[clang] [Clang][RISCV] Support -fcf-protection=return for RISC-V (PR #112477)
Jesse Huang via cfe-commits
cfe-commits at lists.llvm.org
Mon Oct 28 01:13:50 PDT 2024
https://github.com/jaidTw updated https://github.com/llvm/llvm-project/pull/112477
>From fe4a28fb691b69d9af384f1dc2f0667761adef44 Mon Sep 17 00:00:00 2001
From: Jesse Huang <jesse.huang at sifive.com>
Date: Sun, 13 Oct 2024 15:11:06 +0800
Subject: [PATCH 1/5] [Clang][RISCV] Support -fcf-protection=return for RISC-V
---
clang/lib/Basic/Targets/RISCV.h | 7 +++++++
clang/lib/CodeGen/CodeGenFunction.cpp | 4 ++++
2 files changed, 11 insertions(+)
diff --git a/clang/lib/Basic/Targets/RISCV.h b/clang/lib/Basic/Targets/RISCV.h
index bf40edb8683b3e..3f2cee72fc3731 100644
--- a/clang/lib/Basic/Targets/RISCV.h
+++ b/clang/lib/Basic/Targets/RISCV.h
@@ -141,6 +141,13 @@ class RISCVTargetInfo : public TargetInfo {
return true;
}
+ bool
+ checkCFProtectionReturnSupported(DiagnosticsEngine &Diags) const override {
+ if (ISAInfo->hasExtension("zimop"))
+ return true;
+ return TargetInfo::checkCFProtectionReturnSupported(Diags);
+ }
+
CFBranchLabelSchemeKind getDefaultCFBranchLabelScheme() const override {
return CFBranchLabelSchemeKind::FuncSig;
}
diff --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp
index 2306043c90f406..d8f0f7c14f6b40 100644
--- a/clang/lib/CodeGen/CodeGenFunction.cpp
+++ b/clang/lib/CodeGen/CodeGenFunction.cpp
@@ -899,6 +899,10 @@ void CodeGenFunction::StartFunction(GlobalDecl GD, QualType RetTy,
if (CodeGenOpts.PointerAuth.IndirectGotos)
Fn->addFnAttr("ptrauth-indirect-gotos");
+ // Add return control flow integrity attributes.
+ if (CodeGenOpts.CFProtectionReturn)
+ Fn->addFnAttr("hw-shadow-stack");
+
// Apply xray attributes to the function (as a string, for now)
bool AlwaysXRayAttr = false;
if (const auto *XRayAttr = D ? D->getAttr<XRayInstrumentAttr>() : nullptr) {
>From 7dc168af5758d130042c71ba5d6249c042bc356c Mon Sep 17 00:00:00 2001
From: Jesse Huang <jesse.huang at sifive.com>
Date: Wed, 23 Oct 2024 14:42:35 +0800
Subject: [PATCH 2/5] [Clang][RISCV] Add RISCV check for hw-shadow-stack
---
clang/lib/CodeGen/CodeGenFunction.cpp | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp
index d8f0f7c14f6b40..cca52f3769845e 100644
--- a/clang/lib/CodeGen/CodeGenFunction.cpp
+++ b/clang/lib/CodeGen/CodeGenFunction.cpp
@@ -899,8 +899,9 @@ void CodeGenFunction::StartFunction(GlobalDecl GD, QualType RetTy,
if (CodeGenOpts.PointerAuth.IndirectGotos)
Fn->addFnAttr("ptrauth-indirect-gotos");
- // Add return control flow integrity attributes.
- if (CodeGenOpts.CFProtectionReturn)
+ // Add return control flow integrity attributes for RISCV.
+ if (CodeGenOpts.CFProtectionReturn &&
+ getContext().getTargetInfo().getTriple().isRISCV())
Fn->addFnAttr("hw-shadow-stack");
// Apply xray attributes to the function (as a string, for now)
>From 42132c2460333358f6c1aaa646266847a3b8c854 Mon Sep 17 00:00:00 2001
From: Jesse Huang <jesse.huang at sifive.com>
Date: Thu, 24 Oct 2024 15:39:07 +0800
Subject: [PATCH 3/5] [Clang][RISCV] Add function attribute in RISC-V specific
code
---
clang/lib/CodeGen/CodeGenFunction.cpp | 5 -----
clang/lib/CodeGen/Targets/RISCV.cpp | 7 +++++--
2 files changed, 5 insertions(+), 7 deletions(-)
diff --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp
index cca52f3769845e..2306043c90f406 100644
--- a/clang/lib/CodeGen/CodeGenFunction.cpp
+++ b/clang/lib/CodeGen/CodeGenFunction.cpp
@@ -899,11 +899,6 @@ void CodeGenFunction::StartFunction(GlobalDecl GD, QualType RetTy,
if (CodeGenOpts.PointerAuth.IndirectGotos)
Fn->addFnAttr("ptrauth-indirect-gotos");
- // Add return control flow integrity attributes for RISCV.
- if (CodeGenOpts.CFProtectionReturn &&
- getContext().getTargetInfo().getTriple().isRISCV())
- Fn->addFnAttr("hw-shadow-stack");
-
// Apply xray attributes to the function (as a string, for now)
bool AlwaysXRayAttr = false;
if (const auto *XRayAttr = D ? D->getAttr<XRayInstrumentAttr>() : nullptr) {
diff --git a/clang/lib/CodeGen/Targets/RISCV.cpp b/clang/lib/CodeGen/Targets/RISCV.cpp
index fd72fe673b9b14..b04e436c665f52 100644
--- a/clang/lib/CodeGen/Targets/RISCV.cpp
+++ b/clang/lib/CodeGen/Targets/RISCV.cpp
@@ -594,6 +594,11 @@ class RISCVTargetCodeGenInfo : public TargetCodeGenInfo {
const auto *FD = dyn_cast_or_null<FunctionDecl>(D);
if (!FD) return;
+ auto *Fn = cast<llvm::Function>(GV);
+
+ if (CGM.getCodeGenOpts().CFProtectionReturn)
+ Fn->addFnAttr("hw-shadow-stack");
+
const auto *Attr = FD->getAttr<RISCVInterruptAttr>();
if (!Attr)
return;
@@ -604,8 +609,6 @@ class RISCVTargetCodeGenInfo : public TargetCodeGenInfo {
case RISCVInterruptAttr::machine: Kind = "machine"; break;
}
- auto *Fn = cast<llvm::Function>(GV);
-
Fn->addFnAttr("interrupt", Kind);
}
};
>From 62dff012e1791bac6b3ed7725df86c1b2c60c1a1 Mon Sep 17 00:00:00 2001
From: Jesse Huang <jesse.huang at sifive.com>
Date: Fri, 25 Oct 2024 14:13:45 +0800
Subject: [PATCH 4/5] [Clang] Add test for hw-shadodw-stack
---
clang/test/CodeGen/RISCV/attr-hw-shadow-stack.c | 9 +++++++++
1 file changed, 9 insertions(+)
create mode 100644 clang/test/CodeGen/RISCV/attr-hw-shadow-stack.c
diff --git a/clang/test/CodeGen/RISCV/attr-hw-shadow-stack.c b/clang/test/CodeGen/RISCV/attr-hw-shadow-stack.c
new file mode 100644
index 00000000000000..80d20b03f9a913
--- /dev/null
+++ b/clang/test/CodeGen/RISCV/attr-hw-shadow-stack.c
@@ -0,0 +1,9 @@
+// RUN: %clang_cc1 -triple riscv64-unknown-linux -target-feature +zimop -emit-llvm -o - %s -fcf-protection=return | FileCheck %s
+// RUN: %clang_cc1 -triple riscv64-unknown-linux -target-feature +zimop -emit-llvm -o - %s | FileCheck -check-prefix=NOSHADOWSTACK %s
+// RUN: %clang_cc1 -triple riscv32-unknown-linux -target-feature +zimop -emit-llvm -o - %s -fcf-protection=return | FileCheck %s
+// RUN: %clang_cc1 -triple riscv32-unknown-linux -target-feature +zimop -emit-llvm -o - %s | FileCheck -check-prefix=NOSHADOWSTACK %s
+
+int foo(int *a) { return *a; }
+
+// CHECK: attributes {{.*}}"hw-shadow-stack"{{.*}}
+// NOSHADOWSTACK-NOT: attributes {{.*}}"hw-shadow-stack"{{.*}}
>From f2727246e6fb8298e1d1208dd89ae7598ac64610 Mon Sep 17 00:00:00 2001
From: Jesse Huang <jesse.huang at sifive.com>
Date: Mon, 28 Oct 2024 15:21:06 +0800
Subject: [PATCH 5/5] !fixup change requirement back to zicfiss
---
clang/lib/Basic/Targets/RISCV.h | 2 +-
clang/test/CodeGen/RISCV/attr-hw-shadow-stack.c | 8 ++++----
2 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/clang/lib/Basic/Targets/RISCV.h b/clang/lib/Basic/Targets/RISCV.h
index 3f2cee72fc3731..3b418585ab4a39 100644
--- a/clang/lib/Basic/Targets/RISCV.h
+++ b/clang/lib/Basic/Targets/RISCV.h
@@ -143,7 +143,7 @@ class RISCVTargetInfo : public TargetInfo {
bool
checkCFProtectionReturnSupported(DiagnosticsEngine &Diags) const override {
- if (ISAInfo->hasExtension("zimop"))
+ if (ISAInfo->hasExtension("zicfiss"))
return true;
return TargetInfo::checkCFProtectionReturnSupported(Diags);
}
diff --git a/clang/test/CodeGen/RISCV/attr-hw-shadow-stack.c b/clang/test/CodeGen/RISCV/attr-hw-shadow-stack.c
index 80d20b03f9a913..cabff7e598eb02 100644
--- a/clang/test/CodeGen/RISCV/attr-hw-shadow-stack.c
+++ b/clang/test/CodeGen/RISCV/attr-hw-shadow-stack.c
@@ -1,7 +1,7 @@
-// RUN: %clang_cc1 -triple riscv64-unknown-linux -target-feature +zimop -emit-llvm -o - %s -fcf-protection=return | FileCheck %s
-// RUN: %clang_cc1 -triple riscv64-unknown-linux -target-feature +zimop -emit-llvm -o - %s | FileCheck -check-prefix=NOSHADOWSTACK %s
-// RUN: %clang_cc1 -triple riscv32-unknown-linux -target-feature +zimop -emit-llvm -o - %s -fcf-protection=return | FileCheck %s
-// RUN: %clang_cc1 -triple riscv32-unknown-linux -target-feature +zimop -emit-llvm -o - %s | FileCheck -check-prefix=NOSHADOWSTACK %s
+// RUN: %clang_cc1 -triple riscv64 -target-feature +experimental-zicfiss -emit-llvm -o - %s -fcf-protection=return | FileCheck %s
+// RUN: %clang_cc1 -triple riscv64 -target-feature +experimental-zicfiss -emit-llvm -o - %s | FileCheck -check-prefix=NOSHADOWSTACK %s
+// RUN: %clang_cc1 -triple riscv32 -target-feature +experimental-zicfiss -emit-llvm -o - %s -fcf-protection=return | FileCheck %s
+// RUN: %clang_cc1 -triple riscv32 -target-feature +experimental-zicfiss -emit-llvm -o - %s | FileCheck -check-prefix=NOSHADOWSTACK %s
int foo(int *a) { return *a; }
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