//
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "asan"
-
#include "llvm/Transforms/Instrumentation.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/DenseSet.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/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"
#include "llvm/Transforms/Utils/ModuleUtils.h"
-#include "llvm/Transforms/Utils/SpecialCaseList.h"
#include <algorithm>
#include <string>
+#include <system_error>
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 char *const kAsanModuleCtorName = "asan.module_ctor";
static const char *const kAsanModuleDtorName = "asan.module_dtor";
-static const int kAsanCtorAndCtorPriority = 1;
+static const int kAsanCtorAndDtorPriority = 1;
static const char *const kAsanReportErrorTemplate = "__asan_report_";
static const char *const kAsanReportLoadN = "__asan_report_load_n";
static const char *const kAsanReportStoreN = "__asan_report_store_n";
"__asan_unregister_globals";
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 kAsanInitName = "__asan_init_v4";
+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_";
// This flag may need to be replaced with -f[no]asan-stack.
static cl::opt<bool> ClStack("asan-stack",
cl::desc("Handle stack memory"), cl::Hidden, cl::init(true));
-// This flag may need to be replaced with -f[no]asan-use-after-return.
static cl::opt<bool> ClUseAfterReturn("asan-use-after-return",
- cl::desc("Check return-after-free"), cl::Hidden, cl::init(false));
+ cl::desc("Check return-after-free"), cl::Hidden, cl::init(true));
// 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));
+ cl::desc("Handle C++ initializer order"), 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.
"Number of optimized accesses to global vars");
namespace {
-/// A set of dynamically initialized globals extracted from metadata.
-class SetOfDynamicallyInitializedGlobals {
+/// Frontend-provided metadata for source location.
+struct LocationMetadata {
+ StringRef Filename;
+ int LineNo;
+ int ColumnNo;
+
+ LocationMetadata() : Filename(), LineNo(0), ColumnNo(0) {}
+
+ bool empty() const { return Filename.empty(); }
+
+ void parse(MDNode *MDN) {
+ assert(MDN->getNumOperands() == 3);
+ MDString *MDFilename = cast<MDString>(MDN->getOperand(0));
+ Filename = MDFilename->getString();
+ LineNo = cast<ConstantInt>(MDN->getOperand(1))->getLimitedValue();
+ ColumnNo = cast<ConstantInt>(MDN->getOperand(2))->getLimitedValue();
+ }
+};
+
+/// Frontend-provided metadata for global variables.
+class GlobalsMetadata {
public:
- void Init(Module& M) {
- // Clang generates metadata identifying all dynamically initialized globals.
- NamedMDNode *DynamicGlobals =
- M.getNamedMetadata("llvm.asan.dynamically_initialized_globals");
- if (!DynamicGlobals)
+ struct Entry {
+ Entry()
+ : SourceLoc(), Name(), IsDynInit(false),
+ IsBlacklisted(false) {}
+ LocationMetadata SourceLoc;
+ StringRef Name;
+ bool IsDynInit;
+ bool IsBlacklisted;
+ };
+
+ GlobalsMetadata() : inited_(false) {}
+
+ void init(Module& M) {
+ assert(!inited_);
+ inited_ = true;
+ NamedMDNode *Globals = M.getNamedMetadata("llvm.asan.globals");
+ if (!Globals)
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)
+ for (auto MDN : Globals->operands()) {
+ // Metadata node contains the global and the fields of "Entry".
+ assert(MDN->getNumOperands() == 5);
+ Value *V = MDN->getOperand(0);
+ // The optimizer may optimize away a global entirely.
+ if (!V)
continue;
- DynInitGlobals.insert(cast<GlobalVariable>(VG));
+ GlobalVariable *GV = cast<GlobalVariable>(V);
+ // We can already have an entry for GV if it was merged with another
+ // global.
+ Entry &E = Entries[GV];
+ if (Value *Loc = MDN->getOperand(1))
+ E.SourceLoc.parse(cast<MDNode>(Loc));
+ if (Value *Name = MDN->getOperand(2)) {
+ MDString *MDName = cast<MDString>(Name);
+ E.Name = MDName->getString();
+ }
+ ConstantInt *IsDynInit = cast<ConstantInt>(MDN->getOperand(3));
+ E.IsDynInit |= IsDynInit->isOne();
+ ConstantInt *IsBlacklisted = cast<ConstantInt>(MDN->getOperand(4));
+ E.IsBlacklisted |= IsBlacklisted->isOne();
}
}
- bool Contains(GlobalVariable *G) { return DynInitGlobals.count(G) != 0; }
+
+ /// Returns metadata entry for a given global.
+ Entry get(GlobalVariable *G) const {
+ auto Pos = Entries.find(G);
+ return (Pos != Entries.end()) ? Pos->second : Entry();
+ }
+
private:
- SmallSet<GlobalValue*, 32> DynInitGlobals;
+ bool inited_;
+ DenseMap<GlobalVariable*, Entry> Entries;
};
/// This struct defines the shadow mapping using the rule:
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 necessary
- // 1/8-th of the address space.
- Mapping.OrShadowOffset = !IsPPC64 && !ClShort64BitOffset;
-
- Mapping.Offset = IsAndroid ? 0 :
- (LongSize == 32 ?
- (IsMIPS32 ? kMIPS32_ShadowOffset32 :
- (IsFreeBSD ? kFreeBSD_ShadowOffset32 : kDefaultShadowOffset32)) :
- IsPPC64 ? kPPC64_ShadowOffset64 : kDefaultShadowOffset64);
- if (!IsAndroid && ClShort64BitOffset && IsX86_64 && !IsMacOSX) {
- assert(LongSize == 64);
- Mapping.Offset = (IsFreeBSD ?
- kFreeBSD_ShadowOffset64 : kDefaultShort64bitShadowOffset);
- }
- if (!IsAndroid && 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: instrument the code in module to find memory bugs.
struct AddressSanitizer : public FunctionPass {
- AddressSanitizer(bool CheckInitOrder = true,
- 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 {
+ AddressSanitizer() : FunctionPass(ID) {}
+ 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);
+ bool InjectCoverage(Function &F, ArrayRef<BasicBlock*> AllBlocks);
void InjectCoverageAtBlock(Function &F, BasicBlock &BB);
- bool CheckInitOrder;
- bool CheckUseAfterReturn;
- bool CheckLifetime;
- SmallString<64> BlacklistFile;
-
LLVMContext *C;
- DataLayout *TD;
+ const DataLayout *DL;
int LongSize;
Type *IntptrTy;
ShadowMapping Mapping;
Function *AsanInitFunction;
Function *AsanHandleNoReturnFunc;
Function *AsanCovFunction;
- OwningPtr<SpecialCaseList> BL;
+ Function *AsanPtrCmpFunction, *AsanPtrSubFunction;
// 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;
+ GlobalsMetadata GlobalsMD;
friend struct FunctionStackPoisoner;
};
class AddressSanitizerModule : public ModulePass {
public:
- AddressSanitizerModule(bool CheckInitOrder = true,
- StringRef BlacklistFile = StringRef())
- : ModulePass(ID),
- CheckInitOrder(CheckInitOrder || ClInitializers),
- BlacklistFile(BlacklistFile.empty() ? ClBlacklistFile
- : BlacklistFile) {}
- bool runOnModule(Module &M);
+ AddressSanitizerModule() : ModulePass(ID) {}
+ 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";
}
private:
void initializeCallbacks(Module &M);
+ bool InstrumentGlobals(IRBuilder<> &IRB, Module &M);
bool ShouldInstrumentGlobal(GlobalVariable *G);
+ void poisonOneInitializer(Function &GlobalInit, GlobalValue *ModuleName);
void createInitializerPoisonCalls(Module &M, GlobalValue *ModuleName);
size_t MinRedzoneSizeForGlobal() const {
return RedzoneSizeForScale(Mapping.Scale);
}
- bool CheckInitOrder;
- SmallString<64> BlacklistFile;
-
- OwningPtr<SpecialCaseList> BL;
- SetOfDynamicallyInitializedGlobals DynamicallyInitializedGlobals;
+ GlobalsMetadata GlobalsMD;
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.
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());
/// \brief Collect lifetime intrinsic calls to check for use-after-scope
/// errors.
void visitIntrinsicInst(IntrinsicInst &II) {
- if (!ASan.CheckLifetime) return;
+ if (!ClCheckLifetime) return;
Intrinsic::ID ID = II.getIntrinsicID();
if (ID != Intrinsic::lifetime_start &&
ID != Intrinsic::lifetime_end)
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;
}
/// Finds alloca where the value comes from.
AllocaInst *findAllocaForValue(Value *V);
- void poisonRedZones(const ArrayRef<uint8_t> ShadowBytes, IRBuilder<> &IRB,
+ void poisonRedZones(ArrayRef<uint8_t> ShadowBytes, IRBuilder<> &IRB,
Value *ShadowBase, bool DoPoison);
void poisonAlloca(Value *V, uint64_t Size, IRBuilder<> &IRB, bool DoPoison);
INITIALIZE_PASS(AddressSanitizer, "asan",
"AddressSanitizer: detects use-after-free and out-of-bounds bugs.",
false, false)
-FunctionPass *llvm::createAddressSanitizerFunctionPass(
- bool CheckInitOrder, bool CheckUseAfterReturn, bool CheckLifetime,
- StringRef BlacklistFile) {
- return new AddressSanitizer(CheckInitOrder, CheckUseAfterReturn,
- CheckLifetime, BlacklistFile);
+FunctionPass *llvm::createAddressSanitizerFunctionPass() {
+ return new 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);
+ModulePass *llvm::createAddressSanitizerModulePass() {
+ return new AddressSanitizerModule();
}
static size_t TypeSizeToSizeIndex(uint32_t TypeSize) {
static GlobalVariable *createPrivateGlobalForString(
Module &M, StringRef Str, bool AllowMerging) {
Constant *StrConst = ConstantDataArray::getString(M.getContext(), Str);
- // For module-local strings that can be merged with another one we set the
- // private linkage and the unnamed_addr attribute.
- // Non-mergeable strings are made linker_private to remove them from the
- // symbol table. "private" linkage doesn't work for Darwin, where the
- // "L"-prefixed globals end up in __TEXT,__const section
- // (see http://llvm.org/bugs/show_bug.cgi?id=17976 for more info).
- GlobalValue::LinkageTypes linkage =
- AllowMerging ? GlobalValue::PrivateLinkage
- : GlobalValue::LinkerPrivateLinkage;
+ // 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,
- linkage, StrConst, kAsanGenPrefix);
- if (AllowMerging) GV->setUnnamedAddr(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;
}
+/// \brief Create a global describing a source location.
+static GlobalVariable *createPrivateGlobalForSourceLoc(Module &M,
+ LocationMetadata MD) {
+ Constant *LocData[] = {
+ createPrivateGlobalForString(M, MD.Filename, true),
+ ConstantInt::get(Type::getInt32Ty(M.getContext()), MD.LineNo),
+ ConstantInt::get(Type::getInt32Ty(M.getContext()), MD.ColumnNo),
+ };
+ auto LocStruct = ConstantStruct::getAnon(LocData);
+ auto GV = new GlobalVariable(M, LocStruct->getType(), true,
+ GlobalValue::PrivateLinkage, LocStruct,
+ kAsanGenPrefix);
+ GV->setUnnamedAddr(true);
+ return GV;
+}
+
static bool GlobalWasGeneratedByAsan(GlobalVariable *G) {
return G->getName().find(kAsanGenPrefix) == 0;
}
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(Cmp, InsertBefore, 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) {
+ // Skip memory accesses inserted by another instrumentation.
+ if (I->getMetadata("nosanitize"))
+ return nullptr;
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);
+ return G->hasInitializer() && !GlobalsMD.get(G).IsDynInit;
}
-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 || GlobalIsLinkerInitialized(G)) {
+ if (!ClInitializers || GlobalIsLinkerInitialized(G)) {
NumOptimizedAccessesToGlobalVar++;
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);
else
NumInstrumentedReads++;
- // 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).
+ 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)) {
+ // We use branch weights for the slow path check, to indicate that the slow
+ // path is rarely taken. This seems to be the case for SPEC benchmarks.
TerminatorInst *CheckTerm =
- SplitBlockAndInsertIfThen(Cmp, InsertBefore, false);
+ SplitBlockAndInsertIfThen(Cmp, InsertBefore, false,
+ MDBuilder(*C).createBranchWeights(1, 100000));
assert(dyn_cast<BranchInst>(CheckTerm)->isUnconditional());
BasicBlock *NextBB = CheckTerm->getSuccessor(0);
IRB.SetInsertPoint(CheckTerm);
Crash->setDebugLoc(OrigIns->getDebugLoc());
}
-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");
- // If that function is not present, this TU contains no globals, or they have
- // all been optimized away
- if (!GlobalInit)
- return;
-
+void AddressSanitizerModule::poisonOneInitializer(Function &GlobalInit,
+ GlobalValue *ModuleName) {
// Set up the arguments to our poison/unpoison functions.
- IRBuilder<> IRB(GlobalInit->begin()->getFirstInsertionPt());
+ IRBuilder<> IRB(GlobalInit.begin()->getFirstInsertionPt());
// Add a call to poison all external globals before the given function starts.
Value *ModuleNameAddr = ConstantExpr::getPointerCast(ModuleName, IntptrTy);
IRB.CreateCall(AsanPoisonGlobals, ModuleNameAddr);
// Add calls to unpoison all globals before each return instruction.
- for (Function::iterator I = GlobalInit->begin(), E = GlobalInit->end();
- I != E; ++I) {
- if (ReturnInst *RI = dyn_cast<ReturnInst>(I->getTerminator())) {
+ for (auto &BB : GlobalInit.getBasicBlockList())
+ if (ReturnInst *RI = dyn_cast<ReturnInst>(BB.getTerminator()))
CallInst::Create(AsanUnpoisonGlobals, "", RI);
+}
+
+void AddressSanitizerModule::createInitializerPoisonCalls(
+ Module &M, GlobalValue *ModuleName) {
+ GlobalVariable *GV = M.getGlobalVariable("llvm.global_ctors");
+
+ ConstantArray *CA = cast<ConstantArray>(GV->getInitializer());
+ for (Use &OP : CA->operands()) {
+ if (isa<ConstantAggregateZero>(OP))
+ continue;
+ ConstantStruct *CS = cast<ConstantStruct>(OP);
+
+ // Must have a function or null ptr.
+ // (CS->getOperand(0) is the init priority.)
+ if (Function* F = dyn_cast<Function>(CS->getOperand(1))) {
+ if (F->getName() != kAsanModuleCtorName)
+ poisonOneInitializer(*F, ModuleName);
}
}
}
Type *Ty = cast<PointerType>(G->getType())->getElementType();
DEBUG(dbgs() << "GLOBAL: " << *G << "\n");
- if (BL->isIn(*G)) return false;
+ if (GlobalsMD.get(G).IsBlacklisted) return false;
if (!Ty->isSized()) return false;
if (!G->hasInitializer()) return false;
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.
+ // Don't handle ODR linkage types and COMDATs since other modules may be built
+ // without ASan.
if (G->getLinkage() != GlobalVariable::ExternalLinkage &&
G->getLinkage() != GlobalVariable::PrivateLinkage &&
G->getLinkage() != GlobalVariable::InternalLinkage)
return false;
+ if (G->hasComdat())
+ return false;
// Two problems with thread-locals:
// - The address of the main thread's copy can't be computed at link-time.
// - Need to poison all copies, not just the main thread's one.
// 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
// trailing redzones. It also creates a function that poisons
// redzones and inserts this function into llvm.global_ctors.
-bool AddressSanitizerModule::runOnModule(Module &M) {
- if (!ClGlobals) return false;
- TD = getAnalysisIfAvailable<DataLayout>();
- if (!TD)
- return false;
- BL.reset(SpecialCaseList::createOrDie(BlacklistFile));
- if (BL->isIn(M)) return false;
- C = &(M.getContext());
- int LongSize = TD->getPointerSizeInBits();
- IntptrTy = Type::getIntNTy(*C, LongSize);
- Mapping = getShadowMapping(M, LongSize);
- initializeCallbacks(M);
- DynamicallyInitializedGlobals.Init(M);
+bool AddressSanitizerModule::InstrumentGlobals(IRBuilder<> &IRB, Module &M) {
+ GlobalsMD.init(M);
SmallVector<GlobalVariable *, 16> GlobalsToChange;
- for (Module::GlobalListType::iterator G = M.global_begin(),
- E = M.global_end(); G != E; ++G) {
- if (ShouldInstrumentGlobal(G))
- GlobalsToChange.push_back(G);
+ for (auto &G : M.globals()) {
+ if (ShouldInstrumentGlobal(&G))
+ GlobalsToChange.push_back(&G);
}
size_t n = GlobalsToChange.size();
// const char *name;
// const char *module_name;
// size_t has_dynamic_init;
+ // void *source_location;
// We initialize an array of such structures and pass it to a run-time call.
- StructType *GlobalStructTy = StructType::get(IntptrTy, IntptrTy,
- IntptrTy, IntptrTy,
- IntptrTy, IntptrTy, NULL);
+ StructType *GlobalStructTy =
+ StructType::get(IntptrTy, IntptrTy, IntptrTy, IntptrTy, IntptrTy,
+ IntptrTy, IntptrTy, NULL);
SmallVector<Constant *, 16> Initializers(n);
- Function *CtorFunc = M.getFunction(kAsanModuleCtorName);
- assert(CtorFunc);
- IRBuilder<> IRB(CtorFunc->getEntryBlock().getTerminator());
-
bool HasDynamicallyInitializedGlobals = false;
// We shouldn't merge same module names, as this string serves as unique
for (size_t i = 0; i < n; i++) {
static const uint64_t kMaxGlobalRedzone = 1 << 18;
GlobalVariable *G = GlobalsToChange[i];
+
+ auto MD = GlobalsMD.get(G);
+ // Create string holding the global name (use global name from metadata
+ // if it's available, otherwise just write the name of global variable).
+ GlobalVariable *Name = createPrivateGlobalForString(
+ M, MD.Name.empty() ? G->getName() : MD.Name,
+ /*AllowMerging*/ true);
+
PointerType *PtrTy = cast<PointerType>(G->getType());
Type *Ty = PtrTy->getElementType();
- uint64_t SizeInBytes = TD->getTypeAllocSize(Ty);
+ uint64_t SizeInBytes = DL->getTypeAllocSize(Ty);
uint64_t MinRZ = MinRedzoneSizeForGlobal();
// MinRZ <= RZ <= kMaxGlobalRedzone
// and trying to make RZ to be ~ 1/4 of SizeInBytes.
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 =
- DynamicallyInitializedGlobals.Contains(G);
- // Don't check initialization order if this global is blacklisted.
- GlobalHasDynamicInitializer &= !BL->isIn(*G, "init");
StructType *NewTy = StructType::get(Ty, RightRedZoneTy, NULL);
Constant *NewInitializer = ConstantStruct::get(
NewTy, G->getInitializer(),
Constant::getNullValue(RightRedZoneTy), NULL);
- GlobalVariable *Name =
- createPrivateGlobalForString(M, G->getName(), /*AllowMerging*/true);
-
// Create a new global variable with enough space for a redzone.
GlobalValue::LinkageTypes Linkage = G->getLinkage();
if (G->isConstant() && Linkage == GlobalValue::PrivateLinkage)
NewGlobal->takeName(G);
G->eraseFromParent();
+ Constant *SourceLoc;
+ if (!MD.SourceLoc.empty()) {
+ auto SourceLocGlobal = createPrivateGlobalForSourceLoc(M, MD.SourceLoc);
+ SourceLoc = ConstantExpr::getPointerCast(SourceLocGlobal, IntptrTy);
+ } else {
+ SourceLoc = ConstantInt::get(IntptrTy, 0);
+ }
+
Initializers[i] = ConstantStruct::get(
- GlobalStructTy,
- ConstantExpr::getPointerCast(NewGlobal, IntptrTy),
+ GlobalStructTy, ConstantExpr::getPointerCast(NewGlobal, IntptrTy),
ConstantInt::get(IntptrTy, SizeInBytes),
ConstantInt::get(IntptrTy, SizeInBytes + RightRedzoneSize),
ConstantExpr::getPointerCast(Name, IntptrTy),
ConstantExpr::getPointerCast(ModuleName, IntptrTy),
- ConstantInt::get(IntptrTy, GlobalHasDynamicInitializer),
- NULL);
+ ConstantInt::get(IntptrTy, MD.IsDynInit), SourceLoc, NULL);
- // Populate the first and last globals declared in this TU.
- if (CheckInitOrder && GlobalHasDynamicInitializer)
+ if (ClInitializers && MD.IsDynInit)
HasDynamicallyInitializedGlobals = true;
DEBUG(dbgs() << "NEW GLOBAL: " << *NewGlobal << "\n");
ConstantArray::get(ArrayOfGlobalStructTy, Initializers), "");
// Create calls for poisoning before initializers run and unpoisoning after.
- if (CheckInitOrder && HasDynamicallyInitializedGlobals)
+ if (HasDynamicallyInitializedGlobals)
createInitializerPoisonCalls(M, ModuleName);
IRB.CreateCall2(AsanRegisterGlobals,
IRB.CreatePointerCast(AllGlobals, IntptrTy),
IRB_Dtor.CreateCall2(AsanUnregisterGlobals,
IRB.CreatePointerCast(AllGlobals, IntptrTy),
ConstantInt::get(IntptrTy, n));
- appendToGlobalDtors(M, AsanDtorFunction, kAsanCtorAndCtorPriority);
+ appendToGlobalDtors(M, AsanDtorFunction, kAsanCtorAndDtorPriority);
DEBUG(dbgs() << M);
return true;
}
+bool AddressSanitizerModule::runOnModule(Module &M) {
+ DataLayoutPass *DLP = getAnalysisIfAvailable<DataLayoutPass>();
+ if (!DLP)
+ return false;
+ DL = &DLP->getDataLayout();
+ C = &(M.getContext());
+ int LongSize = DL->getPointerSizeInBits();
+ IntptrTy = Type::getIntNTy(*C, LongSize);
+ Mapping = getShadowMapping(M, LongSize);
+ initializeCallbacks(M);
+
+ bool Changed = false;
+
+ Function *CtorFunc = M.getFunction(kAsanModuleCtorName);
+ assert(CtorFunc);
+ IRBuilder<> IRB(CtorFunc->getEntryBlock().getTerminator());
+
+ if (ClCoverage > 0) {
+ Function *CovFunc = M.getFunction(kAsanCovName);
+ int nCov = CovFunc ? CovFunc->getNumUses() : 0;
+ IRB.CreateCall(AsanCovModuleInit, ConstantInt::get(IntptrTy, nCov));
+ Changed = true;
+ }
+
+ if (ClGlobals)
+ Changed |= InstrumentGlobals(IRB, M);
+
+ return Changed;
+}
+
void AddressSanitizer::initializeCallbacks(Module &M) {
IRBuilder<> IRB(*C);
// Create __asan_report* callbacks.
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);
+ GlobalsMD.init(M);
C = &(M.getContext());
- LongSize = TD->getPointerSizeInBits();
+ LongSize = DL->getPointerSizeInBits();
IntptrTy = Type::getIntNTy(*C, LongSize);
AsanCtorFunction = Function::Create(
IRB.CreateCall(AsanInitFunction);
Mapping = getShadowMapping(M, LongSize);
- emitShadowMapping(M, IRB);
- appendToGlobalCtors(M, AsanCtorFunction, kAsanCtorAndCtorPriority);
+ appendToGlobalCtors(M, AsanCtorFunction, kAsanCtorAndDtorPriority);
return true;
}
break;
}
+ DebugLoc EntryLoc = IP->getDebugLoc().getFnDebugLoc(*C);
IRBuilder<> IRB(IP);
+ IRB.SetCurrentDebugLocation(EntryLoc);
Type *Int8Ty = IRB.getInt8Ty();
GlobalVariable *Guard = new GlobalVariable(
*F.getParent(), Int8Ty, false, GlobalValue::PrivateLinkage,
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());
+ IRB.SetCurrentDebugLocation(EntryLoc);
+ // __sanitizer_cov gets the PC of the instruction using GET_CALLER_PC.
+ IRB.CreateCall(AsanCovFunction);
StoreInst *Store = IRB.CreateStore(ConstantInt::get(Int8Ty, 1), Guard);
Store->setAtomic(Monotonic);
Store->setAlignment(1);
// 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);
+// __sanitizer_cov();
// *Guard = 1;
// }
// The accesses to Guard are atomic. The rest of the logic is
// 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) {
+ ArrayRef<BasicBlock *> AllBlocks) {
if (!ClCoverage) return false;
- if (ClCoverage == 1) {
+ 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]);
+ for (auto BB : AllBlocks)
+ InjectCoverageAtBlock(F, *BB);
}
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");
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);
+ for (auto &BB : F) {
+ AllBlocks.push_back(&BB);
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)) {
+ for (auto &Inst : BB) {
+ if (LooksLikeCodeInBug11395(&Inst)) return false;
+ if (Value *Addr =
+ isInterestingMemoryAccess(&Inst, &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(&Inst)) {
+ PointerComparisonsOrSubtracts.push_back(&Inst);
+ continue;
+ } else if (isa<MemIntrinsic>(Inst)) {
// ok, take it.
} else {
- if (isa<AllocaInst>(BI))
+ if (isa<AllocaInst>(Inst))
NumAllocas++;
- CallSite CS(BI);
+ CallSite CS(&Inst);
if (CS) {
// A call inside BB.
TempsToInstrument.clear();
}
continue;
}
- ToInstrument.push_back(BI);
+ ToInstrument.push_back(&Inst);
NumInsnsPerBB++;
if (NumInsnsPerBB >= ClMaxInsnsToInstrumentPerBB)
break;
}
}
- 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];
+ for (auto Inst : ToInstrument) {
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));
}
// 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
- for (size_t i = 0, n = NoReturnCalls.size(); i != n; i++) {
- Instruction *CI = NoReturnCalls[i];
+ for (auto CI : NoReturnCalls) {
IRBuilder<> IRB(CI);
IRB.CreateCall(AsanHandleNoReturnFunc);
}
+ for (auto Inst : PointerComparisonsOrSubtracts) {
+ instrumentPointerComparisonOrSubtraction(Inst);
+ NumInstrumented++;
+ }
+
bool res = NumInstrumented > 0 || ChangedStack || !NoReturnCalls.empty();
if (InjectCoverage(F, AllBlocks))
}
void
-FunctionStackPoisoner::poisonRedZones(const ArrayRef<uint8_t> ShadowBytes,
+FunctionStackPoisoner::poisonRedZones(ArrayRef<uint8_t> ShadowBytes,
IRBuilder<> &IRB, Value *ShadowBase,
bool DoPoison) {
size_t n = ShadowBytes.size();
for (; i + LargeStoreSizeInBytes - 1 < n; i += LargeStoreSizeInBytes) {
uint64_t Val = 0;
for (size_t j = 0; j < LargeStoreSizeInBytes; j++) {
- if (ASan.TD->isLittleEndian())
+ if (ASan.DL->isLittleEndian())
Val |= (uint64_t)ShadowBytes[i + j] << (8 * j);
else
Val = (Val << 8) | ShadowBytes[i + j];
}
}
+static DebugLoc getFunctionEntryDebugLocation(Function &F) {
+ for (const auto &Inst : F.getEntryBlock())
+ if (!isa<AllocaInst>(Inst))
+ return Inst.getDebugLoc();
+ return DebugLoc();
+}
+
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];
+ for (AllocaInst *AI : AllocaVec) {
ASanStackVariableDescription D = { AI->getName().data(),
getAllocaSizeInBytes(AI),
AI->getAlignment(), AI, 0};
DEBUG(dbgs() << L.DescriptionString << " --- " << L.FrameSize << "\n");
uint64_t LocalStackSize = L.FrameSize;
bool DoStackMalloc =
- ASan.CheckUseAfterReturn && LocalStackSize <= kMaxStackMallocSize;
+ ClUseAfterReturn && LocalStackSize <= kMaxStackMallocSize;
Type *ByteArrayTy = ArrayType::get(IRB.getInt8Ty(), LocalStackSize);
AllocaInst *MyAlloca =
new AllocaInst(ByteArrayTy, "MyAlloca", InsBefore);
+ MyAlloca->setDebugLoc(EntryDebugLocation);
assert((ClRealignStack & (ClRealignStack - 1)) == 0);
size_t FrameAlignment = std::max(L.FrameAlignment, (size_t)ClRealignStack);
MyAlloca->setAlignment(FrameAlignment);
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);
// 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];
+ for (const auto &APC : AllocaPoisonCallVec) {
assert(APC.InsBefore);
assert(APC.AI);
IRBuilder<> IRB(APC.InsBefore);
}
// Replace Alloca instructions with base+offset.
- for (size_t i = 0, n = SVD.size(); i < n; i++) {
- AllocaInst *AI = SVD[i].AI;
+ for (const auto &Desc : SVD) {
+ AllocaInst *AI = Desc.AI;
Value *NewAllocaPtr = IRB.CreateIntToPtr(
- IRB.CreateAdd(LocalStackBase,
- ConstantInt::get(IntptrTy, SVD[i].Offset)),
+ IRB.CreateAdd(LocalStackBase, ConstantInt::get(IntptrTy, Desc.Offset)),
AI->getType());
replaceDbgDeclareForAlloca(AI, NewAllocaPtr, DIB);
AI->replaceAllUsesWith(NewAllocaPtr);
poisonRedZones(L.ShadowBytes, IRB, ShadowBase, true);
// (Un)poison the stack before all ret instructions.
- for (size_t i = 0, n = RetVec.size(); i < n; i++) {
- Instruction *Ret = RetVec[i];
+ for (auto Ret : RetVec) {
IRBuilder<> IRBRet(Ret);
// Mark the current frame as retired.
IRBRet.CreateStore(ConstantInt::get(IntptrTy, kRetiredStackFrameMagic),
}
// We are done. Remove the old unused alloca instructions.
- for (size_t i = 0, n = AllocaVec.size(); i < n; i++)
- AllocaVec[i]->eraseFromParent();
+ for (auto AI : AllocaVec)
+ AI->eraseFromParent();
}
void FunctionStackPoisoner::poisonAlloca(Value *V, uint64_t Size,
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