asan_report.cc revision edb39c7942fc9fe5043b7cce348bac0aec4c83eb 
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_symbolizer.h"
24
25namespace __asan {
26
27// -------------------- User-specified callbacks ----------------- {{{1
28static void (*error_report_callback)(const char*);
29static char *error_message_buffer = 0;
30static uptr error_message_buffer_pos = 0;
31static uptr error_message_buffer_size = 0;
32
33void AppendToErrorMessageBuffer(const char *buffer) {
34  if (error_message_buffer) {
35    uptr length = internal_strlen(buffer);
36    CHECK_GE(error_message_buffer_size, error_message_buffer_pos);
37    uptr remaining = error_message_buffer_size - error_message_buffer_pos;
38    internal_strncpy(error_message_buffer + error_message_buffer_pos,
39                     buffer, remaining);
40    error_message_buffer[error_message_buffer_size - 1] = '\0';
41    // FIXME: reallocate the buffer instead of truncating the message.
42    error_message_buffer_pos += remaining > length ? length : remaining;
43  }
44}
45
46// ---------------------- Decorator ------------------------------ {{{1
47class Decorator: private __sanitizer::AnsiColorDecorator {
48 public:
49  Decorator() : __sanitizer::AnsiColorDecorator(PrintsToTtyCached()) { }
50  const char *Warning()    { return Red(); }
51  const char *EndWarning() { return Default(); }
52  const char *Access()     { return Blue(); }
53  const char *EndAccess()  { return Default(); }
54  const char *Location()   { return Green(); }
55  const char *EndLocation() { return Default(); }
56  const char *Allocation()  { return Magenta(); }
57  const char *EndAllocation()  { return Default(); }
58
59  const char *ShadowByte(u8 byte) {
60    switch (byte) {
61      case kAsanHeapLeftRedzoneMagic:
62      case kAsanHeapRightRedzoneMagic:
63        return Red();
64      case kAsanHeapFreeMagic:
65        return Magenta();
66      case kAsanStackLeftRedzoneMagic:
67      case kAsanStackMidRedzoneMagic:
68      case kAsanStackRightRedzoneMagic:
69      case kAsanStackPartialRedzoneMagic:
70        return Red();
71      case kAsanStackAfterReturnMagic:
72        return Magenta();
73      case kAsanInitializationOrderMagic:
74        return Cyan();
75      case kAsanUserPoisonedMemoryMagic:
76        return Blue();
77      case kAsanStackUseAfterScopeMagic:
78        return Magenta();
79      case kAsanGlobalRedzoneMagic:
80        return Red();
81      case kAsanInternalHeapMagic:
82        return Yellow();
83      default:
84        return Default();
85    }
86  }
87  const char *EndShadowByte() { return Default(); }
88};
89
90// ---------------------- Helper functions ----------------------- {{{1
91
92static void PrintShadowByte(const char *before, u8 byte,
93                            const char *after = "\n") {
94  Decorator d;
95  Printf("%s%s%x%x%s%s", before,
96         d.ShadowByte(byte), byte >> 4, byte & 15, d.EndShadowByte(), after);
97}
98
99static void PrintShadowBytes(const char *before, u8 *bytes,
100                             u8 *guilty, uptr n) {
101  Decorator d;
102  if (before)
103    Printf("%s%p:", before, bytes);
104  for (uptr i = 0; i < n; i++) {
105    u8 *p = bytes + i;
106    const char *before = p == guilty ? "[" :
107        (p - 1 == guilty && i != 0) ? "" : " ";
108    const char *after = p == guilty ? "]" : "";
109    PrintShadowByte(before, *p, after);
110  }
111  Printf("\n");
112}
113
114static void PrintLegend() {
115  Printf("Shadow byte legend (one shadow byte represents %d "
116         "application bytes):\n", (int)SHADOW_GRANULARITY);
117  PrintShadowByte("  Addressable:           ", 0);
118  Printf("  Partially addressable: ");
119  for (u8 i = 1; i < SHADOW_GRANULARITY; i++)
120    PrintShadowByte("", i, " ");
121  Printf("\n");
122  PrintShadowByte("  Heap left redzone:     ", kAsanHeapLeftRedzoneMagic);
123  PrintShadowByte("  Heap right redzone:    ", kAsanHeapRightRedzoneMagic);
124  PrintShadowByte("  Freed heap region:     ", kAsanHeapFreeMagic);
125  PrintShadowByte("  Stack left redzone:    ", kAsanStackLeftRedzoneMagic);
126  PrintShadowByte("  Stack mid redzone:     ", kAsanStackMidRedzoneMagic);
127  PrintShadowByte("  Stack right redzone:   ", kAsanStackRightRedzoneMagic);
128  PrintShadowByte("  Stack partial redzone: ", kAsanStackPartialRedzoneMagic);
129  PrintShadowByte("  Stack after return:    ", kAsanStackAfterReturnMagic);
130  PrintShadowByte("  Stack use after scope: ", kAsanStackUseAfterScopeMagic);
131  PrintShadowByte("  Global redzone:        ", kAsanGlobalRedzoneMagic);
132  PrintShadowByte("  Global init order:     ", kAsanInitializationOrderMagic);
133  PrintShadowByte("  Poisoned by user:      ", kAsanUserPoisonedMemoryMagic);
134  PrintShadowByte("  ASan internal:         ", kAsanInternalHeapMagic);
135}
136
137static void PrintShadowMemoryForAddress(uptr addr) {
138  if (!AddrIsInMem(addr))
139    return;
140  uptr shadow_addr = MemToShadow(addr);
141  const uptr n_bytes_per_row = 16;
142  uptr aligned_shadow = shadow_addr & ~(n_bytes_per_row - 1);
143  Printf("Shadow bytes around the buggy address:\n");
144  for (int i = -5; i <= 5; i++) {
145    const char *prefix = (i == 0) ? "=>" : "  ";
146    PrintShadowBytes(prefix,
147                     (u8*)(aligned_shadow + i * n_bytes_per_row),
148                     (u8*)shadow_addr, n_bytes_per_row);
149  }
150  if (flags()->print_legend)
151    PrintLegend();
152}
153
154static void PrintZoneForPointer(uptr ptr, uptr zone_ptr,
155                                const char *zone_name) {
156  if (zone_ptr) {
157    if (zone_name) {
158      Printf("malloc_zone_from_ptr(%p) = %p, which is %s\n",
159                 ptr, zone_ptr, zone_name);
160    } else {
161      Printf("malloc_zone_from_ptr(%p) = %p, which doesn't have a name\n",
162                 ptr, zone_ptr);
163    }
164  } else {
165    Printf("malloc_zone_from_ptr(%p) = 0\n", ptr);
166  }
167}
168
169// ---------------------- Address Descriptions ------------------- {{{1
170
171static bool IsASCII(unsigned char c) {
172  return /*0x00 <= c &&*/ c <= 0x7F;
173}
174
175static const char *MaybeDemangleGlobalName(const char *name) {
176  // We can spoil names of globals with C linkage, so use an heuristic
177  // approach to check if the name should be demangled.
178  return (name[0] == '_' && name[1] == 'Z') ? Demangle(name) : name;
179}
180
181// Check if the global is a zero-terminated ASCII string. If so, print it.
182static void PrintGlobalNameIfASCII(const __asan_global &g) {
183  for (uptr p = g.beg; p < g.beg + g.size - 1; p++) {
184    unsigned char c = *(unsigned char*)p;
185    if (c == '\0' || !IsASCII(c)) return;
186  }
187  if (*(char*)(g.beg + g.size - 1) != '\0') return;
188  Printf("  '%s' is ascii string '%s'\n",
189         MaybeDemangleGlobalName(g.name), (char*)g.beg);
190}
191
192bool DescribeAddressRelativeToGlobal(uptr addr, uptr size,
193                                     const __asan_global &g) {
194  static const uptr kMinimalDistanceFromAnotherGlobal = 64;
195  if (addr <= g.beg - kMinimalDistanceFromAnotherGlobal) return false;
196  if (addr >= g.beg + g.size_with_redzone) return false;
197  Decorator d;
198  Printf("%s", d.Location());
199  if (addr < g.beg) {
200    Printf("%p is located %zd bytes to the left", (void*)addr, g.beg - addr);
201  } else if (addr + size > g.beg + g.size) {
202    if (addr < g.beg + g.size)
203      addr = g.beg + g.size;
204    Printf("%p is located %zd bytes to the right", (void*)addr,
205           addr - (g.beg + g.size));
206  } else {
207    // Can it happen?
208    Printf("%p is located %zd bytes inside", (void*)addr, addr - g.beg);
209  }
210  Printf(" of global variable '%s' from '%s' (0x%zx) of size %zu\n",
211             MaybeDemangleGlobalName(g.name), g.module_name, g.beg, g.size);
212  Printf("%s", d.EndLocation());
213  PrintGlobalNameIfASCII(g);
214  return true;
215}
216
217bool DescribeAddressIfShadow(uptr addr) {
218  if (AddrIsInMem(addr))
219    return false;
220  static const char kAddrInShadowReport[] =
221      "Address %p is located in the %s.\n";
222  if (AddrIsInShadowGap(addr)) {
223    Printf(kAddrInShadowReport, addr, "shadow gap area");
224    return true;
225  }
226  if (AddrIsInHighShadow(addr)) {
227    Printf(kAddrInShadowReport, addr, "high shadow area");
228    return true;
229  }
230  if (AddrIsInLowShadow(addr)) {
231    Printf(kAddrInShadowReport, addr, "low shadow area");
232    return true;
233  }
234  CHECK(0 && "Address is not in memory and not in shadow?");
235  return false;
236}
237
238// Return " (thread_name) " or an empty string if the name is empty.
239const char *ThreadNameWithParenthesis(AsanThreadContext *t, char buff[],
240                                      uptr buff_len) {
241  const char *name = t->name;
242  if (name[0] == '\0') return "";
243  buff[0] = 0;
244  internal_strncat(buff, " (", 3);
245  internal_strncat(buff, name, buff_len - 4);
246  internal_strncat(buff, ")", 2);
247  return buff;
248}
249
250const char *ThreadNameWithParenthesis(u32 tid, char buff[],
251                                      uptr buff_len) {
252  if (tid == kInvalidTid) return "";
253  asanThreadRegistry().CheckLocked();
254  AsanThreadContext *t = GetThreadContextByTidLocked(tid);
255  return ThreadNameWithParenthesis(t, buff, buff_len);
256}
257
258void PrintAccessAndVarIntersection(const char *var_name,
259                                   uptr var_beg, uptr var_size,
260                                   uptr addr, uptr access_size,
261                                   uptr prev_var_end, uptr next_var_beg) {
262  uptr var_end = var_beg + var_size;
263  uptr addr_end = addr + access_size;
264  const char *pos_descr = 0;
265  // If the variable [var_beg, var_end) is the nearest variable to the
266  // current memory access, indicate it in the log.
267  if (addr >= var_beg) {
268    if (addr_end <= var_end)
269      pos_descr = "is inside";  // May happen if this is a use-after-return.
270    else if (addr < var_end)
271      pos_descr = "partially overflows";
272    else if (addr_end <= next_var_beg &&
273             next_var_beg - addr_end >= addr - var_end)
274      pos_descr = "overflows";
275  } else {
276    if (addr_end > var_beg)
277      pos_descr = "partially underflows";
278    else if (addr >= prev_var_end &&
279             addr - prev_var_end >= var_beg - addr_end)
280      pos_descr = "underflows";
281  }
282  Printf("    [%zd, %zd) '%s'", var_beg, var_beg + var_size, var_name);
283  if (pos_descr) {
284    Decorator d;
285    // FIXME: we may want to also print the size of the access here,
286    // but in case of accesses generated by memset it may be confusing.
287    Printf("%s <== Memory access at offset %zd %s this variable%s\n",
288           d.Location(), addr, pos_descr, d.EndLocation());
289  } else {
290    Printf("\n");
291  }
292}
293
294struct StackVarDescr {
295  uptr beg;
296  uptr size;
297  const char *name_pos;
298  s64 name_len;
299};
300
301bool DescribeAddressIfStack(uptr addr, uptr access_size) {
302  AsanThread *t = FindThreadByStackAddress(addr);
303  if (!t) return false;
304  const s64 kBufSize = 4095;
305  char buf[kBufSize];
306  uptr offset = 0;
307  uptr frame_pc = 0;
308  char tname[128];
309  const char *frame_descr = t->GetFrameNameByAddr(addr, &offset, &frame_pc);
310
311#ifdef __powerpc64__
312  // On PowerPC64, the address of a function actually points to a
313  // three-doubleword data structure with the first field containing
314  // the address of the function's code.
315  frame_pc = *reinterpret_cast<uptr *>(frame_pc);
316#endif
317
318  // This string is created by the compiler and has the following form:
319  // "n alloc_1 alloc_2 ... alloc_n"
320  // where alloc_i looks like "offset size len ObjectName ".
321  CHECK(frame_descr);
322  Decorator d;
323  Printf("%s", d.Location());
324  Printf("Address %p is located in stack of thread T%d%s "
325         "at offset %zu in frame\n",
326         addr, t->tid(),
327         ThreadNameWithParenthesis(t->tid(), tname, sizeof(tname)),
328         offset);
329  // Now we print the frame where the alloca has happened.
330  // We print this frame as a stack trace with one element.
331  // The symbolizer may print more than one frame if inlining was involved.
332  // The frame numbers may be different than those in the stack trace printed
333  // previously. That's unfortunate, but I have no better solution,
334  // especially given that the alloca may be from entirely different place
335  // (e.g. use-after-scope, or different thread's stack).
336  StackTrace alloca_stack;
337  alloca_stack.trace[0] = frame_pc + 16;
338  alloca_stack.size = 1;
339  Printf("%s", d.EndLocation());
340  PrintStack(&alloca_stack);
341  // Report the number of stack objects.
342  char *p;
343  s64 n_objects = internal_simple_strtoll(frame_descr, &p, 10);
344  CHECK_GT(n_objects, 0);
345  Printf("  This frame has %zu object(s):\n", n_objects);
346
347  // Report all objects in this frame.
348  InternalScopedBuffer<StackVarDescr> vars(n_objects);
349  for (s64 i = 0; i < n_objects; i++) {
350    s64 beg, size;
351    s64 len;
352    beg  = internal_simple_strtoll(p, &p, 10);
353    size = internal_simple_strtoll(p, &p, 10);
354    len  = internal_simple_strtoll(p, &p, 10);
355    if (beg <= 0 || size <= 0 || len < 0 || *p != ' ') {
356      Printf("AddressSanitizer can't parse the stack frame "
357                 "descriptor: |%s|\n", frame_descr);
358      break;
359    }
360    p++;
361    vars[i].beg = beg;
362    vars[i].size = size;
363    vars[i].name_pos = p;
364    vars[i].name_len = len;
365    p += len;
366  }
367  for (s64 i = 0; i < n_objects; i++) {
368    buf[0] = 0;
369    internal_strncat(buf, vars[i].name_pos,
370                     static_cast<uptr>(Min(kBufSize, vars[i].name_len)));
371    uptr prev_var_end = i ? vars[i - 1].beg + vars[i - 1].size : 0;
372    uptr next_var_beg = i < n_objects - 1 ? vars[i + 1].beg : ~(0UL);
373    PrintAccessAndVarIntersection(buf, vars[i].beg, vars[i].size,
374                                  offset, access_size,
375                                  prev_var_end, next_var_beg);
376  }
377  Printf("HINT: this may be a false positive if your program uses "
378             "some custom stack unwind mechanism or swapcontext\n"
379             "      (longjmp and C++ exceptions *are* supported)\n");
380  DescribeThread(t->context());
381  return true;
382}
383
384static void DescribeAccessToHeapChunk(AsanChunkView chunk, uptr addr,
385                                      uptr access_size) {
386  sptr offset;
387  Decorator d;
388  Printf("%s", d.Location());
389  if (chunk.AddrIsAtLeft(addr, access_size, &offset)) {
390    Printf("%p is located %zd bytes to the left of", (void*)addr, offset);
391  } else if (chunk.AddrIsAtRight(addr, access_size, &offset)) {
392    if (offset < 0) {
393      addr -= offset;
394      offset = 0;
395    }
396    Printf("%p is located %zd bytes to the right of", (void*)addr, offset);
397  } else if (chunk.AddrIsInside(addr, access_size, &offset)) {
398    Printf("%p is located %zd bytes inside of", (void*)addr, offset);
399  } else {
400    Printf("%p is located somewhere around (this is AddressSanitizer bug!)",
401           (void*)addr);
402  }
403  Printf(" %zu-byte region [%p,%p)\n", chunk.UsedSize(),
404         (void*)(chunk.Beg()), (void*)(chunk.End()));
405  Printf("%s", d.EndLocation());
406}
407
408void DescribeHeapAddress(uptr addr, uptr access_size) {
409  AsanChunkView chunk = FindHeapChunkByAddress(addr);
410  if (!chunk.IsValid()) return;
411  DescribeAccessToHeapChunk(chunk, addr, access_size);
412  CHECK(chunk.AllocTid() != kInvalidTid);
413  asanThreadRegistry().CheckLocked();
414  AsanThreadContext *alloc_thread =
415      GetThreadContextByTidLocked(chunk.AllocTid());
416  StackTrace alloc_stack;
417  chunk.GetAllocStack(&alloc_stack);
418  AsanThread *t = GetCurrentThread();
419  CHECK(t);
420  char tname[128];
421  Decorator d;
422  if (chunk.FreeTid() != kInvalidTid) {
423    AsanThreadContext *free_thread =
424        GetThreadContextByTidLocked(chunk.FreeTid());
425    Printf("%sfreed by thread T%d%s here:%s\n", d.Allocation(),
426           free_thread->tid,
427           ThreadNameWithParenthesis(free_thread, tname, sizeof(tname)),
428           d.EndAllocation());
429    StackTrace free_stack;
430    chunk.GetFreeStack(&free_stack);
431    PrintStack(&free_stack);
432    Printf("%spreviously allocated by thread T%d%s here:%s\n",
433           d.Allocation(), alloc_thread->tid,
434           ThreadNameWithParenthesis(alloc_thread, tname, sizeof(tname)),
435           d.EndAllocation());
436    PrintStack(&alloc_stack);
437    DescribeThread(t->context());
438    DescribeThread(free_thread);
439    DescribeThread(alloc_thread);
440  } else {
441    Printf("%sallocated by thread T%d%s here:%s\n", d.Allocation(),
442           alloc_thread->tid,
443           ThreadNameWithParenthesis(alloc_thread, tname, sizeof(tname)),
444           d.EndAllocation());
445    PrintStack(&alloc_stack);
446    DescribeThread(t->context());
447    DescribeThread(alloc_thread);
448  }
449}
450
451void DescribeAddress(uptr addr, uptr access_size) {
452  // Check if this is shadow or shadow gap.
453  if (DescribeAddressIfShadow(addr))
454    return;
455  CHECK(AddrIsInMem(addr));
456  if (DescribeAddressIfGlobal(addr, access_size))
457    return;
458  if (DescribeAddressIfStack(addr, access_size))
459    return;
460  // Assume it is a heap address.
461  DescribeHeapAddress(addr, access_size);
462}
463
464// ------------------- Thread description -------------------- {{{1
465
466void DescribeThread(AsanThreadContext *context) {
467  CHECK(context);
468  asanThreadRegistry().CheckLocked();
469  // No need to announce the main thread.
470  if (context->tid == 0 || context->announced) {
471    return;
472  }
473  context->announced = true;
474  char tname[128];
475  Printf("Thread T%d%s", context->tid,
476         ThreadNameWithParenthesis(context->tid, tname, sizeof(tname)));
477  Printf(" created by T%d%s here:\n",
478         context->parent_tid,
479         ThreadNameWithParenthesis(context->parent_tid,
480                                   tname, sizeof(tname)));
481  PrintStack(&context->stack);
482  // Recursively described parent thread if needed.
483  if (flags()->print_full_thread_history) {
484    AsanThreadContext *parent_context =
485        GetThreadContextByTidLocked(context->parent_tid);
486    DescribeThread(parent_context);
487  }
488}
489
490// -------------------- Different kinds of reports ----------------- {{{1
491
492// Use ScopedInErrorReport to run common actions just before and
493// immediately after printing error report.
494class ScopedInErrorReport {
495 public:
496  ScopedInErrorReport() {
497    static atomic_uint32_t num_calls;
498    static u32 reporting_thread_tid;
499    if (atomic_fetch_add(&num_calls, 1, memory_order_relaxed) != 0) {
500      // Do not print more than one report, otherwise they will mix up.
501      // Error reporting functions shouldn't return at this situation, as
502      // they are defined as no-return.
503      Report("AddressSanitizer: while reporting a bug found another one."
504                 "Ignoring.\n");
505      u32 current_tid = GetCurrentTidOrInvalid();
506      if (current_tid != reporting_thread_tid) {
507        // ASan found two bugs in different threads simultaneously. Sleep
508        // long enough to make sure that the thread which started to print
509        // an error report will finish doing it.
510        SleepForSeconds(Max(100, flags()->sleep_before_dying + 1));
511      }
512      // If we're still not dead for some reason, use raw _exit() instead of
513      // Die() to bypass any additional checks.
514      internal__exit(flags()->exitcode);
515    }
516    ASAN_ON_ERROR();
517    // Make sure the registry and sanitizer report mutexes are locked while
518    // we're printing an error report.
519    // We can lock them only here to avoid self-deadlock in case of
520    // recursive reports.
521    asanThreadRegistry().Lock();
522    CommonSanitizerReportMutex.Lock();
523    reporting_thread_tid = GetCurrentTidOrInvalid();
524    Printf("===================================================="
525           "=============\n");
526    if (reporting_thread_tid != kInvalidTid) {
527      // We started reporting an error message. Stop using the fake stack
528      // in case we call an instrumented function from a symbolizer.
529      AsanThread *curr_thread = GetCurrentThread();
530      CHECK(curr_thread);
531      if (curr_thread->fake_stack())
532        curr_thread->fake_stack()->StopUsingFakeStack();
533    }
534  }
535  // Destructor is NORETURN, as functions that report errors are.
536  NORETURN ~ScopedInErrorReport() {
537    // Make sure the current thread is announced.
538    AsanThread *curr_thread = GetCurrentThread();
539    if (curr_thread) {
540      DescribeThread(curr_thread->context());
541    }
542    // Print memory stats.
543    if (flags()->print_stats)
544      __asan_print_accumulated_stats();
545    if (error_report_callback) {
546      error_report_callback(error_message_buffer);
547    }
548    Report("ABORTING\n");
549    Die();
550  }
551};
552
553static void ReportSummary(const char *error_type, StackTrace *stack) {
554  if (!stack->size) return;
555  if (IsSymbolizerAvailable()) {
556    AddressInfo ai;
557    // Currently, we include the first stack frame into the report summary.
558    // Maybe sometimes we need to choose another frame (e.g. skip memcpy/etc).
559    uptr pc = StackTrace::GetPreviousInstructionPc(stack->trace[0]);
560    SymbolizeCode(pc, &ai, 1);
561    ReportErrorSummary(error_type,
562                       StripPathPrefix(ai.file,
563                                       common_flags()->strip_path_prefix),
564                       ai.line, ai.function);
565  }
566  // FIXME: do we need to print anything at all if there is no symbolizer?
567}
568
569void ReportSIGSEGV(uptr pc, uptr sp, uptr bp, uptr addr) {
570  ScopedInErrorReport in_report;
571  Decorator d;
572  Printf("%s", d.Warning());
573  Report("ERROR: AddressSanitizer: SEGV on unknown address %p"
574             " (pc %p sp %p bp %p T%d)\n",
575             (void*)addr, (void*)pc, (void*)sp, (void*)bp,
576             GetCurrentTidOrInvalid());
577  Printf("%s", d.EndWarning());
578  Printf("AddressSanitizer can not provide additional info.\n");
579  GET_STACK_TRACE_FATAL(pc, bp);
580  PrintStack(&stack);
581  ReportSummary("SEGV", &stack);
582}
583
584void ReportDoubleFree(uptr addr, StackTrace *stack) {
585  ScopedInErrorReport in_report;
586  Decorator d;
587  Printf("%s", d.Warning());
588  char tname[128];
589  u32 curr_tid = GetCurrentTidOrInvalid();
590  Report("ERROR: AddressSanitizer: attempting double-free on %p in "
591         "thread T%d%s:\n",
592         addr, curr_tid,
593         ThreadNameWithParenthesis(curr_tid, tname, sizeof(tname)));
594
595  Printf("%s", d.EndWarning());
596  PrintStack(stack);
597  DescribeHeapAddress(addr, 1);
598  ReportSummary("double-free", stack);
599}
600
601void ReportFreeNotMalloced(uptr addr, StackTrace *stack) {
602  ScopedInErrorReport in_report;
603  Decorator d;
604  Printf("%s", d.Warning());
605  char tname[128];
606  u32 curr_tid = GetCurrentTidOrInvalid();
607  Report("ERROR: AddressSanitizer: attempting free on address "
608             "which was not malloc()-ed: %p in thread T%d%s\n", addr,
609         curr_tid, ThreadNameWithParenthesis(curr_tid, tname, sizeof(tname)));
610  Printf("%s", d.EndWarning());
611  PrintStack(stack);
612  DescribeHeapAddress(addr, 1);
613  ReportSummary("bad-free", stack);
614}
615
616void ReportAllocTypeMismatch(uptr addr, StackTrace *stack,
617                             AllocType alloc_type,
618                             AllocType dealloc_type) {
619  static const char *alloc_names[] =
620    {"INVALID", "malloc", "operator new", "operator new []"};
621  static const char *dealloc_names[] =
622    {"INVALID", "free", "operator delete", "operator delete []"};
623  CHECK_NE(alloc_type, dealloc_type);
624  ScopedInErrorReport in_report;
625  Decorator d;
626  Printf("%s", d.Warning());
627  Report("ERROR: AddressSanitizer: alloc-dealloc-mismatch (%s vs %s) on %p\n",
628        alloc_names[alloc_type], dealloc_names[dealloc_type], addr);
629  Printf("%s", d.EndWarning());
630  PrintStack(stack);
631  DescribeHeapAddress(addr, 1);
632  ReportSummary("alloc-dealloc-mismatch", stack);
633  Report("HINT: if you don't care about these warnings you may set "
634         "ASAN_OPTIONS=alloc_dealloc_mismatch=0\n");
635}
636
637void ReportMallocUsableSizeNotOwned(uptr addr, StackTrace *stack) {
638  ScopedInErrorReport in_report;
639  Decorator d;
640  Printf("%s", d.Warning());
641  Report("ERROR: AddressSanitizer: attempting to call "
642             "malloc_usable_size() for pointer which is "
643             "not owned: %p\n", addr);
644  Printf("%s", d.EndWarning());
645  PrintStack(stack);
646  DescribeHeapAddress(addr, 1);
647  ReportSummary("bad-malloc_usable_size", stack);
648}
649
650void ReportAsanGetAllocatedSizeNotOwned(uptr addr, StackTrace *stack) {
651  ScopedInErrorReport in_report;
652  Decorator d;
653  Printf("%s", d.Warning());
654  Report("ERROR: AddressSanitizer: attempting to call "
655             "__asan_get_allocated_size() for pointer which is "
656             "not owned: %p\n", addr);
657  Printf("%s", d.EndWarning());
658  PrintStack(stack);
659  DescribeHeapAddress(addr, 1);
660  ReportSummary("bad-__asan_get_allocated_size", stack);
661}
662
663void ReportStringFunctionMemoryRangesOverlap(
664    const char *function, const char *offset1, uptr length1,
665    const char *offset2, uptr length2, StackTrace *stack) {
666  ScopedInErrorReport in_report;
667  Decorator d;
668  char bug_type[100];
669  internal_snprintf(bug_type, sizeof(bug_type), "%s-param-overlap", function);
670  Printf("%s", d.Warning());
671  Report("ERROR: AddressSanitizer: %s: "
672             "memory ranges [%p,%p) and [%p, %p) overlap\n", \
673             bug_type, offset1, offset1 + length1, offset2, offset2 + length2);
674  Printf("%s", d.EndWarning());
675  PrintStack(stack);
676  DescribeAddress((uptr)offset1, length1);
677  DescribeAddress((uptr)offset2, length2);
678  ReportSummary(bug_type, stack);
679}
680
681// ----------------------- Mac-specific reports ----------------- {{{1
682
683void WarnMacFreeUnallocated(
684    uptr addr, uptr zone_ptr, const char *zone_name, StackTrace *stack) {
685  // Just print a warning here.
686  Printf("free_common(%p) -- attempting to free unallocated memory.\n"
687             "AddressSanitizer is ignoring this error on Mac OS now.\n",
688             addr);
689  PrintZoneForPointer(addr, zone_ptr, zone_name);
690  PrintStack(stack);
691  DescribeHeapAddress(addr, 1);
692}
693
694void ReportMacMzReallocUnknown(
695    uptr addr, uptr zone_ptr, const char *zone_name, StackTrace *stack) {
696  ScopedInErrorReport in_report;
697  Printf("mz_realloc(%p) -- attempting to realloc unallocated memory.\n"
698             "This is an unrecoverable problem, exiting now.\n",
699             addr);
700  PrintZoneForPointer(addr, zone_ptr, zone_name);
701  PrintStack(stack);
702  DescribeHeapAddress(addr, 1);
703}
704
705void ReportMacCfReallocUnknown(
706    uptr addr, uptr zone_ptr, const char *zone_name, StackTrace *stack) {
707  ScopedInErrorReport in_report;
708  Printf("cf_realloc(%p) -- attempting to realloc unallocated memory.\n"
709             "This is an unrecoverable problem, exiting now.\n",
710             addr);
711  PrintZoneForPointer(addr, zone_ptr, zone_name);
712  PrintStack(stack);
713  DescribeHeapAddress(addr, 1);
714}
715
716}  // namespace __asan
717
718// --------------------------- Interface --------------------- {{{1
719using namespace __asan;  // NOLINT
720
721void __asan_report_error(uptr pc, uptr bp, uptr sp,
722                         uptr addr, bool is_write, uptr access_size) {
723  ScopedInErrorReport in_report;
724
725  // Determine the error type.
726  const char *bug_descr = "unknown-crash";
727  if (AddrIsInMem(addr)) {
728    u8 *shadow_addr = (u8*)MemToShadow(addr);
729    // If we are accessing 16 bytes, look at the second shadow byte.
730    if (*shadow_addr == 0 && access_size > SHADOW_GRANULARITY)
731      shadow_addr++;
732    // If we are in the partial right redzone, look at the next shadow byte.
733    if (*shadow_addr > 0 && *shadow_addr < 128)
734      shadow_addr++;
735    switch (*shadow_addr) {
736      case kAsanHeapLeftRedzoneMagic:
737      case kAsanHeapRightRedzoneMagic:
738        bug_descr = "heap-buffer-overflow";
739        break;
740      case kAsanHeapFreeMagic:
741        bug_descr = "heap-use-after-free";
742        break;
743      case kAsanStackLeftRedzoneMagic:
744        bug_descr = "stack-buffer-underflow";
745        break;
746      case kAsanInitializationOrderMagic:
747        bug_descr = "initialization-order-fiasco";
748        break;
749      case kAsanStackMidRedzoneMagic:
750      case kAsanStackRightRedzoneMagic:
751      case kAsanStackPartialRedzoneMagic:
752        bug_descr = "stack-buffer-overflow";
753        break;
754      case kAsanStackAfterReturnMagic:
755        bug_descr = "stack-use-after-return";
756        break;
757      case kAsanUserPoisonedMemoryMagic:
758        bug_descr = "use-after-poison";
759        break;
760      case kAsanStackUseAfterScopeMagic:
761        bug_descr = "stack-use-after-scope";
762        break;
763      case kAsanGlobalRedzoneMagic:
764        bug_descr = "global-buffer-overflow";
765        break;
766    }
767  }
768  Decorator d;
769  Printf("%s", d.Warning());
770  Report("ERROR: AddressSanitizer: %s on address "
771             "%p at pc 0x%zx bp 0x%zx sp 0x%zx\n",
772             bug_descr, (void*)addr, pc, bp, sp);
773  Printf("%s", d.EndWarning());
774
775  u32 curr_tid = GetCurrentTidOrInvalid();
776  char tname[128];
777  Printf("%s%s of size %zu at %p thread T%d%s%s\n",
778         d.Access(),
779         access_size ? (is_write ? "WRITE" : "READ") : "ACCESS",
780         access_size, (void*)addr, curr_tid,
781         ThreadNameWithParenthesis(curr_tid, tname, sizeof(tname)),
782         d.EndAccess());
783
784  GET_STACK_TRACE_FATAL(pc, bp);
785  PrintStack(&stack);
786
787  DescribeAddress(addr, access_size);
788  ReportSummary(bug_descr, &stack);
789  PrintShadowMemoryForAddress(addr);
790}
791
792void NOINLINE __asan_set_error_report_callback(void (*callback)(const char*)) {
793  error_report_callback = callback;
794  if (callback) {
795    error_message_buffer_size = 1 << 16;
796    error_message_buffer =
797        (char*)MmapOrDie(error_message_buffer_size, __FUNCTION__);
798    error_message_buffer_pos = 0;
799  }
800}
801
802void __asan_describe_address(uptr addr) {
803  DescribeAddress(addr, 1);
804}
805
806#if !SANITIZER_SUPPORTS_WEAK_HOOKS
807// Provide default implementation of __asan_on_error that does nothing
808// and may be overriden by user.
809SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE NOINLINE
810void __asan_on_error() {}
811#endif
812