asan_report.cc revision 17a7c6763224300f6740b5e7fae274734afec675 
1//===-- asan_report.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// This file is a part of AddressSanitizer, an address sanity checker.
11//
12// This file contains error reporting code.
13//===----------------------------------------------------------------------===//
14#include "asan_flags.h"
15#include "asan_internal.h"
16#include "asan_mapping.h"
17#include "asan_report.h"
18#include "asan_stack.h"
19#include "asan_thread.h"
20#include "asan_thread_registry.h"
21#include "sanitizer_common/sanitizer_common.h"
22#include "sanitizer_common/sanitizer_report_decorator.h"
23#include "sanitizer_common/sanitizer_symbolizer.h"
24
25namespace __asan {
26
27// -------------------- User-specified callbacks ----------------- {{{1
28static void (*error_report_callback)(const char*);
29static char *error_message_buffer = 0;
30static uptr error_message_buffer_pos = 0;
31static uptr error_message_buffer_size = 0;
32
33void AppendToErrorMessageBuffer(const char *buffer) {
34  if (error_message_buffer) {
35    uptr length = internal_strlen(buffer);
36    CHECK_GE(error_message_buffer_size, error_message_buffer_pos);
37    uptr remaining = error_message_buffer_size - error_message_buffer_pos;
38    internal_strncpy(error_message_buffer + error_message_buffer_pos,
39                     buffer, remaining);
40    error_message_buffer[error_message_buffer_size - 1] = '\0';
41    // FIXME: reallocate the buffer instead of truncating the message.
42    error_message_buffer_pos += remaining > length ? length : remaining;
43  }
44}
45
46// ---------------------- Decorator ------------------------------ {{{1
47bool PrintsToTtyCached() {
48  static int cached = 0;
49  static bool prints_to_tty;
50  if (!cached) {  // Ok wrt threads since we are printing only from one thread.
51    prints_to_tty = PrintsToTty();
52    cached = 1;
53  }
54  return prints_to_tty;
55}
56class Decorator: private __sanitizer::AnsiColorDecorator {
57 public:
58  Decorator() : __sanitizer::AnsiColorDecorator(PrintsToTtyCached()) { }
59  const char *Warning()    { return Red(); }
60  const char *EndWarning() { return Default(); }
61  const char *Access()     { return Blue(); }
62  const char *EndAccess()  { return Default(); }
63  const char *Location()   { return Green(); }
64  const char *EndLocation() { return Default(); }
65  const char *Allocation()  { return Magenta(); }
66  const char *EndAllocation()  { return Default(); }
67
68  const char *ShadowByte(u8 byte) {
69    switch (byte) {
70      case kAsanHeapLeftRedzoneMagic:
71      case kAsanHeapRightRedzoneMagic:
72        return Red();
73      case kAsanHeapFreeMagic:
74        return Magenta();
75      case kAsanStackLeftRedzoneMagic:
76      case kAsanStackMidRedzoneMagic:
77      case kAsanStackRightRedzoneMagic:
78      case kAsanStackPartialRedzoneMagic:
79        return Red();
80      case kAsanStackAfterReturnMagic:
81        return Magenta();
82      case kAsanInitializationOrderMagic:
83        return Cyan();
84      case kAsanUserPoisonedMemoryMagic:
85        return Blue();
86      case kAsanStackUseAfterScopeMagic:
87        return Magenta();
88      case kAsanGlobalRedzoneMagic:
89        return Red();
90      case kAsanInternalHeapMagic:
91        return Yellow();
92      default:
93        return Default();
94    }
95  }
96  const char *EndShadowByte() { return Default(); }
97};
98
99// ---------------------- Helper functions ----------------------- {{{1
100
101static void PrintShadowByte(const char *before, u8 byte,
102                            const char *after = "\n") {
103  Decorator d;
104  Printf("%s%s%x%x%s%s", before,
105         d.ShadowByte(byte), byte >> 4, byte & 15, d.EndShadowByte(), after);
106}
107
108static void PrintShadowBytes(const char *before, u8 *bytes,
109                             u8 *guilty, uptr n) {
110  Decorator d;
111  if (before)
112    Printf("%s%p:", before, bytes);
113  for (uptr i = 0; i < n; i++) {
114    u8 *p = bytes + i;
115    const char *before = p == guilty ? "[" :
116        p - 1 == guilty ? "" : " ";
117    const char *after = p == guilty ? "]" : "";
118    PrintShadowByte(before, *p, after);
119  }
120  Printf("\n");
121}
122
123static void PrintShadowMemoryForAddress(uptr addr) {
124  if (!AddrIsInMem(addr))
125    return;
126  uptr shadow_addr = MemToShadow(addr);
127  const uptr n_bytes_per_row = 16;
128  uptr aligned_shadow = shadow_addr & ~(n_bytes_per_row - 1);
129  Printf("Shadow bytes around the buggy address:\n");
130  for (int i = -5; i <= 5; i++) {
131    const char *prefix = (i == 0) ? "=>" : "  ";
132    PrintShadowBytes(prefix,
133                     (u8*)(aligned_shadow + i * n_bytes_per_row),
134                     (u8*)shadow_addr, n_bytes_per_row);
135  }
136  Printf("Shadow byte legend (one shadow byte represents %d "
137         "application bytes):\n", (int)SHADOW_GRANULARITY);
138  PrintShadowByte("  Addressable:           ", 0);
139  Printf("  Partially addressable: ");
140  for (uptr i = 1; i < SHADOW_GRANULARITY; i++)
141    PrintShadowByte("", i, " ");
142  Printf("\n");
143  PrintShadowByte("  Heap left redzone:     ", kAsanHeapLeftRedzoneMagic);
144  PrintShadowByte("  Heap righ redzone:     ", kAsanHeapRightRedzoneMagic);
145  PrintShadowByte("  Freed Heap region:     ", kAsanHeapFreeMagic);
146  PrintShadowByte("  Stack left redzone:    ", kAsanStackLeftRedzoneMagic);
147  PrintShadowByte("  Stack mid redzone:     ", kAsanStackMidRedzoneMagic);
148  PrintShadowByte("  Stack right redzone:   ", kAsanStackRightRedzoneMagic);
149  PrintShadowByte("  Stack partial redzone: ", kAsanStackPartialRedzoneMagic);
150  PrintShadowByte("  Stack after return:    ", kAsanStackAfterReturnMagic);
151  PrintShadowByte("  Stack use after scope: ", kAsanStackUseAfterScopeMagic);
152  PrintShadowByte("  Global redzone:        ", kAsanGlobalRedzoneMagic);
153  PrintShadowByte("  Global init order:     ", kAsanInitializationOrderMagic);
154  PrintShadowByte("  Poisoned by user:      ", kAsanUserPoisonedMemoryMagic);
155  PrintShadowByte("  ASan internal:         ", kAsanInternalHeapMagic);
156}
157
158static void PrintZoneForPointer(uptr ptr, uptr zone_ptr,
159                                const char *zone_name) {
160  if (zone_ptr) {
161    if (zone_name) {
162      Printf("malloc_zone_from_ptr(%p) = %p, which is %s\n",
163                 ptr, zone_ptr, zone_name);
164    } else {
165      Printf("malloc_zone_from_ptr(%p) = %p, which doesn't have a name\n",
166                 ptr, zone_ptr);
167    }
168  } else {
169    Printf("malloc_zone_from_ptr(%p) = 0\n", ptr);
170  }
171}
172
173// ---------------------- Address Descriptions ------------------- {{{1
174
175static bool IsASCII(unsigned char c) {
176  return /*0x00 <= c &&*/ c <= 0x7F;
177}
178
179// Check if the global is a zero-terminated ASCII string. If so, print it.
180static void PrintGlobalNameIfASCII(const __asan_global &g) {
181  for (uptr p = g.beg; p < g.beg + g.size - 1; p++) {
182    if (!IsASCII(*(unsigned char*)p)) return;
183  }
184  if (*(char*)(g.beg + g.size - 1) != 0) return;
185  Printf("  '%s' is ascii string '%s'\n", g.name, (char*)g.beg);
186}
187
188bool DescribeAddressRelativeToGlobal(uptr addr, const __asan_global &g) {
189  if (addr < g.beg - kGlobalAndStackRedzone) return false;
190  if (addr >= g.beg + g.size_with_redzone) return false;
191  Decorator d;
192  Printf("%s", d.Location());
193  Printf("%p is located ", (void*)addr);
194  if (addr < g.beg) {
195    Printf("%zd bytes to the left", g.beg - addr);
196  } else if (addr >= g.beg + g.size) {
197    Printf("%zd bytes to the right", addr - (g.beg + g.size));
198  } else {
199    Printf("%zd bytes inside", addr - g.beg);  // Can it happen?
200  }
201  Printf(" of global variable '%s' (0x%zx) of size %zu\n",
202             g.name, g.beg, g.size);
203  Printf("%s", d.EndLocation());
204  PrintGlobalNameIfASCII(g);
205  return true;
206}
207
208bool DescribeAddressIfShadow(uptr addr) {
209  if (AddrIsInMem(addr))
210    return false;
211  static const char kAddrInShadowReport[] =
212      "Address %p is located in the %s.\n";
213  if (AddrIsInShadowGap(addr)) {
214    Printf(kAddrInShadowReport, addr, "shadow gap area");
215    return true;
216  }
217  if (AddrIsInHighShadow(addr)) {
218    Printf(kAddrInShadowReport, addr, "high shadow area");
219    return true;
220  }
221  if (AddrIsInLowShadow(addr)) {
222    Printf(kAddrInShadowReport, addr, "low shadow area");
223    return true;
224  }
225  CHECK(0 && "Address is not in memory and not in shadow?");
226  return false;
227}
228
229bool DescribeAddressIfStack(uptr addr, uptr access_size) {
230  AsanThread *t = asanThreadRegistry().FindThreadByStackAddress(addr);
231  if (!t) return false;
232  const sptr kBufSize = 4095;
233  char buf[kBufSize];
234  uptr offset = 0;
235  const char *frame_descr = t->GetFrameNameByAddr(addr, &offset);
236  // This string is created by the compiler and has the following form:
237  // "FunctioName n alloc_1 alloc_2 ... alloc_n"
238  // where alloc_i looks like "offset size len ObjectName ".
239  CHECK(frame_descr);
240  // Report the function name and the offset.
241  const char *name_end = internal_strchr(frame_descr, ' ');
242  CHECK(name_end);
243  buf[0] = 0;
244  internal_strncat(buf, frame_descr,
245                   Min(kBufSize,
246                       static_cast<sptr>(name_end - frame_descr)));
247  Decorator d;
248  Printf("%s", d.Location());
249  Printf("Address %p is located at offset %zu "
250             "in frame <%s> of T%d's stack:\n",
251             (void*)addr, offset, Demangle(buf), t->tid());
252  Printf("%s", d.EndLocation());
253  // Report the number of stack objects.
254  char *p;
255  uptr n_objects = internal_simple_strtoll(name_end, &p, 10);
256  CHECK(n_objects > 0);
257  Printf("  This frame has %zu object(s):\n", n_objects);
258  // Report all objects in this frame.
259  for (uptr i = 0; i < n_objects; i++) {
260    uptr beg, size;
261    sptr len;
262    beg  = internal_simple_strtoll(p, &p, 10);
263    size = internal_simple_strtoll(p, &p, 10);
264    len  = internal_simple_strtoll(p, &p, 10);
265    if (beg <= 0 || size <= 0 || len < 0 || *p != ' ') {
266      Printf("AddressSanitizer can't parse the stack frame "
267                 "descriptor: |%s|\n", frame_descr);
268      break;
269    }
270    p++;
271    buf[0] = 0;
272    internal_strncat(buf, p, Min(kBufSize, len));
273    p += len;
274    Printf("    [%zu, %zu) '%s'\n", beg, beg + size, buf);
275  }
276  Printf("HINT: this may be a false positive if your program uses "
277             "some custom stack unwind mechanism or swapcontext\n"
278             "      (longjmp and C++ exceptions *are* supported)\n");
279  DescribeThread(t->summary());
280  return true;
281}
282
283static void DescribeAccessToHeapChunk(AsanChunkView chunk, uptr addr,
284                                      uptr access_size) {
285  uptr offset;
286  Decorator d;
287  Printf("%s", d.Location());
288  Printf("%p is located ", (void*)addr);
289  if (chunk.AddrIsInside(addr, access_size, &offset)) {
290    Printf("%zu bytes inside of", offset);
291  } else if (chunk.AddrIsAtLeft(addr, access_size, &offset)) {
292    Printf("%zu bytes to the left of", offset);
293  } else if (chunk.AddrIsAtRight(addr, access_size, &offset)) {
294    Printf("%zu bytes to the right of", offset);
295  } else {
296    Printf(" somewhere around (this is AddressSanitizer bug!)");
297  }
298  Printf(" %zu-byte region [%p,%p)\n", chunk.UsedSize(),
299         (void*)(chunk.Beg()), (void*)(chunk.End()));
300  Printf("%s", d.EndLocation());
301}
302
303// Return " (thread_name) " or an empty string if the name is empty.
304const char *ThreadNameWithParenthesis(AsanThreadSummary *t, char buff[],
305                                      uptr buff_len) {
306  const char *name = t->name();
307  if (*name == 0) return "";
308  buff[0] = 0;
309  internal_strncat(buff, " (", 3);
310  internal_strncat(buff, name, buff_len - 4);
311  internal_strncat(buff, ")", 2);
312  return buff;
313}
314
315const char *ThreadNameWithParenthesis(u32 tid, char buff[],
316                                      uptr buff_len) {
317  if (tid == kInvalidTid) return "";
318  AsanThreadSummary *t = asanThreadRegistry().FindByTid(tid);
319  return ThreadNameWithParenthesis(t, buff, buff_len);
320}
321
322void DescribeHeapAddress(uptr addr, uptr access_size) {
323  AsanChunkView chunk = FindHeapChunkByAddress(addr);
324  if (!chunk.IsValid()) return;
325  DescribeAccessToHeapChunk(chunk, addr, access_size);
326  CHECK(chunk.AllocTid() != kInvalidTid);
327  AsanThreadSummary *alloc_thread =
328      asanThreadRegistry().FindByTid(chunk.AllocTid());
329  StackTrace alloc_stack;
330  chunk.GetAllocStack(&alloc_stack);
331  AsanThread *t = asanThreadRegistry().GetCurrent();
332  CHECK(t);
333  char tname[128];
334  Decorator d;
335  if (chunk.FreeTid() != kInvalidTid) {
336    AsanThreadSummary *free_thread =
337        asanThreadRegistry().FindByTid(chunk.FreeTid());
338    Printf("%sfreed by thread T%d%s here:%s\n", d.Allocation(),
339           free_thread->tid(),
340           ThreadNameWithParenthesis(free_thread, tname, sizeof(tname)),
341           d.EndAllocation());
342    StackTrace free_stack;
343    chunk.GetFreeStack(&free_stack);
344    PrintStack(&free_stack);
345    Printf("%spreviously allocated by thread T%d%s here:%s\n",
346           d.Allocation(), alloc_thread->tid(),
347           ThreadNameWithParenthesis(alloc_thread, tname, sizeof(tname)),
348           d.EndAllocation());
349    PrintStack(&alloc_stack);
350    DescribeThread(t->summary());
351    DescribeThread(free_thread);
352    DescribeThread(alloc_thread);
353  } else {
354    Printf("%sallocated by thread T%d%s here:%s\n", d.Allocation(),
355           alloc_thread->tid(),
356           ThreadNameWithParenthesis(alloc_thread, tname, sizeof(tname)),
357           d.EndAllocation());
358    PrintStack(&alloc_stack);
359    DescribeThread(t->summary());
360    DescribeThread(alloc_thread);
361  }
362}
363
364void DescribeAddress(uptr addr, uptr access_size) {
365  // Check if this is shadow or shadow gap.
366  if (DescribeAddressIfShadow(addr))
367    return;
368  CHECK(AddrIsInMem(addr));
369  if (DescribeAddressIfGlobal(addr))
370    return;
371  if (DescribeAddressIfStack(addr, access_size))
372    return;
373  // Assume it is a heap address.
374  DescribeHeapAddress(addr, access_size);
375}
376
377// ------------------- Thread description -------------------- {{{1
378
379void DescribeThread(AsanThreadSummary *summary) {
380  CHECK(summary);
381  // No need to announce the main thread.
382  if (summary->tid() == 0 || summary->announced()) {
383    return;
384  }
385  summary->set_announced(true);
386  char tname[128];
387  Printf("Thread T%d%s", summary->tid(),
388         ThreadNameWithParenthesis(summary->tid(), tname, sizeof(tname)));
389  Printf(" created by T%d%s here:\n",
390         summary->parent_tid(),
391         ThreadNameWithParenthesis(summary->parent_tid(),
392                                   tname, sizeof(tname)));
393  PrintStack(summary->stack());
394  // Recursively described parent thread if needed.
395  if (flags()->print_full_thread_history) {
396    AsanThreadSummary *parent_summary =
397        asanThreadRegistry().FindByTid(summary->parent_tid());
398    DescribeThread(parent_summary);
399  }
400}
401
402// -------------------- Different kinds of reports ----------------- {{{1
403
404// Use ScopedInErrorReport to run common actions just before and
405// immediately after printing error report.
406class ScopedInErrorReport {
407 public:
408  ScopedInErrorReport() {
409    static atomic_uint32_t num_calls;
410    static u32 reporting_thread_tid;
411    if (atomic_fetch_add(&num_calls, 1, memory_order_relaxed) != 0) {
412      // Do not print more than one report, otherwise they will mix up.
413      // Error reporting functions shouldn't return at this situation, as
414      // they are defined as no-return.
415      Report("AddressSanitizer: while reporting a bug found another one."
416                 "Ignoring.\n");
417      u32 current_tid = asanThreadRegistry().GetCurrentTidOrInvalid();
418      if (current_tid != reporting_thread_tid) {
419        // ASan found two bugs in different threads simultaneously. Sleep
420        // long enough to make sure that the thread which started to print
421        // an error report will finish doing it.
422        SleepForSeconds(Max(100, flags()->sleep_before_dying + 1));
423      }
424      // If we're still not dead for some reason, use raw Exit() instead of
425      // Die() to bypass any additional checks.
426      Exit(flags()->exitcode);
427    }
428    ASAN_ON_ERROR();
429    reporting_thread_tid = asanThreadRegistry().GetCurrentTidOrInvalid();
430    Printf("===================================================="
431           "=============\n");
432    if (reporting_thread_tid != kInvalidTid) {
433      // We started reporting an error message. Stop using the fake stack
434      // in case we call an instrumented function from a symbolizer.
435      AsanThread *curr_thread = asanThreadRegistry().GetCurrent();
436      CHECK(curr_thread);
437      curr_thread->fake_stack().StopUsingFakeStack();
438    }
439  }
440  // Destructor is NORETURN, as functions that report errors are.
441  NORETURN ~ScopedInErrorReport() {
442    // Make sure the current thread is announced.
443    AsanThread *curr_thread = asanThreadRegistry().GetCurrent();
444    if (curr_thread) {
445      DescribeThread(curr_thread->summary());
446    }
447    // Print memory stats.
448    __asan_print_accumulated_stats();
449    if (error_report_callback) {
450      error_report_callback(error_message_buffer);
451    }
452    Report("ABORTING\n");
453    Die();
454  }
455};
456
457void ReportSIGSEGV(uptr pc, uptr sp, uptr bp, uptr addr) {
458  ScopedInErrorReport in_report;
459  Decorator d;
460  Printf("%s", d.Warning());
461  Report("ERROR: AddressSanitizer: SEGV on unknown address %p"
462             " (pc %p sp %p bp %p T%d)\n",
463             (void*)addr, (void*)pc, (void*)sp, (void*)bp,
464             asanThreadRegistry().GetCurrentTidOrInvalid());
465  Printf("%s", d.EndWarning());
466  Printf("AddressSanitizer can not provide additional info.\n");
467  GET_STACK_TRACE_FATAL(pc, bp);
468  PrintStack(&stack);
469}
470
471void ReportDoubleFree(uptr addr, StackTrace *stack) {
472  ScopedInErrorReport in_report;
473  Decorator d;
474  Printf("%s", d.Warning());
475  Report("ERROR: AddressSanitizer: attempting double-free on %p:\n", addr);
476  Printf("%s", d.EndWarning());
477  PrintStack(stack);
478  DescribeHeapAddress(addr, 1);
479}
480
481void ReportFreeNotMalloced(uptr addr, StackTrace *stack) {
482  ScopedInErrorReport in_report;
483  Decorator d;
484  Printf("%s", d.Warning());
485  Report("ERROR: AddressSanitizer: attempting free on address "
486             "which was not malloc()-ed: %p\n", addr);
487  Printf("%s", d.EndWarning());
488  PrintStack(stack);
489  DescribeHeapAddress(addr, 1);
490}
491
492void ReportAllocTypeMismatch(uptr addr, StackTrace *stack,
493                             AllocType alloc_type,
494                             AllocType dealloc_type) {
495  static const char *alloc_names[] =
496    {"INVALID", "malloc", "operator new", "operator new []"};
497  static const char *dealloc_names[] =
498    {"INVALID", "free", "operator delete", "operator delete []"};
499  CHECK_NE(alloc_type, dealloc_type);
500  ScopedInErrorReport in_report;
501  Decorator d;
502  Printf("%s", d.Warning());
503  Report("ERROR: AddressSanitizer: alloc-dealloc-mismatch (%s vs %s) on %p\n",
504        alloc_names[alloc_type], dealloc_names[dealloc_type], addr);
505  Printf("%s", d.EndWarning());
506  PrintStack(stack);
507  DescribeHeapAddress(addr, 1);
508  Report("HINT: if you don't care about these warnings you may set "
509         "ASAN_OPTIONS=alloc_dealloc_mismatch=0\n");
510}
511
512void ReportMallocUsableSizeNotOwned(uptr addr, StackTrace *stack) {
513  ScopedInErrorReport in_report;
514  Decorator d;
515  Printf("%s", d.Warning());
516  Report("ERROR: AddressSanitizer: attempting to call "
517             "malloc_usable_size() for pointer which is "
518             "not owned: %p\n", addr);
519  Printf("%s", d.EndWarning());
520  PrintStack(stack);
521  DescribeHeapAddress(addr, 1);
522}
523
524void ReportAsanGetAllocatedSizeNotOwned(uptr addr, StackTrace *stack) {
525  ScopedInErrorReport in_report;
526  Decorator d;
527  Printf("%s", d.Warning());
528  Report("ERROR: AddressSanitizer: attempting to call "
529             "__asan_get_allocated_size() for pointer which is "
530             "not owned: %p\n", addr);
531  Printf("%s", d.EndWarning());
532  PrintStack(stack);
533  DescribeHeapAddress(addr, 1);
534}
535
536void ReportStringFunctionMemoryRangesOverlap(
537    const char *function, const char *offset1, uptr length1,
538    const char *offset2, uptr length2, StackTrace *stack) {
539  ScopedInErrorReport in_report;
540  Decorator d;
541  Printf("%s", d.Warning());
542  Report("ERROR: AddressSanitizer: %s-param-overlap: "
543             "memory ranges [%p,%p) and [%p, %p) overlap\n", \
544             function, offset1, offset1 + length1, offset2, offset2 + length2);
545  Printf("%s", d.EndWarning());
546  PrintStack(stack);
547  DescribeAddress((uptr)offset1, length1);
548  DescribeAddress((uptr)offset2, length2);
549}
550
551// ----------------------- Mac-specific reports ----------------- {{{1
552
553void WarnMacFreeUnallocated(
554    uptr addr, uptr zone_ptr, const char *zone_name, StackTrace *stack) {
555  // Just print a warning here.
556  Printf("free_common(%p) -- attempting to free unallocated memory.\n"
557             "AddressSanitizer is ignoring this error on Mac OS now.\n",
558             addr);
559  PrintZoneForPointer(addr, zone_ptr, zone_name);
560  PrintStack(stack);
561  DescribeHeapAddress(addr, 1);
562}
563
564void ReportMacMzReallocUnknown(
565    uptr addr, uptr zone_ptr, const char *zone_name, StackTrace *stack) {
566  ScopedInErrorReport in_report;
567  Printf("mz_realloc(%p) -- attempting to realloc unallocated memory.\n"
568             "This is an unrecoverable problem, exiting now.\n",
569             addr);
570  PrintZoneForPointer(addr, zone_ptr, zone_name);
571  PrintStack(stack);
572  DescribeHeapAddress(addr, 1);
573}
574
575void ReportMacCfReallocUnknown(
576    uptr addr, uptr zone_ptr, const char *zone_name, StackTrace *stack) {
577  ScopedInErrorReport in_report;
578  Printf("cf_realloc(%p) -- attempting to realloc unallocated memory.\n"
579             "This is an unrecoverable problem, exiting now.\n",
580             addr);
581  PrintZoneForPointer(addr, zone_ptr, zone_name);
582  PrintStack(stack);
583  DescribeHeapAddress(addr, 1);
584}
585
586}  // namespace __asan
587
588// --------------------------- Interface --------------------- {{{1
589using namespace __asan;  // NOLINT
590
591void __asan_report_error(uptr pc, uptr bp, uptr sp,
592                         uptr addr, bool is_write, uptr access_size) {
593  ScopedInErrorReport in_report;
594
595  // Determine the error type.
596  const char *bug_descr = "unknown-crash";
597  if (AddrIsInMem(addr)) {
598    u8 *shadow_addr = (u8*)MemToShadow(addr);
599    // If we are accessing 16 bytes, look at the second shadow byte.
600    if (*shadow_addr == 0 && access_size > SHADOW_GRANULARITY)
601      shadow_addr++;
602    // If we are in the partial right redzone, look at the next shadow byte.
603    if (*shadow_addr > 0 && *shadow_addr < 128)
604      shadow_addr++;
605    switch (*shadow_addr) {
606      case kAsanHeapLeftRedzoneMagic:
607      case kAsanHeapRightRedzoneMagic:
608        bug_descr = "heap-buffer-overflow";
609        break;
610      case kAsanHeapFreeMagic:
611        bug_descr = "heap-use-after-free";
612        break;
613      case kAsanStackLeftRedzoneMagic:
614        bug_descr = "stack-buffer-underflow";
615        break;
616      case kAsanInitializationOrderMagic:
617        bug_descr = "initialization-order-fiasco";
618        break;
619      case kAsanStackMidRedzoneMagic:
620      case kAsanStackRightRedzoneMagic:
621      case kAsanStackPartialRedzoneMagic:
622        bug_descr = "stack-buffer-overflow";
623        break;
624      case kAsanStackAfterReturnMagic:
625        bug_descr = "stack-use-after-return";
626        break;
627      case kAsanUserPoisonedMemoryMagic:
628        bug_descr = "use-after-poison";
629        break;
630      case kAsanStackUseAfterScopeMagic:
631        bug_descr = "stack-use-after-scope";
632        break;
633      case kAsanGlobalRedzoneMagic:
634        bug_descr = "global-buffer-overflow";
635        break;
636    }
637  }
638  Decorator d;
639  Printf("%s", d.Warning());
640  Report("ERROR: AddressSanitizer: %s on address "
641             "%p at pc 0x%zx bp 0x%zx sp 0x%zx\n",
642             bug_descr, (void*)addr, pc, bp, sp);
643  Printf("%s", d.EndWarning());
644
645  u32 curr_tid = asanThreadRegistry().GetCurrentTidOrInvalid();
646  char tname[128];
647  Printf("%s%s of size %zu at %p thread T%d%s%s\n",
648         d.Access(),
649         access_size ? (is_write ? "WRITE" : "READ") : "ACCESS",
650         access_size, (void*)addr, curr_tid,
651         ThreadNameWithParenthesis(curr_tid, tname, sizeof(tname)),
652         d.EndAccess());
653
654  GET_STACK_TRACE_FATAL(pc, bp);
655  PrintStack(&stack);
656
657  DescribeAddress(addr, access_size);
658
659  PrintShadowMemoryForAddress(addr);
660}
661
662void NOINLINE __asan_set_error_report_callback(void (*callback)(const char*)) {
663  error_report_callback = callback;
664  if (callback) {
665    error_message_buffer_size = 1 << 16;
666    error_message_buffer =
667        (char*)MmapOrDie(error_message_buffer_size, __FUNCTION__);
668    error_message_buffer_pos = 0;
669  }
670}
671
672void __asan_describe_address(uptr addr) {
673  DescribeAddress(addr, 1);
674}
675
676#if !SANITIZER_SUPPORTS_WEAK_HOOKS
677// Provide default implementation of __asan_on_error that does nothing
678// and may be overriden by user.
679SANITIZER_WEAK_ATTRIBUTE SANITIZER_INTERFACE_ATTRIBUTE NOINLINE
680void __asan_on_error() {}
681#endif
682