lib/lsan/lsan_common.cc

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