libsanitizer/lsan/lsan_common.cc

   1 //=-- lsan_common.cc ------------------------------------------------------===//
   2 //
   3 // This file is distributed under the University of Illinois Open Source
   4 // License. See LICENSE.TXT for details.
   5 //
   6 //===----------------------------------------------------------------------===//
   7 //
   8 // This file is a part of LeakSanitizer.
   9 // Implementation of common leak checking functionality.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "lsan_common.h"
  14
  15 #include "sanitizer_common/sanitizer_common.h"
  16 #include "sanitizer_common/sanitizer_flags.h"
  17 #include "sanitizer_common/sanitizer_flag_parser.h"
  18 #include "sanitizer_common/sanitizer_placement_new.h"
  19 #include "sanitizer_common/sanitizer_procmaps.h"
  20 #include "sanitizer_common/sanitizer_stackdepot.h"
  21 #include "sanitizer_common/sanitizer_stacktrace.h"
  22 #include "sanitizer_common/sanitizer_suppressions.h"
  23 #include "sanitizer_common/sanitizer_report_decorator.h"
  24 #include "sanitizer_common/sanitizer_tls_get_addr.h"
  25
  26 #if CAN_SANITIZE_LEAKS
  27 namespace __lsan {
  28
  29 // This mutex is used to prevent races between DoLeakCheck and IgnoreObject, and
  30 // also to protect the global list of root regions.
  31 BlockingMutex global_mutex(LINKER_INITIALIZED);
  32
  33 __attribute__((tls_model("initial-exec")))
  34 THREADLOCAL int disable_counter;
  35 bool DisabledInThisThread() { return disable_counter > 0; }
  36 void DisableInThisThread() { disable_counter++; }
  37 void EnableInThisThread() {
  38   if (!disable_counter && common_flags()->detect_leaks) {
  39     Report("Unmatched call to __lsan_enable().\n");
  40     Die();
  41   }
  42   disable_counter--;
  43 }
  44
  45 Flags lsan_flags;
  46
  47 void Flags::SetDefaults() {
  48 #define LSAN_FLAG(Type, Name, DefaultValue, Description) Name = DefaultValue;
  49 #include "lsan_flags.inc"
  50 #undef LSAN_FLAG
  51 }
  52
  53 void RegisterLsanFlags(FlagParser *parser, Flags *f) {
  54 #define LSAN_FLAG(Type, Name, DefaultValue, Description) \
  55   RegisterFlag(parser, #Name, Description, &f->Name);
  56 #include "lsan_flags.inc"
  57 #undef LSAN_FLAG
  58 }
  59
  60 #define LOG_POINTERS(...)                           \
  61   do {                                              \
  62     if (flags()->log_pointers) Report(__VA_ARGS__); \
  63   } while (0);
  64
  65 #define LOG_THREADS(...)                           \
  66   do {                                             \
  67     if (flags()->log_threads) Report(__VA_ARGS__); \
  68   } while (0);
  69
  70 ALIGNED(64) static char suppression_placeholder[sizeof(SuppressionContext)];
  71 static SuppressionContext *suppression_ctx = nullptr;
  72 static const char kSuppressionLeak[] = "leak";
  73 static const char *kSuppressionTypes[] = { kSuppressionLeak };
  74
  75 void InitializeSuppressions() {
  76   CHECK_EQ(nullptr, suppression_ctx);
  77   suppression_ctx = new (suppression_placeholder) // NOLINT
  78       SuppressionContext(kSuppressionTypes, ARRAY_SIZE(kSuppressionTypes));
  79   suppression_ctx->ParseFromFile(flags()->suppressions);
  80   if (&__lsan_default_suppressions)
  81     suppression_ctx->Parse(__lsan_default_suppressions());
  82 }
  83
  84 static SuppressionContext *GetSuppressionContext() {
  85   CHECK(suppression_ctx);
  86   return suppression_ctx;
  87 }
  88
  89 struct RootRegion {
  90   const void *begin;
  91   uptr size;
  92 };
  93
  94 InternalMmapVector<RootRegion> *root_regions;
  95
  96 void InitializeRootRegions() {
  97   CHECK(!root_regions);
  98   ALIGNED(64) static char placeholder[sizeof(InternalMmapVector<RootRegion>)];
  99   root_regions = new(placeholder) InternalMmapVector<RootRegion>(1);
 100 }
 101
 102 void InitCommonLsan() {
 103   InitializeRootRegions();
 104   if (common_flags()->detect_leaks) {
 105     // Initialization which can fail or print warnings should only be done if
 106     // LSan is actually enabled.
 107     InitializeSuppressions();
 108     InitializePlatformSpecificModules();
 109   }
 110 }
 111
 112 class Decorator: public __sanitizer::SanitizerCommonDecorator {
 113  public:
 114   Decorator() : SanitizerCommonDecorator() { }
 115   const char *Error() { return Red(); }
 116   const char *Leak() { return Blue(); }
 117   const char *End() { return Default(); }
 118 };
 119
 120 static inline bool CanBeAHeapPointer(uptr p) {
 121   // Since our heap is located in mmap-ed memory, we can assume a sensible lower
 122   // bound on heap addresses.
 123   const uptr kMinAddress = 4 * 4096;
 124   if (p < kMinAddress) return false;
 125 #if defined(__x86_64__)
 126   // Accept only canonical form user-space addresses.
 127   return ((p >> 47) == 0);
 128 #elif defined(__mips64)
 129   return ((p >> 40) == 0);
 130 #elif defined(__aarch64__)
 131   unsigned runtimeVMA =
 132     (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1);
 133   return ((p >> runtimeVMA) == 0);
 134 #else
 135   return true;
 136 #endif
 137 }
 138
 139 // Scans the memory range, looking for byte patterns that point into allocator
 140 // chunks. Marks those chunks with |tag| and adds them to |frontier|.
 141 // There are two usage modes for this function: finding reachable chunks
 142 // (|tag| = kReachable) and finding indirectly leaked chunks
 143 // (|tag| = kIndirectlyLeaked). In the second case, there's no flood fill,
 144 // so |frontier| = 0.
 145 void ScanRangeForPointers(uptr begin, uptr end,
 146                           Frontier *frontier,
 147                           const char *region_type, ChunkTag tag) {
 148   CHECK(tag == kReachable || tag == kIndirectlyLeaked);
 149   const uptr alignment = flags()->pointer_alignment();
 150   LOG_POINTERS("Scanning %s range %p-%p.\n", region_type, begin, end);
 151   uptr pp = begin;
 152   if (pp % alignment)
 153     pp = pp + alignment - pp % alignment;
 154   for (; pp + sizeof(void *) <= end; pp += alignment) {  // NOLINT
 155     void *p = *reinterpret_cast<void **>(pp);
 156     if (!CanBeAHeapPointer(reinterpret_cast<uptr>(p))) continue;
 157     uptr chunk = PointsIntoChunk(p);
 158     if (!chunk) continue;
 159     // Pointers to self don't count. This matters when tag == kIndirectlyLeaked.
 160     if (chunk == begin) continue;
 161     LsanMetadata m(chunk);
 162     if (m.tag() == kReachable || m.tag() == kIgnored) continue;
 163
 164     // Do this check relatively late so we can log only the interesting cases.
 165     if (!flags()->use_poisoned && WordIsPoisoned(pp)) {
 166       LOG_POINTERS(
 167           "%p is poisoned: ignoring %p pointing into chunk %p-%p of size "
 168           "%zu.\n",
 169           pp, p, chunk, chunk + m.requested_size(), m.requested_size());
 170       continue;
 171     }
 172
 173     m.set_tag(tag);
 174     LOG_POINTERS("%p: found %p pointing into chunk %p-%p of size %zu.\n", pp, p,
 175                  chunk, chunk + m.requested_size(), m.requested_size());
 176     if (frontier)
 177       frontier->push_back(chunk);
 178   }
 179 }
 180
 181 void ForEachExtraStackRangeCb(uptr begin, uptr end, void* arg) {
 182   Frontier *frontier = reinterpret_cast<Frontier *>(arg);
 183   ScanRangeForPointers(begin, end, frontier, "FAKE STACK", kReachable);
 184 }
 185
 186 // Scans thread data (stacks and TLS) for heap pointers.
 187 static void ProcessThreads(SuspendedThreadsList const &suspended_threads,
 188                            Frontier *frontier) {
 189   InternalScopedBuffer<uptr> registers(SuspendedThreadsList::RegisterCount());
 190   uptr registers_begin = reinterpret_cast<uptr>(registers.data());
 191   uptr registers_end = registers_begin + registers.size();
 192   for (uptr i = 0; i < suspended_threads.thread_count(); i++) {
 193     uptr os_id = static_cast<uptr>(suspended_threads.GetThreadID(i));
 194     LOG_THREADS("Processing thread %d.\n", os_id);
 195     uptr stack_begin, stack_end, tls_begin, tls_end, cache_begin, cache_end;
 196     DTLS *dtls;
 197     bool thread_found = GetThreadRangesLocked(os_id, &stack_begin, &stack_end,
 198                                               &tls_begin, &tls_end,
 199                                               &cache_begin, &cache_end, &dtls);
 200     if (!thread_found) {
 201       // If a thread can't be found in the thread registry, it's probably in the
 202       // process of destruction. Log this event and move on.
 203       LOG_THREADS("Thread %d not found in registry.\n", os_id);
 204       continue;
 205     }
 206     uptr sp;
 207     bool have_registers =
 208         (suspended_threads.GetRegistersAndSP(i, registers.data(), &sp) == 0);
 209     if (!have_registers) {
 210       Report("Unable to get registers from thread %d.\n");
 211       // If unable to get SP, consider the entire stack to be reachable.
 212       sp = stack_begin;
 213     }
 214
 215     if (flags()->use_registers && have_registers)
 216       ScanRangeForPointers(registers_begin, registers_end, frontier,
 217                            "REGISTERS", kReachable);
 218
 219     if (flags()->use_stacks) {
 220       LOG_THREADS("Stack at %p-%p (SP = %p).\n", stack_begin, stack_end, sp);
 221       if (sp < stack_begin || sp >= stack_end) {
 222         // SP is outside the recorded stack range (e.g. the thread is running a
 223         // signal handler on alternate stack, or swapcontext was used).
 224         // Again, consider the entire stack range to be reachable.
 225         LOG_THREADS("WARNING: stack pointer not in stack range.\n");
 226         uptr page_size = GetPageSizeCached();
 227         int skipped = 0;
 228         while (stack_begin < stack_end &&
 229                !IsAccessibleMemoryRange(stack_begin, 1)) {
 230           skipped++;
 231           stack_begin += page_size;
 232         }
 233         LOG_THREADS("Skipped %d guard page(s) to obtain stack %p-%p.\n",
 234                     skipped, stack_begin, stack_end);
 235       } else {
 236         // Shrink the stack range to ignore out-of-scope values.
 237         stack_begin = sp;
 238       }
 239       ScanRangeForPointers(stack_begin, stack_end, frontier, "STACK",
 240                            kReachable);
 241       ForEachExtraStackRange(os_id, ForEachExtraStackRangeCb, frontier);
 242     }
 243
 244     if (flags()->use_tls) {
 245       LOG_THREADS("TLS at %p-%p.\n", tls_begin, tls_end);
 246       if (cache_begin == cache_end) {
 247         ScanRangeForPointers(tls_begin, tls_end, frontier, "TLS", kReachable);
 248       } else {
 249         // Because LSan should not be loaded with dlopen(), we can assume
 250         // that allocator cache will be part of static TLS image.
 251         CHECK_LE(tls_begin, cache_begin);
 252         CHECK_GE(tls_end, cache_end);
 253         if (tls_begin < cache_begin)
 254           ScanRangeForPointers(tls_begin, cache_begin, frontier, "TLS",
 255                                kReachable);
 256         if (tls_end > cache_end)
 257           ScanRangeForPointers(cache_end, tls_end, frontier, "TLS", kReachable);
 258       }
 259       if (dtls) {
 260         for (uptr j = 0; j < dtls->dtv_size; ++j) {
 261           uptr dtls_beg = dtls->dtv[j].beg;
 262           uptr dtls_end = dtls_beg + dtls->dtv[j].size;
 263           if (dtls_beg < dtls_end) {
 264             LOG_THREADS("DTLS %zu at %p-%p.\n", j, dtls_beg, dtls_end);
 265             ScanRangeForPointers(dtls_beg, dtls_end, frontier, "DTLS",
 266                                  kReachable);
 267           }
 268         }
 269       }
 270     }
 271   }
 272 }
 273
 274 static void ProcessRootRegion(Frontier *frontier, uptr root_begin,
 275                               uptr root_end) {
 276   MemoryMappingLayout proc_maps(/*cache_enabled*/true);
 277   uptr begin, end, prot;
 278   while (proc_maps.Next(&begin, &end,
 279                         /*offset*/ nullptr, /*filename*/ nullptr,
 280                         /*filename_size*/ 0, &prot)) {
 281     uptr intersection_begin = Max(root_begin, begin);
 282     uptr intersection_end = Min(end, root_end);
 283     if (intersection_begin >= intersection_end) continue;
 284     bool is_readable = prot & MemoryMappingLayout::kProtectionRead;
 285     LOG_POINTERS("Root region %p-%p intersects with mapped region %p-%p (%s)\n",
 286                  root_begin, root_end, begin, end,
 287                  is_readable ? "readable" : "unreadable");
 288     if (is_readable)
 289       ScanRangeForPointers(intersection_begin, intersection_end, frontier,
 290                            "ROOT", kReachable);
 291   }
 292 }
 293
 294 // Scans root regions for heap pointers.
 295 static void ProcessRootRegions(Frontier *frontier) {
 296   if (!flags()->use_root_regions) return;
 297   CHECK(root_regions);
 298   for (uptr i = 0; i < root_regions->size(); i++) {
 299     RootRegion region = (*root_regions)[i];
 300     uptr begin_addr = reinterpret_cast<uptr>(region.begin);
 301     ProcessRootRegion(frontier, begin_addr, begin_addr + region.size);
 302   }
 303 }
 304
 305 static void FloodFillTag(Frontier *frontier, ChunkTag tag) {
 306   while (frontier->size()) {
 307     uptr next_chunk = frontier->back();
 308     frontier->pop_back();
 309     LsanMetadata m(next_chunk);
 310     ScanRangeForPointers(next_chunk, next_chunk + m.requested_size(), frontier,
 311                          "HEAP", tag);
 312   }
 313 }
 314
 315 // ForEachChunk callback. If the chunk is marked as leaked, marks all chunks
 316 // which are reachable from it as indirectly leaked.
 317 static void MarkIndirectlyLeakedCb(uptr chunk, void *arg) {
 318   chunk = GetUserBegin(chunk);
 319   LsanMetadata m(chunk);
 320   if (m.allocated() && m.tag() != kReachable) {
 321     ScanRangeForPointers(chunk, chunk + m.requested_size(),
 322                          /* frontier */ nullptr, "HEAP", kIndirectlyLeaked);
 323   }
 324 }
 325
 326 // ForEachChunk callback. If chunk is marked as ignored, adds its address to
 327 // frontier.
 328 static void CollectIgnoredCb(uptr chunk, void *arg) {
 329   CHECK(arg);
 330   chunk = GetUserBegin(chunk);
 331   LsanMetadata m(chunk);
 332   if (m.allocated() && m.tag() == kIgnored) {
 333     LOG_POINTERS("Ignored: chunk %p-%p of size %zu.\n",
 334                  chunk, chunk + m.requested_size(), m.requested_size());
 335     reinterpret_cast<Frontier *>(arg)->push_back(chunk);
 336   }
 337 }
 338
 339 // Sets the appropriate tag on each chunk.
 340 static void ClassifyAllChunks(SuspendedThreadsList const &suspended_threads) {
 341   // Holds the flood fill frontier.
 342   Frontier frontier(1);
 343
 344   ForEachChunk(CollectIgnoredCb, &frontier);
 345   ProcessGlobalRegions(&frontier);
 346   ProcessThreads(suspended_threads, &frontier);
 347   ProcessRootRegions(&frontier);
 348   FloodFillTag(&frontier, kReachable);
 349
 350   // The check here is relatively expensive, so we do this in a separate flood
 351   // fill. That way we can skip the check for chunks that are reachable
 352   // otherwise.
 353   LOG_POINTERS("Processing platform-specific allocations.\n");
 354   CHECK_EQ(0, frontier.size());
 355   ProcessPlatformSpecificAllocations(&frontier);
 356   FloodFillTag(&frontier, kReachable);
 357
 358   // Iterate over leaked chunks and mark those that are reachable from other
 359   // leaked chunks.
 360   LOG_POINTERS("Scanning leaked chunks.\n");
 361   ForEachChunk(MarkIndirectlyLeakedCb, nullptr);
 362 }
 363
 364 // ForEachChunk callback. Resets the tags to pre-leak-check state.
 365 static void ResetTagsCb(uptr chunk, void *arg) {
 366   (void)arg;
 367   chunk = GetUserBegin(chunk);
 368   LsanMetadata m(chunk);
 369   if (m.allocated() && m.tag() != kIgnored)
 370     m.set_tag(kDirectlyLeaked);
 371 }
 372
 373 static void PrintStackTraceById(u32 stack_trace_id) {
 374   CHECK(stack_trace_id);
 375   StackDepotGet(stack_trace_id).Print();
 376 }
 377
 378 // ForEachChunk callback. Aggregates information about unreachable chunks into
 379 // a LeakReport.
 380 static void CollectLeaksCb(uptr chunk, void *arg) {
 381   CHECK(arg);
 382   LeakReport *leak_report = reinterpret_cast<LeakReport *>(arg);
 383   chunk = GetUserBegin(chunk);
 384   LsanMetadata m(chunk);
 385   if (!m.allocated()) return;
 386   if (m.tag() == kDirectlyLeaked || m.tag() == kIndirectlyLeaked) {
 387     u32 resolution = flags()->resolution;
 388     u32 stack_trace_id = 0;
 389     if (resolution > 0) {
 390       StackTrace stack = StackDepotGet(m.stack_trace_id());
 391       stack.size = Min(stack.size, resolution);
 392       stack_trace_id = StackDepotPut(stack);
 393     } else {
 394       stack_trace_id = m.stack_trace_id();
 395     }
 396     leak_report->AddLeakedChunk(chunk, stack_trace_id, m.requested_size(),
 397                                 m.tag());
 398   }
 399 }
 400
 401 static void PrintMatchedSuppressions() {
 402   InternalMmapVector<Suppression *> matched(1);
 403   GetSuppressionContext()->GetMatched(&matched);
 404   if (!matched.size())
 405     return;
 406   const char *line = "-----------------------------------------------------";
 407   Printf("%s\n", line);
 408   Printf("Suppressions used:\n");
 409   Printf("  count      bytes template\n");
 410   for (uptr i = 0; i < matched.size(); i++)
 411     Printf("%7zu %10zu %s\n", static_cast<uptr>(atomic_load_relaxed(
 412         &matched[i]->hit_count)), matched[i]->weight, matched[i]->templ);
 413   Printf("%s\n\n", line);
 414 }
 415
 416 struct CheckForLeaksParam {
 417   bool success;
 418   LeakReport leak_report;
 419 };
 420
 421 static void CheckForLeaksCallback(const SuspendedThreadsList &suspended_threads,
 422                                   void *arg) {
 423   CheckForLeaksParam *param = reinterpret_cast<CheckForLeaksParam *>(arg);
 424   CHECK(param);
 425   CHECK(!param->success);
 426   ClassifyAllChunks(suspended_threads);
 427   ForEachChunk(CollectLeaksCb, &param->leak_report);
 428   // Clean up for subsequent leak checks. This assumes we did not overwrite any
 429   // kIgnored tags.
 430   ForEachChunk(ResetTagsCb, nullptr);
 431   param->success = true;
 432 }
 433
 434 static bool CheckForLeaks() {
 435   if (&__lsan_is_turned_off && __lsan_is_turned_off())
 436       return false;
 437   EnsureMainThreadIDIsCorrect();
 438   CheckForLeaksParam param;
 439   param.success = false;
 440   LockThreadRegistry();
 441   LockAllocator();
 442   DoStopTheWorld(CheckForLeaksCallback, &param);
 443   UnlockAllocator();
 444   UnlockThreadRegistry();
 445
 446   if (!param.success) {
 447     Report("LeakSanitizer has encountered a fatal error.\n");
 448     Report(
 449         "HINT: For debugging, try setting environment variable "
 450         "LSAN_OPTIONS=verbosity=1:log_threads=1\n");
 451     Report(
 452         "HINT: LeakSanitizer does not work under ptrace (strace, gdb, etc)\n");
 453     Die();
 454   }
 455   param.leak_report.ApplySuppressions();
 456   uptr unsuppressed_count = param.leak_report.UnsuppressedLeakCount();
 457   if (unsuppressed_count > 0) {
 458     Decorator d;
 459     Printf("\n"
 460            "================================================================="
 461            "\n");
 462     Printf("%s", d.Error());
 463     Report("ERROR: LeakSanitizer: detected memory leaks\n");
 464     Printf("%s", d.End());
 465     param.leak_report.ReportTopLeaks(flags()->max_leaks);
 466   }
 467   if (common_flags()->print_suppressions)
 468     PrintMatchedSuppressions();
 469   if (unsuppressed_count > 0) {
 470     param.leak_report.PrintSummary();
 471     return true;
 472   }
 473   return false;
 474 }
 475
 476 void DoLeakCheck() {
 477   BlockingMutexLock l(&global_mutex);
 478   static bool already_done;
 479   if (already_done) return;
 480   already_done = true;
 481   bool have_leaks = CheckForLeaks();
 482   if (!have_leaks) {
 483     return;
 484   }
 485   if (common_flags()->exitcode) {
 486     Die();
 487   }
 488 }
 489
 490 static int DoRecoverableLeakCheck() {
 491   BlockingMutexLock l(&global_mutex);
 492   bool have_leaks = CheckForLeaks();
 493   return have_leaks ? 1 : 0;
 494 }
 495
 496 static Suppression *GetSuppressionForAddr(uptr addr) {
 497   Suppression *s = nullptr;
 498
 499   // Suppress by module name.
 500   SuppressionContext *suppressions = GetSuppressionContext();
 501   if (const char *module_name =
 502           Symbolizer::GetOrInit()->GetModuleNameForPc(addr))
 503     if (suppressions->Match(module_name, kSuppressionLeak, &s))
 504       return s;
 505
 506   // Suppress by file or function name.
 507   SymbolizedStack *frames = Symbolizer::GetOrInit()->SymbolizePC(addr);
 508   for (SymbolizedStack *cur = frames; cur; cur = cur->next) {
 509     if (suppressions->Match(cur->info.function, kSuppressionLeak, &s) ||
 510         suppressions->Match(cur->info.file, kSuppressionLeak, &s)) {
 511       break;
 512     }
 513   }
 514   frames->ClearAll();
 515   return s;
 516 }
 517
 518 static Suppression *GetSuppressionForStack(u32 stack_trace_id) {
 519   StackTrace stack = StackDepotGet(stack_trace_id);
 520   for (uptr i = 0; i < stack.size; i++) {
 521     Suppression *s = GetSuppressionForAddr(
 522         StackTrace::GetPreviousInstructionPc(stack.trace[i]));
 523     if (s) return s;
 524   }
 525   return nullptr;
 526 }
 527
 528 ///// LeakReport implementation. /////
 529
 530 // A hard limit on the number of distinct leaks, to avoid quadratic complexity
 531 // in LeakReport::AddLeakedChunk(). We don't expect to ever see this many leaks
 532 // in real-world applications.
 533 // FIXME: Get rid of this limit by changing the implementation of LeakReport to
 534 // use a hash table.
 535 const uptr kMaxLeaksConsidered = 5000;
 536
 537 void LeakReport::AddLeakedChunk(uptr chunk, u32 stack_trace_id,
 538                                 uptr leaked_size, ChunkTag tag) {
 539   CHECK(tag == kDirectlyLeaked || tag == kIndirectlyLeaked);
 540   bool is_directly_leaked = (tag == kDirectlyLeaked);
 541   uptr i;
 542   for (i = 0; i < leaks_.size(); i++) {
 543     if (leaks_[i].stack_trace_id == stack_trace_id &&
 544         leaks_[i].is_directly_leaked == is_directly_leaked) {
 545       leaks_[i].hit_count++;
 546       leaks_[i].total_size += leaked_size;
 547       break;
 548     }
 549   }
 550   if (i == leaks_.size()) {
 551     if (leaks_.size() == kMaxLeaksConsidered) return;
 552     Leak leak = { next_id_++, /* hit_count */ 1, leaked_size, stack_trace_id,
 553                   is_directly_leaked, /* is_suppressed */ false };
 554     leaks_.push_back(leak);
 555   }
 556   if (flags()->report_objects) {
 557     LeakedObject obj = {leaks_[i].id, chunk, leaked_size};
 558     leaked_objects_.push_back(obj);
 559   }
 560 }
 561
 562 static bool LeakComparator(const Leak &leak1, const Leak &leak2) {
 563   if (leak1.is_directly_leaked == leak2.is_directly_leaked)
 564     return leak1.total_size > leak2.total_size;
 565   else
 566     return leak1.is_directly_leaked;
 567 }
 568
 569 void LeakReport::ReportTopLeaks(uptr num_leaks_to_report) {
 570   CHECK(leaks_.size() <= kMaxLeaksConsidered);
 571   Printf("\n");
 572   if (leaks_.size() == kMaxLeaksConsidered)
 573     Printf("Too many leaks! Only the first %zu leaks encountered will be "
 574            "reported.\n",
 575            kMaxLeaksConsidered);
 576
 577   uptr unsuppressed_count = UnsuppressedLeakCount();
 578   if (num_leaks_to_report > 0 && num_leaks_to_report < unsuppressed_count)
 579     Printf("The %zu top leak(s):\n", num_leaks_to_report);
 580   InternalSort(&leaks_, leaks_.size(), LeakComparator);
 581   uptr leaks_reported = 0;
 582   for (uptr i = 0; i < leaks_.size(); i++) {
 583     if (leaks_[i].is_suppressed) continue;
 584     PrintReportForLeak(i);
 585     leaks_reported++;
 586     if (leaks_reported == num_leaks_to_report) break;
 587   }
 588   if (leaks_reported < unsuppressed_count) {
 589     uptr remaining = unsuppressed_count - leaks_reported;
 590     Printf("Omitting %zu more leak(s).\n", remaining);
 591   }
 592 }
 593
 594 void LeakReport::PrintReportForLeak(uptr index) {
 595   Decorator d;
 596   Printf("%s", d.Leak());
 597   Printf("%s leak of %zu byte(s) in %zu object(s) allocated from:\n",
 598          leaks_[index].is_directly_leaked ? "Direct" : "Indirect",
 599          leaks_[index].total_size, leaks_[index].hit_count);
 600   Printf("%s", d.End());
 601
 602   PrintStackTraceById(leaks_[index].stack_trace_id);
 603
 604   if (flags()->report_objects) {
 605     Printf("Objects leaked above:\n");
 606     PrintLeakedObjectsForLeak(index);
 607     Printf("\n");
 608   }
 609 }
 610
 611 void LeakReport::PrintLeakedObjectsForLeak(uptr index) {
 612   u32 leak_id = leaks_[index].id;
 613   for (uptr j = 0; j < leaked_objects_.size(); j++) {
 614     if (leaked_objects_[j].leak_id == leak_id)
 615       Printf("%p (%zu bytes)\n", leaked_objects_[j].addr,
 616              leaked_objects_[j].size);
 617   }
 618 }
 619
 620 void LeakReport::PrintSummary() {
 621   CHECK(leaks_.size() <= kMaxLeaksConsidered);
 622   uptr bytes = 0, allocations = 0;
 623   for (uptr i = 0; i < leaks_.size(); i++) {
 624       if (leaks_[i].is_suppressed) continue;
 625       bytes += leaks_[i].total_size;
 626       allocations += leaks_[i].hit_count;
 627   }
 628   InternalScopedString summary(kMaxSummaryLength);
 629   summary.append("%zu byte(s) leaked in %zu allocation(s).", bytes,
 630                  allocations);
 631   ReportErrorSummary(summary.data());
 632 }
 633
 634 void LeakReport::ApplySuppressions() {
 635   for (uptr i = 0; i < leaks_.size(); i++) {
 636     Suppression *s = GetSuppressionForStack(leaks_[i].stack_trace_id);
 637     if (s) {
 638       s->weight += leaks_[i].total_size;
 639       atomic_store_relaxed(&s->hit_count, atomic_load_relaxed(&s->hit_count) +
 640           leaks_[i].hit_count);
 641       leaks_[i].is_suppressed = true;
 642     }
 643   }
 644 }
 645
 646 uptr LeakReport::UnsuppressedLeakCount() {
 647   uptr result = 0;
 648   for (uptr i = 0; i < leaks_.size(); i++)
 649     if (!leaks_[i].is_suppressed) result++;
 650   return result;
 651 }
 652
 653 } // namespace __lsan
 654 #else // CAN_SANITIZE_LEAKS
 655 namespace __lsan {
 656 void InitCommonLsan() { }
 657 void DoLeakCheck() { }
 658 void DisableInThisThread() { }
 659 void EnableInThisThread() { }
 660 }
 661 #endif // CAN_SANITIZE_LEAKS
 662
 663 using namespace __lsan;  // NOLINT
 664
 665 extern "C" {
 666 SANITIZER_INTERFACE_ATTRIBUTE
 667 void __lsan_ignore_object(const void *p) {
 668 #if CAN_SANITIZE_LEAKS
 669   if (!common_flags()->detect_leaks)
 670     return;
 671   // Cannot use PointsIntoChunk or LsanMetadata here, since the allocator is not
 672   // locked.
 673   BlockingMutexLock l(&global_mutex);
 674   IgnoreObjectResult res = IgnoreObjectLocked(p);
 675   if (res == kIgnoreObjectInvalid)
 676     VReport(1, "__lsan_ignore_object(): no heap object found at %p", p);
 677   if (res == kIgnoreObjectAlreadyIgnored)
 678     VReport(1, "__lsan_ignore_object(): "
 679            "heap object at %p is already being ignored\n", p);
 680   if (res == kIgnoreObjectSuccess)
 681     VReport(1, "__lsan_ignore_object(): ignoring heap object at %p\n", p);
 682 #endif // CAN_SANITIZE_LEAKS
 683 }
 684
 685 SANITIZER_INTERFACE_ATTRIBUTE
 686 void __lsan_register_root_region(const void *begin, uptr size) {
 687 #if CAN_SANITIZE_LEAKS
 688   BlockingMutexLock l(&global_mutex);
 689   CHECK(root_regions);
 690   RootRegion region = {begin, size};
 691   root_regions->push_back(region);
 692   VReport(1, "Registered root region at %p of size %llu\n", begin, size);
 693 #endif // CAN_SANITIZE_LEAKS
 694 }
 695
 696 SANITIZER_INTERFACE_ATTRIBUTE
 697 void __lsan_unregister_root_region(const void *begin, uptr size) {
 698 #if CAN_SANITIZE_LEAKS
 699   BlockingMutexLock l(&global_mutex);
 700   CHECK(root_regions);
 701   bool removed = false;
 702   for (uptr i = 0; i < root_regions->size(); i++) {
 703     RootRegion region = (*root_regions)[i];
 704     if (region.begin == begin && region.size == size) {
 705       removed = true;
 706       uptr last_index = root_regions->size() - 1;
 707       (*root_regions)[i] = (*root_regions)[last_index];
 708       root_regions->pop_back();
 709       VReport(1, "Unregistered root region at %p of size %llu\n", begin, size);
 710       break;
 711     }
 712   }
 713   if (!removed) {
 714     Report(
 715         "__lsan_unregister_root_region(): region at %p of size %llu has not "
 716         "been registered.\n",
 717         begin, size);
 718     Die();
 719   }
 720 #endif // CAN_SANITIZE_LEAKS
 721 }
 722
 723 SANITIZER_INTERFACE_ATTRIBUTE
 724 void __lsan_disable() {
 725 #if CAN_SANITIZE_LEAKS
 726   __lsan::DisableInThisThread();
 727 #endif
 728 }
 729
 730 SANITIZER_INTERFACE_ATTRIBUTE
 731 void __lsan_enable() {
 732 #if CAN_SANITIZE_LEAKS
 733   __lsan::EnableInThisThread();
 734 #endif
 735 }
 736
 737 SANITIZER_INTERFACE_ATTRIBUTE
 738 void __lsan_do_leak_check() {
 739 #if CAN_SANITIZE_LEAKS
 740   if (common_flags()->detect_leaks)
 741     __lsan::DoLeakCheck();
 742 #endif // CAN_SANITIZE_LEAKS
 743 }
 744
 745 SANITIZER_INTERFACE_ATTRIBUTE
 746 int __lsan_do_recoverable_leak_check() {
 747 #if CAN_SANITIZE_LEAKS
 748   if (common_flags()->detect_leaks)
 749     return __lsan::DoRecoverableLeakCheck();
 750 #endif // CAN_SANITIZE_LEAKS
 751   return 0;
 752 }
 753
 754 #if !SANITIZER_SUPPORTS_WEAK_HOOKS
 755 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
 756 int __lsan_is_turned_off() {
 757   return 0;
 758 }
 759 #endif
 760 } // extern "C"