diff options
Diffstat (limited to 'lib/CodeGen/StackProtector.cpp')
| -rw-r--r-- | lib/CodeGen/StackProtector.cpp | 66 |
1 files changed, 34 insertions, 32 deletions
diff --git a/lib/CodeGen/StackProtector.cpp b/lib/CodeGen/StackProtector.cpp index 45f97ac..d1fae95 100644 --- a/lib/CodeGen/StackProtector.cpp +++ b/lib/CodeGen/StackProtector.cpp @@ -17,6 +17,7 @@ #include "llvm/CodeGen/StackProtector.h" #include "llvm/ADT/SmallPtrSet.h" #include "llvm/ADT/Statistic.h" +#include "llvm/Analysis/BranchProbabilityInfo.h" #include "llvm/Analysis/ValueTracking.h" #include "llvm/CodeGen/Analysis.h" #include "llvm/CodeGen/Passes.h" @@ -31,6 +32,7 @@ #include "llvm/IR/Instructions.h" #include "llvm/IR/IntrinsicInst.h" #include "llvm/IR/Intrinsics.h" +#include "llvm/IR/MDBuilder.h" #include "llvm/IR/Module.h" #include "llvm/Support/CommandLine.h" #include "llvm/Target/TargetSubtargetInfo.h" @@ -86,10 +88,9 @@ bool StackProtector::runOnFunction(Function &Fn) { DominatorTreeWrapperPass *DTWP = getAnalysisIfAvailable<DominatorTreeWrapperPass>(); DT = DTWP ? &DTWP->getDomTree() : nullptr; - TLI = TM->getSubtargetImpl()->getTargetLowering(); + TLI = TM->getSubtargetImpl(Fn)->getTargetLowering(); - Attribute Attr = Fn.getAttributes().getAttribute( - AttributeSet::FunctionIndex, "stack-protector-buffer-size"); + Attribute Attr = Fn.getFnAttribute("stack-protector-buffer-size"); if (Attr.isStringAttribute() && Attr.getValueAsString().getAsInteger(10, SSPBufferSize)) return false; // Invalid integer string @@ -199,31 +200,24 @@ bool StackProtector::HasAddressTaken(const Instruction *AI) { bool StackProtector::RequiresStackProtector() { bool Strong = false; bool NeedsProtector = false; - if (F->getAttributes().hasAttribute(AttributeSet::FunctionIndex, - Attribute::StackProtectReq)) { + if (F->hasFnAttribute(Attribute::StackProtectReq)) { NeedsProtector = true; Strong = true; // Use the same heuristic as strong to determine SSPLayout - } else if (F->getAttributes().hasAttribute(AttributeSet::FunctionIndex, - Attribute::StackProtectStrong)) + } else if (F->hasFnAttribute(Attribute::StackProtectStrong)) Strong = true; - else if (!F->getAttributes().hasAttribute(AttributeSet::FunctionIndex, - Attribute::StackProtect)) + else if (!F->hasFnAttribute(Attribute::StackProtect)) return false; - for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I) { - BasicBlock *BB = I; - - for (BasicBlock::iterator II = BB->begin(), IE = BB->end(); II != IE; - ++II) { - if (AllocaInst *AI = dyn_cast<AllocaInst>(II)) { + for (const BasicBlock &BB : *F) { + for (const Instruction &I : BB) { + if (const AllocaInst *AI = dyn_cast<AllocaInst>(&I)) { if (AI->isArrayAllocation()) { // SSP-Strong: Enable protectors for any call to alloca, regardless // of size. if (Strong) return true; - if (const ConstantInt *CI = - dyn_cast<ConstantInt>(AI->getArraySize())) { + if (const auto *CI = dyn_cast<ConstantInt>(AI->getArraySize())) { if (CI->getLimitedValue(SSPBufferSize) >= SSPBufferSize) { // A call to alloca with size >= SSPBufferSize requires // stack protectors. @@ -335,7 +329,7 @@ static CallInst *FindPotentialTailCall(BasicBlock *BB, ReturnInst *RI, /// Returns true if the platform/triple supports the stackprotectorcreate pseudo /// node. static bool CreatePrologue(Function *F, Module *M, ReturnInst *RI, - const TargetLoweringBase *TLI, const Triple &Trip, + const TargetLoweringBase *TLI, const Triple &TT, AllocaInst *&AI, Value *&StackGuardVar) { bool SupportsSelectionDAGSP = false; PointerType *PtrTy = Type::getInt8PtrTy(RI->getContext()); @@ -344,9 +338,10 @@ static bool CreatePrologue(Function *F, Module *M, ReturnInst *RI, Constant *OffsetVal = ConstantInt::get(Type::getInt32Ty(RI->getContext()), Offset); - StackGuardVar = ConstantExpr::getIntToPtr( - OffsetVal, PointerType::get(PtrTy, AddressSpace)); - } else if (Trip.getOS() == llvm::Triple::OpenBSD) { + StackGuardVar = + ConstantExpr::getIntToPtr(OffsetVal, PointerType::get(PtrTy, + AddressSpace)); + } else if (TT.isOSOpenBSD()) { StackGuardVar = M->getOrInsertGlobal("__guard_local", PtrTy); cast<GlobalValue>(StackGuardVar) ->setVisibility(GlobalValue::HiddenVisibility); @@ -399,14 +394,13 @@ bool StackProtector::InsertStackProtectors() { InsertionPt = RI; // At this point we know that BB has a return statement so it *DOES* // have a terminator. - assert(InsertionPt != nullptr && "BB must have a terminator instruction at " - "this point."); + assert(InsertionPt != nullptr && + "BB must have a terminator instruction at this point."); } Function *Intrinsic = Intrinsic::getDeclaration(M, Intrinsic::stackprotectorcheck); CallInst::Create(Intrinsic, StackGuardVar, "", InsertionPt); - } else { // If we do not support SelectionDAG based tail calls, generate IR level // tail calls. @@ -459,11 +453,17 @@ bool StackProtector::InsertStackProtectors() { LoadInst *LI1 = B.CreateLoad(StackGuardVar); LoadInst *LI2 = B.CreateLoad(AI); Value *Cmp = B.CreateICmpEQ(LI1, LI2); - B.CreateCondBr(Cmp, NewBB, FailBB); + unsigned SuccessWeight = + BranchProbabilityInfo::getBranchWeightStackProtector(true); + unsigned FailureWeight = + BranchProbabilityInfo::getBranchWeightStackProtector(false); + MDNode *Weights = MDBuilder(F->getContext()) + .createBranchWeights(SuccessWeight, FailureWeight); + B.CreateCondBr(Cmp, NewBB, FailBB, Weights); } } - // Return if we didn't modify any basic blocks. I.e., there are no return + // Return if we didn't modify any basic blocks. i.e., there are no return // statements in the function. if (!HasPrologue) return false; @@ -477,15 +477,17 @@ BasicBlock *StackProtector::CreateFailBB() { LLVMContext &Context = F->getContext(); BasicBlock *FailBB = BasicBlock::Create(Context, "CallStackCheckFailBlk", F); IRBuilder<> B(FailBB); - if (Trip.getOS() == llvm::Triple::OpenBSD) { - Constant *StackChkFail = M->getOrInsertFunction( - "__stack_smash_handler", Type::getVoidTy(Context), - Type::getInt8PtrTy(Context), nullptr); + if (Trip.isOSOpenBSD()) { + Constant *StackChkFail = + M->getOrInsertFunction("__stack_smash_handler", + Type::getVoidTy(Context), + Type::getInt8PtrTy(Context), nullptr); B.CreateCall(StackChkFail, B.CreateGlobalStringPtr(F->getName(), "SSH")); } else { - Constant *StackChkFail = M->getOrInsertFunction( - "__stack_chk_fail", Type::getVoidTy(Context), nullptr); + Constant *StackChkFail = + M->getOrInsertFunction("__stack_chk_fail", Type::getVoidTy(Context), + nullptr); B.CreateCall(StackChkFail); } B.CreateUnreachable(); |