[llvm] [CFI] Fix Direct Call Issues in CFI Dispatch Table (PR #69663)

via llvm-commits llvm-commits at lists.llvm.org
Thu Oct 19 17:30:33 PDT 2023


llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-transforms

Author: Oskar Wirga (oskarwirga)

<details>
<summary>Changes</summary>

I discovered two issues for when a CFI dispatch table entry is used as a direct call. 
# Inlining
There is the possibility that the dispatch table entry contains only a single function pointer: 
```
; Function Attrs: naked nocf_check
define private void @.cfi.jumptable() #<!-- -->6 align 8 { entry:
  call void asm sideeffect "jmp ${0:c}@<!-- -->plt\0Aint3\0Aint3\0Aint3\0A", "s"(ptr @<!-- -->_Z7throw_ei)
  unreachable
}
```
If this function is inlined, the unreachable follows and ruins the containing function. 
# Exception Handling
The dispatch table is always marked NoUnwind. This is fine if the entries are never used directly, but if a direct call is used which the containing function expects to throw, it will no longer throw and the exception handling code will be lost.

---
Full diff: https://github.com/llvm/llvm-project/pull/69663.diff


5 Files Affected:

- (modified) llvm/lib/Transforms/IPO/LowerTypeTests.cpp (+14-5) 
- (modified) llvm/test/Transforms/LowerTypeTests/aarch64-jumptable.ll (+27-8) 
- (added) llvm/test/Transforms/LowerTypeTests/cfi-unwind-direct-call.ll (+217) 
- (modified) llvm/test/Transforms/LowerTypeTests/function.ll (+8-8) 
- (modified) llvm/test/Transforms/LowerTypeTests/x86-jumptable.ll (+1-1) 


``````````diff
diff --git a/llvm/lib/Transforms/IPO/LowerTypeTests.cpp b/llvm/lib/Transforms/IPO/LowerTypeTests.cpp
index 2bf0fc2a4a84459..ad6495a5669c9b6 100644
--- a/llvm/lib/Transforms/IPO/LowerTypeTests.cpp
+++ b/llvm/lib/Transforms/IPO/LowerTypeTests.cpp
@@ -500,7 +500,7 @@ class LowerTypeTestsModule {
   Type *getJumpTableEntryType();
   void createJumpTableEntry(raw_ostream &AsmOS, raw_ostream &ConstraintOS,
                             Triple::ArchType JumpTableArch,
-                            SmallVectorImpl<Value *> &AsmArgs, Function *Dest);
+                            SmallVectorImpl<Value *> &AsmArgs, Function *Dest, bool& doesEntryHaveNoUnwind);
   void verifyTypeMDNode(GlobalObject *GO, MDNode *Type);
   void buildBitSetsFromFunctions(ArrayRef<Metadata *> TypeIds,
                                  ArrayRef<GlobalTypeMember *> Functions);
@@ -1254,7 +1254,10 @@ unsigned LowerTypeTestsModule::getJumpTableEntrySize() {
 void LowerTypeTestsModule::createJumpTableEntry(
     raw_ostream &AsmOS, raw_ostream &ConstraintOS,
     Triple::ArchType JumpTableArch, SmallVectorImpl<Value *> &AsmArgs,
-    Function *Dest) {
+    Function *Dest, bool& doesEntryHaveNoUnwind) {
+  if (Dest->hasFnAttribute(llvm::Attribute::NoUnwind))
+    doesEntryHaveNoUnwind = true;
+
   unsigned ArgIndex = AsmArgs.size();
 
   if (JumpTableArch == Triple::x86 || JumpTableArch == Triple::x86_64) {
@@ -1470,10 +1473,11 @@ void LowerTypeTestsModule::createJumpTable(
   raw_string_ostream AsmOS(AsmStr), ConstraintOS(ConstraintStr);
   SmallVector<Value *, 16> AsmArgs;
   AsmArgs.reserve(Functions.size() * 2);
+  bool doesEntryHaveNoUnwind = false;
 
   for (GlobalTypeMember *GTM : Functions)
     createJumpTableEntry(AsmOS, ConstraintOS, JumpTableArch, AsmArgs,
-                         cast<Function>(GTM->getGlobal()));
+                         cast<Function>(GTM->getGlobal()), doesEntryHaveNoUnwind);
 
   // Align the whole table by entry size.
   F->setAlignment(Align(getJumpTableEntrySize()));
@@ -1516,8 +1520,13 @@ void LowerTypeTestsModule::createJumpTable(
   // -fcf-protection=.
   if (JumpTableArch == Triple::x86 || JumpTableArch == Triple::x86_64)
     F->addFnAttr(Attribute::NoCfCheck);
-  // Make sure we don't emit .eh_frame for this function.
-  F->addFnAttr(Attribute::NoUnwind);
+
+  // Make sure we don't emit .eh_frame for this function if it isn't needed.
+  if(doesEntryHaveNoUnwind)
+    F->addFnAttr(Attribute::NoUnwind);
+
+  // Make sure we do not inline any calls to the cfi.jumptable.
+  F->addFnAttr(Attribute::NoInline);
 
   BasicBlock *BB = BasicBlock::Create(M.getContext(), "entry", F);
   IRBuilder<> IRB(BB);
diff --git a/llvm/test/Transforms/LowerTypeTests/aarch64-jumptable.ll b/llvm/test/Transforms/LowerTypeTests/aarch64-jumptable.ll
index 139df60a7b916f4..3464a748778b668 100644
--- a/llvm/test/Transforms/LowerTypeTests/aarch64-jumptable.ll
+++ b/llvm/test/Transforms/LowerTypeTests/aarch64-jumptable.ll
@@ -1,3 +1,4 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-attributes --include-generated-funcs --version 2
 ; RUN: opt -S -passes=lowertypetests -mtriple=aarch64-unknown-linux-gnu %s | FileCheck --check-prefixes=AARCH64 %s
 
 ; Test for the jump table generation with branch protection on AArch64
@@ -6,7 +7,6 @@ target datalayout = "e-p:64:64"
 
 @0 = private unnamed_addr constant [2 x ptr] [ptr @f, ptr @g], align 16
 
-; AARCH64: @f = alias void (), ptr @[[JT:.*]]
 
 define void @f() !type !0 {
   ret void
@@ -29,11 +29,30 @@ define i1 @foo(ptr %p) {
 
 !1 = !{i32 4, !"branch-target-enforcement", i32 1}
 
-; AARCH64:   define private void @[[JT]]() #[[ATTR:.*]] align 8 {
 
-; AARCH64:      bti c
-; AARCH64-SAME: b $0
-; AARCH64-SAME: bti c
-; AARCH64-SAME: b $1
-
-; AARCH64: attributes #[[ATTR]] = { naked nounwind "branch-target-enforcement"="false" "sign-return-address"="none"
+; AARCH64-LABEL: define hidden void @f.cfi() !type !1 {
+; AARCH64-NEXT:    ret void
+;
+;
+; AARCH64-LABEL: define internal void @g.cfi() !type !1 {
+; AARCH64-NEXT:    ret void
+;
+;
+; AARCH64-LABEL: define i1 @foo
+; AARCH64-SAME: (ptr [[P:%.*]]) {
+; AARCH64-NEXT:    [[TMP1:%.*]] = ptrtoint ptr [[P]] to i64
+; AARCH64-NEXT:    [[TMP2:%.*]] = sub i64 [[TMP1]], ptrtoint (ptr @.cfi.jumptable to i64)
+; AARCH64-NEXT:    [[TMP3:%.*]] = lshr i64 [[TMP2]], 3
+; AARCH64-NEXT:    [[TMP4:%.*]] = shl i64 [[TMP2]], 61
+; AARCH64-NEXT:    [[TMP5:%.*]] = or i64 [[TMP3]], [[TMP4]]
+; AARCH64-NEXT:    [[TMP6:%.*]] = icmp ule i64 [[TMP5]], 1
+; AARCH64-NEXT:    ret i1 [[TMP6]]
+;
+;
+; AARCH64: Function Attrs: naked noinline
+; AARCH64-LABEL: define private void @.cfi.jumptable
+; AARCH64-SAME: () #[[ATTR1:[0-9]+]] align 8 {
+; AARCH64-NEXT:  entry:
+; AARCH64-NEXT:    call void asm sideeffect "bti c\0Ab $0\0Abti c\0Ab $1\0A", "s,s"(ptr @f.cfi, ptr @g.cfi)
+; AARCH64-NEXT:    unreachable
+;
diff --git a/llvm/test/Transforms/LowerTypeTests/cfi-unwind-direct-call.ll b/llvm/test/Transforms/LowerTypeTests/cfi-unwind-direct-call.ll
new file mode 100644
index 000000000000000..d729f9bfaf20fdf
--- /dev/null
+++ b/llvm/test/Transforms/LowerTypeTests/cfi-unwind-direct-call.ll
@@ -0,0 +1,217 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 2
+; RUN: opt < %s -passes='lowertypetests,default<O3>' -S | FileCheck %s
+
+; This IR is based of the following C++
+; which was compiled with:
+; clang -cc1 -fexceptions -fcxx-exceptions \
+; -std=c++11 -internal-isystem llvm-project/build/lib/clang/17/include \
+; -nostdsysteminc -triple x86_64-unknown-linux -fsanitize=cfi-icall \
+; -fsanitize-cfi-cross-dso -fsanitize-trap=cfi-icall -Oz -S -emit-llvm
+;
+; void (*catch_ptr)(int);
+;
+; void throw_e (int num) {
+;   if (num) throw 20;
+; }
+;
+; void call_catch(int num) {
+;   catch_ptr = &throw_e;
+;   try{
+;     catch_ptr(num);
+;   } catch (int i) {
+;   }
+; }
+
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux"
+
+ at catch_ptr = local_unnamed_addr global ptr null, align 8
+ at _ZTIi = external constant ptr
+ at llvm.used = appending global [1 x ptr] [ptr @__cfi_check_fail], section "llvm.metadata"
+
+; Function Attrs: minsize mustprogress optsize
+define dso_local void @_Z7throw_ei(i32 noundef %num) #0 !type !4 !type !5 !type !6 {
+; CHECK-LABEL: define dso_local void @_Z7throw_ei
+; CHECK-SAME: (i32 noundef [[NUM:%.*]]) #[[ATTR0:[0-9]+]] !type !4 !type !5 !type !6 {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[TOBOOL_NOT:%.*]] = icmp eq i32 [[NUM]], 0
+; CHECK-NEXT:    br i1 [[TOBOOL_NOT]], label [[IF_END:%.*]], label [[IF_THEN:%.*]]
+; CHECK:       if.then:
+; CHECK-NEXT:    [[EXCEPTION:%.*]] = tail call ptr @__cxa_allocate_exception(i64 4) #[[ATTR5:[0-9]+]]
+; CHECK-NEXT:    store i32 20, ptr [[EXCEPTION]], align 16, !tbaa [[TBAA7:![0-9]+]]
+; CHECK-NEXT:    tail call void @__cxa_throw(ptr nonnull [[EXCEPTION]], ptr nonnull @_ZTIi, ptr null) #[[ATTR6:[0-9]+]]
+; CHECK-NEXT:    unreachable
+; CHECK:       if.end:
+; CHECK-NEXT:    ret void
+;
+entry:
+  %tobool.not = icmp eq i32 %num, 0
+  br i1 %tobool.not, label %if.end, label %if.then
+
+if.then:                                          ; preds = %entry
+  %exception = tail call ptr @__cxa_allocate_exception(i64 4) #5
+  store i32 20, ptr %exception, align 16, !tbaa !7
+  tail call void @__cxa_throw(ptr nonnull %exception, ptr nonnull @_ZTIi, ptr null) #6
+  unreachable
+
+if.end:                                           ; preds = %entry
+  ret void
+}
+
+declare ptr @__cxa_allocate_exception(i64) local_unnamed_addr
+
+declare void @__cxa_throw(ptr, ptr, ptr) local_unnamed_addr
+
+; Function Attrs: minsize mustprogress optsize
+define dso_local void @_Z10call_catchi(i32 noundef %num) local_unnamed_addr #0 personality ptr @__gxx_personality_v0 !type !4 !type !5 !type !6 {
+; CHECK-LABEL: define dso_local void @_Z10call_catchi
+; CHECK-SAME: (i32 noundef [[NUM:%.*]]) local_unnamed_addr #[[ATTR0]] personality ptr @__gxx_personality_v0 !type !4 !type !5 !type !6 {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    store ptr @_Z7throw_ei.cfi_jt, ptr @catch_ptr, align 8, !tbaa [[TBAA11:![0-9]+]]
+; CHECK-NEXT:    invoke void @_Z7throw_ei.cfi_jt() #[[ATTR7:[0-9]+]]
+; CHECK-NEXT:    to label [[TRY_CONT:%.*]] unwind label [[LPAD:%.*]]
+; CHECK:       lpad:
+; CHECK-NEXT:    [[TMP0:%.*]] = landingpad { ptr, i32 }
+; CHECK-NEXT:    catch ptr @_ZTIi
+; CHECK-NEXT:    [[TMP1:%.*]] = extractvalue { ptr, i32 } [[TMP0]], 1
+; CHECK-NEXT:    [[TMP2:%.*]] = tail call i32 @llvm.eh.typeid.for(ptr nonnull @_ZTIi) #[[ATTR5]]
+; CHECK-NEXT:    [[MATCHES:%.*]] = icmp eq i32 [[TMP1]], [[TMP2]]
+; CHECK-NEXT:    br i1 [[MATCHES]], label [[CATCH:%.*]], label [[EH_RESUME:%.*]]
+; CHECK:       catch:
+; CHECK-NEXT:    [[TMP3:%.*]] = extractvalue { ptr, i32 } [[TMP0]], 0
+; CHECK-NEXT:    [[TMP4:%.*]] = tail call ptr @__cxa_begin_catch(ptr [[TMP3]]) #[[ATTR5]]
+; CHECK-NEXT:    tail call void @__cxa_end_catch() #[[ATTR5]]
+; CHECK-NEXT:    br label [[TRY_CONT]]
+; CHECK:       try.cont:
+; CHECK-NEXT:    ret void
+; CHECK:       eh.resume:
+; CHECK-NEXT:    resume { ptr, i32 } [[TMP0]]
+;
+entry:
+  store ptr @_Z7throw_ei, ptr @catch_ptr, align 8, !tbaa !11
+  %0 = tail call i1 @llvm.type.test(ptr nonnull @_Z7throw_ei, metadata !"_ZTSFviE"), !nosanitize !13
+  br i1 %0, label %cfi.cont, label %cfi.slowpath, !prof !14, !nosanitize !13
+
+cfi.slowpath:                                     ; preds = %entry
+  tail call void @__cfi_slowpath(i64 -8738933900360652027, ptr nonnull @_Z7throw_ei) #5, !nosanitize !13
+  br label %cfi.cont, !nosanitize !13
+
+cfi.cont:                                         ; preds = %cfi.slowpath, %entry
+  invoke void @_Z7throw_ei(i32 noundef %num) #7
+  to label %try.cont unwind label %lpad
+
+lpad:                                             ; preds = %cfi.cont
+  %1 = landingpad { ptr, i32 }
+  catch ptr @_ZTIi
+  %2 = extractvalue { ptr, i32 } %1, 1
+  %3 = tail call i32 @llvm.eh.typeid.for(ptr nonnull @_ZTIi) #5
+  %matches = icmp eq i32 %2, %3
+  br i1 %matches, label %catch, label %eh.resume
+
+catch:                                            ; preds = %lpad
+  %4 = extractvalue { ptr, i32 } %1, 0
+  %5 = tail call ptr @__cxa_begin_catch(ptr %4) #5
+  tail call void @__cxa_end_catch() #5
+  br label %try.cont
+
+try.cont:                                         ; preds = %cfi.cont, %catch
+  ret void
+
+eh.resume:                                        ; preds = %lpad
+  resume { ptr, i32 } %1
+}
+
+; Function Attrs: mustprogress nocallback nofree nosync nounwind speculatable willreturn memory(none)
+declare i1 @llvm.type.test(ptr, metadata) #1
+
+declare void @__cfi_slowpath(i64, ptr) local_unnamed_addr
+
+declare i32 @__gxx_personality_v0(...)
+
+; Function Attrs: nofree nosync nounwind memory(none)
+declare i32 @llvm.eh.typeid.for(ptr) #2
+
+declare ptr @__cxa_begin_catch(ptr) local_unnamed_addr
+
+declare void @__cxa_end_catch() local_unnamed_addr
+
+; Function Attrs: minsize optsize
+define weak_odr hidden void @__cfi_check_fail(ptr noundef %0, ptr noundef %1) #3 {
+; CHECK-LABEL: define weak_odr hidden void @__cfi_check_fail
+; CHECK-SAME: (ptr noundef [[TMP0:%.*]], ptr noundef [[TMP1:%.*]]) #[[ATTR2:[0-9]+]] {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[DOTNOT:%.*]] = icmp eq ptr [[TMP0]], null, !nosanitize !13
+; CHECK-NEXT:    br i1 [[DOTNOT]], label [[TRAP:%.*]], label [[CONT:%.*]], !nosanitize !13
+; CHECK:       trap:
+; CHECK-NEXT:    tail call void @llvm.ubsantrap(i8 2) #[[ATTR8:[0-9]+]], !nosanitize !13
+; CHECK-NEXT:    unreachable, !nosanitize !13
+; CHECK:       cont:
+; CHECK-NEXT:    [[TMP2:%.*]] = load i8, ptr [[TMP0]], align 4, !nosanitize !13
+; CHECK-NEXT:    [[SWITCH:%.*]] = icmp ult i8 [[TMP2]], 5
+; CHECK-NEXT:    br i1 [[SWITCH]], label [[TRAP]], label [[CONT6:%.*]]
+; CHECK:       cont6:
+; CHECK-NEXT:    ret void, !nosanitize !13
+;
+entry:
+  %.not = icmp eq ptr %0, null, !nosanitize !13
+  br i1 %.not, label %trap, label %cont, !nosanitize !13
+
+trap:                                             ; preds = %cont, %entry
+  tail call void @llvm.ubsantrap(i8 2) #8, !nosanitize !13
+  unreachable, !nosanitize !13
+
+cont:                                             ; preds = %entry
+  %2 = load i8, ptr %0, align 4, !nosanitize !13
+  %switch = icmp ult i8 %2, 5
+  br i1 %switch, label %trap, label %cont6
+
+cont6:                                            ; preds = %cont
+  ret void, !nosanitize !13
+}
+
+; Function Attrs: cold noreturn nounwind
+declare void @llvm.ubsantrap(i8 immarg) #4
+
+define weak void @__cfi_check(i64 %0, ptr %1, ptr %2) local_unnamed_addr {
+; CHECK-LABEL: define weak void @__cfi_check
+; CHECK-SAME: (i64 [[TMP0:%.*]], ptr [[TMP1:%.*]], ptr [[TMP2:%.*]]) local_unnamed_addr {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    tail call void @llvm.trap()
+; CHECK-NEXT:    unreachable
+;
+entry:
+  tail call void @llvm.trap()
+  unreachable
+}
+
+; Function Attrs: cold noreturn nounwind
+declare void @llvm.trap() #4
+
+attributes #0 = { minsize mustprogress optsize "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+cx8,+mmx,+sse,+sse2,+x87" }
+attributes #1 = { mustprogress nocallback nofree nosync nounwind speculatable willreturn memory(none) }
+attributes #2 = { nofree nosync nounwind memory(none) }
+attributes #3 = { minsize optsize "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+cx8,+mmx,+sse,+sse2,+x87" }
+attributes #4 = { cold noreturn nounwind }
+attributes #5 = { nounwind }
+attributes #6 = { noreturn }
+attributes #7 = { minsize optsize }
+attributes #8 = { noreturn nounwind }
+
+!llvm.module.flags = !{!0, !1, !2}
+!llvm.ident = !{!3}
+
+!0 = !{i32 1, !"wchar_size", i32 4}
+!1 = !{i32 4, !"Cross-DSO CFI", i32 1}
+!2 = !{i32 4, !"CFI Canonical Jump Tables", i32 0}
+!3 = !{!"clang version 17.0.2"}
+!4 = !{i64 0, !"_ZTSFviE"}
+!5 = !{i64 0, !"_ZTSFviE.generalized"}
+!6 = !{i64 0, i64 -8738933900360652027}
+!7 = !{!8, !8, i64 0}
+!8 = !{!"int", !9, i64 0}
+!9 = !{!"omnipotent char", !10, i64 0}
+!10 = !{!"Simple C++ TBAA"}
+!11 = !{!12, !12, i64 0}
+!12 = !{!"any pointer", !9, i64 0}
+!13 = !{}
+!14 = !{!"branch_weights", i32 1048575, i32 1}
diff --git a/llvm/test/Transforms/LowerTypeTests/function.ll b/llvm/test/Transforms/LowerTypeTests/function.ll
index 5ba69e236e41355..a858aace834d6b3 100644
--- a/llvm/test/Transforms/LowerTypeTests/function.ll
+++ b/llvm/test/Transforms/LowerTypeTests/function.ll
@@ -51,7 +51,7 @@ define internal void @g() !type !0 {
 
 !0 = !{i32 0, !"typeid1"}
 
-declare i1 @llvm.type.test(ptr %ptr, metadata %bitset) nounwind readnone
+declare i1 @llvm.type.test(ptr %ptr, metadata %bitset) noinline readnone
 
 define i1 @foo(ptr %p) {
   ; NATIVE: sub i64 {{.*}}, ptrtoint (ptr @[[JT]] to i64)
@@ -109,13 +109,13 @@ define i1 @foo(ptr %p) {
 
 ; NATIVE-SAME: "s,s"(ptr @f.cfi, ptr @g.cfi)
 
-; X86-LINUX: attributes #[[ATTR]] = { naked nocf_check nounwind }
-; X86-WIN32: attributes #[[ATTR]] = { nocf_check nounwind }
-; ARM: attributes #[[ATTR]] = { naked nounwind
-; THUMB: attributes #[[ATTR]] = { naked nounwind "branch-target-enforcement"="false" "sign-return-address"="none" "target-cpu"="cortex-a8" "target-features"="+thumb-mode" }
-; THUMBV6M: attributes #[[ATTR]] = { naked nounwind "branch-target-enforcement"="false" "sign-return-address"="none" "target-features"="+thumb-mode" }
-; RISCV: attributes #[[ATTR]] = { naked nounwind "target-features"="-c,-relax" }
-; LOONGARCH64: attributes #[[ATTR]] = { naked nounwind }
+; X86-LINUX: attributes #[[ATTR]] = { naked nocf_check noinline }
+; X86-WIN32: attributes #[[ATTR]] = { nocf_check noinline }
+; ARM: attributes #[[ATTR]] = { naked noinline
+; THUMB: attributes #[[ATTR]] = { naked noinline "branch-target-enforcement"="false" "sign-return-address"="none" "target-cpu"="cortex-a8" "target-features"="+thumb-mode" }
+; THUMBV6M: attributes #[[ATTR]] = { naked noinline "branch-target-enforcement"="false" "sign-return-address"="none" "target-features"="+thumb-mode" }
+; RISCV: attributes #[[ATTR]] = { naked noinline "target-features"="-c,-relax" }
+; LOONGARCH64: attributes #[[ATTR]] = { naked noinline }
 
 ; WASM32: ![[I0]] = !{i64 1}
 ; WASM32: ![[I1]] = !{i64 2}
diff --git a/llvm/test/Transforms/LowerTypeTests/x86-jumptable.ll b/llvm/test/Transforms/LowerTypeTests/x86-jumptable.ll
index a88a45a65d59c28..f56d30be37959ff 100644
--- a/llvm/test/Transforms/LowerTypeTests/x86-jumptable.ll
+++ b/llvm/test/Transforms/LowerTypeTests/x86-jumptable.ll
@@ -28,4 +28,4 @@ define i1 @foo(ptr %p) {
 ; X86_32-NEXT:   call void asm sideeffect "endbr32\0Ajmp ${0:c}@plt\0A.balign 16, 0xcc\0Aendbr32\0Ajmp ${1:c}@plt\0A.balign 16, 0xcc\0A", "s,s"(ptr @f.cfi, ptr @g.cfi)
 ; X86_64-NEXT:   call void asm sideeffect "endbr64\0Ajmp ${0:c}@plt\0A.balign 16, 0xcc\0Aendbr64\0Ajmp ${1:c}@plt\0A.balign 16, 0xcc\0A", "s,s"(ptr @f.cfi, ptr @g.cfi)
 
-; X86_64: attributes #[[#ATTR]] = { naked nocf_check nounwind }
+; X86_64: attributes #[[#ATTR]] = { naked nocf_check noinline }

``````````

</details>


https://github.com/llvm/llvm-project/pull/69663


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