//===-- ubsan_handlers.cc -------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Error logging entry points for the UBSan runtime.
//
//===----------------------------------------------------------------------===//
#include "ubsan_platform.h"
#if CAN_SANITIZE_UB
#include "ubsan_handlers.h"
#include "ubsan_diag.h"
#include "sanitizer_common/sanitizer_common.h"
using namespace __sanitizer;
using namespace __ubsan;
namespace __ubsan {
bool ignoreReport(SourceLocation SLoc, ReportOptions Opts, ErrorType ET) {
// We are not allowed to skip error report: if we are in unrecoverable
// handler, we have to terminate the program right now, and therefore
// have to print some diagnostic.
//
// Even if source location is disabled, it doesn't mean that we have
// already report an error to the user: some concurrently running
// thread could have acquired it, but not yet printed the report.
if (Opts.FromUnrecoverableHandler)
return false;
return SLoc.isDisabled() || IsPCSuppressed(ET, Opts.pc, SLoc.getFilename());
}
const char *TypeCheckKinds[] = {
"load of", "store to", "reference binding to", "member access within",
"member call on", "constructor call on", "downcast of", "downcast of",
"upcast of", "cast to virtual base of"};
}
static void handleTypeMismatchImpl(TypeMismatchData *Data, ValueHandle Pointer,
ReportOptions Opts) {
Location Loc = Data->Loc.acquire();
ErrorType ET;
if (!Pointer)
ET = ErrorType::NullPointerUse;
else if (Data->Alignment && (Pointer & (Data->Alignment - 1)))
ET = ErrorType::MisalignedPointerUse;
else
ET = ErrorType::InsufficientObjectSize;
// Use the SourceLocation from Data to track deduplication, even if it's
// invalid.
if (ignoreReport(Loc.getSourceLocation(), Opts, ET))
return;
SymbolizedStackHolder FallbackLoc;
if (Data->Loc.isInvalid()) {
FallbackLoc.reset(getCallerLocation(Opts.pc));
Loc = FallbackLoc;
}
ScopedReport R(Opts, Loc, ET);
switch (ET) {
case ErrorType::NullPointerUse:
Diag(Loc, DL_Error, "%0 null pointer of type %1")
<< TypeCheckKinds[Data->TypeCheckKind] << Data->Type;
break;
case ErrorType::MisalignedPointerUse:
Diag(Loc, DL_Error, "%0 misaligned address %1 for type %3, "
"which requires %2 byte alignment")
<< TypeCheckKinds[Data->TypeCheckKind] << (void *)Pointer
<< Data->Alignment << Data->Type;
break;
case ErrorType::InsufficientObjectSize:
Diag(Loc, DL_Error, "%0 address %1 with insufficient space "
"for an object of type %2")
<< TypeCheckKinds[Data->TypeCheckKind] << (void *)Pointer << Data->Type;
break;
default:
UNREACHABLE("unexpected error type!");
}
if (Pointer)
Diag(Pointer, DL_Note, "pointer points here");
}
void __ubsan::__ubsan_handle_type_mismatch(TypeMismatchData *Data,
ValueHandle Pointer) {
GET_REPORT_OPTIONS(false);
handleTypeMismatchImpl(Data, Pointer, Opts);
}
void __ubsan::__ubsan_handle_type_mismatch_abort(TypeMismatchData *Data,
ValueHandle Pointer) {
GET_REPORT_OPTIONS(true);
handleTypeMismatchImpl(Data, Pointer, Opts);
Die();
}
/// \brief Common diagnostic emission for various forms of integer overflow.
template <typename T>
static void handleIntegerOverflowImpl(OverflowData *Data, ValueHandle LHS,
const char *Operator, T RHS,
ReportOptions Opts) {
SourceLocation Loc = Data->Loc.acquire();
bool IsSigned = Data->Type.isSignedIntegerTy();
ErrorType ET = IsSigned ? ErrorType::SignedIntegerOverflow
: ErrorType::UnsignedIntegerOverflow;
if (ignoreReport(Loc, Opts, ET))
return;
ScopedReport R(Opts, Loc, ET);
Diag(Loc, DL_Error, "%0 integer overflow: "
"%1 %2 %3 cannot be represented in type %4")
<< (IsSigned ? "signed" : "unsigned")
<< Value(Data->Type, LHS) << Operator << RHS << Data->Type;
}
#define UBSAN_OVERFLOW_HANDLER(handler_name, op, unrecoverable) \
void __ubsan::handler_name(OverflowData *Data, ValueHandle LHS, \
ValueHandle RHS) { \
GET_REPORT_OPTIONS(unrecoverable); \
handleIntegerOverflowImpl(Data, LHS, op, Value(Data->Type, RHS), Opts); \
if (unrecoverable) \
Die(); \
}
UBSAN_OVERFLOW_HANDLER(__ubsan_handle_add_overflow, "+", false)
UBSAN_OVERFLOW_HANDLER(__ubsan_handle_add_overflow_abort, "+", true)
UBSAN_OVERFLOW_HANDLER(__ubsan_handle_sub_overflow, "-", false)
UBSAN_OVERFLOW_HANDLER(__ubsan_handle_sub_overflow_abort, "-", true)
UBSAN_OVERFLOW_HANDLER(__ubsan_handle_mul_overflow, "*", false)
UBSAN_OVERFLOW_HANDLER(__ubsan_handle_mul_overflow_abort, "*", true)
static void handleNegateOverflowImpl(OverflowData *Data, ValueHandle OldVal,
ReportOptions Opts) {
SourceLocation Loc = Data->Loc.acquire();
bool IsSigned = Data->Type.isSignedIntegerTy();
ErrorType ET = IsSigned ? ErrorType::SignedIntegerOverflow
: ErrorType::UnsignedIntegerOverflow;
if (ignoreReport(Loc, Opts, ET))
return;
ScopedReport R(Opts, Loc, ET);
if (IsSigned)
Diag(Loc, DL_Error,
"negation of %0 cannot be represented in type %1; "
"cast to an unsigned type to negate this value to itself")
<< Value(Data->Type, OldVal) << Data->Type;
else
Diag(Loc, DL_Error, "negation of %0 cannot be represented in type %1")
<< Value(Data->Type, OldVal) << Data->Type;
}
void __ubsan::__ubsan_handle_negate_overflow(OverflowData *Data,
ValueHandle OldVal) {
GET_REPORT_OPTIONS(false);
handleNegateOverflowImpl(Data, OldVal, Opts);
}
void __ubsan::__ubsan_handle_negate_overflow_abort(OverflowData *Data,
ValueHandle OldVal) {
GET_REPORT_OPTIONS(true);
handleNegateOverflowImpl(Data, OldVal, Opts);
Die();
}
static void handleDivremOverflowImpl(OverflowData *Data, ValueHandle LHS,
ValueHandle RHS, ReportOptions Opts) {
SourceLocation Loc = Data->Loc.acquire();
Value LHSVal(Data->Type, LHS);
Value RHSVal(Data->Type, RHS);
ErrorType ET;
if (RHSVal.isMinusOne())
ET = ErrorType::SignedIntegerOverflow;
else if (Data->Type.isIntegerTy())
ET = ErrorType::IntegerDivideByZero;
else
ET = ErrorType::FloatDivideByZero;
if (ignoreReport(Loc, Opts, ET))
return;
ScopedReport R(Opts, Loc, ET);
switch (ET) {
case ErrorType::SignedIntegerOverflow:
Diag(Loc, DL_Error, "division of %0 by -1 cannot be represented in type %1")
<< LHSVal << Data->Type;
break;
default:
Diag(Loc, DL_Error, "division by zero");
break;
}
}
void __ubsan::__ubsan_handle_divrem_overflow(OverflowData *Data,
ValueHandle LHS, ValueHandle RHS) {
GET_REPORT_OPTIONS(false);
handleDivremOverflowImpl(Data, LHS, RHS, Opts);
}
void __ubsan::__ubsan_handle_divrem_overflow_abort(OverflowData *Data,
ValueHandle LHS,
ValueHandle RHS) {
GET_REPORT_OPTIONS(true);
handleDivremOverflowImpl(Data, LHS, RHS, Opts);
Die();
}
static void handleShiftOutOfBoundsImpl(ShiftOutOfBoundsData *Data,
ValueHandle LHS, ValueHandle RHS,
ReportOptions Opts) {
SourceLocation Loc = Data->Loc.acquire();
Value LHSVal(Data->LHSType, LHS);
Value RHSVal(Data->RHSType, RHS);
ErrorType ET;
if (RHSVal.isNegative() ||
RHSVal.getPositiveIntValue() >= Data->LHSType.getIntegerBitWidth())
ET = ErrorType::InvalidShiftExponent;
else
ET = ErrorType::InvalidShiftBase;
if (ignoreReport(Loc, Opts, ET))
return;
ScopedReport R(Opts, Loc, ET);
if (ET == ErrorType::InvalidShiftExponent) {
if (RHSVal.isNegative())
Diag(Loc, DL_Error, "shift exponent %0 is negative") << RHSVal;
else
Diag(Loc, DL_Error, "shift exponent %0 is too large for %1-bit type %2")
<< RHSVal << Data->LHSType.getIntegerBitWidth() << Data->LHSType;
} else {
if (LHSVal.isNegative())
Diag(Loc, DL_Error, "left shift of negative value %0") << LHSVal;
else
Diag(Loc, DL_Error,
"left shift of %0 by %1 places cannot be represented in type %2")
<< LHSVal << RHSVal << Data->LHSType;
}
}
void __ubsan::__ubsan_handle_shift_out_of_bounds(ShiftOutOfBoundsData *Data,
ValueHandle LHS,
ValueHandle RHS) {
GET_REPORT_OPTIONS(false);
handleShiftOutOfBoundsImpl(Data, LHS, RHS, Opts);
}
void __ubsan::__ubsan_handle_shift_out_of_bounds_abort(
ShiftOutOfBoundsData *Data,
ValueHandle LHS,
ValueHandle RHS) {
GET_REPORT_OPTIONS(true);
handleShiftOutOfBoundsImpl(Data, LHS, RHS, Opts);
Die();
}
static void handleOutOfBoundsImpl(OutOfBoundsData *Data, ValueHandle Index,
ReportOptions Opts) {
SourceLocation Loc = Data->Loc.acquire();
ErrorType ET = ErrorType::OutOfBoundsIndex;
if (ignoreReport(Loc, Opts, ET))
return;
ScopedReport R(Opts, Loc, ET);
Value IndexVal(Data->IndexType, Index);
Diag(Loc, DL_Error, "index %0 out of bounds for type %1")
<< IndexVal << Data->ArrayType;
}
void __ubsan::__ubsan_handle_out_of_bounds(OutOfBoundsData *Data,
ValueHandle Index) {
GET_REPORT_OPTIONS(false);
handleOutOfBoundsImpl(Data, Index, Opts);
}
void __ubsan::__ubsan_handle_out_of_bounds_abort(OutOfBoundsData *Data,
ValueHandle Index) {
GET_REPORT_OPTIONS(true);
handleOutOfBoundsImpl(Data, Index, Opts);
Die();
}
static void handleBuiltinUnreachableImpl(UnreachableData *Data,
ReportOptions Opts) {
ScopedReport R(Opts, Data->Loc, ErrorType::UnreachableCall);
Diag(Data->Loc, DL_Error, "execution reached a __builtin_unreachable() call");
}
void __ubsan::__ubsan_handle_builtin_unreachable(UnreachableData *Data) {
GET_REPORT_OPTIONS(true);
handleBuiltinUnreachableImpl(Data, Opts);
Die();
}
static void handleMissingReturnImpl(UnreachableData *Data, ReportOptions Opts) {
ScopedReport R(Opts, Data->Loc, ErrorType::MissingReturn);
Diag(Data->Loc, DL_Error,
"execution reached the end of a value-returning function "
"without returning a value");
}
void __ubsan::__ubsan_handle_missing_return(UnreachableData *Data) {
GET_REPORT_OPTIONS(true);
handleMissingReturnImpl(Data, Opts);
Die();
}
static void handleVLABoundNotPositive(VLABoundData *Data, ValueHandle Bound,
ReportOptions Opts) {
SourceLocation Loc = Data->Loc.acquire();
ErrorType ET = ErrorType::NonPositiveVLAIndex;
if (ignoreReport(Loc, Opts, ET))
return;
ScopedReport R(Opts, Loc, ET);
Diag(Loc, DL_Error, "variable length array bound evaluates to "
"non-positive value %0")
<< Value(Data->Type, Bound);
}
void __ubsan::__ubsan_handle_vla_bound_not_positive(VLABoundData *Data,
ValueHandle Bound) {
GET_REPORT_OPTIONS(false);
handleVLABoundNotPositive(Data, Bound, Opts);
}
void __ubsan::__ubsan_handle_vla_bound_not_positive_abort(VLABoundData *Data,
ValueHandle Bound) {
GET_REPORT_OPTIONS(true);
handleVLABoundNotPositive(Data, Bound, Opts);
Die();
}
static bool looksLikeFloatCastOverflowDataV1(void *Data) {
// First field is either a pointer to filename or a pointer to a
// TypeDescriptor.
u8 *FilenameOrTypeDescriptor;
internal_memcpy(&FilenameOrTypeDescriptor, Data,
sizeof(FilenameOrTypeDescriptor));
// Heuristic: For float_cast_overflow, the TypeKind will be either TK_Integer
// (0x0), TK_Float (0x1) or TK_Unknown (0xff). If both types are known,
// adding both bytes will be 0 or 1 (for BE or LE). If it were a filename,
// adding two printable characters will not yield such a value. Otherwise,
// if one of them is 0xff, this is most likely TK_Unknown type descriptor.
u16 MaybeFromTypeKind =
FilenameOrTypeDescriptor[0] + FilenameOrTypeDescriptor[1];
return MaybeFromTypeKind < 2 || FilenameOrTypeDescriptor[0] == 0xff ||
FilenameOrTypeDescriptor[1] == 0xff;
}
static void handleFloatCastOverflow(void *DataPtr, ValueHandle From,
ReportOptions Opts) {
SymbolizedStackHolder CallerLoc;
Location Loc;
const TypeDescriptor *FromType, *ToType;
ErrorType ET = ErrorType::FloatCastOverflow;
if (looksLikeFloatCastOverflowDataV1(DataPtr)) {
auto Data = reinterpret_cast<FloatCastOverflowData *>(DataPtr);
CallerLoc.reset(getCallerLocation(Opts.pc));
Loc = CallerLoc;
FromType = &Data->FromType;
ToType = &Data->ToType;
} else {
auto Data = reinterpret_cast<FloatCastOverflowDataV2 *>(DataPtr);
SourceLocation SLoc = Data->Loc.acquire();
if (ignoreReport(SLoc, Opts, ET))
return;
Loc = SLoc;
FromType = &Data->FromType;
ToType = &Data->ToType;
}
ScopedReport R(Opts, Loc, ET);
Diag(Loc, DL_Error,
"value %0 is outside the range of representable values of type %2")
<< Value(*FromType, From) << *FromType << *ToType;
}
void __ubsan::__ubsan_handle_float_cast_overflow(void *Data, ValueHandle From) {
GET_REPORT_OPTIONS(false);
handleFloatCastOverflow(Data, From, Opts);
}
void __ubsan::__ubsan_handle_float_cast_overflow_abort(void *Data,
ValueHandle From) {
GET_REPORT_OPTIONS(true);
handleFloatCastOverflow(Data, From, Opts);
Die();
}
static void handleLoadInvalidValue(InvalidValueData *Data, ValueHandle Val,
ReportOptions Opts) {
SourceLocation Loc = Data->Loc.acquire();
// This check could be more precise if we used different handlers for
// -fsanitize=bool and -fsanitize=enum.
bool IsBool = (0 == internal_strcmp(Data->Type.getTypeName(), "'bool'"));
ErrorType ET =
IsBool ? ErrorType::InvalidBoolLoad : ErrorType::InvalidEnumLoad;
if (ignoreReport(Loc, Opts, ET))
return;
ScopedReport R(Opts, Loc, ET);
Diag(Loc, DL_Error,
"load of value %0, which is not a valid value for type %1")
<< Value(Data->Type, Val) << Data->Type;
}
void __ubsan::__ubsan_handle_load_invalid_value(InvalidValueData *Data,
ValueHandle Val) {
GET_REPORT_OPTIONS(false);
handleLoadInvalidValue(Data, Val, Opts);
}
void __ubsan::__ubsan_handle_load_invalid_value_abort(InvalidValueData *Data,
ValueHandle Val) {
GET_REPORT_OPTIONS(true);
handleLoadInvalidValue(Data, Val, Opts);
Die();
}
static void handleFunctionTypeMismatch(FunctionTypeMismatchData *Data,
ValueHandle Function,
ReportOptions Opts) {
SourceLocation CallLoc = Data->Loc.acquire();
ErrorType ET = ErrorType::FunctionTypeMismatch;
if (ignoreReport(CallLoc, Opts, ET))
return;
ScopedReport R(Opts, CallLoc, ET);
SymbolizedStackHolder FLoc(getSymbolizedLocation(Function));
const char *FName = FLoc.get()->info.function;
if (!FName)
FName = "(unknown)";
Diag(CallLoc, DL_Error,
"call to function %0 through pointer to incorrect function type %1")
<< FName << Data->Type;
Diag(FLoc, DL_Note, "%0 defined here") << FName;
}
void
__ubsan::__ubsan_handle_function_type_mismatch(FunctionTypeMismatchData *Data,
ValueHandle Function) {
GET_REPORT_OPTIONS(false);
handleFunctionTypeMismatch(Data, Function, Opts);
}
void __ubsan::__ubsan_handle_function_type_mismatch_abort(
FunctionTypeMismatchData *Data, ValueHandle Function) {
GET_REPORT_OPTIONS(true);
handleFunctionTypeMismatch(Data, Function, Opts);
Die();
}
static void handleNonNullReturn(NonNullReturnData *Data, ReportOptions Opts) {
SourceLocation Loc = Data->Loc.acquire();
ErrorType ET = ErrorType::InvalidNullReturn;
if (ignoreReport(Loc, Opts, ET))
return;
ScopedReport R(Opts, Loc, ET);
Diag(Loc, DL_Error, "null pointer returned from function declared to never "
"return null");
if (!Data->AttrLoc.isInvalid())
Diag(Data->AttrLoc, DL_Note, "returns_nonnull attribute specified here");
}
void __ubsan::__ubsan_handle_nonnull_return(NonNullReturnData *Data) {
GET_REPORT_OPTIONS(false);
handleNonNullReturn(Data, Opts);
}
void __ubsan::__ubsan_handle_nonnull_return_abort(NonNullReturnData *Data) {
GET_REPORT_OPTIONS(true);
handleNonNullReturn(Data, Opts);
Die();
}
static void handleNonNullArg(NonNullArgData *Data, ReportOptions Opts) {
SourceLocation Loc = Data->Loc.acquire();
ErrorType ET = ErrorType::InvalidNullArgument;
if (ignoreReport(Loc, Opts, ET))
return;
ScopedReport R(Opts, Loc, ET);
Diag(Loc, DL_Error, "null pointer passed as argument %0, which is declared to "
"never be null") << Data->ArgIndex;
if (!Data->AttrLoc.isInvalid())
Diag(Data->AttrLoc, DL_Note, "nonnull attribute specified here");
}
void __ubsan::__ubsan_handle_nonnull_arg(NonNullArgData *Data) {
GET_REPORT_OPTIONS(false);
handleNonNullArg(Data, Opts);
}
void __ubsan::__ubsan_handle_nonnull_arg_abort(NonNullArgData *Data) {
GET_REPORT_OPTIONS(true);
handleNonNullArg(Data, Opts);
Die();
}
static void handleCFIBadIcall(CFICheckFailData *Data, ValueHandle Function,
ReportOptions Opts) {
if (Data->CheckKind != CFITCK_ICall)
Die();
SourceLocation Loc = Data->Loc.acquire();
ErrorType ET = ErrorType::CFIBadType;
if (ignoreReport(Loc, Opts, ET))
return;
ScopedReport R(Opts, Loc, ET);
Diag(Loc, DL_Error, "control flow integrity check for type %0 failed during "
"indirect function call")
<< Data->Type;
SymbolizedStackHolder FLoc(getSymbolizedLocation(Function));
const char *FName = FLoc.get()->info.function;
if (!FName)
FName = "(unknown)";
Diag(FLoc, DL_Note, "%0 defined here") << FName;
}
namespace __ubsan {
#ifdef UBSAN_CAN_USE_CXXABI
SANITIZER_WEAK_ATTRIBUTE
void HandleCFIBadType(CFICheckFailData *Data, ValueHandle Vtable,
bool ValidVtable, ReportOptions Opts);
#else
static void HandleCFIBadType(CFICheckFailData *Data, ValueHandle Vtable,
bool ValidVtable, ReportOptions Opts) {
Die();
}
#endif
} // namespace __ubsan
void __ubsan::__ubsan_handle_cfi_check_fail(CFICheckFailData *Data,
ValueHandle Value,
uptr ValidVtable) {
GET_REPORT_OPTIONS(false);
if (Data->CheckKind == CFITCK_ICall)
handleCFIBadIcall(Data, Value, Opts);
else
HandleCFIBadType(Data, Value, ValidVtable, Opts);
}
void __ubsan::__ubsan_handle_cfi_check_fail_abort(CFICheckFailData *Data,
ValueHandle Value,
uptr ValidVtable) {
GET_REPORT_OPTIONS(true);
if (Data->CheckKind == CFITCK_ICall)
handleCFIBadIcall(Data, Value, Opts);
else
HandleCFIBadType(Data, Value, ValidVtable, Opts);
Die();
}
#endif // CAN_SANITIZE_UB