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