asan_report.cc revision ac3ae5dc29d3623ada2bcb0db22ee88b0382e3b1 
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
169static void DescribeThread(AsanThread *t) {
170  if (t)
171    DescribeThread(t->context());
172}
173
174// ---------------------- Address Descriptions ------------------- {{{1
175
176static bool IsASCII(unsigned char c) {
177  return /*0x00 <= c &&*/ c <= 0x7F;
178}
179
180static const char *MaybeDemangleGlobalName(const char *name) {
181  // We can spoil names of globals with C linkage, so use an heuristic
182  // approach to check if the name should be demangled.
183  return (name[0] == '_' && name[1] == 'Z') ? getSymbolizer()->Demangle(name)
184                                            : name;
185}
186
187// Check if the global is a zero-terminated ASCII string. If so, print it.
188static void PrintGlobalNameIfASCII(const __asan_global &g) {
189  for (uptr p = g.beg; p < g.beg + g.size - 1; p++) {
190    unsigned char c = *(unsigned char*)p;
191    if (c == '\0' || !IsASCII(c)) return;
192  }
193  if (*(char*)(g.beg + g.size - 1) != '\0') return;
194  Printf("  '%s' is ascii string '%s'\n",
195         MaybeDemangleGlobalName(g.name), (char*)g.beg);
196}
197
198bool DescribeAddressRelativeToGlobal(uptr addr, uptr size,
199                                     const __asan_global &g) {
200  static const uptr kMinimalDistanceFromAnotherGlobal = 64;
201  if (addr <= g.beg - kMinimalDistanceFromAnotherGlobal) return false;
202  if (addr >= g.beg + g.size_with_redzone) return false;
203  Decorator d;
204  Printf("%s", d.Location());
205  if (addr < g.beg) {
206    Printf("%p is located %zd bytes to the left", (void*)addr, g.beg - addr);
207  } else if (addr + size > g.beg + g.size) {
208    if (addr < g.beg + g.size)
209      addr = g.beg + g.size;
210    Printf("%p is located %zd bytes to the right", (void*)addr,
211           addr - (g.beg + g.size));
212  } else {
213    // Can it happen?
214    Printf("%p is located %zd bytes inside", (void*)addr, addr - g.beg);
215  }
216  Printf(" of global variable '%s' from '%s' (0x%zx) of size %zu\n",
217             MaybeDemangleGlobalName(g.name), g.module_name, g.beg, g.size);
218  Printf("%s", d.EndLocation());
219  PrintGlobalNameIfASCII(g);
220  return true;
221}
222
223bool DescribeAddressIfShadow(uptr addr) {
224  if (AddrIsInMem(addr))
225    return false;
226  static const char kAddrInShadowReport[] =
227      "Address %p is located in the %s.\n";
228  if (AddrIsInShadowGap(addr)) {
229    Printf(kAddrInShadowReport, addr, "shadow gap area");
230    return true;
231  }
232  if (AddrIsInHighShadow(addr)) {
233    Printf(kAddrInShadowReport, addr, "high shadow area");
234    return true;
235  }
236  if (AddrIsInLowShadow(addr)) {
237    Printf(kAddrInShadowReport, addr, "low shadow area");
238    return true;
239  }
240  CHECK(0 && "Address is not in memory and not in shadow?");
241  return false;
242}
243
244// Return " (thread_name) " or an empty string if the name is empty.
245const char *ThreadNameWithParenthesis(AsanThreadContext *t, char buff[],
246                                      uptr buff_len) {
247  const char *name = t->name;
248  if (name[0] == '\0') return "";
249  buff[0] = 0;
250  internal_strncat(buff, " (", 3);
251  internal_strncat(buff, name, buff_len - 4);
252  internal_strncat(buff, ")", 2);
253  return buff;
254}
255
256const char *ThreadNameWithParenthesis(u32 tid, char buff[],
257                                      uptr buff_len) {
258  if (tid == kInvalidTid) return "";
259  asanThreadRegistry().CheckLocked();
260  AsanThreadContext *t = GetThreadContextByTidLocked(tid);
261  return ThreadNameWithParenthesis(t, buff, buff_len);
262}
263
264void PrintAccessAndVarIntersection(const char *var_name,
265                                   uptr var_beg, uptr var_size,
266                                   uptr addr, uptr access_size,
267                                   uptr prev_var_end, uptr next_var_beg) {
268  uptr var_end = var_beg + var_size;
269  uptr addr_end = addr + access_size;
270  const char *pos_descr = 0;
271  // If the variable [var_beg, var_end) is the nearest variable to the
272  // current memory access, indicate it in the log.
273  if (addr >= var_beg) {
274    if (addr_end <= var_end)
275      pos_descr = "is inside";  // May happen if this is a use-after-return.
276    else if (addr < var_end)
277      pos_descr = "partially overflows";
278    else if (addr_end <= next_var_beg &&
279             next_var_beg - addr_end >= addr - var_end)
280      pos_descr = "overflows";
281  } else {
282    if (addr_end > var_beg)
283      pos_descr = "partially underflows";
284    else if (addr >= prev_var_end &&
285             addr - prev_var_end >= var_beg - addr_end)
286      pos_descr = "underflows";
287  }
288  Printf("    [%zd, %zd) '%s'", var_beg, var_beg + var_size, var_name);
289  if (pos_descr) {
290    Decorator d;
291    // FIXME: we may want to also print the size of the access here,
292    // but in case of accesses generated by memset it may be confusing.
293    Printf("%s <== Memory access at offset %zd %s this variable%s\n",
294           d.Location(), addr, pos_descr, d.EndLocation());
295  } else {
296    Printf("\n");
297  }
298}
299
300struct StackVarDescr {
301  uptr beg;
302  uptr size;
303  const char *name_pos;
304  uptr name_len;
305};
306
307bool DescribeAddressIfStack(uptr addr, uptr access_size) {
308  AsanThread *t = FindThreadByStackAddress(addr);
309  if (!t) return false;
310  const uptr kBufSize = 4095;
311  char buf[kBufSize];
312  uptr offset = 0;
313  uptr frame_pc = 0;
314  char tname[128];
315  const char *frame_descr = t->GetFrameNameByAddr(addr, &offset, &frame_pc);
316
317#ifdef __powerpc64__
318  // On PowerPC64, the address of a function actually points to a
319  // three-doubleword data structure with the first field containing
320  // the address of the function's code.
321  frame_pc = *reinterpret_cast<uptr *>(frame_pc);
322#endif
323
324  // This string is created by the compiler and has the following form:
325  // "n alloc_1 alloc_2 ... alloc_n"
326  // where alloc_i looks like "offset size len ObjectName ".
327  CHECK(frame_descr);
328  Decorator d;
329  Printf("%s", d.Location());
330  Printf("Address %p is located in stack of thread T%d%s "
331         "at offset %zu in frame\n",
332         addr, t->tid(),
333         ThreadNameWithParenthesis(t->tid(), tname, sizeof(tname)),
334         offset);
335  // Now we print the frame where the alloca has happened.
336  // We print this frame as a stack trace with one element.
337  // The symbolizer may print more than one frame if inlining was involved.
338  // The frame numbers may be different than those in the stack trace printed
339  // previously. That's unfortunate, but I have no better solution,
340  // especially given that the alloca may be from entirely different place
341  // (e.g. use-after-scope, or different thread's stack).
342  StackTrace alloca_stack;
343  alloca_stack.trace[0] = frame_pc + 16;
344  alloca_stack.size = 1;
345  Printf("%s", d.EndLocation());
346  PrintStack(&alloca_stack);
347  // Report the number of stack objects.
348  char *p;
349  uptr n_objects = (uptr)internal_simple_strtoll(frame_descr, &p, 10);
350  CHECK_GT(n_objects, 0);
351  Printf("  This frame has %zu object(s):\n", n_objects);
352
353  // Report all objects in this frame.
354  InternalScopedBuffer<StackVarDescr> vars(n_objects);
355  for (uptr i = 0; i < n_objects; i++) {
356    uptr beg, size;
357    uptr len;
358    beg  = (uptr)internal_simple_strtoll(p, &p, 10);
359    size = (uptr)internal_simple_strtoll(p, &p, 10);
360    len  = (uptr)internal_simple_strtoll(p, &p, 10);
361    if (beg == 0 || size == 0 || *p != ' ') {
362      Printf("AddressSanitizer can't parse the stack frame "
363                 "descriptor: |%s|\n", frame_descr);
364      break;
365    }
366    p++;
367    vars[i].beg = beg;
368    vars[i].size = size;
369    vars[i].name_pos = p;
370    vars[i].name_len = len;
371    p += len;
372  }
373  for (uptr i = 0; i < n_objects; i++) {
374    buf[0] = 0;
375    internal_strncat(buf, vars[i].name_pos,
376                     static_cast<uptr>(Min(kBufSize, vars[i].name_len)));
377    uptr prev_var_end = i ? vars[i - 1].beg + vars[i - 1].size : 0;
378    uptr next_var_beg = i + 1 < n_objects ? vars[i + 1].beg : ~(0UL);
379    PrintAccessAndVarIntersection(buf, vars[i].beg, vars[i].size,
380                                  offset, access_size,
381                                  prev_var_end, next_var_beg);
382  }
383  Printf("HINT: this may be a false positive if your program uses "
384             "some custom stack unwind mechanism or swapcontext\n"
385             "      (longjmp and C++ exceptions *are* supported)\n");
386  DescribeThread(t);
387  return true;
388}
389
390static void DescribeAccessToHeapChunk(AsanChunkView chunk, uptr addr,
391                                      uptr access_size) {
392  sptr offset;
393  Decorator d;
394  Printf("%s", d.Location());
395  if (chunk.AddrIsAtLeft(addr, access_size, &offset)) {
396    Printf("%p is located %zd bytes to the left of", (void*)addr, offset);
397  } else if (chunk.AddrIsAtRight(addr, access_size, &offset)) {
398    if (offset < 0) {
399      addr -= offset;
400      offset = 0;
401    }
402    Printf("%p is located %zd bytes to the right of", (void*)addr, offset);
403  } else if (chunk.AddrIsInside(addr, access_size, &offset)) {
404    Printf("%p is located %zd bytes inside of", (void*)addr, offset);
405  } else {
406    Printf("%p is located somewhere around (this is AddressSanitizer bug!)",
407           (void*)addr);
408  }
409  Printf(" %zu-byte region [%p,%p)\n", chunk.UsedSize(),
410         (void*)(chunk.Beg()), (void*)(chunk.End()));
411  Printf("%s", d.EndLocation());
412}
413
414void DescribeHeapAddress(uptr addr, uptr access_size) {
415  AsanChunkView chunk = FindHeapChunkByAddress(addr);
416  if (!chunk.IsValid()) return;
417  DescribeAccessToHeapChunk(chunk, addr, access_size);
418  CHECK(chunk.AllocTid() != kInvalidTid);
419  asanThreadRegistry().CheckLocked();
420  AsanThreadContext *alloc_thread =
421      GetThreadContextByTidLocked(chunk.AllocTid());
422  StackTrace alloc_stack;
423  chunk.GetAllocStack(&alloc_stack);
424  char tname[128];
425  Decorator d;
426  AsanThreadContext *free_thread = 0;
427  if (chunk.FreeTid() != kInvalidTid) {
428    free_thread = GetThreadContextByTidLocked(chunk.FreeTid());
429    Printf("%sfreed by thread T%d%s here:%s\n", d.Allocation(),
430           free_thread->tid,
431           ThreadNameWithParenthesis(free_thread, tname, sizeof(tname)),
432           d.EndAllocation());
433    StackTrace free_stack;
434    chunk.GetFreeStack(&free_stack);
435    PrintStack(&free_stack);
436    Printf("%spreviously allocated by thread T%d%s here:%s\n",
437           d.Allocation(), alloc_thread->tid,
438           ThreadNameWithParenthesis(alloc_thread, tname, sizeof(tname)),
439           d.EndAllocation());
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  }
446  PrintStack(&alloc_stack);
447  DescribeThread(GetCurrentThread());
448  if (free_thread)
449    DescribeThread(free_thread);
450  DescribeThread(alloc_thread);
451}
452
453void DescribeAddress(uptr addr, uptr access_size) {
454  // Check if this is shadow or shadow gap.
455  if (DescribeAddressIfShadow(addr))
456    return;
457  CHECK(AddrIsInMem(addr));
458  if (DescribeAddressIfGlobal(addr, access_size))
459    return;
460  if (DescribeAddressIfStack(addr, access_size))
461    return;
462  // Assume it is a heap address.
463  DescribeHeapAddress(addr, access_size);
464}
465
466// ------------------- Thread description -------------------- {{{1
467
468void DescribeThread(AsanThreadContext *context) {
469  CHECK(context);
470  asanThreadRegistry().CheckLocked();
471  // No need to announce the main thread.
472  if (context->tid == 0 || context->announced) {
473    return;
474  }
475  context->announced = true;
476  char tname[128];
477  Printf("Thread T%d%s", context->tid,
478         ThreadNameWithParenthesis(context->tid, tname, sizeof(tname)));
479  Printf(" created by T%d%s here:\n",
480         context->parent_tid,
481         ThreadNameWithParenthesis(context->parent_tid,
482                                   tname, sizeof(tname)));
483  PrintStack(&context->stack);
484  // Recursively described parent thread if needed.
485  if (flags()->print_full_thread_history) {
486    AsanThreadContext *parent_context =
487        GetThreadContextByTidLocked(context->parent_tid);
488    DescribeThread(parent_context);
489  }
490}
491
492// -------------------- Different kinds of reports ----------------- {{{1
493
494// Use ScopedInErrorReport to run common actions just before and
495// immediately after printing error report.
496class ScopedInErrorReport {
497 public:
498  ScopedInErrorReport() {
499    static atomic_uint32_t num_calls;
500    static u32 reporting_thread_tid;
501    if (atomic_fetch_add(&num_calls, 1, memory_order_relaxed) != 0) {
502      // Do not print more than one report, otherwise they will mix up.
503      // Error reporting functions shouldn't return at this situation, as
504      // they are defined as no-return.
505      Report("AddressSanitizer: while reporting a bug found another one."
506                 "Ignoring.\n");
507      u32 current_tid = GetCurrentTidOrInvalid();
508      if (current_tid != reporting_thread_tid) {
509        // ASan found two bugs in different threads simultaneously. Sleep
510        // long enough to make sure that the thread which started to print
511        // an error report will finish doing it.
512        SleepForSeconds(Max(100, flags()->sleep_before_dying + 1));
513      }
514      // If we're still not dead for some reason, use raw _exit() instead of
515      // Die() to bypass any additional checks.
516      internal__exit(flags()->exitcode);
517    }
518    ASAN_ON_ERROR();
519    // Make sure the registry and sanitizer report mutexes are locked while
520    // we're printing an error report.
521    // We can lock them only here to avoid self-deadlock in case of
522    // recursive reports.
523    asanThreadRegistry().Lock();
524    CommonSanitizerReportMutex.Lock();
525    reporting_thread_tid = GetCurrentTidOrInvalid();
526    Printf("===================================================="
527           "=============\n");
528  }
529  // Destructor is NORETURN, as functions that report errors are.
530  NORETURN ~ScopedInErrorReport() {
531    // Make sure the current thread is announced.
532    DescribeThread(GetCurrentThread());
533    // Print memory stats.
534    if (flags()->print_stats)
535      __asan_print_accumulated_stats();
536    if (error_report_callback) {
537      error_report_callback(error_message_buffer);
538    }
539    Report("ABORTING\n");
540    Die();
541  }
542};
543
544static void ReportSummary(const char *error_type, StackTrace *stack) {
545  if (!stack->size) return;
546  if (getSymbolizer()->IsAvailable()) {
547    AddressInfo ai;
548    // Currently, we include the first stack frame into the report summary.
549    // Maybe sometimes we need to choose another frame (e.g. skip memcpy/etc).
550    uptr pc = StackTrace::GetPreviousInstructionPc(stack->trace[0]);
551    getSymbolizer()->SymbolizeCode(pc, &ai, 1);
552    ReportErrorSummary(error_type,
553                       StripPathPrefix(ai.file,
554                                       common_flags()->strip_path_prefix),
555                       ai.line, ai.function);
556  }
557  // FIXME: do we need to print anything at all if there is no symbolizer?
558}
559
560void ReportSIGSEGV(uptr pc, uptr sp, uptr bp, uptr addr) {
561  ScopedInErrorReport in_report;
562  Decorator d;
563  Printf("%s", d.Warning());
564  Report("ERROR: AddressSanitizer: SEGV on unknown address %p"
565             " (pc %p sp %p bp %p T%d)\n",
566             (void*)addr, (void*)pc, (void*)sp, (void*)bp,
567             GetCurrentTidOrInvalid());
568  Printf("%s", d.EndWarning());
569  Printf("AddressSanitizer can not provide additional info.\n");
570  GET_STACK_TRACE_FATAL(pc, bp);
571  PrintStack(&stack);
572  ReportSummary("SEGV", &stack);
573}
574
575void ReportDoubleFree(uptr addr, StackTrace *stack) {
576  ScopedInErrorReport in_report;
577  Decorator d;
578  Printf("%s", d.Warning());
579  char tname[128];
580  u32 curr_tid = GetCurrentTidOrInvalid();
581  Report("ERROR: AddressSanitizer: attempting double-free on %p in "
582         "thread T%d%s:\n",
583         addr, curr_tid,
584         ThreadNameWithParenthesis(curr_tid, tname, sizeof(tname)));
585
586  Printf("%s", d.EndWarning());
587  PrintStack(stack);
588  DescribeHeapAddress(addr, 1);
589  ReportSummary("double-free", stack);
590}
591
592void ReportFreeNotMalloced(uptr addr, StackTrace *stack) {
593  ScopedInErrorReport in_report;
594  Decorator d;
595  Printf("%s", d.Warning());
596  char tname[128];
597  u32 curr_tid = GetCurrentTidOrInvalid();
598  Report("ERROR: AddressSanitizer: attempting free on address "
599             "which was not malloc()-ed: %p in thread T%d%s\n", addr,
600         curr_tid, ThreadNameWithParenthesis(curr_tid, tname, sizeof(tname)));
601  Printf("%s", d.EndWarning());
602  PrintStack(stack);
603  DescribeHeapAddress(addr, 1);
604  ReportSummary("bad-free", stack);
605}
606
607void ReportAllocTypeMismatch(uptr addr, StackTrace *stack,
608                             AllocType alloc_type,
609                             AllocType dealloc_type) {
610  static const char *alloc_names[] =
611    {"INVALID", "malloc", "operator new", "operator new []"};
612  static const char *dealloc_names[] =
613    {"INVALID", "free", "operator delete", "operator delete []"};
614  CHECK_NE(alloc_type, dealloc_type);
615  ScopedInErrorReport in_report;
616  Decorator d;
617  Printf("%s", d.Warning());
618  Report("ERROR: AddressSanitizer: alloc-dealloc-mismatch (%s vs %s) on %p\n",
619        alloc_names[alloc_type], dealloc_names[dealloc_type], addr);
620  Printf("%s", d.EndWarning());
621  PrintStack(stack);
622  DescribeHeapAddress(addr, 1);
623  ReportSummary("alloc-dealloc-mismatch", stack);
624  Report("HINT: if you don't care about these warnings you may set "
625         "ASAN_OPTIONS=alloc_dealloc_mismatch=0\n");
626}
627
628void ReportMallocUsableSizeNotOwned(uptr addr, StackTrace *stack) {
629  ScopedInErrorReport in_report;
630  Decorator d;
631  Printf("%s", d.Warning());
632  Report("ERROR: AddressSanitizer: attempting to call "
633             "malloc_usable_size() for pointer which is "
634             "not owned: %p\n", addr);
635  Printf("%s", d.EndWarning());
636  PrintStack(stack);
637  DescribeHeapAddress(addr, 1);
638  ReportSummary("bad-malloc_usable_size", stack);
639}
640
641void ReportAsanGetAllocatedSizeNotOwned(uptr addr, StackTrace *stack) {
642  ScopedInErrorReport in_report;
643  Decorator d;
644  Printf("%s", d.Warning());
645  Report("ERROR: AddressSanitizer: attempting to call "
646             "__asan_get_allocated_size() for pointer which is "
647             "not owned: %p\n", addr);
648  Printf("%s", d.EndWarning());
649  PrintStack(stack);
650  DescribeHeapAddress(addr, 1);
651  ReportSummary("bad-__asan_get_allocated_size", stack);
652}
653
654void ReportStringFunctionMemoryRangesOverlap(
655    const char *function, const char *offset1, uptr length1,
656    const char *offset2, uptr length2, StackTrace *stack) {
657  ScopedInErrorReport in_report;
658  Decorator d;
659  char bug_type[100];
660  internal_snprintf(bug_type, sizeof(bug_type), "%s-param-overlap", function);
661  Printf("%s", d.Warning());
662  Report("ERROR: AddressSanitizer: %s: "
663             "memory ranges [%p,%p) and [%p, %p) overlap\n", \
664             bug_type, offset1, offset1 + length1, offset2, offset2 + length2);
665  Printf("%s", d.EndWarning());
666  PrintStack(stack);
667  DescribeAddress((uptr)offset1, length1);
668  DescribeAddress((uptr)offset2, length2);
669  ReportSummary(bug_type, stack);
670}
671
672// ----------------------- Mac-specific reports ----------------- {{{1
673
674void WarnMacFreeUnallocated(
675    uptr addr, uptr zone_ptr, const char *zone_name, StackTrace *stack) {
676  // Just print a warning here.
677  Printf("free_common(%p) -- attempting to free unallocated memory.\n"
678             "AddressSanitizer is ignoring this error on Mac OS now.\n",
679             addr);
680  PrintZoneForPointer(addr, zone_ptr, zone_name);
681  PrintStack(stack);
682  DescribeHeapAddress(addr, 1);
683}
684
685void ReportMacMzReallocUnknown(
686    uptr addr, uptr zone_ptr, const char *zone_name, StackTrace *stack) {
687  ScopedInErrorReport in_report;
688  Printf("mz_realloc(%p) -- attempting to realloc unallocated memory.\n"
689             "This is an unrecoverable problem, exiting now.\n",
690             addr);
691  PrintZoneForPointer(addr, zone_ptr, zone_name);
692  PrintStack(stack);
693  DescribeHeapAddress(addr, 1);
694}
695
696void ReportMacCfReallocUnknown(
697    uptr addr, uptr zone_ptr, const char *zone_name, StackTrace *stack) {
698  ScopedInErrorReport in_report;
699  Printf("cf_realloc(%p) -- attempting to realloc unallocated memory.\n"
700             "This is an unrecoverable problem, exiting now.\n",
701             addr);
702  PrintZoneForPointer(addr, zone_ptr, zone_name);
703  PrintStack(stack);
704  DescribeHeapAddress(addr, 1);
705}
706
707}  // namespace __asan
708
709// --------------------------- Interface --------------------- {{{1
710using namespace __asan;  // NOLINT
711
712void __asan_report_error(uptr pc, uptr bp, uptr sp,
713                         uptr addr, bool is_write, uptr access_size) {
714  ScopedInErrorReport in_report;
715
716  // Determine the error type.
717  const char *bug_descr = "unknown-crash";
718  if (AddrIsInMem(addr)) {
719    u8 *shadow_addr = (u8*)MemToShadow(addr);
720    // If we are accessing 16 bytes, look at the second shadow byte.
721    if (*shadow_addr == 0 && access_size > SHADOW_GRANULARITY)
722      shadow_addr++;
723    // If we are in the partial right redzone, look at the next shadow byte.
724    if (*shadow_addr > 0 && *shadow_addr < 128)
725      shadow_addr++;
726    switch (*shadow_addr) {
727      case kAsanHeapLeftRedzoneMagic:
728      case kAsanHeapRightRedzoneMagic:
729        bug_descr = "heap-buffer-overflow";
730        break;
731      case kAsanHeapFreeMagic:
732        bug_descr = "heap-use-after-free";
733        break;
734      case kAsanStackLeftRedzoneMagic:
735        bug_descr = "stack-buffer-underflow";
736        break;
737      case kAsanInitializationOrderMagic:
738        bug_descr = "initialization-order-fiasco";
739        break;
740      case kAsanStackMidRedzoneMagic:
741      case kAsanStackRightRedzoneMagic:
742      case kAsanStackPartialRedzoneMagic:
743        bug_descr = "stack-buffer-overflow";
744        break;
745      case kAsanStackAfterReturnMagic:
746        bug_descr = "stack-use-after-return";
747        break;
748      case kAsanUserPoisonedMemoryMagic:
749        bug_descr = "use-after-poison";
750        break;
751      case kAsanStackUseAfterScopeMagic:
752        bug_descr = "stack-use-after-scope";
753        break;
754      case kAsanGlobalRedzoneMagic:
755        bug_descr = "global-buffer-overflow";
756        break;
757    }
758  }
759  Decorator d;
760  Printf("%s", d.Warning());
761  Report("ERROR: AddressSanitizer: %s on address "
762             "%p at pc 0x%zx bp 0x%zx sp 0x%zx\n",
763             bug_descr, (void*)addr, pc, bp, sp);
764  Printf("%s", d.EndWarning());
765
766  u32 curr_tid = GetCurrentTidOrInvalid();
767  char tname[128];
768  Printf("%s%s of size %zu at %p thread T%d%s%s\n",
769         d.Access(),
770         access_size ? (is_write ? "WRITE" : "READ") : "ACCESS",
771         access_size, (void*)addr, curr_tid,
772         ThreadNameWithParenthesis(curr_tid, tname, sizeof(tname)),
773         d.EndAccess());
774
775  GET_STACK_TRACE_FATAL(pc, bp);
776  PrintStack(&stack);
777
778  DescribeAddress(addr, access_size);
779  ReportSummary(bug_descr, &stack);
780  PrintShadowMemoryForAddress(addr);
781}
782
783void NOINLINE __asan_set_error_report_callback(void (*callback)(const char*)) {
784  error_report_callback = callback;
785  if (callback) {
786    error_message_buffer_size = 1 << 16;
787    error_message_buffer =
788        (char*)MmapOrDie(error_message_buffer_size, __FUNCTION__);
789    error_message_buffer_pos = 0;
790  }
791}
792
793void __asan_describe_address(uptr addr) {
794  DescribeAddress(addr, 1);
795}
796
797#if !SANITIZER_SUPPORTS_WEAK_HOOKS
798// Provide default implementation of __asan_on_error that does nothing
799// and may be overriden by user.
800SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE NOINLINE
801void __asan_on_error() {}
802#endif
803