X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FShadowStackGC.cpp;h=d8f63ca4a9f31e47c5fcb87dad252e053afff375;hb=021e3b6444e9179751002db7b20de96455e03171;hp=26da05f2b302b85fb1e9322d3d126fbba50ca168;hpb=6726b6d75a8b679068a58cb954ba97cf9d1690ba;p=oota-llvm.git diff --git a/lib/CodeGen/ShadowStackGC.cpp b/lib/CodeGen/ShadowStackGC.cpp index 26da05f2b30..d8f63ca4a9f 100644 --- a/lib/CodeGen/ShadowStackGC.cpp +++ b/lib/CodeGen/ShadowStackGC.cpp @@ -29,10 +29,10 @@ #include "llvm/CodeGen/GCs.h" #include "llvm/ADT/StringExtras.h" #include "llvm/CodeGen/GCStrategy.h" +#include "llvm/IRBuilder.h" #include "llvm/IntrinsicInst.h" #include "llvm/Module.h" -#include "llvm/Support/Compiler.h" -#include "llvm/Support/IRBuilder.h" +#include "llvm/Support/CallSite.h" using namespace llvm; @@ -45,7 +45,8 @@ namespace { /// StackEntryTy - Abstract type of a link in the shadow stack. /// - const StructType *StackEntryTy; + StructType *StackEntryTy; + StructType *FrameMapTy; /// Roots - GC roots in the current function. Each is a pair of the /// intrinsic call and its corresponding alloca. @@ -60,7 +61,7 @@ namespace { private: bool IsNullValue(Value *V); Constant *GetFrameMap(Function &F); - const Type* GetConcreteStackEntryType(Function &F); + Type* GetConcreteStackEntryType(Function &F); void CollectRoots(Function &F); static GetElementPtrInst *CreateGEP(LLVMContext &Context, IRBuilder<> &B, Value *BasePtr, @@ -108,13 +109,14 @@ namespace { State = 1; case 1: - // Find all 'return' and 'unwind' instructions. + // Find all 'return', 'resume', and 'unwind' instructions. while (StateBB != StateE) { BasicBlock *CurBB = StateBB++; - // Branches and invokes do not escape, only unwind and return do. + // Branches and invokes do not escape, only unwind, resume, and return + // do. TerminatorInst *TI = CurBB->getTerminator(); - if (!isa(TI) && !isa(TI)) + if (!isa(TI) && !isa(TI)) continue; Builder.SetInsertPoint(TI->getParent(), TI); @@ -138,9 +140,19 @@ namespace { return 0; // Create a cleanup block. - BasicBlock *CleanupBB = BasicBlock::Create(F.getContext(), - CleanupBBName, &F); - UnwindInst *UI = new UnwindInst(F.getContext(), CleanupBB); + LLVMContext &C = F.getContext(); + BasicBlock *CleanupBB = BasicBlock::Create(C, CleanupBBName, &F); + Type *ExnTy = StructType::get(Type::getInt8PtrTy(C), + Type::getInt32Ty(C), NULL); + Constant *PersFn = + F.getParent()-> + getOrInsertFunction("__gcc_personality_v0", + FunctionType::get(Type::getInt32Ty(C), true)); + LandingPadInst *LPad = LandingPadInst::Create(ExnTy, PersFn, 1, + "cleanup.lpad", + CleanupBB); + LPad->setCleanup(true); + ResumeInst *RI = ResumeInst::Create(LPad, CleanupBB); // Transform the 'call' instructions into 'invoke's branching to the // cleanup block. Go in reverse order to make prettier BB names. @@ -159,19 +171,19 @@ namespace { // Create a new invoke instruction. Args.clear(); - Args.append(CI->op_begin() + 1, CI->op_end()); + CallSite CS(CI); + Args.append(CS.arg_begin(), CS.arg_end()); - InvokeInst *II = InvokeInst::Create(CI->getOperand(0), + InvokeInst *II = InvokeInst::Create(CI->getCalledValue(), NewBB, CleanupBB, - Args.begin(), Args.end(), - CI->getName(), CallBB); + Args, CI->getName(), CallBB); II->setCallingConv(CI->getCallingConv()); II->setAttributes(CI->getAttributes()); CI->replaceAllUsesWith(II); delete CI; } - Builder.SetInsertPoint(UI->getParent(), UI); + Builder.SetInsertPoint(RI->getParent(), RI); return &Builder; } } @@ -189,35 +201,35 @@ ShadowStackGC::ShadowStackGC() : Head(0), StackEntryTy(0) { Constant *ShadowStackGC::GetFrameMap(Function &F) { // doInitialization creates the abstract type of this value. - const Type *VoidPtr = Type::getInt8PtrTy(F.getContext()); + Type *VoidPtr = Type::getInt8PtrTy(F.getContext()); // Truncate the ShadowStackDescriptor if some metadata is null. unsigned NumMeta = 0; - SmallVector Metadata; + SmallVector Metadata; for (unsigned I = 0; I != Roots.size(); ++I) { - Constant *C = cast(Roots[I].first->getOperand(2)); + Constant *C = cast(Roots[I].first->getArgOperand(1)); if (!C->isNullValue()) NumMeta = I + 1; Metadata.push_back(ConstantExpr::getBitCast(C, VoidPtr)); } + Metadata.resize(NumMeta); + Type *Int32Ty = Type::getInt32Ty(F.getContext()); + Constant *BaseElts[] = { - ConstantInt::get(Type::getInt32Ty(F.getContext()), Roots.size(), false), - ConstantInt::get(Type::getInt32Ty(F.getContext()), NumMeta, false), + ConstantInt::get(Int32Ty, Roots.size(), false), + ConstantInt::get(Int32Ty, NumMeta, false), }; Constant *DescriptorElts[] = { - ConstantStruct::get(F.getContext(), BaseElts, 2, false), - ConstantArray::get(ArrayType::get(VoidPtr, NumMeta), - Metadata.begin(), NumMeta) + ConstantStruct::get(FrameMapTy, BaseElts), + ConstantArray::get(ArrayType::get(VoidPtr, NumMeta), Metadata) }; - Constant *FrameMap = ConstantStruct::get(F.getContext(), DescriptorElts, 2, - false); - - std::string TypeName("gc_map."); - TypeName += utostr(NumMeta); - F.getParent()->addTypeName(TypeName, FrameMap->getType()); + Type *EltTys[] = { DescriptorElts[0]->getType(),DescriptorElts[1]->getType()}; + StructType *STy = StructType::create(EltTys, "gc_map."+utostr(NumMeta)); + + Constant *FrameMap = ConstantStruct::get(STy, DescriptorElts); // FIXME: Is this actually dangerous as WritingAnLLVMPass.html claims? Seems // that, short of multithreaded LLVM, it should be safe; all that is @@ -240,22 +252,17 @@ Constant *ShadowStackGC::GetFrameMap(Function &F) { ConstantInt::get(Type::getInt32Ty(F.getContext()), 0), ConstantInt::get(Type::getInt32Ty(F.getContext()), 0) }; - return ConstantExpr::getGetElementPtr(GV, GEPIndices, 2); + return ConstantExpr::getGetElementPtr(GV, GEPIndices); } -const Type* ShadowStackGC::GetConcreteStackEntryType(Function &F) { +Type* ShadowStackGC::GetConcreteStackEntryType(Function &F) { // doInitialization creates the generic version of this type. - std::vector EltTys; + std::vector EltTys; EltTys.push_back(StackEntryTy); for (size_t I = 0; I != Roots.size(); I++) EltTys.push_back(Roots[I].second->getAllocatedType()); - Type *Ty = StructType::get(F.getContext(), EltTys); - - std::string TypeName("gc_stackentry."); - TypeName += F.getName(); - F.getParent()->addTypeName(TypeName, Ty); - - return Ty; + + return StructType::create(EltTys, "gc_stackentry."+F.getName().str()); } /// doInitialization - If this module uses the GC intrinsics, find them now. If @@ -266,13 +273,12 @@ bool ShadowStackGC::initializeCustomLowering(Module &M) { // int32_t NumMeta; // Number of metadata descriptors. May be < NumRoots. // void *Meta[]; // May be absent for roots without metadata. // }; - std::vector EltTys; + std::vector EltTys; // 32 bits is ok up to a 32GB stack frame. :) EltTys.push_back(Type::getInt32Ty(M.getContext())); // Specifies length of variable length array. EltTys.push_back(Type::getInt32Ty(M.getContext())); - StructType *FrameMapTy = StructType::get(M.getContext(), EltTys); - M.addTypeName("gc_map", FrameMapTy); + FrameMapTy = StructType::create(EltTys, "gc_map"); PointerType *FrameMapPtrTy = PointerType::getUnqual(FrameMapTy); // struct StackEntry { @@ -280,18 +286,14 @@ bool ShadowStackGC::initializeCustomLowering(Module &M) { // FrameMap *Map; // Pointer to constant FrameMap. // void *Roots[]; // Stack roots (in-place array, so we pretend). // }; - OpaqueType *RecursiveTy = OpaqueType::get(M.getContext()); - + + StackEntryTy = StructType::create(M.getContext(), "gc_stackentry"); + EltTys.clear(); - EltTys.push_back(PointerType::getUnqual(RecursiveTy)); + EltTys.push_back(PointerType::getUnqual(StackEntryTy)); EltTys.push_back(FrameMapPtrTy); - PATypeHolder LinkTyH = StructType::get(M.getContext(), EltTys); - - RecursiveTy->refineAbstractTypeTo(LinkTyH.get()); - StackEntryTy = cast(LinkTyH.get()); - const PointerType *StackEntryPtrTy = PointerType::getUnqual(StackEntryTy); - M.addTypeName("gc_stackentry", LinkTyH.get()); // FIXME: Is this safe from - // a FunctionPass? + StackEntryTy->setBody(EltTys); + PointerType *StackEntryPtrTy = PointerType::getUnqual(StackEntryTy); // Get the root chain if it already exists. Head = M.getGlobalVariable("llvm_gc_root_chain"); @@ -323,16 +325,16 @@ void ShadowStackGC::CollectRoots(Function &F) { assert(Roots.empty() && "Not cleaned up?"); - SmallVector,16> MetaRoots; + SmallVector, 16> MetaRoots; for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) for (BasicBlock::iterator II = BB->begin(), E = BB->end(); II != E;) if (IntrinsicInst *CI = dyn_cast(II++)) if (Function *F = CI->getCalledFunction()) if (F->getIntrinsicID() == Intrinsic::gcroot) { - std::pair Pair = std::make_pair( - CI, cast(CI->getOperand(1)->stripPointerCasts())); - if (IsNullValue(CI->getOperand(2))) + std::pair Pair = std::make_pair( + CI, cast(CI->getArgOperand(0)->stripPointerCasts())); + if (IsNullValue(CI->getArgOperand(1))) Roots.push_back(Pair); else MetaRoots.push_back(Pair); @@ -349,7 +351,7 @@ ShadowStackGC::CreateGEP(LLVMContext &Context, IRBuilder<> &B, Value *BasePtr, Value *Indices[] = { ConstantInt::get(Type::getInt32Ty(Context), 0), ConstantInt::get(Type::getInt32Ty(Context), Idx), ConstantInt::get(Type::getInt32Ty(Context), Idx2) }; - Value* Val = B.CreateGEP(BasePtr, Indices, Indices + 3, Name); + Value* Val = B.CreateGEP(BasePtr, Indices, Name); assert(isa(Val) && "Unexpected folded constant"); @@ -361,7 +363,7 @@ ShadowStackGC::CreateGEP(LLVMContext &Context, IRBuilder<> &B, Value *BasePtr, int Idx, const char *Name) { Value *Indices[] = { ConstantInt::get(Type::getInt32Ty(Context), 0), ConstantInt::get(Type::getInt32Ty(Context), Idx) }; - Value *Val = B.CreateGEP(BasePtr, Indices, Indices + 2, Name); + Value *Val = B.CreateGEP(BasePtr, Indices, Name); assert(isa(Val) && "Unexpected folded constant"); @@ -382,7 +384,7 @@ bool ShadowStackGC::performCustomLowering(Function &F) { // Build the constant map and figure the type of the shadow stack entry. Value *FrameMap = GetFrameMap(F); - const Type *ConcreteStackEntryTy = GetConcreteStackEntryType(F); + Type *ConcreteStackEntryTy = GetConcreteStackEntryType(F); // Build the shadow stack entry at the very start of the function. BasicBlock::iterator IP = F.getEntryBlock().begin(); @@ -398,7 +400,7 @@ bool ShadowStackGC::performCustomLowering(Function &F) { Instruction *CurrentHead = AtEntry.CreateLoad(Head, "gc_currhead"); Instruction *EntryMapPtr = CreateGEP(Context, AtEntry, StackEntry, 0,1,"gc_frame.map"); - AtEntry.CreateStore(FrameMap, EntryMapPtr); + AtEntry.CreateStore(FrameMap, EntryMapPtr); // After all the allocas... for (unsigned I = 0, E = Roots.size(); I != E; ++I) {