//===-- ubsan_handlers.cc -------------------------------------------------===// // // 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", "_Nonnull binding to"}; } static void handleTypeMismatchImpl(TypeMismatchData *Data, ValueHandle Pointer, ReportOptions Opts) { Location Loc = Data->Loc.acquire(); uptr Alignment = (uptr)1 << Data->LogAlignment; ErrorType ET; if (!Pointer) ET = ErrorType::NullPointerUse; else if (Pointer & (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 << 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_v1(TypeMismatchData *Data, ValueHandle Pointer) { GET_REPORT_OPTIONS(false); handleTypeMismatchImpl(Data, Pointer, Opts); } void __ubsan::__ubsan_handle_type_mismatch_v1_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 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(DataPtr); CallerLoc.reset(getCallerLocation(Opts.pc)); Loc = CallerLoc; FromType = &Data->FromType; ToType = &Data->ToType; } else { auto Data = reinterpret_cast(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, "%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'")) || (0 == internal_strncmp(Data->Type.getTypeName(), "'BOOL'", 6)); 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 handleInvalidBuiltin(InvalidBuiltinData *Data, ReportOptions Opts) { SourceLocation Loc = Data->Loc.acquire(); ErrorType ET = ErrorType::InvalidBuiltin; if (ignoreReport(Loc, Opts, ET)) return; ScopedReport R(Opts, Loc, ET); Diag(Loc, DL_Error, "passing zero to %0, which is not a valid argument") << ((Data->Kind == BCK_CTZPassedZero) ? "ctz()" : "clz()"); } void __ubsan::__ubsan_handle_invalid_builtin(InvalidBuiltinData *Data) { GET_REPORT_OPTIONS(true); handleInvalidBuiltin(Data, Opts); } void __ubsan::__ubsan_handle_invalid_builtin_abort(InvalidBuiltinData *Data) { GET_REPORT_OPTIONS(true); handleInvalidBuiltin(Data, 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, SourceLocation *LocPtr, ReportOptions Opts, bool IsAttr) { if (!LocPtr) UNREACHABLE("source location pointer is null!"); SourceLocation Loc = LocPtr->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, "%0 specified here") << (IsAttr ? "returns_nonnull attribute" : "_Nonnull return type annotation"); } void __ubsan::__ubsan_handle_nonnull_return_v1(NonNullReturnData *Data, SourceLocation *LocPtr) { GET_REPORT_OPTIONS(false); handleNonNullReturn(Data, LocPtr, Opts, true); } void __ubsan::__ubsan_handle_nonnull_return_v1_abort(NonNullReturnData *Data, SourceLocation *LocPtr) { GET_REPORT_OPTIONS(true); handleNonNullReturn(Data, LocPtr, Opts, true); Die(); } void __ubsan::__ubsan_handle_nullability_return_v1(NonNullReturnData *Data, SourceLocation *LocPtr) { GET_REPORT_OPTIONS(false); handleNonNullReturn(Data, LocPtr, Opts, false); } void __ubsan::__ubsan_handle_nullability_return_v1_abort( NonNullReturnData *Data, SourceLocation *LocPtr) { GET_REPORT_OPTIONS(true); handleNonNullReturn(Data, LocPtr, Opts, false); Die(); } static void handleNonNullArg(NonNullArgData *Data, ReportOptions Opts, bool IsAttr) { 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, "%0 specified here") << (IsAttr ? "nonnull attribute" : "_Nonnull type annotation"); } void __ubsan::__ubsan_handle_nonnull_arg(NonNullArgData *Data) { GET_REPORT_OPTIONS(false); handleNonNullArg(Data, Opts, true); } void __ubsan::__ubsan_handle_nonnull_arg_abort(NonNullArgData *Data) { GET_REPORT_OPTIONS(true); handleNonNullArg(Data, Opts, true); Die(); } void __ubsan::__ubsan_handle_nullability_arg(NonNullArgData *Data) { GET_REPORT_OPTIONS(false); handleNonNullArg(Data, Opts, false); } void __ubsan::__ubsan_handle_nullability_arg_abort(NonNullArgData *Data) { GET_REPORT_OPTIONS(true); handleNonNullArg(Data, Opts, false); Die(); } static void handlePointerOverflowImpl(PointerOverflowData *Data, ValueHandle Base, ValueHandle Result, ReportOptions Opts) { SourceLocation Loc = Data->Loc.acquire(); ErrorType ET = ErrorType::PointerOverflow; if (ignoreReport(Loc, Opts, ET)) return; ScopedReport R(Opts, Loc, ET); if ((sptr(Base) >= 0) == (sptr(Result) >= 0)) { if (Base > Result) Diag(Loc, DL_Error, "addition of unsigned offset to %0 overflowed to %1") << (void *)Base << (void *)Result; else Diag(Loc, DL_Error, "subtraction of unsigned offset from %0 overflowed to %1") << (void *)Base << (void *)Result; } else { Diag(Loc, DL_Error, "pointer index expression with base %0 overflowed to %1") << (void *)Base << (void *)Result; } } void __ubsan::__ubsan_handle_pointer_overflow(PointerOverflowData *Data, ValueHandle Base, ValueHandle Result) { GET_REPORT_OPTIONS(false); handlePointerOverflowImpl(Data, Base, Result, Opts); } void __ubsan::__ubsan_handle_pointer_overflow_abort(PointerOverflowData *Data, ValueHandle Base, ValueHandle Result) { GET_REPORT_OPTIONS(true); handlePointerOverflowImpl(Data, Base, Result, 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 #ifdef _WIN32 extern "C" void __ubsan_handle_cfi_bad_type_default(CFICheckFailData *Data, ValueHandle Vtable, bool ValidVtable, ReportOptions Opts) { Die(); } WIN_WEAK_ALIAS(__ubsan_handle_cfi_bad_type, __ubsan_handle_cfi_bad_type_default) #else SANITIZER_WEAK_ATTRIBUTE #endif void __ubsan_handle_cfi_bad_type(CFICheckFailData *Data, ValueHandle Vtable, bool ValidVtable, ReportOptions Opts); #else void __ubsan_handle_cfi_bad_type(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 __ubsan_handle_cfi_bad_type(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 __ubsan_handle_cfi_bad_type(Data, Value, ValidVtable, Opts); Die(); } #endif // CAN_SANITIZE_UB