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committedOct 20, 2013
Implement function type checker for the undefined behavior sanitizer.
This uses function prefix data to store function type information at the function pointer. Differential Revision: http://llvm-reviews.chandlerc.com/D1338 llvm-svn: 193058
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‎clang/docs/UsersManual.rst

+2
Original file line numberDiff line numberDiff line change
@@ -921,6 +921,8 @@ are listed below.
921921
destination.
922922
- ``-fsanitize=float-divide-by-zero``: Floating point division by
923923
zero.
924+
- ``-fsanitize=function``: Indirect call of a function through a
925+
function pointer of the wrong type (C++ and x86/x86_64 only).
924926
- ``-fsanitize=integer-divide-by-zero``: Integer division by zero.
925927
- ``-fsanitize=null``: Use of a null pointer or creation of a null
926928
reference.

‎clang/include/clang/Basic/Sanitizers.def

+4-3
Original file line numberDiff line numberDiff line change
@@ -64,6 +64,7 @@ SANITIZER("bounds", Bounds)
6464
SANITIZER("enum", Enum)
6565
SANITIZER("float-cast-overflow", FloatCastOverflow)
6666
SANITIZER("float-divide-by-zero", FloatDivideByZero)
67+
SANITIZER("function", Function)
6768
SANITIZER("integer-divide-by-zero", IntegerDivideByZero)
6869
SANITIZER("null", Null)
6970
SANITIZER("object-size", ObjectSize)
@@ -84,9 +85,9 @@ SANITIZER("dataflow", DataFlow)
8485
// ABI or address space layout implications, and only catch undefined behavior.
8586
SANITIZER_GROUP("undefined", Undefined,
8687
Alignment | Bool | Bounds | Enum | FloatCastOverflow |
87-
FloatDivideByZero | IntegerDivideByZero | Null | ObjectSize |
88-
Return | Shift | SignedIntegerOverflow | Unreachable |
89-
VLABound | Vptr)
88+
FloatDivideByZero | Function | IntegerDivideByZero | Null |
89+
ObjectSize | Return | Shift | SignedIntegerOverflow |
90+
Unreachable | VLABound | Vptr)
9091

9192
// -fsanitize=undefined-trap (and its alias -fcatch-undefined-behavior) includes
9293
// all sanitizers included by -fsanitize=undefined, except those that require

‎clang/lib/CodeGen/CGBuiltin.cpp

+1-1
Original file line numberDiff line numberDiff line change
@@ -165,7 +165,7 @@ static Value *EmitFAbs(CodeGenFunction &CGF, Value *V, QualType ValTy) {
165165

166166
static RValue emitLibraryCall(CodeGenFunction &CGF, const FunctionDecl *Fn,
167167
const CallExpr *E, llvm::Value *calleeValue) {
168-
return CGF.EmitCall(E->getCallee()->getType(), calleeValue,
168+
return CGF.EmitCall(E->getCallee()->getType(), calleeValue, E->getLocStart(),
169169
ReturnValueSlot(), E->arg_begin(), E->arg_end(), Fn);
170170
}
171171

‎clang/lib/CodeGen/CGCUDARuntime.cpp

+2-2
Original file line numberDiff line numberDiff line change
@@ -44,8 +44,8 @@ RValue CGCUDARuntime::EmitCUDAKernelCallExpr(CodeGenFunction &CGF,
4444
}
4545

4646
llvm::Value *Callee = CGF.EmitScalarExpr(E->getCallee());
47-
CGF.EmitCall(E->getCallee()->getType(), Callee, ReturnValue,
48-
E->arg_begin(), E->arg_end(), TargetDecl);
47+
CGF.EmitCall(E->getCallee()->getType(), Callee, E->getLocStart(),
48+
ReturnValue, E->arg_begin(), E->arg_end(), TargetDecl);
4949
CGF.EmitBranch(ContBlock);
5050

5151
CGF.EmitBlock(ContBlock);

‎clang/lib/CodeGen/CGExpr.cpp

+48-2
Original file line numberDiff line numberDiff line change
@@ -2931,8 +2931,8 @@ RValue CodeGenFunction::EmitCallExpr(const CallExpr *E,
29312931
}
29322932

29332933
llvm::Value *Callee = EmitScalarExpr(E->getCallee());
2934-
return EmitCall(E->getCallee()->getType(), Callee, ReturnValue,
2935-
E->arg_begin(), E->arg_end(), TargetDecl);
2934+
return EmitCall(E->getCallee()->getType(), Callee, E->getLocStart(),
2935+
ReturnValue, E->arg_begin(), E->arg_end(), TargetDecl);
29362936
}
29372937

29382938
LValue CodeGenFunction::EmitBinaryOperatorLValue(const BinaryOperator *E) {
@@ -3103,6 +3103,7 @@ LValue CodeGenFunction::EmitStmtExprLValue(const StmtExpr *E) {
31033103
}
31043104

31053105
RValue CodeGenFunction::EmitCall(QualType CalleeType, llvm::Value *Callee,
3106+
SourceLocation CallLoc,
31063107
ReturnValueSlot ReturnValue,
31073108
CallExpr::const_arg_iterator ArgBeg,
31083109
CallExpr::const_arg_iterator ArgEnd,
@@ -3123,6 +3124,51 @@ RValue CodeGenFunction::EmitCall(QualType CalleeType, llvm::Value *Callee,
31233124
if (const FunctionDecl* FD = dyn_cast_or_null<const FunctionDecl>(TargetDecl))
31243125
ForceColumnInfo = FD->isInlineSpecified();
31253126

3127+
if (getLangOpts().CPlusPlus && SanOpts->Function &&
3128+
(!TargetDecl || !isa<FunctionDecl>(TargetDecl))) {
3129+
if (llvm::Constant *PrefixSig =
3130+
CGM.getTargetCodeGenInfo().getUBSanFunctionSignature(CGM)) {
3131+
llvm::Constant *FTRTTIConst =
3132+
CGM.GetAddrOfRTTIDescriptor(QualType(FnType, 0), /*ForEH=*/true);
3133+
llvm::Type *PrefixStructTyElems[] = {
3134+
PrefixSig->getType(),
3135+
FTRTTIConst->getType()
3136+
};
3137+
llvm::StructType *PrefixStructTy = llvm::StructType::get(
3138+
CGM.getLLVMContext(), PrefixStructTyElems, /*isPacked=*/true);
3139+
3140+
llvm::Value *CalleePrefixStruct = Builder.CreateBitCast(
3141+
Callee, llvm::PointerType::getUnqual(PrefixStructTy));
3142+
llvm::Value *CalleeSigPtr =
3143+
Builder.CreateConstGEP2_32(CalleePrefixStruct, 0, 0);
3144+
llvm::Value *CalleeSig = Builder.CreateLoad(CalleeSigPtr);
3145+
llvm::Value *CalleeSigMatch = Builder.CreateICmpEQ(CalleeSig, PrefixSig);
3146+
3147+
llvm::BasicBlock *Cont = createBasicBlock("cont");
3148+
llvm::BasicBlock *TypeCheck = createBasicBlock("typecheck");
3149+
Builder.CreateCondBr(CalleeSigMatch, TypeCheck, Cont);
3150+
3151+
EmitBlock(TypeCheck);
3152+
llvm::Value *CalleeRTTIPtr =
3153+
Builder.CreateConstGEP2_32(CalleePrefixStruct, 0, 1);
3154+
llvm::Value *CalleeRTTI = Builder.CreateLoad(CalleeRTTIPtr);
3155+
llvm::Value *CalleeRTTIMatch =
3156+
Builder.CreateICmpEQ(CalleeRTTI, FTRTTIConst);
3157+
llvm::Constant *StaticData[] = {
3158+
EmitCheckSourceLocation(CallLoc),
3159+
EmitCheckTypeDescriptor(CalleeType)
3160+
};
3161+
EmitCheck(CalleeRTTIMatch,
3162+
"function_type_mismatch",
3163+
StaticData,
3164+
Callee,
3165+
CRK_Recoverable);
3166+
3167+
Builder.CreateBr(Cont);
3168+
EmitBlock(Cont);
3169+
}
3170+
}
3171+
31263172
CallArgList Args;
31273173
EmitCallArgs(Args, dyn_cast<FunctionProtoType>(FnType), ArgBeg, ArgEnd,
31283174
ForceColumnInfo);

‎clang/lib/CodeGen/CGExprCXX.cpp

+2-1
Original file line numberDiff line numberDiff line change
@@ -86,7 +86,8 @@ RValue CodeGenFunction::EmitCXXMemberCallExpr(const CXXMemberCallExpr *CE,
8686
// The method is static, emit it as we would a regular call.
8787
llvm::Value *Callee = CGM.GetAddrOfFunction(MD);
8888
return EmitCall(getContext().getPointerType(MD->getType()), Callee,
89-
ReturnValue, CE->arg_begin(), CE->arg_end());
89+
CE->getLocStart(), ReturnValue, CE->arg_begin(),
90+
CE->arg_end());
9091
}
9192

9293
// Compute the object pointer.

‎clang/lib/CodeGen/CodeGenFunction.cpp

+17
Original file line numberDiff line numberDiff line change
@@ -16,6 +16,7 @@
1616
#include "CGCXXABI.h"
1717
#include "CGDebugInfo.h"
1818
#include "CodeGenModule.h"
19+
#include "TargetInfo.h"
1920
#include "clang/AST/ASTContext.h"
2021
#include "clang/AST/Decl.h"
2122
#include "clang/AST/DeclCXX.h"
@@ -519,6 +520,22 @@ void CodeGenFunction::StartFunction(GlobalDecl GD,
519520
EmitOpenCLKernelMetadata(FD, Fn);
520521
}
521522

523+
// If we are checking function types, emit a function type signature as
524+
// prefix data.
525+
if (getLangOpts().CPlusPlus && SanOpts->Function) {
526+
if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(D)) {
527+
if (llvm::Constant *PrefixSig =
528+
CGM.getTargetCodeGenInfo().getUBSanFunctionSignature(CGM)) {
529+
llvm::Constant *FTRTTIConst =
530+
CGM.GetAddrOfRTTIDescriptor(FD->getType(), /*ForEH=*/true);
531+
llvm::Constant *PrefixStructElems[] = { PrefixSig, FTRTTIConst };
532+
llvm::Constant *PrefixStructConst =
533+
llvm::ConstantStruct::getAnon(PrefixStructElems, /*Packed=*/true);
534+
Fn->setPrefixData(PrefixStructConst);
535+
}
536+
}
537+
}
538+
522539
llvm::BasicBlock *EntryBB = createBasicBlock("entry", CurFn);
523540

524541
// Create a marker to make it easy to insert allocas into the entryblock

‎clang/lib/CodeGen/CodeGenFunction.h

+1
Original file line numberDiff line numberDiff line change
@@ -2073,6 +2073,7 @@ class CodeGenFunction : public CodeGenTypeCache {
20732073
llvm::Instruction **callOrInvoke = 0);
20742074

20752075
RValue EmitCall(QualType FnType, llvm::Value *Callee,
2076+
SourceLocation CallLoc,
20762077
ReturnValueSlot ReturnValue,
20772078
CallExpr::const_arg_iterator ArgBeg,
20782079
CallExpr::const_arg_iterator ArgEnd,

‎clang/lib/CodeGen/TargetInfo.cpp

+16
Original file line numberDiff line numberDiff line change
@@ -601,6 +601,14 @@ class X86_32TargetCodeGenInfo : public TargetCodeGenInfo {
601601
return X86AdjustInlineAsmType(CGF, Constraint, Ty);
602602
}
603603

604+
llvm::Constant *getUBSanFunctionSignature(CodeGen::CodeGenModule &CGM) const {
605+
unsigned Sig = (0xeb << 0) | // jmp rel8
606+
(0x06 << 8) | // .+0x08
607+
('F' << 16) |
608+
('T' << 24);
609+
return llvm::ConstantInt::get(CGM.Int32Ty, Sig);
610+
}
611+
604612
};
605613

606614
}
@@ -1284,6 +1292,14 @@ class X86_64TargetCodeGenInfo : public TargetCodeGenInfo {
12841292
return TargetCodeGenInfo::isNoProtoCallVariadic(args, fnType);
12851293
}
12861294

1295+
llvm::Constant *getUBSanFunctionSignature(CodeGen::CodeGenModule &CGM) const {
1296+
unsigned Sig = (0xeb << 0) | // jmp rel8
1297+
(0x0a << 8) | // .+0x0c
1298+
('F' << 16) |
1299+
('T' << 24);
1300+
return llvm::ConstantInt::get(CGM.Int32Ty, Sig);
1301+
}
1302+
12871303
};
12881304

12891305
static std::string qualifyWindowsLibrary(llvm::StringRef Lib) {

‎clang/lib/CodeGen/TargetInfo.h

+8
Original file line numberDiff line numberDiff line change
@@ -21,6 +21,7 @@
2121
#include "llvm/ADT/SmallString.h"
2222

2323
namespace llvm {
24+
class Constant;
2425
class GlobalValue;
2526
class Type;
2627
class Value;
@@ -136,6 +137,13 @@ namespace clang {
136137
return "";
137138
}
138139

140+
/// Return a constant used by UBSan as a signature to identify functions
141+
/// possessing type information, or 0 if the platform is unsupported.
142+
virtual llvm::Constant *getUBSanFunctionSignature(
143+
CodeGen::CodeGenModule &CGM) const {
144+
return 0;
145+
}
146+
139147
/// Determine whether a call to an unprototyped functions under
140148
/// the given calling convention should use the variadic
141149
/// convention or the non-variadic convention.

‎clang/test/CodeGenCXX/catch-undef-behavior.cpp

+19-1
Original file line numberDiff line numberDiff line change
@@ -1,4 +1,4 @@
1-
// RUN: %clang_cc1 -std=c++11 -fsanitize=signed-integer-overflow,integer-divide-by-zero,float-divide-by-zero,shift,unreachable,return,vla-bound,alignment,null,vptr,object-size,float-cast-overflow,bool,enum,bounds -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck %s
1+
// RUN: %clang_cc1 -std=c++11 -fsanitize=signed-integer-overflow,integer-divide-by-zero,float-divide-by-zero,shift,unreachable,return,vla-bound,alignment,null,vptr,object-size,float-cast-overflow,bool,enum,bounds,function -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck %s
22

33
struct S {
44
double d;
@@ -372,6 +372,24 @@ void downcast_reference(B &b) {
372372
// CHECK-NEXT: br i1 [[AND]]
373373
}
374374

375+
// CHECK-LABEL: @_Z22indirect_function_callPFviE({{.*}} prefix <{ i32, i8* }> <{ i32 1413876459, i8* bitcast ({ i8*, i8* }* @_ZTIFvPFviEE to i8*) }>
376+
void indirect_function_call(void (*p)(int)) {
377+
// CHECK: [[PTR:%[0-9]*]] = bitcast void (i32)* {{.*}} to <{ i32, i8* }>*
378+
379+
// Signature check
380+
// CHECK-NEXT: [[SIGPTR:%[0-9]*]] = getelementptr <{ i32, i8* }>* [[PTR]], i32 0, i32 0
381+
// CHECK-NEXT: [[SIG:%[0-9]*]] = load i32* [[SIGPTR]]
382+
// CHECK-NEXT: [[SIGCMP:%[0-9]*]] = icmp eq i32 [[SIG]], 1413876459
383+
// CHECK-NEXT: br i1 [[SIGCMP]]
384+
385+
// RTTI pointer check
386+
// CHECK: [[RTTIPTR:%[0-9]*]] = getelementptr <{ i32, i8* }>* [[PTR]], i32 0, i32 1
387+
// CHECK-NEXT: [[RTTI:%[0-9]*]] = load i8** [[RTTIPTR]]
388+
// CHECK-NEXT: [[RTTICMP:%[0-9]*]] = icmp eq i8* [[RTTI]], bitcast ({ i8*, i8* }* @_ZTIFviE to i8*)
389+
// CHECK-NEXT: br i1 [[RTTICMP]]
390+
p(42);
391+
}
392+
375393
namespace CopyValueRepresentation {
376394
// CHECK-LABEL: define {{.*}} @_ZN23CopyValueRepresentation2S3aSERKS0_
377395
// CHECK-NOT: call {{.*}} @__ubsan_handle_load_invalid_value

‎clang/test/Driver/fsanitize.c

+2-2
Original file line numberDiff line numberDiff line change
@@ -5,13 +5,13 @@
55
// CHECK-UNDEFINED-TRAP: "-fsanitize-undefined-trap-on-error"
66

77
// RUN: %clang -target x86_64-linux-gnu -fsanitize=undefined %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-UNDEFINED
8-
// CHECK-UNDEFINED: "-fsanitize={{((signed-integer-overflow|integer-divide-by-zero|float-divide-by-zero|shift|unreachable|return|vla-bound|alignment|null|vptr|object-size|float-cast-overflow|bounds|enum|bool),?){15}"}}
8+
// CHECK-UNDEFINED: "-fsanitize={{((signed-integer-overflow|integer-divide-by-zero|float-divide-by-zero|function|shift|unreachable|return|vla-bound|alignment|null|vptr|object-size|float-cast-overflow|bounds|enum|bool),?){16}"}}
99

1010
// RUN: %clang -target x86_64-linux-gnu -fsanitize=integer %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-INTEGER
1111
// CHECK-INTEGER: "-fsanitize={{((signed-integer-overflow|unsigned-integer-overflow|integer-divide-by-zero|shift),?){4}"}}
1212

1313
// RUN: %clang -target x86_64-linux-gnu -fsanitize=thread,undefined -fno-thread-sanitizer -fno-sanitize=float-cast-overflow,vptr,bool,enum %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-PARTIAL-UNDEFINED
14-
// CHECK-PARTIAL-UNDEFINED: "-fsanitize={{((signed-integer-overflow|integer-divide-by-zero|float-divide-by-zero|shift|unreachable|return|vla-bound|alignment|null|object-size|bounds),?){11}"}}
14+
// CHECK-PARTIAL-UNDEFINED: "-fsanitize={{((signed-integer-overflow|integer-divide-by-zero|float-divide-by-zero|function|shift|unreachable|return|vla-bound|alignment|null|object-size|bounds),?){12}"}}
1515

1616
// RUN: %clang -target x86_64-linux-gnu -fsanitize=address-full %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-ASAN-FULL
1717
// CHECK-ASAN-FULL: "-fsanitize={{((address|init-order|use-after-return|use-after-scope),?){4}"}}

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