lib/asan/asan_report.cc

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