1 //===-- ubsan_handlers.cpp ------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // Error logging entry points for the UBSan runtime.
10 //
11 //===----------------------------------------------------------------------===//
12
13 #include "ubsan_platform.h"
14 #if CAN_SANITIZE_UB
15 #include "ubsan_handlers.h"
16 #include "ubsan_diag.h"
17 #include "ubsan_flags.h"
18 #include "ubsan_monitor.h"
19 #include "ubsan_value.h"
20
21 #include "sanitizer_common/sanitizer_common.h"
22
23 using namespace __sanitizer;
24 using namespace __ubsan;
25
26 namespace __ubsan {
ignoreReport(SourceLocation SLoc,ReportOptions Opts,ErrorType ET)27 bool ignoreReport(SourceLocation SLoc, ReportOptions Opts, ErrorType ET) {
28 // We are not allowed to skip error report: if we are in unrecoverable
29 // handler, we have to terminate the program right now, and therefore
30 // have to print some diagnostic.
31 //
32 // Even if source location is disabled, it doesn't mean that we have
33 // already report an error to the user: some concurrently running
34 // thread could have acquired it, but not yet printed the report.
35 if (Opts.FromUnrecoverableHandler)
36 return false;
37 return SLoc.isDisabled() || IsPCSuppressed(ET, Opts.pc, SLoc.getFilename());
38 }
39
40 /// Situations in which we might emit a check for the suitability of a
41 /// pointer or glvalue. Needs to be kept in sync with CodeGenFunction.h in
42 /// clang.
43 enum TypeCheckKind {
44 /// Checking the operand of a load. Must be suitably sized and aligned.
45 TCK_Load,
46 /// Checking the destination of a store. Must be suitably sized and aligned.
47 TCK_Store,
48 /// Checking the bound value in a reference binding. Must be suitably sized
49 /// and aligned, but is not required to refer to an object (until the
50 /// reference is used), per core issue 453.
51 TCK_ReferenceBinding,
52 /// Checking the object expression in a non-static data member access. Must
53 /// be an object within its lifetime.
54 TCK_MemberAccess,
55 /// Checking the 'this' pointer for a call to a non-static member function.
56 /// Must be an object within its lifetime.
57 TCK_MemberCall,
58 /// Checking the 'this' pointer for a constructor call.
59 TCK_ConstructorCall,
60 /// Checking the operand of a static_cast to a derived pointer type. Must be
61 /// null or an object within its lifetime.
62 TCK_DowncastPointer,
63 /// Checking the operand of a static_cast to a derived reference type. Must
64 /// be an object within its lifetime.
65 TCK_DowncastReference,
66 /// Checking the operand of a cast to a base object. Must be suitably sized
67 /// and aligned.
68 TCK_Upcast,
69 /// Checking the operand of a cast to a virtual base object. Must be an
70 /// object within its lifetime.
71 TCK_UpcastToVirtualBase,
72 /// Checking the value assigned to a _Nonnull pointer. Must not be null.
73 TCK_NonnullAssign,
74 /// Checking the operand of a dynamic_cast or a typeid expression. Must be
75 /// null or an object within its lifetime.
76 TCK_DynamicOperation
77 };
78
79 const char *TypeCheckKinds[] = {
80 "load of", "store to", "reference binding to", "member access within",
81 "member call on", "constructor call on", "downcast of", "downcast of",
82 "upcast of", "cast to virtual base of", "_Nonnull binding to",
83 "dynamic operation on"};
84 }
85
handleTypeMismatchImpl(TypeMismatchData * Data,ValueHandle Pointer,ReportOptions Opts)86 static void handleTypeMismatchImpl(TypeMismatchData *Data, ValueHandle Pointer,
87 ReportOptions Opts) {
88 Location Loc = Data->Loc.acquire();
89
90 uptr Alignment = (uptr)1 << Data->LogAlignment;
91 ErrorType ET;
92 if (!Pointer)
93 ET = (Data->TypeCheckKind == TCK_NonnullAssign)
94 ? ErrorType::NullPointerUseWithNullability
95 : ErrorType::NullPointerUse;
96 else if (Pointer & (Alignment - 1))
97 ET = ErrorType::MisalignedPointerUse;
98 else
99 ET = ErrorType::InsufficientObjectSize;
100
101 // Use the SourceLocation from Data to track deduplication, even if it's
102 // invalid.
103 if (ignoreReport(Loc.getSourceLocation(), Opts, ET))
104 return;
105
106 SymbolizedStackHolder FallbackLoc;
107 if (Data->Loc.isInvalid()) {
108 FallbackLoc.reset(getCallerLocation(Opts.pc));
109 Loc = FallbackLoc;
110 }
111
112 ScopedReport R(Opts, Loc, ET);
113
114 switch (ET) {
115 case ErrorType::NullPointerUse:
116 case ErrorType::NullPointerUseWithNullability:
117 Diag(Loc, DL_Error, ET, "%0 null pointer of type %1")
118 << TypeCheckKinds[Data->TypeCheckKind] << Data->Type;
119 break;
120 case ErrorType::MisalignedPointerUse:
121 Diag(Loc, DL_Error, ET, "%0 misaligned address %1 for type %3, "
122 "which requires %2 byte alignment")
123 << TypeCheckKinds[Data->TypeCheckKind] << (void *)Pointer << Alignment
124 << Data->Type;
125 break;
126 case ErrorType::InsufficientObjectSize:
127 Diag(Loc, DL_Error, ET, "%0 address %1 with insufficient space "
128 "for an object of type %2")
129 << TypeCheckKinds[Data->TypeCheckKind] << (void *)Pointer << Data->Type;
130 break;
131 default:
132 UNREACHABLE("unexpected error type!");
133 }
134
135 if (Pointer)
136 Diag(Pointer, DL_Note, ET, "pointer points here");
137 }
138
__ubsan_handle_type_mismatch_v1(TypeMismatchData * Data,ValueHandle Pointer)139 void __ubsan::__ubsan_handle_type_mismatch_v1(TypeMismatchData *Data,
140 ValueHandle Pointer) {
141 GET_REPORT_OPTIONS(false);
142 handleTypeMismatchImpl(Data, Pointer, Opts);
143 }
__ubsan_handle_type_mismatch_v1_abort(TypeMismatchData * Data,ValueHandle Pointer)144 void __ubsan::__ubsan_handle_type_mismatch_v1_abort(TypeMismatchData *Data,
145 ValueHandle Pointer) {
146 GET_REPORT_OPTIONS(true);
147 handleTypeMismatchImpl(Data, Pointer, Opts);
148 Die();
149 }
150
handleAlignmentAssumptionImpl(AlignmentAssumptionData * Data,ValueHandle Pointer,ValueHandle Alignment,ValueHandle Offset,ReportOptions Opts)151 static void handleAlignmentAssumptionImpl(AlignmentAssumptionData *Data,
152 ValueHandle Pointer,
153 ValueHandle Alignment,
154 ValueHandle Offset,
155 ReportOptions Opts) {
156 Location Loc = Data->Loc.acquire();
157 SourceLocation AssumptionLoc = Data->AssumptionLoc.acquire();
158
159 ErrorType ET = ErrorType::AlignmentAssumption;
160
161 if (ignoreReport(Loc.getSourceLocation(), Opts, ET))
162 return;
163
164 ScopedReport R(Opts, Loc, ET);
165
166 uptr RealPointer = Pointer - Offset;
167 uptr LSB = LeastSignificantSetBitIndex(RealPointer);
168 uptr ActualAlignment = uptr(1) << LSB;
169
170 uptr Mask = Alignment - 1;
171 uptr MisAlignmentOffset = RealPointer & Mask;
172
173 if (!Offset) {
174 Diag(Loc, DL_Error, ET,
175 "assumption of %0 byte alignment for pointer of type %1 failed")
176 << Alignment << Data->Type;
177 } else {
178 Diag(Loc, DL_Error, ET,
179 "assumption of %0 byte alignment (with offset of %1 byte) for pointer "
180 "of type %2 failed")
181 << Alignment << Offset << Data->Type;
182 }
183
184 if (!AssumptionLoc.isInvalid())
185 Diag(AssumptionLoc, DL_Note, ET, "alignment assumption was specified here");
186
187 Diag(RealPointer, DL_Note, ET,
188 "%0address is %1 aligned, misalignment offset is %2 bytes")
189 << (Offset ? "offset " : "") << ActualAlignment << MisAlignmentOffset;
190 }
191
__ubsan_handle_alignment_assumption(AlignmentAssumptionData * Data,ValueHandle Pointer,ValueHandle Alignment,ValueHandle Offset)192 void __ubsan::__ubsan_handle_alignment_assumption(AlignmentAssumptionData *Data,
193 ValueHandle Pointer,
194 ValueHandle Alignment,
195 ValueHandle Offset) {
196 GET_REPORT_OPTIONS(false);
197 handleAlignmentAssumptionImpl(Data, Pointer, Alignment, Offset, Opts);
198 }
__ubsan_handle_alignment_assumption_abort(AlignmentAssumptionData * Data,ValueHandle Pointer,ValueHandle Alignment,ValueHandle Offset)199 void __ubsan::__ubsan_handle_alignment_assumption_abort(
200 AlignmentAssumptionData *Data, ValueHandle Pointer, ValueHandle Alignment,
201 ValueHandle Offset) {
202 GET_REPORT_OPTIONS(true);
203 handleAlignmentAssumptionImpl(Data, Pointer, Alignment, Offset, Opts);
204 Die();
205 }
206
207 /// \brief Common diagnostic emission for various forms of integer overflow.
208 template <typename T>
handleIntegerOverflowImpl(OverflowData * Data,ValueHandle LHS,const char * Operator,T RHS,ReportOptions Opts)209 static void handleIntegerOverflowImpl(OverflowData *Data, ValueHandle LHS,
210 const char *Operator, T RHS,
211 ReportOptions Opts) {
212 SourceLocation Loc = Data->Loc.acquire();
213 bool IsSigned = Data->Type.isSignedIntegerTy();
214 ErrorType ET = IsSigned ? ErrorType::SignedIntegerOverflow
215 : ErrorType::UnsignedIntegerOverflow;
216
217 if (ignoreReport(Loc, Opts, ET))
218 return;
219
220 // If this is an unsigned overflow in non-fatal mode, potentially ignore it.
221 if (!IsSigned && !Opts.FromUnrecoverableHandler &&
222 flags()->silence_unsigned_overflow)
223 return;
224
225 ScopedReport R(Opts, Loc, ET);
226
227 Diag(Loc, DL_Error, ET, "%0 integer overflow: "
228 "%1 %2 %3 cannot be represented in type %4")
229 << (IsSigned ? "signed" : "unsigned") << Value(Data->Type, LHS)
230 << Operator << RHS << Data->Type;
231 }
232
233 #define UBSAN_OVERFLOW_HANDLER(handler_name, op, unrecoverable) \
234 void __ubsan::handler_name(OverflowData *Data, ValueHandle LHS, \
235 ValueHandle RHS) { \
236 GET_REPORT_OPTIONS(unrecoverable); \
237 handleIntegerOverflowImpl(Data, LHS, op, Value(Data->Type, RHS), Opts); \
238 if (unrecoverable) \
239 Die(); \
240 }
241
242 UBSAN_OVERFLOW_HANDLER(__ubsan_handle_add_overflow, "+", false)
243 UBSAN_OVERFLOW_HANDLER(__ubsan_handle_add_overflow_abort, "+", true)
244 UBSAN_OVERFLOW_HANDLER(__ubsan_handle_sub_overflow, "-", false)
245 UBSAN_OVERFLOW_HANDLER(__ubsan_handle_sub_overflow_abort, "-", true)
246 UBSAN_OVERFLOW_HANDLER(__ubsan_handle_mul_overflow, "*", false)
247 UBSAN_OVERFLOW_HANDLER(__ubsan_handle_mul_overflow_abort, "*", true)
248
handleNegateOverflowImpl(OverflowData * Data,ValueHandle OldVal,ReportOptions Opts)249 static void handleNegateOverflowImpl(OverflowData *Data, ValueHandle OldVal,
250 ReportOptions Opts) {
251 SourceLocation Loc = Data->Loc.acquire();
252 bool IsSigned = Data->Type.isSignedIntegerTy();
253 ErrorType ET = IsSigned ? ErrorType::SignedIntegerOverflow
254 : ErrorType::UnsignedIntegerOverflow;
255
256 if (ignoreReport(Loc, Opts, ET))
257 return;
258
259 if (!IsSigned && flags()->silence_unsigned_overflow)
260 return;
261
262 ScopedReport R(Opts, Loc, ET);
263
264 if (IsSigned)
265 Diag(Loc, DL_Error, ET,
266 "negation of %0 cannot be represented in type %1; "
267 "cast to an unsigned type to negate this value to itself")
268 << Value(Data->Type, OldVal) << Data->Type;
269 else
270 Diag(Loc, DL_Error, ET, "negation of %0 cannot be represented in type %1")
271 << Value(Data->Type, OldVal) << Data->Type;
272 }
273
__ubsan_handle_negate_overflow(OverflowData * Data,ValueHandle OldVal)274 void __ubsan::__ubsan_handle_negate_overflow(OverflowData *Data,
275 ValueHandle OldVal) {
276 GET_REPORT_OPTIONS(false);
277 handleNegateOverflowImpl(Data, OldVal, Opts);
278 }
__ubsan_handle_negate_overflow_abort(OverflowData * Data,ValueHandle OldVal)279 void __ubsan::__ubsan_handle_negate_overflow_abort(OverflowData *Data,
280 ValueHandle OldVal) {
281 GET_REPORT_OPTIONS(true);
282 handleNegateOverflowImpl(Data, OldVal, Opts);
283 Die();
284 }
285
handleDivremOverflowImpl(OverflowData * Data,ValueHandle LHS,ValueHandle RHS,ReportOptions Opts)286 static void handleDivremOverflowImpl(OverflowData *Data, ValueHandle LHS,
287 ValueHandle RHS, ReportOptions Opts) {
288 SourceLocation Loc = Data->Loc.acquire();
289 Value LHSVal(Data->Type, LHS);
290 Value RHSVal(Data->Type, RHS);
291
292 ErrorType ET;
293 if (RHSVal.isMinusOne())
294 ET = ErrorType::SignedIntegerOverflow;
295 else if (Data->Type.isIntegerTy())
296 ET = ErrorType::IntegerDivideByZero;
297 else
298 ET = ErrorType::FloatDivideByZero;
299
300 if (ignoreReport(Loc, Opts, ET))
301 return;
302
303 ScopedReport R(Opts, Loc, ET);
304
305 switch (ET) {
306 case ErrorType::SignedIntegerOverflow:
307 Diag(Loc, DL_Error, ET,
308 "division of %0 by -1 cannot be represented in type %1")
309 << LHSVal << Data->Type;
310 break;
311 default:
312 Diag(Loc, DL_Error, ET, "division by zero");
313 break;
314 }
315 }
316
__ubsan_handle_divrem_overflow(OverflowData * Data,ValueHandle LHS,ValueHandle RHS)317 void __ubsan::__ubsan_handle_divrem_overflow(OverflowData *Data,
318 ValueHandle LHS, ValueHandle RHS) {
319 GET_REPORT_OPTIONS(false);
320 handleDivremOverflowImpl(Data, LHS, RHS, Opts);
321 }
__ubsan_handle_divrem_overflow_abort(OverflowData * Data,ValueHandle LHS,ValueHandle RHS)322 void __ubsan::__ubsan_handle_divrem_overflow_abort(OverflowData *Data,
323 ValueHandle LHS,
324 ValueHandle RHS) {
325 GET_REPORT_OPTIONS(true);
326 handleDivremOverflowImpl(Data, LHS, RHS, Opts);
327 Die();
328 }
329
handleShiftOutOfBoundsImpl(ShiftOutOfBoundsData * Data,ValueHandle LHS,ValueHandle RHS,ReportOptions Opts)330 static void handleShiftOutOfBoundsImpl(ShiftOutOfBoundsData *Data,
331 ValueHandle LHS, ValueHandle RHS,
332 ReportOptions Opts) {
333 SourceLocation Loc = Data->Loc.acquire();
334 Value LHSVal(Data->LHSType, LHS);
335 Value RHSVal(Data->RHSType, RHS);
336
337 ErrorType ET;
338 if (RHSVal.isNegative() ||
339 RHSVal.getPositiveIntValue() >= Data->LHSType.getIntegerBitWidth())
340 ET = ErrorType::InvalidShiftExponent;
341 else
342 ET = ErrorType::InvalidShiftBase;
343
344 if (ignoreReport(Loc, Opts, ET))
345 return;
346
347 ScopedReport R(Opts, Loc, ET);
348
349 if (ET == ErrorType::InvalidShiftExponent) {
350 if (RHSVal.isNegative())
351 Diag(Loc, DL_Error, ET, "shift exponent %0 is negative") << RHSVal;
352 else
353 Diag(Loc, DL_Error, ET,
354 "shift exponent %0 is too large for %1-bit type %2")
355 << RHSVal << Data->LHSType.getIntegerBitWidth() << Data->LHSType;
356 } else {
357 if (LHSVal.isNegative())
358 Diag(Loc, DL_Error, ET, "left shift of negative value %0") << LHSVal;
359 else
360 Diag(Loc, DL_Error, ET,
361 "left shift of %0 by %1 places cannot be represented in type %2")
362 << LHSVal << RHSVal << Data->LHSType;
363 }
364 }
365
__ubsan_handle_shift_out_of_bounds(ShiftOutOfBoundsData * Data,ValueHandle LHS,ValueHandle RHS)366 void __ubsan::__ubsan_handle_shift_out_of_bounds(ShiftOutOfBoundsData *Data,
367 ValueHandle LHS,
368 ValueHandle RHS) {
369 GET_REPORT_OPTIONS(false);
370 handleShiftOutOfBoundsImpl(Data, LHS, RHS, Opts);
371 }
__ubsan_handle_shift_out_of_bounds_abort(ShiftOutOfBoundsData * Data,ValueHandle LHS,ValueHandle RHS)372 void __ubsan::__ubsan_handle_shift_out_of_bounds_abort(
373 ShiftOutOfBoundsData *Data,
374 ValueHandle LHS,
375 ValueHandle RHS) {
376 GET_REPORT_OPTIONS(true);
377 handleShiftOutOfBoundsImpl(Data, LHS, RHS, Opts);
378 Die();
379 }
380
handleOutOfBoundsImpl(OutOfBoundsData * Data,ValueHandle Index,ReportOptions Opts)381 static void handleOutOfBoundsImpl(OutOfBoundsData *Data, ValueHandle Index,
382 ReportOptions Opts) {
383 SourceLocation Loc = Data->Loc.acquire();
384 ErrorType ET = ErrorType::OutOfBoundsIndex;
385
386 if (ignoreReport(Loc, Opts, ET))
387 return;
388
389 ScopedReport R(Opts, Loc, ET);
390
391 Value IndexVal(Data->IndexType, Index);
392 Diag(Loc, DL_Error, ET, "index %0 out of bounds for type %1")
393 << IndexVal << Data->ArrayType;
394 }
395
__ubsan_handle_out_of_bounds(OutOfBoundsData * Data,ValueHandle Index)396 void __ubsan::__ubsan_handle_out_of_bounds(OutOfBoundsData *Data,
397 ValueHandle Index) {
398 GET_REPORT_OPTIONS(false);
399 handleOutOfBoundsImpl(Data, Index, Opts);
400 }
__ubsan_handle_out_of_bounds_abort(OutOfBoundsData * Data,ValueHandle Index)401 void __ubsan::__ubsan_handle_out_of_bounds_abort(OutOfBoundsData *Data,
402 ValueHandle Index) {
403 GET_REPORT_OPTIONS(true);
404 handleOutOfBoundsImpl(Data, Index, Opts);
405 Die();
406 }
407
handleBuiltinUnreachableImpl(UnreachableData * Data,ReportOptions Opts)408 static void handleBuiltinUnreachableImpl(UnreachableData *Data,
409 ReportOptions Opts) {
410 ErrorType ET = ErrorType::UnreachableCall;
411 ScopedReport R(Opts, Data->Loc, ET);
412 Diag(Data->Loc, DL_Error, ET,
413 "execution reached an unreachable program point");
414 }
415
__ubsan_handle_builtin_unreachable(UnreachableData * Data)416 void __ubsan::__ubsan_handle_builtin_unreachable(UnreachableData *Data) {
417 GET_REPORT_OPTIONS(true);
418 handleBuiltinUnreachableImpl(Data, Opts);
419 Die();
420 }
421
handleMissingReturnImpl(UnreachableData * Data,ReportOptions Opts)422 static void handleMissingReturnImpl(UnreachableData *Data, ReportOptions Opts) {
423 ErrorType ET = ErrorType::MissingReturn;
424 ScopedReport R(Opts, Data->Loc, ET);
425 Diag(Data->Loc, DL_Error, ET,
426 "execution reached the end of a value-returning function "
427 "without returning a value");
428 }
429
__ubsan_handle_missing_return(UnreachableData * Data)430 void __ubsan::__ubsan_handle_missing_return(UnreachableData *Data) {
431 GET_REPORT_OPTIONS(true);
432 handleMissingReturnImpl(Data, Opts);
433 Die();
434 }
435
handleVLABoundNotPositive(VLABoundData * Data,ValueHandle Bound,ReportOptions Opts)436 static void handleVLABoundNotPositive(VLABoundData *Data, ValueHandle Bound,
437 ReportOptions Opts) {
438 SourceLocation Loc = Data->Loc.acquire();
439 ErrorType ET = ErrorType::NonPositiveVLAIndex;
440
441 if (ignoreReport(Loc, Opts, ET))
442 return;
443
444 ScopedReport R(Opts, Loc, ET);
445
446 Diag(Loc, DL_Error, ET, "variable length array bound evaluates to "
447 "non-positive value %0")
448 << Value(Data->Type, Bound);
449 }
450
__ubsan_handle_vla_bound_not_positive(VLABoundData * Data,ValueHandle Bound)451 void __ubsan::__ubsan_handle_vla_bound_not_positive(VLABoundData *Data,
452 ValueHandle Bound) {
453 GET_REPORT_OPTIONS(false);
454 handleVLABoundNotPositive(Data, Bound, Opts);
455 }
__ubsan_handle_vla_bound_not_positive_abort(VLABoundData * Data,ValueHandle Bound)456 void __ubsan::__ubsan_handle_vla_bound_not_positive_abort(VLABoundData *Data,
457 ValueHandle Bound) {
458 GET_REPORT_OPTIONS(true);
459 handleVLABoundNotPositive(Data, Bound, Opts);
460 Die();
461 }
462
looksLikeFloatCastOverflowDataV1(void * Data)463 static bool looksLikeFloatCastOverflowDataV1(void *Data) {
464 // First field is either a pointer to filename or a pointer to a
465 // TypeDescriptor.
466 u8 *FilenameOrTypeDescriptor;
467 internal_memcpy(&FilenameOrTypeDescriptor, Data,
468 sizeof(FilenameOrTypeDescriptor));
469
470 // Heuristic: For float_cast_overflow, the TypeKind will be either TK_Integer
471 // (0x0), TK_Float (0x1) or TK_Unknown (0xff). If both types are known,
472 // adding both bytes will be 0 or 1 (for BE or LE). If it were a filename,
473 // adding two printable characters will not yield such a value. Otherwise,
474 // if one of them is 0xff, this is most likely TK_Unknown type descriptor.
475 u16 MaybeFromTypeKind =
476 FilenameOrTypeDescriptor[0] + FilenameOrTypeDescriptor[1];
477 return MaybeFromTypeKind < 2 || FilenameOrTypeDescriptor[0] == 0xff ||
478 FilenameOrTypeDescriptor[1] == 0xff;
479 }
480
handleFloatCastOverflow(void * DataPtr,ValueHandle From,ReportOptions Opts)481 static void handleFloatCastOverflow(void *DataPtr, ValueHandle From,
482 ReportOptions Opts) {
483 SymbolizedStackHolder CallerLoc;
484 Location Loc;
485 const TypeDescriptor *FromType, *ToType;
486 ErrorType ET = ErrorType::FloatCastOverflow;
487
488 if (looksLikeFloatCastOverflowDataV1(DataPtr)) {
489 auto Data = reinterpret_cast<FloatCastOverflowData *>(DataPtr);
490 CallerLoc.reset(getCallerLocation(Opts.pc));
491 Loc = CallerLoc;
492 FromType = &Data->FromType;
493 ToType = &Data->ToType;
494 } else {
495 auto Data = reinterpret_cast<FloatCastOverflowDataV2 *>(DataPtr);
496 SourceLocation SLoc = Data->Loc.acquire();
497 if (ignoreReport(SLoc, Opts, ET))
498 return;
499 Loc = SLoc;
500 FromType = &Data->FromType;
501 ToType = &Data->ToType;
502 }
503
504 ScopedReport R(Opts, Loc, ET);
505
506 Diag(Loc, DL_Error, ET,
507 "%0 is outside the range of representable values of type %2")
508 << Value(*FromType, From) << *FromType << *ToType;
509 }
510
__ubsan_handle_float_cast_overflow(void * Data,ValueHandle From)511 void __ubsan::__ubsan_handle_float_cast_overflow(void *Data, ValueHandle From) {
512 GET_REPORT_OPTIONS(false);
513 handleFloatCastOverflow(Data, From, Opts);
514 }
__ubsan_handle_float_cast_overflow_abort(void * Data,ValueHandle From)515 void __ubsan::__ubsan_handle_float_cast_overflow_abort(void *Data,
516 ValueHandle From) {
517 GET_REPORT_OPTIONS(true);
518 handleFloatCastOverflow(Data, From, Opts);
519 Die();
520 }
521
handleLoadInvalidValue(InvalidValueData * Data,ValueHandle Val,ReportOptions Opts)522 static void handleLoadInvalidValue(InvalidValueData *Data, ValueHandle Val,
523 ReportOptions Opts) {
524 SourceLocation Loc = Data->Loc.acquire();
525 // This check could be more precise if we used different handlers for
526 // -fsanitize=bool and -fsanitize=enum.
527 bool IsBool = (0 == internal_strcmp(Data->Type.getTypeName(), "'bool'")) ||
528 (0 == internal_strncmp(Data->Type.getTypeName(), "'BOOL'", 6));
529 ErrorType ET =
530 IsBool ? ErrorType::InvalidBoolLoad : ErrorType::InvalidEnumLoad;
531
532 if (ignoreReport(Loc, Opts, ET))
533 return;
534
535 ScopedReport R(Opts, Loc, ET);
536
537 Diag(Loc, DL_Error, ET,
538 "load of value %0, which is not a valid value for type %1")
539 << Value(Data->Type, Val) << Data->Type;
540 }
541
__ubsan_handle_load_invalid_value(InvalidValueData * Data,ValueHandle Val)542 void __ubsan::__ubsan_handle_load_invalid_value(InvalidValueData *Data,
543 ValueHandle Val) {
544 GET_REPORT_OPTIONS(false);
545 handleLoadInvalidValue(Data, Val, Opts);
546 }
__ubsan_handle_load_invalid_value_abort(InvalidValueData * Data,ValueHandle Val)547 void __ubsan::__ubsan_handle_load_invalid_value_abort(InvalidValueData *Data,
548 ValueHandle Val) {
549 GET_REPORT_OPTIONS(true);
550 handleLoadInvalidValue(Data, Val, Opts);
551 Die();
552 }
553
handleImplicitConversion(ImplicitConversionData * Data,ReportOptions Opts,ValueHandle Src,ValueHandle Dst)554 static void handleImplicitConversion(ImplicitConversionData *Data,
555 ReportOptions Opts, ValueHandle Src,
556 ValueHandle Dst) {
557 SourceLocation Loc = Data->Loc.acquire();
558 ErrorType ET = ErrorType::GenericUB;
559
560 const TypeDescriptor &SrcTy = Data->FromType;
561 const TypeDescriptor &DstTy = Data->ToType;
562
563 bool SrcSigned = SrcTy.isSignedIntegerTy();
564 bool DstSigned = DstTy.isSignedIntegerTy();
565
566 switch (Data->Kind) {
567 case ICCK_IntegerTruncation: { // Legacy, no longer used.
568 // Let's figure out what it should be as per the new types, and upgrade.
569 // If both types are unsigned, then it's an unsigned truncation.
570 // Else, it is a signed truncation.
571 if (!SrcSigned && !DstSigned) {
572 ET = ErrorType::ImplicitUnsignedIntegerTruncation;
573 } else {
574 ET = ErrorType::ImplicitSignedIntegerTruncation;
575 }
576 break;
577 }
578 case ICCK_UnsignedIntegerTruncation:
579 ET = ErrorType::ImplicitUnsignedIntegerTruncation;
580 break;
581 case ICCK_SignedIntegerTruncation:
582 ET = ErrorType::ImplicitSignedIntegerTruncation;
583 break;
584 case ICCK_IntegerSignChange:
585 ET = ErrorType::ImplicitIntegerSignChange;
586 break;
587 case ICCK_SignedIntegerTruncationOrSignChange:
588 ET = ErrorType::ImplicitSignedIntegerTruncationOrSignChange;
589 break;
590 }
591
592 if (ignoreReport(Loc, Opts, ET))
593 return;
594
595 ScopedReport R(Opts, Loc, ET);
596
597 // FIXME: is it possible to dump the values as hex with fixed width?
598
599 Diag(Loc, DL_Error, ET,
600 "implicit conversion from type %0 of value %1 (%2-bit, %3signed) to "
601 "type %4 changed the value to %5 (%6-bit, %7signed)")
602 << SrcTy << Value(SrcTy, Src) << SrcTy.getIntegerBitWidth()
603 << (SrcSigned ? "" : "un") << DstTy << Value(DstTy, Dst)
604 << DstTy.getIntegerBitWidth() << (DstSigned ? "" : "un");
605 }
606
__ubsan_handle_implicit_conversion(ImplicitConversionData * Data,ValueHandle Src,ValueHandle Dst)607 void __ubsan::__ubsan_handle_implicit_conversion(ImplicitConversionData *Data,
608 ValueHandle Src,
609 ValueHandle Dst) {
610 GET_REPORT_OPTIONS(false);
611 handleImplicitConversion(Data, Opts, Src, Dst);
612 }
__ubsan_handle_implicit_conversion_abort(ImplicitConversionData * Data,ValueHandle Src,ValueHandle Dst)613 void __ubsan::__ubsan_handle_implicit_conversion_abort(
614 ImplicitConversionData *Data, ValueHandle Src, ValueHandle Dst) {
615 GET_REPORT_OPTIONS(true);
616 handleImplicitConversion(Data, Opts, Src, Dst);
617 Die();
618 }
619
handleInvalidBuiltin(InvalidBuiltinData * Data,ReportOptions Opts)620 static void handleInvalidBuiltin(InvalidBuiltinData *Data, ReportOptions Opts) {
621 SourceLocation Loc = Data->Loc.acquire();
622 ErrorType ET = ErrorType::InvalidBuiltin;
623
624 if (ignoreReport(Loc, Opts, ET))
625 return;
626
627 ScopedReport R(Opts, Loc, ET);
628
629 Diag(Loc, DL_Error, ET,
630 "passing zero to %0, which is not a valid argument")
631 << ((Data->Kind == BCK_CTZPassedZero) ? "ctz()" : "clz()");
632 }
633
__ubsan_handle_invalid_builtin(InvalidBuiltinData * Data)634 void __ubsan::__ubsan_handle_invalid_builtin(InvalidBuiltinData *Data) {
635 GET_REPORT_OPTIONS(true);
636 handleInvalidBuiltin(Data, Opts);
637 }
__ubsan_handle_invalid_builtin_abort(InvalidBuiltinData * Data)638 void __ubsan::__ubsan_handle_invalid_builtin_abort(InvalidBuiltinData *Data) {
639 GET_REPORT_OPTIONS(true);
640 handleInvalidBuiltin(Data, Opts);
641 Die();
642 }
643
handleInvalidObjCCast(InvalidObjCCast * Data,ValueHandle Pointer,ReportOptions Opts)644 static void handleInvalidObjCCast(InvalidObjCCast *Data, ValueHandle Pointer,
645 ReportOptions Opts) {
646 SourceLocation Loc = Data->Loc.acquire();
647 ErrorType ET = ErrorType::InvalidObjCCast;
648
649 if (ignoreReport(Loc, Opts, ET))
650 return;
651
652 ScopedReport R(Opts, Loc, ET);
653
654 const char *GivenClass = getObjCClassName(Pointer);
655 const char *GivenClassStr = GivenClass ? GivenClass : "<unknown type>";
656
657 Diag(Loc, DL_Error, ET,
658 "invalid ObjC cast, object is a '%0', but expected a %1")
659 << GivenClassStr << Data->ExpectedType;
660 }
661
__ubsan_handle_invalid_objc_cast(InvalidObjCCast * Data,ValueHandle Pointer)662 void __ubsan::__ubsan_handle_invalid_objc_cast(InvalidObjCCast *Data,
663 ValueHandle Pointer) {
664 GET_REPORT_OPTIONS(false);
665 handleInvalidObjCCast(Data, Pointer, Opts);
666 }
__ubsan_handle_invalid_objc_cast_abort(InvalidObjCCast * Data,ValueHandle Pointer)667 void __ubsan::__ubsan_handle_invalid_objc_cast_abort(InvalidObjCCast *Data,
668 ValueHandle Pointer) {
669 GET_REPORT_OPTIONS(true);
670 handleInvalidObjCCast(Data, Pointer, Opts);
671 Die();
672 }
673
handleNonNullReturn(NonNullReturnData * Data,SourceLocation * LocPtr,ReportOptions Opts,bool IsAttr)674 static void handleNonNullReturn(NonNullReturnData *Data, SourceLocation *LocPtr,
675 ReportOptions Opts, bool IsAttr) {
676 if (!LocPtr)
677 UNREACHABLE("source location pointer is null!");
678
679 SourceLocation Loc = LocPtr->acquire();
680 ErrorType ET = IsAttr ? ErrorType::InvalidNullReturn
681 : ErrorType::InvalidNullReturnWithNullability;
682
683 if (ignoreReport(Loc, Opts, ET))
684 return;
685
686 ScopedReport R(Opts, Loc, ET);
687
688 Diag(Loc, DL_Error, ET,
689 "null pointer returned from function declared to never return null");
690 if (!Data->AttrLoc.isInvalid())
691 Diag(Data->AttrLoc, DL_Note, ET, "%0 specified here")
692 << (IsAttr ? "returns_nonnull attribute"
693 : "_Nonnull return type annotation");
694 }
695
__ubsan_handle_nonnull_return_v1(NonNullReturnData * Data,SourceLocation * LocPtr)696 void __ubsan::__ubsan_handle_nonnull_return_v1(NonNullReturnData *Data,
697 SourceLocation *LocPtr) {
698 GET_REPORT_OPTIONS(false);
699 handleNonNullReturn(Data, LocPtr, Opts, true);
700 }
701
__ubsan_handle_nonnull_return_v1_abort(NonNullReturnData * Data,SourceLocation * LocPtr)702 void __ubsan::__ubsan_handle_nonnull_return_v1_abort(NonNullReturnData *Data,
703 SourceLocation *LocPtr) {
704 GET_REPORT_OPTIONS(true);
705 handleNonNullReturn(Data, LocPtr, Opts, true);
706 Die();
707 }
708
__ubsan_handle_nullability_return_v1(NonNullReturnData * Data,SourceLocation * LocPtr)709 void __ubsan::__ubsan_handle_nullability_return_v1(NonNullReturnData *Data,
710 SourceLocation *LocPtr) {
711 GET_REPORT_OPTIONS(false);
712 handleNonNullReturn(Data, LocPtr, Opts, false);
713 }
714
__ubsan_handle_nullability_return_v1_abort(NonNullReturnData * Data,SourceLocation * LocPtr)715 void __ubsan::__ubsan_handle_nullability_return_v1_abort(
716 NonNullReturnData *Data, SourceLocation *LocPtr) {
717 GET_REPORT_OPTIONS(true);
718 handleNonNullReturn(Data, LocPtr, Opts, false);
719 Die();
720 }
721
handleNonNullArg(NonNullArgData * Data,ReportOptions Opts,bool IsAttr)722 static void handleNonNullArg(NonNullArgData *Data, ReportOptions Opts,
723 bool IsAttr) {
724 SourceLocation Loc = Data->Loc.acquire();
725 ErrorType ET = IsAttr ? ErrorType::InvalidNullArgument
726 : ErrorType::InvalidNullArgumentWithNullability;
727
728 if (ignoreReport(Loc, Opts, ET))
729 return;
730
731 ScopedReport R(Opts, Loc, ET);
732
733 Diag(Loc, DL_Error, ET,
734 "null pointer passed as argument %0, which is declared to "
735 "never be null")
736 << Data->ArgIndex;
737 if (!Data->AttrLoc.isInvalid())
738 Diag(Data->AttrLoc, DL_Note, ET, "%0 specified here")
739 << (IsAttr ? "nonnull attribute" : "_Nonnull type annotation");
740 }
741
__ubsan_handle_nonnull_arg(NonNullArgData * Data)742 void __ubsan::__ubsan_handle_nonnull_arg(NonNullArgData *Data) {
743 GET_REPORT_OPTIONS(false);
744 handleNonNullArg(Data, Opts, true);
745 }
746
__ubsan_handle_nonnull_arg_abort(NonNullArgData * Data)747 void __ubsan::__ubsan_handle_nonnull_arg_abort(NonNullArgData *Data) {
748 GET_REPORT_OPTIONS(true);
749 handleNonNullArg(Data, Opts, true);
750 Die();
751 }
752
__ubsan_handle_nullability_arg(NonNullArgData * Data)753 void __ubsan::__ubsan_handle_nullability_arg(NonNullArgData *Data) {
754 GET_REPORT_OPTIONS(false);
755 handleNonNullArg(Data, Opts, false);
756 }
757
__ubsan_handle_nullability_arg_abort(NonNullArgData * Data)758 void __ubsan::__ubsan_handle_nullability_arg_abort(NonNullArgData *Data) {
759 GET_REPORT_OPTIONS(true);
760 handleNonNullArg(Data, Opts, false);
761 Die();
762 }
763
handlePointerOverflowImpl(PointerOverflowData * Data,ValueHandle Base,ValueHandle Result,ReportOptions Opts)764 static void handlePointerOverflowImpl(PointerOverflowData *Data,
765 ValueHandle Base,
766 ValueHandle Result,
767 ReportOptions Opts) {
768 SourceLocation Loc = Data->Loc.acquire();
769 ErrorType ET;
770
771 if (Base == 0 && Result == 0)
772 ET = ErrorType::NullptrWithOffset;
773 else if (Base == 0 && Result != 0)
774 ET = ErrorType::NullptrWithNonZeroOffset;
775 else if (Base != 0 && Result == 0)
776 ET = ErrorType::NullptrAfterNonZeroOffset;
777 else
778 ET = ErrorType::PointerOverflow;
779
780 if (ignoreReport(Loc, Opts, ET))
781 return;
782
783 ScopedReport R(Opts, Loc, ET);
784
785 if (ET == ErrorType::NullptrWithOffset) {
786 Diag(Loc, DL_Error, ET, "applying zero offset to null pointer");
787 } else if (ET == ErrorType::NullptrWithNonZeroOffset) {
788 Diag(Loc, DL_Error, ET, "applying non-zero offset %0 to null pointer")
789 << Result;
790 } else if (ET == ErrorType::NullptrAfterNonZeroOffset) {
791 Diag(
792 Loc, DL_Error, ET,
793 "applying non-zero offset to non-null pointer %0 produced null pointer")
794 << (void *)Base;
795 } else if ((sptr(Base) >= 0) == (sptr(Result) >= 0)) {
796 if (Base > Result)
797 Diag(Loc, DL_Error, ET,
798 "addition of unsigned offset to %0 overflowed to %1")
799 << (void *)Base << (void *)Result;
800 else
801 Diag(Loc, DL_Error, ET,
802 "subtraction of unsigned offset from %0 overflowed to %1")
803 << (void *)Base << (void *)Result;
804 } else {
805 Diag(Loc, DL_Error, ET,
806 "pointer index expression with base %0 overflowed to %1")
807 << (void *)Base << (void *)Result;
808 }
809 }
810
__ubsan_handle_pointer_overflow(PointerOverflowData * Data,ValueHandle Base,ValueHandle Result)811 void __ubsan::__ubsan_handle_pointer_overflow(PointerOverflowData *Data,
812 ValueHandle Base,
813 ValueHandle Result) {
814 GET_REPORT_OPTIONS(false);
815 handlePointerOverflowImpl(Data, Base, Result, Opts);
816 }
817
__ubsan_handle_pointer_overflow_abort(PointerOverflowData * Data,ValueHandle Base,ValueHandle Result)818 void __ubsan::__ubsan_handle_pointer_overflow_abort(PointerOverflowData *Data,
819 ValueHandle Base,
820 ValueHandle Result) {
821 GET_REPORT_OPTIONS(true);
822 handlePointerOverflowImpl(Data, Base, Result, Opts);
823 Die();
824 }
825
handleCFIBadIcall(CFICheckFailData * Data,ValueHandle Function,ReportOptions Opts)826 static void handleCFIBadIcall(CFICheckFailData *Data, ValueHandle Function,
827 ReportOptions Opts) {
828 if (Data->CheckKind != CFITCK_ICall && Data->CheckKind != CFITCK_NVMFCall)
829 Die();
830
831 SourceLocation Loc = Data->Loc.acquire();
832 ErrorType ET = ErrorType::CFIBadType;
833
834 if (ignoreReport(Loc, Opts, ET))
835 return;
836
837 ScopedReport R(Opts, Loc, ET);
838
839 const char *CheckKindStr = Data->CheckKind == CFITCK_NVMFCall
840 ? "non-virtual pointer to member function call"
841 : "indirect function call";
842 Diag(Loc, DL_Error, ET,
843 "control flow integrity check for type %0 failed during %1")
844 << Data->Type << CheckKindStr;
845
846 SymbolizedStackHolder FLoc(getSymbolizedLocation(Function));
847 const char *FName = FLoc.get()->info.function;
848 if (!FName)
849 FName = "(unknown)";
850 Diag(FLoc, DL_Note, ET, "%0 defined here") << FName;
851
852 // If the failure involved different DSOs for the check location and icall
853 // target, report the DSO names.
854 const char *DstModule = FLoc.get()->info.module;
855 if (!DstModule)
856 DstModule = "(unknown)";
857
858 const char *SrcModule = Symbolizer::GetOrInit()->GetModuleNameForPc(Opts.pc);
859 if (!SrcModule)
860 SrcModule = "(unknown)";
861
862 if (internal_strcmp(SrcModule, DstModule))
863 Diag(Loc, DL_Note, ET,
864 "check failed in %0, destination function located in %1")
865 << SrcModule << DstModule;
866 }
867
868 namespace __ubsan {
869
870 #ifdef UBSAN_CAN_USE_CXXABI
871
872 #ifdef _WIN32
873
__ubsan_handle_cfi_bad_type_default(CFICheckFailData * Data,ValueHandle Vtable,bool ValidVtable,ReportOptions Opts)874 extern "C" void __ubsan_handle_cfi_bad_type_default(CFICheckFailData *Data,
875 ValueHandle Vtable,
876 bool ValidVtable,
877 ReportOptions Opts) {
878 Die();
879 }
880
881 WIN_WEAK_ALIAS(__ubsan_handle_cfi_bad_type, __ubsan_handle_cfi_bad_type_default)
882 #else
883 SANITIZER_WEAK_ATTRIBUTE
884 #endif
885 void __ubsan_handle_cfi_bad_type(CFICheckFailData *Data, ValueHandle Vtable,
886 bool ValidVtable, ReportOptions Opts);
887
888 #else
889 void __ubsan_handle_cfi_bad_type(CFICheckFailData *Data, ValueHandle Vtable,
890 bool ValidVtable, ReportOptions Opts) {
891 Die();
892 }
893 #endif
894
895 } // namespace __ubsan
896
__ubsan_handle_cfi_check_fail(CFICheckFailData * Data,ValueHandle Value,uptr ValidVtable)897 void __ubsan::__ubsan_handle_cfi_check_fail(CFICheckFailData *Data,
898 ValueHandle Value,
899 uptr ValidVtable) {
900 GET_REPORT_OPTIONS(false);
901 if (Data->CheckKind == CFITCK_ICall || Data->CheckKind == CFITCK_NVMFCall)
902 handleCFIBadIcall(Data, Value, Opts);
903 else
904 __ubsan_handle_cfi_bad_type(Data, Value, ValidVtable, Opts);
905 }
906
__ubsan_handle_cfi_check_fail_abort(CFICheckFailData * Data,ValueHandle Value,uptr ValidVtable)907 void __ubsan::__ubsan_handle_cfi_check_fail_abort(CFICheckFailData *Data,
908 ValueHandle Value,
909 uptr ValidVtable) {
910 GET_REPORT_OPTIONS(true);
911 if (Data->CheckKind == CFITCK_ICall || Data->CheckKind == CFITCK_NVMFCall)
912 handleCFIBadIcall(Data, Value, Opts);
913 else
914 __ubsan_handle_cfi_bad_type(Data, Value, ValidVtable, Opts);
915 Die();
916 }
917
918 #endif // CAN_SANITIZE_UB
919