asan_report.cc revision 5d71de26cedae3dafc17449fe0182045c0bd20e8 
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 "sanitizer_common/sanitizer_common.h"
21#include "sanitizer_common/sanitizer_flags.h"
22#include "sanitizer_common/sanitizer_report_decorator.h"
23#include "sanitizer_common/sanitizer_stackdepot.h"
24#include "sanitizer_common/sanitizer_symbolizer.h"
25
26namespace __asan {
27
28// -------------------- User-specified callbacks ----------------- {{{1
29static void (*error_report_callback)(const char*);
30static char *error_message_buffer = 0;
31static uptr error_message_buffer_pos = 0;
32static uptr error_message_buffer_size = 0;
33
34void AppendToErrorMessageBuffer(const char *buffer) {
35  if (error_message_buffer) {
36    uptr length = internal_strlen(buffer);
37    CHECK_GE(error_message_buffer_size, error_message_buffer_pos);
38    uptr remaining = error_message_buffer_size - error_message_buffer_pos;
39    internal_strncpy(error_message_buffer + error_message_buffer_pos,
40                     buffer, remaining);
41    error_message_buffer[error_message_buffer_size - 1] = '\0';
42    // FIXME: reallocate the buffer instead of truncating the message.
43    error_message_buffer_pos += remaining > length ? length : remaining;
44  }
45}
46
47// ---------------------- Decorator ------------------------------ {{{1
48class Decorator: public __sanitizer::SanitizerCommonDecorator {
49 public:
50  Decorator() : SanitizerCommonDecorator() { }
51  const char *Access()     { return Blue(); }
52  const char *EndAccess()  { return Default(); }
53  const char *Location()   { return Green(); }
54  const char *EndLocation() { return Default(); }
55  const char *Allocation()  { return Magenta(); }
56  const char *EndAllocation()  { return Default(); }
57
58  const char *ShadowByte(u8 byte) {
59    switch (byte) {
60      case kAsanHeapLeftRedzoneMagic:
61      case kAsanHeapRightRedzoneMagic:
62        return Red();
63      case kAsanHeapFreeMagic:
64        return Magenta();
65      case kAsanStackLeftRedzoneMagic:
66      case kAsanStackMidRedzoneMagic:
67      case kAsanStackRightRedzoneMagic:
68      case kAsanStackPartialRedzoneMagic:
69        return Red();
70      case kAsanStackAfterReturnMagic:
71        return Magenta();
72      case kAsanInitializationOrderMagic:
73        return Cyan();
74      case kAsanUserPoisonedMemoryMagic:
75      case kAsanContiguousContainerOOBMagic:
76        return Blue();
77      case kAsanStackUseAfterScopeMagic:
78        return Magenta();
79      case kAsanGlobalRedzoneMagic:
80        return Red();
81      case kAsanInternalHeapMagic:
82        return Yellow();
83      default:
84        return Default();
85    }
86  }
87  const char *EndShadowByte() { return Default(); }
88};
89
90// ---------------------- Helper functions ----------------------- {{{1
91
92static void PrintShadowByte(InternalScopedString *str, const char *before,
93                            u8 byte, const char *after = "\n") {
94  Decorator d;
95  str->append("%s%s%x%x%s%s", before, d.ShadowByte(byte), byte >> 4, byte & 15,
96              d.EndShadowByte(), after);
97}
98
99static void PrintShadowBytes(InternalScopedString *str, const char *before,
100                             u8 *bytes, u8 *guilty, uptr n) {
101  Decorator d;
102  if (before) str->append("%s%p:", before, bytes);
103  for (uptr i = 0; i < n; i++) {
104    u8 *p = bytes + i;
105    const char *before =
106        p == guilty ? "[" : (p - 1 == guilty && i != 0) ? "" : " ";
107    const char *after = p == guilty ? "]" : "";
108    PrintShadowByte(str, before, *p, after);
109  }
110  str->append("\n");
111}
112
113static void PrintLegend(InternalScopedString *str) {
114  str->append(
115      "Shadow byte legend (one shadow byte represents %d "
116      "application bytes):\n",
117      (int)SHADOW_GRANULARITY);
118  PrintShadowByte(str, "  Addressable:           ", 0);
119  str->append("  Partially addressable: ");
120  for (u8 i = 1; i < SHADOW_GRANULARITY; i++) PrintShadowByte(str, "", i, " ");
121  str->append("\n");
122  PrintShadowByte(str, "  Heap left redzone:       ",
123                  kAsanHeapLeftRedzoneMagic);
124  PrintShadowByte(str, "  Heap right redzone:      ",
125                  kAsanHeapRightRedzoneMagic);
126  PrintShadowByte(str, "  Freed heap region:       ", kAsanHeapFreeMagic);
127  PrintShadowByte(str, "  Stack left redzone:      ",
128                  kAsanStackLeftRedzoneMagic);
129  PrintShadowByte(str, "  Stack mid redzone:       ",
130                  kAsanStackMidRedzoneMagic);
131  PrintShadowByte(str, "  Stack right redzone:     ",
132                  kAsanStackRightRedzoneMagic);
133  PrintShadowByte(str, "  Stack partial redzone:   ",
134                  kAsanStackPartialRedzoneMagic);
135  PrintShadowByte(str, "  Stack after return:      ",
136                  kAsanStackAfterReturnMagic);
137  PrintShadowByte(str, "  Stack use after scope:   ",
138                  kAsanStackUseAfterScopeMagic);
139  PrintShadowByte(str, "  Global redzone:          ", kAsanGlobalRedzoneMagic);
140  PrintShadowByte(str, "  Global init order:       ",
141                  kAsanInitializationOrderMagic);
142  PrintShadowByte(str, "  Poisoned by user:        ",
143                  kAsanUserPoisonedMemoryMagic);
144  PrintShadowByte(str, "  Container overflow:      ",
145                  kAsanContiguousContainerOOBMagic);
146  PrintShadowByte(str, "  ASan internal:           ", kAsanInternalHeapMagic);
147}
148
149static void PrintShadowMemoryForAddress(uptr addr) {
150  if (!AddrIsInMem(addr)) return;
151  uptr shadow_addr = MemToShadow(addr);
152  const uptr n_bytes_per_row = 16;
153  uptr aligned_shadow = shadow_addr & ~(n_bytes_per_row - 1);
154  InternalScopedString str(4096 * 8);
155  str.append("Shadow bytes around the buggy address:\n");
156  for (int i = -5; i <= 5; i++) {
157    const char *prefix = (i == 0) ? "=>" : "  ";
158    PrintShadowBytes(&str, prefix, (u8 *)(aligned_shadow + i * n_bytes_per_row),
159                     (u8 *)shadow_addr, n_bytes_per_row);
160  }
161  if (flags()->print_legend) PrintLegend(&str);
162  Printf("%s", str.data());
163}
164
165static void PrintZoneForPointer(uptr ptr, uptr zone_ptr,
166                                const char *zone_name) {
167  if (zone_ptr) {
168    if (zone_name) {
169      Printf("malloc_zone_from_ptr(%p) = %p, which is %s\n",
170                 ptr, zone_ptr, zone_name);
171    } else {
172      Printf("malloc_zone_from_ptr(%p) = %p, which doesn't have a name\n",
173                 ptr, zone_ptr);
174    }
175  } else {
176    Printf("malloc_zone_from_ptr(%p) = 0\n", ptr);
177  }
178}
179
180static void DescribeThread(AsanThread *t) {
181  if (t)
182    DescribeThread(t->context());
183}
184
185// ---------------------- Address Descriptions ------------------- {{{1
186
187static bool IsASCII(unsigned char c) {
188  return /*0x00 <= c &&*/ c <= 0x7F;
189}
190
191static const char *MaybeDemangleGlobalName(const char *name) {
192  // We can spoil names of globals with C linkage, so use an heuristic
193  // approach to check if the name should be demangled.
194  bool should_demangle = false;
195  if (name[0] == '_' && name[1] == 'Z')
196    should_demangle = true;
197  else if (SANITIZER_WINDOWS && name[0] == '\01' && name[1] == '?')
198    should_demangle = true;
199
200  return should_demangle ? Symbolizer::Get()->Demangle(name) : name;
201}
202
203// Check if the global is a zero-terminated ASCII string. If so, print it.
204static void PrintGlobalNameIfASCII(InternalScopedString *str,
205                                   const __asan_global &g) {
206  for (uptr p = g.beg; p < g.beg + g.size - 1; p++) {
207    unsigned char c = *(unsigned char*)p;
208    if (c == '\0' || !IsASCII(c)) return;
209  }
210  if (*(char*)(g.beg + g.size - 1) != '\0') return;
211  str->append("  '%s' is ascii string '%s'\n", MaybeDemangleGlobalName(g.name),
212              (char *)g.beg);
213}
214
215static const char *GlobalFilename(const __asan_global &g) {
216  const char *res = g.module_name;
217  // Prefer the filename from source location, if is available.
218  if (g.location)
219    res = g.location->filename;
220  CHECK(res);
221  return res;
222}
223
224static void PrintGlobalLocation(InternalScopedString *str,
225                                const __asan_global &g) {
226  str->append("%s", GlobalFilename(g));
227  if (!g.location)
228    return;
229  if (g.location->line_no)
230    str->append(":%d", g.location->line_no);
231  if (g.location->column_no)
232    str->append(":%d", g.location->column_no);
233}
234
235bool DescribeAddressRelativeToGlobal(uptr addr, uptr size,
236                                     const __asan_global &g) {
237  static const uptr kMinimalDistanceFromAnotherGlobal = 64;
238  if (addr <= g.beg - kMinimalDistanceFromAnotherGlobal) return false;
239  if (addr >= g.beg + g.size_with_redzone) return false;
240  InternalScopedString str(4096);
241  Decorator d;
242  str.append("%s", d.Location());
243  if (addr < g.beg) {
244    str.append("%p is located %zd bytes to the left", (void *)addr,
245               g.beg - addr);
246  } else if (addr + size > g.beg + g.size) {
247    if (addr < g.beg + g.size)
248      addr = g.beg + g.size;
249    str.append("%p is located %zd bytes to the right", (void *)addr,
250               addr - (g.beg + g.size));
251  } else {
252    // Can it happen?
253    str.append("%p is located %zd bytes inside", (void *)addr, addr - g.beg);
254  }
255  str.append(" of global variable '%s' defined in '",
256             MaybeDemangleGlobalName(g.name));
257  PrintGlobalLocation(&str, g);
258  str.append("' (0x%zx) of size %zu\n", g.beg, g.size);
259  str.append("%s", d.EndLocation());
260  PrintGlobalNameIfASCII(&str, g);
261  Printf("%s", str.data());
262  return true;
263}
264
265bool DescribeAddressIfShadow(uptr addr) {
266  if (AddrIsInMem(addr))
267    return false;
268  static const char kAddrInShadowReport[] =
269      "Address %p is located in the %s.\n";
270  if (AddrIsInShadowGap(addr)) {
271    Printf(kAddrInShadowReport, addr, "shadow gap area");
272    return true;
273  }
274  if (AddrIsInHighShadow(addr)) {
275    Printf(kAddrInShadowReport, addr, "high shadow area");
276    return true;
277  }
278  if (AddrIsInLowShadow(addr)) {
279    Printf(kAddrInShadowReport, addr, "low shadow area");
280    return true;
281  }
282  CHECK(0 && "Address is not in memory and not in shadow?");
283  return false;
284}
285
286// Return " (thread_name) " or an empty string if the name is empty.
287const char *ThreadNameWithParenthesis(AsanThreadContext *t, char buff[],
288                                      uptr buff_len) {
289  const char *name = t->name;
290  if (name[0] == '\0') return "";
291  buff[0] = 0;
292  internal_strncat(buff, " (", 3);
293  internal_strncat(buff, name, buff_len - 4);
294  internal_strncat(buff, ")", 2);
295  return buff;
296}
297
298const char *ThreadNameWithParenthesis(u32 tid, char buff[],
299                                      uptr buff_len) {
300  if (tid == kInvalidTid) return "";
301  asanThreadRegistry().CheckLocked();
302  AsanThreadContext *t = GetThreadContextByTidLocked(tid);
303  return ThreadNameWithParenthesis(t, buff, buff_len);
304}
305
306void PrintAccessAndVarIntersection(const char *var_name,
307                                   uptr var_beg, uptr var_size,
308                                   uptr addr, uptr access_size,
309                                   uptr prev_var_end, uptr next_var_beg) {
310  uptr var_end = var_beg + var_size;
311  uptr addr_end = addr + access_size;
312  const char *pos_descr = 0;
313  // If the variable [var_beg, var_end) is the nearest variable to the
314  // current memory access, indicate it in the log.
315  if (addr >= var_beg) {
316    if (addr_end <= var_end)
317      pos_descr = "is inside";  // May happen if this is a use-after-return.
318    else if (addr < var_end)
319      pos_descr = "partially overflows";
320    else if (addr_end <= next_var_beg &&
321             next_var_beg - addr_end >= addr - var_end)
322      pos_descr = "overflows";
323  } else {
324    if (addr_end > var_beg)
325      pos_descr = "partially underflows";
326    else if (addr >= prev_var_end &&
327             addr - prev_var_end >= var_beg - addr_end)
328      pos_descr = "underflows";
329  }
330  InternalScopedString str(1024);
331  str.append("    [%zd, %zd) '%s'", var_beg, var_beg + var_size, var_name);
332  if (pos_descr) {
333    Decorator d;
334    // FIXME: we may want to also print the size of the access here,
335    // but in case of accesses generated by memset it may be confusing.
336    str.append("%s <== Memory access at offset %zd %s this variable%s\n",
337               d.Location(), addr, pos_descr, d.EndLocation());
338  } else {
339    str.append("\n");
340  }
341  Printf("%s", str.data());
342}
343
344struct StackVarDescr {
345  uptr beg;
346  uptr size;
347  const char *name_pos;
348  uptr name_len;
349};
350
351bool DescribeAddressIfStack(uptr addr, uptr access_size) {
352  AsanThread *t = FindThreadByStackAddress(addr);
353  if (!t) return false;
354  const uptr kBufSize = 4095;
355  char buf[kBufSize];
356  uptr offset = 0;
357  uptr frame_pc = 0;
358  char tname[128];
359  const char *frame_descr = t->GetFrameNameByAddr(addr, &offset, &frame_pc);
360
361#ifdef __powerpc64__
362  // On PowerPC64, the address of a function actually points to a
363  // three-doubleword data structure with the first field containing
364  // the address of the function's code.
365  frame_pc = *reinterpret_cast<uptr *>(frame_pc);
366#endif
367
368  // This string is created by the compiler and has the following form:
369  // "n alloc_1 alloc_2 ... alloc_n"
370  // where alloc_i looks like "offset size len ObjectName ".
371  CHECK(frame_descr);
372  Decorator d;
373  Printf("%s", d.Location());
374  Printf("Address %p is located in stack of thread T%d%s "
375         "at offset %zu in frame\n",
376         addr, t->tid(),
377         ThreadNameWithParenthesis(t->tid(), tname, sizeof(tname)),
378         offset);
379  // Now we print the frame where the alloca has happened.
380  // We print this frame as a stack trace with one element.
381  // The symbolizer may print more than one frame if inlining was involved.
382  // The frame numbers may be different than those in the stack trace printed
383  // previously. That's unfortunate, but I have no better solution,
384  // especially given that the alloca may be from entirely different place
385  // (e.g. use-after-scope, or different thread's stack).
386  StackTrace alloca_stack;
387  alloca_stack.trace[0] = frame_pc + 16;
388  alloca_stack.size = 1;
389  Printf("%s", d.EndLocation());
390  alloca_stack.Print();
391  // Report the number of stack objects.
392  char *p;
393  uptr n_objects = (uptr)internal_simple_strtoll(frame_descr, &p, 10);
394  CHECK_GT(n_objects, 0);
395  Printf("  This frame has %zu object(s):\n", n_objects);
396
397  // Report all objects in this frame.
398  InternalScopedBuffer<StackVarDescr> vars(n_objects);
399  for (uptr i = 0; i < n_objects; i++) {
400    uptr beg, size;
401    uptr len;
402    beg  = (uptr)internal_simple_strtoll(p, &p, 10);
403    size = (uptr)internal_simple_strtoll(p, &p, 10);
404    len  = (uptr)internal_simple_strtoll(p, &p, 10);
405    if (beg == 0 || size == 0 || *p != ' ') {
406      Printf("AddressSanitizer can't parse the stack frame "
407                 "descriptor: |%s|\n", frame_descr);
408      break;
409    }
410    p++;
411    vars[i].beg = beg;
412    vars[i].size = size;
413    vars[i].name_pos = p;
414    vars[i].name_len = len;
415    p += len;
416  }
417  for (uptr i = 0; i < n_objects; i++) {
418    buf[0] = 0;
419    internal_strncat(buf, vars[i].name_pos,
420                     static_cast<uptr>(Min(kBufSize, vars[i].name_len)));
421    uptr prev_var_end = i ? vars[i - 1].beg + vars[i - 1].size : 0;
422    uptr next_var_beg = i + 1 < n_objects ? vars[i + 1].beg : ~(0UL);
423    PrintAccessAndVarIntersection(buf, vars[i].beg, vars[i].size,
424                                  offset, access_size,
425                                  prev_var_end, next_var_beg);
426  }
427  Printf("HINT: this may be a false positive if your program uses "
428             "some custom stack unwind mechanism or swapcontext\n"
429             "      (longjmp and C++ exceptions *are* supported)\n");
430  DescribeThread(t);
431  return true;
432}
433
434static void DescribeAccessToHeapChunk(AsanChunkView chunk, uptr addr,
435                                      uptr access_size) {
436  sptr offset;
437  Decorator d;
438  InternalScopedString str(4096);
439  str.append("%s", d.Location());
440  if (chunk.AddrIsAtLeft(addr, access_size, &offset)) {
441    str.append("%p is located %zd bytes to the left of", (void *)addr, offset);
442  } else if (chunk.AddrIsAtRight(addr, access_size, &offset)) {
443    if (offset < 0) {
444      addr -= offset;
445      offset = 0;
446    }
447    str.append("%p is located %zd bytes to the right of", (void *)addr, offset);
448  } else if (chunk.AddrIsInside(addr, access_size, &offset)) {
449    str.append("%p is located %zd bytes inside of", (void*)addr, offset);
450  } else {
451    str.append("%p is located somewhere around (this is AddressSanitizer bug!)",
452               (void *)addr);
453  }
454  str.append(" %zu-byte region [%p,%p)\n", chunk.UsedSize(),
455             (void *)(chunk.Beg()), (void *)(chunk.End()));
456  str.append("%s", d.EndLocation());
457  Printf("%s", str.data());
458}
459
460void DescribeHeapAddress(uptr addr, uptr access_size) {
461  AsanChunkView chunk = FindHeapChunkByAddress(addr);
462  if (!chunk.IsValid()) {
463    Printf("AddressSanitizer can not describe address in more detail "
464           "(wild memory access suspected).\n");
465    return;
466  }
467  DescribeAccessToHeapChunk(chunk, addr, access_size);
468  CHECK(chunk.AllocTid() != kInvalidTid);
469  asanThreadRegistry().CheckLocked();
470  AsanThreadContext *alloc_thread =
471      GetThreadContextByTidLocked(chunk.AllocTid());
472  StackTrace alloc_stack;
473  chunk.GetAllocStack(&alloc_stack);
474  char tname[128];
475  Decorator d;
476  AsanThreadContext *free_thread = 0;
477  if (chunk.FreeTid() != kInvalidTid) {
478    free_thread = GetThreadContextByTidLocked(chunk.FreeTid());
479    Printf("%sfreed by thread T%d%s here:%s\n", d.Allocation(),
480           free_thread->tid,
481           ThreadNameWithParenthesis(free_thread, tname, sizeof(tname)),
482           d.EndAllocation());
483    StackTrace free_stack;
484    chunk.GetFreeStack(&free_stack);
485    free_stack.Print();
486    Printf("%spreviously allocated by thread T%d%s here:%s\n",
487           d.Allocation(), alloc_thread->tid,
488           ThreadNameWithParenthesis(alloc_thread, tname, sizeof(tname)),
489           d.EndAllocation());
490  } else {
491    Printf("%sallocated by thread T%d%s here:%s\n", d.Allocation(),
492           alloc_thread->tid,
493           ThreadNameWithParenthesis(alloc_thread, tname, sizeof(tname)),
494           d.EndAllocation());
495  }
496  alloc_stack.Print();
497  DescribeThread(GetCurrentThread());
498  if (free_thread)
499    DescribeThread(free_thread);
500  DescribeThread(alloc_thread);
501}
502
503void DescribeAddress(uptr addr, uptr access_size) {
504  // Check if this is shadow or shadow gap.
505  if (DescribeAddressIfShadow(addr))
506    return;
507  CHECK(AddrIsInMem(addr));
508  if (DescribeAddressIfGlobal(addr, access_size))
509    return;
510  if (DescribeAddressIfStack(addr, access_size))
511    return;
512  // Assume it is a heap address.
513  DescribeHeapAddress(addr, access_size);
514}
515
516// ------------------- Thread description -------------------- {{{1
517
518void DescribeThread(AsanThreadContext *context) {
519  CHECK(context);
520  asanThreadRegistry().CheckLocked();
521  // No need to announce the main thread.
522  if (context->tid == 0 || context->announced) {
523    return;
524  }
525  context->announced = true;
526  char tname[128];
527  InternalScopedString str(1024);
528  str.append("Thread T%d%s", context->tid,
529             ThreadNameWithParenthesis(context->tid, tname, sizeof(tname)));
530  str.append(
531      " created by T%d%s here:\n", context->parent_tid,
532      ThreadNameWithParenthesis(context->parent_tid, tname, sizeof(tname)));
533  Printf("%s", str.data());
534  uptr stack_size;
535  const uptr *stack_trace = StackDepotGet(context->stack_id, &stack_size);
536  StackTrace::PrintStack(stack_trace, stack_size);
537  // Recursively described parent thread if needed.
538  if (flags()->print_full_thread_history) {
539    AsanThreadContext *parent_context =
540        GetThreadContextByTidLocked(context->parent_tid);
541    DescribeThread(parent_context);
542  }
543}
544
545// -------------------- Different kinds of reports ----------------- {{{1
546
547// Use ScopedInErrorReport to run common actions just before and
548// immediately after printing error report.
549class ScopedInErrorReport {
550 public:
551  ScopedInErrorReport() {
552    static atomic_uint32_t num_calls;
553    static u32 reporting_thread_tid;
554    if (atomic_fetch_add(&num_calls, 1, memory_order_relaxed) != 0) {
555      // Do not print more than one report, otherwise they will mix up.
556      // Error reporting functions shouldn't return at this situation, as
557      // they are defined as no-return.
558      Report("AddressSanitizer: while reporting a bug found another one."
559                 "Ignoring.\n");
560      u32 current_tid = GetCurrentTidOrInvalid();
561      if (current_tid != reporting_thread_tid) {
562        // ASan found two bugs in different threads simultaneously. Sleep
563        // long enough to make sure that the thread which started to print
564        // an error report will finish doing it.
565        SleepForSeconds(Max(100, flags()->sleep_before_dying + 1));
566      }
567      // If we're still not dead for some reason, use raw _exit() instead of
568      // Die() to bypass any additional checks.
569      internal__exit(flags()->exitcode);
570    }
571    ASAN_ON_ERROR();
572    // Make sure the registry and sanitizer report mutexes are locked while
573    // we're printing an error report.
574    // We can lock them only here to avoid self-deadlock in case of
575    // recursive reports.
576    asanThreadRegistry().Lock();
577    CommonSanitizerReportMutex.Lock();
578    reporting_thread_tid = GetCurrentTidOrInvalid();
579    Printf("===================================================="
580           "=============\n");
581  }
582  // Destructor is NORETURN, as functions that report errors are.
583  NORETURN ~ScopedInErrorReport() {
584    // Make sure the current thread is announced.
585    DescribeThread(GetCurrentThread());
586    // We may want to grab this lock again when printing stats.
587    asanThreadRegistry().Unlock();
588    // Print memory stats.
589    if (flags()->print_stats)
590      __asan_print_accumulated_stats();
591    if (error_report_callback) {
592      error_report_callback(error_message_buffer);
593    }
594    Report("ABORTING\n");
595    Die();
596  }
597};
598
599void ReportStackOverflow(uptr pc, uptr sp, uptr bp, void *context, uptr addr) {
600  ScopedInErrorReport in_report;
601  Decorator d;
602  Printf("%s", d.Warning());
603  Report(
604      "ERROR: AddressSanitizer: stack-overflow on address %p"
605      " (pc %p sp %p bp %p T%d)\n",
606      (void *)addr, (void *)pc, (void *)sp, (void *)bp,
607      GetCurrentTidOrInvalid());
608  Printf("%s", d.EndWarning());
609  GET_STACK_TRACE_SIGNAL(pc, bp, context);
610  stack.Print();
611  ReportErrorSummary("stack-overflow", &stack);
612}
613
614void ReportSIGSEGV(uptr pc, uptr sp, uptr bp, void *context, uptr addr) {
615  ScopedInErrorReport in_report;
616  Decorator d;
617  Printf("%s", d.Warning());
618  Report(
619      "ERROR: AddressSanitizer: SEGV on unknown address %p"
620      " (pc %p sp %p bp %p T%d)\n",
621      (void *)addr, (void *)pc, (void *)sp, (void *)bp,
622      GetCurrentTidOrInvalid());
623  Printf("%s", d.EndWarning());
624  GET_STACK_TRACE_SIGNAL(pc, bp, context);
625  stack.Print();
626  Printf("AddressSanitizer can not provide additional info.\n");
627  ReportErrorSummary("SEGV", &stack);
628}
629
630void ReportDoubleFree(uptr addr, StackTrace *free_stack) {
631  ScopedInErrorReport in_report;
632  Decorator d;
633  Printf("%s", d.Warning());
634  char tname[128];
635  u32 curr_tid = GetCurrentTidOrInvalid();
636  Report("ERROR: AddressSanitizer: attempting double-free on %p in "
637         "thread T%d%s:\n",
638         addr, curr_tid,
639         ThreadNameWithParenthesis(curr_tid, tname, sizeof(tname)));
640  Printf("%s", d.EndWarning());
641  CHECK_GT(free_stack->size, 0);
642  GET_STACK_TRACE_FATAL(free_stack->trace[0], free_stack->top_frame_bp);
643  stack.Print();
644  DescribeHeapAddress(addr, 1);
645  ReportErrorSummary("double-free", &stack);
646}
647
648void ReportFreeNotMalloced(uptr addr, StackTrace *free_stack) {
649  ScopedInErrorReport in_report;
650  Decorator d;
651  Printf("%s", d.Warning());
652  char tname[128];
653  u32 curr_tid = GetCurrentTidOrInvalid();
654  Report("ERROR: AddressSanitizer: attempting free on address "
655             "which was not malloc()-ed: %p in thread T%d%s\n", addr,
656         curr_tid, ThreadNameWithParenthesis(curr_tid, tname, sizeof(tname)));
657  Printf("%s", d.EndWarning());
658  CHECK_GT(free_stack->size, 0);
659  GET_STACK_TRACE_FATAL(free_stack->trace[0], free_stack->top_frame_bp);
660  stack.Print();
661  DescribeHeapAddress(addr, 1);
662  ReportErrorSummary("bad-free", &stack);
663}
664
665void ReportAllocTypeMismatch(uptr addr, StackTrace *free_stack,
666                             AllocType alloc_type,
667                             AllocType dealloc_type) {
668  static const char *alloc_names[] =
669    {"INVALID", "malloc", "operator new", "operator new []"};
670  static const char *dealloc_names[] =
671    {"INVALID", "free", "operator delete", "operator delete []"};
672  CHECK_NE(alloc_type, dealloc_type);
673  ScopedInErrorReport in_report;
674  Decorator d;
675  Printf("%s", d.Warning());
676  Report("ERROR: AddressSanitizer: alloc-dealloc-mismatch (%s vs %s) on %p\n",
677        alloc_names[alloc_type], dealloc_names[dealloc_type], addr);
678  Printf("%s", d.EndWarning());
679  CHECK_GT(free_stack->size, 0);
680  GET_STACK_TRACE_FATAL(free_stack->trace[0], free_stack->top_frame_bp);
681  stack.Print();
682  DescribeHeapAddress(addr, 1);
683  ReportErrorSummary("alloc-dealloc-mismatch", &stack);
684  Report("HINT: if you don't care about these warnings you may set "
685         "ASAN_OPTIONS=alloc_dealloc_mismatch=0\n");
686}
687
688void ReportMallocUsableSizeNotOwned(uptr addr, StackTrace *stack) {
689  ScopedInErrorReport in_report;
690  Decorator d;
691  Printf("%s", d.Warning());
692  Report("ERROR: AddressSanitizer: attempting to call "
693             "malloc_usable_size() for pointer which is "
694             "not owned: %p\n", addr);
695  Printf("%s", d.EndWarning());
696  stack->Print();
697  DescribeHeapAddress(addr, 1);
698  ReportErrorSummary("bad-malloc_usable_size", stack);
699}
700
701void ReportSanitizerGetAllocatedSizeNotOwned(uptr addr, StackTrace *stack) {
702  ScopedInErrorReport in_report;
703  Decorator d;
704  Printf("%s", d.Warning());
705  Report("ERROR: AddressSanitizer: attempting to call "
706             "__sanitizer_get_allocated_size() for pointer which is "
707             "not owned: %p\n", addr);
708  Printf("%s", d.EndWarning());
709  stack->Print();
710  DescribeHeapAddress(addr, 1);
711  ReportErrorSummary("bad-__sanitizer_get_allocated_size", stack);
712}
713
714void ReportStringFunctionMemoryRangesOverlap(
715    const char *function, const char *offset1, uptr length1,
716    const char *offset2, uptr length2, StackTrace *stack) {
717  ScopedInErrorReport in_report;
718  Decorator d;
719  char bug_type[100];
720  internal_snprintf(bug_type, sizeof(bug_type), "%s-param-overlap", function);
721  Printf("%s", d.Warning());
722  Report("ERROR: AddressSanitizer: %s: "
723             "memory ranges [%p,%p) and [%p, %p) overlap\n", \
724             bug_type, offset1, offset1 + length1, offset2, offset2 + length2);
725  Printf("%s", d.EndWarning());
726  stack->Print();
727  DescribeAddress((uptr)offset1, length1);
728  DescribeAddress((uptr)offset2, length2);
729  ReportErrorSummary(bug_type, stack);
730}
731
732void ReportStringFunctionSizeOverflow(uptr offset, uptr size,
733                                      StackTrace *stack) {
734  ScopedInErrorReport in_report;
735  Decorator d;
736  const char *bug_type = "negative-size-param";
737  Printf("%s", d.Warning());
738  Report("ERROR: AddressSanitizer: %s: (size=%zd)\n", bug_type, size);
739  Printf("%s", d.EndWarning());
740  stack->Print();
741  DescribeAddress(offset, size);
742  ReportErrorSummary(bug_type, stack);
743}
744
745void ReportBadParamsToAnnotateContiguousContainer(uptr beg, uptr end,
746                                                  uptr old_mid, uptr new_mid,
747                                                  StackTrace *stack) {
748  ScopedInErrorReport in_report;
749  Report("ERROR: AddressSanitizer: bad parameters to "
750         "__sanitizer_annotate_contiguous_container:\n"
751         "      beg     : %p\n"
752         "      end     : %p\n"
753         "      old_mid : %p\n"
754         "      new_mid : %p\n",
755         beg, end, old_mid, new_mid);
756  stack->Print();
757  ReportErrorSummary("bad-__sanitizer_annotate_contiguous_container", stack);
758}
759
760void ReportODRViolation(const __asan_global *g1, u32 stack_id1,
761                        const __asan_global *g2, u32 stack_id2) {
762  ScopedInErrorReport in_report;
763  Decorator d;
764  Printf("%s", d.Warning());
765  Report("ERROR: AddressSanitizer: odr-violation (%p):\n", g1->beg);
766  Printf("%s", d.EndWarning());
767  InternalScopedString g1_loc(256), g2_loc(256);
768  PrintGlobalLocation(&g1_loc, *g1);
769  PrintGlobalLocation(&g2_loc, *g2);
770  Printf("  [1] size=%zd %s %s\n", g1->size, g1->name, g1_loc.data());
771  Printf("  [2] size=%zd %s %s\n", g2->size, g2->name, g2_loc.data());
772  if (stack_id1 && stack_id2) {
773    Printf("These globals were registered at these points:\n");
774    Printf("  [1]:\n");
775    uptr stack_size;
776    const uptr *stack_trace = StackDepotGet(stack_id1, &stack_size);
777    StackTrace::PrintStack(stack_trace, stack_size);
778    Printf("  [2]:\n");
779    stack_trace = StackDepotGet(stack_id2, &stack_size);
780    StackTrace::PrintStack(stack_trace, stack_size);
781  }
782  Report("HINT: if you don't care about these warnings you may set "
783         "ASAN_OPTIONS=detect_odr_violation=0\n");
784  ReportErrorSummary("odr-violation", g1_loc.data(), 0, g1->name);
785}
786
787// ----------------------- CheckForInvalidPointerPair ----------- {{{1
788static NOINLINE void
789ReportInvalidPointerPair(uptr pc, uptr bp, uptr sp, uptr a1, uptr a2) {
790  ScopedInErrorReport in_report;
791  Decorator d;
792  Printf("%s", d.Warning());
793  Report("ERROR: AddressSanitizer: invalid-pointer-pair: %p %p\n", a1, a2);
794  Printf("%s", d.EndWarning());
795  GET_STACK_TRACE_FATAL(pc, bp);
796  stack.Print();
797  DescribeAddress(a1, 1);
798  DescribeAddress(a2, 1);
799  ReportErrorSummary("invalid-pointer-pair", &stack);
800}
801
802static INLINE void CheckForInvalidPointerPair(void *p1, void *p2) {
803  if (!flags()->detect_invalid_pointer_pairs) return;
804  uptr a1 = reinterpret_cast<uptr>(p1);
805  uptr a2 = reinterpret_cast<uptr>(p2);
806  AsanChunkView chunk1 = FindHeapChunkByAddress(a1);
807  AsanChunkView chunk2 = FindHeapChunkByAddress(a2);
808  bool valid1 = chunk1.IsValid();
809  bool valid2 = chunk2.IsValid();
810  if ((valid1 != valid2) || (valid1 && valid2 && !chunk1.Eq(chunk2))) {
811    GET_CALLER_PC_BP_SP;                                              \
812    return ReportInvalidPointerPair(pc, bp, sp, a1, a2);
813  }
814}
815// ----------------------- Mac-specific reports ----------------- {{{1
816
817void WarnMacFreeUnallocated(
818    uptr addr, uptr zone_ptr, const char *zone_name, StackTrace *stack) {
819  // Just print a warning here.
820  Printf("free_common(%p) -- attempting to free unallocated memory.\n"
821             "AddressSanitizer is ignoring this error on Mac OS now.\n",
822             addr);
823  PrintZoneForPointer(addr, zone_ptr, zone_name);
824  stack->Print();
825  DescribeHeapAddress(addr, 1);
826}
827
828void ReportMacMzReallocUnknown(
829    uptr addr, uptr zone_ptr, const char *zone_name, StackTrace *stack) {
830  ScopedInErrorReport in_report;
831  Printf("mz_realloc(%p) -- attempting to realloc unallocated memory.\n"
832             "This is an unrecoverable problem, exiting now.\n",
833             addr);
834  PrintZoneForPointer(addr, zone_ptr, zone_name);
835  stack->Print();
836  DescribeHeapAddress(addr, 1);
837}
838
839void ReportMacCfReallocUnknown(
840    uptr addr, uptr zone_ptr, const char *zone_name, StackTrace *stack) {
841  ScopedInErrorReport in_report;
842  Printf("cf_realloc(%p) -- attempting to realloc unallocated memory.\n"
843             "This is an unrecoverable problem, exiting now.\n",
844             addr);
845  PrintZoneForPointer(addr, zone_ptr, zone_name);
846  stack->Print();
847  DescribeHeapAddress(addr, 1);
848}
849
850}  // namespace __asan
851
852// --------------------------- Interface --------------------- {{{1
853using namespace __asan;  // NOLINT
854
855void __asan_report_error(uptr pc, uptr bp, uptr sp, uptr addr, int is_write,
856                         uptr access_size) {
857  ScopedInErrorReport in_report;
858
859  // Determine the error type.
860  const char *bug_descr = "unknown-crash";
861  if (AddrIsInMem(addr)) {
862    u8 *shadow_addr = (u8*)MemToShadow(addr);
863    // If we are accessing 16 bytes, look at the second shadow byte.
864    if (*shadow_addr == 0 && access_size > SHADOW_GRANULARITY)
865      shadow_addr++;
866    // If we are in the partial right redzone, look at the next shadow byte.
867    if (*shadow_addr > 0 && *shadow_addr < 128)
868      shadow_addr++;
869    switch (*shadow_addr) {
870      case kAsanHeapLeftRedzoneMagic:
871      case kAsanHeapRightRedzoneMagic:
872        bug_descr = "heap-buffer-overflow";
873        break;
874      case kAsanHeapFreeMagic:
875        bug_descr = "heap-use-after-free";
876        break;
877      case kAsanStackLeftRedzoneMagic:
878        bug_descr = "stack-buffer-underflow";
879        break;
880      case kAsanInitializationOrderMagic:
881        bug_descr = "initialization-order-fiasco";
882        break;
883      case kAsanStackMidRedzoneMagic:
884      case kAsanStackRightRedzoneMagic:
885      case kAsanStackPartialRedzoneMagic:
886        bug_descr = "stack-buffer-overflow";
887        break;
888      case kAsanStackAfterReturnMagic:
889        bug_descr = "stack-use-after-return";
890        break;
891      case kAsanUserPoisonedMemoryMagic:
892        bug_descr = "use-after-poison";
893        break;
894      case kAsanContiguousContainerOOBMagic:
895        bug_descr = "container-overflow";
896        break;
897      case kAsanStackUseAfterScopeMagic:
898        bug_descr = "stack-use-after-scope";
899        break;
900      case kAsanGlobalRedzoneMagic:
901        bug_descr = "global-buffer-overflow";
902        break;
903    }
904  }
905  Decorator d;
906  Printf("%s", d.Warning());
907  Report("ERROR: AddressSanitizer: %s on address "
908             "%p at pc 0x%zx bp 0x%zx sp 0x%zx\n",
909             bug_descr, (void*)addr, pc, bp, sp);
910  Printf("%s", d.EndWarning());
911
912  u32 curr_tid = GetCurrentTidOrInvalid();
913  char tname[128];
914  Printf("%s%s of size %zu at %p thread T%d%s%s\n",
915         d.Access(),
916         access_size ? (is_write ? "WRITE" : "READ") : "ACCESS",
917         access_size, (void*)addr, curr_tid,
918         ThreadNameWithParenthesis(curr_tid, tname, sizeof(tname)),
919         d.EndAccess());
920
921  GET_STACK_TRACE_FATAL(pc, bp);
922  stack.Print();
923
924  DescribeAddress(addr, access_size);
925  ReportErrorSummary(bug_descr, &stack);
926  PrintShadowMemoryForAddress(addr);
927}
928
929void NOINLINE __asan_set_error_report_callback(void (*callback)(const char*)) {
930  error_report_callback = callback;
931  if (callback) {
932    error_message_buffer_size = 1 << 16;
933    error_message_buffer =
934        (char*)MmapOrDie(error_message_buffer_size, __func__);
935    error_message_buffer_pos = 0;
936  }
937}
938
939void __asan_describe_address(uptr addr) {
940  DescribeAddress(addr, 1);
941}
942
943extern "C" {
944SANITIZER_INTERFACE_ATTRIBUTE
945void __sanitizer_ptr_sub(void *a, void *b) {
946  CheckForInvalidPointerPair(a, b);
947}
948SANITIZER_INTERFACE_ATTRIBUTE
949void __sanitizer_ptr_cmp(void *a, void *b) {
950  CheckForInvalidPointerPair(a, b);
951}
952}  // extern "C"
953
954#if !SANITIZER_SUPPORTS_WEAK_HOOKS
955// Provide default implementation of __asan_on_error that does nothing
956// and may be overriden by user.
957SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE NOINLINE
958void __asan_on_error() {}
959#endif
960