https://github.com/llvmbot created
https://github.com/llvm/llvm-project/pull/113938
Backport e1c36bde0551977d4b2efae032af6dfc4b2b3936
Requested by: @samitolvanen
>From cd089dd3ac6e1bcef6523514763428a55d80e462 Mon Sep 17 00:00:00 2001
From: Sami Tolvanen <samitolva...@users.noreply.github.com>
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 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}
_______________________________________________
llvm-branch-commits mailing list
llvm-branch-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
