This revision was automatically updated to reflect the committed changes.
Closed by commit rGfd5e26270660: [ModuleUtils][KCFI] Set
patchable-function-prefix for synthesized functions (authored by samitolvanen).
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D141172/new/
https://reviews.llvm.org/D141172
Files:
clang/lib/CodeGen/CodeGenModule.cpp
clang/test/CodeGen/kcfi.c
llvm/lib/Transforms/Utils/ModuleUtils.cpp
llvm/test/Instrumentation/AddressSanitizer/kcfi-offset.ll
Index: llvm/test/Instrumentation/AddressSanitizer/kcfi-offset.ll
===================================================================
--- /dev/null
+++ llvm/test/Instrumentation/AddressSanitizer/kcfi-offset.ll
@@ -0,0 +1,15 @@
+;; Test that we set patchable-function-prefix for asan.module_ctor when
kcfi-offset is defined.
+
+; RUN: opt < %s -passes=asan -S | FileCheck %s
+
+; CHECK: @llvm.global_ctors = {{.*}}{ i32 1, ptr @asan.module_ctor, ptr
@asan.module_ctor }
+
+; CHECK: define internal void @asan.module_ctor()
+; CHECK-SAME: #[[#ATTR:]]
+; CHECK-SAME: !kcfi_type
+
+; CHECK: attributes #[[#ATTR]] = { {{.*}} "patchable-function-prefix"="3" }
+
+!llvm.module.flags = !{!0, !1}
+!0 = !{i32 4, !"kcfi", i32 1}
+!1 = !{i32 4, !"kcfi-offset", i32 3}
Index: llvm/lib/Transforms/Utils/ModuleUtils.cpp
===================================================================
--- llvm/lib/Transforms/Utils/ModuleUtils.cpp
+++ llvm/lib/Transforms/Utils/ModuleUtils.cpp
@@ -161,6 +161,13 @@
MDNode::get(Ctx, MDB.createConstant(ConstantInt::get(
Type::getInt32Ty(Ctx),
static_cast<uint32_t>(xxHash64(MangledType))))));
+ // 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>(
+ M.getModuleFlag("kcfi-offset"))) {
+ if (unsigned Offset = MD->getZExtValue())
+ F.addFnAttr("patchable-function-prefix", std::to_string(Offset));
+ }
}
FunctionCallee
Index: clang/test/CodeGen/kcfi.c
===================================================================
--- clang/test/CodeGen/kcfi.c
+++ clang/test/CodeGen/kcfi.c
@@ -1,5 +1,6 @@
// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -emit-llvm -fsanitize=kcfi
-o - %s | FileCheck %s
// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -emit-llvm -fsanitize=kcfi
-x c++ -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -emit-llvm -fsanitize=kcfi
-fpatchable-function-entry-offset=3 -o - %s | FileCheck %s
--check-prefixes=CHECK,OFFSET
#if !__has_feature(kcfi)
#error Missing kcfi?
#endif
@@ -54,5 +55,6 @@
}
// CHECK-DAG: ![[#]] = !{i32 4, !"kcfi", i32 1}
+// OFFSET-DAG: ![[#]] = !{i32 4, !"kcfi-offset", i32 3}
// CHECK-DAG: ![[#TYPE]] = !{i32 [[#HASH]]}
// CHECK-DAG: ![[#TYPE2]] = !{i32 [[#%d,HASH2:]]}
Index: clang/lib/CodeGen/CodeGenModule.cpp
===================================================================
--- clang/lib/CodeGen/CodeGenModule.cpp
+++ clang/lib/CodeGen/CodeGenModule.cpp
@@ -758,8 +758,14 @@
CodeGenOpts.SanitizeCfiCanonicalJumpTables);
}
- if (LangOpts.Sanitize.has(SanitizerKind::KCFI))
+ if (LangOpts.Sanitize.has(SanitizerKind::KCFI)) {
getModule().addModuleFlag(llvm::Module::Override, "kcfi", 1);
+ // KCFI assumes patchable-function-prefix is the same for all indirectly
+ // called functions. Store the expected offset for code generation.
+ if (CodeGenOpts.PatchableFunctionEntryOffset)
+ getModule().addModuleFlag(llvm::Module::Override, "kcfi-offset",
+ CodeGenOpts.PatchableFunctionEntryOffset);
+ }
if (CodeGenOpts.CFProtectionReturn &&
Target.checkCFProtectionReturnSupported(getDiags())) {
Index: llvm/test/Instrumentation/AddressSanitizer/kcfi-offset.ll
===================================================================
--- /dev/null
+++ llvm/test/Instrumentation/AddressSanitizer/kcfi-offset.ll
@@ -0,0 +1,15 @@
+;; Test that we set patchable-function-prefix for asan.module_ctor when kcfi-offset is defined.
+
+; RUN: opt < %s -passes=asan -S | FileCheck %s
+
+; CHECK: @llvm.global_ctors = {{.*}}{ i32 1, ptr @asan.module_ctor, ptr @asan.module_ctor }
+
+; CHECK: define internal void @asan.module_ctor()
+; CHECK-SAME: #[[#ATTR:]]
+; CHECK-SAME: !kcfi_type
+
+; CHECK: attributes #[[#ATTR]] = { {{.*}} "patchable-function-prefix"="3" }
+
+!llvm.module.flags = !{!0, !1}
+!0 = !{i32 4, !"kcfi", i32 1}
+!1 = !{i32 4, !"kcfi-offset", i32 3}
Index: llvm/lib/Transforms/Utils/ModuleUtils.cpp
===================================================================
--- llvm/lib/Transforms/Utils/ModuleUtils.cpp
+++ llvm/lib/Transforms/Utils/ModuleUtils.cpp
@@ -161,6 +161,13 @@
MDNode::get(Ctx, MDB.createConstant(ConstantInt::get(
Type::getInt32Ty(Ctx),
static_cast<uint32_t>(xxHash64(MangledType))))));
+ // 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>(
+ M.getModuleFlag("kcfi-offset"))) {
+ if (unsigned Offset = MD->getZExtValue())
+ F.addFnAttr("patchable-function-prefix", std::to_string(Offset));
+ }
}
FunctionCallee
Index: clang/test/CodeGen/kcfi.c
===================================================================
--- clang/test/CodeGen/kcfi.c
+++ clang/test/CodeGen/kcfi.c
@@ -1,5 +1,6 @@
// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -emit-llvm -fsanitize=kcfi -o - %s | FileCheck %s
// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -emit-llvm -fsanitize=kcfi -x c++ -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -emit-llvm -fsanitize=kcfi -fpatchable-function-entry-offset=3 -o - %s | FileCheck %s --check-prefixes=CHECK,OFFSET
#if !__has_feature(kcfi)
#error Missing kcfi?
#endif
@@ -54,5 +55,6 @@
}
// CHECK-DAG: ![[#]] = !{i32 4, !"kcfi", i32 1}
+// OFFSET-DAG: ![[#]] = !{i32 4, !"kcfi-offset", i32 3}
// CHECK-DAG: ![[#TYPE]] = !{i32 [[#HASH]]}
// CHECK-DAG: ![[#TYPE2]] = !{i32 [[#%d,HASH2:]]}
Index: clang/lib/CodeGen/CodeGenModule.cpp
===================================================================
--- clang/lib/CodeGen/CodeGenModule.cpp
+++ clang/lib/CodeGen/CodeGenModule.cpp
@@ -758,8 +758,14 @@
CodeGenOpts.SanitizeCfiCanonicalJumpTables);
}
- if (LangOpts.Sanitize.has(SanitizerKind::KCFI))
+ if (LangOpts.Sanitize.has(SanitizerKind::KCFI)) {
getModule().addModuleFlag(llvm::Module::Override, "kcfi", 1);
+ // KCFI assumes patchable-function-prefix is the same for all indirectly
+ // called functions. Store the expected offset for code generation.
+ if (CodeGenOpts.PatchableFunctionEntryOffset)
+ getModule().addModuleFlag(llvm::Module::Override, "kcfi-offset",
+ CodeGenOpts.PatchableFunctionEntryOffset);
+ }
if (CodeGenOpts.CFProtectionReturn &&
Target.checkCFProtectionReturnSupported(getDiags())) {
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