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[ubsan] Detect invalid unsigned pointer index expression (clang) 

Adding an unsigned offset to a base pointer has undefined behavior if
the result of the expression would precede the base. An example from
@regehr:

  int foo(char *p, unsigned offset) {
    return p + offset >= p; // This may be optimized to '1'.
  }

  foo(p, -1); // UB.

This patch extends the pointer overflow check in ubsan to detect invalid
unsigned pointer index expressions. It changes the instrumentation to
only permit non-negative offsets in pointer index expressions when all
of the GEP indices are unsigned.

Testing: check-llvm, check-clang run on a stage2, ubsan-instrumented
build.

Differential Revision: https://reviews.llvm.org/D33910

llvm-svn: 305216
This commit is contained in:
Vedant Kumar 2017-06-12 18:42:51 +00:00
parent 374b41a6aa
commit 6dbf4274a5
4 changed files with 110 additions and 52 deletions
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37
clang/lib/CodeGen/CGExpr.cpp
View File

@ -3002,10 +3002,11 @@ static llvm::Value *emitArraySubscriptGEP(CodeGenFunction &CGF,
llvm::Value *ptr,
ArrayRef<llvm::Value*> indices,
bool inbounds,
bool signedIndices,
SourceLocation loc,
const llvm::Twine &name = "arrayidx") {
if (inbounds) {
return CGF.EmitCheckedInBoundsGEP(ptr, indices, loc, name);
return CGF.EmitCheckedInBoundsGEP(ptr, indices, signedIndices, loc, name);
} else {
return CGF.Builder.CreateGEP(ptr, indices, name);
}
@ -3038,7 +3039,7 @@ static QualType getFixedSizeElementType(const ASTContext &ctx,
static Address emitArraySubscriptGEP(CodeGenFunction &CGF, Address addr,
ArrayRef<llvm::Value *> indices,
QualType eltType, bool inbounds,
SourceLocation loc,
bool signedIndices, SourceLocation loc,
const llvm::Twine &name = "arrayidx") {
// All the indices except that last must be zero.
#ifndef NDEBUG
@ -3058,8 +3059,8 @@ static Address emitArraySubscriptGEP(CodeGenFunction &CGF, Address addr,
CharUnits eltAlign =
getArrayElementAlign(addr.getAlignment(), indices.back(), eltSize);
llvm::Value *eltPtr =
emitArraySubscriptGEP(CGF, addr.getPointer(), indices, inbounds, loc, name);
llvm::Value *eltPtr = emitArraySubscriptGEP(
CGF, addr.getPointer(), indices, inbounds, signedIndices, loc, name);
return Address(eltPtr, eltAlign);
}
@ -3069,6 +3070,7 @@ LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E,
// in lexical order (this complexity is, sadly, required by C++17).
llvm::Value *IdxPre =
(E->getLHS() == E->getIdx()) ? EmitScalarExpr(E->getIdx()) : nullptr;
bool SignedIndices = false;
auto EmitIdxAfterBase = [&, IdxPre](bool Promote) -> llvm::Value * {
auto *Idx = IdxPre;
if (E->getLHS() != E->getIdx()) {
@ -3078,6 +3080,7 @@ LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E,
QualType IdxTy = E->getIdx()->getType();
bool IdxSigned = IdxTy->isSignedIntegerOrEnumerationType();
SignedIndices |= IdxSigned;
if (SanOpts.has(SanitizerKind::ArrayBounds))
EmitBoundsCheck(E, E->getBase(), Idx, IdxTy, Accessed);
@ -3113,7 +3116,7 @@ LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E,
QualType EltType = LV.getType()->castAs<VectorType>()->getElementType();
Addr = emitArraySubscriptGEP(*this, Addr, Idx, EltType, /*inbounds*/ true,
E->getExprLoc());
SignedIndices, E->getExprLoc());
return MakeAddrLValue(Addr, EltType, LV.getBaseInfo());
}
@ -3142,7 +3145,7 @@ LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E,
Addr = emitArraySubscriptGEP(*this, Addr, Idx, vla->getElementType(),
!getLangOpts().isSignedOverflowDefined(),
E->getExprLoc());
SignedIndices, E->getExprLoc());
} else if (const ObjCObjectType *OIT = E->getType()->getAs<ObjCObjectType>()){
// Indexing over an interface, as in "NSString *P; P[4];"
@ -3167,8 +3170,9 @@ LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E,
// Do the GEP.
CharUnits EltAlign =
getArrayElementAlign(Addr.getAlignment(), Idx, InterfaceSize);
llvm::Value *EltPtr = emitArraySubscriptGEP(
*this, Addr.getPointer(), ScaledIdx, false, E->getExprLoc());
llvm::Value *EltPtr =
emitArraySubscriptGEP(*this, Addr.getPointer(), ScaledIdx, false,
SignedIndices, E->getExprLoc());
Addr = Address(EltPtr, EltAlign);
// Cast back.
@ -3190,11 +3194,10 @@ LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E,
auto *Idx = EmitIdxAfterBase(/*Promote*/true);
// Propagate the alignment from the array itself to the result.
Addr = emitArraySubscriptGEP(*this, ArrayLV.getAddress(),
{CGM.getSize(CharUnits::Zero()), Idx},
E->getType(),
!getLangOpts().isSignedOverflowDefined(),
E->getExprLoc());
Addr = emitArraySubscriptGEP(
*this, ArrayLV.getAddress(), {CGM.getSize(CharUnits::Zero()), Idx},
E->getType(), !getLangOpts().isSignedOverflowDefined(), SignedIndices,
E->getExprLoc());
BaseInfo = ArrayLV.getBaseInfo();
} else {
// The base must be a pointer; emit it with an estimate of its alignment.
@ -3202,7 +3205,7 @@ LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E,
auto *Idx = EmitIdxAfterBase(/*Promote*/true);
Addr = emitArraySubscriptGEP(*this, Addr, Idx, E->getType(),
!getLangOpts().isSignedOverflowDefined(),
E->getExprLoc());
SignedIndices, E->getExprLoc());
}
LValue LV = MakeAddrLValue(Addr, E->getType(), BaseInfo);
@ -3375,7 +3378,7 @@ LValue CodeGenFunction::EmitOMPArraySectionExpr(const OMPArraySectionExpr *E,
Idx = Builder.CreateNSWMul(Idx, NumElements);
EltPtr = emitArraySubscriptGEP(*this, Base, Idx, VLA->getElementType(),
!getLangOpts().isSignedOverflowDefined(),
E->getExprLoc());
/*SignedIndices=*/false, E->getExprLoc());
} else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
// If this is A[i] where A is an array, the frontend will have decayed the
// base to be a ArrayToPointerDecay implicit cast. While correct, it is
@ -3395,14 +3398,14 @@ LValue CodeGenFunction::EmitOMPArraySectionExpr(const OMPArraySectionExpr *E,
EltPtr = emitArraySubscriptGEP(
*this, ArrayLV.getAddress(), {CGM.getSize(CharUnits::Zero()), Idx},
ResultExprTy, !getLangOpts().isSignedOverflowDefined(),
E->getExprLoc());
/*SignedIndices=*/false, E->getExprLoc());
BaseInfo = ArrayLV.getBaseInfo();
} else {
Address Base = emitOMPArraySectionBase(*this, E->getBase(), BaseInfo,
BaseTy, ResultExprTy, IsLowerBound);
EltPtr = emitArraySubscriptGEP(*this, Base, Idx, ResultExprTy,
!getLangOpts().isSignedOverflowDefined(),
E->getExprLoc());
/*SignedIndices=*/false, E->getExprLoc());
}
return MakeAddrLValue(EltPtr, ResultExprTy, BaseInfo);

51
clang/lib/CodeGen/CGExprScalar.cpp
View File

@ -1851,6 +1851,7 @@ ScalarExprEmitter::EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV,
llvm::Value *input;
int amount = (isInc ? 1 : -1);
bool signedIndex = !isInc;
if (const AtomicType *atomicTy = type->getAs<AtomicType>()) {
type = atomicTy->getValueType();
@ -1940,8 +1941,8 @@ ScalarExprEmitter::EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV,
if (CGF.getLangOpts().isSignedOverflowDefined())
value = Builder.CreateGEP(value, numElts, "vla.inc");
else
value = CGF.EmitCheckedInBoundsGEP(value, numElts, E->getExprLoc(),
"vla.inc");
value = CGF.EmitCheckedInBoundsGEP(value, numElts, signedIndex,
E->getExprLoc(), "vla.inc");
// Arithmetic on function pointers (!) is just +-1.
} else if (type->isFunctionType()) {
@ -1951,8 +1952,8 @@ ScalarExprEmitter::EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV,
if (CGF.getLangOpts().isSignedOverflowDefined())
value = Builder.CreateGEP(value, amt, "incdec.funcptr");
else
value = CGF.EmitCheckedInBoundsGEP(value, amt, E->getExprLoc(),
"incdec.funcptr");
value = CGF.EmitCheckedInBoundsGEP(value, amt, signedIndex,
E->getExprLoc(), "incdec.funcptr");
value = Builder.CreateBitCast(value, input->getType());
// For everything else, we can just do a simple increment.
@ -1961,8 +1962,8 @@ ScalarExprEmitter::EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV,
if (CGF.getLangOpts().isSignedOverflowDefined())
value = Builder.CreateGEP(value, amt, "incdec.ptr");
else
value = CGF.EmitCheckedInBoundsGEP(value, amt, E->getExprLoc(),
"incdec.ptr");
value = CGF.EmitCheckedInBoundsGEP(value, amt, signedIndex,
E->getExprLoc(), "incdec.ptr");
}
// Vector increment/decrement.
@ -2043,8 +2044,8 @@ ScalarExprEmitter::EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV,
if (CGF.getLangOpts().isSignedOverflowDefined())
value = Builder.CreateGEP(value, sizeValue, "incdec.objptr");
else
value = CGF.EmitCheckedInBoundsGEP(value, sizeValue, E->getExprLoc(),
"incdec.objptr");
value = CGF.EmitCheckedInBoundsGEP(value, sizeValue, signedIndex,
E->getExprLoc(), "incdec.objptr");
value = Builder.CreateBitCast(value, input->getType());
}
@ -2661,13 +2662,15 @@ static Value *emitPointerArithmetic(CodeGenFunction &CGF,
std::swap(pointerOperand, indexOperand);
}
bool isSigned = indexOperand->getType()->isSignedIntegerOrEnumerationType();
bool mayHaveNegativeGEPIndex = isSigned || isSubtraction;
unsigned width = cast<llvm::IntegerType>(index->getType())->getBitWidth();
auto &DL = CGF.CGM.getDataLayout();
auto PtrTy = cast<llvm::PointerType>(pointer->getType());
if (width != DL.getTypeSizeInBits(PtrTy)) {
// Zero-extend or sign-extend the pointer value according to
// whether the index is signed or not.
bool isSigned = indexOperand->getType()->isSignedIntegerOrEnumerationType();
index = CGF.Builder.CreateIntCast(index, DL.getIntPtrType(PtrTy), isSigned,
"idx.ext");
}
@ -2711,8 +2714,9 @@ static Value *emitPointerArithmetic(CodeGenFunction &CGF,
pointer = CGF.Builder.CreateGEP(pointer, index, "add.ptr");
} else {
index = CGF.Builder.CreateNSWMul(index, numElements, "vla.index");
pointer = CGF.EmitCheckedInBoundsGEP(pointer, index, op.E->getExprLoc(),
"add.ptr");
pointer =
CGF.EmitCheckedInBoundsGEP(pointer, index, mayHaveNegativeGEPIndex,
op.E->getExprLoc(), "add.ptr");
}
return pointer;
}
@ -2729,8 +2733,8 @@ static Value *emitPointerArithmetic(CodeGenFunction &CGF,
if (CGF.getLangOpts().isSignedOverflowDefined())
return CGF.Builder.CreateGEP(pointer, index, "add.ptr");
return CGF.EmitCheckedInBoundsGEP(pointer, index, op.E->getExprLoc(),
"add.ptr");
return CGF.EmitCheckedInBoundsGEP(pointer, index, mayHaveNegativeGEPIndex,
op.E->getExprLoc(), "add.ptr");
}
// Construct an fmuladd intrinsic to represent a fused mul-add of MulOp and
@ -3848,6 +3852,7 @@ LValue CodeGenFunction::EmitCompoundAssignmentLValue(
Value *CodeGenFunction::EmitCheckedInBoundsGEP(Value *Ptr,
ArrayRef<Value *> IdxList,
bool SignedIndices,
SourceLocation Loc,
const Twine &Name) {
Value *GEPVal = Builder.CreateInBoundsGEP(Ptr, IdxList, Name);
@ -3905,7 +3910,7 @@ Value *CodeGenFunction::EmitCheckedInBoundsGEP(Value *Ptr,
auto *ResultAndOverflow = Builder.CreateCall(
(Opcode == BO_Add) ? SAddIntrinsic : SMulIntrinsic, {LHS, RHS});
OffsetOverflows = Builder.CreateOr(
OffsetOverflows, Builder.CreateExtractValue(ResultAndOverflow, 1));
Builder.CreateExtractValue(ResultAndOverflow, 1), OffsetOverflows);
return Builder.CreateExtractValue(ResultAndOverflow, 0);
};
@ -3951,12 +3956,18 @@ Value *CodeGenFunction::EmitCheckedInBoundsGEP(Value *Ptr,
// 1) The total offset doesn't overflow, and
// 2) The sign of the difference between the computed address and the base
// pointer matches the sign of the total offset.
llvm::Value *PosOrZeroValid = Builder.CreateICmpUGE(ComputedGEP, IntPtr);
llvm::Value *NegValid = Builder.CreateICmpULT(ComputedGEP, IntPtr);
auto *PosOrZeroOffset = Builder.CreateICmpSGE(TotalOffset, Zero);
llvm::Value *ValidGEP = Builder.CreateAnd(
Builder.CreateNot(OffsetOverflows),
Builder.CreateSelect(PosOrZeroOffset, PosOrZeroValid, NegValid));
llvm::Value *ValidGEP;
auto *NoOffsetOverflow = Builder.CreateNot(OffsetOverflows);
auto *PosOrZeroValid = Builder.CreateICmpUGE(ComputedGEP, IntPtr);
if (SignedIndices) {
auto *PosOrZeroOffset = Builder.CreateICmpSGE(TotalOffset, Zero);
llvm::Value *NegValid = Builder.CreateICmpULT(ComputedGEP, IntPtr);
ValidGEP = Builder.CreateAnd(
Builder.CreateSelect(PosOrZeroOffset, PosOrZeroValid, NegValid),
NoOffsetOverflow);
} else {
ValidGEP = Builder.CreateAnd(PosOrZeroValid, NoOffsetOverflow);
}
llvm::Constant *StaticArgs[] = {EmitCheckSourceLocation(Loc)};
// Pass the computed GEP to the runtime to avoid emitting poisoned arguments.

2
clang/lib/CodeGen/CodeGenFunction.h
View File

@ -3554,8 +3554,10 @@ public:
/// Same as IRBuilder::CreateInBoundsGEP, but additionally emits a check to
/// detect undefined behavior when the pointer overflow sanitizer is enabled.
/// \p SignedIndices indicates whether any of the GEP indices are signed.
llvm::Value *EmitCheckedInBoundsGEP(llvm::Value *Ptr,
ArrayRef<llvm::Value *> IdxList,
bool SignedIndices,
SourceLocation Loc,
const Twine &Name = "");

72
clang/test/CodeGen/ubsan-pointer-overflow.m
View File

@ -5,23 +5,21 @@ void unary_arith(char *p) {
// CHECK: [[BASE:%.*]] = ptrtoint i8* {{.*}} to i64, !nosanitize
// CHECK-NEXT: [[COMPGEP:%.*]] = add i64 [[BASE]], 1, !nosanitize
// CHECK-NEXT: [[POSVALID:%.*]] = icmp uge i64 [[COMPGEP]], [[BASE]], !nosanitize
// CHECK-NEXT: [[NEGVALID:%.*]] = icmp ult i64 [[COMPGEP]], [[BASE]], !nosanitize
// CHECK-NEXT: [[DIFFVALID:%.*]] = select i1 true, i1 [[POSVALID]], i1 [[NEGVALID]], !nosanitize
// CHECK-NEXT: [[VALID:%.*]] = and i1 true, [[DIFFVALID]], !nosanitize
// CHECK-NEXT: br i1 [[VALID]]{{.*}}, !nosanitize
// CHECK-NEXT: br i1 [[POSVALID]]{{.*}}, !nosanitize
// CHECK: call void @__ubsan_handle_pointer_overflow{{.*}}, i64 [[BASE]], i64 [[COMPGEP]]){{.*}}, !nosanitize
++p;
// CHECK: ptrtoint i8* {{.*}} to i64, !nosanitize
// CHECK-NEXT: add i64 {{.*}}, -1, !nosanitize
// CHECK: select i1 false{{.*}}, !nosanitize
// CHECK-NEXT: and i1 true{{.*}}, !nosanitize
// CHECK: call void @__ubsan_handle_pointer_overflow{{.*}}
--p;
// CHECK-NOT: select
// CHECK: call void @__ubsan_handle_pointer_overflow{{.*}}
p++;
// CHECK: select
// CHECK: call void @__ubsan_handle_pointer_overflow{{.*}}
p--;
}
@ -30,22 +28,43 @@ void unary_arith(char *p) {
void binary_arith(char *p, int i) {
// CHECK: [[SMUL:%.*]] = call { i64, i1 } @llvm.smul.with.overflow.i64(i64 1, i64 %{{.*}}), !nosanitize
// CHECK-NEXT: [[SMULOFLOW:%.*]] = extractvalue { i64, i1 } [[SMUL]], 1, !nosanitize
// CHECK-NEXT: [[OFFSETOFLOW:%.*]] = or i1 false, [[SMULOFLOW]], !nosanitize
// CHECK-NEXT: [[SMULVAL:%.*]] = extractvalue { i64, i1 } [[SMUL]], 0, !nosanitize
// CHECK-NEXT: [[BASE:%.*]] = ptrtoint i8* {{.*}} to i64, !nosanitize
// CHECK-NEXT: [[COMPGEP:%.*]] = add i64 [[BASE]], [[SMULVAL]], !nosanitize
// CHECK-NEXT: [[OFFSETVALID:%.*]] = xor i1 [[SMULOFLOW]], true, !nosanitize
// CHECK-NEXT: [[POSVALID:%.*]] = icmp uge i64 [[COMPGEP]], [[BASE]], !nosanitize
// CHECK-NEXT: [[NEGVALID:%.*]] = icmp ult i64 [[COMPGEP]], [[BASE]], !nosanitize
// CHECK-NEXT: [[POSOFFSET:%.*]] = icmp sge i64 [[SMULVAL]], 0, !nosanitize
// CHECK-DAG: [[OFFSETVALID:%.*]] = xor i1 [[OFFSETOFLOW]], true, !nosanitize
// CHECK-DAG: [[DIFFVALID:%.*]] = select i1 [[POSOFFSET]], i1 [[POSVALID]], i1 [[NEGVALID]], !nosanitize
// CHECK: [[VALID:%.*]] = and i1 [[OFFSETVALID]], [[DIFFVALID]], !nosanitize
// CHECK-NEXT: [[NEGVALID:%.*]] = icmp ult i64 [[COMPGEP]], [[BASE]], !nosanitize
// CHECK-NEXT: [[DIFFVALID:%.*]] = select i1 [[POSOFFSET]], i1 [[POSVALID]], i1 [[NEGVALID]], !nosanitize
// CHECK: [[VALID:%.*]] = and i1 [[DIFFVALID]], [[OFFSETVALID]], !nosanitize
// CHECK-NEXT: br i1 [[VALID]]{{.*}}, !nosanitize
// CHECK: call void @__ubsan_handle_pointer_overflow{{.*}}, i64 [[BASE]], i64 [[COMPGEP]]){{.*}}, !nosanitize
p + i;
// CHECK: [[OFFSET:%.*]] = sub i64 0, {{.*}}
// CHECK-NEXT: getelementptr inbounds {{.*}} [[OFFSET]]
// CHECK: select
// CHECK: call void @__ubsan_handle_pointer_overflow{{.*}}
p - i;
}
// CHECK-LABEL: define void @binary_arith_unsigned
void binary_arith_unsigned(char *p, unsigned i) {
// CHECK: [[SMUL:%.*]] = call { i64, i1 } @llvm.smul.with.overflow.i64(i64 1, i64 %{{.*}}), !nosanitize
// CHECK-NEXT: [[SMULOFLOW:%.*]] = extractvalue { i64, i1 } [[SMUL]], 1, !nosanitize
// CHECK-NEXT: [[SMULVAL:%.*]] = extractvalue { i64, i1 } [[SMUL]], 0, !nosanitize
// CHECK-NEXT: [[BASE:%.*]] = ptrtoint i8* {{.*}} to i64, !nosanitize
// CHECK-NEXT: [[COMPGEP:%.*]] = add i64 [[BASE]], [[SMULVAL]], !nosanitize
// CHECK-NEXT: [[OFFSETVALID:%.*]] = xor i1 [[SMULOFLOW]], true, !nosanitize
// CHECK-NEXT: [[POSVALID:%.*]] = icmp uge i64 [[COMPGEP]], [[BASE]], !nosanitize
// CHECK: [[VALID:%.*]] = and i1 [[POSVALID]], [[OFFSETVALID]], !nosanitize
// CHECK-NEXT: br i1 [[VALID]]{{.*}}, !nosanitize
// CHECK: call void @__ubsan_handle_pointer_overflow{{.*}}, i64 [[BASE]], i64 [[COMPGEP]]){{.*}}, !nosanitize
p + i;
// CHECK: [[OFFSET:%.*]] = sub i64 0, {{.*}}
// CHECK-NEXT: getelementptr inbounds {{.*}} [[OFFSET]]
// CHECK: select
// CHECK: call void @__ubsan_handle_pointer_overflow{{.*}}
p - i;
}
@ -55,16 +74,15 @@ void fixed_len_array(int k) {
// CHECK: getelementptr inbounds [10 x [10 x i32]], [10 x [10 x i32]]* [[ARR:%.*]], i64 0, i64 [[IDXPROM:%.*]]
// CHECK-NEXT: [[SMUL:%.*]] = call { i64, i1 } @llvm.smul.with.overflow.i64(i64 40, i64 [[IDXPROM]]), !nosanitize
// CHECK-NEXT: [[SMULOFLOW:%.*]] = extractvalue { i64, i1 } [[SMUL]], 1, !nosanitize
// CHECK-NEXT: [[OFFSETOFLOW:%.*]] = or i1 false, [[SMULOFLOW]], !nosanitize
// CHECK-NEXT: [[SMULVAL:%.*]] = extractvalue { i64, i1 } [[SMUL]], 0, !nosanitize
// CHECK-NEXT: [[BASE:%.*]] = ptrtoint [10 x [10 x i32]]* [[ARR]] to i64, !nosanitize
// CHECK-NEXT: [[COMPGEP:%.*]] = add i64 [[BASE]], [[SMULVAL]], !nosanitize
// CHECK-NEXT: [[OFFSETVALID:%.*]] = xor i1 [[SMULOFLOW]], true, !nosanitize
// CHECK-NEXT: [[POSVALID:%.*]] = icmp uge i64 [[COMPGEP]], [[BASE]], !nosanitize
// CHECK-NEXT: [[NEGVALID:%.*]] = icmp ult i64 [[COMPGEP]], [[BASE]], !nosanitize
// CHECK-NEXT: [[POSOFFSET:%.*]] = icmp sge i64 [[SMULVAL]], 0, !nosanitize
// CHECK-DAG: [[OFFSETVALID:%.*]] = xor i1 [[OFFSETOFLOW]], true, !nosanitize
// CHECK-DAG: [[DIFFVALID:%.*]] = select i1 [[POSOFFSET]], i1 [[POSVALID]], i1 [[NEGVALID]], !nosanitize
// CHECK: [[VALID:%.*]] = and i1 [[OFFSETVALID]], [[DIFFVALID]], !nosanitize
// CHECK-NEXT: [[NEGVALID:%.*]] = icmp ult i64 [[COMPGEP]], [[BASE]], !nosanitize
// CHECK-NEXT: [[DIFFVALID:%.*]] = select i1 [[POSOFFSET]], i1 [[POSVALID]], i1 [[NEGVALID]], !nosanitize
// CHECK: [[VALID:%.*]] = and i1 [[DIFFVALID]], [[OFFSETVALID]], !nosanitize
// CHECK-NEXT: br i1 [[VALID]]{{.*}}, !nosanitize
// CHECK: call void @__ubsan_handle_pointer_overflow{{.*}}, i64 [[BASE]], i64 [[COMPGEP]]){{.*}}, !nosanitize
@ -101,6 +119,24 @@ void pointer_array(int **arr, int k) {
arr[k][k];
}
// CHECK-LABEL: define void @pointer_array_unsigned_indices
void pointer_array_unsigned_indices(int **arr, unsigned k) {
// CHECK-NOT: select
// CHECK: call void @__ubsan_handle_pointer_overflow{{.*}}
// CHECK-NOT: select
// CHECK: call void @__ubsan_handle_pointer_overflow{{.*}}
arr[k][k];
}
// CHECK-LABEL: define void @pointer_array_mixed_indices
void pointer_array_mixed_indices(int **arr, int i, unsigned j) {
// CHECK: select
// CHECK: call void @__ubsan_handle_pointer_overflow{{.*}}
// CHECK-NOT: select
// CHECK: call void @__ubsan_handle_pointer_overflow{{.*}}
arr[i][j];
}
struct S1 {
int pad1;
union {
@ -118,6 +154,7 @@ void struct_index(struct S1 *p) {
// CHECK: getelementptr inbounds %struct.S1, %struct.S1* [[P:%.*]], i64 10
// CHECK-NEXT: [[BASE:%.*]] = ptrtoint %struct.S1* [[P]] to i64, !nosanitize
// CHECK-NEXT: [[COMPGEP:%.*]] = add i64 [[BASE]], 240, !nosanitize
// CHECK: select
// CHECK: @__ubsan_handle_pointer_overflow{{.*}} i64 [[BASE]], i64 [[COMPGEP]]) {{.*}}, !nosanitize
// CHECK-NOT: @__ubsan_handle_pointer_overflow
@ -130,10 +167,12 @@ typedef void (*funcptr_t)(void);
// CHECK-LABEL: define void @function_pointer_arith
void function_pointer_arith(funcptr_t *p, int k) {
// CHECK: add i64 {{.*}}, 8, !nosanitize
// CHECK-NOT: select
// CHECK: @__ubsan_handle_pointer_overflow{{.*}}
++p;
// CHECK: @llvm.smul.with.overflow.i64(i64 8, i64 {{.*}}), !nosanitize
// CHECK: select
// CHECK: call void @__ubsan_handle_pointer_overflow{{.*}}
p + k;
}
@ -145,11 +184,13 @@ void variable_len_array_arith(int n, int k) {
// CHECK: getelementptr inbounds i32, i32* {{.*}}, i64 [[INC:%.*]]
// CHECK: @llvm.smul.with.overflow.i64(i64 4, i64 [[INC]]), !nosanitize
// CHECK-NOT: select
// CHECK: call void @__ubsan_handle_pointer_overflow{{.*}}
++p;
// CHECK: getelementptr inbounds i32, i32* {{.*}}, i64 [[IDXPROM:%.*]]
// CHECK: @llvm.smul.with.overflow.i64(i64 4, i64 [[IDXPROM]]), !nosanitize
// CHECK: select
// CHECK: call void @__ubsan_handle_pointer_overflow{{.*}}
p + k;
}
@ -157,6 +198,7 @@ void variable_len_array_arith(int n, int k) {
// CHECK-LABEL: define void @objc_id
void objc_id(id *p) {
// CHECK: add i64 {{.*}}, 8, !nosanitize
// CHECK-NOT: select
// CHECK: @__ubsan_handle_pointer_overflow{{.*}}
p++;
}