From def7925c48337574df23156e3a8b23a8470cdc16 Mon Sep 17 00:00:00 2001 From: Sami Tolvanen Date: Tue, 20 Aug 2024 16:51:16 -0700 Subject: [PATCH] Fix KCFI types for generated functions with integer normalization (#104826) With -fsanitize-cfi-icall-experimental-normalize-integers, Clang appends ".normalized" to KCFI types in CodeGenModule::CreateKCFITypeId, which changes type hashes also for functions that don't have integer types in their signatures. However, llvm::setKCFIType does not take integer normalization into account, which means LLVM generated functions with KCFI types, e.g. sanitizer constructors, will fail KCFI checks when integer normalization is enabled in Clang. Add a cfi-normalize-integers module flag to indicate integer normalization is used, and append ".normalized" to KCFI types also in llvm::setKCFIType to fix the type mismatch. (cherry picked from commit e1c36bde0551977d4b2efae032af6dfc4b2b3936) --- clang/lib/CodeGen/CodeGenModule.cpp | 5 +++ clang/test/CodeGen/kcfi-normalize.c | 1 + llvm/lib/Transforms/Utils/ModuleUtils.cpp | 12 ++++--- .../GCOVProfiling/kcfi-normalize.ll | 35 +++++++++++++++++++ llvm/test/Transforms/GCOVProfiling/kcfi.ll | 8 +++-- 5 files changed, 53 insertions(+), 8 deletions(-) create mode 100644 llvm/test/Transforms/GCOVProfiling/kcfi-normalize.ll diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp index 8d9beab9fa7f8..151505baf38db 100644 --- a/clang/lib/CodeGen/CodeGenModule.cpp +++ b/clang/lib/CodeGen/CodeGenModule.cpp @@ -1134,6 +1134,11 @@ void CodeGenModule::Release() { CodeGenOpts.SanitizeCfiCanonicalJumpTables); } + if (CodeGenOpts.SanitizeCfiICallNormalizeIntegers) { + getModule().addModuleFlag(llvm::Module::Override, "cfi-normalize-integers", + 1); + } + if (LangOpts.Sanitize.has(SanitizerKind::KCFI)) { getModule().addModuleFlag(llvm::Module::Override, "kcfi", 1); // KCFI assumes patchable-function-prefix is the same for all indirectly diff --git a/clang/test/CodeGen/kcfi-normalize.c b/clang/test/CodeGen/kcfi-normalize.c index 7660c908a7bdd..b9150e88f6ab5 100644 --- a/clang/test/CodeGen/kcfi-normalize.c +++ b/clang/test/CodeGen/kcfi-normalize.c @@ -28,6 +28,7 @@ void baz(void (*fn)(int, int, int), int arg1, int arg2, int arg3) { fn(arg1, arg2, arg3); } +// CHECK: ![[#]] = !{i32 4, !"cfi-normalize-integers", i32 1} // CHECK: ![[TYPE1]] = !{i32 -1143117868} // CHECK: ![[TYPE2]] = !{i32 -460921415} // CHECK: ![[TYPE3]] = !{i32 -333839615} diff --git a/llvm/lib/Transforms/Utils/ModuleUtils.cpp b/llvm/lib/Transforms/Utils/ModuleUtils.cpp index 122279160cc7e..95bf9f06bc331 100644 --- a/llvm/lib/Transforms/Utils/ModuleUtils.cpp +++ b/llvm/lib/Transforms/Utils/ModuleUtils.cpp @@ -161,11 +161,13 @@ void llvm::setKCFIType(Module &M, Function &F, StringRef MangledType) { // Matches CodeGenModule::CreateKCFITypeId in Clang. LLVMContext &Ctx = M.getContext(); MDBuilder MDB(Ctx); - F.setMetadata( - LLVMContext::MD_kcfi_type, - MDNode::get(Ctx, MDB.createConstant(ConstantInt::get( - Type::getInt32Ty(Ctx), - static_cast(xxHash64(MangledType)))))); + std::string Type = MangledType.str(); + if (M.getModuleFlag("cfi-normalize-integers")) + Type += ".normalized"; + F.setMetadata(LLVMContext::MD_kcfi_type, + MDNode::get(Ctx, MDB.createConstant(ConstantInt::get( + Type::getInt32Ty(Ctx), + static_cast(xxHash64(Type)))))); // If the module was compiled with -fpatchable-function-entry, ensure // we use the same patchable-function-prefix. if (auto *MD = mdconst::extract_or_null( diff --git a/llvm/test/Transforms/GCOVProfiling/kcfi-normalize.ll b/llvm/test/Transforms/GCOVProfiling/kcfi-normalize.ll new file mode 100644 index 0000000000000..19122b920d1ca --- /dev/null +++ b/llvm/test/Transforms/GCOVProfiling/kcfi-normalize.ll @@ -0,0 +1,35 @@ +;; Ensure __llvm_gcov_(writeout|reset|init) have the correct !kcfi_type +;; with integer normalization. +; RUN: mkdir -p %t && cd %t +; RUN: opt < %s -S -passes=insert-gcov-profiling | FileCheck %s + +target triple = "x86_64-unknown-linux-gnu" + +define dso_local void @empty() !dbg !5 { +entry: + ret void, !dbg !8 +} + +!llvm.dbg.cu = !{!0} +!llvm.module.flags = !{!3, !4, !9, !10} + +!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, emissionKind: FullDebug, enums: !2) +!1 = !DIFile(filename: "a.c", directory: "") +!2 = !{} +!3 = !{i32 7, !"Dwarf Version", i32 5} +!4 = !{i32 2, !"Debug Info Version", i32 3} +!5 = distinct !DISubprogram(name: "empty", scope: !1, file: !1, line: 1, type: !6, scopeLine: 1, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !2) +!6 = !DISubroutineType(types: !7) +!7 = !{null} +!8 = !DILocation(line: 2, column: 1, scope: !5) +!9 = !{i32 4, !"kcfi", i32 1} +!10 = !{i32 4, !"cfi-normalize-integers", i32 1} + +; CHECK: define internal void @__llvm_gcov_writeout() +; CHECK-SAME: !kcfi_type ![[#TYPE:]] +; CHECK: define internal void @__llvm_gcov_reset() +; CHECK-SAME: !kcfi_type ![[#TYPE]] +; CHECK: define internal void @__llvm_gcov_init() +; CHECK-SAME: !kcfi_type ![[#TYPE]] + +; CHECK: ![[#TYPE]] = !{i32 -440107680} diff --git a/llvm/test/Transforms/GCOVProfiling/kcfi.ll b/llvm/test/Transforms/GCOVProfiling/kcfi.ll index b25f40f05d5bc..1b97d25294cd6 100644 --- a/llvm/test/Transforms/GCOVProfiling/kcfi.ll +++ b/llvm/test/Transforms/GCOVProfiling/kcfi.ll @@ -24,8 +24,10 @@ entry: !9 = !{i32 4, !"kcfi", i32 1} ; CHECK: define internal void @__llvm_gcov_writeout() -; CHECK-SAME: !kcfi_type +; CHECK-SAME: !kcfi_type ![[#TYPE:]] ; CHECK: define internal void @__llvm_gcov_reset() -; CHECK-SAME: !kcfi_type +; CHECK-SAME: !kcfi_type ![[#TYPE]] ; CHECK: define internal void @__llvm_gcov_init() -; CHECK-SAME: !kcfi_type +; CHECK-SAME: !kcfi_type ![[#TYPE]] + +; CHECK: ![[#TYPE]] = !{i32 -1522505972}