[llvm] [HWASan] fix missing BTI attribute on personality function thunks (PR #139138)
Florian Mayer via llvm-commits
llvm-commits at lists.llvm.org
Thu May 8 12:54:16 PDT 2025
https://github.com/fmayer created https://github.com/llvm/llvm-project/pull/139138
This used to work because the BTI attribute was taken from the module in
the CodeGen.
e15d67cfc2e5775cc79281aa860f3ad3be628f39 changed that to actually look
at the function attributes. This led to crashes for BTI, because we did
not emit the proper landing pads for the thunk.
>From 5c95f938135aba8c03a1482feb738c33258d043c Mon Sep 17 00:00:00 2001
From: Florian Mayer <fmayer at google.com>
Date: Thu, 8 May 2025 12:53:59 -0700
Subject: [PATCH] =?UTF-8?q?[=F0=9D=98=80=F0=9D=97=BD=F0=9D=97=BF]=20initia?=
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Created using spr 1.3.4
---
.../Instrumentation/HWAddressSanitizer.cpp | 6 ++
.../HWAddressSanitizer/personality-bti.ll | 95 +++++++++++++++++++
2 files changed, 101 insertions(+)
create mode 100644 llvm/test/Instrumentation/HWAddressSanitizer/personality-bti.ll
diff --git a/llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp
index 61dfc6411fc3a..2f7712171bab2 100644
--- a/llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp
@@ -1847,6 +1847,12 @@ void HWAddressSanitizer::instrumentPersonalityFunctions() {
IsLocal ? GlobalValue::InternalLinkage
: GlobalValue::LinkOnceODRLinkage,
ThunkName, &M);
+ // TODO: think about other attributes as well.
+ if (any_of(P.second, [](const Function *F) {
+ return F->hasFnAttribute("branch-target-enforcement");
+ })) {
+ ThunkFn->addFnAttr("branch-target-enforcement");
+ }
if (!IsLocal) {
ThunkFn->setVisibility(GlobalValue::HiddenVisibility);
ThunkFn->setComdat(M.getOrInsertComdat(ThunkName));
diff --git a/llvm/test/Instrumentation/HWAddressSanitizer/personality-bti.ll b/llvm/test/Instrumentation/HWAddressSanitizer/personality-bti.ll
new file mode 100644
index 0000000000000..bdbbbdb90439c
--- /dev/null
+++ b/llvm/test/Instrumentation/HWAddressSanitizer/personality-bti.ll
@@ -0,0 +1,95 @@
+; RUN: opt < %s -mtriple aarch64-linux-android29 -passes=hwasan -S | FileCheck %s --check-prefix=NOPERS
+; RUN: opt < %s -mtriple aarch64-linux-android30 -passes=hwasan -S | FileCheck %s --check-prefix=PERS
+
+; NOPERS: define void @nostack() #{{[0-9]+}} {
+; PERS: define void @nostack() #{{[0-9]+}} {
+define void @nostack() sanitize_hwaddress "branch-target-enforcement" {
+ ret void
+}
+
+; NOPERS: define void @stack1() #{{[0-9]+}} {
+; PERS: personality {{.*}} @__hwasan_personality_thunk
+define void @stack1() sanitize_hwaddress "branch-target-enforcement" {
+ %p = alloca i8
+ call void @sink(ptr %p)
+ ret void
+}
+
+
+; NOPERS: personality ptr @global
+; PERS: personality {{.*}} @__hwasan_personality_thunk.global
+define void @stack2() sanitize_hwaddress "branch-target-enforcement" personality ptr @global {
+ %p = alloca i8
+ call void @sink(ptr %p)
+ ret void
+}
+
+define internal void @local() {
+ ret void
+}
+
+ at local_alias = internal alias void (), ptr @local
+
+; NOPERS: personality ptr @local
+; PERS: personality {{.*}} @__hwasan_personality_thunk.local
+define void @stack3() sanitize_hwaddress "branch-target-enforcement" personality ptr @local {
+ %p = alloca i8
+ call void @sink(ptr %p)
+ ret void
+}
+
+; NOPERS: personality ptr @local_alias
+; PERS: personality {{.*}} @__hwasan_personality_thunk.local_alias
+define void @stack4() sanitize_hwaddress "branch-target-enforcement" personality ptr @local_alias {
+ %p = alloca i8
+ call void @sink(ptr %p)
+ ret void
+}
+
+; NOPERS: personality ptr inttoptr (i64 1 to ptr)
+; PERS: personality ptr @__hwasan_personality_thunk.
+define void @stack5() sanitize_hwaddress "branch-target-enforcement" personality ptr inttoptr (i64 1 to ptr) {
+ %p = alloca i8
+ call void @sink(ptr %p)
+ ret void
+}
+
+; NOPERS: personality ptr inttoptr (i64 2 to ptr)
+; PERS: personality ptr @__hwasan_personality_thunk..1
+define void @stack6() sanitize_hwaddress "branch-target-enforcement" personality ptr inttoptr (i64 2 to ptr) {
+ %p = alloca i8
+ call void @sink(ptr %p)
+ ret void
+}
+
+declare void @global()
+declare void @sink(ptr)
+
+!llvm.module.flags = !{!0}
+!0 = !{i32 8, !"branch-target-enforcement", i32 1}
+
+; PERS: define linkonce_odr hidden i32 @__hwasan_personality_thunk(i32 %0, i32 %1, i64 %2, ptr %3, ptr %4) [[ATTRS:#[0-9]+]] comdat
+; PERS: %5 = tail call i32 @__hwasan_personality_wrapper(i32 %0, i32 %1, i64 %2, ptr %3, ptr %4, ptr null, ptr @_Unwind_GetGR, ptr @_Unwind_GetCFA)
+; PERS: ret i32 %5
+
+; PERS: define linkonce_odr hidden i32 @__hwasan_personality_thunk.global(i32 %0, i32 %1, i64 %2, ptr %3, ptr %4) {{.*}}[[ATTRS]] comdat
+; PERS: %5 = tail call i32 @__hwasan_personality_wrapper(i32 %0, i32 %1, i64 %2, ptr %3, ptr %4, ptr @global, ptr @_Unwind_GetGR, ptr @_Unwind_GetCFA)
+; PERS: ret i32 %5
+
+; PERS: define internal i32 @__hwasan_personality_thunk.local(i32 %0, i32 %1, i64 %2, ptr %3, ptr %4) {{.*}}[[ATTRS]]
+; PERS: %5 = tail call i32 @__hwasan_personality_wrapper(i32 %0, i32 %1, i64 %2, ptr %3, ptr %4, ptr @local, ptr @_Unwind_GetGR, ptr @_Unwind_GetCFA)
+; PERS: ret i32 %5
+
+; PERS: define internal i32 @__hwasan_personality_thunk.local_alias(i32 %0, i32 %1, i64 %2, ptr %3, ptr %4) {{.*}}[[ATTRS]]
+; PERS: %5 = tail call i32 @__hwasan_personality_wrapper(i32 %0, i32 %1, i64 %2, ptr %3, ptr %4, ptr @local_alias, ptr @_Unwind_GetGR, ptr @_Unwind_GetCFA)
+; PERS: ret i32 %5
+
+; PERS: define internal i32 @__hwasan_personality_thunk.(i32 %0, i32 %1, i64 %2, ptr %3, ptr %4) {{.*}}[[ATTRS]] {
+; PERS: %5 = tail call i32 @__hwasan_personality_wrapper(i32 %0, i32 %1, i64 %2, ptr %3, ptr %4, ptr inttoptr (i64 1 to ptr), ptr @_Unwind_GetGR, ptr @_Unwind_GetCFA)
+; PERS: ret i32 %5
+
+; PERS: define internal i32 @__hwasan_personality_thunk..1(i32 %0, i32 %1, i64 %2, ptr %3, ptr %4) {{.*}}[[ATTRS]] {
+; PERS: %5 = tail call i32 @__hwasan_personality_wrapper(i32 %0, i32 %1, i64 %2, ptr %3, ptr %4, ptr inttoptr (i64 2 to ptr), ptr @_Unwind_GetGR, ptr @_Unwind_GetCFA)
+; PERS: ret i32 %5
+
+; PERS: {{.*}}[[ATTRS]]
\ No newline at end of file
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