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1a4d82fc JJ |
1 | //===-- ubsan_diag.cc -----------------------------------------------------===// |
2 | // | |
3 | // The LLVM Compiler Infrastructure | |
4 | // | |
5 | // This file is distributed under the University of Illinois Open Source | |
6 | // License. See LICENSE.TXT for details. | |
7 | // | |
8 | //===----------------------------------------------------------------------===// | |
9 | // | |
10 | // Diagnostic reporting for the UBSan runtime. | |
11 | // | |
12 | //===----------------------------------------------------------------------===// | |
13 | ||
92a42be0 SL |
14 | #include "ubsan_platform.h" |
15 | #if CAN_SANITIZE_UB | |
1a4d82fc | 16 | #include "ubsan_diag.h" |
92a42be0 SL |
17 | #include "ubsan_init.h" |
18 | #include "ubsan_flags.h" | |
19 | #include "sanitizer_common/sanitizer_placement_new.h" | |
1a4d82fc JJ |
20 | #include "sanitizer_common/sanitizer_report_decorator.h" |
21 | #include "sanitizer_common/sanitizer_stacktrace.h" | |
92a42be0 SL |
22 | #include "sanitizer_common/sanitizer_stacktrace_printer.h" |
23 | #include "sanitizer_common/sanitizer_suppressions.h" | |
1a4d82fc JJ |
24 | #include "sanitizer_common/sanitizer_symbolizer.h" |
25 | #include <stdio.h> | |
26 | ||
27 | using namespace __ubsan; | |
28 | ||
92a42be0 SL |
29 | static void MaybePrintStackTrace(uptr pc, uptr bp) { |
30 | // We assume that flags are already parsed, as UBSan runtime | |
31 | // will definitely be called when we print the first diagnostics message. | |
32 | if (!flags()->print_stacktrace) | |
33 | return; | |
34 | // We can only use slow unwind, as we don't have any information about stack | |
35 | // top/bottom. | |
36 | // FIXME: It's better to respect "fast_unwind_on_fatal" runtime flag and | |
37 | // fetch stack top/bottom information if we have it (e.g. if we're running | |
38 | // under ASan). | |
39 | if (StackTrace::WillUseFastUnwind(false)) | |
40 | return; | |
41 | BufferedStackTrace stack; | |
42 | stack.Unwind(kStackTraceMax, pc, bp, 0, 0, 0, false); | |
43 | stack.Print(); | |
1a4d82fc JJ |
44 | } |
45 | ||
92a42be0 SL |
46 | static const char *ConvertTypeToString(ErrorType Type) { |
47 | switch (Type) { | |
3157f602 | 48 | #define UBSAN_CHECK(Name, SummaryKind, FSanitizeFlagName) \ |
92a42be0 SL |
49 | case ErrorType::Name: \ |
50 | return SummaryKind; | |
51 | #include "ubsan_checks.inc" | |
52 | #undef UBSAN_CHECK | |
53 | } | |
54 | UNREACHABLE("unknown ErrorType!"); | |
1a4d82fc JJ |
55 | } |
56 | ||
3157f602 XL |
57 | static const char *ConvertTypeToFlagName(ErrorType Type) { |
58 | switch (Type) { | |
59 | #define UBSAN_CHECK(Name, SummaryKind, FSanitizeFlagName) \ | |
60 | case ErrorType::Name: \ | |
61 | return FSanitizeFlagName; | |
62 | #include "ubsan_checks.inc" | |
63 | #undef UBSAN_CHECK | |
64 | } | |
65 | UNREACHABLE("unknown ErrorType!"); | |
66 | } | |
67 | ||
92a42be0 SL |
68 | static void MaybeReportErrorSummary(Location Loc, ErrorType Type) { |
69 | if (!common_flags()->print_summary) | |
70 | return; | |
71 | if (!flags()->report_error_type) | |
72 | Type = ErrorType::GenericUB; | |
73 | const char *ErrorKind = ConvertTypeToString(Type); | |
74 | if (Loc.isSourceLocation()) { | |
75 | SourceLocation SLoc = Loc.getSourceLocation(); | |
76 | if (!SLoc.isInvalid()) { | |
77 | AddressInfo AI; | |
78 | AI.file = internal_strdup(SLoc.getFilename()); | |
79 | AI.line = SLoc.getLine(); | |
80 | AI.column = SLoc.getColumn(); | |
81 | AI.function = internal_strdup(""); // Avoid printing ?? as function name. | |
82 | ReportErrorSummary(ErrorKind, AI); | |
83 | AI.Clear(); | |
84 | return; | |
85 | } | |
86 | } else if (Loc.isSymbolizedStack()) { | |
87 | const AddressInfo &AI = Loc.getSymbolizedStack()->info; | |
88 | ReportErrorSummary(ErrorKind, AI); | |
89 | return; | |
90 | } | |
91 | ReportErrorSummary(ErrorKind); | |
92 | } | |
1a4d82fc | 93 | |
92a42be0 SL |
94 | namespace { |
95 | class Decorator : public SanitizerCommonDecorator { | |
96 | public: | |
97 | Decorator() : SanitizerCommonDecorator() {} | |
98 | const char *Highlight() const { return Green(); } | |
99 | const char *EndHighlight() const { return Default(); } | |
100 | const char *Note() const { return Black(); } | |
101 | const char *EndNote() const { return Default(); } | |
102 | }; | |
103 | } | |
1a4d82fc | 104 | |
92a42be0 SL |
105 | SymbolizedStack *__ubsan::getSymbolizedLocation(uptr PC) { |
106 | InitAsStandaloneIfNecessary(); | |
107 | return Symbolizer::GetOrInit()->SymbolizePC(PC); | |
1a4d82fc JJ |
108 | } |
109 | ||
110 | Diag &Diag::operator<<(const TypeDescriptor &V) { | |
111 | return AddArg(V.getTypeName()); | |
112 | } | |
113 | ||
114 | Diag &Diag::operator<<(const Value &V) { | |
115 | if (V.getType().isSignedIntegerTy()) | |
116 | AddArg(V.getSIntValue()); | |
117 | else if (V.getType().isUnsignedIntegerTy()) | |
118 | AddArg(V.getUIntValue()); | |
119 | else if (V.getType().isFloatTy()) | |
120 | AddArg(V.getFloatValue()); | |
121 | else | |
122 | AddArg("<unknown>"); | |
123 | return *this; | |
124 | } | |
125 | ||
126 | /// Hexadecimal printing for numbers too large for Printf to handle directly. | |
5bcae85e | 127 | static void RenderHex(InternalScopedString *Buffer, UIntMax Val) { |
1a4d82fc | 128 | #if HAVE_INT128_T |
5bcae85e SL |
129 | Buffer->append("0x%08x%08x%08x%08x", (unsigned int)(Val >> 96), |
130 | (unsigned int)(Val >> 64), (unsigned int)(Val >> 32), | |
131 | (unsigned int)(Val)); | |
1a4d82fc JJ |
132 | #else |
133 | UNREACHABLE("long long smaller than 64 bits?"); | |
134 | #endif | |
135 | } | |
136 | ||
5bcae85e | 137 | static void RenderLocation(InternalScopedString *Buffer, Location Loc) { |
1a4d82fc JJ |
138 | switch (Loc.getKind()) { |
139 | case Location::LK_Source: { | |
140 | SourceLocation SLoc = Loc.getSourceLocation(); | |
141 | if (SLoc.isInvalid()) | |
5bcae85e | 142 | Buffer->append("<unknown>"); |
1a4d82fc | 143 | else |
5bcae85e | 144 | RenderSourceLocation(Buffer, SLoc.getFilename(), SLoc.getLine(), |
92a42be0 SL |
145 | SLoc.getColumn(), common_flags()->symbolize_vs_style, |
146 | common_flags()->strip_path_prefix); | |
5bcae85e | 147 | return; |
1a4d82fc | 148 | } |
1a4d82fc | 149 | case Location::LK_Memory: |
5bcae85e SL |
150 | Buffer->append("%p", Loc.getMemoryLocation()); |
151 | return; | |
92a42be0 SL |
152 | case Location::LK_Symbolized: { |
153 | const AddressInfo &Info = Loc.getSymbolizedStack()->info; | |
5bcae85e SL |
154 | if (Info.file) |
155 | RenderSourceLocation(Buffer, Info.file, Info.line, Info.column, | |
92a42be0 SL |
156 | common_flags()->symbolize_vs_style, |
157 | common_flags()->strip_path_prefix); | |
5bcae85e SL |
158 | else if (Info.module) |
159 | RenderModuleLocation(Buffer, Info.module, Info.module_offset, | |
92a42be0 | 160 | common_flags()->strip_path_prefix); |
5bcae85e SL |
161 | else |
162 | Buffer->append("%p", Info.address); | |
163 | return; | |
92a42be0 | 164 | } |
1a4d82fc | 165 | case Location::LK_Null: |
5bcae85e SL |
166 | Buffer->append("<unknown>"); |
167 | return; | |
1a4d82fc | 168 | } |
1a4d82fc JJ |
169 | } |
170 | ||
5bcae85e SL |
171 | static void RenderText(InternalScopedString *Buffer, const char *Message, |
172 | const Diag::Arg *Args) { | |
1a4d82fc JJ |
173 | for (const char *Msg = Message; *Msg; ++Msg) { |
174 | if (*Msg != '%') { | |
5bcae85e SL |
175 | Buffer->append("%c", *Msg); |
176 | continue; | |
177 | } | |
178 | const Diag::Arg &A = Args[*++Msg - '0']; | |
179 | switch (A.Kind) { | |
180 | case Diag::AK_String: | |
181 | Buffer->append("%s", A.String); | |
182 | break; | |
183 | case Diag::AK_TypeName: { | |
184 | if (SANITIZER_WINDOWS) | |
185 | // The Windows implementation demangles names early. | |
186 | Buffer->append("'%s'", A.String); | |
187 | else | |
188 | Buffer->append("'%s'", Symbolizer::GetOrInit()->Demangle(A.String)); | |
189 | break; | |
190 | } | |
191 | case Diag::AK_SInt: | |
192 | // 'long long' is guaranteed to be at least 64 bits wide. | |
193 | if (A.SInt >= INT64_MIN && A.SInt <= INT64_MAX) | |
194 | Buffer->append("%lld", (long long)A.SInt); | |
195 | else | |
196 | RenderHex(Buffer, A.SInt); | |
197 | break; | |
198 | case Diag::AK_UInt: | |
199 | if (A.UInt <= UINT64_MAX) | |
200 | Buffer->append("%llu", (unsigned long long)A.UInt); | |
201 | else | |
202 | RenderHex(Buffer, A.UInt); | |
203 | break; | |
204 | case Diag::AK_Float: { | |
205 | // FIXME: Support floating-point formatting in sanitizer_common's | |
206 | // printf, and stop using snprintf here. | |
207 | char FloatBuffer[32]; | |
92a42be0 | 208 | #if SANITIZER_WINDOWS |
5bcae85e | 209 | sprintf_s(FloatBuffer, sizeof(FloatBuffer), "%Lg", (long double)A.Float); |
92a42be0 | 210 | #else |
5bcae85e | 211 | snprintf(FloatBuffer, sizeof(FloatBuffer), "%Lg", (long double)A.Float); |
92a42be0 | 212 | #endif |
5bcae85e SL |
213 | Buffer->append("%s", FloatBuffer); |
214 | break; | |
215 | } | |
216 | case Diag::AK_Pointer: | |
217 | Buffer->append("%p", A.Pointer); | |
218 | break; | |
1a4d82fc JJ |
219 | } |
220 | } | |
221 | } | |
222 | ||
223 | /// Find the earliest-starting range in Ranges which ends after Loc. | |
224 | static Range *upperBound(MemoryLocation Loc, Range *Ranges, | |
225 | unsigned NumRanges) { | |
226 | Range *Best = 0; | |
227 | for (unsigned I = 0; I != NumRanges; ++I) | |
228 | if (Ranges[I].getEnd().getMemoryLocation() > Loc && | |
229 | (!Best || | |
230 | Best->getStart().getMemoryLocation() > | |
231 | Ranges[I].getStart().getMemoryLocation())) | |
232 | Best = &Ranges[I]; | |
233 | return Best; | |
234 | } | |
235 | ||
92a42be0 SL |
236 | static inline uptr subtractNoOverflow(uptr LHS, uptr RHS) { |
237 | return (LHS < RHS) ? 0 : LHS - RHS; | |
238 | } | |
239 | ||
240 | static inline uptr addNoOverflow(uptr LHS, uptr RHS) { | |
241 | const uptr Limit = (uptr)-1; | |
242 | return (LHS > Limit - RHS) ? Limit : LHS + RHS; | |
243 | } | |
244 | ||
1a4d82fc | 245 | /// Render a snippet of the address space near a location. |
5bcae85e SL |
246 | static void PrintMemorySnippet(const Decorator &Decor, MemoryLocation Loc, |
247 | Range *Ranges, unsigned NumRanges, | |
248 | const Diag::Arg *Args) { | |
1a4d82fc | 249 | // Show at least the 8 bytes surrounding Loc. |
92a42be0 SL |
250 | const unsigned MinBytesNearLoc = 4; |
251 | MemoryLocation Min = subtractNoOverflow(Loc, MinBytesNearLoc); | |
252 | MemoryLocation Max = addNoOverflow(Loc, MinBytesNearLoc); | |
253 | MemoryLocation OrigMin = Min; | |
1a4d82fc JJ |
254 | for (unsigned I = 0; I < NumRanges; ++I) { |
255 | Min = __sanitizer::Min(Ranges[I].getStart().getMemoryLocation(), Min); | |
256 | Max = __sanitizer::Max(Ranges[I].getEnd().getMemoryLocation(), Max); | |
257 | } | |
258 | ||
259 | // If we have too many interesting bytes, prefer to show bytes after Loc. | |
92a42be0 | 260 | const unsigned BytesToShow = 32; |
1a4d82fc | 261 | if (Max - Min > BytesToShow) |
92a42be0 SL |
262 | Min = __sanitizer::Min(Max - BytesToShow, OrigMin); |
263 | Max = addNoOverflow(Min, BytesToShow); | |
264 | ||
265 | if (!IsAccessibleMemoryRange(Min, Max - Min)) { | |
266 | Printf("<memory cannot be printed>\n"); | |
267 | return; | |
268 | } | |
1a4d82fc JJ |
269 | |
270 | // Emit data. | |
5bcae85e | 271 | InternalScopedString Buffer(1024); |
1a4d82fc | 272 | for (uptr P = Min; P != Max; ++P) { |
1a4d82fc | 273 | unsigned char C = *reinterpret_cast<const unsigned char*>(P); |
5bcae85e | 274 | Buffer.append("%s%02x", (P % 8 == 0) ? " " : " ", C); |
1a4d82fc | 275 | } |
5bcae85e | 276 | Buffer.append("\n"); |
1a4d82fc JJ |
277 | |
278 | // Emit highlights. | |
5bcae85e | 279 | Buffer.append(Decor.Highlight()); |
1a4d82fc JJ |
280 | Range *InRange = upperBound(Min, Ranges, NumRanges); |
281 | for (uptr P = Min; P != Max; ++P) { | |
282 | char Pad = ' ', Byte = ' '; | |
283 | if (InRange && InRange->getEnd().getMemoryLocation() == P) | |
284 | InRange = upperBound(P, Ranges, NumRanges); | |
285 | if (!InRange && P > Loc) | |
286 | break; | |
287 | if (InRange && InRange->getStart().getMemoryLocation() < P) | |
288 | Pad = '~'; | |
289 | if (InRange && InRange->getStart().getMemoryLocation() <= P) | |
290 | Byte = '~'; | |
5bcae85e SL |
291 | if (P % 8 == 0) |
292 | Buffer.append("%c", Pad); | |
293 | Buffer.append("%c", Pad); | |
294 | Buffer.append("%c", P == Loc ? '^' : Byte); | |
295 | Buffer.append("%c", Byte); | |
1a4d82fc | 296 | } |
5bcae85e | 297 | Buffer.append("%s\n", Decor.EndHighlight()); |
1a4d82fc JJ |
298 | |
299 | // Go over the line again, and print names for the ranges. | |
300 | InRange = 0; | |
301 | unsigned Spaces = 0; | |
302 | for (uptr P = Min; P != Max; ++P) { | |
303 | if (!InRange || InRange->getEnd().getMemoryLocation() == P) | |
304 | InRange = upperBound(P, Ranges, NumRanges); | |
305 | if (!InRange) | |
306 | break; | |
307 | ||
308 | Spaces += (P % 8) == 0 ? 2 : 1; | |
309 | ||
310 | if (InRange && InRange->getStart().getMemoryLocation() == P) { | |
311 | while (Spaces--) | |
5bcae85e SL |
312 | Buffer.append(" "); |
313 | RenderText(&Buffer, InRange->getText(), Args); | |
314 | Buffer.append("\n"); | |
1a4d82fc JJ |
315 | // FIXME: We only support naming one range for now! |
316 | break; | |
317 | } | |
318 | ||
319 | Spaces += 2; | |
320 | } | |
321 | ||
5bcae85e | 322 | Printf("%s", Buffer.data()); |
1a4d82fc JJ |
323 | // FIXME: Print names for anything we can identify within the line: |
324 | // | |
325 | // * If we can identify the memory itself as belonging to a particular | |
326 | // global, stack variable, or dynamic allocation, then do so. | |
327 | // | |
328 | // * If we have a pointer-size, pointer-aligned range highlighted, | |
329 | // determine whether the value of that range is a pointer to an | |
330 | // entity which we can name, and if so, print that name. | |
331 | // | |
332 | // This needs an external symbolizer, or (preferably) ASan instrumentation. | |
333 | } | |
334 | ||
335 | Diag::~Diag() { | |
92a42be0 SL |
336 | // All diagnostics should be printed under report mutex. |
337 | CommonSanitizerReportMutex.CheckLocked(); | |
338 | Decorator Decor; | |
5bcae85e | 339 | InternalScopedString Buffer(1024); |
1a4d82fc | 340 | |
5bcae85e SL |
341 | Buffer.append(Decor.Bold()); |
342 | RenderLocation(&Buffer, Loc); | |
343 | Buffer.append(":"); | |
1a4d82fc JJ |
344 | |
345 | switch (Level) { | |
346 | case DL_Error: | |
5bcae85e SL |
347 | Buffer.append("%s runtime error: %s%s", Decor.Warning(), Decor.EndWarning(), |
348 | Decor.Bold()); | |
1a4d82fc JJ |
349 | break; |
350 | ||
351 | case DL_Note: | |
5bcae85e | 352 | Buffer.append("%s note: %s", Decor.Note(), Decor.EndNote()); |
1a4d82fc JJ |
353 | break; |
354 | } | |
355 | ||
5bcae85e | 356 | RenderText(&Buffer, Message, Args); |
1a4d82fc | 357 | |
5bcae85e SL |
358 | Buffer.append("%s\n", Decor.Default()); |
359 | Printf("%s", Buffer.data()); | |
1a4d82fc JJ |
360 | |
361 | if (Loc.isMemoryLocation()) | |
5bcae85e | 362 | PrintMemorySnippet(Decor, Loc.getMemoryLocation(), Ranges, NumRanges, Args); |
1a4d82fc | 363 | } |
92a42be0 SL |
364 | |
365 | ScopedReport::ScopedReport(ReportOptions Opts, Location SummaryLoc, | |
366 | ErrorType Type) | |
367 | : Opts(Opts), SummaryLoc(SummaryLoc), Type(Type) { | |
368 | InitAsStandaloneIfNecessary(); | |
369 | CommonSanitizerReportMutex.Lock(); | |
370 | } | |
371 | ||
372 | ScopedReport::~ScopedReport() { | |
373 | MaybePrintStackTrace(Opts.pc, Opts.bp); | |
374 | MaybeReportErrorSummary(SummaryLoc, Type); | |
375 | CommonSanitizerReportMutex.Unlock(); | |
3157f602 | 376 | if (flags()->halt_on_error) |
92a42be0 SL |
377 | Die(); |
378 | } | |
379 | ||
380 | ALIGNED(64) static char suppression_placeholder[sizeof(SuppressionContext)]; | |
381 | static SuppressionContext *suppression_ctx = nullptr; | |
382 | static const char kVptrCheck[] = "vptr_check"; | |
3157f602 XL |
383 | static const char *kSuppressionTypes[] = { |
384 | #define UBSAN_CHECK(Name, SummaryKind, FSanitizeFlagName) FSanitizeFlagName, | |
385 | #include "ubsan_checks.inc" | |
386 | #undef UBSAN_CHECK | |
387 | kVptrCheck, | |
388 | }; | |
92a42be0 SL |
389 | |
390 | void __ubsan::InitializeSuppressions() { | |
391 | CHECK_EQ(nullptr, suppression_ctx); | |
392 | suppression_ctx = new (suppression_placeholder) // NOLINT | |
393 | SuppressionContext(kSuppressionTypes, ARRAY_SIZE(kSuppressionTypes)); | |
394 | suppression_ctx->ParseFromFile(flags()->suppressions); | |
395 | } | |
396 | ||
397 | bool __ubsan::IsVptrCheckSuppressed(const char *TypeName) { | |
398 | InitAsStandaloneIfNecessary(); | |
399 | CHECK(suppression_ctx); | |
400 | Suppression *s; | |
401 | return suppression_ctx->Match(TypeName, kVptrCheck, &s); | |
402 | } | |
403 | ||
3157f602 XL |
404 | bool __ubsan::IsPCSuppressed(ErrorType ET, uptr PC, const char *Filename) { |
405 | InitAsStandaloneIfNecessary(); | |
406 | CHECK(suppression_ctx); | |
407 | const char *SuppType = ConvertTypeToFlagName(ET); | |
408 | // Fast path: don't symbolize PC if there is no suppressions for given UB | |
409 | // type. | |
410 | if (!suppression_ctx->HasSuppressionType(SuppType)) | |
411 | return false; | |
412 | Suppression *s = nullptr; | |
413 | // Suppress by file name known to runtime. | |
414 | if (Filename != nullptr && suppression_ctx->Match(Filename, SuppType, &s)) | |
415 | return true; | |
416 | // Suppress by module name. | |
417 | if (const char *Module = Symbolizer::GetOrInit()->GetModuleNameForPc(PC)) { | |
418 | if (suppression_ctx->Match(Module, SuppType, &s)) | |
419 | return true; | |
420 | } | |
421 | // Suppress by function or source file name from debug info. | |
422 | SymbolizedStackHolder Stack(Symbolizer::GetOrInit()->SymbolizePC(PC)); | |
423 | const AddressInfo &AI = Stack.get()->info; | |
424 | return suppression_ctx->Match(AI.function, SuppType, &s) || | |
425 | suppression_ctx->Match(AI.file, SuppType, &s); | |
426 | } | |
427 | ||
92a42be0 | 428 | #endif // CAN_SANITIZE_UB |