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      1 //===-- asan_report.cc ----------------------------------------------------===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 // This file is a part of AddressSanitizer, an address sanity checker.
     11 //
     12 // This file contains error reporting code.
     13 //===----------------------------------------------------------------------===//
     14 #include "asan_flags.h"
     15 #include "asan_internal.h"
     16 #include "asan_mapping.h"
     17 #include "asan_report.h"
     18 #include "asan_stack.h"
     19 #include "asan_thread.h"
     20 #include "asan_thread_registry.h"
     21 #include "sanitizer_common/sanitizer_common.h"
     22 #include "sanitizer_common/sanitizer_report_decorator.h"
     23 #include "sanitizer_common/sanitizer_symbolizer.h"
     24 
     25 namespace __asan {
     26 
     27 // -------------------- User-specified callbacks ----------------- {{{1
     28 static void (*error_report_callback)(const char*);
     29 static char *error_message_buffer = 0;
     30 static uptr error_message_buffer_pos = 0;
     31 static uptr error_message_buffer_size = 0;
     32 
     33 void AppendToErrorMessageBuffer(const char *buffer) {
     34   if (error_message_buffer) {
     35     uptr length = internal_strlen(buffer);
     36     CHECK_GE(error_message_buffer_size, error_message_buffer_pos);
     37     uptr remaining = error_message_buffer_size - error_message_buffer_pos;
     38     internal_strncpy(error_message_buffer + error_message_buffer_pos,
     39                      buffer, remaining);
     40     error_message_buffer[error_message_buffer_size - 1] = '\0';
     41     // FIXME: reallocate the buffer instead of truncating the message.
     42     error_message_buffer_pos += remaining > length ? length : remaining;
     43   }
     44 }
     45 
     46 // ---------------------- Decorator ------------------------------ {{{1
     47 bool PrintsToTtyCached() {
     48   static int cached = 0;
     49   static bool prints_to_tty;
     50   if (!cached) {  // Ok wrt threads since we are printing only from one thread.
     51     prints_to_tty = PrintsToTty();
     52     cached = 1;
     53   }
     54   return prints_to_tty;
     55 }
     56 class Decorator: private __sanitizer::AnsiColorDecorator {
     57  public:
     58   Decorator() : __sanitizer::AnsiColorDecorator(PrintsToTtyCached()) { }
     59   const char *Warning()    { return Red(); }
     60   const char *EndWarning() { return Default(); }
     61   const char *Access()     { return Blue(); }
     62   const char *EndAccess()  { return Default(); }
     63   const char *Location()   { return Green(); }
     64   const char *EndLocation() { return Default(); }
     65   const char *Allocation()  { return Magenta(); }
     66   const char *EndAllocation()  { return Default(); }
     67 
     68   const char *ShadowByte(u8 byte) {
     69     switch (byte) {
     70       case kAsanHeapLeftRedzoneMagic:
     71       case kAsanHeapRightRedzoneMagic:
     72         return Red();
     73       case kAsanHeapFreeMagic:
     74         return Magenta();
     75       case kAsanStackLeftRedzoneMagic:
     76       case kAsanStackMidRedzoneMagic:
     77       case kAsanStackRightRedzoneMagic:
     78       case kAsanStackPartialRedzoneMagic:
     79         return Red();
     80       case kAsanStackAfterReturnMagic:
     81         return Magenta();
     82       case kAsanInitializationOrderMagic:
     83         return Cyan();
     84       case kAsanUserPoisonedMemoryMagic:
     85         return Blue();
     86       case kAsanStackUseAfterScopeMagic:
     87         return Magenta();
     88       case kAsanGlobalRedzoneMagic:
     89         return Red();
     90       case kAsanInternalHeapMagic:
     91         return Yellow();
     92       default:
     93         return Default();
     94     }
     95   }
     96   const char *EndShadowByte() { return Default(); }
     97 };
     98 
     99 // ---------------------- Helper functions ----------------------- {{{1
    100 
    101 static void PrintShadowByte(const char *before, u8 byte,
    102                             const char *after = "\n") {
    103   Decorator d;
    104   Printf("%s%s%x%x%s%s", before,
    105          d.ShadowByte(byte), byte >> 4, byte & 15, d.EndShadowByte(), after);
    106 }
    107 
    108 static void PrintShadowBytes(const char *before, u8 *bytes,
    109                              u8 *guilty, uptr n) {
    110   Decorator d;
    111   if (before)
    112     Printf("%s%p:", before, bytes);
    113   for (uptr i = 0; i < n; i++) {
    114     u8 *p = bytes + i;
    115     const char *before = p == guilty ? "[" :
    116         p - 1 == guilty ? "" : " ";
    117     const char *after = p == guilty ? "]" : "";
    118     PrintShadowByte(before, *p, after);
    119   }
    120   Printf("\n");
    121 }
    122 
    123 static void PrintLegend() {
    124   Printf("Shadow byte legend (one shadow byte represents %d "
    125          "application bytes):\n", (int)SHADOW_GRANULARITY);
    126   PrintShadowByte("  Addressable:           ", 0);
    127   Printf("  Partially addressable: ");
    128   for (uptr i = 1; i < SHADOW_GRANULARITY; i++)
    129     PrintShadowByte("", i, " ");
    130   Printf("\n");
    131   PrintShadowByte("  Heap left redzone:     ", kAsanHeapLeftRedzoneMagic);
    132   PrintShadowByte("  Heap righ redzone:     ", kAsanHeapRightRedzoneMagic);
    133   PrintShadowByte("  Freed Heap region:     ", kAsanHeapFreeMagic);
    134   PrintShadowByte("  Stack left redzone:    ", kAsanStackLeftRedzoneMagic);
    135   PrintShadowByte("  Stack mid redzone:     ", kAsanStackMidRedzoneMagic);
    136   PrintShadowByte("  Stack right redzone:   ", kAsanStackRightRedzoneMagic);
    137   PrintShadowByte("  Stack partial redzone: ", kAsanStackPartialRedzoneMagic);
    138   PrintShadowByte("  Stack after return:    ", kAsanStackAfterReturnMagic);
    139   PrintShadowByte("  Stack use after scope: ", kAsanStackUseAfterScopeMagic);
    140   PrintShadowByte("  Global redzone:        ", kAsanGlobalRedzoneMagic);
    141   PrintShadowByte("  Global init order:     ", kAsanInitializationOrderMagic);
    142   PrintShadowByte("  Poisoned by user:      ", kAsanUserPoisonedMemoryMagic);
    143   PrintShadowByte("  ASan internal:         ", kAsanInternalHeapMagic);
    144 }
    145 
    146 static void PrintShadowMemoryForAddress(uptr addr) {
    147   if (!AddrIsInMem(addr))
    148     return;
    149   uptr shadow_addr = MemToShadow(addr);
    150   const uptr n_bytes_per_row = 16;
    151   uptr aligned_shadow = shadow_addr & ~(n_bytes_per_row - 1);
    152   Printf("Shadow bytes around the buggy address:\n");
    153   for (int i = -5; i <= 5; i++) {
    154     const char *prefix = (i == 0) ? "=>" : "  ";
    155     PrintShadowBytes(prefix,
    156                      (u8*)(aligned_shadow + i * n_bytes_per_row),
    157                      (u8*)shadow_addr, n_bytes_per_row);
    158   }
    159   if (flags()->print_legend)
    160     PrintLegend();
    161 }
    162 
    163 static void PrintZoneForPointer(uptr ptr, uptr zone_ptr,
    164                                 const char *zone_name) {
    165   if (zone_ptr) {
    166     if (zone_name) {
    167       Printf("malloc_zone_from_ptr(%p) = %p, which is %s\n",
    168                  ptr, zone_ptr, zone_name);
    169     } else {
    170       Printf("malloc_zone_from_ptr(%p) = %p, which doesn't have a name\n",
    171                  ptr, zone_ptr);
    172     }
    173   } else {
    174     Printf("malloc_zone_from_ptr(%p) = 0\n", ptr);
    175   }
    176 }
    177 
    178 // ---------------------- Address Descriptions ------------------- {{{1
    179 
    180 static bool IsASCII(unsigned char c) {
    181   return /*0x00 <= c &&*/ c <= 0x7F;
    182 }
    183 
    184 // Check if the global is a zero-terminated ASCII string. If so, print it.
    185 static void PrintGlobalNameIfASCII(const __asan_global &g) {
    186   for (uptr p = g.beg; p < g.beg + g.size - 1; p++) {
    187     if (!IsASCII(*(unsigned char*)p)) return;
    188   }
    189   if (*(char*)(g.beg + g.size - 1) != 0) return;
    190   Printf("  '%s' is ascii string '%s'\n", g.name, (char*)g.beg);
    191 }
    192 
    193 bool DescribeAddressRelativeToGlobal(uptr addr, uptr size,
    194                                      const __asan_global &g) {
    195   static const uptr kMinimalDistanceFromAnotherGlobal = 64;
    196   if (addr <= g.beg - kMinimalDistanceFromAnotherGlobal) return false;
    197   if (addr >= g.beg + g.size_with_redzone) return false;
    198   Decorator d;
    199   Printf("%s", d.Location());
    200   if (addr < g.beg) {
    201     Printf("%p is located %zd bytes to the left", (void*)addr, g.beg - addr);
    202   } else if (addr + size > g.beg + g.size) {
    203     if (addr < g.beg + g.size)
    204       addr = g.beg + g.size;
    205     Printf("%p is located %zd bytes to the right", (void*)addr,
    206            addr - (g.beg + g.size));
    207   } else {
    208     // Can it happen?
    209     Printf("%p is located %zd bytes inside", (void*)addr, addr - g.beg);
    210   }
    211   Printf(" of global variable '%s' from '%s' (0x%zx) of size %zu\n",
    212              g.name, g.module_name, g.beg, g.size);
    213   Printf("%s", d.EndLocation());
    214   PrintGlobalNameIfASCII(g);
    215   return true;
    216 }
    217 
    218 bool DescribeAddressIfShadow(uptr addr) {
    219   if (AddrIsInMem(addr))
    220     return false;
    221   static const char kAddrInShadowReport[] =
    222       "Address %p is located in the %s.\n";
    223   if (AddrIsInShadowGap(addr)) {
    224     Printf(kAddrInShadowReport, addr, "shadow gap area");
    225     return true;
    226   }
    227   if (AddrIsInHighShadow(addr)) {
    228     Printf(kAddrInShadowReport, addr, "high shadow area");
    229     return true;
    230   }
    231   if (AddrIsInLowShadow(addr)) {
    232     Printf(kAddrInShadowReport, addr, "low shadow area");
    233     return true;
    234   }
    235   CHECK(0 && "Address is not in memory and not in shadow?");
    236   return false;
    237 }
    238 
    239 bool DescribeAddressIfStack(uptr addr, uptr access_size) {
    240   AsanThread *t = asanThreadRegistry().FindThreadByStackAddress(addr);
    241   if (!t) return false;
    242   const sptr kBufSize = 4095;
    243   char buf[kBufSize];
    244   uptr offset = 0;
    245   const char *frame_descr = t->GetFrameNameByAddr(addr, &offset);
    246   // This string is created by the compiler and has the following form:
    247   // "FunctioName n alloc_1 alloc_2 ... alloc_n"
    248   // where alloc_i looks like "offset size len ObjectName ".
    249   CHECK(frame_descr);
    250   // Report the function name and the offset.
    251   const char *name_end = internal_strchr(frame_descr, ' ');
    252   CHECK(name_end);
    253   buf[0] = 0;
    254   internal_strncat(buf, frame_descr,
    255                    Min(kBufSize,
    256                        static_cast<sptr>(name_end - frame_descr)));
    257   Decorator d;
    258   Printf("%s", d.Location());
    259   Printf("Address %p is located at offset %zu "
    260              "in frame <%s> of T%d's stack:\n",
    261              (void*)addr, offset, Demangle(buf), t->tid());
    262   Printf("%s", d.EndLocation());
    263   // Report the number of stack objects.
    264   char *p;
    265   uptr n_objects = internal_simple_strtoll(name_end, &p, 10);
    266   CHECK(n_objects > 0);
    267   Printf("  This frame has %zu object(s):\n", n_objects);
    268   // Report all objects in this frame.
    269   for (uptr i = 0; i < n_objects; i++) {
    270     uptr beg, size;
    271     sptr len;
    272     beg  = internal_simple_strtoll(p, &p, 10);
    273     size = internal_simple_strtoll(p, &p, 10);
    274     len  = internal_simple_strtoll(p, &p, 10);
    275     if (beg <= 0 || size <= 0 || len < 0 || *p != ' ') {
    276       Printf("AddressSanitizer can't parse the stack frame "
    277                  "descriptor: |%s|\n", frame_descr);
    278       break;
    279     }
    280     p++;
    281     buf[0] = 0;
    282     internal_strncat(buf, p, Min(kBufSize, len));
    283     p += len;
    284     Printf("    [%zu, %zu) '%s'\n", beg, beg + size, buf);
    285   }
    286   Printf("HINT: this may be a false positive if your program uses "
    287              "some custom stack unwind mechanism or swapcontext\n"
    288              "      (longjmp and C++ exceptions *are* supported)\n");
    289   DescribeThread(t->summary());
    290   return true;
    291 }
    292 
    293 static void DescribeAccessToHeapChunk(AsanChunkView chunk, uptr addr,
    294                                       uptr access_size) {
    295   sptr offset;
    296   Decorator d;
    297   Printf("%s", d.Location());
    298   if (chunk.AddrIsAtLeft(addr, access_size, &offset)) {
    299     Printf("%p is located %zd bytes to the left of", (void*)addr, offset);
    300   } else if (chunk.AddrIsAtRight(addr, access_size, &offset)) {
    301     if (offset < 0) {
    302       addr -= offset;
    303       offset = 0;
    304     }
    305     Printf("%p is located %zd bytes to the right of", (void*)addr, offset);
    306   } else if (chunk.AddrIsInside(addr, access_size, &offset)) {
    307     Printf("%p is located %zd bytes inside of", (void*)addr, offset);
    308   } else {
    309     Printf("%p is located somewhere around (this is AddressSanitizer bug!)",
    310            (void*)addr);
    311   }
    312   Printf(" %zu-byte region [%p,%p)\n", chunk.UsedSize(),
    313          (void*)(chunk.Beg()), (void*)(chunk.End()));
    314   Printf("%s", d.EndLocation());
    315 }
    316 
    317 // Return " (thread_name) " or an empty string if the name is empty.
    318 const char *ThreadNameWithParenthesis(AsanThreadSummary *t, char buff[],
    319                                       uptr buff_len) {
    320   const char *name = t->name();
    321   if (*name == 0) return "";
    322   buff[0] = 0;
    323   internal_strncat(buff, " (", 3);
    324   internal_strncat(buff, name, buff_len - 4);
    325   internal_strncat(buff, ")", 2);
    326   return buff;
    327 }
    328 
    329 const char *ThreadNameWithParenthesis(u32 tid, char buff[],
    330                                       uptr buff_len) {
    331   if (tid == kInvalidTid) return "";
    332   AsanThreadSummary *t = asanThreadRegistry().FindByTid(tid);
    333   return ThreadNameWithParenthesis(t, buff, buff_len);
    334 }
    335 
    336 void DescribeHeapAddress(uptr addr, uptr access_size) {
    337   AsanChunkView chunk = FindHeapChunkByAddress(addr);
    338   if (!chunk.IsValid()) return;
    339   DescribeAccessToHeapChunk(chunk, addr, access_size);
    340   CHECK(chunk.AllocTid() != kInvalidTid);
    341   AsanThreadSummary *alloc_thread =
    342       asanThreadRegistry().FindByTid(chunk.AllocTid());
    343   StackTrace alloc_stack;
    344   chunk.GetAllocStack(&alloc_stack);
    345   AsanThread *t = asanThreadRegistry().GetCurrent();
    346   CHECK(t);
    347   char tname[128];
    348   Decorator d;
    349   if (chunk.FreeTid() != kInvalidTid) {
    350     AsanThreadSummary *free_thread =
    351         asanThreadRegistry().FindByTid(chunk.FreeTid());
    352     Printf("%sfreed by thread T%d%s here:%s\n", d.Allocation(),
    353            free_thread->tid(),
    354            ThreadNameWithParenthesis(free_thread, tname, sizeof(tname)),
    355            d.EndAllocation());
    356     StackTrace free_stack;
    357     chunk.GetFreeStack(&free_stack);
    358     PrintStack(&free_stack);
    359     Printf("%spreviously allocated by thread T%d%s here:%s\n",
    360            d.Allocation(), alloc_thread->tid(),
    361            ThreadNameWithParenthesis(alloc_thread, tname, sizeof(tname)),
    362            d.EndAllocation());
    363     PrintStack(&alloc_stack);
    364     DescribeThread(t->summary());
    365     DescribeThread(free_thread);
    366     DescribeThread(alloc_thread);
    367   } else {
    368     Printf("%sallocated by thread T%d%s here:%s\n", d.Allocation(),
    369            alloc_thread->tid(),
    370            ThreadNameWithParenthesis(alloc_thread, tname, sizeof(tname)),
    371            d.EndAllocation());
    372     PrintStack(&alloc_stack);
    373     DescribeThread(t->summary());
    374     DescribeThread(alloc_thread);
    375   }
    376 }
    377 
    378 void DescribeAddress(uptr addr, uptr access_size) {
    379   // Check if this is shadow or shadow gap.
    380   if (DescribeAddressIfShadow(addr))
    381     return;
    382   CHECK(AddrIsInMem(addr));
    383   if (DescribeAddressIfGlobal(addr, access_size))
    384     return;
    385   if (DescribeAddressIfStack(addr, access_size))
    386     return;
    387   // Assume it is a heap address.
    388   DescribeHeapAddress(addr, access_size);
    389 }
    390 
    391 // ------------------- Thread description -------------------- {{{1
    392 
    393 void DescribeThread(AsanThreadSummary *summary) {
    394   CHECK(summary);
    395   // No need to announce the main thread.
    396   if (summary->tid() == 0 || summary->announced()) {
    397     return;
    398   }
    399   summary->set_announced(true);
    400   char tname[128];
    401   Printf("Thread T%d%s", summary->tid(),
    402          ThreadNameWithParenthesis(summary->tid(), tname, sizeof(tname)));
    403   Printf(" created by T%d%s here:\n",
    404          summary->parent_tid(),
    405          ThreadNameWithParenthesis(summary->parent_tid(),
    406                                    tname, sizeof(tname)));
    407   PrintStack(summary->stack());
    408   // Recursively described parent thread if needed.
    409   if (flags()->print_full_thread_history) {
    410     AsanThreadSummary *parent_summary =
    411         asanThreadRegistry().FindByTid(summary->parent_tid());
    412     DescribeThread(parent_summary);
    413   }
    414 }
    415 
    416 // -------------------- Different kinds of reports ----------------- {{{1
    417 
    418 // Use ScopedInErrorReport to run common actions just before and
    419 // immediately after printing error report.
    420 class ScopedInErrorReport {
    421  public:
    422   ScopedInErrorReport() {
    423     static atomic_uint32_t num_calls;
    424     static u32 reporting_thread_tid;
    425     if (atomic_fetch_add(&num_calls, 1, memory_order_relaxed) != 0) {
    426       // Do not print more than one report, otherwise they will mix up.
    427       // Error reporting functions shouldn't return at this situation, as
    428       // they are defined as no-return.
    429       Report("AddressSanitizer: while reporting a bug found another one."
    430                  "Ignoring.\n");
    431       u32 current_tid = asanThreadRegistry().GetCurrentTidOrInvalid();
    432       if (current_tid != reporting_thread_tid) {
    433         // ASan found two bugs in different threads simultaneously. Sleep
    434         // long enough to make sure that the thread which started to print
    435         // an error report will finish doing it.
    436         SleepForSeconds(Max(100, flags()->sleep_before_dying + 1));
    437       }
    438       // If we're still not dead for some reason, use raw _exit() instead of
    439       // Die() to bypass any additional checks.
    440       internal__exit(flags()->exitcode);
    441     }
    442     ASAN_ON_ERROR();
    443     reporting_thread_tid = asanThreadRegistry().GetCurrentTidOrInvalid();
    444     Printf("===================================================="
    445            "=============\n");
    446     if (reporting_thread_tid != kInvalidTid) {
    447       // We started reporting an error message. Stop using the fake stack
    448       // in case we call an instrumented function from a symbolizer.
    449       AsanThread *curr_thread = asanThreadRegistry().GetCurrent();
    450       CHECK(curr_thread);
    451       curr_thread->fake_stack().StopUsingFakeStack();
    452     }
    453   }
    454   // Destructor is NORETURN, as functions that report errors are.
    455   NORETURN ~ScopedInErrorReport() {
    456     // Make sure the current thread is announced.
    457     AsanThread *curr_thread = asanThreadRegistry().GetCurrent();
    458     if (curr_thread) {
    459       DescribeThread(curr_thread->summary());
    460     }
    461     // Print memory stats.
    462     if (flags()->print_stats)
    463       __asan_print_accumulated_stats();
    464     if (error_report_callback) {
    465       error_report_callback(error_message_buffer);
    466     }
    467     Report("ABORTING\n");
    468     Die();
    469   }
    470 };
    471 
    472 static void ReportSummary(const char *error_type, StackTrace *stack) {
    473   if (!stack->size) return;
    474   if (IsSymbolizerAvailable()) {
    475     AddressInfo ai;
    476     // Currently, we include the first stack frame into the report summary.
    477     // Maybe sometimes we need to choose another frame (e.g. skip memcpy/etc).
    478     SymbolizeCode(stack->trace[0], &ai, 1);
    479     ReportErrorSummary(error_type,
    480                        StripPathPrefix(ai.file, flags()->strip_path_prefix),
    481                        ai.line, ai.function);
    482   }
    483   // FIXME: do we need to print anything at all if there is no symbolizer?
    484 }
    485 
    486 void ReportSIGSEGV(uptr pc, uptr sp, uptr bp, uptr addr) {
    487   ScopedInErrorReport in_report;
    488   Decorator d;
    489   Printf("%s", d.Warning());
    490   Report("ERROR: AddressSanitizer: SEGV on unknown address %p"
    491              " (pc %p sp %p bp %p T%d)\n",
    492              (void*)addr, (void*)pc, (void*)sp, (void*)bp,
    493              asanThreadRegistry().GetCurrentTidOrInvalid());
    494   Printf("%s", d.EndWarning());
    495   Printf("AddressSanitizer can not provide additional info.\n");
    496   GET_STACK_TRACE_FATAL(pc, bp);
    497   PrintStack(&stack);
    498   ReportSummary("SEGV", &stack);
    499 }
    500 
    501 void ReportDoubleFree(uptr addr, StackTrace *stack) {
    502   ScopedInErrorReport in_report;
    503   Decorator d;
    504   Printf("%s", d.Warning());
    505   Report("ERROR: AddressSanitizer: attempting double-free on %p:\n", addr);
    506   Printf("%s", d.EndWarning());
    507   PrintStack(stack);
    508   DescribeHeapAddress(addr, 1);
    509   ReportSummary("double-free", stack);
    510 }
    511 
    512 void ReportFreeNotMalloced(uptr addr, StackTrace *stack) {
    513   ScopedInErrorReport in_report;
    514   Decorator d;
    515   Printf("%s", d.Warning());
    516   Report("ERROR: AddressSanitizer: attempting free on address "
    517              "which was not malloc()-ed: %p\n", addr);
    518   Printf("%s", d.EndWarning());
    519   PrintStack(stack);
    520   DescribeHeapAddress(addr, 1);
    521   ReportSummary("bad-free", stack);
    522 }
    523 
    524 void ReportAllocTypeMismatch(uptr addr, StackTrace *stack,
    525                              AllocType alloc_type,
    526                              AllocType dealloc_type) {
    527   static const char *alloc_names[] =
    528     {"INVALID", "malloc", "operator new", "operator new []"};
    529   static const char *dealloc_names[] =
    530     {"INVALID", "free", "operator delete", "operator delete []"};
    531   CHECK_NE(alloc_type, dealloc_type);
    532   ScopedInErrorReport in_report;
    533   Decorator d;
    534   Printf("%s", d.Warning());
    535   Report("ERROR: AddressSanitizer: alloc-dealloc-mismatch (%s vs %s) on %p\n",
    536         alloc_names[alloc_type], dealloc_names[dealloc_type], addr);
    537   Printf("%s", d.EndWarning());
    538   PrintStack(stack);
    539   DescribeHeapAddress(addr, 1);
    540   ReportSummary("alloc-dealloc-mismatch", stack);
    541   Report("HINT: if you don't care about these warnings you may set "
    542          "ASAN_OPTIONS=alloc_dealloc_mismatch=0\n");
    543 }
    544 
    545 void ReportMallocUsableSizeNotOwned(uptr addr, StackTrace *stack) {
    546   ScopedInErrorReport in_report;
    547   Decorator d;
    548   Printf("%s", d.Warning());
    549   Report("ERROR: AddressSanitizer: attempting to call "
    550              "malloc_usable_size() for pointer which is "
    551              "not owned: %p\n", addr);
    552   Printf("%s", d.EndWarning());
    553   PrintStack(stack);
    554   DescribeHeapAddress(addr, 1);
    555   ReportSummary("bad-malloc_usable_size", stack);
    556 }
    557 
    558 void ReportAsanGetAllocatedSizeNotOwned(uptr addr, StackTrace *stack) {
    559   ScopedInErrorReport in_report;
    560   Decorator d;
    561   Printf("%s", d.Warning());
    562   Report("ERROR: AddressSanitizer: attempting to call "
    563              "__asan_get_allocated_size() for pointer which is "
    564              "not owned: %p\n", addr);
    565   Printf("%s", d.EndWarning());
    566   PrintStack(stack);
    567   DescribeHeapAddress(addr, 1);
    568   ReportSummary("bad-__asan_get_allocated_size", stack);
    569 }
    570 
    571 void ReportStringFunctionMemoryRangesOverlap(
    572     const char *function, const char *offset1, uptr length1,
    573     const char *offset2, uptr length2, StackTrace *stack) {
    574   ScopedInErrorReport in_report;
    575   Decorator d;
    576   char bug_type[100];
    577   internal_snprintf(bug_type, sizeof(bug_type), "%s-param-overlap", function);
    578   Printf("%s", d.Warning());
    579   Report("ERROR: AddressSanitizer: %s: "
    580              "memory ranges [%p,%p) and [%p, %p) overlap\n", \
    581              bug_type, offset1, offset1 + length1, offset2, offset2 + length2);
    582   Printf("%s", d.EndWarning());
    583   PrintStack(stack);
    584   DescribeAddress((uptr)offset1, length1);
    585   DescribeAddress((uptr)offset2, length2);
    586   ReportSummary(bug_type, stack);
    587 }
    588 
    589 // ----------------------- Mac-specific reports ----------------- {{{1
    590 
    591 void WarnMacFreeUnallocated(
    592     uptr addr, uptr zone_ptr, const char *zone_name, StackTrace *stack) {
    593   // Just print a warning here.
    594   Printf("free_common(%p) -- attempting to free unallocated memory.\n"
    595              "AddressSanitizer is ignoring this error on Mac OS now.\n",
    596              addr);
    597   PrintZoneForPointer(addr, zone_ptr, zone_name);
    598   PrintStack(stack);
    599   DescribeHeapAddress(addr, 1);
    600 }
    601 
    602 void ReportMacMzReallocUnknown(
    603     uptr addr, uptr zone_ptr, const char *zone_name, StackTrace *stack) {
    604   ScopedInErrorReport in_report;
    605   Printf("mz_realloc(%p) -- attempting to realloc unallocated memory.\n"
    606              "This is an unrecoverable problem, exiting now.\n",
    607              addr);
    608   PrintZoneForPointer(addr, zone_ptr, zone_name);
    609   PrintStack(stack);
    610   DescribeHeapAddress(addr, 1);
    611 }
    612 
    613 void ReportMacCfReallocUnknown(
    614     uptr addr, uptr zone_ptr, const char *zone_name, StackTrace *stack) {
    615   ScopedInErrorReport in_report;
    616   Printf("cf_realloc(%p) -- attempting to realloc unallocated memory.\n"
    617              "This is an unrecoverable problem, exiting now.\n",
    618              addr);
    619   PrintZoneForPointer(addr, zone_ptr, zone_name);
    620   PrintStack(stack);
    621   DescribeHeapAddress(addr, 1);
    622 }
    623 
    624 }  // namespace __asan
    625 
    626 // --------------------------- Interface --------------------- {{{1
    627 using namespace __asan;  // NOLINT
    628 
    629 void __asan_report_error(uptr pc, uptr bp, uptr sp,
    630                          uptr addr, bool is_write, uptr access_size) {
    631   ScopedInErrorReport in_report;
    632 
    633   // Determine the error type.
    634   const char *bug_descr = "unknown-crash";
    635   if (AddrIsInMem(addr)) {
    636     u8 *shadow_addr = (u8*)MemToShadow(addr);
    637     // If we are accessing 16 bytes, look at the second shadow byte.
    638     if (*shadow_addr == 0 && access_size > SHADOW_GRANULARITY)
    639       shadow_addr++;
    640     // If we are in the partial right redzone, look at the next shadow byte.
    641     if (*shadow_addr > 0 && *shadow_addr < 128)
    642       shadow_addr++;
    643     switch (*shadow_addr) {
    644       case kAsanHeapLeftRedzoneMagic:
    645       case kAsanHeapRightRedzoneMagic:
    646         bug_descr = "heap-buffer-overflow";
    647         break;
    648       case kAsanHeapFreeMagic:
    649         bug_descr = "heap-use-after-free";
    650         break;
    651       case kAsanStackLeftRedzoneMagic:
    652         bug_descr = "stack-buffer-underflow";
    653         break;
    654       case kAsanInitializationOrderMagic:
    655         bug_descr = "initialization-order-fiasco";
    656         break;
    657       case kAsanStackMidRedzoneMagic:
    658       case kAsanStackRightRedzoneMagic:
    659       case kAsanStackPartialRedzoneMagic:
    660         bug_descr = "stack-buffer-overflow";
    661         break;
    662       case kAsanStackAfterReturnMagic:
    663         bug_descr = "stack-use-after-return";
    664         break;
    665       case kAsanUserPoisonedMemoryMagic:
    666         bug_descr = "use-after-poison";
    667         break;
    668       case kAsanStackUseAfterScopeMagic:
    669         bug_descr = "stack-use-after-scope";
    670         break;
    671       case kAsanGlobalRedzoneMagic:
    672         bug_descr = "global-buffer-overflow";
    673         break;
    674     }
    675   }
    676   Decorator d;
    677   Printf("%s", d.Warning());
    678   Report("ERROR: AddressSanitizer: %s on address "
    679              "%p at pc 0x%zx bp 0x%zx sp 0x%zx\n",
    680              bug_descr, (void*)addr, pc, bp, sp);
    681   Printf("%s", d.EndWarning());
    682 
    683   u32 curr_tid = asanThreadRegistry().GetCurrentTidOrInvalid();
    684   char tname[128];
    685   Printf("%s%s of size %zu at %p thread T%d%s%s\n",
    686          d.Access(),
    687          access_size ? (is_write ? "WRITE" : "READ") : "ACCESS",
    688          access_size, (void*)addr, curr_tid,
    689          ThreadNameWithParenthesis(curr_tid, tname, sizeof(tname)),
    690          d.EndAccess());
    691 
    692   GET_STACK_TRACE_FATAL(pc, bp);
    693   PrintStack(&stack);
    694 
    695   DescribeAddress(addr, access_size);
    696   ReportSummary(bug_descr, &stack);
    697   PrintShadowMemoryForAddress(addr);
    698 }
    699 
    700 void NOINLINE __asan_set_error_report_callback(void (*callback)(const char*)) {
    701   error_report_callback = callback;
    702   if (callback) {
    703     error_message_buffer_size = 1 << 16;
    704     error_message_buffer =
    705         (char*)MmapOrDie(error_message_buffer_size, __FUNCTION__);
    706     error_message_buffer_pos = 0;
    707   }
    708 }
    709 
    710 void __asan_describe_address(uptr addr) {
    711   DescribeAddress(addr, 1);
    712 }
    713 
    714 #if !SANITIZER_SUPPORTS_WEAK_HOOKS
    715 // Provide default implementation of __asan_on_error that does nothing
    716 // and may be overriden by user.
    717 SANITIZER_WEAK_ATTRIBUTE SANITIZER_INTERFACE_ATTRIBUTE NOINLINE
    718 void __asan_on_error() {}
    719 #endif
    720