diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp --- a/clang/lib/CodeGen/CGExpr.cpp +++ b/clang/lib/CodeGen/CGExpr.cpp @@ -5168,6 +5168,9 @@ if (getLangOpts().CPlusPlus && SanOpts.has(SanitizerKind::Function) && (!TargetDecl || !isa(TargetDecl))) { + assert((CGM.getCodeGenOpts().CodeModel == "default" || + CGM.getCodeGenOpts().CodeModel == "small") && + "function sanitizer only works with the small code model"); if (llvm::Constant *PrefixSig = CGM.getTargetCodeGenInfo().getUBSanFunctionSignature(CGM)) { SanitizerScope SanScope(this); diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h --- a/clang/lib/CodeGen/CodeGenFunction.h +++ b/clang/lib/CodeGen/CodeGenFunction.h @@ -2352,10 +2352,6 @@ /// XRay typed event handling calls. bool AlwaysEmitXRayTypedEvents() const; - /// Encode an address into a form suitable for use in a function prologue. - llvm::Constant *EncodeAddrForUseInPrologue(llvm::Function *F, - llvm::Constant *Addr); - /// Decode an address used in a function prologue, encoded by \c /// EncodeAddrForUseInPrologue. llvm::Value *DecodeAddrUsedInPrologue(llvm::Value *F, diff --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp --- a/clang/lib/CodeGen/CodeGenFunction.cpp +++ b/clang/lib/CodeGen/CodeGenFunction.cpp @@ -559,29 +559,6 @@ XRayInstrKind::Typed); } -llvm::Constant * -CodeGenFunction::EncodeAddrForUseInPrologue(llvm::Function *F, - llvm::Constant *Addr) { - // Addresses stored in prologue data can't require run-time fixups and must - // be PC-relative. Run-time fixups are undesirable because they necessitate - // writable text segments, which are unsafe. And absolute addresses are - // undesirable because they break PIE mode. - - // Add a layer of indirection through a private global. Taking its address - // won't result in a run-time fixup, even if Addr has linkonce_odr linkage. - auto *GV = new llvm::GlobalVariable(CGM.getModule(), Addr->getType(), - /*isConstant=*/true, - llvm::GlobalValue::PrivateLinkage, Addr); - - // Create a PC-relative address. - auto *GOTAsInt = llvm::ConstantExpr::getPtrToInt(GV, IntPtrTy); - auto *FuncAsInt = llvm::ConstantExpr::getPtrToInt(F, IntPtrTy); - auto *PCRelAsInt = llvm::ConstantExpr::getSub(GOTAsInt, FuncAsInt); - return (IntPtrTy == Int32Ty) - ? PCRelAsInt - : llvm::ConstantExpr::getTrunc(PCRelAsInt, Int32Ty); -} - llvm::Value * CodeGenFunction::DecodeAddrUsedInPrologue(llvm::Value *F, llvm::Value *EncodedAddr) { @@ -918,12 +895,13 @@ FD->getType(), EST_None); llvm::Constant *FTRTTIConst = CGM.GetAddrOfRTTIDescriptor(ProtoTy, /*ForEH=*/true); - llvm::Constant *FTRTTIConstEncoded = - EncodeAddrForUseInPrologue(Fn, FTRTTIConst); - llvm::Constant *PrologueStructElems[] = {PrologueSig, FTRTTIConstEncoded}; - llvm::Constant *PrologueStructConst = - llvm::ConstantStruct::getAnon(PrologueStructElems, /*Packed=*/true); - Fn->setPrologueData(PrologueStructConst); + llvm::GlobalVariable *FTRTTIProxy = + CGM.GetOrCreateRTTIProxyGlobalVariable(FTRTTIConst); + llvm::LLVMContext &Ctx = Fn->getContext(); + llvm::MDBuilder MDB(Ctx); + Fn->setMetadata(llvm::LLVMContext::MD_func_sanitize, + MDB.createRTTIPointerPrologue(PrologueSig, FTRTTIProxy)); + CGM.addCompilerUsedGlobal(FTRTTIProxy); } } diff --git a/clang/lib/CodeGen/CodeGenModule.h b/clang/lib/CodeGen/CodeGenModule.h --- a/clang/lib/CodeGen/CodeGenModule.h +++ b/clang/lib/CodeGen/CodeGenModule.h @@ -578,6 +578,8 @@ MetadataTypeMap VirtualMetadataIdMap; MetadataTypeMap GeneralizedMetadataIdMap; + llvm::DenseMap RTTIProxyMap; + public: CodeGenModule(ASTContext &C, const HeaderSearchOptions &headersearchopts, const PreprocessorOptions &ppopts, @@ -1425,6 +1427,9 @@ std::vector getMostBaseClasses(const CXXRecordDecl *RD); + llvm::GlobalVariable * + GetOrCreateRTTIProxyGlobalVariable(llvm::Constant *Addr); + /// Get the declaration of std::terminate for the platform. llvm::FunctionCallee getTerminateFn(); diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp --- a/clang/lib/CodeGen/CodeGenModule.cpp +++ b/clang/lib/CodeGen/CodeGenModule.cpp @@ -1817,6 +1817,22 @@ return MostBases.takeVector(); } +llvm::GlobalVariable * +CodeGenModule::GetOrCreateRTTIProxyGlobalVariable(llvm::Constant *Addr) { + auto It = RTTIProxyMap.find(Addr); + if (It != RTTIProxyMap.end()) + return It->second; + + auto *FTRTTIProxy = new llvm::GlobalVariable( + TheModule, Addr->getType(), + /*isConstant=*/true, llvm::GlobalValue::PrivateLinkage, Addr, + "__llvm_rtti_proxy"); + FTRTTIProxy->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global); + + RTTIProxyMap[Addr] = FTRTTIProxy; + return FTRTTIProxy; +} + void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D, llvm::Function *F) { llvm::AttrBuilder B; diff --git a/clang/test/CodeGen/ubsan-function.cpp b/clang/test/CodeGen/ubsan-function.cpp --- a/clang/test/CodeGen/ubsan-function.cpp +++ b/clang/test/CodeGen/ubsan-function.cpp @@ -1,6 +1,7 @@ // RUN: %clang_cc1 -triple x86_64-linux-gnu -emit-llvm -o - %s -fsanitize=function -fno-sanitize-recover=all | FileCheck %s -// CHECK-LABEL: define{{.*}} void @_Z3funv() #0 prologue <{ i32, i32 }> <{ i32 846595819, i32 trunc (i64 sub (i64 ptrtoint (i8** @0 to i64), i64 ptrtoint (void ()* @_Z3funv to i64)) to i32) }> { +// CHECK: @[[PROXY:.*]] = private unnamed_addr constant i8* bitcast ({ i8*, i8* }* @_ZTIFvvE to i8*) +// CHECK: define{{.*}} void @_Z3funv() #0 !func_sanitize ![[FUNCSAN:.*]] { void fun() {} // CHECK-LABEL: define{{.*}} void @_Z6callerPFvvE(void ()* %f) @@ -20,3 +21,5 @@ // CHECK: [[LABEL3]]: // CHECK: br label %[[LABEL4]], !nosanitize void caller(void (*f)()) { f(); } + +// CHECK: ![[FUNCSAN]] = !{i32 846595819, i8** @[[PROXY]]} diff --git a/clang/test/CodeGenCXX/catch-undef-behavior.cpp b/clang/test/CodeGenCXX/catch-undef-behavior.cpp --- a/clang/test/CodeGenCXX/catch-undef-behavior.cpp +++ b/clang/test/CodeGenCXX/catch-undef-behavior.cpp @@ -1,8 +1,8 @@ -// RUN: %clang_cc1 -std=c++11 -fsanitize=signed-integer-overflow,integer-divide-by-zero,float-divide-by-zero,shift-base,shift-exponent,unreachable,return,vla-bound,alignment,null,vptr,object-size,float-cast-overflow,bool,enum,array-bounds,function -fsanitize-recover=signed-integer-overflow,integer-divide-by-zero,float-divide-by-zero,shift-base,shift-exponent,vla-bound,alignment,null,vptr,object-size,float-cast-overflow,bool,enum,array-bounds,function -emit-llvm %s -o - -triple x86_64-linux-gnu | opt -instnamer -S | FileCheck %s +// RUN: %clang_cc1 -std=c++11 -fsanitize=signed-integer-overflow,integer-divide-by-zero,float-divide-by-zero,shift-base,shift-exponent,unreachable,return,vla-bound,alignment,null,vptr,object-size,float-cast-overflow,bool,enum,array-bounds,function -fsanitize-recover=signed-integer-overflow,integer-divide-by-zero,float-divide-by-zero,shift-base,shift-exponent,vla-bound,alignment,null,vptr,object-size,float-cast-overflow,bool,enum,array-bounds,function -emit-llvm %s -o - -triple x86_64-linux-gnu | opt -instnamer -S | FileCheck %s --check-prefixes=CHECK,CHECK-FUNCSAN // RUN: %clang_cc1 -std=c++11 -fsanitize=vptr,address -fsanitize-recover=vptr,address -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck %s --check-prefix=CHECK-ASAN // RUN: %clang_cc1 -std=c++11 -fsanitize=vptr -fsanitize-recover=vptr -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck %s --check-prefix=DOWNCAST-NULL -// RUN: %clang_cc1 -std=c++11 -fsanitize=function -emit-llvm %s -o - -triple x86_64-linux-gnux32 | FileCheck %s --check-prefix=CHECK-X32 -// RUN: %clang_cc1 -std=c++11 -fsanitize=function -emit-llvm %s -o - -triple i386-linux-gnu | FileCheck %s --check-prefix=CHECK-X86 +// RUN: %clang_cc1 -std=c++11 -fsanitize=function -emit-llvm %s -o - -triple x86_64-linux-gnux32 | FileCheck %s --check-prefix=CHECK-FUNCSAN +// RUN: %clang_cc1 -std=c++11 -fsanitize=function -emit-llvm %s -o - -triple i386-linux-gnu | FileCheck %s --check-prefix=CHECK-FUNCSAN struct S { double d; @@ -16,9 +16,7 @@ // Check that type mismatch handler is not modified by ASan. // CHECK-ASAN: private unnamed_addr global { { [{{.*}} x i8]*, i32, i32 }, { i16, i16, [4 x i8] }*, i8*, i8 } { {{.*}}, { i16, i16, [4 x i8] }* [[TYPE_DESCR]], {{.*}} } -// CHECK: [[IndirectRTTI_ZTIFvPFviEE:@.+]] = private constant i8* bitcast ({ i8*, i8* }* @_ZTIFvPFviEE to i8*) -// CHECK-X86: [[IndirectRTTI_ZTIFvPFviEE:@.+]] = private constant i8* bitcast ({ i8*, i8* }* @_ZTIFvPFviEE to i8*) -// CHECK-X32: [[IndirectRTTI_ZTIFvPFviEE:@.+]] = private constant i8* bitcast ({ i8*, i8* }* @_ZTIFvPFviEE to i8*) +// CHECK-FUNCSAN: [[PROXY:@.+]] = private unnamed_addr constant i8* bitcast ({ i8*, i8* }* @_ZTIFvPFviEE to i8*) struct T : S {}; @@ -399,10 +397,7 @@ // CHECK-NEXT: br i1 [[AND]] } -// -// CHECK-LABEL: @_Z22indirect_function_callPFviE({{.*}} prologue <{ i32, i32 }> <{ i32 846595819, i32 trunc (i64 sub (i64 ptrtoint (i8** {{.*}} to i64), i64 ptrtoint (void (void (i32)*)* @_Z22indirect_function_callPFviE to i64)) to i32) }> -// CHECK-X32: @_Z22indirect_function_callPFviE({{.*}} prologue <{ i32, i32 }> <{ i32 846595819, i32 sub (i32 ptrtoint (i8** [[IndirectRTTI_ZTIFvPFviEE]] to i32), i32 ptrtoint (void (void (i32)*)* @_Z22indirect_function_callPFviE to i32)) }> -// CHECK-X86: @_Z22indirect_function_callPFviE({{.*}} prologue <{ i32, i32 }> <{ i32 846595819, i32 sub (i32 ptrtoint (i8** [[IndirectRTTI_ZTIFvPFviEE]] to i32), i32 ptrtoint (void (void (i32)*)* @_Z22indirect_function_callPFviE to i32)) }> +// CHECK-FUNCSAN: @_Z22indirect_function_callPFviE({{.*}} !func_sanitize ![[FUNCSAN:.*]] { void indirect_function_call(void (*p)(int)) { // CHECK: [[PTR:%.+]] = bitcast void (i32)* {{.*}} to <{ i32, i32 }>* @@ -483,34 +478,34 @@ } // CHECK-LABEL: define{{.*}} void @_ZN29FunctionSanitizerVirtualCalls1B1fEv -// CHECK-NOT: prologue +// CHECK-NOT: !func_sanitize // // CHECK-LABEL: define{{.*}} void @_ZTv0_n24_N29FunctionSanitizerVirtualCalls1B1fEv -// CHECK-NOT: prologue +// CHECK-NOT: !func_sanitize // // CHECK-LABEL: define{{.*}} void @_ZN29FunctionSanitizerVirtualCalls11force_irgenEv() -// CHECK: prologue +// CHECK: !func_sanitize // // CHECK-LABEL: define linkonce_odr void @_ZN29FunctionSanitizerVirtualCalls1AC1Ev -// CHECK-NOT: prologue +// CHECK-NOT: !func_sanitize // // CHECK-LABEL: define linkonce_odr void @_ZN29FunctionSanitizerVirtualCalls1A1gEv -// CHECK-NOT: prologue +// CHECK-NOT: !func_sanitize // // CHECK-LABEL: define linkonce_odr void @_ZN29FunctionSanitizerVirtualCalls1A1hEv -// CHECK-NOT: prologue +// CHECK-NOT: !func_sanitize // // CHECK-LABEL: define linkonce_odr void @_ZN29FunctionSanitizerVirtualCalls1BC1Ev -// CHECK-NOT: prologue +// CHECK-NOT: !func_sanitize // // CHECK-LABEL: define linkonce_odr void @_ZN29FunctionSanitizerVirtualCalls1B1bEv -// CHECK-NOT: prologue +// CHECK-NOT: !func_sanitize // // CHECK-LABEL: define linkonce_odr void @_ZN29FunctionSanitizerVirtualCalls1B1gEv -// CHECK-NOT: prologue +// CHECK-NOT: !func_sanitize // // CHECK-LABEL: define linkonce_odr void @_ZN29FunctionSanitizerVirtualCalls1B1qEv -// CHECK: prologue +// CHECK: !func_sanitize } @@ -754,3 +749,5 @@ } // CHECK: attributes [[NR_NUW]] = { noreturn nounwind } + +// CHECK-FUNCSAN: ![[FUNCSAN]] = !{i32 846595819, i8** [[PROXY]]} diff --git a/clang/test/CodeGenCXX/ubsan-function-noexcept.cpp b/clang/test/CodeGenCXX/ubsan-function-noexcept.cpp --- a/clang/test/CodeGenCXX/ubsan-function-noexcept.cpp +++ b/clang/test/CodeGenCXX/ubsan-function-noexcept.cpp @@ -2,8 +2,8 @@ // Check that typeinfo recorded in function prolog doesn't have "Do" noexcept // qualifier in its mangled name. -// CHECK: @[[RTTI:[0-9]+]] = private constant i8* bitcast ({ i8*, i8* }* @_ZTIFvvE to i8*) -// CHECK: define{{.*}} void @_Z1fv() #{{.*}} prologue <{ i32, i32 }> <{ i32 {{.*}}, i32 trunc (i64 sub (i64 ptrtoint (i8** @[[RTTI]] to i64), i64 ptrtoint (void ()* @_Z1fv to i64)) to i32) }> +// CHECK: [[PROXY:@.*]] = private unnamed_addr constant i8* bitcast ({ i8*, i8* }* @_ZTIFvvE to i8*) +// CHECK: define{{.*}} void @_Z1fv() #{{.*}} !func_sanitize ![[FUNCSAN:.*]] { void f() noexcept {} // CHECK: define{{.*}} void @_Z1gPDoFvvE @@ -13,3 +13,5 @@ // CHECK: icmp eq i8* %{{.*}}, bitcast ({ i8*, i8* }* @_ZTIFvvE to i8*), !nosanitize p(); } + +// CHECK: ![[FUNCSAN]] = !{i32 846595819, i8** [[PROXY]]} diff --git a/llvm/include/llvm/IR/FixedMetadataKinds.def b/llvm/include/llvm/IR/FixedMetadataKinds.def --- a/llvm/include/llvm/IR/FixedMetadataKinds.def +++ b/llvm/include/llvm/IR/FixedMetadataKinds.def @@ -42,3 +42,4 @@ LLVM_FIXED_MD_KIND(MD_vcall_visibility, "vcall_visibility", 28) LLVM_FIXED_MD_KIND(MD_noundef, "noundef", 29) LLVM_FIXED_MD_KIND(MD_annotation, "annotation", 30) +LLVM_FIXED_MD_KIND(MD_func_sanitize, "func_sanitize", 31) diff --git a/llvm/include/llvm/IR/MDBuilder.h b/llvm/include/llvm/IR/MDBuilder.h --- a/llvm/include/llvm/IR/MDBuilder.h +++ b/llvm/include/llvm/IR/MDBuilder.h @@ -108,6 +108,10 @@ /// Merge the new callback encoding \p NewCB into \p ExistingCallbacks. MDNode *mergeCallbackEncodings(MDNode *ExistingCallbacks, MDNode *NewCB); + /// Return metadata feeding to the CodeGen about how to generate a function + /// prologue for the "function" santizier. + MDNode *createRTTIPointerPrologue(Constant *PrologueSig, Constant *RTTI); + //===------------------------------------------------------------------===// // AA metadata. //===------------------------------------------------------------------===// diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp --- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp +++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp @@ -839,6 +839,24 @@ // Emit the prologue data. if (F.hasPrologueData()) emitGlobalConstant(F.getParent()->getDataLayout(), F.getPrologueData()); + + // Emit the function prologue data for the indirect call sanitizer. + if (const MDNode *MD = F.getMetadata(LLVMContext::MD_func_sanitize)) { + assert(TM.getTargetTriple().getArch() == Triple::x86 || + TM.getTargetTriple().getArch() == Triple::x86_64); + assert(MD->getNumOperands() == 2); + + auto *PrologueSig = mdconst::extract(MD->getOperand(0)); + auto *FTRTTIProxy = mdconst::extract(MD->getOperand(1)); + assert(PrologueSig && FTRTTIProxy); + emitGlobalConstant(F.getParent()->getDataLayout(), PrologueSig); + + const MCExpr *Proxy = lowerConstant(FTRTTIProxy); + const MCExpr *FnExp = MCSymbolRefExpr::create(CurrentFnSym, OutContext); + const MCExpr *PCRel = MCBinaryExpr::createSub(Proxy, FnExp, OutContext); + // Use 32 bit since only small code model is supported. + OutStreamer->emitValue(PCRel, 4u); + } } /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the diff --git a/llvm/lib/IR/MDBuilder.cpp b/llvm/lib/IR/MDBuilder.cpp --- a/llvm/lib/IR/MDBuilder.cpp +++ b/llvm/lib/IR/MDBuilder.cpp @@ -150,6 +150,14 @@ return MDNode::get(Context, Ops); } +MDNode *MDBuilder::createRTTIPointerPrologue(Constant *PrologueSig, + Constant *RTTI) { + SmallVector Ops; + Ops.push_back(createConstant(PrologueSig)); + Ops.push_back(createConstant(RTTI)); + return MDNode::get(Context, Ops); +} + MDNode *MDBuilder::createAnonymousAARoot(StringRef Name, MDNode *Extra) { SmallVector Args(1, nullptr); if (Extra) diff --git a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp --- a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp +++ b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp @@ -1405,7 +1405,11 @@ /// Check if \p G has been created by a trusted compiler pass. static bool GlobalWasGeneratedByCompiler(GlobalVariable *G) { // Do not instrument @llvm.global_ctors, @llvm.used, etc. - if (G->getName().startswith("llvm.")) + if (G->getName().startswith("llvm.") || + // Do not instrument gcov counter arrays. + G->getName().startswith("__llvm_gcov_ctr") || + // Do not instrument rtti proxy symbols for function sanitizer. + G->getName().startswith("__llvm_rtti_proxy")) return true; // Do not instrument asan globals. @@ -1414,10 +1418,6 @@ G->getName().startswith(kODRGenPrefix)) return true; - // Do not instrument gcov counter arrays. - if (G->getName() == "__llvm_gcov_ctr") - return true; - return false; }