[llvm] a48f607 - [AArch64] Generate .note.gnu.property based on module flags.
Daniel Kiss via llvm-commits
llvm-commits at lists.llvm.org
Mon Sep 28 05:14:10 PDT 2020
Author: Daniel Kiss
Date: 2020-09-28T14:14:04+02:00
New Revision: a48f6079f288619fcc7656e89e8aa7cd0aac1281
URL: https://github.com/llvm/llvm-project/commit/a48f6079f288619fcc7656e89e8aa7cd0aac1281
DIFF: https://github.com/llvm/llvm-project/commit/a48f6079f288619fcc7656e89e8aa7cd0aac1281.diff
LOG: [AArch64] Generate .note.gnu.property based on module flags.
Flags of the module derived exclusively from the compiler flag `-mbranch-protection`.
The note is generated based on the module flags accordingly.
After this change in case of compile unit without function won't have
the .note.gnu.property if the compiler flag is not present [1].
[1] https://bugs.llvm.org/show_bug.cgi?id=46480
Reviewed By: chill
Differential Revision: https://reviews.llvm.org/D80791
Added:
Modified:
llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-0.ll
llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-1.ll
llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-2.ll
llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-3.ll
llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-4.ll
Removed:
llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-5.ll
llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-6.ll
llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-7.ll
llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-8.ll
################################################################################
diff --git a/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp b/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
index 9cf9679045c7..7c4a8555a1a1 100644
--- a/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
+++ b/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
@@ -192,33 +192,16 @@ void AArch64AsmPrinter::emitStartOfAsmFile(Module &M) {
return;
// Assemble feature flags that may require creation of a note section.
- unsigned Flags = ELF::GNU_PROPERTY_AARCH64_FEATURE_1_BTI |
- ELF::GNU_PROPERTY_AARCH64_FEATURE_1_PAC;
-
- if (any_of(M, [](const Function &F) {
- return !F.isDeclaration() &&
- !F.hasFnAttribute("branch-target-enforcement");
- })) {
- Flags &= ~ELF::GNU_PROPERTY_AARCH64_FEATURE_1_BTI;
- }
-
- if ((Flags & ELF::GNU_PROPERTY_AARCH64_FEATURE_1_BTI) == 0 &&
- any_of(M, [](const Function &F) {
- return F.hasFnAttribute("branch-target-enforcement");
- })) {
- errs() << "warning: some functions compiled with BTI and some compiled "
- "without BTI\n"
- << "warning: not setting BTI in feature flags\n";
- }
-
- if (any_of(M, [](const Function &F) {
- if (F.isDeclaration())
- return false;
- Attribute A = F.getFnAttribute("sign-return-address");
- return !A.isStringAttribute() || A.getValueAsString() == "none";
- })) {
- Flags &= ~ELF::GNU_PROPERTY_AARCH64_FEATURE_1_PAC;
- }
+ unsigned Flags = 0;
+ if (const auto *BTE = mdconst::extract_or_null<ConstantInt>(
+ M.getModuleFlag("branch-target-enforcement")))
+ if (BTE->getZExtValue())
+ Flags |= ELF::GNU_PROPERTY_AARCH64_FEATURE_1_BTI;
+
+ if (const auto *Sign = mdconst::extract_or_null<ConstantInt>(
+ M.getModuleFlag("sign-return-address")))
+ if (Sign->getZExtValue())
+ Flags |= ELF::GNU_PROPERTY_AARCH64_FEATURE_1_PAC;
if (Flags == 0)
return;
diff --git a/llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-0.ll b/llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-0.ll
index fdd1d63b267b..b64fda769df9 100644
--- a/llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-0.ll
+++ b/llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-0.ll
@@ -6,6 +6,13 @@
attributes #0 = { "branch-target-enforcement"="true" }
+!llvm.module.flags = !{!0, !1, !2, !3}
+
+!0 = !{i32 1, !"branch-target-enforcement", i32 1}
+!1 = !{i32 1, !"sign-return-address", i32 1}
+!2 = !{i32 1, !"sign-return-address-all", i32 0}
+!3 = !{i32 1, !"sign-return-address-with-bkey", i32 0}
+
; Both attributes present in a file with no functions.
; ASM: .word 3221225472
; ASM-NEXT: .word 4
diff --git a/llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-1.ll b/llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-1.ll
index 9757dec1f844..4996d8e66f7f 100644
--- a/llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-1.ll
+++ b/llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-1.ll
@@ -3,12 +3,17 @@
; RUN: llc -mtriple=aarch64-linux %s -filetype=obj -o - | \
; RUN: llvm-readelf --notes - | FileCheck %s --check-prefix=OBJ
-define dso_local i32 @f() #0 {
+define dso_local i32 @f() {
entry:
ret i32 0
}
-attributes #0 = { "branch-target-enforcement"="true" }
+!llvm.module.flags = !{!0, !1, !2, !3}
+
+!0 = !{i32 1, !"branch-target-enforcement", i32 1}
+!1 = !{i32 1, !"sign-return-address", i32 0}
+!2 = !{i32 1, !"sign-return-address-all", i32 0}
+!3 = !{i32 1, !"sign-return-address-with-bkey", i32 0}
; BTI attribute present
; ASM: .word 3221225472
diff --git a/llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-2.ll b/llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-2.ll
index 71b310932199..f765aeb5c417 100644
--- a/llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-2.ll
+++ b/llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-2.ll
@@ -3,12 +3,17 @@
; RUN: llc -mtriple=aarch64-linux %s -filetype=obj -o - | \
; RUN: llvm-readelf --notes - | FileCheck %s --check-prefix=OBJ
-define dso_local i32 @f() #0 {
+define dso_local i32 @f() {
entry:
ret i32 0
}
-attributes #0 = { "sign-return-address"="all" }
+!llvm.module.flags = !{!0, !1, !2, !3}
+
+!0 = !{i32 1, !"branch-target-enforcement", i32 0}
+!1 = !{i32 1, !"sign-return-address", i32 1}
+!2 = !{i32 1, !"sign-return-address-all", i32 0}
+!3 = !{i32 1, !"sign-return-address-with-bkey", i32 0}
; PAC attribute present
; ASM: .word 3221225472
diff --git a/llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-3.ll b/llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-3.ll
index 5082fa01f1d4..f5ef65b7b903 100644
--- a/llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-3.ll
+++ b/llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-3.ll
@@ -3,12 +3,17 @@
; RUN: llc -mtriple=aarch64-linux %s -filetype=obj -o - | \
; RUN: llvm-readelf --notes - | FileCheck %s --check-prefix=OBJ
-define dso_local i32 @f() #0 {
+define dso_local i32 @f() {
entry:
ret i32 0
}
-attributes #0 = { "branch-target-enforcement"="true" "sign-return-address"="non-leaf" }
+!llvm.module.flags = !{!0, !1, !2, !3}
+
+!0 = !{i32 1, !"branch-target-enforcement", i32 1}
+!1 = !{i32 1, !"sign-return-address", i32 1}
+!2 = !{i32 1, !"sign-return-address-all", i32 0}
+!3 = !{i32 1, !"sign-return-address-with-bkey", i32 0}
; Both attribute present
; ASM: .word 3221225472
diff --git a/llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-4.ll b/llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-4.ll
index 5d81669db7ff..67ad5f07080b 100644
--- a/llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-4.ll
+++ b/llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-4.ll
@@ -1,7 +1,5 @@
; RUN: llc -mtriple=aarch64-linux %s -o - | \
; RUN: FileCheck %s --check-prefix=ASM
-; RUN: llc -mtriple=aarch64-linux %s -filetype=obj -o - | \
-; RUN: llvm-readelf --notes - | FileCheck %s --check-prefix=OBJ
define dso_local i32 @f() #0 {
entry:
@@ -17,9 +15,12 @@ attributes #0 = { "branch-target-enforcement"="true" "sign-return-address"="non-
attributes #1 = { "branch-target-enforcement"="true" }
-; Only the common atttribute (BTI)
-; ASM: .word 3221225472
-; ASM-NEXT: .word 4
-; ASM-NEXT: .word 1
+!llvm.module.flags = !{!0, !1, !2, !3}
-; OBJ: Properties: aarch64 feature: BTI
+!0 = !{i32 1, !"branch-target-enforcement", i32 0}
+!1 = !{i32 1, !"sign-return-address", i32 0}
+!2 = !{i32 1, !"sign-return-address-all", i32 0}
+!3 = !{i32 1, !"sign-return-address-with-bkey", i32 0}
+
+; Note is not emited if module has no properties
+; ASM-NOT: .note.gnu.property
\ No newline at end of file
diff --git a/llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-5.ll b/llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-5.ll
deleted file mode 100644
index 942eb5970c59..000000000000
--- a/llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-5.ll
+++ /dev/null
@@ -1,26 +0,0 @@
-; RUN: llc -mtriple=aarch64-linux %s -o - 2>&1 | \
-; RUN: FileCheck %s --check-prefix=ASM
-; RUN: llc -mtriple=aarch64-linux %s -filetype=obj -o - | \
-; RUN: llvm-readelf --notes - | FileCheck %s --check-prefix=OBJ
-
-define dso_local i32 @f() #0 {
-entry:
- ret i32 0
-}
-
-define dso_local i32 @g() #1 {
-entry:
- ret i32 0
-}
-
-attributes #0 = { "branch-target-enforcement"="true" "sign-return-address"="non-leaf" }
-
-attributes #1 = { "sign-return-address"="all" }
-
-; Only the common atttribute (PAC)
-; ASM: warning: not setting BTI in feature flags
-; ASM: .word 3221225472
-; ASM-NEXT: .word 4
-; ASM-NEXT: .word 2
-
-; OBJ: Properties: aarch64 feature: PAC
diff --git a/llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-6.ll b/llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-6.ll
deleted file mode 100644
index 8fb550bcef48..000000000000
--- a/llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-6.ll
+++ /dev/null
@@ -1,22 +0,0 @@
-; RUN: llc -mtriple=aarch64-linux %s -o - | \
-; RUN: FileCheck %s --check-prefix=ASM
-; RUN: llc -mtriple=aarch64-linux %s -filetype=obj -o - | \
-; RUN: llvm-readelf -S - | FileCheck %s --check-prefix=OBJ
-
-define dso_local i32 @f() #0 {
-entry:
- ret i32 0
-}
-
-define dso_local i32 @g() #1 {
-entry:
- ret i32 0
-}
-
-attributes #0 = { "sign-return-address"="non-leaf" }
-
-attributes #1 = { "sign-return-address"="none" }
-
-; No common attribute, no note section
-; ASM-NOT: .note.gnu.property
-; OBJ-NOT: .note.gnu.property
diff --git a/llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-7.ll b/llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-7.ll
deleted file mode 100644
index 67f0b2b71c4c..000000000000
--- a/llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-7.ll
+++ /dev/null
@@ -1,23 +0,0 @@
-; RUN: llc -mtriple=aarch64-linux %s -o - 2>&1 | \
-; RUN: FileCheck %s --check-prefix=ASM
-; RUN: llc -mtriple=aarch64-linux %s -filetype=obj -o - | \
-; RUN: llvm-readelf -S - | FileCheck %s --check-prefix=OBJ
-
-define dso_local i32 @f() #0 {
-entry:
- ret i32 0
-}
-
-define dso_local i32 @g() #1 {
-entry:
- ret i32 0
-}
-
-attributes #0 = { "sign-return-address"="non-leaf" }
-
-attributes #1 = { "branch-target-enforcement"="true" }
-
-; No common attribute, no note section
-; ASM: warning: not setting BTI in feature flags
-; ASM-NOT: .note.gnu.property
-; OBJ-NOT: .note.gnu.property
diff --git a/llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-8.ll b/llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-8.ll
deleted file mode 100644
index 8549491186f5..000000000000
--- a/llvm/test/CodeGen/AArch64/note-gnu-property-pac-bti-8.ll
+++ /dev/null
@@ -1,21 +0,0 @@
-; RUN: llc -mtriple=aarch64-linux %s -o - | \
-; RUN: FileCheck %s --check-prefix=ASM
-; RUN: llc -mtriple=aarch64-linux %s -filetype=obj -o - | \
-; RUN: llvm-readelf --notes - | FileCheck %s --check-prefix=OBJ
-
-define dso_local i32 @f() #0 {
-entry:
- %r = tail call i32 @g()
- ret i32 %r
-}
-
-declare dso_local i32 @g()
-
-attributes #0 = { "branch-target-enforcement"="true" }
-
-; Declarations don't prevent setting BTI
-; ASM: .word 3221225472
-; ASM-NEXT: .word 4
-; ASM-NEXT: .word 1
-
-; OBJ: Properties: aarch64 feature: BTI
More information about the llvm-commits
mailing list