1//===-- asan_errors.cpp -----------------------------------------*- C++ -*-===//
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// This file is a part of AddressSanitizer, an address sanity checker.
10//
11// ASan implementation for error structures.
12//===----------------------------------------------------------------------===//
13
14#include "asan_errors.h"
15#include "asan_descriptions.h"
16#include "asan_mapping.h"
17#include "asan_report.h"
18#include "asan_stack.h"
19#include "sanitizer_common/sanitizer_stackdepot.h"
20
21namespace __asan {
22
23static void OnStackUnwind(const SignalContext &sig,
24                          const void *callback_context,
25                          BufferedStackTrace *stack) {
26  bool fast = common_flags()->fast_unwind_on_fatal;
27#if SANITIZER_FREEBSD || SANITIZER_NETBSD
28  // On FreeBSD the slow unwinding that leverages _Unwind_Backtrace()
29  // yields the call stack of the signal's handler and not of the code
30  // that raised the signal (as it does on Linux).
31  fast = true;
32#endif
33  // Tests and maybe some users expect that scariness is going to be printed
34  // just before the stack. As only asan has scariness score we have no
35  // corresponding code in the sanitizer_common and we use this callback to
36  // print it.
37  static_cast<const ScarinessScoreBase *>(callback_context)->Print();
38  stack->Unwind(StackTrace::GetNextInstructionPc(sig.pc), sig.bp, sig.context,
39                fast);
40}
41
42void ErrorDeadlySignal::Print() {
43  ReportDeadlySignal(signal, tid, &OnStackUnwind, &scariness);
44}
45
46void ErrorDoubleFree::Print() {
47  Decorator d;
48  Printf("%s", d.Error());
49  Report("ERROR: AddressSanitizer: attempting %s on %p in thread %s:\n",
50         scariness.GetDescription(), (void *)addr_description.addr,
51         AsanThreadIdAndName(tid).c_str());
52  Printf("%s", d.Default());
53  scariness.Print();
54  GET_STACK_TRACE_FATAL(second_free_stack->trace[0],
55                        second_free_stack->top_frame_bp);
56  stack.Print();
57  addr_description.Print();
58  ReportErrorSummary(scariness.GetDescription(), &stack);
59}
60
61void ErrorNewDeleteTypeMismatch::Print() {
62  Decorator d;
63  Printf("%s", d.Error());
64  Report("ERROR: AddressSanitizer: %s on %p in thread %s:\n",
65         scariness.GetDescription(), (void *)addr_description.addr,
66         AsanThreadIdAndName(tid).c_str());
67  Printf("%s  object passed to delete has wrong type:\n", d.Default());
68  if (delete_size != 0) {
69    Printf(
70        "  size of the allocated type:   %zd bytes;\n"
71        "  size of the deallocated type: %zd bytes.\n",
72        addr_description.chunk_access.chunk_size, delete_size);
73  }
74  const uptr user_alignment =
75      addr_description.chunk_access.user_requested_alignment;
76  if (delete_alignment != user_alignment) {
77    char user_alignment_str[32];
78    char delete_alignment_str[32];
79    internal_snprintf(user_alignment_str, sizeof(user_alignment_str),
80                      "%zd bytes", user_alignment);
81    internal_snprintf(delete_alignment_str, sizeof(delete_alignment_str),
82                      "%zd bytes", delete_alignment);
83    static const char *kDefaultAlignment = "default-aligned";
84    Printf(
85        "  alignment of the allocated type:   %s;\n"
86        "  alignment of the deallocated type: %s.\n",
87        user_alignment > 0 ? user_alignment_str : kDefaultAlignment,
88        delete_alignment > 0 ? delete_alignment_str : kDefaultAlignment);
89  }
90  CHECK_GT(free_stack->size, 0);
91  scariness.Print();
92  GET_STACK_TRACE_FATAL(free_stack->trace[0], free_stack->top_frame_bp);
93  stack.Print();
94  addr_description.Print();
95  ReportErrorSummary(scariness.GetDescription(), &stack);
96  Report(
97      "HINT: if you don't care about these errors you may set "
98      "ASAN_OPTIONS=new_delete_type_mismatch=0\n");
99}
100
101void ErrorFreeNotMalloced::Print() {
102  Decorator d;
103  Printf("%s", d.Error());
104  Report(
105      "ERROR: AddressSanitizer: attempting free on address "
106      "which was not malloc()-ed: %p in thread %s\n",
107      (void *)addr_description.Address(), AsanThreadIdAndName(tid).c_str());
108  Printf("%s", d.Default());
109  CHECK_GT(free_stack->size, 0);
110  scariness.Print();
111  GET_STACK_TRACE_FATAL(free_stack->trace[0], free_stack->top_frame_bp);
112  stack.Print();
113  addr_description.Print();
114  ReportErrorSummary(scariness.GetDescription(), &stack);
115}
116
117void ErrorAllocTypeMismatch::Print() {
118  static const char *alloc_names[] = {"INVALID", "malloc", "operator new",
119                                      "operator new []"};
120  static const char *dealloc_names[] = {"INVALID", "free", "operator delete",
121                                        "operator delete []"};
122  CHECK_NE(alloc_type, dealloc_type);
123  Decorator d;
124  Printf("%s", d.Error());
125  Report("ERROR: AddressSanitizer: %s (%s vs %s) on %p\n",
126         scariness.GetDescription(), alloc_names[alloc_type],
127         dealloc_names[dealloc_type], (void *)addr_description.Address());
128  Printf("%s", d.Default());
129  CHECK_GT(dealloc_stack->size, 0);
130  scariness.Print();
131  GET_STACK_TRACE_FATAL(dealloc_stack->trace[0], dealloc_stack->top_frame_bp);
132  stack.Print();
133  addr_description.Print();
134  ReportErrorSummary(scariness.GetDescription(), &stack);
135  Report(
136      "HINT: if you don't care about these errors you may set "
137      "ASAN_OPTIONS=alloc_dealloc_mismatch=0\n");
138}
139
140void ErrorMallocUsableSizeNotOwned::Print() {
141  Decorator d;
142  Printf("%s", d.Error());
143  Report(
144      "ERROR: AddressSanitizer: attempting to call malloc_usable_size() for "
145      "pointer which is not owned: %p\n",
146      (void *)addr_description.Address());
147  Printf("%s", d.Default());
148  stack->Print();
149  addr_description.Print();
150  ReportErrorSummary(scariness.GetDescription(), stack);
151}
152
153void ErrorSanitizerGetAllocatedSizeNotOwned::Print() {
154  Decorator d;
155  Printf("%s", d.Error());
156  Report(
157      "ERROR: AddressSanitizer: attempting to call "
158      "__sanitizer_get_allocated_size() for pointer which is not owned: %p\n",
159      (void *)addr_description.Address());
160  Printf("%s", d.Default());
161  stack->Print();
162  addr_description.Print();
163  ReportErrorSummary(scariness.GetDescription(), stack);
164}
165
166void ErrorCallocOverflow::Print() {
167  Decorator d;
168  Printf("%s", d.Error());
169  Report(
170      "ERROR: AddressSanitizer: calloc parameters overflow: count * size "
171      "(%zd * %zd) cannot be represented in type size_t (thread %s)\n",
172      count, size, AsanThreadIdAndName(tid).c_str());
173  Printf("%s", d.Default());
174  stack->Print();
175  PrintHintAllocatorCannotReturnNull();
176  ReportErrorSummary(scariness.GetDescription(), stack);
177}
178
179void ErrorReallocArrayOverflow::Print() {
180  Decorator d;
181  Printf("%s", d.Error());
182  Report(
183      "ERROR: AddressSanitizer: reallocarray parameters overflow: count * size "
184      "(%zd * %zd) cannot be represented in type size_t (thread %s)\n",
185      count, size, AsanThreadIdAndName(tid).c_str());
186  Printf("%s", d.Default());
187  stack->Print();
188  PrintHintAllocatorCannotReturnNull();
189  ReportErrorSummary(scariness.GetDescription(), stack);
190}
191
192void ErrorPvallocOverflow::Print() {
193  Decorator d;
194  Printf("%s", d.Error());
195  Report(
196      "ERROR: AddressSanitizer: pvalloc parameters overflow: size 0x%zx "
197      "rounded up to system page size 0x%zx cannot be represented in type "
198      "size_t (thread %s)\n",
199      size, GetPageSizeCached(), AsanThreadIdAndName(tid).c_str());
200  Printf("%s", d.Default());
201  stack->Print();
202  PrintHintAllocatorCannotReturnNull();
203  ReportErrorSummary(scariness.GetDescription(), stack);
204}
205
206void ErrorInvalidAllocationAlignment::Print() {
207  Decorator d;
208  Printf("%s", d.Error());
209  Report(
210      "ERROR: AddressSanitizer: invalid allocation alignment: %zd, "
211      "alignment must be a power of two (thread %s)\n",
212      alignment, AsanThreadIdAndName(tid).c_str());
213  Printf("%s", d.Default());
214  stack->Print();
215  PrintHintAllocatorCannotReturnNull();
216  ReportErrorSummary(scariness.GetDescription(), stack);
217}
218
219void ErrorInvalidAlignedAllocAlignment::Print() {
220  Decorator d;
221  Printf("%s", d.Error());
222#if SANITIZER_POSIX
223  Report("ERROR: AddressSanitizer: invalid alignment requested in "
224         "aligned_alloc: %zd, alignment must be a power of two and the "
225         "requested size 0x%zx must be a multiple of alignment "
226         "(thread %s)\n", alignment, size, AsanThreadIdAndName(tid).c_str());
227#else
228  Report("ERROR: AddressSanitizer: invalid alignment requested in "
229         "aligned_alloc: %zd, the requested size 0x%zx must be a multiple of "
230         "alignment (thread %s)\n", alignment, size,
231         AsanThreadIdAndName(tid).c_str());
232#endif
233  Printf("%s", d.Default());
234  stack->Print();
235  PrintHintAllocatorCannotReturnNull();
236  ReportErrorSummary(scariness.GetDescription(), stack);
237}
238
239void ErrorInvalidPosixMemalignAlignment::Print() {
240  Decorator d;
241  Printf("%s", d.Error());
242  Report(
243      "ERROR: AddressSanitizer: invalid alignment requested in posix_memalign: "
244      "%zd, alignment must be a power of two and a multiple of sizeof(void*) "
245      "== %zd (thread %s)\n",
246      alignment, sizeof(void *), AsanThreadIdAndName(tid).c_str());
247  Printf("%s", d.Default());
248  stack->Print();
249  PrintHintAllocatorCannotReturnNull();
250  ReportErrorSummary(scariness.GetDescription(), stack);
251}
252
253void ErrorAllocationSizeTooBig::Print() {
254  Decorator d;
255  Printf("%s", d.Error());
256  Report(
257      "ERROR: AddressSanitizer: requested allocation size 0x%zx (0x%zx after "
258      "adjustments for alignment, red zones etc.) exceeds maximum supported "
259      "size of 0x%zx (thread %s)\n",
260      user_size, total_size, max_size, AsanThreadIdAndName(tid).c_str());
261  Printf("%s", d.Default());
262  stack->Print();
263  PrintHintAllocatorCannotReturnNull();
264  ReportErrorSummary(scariness.GetDescription(), stack);
265}
266
267void ErrorRssLimitExceeded::Print() {
268  Decorator d;
269  Printf("%s", d.Error());
270  Report(
271      "ERROR: AddressSanitizer: specified RSS limit exceeded, currently set to "
272      "soft_rss_limit_mb=%zd\n", common_flags()->soft_rss_limit_mb);
273  Printf("%s", d.Default());
274  stack->Print();
275  PrintHintAllocatorCannotReturnNull();
276  ReportErrorSummary(scariness.GetDescription(), stack);
277}
278
279void ErrorOutOfMemory::Print() {
280  Decorator d;
281  Printf("%s", d.Error());
282  ERROR_OOM("allocator is trying to allocate 0x%zx bytes\n", requested_size);
283  Printf("%s", d.Default());
284  stack->Print();
285  PrintHintAllocatorCannotReturnNull();
286  ReportErrorSummary(scariness.GetDescription(), stack);
287}
288
289void ErrorStringFunctionMemoryRangesOverlap::Print() {
290  Decorator d;
291  char bug_type[100];
292  internal_snprintf(bug_type, sizeof(bug_type), "%s-param-overlap", function);
293  Printf("%s", d.Error());
294  Report(
295      "ERROR: AddressSanitizer: %s: memory ranges [%p,%p) and [%p, %p) "
296      "overlap\n",
297      bug_type, (void *)addr1_description.Address(),
298      (void *)(addr1_description.Address() + length1),
299      (void *)addr2_description.Address(),
300      (void *)(addr2_description.Address() + length2));
301  Printf("%s", d.Default());
302  scariness.Print();
303  stack->Print();
304  addr1_description.Print();
305  addr2_description.Print();
306  ReportErrorSummary(bug_type, stack);
307}
308
309void ErrorStringFunctionSizeOverflow::Print() {
310  Decorator d;
311  Printf("%s", d.Error());
312  Report("ERROR: AddressSanitizer: %s: (size=%zd)\n",
313         scariness.GetDescription(), size);
314  Printf("%s", d.Default());
315  scariness.Print();
316  stack->Print();
317  addr_description.Print();
318  ReportErrorSummary(scariness.GetDescription(), stack);
319}
320
321void ErrorBadParamsToAnnotateContiguousContainer::Print() {
322  Report(
323      "ERROR: AddressSanitizer: bad parameters to "
324      "__sanitizer_annotate_contiguous_container:\n"
325      "      beg     : %p\n"
326      "      end     : %p\n"
327      "      old_mid : %p\n"
328      "      new_mid : %p\n",
329      (void *)beg, (void *)end, (void *)old_mid, (void *)new_mid);
330  uptr granularity = ASAN_SHADOW_GRANULARITY;
331  if (!IsAligned(beg, granularity))
332    Report("ERROR: beg is not aligned by %zu\n", granularity);
333  stack->Print();
334  ReportErrorSummary(scariness.GetDescription(), stack);
335}
336
337void ErrorBadParamsToAnnotateDoubleEndedContiguousContainer::Print() {
338  Report(
339      "ERROR: AddressSanitizer: bad parameters to "
340      "__sanitizer_annotate_double_ended_contiguous_container:\n"
341      "      storage_beg        : %p\n"
342      "      storage_end        : %p\n"
343      "      old_container_beg  : %p\n"
344      "      old_container_end  : %p\n"
345      "      new_container_beg  : %p\n"
346      "      new_container_end  : %p\n",
347      (void *)storage_beg, (void *)storage_end, (void *)old_container_beg,
348      (void *)old_container_end, (void *)new_container_beg,
349      (void *)new_container_end);
350  uptr granularity = ASAN_SHADOW_GRANULARITY;
351  if (!IsAligned(storage_beg, granularity))
352    Report("ERROR: storage_beg is not aligned by %zu\n", granularity);
353  stack->Print();
354  ReportErrorSummary(scariness.GetDescription(), stack);
355}
356
357void ErrorODRViolation::Print() {
358  Decorator d;
359  Printf("%s", d.Error());
360  Report("ERROR: AddressSanitizer: %s (%p):\n", scariness.GetDescription(),
361         (void *)global1.beg);
362  Printf("%s", d.Default());
363  InternalScopedString g1_loc;
364  InternalScopedString g2_loc;
365  PrintGlobalLocation(&g1_loc, global1, /*print_module_name=*/true);
366  PrintGlobalLocation(&g2_loc, global2, /*print_module_name=*/true);
367  Printf("  [1] size=%zd '%s' %s\n", global1.size,
368         MaybeDemangleGlobalName(global1.name), g1_loc.data());
369  Printf("  [2] size=%zd '%s' %s\n", global2.size,
370         MaybeDemangleGlobalName(global2.name), g2_loc.data());
371  if (stack_id1 && stack_id2) {
372    Printf("These globals were registered at these points:\n");
373    Printf("  [1]:\n");
374    StackDepotGet(stack_id1).Print();
375    Printf("  [2]:\n");
376    StackDepotGet(stack_id2).Print();
377  }
378  Report(
379      "HINT: if you don't care about these errors you may set "
380      "ASAN_OPTIONS=detect_odr_violation=0\n");
381  InternalScopedString error_msg;
382  error_msg.AppendF("%s: global '%s' at %s", scariness.GetDescription(),
383                    MaybeDemangleGlobalName(global1.name), g1_loc.data());
384  ReportErrorSummary(error_msg.data());
385}
386
387void ErrorInvalidPointerPair::Print() {
388  Decorator d;
389  Printf("%s", d.Error());
390  Report("ERROR: AddressSanitizer: %s: %p %p\n", scariness.GetDescription(),
391         (void *)addr1_description.Address(),
392         (void *)addr2_description.Address());
393  Printf("%s", d.Default());
394  GET_STACK_TRACE_FATAL(pc, bp);
395  stack.Print();
396  addr1_description.Print();
397  addr2_description.Print();
398  ReportErrorSummary(scariness.GetDescription(), &stack);
399}
400
401static bool AdjacentShadowValuesAreFullyPoisoned(u8 *s) {
402  return s[-1] > 127 && s[1] > 127;
403}
404
405ErrorGeneric::ErrorGeneric(u32 tid, uptr pc_, uptr bp_, uptr sp_, uptr addr,
406                           bool is_write_, uptr access_size_)
407    : ErrorBase(tid),
408      addr_description(addr, access_size_, /*shouldLockThreadRegistry=*/false),
409      pc(pc_),
410      bp(bp_),
411      sp(sp_),
412      access_size(access_size_),
413      is_write(is_write_),
414      shadow_val(0) {
415  scariness.Clear();
416  if (access_size) {
417    if (access_size <= 9) {
418      char desr[] = "?-byte";
419      desr[0] = '0' + access_size;
420      scariness.Scare(access_size + access_size / 2, desr);
421    } else if (access_size >= 10) {
422      scariness.Scare(15, "multi-byte");
423    }
424    is_write ? scariness.Scare(20, "write") : scariness.Scare(1, "read");
425
426    // Determine the error type.
427    bug_descr = "unknown-crash";
428    if (AddrIsInMem(addr)) {
429      u8 *shadow_addr = (u8 *)MemToShadow(addr);
430      // If we are accessing 16 bytes, look at the second shadow byte.
431      if (*shadow_addr == 0 && access_size > ASAN_SHADOW_GRANULARITY)
432        shadow_addr++;
433      // If we are in the partial right redzone, look at the next shadow byte.
434      if (*shadow_addr > 0 && *shadow_addr < 128) shadow_addr++;
435      bool far_from_bounds = false;
436      shadow_val = *shadow_addr;
437      int bug_type_score = 0;
438      // For use-after-frees reads are almost as bad as writes.
439      int read_after_free_bonus = 0;
440      switch (shadow_val) {
441        case kAsanHeapLeftRedzoneMagic:
442        case kAsanArrayCookieMagic:
443          bug_descr = "heap-buffer-overflow";
444          bug_type_score = 10;
445          far_from_bounds = AdjacentShadowValuesAreFullyPoisoned(shadow_addr);
446          break;
447        case kAsanHeapFreeMagic:
448          bug_descr = "heap-use-after-free";
449          bug_type_score = 20;
450          if (!is_write) read_after_free_bonus = 18;
451          break;
452        case kAsanStackLeftRedzoneMagic:
453          bug_descr = "stack-buffer-underflow";
454          bug_type_score = 25;
455          far_from_bounds = AdjacentShadowValuesAreFullyPoisoned(shadow_addr);
456          break;
457        case kAsanInitializationOrderMagic:
458          bug_descr = "initialization-order-fiasco";
459          bug_type_score = 1;
460          break;
461        case kAsanStackMidRedzoneMagic:
462        case kAsanStackRightRedzoneMagic:
463          bug_descr = "stack-buffer-overflow";
464          bug_type_score = 25;
465          far_from_bounds = AdjacentShadowValuesAreFullyPoisoned(shadow_addr);
466          break;
467        case kAsanStackAfterReturnMagic:
468          bug_descr = "stack-use-after-return";
469          bug_type_score = 30;
470          if (!is_write) read_after_free_bonus = 18;
471          break;
472        case kAsanUserPoisonedMemoryMagic:
473          bug_descr = "use-after-poison";
474          bug_type_score = 20;
475          break;
476        case kAsanContiguousContainerOOBMagic:
477          bug_descr = "container-overflow";
478          bug_type_score = 10;
479          break;
480        case kAsanStackUseAfterScopeMagic:
481          bug_descr = "stack-use-after-scope";
482          bug_type_score = 10;
483          break;
484        case kAsanGlobalRedzoneMagic:
485          bug_descr = "global-buffer-overflow";
486          bug_type_score = 10;
487          far_from_bounds = AdjacentShadowValuesAreFullyPoisoned(shadow_addr);
488          break;
489        case kAsanIntraObjectRedzone:
490          bug_descr = "intra-object-overflow";
491          bug_type_score = 10;
492          break;
493        case kAsanAllocaLeftMagic:
494        case kAsanAllocaRightMagic:
495          bug_descr = "dynamic-stack-buffer-overflow";
496          bug_type_score = 25;
497          far_from_bounds = AdjacentShadowValuesAreFullyPoisoned(shadow_addr);
498          break;
499      }
500      scariness.Scare(bug_type_score + read_after_free_bonus, bug_descr);
501      if (far_from_bounds) scariness.Scare(10, "far-from-bounds");
502    }
503  }
504}
505
506static void PrintContainerOverflowHint() {
507  Printf("HINT: if you don't care about these errors you may set "
508         "ASAN_OPTIONS=detect_container_overflow=0.\n"
509         "If you suspect a false positive see also: "
510         "https://github.com/google/sanitizers/wiki/"
511         "AddressSanitizerContainerOverflow.\n");
512}
513
514static void PrintShadowByte(InternalScopedString *str, const char *before,
515    u8 byte, const char *after = "\n") {
516  PrintMemoryByte(str, before, byte, /*in_shadow*/true, after);
517}
518
519static void PrintLegend(InternalScopedString *str) {
520  str->AppendF(
521      "Shadow byte legend (one shadow byte represents %d "
522      "application bytes):\n",
523      (int)ASAN_SHADOW_GRANULARITY);
524  PrintShadowByte(str, "  Addressable:           ", 0);
525  str->AppendF("  Partially addressable: ");
526  for (u8 i = 1; i < ASAN_SHADOW_GRANULARITY; i++)
527    PrintShadowByte(str, "", i, " ");
528  str->AppendF("\n");
529  PrintShadowByte(str, "  Heap left redzone:       ",
530                  kAsanHeapLeftRedzoneMagic);
531  PrintShadowByte(str, "  Freed heap region:       ", kAsanHeapFreeMagic);
532  PrintShadowByte(str, "  Stack left redzone:      ",
533                  kAsanStackLeftRedzoneMagic);
534  PrintShadowByte(str, "  Stack mid redzone:       ",
535                  kAsanStackMidRedzoneMagic);
536  PrintShadowByte(str, "  Stack right redzone:     ",
537                  kAsanStackRightRedzoneMagic);
538  PrintShadowByte(str, "  Stack after return:      ",
539                  kAsanStackAfterReturnMagic);
540  PrintShadowByte(str, "  Stack use after scope:   ",
541                  kAsanStackUseAfterScopeMagic);
542  PrintShadowByte(str, "  Global redzone:          ", kAsanGlobalRedzoneMagic);
543  PrintShadowByte(str, "  Global init order:       ",
544                  kAsanInitializationOrderMagic);
545  PrintShadowByte(str, "  Poisoned by user:        ",
546                  kAsanUserPoisonedMemoryMagic);
547  PrintShadowByte(str, "  Container overflow:      ",
548                  kAsanContiguousContainerOOBMagic);
549  PrintShadowByte(str, "  Array cookie:            ",
550                  kAsanArrayCookieMagic);
551  PrintShadowByte(str, "  Intra object redzone:    ",
552                  kAsanIntraObjectRedzone);
553  PrintShadowByte(str, "  ASan internal:           ", kAsanInternalHeapMagic);
554  PrintShadowByte(str, "  Left alloca redzone:     ", kAsanAllocaLeftMagic);
555  PrintShadowByte(str, "  Right alloca redzone:    ", kAsanAllocaRightMagic);
556}
557
558static void PrintShadowBytes(InternalScopedString *str, const char *before,
559                             u8 *bytes, u8 *guilty, uptr n) {
560  Decorator d;
561  if (before)
562    str->AppendF("%s%p:", before,
563                 (void *)ShadowToMem(reinterpret_cast<uptr>(bytes)));
564  for (uptr i = 0; i < n; i++) {
565    u8 *p = bytes + i;
566    const char *before =
567        p == guilty ? "[" : (p - 1 == guilty && i != 0) ? "" : " ";
568    const char *after = p == guilty ? "]" : "";
569    PrintShadowByte(str, before, *p, after);
570  }
571  str->AppendF("\n");
572}
573
574static void PrintShadowMemoryForAddress(uptr addr) {
575  if (!AddrIsInMem(addr)) return;
576  uptr shadow_addr = MemToShadow(addr);
577  const uptr n_bytes_per_row = 16;
578  uptr aligned_shadow = shadow_addr & ~(n_bytes_per_row - 1);
579  InternalScopedString str;
580  str.AppendF("Shadow bytes around the buggy address:\n");
581  for (int i = -5; i <= 5; i++) {
582    uptr row_shadow_addr = aligned_shadow + i * n_bytes_per_row;
583    // Skip rows that would be outside the shadow range. This can happen when
584    // the user address is near the bottom, top, or shadow gap of the address
585    // space.
586    if (!AddrIsInShadow(row_shadow_addr)) continue;
587    const char *prefix = (i == 0) ? "=>" : "  ";
588    PrintShadowBytes(&str, prefix, (u8 *)row_shadow_addr, (u8 *)shadow_addr,
589                     n_bytes_per_row);
590  }
591  if (flags()->print_legend) PrintLegend(&str);
592  Printf("%s", str.data());
593}
594
595void ErrorGeneric::Print() {
596  Decorator d;
597  Printf("%s", d.Error());
598  uptr addr = addr_description.Address();
599  Report("ERROR: AddressSanitizer: %s on address %p at pc %p bp %p sp %p\n",
600         bug_descr, (void *)addr, (void *)pc, (void *)bp, (void *)sp);
601  Printf("%s", d.Default());
602
603  Printf("%s%s of size %zu at %p thread %s%s\n", d.Access(),
604         access_size ? (is_write ? "WRITE" : "READ") : "ACCESS", access_size,
605         (void *)addr, AsanThreadIdAndName(tid).c_str(), d.Default());
606
607  scariness.Print();
608  GET_STACK_TRACE_FATAL(pc, bp);
609  stack.Print();
610
611  // Pass bug_descr because we have a special case for
612  // initialization-order-fiasco
613  addr_description.Print(bug_descr);
614  if (shadow_val == kAsanContiguousContainerOOBMagic)
615    PrintContainerOverflowHint();
616  ReportErrorSummary(bug_descr, &stack);
617  PrintShadowMemoryForAddress(addr);
618}
619
620}  // namespace __asan
621