[llvm-branch-commits] [clang] [llvm] release/19.x: Fix KCFI types for generated functions with integer normalization (#104826) (PR #113938)

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llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: None (llvmbot)

<details>
<summary>Changes</summary>

Backport e1c36bde0551977d4b2efae032af6dfc4b2b3936

Requested by: @<!-- -->samitolvanen

---
Full diff: https://github.com/llvm/llvm-project/pull/113938.diff


5 Files Affected:

- (modified) clang/lib/CodeGen/CodeGenModule.cpp (+5) 
- (modified) clang/test/CodeGen/kcfi-normalize.c (+1) 
- (modified) llvm/lib/Transforms/Utils/ModuleUtils.cpp (+7-5) 
- (added) llvm/test/Transforms/GCOVProfiling/kcfi-normalize.ll (+35) 
- (modified) llvm/test/Transforms/GCOVProfiling/kcfi.ll (+5-3) 


``````````diff
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index cf5e29e5a3db8d..49266f3e3982e1 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -1137,6 +1137,11 @@ 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 7660c908a7bdd5..b9150e88f6ab5f 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 122279160cc7e8..95bf9f06bc331c 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<uint32_t>(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<uint32_t>(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<ConstantInt>(
diff --git a/llvm/test/Transforms/GCOVProfiling/kcfi-normalize.ll b/llvm/test/Transforms/GCOVProfiling/kcfi-normalize.ll
new file mode 100644
index 00000000000000..19122b920d1ca4
--- /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 b25f40f05d5bc4..1b97d25294cd65 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}

``````````

</details>


https://github.com/llvm/llvm-project/pull/113938