``setjmp`` is an example of such a function. The compiler disables
some optimizations (like tail calls) in the caller of these
functions.
+``safestack``
+ This attribute indicates that
+ `SafeStack <http://clang.llvm.org/docs/SafeStack.html>`_
+ protection is enabled for this function.
+
+ If a function that has a ``safestack`` attribute is inlined into a
+ function that doesn't have a ``safestack`` attribute or which has an
+ ``ssp``, ``sspstrong`` or ``sspreq`` attribute, then the resulting
+ function will have a ``safestack`` attribute.
``sanitize_address``
This attribute indicates that AddressSanitizer checks
(dynamic address safety analysis) are enabled for this function.
ATTR_KIND_JUMP_TABLE = 40,
ATTR_KIND_DEREFERENCEABLE = 41,
ATTR_KIND_DEREFERENCEABLE_OR_NULL = 42,
- ATTR_KIND_CONVERGENT = 43
+ ATTR_KIND_CONVERGENT = 43,
+ ATTR_KIND_SAFESTACK = 44,
};
enum ComdatSelectionKindCodes {
StackProtect, ///< Stack protection.
StackProtectReq, ///< Stack protection required.
StackProtectStrong, ///< Strong Stack protection.
+ SafeStack, ///< Safe Stack protection.
StructRet, ///< Hidden pointer to structure to return
SanitizeAddress, ///< AddressSanitizer is on.
SanitizeThread, ///< ThreadSanitizer is on.
void initializeRegionPrinterPass(PassRegistry&);
void initializeRegionViewerPass(PassRegistry&);
void initializeRewriteStatepointsForGCPass(PassRegistry&);
+void initializeSafeStackPass(PassRegistry&);
void initializeSCCPPass(PassRegistry&);
void initializeSROAPass(PassRegistry&);
void initializeSROA_DTPass(PassRegistry&);
(void) llvm::createRegionPrinterPass();
(void) llvm::createRegionViewerPass();
(void) llvm::createSCCPPass();
+ (void) llvm::createSafeStackPass();
(void) llvm::createScalarReplAggregatesPass();
(void) llvm::createSingleLoopExtractorPass();
(void) llvm::createStripSymbolsPass();
// checking on loads, stores, and other memory intrinsics.
FunctionPass *createBoundsCheckingPass();
+/// \brief This pass splits the stack into a safe stack and an unsafe stack to
+/// protect against stack-based overflow vulnerabilities.
+FunctionPass *createSafeStackPass();
+
} // End llvm namespace
#endif
KEYWORD(ssp);
KEYWORD(sspreq);
KEYWORD(sspstrong);
+ KEYWORD(safestack);
KEYWORD(sanitize_address);
KEYWORD(sanitize_thread);
KEYWORD(sanitize_memory);
case lltok::kw_ssp: B.addAttribute(Attribute::StackProtect); break;
case lltok::kw_sspreq: B.addAttribute(Attribute::StackProtectReq); break;
case lltok::kw_sspstrong: B.addAttribute(Attribute::StackProtectStrong); break;
+ case lltok::kw_safestack: B.addAttribute(Attribute::SafeStack); break;
case lltok::kw_sanitize_address: B.addAttribute(Attribute::SanitizeAddress); break;
case lltok::kw_sanitize_thread: B.addAttribute(Attribute::SanitizeThread); break;
case lltok::kw_sanitize_memory: B.addAttribute(Attribute::SanitizeMemory); break;
case lltok::kw_ssp:
case lltok::kw_sspreq:
case lltok::kw_sspstrong:
+ case lltok::kw_safestack:
case lltok::kw_uwtable:
HaveError |= Error(Lex.getLoc(), "invalid use of function-only attribute");
break;
case lltok::kw_ssp:
case lltok::kw_sspreq:
case lltok::kw_sspstrong:
+ case lltok::kw_safestack:
case lltok::kw_uwtable:
HaveError |= Error(Lex.getLoc(), "invalid use of function-only attribute");
break;
kw_ssp,
kw_sspreq,
kw_sspstrong,
+ kw_safestack,
kw_sret,
kw_sanitize_thread,
kw_sanitize_memory,
return Attribute::StackProtectReq;
case bitc::ATTR_KIND_STACK_PROTECT_STRONG:
return Attribute::StackProtectStrong;
+ case bitc::ATTR_KIND_SAFESTACK:
+ return Attribute::SafeStack;
case bitc::ATTR_KIND_STRUCT_RET:
return Attribute::StructRet;
case bitc::ATTR_KIND_SANITIZE_ADDRESS:
return bitc::ATTR_KIND_STACK_PROTECT_REQ;
case Attribute::StackProtectStrong:
return bitc::ATTR_KIND_STACK_PROTECT_STRONG;
+ case Attribute::SafeStack:
+ return bitc::ATTR_KIND_SAFESTACK;
case Attribute::StructRet:
return bitc::ATTR_KIND_STRUCT_RET;
case Attribute::SanitizeAddress:
type = Library
name = CodeGen
parent = Libraries
-required_libraries = Analysis Core MC Scalar Support Target TransformUtils
+required_libraries = Analysis Core Instrumentation MC Scalar Support Target TransformUtils
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
+#include "llvm/Transforms/Instrumentation.h"
#include "llvm/Transforms/Scalar.h"
#include "llvm/Transforms/Utils/SymbolRewriter.h"
void TargetPassConfig::addISelPrepare() {
addPreISel();
+ // Add both the safe stack and the stack protection passes: each of them will
+ // only protect functions that have corresponding attributes.
+ addPass(createSafeStackPass());
addPass(createStackProtectorPass(TM));
if (PrintISelInput)
return "sspreq";
if (hasAttribute(Attribute::StackProtectStrong))
return "sspstrong";
+ if (hasAttribute(Attribute::SafeStack))
+ return "safestack";
if (hasAttribute(Attribute::StructRet))
return "sret";
if (hasAttribute(Attribute::SanitizeThread))
case Attribute::NonNull: return 1ULL << 44;
case Attribute::JumpTable: return 1ULL << 45;
case Attribute::Convergent: return 1ULL << 46;
+ case Attribute::SafeStack: return 1ULL << 47;
case Attribute::Dereferenceable:
llvm_unreachable("dereferenceable attribute not supported in raw format");
break;
I->getKindAsEnum() == Attribute::StackProtect ||
I->getKindAsEnum() == Attribute::StackProtectReq ||
I->getKindAsEnum() == Attribute::StackProtectStrong ||
+ I->getKindAsEnum() == Attribute::SafeStack ||
I->getKindAsEnum() == Attribute::NoRedZone ||
I->getKindAsEnum() == Attribute::NoImplicitFloat ||
I->getKindAsEnum() == Attribute::Naked ||
HANDLE_ATTR(StackProtect);
HANDLE_ATTR(StackProtectReq);
HANDLE_ATTR(StackProtectStrong);
+ HANDLE_ATTR(SafeStack);
HANDLE_ATTR(NoCapture);
HANDLE_ATTR(NoRedZone);
HANDLE_ATTR(NoImplicitFloat);
// clutter to the IR.
AttrBuilder B;
B.addAttribute(Attribute::StackProtect)
- .addAttribute(Attribute::StackProtectStrong);
+ .addAttribute(Attribute::StackProtectStrong)
+ .addAttribute(Attribute::StackProtectReq);
AttributeSet OldSSPAttr = AttributeSet::get(Caller->getContext(),
AttributeSet::FunctionIndex,
B);
- if (Callee->hasFnAttribute(Attribute::StackProtectReq)) {
+ if (Callee->hasFnAttribute(Attribute::SafeStack)) {
+ Caller->removeAttributes(AttributeSet::FunctionIndex, OldSSPAttr);
+ Caller->addFnAttr(Attribute::SafeStack);
+ } else if (Callee->hasFnAttribute(Attribute::StackProtectReq) &&
+ !Caller->hasFnAttribute(Attribute::SafeStack)) {
Caller->removeAttributes(AttributeSet::FunctionIndex, OldSSPAttr);
Caller->addFnAttr(Attribute::StackProtectReq);
} else if (Callee->hasFnAttribute(Attribute::StackProtectStrong) &&
+ !Caller->hasFnAttribute(Attribute::SafeStack) &&
!Caller->hasFnAttribute(Attribute::StackProtectReq)) {
Caller->removeAttributes(AttributeSet::FunctionIndex, OldSSPAttr);
Caller->addFnAttr(Attribute::StackProtectStrong);
} else if (Callee->hasFnAttribute(Attribute::StackProtect) &&
+ !Caller->hasFnAttribute(Attribute::SafeStack) &&
!Caller->hasFnAttribute(Attribute::StackProtectReq) &&
!Caller->hasFnAttribute(Attribute::StackProtectStrong))
Caller->addFnAttr(Attribute::StackProtect);
MemorySanitizer.cpp
Instrumentation.cpp
InstrProfiling.cpp
+ SafeStack.cpp
SanitizerCoverage.cpp
ThreadSanitizer.cpp
initializeThreadSanitizerPass(Registry);
initializeSanitizerCoverageModulePass(Registry);
initializeDataFlowSanitizerPass(Registry);
+ initializeSafeStackPass(Registry);
}
/// LLVMInitializeInstrumentation - C binding for
--- /dev/null
+//===-- SafeStack.cpp - Safe Stack Insertion ------------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This pass splits the stack into the safe stack (kept as-is for LLVM backend)
+// and the unsafe stack (explicitly allocated and managed through the runtime
+// support library).
+//
+// http://clang.llvm.org/docs/SafeStack.html
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Transforms/Instrumentation.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/ADT/Triple.h"
+#include "llvm/Analysis/AliasAnalysis.h"
+#include "llvm/Analysis/TargetTransformInfo.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/DIBuilder.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/InstIterator.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/Intrinsics.h"
+#include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Pass.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/Format.h"
+#include "llvm/Support/MathExtras.h"
+#include "llvm/Support/raw_os_ostream.h"
+#include "llvm/Transforms/Utils/Local.h"
+#include "llvm/Transforms/Utils/ModuleUtils.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "safestack"
+
+namespace llvm {
+
+STATISTIC(NumFunctions, "Total number of functions");
+STATISTIC(NumUnsafeStackFunctions, "Number of functions with unsafe stack");
+STATISTIC(NumUnsafeStackRestorePointsFunctions,
+ "Number of functions that use setjmp or exceptions");
+
+STATISTIC(NumAllocas, "Total number of allocas");
+STATISTIC(NumUnsafeStaticAllocas, "Number of unsafe static allocas");
+STATISTIC(NumUnsafeDynamicAllocas, "Number of unsafe dynamic allocas");
+STATISTIC(NumUnsafeStackRestorePoints, "Number of setjmps and landingpads");
+
+} // namespace llvm
+
+namespace {
+
+/// Check whether a given alloca instruction (AI) should be put on the safe
+/// stack or not. The function analyzes all uses of AI and checks whether it is
+/// only accessed in a memory safe way (as decided statically).
+bool IsSafeStackAlloca(const AllocaInst *AI) {
+ // Go through all uses of this alloca and check whether all accesses to the
+ // allocated object are statically known to be memory safe and, hence, the
+ // object can be placed on the safe stack.
+
+ SmallPtrSet<const Value *, 16> Visited;
+ SmallVector<const Instruction *, 8> WorkList;
+ WorkList.push_back(AI);
+
+ // A DFS search through all uses of the alloca in bitcasts/PHI/GEPs/etc.
+ while (!WorkList.empty()) {
+ const Instruction *V = WorkList.pop_back_val();
+ for (const Use &UI : V->uses()) {
+ auto I = cast<const Instruction>(UI.getUser());
+ assert(V == UI.get());
+
+ switch (I->getOpcode()) {
+ case Instruction::Load:
+ // Loading from a pointer is safe.
+ break;
+ case Instruction::VAArg:
+ // "va-arg" from a pointer is safe.
+ break;
+ case Instruction::Store:
+ if (V == I->getOperand(0))
+ // Stored the pointer - conservatively assume it may be unsafe.
+ return false;
+ // Storing to the pointee is safe.
+ break;
+
+ case Instruction::GetElementPtr:
+ if (!cast<const GetElementPtrInst>(I)->hasAllConstantIndices())
+ // GEP with non-constant indices can lead to memory errors.
+ // This also applies to inbounds GEPs, as the inbounds attribute
+ // represents an assumption that the address is in bounds, rather than
+ // an assertion that it is.
+ return false;
+
+ // We assume that GEP on static alloca with constant indices is safe,
+ // otherwise a compiler would detect it and warn during compilation.
+
+ if (!isa<const ConstantInt>(AI->getArraySize()))
+ // However, if the array size itself is not constant, the access
+ // might still be unsafe at runtime.
+ return false;
+
+ /* fallthrough */
+
+ case Instruction::BitCast:
+ case Instruction::IntToPtr:
+ case Instruction::PHI:
+ case Instruction::PtrToInt:
+ case Instruction::Select:
+ // The object can be safe or not, depending on how the result of the
+ // instruction is used.
+ if (Visited.insert(I).second)
+ WorkList.push_back(cast<const Instruction>(I));
+ break;
+
+ case Instruction::Call:
+ case Instruction::Invoke: {
+ // FIXME: add support for memset and memcpy intrinsics.
+ ImmutableCallSite CS(I);
+
+ // LLVM 'nocapture' attribute is only set for arguments whose address
+ // is not stored, passed around, or used in any other non-trivial way.
+ // We assume that passing a pointer to an object as a 'nocapture'
+ // argument is safe.
+ // FIXME: a more precise solution would require an interprocedural
+ // analysis here, which would look at all uses of an argument inside
+ // the function being called.
+ ImmutableCallSite::arg_iterator B = CS.arg_begin(), E = CS.arg_end();
+ for (ImmutableCallSite::arg_iterator A = B; A != E; ++A)
+ if (A->get() == V && !CS.doesNotCapture(A - B))
+ // The parameter is not marked 'nocapture' - unsafe.
+ return false;
+ continue;
+ }
+
+ default:
+ // The object is unsafe if it is used in any other way.
+ return false;
+ }
+ }
+ }
+
+ // All uses of the alloca are safe, we can place it on the safe stack.
+ return true;
+}
+
+/// The SafeStack pass splits the stack of each function into the
+/// safe stack, which is only accessed through memory safe dereferences
+/// (as determined statically), and the unsafe stack, which contains all
+/// local variables that are accessed in unsafe ways.
+class SafeStack : public FunctionPass {
+ const DataLayout *DL;
+
+ Type *StackPtrTy;
+ Type *IntPtrTy;
+ Type *Int32Ty;
+ Type *Int8Ty;
+
+ Constant *UnsafeStackPtr;
+
+ /// Unsafe stack alignment. Each stack frame must ensure that the stack is
+ /// aligned to this value. We need to re-align the unsafe stack if the
+ /// alignment of any object on the stack exceeds this value.
+ ///
+ /// 16 seems like a reasonable upper bound on the alignment of objects that we
+ /// might expect to appear on the stack on most common targets.
+ enum { StackAlignment = 16 };
+
+ /// \brief Build a constant representing a pointer to the unsafe stack
+ /// pointer.
+ Constant *getOrCreateUnsafeStackPtr(Module &M);
+
+ /// \brief Find all static allocas, dynamic allocas, return instructions and
+ /// stack restore points (exception unwind blocks and setjmp calls) in the
+ /// given function and append them to the respective vectors.
+ void findInsts(Function &F, SmallVectorImpl<AllocaInst *> &StaticAllocas,
+ SmallVectorImpl<AllocaInst *> &DynamicAllocas,
+ SmallVectorImpl<ReturnInst *> &Returns,
+ SmallVectorImpl<Instruction *> &StackRestorePoints);
+
+ /// \brief Allocate space for all static allocas in \p StaticAllocas,
+ /// replace allocas with pointers into the unsafe stack and generate code to
+ /// restore the stack pointer before all return instructions in \p Returns.
+ ///
+ /// \returns A pointer to the top of the unsafe stack after all unsafe static
+ /// allocas are allocated.
+ Value *moveStaticAllocasToUnsafeStack(Function &F,
+ ArrayRef<AllocaInst *> StaticAllocas,
+ ArrayRef<ReturnInst *> Returns);
+
+ /// \brief Generate code to restore the stack after all stack restore points
+ /// in \p StackRestorePoints.
+ ///
+ /// \returns A local variable in which to maintain the dynamic top of the
+ /// unsafe stack if needed.
+ AllocaInst *
+ createStackRestorePoints(Function &F,
+ ArrayRef<Instruction *> StackRestorePoints,
+ Value *StaticTop, bool NeedDynamicTop);
+
+ /// \brief Replace all allocas in \p DynamicAllocas with code to allocate
+ /// space dynamically on the unsafe stack and store the dynamic unsafe stack
+ /// top to \p DynamicTop if non-null.
+ void moveDynamicAllocasToUnsafeStack(Function &F, Value *UnsafeStackPtr,
+ AllocaInst *DynamicTop,
+ ArrayRef<AllocaInst *> DynamicAllocas);
+
+public:
+ static char ID; // Pass identification, replacement for typeid.
+ SafeStack() : FunctionPass(ID), DL(nullptr) {
+ initializeSafeStackPass(*PassRegistry::getPassRegistry());
+ }
+
+ virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.addRequired<AliasAnalysis>();
+ }
+
+ virtual bool doInitialization(Module &M) {
+ DL = &M.getDataLayout();
+
+ StackPtrTy = Type::getInt8PtrTy(M.getContext());
+ IntPtrTy = DL->getIntPtrType(M.getContext());
+ Int32Ty = Type::getInt32Ty(M.getContext());
+ Int8Ty = Type::getInt8Ty(M.getContext());
+
+ UnsafeStackPtr = getOrCreateUnsafeStackPtr(M);
+
+ return false;
+ }
+
+ bool runOnFunction(Function &F);
+
+}; // class SafeStack
+
+Constant *SafeStack::getOrCreateUnsafeStackPtr(Module &M) {
+ // The unsafe stack pointer is stored in a global variable with a magic name.
+ const char *kUnsafeStackPtrVar = "__safestack_unsafe_stack_ptr";
+
+ auto UnsafeStackPtr =
+ dyn_cast_or_null<GlobalVariable>(M.getNamedValue(kUnsafeStackPtrVar));
+
+ if (!UnsafeStackPtr) {
+ // The global variable is not defined yet, define it ourselves.
+ // We use the initial-exec TLS model because we do not support the variable
+ // living anywhere other than in the main executable.
+ UnsafeStackPtr = new GlobalVariable(
+ /*Module=*/M, /*Type=*/StackPtrTy,
+ /*isConstant=*/false, /*Linkage=*/GlobalValue::ExternalLinkage,
+ /*Initializer=*/0, /*Name=*/kUnsafeStackPtrVar,
+ /*InsertBefore=*/nullptr,
+ /*ThreadLocalMode=*/GlobalValue::InitialExecTLSModel);
+ } else {
+ // The variable exists, check its type and attributes.
+ if (UnsafeStackPtr->getValueType() != StackPtrTy) {
+ report_fatal_error(Twine(kUnsafeStackPtrVar) + " must have void* type");
+ }
+
+ if (!UnsafeStackPtr->isThreadLocal()) {
+ report_fatal_error(Twine(kUnsafeStackPtrVar) + " must be thread-local");
+ }
+ }
+
+ return UnsafeStackPtr;
+}
+
+void SafeStack::findInsts(Function &F,
+ SmallVectorImpl<AllocaInst *> &StaticAllocas,
+ SmallVectorImpl<AllocaInst *> &DynamicAllocas,
+ SmallVectorImpl<ReturnInst *> &Returns,
+ SmallVectorImpl<Instruction *> &StackRestorePoints) {
+ for (Instruction &I : inst_range(&F)) {
+ if (auto AI = dyn_cast<AllocaInst>(&I)) {
+ ++NumAllocas;
+
+ if (IsSafeStackAlloca(AI))
+ continue;
+
+ if (AI->isStaticAlloca()) {
+ ++NumUnsafeStaticAllocas;
+ StaticAllocas.push_back(AI);
+ } else {
+ ++NumUnsafeDynamicAllocas;
+ DynamicAllocas.push_back(AI);
+ }
+ } else if (auto RI = dyn_cast<ReturnInst>(&I)) {
+ Returns.push_back(RI);
+ } else if (auto CI = dyn_cast<CallInst>(&I)) {
+ // setjmps require stack restore.
+ if (CI->getCalledFunction() && CI->canReturnTwice())
+ StackRestorePoints.push_back(CI);
+ } else if (auto LP = dyn_cast<LandingPadInst>(&I)) {
+ // Exception landing pads require stack restore.
+ StackRestorePoints.push_back(LP);
+ } else if (auto II = dyn_cast<IntrinsicInst>(&I)) {
+ if (II->getIntrinsicID() == Intrinsic::gcroot)
+ llvm::report_fatal_error(
+ "gcroot intrinsic not compatible with safestack attribute");
+ }
+ }
+}
+
+AllocaInst *
+SafeStack::createStackRestorePoints(Function &F,
+ ArrayRef<Instruction *> StackRestorePoints,
+ Value *StaticTop, bool NeedDynamicTop) {
+ if (StackRestorePoints.empty())
+ return nullptr;
+
+ IRBuilder<> IRB(StaticTop
+ ? cast<Instruction>(StaticTop)->getNextNode()
+ : (Instruction *)F.getEntryBlock().getFirstInsertionPt());
+
+ // We need the current value of the shadow stack pointer to restore
+ // after longjmp or exception catching.
+
+ // FIXME: On some platforms this could be handled by the longjmp/exception
+ // runtime itself.
+
+ AllocaInst *DynamicTop = nullptr;
+ if (NeedDynamicTop)
+ // If we also have dynamic alloca's, the stack pointer value changes
+ // throughout the function. For now we store it in an alloca.
+ DynamicTop = IRB.CreateAlloca(StackPtrTy, /*ArraySize=*/nullptr,
+ "unsafe_stack_dynamic_ptr");
+
+ if (!StaticTop)
+ // We need the original unsafe stack pointer value, even if there are
+ // no unsafe static allocas.
+ StaticTop = IRB.CreateLoad(UnsafeStackPtr, false, "unsafe_stack_ptr");
+
+ if (NeedDynamicTop)
+ IRB.CreateStore(StaticTop, DynamicTop);
+
+ // Restore current stack pointer after longjmp/exception catch.
+ for (Instruction *I : StackRestorePoints) {
+ ++NumUnsafeStackRestorePoints;
+
+ IRB.SetInsertPoint(cast<Instruction>(I->getNextNode()));
+ Value *CurrentTop = DynamicTop ? IRB.CreateLoad(DynamicTop) : StaticTop;
+ IRB.CreateStore(CurrentTop, UnsafeStackPtr);
+ }
+
+ return DynamicTop;
+}
+
+Value *
+SafeStack::moveStaticAllocasToUnsafeStack(Function &F,
+ ArrayRef<AllocaInst *> StaticAllocas,
+ ArrayRef<ReturnInst *> Returns) {
+ if (StaticAllocas.empty())
+ return nullptr;
+
+ IRBuilder<> IRB(F.getEntryBlock().getFirstInsertionPt());
+ DIBuilder DIB(*F.getParent());
+
+ // We explicitly compute and set the unsafe stack layout for all unsafe
+ // static alloca instructions. We save the unsafe "base pointer" in the
+ // prologue into a local variable and restore it in the epilogue.
+
+ // Load the current stack pointer (we'll also use it as a base pointer).
+ // FIXME: use a dedicated register for it ?
+ Instruction *BasePointer =
+ IRB.CreateLoad(UnsafeStackPtr, false, "unsafe_stack_ptr");
+ assert(BasePointer->getType() == StackPtrTy);
+
+ for (ReturnInst *RI : Returns) {
+ IRB.SetInsertPoint(RI);
+ IRB.CreateStore(BasePointer, UnsafeStackPtr);
+ }
+
+ // Compute maximum alignment among static objects on the unsafe stack.
+ unsigned MaxAlignment = 0;
+ for (AllocaInst *AI : StaticAllocas) {
+ Type *Ty = AI->getAllocatedType();
+ unsigned Align =
+ std::max((unsigned)DL->getPrefTypeAlignment(Ty), AI->getAlignment());
+ if (Align > MaxAlignment)
+ MaxAlignment = Align;
+ }
+
+ if (MaxAlignment > StackAlignment) {
+ // Re-align the base pointer according to the max requested alignment.
+ assert(isPowerOf2_32(MaxAlignment));
+ IRB.SetInsertPoint(cast<Instruction>(BasePointer->getNextNode()));
+ BasePointer = cast<Instruction>(IRB.CreateIntToPtr(
+ IRB.CreateAnd(IRB.CreatePtrToInt(BasePointer, IntPtrTy),
+ ConstantInt::get(IntPtrTy, ~uint64_t(MaxAlignment - 1))),
+ StackPtrTy));
+ }
+
+ // Allocate space for every unsafe static AllocaInst on the unsafe stack.
+ int64_t StaticOffset = 0; // Current stack top.
+ for (AllocaInst *AI : StaticAllocas) {
+ IRB.SetInsertPoint(AI);
+
+ auto CArraySize = cast<ConstantInt>(AI->getArraySize());
+ Type *Ty = AI->getAllocatedType();
+
+ uint64_t Size = DL->getTypeAllocSize(Ty) * CArraySize->getZExtValue();
+ if (Size == 0)
+ Size = 1; // Don't create zero-sized stack objects.
+
+ // Ensure the object is properly aligned.
+ unsigned Align =
+ std::max((unsigned)DL->getPrefTypeAlignment(Ty), AI->getAlignment());
+
+ // Add alignment.
+ // NOTE: we ensure that BasePointer itself is aligned to >= Align.
+ StaticOffset += Size;
+ StaticOffset = RoundUpToAlignment(StaticOffset, Align);
+
+ Value *Off = IRB.CreateGEP(BasePointer, // BasePointer is i8*
+ ConstantInt::get(Int32Ty, -StaticOffset));
+ Value *NewAI = IRB.CreateBitCast(Off, AI->getType(), AI->getName());
+ if (AI->hasName() && isa<Instruction>(NewAI))
+ cast<Instruction>(NewAI)->takeName(AI);
+
+ // Replace alloc with the new location.
+ replaceDbgDeclareForAlloca(AI, NewAI, DIB, /*Deref=*/true);
+ AI->replaceAllUsesWith(NewAI);
+ AI->eraseFromParent();
+ }
+
+ // Re-align BasePointer so that our callees would see it aligned as
+ // expected.
+ // FIXME: no need to update BasePointer in leaf functions.
+ StaticOffset = RoundUpToAlignment(StaticOffset, StackAlignment);
+
+ // Update shadow stack pointer in the function epilogue.
+ IRB.SetInsertPoint(cast<Instruction>(BasePointer->getNextNode()));
+
+ Value *StaticTop =
+ IRB.CreateGEP(BasePointer, ConstantInt::get(Int32Ty, -StaticOffset),
+ "unsafe_stack_static_top");
+ IRB.CreateStore(StaticTop, UnsafeStackPtr);
+ return StaticTop;
+}
+
+void SafeStack::moveDynamicAllocasToUnsafeStack(
+ Function &F, Value *UnsafeStackPtr, AllocaInst *DynamicTop,
+ ArrayRef<AllocaInst *> DynamicAllocas) {
+ DIBuilder DIB(*F.getParent());
+
+ for (AllocaInst *AI : DynamicAllocas) {
+ IRBuilder<> IRB(AI);
+
+ // Compute the new SP value (after AI).
+ Value *ArraySize = AI->getArraySize();
+ if (ArraySize->getType() != IntPtrTy)
+ ArraySize = IRB.CreateIntCast(ArraySize, IntPtrTy, false);
+
+ Type *Ty = AI->getAllocatedType();
+ uint64_t TySize = DL->getTypeAllocSize(Ty);
+ Value *Size = IRB.CreateMul(ArraySize, ConstantInt::get(IntPtrTy, TySize));
+
+ Value *SP = IRB.CreatePtrToInt(IRB.CreateLoad(UnsafeStackPtr), IntPtrTy);
+ SP = IRB.CreateSub(SP, Size);
+
+ // Align the SP value to satisfy the AllocaInst, type and stack alignments.
+ unsigned Align = std::max(
+ std::max((unsigned)DL->getPrefTypeAlignment(Ty), AI->getAlignment()),
+ (unsigned)StackAlignment);
+
+ assert(isPowerOf2_32(Align));
+ Value *NewTop = IRB.CreateIntToPtr(
+ IRB.CreateAnd(SP, ConstantInt::get(IntPtrTy, ~uint64_t(Align - 1))),
+ StackPtrTy);
+
+ // Save the stack pointer.
+ IRB.CreateStore(NewTop, UnsafeStackPtr);
+ if (DynamicTop)
+ IRB.CreateStore(NewTop, DynamicTop);
+
+ Value *NewAI = IRB.CreateIntToPtr(SP, AI->getType());
+ if (AI->hasName() && isa<Instruction>(NewAI))
+ NewAI->takeName(AI);
+
+ replaceDbgDeclareForAlloca(AI, NewAI, DIB, /*Deref=*/true);
+ AI->replaceAllUsesWith(NewAI);
+ AI->eraseFromParent();
+ }
+
+ if (!DynamicAllocas.empty()) {
+ // Now go through the instructions again, replacing stacksave/stackrestore.
+ for (inst_iterator It = inst_begin(&F), Ie = inst_end(&F); It != Ie;) {
+ Instruction *I = &*(It++);
+ auto II = dyn_cast<IntrinsicInst>(I);
+ if (!II)
+ continue;
+
+ if (II->getIntrinsicID() == Intrinsic::stacksave) {
+ IRBuilder<> IRB(II);
+ Instruction *LI = IRB.CreateLoad(UnsafeStackPtr);
+ LI->takeName(II);
+ II->replaceAllUsesWith(LI);
+ II->eraseFromParent();
+ } else if (II->getIntrinsicID() == Intrinsic::stackrestore) {
+ IRBuilder<> IRB(II);
+ Instruction *SI = IRB.CreateStore(II->getArgOperand(0), UnsafeStackPtr);
+ SI->takeName(II);
+ assert(II->use_empty());
+ II->eraseFromParent();
+ }
+ }
+ }
+}
+
+bool SafeStack::runOnFunction(Function &F) {
+ auto AA = &getAnalysis<AliasAnalysis>();
+
+ DEBUG(dbgs() << "[SafeStack] Function: " << F.getName() << "\n");
+
+ if (!F.hasFnAttribute(Attribute::SafeStack)) {
+ DEBUG(dbgs() << "[SafeStack] safestack is not requested"
+ " for this function\n");
+ return false;
+ }
+
+ if (F.isDeclaration()) {
+ DEBUG(dbgs() << "[SafeStack] function definition"
+ " is not available\n");
+ return false;
+ }
+
+ {
+ // Make sure the regular stack protector won't run on this function
+ // (safestack attribute takes precedence).
+ AttrBuilder B;
+ B.addAttribute(Attribute::StackProtect)
+ .addAttribute(Attribute::StackProtectReq)
+ .addAttribute(Attribute::StackProtectStrong);
+ F.removeAttributes(
+ AttributeSet::FunctionIndex,
+ AttributeSet::get(F.getContext(), AttributeSet::FunctionIndex, B));
+ }
+
+ if (AA->onlyReadsMemory(&F)) {
+ // XXX: we don't protect against information leak attacks for now.
+ DEBUG(dbgs() << "[SafeStack] function only reads memory\n");
+ return false;
+ }
+
+ ++NumFunctions;
+
+ SmallVector<AllocaInst *, 16> StaticAllocas;
+ SmallVector<AllocaInst *, 4> DynamicAllocas;
+ SmallVector<ReturnInst *, 4> Returns;
+
+ // Collect all points where stack gets unwound and needs to be restored
+ // This is only necessary because the runtime (setjmp and unwind code) is
+ // not aware of the unsafe stack and won't unwind/restore it prorerly.
+ // To work around this problem without changing the runtime, we insert
+ // instrumentation to restore the unsafe stack pointer when necessary.
+ SmallVector<Instruction *, 4> StackRestorePoints;
+
+ // Find all static and dynamic alloca instructions that must be moved to the
+ // unsafe stack, all return instructions and stack restore points.
+ findInsts(F, StaticAllocas, DynamicAllocas, Returns, StackRestorePoints);
+
+ if (StaticAllocas.empty() && DynamicAllocas.empty() &&
+ StackRestorePoints.empty())
+ return false; // Nothing to do in this function.
+
+ if (!StaticAllocas.empty() || !DynamicAllocas.empty())
+ ++NumUnsafeStackFunctions; // This function has the unsafe stack.
+
+ if (!StackRestorePoints.empty())
+ ++NumUnsafeStackRestorePointsFunctions;
+
+ // The top of the unsafe stack after all unsafe static allocas are allocated.
+ Value *StaticTop = moveStaticAllocasToUnsafeStack(F, StaticAllocas, Returns);
+
+ // Safe stack object that stores the current unsafe stack top. It is updated
+ // as unsafe dynamic (non-constant-sized) allocas are allocated and freed.
+ // This is only needed if we need to restore stack pointer after longjmp
+ // or exceptions, and we have dynamic allocations.
+ // FIXME: a better alternative might be to store the unsafe stack pointer
+ // before setjmp / invoke instructions.
+ AllocaInst *DynamicTop = createStackRestorePoints(
+ F, StackRestorePoints, StaticTop, !DynamicAllocas.empty());
+
+ // Handle dynamic allocas.
+ moveDynamicAllocasToUnsafeStack(F, UnsafeStackPtr, DynamicTop,
+ DynamicAllocas);
+
+ DEBUG(dbgs() << "[SafeStack] safestack applied\n");
+ return true;
+}
+
+} // end anonymous namespace
+
+char SafeStack::ID = 0;
+INITIALIZE_PASS_BEGIN(SafeStack, "safe-stack",
+ "Safe Stack instrumentation pass", false, false)
+INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
+INITIALIZE_PASS_END(SafeStack, "safe-stack", "Safe Stack instrumentation pass",
+ false, false)
+
+FunctionPass *llvm::createSafeStackPass() { return new SafeStack(); }
--- /dev/null
+; RUN: opt -safe-stack -S -mtriple=i386-pc-linux-gnu < %s -o - | FileCheck %s
+; RUN: opt -safe-stack -S -mtriple=x86_64-pc-linux-gnu < %s -o - | FileCheck %s
+
+@.str = private unnamed_addr constant [4 x i8] c"%s\0A\00", align 1
+
+; Address-of local taken (j = &a)
+; Requires protector.
+
+define void @foo() nounwind uwtable safestack {
+entry:
+ ; CHECK: __safestack_unsafe_stack_ptr
+ %retval = alloca i32, align 4
+ %a = alloca i32, align 4
+ %j = alloca i32*, align 8
+ store i32 0, i32* %retval
+ %0 = load i32, i32* %a, align 4
+ %add = add nsw i32 %0, 1
+ store i32 %add, i32* %a, align 4
+ store i32* %a, i32** %j, align 8
+ ret void
+}
+
--- /dev/null
+; RUN: opt -safe-stack -S -mtriple=i386-pc-linux-gnu < %s -o - | FileCheck %s
+; RUN: opt -safe-stack -S -mtriple=x86_64-pc-linux-gnu < %s -o - | FileCheck %s
+
+@.str = private unnamed_addr constant [4 x i8] c"%s\0A\00", align 1
+
+; array of [16 x i8]
+
+define void @foo(i8* %a) nounwind uwtable safestack {
+entry:
+ ; CHECK: %[[USP:.*]] = load i8*, i8** @__safestack_unsafe_stack_ptr
+
+ ; CHECK: %[[USST:.*]] = getelementptr i8, i8* %[[USP]], i32 -16
+
+ ; CHECK: store i8* %[[USST]], i8** @__safestack_unsafe_stack_ptr
+
+ ; CHECK: %[[AADDR:.*]] = alloca i8*, align 8
+ %a.addr = alloca i8*, align 8
+
+ ; CHECK: %[[BUFPTR:.*]] = getelementptr i8, i8* %[[USP]], i32 -16
+ ; CHECK: %[[BUFPTR2:.*]] = bitcast i8* %[[BUFPTR]] to [16 x i8]*
+ %buf = alloca [16 x i8], align 16
+
+ ; CHECK: store i8* {{.*}}, i8** %[[AADDR]], align 8
+ store i8* %a, i8** %a.addr, align 8
+
+ ; CHECK: %[[GEP:.*]] = getelementptr inbounds [16 x i8], [16 x i8]* %[[BUFPTR2]], i32 0, i32 0
+ %gep = getelementptr inbounds [16 x i8], [16 x i8]* %buf, i32 0, i32 0
+
+ ; CHECK: %[[A2:.*]] = load i8*, i8** %[[AADDR]], align 8
+ %a2 = load i8*, i8** %a.addr, align 8
+
+ ; CHECK: call i8* @strcpy(i8* %[[GEP]], i8* %[[A2]])
+ %call = call i8* @strcpy(i8* %gep, i8* %a2)
+
+ ; CHECK: store i8* %[[USP]], i8** @__safestack_unsafe_stack_ptr
+ ret void
+}
+
+declare i8* @strcpy(i8*, i8*)
--- /dev/null
+; RUN: opt -safe-stack -S -mtriple=i386-pc-linux-gnu < %s -o - | FileCheck %s
+; RUN: opt -safe-stack -S -mtriple=x86_64-pc-linux-gnu < %s -o - | FileCheck %s
+
+; array [4 x i8]
+; Requires protector.
+
+define void @foo(i8* %a) nounwind uwtable safestack {
+entry:
+ ; CHECK: %[[USP:.*]] = load i8*, i8** @__safestack_unsafe_stack_ptr
+
+ ; CHECK: %[[USST:.*]] = getelementptr i8, i8* %[[USP]], i32 -16
+
+ ; CHECK: store i8* %[[USST]], i8** @__safestack_unsafe_stack_ptr
+
+ ; CHECK: %[[AADDR:.*]] = alloca i8*, align 8
+ %a.addr = alloca i8*, align 8
+
+ ; CHECK: %[[BUFPTR:.*]] = getelementptr i8, i8* %[[USP]], i32 -4
+ ; CHECK: %[[BUFPTR2:.*]] = bitcast i8* %[[BUFPTR]] to [4 x i8]*
+ %buf = alloca [4 x i8], align 1
+
+ ; CHECK: store i8* {{.*}}, i8** %[[AADDR]], align 8
+ store i8* %a, i8** %a.addr, align 8
+
+ ; CHECK: %[[GEP:.*]] = getelementptr inbounds [4 x i8], [4 x i8]* %[[BUFPTR2]], i32 0, i32 0
+ %gep = getelementptr inbounds [4 x i8], [4 x i8]* %buf, i32 0, i32 0
+
+ ; CHECK: %[[A2:.*]] = load i8*, i8** %[[AADDR]], align 8
+ %a2 = load i8*, i8** %a.addr, align 8
+
+ ; CHECK: call i8* @strcpy(i8* %[[GEP]], i8* %[[A2]])
+ %call = call i8* @strcpy(i8* %gep, i8* %a2)
+
+ ; CHECK: store i8* %[[USP]], i8** @__safestack_unsafe_stack_ptr
+ ret void
+}
+
+declare i8* @strcpy(i8*, i8*)
--- /dev/null
+; RUN: opt -safe-stack -S -mtriple=i386-pc-linux-gnu < %s -o - | FileCheck %s
+; RUN: opt -safe-stack -S -mtriple=x86_64-pc-linux-gnu < %s -o - | FileCheck %s
+
+@.str = private unnamed_addr constant [4 x i8] c"%s\0A\00", align 1
+
+; no arrays / no nested arrays
+; Requires no protector.
+
+; CHECK-LABEL: @foo(
+define void @foo(i8* %a) nounwind uwtable safestack {
+entry:
+ ; CHECK-NOT: __safestack_unsafe_stack_ptr
+ %a.addr = alloca i8*, align 8
+ store i8* %a, i8** %a.addr, align 8
+ %0 = load i8*, i8** %a.addr, align 8
+ %call = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str, i32 0, i32 0), i8* %0)
+ ret void
+}
+
+declare i32 @printf(i8*, ...)
--- /dev/null
+; RUN: opt -safe-stack -S -mtriple=i386-pc-linux-gnu < %s -o - | FileCheck %s
+; RUN: opt -safe-stack -S -mtriple=x86_64-pc-linux-gnu < %s -o - | FileCheck %s
+
+@.str = private unnamed_addr constant [4 x i8] c"%s\0A\00", align 1
+
+; PtrToInt/IntToPtr Cast
+; Requires no protector.
+
+; CHECK-LABEL: @foo(
+define void @foo() nounwind uwtable safestack {
+entry:
+ ; CHECK-NOT: __safestack_unsafe_stack_ptr
+ %a = alloca i32, align 4
+ %0 = ptrtoint i32* %a to i64
+ %1 = inttoptr i64 %0 to i32*
+ ret void
+}
--- /dev/null
+; RUN: opt -safe-stack -S -mtriple=i386-pc-linux-gnu < %s -o - | FileCheck %s
+; RUN: opt -safe-stack -S -mtriple=x86_64-pc-linux-gnu < %s -o - | FileCheck %s
+
+%struct.nest = type { %struct.pair, %struct.pair }
+%struct.pair = type { i32, i32 }
+
+@.str = private unnamed_addr constant [4 x i8] c"%s\0A\00", align 1
+
+; Nested structure, no arrays, no address-of expressions.
+; Verify that the resulting gep-of-gep does not incorrectly trigger
+; a safe stack protector.
+; safestack attribute
+; Requires no protector.
+; CHECK-LABEL: @foo(
+define void @foo() nounwind uwtable safestack {
+entry:
+ ; CHECK-NOT: __safestack_unsafe_stack_ptr
+ %c = alloca %struct.nest, align 4
+ %b = getelementptr inbounds %struct.nest, %struct.nest* %c, i32 0, i32 1
+ %_a = getelementptr inbounds %struct.pair, %struct.pair* %b, i32 0, i32 0
+ %0 = load i32, i32* %_a, align 4
+ %call = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str, i32 0, i32 0), i32 %0)
+ ret void
+}
+
+declare i32 @printf(i8*, ...)
--- /dev/null
+; RUN: opt -safe-stack -S -mtriple=i386-pc-linux-gnu < %s -o - | FileCheck %s
+; RUN: opt -safe-stack -S -mtriple=x86_64-pc-linux-gnu < %s -o - | FileCheck %s
+
+%class.A = type { [2 x i8] }
+
+@.str = private unnamed_addr constant [4 x i8] c"%s\0A\00", align 1
+
+; [2 x i8] in a class
+; safestack attribute
+; Requires no protector.
+; CHECK-LABEL: @foo(
+define signext i8 @foo() nounwind uwtable safestack {
+entry:
+ ; CHECK-NOT: __safestack_unsafe_stack_ptr
+ %a = alloca %class.A, align 1
+ %array = getelementptr inbounds %class.A, %class.A* %a, i32 0, i32 0
+ %arrayidx = getelementptr inbounds [2 x i8], [2 x i8]* %array, i32 0, i64 0
+ %0 = load i8, i8* %arrayidx, align 1
+ ret i8 %0
+}
--- /dev/null
+; RUN: opt -safe-stack -S -mtriple=i386-pc-linux-gnu < %s -o - | FileCheck %s
+; RUN: opt -safe-stack -S -mtriple=x86_64-pc-linux-gnu < %s -o - | FileCheck %s
+
+%struct.deep = type { %union.anon }
+%union.anon = type { %struct.anon }
+%struct.anon = type { %struct.anon.0 }
+%struct.anon.0 = type { %union.anon.1 }
+%union.anon.1 = type { [2 x i8] }
+
+@.str = private unnamed_addr constant [4 x i8] c"%s\0A\00", align 1
+
+; [2 x i8] nested in several layers of structs and unions
+; safestack attribute
+; Requires no protector.
+; CHECK-LABEL: @foo(
+define signext i8 @foo() nounwind uwtable safestack {
+entry:
+ ; CHECK-NOT: __safestack_unsafe_stack_ptr
+ %x = alloca %struct.deep, align 1
+ %b = getelementptr inbounds %struct.deep, %struct.deep* %x, i32 0, i32 0
+ %c = bitcast %union.anon* %b to %struct.anon*
+ %d = getelementptr inbounds %struct.anon, %struct.anon* %c, i32 0, i32 0
+ %e = getelementptr inbounds %struct.anon.0, %struct.anon.0* %d, i32 0, i32 0
+ %array = bitcast %union.anon.1* %e to [2 x i8]*
+ %arrayidx = getelementptr inbounds [2 x i8], [2 x i8]* %array, i32 0, i64 0
+ %0 = load i8, i8* %arrayidx, align 1
+ ret i8 %0
+}
--- /dev/null
+; RUN: opt -safe-stack -S -mtriple=i386-pc-linux-gnu < %s -o - | FileCheck %s
+; RUN: opt -safe-stack -S -mtriple=x86_64-pc-linux-gnu < %s -o - | FileCheck %s
+
+@.str = private unnamed_addr constant [4 x i8] c"%s\0A\00", align 1
+
+; Variable sized alloca
+; safestack attribute
+; Requires protector.
+define void @foo(i32 %n) nounwind uwtable safestack {
+entry:
+ ; CHECK: __safestack_unsafe_stack_ptr
+ %n.addr = alloca i32, align 4
+ %a = alloca i32*, align 8
+ store i32 %n, i32* %n.addr, align 4
+ %0 = load i32, i32* %n.addr, align 4
+ %conv = sext i32 %0 to i64
+ %1 = alloca i8, i64 %conv
+ %2 = bitcast i8* %1 to i32*
+ store i32* %2, i32** %a, align 8
+ ret void
+}
--- /dev/null
+; RUN: opt -safe-stack -S -mtriple=i386-pc-linux-gnu < %s -o - | FileCheck %s
+; RUN: opt -safe-stack -S -mtriple=x86_64-pc-linux-gnu < %s -o - | FileCheck %s
+
+@.str = private unnamed_addr constant [4 x i8] c"%s\0A\00", align 1
+
+; Addr-of a pointer
+; safestack attribute
+; Requires protector.
+define void @foo() nounwind uwtable safestack {
+entry:
+ ; CHECK: __safestack_unsafe_stack_ptr
+ %a = alloca i32*, align 8
+ %b = alloca i32**, align 8
+ %call = call i32* @getp()
+ store i32* %call, i32** %a, align 8
+ store i32** %a, i32*** %b, align 8
+ %0 = load i32**, i32*** %b, align 8
+ call void @funcall2(i32** %0)
+ ret void
+}
+
+declare void @funcall2(i32**)
+declare i32* @getp()
--- /dev/null
+; RUN: opt -safe-stack -S -mtriple=i386-pc-linux-gnu < %s -o - | FileCheck %s
+; RUN: opt -safe-stack -S -mtriple=x86_64-pc-linux-gnu < %s -o - | FileCheck %s
+
+@.str = private unnamed_addr constant [4 x i8] c"%s\0A\00", align 1
+
+; Addr-of a local cast to a ptr of a different type
+; (e.g., int a; ... ; float *b = &a;)
+; safestack attribute
+; Requires protector.
+define void @foo() nounwind uwtable safestack {
+entry:
+ ; CHECK: __safestack_unsafe_stack_ptr
+ %a = alloca i32, align 4
+ %b = alloca float*, align 8
+ store i32 0, i32* %a, align 4
+ %0 = bitcast i32* %a to float*
+ store float* %0, float** %b, align 8
+ %1 = load float*, float** %b, align 8
+ %call = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str, i32 0, i32 0), float* %1)
+ ret void
+}
+
+declare i32 @printf(i8*, ...)
--- /dev/null
+; RUN: opt -safe-stack -S -mtriple=i386-pc-linux-gnu < %s -o - | FileCheck %s
+; RUN: opt -safe-stack -S -mtriple=x86_64-pc-linux-gnu < %s -o - | FileCheck %s
+
+@.str = private unnamed_addr constant [4 x i8] c"%s\0A\00", align 1
+
+; Addr-of a local cast to a ptr of a different type (optimized)
+; (e.g., int a; ... ; float *b = &a;)
+; safestack attribute
+; Requires protector.
+define void @foo() nounwind uwtable safestack {
+entry:
+ ; CHECK: __safestack_unsafe_stack_ptr
+ %a = alloca i32, align 4
+ store i32 0, i32* %a, align 4
+ %0 = bitcast i32* %a to float*
+ call void @funfloat(float* %0) nounwind
+ ret void
+}
+
+declare void @funfloat(float*)
--- /dev/null
+; RUN: opt -safe-stack -S -mtriple=i386-pc-linux-gnu < %s -o - | FileCheck %s
+; RUN: opt -safe-stack -S -mtriple=x86_64-pc-linux-gnu < %s -o - | FileCheck %s
+
+@.str = private unnamed_addr constant [4 x i8] c"%s\0A\00", align 1
+
+; Passing addr-of to function call
+; Requires protector.
+define void @foo() nounwind uwtable safestack {
+entry:
+ ; CHECK: __safestack_unsafe_stack_ptr
+ %b = alloca i32, align 4
+ call void @funcall(i32* %b) nounwind
+ ret void
+}
+
+declare void @funcall(i32*)
--- /dev/null
+; RUN: opt -safe-stack -S -mtriple=i386-pc-linux-gnu < %s -o - | FileCheck %s
+; RUN: opt -safe-stack -S -mtriple=x86_64-pc-linux-gnu < %s -o - | FileCheck %s
+
+@.str = private unnamed_addr constant [4 x i8] c"%s\0A\00", align 1
+
+; Addr-of a casted pointer
+; safestack attribute
+; Requires protector.
+define void @foo() nounwind uwtable safestack {
+entry:
+ ; CHECK: __safestack_unsafe_stack_ptr
+ %a = alloca i32*, align 8
+ %b = alloca float**, align 8
+ %call = call i32* @getp()
+ store i32* %call, i32** %a, align 8
+ %0 = bitcast i32** %a to float**
+ store float** %0, float*** %b, align 8
+ %1 = load float**, float*** %b, align 8
+ call void @funfloat2(float** %1)
+ ret void
+}
+
+declare void @funfloat2(float**)
+declare i32* @getp()
--- /dev/null
+; RUN: opt -safe-stack -S -mtriple=i386-pc-linux-gnu < %s -o - | FileCheck %s
+; RUN: opt -safe-stack -S -mtriple=x86_64-pc-linux-gnu < %s -o - | FileCheck %s
+
+%struct.pair = type { i32, i32 }
+
+@.str = private unnamed_addr constant [4 x i8] c"%s\0A\00", align 1
+
+; Addr-of struct element, GEP followed by callinst.
+; safestack attribute
+; Requires protector.
+define void @foo() nounwind uwtable safestack {
+entry:
+ ; CHECK: __safestack_unsafe_stack_ptr
+ %c = alloca %struct.pair, align 4
+ %y = getelementptr inbounds %struct.pair, %struct.pair* %c, i64 0, i32 1
+ %call = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str, i64 0, i64 0), i32* %y) nounwind
+ ret void
+}
+
+declare i32 @printf(i8*, ...)
--- /dev/null
+; RUN: opt -safe-stack -S -mtriple=i386-pc-linux-gnu < %s -o - | FileCheck %s
+; RUN: opt -safe-stack -S -mtriple=x86_64-pc-linux-gnu < %s -o - | FileCheck %s
+
+%struct.pair = type { i32, i32 }
+
+@.str = private unnamed_addr constant [4 x i8] c"%s\0A\00", align 1
+
+; Addr-of a struct element passed into an invoke instruction.
+; (GEP followed by an invoke)
+; safestack attribute
+; Requires protector.
+define i32 @foo() uwtable safestack {
+entry:
+ ; CHECK: __safestack_unsafe_stack_ptr
+ %c = alloca %struct.pair, align 4
+ %exn.slot = alloca i8*
+ %ehselector.slot = alloca i32
+ %a = getelementptr inbounds %struct.pair, %struct.pair* %c, i32 0, i32 0
+ store i32 0, i32* %a, align 4
+ %a1 = getelementptr inbounds %struct.pair, %struct.pair* %c, i32 0, i32 0
+ invoke void @_Z3exceptPi(i32* %a1)
+ to label %invoke.cont unwind label %lpad
+
+invoke.cont:
+ ret i32 0
+
+lpad:
+ %0 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*)
+ catch i8* null
+ ret i32 0
+}
+
+declare void @_Z3exceptPi(i32*)
+declare i32 @__gxx_personality_v0(...)
--- /dev/null
+; RUN: opt -safe-stack -S -mtriple=i386-pc-linux-gnu < %s -o - | FileCheck %s
+; RUN: opt -safe-stack -S -mtriple=x86_64-pc-linux-gnu < %s -o - | FileCheck %s
+
+@.str = private unnamed_addr constant [4 x i8] c"%s\0A\00", align 1
+
+; Addr-of a local, optimized into a GEP (e.g., &a - 12)
+; safestack attribute
+; Requires protector.
+define void @foo() nounwind uwtable safestack {
+entry:
+ ; CHECK: __safestack_unsafe_stack_ptr
+ %a = alloca i32, align 4
+ %add.ptr5 = getelementptr inbounds i32, i32* %a, i64 -12
+ %call = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str, i64 0, i64 0), i32* %add.ptr5) nounwind
+ ret void
+}
+
+declare i32 @printf(i8*, ...)
--- /dev/null
+; RUN: opt -safe-stack -S -mtriple=i386-pc-linux-gnu < %s -o - | FileCheck %s
+; RUN: opt -safe-stack -S -mtriple=x86_64-pc-linux-gnu < %s -o - | FileCheck %s
+
+%struct.pair = type { i32, i32 }
+
+@.str = private unnamed_addr constant [4 x i8] c"%s\0A\00", align 1
+
+; Addr-of struct element, GEP followed by ptrtoint.
+; safestack attribute
+; Requires protector.
+define void @foo() nounwind uwtable safestack {
+entry:
+ ; CHECK: __safestack_unsafe_stack_ptr
+ %c = alloca %struct.pair, align 4
+ %b = alloca i32*, align 8
+ %y = getelementptr inbounds %struct.pair, %struct.pair* %c, i32 0, i32 1
+ %0 = ptrtoint i32* %y to i64
+ %call = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str, i32 0, i32 0), i64 %0)
+ ret void
+}
+
+declare i32 @printf(i8*, ...)
--- /dev/null
+; RUN: opt -safe-stack -S -mtriple=i386-pc-linux-gnu < %s -o - | FileCheck %s
+; RUN: opt -safe-stack -S -mtriple=x86_64-pc-linux-gnu < %s -o - | FileCheck %s
+
+%struct.pair = type { i32, i32 }
+
+@.str = private unnamed_addr constant [4 x i8] c"%s\0A\00", align 1
+
+; Addr-of struct element. (GEP followed by store).
+; safestack attribute
+; Requires protector.
+define void @foo() nounwind uwtable safestack {
+entry:
+ ; CHECK: __safestack_unsafe_stack_ptr
+ %c = alloca %struct.pair, align 4
+ %b = alloca i32*, align 8
+ %y = getelementptr inbounds %struct.pair, %struct.pair* %c, i32 0, i32 1
+ store i32* %y, i32** %b, align 8
+ %0 = load i32*, i32** %b, align 8
+ %call = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str, i32 0, i32 0), i32* %0)
+ ret void
+}
+
+declare i32 @printf(i8*, ...)
--- /dev/null
+; RUN: opt -safe-stack -S -mtriple=i386-pc-linux-gnu < %s -o - | FileCheck %s
+; RUN: opt -safe-stack -S -mtriple=x86_64-pc-linux-gnu < %s -o - | FileCheck %s
+
+@.str = private unnamed_addr constant [4 x i8] c"%s\0A\00", align 1
+
+; Addr-of in phi instruction
+; Requires protector.
+define void @foo() nounwind uwtable safestack {
+entry:
+ ; CHECK: __safestack_unsafe_stack_ptr
+ %x = alloca double, align 8
+ %call = call double @testi_aux() nounwind
+ store double %call, double* %x, align 8
+ %cmp = fcmp ogt double %call, 3.140000e+00
+ br i1 %cmp, label %if.then, label %if.else
+
+if.then: ; preds = %entry
+ %call1 = call double @testi_aux() nounwind
+ store double %call1, double* %x, align 8
+ br label %if.end4
+
+if.else: ; preds = %entry
+ %cmp2 = fcmp ogt double %call, 1.000000e+00
+ br i1 %cmp2, label %if.then3, label %if.end4
+
+if.then3: ; preds = %if.else
+ br label %if.end4
+
+if.end4: ; preds = %if.else, %if.then3, %if.then
+ %y.0 = phi double* [ null, %if.then ], [ %x, %if.then3 ], [ null, %if.else ]
+ %call5 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str, i64 0, i64 0), double* %y.0) nounwind
+ ret void
+}
+
+declare double @testi_aux()
+declare i32 @printf(i8*, ...)
--- /dev/null
+; RUN: opt -safe-stack -S -mtriple=i386-pc-linux-gnu < %s -o - | FileCheck %s
+; RUN: opt -safe-stack -S -mtriple=x86_64-pc-linux-gnu < %s -o - | FileCheck %s
+
+@.str = private unnamed_addr constant [4 x i8] c"%s\0A\00", align 1
+
+; Addr-of in select instruction
+; safestack attribute
+; Requires protector.
+define void @foo() nounwind uwtable safestack {
+entry:
+ ; CHECK: __safestack_unsafe_stack_ptr
+ %x = alloca double, align 8
+ %call = call double @testi_aux() nounwind
+ store double %call, double* %x, align 8
+ %cmp2 = fcmp ogt double %call, 0.000000e+00
+ %y.1 = select i1 %cmp2, double* %x, double* null
+ %call2 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str, i32 0, i32 0), double* %y.1)
+ ret void
+}
+
+declare double @testi_aux()
+declare i32 @printf(i8*, ...)
--- /dev/null
+; RUN: opt -safe-stack -S -mtriple=i386-pc-linux-gnu < %s -o - | FileCheck %s
+; RUN: opt -safe-stack -S -mtriple=x86_64-pc-linux-gnu < %s -o - | FileCheck %s
+
+%struct.vec = type { <4 x i32> }
+
+@.str = private unnamed_addr constant [4 x i8] c"%s\0A\00", align 1
+
+; Addr-of a vector nested in a struct
+; safestack attribute
+; Requires protector.
+define void @foo() nounwind uwtable safestack {
+entry:
+ ; CHECK: __safestack_unsafe_stack_ptr
+ %c = alloca %struct.vec, align 16
+ %y = getelementptr inbounds %struct.vec, %struct.vec* %c, i64 0, i32 0
+ %add.ptr = getelementptr inbounds <4 x i32>, <4 x i32>* %y, i64 -12
+ %call = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str, i64 0, i64 0), <4 x i32>* %add.ptr) nounwind
+ ret void
+}
+
+declare i32 @printf(i8*, ...)
--- /dev/null
+; RUN: opt -safe-stack -S -mtriple=i386-pc-linux-gnu < %s -o - | FileCheck %s
+; RUN: opt -safe-stack -S -mtriple=x86_64-pc-linux-gnu < %s -o - | FileCheck %s
+
+@.str = private unnamed_addr constant [4 x i8] c"%s\0A\00", align 1
+
+; Addr-of a variable passed into an invoke instruction.
+; safestack attribute
+; Requires protector and stack restore after landing pad.
+define i32 @foo() uwtable safestack {
+entry:
+ ; CHECK: %[[SP:.*]] = load i8*, i8** @__safestack_unsafe_stack_ptr
+ ; CHECK: %[[STATICTOP:.*]] = getelementptr i8, i8* %[[SP]], i32 -16
+ %a = alloca i32, align 4
+ %exn.slot = alloca i8*
+ %ehselector.slot = alloca i32
+ store i32 0, i32* %a, align 4
+ invoke void @_Z3exceptPi(i32* %a)
+ to label %invoke.cont unwind label %lpad
+
+invoke.cont:
+ ret i32 0
+
+lpad:
+ ; CHECK: landingpad
+ ; CHECK-NEXT: catch
+ %0 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*)
+ catch i8* null
+ ; CHECK-NEXT: store i8* %[[STATICTOP]], i8** @__safestack_unsafe_stack_ptr
+ ret i32 0
+}
+
+declare void @_Z3exceptPi(i32*)
+declare i32 @__gxx_personality_v0(...)
--- /dev/null
+; RUN: opt -safe-stack -S -mtriple=i386-pc-linux-gnu < %s -o - | FileCheck %s
+; RUN: opt -safe-stack -S -mtriple=x86_64-pc-linux-gnu < %s -o - | FileCheck %s
+
+@.str = private unnamed_addr constant [4 x i8] c"%s\0A\00", align 1
+
+; no safestack attribute
+; Requires no protector.
+
+; CHECK: @foo
+define void @foo(i8* %a) nounwind uwtable {
+entry:
+ ; CHECK-NOT: __safestack_unsafe_stack_ptr
+ %a.addr = alloca i8*, align 8
+ %buf = alloca [16 x i8], align 16
+ store i8* %a, i8** %a.addr, align 8
+ %arraydecay = getelementptr inbounds [16 x i8], [16 x i8]* %buf, i32 0, i32 0
+ %0 = load i8*, i8** %a.addr, align 8
+ %call = call i8* @strcpy(i8* %arraydecay, i8* %0)
+ %arraydecay1 = getelementptr inbounds [16 x i8], [16 x i8]* %buf, i32 0, i32 0
+ %call2 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str, i32 0, i32 0), i8* %arraydecay1)
+ ret void
+}
+
+declare i8* @strcpy(i8*, i8*)
+declare i32 @printf(i8*, ...)
--- /dev/null
+; RUN: opt -safe-stack -S -mtriple=i386-pc-linux-gnu < %s -o - | FileCheck %s
+; RUN: opt -safe-stack -S -mtriple=x86_64-pc-linux-gnu < %s -o - | FileCheck %s
+
+%struct.small = type { i8 }
+
+@.str = private unnamed_addr constant [4 x i8] c"%s\0A\00", align 1
+
+; Address-of a structure taken in a function with a loop where
+; the alloca is an incoming value to a PHI node and a use of that PHI
+; node is also an incoming value.
+; Verify that the address-of analysis does not get stuck in infinite
+; recursion when chasing the alloca through the PHI nodes.
+; Requires protector.
+define i32 @foo(i32 %arg) nounwind uwtable safestack {
+bb:
+ ; CHECK: __safestack_unsafe_stack_ptr
+ %tmp = alloca %struct.small*, align 8
+ %tmp1 = call i32 (...) @dummy(%struct.small** %tmp) nounwind
+ %tmp2 = load %struct.small*, %struct.small** %tmp, align 8
+ %tmp3 = ptrtoint %struct.small* %tmp2 to i64
+ %tmp4 = trunc i64 %tmp3 to i32
+ %tmp5 = icmp sgt i32 %tmp4, 0
+ br i1 %tmp5, label %bb6, label %bb21
+
+bb6: ; preds = %bb17, %bb
+ %tmp7 = phi %struct.small* [ %tmp19, %bb17 ], [ %tmp2, %bb ]
+ %tmp8 = phi i64 [ %tmp20, %bb17 ], [ 1, %bb ]
+ %tmp9 = phi i32 [ %tmp14, %bb17 ], [ %tmp1, %bb ]
+ %tmp10 = getelementptr inbounds %struct.small, %struct.small* %tmp7, i64 0, i32 0
+ %tmp11 = load i8, i8* %tmp10, align 1
+ %tmp12 = icmp eq i8 %tmp11, 1
+ %tmp13 = add nsw i32 %tmp9, 8
+ %tmp14 = select i1 %tmp12, i32 %tmp13, i32 %tmp9
+ %tmp15 = trunc i64 %tmp8 to i32
+ %tmp16 = icmp eq i32 %tmp15, %tmp4
+ br i1 %tmp16, label %bb21, label %bb17
+
+bb17: ; preds = %bb6
+ %tmp18 = getelementptr inbounds %struct.small*, %struct.small** %tmp, i64 %tmp8
+ %tmp19 = load %struct.small*, %struct.small** %tmp18, align 8
+ %tmp20 = add i64 %tmp8, 1
+ br label %bb6
+
+bb21: ; preds = %bb6, %bb
+ %tmp22 = phi i32 [ %tmp1, %bb ], [ %tmp14, %bb6 ]
+ %tmp23 = call i32 (...) @dummy(i32 %tmp22) nounwind
+ ret i32 undef
+}
+
+declare i32 @dummy(...)
--- /dev/null
+; RUN: opt -safe-stack -S -mtriple=i386-pc-linux-gnu < %s -o - | FileCheck %s
+; RUN: opt -safe-stack -S -mtriple=x86_64-pc-linux-gnu < %s -o - | FileCheck %s
+
+%struct.__jmp_buf_tag = type { [8 x i64], i32, %struct.__sigset_t }
+%struct.__sigset_t = type { [16 x i64] }
+
+@.str = private unnamed_addr constant [4 x i8] c"%s\0A\00", align 1
+@buf = internal global [1 x %struct.__jmp_buf_tag] zeroinitializer, align 16
+
+; setjmp/longjmp test.
+; Requires protector.
+define i32 @foo() nounwind uwtable safestack {
+entry:
+ ; CHECK: %[[SP:.*]] = load i8*, i8** @__safestack_unsafe_stack_ptr
+ ; CHECK: %[[STATICTOP:.*]] = getelementptr i8, i8* %[[SP]], i32 -16
+ %retval = alloca i32, align 4
+ %x = alloca i32, align 4
+ store i32 0, i32* %retval
+ store i32 42, i32* %x, align 4
+ %call = call i32 @_setjmp(%struct.__jmp_buf_tag* getelementptr inbounds ([1 x %struct.__jmp_buf_tag], [1 x %struct.__jmp_buf_tag]* @buf, i32 0, i32 0)) returns_twice
+ ; CHECK: setjmp
+ ; CHECK-NEXT: store i8* %[[STATICTOP]], i8** @__safestack_unsafe_stack_ptr
+ %tobool = icmp ne i32 %call, 0
+ br i1 %tobool, label %if.else, label %if.then
+if.then: ; preds = %entry
+ call void @funcall(i32* %x)
+ br label %if.end
+if.else: ; preds = %entry
+ call i32 (...) @dummy()
+ br label %if.end
+if.end: ; preds = %if.else, %if.then
+ ret i32 0
+}
+
+declare i32 @_setjmp(%struct.__jmp_buf_tag*)
+declare void @funcall(i32*)
+declare i32 @dummy(...)
--- /dev/null
+; RUN: opt -safe-stack -S -mtriple=i386-pc-linux-gnu < %s -o - | FileCheck %s
+; RUN: opt -safe-stack -S -mtriple=x86_64-pc-linux-gnu < %s -o - | FileCheck %s
+
+%struct.__jmp_buf_tag = type { [8 x i64], i32, %struct.__sigset_t }
+%struct.__sigset_t = type { [16 x i64] }
+
+@.str = private unnamed_addr constant [4 x i8] c"%s\0A\00", align 1
+@buf = internal global [1 x %struct.__jmp_buf_tag] zeroinitializer, align 16
+
+; setjmp/longjmp test with dynamically sized array.
+; Requires protector.
+; CHECK: @foo(i32 %[[ARG:.*]])
+define i32 @foo(i32 %size) nounwind uwtable safestack {
+entry:
+ ; CHECK: %[[DYNPTR:.*]] = alloca i8*
+ ; CHECK-NEXT: %[[SP:.*]] = load i8*, i8** @__safestack_unsafe_stack_ptr
+ ; CHECK-NEXT: store i8* %[[SP]], i8** %[[DYNPTR]]
+
+ ; CHECK-NEXT: %[[ZEXT:.*]] = zext i32 %[[ARG]] to i64
+ ; CHECK-NEXT: %[[MUL:.*]] = mul i64 %[[ZEXT]], 4
+ ; CHECK-NEXT: %[[SP2:.*]] = load i8*, i8** @__safestack_unsafe_stack_ptr
+ ; CHECK-NEXT: %[[PTRTOINT:.*]] = ptrtoint i8* %[[SP2]] to i64
+ ; CHECK-NEXT: %[[SUB:.*]] = sub i64 %[[PTRTOINT]], %[[MUL]]
+ ; CHECK-NEXT: %[[AND:.*]] = and i64 %[[SUB]], -16
+ ; CHECK-NEXT: %[[INTTOPTR:.*]] = inttoptr i64 %[[AND]] to i8*
+ ; CHECK-NEXT: store i8* %[[INTTOPTR]], i8** @__safestack_unsafe_stack_ptr
+ ; CHECK-NEXT: store i8* %[[INTTOPTR]], i8** %unsafe_stack_dynamic_ptr
+ ; CHECK-NEXT: %[[ALLOCA:.*]] = inttoptr i64 %[[SUB]] to i32*
+ %a = alloca i32, i32 %size
+
+ ; CHECK: setjmp
+ ; CHECK-NEXT: %[[LOAD:.*]] = load i8*, i8** %[[DYNPTR]]
+ ; CHECK-NEXT: store i8* %[[LOAD]], i8** @__safestack_unsafe_stack_ptr
+ %call = call i32 @_setjmp(%struct.__jmp_buf_tag* getelementptr inbounds ([1 x %struct.__jmp_buf_tag], [1 x %struct.__jmp_buf_tag]* @buf, i32 0, i32 0)) returns_twice
+
+ ; CHECK: call void @funcall(i32* %[[ALLOCA]])
+ call void @funcall(i32* %a)
+ ret i32 0
+}
+
+declare i32 @_setjmp(%struct.__jmp_buf_tag*)
+declare void @funcall(i32*)
--- /dev/null
+; RUN: opt -safe-stack -S -mtriple=i386-pc-linux-gnu < %s -o - | FileCheck %s
+; RUN: opt -safe-stack -S -mtriple=x86_64-pc-linux-gnu < %s -o - | FileCheck %s
+
+%struct.foo = type { [16 x i8] }
+
+@.str = private unnamed_addr constant [4 x i8] c"%s\0A\00", align 1
+
+; struct { [16 x i8] }
+
+define void @foo(i8* %a) nounwind uwtable safestack {
+entry:
+ ; CHECK: %[[USP:.*]] = load i8*, i8** @__safestack_unsafe_stack_ptr
+
+ ; CHECK: %[[USST:.*]] = getelementptr i8, i8* %[[USP]], i32 -16
+
+ ; CHECK: store i8* %[[USST]], i8** @__safestack_unsafe_stack_ptr
+
+ ; CHECK: %[[AADDR:.*]] = alloca i8*, align 8
+ %a.addr = alloca i8*, align 8
+
+ ; CHECK: %[[BUFPTR:.*]] = getelementptr i8, i8* %[[USP]], i32 -16
+ ; CHECK: %[[BUFPTR2:.*]] = bitcast i8* %[[BUFPTR]] to %struct.foo*
+ %buf = alloca %struct.foo, align 1
+
+ ; CHECK: store i8* {{.*}}, i8** %[[AADDR]], align 8
+ store i8* %a, i8** %a.addr, align 8
+
+ ; CHECK: %[[GEP:.*]] = getelementptr inbounds %struct.foo, %struct.foo* %[[BUFPTR2]], i32 0, i32 0, i32 0
+ %gep = getelementptr inbounds %struct.foo, %struct.foo* %buf, i32 0, i32 0, i32 0
+
+ ; CHECK: %[[A:.*]] = load i8*, i8** %[[AADDR]], align 8
+ %a2 = load i8*, i8** %a.addr, align 8
+
+ ; CHECK: call i8* @strcpy(i8* %[[GEP]], i8* %[[A]])
+ %call = call i8* @strcpy(i8* %gep, i8* %a2)
+
+ ; CHECK: store i8* %[[USP]], i8** @__safestack_unsafe_stack_ptr
+ ret void
+}
+
+declare i8* @strcpy(i8*, i8*)
projects / oota-llvm.git / commitdiff