[clang][KCFI] Respect -fsanitize-cfi-icall-generalize-pointers

[fmayer]

This flag was previously ignored by KCFI.

[llvmbot]

@llvm/pr-subscribers-clang-driver
@llvm/pr-subscribers-clang-codegen

@llvm/pr-subscribers-clang

Author: Florian Mayer (fmayer)

Changes

This flag was previously ignored by KCFI.

---

Full diff: https://github.com/llvm/llvm-project/pull/152400.diff

1 Files Affected:

• (modified) clang/lib/CodeGen/CodeGenModule.cpp (+34-32)

diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 834b1c067d84c..d75b24083c29b 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -2335,7 +2335,39 @@ llvm::ConstantInt *CodeGenModule::CreateCrossDsoCfiTypeId(llvm::Metadata *MD) {
   return llvm::ConstantInt::get(Int64Ty, llvm::MD5Hash(MDS->getString()));
 }
 
+// Generalize pointer types to a void pointer with the qualifiers of the
+// originally pointed-to type, e.g. 'const char *' and 'char * const *'
+// generalize to 'const void *' while 'char *' and 'const char **' generalize to
+// 'void *'.
+static QualType GeneralizeType(ASTContext &Ctx, QualType Ty) {
+  if (!Ty->isPointerType())
+    return Ty;
+
+  return Ctx.getPointerType(
+      QualType(Ctx.VoidTy)
+          .withCVRQualifiers(Ty->getPointeeType().getCVRQualifiers()));
+}
+
+// Apply type generalization to a FunctionType's return and argument types
+static QualType GeneralizeFunctionType(ASTContext &Ctx, QualType Ty) {
+  if (auto *FnType = Ty->getAs<FunctionProtoType>()) {
+    SmallVector<QualType, 8> GeneralizedParams;
+    for (auto &Param : FnType->param_types())
+      GeneralizedParams.push_back(GeneralizeType(Ctx, Param));
+
+    return Ctx.getFunctionType(GeneralizeType(Ctx, FnType->getReturnType()),
+                               GeneralizedParams, FnType->getExtProtoInfo());
+  }
+
+  if (auto *FnType = Ty->getAs<FunctionNoProtoType>())
+    return Ctx.getFunctionNoProtoType(
+        GeneralizeType(Ctx, FnType->getReturnType()));
+
+  llvm_unreachable("Encountered unknown FunctionType");
+}
 llvm::ConstantInt *CodeGenModule::CreateKCFITypeId(QualType T) {
+  if (getCodeGenOpts().SanitizeCfiICallGeneralizePointers)
+    T = GeneralizeFunctionType(getContext(), T);
   if (auto *FnType = T->getAs<FunctionProtoType>())
     T = getContext().getFunctionType(
         FnType->getReturnType(), FnType->getParamTypes(),
@@ -2348,6 +2380,8 @@ llvm::ConstantInt *CodeGenModule::CreateKCFITypeId(QualType T) {
 
   if (getCodeGenOpts().SanitizeCfiICallNormalizeIntegers)
     Out << ".normalized";
+  if (getCodeGenOpts().SanitizeCfiICallGeneralizePointers)
+    Out << ".generalized";
 
   return llvm::ConstantInt::get(Int32Ty,
                                 static_cast<uint32_t>(llvm::xxHash64(OutName)));
@@ -7880,38 +7914,6 @@ CodeGenModule::CreateMetadataIdentifierForVirtualMemPtrType(QualType T) {
   return CreateMetadataIdentifierImpl(T, VirtualMetadataIdMap, ".virtual");
 }
 
-// Generalize pointer types to a void pointer with the qualifiers of the
-// originally pointed-to type, e.g. 'const char *' and 'char * const *'
-// generalize to 'const void *' while 'char *' and 'const char **' generalize to
-// 'void *'.
-static QualType GeneralizeType(ASTContext &Ctx, QualType Ty) {
-  if (!Ty->isPointerType())
-    return Ty;
-
-  return Ctx.getPointerType(
-      QualType(Ctx.VoidTy).withCVRQualifiers(
-          Ty->getPointeeType().getCVRQualifiers()));
-}
-
-// Apply type generalization to a FunctionType's return and argument types
-static QualType GeneralizeFunctionType(ASTContext &Ctx, QualType Ty) {
-  if (auto *FnType = Ty->getAs<FunctionProtoType>()) {
-    SmallVector<QualType, 8> GeneralizedParams;
-    for (auto &Param : FnType->param_types())
-      GeneralizedParams.push_back(GeneralizeType(Ctx, Param));
-
-    return Ctx.getFunctionType(
-        GeneralizeType(Ctx, FnType->getReturnType()),
-        GeneralizedParams, FnType->getExtProtoInfo());
-  }
-
-  if (auto *FnType = Ty->getAs<FunctionNoProtoType>())
-    return Ctx.getFunctionNoProtoType(
-        GeneralizeType(Ctx, FnType->getReturnType()));
-
-  llvm_unreachable("Encountered unknown FunctionType");
-}
-
 llvm::Metadata *CodeGenModule::CreateMetadataIdentifierGeneralized(QualType T) {
   return CreateMetadataIdentifierImpl(GeneralizeFunctionType(getContext(), T),
                                       GeneralizedMetadataIdMap, ".generalized");

[fmayer]

Added test I forgot to git add before. PTAQL