src/compiler-rt/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_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 #include "sanitizer_common/sanitizer_tls_get_addr.h"
  27
  28 #if CAN_SANITIZE_LEAKS
  29 namespace __lsan {
  30
  31 // This mutex is used to prevent races between DoLeakCheck and IgnoreObject, and
  32 // also to protect the global list of root regions.
  33 BlockingMutex global_mutex(LINKER_INITIALIZED);
  34
  35 __attribute__((tls_model("initial-exec")))
  36 THREADLOCAL int disable_counter;
  37 bool DisabledInThisThread() { return disable_counter > 0; }
  38 void DisableInThisThread() { disable_counter++; }
  39 void EnableInThisThread() {
  40   if (!disable_counter && common_flags()->detect_leaks) {
  41     Report("Unmatched call to __lsan_enable().\n");
  42     Die();
  43   }
  44   disable_counter--;
  45 }
  46
  47 Flags lsan_flags;
  48
  49 void Flags::SetDefaults() {
  50 #define LSAN_FLAG(Type, Name, DefaultValue, Description) Name = DefaultValue;
  51 #include "lsan_flags.inc"
  52 #undef LSAN_FLAG
  53 }
  54
  55 void RegisterLsanFlags(FlagParser *parser, Flags *f) {
  56 #define LSAN_FLAG(Type, Name, DefaultValue, Description) \
  57   RegisterFlag(parser, #Name, Description, &f->Name);
  58 #include "lsan_flags.inc"
  59 #undef LSAN_FLAG
  60 }
  61
  62 #define LOG_POINTERS(...)                           \
  63   do {                                              \
  64     if (flags()->log_pointers) Report(__VA_ARGS__); \
  65   } while (0);
  66
  67 #define LOG_THREADS(...)                           \
  68   do {                                             \
  69     if (flags()->log_threads) Report(__VA_ARGS__); \
  70   } while (0);
  71
  72 ALIGNED(64) static char suppression_placeholder[sizeof(SuppressionContext)];
  73 static SuppressionContext *suppression_ctx = nullptr;
  74 static const char kSuppressionLeak[] = "leak";
  75 static const char *kSuppressionTypes[] = { kSuppressionLeak };
  76
  77 void InitializeSuppressions() {
  78   CHECK_EQ(nullptr, suppression_ctx);
  79   suppression_ctx = new (suppression_placeholder) // NOLINT
  80       SuppressionContext(kSuppressionTypes, ARRAY_SIZE(kSuppressionTypes));
  81   suppression_ctx->ParseFromFile(flags()->suppressions);
  82   if (&__lsan_default_suppressions)
  83     suppression_ctx->Parse(__lsan_default_suppressions());
  84 }
  85
  86 static SuppressionContext *GetSuppressionContext() {
  87   CHECK(suppression_ctx);
  88   return suppression_ctx;
  89 }
  90
  91 struct RootRegion {
  92   const void *begin;
  93   uptr size;
  94 };
  95
  96 InternalMmapVector<RootRegion> *root_regions;
  97
  98 void InitializeRootRegions() {
  99   CHECK(!root_regions);
 100   ALIGNED(64) static char placeholder[sizeof(InternalMmapVector<RootRegion>)];
 101   root_regions = new(placeholder) InternalMmapVector<RootRegion>(1);
 102 }
 103
 104 void InitCommonLsan() {
 105   InitializeRootRegions();
 106   if (common_flags()->detect_leaks) {
 107     // Initialization which can fail or print warnings should only be done if
 108     // LSan is actually enabled.
 109     InitializeSuppressions();
 110     InitializePlatformSpecificModules();
 111   }
 112 }
 113
 114 class Decorator: public __sanitizer::SanitizerCommonDecorator {
 115  public:
 116   Decorator() : SanitizerCommonDecorator() { }
 117   const char *Error() { return Red(); }
 118   const char *Leak() { return Blue(); }
 119   const char *End() { return Default(); }
 120 };
 121
 122 static inline bool CanBeAHeapPointer(uptr p) {
 123   // Since our heap is located in mmap-ed memory, we can assume a sensible lower
 124   // bound on heap addresses.
 125   const uptr kMinAddress = 4 * 4096;
 126   if (p < kMinAddress) return false;
 127 #if defined(__x86_64__)
 128   // Accept only canonical form user-space addresses.
 129   return ((p >> 47) == 0);
 130 #elif defined(__mips64)
 131   return ((p >> 40) == 0);
 132 #elif defined(__aarch64__)
 133   unsigned runtimeVMA =
 134     (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1);
 135   return ((p >> runtimeVMA) == 0);
 136 #else
 137   return true;
 138 #endif
 139 }
 140
 141 // Scans the memory range, looking for byte patterns that point into allocator
 142 // chunks. Marks those chunks with |tag| and adds them to |frontier|.
 143 // There are two usage modes for this function: finding reachable chunks
 144 // (|tag| = kReachable) and finding indirectly leaked chunks
 145 // (|tag| = kIndirectlyLeaked). In the second case, there's no flood fill,
 146 // so |frontier| = 0.
 147 void ScanRangeForPointers(uptr begin, uptr end,
 148                           Frontier *frontier,
 149                           const char *region_type, ChunkTag tag) {
 150   CHECK(tag == kReachable || tag == kIndirectlyLeaked);
 151   const uptr alignment = flags()->pointer_alignment();
 152   LOG_POINTERS("Scanning %s range %p-%p.\n", region_type, begin, end);
 153   uptr pp = begin;
 154   if (pp % alignment)
 155     pp = pp + alignment - pp % alignment;
 156   for (; pp + sizeof(void *) <= end; pp += alignment) {  // NOLINT
 157     void *p = *reinterpret_cast<void **>(pp);
 158     if (!CanBeAHeapPointer(reinterpret_cast<uptr>(p))) continue;
 159     uptr chunk = PointsIntoChunk(p);
 160     if (!chunk) continue;
 161     // Pointers to self don't count. This matters when tag == kIndirectlyLeaked.
 162     if (chunk == begin) continue;
 163     LsanMetadata m(chunk);
 164     if (m.tag() == kReachable || m.tag() == kIgnored) continue;
 165
 166     // Do this check relatively late so we can log only the interesting cases.
 167     if (!flags()->use_poisoned && WordIsPoisoned(pp)) {
 168       LOG_POINTERS(
 169           "%p is poisoned: ignoring %p pointing into chunk %p-%p of size "
 170           "%zu.\n",
 171           pp, p, chunk, chunk + m.requested_size(), m.requested_size());
 172       continue;
 173     }
 174
 175     m.set_tag(tag);
 176     LOG_POINTERS("%p: found %p pointing into chunk %p-%p of size %zu.\n", pp, p,
 177                  chunk, chunk + m.requested_size(), m.requested_size());
 178     if (frontier)
 179       frontier->push_back(chunk);
 180   }
 181 }
 182
 183 void ForEachExtraStackRangeCb(uptr begin, uptr end, void* arg) {
 184   Frontier *frontier = reinterpret_cast<Frontier *>(arg);
 185   ScanRangeForPointers(begin, end, frontier, "FAKE STACK", kReachable);
 186 }
 187
 188 // Scans thread data (stacks and TLS) for heap pointers.
 189 static void ProcessThreads(SuspendedThreadsList const &suspended_threads,
 190                            Frontier *frontier) {
 191   InternalScopedBuffer<uptr> registers(SuspendedThreadsList::RegisterCount());
 192   uptr registers_begin = reinterpret_cast<uptr>(registers.data());
 193   uptr registers_end = registers_begin + registers.size();
 194   for (uptr i = 0; i < suspended_threads.thread_count(); i++) {
 195     uptr os_id = static_cast<uptr>(suspended_threads.GetThreadID(i));
 196     LOG_THREADS("Processing thread %d.\n", os_id);
 197     uptr stack_begin, stack_end, tls_begin, tls_end, cache_begin, cache_end;
 198     DTLS *dtls;
 199     bool thread_found = GetThreadRangesLocked(os_id, &stack_begin, &stack_end,
 200                                               &tls_begin, &tls_end,
 201                                               &cache_begin, &cache_end, &dtls);
 202     if (!thread_found) {
 203       // If a thread can't be found in the thread registry, it's probably in the
 204       // process of destruction. Log this event and move on.
 205       LOG_THREADS("Thread %d not found in registry.\n", os_id);
 206       continue;
 207     }
 208     uptr sp;
 209     bool have_registers =
 210         (suspended_threads.GetRegistersAndSP(i, registers.data(), &sp) == 0);
 211     if (!have_registers) {
 212       Report("Unable to get registers from thread %d.\n");
 213       // If unable to get SP, consider the entire stack to be reachable.
 214       sp = stack_begin;
 215     }
 216
 217     if (flags()->use_registers && have_registers)
 218       ScanRangeForPointers(registers_begin, registers_end, frontier,
 219                            "REGISTERS", kReachable);
 220
 221     if (flags()->use_stacks) {
 222       LOG_THREADS("Stack at %p-%p (SP = %p).\n", stack_begin, stack_end, sp);
 223       if (sp < stack_begin || sp >= stack_end) {
 224         // SP is outside the recorded stack range (e.g. the thread is running a
 225         // signal handler on alternate stack, or swapcontext was used).
 226         // Again, consider the entire stack range to be reachable.
 227         LOG_THREADS("WARNING: stack pointer not in stack range.\n");
 228         uptr page_size = GetPageSizeCached();
 229         int skipped = 0;
 230         while (stack_begin < stack_end &&
 231                !IsAccessibleMemoryRange(stack_begin, 1)) {
 232           skipped++;
 233           stack_begin += page_size;
 234         }
 235         LOG_THREADS("Skipped %d guard page(s) to obtain stack %p-%p.\n",
 236                     skipped, stack_begin, stack_end);
 237       } else {
 238         // Shrink the stack range to ignore out-of-scope values.
 239         stack_begin = sp;
 240       }
 241       ScanRangeForPointers(stack_begin, stack_end, frontier, "STACK",
 242                            kReachable);
 243       ForEachExtraStackRange(os_id, ForEachExtraStackRangeCb, frontier);
 244     }
 245
 246     if (flags()->use_tls) {
 247       LOG_THREADS("TLS at %p-%p.\n", tls_begin, tls_end);
 248       if (cache_begin == cache_end) {
 249         ScanRangeForPointers(tls_begin, tls_end, frontier, "TLS", kReachable);
 250       } else {
 251         // Because LSan should not be loaded with dlopen(), we can assume
 252         // that allocator cache will be part of static TLS image.
 253         CHECK_LE(tls_begin, cache_begin);
 254         CHECK_GE(tls_end, cache_end);
 255         if (tls_begin < cache_begin)
 256           ScanRangeForPointers(tls_begin, cache_begin, frontier, "TLS",
 257                                kReachable);
 258         if (tls_end > cache_end)
 259           ScanRangeForPointers(cache_end, tls_end, frontier, "TLS", kReachable);
 260       }
 261       if (dtls) {
 262         for (uptr j = 0; j < dtls->dtv_size; ++j) {
 263           uptr dtls_beg = dtls->dtv[j].beg;
 264           uptr dtls_end = dtls_beg + dtls->dtv[j].size;
 265           if (dtls_beg < dtls_end) {
 266             LOG_THREADS("DTLS %zu at %p-%p.\n", j, dtls_beg, dtls_end);
 267             ScanRangeForPointers(dtls_beg, dtls_end, frontier, "DTLS",
 268                                  kReachable);
 269           }
 270         }
 271       }
 272     }
 273   }
 274 }
 275
 276 static void ProcessRootRegion(Frontier *frontier, uptr root_begin,
 277                               uptr root_end) {
 278   MemoryMappingLayout proc_maps(/*cache_enabled*/true);
 279   uptr begin, end, prot;
 280   while (proc_maps.Next(&begin, &end,
 281                         /*offset*/ nullptr, /*filename*/ nullptr,
 282                         /*filename_size*/ 0, &prot)) {
 283     uptr intersection_begin = Max(root_begin, begin);
 284     uptr intersection_end = Min(end, root_end);
 285     if (intersection_begin >= intersection_end) continue;
 286     bool is_readable = prot & MemoryMappingLayout::kProtectionRead;
 287     LOG_POINTERS("Root region %p-%p intersects with mapped region %p-%p (%s)\n",
 288                  root_begin, root_end, begin, end,
 289                  is_readable ? "readable" : "unreadable");
 290     if (is_readable)
 291       ScanRangeForPointers(intersection_begin, intersection_end, frontier,
 292                            "ROOT", kReachable);
 293   }
 294 }
 295
 296 // Scans root regions for heap pointers.
 297 static void ProcessRootRegions(Frontier *frontier) {
 298   if (!flags()->use_root_regions) return;
 299   CHECK(root_regions);
 300   for (uptr i = 0; i < root_regions->size(); i++) {
 301     RootRegion region = (*root_regions)[i];
 302     uptr begin_addr = reinterpret_cast<uptr>(region.begin);
 303     ProcessRootRegion(frontier, begin_addr, begin_addr + region.size);
 304   }
 305 }
 306
 307 static void FloodFillTag(Frontier *frontier, ChunkTag tag) {
 308   while (frontier->size()) {
 309     uptr next_chunk = frontier->back();
 310     frontier->pop_back();
 311     LsanMetadata m(next_chunk);
 312     ScanRangeForPointers(next_chunk, next_chunk + m.requested_size(), frontier,
 313                          "HEAP", tag);
 314   }
 315 }
 316
 317 // ForEachChunk callback. If the chunk is marked as leaked, marks all chunks
 318 // which are reachable from it as indirectly leaked.
 319 static void MarkIndirectlyLeakedCb(uptr chunk, void *arg) {
 320   chunk = GetUserBegin(chunk);
 321   LsanMetadata m(chunk);
 322   if (m.allocated() && m.tag() != kReachable) {
 323     ScanRangeForPointers(chunk, chunk + m.requested_size(),
 324                          /* frontier */ nullptr, "HEAP", kIndirectlyLeaked);
 325   }
 326 }
 327
 328 // ForEachChunk callback. If chunk is marked as ignored, adds its address to
 329 // frontier.
 330 static void CollectIgnoredCb(uptr chunk, void *arg) {
 331   CHECK(arg);
 332   chunk = GetUserBegin(chunk);
 333   LsanMetadata m(chunk);
 334   if (m.allocated() && m.tag() == kIgnored) {
 335     LOG_POINTERS("Ignored: chunk %p-%p of size %zu.\n",
 336                  chunk, chunk + m.requested_size(), m.requested_size());
 337     reinterpret_cast<Frontier *>(arg)->push_back(chunk);
 338   }
 339 }
 340
 341 // Sets the appropriate tag on each chunk.
 342 static void ClassifyAllChunks(SuspendedThreadsList const &suspended_threads) {
 343   // Holds the flood fill frontier.
 344   Frontier frontier(1);
 345
 346   ForEachChunk(CollectIgnoredCb, &frontier);
 347   ProcessGlobalRegions(&frontier);
 348   ProcessThreads(suspended_threads, &frontier);
 349   ProcessRootRegions(&frontier);
 350   FloodFillTag(&frontier, kReachable);
 351
 352   // The check here is relatively expensive, so we do this in a separate flood
 353   // fill. That way we can skip the check for chunks that are reachable
 354   // otherwise.
 355   LOG_POINTERS("Processing platform-specific allocations.\n");
 356   CHECK_EQ(0, frontier.size());
 357   ProcessPlatformSpecificAllocations(&frontier);
 358   FloodFillTag(&frontier, kReachable);
 359
 360   // Iterate over leaked chunks and mark those that are reachable from other
 361   // leaked chunks.
 362   LOG_POINTERS("Scanning leaked chunks.\n");
 363   ForEachChunk(MarkIndirectlyLeakedCb, nullptr);
 364 }
 365
 366 // ForEachChunk callback. Resets the tags to pre-leak-check state.
 367 static void ResetTagsCb(uptr chunk, void *arg) {
 368   (void)arg;
 369   chunk = GetUserBegin(chunk);
 370   LsanMetadata m(chunk);
 371   if (m.allocated() && m.tag() != kIgnored)
 372     m.set_tag(kDirectlyLeaked);
 373 }
 374
 375 static void PrintStackTraceById(u32 stack_trace_id) {
 376   CHECK(stack_trace_id);
 377   StackDepotGet(stack_trace_id).Print();
 378 }
 379
 380 // ForEachChunk callback. Aggregates information about unreachable chunks into
 381 // a LeakReport.
 382 static void CollectLeaksCb(uptr chunk, void *arg) {
 383   CHECK(arg);
 384   LeakReport *leak_report = reinterpret_cast<LeakReport *>(arg);
 385   chunk = GetUserBegin(chunk);
 386   LsanMetadata m(chunk);
 387   if (!m.allocated()) return;
 388   if (m.tag() == kDirectlyLeaked || m.tag() == kIndirectlyLeaked) {
 389     u32 resolution = flags()->resolution;
 390     u32 stack_trace_id = 0;
 391     if (resolution > 0) {
 392       StackTrace stack = StackDepotGet(m.stack_trace_id());
 393       stack.size = Min(stack.size, resolution);
 394       stack_trace_id = StackDepotPut(stack);
 395     } else {
 396       stack_trace_id = m.stack_trace_id();
 397     }
 398     leak_report->AddLeakedChunk(chunk, stack_trace_id, m.requested_size(),
 399                                 m.tag());
 400   }
 401 }
 402
 403 static void PrintMatchedSuppressions() {
 404   InternalMmapVector<Suppression *> matched(1);
 405   GetSuppressionContext()->GetMatched(&matched);
 406   if (!matched.size())
 407     return;
 408   const char *line = "-----------------------------------------------------";
 409   Printf("%s\n", line);
 410   Printf("Suppressions used:\n");
 411   Printf("  count      bytes template\n");
 412   for (uptr i = 0; i < matched.size(); i++)
 413     Printf("%7zu %10zu %s\n", static_cast<uptr>(atomic_load_relaxed(
 414         &matched[i]->hit_count)), matched[i]->weight, matched[i]->templ);
 415   Printf("%s\n\n", line);
 416 }
 417
 418 struct CheckForLeaksParam {
 419   bool success;
 420   LeakReport leak_report;
 421 };
 422
 423 static void CheckForLeaksCallback(const SuspendedThreadsList &suspended_threads,
 424                                   void *arg) {
 425   CheckForLeaksParam *param = reinterpret_cast<CheckForLeaksParam *>(arg);
 426   CHECK(param);
 427   CHECK(!param->success);
 428   ClassifyAllChunks(suspended_threads);
 429   ForEachChunk(CollectLeaksCb, &param->leak_report);
 430   // Clean up for subsequent leak checks. This assumes we did not overwrite any
 431   // kIgnored tags.
 432   ForEachChunk(ResetTagsCb, nullptr);
 433   param->success = true;
 434 }
 435
 436 static bool CheckForLeaks() {
 437   if (&__lsan_is_turned_off && __lsan_is_turned_off())
 438       return false;
 439   EnsureMainThreadIDIsCorrect();
 440   CheckForLeaksParam param;
 441   param.success = false;
 442   LockThreadRegistry();
 443   LockAllocator();
 444   DoStopTheWorld(CheckForLeaksCallback, &param);
 445   UnlockAllocator();
 446   UnlockThreadRegistry();
 447
 448   if (!param.success) {
 449     Report("LeakSanitizer has encountered a fatal error.\n");
 450     Report(
 451         "HINT: For debugging, try setting environment variable "
 452         "LSAN_OPTIONS=verbosity=1:log_threads=1\n");
 453     Report(
 454         "HINT: LeakSanitizer does not work under ptrace (strace, gdb, etc)\n");
 455     Die();
 456   }
 457   param.leak_report.ApplySuppressions();
 458   uptr unsuppressed_count = param.leak_report.UnsuppressedLeakCount();
 459   if (unsuppressed_count > 0) {
 460     Decorator d;
 461     Printf("\n"
 462            "================================================================="
 463            "\n");
 464     Printf("%s", d.Error());
 465     Report("ERROR: LeakSanitizer: detected memory leaks\n");
 466     Printf("%s", d.End());
 467     param.leak_report.ReportTopLeaks(flags()->max_leaks);
 468   }
 469   if (common_flags()->print_suppressions)
 470     PrintMatchedSuppressions();
 471   if (unsuppressed_count > 0) {
 472     param.leak_report.PrintSummary();
 473     return true;
 474   }
 475   return false;
 476 }
 477
 478 void DoLeakCheck() {
 479   BlockingMutexLock l(&global_mutex);
 480   static bool already_done;
 481   if (already_done) return;
 482   already_done = true;
 483   bool have_leaks = CheckForLeaks();
 484   if (!have_leaks) {
 485     return;
 486   }
 487   if (common_flags()->exitcode) {
 488     Die();
 489   }
 490 }
 491
 492 static int DoRecoverableLeakCheck() {
 493   BlockingMutexLock l(&global_mutex);
 494   bool have_leaks = CheckForLeaks();
 495   return have_leaks ? 1 : 0;
 496 }
 497
 498 static Suppression *GetSuppressionForAddr(uptr addr) {
 499   Suppression *s = nullptr;
 500
 501   // Suppress by module name.
 502   SuppressionContext *suppressions = GetSuppressionContext();
 503   if (const char *module_name =
 504           Symbolizer::GetOrInit()->GetModuleNameForPc(addr))
 505     if (suppressions->Match(module_name, kSuppressionLeak, &s))
 506       return s;
 507
 508   // Suppress by file or function name.
 509   SymbolizedStack *frames = Symbolizer::GetOrInit()->SymbolizePC(addr);
 510   for (SymbolizedStack *cur = frames; cur; cur = cur->next) {
 511     if (suppressions->Match(cur->info.function, kSuppressionLeak, &s) ||
 512         suppressions->Match(cur->info.file, kSuppressionLeak, &s)) {
 513       break;
 514     }
 515   }
 516   frames->ClearAll();
 517   return s;
 518 }
 519
 520 static Suppression *GetSuppressionForStack(u32 stack_trace_id) {
 521   StackTrace stack = StackDepotGet(stack_trace_id);
 522   for (uptr i = 0; i < stack.size; i++) {
 523     Suppression *s = GetSuppressionForAddr(
 524         StackTrace::GetPreviousInstructionPc(stack.trace[i]));
 525     if (s) return s;
 526   }
 527   return nullptr;
 528 }
 529
 530 ///// LeakReport implementation. /////
 531
 532 // A hard limit on the number of distinct leaks, to avoid quadratic complexity
 533 // in LeakReport::AddLeakedChunk(). We don't expect to ever see this many leaks
 534 // in real-world applications.
 535 // FIXME: Get rid of this limit by changing the implementation of LeakReport to
 536 // use a hash table.
 537 const uptr kMaxLeaksConsidered = 5000;
 538
 539 void LeakReport::AddLeakedChunk(uptr chunk, u32 stack_trace_id,
 540                                 uptr leaked_size, ChunkTag tag) {
 541   CHECK(tag == kDirectlyLeaked || tag == kIndirectlyLeaked);
 542   bool is_directly_leaked = (tag == kDirectlyLeaked);
 543   uptr i;
 544   for (i = 0; i < leaks_.size(); i++) {
 545     if (leaks_[i].stack_trace_id == stack_trace_id &&
 546         leaks_[i].is_directly_leaked == is_directly_leaked) {
 547       leaks_[i].hit_count++;
 548       leaks_[i].total_size += leaked_size;
 549       break;
 550     }
 551   }
 552   if (i == leaks_.size()) {
 553     if (leaks_.size() == kMaxLeaksConsidered) return;
 554     Leak leak = { next_id_++, /* hit_count */ 1, leaked_size, stack_trace_id,
 555                   is_directly_leaked, /* is_suppressed */ false };
 556     leaks_.push_back(leak);
 557   }
 558   if (flags()->report_objects) {
 559     LeakedObject obj = {leaks_[i].id, chunk, leaked_size};
 560     leaked_objects_.push_back(obj);
 561   }
 562 }
 563
 564 static bool LeakComparator(const Leak &leak1, const Leak &leak2) {
 565   if (leak1.is_directly_leaked == leak2.is_directly_leaked)
 566     return leak1.total_size > leak2.total_size;
 567   else
 568     return leak1.is_directly_leaked;
 569 }
 570
 571 void LeakReport::ReportTopLeaks(uptr num_leaks_to_report) {
 572   CHECK(leaks_.size() <= kMaxLeaksConsidered);
 573   Printf("\n");
 574   if (leaks_.size() == kMaxLeaksConsidered)
 575     Printf("Too many leaks! Only the first %zu leaks encountered will be "
 576            "reported.\n",
 577            kMaxLeaksConsidered);
 578
 579   uptr unsuppressed_count = UnsuppressedLeakCount();
 580   if (num_leaks_to_report > 0 && num_leaks_to_report < unsuppressed_count)
 581     Printf("The %zu top leak(s):\n", num_leaks_to_report);
 582   InternalSort(&leaks_, leaks_.size(), LeakComparator);
 583   uptr leaks_reported = 0;
 584   for (uptr i = 0; i < leaks_.size(); i++) {
 585     if (leaks_[i].is_suppressed) continue;
 586     PrintReportForLeak(i);
 587     leaks_reported++;
 588     if (leaks_reported == num_leaks_to_report) break;
 589   }
 590   if (leaks_reported < unsuppressed_count) {
 591     uptr remaining = unsuppressed_count - leaks_reported;
 592     Printf("Omitting %zu more leak(s).\n", remaining);
 593   }
 594 }
 595
 596 void LeakReport::PrintReportForLeak(uptr index) {
 597   Decorator d;
 598   Printf("%s", d.Leak());
 599   Printf("%s leak of %zu byte(s) in %zu object(s) allocated from:\n",
 600          leaks_[index].is_directly_leaked ? "Direct" : "Indirect",
 601          leaks_[index].total_size, leaks_[index].hit_count);
 602   Printf("%s", d.End());
 603
 604   PrintStackTraceById(leaks_[index].stack_trace_id);
 605
 606   if (flags()->report_objects) {
 607     Printf("Objects leaked above:\n");
 608     PrintLeakedObjectsForLeak(index);
 609     Printf("\n");
 610   }
 611 }
 612
 613 void LeakReport::PrintLeakedObjectsForLeak(uptr index) {
 614   u32 leak_id = leaks_[index].id;
 615   for (uptr j = 0; j < leaked_objects_.size(); j++) {
 616     if (leaked_objects_[j].leak_id == leak_id)
 617       Printf("%p (%zu bytes)\n", leaked_objects_[j].addr,
 618              leaked_objects_[j].size);
 619   }
 620 }
 621
 622 void LeakReport::PrintSummary() {
 623   CHECK(leaks_.size() <= kMaxLeaksConsidered);
 624   uptr bytes = 0, allocations = 0;
 625   for (uptr i = 0; i < leaks_.size(); i++) {
 626       if (leaks_[i].is_suppressed) continue;
 627       bytes += leaks_[i].total_size;
 628       allocations += leaks_[i].hit_count;
 629   }
 630   InternalScopedString summary(kMaxSummaryLength);
 631   summary.append("%zu byte(s) leaked in %zu allocation(s).", bytes,
 632                  allocations);
 633   ReportErrorSummary(summary.data());
 634 }
 635
 636 void LeakReport::ApplySuppressions() {
 637   for (uptr i = 0; i < leaks_.size(); i++) {
 638     Suppression *s = GetSuppressionForStack(leaks_[i].stack_trace_id);
 639     if (s) {
 640       s->weight += leaks_[i].total_size;
 641       atomic_store_relaxed(&s->hit_count, atomic_load_relaxed(&s->hit_count) +
 642           leaks_[i].hit_count);
 643       leaks_[i].is_suppressed = true;
 644     }
 645   }
 646 }
 647
 648 uptr LeakReport::UnsuppressedLeakCount() {
 649   uptr result = 0;
 650   for (uptr i = 0; i < leaks_.size(); i++)
 651     if (!leaks_[i].is_suppressed) result++;
 652   return result;
 653 }
 654
 655 } // namespace __lsan
 656 #else // CAN_SANITIZE_LEAKS
 657 namespace __lsan {
 658 void InitCommonLsan() { }
 659 void DoLeakCheck() { }
 660 void DisableInThisThread() { }
 661 void EnableInThisThread() { }
 662 }
 663 #endif // CAN_SANITIZE_LEAKS
 664
 665 using namespace __lsan;  // NOLINT
 666
 667 extern "C" {
 668 SANITIZER_INTERFACE_ATTRIBUTE
 669 void __lsan_ignore_object(const void *p) {
 670 #if CAN_SANITIZE_LEAKS
 671   if (!common_flags()->detect_leaks)
 672     return;
 673   // Cannot use PointsIntoChunk or LsanMetadata here, since the allocator is not
 674   // locked.
 675   BlockingMutexLock l(&global_mutex);
 676   IgnoreObjectResult res = IgnoreObjectLocked(p);
 677   if (res == kIgnoreObjectInvalid)
 678     VReport(1, "__lsan_ignore_object(): no heap object found at %p", p);
 679   if (res == kIgnoreObjectAlreadyIgnored)
 680     VReport(1, "__lsan_ignore_object(): "
 681            "heap object at %p is already being ignored\n", p);
 682   if (res == kIgnoreObjectSuccess)
 683     VReport(1, "__lsan_ignore_object(): ignoring heap object at %p\n", p);
 684 #endif // CAN_SANITIZE_LEAKS
 685 }
 686
 687 SANITIZER_INTERFACE_ATTRIBUTE
 688 void __lsan_register_root_region(const void *begin, uptr size) {
 689 #if CAN_SANITIZE_LEAKS
 690   BlockingMutexLock l(&global_mutex);
 691   CHECK(root_regions);
 692   RootRegion region = {begin, size};
 693   root_regions->push_back(region);
 694   VReport(1, "Registered root region at %p of size %llu\n", begin, size);
 695 #endif // CAN_SANITIZE_LEAKS
 696 }
 697
 698 SANITIZER_INTERFACE_ATTRIBUTE
 699 void __lsan_unregister_root_region(const void *begin, uptr size) {
 700 #if CAN_SANITIZE_LEAKS
 701   BlockingMutexLock l(&global_mutex);
 702   CHECK(root_regions);
 703   bool removed = false;
 704   for (uptr i = 0; i < root_regions->size(); i++) {
 705     RootRegion region = (*root_regions)[i];
 706     if (region.begin == begin && region.size == size) {
 707       removed = true;
 708       uptr last_index = root_regions->size() - 1;
 709       (*root_regions)[i] = (*root_regions)[last_index];
 710       root_regions->pop_back();
 711       VReport(1, "Unregistered root region at %p of size %llu\n", begin, size);
 712       break;
 713     }
 714   }
 715   if (!removed) {
 716     Report(
 717         "__lsan_unregister_root_region(): region at %p of size %llu has not "
 718         "been registered.\n",
 719         begin, size);
 720     Die();
 721   }
 722 #endif // CAN_SANITIZE_LEAKS
 723 }
 724
 725 SANITIZER_INTERFACE_ATTRIBUTE
 726 void __lsan_disable() {
 727 #if CAN_SANITIZE_LEAKS
 728   __lsan::DisableInThisThread();
 729 #endif
 730 }
 731
 732 SANITIZER_INTERFACE_ATTRIBUTE
 733 void __lsan_enable() {
 734 #if CAN_SANITIZE_LEAKS
 735   __lsan::EnableInThisThread();
 736 #endif
 737 }
 738
 739 SANITIZER_INTERFACE_ATTRIBUTE
 740 void __lsan_do_leak_check() {
 741 #if CAN_SANITIZE_LEAKS
 742   if (common_flags()->detect_leaks)
 743     __lsan::DoLeakCheck();
 744 #endif // CAN_SANITIZE_LEAKS
 745 }
 746
 747 SANITIZER_INTERFACE_ATTRIBUTE
 748 int __lsan_do_recoverable_leak_check() {
 749 #if CAN_SANITIZE_LEAKS
 750   if (common_flags()->detect_leaks)
 751     return __lsan::DoRecoverableLeakCheck();
 752 #endif // CAN_SANITIZE_LEAKS
 753   return 0;
 754 }
 755
 756 #if !SANITIZER_SUPPORTS_WEAK_HOOKS
 757 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
 758 int __lsan_is_turned_off() {
 759   return 0;
 760 }
 761
 762 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
 763 const char *__lsan_default_suppressions() {
 764   return "";
 765 }
 766 #endif
 767 } // extern "C"