asan_report.cc revision 6d95869fa900da9ddd68e15e2aa065854cfa176b 
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: private __sanitizer::AnsiColorDecorator {
49 public:
50  Decorator() : __sanitizer::AnsiColorDecorator(PrintsToTtyCached()) { }
51  const char *Warning()    { return Red(); }
52  const char *EndWarning() { return Default(); }
53  const char *Access()     { return Blue(); }
54  const char *EndAccess()  { return Default(); }
55  const char *Location()   { return Green(); }
56  const char *EndLocation() { return Default(); }
57  const char *Allocation()  { return Magenta(); }
58  const char *EndAllocation()  { return Default(); }
59
60  const char *ShadowByte(u8 byte) {
61    switch (byte) {
62      case kAsanHeapLeftRedzoneMagic:
63      case kAsanHeapRightRedzoneMagic:
64        return Red();
65      case kAsanHeapFreeMagic:
66        return Magenta();
67      case kAsanStackLeftRedzoneMagic:
68      case kAsanStackMidRedzoneMagic:
69      case kAsanStackRightRedzoneMagic:
70      case kAsanStackPartialRedzoneMagic:
71        return Red();
72      case kAsanStackAfterReturnMagic:
73        return Magenta();
74      case kAsanInitializationOrderMagic:
75        return Cyan();
76      case kAsanUserPoisonedMemoryMagic:
77        return Blue();
78      case kAsanStackUseAfterScopeMagic:
79        return Magenta();
80      case kAsanGlobalRedzoneMagic:
81        return Red();
82      case kAsanInternalHeapMagic:
83        return Yellow();
84      default:
85        return Default();
86    }
87  }
88  const char *EndShadowByte() { return Default(); }
89};
90
91// ---------------------- Helper functions ----------------------- {{{1
92
93static void PrintShadowByte(const char *before, u8 byte,
94                            const char *after = "\n") {
95  Decorator d;
96  Printf("%s%s%x%x%s%s", before,
97         d.ShadowByte(byte), byte >> 4, byte & 15, d.EndShadowByte(), after);
98}
99
100static void PrintShadowBytes(const char *before, u8 *bytes,
101                             u8 *guilty, uptr n) {
102  Decorator d;
103  if (before)
104    Printf("%s%p:", before, bytes);
105  for (uptr i = 0; i < n; i++) {
106    u8 *p = bytes + i;
107    const char *before = p == guilty ? "[" :
108        (p - 1 == guilty && i != 0) ? "" : " ";
109    const char *after = p == guilty ? "]" : "";
110    PrintShadowByte(before, *p, after);
111  }
112  Printf("\n");
113}
114
115static void PrintLegend() {
116  Printf("Shadow byte legend (one shadow byte represents %d "
117         "application bytes):\n", (int)SHADOW_GRANULARITY);
118  PrintShadowByte("  Addressable:           ", 0);
119  Printf("  Partially addressable: ");
120  for (u8 i = 1; i < SHADOW_GRANULARITY; i++)
121    PrintShadowByte("", i, " ");
122  Printf("\n");
123  PrintShadowByte("  Heap left redzone:     ", kAsanHeapLeftRedzoneMagic);
124  PrintShadowByte("  Heap right redzone:    ", kAsanHeapRightRedzoneMagic);
125  PrintShadowByte("  Freed heap region:     ", kAsanHeapFreeMagic);
126  PrintShadowByte("  Stack left redzone:    ", kAsanStackLeftRedzoneMagic);
127  PrintShadowByte("  Stack mid redzone:     ", kAsanStackMidRedzoneMagic);
128  PrintShadowByte("  Stack right redzone:   ", kAsanStackRightRedzoneMagic);
129  PrintShadowByte("  Stack partial redzone: ", kAsanStackPartialRedzoneMagic);
130  PrintShadowByte("  Stack after return:    ", kAsanStackAfterReturnMagic);
131  PrintShadowByte("  Stack use after scope: ", kAsanStackUseAfterScopeMagic);
132  PrintShadowByte("  Global redzone:        ", kAsanGlobalRedzoneMagic);
133  PrintShadowByte("  Global init order:     ", kAsanInitializationOrderMagic);
134  PrintShadowByte("  Poisoned by user:      ", kAsanUserPoisonedMemoryMagic);
135  PrintShadowByte("  ASan internal:         ", kAsanInternalHeapMagic);
136}
137
138static void PrintShadowMemoryForAddress(uptr addr) {
139  if (!AddrIsInMem(addr))
140    return;
141  uptr shadow_addr = MemToShadow(addr);
142  const uptr n_bytes_per_row = 16;
143  uptr aligned_shadow = shadow_addr & ~(n_bytes_per_row - 1);
144  Printf("Shadow bytes around the buggy address:\n");
145  for (int i = -5; i <= 5; i++) {
146    const char *prefix = (i == 0) ? "=>" : "  ";
147    PrintShadowBytes(prefix,
148                     (u8*)(aligned_shadow + i * n_bytes_per_row),
149                     (u8*)shadow_addr, n_bytes_per_row);
150  }
151  if (flags()->print_legend)
152    PrintLegend();
153}
154
155static void PrintZoneForPointer(uptr ptr, uptr zone_ptr,
156                                const char *zone_name) {
157  if (zone_ptr) {
158    if (zone_name) {
159      Printf("malloc_zone_from_ptr(%p) = %p, which is %s\n",
160                 ptr, zone_ptr, zone_name);
161    } else {
162      Printf("malloc_zone_from_ptr(%p) = %p, which doesn't have a name\n",
163                 ptr, zone_ptr);
164    }
165  } else {
166    Printf("malloc_zone_from_ptr(%p) = 0\n", ptr);
167  }
168}
169
170static void DescribeThread(AsanThread *t) {
171  if (t)
172    DescribeThread(t->context());
173}
174
175// ---------------------- Address Descriptions ------------------- {{{1
176
177static bool IsASCII(unsigned char c) {
178  return /*0x00 <= c &&*/ c <= 0x7F;
179}
180
181static const char *MaybeDemangleGlobalName(const char *name) {
182  // We can spoil names of globals with C linkage, so use an heuristic
183  // approach to check if the name should be demangled.
184  return (name[0] == '_' && name[1] == 'Z' && &getSymbolizer)
185             ? getSymbolizer()->Demangle(name)
186             : name;
187}
188
189// Check if the global is a zero-terminated ASCII string. If so, print it.
190static void PrintGlobalNameIfASCII(const __asan_global &g) {
191  for (uptr p = g.beg; p < g.beg + g.size - 1; p++) {
192    unsigned char c = *(unsigned char*)p;
193    if (c == '\0' || !IsASCII(c)) return;
194  }
195  if (*(char*)(g.beg + g.size - 1) != '\0') return;
196  Printf("  '%s' is ascii string '%s'\n",
197         MaybeDemangleGlobalName(g.name), (char*)g.beg);
198}
199
200bool DescribeAddressRelativeToGlobal(uptr addr, uptr size,
201                                     const __asan_global &g) {
202  static const uptr kMinimalDistanceFromAnotherGlobal = 64;
203  if (addr <= g.beg - kMinimalDistanceFromAnotherGlobal) return false;
204  if (addr >= g.beg + g.size_with_redzone) return false;
205  Decorator d;
206  Printf("%s", d.Location());
207  if (addr < g.beg) {
208    Printf("%p is located %zd bytes to the left", (void*)addr, g.beg - addr);
209  } else if (addr + size > g.beg + g.size) {
210    if (addr < g.beg + g.size)
211      addr = g.beg + g.size;
212    Printf("%p is located %zd bytes to the right", (void*)addr,
213           addr - (g.beg + g.size));
214  } else {
215    // Can it happen?
216    Printf("%p is located %zd bytes inside", (void*)addr, addr - g.beg);
217  }
218  Printf(" of global variable '%s' from '%s' (0x%zx) of size %zu\n",
219             MaybeDemangleGlobalName(g.name), g.module_name, g.beg, g.size);
220  Printf("%s", d.EndLocation());
221  PrintGlobalNameIfASCII(g);
222  return true;
223}
224
225bool DescribeAddressIfShadow(uptr addr) {
226  if (AddrIsInMem(addr))
227    return false;
228  static const char kAddrInShadowReport[] =
229      "Address %p is located in the %s.\n";
230  if (AddrIsInShadowGap(addr)) {
231    Printf(kAddrInShadowReport, addr, "shadow gap area");
232    return true;
233  }
234  if (AddrIsInHighShadow(addr)) {
235    Printf(kAddrInShadowReport, addr, "high shadow area");
236    return true;
237  }
238  if (AddrIsInLowShadow(addr)) {
239    Printf(kAddrInShadowReport, addr, "low shadow area");
240    return true;
241  }
242  CHECK(0 && "Address is not in memory and not in shadow?");
243  return false;
244}
245
246// Return " (thread_name) " or an empty string if the name is empty.
247const char *ThreadNameWithParenthesis(AsanThreadContext *t, char buff[],
248                                      uptr buff_len) {
249  const char *name = t->name;
250  if (name[0] == '\0') return "";
251  buff[0] = 0;
252  internal_strncat(buff, " (", 3);
253  internal_strncat(buff, name, buff_len - 4);
254  internal_strncat(buff, ")", 2);
255  return buff;
256}
257
258const char *ThreadNameWithParenthesis(u32 tid, char buff[],
259                                      uptr buff_len) {
260  if (tid == kInvalidTid) return "";
261  asanThreadRegistry().CheckLocked();
262  AsanThreadContext *t = GetThreadContextByTidLocked(tid);
263  return ThreadNameWithParenthesis(t, buff, buff_len);
264}
265
266void PrintAccessAndVarIntersection(const char *var_name,
267                                   uptr var_beg, uptr var_size,
268                                   uptr addr, uptr access_size,
269                                   uptr prev_var_end, uptr next_var_beg) {
270  uptr var_end = var_beg + var_size;
271  uptr addr_end = addr + access_size;
272  const char *pos_descr = 0;
273  // If the variable [var_beg, var_end) is the nearest variable to the
274  // current memory access, indicate it in the log.
275  if (addr >= var_beg) {
276    if (addr_end <= var_end)
277      pos_descr = "is inside";  // May happen if this is a use-after-return.
278    else if (addr < var_end)
279      pos_descr = "partially overflows";
280    else if (addr_end <= next_var_beg &&
281             next_var_beg - addr_end >= addr - var_end)
282      pos_descr = "overflows";
283  } else {
284    if (addr_end > var_beg)
285      pos_descr = "partially underflows";
286    else if (addr >= prev_var_end &&
287             addr - prev_var_end >= var_beg - addr_end)
288      pos_descr = "underflows";
289  }
290  Printf("    [%zd, %zd) '%s'", var_beg, var_beg + var_size, var_name);
291  if (pos_descr) {
292    Decorator d;
293    // FIXME: we may want to also print the size of the access here,
294    // but in case of accesses generated by memset it may be confusing.
295    Printf("%s <== Memory access at offset %zd %s this variable%s\n",
296           d.Location(), addr, pos_descr, d.EndLocation());
297  } else {
298    Printf("\n");
299  }
300}
301
302struct StackVarDescr {
303  uptr beg;
304  uptr size;
305  const char *name_pos;
306  uptr name_len;
307};
308
309bool DescribeAddressIfStack(uptr addr, uptr access_size) {
310  AsanThread *t = FindThreadByStackAddress(addr);
311  if (!t) return false;
312  const uptr kBufSize = 4095;
313  char buf[kBufSize];
314  uptr offset = 0;
315  uptr frame_pc = 0;
316  char tname[128];
317  const char *frame_descr = t->GetFrameNameByAddr(addr, &offset, &frame_pc);
318
319#ifdef __powerpc64__
320  // On PowerPC64, the address of a function actually points to a
321  // three-doubleword data structure with the first field containing
322  // the address of the function's code.
323  frame_pc = *reinterpret_cast<uptr *>(frame_pc);
324#endif
325
326  // This string is created by the compiler and has the following form:
327  // "n alloc_1 alloc_2 ... alloc_n"
328  // where alloc_i looks like "offset size len ObjectName ".
329  CHECK(frame_descr);
330  Decorator d;
331  Printf("%s", d.Location());
332  Printf("Address %p is located in stack of thread T%d%s "
333         "at offset %zu in frame\n",
334         addr, t->tid(),
335         ThreadNameWithParenthesis(t->tid(), tname, sizeof(tname)),
336         offset);
337  // Now we print the frame where the alloca has happened.
338  // We print this frame as a stack trace with one element.
339  // The symbolizer may print more than one frame if inlining was involved.
340  // The frame numbers may be different than those in the stack trace printed
341  // previously. That's unfortunate, but I have no better solution,
342  // especially given that the alloca may be from entirely different place
343  // (e.g. use-after-scope, or different thread's stack).
344  StackTrace alloca_stack;
345  alloca_stack.trace[0] = frame_pc + 16;
346  alloca_stack.size = 1;
347  Printf("%s", d.EndLocation());
348  PrintStack(&alloca_stack);
349  // Report the number of stack objects.
350  char *p;
351  uptr n_objects = (uptr)internal_simple_strtoll(frame_descr, &p, 10);
352  CHECK_GT(n_objects, 0);
353  Printf("  This frame has %zu object(s):\n", n_objects);
354
355  // Report all objects in this frame.
356  InternalScopedBuffer<StackVarDescr> vars(n_objects);
357  for (uptr i = 0; i < n_objects; i++) {
358    uptr beg, size;
359    uptr len;
360    beg  = (uptr)internal_simple_strtoll(p, &p, 10);
361    size = (uptr)internal_simple_strtoll(p, &p, 10);
362    len  = (uptr)internal_simple_strtoll(p, &p, 10);
363    if (beg == 0 || size == 0 || *p != ' ') {
364      Printf("AddressSanitizer can't parse the stack frame "
365                 "descriptor: |%s|\n", frame_descr);
366      break;
367    }
368    p++;
369    vars[i].beg = beg;
370    vars[i].size = size;
371    vars[i].name_pos = p;
372    vars[i].name_len = len;
373    p += len;
374  }
375  for (uptr i = 0; i < n_objects; i++) {
376    buf[0] = 0;
377    internal_strncat(buf, vars[i].name_pos,
378                     static_cast<uptr>(Min(kBufSize, vars[i].name_len)));
379    uptr prev_var_end = i ? vars[i - 1].beg + vars[i - 1].size : 0;
380    uptr next_var_beg = i + 1 < n_objects ? vars[i + 1].beg : ~(0UL);
381    PrintAccessAndVarIntersection(buf, vars[i].beg, vars[i].size,
382                                  offset, access_size,
383                                  prev_var_end, next_var_beg);
384  }
385  Printf("HINT: this may be a false positive if your program uses "
386             "some custom stack unwind mechanism or swapcontext\n"
387             "      (longjmp and C++ exceptions *are* supported)\n");
388  DescribeThread(t);
389  return true;
390}
391
392static void DescribeAccessToHeapChunk(AsanChunkView chunk, uptr addr,
393                                      uptr access_size) {
394  sptr offset;
395  Decorator d;
396  Printf("%s", d.Location());
397  if (chunk.AddrIsAtLeft(addr, access_size, &offset)) {
398    Printf("%p is located %zd bytes to the left of", (void*)addr, offset);
399  } else if (chunk.AddrIsAtRight(addr, access_size, &offset)) {
400    if (offset < 0) {
401      addr -= offset;
402      offset = 0;
403    }
404    Printf("%p is located %zd bytes to the right of", (void*)addr, offset);
405  } else if (chunk.AddrIsInside(addr, access_size, &offset)) {
406    Printf("%p is located %zd bytes inside of", (void*)addr, offset);
407  } else {
408    Printf("%p is located somewhere around (this is AddressSanitizer bug!)",
409           (void*)addr);
410  }
411  Printf(" %zu-byte region [%p,%p)\n", chunk.UsedSize(),
412         (void*)(chunk.Beg()), (void*)(chunk.End()));
413  Printf("%s", d.EndLocation());
414}
415
416void DescribeHeapAddress(uptr addr, uptr access_size) {
417  AsanChunkView chunk = FindHeapChunkByAddress(addr);
418  if (!chunk.IsValid()) {
419    Printf("AddressSanitizer can not describe address in more detail "
420           "(wild memory access suspected).\n");
421    return;
422  }
423  DescribeAccessToHeapChunk(chunk, addr, access_size);
424  CHECK(chunk.AllocTid() != kInvalidTid);
425  asanThreadRegistry().CheckLocked();
426  AsanThreadContext *alloc_thread =
427      GetThreadContextByTidLocked(chunk.AllocTid());
428  StackTrace alloc_stack;
429  chunk.GetAllocStack(&alloc_stack);
430  char tname[128];
431  Decorator d;
432  AsanThreadContext *free_thread = 0;
433  if (chunk.FreeTid() != kInvalidTid) {
434    free_thread = GetThreadContextByTidLocked(chunk.FreeTid());
435    Printf("%sfreed by thread T%d%s here:%s\n", d.Allocation(),
436           free_thread->tid,
437           ThreadNameWithParenthesis(free_thread, tname, sizeof(tname)),
438           d.EndAllocation());
439    StackTrace free_stack;
440    chunk.GetFreeStack(&free_stack);
441    PrintStack(&free_stack);
442    Printf("%spreviously allocated by thread T%d%s here:%s\n",
443           d.Allocation(), alloc_thread->tid,
444           ThreadNameWithParenthesis(alloc_thread, tname, sizeof(tname)),
445           d.EndAllocation());
446  } else {
447    Printf("%sallocated by thread T%d%s here:%s\n", d.Allocation(),
448           alloc_thread->tid,
449           ThreadNameWithParenthesis(alloc_thread, tname, sizeof(tname)),
450           d.EndAllocation());
451  }
452  PrintStack(&alloc_stack);
453  DescribeThread(GetCurrentThread());
454  if (free_thread)
455    DescribeThread(free_thread);
456  DescribeThread(alloc_thread);
457}
458
459void DescribeAddress(uptr addr, uptr access_size) {
460  // Check if this is shadow or shadow gap.
461  if (DescribeAddressIfShadow(addr))
462    return;
463  CHECK(AddrIsInMem(addr));
464  if (DescribeAddressIfGlobal(addr, access_size))
465    return;
466  if (DescribeAddressIfStack(addr, access_size))
467    return;
468  // Assume it is a heap address.
469  DescribeHeapAddress(addr, access_size);
470}
471
472// ------------------- Thread description -------------------- {{{1
473
474void DescribeThread(AsanThreadContext *context) {
475  CHECK(context);
476  asanThreadRegistry().CheckLocked();
477  // No need to announce the main thread.
478  if (context->tid == 0 || context->announced) {
479    return;
480  }
481  context->announced = true;
482  char tname[128];
483  Printf("Thread T%d%s", context->tid,
484         ThreadNameWithParenthesis(context->tid, tname, sizeof(tname)));
485  Printf(" created by T%d%s here:\n",
486         context->parent_tid,
487         ThreadNameWithParenthesis(context->parent_tid,
488                                   tname, sizeof(tname)));
489  uptr stack_size;
490  const uptr *stack_trace = StackDepotGet(context->stack_id, &stack_size);
491  PrintStack(stack_trace, stack_size);
492  // Recursively described parent thread if needed.
493  if (flags()->print_full_thread_history) {
494    AsanThreadContext *parent_context =
495        GetThreadContextByTidLocked(context->parent_tid);
496    DescribeThread(parent_context);
497  }
498}
499
500// -------------------- Different kinds of reports ----------------- {{{1
501
502// Use ScopedInErrorReport to run common actions just before and
503// immediately after printing error report.
504class ScopedInErrorReport {
505 public:
506  ScopedInErrorReport() {
507    static atomic_uint32_t num_calls;
508    static u32 reporting_thread_tid;
509    if (atomic_fetch_add(&num_calls, 1, memory_order_relaxed) != 0) {
510      // Do not print more than one report, otherwise they will mix up.
511      // Error reporting functions shouldn't return at this situation, as
512      // they are defined as no-return.
513      Report("AddressSanitizer: while reporting a bug found another one."
514                 "Ignoring.\n");
515      u32 current_tid = GetCurrentTidOrInvalid();
516      if (current_tid != reporting_thread_tid) {
517        // ASan found two bugs in different threads simultaneously. Sleep
518        // long enough to make sure that the thread which started to print
519        // an error report will finish doing it.
520        SleepForSeconds(Max(100, flags()->sleep_before_dying + 1));
521      }
522      // If we're still not dead for some reason, use raw _exit() instead of
523      // Die() to bypass any additional checks.
524      internal__exit(flags()->exitcode);
525    }
526    ASAN_ON_ERROR();
527    // Make sure the registry and sanitizer report mutexes are locked while
528    // we're printing an error report.
529    // We can lock them only here to avoid self-deadlock in case of
530    // recursive reports.
531    asanThreadRegistry().Lock();
532    CommonSanitizerReportMutex.Lock();
533    reporting_thread_tid = GetCurrentTidOrInvalid();
534    Printf("===================================================="
535           "=============\n");
536  }
537  // Destructor is NORETURN, as functions that report errors are.
538  NORETURN ~ScopedInErrorReport() {
539    // Make sure the current thread is announced.
540    DescribeThread(GetCurrentThread());
541    // Print memory stats.
542    if (flags()->print_stats)
543      __asan_print_accumulated_stats();
544    if (error_report_callback) {
545      error_report_callback(error_message_buffer);
546    }
547    Report("ABORTING\n");
548    Die();
549  }
550};
551
552static void ReportSummary(const char *error_type, StackTrace *stack) {
553  if (!stack->size) return;
554  if (&getSymbolizer && getSymbolizer()->IsAvailable()) {
555    AddressInfo ai;
556    // Currently, we include the first stack frame into the report summary.
557    // Maybe sometimes we need to choose another frame (e.g. skip memcpy/etc).
558    uptr pc = StackTrace::GetPreviousInstructionPc(stack->trace[0]);
559    getSymbolizer()->SymbolizeCode(pc, &ai, 1);
560    ReportErrorSummary(error_type, ai.file, ai.line, ai.function);
561  }
562  // FIXME: do we need to print anything at all if there is no symbolizer?
563}
564
565void ReportSIGSEGV(uptr pc, uptr sp, uptr bp, uptr addr) {
566  ScopedInErrorReport in_report;
567  Decorator d;
568  Printf("%s", d.Warning());
569  Report("ERROR: AddressSanitizer: SEGV on unknown address %p"
570             " (pc %p sp %p bp %p T%d)\n",
571             (void*)addr, (void*)pc, (void*)sp, (void*)bp,
572             GetCurrentTidOrInvalid());
573  Printf("%s", d.EndWarning());
574  GET_STACK_TRACE_FATAL(pc, bp);
575  PrintStack(&stack);
576  Printf("AddressSanitizer can not provide additional info.\n");
577  ReportSummary("SEGV", &stack);
578}
579
580void ReportDoubleFree(uptr addr, StackTrace *stack) {
581  ScopedInErrorReport in_report;
582  Decorator d;
583  Printf("%s", d.Warning());
584  char tname[128];
585  u32 curr_tid = GetCurrentTidOrInvalid();
586  Report("ERROR: AddressSanitizer: attempting double-free on %p in "
587         "thread T%d%s:\n",
588         addr, curr_tid,
589         ThreadNameWithParenthesis(curr_tid, tname, sizeof(tname)));
590
591  Printf("%s", d.EndWarning());
592  PrintStack(stack);
593  DescribeHeapAddress(addr, 1);
594  ReportSummary("double-free", stack);
595}
596
597void ReportFreeNotMalloced(uptr addr, StackTrace *stack) {
598  ScopedInErrorReport in_report;
599  Decorator d;
600  Printf("%s", d.Warning());
601  char tname[128];
602  u32 curr_tid = GetCurrentTidOrInvalid();
603  Report("ERROR: AddressSanitizer: attempting free on address "
604             "which was not malloc()-ed: %p in thread T%d%s\n", addr,
605         curr_tid, ThreadNameWithParenthesis(curr_tid, tname, sizeof(tname)));
606  Printf("%s", d.EndWarning());
607  PrintStack(stack);
608  DescribeHeapAddress(addr, 1);
609  ReportSummary("bad-free", stack);
610}
611
612void ReportAllocTypeMismatch(uptr addr, StackTrace *stack,
613                             AllocType alloc_type,
614                             AllocType dealloc_type) {
615  static const char *alloc_names[] =
616    {"INVALID", "malloc", "operator new", "operator new []"};
617  static const char *dealloc_names[] =
618    {"INVALID", "free", "operator delete", "operator delete []"};
619  CHECK_NE(alloc_type, dealloc_type);
620  ScopedInErrorReport in_report;
621  Decorator d;
622  Printf("%s", d.Warning());
623  Report("ERROR: AddressSanitizer: alloc-dealloc-mismatch (%s vs %s) on %p\n",
624        alloc_names[alloc_type], dealloc_names[dealloc_type], addr);
625  Printf("%s", d.EndWarning());
626  PrintStack(stack);
627  DescribeHeapAddress(addr, 1);
628  ReportSummary("alloc-dealloc-mismatch", stack);
629  Report("HINT: if you don't care about these warnings you may set "
630         "ASAN_OPTIONS=alloc_dealloc_mismatch=0\n");
631}
632
633void ReportMallocUsableSizeNotOwned(uptr addr, StackTrace *stack) {
634  ScopedInErrorReport in_report;
635  Decorator d;
636  Printf("%s", d.Warning());
637  Report("ERROR: AddressSanitizer: attempting to call "
638             "malloc_usable_size() for pointer which is "
639             "not owned: %p\n", addr);
640  Printf("%s", d.EndWarning());
641  PrintStack(stack);
642  DescribeHeapAddress(addr, 1);
643  ReportSummary("bad-malloc_usable_size", stack);
644}
645
646void ReportAsanGetAllocatedSizeNotOwned(uptr addr, StackTrace *stack) {
647  ScopedInErrorReport in_report;
648  Decorator d;
649  Printf("%s", d.Warning());
650  Report("ERROR: AddressSanitizer: attempting to call "
651             "__asan_get_allocated_size() for pointer which is "
652             "not owned: %p\n", addr);
653  Printf("%s", d.EndWarning());
654  PrintStack(stack);
655  DescribeHeapAddress(addr, 1);
656  ReportSummary("bad-__asan_get_allocated_size", stack);
657}
658
659void ReportStringFunctionMemoryRangesOverlap(
660    const char *function, const char *offset1, uptr length1,
661    const char *offset2, uptr length2, StackTrace *stack) {
662  ScopedInErrorReport in_report;
663  Decorator d;
664  char bug_type[100];
665  internal_snprintf(bug_type, sizeof(bug_type), "%s-param-overlap", function);
666  Printf("%s", d.Warning());
667  Report("ERROR: AddressSanitizer: %s: "
668             "memory ranges [%p,%p) and [%p, %p) overlap\n", \
669             bug_type, offset1, offset1 + length1, offset2, offset2 + length2);
670  Printf("%s", d.EndWarning());
671  PrintStack(stack);
672  DescribeAddress((uptr)offset1, length1);
673  DescribeAddress((uptr)offset2, length2);
674  ReportSummary(bug_type, stack);
675}
676
677// ----------------------- Mac-specific reports ----------------- {{{1
678
679void WarnMacFreeUnallocated(
680    uptr addr, uptr zone_ptr, const char *zone_name, StackTrace *stack) {
681  // Just print a warning here.
682  Printf("free_common(%p) -- attempting to free unallocated memory.\n"
683             "AddressSanitizer is ignoring this error on Mac OS now.\n",
684             addr);
685  PrintZoneForPointer(addr, zone_ptr, zone_name);
686  PrintStack(stack);
687  DescribeHeapAddress(addr, 1);
688}
689
690void ReportMacMzReallocUnknown(
691    uptr addr, uptr zone_ptr, const char *zone_name, StackTrace *stack) {
692  ScopedInErrorReport in_report;
693  Printf("mz_realloc(%p) -- attempting to realloc unallocated memory.\n"
694             "This is an unrecoverable problem, exiting now.\n",
695             addr);
696  PrintZoneForPointer(addr, zone_ptr, zone_name);
697  PrintStack(stack);
698  DescribeHeapAddress(addr, 1);
699}
700
701void ReportMacCfReallocUnknown(
702    uptr addr, uptr zone_ptr, const char *zone_name, StackTrace *stack) {
703  ScopedInErrorReport in_report;
704  Printf("cf_realloc(%p) -- attempting to realloc unallocated memory.\n"
705             "This is an unrecoverable problem, exiting now.\n",
706             addr);
707  PrintZoneForPointer(addr, zone_ptr, zone_name);
708  PrintStack(stack);
709  DescribeHeapAddress(addr, 1);
710}
711
712}  // namespace __asan
713
714// --------------------------- Interface --------------------- {{{1
715using namespace __asan;  // NOLINT
716
717void __asan_report_error(uptr pc, uptr bp, uptr sp,
718                         uptr addr, bool is_write, uptr access_size) {
719  ScopedInErrorReport in_report;
720
721  // Determine the error type.
722  const char *bug_descr = "unknown-crash";
723  if (AddrIsInMem(addr)) {
724    u8 *shadow_addr = (u8*)MemToShadow(addr);
725    // If we are accessing 16 bytes, look at the second shadow byte.
726    if (*shadow_addr == 0 && access_size > SHADOW_GRANULARITY)
727      shadow_addr++;
728    // If we are in the partial right redzone, look at the next shadow byte.
729    if (*shadow_addr > 0 && *shadow_addr < 128)
730      shadow_addr++;
731    switch (*shadow_addr) {
732      case kAsanHeapLeftRedzoneMagic:
733      case kAsanHeapRightRedzoneMagic:
734        bug_descr = "heap-buffer-overflow";
735        break;
736      case kAsanHeapFreeMagic:
737        bug_descr = "heap-use-after-free";
738        break;
739      case kAsanStackLeftRedzoneMagic:
740        bug_descr = "stack-buffer-underflow";
741        break;
742      case kAsanInitializationOrderMagic:
743        bug_descr = "initialization-order-fiasco";
744        break;
745      case kAsanStackMidRedzoneMagic:
746      case kAsanStackRightRedzoneMagic:
747      case kAsanStackPartialRedzoneMagic:
748        bug_descr = "stack-buffer-overflow";
749        break;
750      case kAsanStackAfterReturnMagic:
751        bug_descr = "stack-use-after-return";
752        break;
753      case kAsanUserPoisonedMemoryMagic:
754        bug_descr = "use-after-poison";
755        break;
756      case kAsanStackUseAfterScopeMagic:
757        bug_descr = "stack-use-after-scope";
758        break;
759      case kAsanGlobalRedzoneMagic:
760        bug_descr = "global-buffer-overflow";
761        break;
762    }
763  }
764  Decorator d;
765  Printf("%s", d.Warning());
766  Report("ERROR: AddressSanitizer: %s on address "
767             "%p at pc 0x%zx bp 0x%zx sp 0x%zx\n",
768             bug_descr, (void*)addr, pc, bp, sp);
769  Printf("%s", d.EndWarning());
770
771  u32 curr_tid = GetCurrentTidOrInvalid();
772  char tname[128];
773  Printf("%s%s of size %zu at %p thread T%d%s%s\n",
774         d.Access(),
775         access_size ? (is_write ? "WRITE" : "READ") : "ACCESS",
776         access_size, (void*)addr, curr_tid,
777         ThreadNameWithParenthesis(curr_tid, tname, sizeof(tname)),
778         d.EndAccess());
779
780  GET_STACK_TRACE_FATAL(pc, bp);
781  PrintStack(&stack);
782
783  DescribeAddress(addr, access_size);
784  ReportSummary(bug_descr, &stack);
785  PrintShadowMemoryForAddress(addr);
786}
787
788void NOINLINE __asan_set_error_report_callback(void (*callback)(const char*)) {
789  error_report_callback = callback;
790  if (callback) {
791    error_message_buffer_size = 1 << 16;
792    error_message_buffer =
793        (char*)MmapOrDie(error_message_buffer_size, __FUNCTION__);
794    error_message_buffer_pos = 0;
795  }
796}
797
798void __asan_describe_address(uptr addr) {
799  DescribeAddress(addr, 1);
800}
801
802#if !SANITIZER_SUPPORTS_WEAK_HOOKS
803// Provide default implementation of __asan_on_error that does nothing
804// and may be overriden by user.
805SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE NOINLINE
806void __asan_on_error() {}
807#endif
808