[clang] 6678f8e - [ubsan] Using metadata instead of prologue data for function sanitizer
Yuanfang Chen via cfe-commits
cfe-commits at lists.llvm.org
Mon Jun 27 12:11:52 PDT 2022
Author: Yuanfang Chen
Date: 2022-06-27T12:09:13-07:00
New Revision: 6678f8e505b19069a9dbdc3e3ee088d543752412
URL: https://github.com/llvm/llvm-project/commit/6678f8e505b19069a9dbdc3e3ee088d543752412
DIFF: https://github.com/llvm/llvm-project/commit/6678f8e505b19069a9dbdc3e3ee088d543752412.diff
LOG: [ubsan] Using metadata instead of prologue data for function sanitizer
Information in the function `Prologue Data` is intentionally opaque.
When a function with `Prologue Data` is duplicated. The self (global
value) references inside `Prologue Data` is still pointing to the
original function. This may cause errors like `fatal error: error in backend: Cannot represent a difference across sections`.
This patch detaches the information from function `Prologue Data`
and attaches it to a function metadata node.
This and D116130 fix https://github.com/llvm/llvm-project/issues/49689.
Reviewed By: pcc
Differential Revision: https://reviews.llvm.org/D115844
Added:
llvm/test/CodeGen/X86/func-sanitizer.ll
Modified:
clang/lib/CodeGen/CodeGenFunction.cpp
clang/lib/CodeGen/CodeGenFunction.h
clang/lib/CodeGen/CodeGenModule.cpp
clang/lib/CodeGen/CodeGenModule.h
clang/lib/Driver/SanitizerArgs.cpp
clang/test/CodeGen/ubsan-function.cpp
clang/test/CodeGenCXX/catch-undef-behavior.cpp
clang/test/CodeGenCXX/ubsan-function-noexcept.cpp
clang/test/Driver/fsanitize.c
llvm/docs/LangRef.rst
llvm/include/llvm/IR/FixedMetadataKinds.def
llvm/include/llvm/IR/MDBuilder.h
llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
llvm/lib/IR/MDBuilder.cpp
llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
Removed:
################################################################################
diff --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp
index 4255f1ca9759c..05942f462dd1d 100644
--- a/clang/lib/CodeGen/CodeGenFunction.cpp
+++ b/clang/lib/CodeGen/CodeGenFunction.cpp
@@ -559,29 +559,6 @@ bool CodeGenFunction::AlwaysEmitXRayTypedEvents() const {
XRayInstrKind::Typed);
}
-llvm::Constant *
-CodeGenFunction::EncodeAddrForUseInPrologue(llvm::Function *F,
- llvm::Constant *Addr) {
- // Addresses stored in prologue data can't require run-time fixups and must
- // be PC-relative. Run-time fixups are undesirable because they necessitate
- // writable text segments, which are unsafe. And absolute addresses are
- // undesirable because they break PIE mode.
-
- // Add a layer of indirection through a private global. Taking its address
- // won't result in a run-time fixup, even if Addr has linkonce_odr linkage.
- auto *GV = new llvm::GlobalVariable(CGM.getModule(), Addr->getType(),
- /*isConstant=*/true,
- llvm::GlobalValue::PrivateLinkage, Addr);
-
- // Create a PC-relative address.
- auto *GOTAsInt = llvm::ConstantExpr::getPtrToInt(GV, IntPtrTy);
- auto *FuncAsInt = llvm::ConstantExpr::getPtrToInt(F, IntPtrTy);
- auto *PCRelAsInt = llvm::ConstantExpr::getSub(GOTAsInt, FuncAsInt);
- return (IntPtrTy == Int32Ty)
- ? PCRelAsInt
- : llvm::ConstantExpr::getTrunc(PCRelAsInt, Int32Ty);
-}
-
llvm::Value *
CodeGenFunction::DecodeAddrUsedInPrologue(llvm::Value *F,
llvm::Value *EncodedAddr) {
@@ -937,12 +914,13 @@ void CodeGenFunction::StartFunction(GlobalDecl GD, QualType RetTy,
FD->getType(), EST_None);
llvm::Constant *FTRTTIConst =
CGM.GetAddrOfRTTIDescriptor(ProtoTy, /*ForEH=*/true);
- llvm::Constant *FTRTTIConstEncoded =
- EncodeAddrForUseInPrologue(Fn, FTRTTIConst);
- llvm::Constant *PrologueStructElems[] = {PrologueSig, FTRTTIConstEncoded};
- llvm::Constant *PrologueStructConst =
- llvm::ConstantStruct::getAnon(PrologueStructElems, /*Packed=*/true);
- Fn->setPrologueData(PrologueStructConst);
+ llvm::GlobalVariable *FTRTTIProxy =
+ CGM.GetOrCreateRTTIProxyGlobalVariable(FTRTTIConst);
+ llvm::LLVMContext &Ctx = Fn->getContext();
+ llvm::MDBuilder MDB(Ctx);
+ Fn->setMetadata(llvm::LLVMContext::MD_func_sanitize,
+ MDB.createRTTIPointerPrologue(PrologueSig, FTRTTIProxy));
+ CGM.addCompilerUsedGlobal(FTRTTIProxy);
}
}
diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index 118d3144069bd..fe0890f433e8c 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -2356,10 +2356,6 @@ class CodeGenFunction : public CodeGenTypeCache {
/// XRay typed event handling calls.
bool AlwaysEmitXRayTypedEvents() const;
- /// Encode an address into a form suitable for use in a function prologue.
- llvm::Constant *EncodeAddrForUseInPrologue(llvm::Function *F,
- llvm::Constant *Addr);
-
/// Decode an address used in a function prologue, encoded by \c
/// EncodeAddrForUseInPrologue.
llvm::Value *DecodeAddrUsedInPrologue(llvm::Value *F,
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 34d8b3a7d3609..56ed59d1e3f15 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -1890,6 +1890,22 @@ CodeGenModule::getMostBaseClasses(const CXXRecordDecl *RD) {
return MostBases.takeVector();
}
+llvm::GlobalVariable *
+CodeGenModule::GetOrCreateRTTIProxyGlobalVariable(llvm::Constant *Addr) {
+ auto It = RTTIProxyMap.find(Addr);
+ if (It != RTTIProxyMap.end())
+ return It->second;
+
+ auto *FTRTTIProxy = new llvm::GlobalVariable(
+ TheModule, Addr->getType(),
+ /*isConstant=*/true, llvm::GlobalValue::PrivateLinkage, Addr,
+ "__llvm_rtti_proxy");
+ FTRTTIProxy->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
+
+ RTTIProxyMap[Addr] = FTRTTIProxy;
+ return FTRTTIProxy;
+}
+
void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D,
llvm::Function *F) {
llvm::AttrBuilder B(F->getContext());
diff --git a/clang/lib/CodeGen/CodeGenModule.h b/clang/lib/CodeGen/CodeGenModule.h
index f5cbdafc8db62..da43b9616c88e 100644
--- a/clang/lib/CodeGen/CodeGenModule.h
+++ b/clang/lib/CodeGen/CodeGenModule.h
@@ -567,6 +567,8 @@ class CodeGenModule : public CodeGenTypeCache {
MetadataTypeMap VirtualMetadataIdMap;
MetadataTypeMap GeneralizedMetadataIdMap;
+ llvm::DenseMap<const llvm::Constant *, llvm::GlobalVariable *> RTTIProxyMap;
+
public:
CodeGenModule(ASTContext &C, const HeaderSearchOptions &headersearchopts,
const PreprocessorOptions &ppopts,
@@ -1442,6 +1444,9 @@ class CodeGenModule : public CodeGenTypeCache {
std::vector<const CXXRecordDecl *>
getMostBaseClasses(const CXXRecordDecl *RD);
+ llvm::GlobalVariable *
+ GetOrCreateRTTIProxyGlobalVariable(llvm::Constant *Addr);
+
/// Get the declaration of std::terminate for the platform.
llvm::FunctionCallee getTerminateFn();
diff --git a/clang/lib/Driver/SanitizerArgs.cpp b/clang/lib/Driver/SanitizerArgs.cpp
index 55d44691050bf..68fe90c7a69d9 100644
--- a/clang/lib/Driver/SanitizerArgs.cpp
+++ b/clang/lib/Driver/SanitizerArgs.cpp
@@ -369,6 +369,19 @@ SanitizerArgs::SanitizerArgs(const ToolChain &TC,
Add &= ~NotAllowedWithMinimalRuntime;
}
+ if (llvm::opt::Arg *A = Args.getLastArg(options::OPT_mcmodel_EQ)) {
+ StringRef CM = A->getValue();
+ if (CM != "small" &&
+ (Add & SanitizerKind::Function & ~DiagnosedKinds)) {
+ if (DiagnoseErrors)
+ D.Diag(diag::err_drv_argument_only_allowed_with)
+ << "-fsanitize=function"
+ << "-mcmodel=small";
+ Add &= ~SanitizerKind::Function;
+ DiagnosedKinds |= SanitizerKind::Function;
+ }
+ }
+
// FIXME: Make CFI on member function calls compatible with cross-DSO CFI.
// There are currently two problems:
// - Virtual function call checks need to pass a pointer to the function
diff --git a/clang/test/CodeGen/ubsan-function.cpp b/clang/test/CodeGen/ubsan-function.cpp
index b7ae929e4e1cd..e2134a960fbfd 100644
--- a/clang/test/CodeGen/ubsan-function.cpp
+++ b/clang/test/CodeGen/ubsan-function.cpp
@@ -1,6 +1,7 @@
// RUN: %clang_cc1 -no-opaque-pointers -triple x86_64-linux-gnu -emit-llvm -o - %s -fsanitize=function -fno-sanitize-recover=all | FileCheck %s
-// CHECK-LABEL: define{{.*}} void @_Z3funv() #0 prologue <{ i32, i32 }> <{ i32 846595819, i32 trunc (i64 sub (i64 ptrtoint (i8** @0 to i64), i64 ptrtoint (void ()* @_Z3funv to i64)) to i32) }> {
+// CHECK: @[[PROXY:.*]] = private unnamed_addr constant i8* bitcast ({ i8*, i8* }* @_ZTIFvvE to i8*)
+// CHECK: define{{.*}} void @_Z3funv() #0 !func_sanitize ![[FUNCSAN:.*]] {
void fun() {}
// CHECK-LABEL: define{{.*}} void @_Z6callerPFvvE(void ()* noundef %f)
@@ -20,3 +21,5 @@ void fun() {}
// CHECK: [[LABEL3]]:
// CHECK: br label %[[LABEL4]], !nosanitize
void caller(void (*f)()) { f(); }
+
+// CHECK: ![[FUNCSAN]] = !{i32 846595819, i8** @[[PROXY]]}
diff --git a/clang/test/CodeGenCXX/catch-undef-behavior.cpp b/clang/test/CodeGenCXX/catch-undef-behavior.cpp
index 7713491b75041..9869b1a862526 100644
--- a/clang/test/CodeGenCXX/catch-undef-behavior.cpp
+++ b/clang/test/CodeGenCXX/catch-undef-behavior.cpp
@@ -1,8 +1,8 @@
-// RUN: %clang_cc1 -no-opaque-pointers -no-enable-noundef-analysis -std=c++11 -fsanitize=signed-integer-overflow,integer-divide-by-zero,float-divide-by-zero,shift-base,shift-exponent,unreachable,return,vla-bound,alignment,null,vptr,object-size,float-cast-overflow,bool,enum,array-bounds,function -fsanitize-recover=signed-integer-overflow,integer-divide-by-zero,float-divide-by-zero,shift-base,shift-exponent,vla-bound,alignment,null,vptr,object-size,float-cast-overflow,bool,enum,array-bounds,function -emit-llvm %s -o - -triple x86_64-linux-gnu | opt -instnamer -S | FileCheck %s
+// RUN: %clang_cc1 -no-opaque-pointers -no-enable-noundef-analysis -std=c++11 -fsanitize=signed-integer-overflow,integer-divide-by-zero,float-divide-by-zero,shift-base,shift-exponent,unreachable,return,vla-bound,alignment,null,vptr,object-size,float-cast-overflow,bool,enum,array-bounds,function -fsanitize-recover=signed-integer-overflow,integer-divide-by-zero,float-divide-by-zero,shift-base,shift-exponent,vla-bound,alignment,null,vptr,object-size,float-cast-overflow,bool,enum,array-bounds,function -emit-llvm %s -o - -triple x86_64-linux-gnu | opt -instnamer -S | FileCheck %s --check-prefixes=CHECK,CHECK-FUNCSAN
// RUN: %clang_cc1 -no-opaque-pointers -no-enable-noundef-analysis -std=c++11 -fsanitize=vptr,address -fsanitize-recover=vptr,address -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck %s --check-prefix=CHECK-ASAN
// RUN: %clang_cc1 -no-opaque-pointers -no-enable-noundef-analysis -std=c++11 -fsanitize=vptr -fsanitize-recover=vptr -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck %s --check-prefix=DOWNCAST-NULL
-// RUN: %clang_cc1 -no-opaque-pointers -no-enable-noundef-analysis -std=c++11 -fsanitize=function -emit-llvm %s -o - -triple x86_64-linux-gnux32 | FileCheck %s --check-prefix=CHECK-X32
-// RUN: %clang_cc1 -no-opaque-pointers -no-enable-noundef-analysis -std=c++11 -fsanitize=function -emit-llvm %s -o - -triple i386-linux-gnu | FileCheck %s --check-prefix=CHECK-X86
+// RUN: %clang_cc1 -no-opaque-pointers -no-enable-noundef-analysis -std=c++11 -fsanitize=function -emit-llvm %s -o - -triple x86_64-linux-gnux32 | FileCheck %s --check-prefix=CHECK-FUNCSAN
+// RUN: %clang_cc1 -no-opaque-pointers -no-enable-noundef-analysis -std=c++11 -fsanitize=function -emit-llvm %s -o - -triple i386-linux-gnu | FileCheck %s --check-prefix=CHECK-FUNCSAN
struct S {
double d;
@@ -16,9 +16,7 @@ struct S {
// Check that type mismatch handler is not modified by ASan.
// CHECK-ASAN: private unnamed_addr global { { [{{.*}} x i8]*, i32, i32 }, { i16, i16, [4 x i8] }*, i8*, i8 } { {{.*}}, { i16, i16, [4 x i8] }* [[TYPE_DESCR]], {{.*}} }
-// CHECK: [[IndirectRTTI_ZTIFvPFviEE:@.+]] = private constant i8* bitcast ({ i8*, i8* }* @_ZTIFvPFviEE to i8*)
-// CHECK-X86: [[IndirectRTTI_ZTIFvPFviEE:@.+]] = private constant i8* bitcast ({ i8*, i8* }* @_ZTIFvPFviEE to i8*)
-// CHECK-X32: [[IndirectRTTI_ZTIFvPFviEE:@.+]] = private constant i8* bitcast ({ i8*, i8* }* @_ZTIFvPFviEE to i8*)
+// CHECK-FUNCSAN: [[PROXY:@.+]] = private unnamed_addr constant i8* bitcast ({ i8*, i8* }* @_ZTIFvPFviEE to i8*)
struct T : S {};
@@ -399,10 +397,7 @@ void downcast_reference(B &b) {
// CHECK-NEXT: br i1 [[AND]]
}
-//
-// CHECK-LABEL: @_Z22indirect_function_callPFviE({{.*}} prologue <{ i32, i32 }> <{ i32 846595819, i32 trunc (i64 sub (i64 ptrtoint (i8** {{.*}} to i64), i64 ptrtoint (void (void (i32)*)* @_Z22indirect_function_callPFviE to i64)) to i32) }>
-// CHECK-X32: @_Z22indirect_function_callPFviE({{.*}} prologue <{ i32, i32 }> <{ i32 846595819, i32 sub (i32 ptrtoint (i8** [[IndirectRTTI_ZTIFvPFviEE]] to i32), i32 ptrtoint (void (void (i32)*)* @_Z22indirect_function_callPFviE to i32)) }>
-// CHECK-X86: @_Z22indirect_function_callPFviE({{.*}} prologue <{ i32, i32 }> <{ i32 846595819, i32 sub (i32 ptrtoint (i8** [[IndirectRTTI_ZTIFvPFviEE]] to i32), i32 ptrtoint (void (void (i32)*)* @_Z22indirect_function_callPFviE to i32)) }>
+// CHECK-FUNCSAN: @_Z22indirect_function_callPFviE({{.*}} !func_sanitize ![[FUNCSAN:.*]] {
void indirect_function_call(void (*p)(int)) {
// CHECK: [[PTR:%.+]] = bitcast void (i32)* {{.*}} to <{ i32, i32 }>*
@@ -483,34 +478,34 @@ void force_irgen() {
}
// CHECK-LABEL: define{{.*}} void @_ZN29FunctionSanitizerVirtualCalls1B1fEv
-// CHECK-NOT: prologue
+// CHECK-NOT: !func_sanitize
//
// CHECK-LABEL: define{{.*}} void @_ZTv0_n24_N29FunctionSanitizerVirtualCalls1B1fEv
-// CHECK-NOT: prologue
+// CHECK-NOT: !func_sanitize
//
// CHECK-LABEL: define{{.*}} void @_ZN29FunctionSanitizerVirtualCalls11force_irgenEv()
-// CHECK: prologue
+// CHECK: !func_sanitize
//
// CHECK-LABEL: define linkonce_odr void @_ZN29FunctionSanitizerVirtualCalls1AC1Ev
-// CHECK-NOT: prologue
+// CHECK-NOT: !func_sanitize
//
// CHECK-LABEL: define linkonce_odr void @_ZN29FunctionSanitizerVirtualCalls1A1gEv
-// CHECK-NOT: prologue
+// CHECK-NOT: !func_sanitize
//
// CHECK-LABEL: define linkonce_odr void @_ZN29FunctionSanitizerVirtualCalls1A1hEv
-// CHECK-NOT: prologue
+// CHECK-NOT: !func_sanitize
//
// CHECK-LABEL: define linkonce_odr void @_ZN29FunctionSanitizerVirtualCalls1BC1Ev
-// CHECK-NOT: prologue
+// CHECK-NOT: !func_sanitize
//
// CHECK-LABEL: define linkonce_odr void @_ZN29FunctionSanitizerVirtualCalls1B1bEv
-// CHECK-NOT: prologue
+// CHECK-NOT: !func_sanitize
//
// CHECK-LABEL: define linkonce_odr void @_ZN29FunctionSanitizerVirtualCalls1B1gEv
-// CHECK-NOT: prologue
+// CHECK-NOT: !func_sanitize
//
// CHECK-LABEL: define linkonce_odr void @_ZN29FunctionSanitizerVirtualCalls1B1qEv
-// CHECK: prologue
+// CHECK: !func_sanitize
}
@@ -754,3 +749,5 @@ void ThisAlign::this_align_lambda_2() {
}
// CHECK: attributes [[NR_NUW]] = { noreturn nounwind }
+
+// CHECK-FUNCSAN: ![[FUNCSAN]] = !{i32 846595819, i8** [[PROXY]]}
diff --git a/clang/test/CodeGenCXX/ubsan-function-noexcept.cpp b/clang/test/CodeGenCXX/ubsan-function-noexcept.cpp
index c45703feec111..2084f2c00da72 100644
--- a/clang/test/CodeGenCXX/ubsan-function-noexcept.cpp
+++ b/clang/test/CodeGenCXX/ubsan-function-noexcept.cpp
@@ -2,8 +2,8 @@
// Check that typeinfo recorded in function prolog doesn't have "Do" noexcept
// qualifier in its mangled name.
-// CHECK: @[[RTTI:[0-9]+]] = private constant i8* bitcast ({ i8*, i8* }* @_ZTIFvvE to i8*)
-// CHECK: define{{.*}} void @_Z1fv() #{{.*}} prologue <{ i32, i32 }> <{ i32 {{.*}}, i32 trunc (i64 sub (i64 ptrtoint (i8** @[[RTTI]] to i64), i64 ptrtoint (void ()* @_Z1fv to i64)) to i32) }>
+// CHECK: [[PROXY:@.*]] = private unnamed_addr constant i8* bitcast ({ i8*, i8* }* @_ZTIFvvE to i8*)
+// CHECK: define{{.*}} void @_Z1fv() #{{.*}} !func_sanitize ![[FUNCSAN:.*]] {
void f() noexcept {}
// CHECK: define{{.*}} void @_Z1gPDoFvvE
@@ -13,3 +13,5 @@ void g(void (*p)() noexcept) {
// CHECK: icmp eq i8* %{{.*}}, bitcast ({ i8*, i8* }* @_ZTIFvvE to i8*), !nosanitize
p();
}
+
+// CHECK: ![[FUNCSAN]] = !{i32 846595819, i8** [[PROXY]]}
diff --git a/clang/test/Driver/fsanitize.c b/clang/test/Driver/fsanitize.c
index 1d97e99058b9e..d7fbeaa8c6f1e 100644
--- a/clang/test/Driver/fsanitize.c
+++ b/clang/test/Driver/fsanitize.c
@@ -942,3 +942,6 @@
// RUN: %clang -fsanitize=undefined,float-divide-by-zero %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-DIVBYZERO-UBSAN
// CHECK-DIVBYZERO-UBSAN: "-fsanitize={{.*}},float-divide-by-zero,{{.*}}"
+
+// RUN: %clang -target x86_64-linux-gnu -fsanitize=undefined,function -mcmodel=large %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-UBSAN-FUNCTION-CODE-MODEL
+// CHECK-UBSAN-FUNCTION-CODE-MODEL: error: invalid argument '-fsanitize=function' only allowed with '-mcmodel=small'
diff --git a/llvm/docs/LangRef.rst b/llvm/docs/LangRef.rst
index b42e9ccfecf5d..2fcf2a5f2dc26 100644
--- a/llvm/docs/LangRef.rst
+++ b/llvm/docs/LangRef.rst
@@ -5287,7 +5287,7 @@ multiple metadata attachments with the same identifier.
A transformation is required to drop any metadata attachment that it does not
know or know it can't preserve. Currently there is an exception for metadata
-attachment to globals for ``!type`` and ``!absolute_symbol`` which can't be
+attachment to globals for ``!func_sanitize``, ``!type`` and ``!absolute_symbol`` which can't be
unconditionally dropped unless the global is itself deleted.
Metadata attached to a module using named metadata may not be dropped, with
@@ -7175,6 +7175,26 @@ Example:
%a.addr = alloca float*, align 8, !annotation !0
!0 = !{!"auto-init"}
+'``func_sanitize``' Metadata
+^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The ``func_sanitize`` metadata is used to attach two values for the function
+sanitizer instrumentation. The first value is the ubsan function signature.
+The second value is the address of the proxy variable which stores the address
+of the RTTI descriptor. If :ref:`prologue <prologuedata>` and '``func_sanitize``'
+are used at the same time, :ref:`prologue <prologuedata>` is emitted before
+'``func_sanitize``' in the output.
+
+Example:
+
+.. code-block:: text
+
+ @__llvm_rtti_proxy = private unnamed_addr constant i8* bitcast ({ i8*, i8* }* @_ZTIFvvE to i8*)
+ define void @_Z3funv() !func_sanitize !0 {
+ return void
+ }
+ !0 = !{i32 846595819, i8** @__llvm_rtti_proxy}
+
Module Flags Metadata
=====================
diff --git a/llvm/include/llvm/IR/FixedMetadataKinds.def b/llvm/include/llvm/IR/FixedMetadataKinds.def
index 9a78fd895fe29..7c32c5d13760b 100644
--- a/llvm/include/llvm/IR/FixedMetadataKinds.def
+++ b/llvm/include/llvm/IR/FixedMetadataKinds.def
@@ -43,3 +43,4 @@ LLVM_FIXED_MD_KIND(MD_vcall_visibility, "vcall_visibility", 28)
LLVM_FIXED_MD_KIND(MD_noundef, "noundef", 29)
LLVM_FIXED_MD_KIND(MD_annotation, "annotation", 30)
LLVM_FIXED_MD_KIND(MD_nosanitize, "nosanitize", 31)
+LLVM_FIXED_MD_KIND(MD_func_sanitize, "func_sanitize", 32)
diff --git a/llvm/include/llvm/IR/MDBuilder.h b/llvm/include/llvm/IR/MDBuilder.h
index 42829388b79a9..21d7b8b6da715 100644
--- a/llvm/include/llvm/IR/MDBuilder.h
+++ b/llvm/include/llvm/IR/MDBuilder.h
@@ -108,6 +108,10 @@ class MDBuilder {
/// Merge the new callback encoding \p NewCB into \p ExistingCallbacks.
MDNode *mergeCallbackEncodings(MDNode *ExistingCallbacks, MDNode *NewCB);
+ /// Return metadata feeding to the CodeGen about how to generate a function
+ /// prologue for the "function" santizier.
+ MDNode *createRTTIPointerPrologue(Constant *PrologueSig, Constant *RTTI);
+
//===------------------------------------------------------------------===//
// AA metadata.
//===------------------------------------------------------------------===//
diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 942bce377a3d5..593ef04cf8ed5 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -1004,6 +1004,24 @@ void AsmPrinter::emitFunctionHeader() {
// Emit the prologue data.
if (F.hasPrologueData())
emitGlobalConstant(F.getParent()->getDataLayout(), F.getPrologueData());
+
+ // Emit the function prologue data for the indirect call sanitizer.
+ if (const MDNode *MD = F.getMetadata(LLVMContext::MD_func_sanitize)) {
+ assert(TM.getTargetTriple().getArch() == Triple::x86 ||
+ TM.getTargetTriple().getArch() == Triple::x86_64);
+ assert(MD->getNumOperands() == 2);
+
+ auto *PrologueSig = mdconst::extract<Constant>(MD->getOperand(0));
+ auto *FTRTTIProxy = mdconst::extract<Constant>(MD->getOperand(1));
+ assert(PrologueSig && FTRTTIProxy);
+ emitGlobalConstant(F.getParent()->getDataLayout(), PrologueSig);
+
+ const MCExpr *Proxy = lowerConstant(FTRTTIProxy);
+ const MCExpr *FnExp = MCSymbolRefExpr::create(CurrentFnSym, OutContext);
+ const MCExpr *PCRel = MCBinaryExpr::createSub(Proxy, FnExp, OutContext);
+ // Use 32 bit since only small code model is supported.
+ OutStreamer->emitValue(PCRel, 4u);
+ }
}
/// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
diff --git a/llvm/lib/IR/MDBuilder.cpp b/llvm/lib/IR/MDBuilder.cpp
index 35af8490287b2..fc59fda9fe221 100644
--- a/llvm/lib/IR/MDBuilder.cpp
+++ b/llvm/lib/IR/MDBuilder.cpp
@@ -150,6 +150,14 @@ MDNode *MDBuilder::mergeCallbackEncodings(MDNode *ExistingCallbacks,
return MDNode::get(Context, Ops);
}
+MDNode *MDBuilder::createRTTIPointerPrologue(Constant *PrologueSig,
+ Constant *RTTI) {
+ SmallVector<Metadata *, 4> Ops;
+ Ops.push_back(createConstant(PrologueSig));
+ Ops.push_back(createConstant(RTTI));
+ return MDNode::get(Context, Ops);
+}
+
MDNode *MDBuilder::createAnonymousAARoot(StringRef Name, MDNode *Extra) {
SmallVector<Metadata *, 3> Args(1, nullptr);
if (Extra)
diff --git a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index 673738ee931ec..5071f3bae0c56 100644
--- a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -1217,7 +1217,11 @@ static GlobalVariable *createPrivateGlobalForSourceLoc(Module &M,
/// Check if \p G has been created by a trusted compiler pass.
static bool GlobalWasGeneratedByCompiler(GlobalVariable *G) {
// Do not instrument @llvm.global_ctors, @llvm.used, etc.
- if (G->getName().startswith("llvm."))
+ if (G->getName().startswith("llvm.") ||
+ // Do not instrument gcov counter arrays.
+ G->getName().startswith("__llvm_gcov_ctr") ||
+ // Do not instrument rtti proxy symbols for function sanitizer.
+ G->getName().startswith("__llvm_rtti_proxy"))
return true;
// Do not instrument asan globals.
@@ -1226,10 +1230,6 @@ static bool GlobalWasGeneratedByCompiler(GlobalVariable *G) {
G->getName().startswith(kODRGenPrefix))
return true;
- // Do not instrument gcov counter arrays.
- if (G->getName() == "__llvm_gcov_ctr")
- return true;
-
return false;
}
diff --git a/llvm/test/CodeGen/X86/func-sanitizer.ll b/llvm/test/CodeGen/X86/func-sanitizer.ll
new file mode 100644
index 0000000000000..b8d96a346d0c5
--- /dev/null
+++ b/llvm/test/CodeGen/X86/func-sanitizer.ll
@@ -0,0 +1,18 @@
+; RUN: llc -mtriple=x86_64-unknown-linux-gnu < %s | FileCheck %s
+
+; CHECK: _Z3funv:
+; CHECK: .cfi_startproc
+; CHECK: .long 846595819
+; CHECK: .long .L__llvm_rtti_proxy-_Z3funv
+; CHECK: .L__llvm_rtti_proxy:
+; CHECK: .quad i
+; CHECK: .size .L__llvm_rtti_proxy, 8
+
+ at i = linkonce_odr constant i32 1
+ at __llvm_rtti_proxy = private unnamed_addr constant i32* @i
+
+define dso_local void @_Z3funv() !func_sanitize !0 {
+ ret void
+}
+
+!0 = !{i32 846595819, i32** @__llvm_rtti_proxy}
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