.CreateCall3(AsanStackFreeFunc, LocalStackBase,
ConstantInt::get(IntptrTy, LocalStackSize),
OrigStackBase);
+ } 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);
}
}
@@ -1130,3 +1286,13 @@ bool AddressSanitizer::poisonStackInFunction(Function &F) {
return true;
}
+
+void AddressSanitizer::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);
+ IRB.CreateCall2(DoPoison ? AsanPoisonStackMemoryFunc
+ : AsanUnpoisonStackMemoryFunc,
+ AddrArg, SizeArg);
+}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-09-04 17:27:32 +0000