libsanitizer/asan/asan_allocator.cpp

   1 //===-- asan_allocator.cpp ------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file is a part of AddressSanitizer, an address sanity checker.
  10 //
  11 // Implementation of ASan's memory allocator, 2-nd version.
  12 // This variant uses the allocator from sanitizer_common, i.e. the one shared
  13 // with ThreadSanitizer and MemorySanitizer.
  14 //
  15 //===----------------------------------------------------------------------===//
  16
  17 #include "asan_allocator.h"
  18
  19 #include "asan_mapping.h"
  20 #include "asan_poisoning.h"
  21 #include "asan_report.h"
  22 #include "asan_stack.h"
  23 #include "asan_thread.h"
  24 #include "lsan/lsan_common.h"
  25 #include "sanitizer_common/sanitizer_allocator_checks.h"
  26 #include "sanitizer_common/sanitizer_allocator_interface.h"
  27 #include "sanitizer_common/sanitizer_errno.h"
  28 #include "sanitizer_common/sanitizer_flags.h"
  29 #include "sanitizer_common/sanitizer_internal_defs.h"
  30 #include "sanitizer_common/sanitizer_list.h"
  31 #include "sanitizer_common/sanitizer_quarantine.h"
  32 #include "sanitizer_common/sanitizer_stackdepot.h"
  33
  34 namespace __asan {
  35
  36 // Valid redzone sizes are 16, 32, 64, ... 2048, so we encode them in 3 bits.
  37 // We use adaptive redzones: for larger allocation larger redzones are used.
  38 static u32 RZLog2Size(u32 rz_log) {
  39   CHECK_LT(rz_log, 8);
  40   return 16 << rz_log;
  41 }
  42
  43 static u32 RZSize2Log(u32 rz_size) {
  44   CHECK_GE(rz_size, 16);
  45   CHECK_LE(rz_size, 2048);
  46   CHECK(IsPowerOfTwo(rz_size));
  47   u32 res = Log2(rz_size) - 4;
  48   CHECK_EQ(rz_size, RZLog2Size(res));
  49   return res;
  50 }
  51
  52 static AsanAllocator &get_allocator();
  53
  54 static void AtomicContextStore(volatile atomic_uint64_t *atomic_context,
  55                                u32 tid, u32 stack) {
  56   u64 context = tid;
  57   context <<= 32;
  58   context += stack;
  59   atomic_store(atomic_context, context, memory_order_relaxed);
  60 }
  61
  62 static void AtomicContextLoad(const volatile atomic_uint64_t *atomic_context,
  63                               u32 &tid, u32 &stack) {
  64   u64 context = atomic_load(atomic_context, memory_order_relaxed);
  65   stack = context;
  66   context >>= 32;
  67   tid = context;
  68 }
  69
  70 // The memory chunk allocated from the underlying allocator looks like this:
  71 // L L L L L L H H U U U U U U R R
  72 //   L -- left redzone words (0 or more bytes)
  73 //   H -- ChunkHeader (16 bytes), which is also a part of the left redzone.
  74 //   U -- user memory.
  75 //   R -- right redzone (0 or more bytes)
  76 // ChunkBase consists of ChunkHeader and other bytes that overlap with user
  77 // memory.
  78
  79 // If the left redzone is greater than the ChunkHeader size we store a magic
  80 // value in the first uptr word of the memory block and store the address of
  81 // ChunkBase in the next uptr.
  82 // M B L L L L L L L L L  H H U U U U U U
  83 //   |                    ^
  84 //   ---------------------|
  85 //   M -- magic value kAllocBegMagic
  86 //   B -- address of ChunkHeader pointing to the first 'H'
  87
  88 class ChunkHeader {
  89  public:
  90   atomic_uint8_t chunk_state;
  91   u8 alloc_type : 2;
  92   u8 lsan_tag : 2;
  93
  94   // align < 8 -> 0
  95   // else      -> log2(min(align, 512)) - 2
  96   u8 user_requested_alignment_log : 3;
  97
  98  private:
  99   u16 user_requested_size_hi;
 100   u32 user_requested_size_lo;
 101   atomic_uint64_t alloc_context_id;
 102
 103  public:
 104   uptr UsedSize() const {
 105     uptr R = user_requested_size_lo;
 106     if (sizeof(uptr) > sizeof(user_requested_size_lo))
 107       R += (uptr)user_requested_size_hi << (8 * sizeof(user_requested_size_lo));
 108     return R;
 109   }
 110
 111   void SetUsedSize(uptr size) {
 112     user_requested_size_lo = size;
 113     if (sizeof(uptr) > sizeof(user_requested_size_lo)) {
 114       size >>= (8 * sizeof(user_requested_size_lo));
 115       user_requested_size_hi = size;
 116       CHECK_EQ(user_requested_size_hi, size);
 117     }
 118   }
 119
 120   void SetAllocContext(u32 tid, u32 stack) {
 121     AtomicContextStore(&alloc_context_id, tid, stack);
 122   }
 123
 124   void GetAllocContext(u32 &tid, u32 &stack) const {
 125     AtomicContextLoad(&alloc_context_id, tid, stack);
 126   }
 127 };
 128
 129 class ChunkBase : public ChunkHeader {
 130   atomic_uint64_t free_context_id;
 131
 132  public:
 133   void SetFreeContext(u32 tid, u32 stack) {
 134     AtomicContextStore(&free_context_id, tid, stack);
 135   }
 136
 137   void GetFreeContext(u32 &tid, u32 &stack) const {
 138     AtomicContextLoad(&free_context_id, tid, stack);
 139   }
 140 };
 141
 142 static const uptr kChunkHeaderSize = sizeof(ChunkHeader);
 143 static const uptr kChunkHeader2Size = sizeof(ChunkBase) - kChunkHeaderSize;
 144 COMPILER_CHECK(kChunkHeaderSize == 16);
 145 COMPILER_CHECK(kChunkHeader2Size <= 16);
 146
 147 enum {
 148   // Either just allocated by underlying allocator, but AsanChunk is not yet
 149   // ready, or almost returned to undelying allocator and AsanChunk is already
 150   // meaningless.
 151   CHUNK_INVALID = 0,
 152   // The chunk is allocated and not yet freed.
 153   CHUNK_ALLOCATED = 2,
 154   // The chunk was freed and put into quarantine zone.
 155   CHUNK_QUARANTINE = 3,
 156 };
 157
 158 class AsanChunk : public ChunkBase {
 159  public:
 160   uptr Beg() { return reinterpret_cast<uptr>(this) + kChunkHeaderSize; }
 161   bool AddrIsInside(uptr addr) {
 162     return (addr >= Beg()) && (addr < Beg() + UsedSize());
 163   }
 164 };
 165
 166 class LargeChunkHeader {
 167   static constexpr uptr kAllocBegMagic =
 168       FIRST_32_SECOND_64(0xCC6E96B9, 0xCC6E96B9CC6E96B9ULL);
 169   atomic_uintptr_t magic;
 170   AsanChunk *chunk_header;
 171
 172  public:
 173   AsanChunk *Get() const {
 174     return atomic_load(&magic, memory_order_acquire) == kAllocBegMagic
 175                ? chunk_header
 176                : nullptr;
 177   }
 178
 179   void Set(AsanChunk *p) {
 180     if (p) {
 181       chunk_header = p;
 182       atomic_store(&magic, kAllocBegMagic, memory_order_release);
 183       return;
 184     }
 185
 186     uptr old = kAllocBegMagic;
 187     if (!atomic_compare_exchange_strong(&magic, &old, 0,
 188                                         memory_order_release)) {
 189       CHECK_EQ(old, kAllocBegMagic);
 190     }
 191   }
 192 };
 193
 194 struct QuarantineCallback {
 195   QuarantineCallback(AllocatorCache *cache, BufferedStackTrace *stack)
 196       : cache_(cache),
 197         stack_(stack) {
 198   }
 199
 200   void Recycle(AsanChunk *m) {
 201     void *p = get_allocator().GetBlockBegin(m);
 202     if (p != m) {
 203       // Clear the magic value, as allocator internals may overwrite the
 204       // contents of deallocated chunk, confusing GetAsanChunk lookup.
 205       reinterpret_cast<LargeChunkHeader *>(p)->Set(nullptr);
 206     }
 207
 208     u8 old_chunk_state = CHUNK_QUARANTINE;
 209     if (!atomic_compare_exchange_strong(&m->chunk_state, &old_chunk_state,
 210                                         CHUNK_INVALID, memory_order_acquire)) {
 211       CHECK_EQ(old_chunk_state, CHUNK_QUARANTINE);
 212     }
 213
 214     PoisonShadow(m->Beg(),
 215                  RoundUpTo(m->UsedSize(), SHADOW_GRANULARITY),
 216                  kAsanHeapLeftRedzoneMagic);
 217
 218     // Statistics.
 219     AsanStats &thread_stats = GetCurrentThreadStats();
 220     thread_stats.real_frees++;
 221     thread_stats.really_freed += m->UsedSize();
 222
 223     get_allocator().Deallocate(cache_, p);
 224   }
 225
 226   void *Allocate(uptr size) {
 227     void *res = get_allocator().Allocate(cache_, size, 1);
 228     // TODO(alekseys): Consider making quarantine OOM-friendly.
 229     if (UNLIKELY(!res))
 230       ReportOutOfMemory(size, stack_);
 231     return res;
 232   }
 233
 234   void Deallocate(void *p) {
 235     get_allocator().Deallocate(cache_, p);
 236   }
 237
 238  private:
 239   AllocatorCache* const cache_;
 240   BufferedStackTrace* const stack_;
 241 };
 242
 243 typedef Quarantine<QuarantineCallback, AsanChunk> AsanQuarantine;
 244 typedef AsanQuarantine::Cache QuarantineCache;
 245
 246 void AsanMapUnmapCallback::OnMap(uptr p, uptr size) const {
 247   PoisonShadow(p, size, kAsanHeapLeftRedzoneMagic);
 248   // Statistics.
 249   AsanStats &thread_stats = GetCurrentThreadStats();
 250   thread_stats.mmaps++;
 251   thread_stats.mmaped += size;
 252 }
 253 void AsanMapUnmapCallback::OnUnmap(uptr p, uptr size) const {
 254   PoisonShadow(p, size, 0);
 255   // We are about to unmap a chunk of user memory.
 256   // Mark the corresponding shadow memory as not needed.
 257   FlushUnneededASanShadowMemory(p, size);
 258   // Statistics.
 259   AsanStats &thread_stats = GetCurrentThreadStats();
 260   thread_stats.munmaps++;
 261   thread_stats.munmaped += size;
 262 }
 263
 264 // We can not use THREADLOCAL because it is not supported on some of the
 265 // platforms we care about (OSX 10.6, Android).
 266 // static THREADLOCAL AllocatorCache cache;
 267 AllocatorCache *GetAllocatorCache(AsanThreadLocalMallocStorage *ms) {
 268   CHECK(ms);
 269   return &ms->allocator_cache;
 270 }
 271
 272 QuarantineCache *GetQuarantineCache(AsanThreadLocalMallocStorage *ms) {
 273   CHECK(ms);
 274   CHECK_LE(sizeof(QuarantineCache), sizeof(ms->quarantine_cache));
 275   return reinterpret_cast<QuarantineCache *>(ms->quarantine_cache);
 276 }
 277
 278 void AllocatorOptions::SetFrom(const Flags *f, const CommonFlags *cf) {
 279   quarantine_size_mb = f->quarantine_size_mb;
 280   thread_local_quarantine_size_kb = f->thread_local_quarantine_size_kb;
 281   min_redzone = f->redzone;
 282   max_redzone = f->max_redzone;
 283   may_return_null = cf->allocator_may_return_null;
 284   alloc_dealloc_mismatch = f->alloc_dealloc_mismatch;
 285   release_to_os_interval_ms = cf->allocator_release_to_os_interval_ms;
 286 }
 287
 288 void AllocatorOptions::CopyTo(Flags *f, CommonFlags *cf) {
 289   f->quarantine_size_mb = quarantine_size_mb;
 290   f->thread_local_quarantine_size_kb = thread_local_quarantine_size_kb;
 291   f->redzone = min_redzone;
 292   f->max_redzone = max_redzone;
 293   cf->allocator_may_return_null = may_return_null;
 294   f->alloc_dealloc_mismatch = alloc_dealloc_mismatch;
 295   cf->allocator_release_to_os_interval_ms = release_to_os_interval_ms;
 296 }
 297
 298 struct Allocator {
 299   static const uptr kMaxAllowedMallocSize =
 300       FIRST_32_SECOND_64(3UL << 30, 1ULL << 40);
 301
 302   AsanAllocator allocator;
 303   AsanQuarantine quarantine;
 304   StaticSpinMutex fallback_mutex;
 305   AllocatorCache fallback_allocator_cache;
 306   QuarantineCache fallback_quarantine_cache;
 307
 308   uptr max_user_defined_malloc_size;
 309   atomic_uint8_t rss_limit_exceeded;
 310
 311   // ------------------- Options --------------------------
 312   atomic_uint16_t min_redzone;
 313   atomic_uint16_t max_redzone;
 314   atomic_uint8_t alloc_dealloc_mismatch;
 315
 316   // ------------------- Initialization ------------------------
 317   explicit Allocator(LinkerInitialized)
 318       : quarantine(LINKER_INITIALIZED),
 319         fallback_quarantine_cache(LINKER_INITIALIZED) {}
 320
 321   void CheckOptions(const AllocatorOptions &options) const {
 322     CHECK_GE(options.min_redzone, 16);
 323     CHECK_GE(options.max_redzone, options.min_redzone);
 324     CHECK_LE(options.max_redzone, 2048);
 325     CHECK(IsPowerOfTwo(options.min_redzone));
 326     CHECK(IsPowerOfTwo(options.max_redzone));
 327   }
 328
 329   void SharedInitCode(const AllocatorOptions &options) {
 330     CheckOptions(options);
 331     quarantine.Init((uptr)options.quarantine_size_mb << 20,
 332                     (uptr)options.thread_local_quarantine_size_kb << 10);
 333     atomic_store(&alloc_dealloc_mismatch, options.alloc_dealloc_mismatch,
 334                  memory_order_release);
 335     atomic_store(&min_redzone, options.min_redzone, memory_order_release);
 336     atomic_store(&max_redzone, options.max_redzone, memory_order_release);
 337   }
 338
 339   void InitLinkerInitialized(const AllocatorOptions &options) {
 340     SetAllocatorMayReturnNull(options.may_return_null);
 341     allocator.InitLinkerInitialized(options.release_to_os_interval_ms);
 342     SharedInitCode(options);
 343     max_user_defined_malloc_size = common_flags()->max_allocation_size_mb
 344                                        ? common_flags()->max_allocation_size_mb
 345                                              << 20
 346                                        : kMaxAllowedMallocSize;
 347   }
 348
 349   bool RssLimitExceeded() {
 350     return atomic_load(&rss_limit_exceeded, memory_order_relaxed);
 351   }
 352
 353   void SetRssLimitExceeded(bool limit_exceeded) {
 354     atomic_store(&rss_limit_exceeded, limit_exceeded, memory_order_relaxed);
 355   }
 356
 357   void RePoisonChunk(uptr chunk) {
 358     // This could be a user-facing chunk (with redzones), or some internal
 359     // housekeeping chunk, like TransferBatch. Start by assuming the former.
 360     AsanChunk *ac = GetAsanChunk((void *)chunk);
 361     uptr allocated_size = allocator.GetActuallyAllocatedSize((void *)chunk);
 362     if (ac && atomic_load(&ac->chunk_state, memory_order_acquire) ==
 363                   CHUNK_ALLOCATED) {
 364       uptr beg = ac->Beg();
 365       uptr end = ac->Beg() + ac->UsedSize();
 366       uptr chunk_end = chunk + allocated_size;
 367       if (chunk < beg && beg < end && end <= chunk_end) {
 368         // Looks like a valid AsanChunk in use, poison redzones only.
 369         PoisonShadow(chunk, beg - chunk, kAsanHeapLeftRedzoneMagic);
 370         uptr end_aligned_down = RoundDownTo(end, SHADOW_GRANULARITY);
 371         FastPoisonShadowPartialRightRedzone(
 372             end_aligned_down, end - end_aligned_down,
 373             chunk_end - end_aligned_down, kAsanHeapLeftRedzoneMagic);
 374         return;
 375       }
 376     }
 377
 378     // This is either not an AsanChunk or freed or quarantined AsanChunk.
 379     // In either case, poison everything.
 380     PoisonShadow(chunk, allocated_size, kAsanHeapLeftRedzoneMagic);
 381   }
 382
 383   void ReInitialize(const AllocatorOptions &options) {
 384     SetAllocatorMayReturnNull(options.may_return_null);
 385     allocator.SetReleaseToOSIntervalMs(options.release_to_os_interval_ms);
 386     SharedInitCode(options);
 387
 388     // Poison all existing allocation's redzones.
 389     if (CanPoisonMemory()) {
 390       allocator.ForceLock();
 391       allocator.ForEachChunk(
 392           [](uptr chunk, void *alloc) {
 393             ((Allocator *)alloc)->RePoisonChunk(chunk);
 394           },
 395           this);
 396       allocator.ForceUnlock();
 397     }
 398   }
 399
 400   void GetOptions(AllocatorOptions *options) const {
 401     options->quarantine_size_mb = quarantine.GetSize() >> 20;
 402     options->thread_local_quarantine_size_kb = quarantine.GetCacheSize() >> 10;
 403     options->min_redzone = atomic_load(&min_redzone, memory_order_acquire);
 404     options->max_redzone = atomic_load(&max_redzone, memory_order_acquire);
 405     options->may_return_null = AllocatorMayReturnNull();
 406     options->alloc_dealloc_mismatch =
 407         atomic_load(&alloc_dealloc_mismatch, memory_order_acquire);
 408     options->release_to_os_interval_ms = allocator.ReleaseToOSIntervalMs();
 409   }
 410
 411   // -------------------- Helper methods. -------------------------
 412   uptr ComputeRZLog(uptr user_requested_size) {
 413     u32 rz_log = user_requested_size <= 64 - 16            ? 0
 414                  : user_requested_size <= 128 - 32         ? 1
 415                  : user_requested_size <= 512 - 64         ? 2
 416                  : user_requested_size <= 4096 - 128       ? 3
 417                  : user_requested_size <= (1 << 14) - 256  ? 4
 418                  : user_requested_size <= (1 << 15) - 512  ? 5
 419                  : user_requested_size <= (1 << 16) - 1024 ? 6
 420                                                            : 7;
 421     u32 hdr_log = RZSize2Log(RoundUpToPowerOfTwo(sizeof(ChunkHeader)));
 422     u32 min_log = RZSize2Log(atomic_load(&min_redzone, memory_order_acquire));
 423     u32 max_log = RZSize2Log(atomic_load(&max_redzone, memory_order_acquire));
 424     return Min(Max(rz_log, Max(min_log, hdr_log)), Max(max_log, hdr_log));
 425   }
 426
 427   static uptr ComputeUserRequestedAlignmentLog(uptr user_requested_alignment) {
 428     if (user_requested_alignment < 8)
 429       return 0;
 430     if (user_requested_alignment > 512)
 431       user_requested_alignment = 512;
 432     return Log2(user_requested_alignment) - 2;
 433   }
 434
 435   static uptr ComputeUserAlignment(uptr user_requested_alignment_log) {
 436     if (user_requested_alignment_log == 0)
 437       return 0;
 438     return 1LL << (user_requested_alignment_log + 2);
 439   }
 440
 441   // We have an address between two chunks, and we want to report just one.
 442   AsanChunk *ChooseChunk(uptr addr, AsanChunk *left_chunk,
 443                          AsanChunk *right_chunk) {
 444     if (!left_chunk)
 445       return right_chunk;
 446     if (!right_chunk)
 447       return left_chunk;
 448     // Prefer an allocated chunk over freed chunk and freed chunk
 449     // over available chunk.
 450     u8 left_state = atomic_load(&left_chunk->chunk_state, memory_order_relaxed);
 451     u8 right_state =
 452         atomic_load(&right_chunk->chunk_state, memory_order_relaxed);
 453     if (left_state != right_state) {
 454       if (left_state == CHUNK_ALLOCATED)
 455         return left_chunk;
 456       if (right_state == CHUNK_ALLOCATED)
 457         return right_chunk;
 458       if (left_state == CHUNK_QUARANTINE)
 459         return left_chunk;
 460       if (right_state == CHUNK_QUARANTINE)
 461         return right_chunk;
 462     }
 463     // Same chunk_state: choose based on offset.
 464     sptr l_offset = 0, r_offset = 0;
 465     CHECK(AsanChunkView(left_chunk).AddrIsAtRight(addr, 1, &l_offset));
 466     CHECK(AsanChunkView(right_chunk).AddrIsAtLeft(addr, 1, &r_offset));
 467     if (l_offset < r_offset)
 468       return left_chunk;
 469     return right_chunk;
 470   }
 471
 472   bool UpdateAllocationStack(uptr addr, BufferedStackTrace *stack) {
 473     AsanChunk *m = GetAsanChunkByAddr(addr);
 474     if (!m) return false;
 475     if (atomic_load(&m->chunk_state, memory_order_acquire) != CHUNK_ALLOCATED)
 476       return false;
 477     if (m->Beg() != addr) return false;
 478     AsanThread *t = GetCurrentThread();
 479     m->SetAllocContext(t ? t->tid() : kMainTid, StackDepotPut(*stack));
 480     return true;
 481   }
 482
 483   // -------------------- Allocation/Deallocation routines ---------------
 484   void *Allocate(uptr size, uptr alignment, BufferedStackTrace *stack,
 485                  AllocType alloc_type, bool can_fill) {
 486     if (UNLIKELY(!asan_inited))
 487       AsanInitFromRtl();
 488     if (RssLimitExceeded()) {
 489       if (AllocatorMayReturnNull())
 490         return nullptr;
 491       ReportRssLimitExceeded(stack);
 492     }
 493     Flags &fl = *flags();
 494     CHECK(stack);
 495     const uptr min_alignment = SHADOW_GRANULARITY;
 496     const uptr user_requested_alignment_log =
 497         ComputeUserRequestedAlignmentLog(alignment);
 498     if (alignment < min_alignment)
 499       alignment = min_alignment;
 500     if (size == 0) {
 501       // We'd be happy to avoid allocating memory for zero-size requests, but
 502       // some programs/tests depend on this behavior and assume that malloc
 503       // would not return NULL even for zero-size allocations. Moreover, it
 504       // looks like operator new should never return NULL, and results of
 505       // consecutive "new" calls must be different even if the allocated size
 506       // is zero.
 507       size = 1;
 508     }
 509     CHECK(IsPowerOfTwo(alignment));
 510     uptr rz_log = ComputeRZLog(size);
 511     uptr rz_size = RZLog2Size(rz_log);
 512     uptr rounded_size = RoundUpTo(Max(size, kChunkHeader2Size), alignment);
 513     uptr needed_size = rounded_size + rz_size;
 514     if (alignment > min_alignment)
 515       needed_size += alignment;
 516     // If we are allocating from the secondary allocator, there will be no
 517     // automatic right redzone, so add the right redzone manually.
 518     if (!PrimaryAllocator::CanAllocate(needed_size, alignment))
 519       needed_size += rz_size;
 520     CHECK(IsAligned(needed_size, min_alignment));
 521     if (size > kMaxAllowedMallocSize || needed_size > kMaxAllowedMallocSize ||
 522         size > max_user_defined_malloc_size) {
 523       if (AllocatorMayReturnNull()) {
 524         Report("WARNING: AddressSanitizer failed to allocate 0x%zx bytes\n",
 525                (void*)size);
 526         return nullptr;
 527       }
 528       uptr malloc_limit =
 529           Min(kMaxAllowedMallocSize, max_user_defined_malloc_size);
 530       ReportAllocationSizeTooBig(size, needed_size, malloc_limit, stack);
 531     }
 532
 533     AsanThread *t = GetCurrentThread();
 534     void *allocated;
 535     if (t) {
 536       AllocatorCache *cache = GetAllocatorCache(&t->malloc_storage());
 537       allocated = allocator.Allocate(cache, needed_size, 8);
 538     } else {
 539       SpinMutexLock l(&fallback_mutex);
 540       AllocatorCache *cache = &fallback_allocator_cache;
 541       allocated = allocator.Allocate(cache, needed_size, 8);
 542     }
 543     if (UNLIKELY(!allocated)) {
 544       SetAllocatorOutOfMemory();
 545       if (AllocatorMayReturnNull())
 546         return nullptr;
 547       ReportOutOfMemory(size, stack);
 548     }
 549
 550     if (*(u8 *)MEM_TO_SHADOW((uptr)allocated) == 0 && CanPoisonMemory()) {
 551       // Heap poisoning is enabled, but the allocator provides an unpoisoned
 552       // chunk. This is possible if CanPoisonMemory() was false for some
 553       // time, for example, due to flags()->start_disabled.
 554       // Anyway, poison the block before using it for anything else.
 555       uptr allocated_size = allocator.GetActuallyAllocatedSize(allocated);
 556       PoisonShadow((uptr)allocated, allocated_size, kAsanHeapLeftRedzoneMagic);
 557     }
 558
 559     uptr alloc_beg = reinterpret_cast<uptr>(allocated);
 560     uptr alloc_end = alloc_beg + needed_size;
 561     uptr user_beg = alloc_beg + rz_size;
 562     if (!IsAligned(user_beg, alignment))
 563       user_beg = RoundUpTo(user_beg, alignment);
 564     uptr user_end = user_beg + size;
 565     CHECK_LE(user_end, alloc_end);
 566     uptr chunk_beg = user_beg - kChunkHeaderSize;
 567     AsanChunk *m = reinterpret_cast<AsanChunk *>(chunk_beg);
 568     m->alloc_type = alloc_type;
 569     CHECK(size);
 570     m->SetUsedSize(size);
 571     m->user_requested_alignment_log = user_requested_alignment_log;
 572
 573     m->SetAllocContext(t ? t->tid() : kMainTid, StackDepotPut(*stack));
 574
 575     uptr size_rounded_down_to_granularity =
 576         RoundDownTo(size, SHADOW_GRANULARITY);
 577     // Unpoison the bulk of the memory region.
 578     if (size_rounded_down_to_granularity)
 579       PoisonShadow(user_beg, size_rounded_down_to_granularity, 0);
 580     // Deal with the end of the region if size is not aligned to granularity.
 581     if (size != size_rounded_down_to_granularity && CanPoisonMemory()) {
 582       u8 *shadow =
 583           (u8 *)MemToShadow(user_beg + size_rounded_down_to_granularity);
 584       *shadow = fl.poison_partial ? (size & (SHADOW_GRANULARITY - 1)) : 0;
 585     }
 586
 587     AsanStats &thread_stats = GetCurrentThreadStats();
 588     thread_stats.mallocs++;
 589     thread_stats.malloced += size;
 590     thread_stats.malloced_redzones += needed_size - size;
 591     if (needed_size > SizeClassMap::kMaxSize)
 592       thread_stats.malloc_large++;
 593     else
 594       thread_stats.malloced_by_size[SizeClassMap::ClassID(needed_size)]++;
 595
 596     void *res = reinterpret_cast<void *>(user_beg);
 597     if (can_fill && fl.max_malloc_fill_size) {
 598       uptr fill_size = Min(size, (uptr)fl.max_malloc_fill_size);
 599       REAL(memset)(res, fl.malloc_fill_byte, fill_size);
 600     }
 601 #if CAN_SANITIZE_LEAKS
 602     m->lsan_tag = __lsan::DisabledInThisThread() ? __lsan::kIgnored
 603                                                  : __lsan::kDirectlyLeaked;
 604 #endif
 605     // Must be the last mutation of metadata in this function.
 606     atomic_store(&m->chunk_state, CHUNK_ALLOCATED, memory_order_release);
 607     if (alloc_beg != chunk_beg) {
 608       CHECK_LE(alloc_beg + sizeof(LargeChunkHeader), chunk_beg);
 609       reinterpret_cast<LargeChunkHeader *>(alloc_beg)->Set(m);
 610     }
 611     ASAN_MALLOC_HOOK(res, size);
 612     return res;
 613   }
 614
 615   // Set quarantine flag if chunk is allocated, issue ASan error report on
 616   // available and quarantined chunks. Return true on success, false otherwise.
 617   bool AtomicallySetQuarantineFlagIfAllocated(AsanChunk *m, void *ptr,
 618                                               BufferedStackTrace *stack) {
 619     u8 old_chunk_state = CHUNK_ALLOCATED;
 620     // Flip the chunk_state atomically to avoid race on double-free.
 621     if (!atomic_compare_exchange_strong(&m->chunk_state, &old_chunk_state,
 622                                         CHUNK_QUARANTINE,
 623                                         memory_order_acquire)) {
 624       ReportInvalidFree(ptr, old_chunk_state, stack);
 625       // It's not safe to push a chunk in quarantine on invalid free.
 626       return false;
 627     }
 628     CHECK_EQ(CHUNK_ALLOCATED, old_chunk_state);
 629     // It was a user data.
 630     m->SetFreeContext(kInvalidTid, 0);
 631     return true;
 632   }
 633
 634   // Expects the chunk to already be marked as quarantined by using
 635   // AtomicallySetQuarantineFlagIfAllocated.
 636   void QuarantineChunk(AsanChunk *m, void *ptr, BufferedStackTrace *stack) {
 637     CHECK_EQ(atomic_load(&m->chunk_state, memory_order_relaxed),
 638              CHUNK_QUARANTINE);
 639     AsanThread *t = GetCurrentThread();
 640     m->SetFreeContext(t ? t->tid() : 0, StackDepotPut(*stack));
 641
 642     Flags &fl = *flags();
 643     if (fl.max_free_fill_size > 0) {
 644       // We have to skip the chunk header, it contains free_context_id.
 645       uptr scribble_start = (uptr)m + kChunkHeaderSize + kChunkHeader2Size;
 646       if (m->UsedSize() >= kChunkHeader2Size) {  // Skip Header2 in user area.
 647         uptr size_to_fill = m->UsedSize() - kChunkHeader2Size;
 648         size_to_fill = Min(size_to_fill, (uptr)fl.max_free_fill_size);
 649         REAL(memset)((void *)scribble_start, fl.free_fill_byte, size_to_fill);
 650       }
 651     }
 652
 653     // Poison the region.
 654     PoisonShadow(m->Beg(),
 655                  RoundUpTo(m->UsedSize(), SHADOW_GRANULARITY),
 656                  kAsanHeapFreeMagic);
 657
 658     AsanStats &thread_stats = GetCurrentThreadStats();
 659     thread_stats.frees++;
 660     thread_stats.freed += m->UsedSize();
 661
 662     // Push into quarantine.
 663     if (t) {
 664       AsanThreadLocalMallocStorage *ms = &t->malloc_storage();
 665       AllocatorCache *ac = GetAllocatorCache(ms);
 666       quarantine.Put(GetQuarantineCache(ms), QuarantineCallback(ac, stack), m,
 667                      m->UsedSize());
 668     } else {
 669       SpinMutexLock l(&fallback_mutex);
 670       AllocatorCache *ac = &fallback_allocator_cache;
 671       quarantine.Put(&fallback_quarantine_cache, QuarantineCallback(ac, stack),
 672                      m, m->UsedSize());
 673     }
 674   }
 675
 676   void Deallocate(void *ptr, uptr delete_size, uptr delete_alignment,
 677                   BufferedStackTrace *stack, AllocType alloc_type) {
 678     uptr p = reinterpret_cast<uptr>(ptr);
 679     if (p == 0) return;
 680
 681     uptr chunk_beg = p - kChunkHeaderSize;
 682     AsanChunk *m = reinterpret_cast<AsanChunk *>(chunk_beg);
 683
 684     // On Windows, uninstrumented DLLs may allocate memory before ASan hooks
 685     // malloc. Don't report an invalid free in this case.
 686     if (SANITIZER_WINDOWS &&
 687         !get_allocator().PointerIsMine(ptr)) {
 688       if (!IsSystemHeapAddress(p))
 689         ReportFreeNotMalloced(p, stack);
 690       return;
 691     }
 692
 693     ASAN_FREE_HOOK(ptr);
 694
 695     // Must mark the chunk as quarantined before any changes to its metadata.
 696     // Do not quarantine given chunk if we failed to set CHUNK_QUARANTINE flag.
 697     if (!AtomicallySetQuarantineFlagIfAllocated(m, ptr, stack)) return;
 698
 699     if (m->alloc_type != alloc_type) {
 700       if (atomic_load(&alloc_dealloc_mismatch, memory_order_acquire)) {
 701         ReportAllocTypeMismatch((uptr)ptr, stack, (AllocType)m->alloc_type,
 702                                 (AllocType)alloc_type);
 703       }
 704     } else {
 705       if (flags()->new_delete_type_mismatch &&
 706           (alloc_type == FROM_NEW || alloc_type == FROM_NEW_BR) &&
 707           ((delete_size && delete_size != m->UsedSize()) ||
 708            ComputeUserRequestedAlignmentLog(delete_alignment) !=
 709                m->user_requested_alignment_log)) {
 710         ReportNewDeleteTypeMismatch(p, delete_size, delete_alignment, stack);
 711       }
 712     }
 713
 714     QuarantineChunk(m, ptr, stack);
 715   }
 716
 717   void *Reallocate(void *old_ptr, uptr new_size, BufferedStackTrace *stack) {
 718     CHECK(old_ptr && new_size);
 719     uptr p = reinterpret_cast<uptr>(old_ptr);
 720     uptr chunk_beg = p - kChunkHeaderSize;
 721     AsanChunk *m = reinterpret_cast<AsanChunk *>(chunk_beg);
 722
 723     AsanStats &thread_stats = GetCurrentThreadStats();
 724     thread_stats.reallocs++;
 725     thread_stats.realloced += new_size;
 726
 727     void *new_ptr = Allocate(new_size, 8, stack, FROM_MALLOC, true);
 728     if (new_ptr) {
 729       u8 chunk_state = atomic_load(&m->chunk_state, memory_order_acquire);
 730       if (chunk_state != CHUNK_ALLOCATED)
 731         ReportInvalidFree(old_ptr, chunk_state, stack);
 732       CHECK_NE(REAL(memcpy), nullptr);
 733       uptr memcpy_size = Min(new_size, m->UsedSize());
 734       // If realloc() races with free(), we may start copying freed memory.
 735       // However, we will report racy double-free later anyway.
 736       REAL(memcpy)(new_ptr, old_ptr, memcpy_size);
 737       Deallocate(old_ptr, 0, 0, stack, FROM_MALLOC);
 738     }
 739     return new_ptr;
 740   }
 741
 742   void *Calloc(uptr nmemb, uptr size, BufferedStackTrace *stack) {
 743     if (UNLIKELY(CheckForCallocOverflow(size, nmemb))) {
 744       if (AllocatorMayReturnNull())
 745         return nullptr;
 746       ReportCallocOverflow(nmemb, size, stack);
 747     }
 748     void *ptr = Allocate(nmemb * size, 8, stack, FROM_MALLOC, false);
 749     // If the memory comes from the secondary allocator no need to clear it
 750     // as it comes directly from mmap.
 751     if (ptr && allocator.FromPrimary(ptr))
 752       REAL(memset)(ptr, 0, nmemb * size);
 753     return ptr;
 754   }
 755
 756   void ReportInvalidFree(void *ptr, u8 chunk_state, BufferedStackTrace *stack) {
 757     if (chunk_state == CHUNK_QUARANTINE)
 758       ReportDoubleFree((uptr)ptr, stack);
 759     else
 760       ReportFreeNotMalloced((uptr)ptr, stack);
 761   }
 762
 763   void CommitBack(AsanThreadLocalMallocStorage *ms, BufferedStackTrace *stack) {
 764     AllocatorCache *ac = GetAllocatorCache(ms);
 765     quarantine.Drain(GetQuarantineCache(ms), QuarantineCallback(ac, stack));
 766     allocator.SwallowCache(ac);
 767   }
 768
 769   // -------------------------- Chunk lookup ----------------------
 770
 771   // Assumes alloc_beg == allocator.GetBlockBegin(alloc_beg).
 772   // Returns nullptr if AsanChunk is not yet initialized just after
 773   // get_allocator().Allocate(), or is being destroyed just before
 774   // get_allocator().Deallocate().
 775   AsanChunk *GetAsanChunk(void *alloc_beg) {
 776     if (!alloc_beg)
 777       return nullptr;
 778     AsanChunk *p = reinterpret_cast<LargeChunkHeader *>(alloc_beg)->Get();
 779     if (!p) {
 780       if (!allocator.FromPrimary(alloc_beg))
 781         return nullptr;
 782       p = reinterpret_cast<AsanChunk *>(alloc_beg);
 783     }
 784     u8 state = atomic_load(&p->chunk_state, memory_order_relaxed);
 785     // It does not guaranty that Chunk is initialized, but it's
 786     // definitely not for any other value.
 787     if (state == CHUNK_ALLOCATED || state == CHUNK_QUARANTINE)
 788       return p;
 789     return nullptr;
 790   }
 791
 792   AsanChunk *GetAsanChunkByAddr(uptr p) {
 793     void *alloc_beg = allocator.GetBlockBegin(reinterpret_cast<void *>(p));
 794     return GetAsanChunk(alloc_beg);
 795   }
 796
 797   // Allocator must be locked when this function is called.
 798   AsanChunk *GetAsanChunkByAddrFastLocked(uptr p) {
 799     void *alloc_beg =
 800         allocator.GetBlockBeginFastLocked(reinterpret_cast<void *>(p));
 801     return GetAsanChunk(alloc_beg);
 802   }
 803
 804   uptr AllocationSize(uptr p) {
 805     AsanChunk *m = GetAsanChunkByAddr(p);
 806     if (!m) return 0;
 807     if (atomic_load(&m->chunk_state, memory_order_acquire) != CHUNK_ALLOCATED)
 808       return 0;
 809     if (m->Beg() != p) return 0;
 810     return m->UsedSize();
 811   }
 812
 813   AsanChunkView FindHeapChunkByAddress(uptr addr) {
 814     AsanChunk *m1 = GetAsanChunkByAddr(addr);
 815     sptr offset = 0;
 816     if (!m1 || AsanChunkView(m1).AddrIsAtLeft(addr, 1, &offset)) {
 817       // The address is in the chunk's left redzone, so maybe it is actually
 818       // a right buffer overflow from the other chunk to the left.
 819       // Search a bit to the left to see if there is another chunk.
 820       AsanChunk *m2 = nullptr;
 821       for (uptr l = 1; l < GetPageSizeCached(); l++) {
 822         m2 = GetAsanChunkByAddr(addr - l);
 823         if (m2 == m1) continue;  // Still the same chunk.
 824         break;
 825       }
 826       if (m2 && AsanChunkView(m2).AddrIsAtRight(addr, 1, &offset))
 827         m1 = ChooseChunk(addr, m2, m1);
 828     }
 829     return AsanChunkView(m1);
 830   }
 831
 832   void Purge(BufferedStackTrace *stack) {
 833     AsanThread *t = GetCurrentThread();
 834     if (t) {
 835       AsanThreadLocalMallocStorage *ms = &t->malloc_storage();
 836       quarantine.DrainAndRecycle(GetQuarantineCache(ms),
 837                                  QuarantineCallback(GetAllocatorCache(ms),
 838                                                     stack));
 839     }
 840     {
 841       SpinMutexLock l(&fallback_mutex);
 842       quarantine.DrainAndRecycle(&fallback_quarantine_cache,
 843                                  QuarantineCallback(&fallback_allocator_cache,
 844                                                     stack));
 845     }
 846
 847     allocator.ForceReleaseToOS();
 848   }
 849
 850   void PrintStats() {
 851     allocator.PrintStats();
 852     quarantine.PrintStats();
 853   }
 854
 855   void ForceLock() {
 856     allocator.ForceLock();
 857     fallback_mutex.Lock();
 858   }
 859
 860   void ForceUnlock() {
 861     fallback_mutex.Unlock();
 862     allocator.ForceUnlock();
 863   }
 864 };
 865
 866 static Allocator instance(LINKER_INITIALIZED);
 867
 868 static AsanAllocator &get_allocator() {
 869   return instance.allocator;
 870 }
 871
 872 bool AsanChunkView::IsValid() const {
 873   return chunk_ && atomic_load(&chunk_->chunk_state, memory_order_relaxed) !=
 874                        CHUNK_INVALID;
 875 }
 876 bool AsanChunkView::IsAllocated() const {
 877   return chunk_ && atomic_load(&chunk_->chunk_state, memory_order_relaxed) ==
 878                        CHUNK_ALLOCATED;
 879 }
 880 bool AsanChunkView::IsQuarantined() const {
 881   return chunk_ && atomic_load(&chunk_->chunk_state, memory_order_relaxed) ==
 882                        CHUNK_QUARANTINE;
 883 }
 884 uptr AsanChunkView::Beg() const { return chunk_->Beg(); }
 885 uptr AsanChunkView::End() const { return Beg() + UsedSize(); }
 886 uptr AsanChunkView::UsedSize() const { return chunk_->UsedSize(); }
 887 u32 AsanChunkView::UserRequestedAlignment() const {
 888   return Allocator::ComputeUserAlignment(chunk_->user_requested_alignment_log);
 889 }
 890
 891 uptr AsanChunkView::AllocTid() const {
 892   u32 tid = 0;
 893   u32 stack = 0;
 894   chunk_->GetAllocContext(tid, stack);
 895   return tid;
 896 }
 897
 898 uptr AsanChunkView::FreeTid() const {
 899   if (!IsQuarantined())
 900     return kInvalidTid;
 901   u32 tid = 0;
 902   u32 stack = 0;
 903   chunk_->GetFreeContext(tid, stack);
 904   return tid;
 905 }
 906
 907 AllocType AsanChunkView::GetAllocType() const {
 908   return (AllocType)chunk_->alloc_type;
 909 }
 910
 911 static StackTrace GetStackTraceFromId(u32 id) {
 912   CHECK(id);
 913   StackTrace res = StackDepotGet(id);
 914   CHECK(res.trace);
 915   return res;
 916 }
 917
 918 u32 AsanChunkView::GetAllocStackId() const {
 919   u32 tid = 0;
 920   u32 stack = 0;
 921   chunk_->GetAllocContext(tid, stack);
 922   return stack;
 923 }
 924
 925 u32 AsanChunkView::GetFreeStackId() const {
 926   if (!IsQuarantined())
 927     return 0;
 928   u32 tid = 0;
 929   u32 stack = 0;
 930   chunk_->GetFreeContext(tid, stack);
 931   return stack;
 932 }
 933
 934 StackTrace AsanChunkView::GetAllocStack() const {
 935   return GetStackTraceFromId(GetAllocStackId());
 936 }
 937
 938 StackTrace AsanChunkView::GetFreeStack() const {
 939   return GetStackTraceFromId(GetFreeStackId());
 940 }
 941
 942 void InitializeAllocator(const AllocatorOptions &options) {
 943   instance.InitLinkerInitialized(options);
 944 }
 945
 946 void ReInitializeAllocator(const AllocatorOptions &options) {
 947   instance.ReInitialize(options);
 948 }
 949
 950 void GetAllocatorOptions(AllocatorOptions *options) {
 951   instance.GetOptions(options);
 952 }
 953
 954 AsanChunkView FindHeapChunkByAddress(uptr addr) {
 955   return instance.FindHeapChunkByAddress(addr);
 956 }
 957 AsanChunkView FindHeapChunkByAllocBeg(uptr addr) {
 958   return AsanChunkView(instance.GetAsanChunk(reinterpret_cast<void*>(addr)));
 959 }
 960
 961 void AsanThreadLocalMallocStorage::CommitBack() {
 962   GET_STACK_TRACE_MALLOC;
 963   instance.CommitBack(this, &stack);
 964 }
 965
 966 void PrintInternalAllocatorStats() {
 967   instance.PrintStats();
 968 }
 969
 970 void asan_free(void *ptr, BufferedStackTrace *stack, AllocType alloc_type) {
 971   instance.Deallocate(ptr, 0, 0, stack, alloc_type);
 972 }
 973
 974 void asan_delete(void *ptr, uptr size, uptr alignment,
 975                  BufferedStackTrace *stack, AllocType alloc_type) {
 976   instance.Deallocate(ptr, size, alignment, stack, alloc_type);
 977 }
 978
 979 void *asan_malloc(uptr size, BufferedStackTrace *stack) {
 980   return SetErrnoOnNull(instance.Allocate(size, 8, stack, FROM_MALLOC, true));
 981 }
 982
 983 void *asan_calloc(uptr nmemb, uptr size, BufferedStackTrace *stack) {
 984   return SetErrnoOnNull(instance.Calloc(nmemb, size, stack));
 985 }
 986
 987 void *asan_reallocarray(void *p, uptr nmemb, uptr size,
 988                         BufferedStackTrace *stack) {
 989   if (UNLIKELY(CheckForCallocOverflow(size, nmemb))) {
 990     errno = errno_ENOMEM;
 991     if (AllocatorMayReturnNull())
 992       return nullptr;
 993     ReportReallocArrayOverflow(nmemb, size, stack);
 994   }
 995   return asan_realloc(p, nmemb * size, stack);
 996 }
 997
 998 void *asan_realloc(void *p, uptr size, BufferedStackTrace *stack) {
 999   if (!p)
1000     return SetErrnoOnNull(instance.Allocate(size, 8, stack, FROM_MALLOC, true));
1001   if (size == 0) {
1002     if (flags()->allocator_frees_and_returns_null_on_realloc_zero) {
1003       instance.Deallocate(p, 0, 0, stack, FROM_MALLOC);
1004       return nullptr;
1005     }
1006     // Allocate a size of 1 if we shouldn't free() on Realloc to 0
1007     size = 1;
1008   }
1009   return SetErrnoOnNull(instance.Reallocate(p, size, stack));
1010 }
1011
1012 void *asan_valloc(uptr size, BufferedStackTrace *stack) {
1013   return SetErrnoOnNull(
1014       instance.Allocate(size, GetPageSizeCached(), stack, FROM_MALLOC, true));
1015 }
1016
1017 void *asan_pvalloc(uptr size, BufferedStackTrace *stack) {
1018   uptr PageSize = GetPageSizeCached();
1019   if (UNLIKELY(CheckForPvallocOverflow(size, PageSize))) {
1020     errno = errno_ENOMEM;
1021     if (AllocatorMayReturnNull())
1022       return nullptr;
1023     ReportPvallocOverflow(size, stack);
1024   }
1025   // pvalloc(0) should allocate one page.
1026   size = size ? RoundUpTo(size, PageSize) : PageSize;
1027   return SetErrnoOnNull(
1028       instance.Allocate(size, PageSize, stack, FROM_MALLOC, true));
1029 }
1030
1031 void *asan_memalign(uptr alignment, uptr size, BufferedStackTrace *stack,
1032                     AllocType alloc_type) {
1033   if (UNLIKELY(!IsPowerOfTwo(alignment))) {
1034     errno = errno_EINVAL;
1035     if (AllocatorMayReturnNull())
1036       return nullptr;
1037     ReportInvalidAllocationAlignment(alignment, stack);
1038   }
1039   return SetErrnoOnNull(
1040       instance.Allocate(size, alignment, stack, alloc_type, true));
1041 }
1042
1043 void *asan_aligned_alloc(uptr alignment, uptr size, BufferedStackTrace *stack) {
1044   if (UNLIKELY(!CheckAlignedAllocAlignmentAndSize(alignment, size))) {
1045     errno = errno_EINVAL;
1046     if (AllocatorMayReturnNull())
1047       return nullptr;
1048     ReportInvalidAlignedAllocAlignment(size, alignment, stack);
1049   }
1050   return SetErrnoOnNull(
1051       instance.Allocate(size, alignment, stack, FROM_MALLOC, true));
1052 }
1053
1054 int asan_posix_memalign(void **memptr, uptr alignment, uptr size,
1055                         BufferedStackTrace *stack) {
1056   if (UNLIKELY(!CheckPosixMemalignAlignment(alignment))) {
1057     if (AllocatorMayReturnNull())
1058       return errno_EINVAL;
1059     ReportInvalidPosixMemalignAlignment(alignment, stack);
1060   }
1061   void *ptr = instance.Allocate(size, alignment, stack, FROM_MALLOC, true);
1062   if (UNLIKELY(!ptr))
1063     // OOM error is already taken care of by Allocate.
1064     return errno_ENOMEM;
1065   CHECK(IsAligned((uptr)ptr, alignment));
1066   *memptr = ptr;
1067   return 0;
1068 }
1069
1070 uptr asan_malloc_usable_size(const void *ptr, uptr pc, uptr bp) {
1071   if (!ptr) return 0;
1072   uptr usable_size = instance.AllocationSize(reinterpret_cast<uptr>(ptr));
1073   if (flags()->check_malloc_usable_size && (usable_size == 0)) {
1074     GET_STACK_TRACE_FATAL(pc, bp);
1075     ReportMallocUsableSizeNotOwned((uptr)ptr, &stack);
1076   }
1077   return usable_size;
1078 }
1079
1080 uptr asan_mz_size(const void *ptr) {
1081   return instance.AllocationSize(reinterpret_cast<uptr>(ptr));
1082 }
1083
1084 void asan_mz_force_lock() {
1085   instance.ForceLock();
1086 }
1087
1088 void asan_mz_force_unlock() {
1089   instance.ForceUnlock();
1090 }
1091
1092 void AsanSoftRssLimitExceededCallback(bool limit_exceeded) {
1093   instance.SetRssLimitExceeded(limit_exceeded);
1094 }
1095
1096 }  // namespace __asan
1097
1098 // --- Implementation of LSan-specific functions --- {{{1
1099 namespace __lsan {
1100 void LockAllocator() {
1101   __asan::get_allocator().ForceLock();
1102 }
1103
1104 void UnlockAllocator() {
1105   __asan::get_allocator().ForceUnlock();
1106 }
1107
1108 void GetAllocatorGlobalRange(uptr *begin, uptr *end) {
1109   *begin = (uptr)&__asan::get_allocator();
1110   *end = *begin + sizeof(__asan::get_allocator());
1111 }
1112
1113 uptr PointsIntoChunk(void *p) {
1114   uptr addr = reinterpret_cast<uptr>(p);
1115   __asan::AsanChunk *m = __asan::instance.GetAsanChunkByAddrFastLocked(addr);
1116   if (!m || atomic_load(&m->chunk_state, memory_order_acquire) !=
1117                 __asan::CHUNK_ALLOCATED)
1118     return 0;
1119   uptr chunk = m->Beg();
1120   if (m->AddrIsInside(addr))
1121     return chunk;
1122   if (IsSpecialCaseOfOperatorNew0(chunk, m->UsedSize(), addr))
1123     return chunk;
1124   return 0;
1125 }
1126
1127 uptr GetUserBegin(uptr chunk) {
1128   __asan::AsanChunk *m = __asan::instance.GetAsanChunkByAddrFastLocked(chunk);
1129   return m ? m->Beg() : 0;
1130 }
1131
1132 LsanMetadata::LsanMetadata(uptr chunk) {
1133   metadata_ = chunk ? reinterpret_cast<void *>(chunk - __asan::kChunkHeaderSize)
1134                     : nullptr;
1135 }
1136
1137 bool LsanMetadata::allocated() const {
1138   if (!metadata_)
1139     return false;
1140   __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
1141   return atomic_load(&m->chunk_state, memory_order_relaxed) ==
1142          __asan::CHUNK_ALLOCATED;
1143 }
1144
1145 ChunkTag LsanMetadata::tag() const {
1146   __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
1147   return static_cast<ChunkTag>(m->lsan_tag);
1148 }
1149
1150 void LsanMetadata::set_tag(ChunkTag value) {
1151   __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
1152   m->lsan_tag = value;
1153 }
1154
1155 uptr LsanMetadata::requested_size() const {
1156   __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
1157   return m->UsedSize();
1158 }
1159
1160 u32 LsanMetadata::stack_trace_id() const {
1161   __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
1162   u32 tid = 0;
1163   u32 stack = 0;
1164   m->GetAllocContext(tid, stack);
1165   return stack;
1166 }
1167
1168 void ForEachChunk(ForEachChunkCallback callback, void *arg) {
1169   __asan::get_allocator().ForEachChunk(callback, arg);
1170 }
1171
1172 IgnoreObjectResult IgnoreObjectLocked(const void *p) {
1173   uptr addr = reinterpret_cast<uptr>(p);
1174   __asan::AsanChunk *m = __asan::instance.GetAsanChunkByAddr(addr);
1175   if (!m ||
1176       (atomic_load(&m->chunk_state, memory_order_acquire) !=
1177        __asan::CHUNK_ALLOCATED) ||
1178       !m->AddrIsInside(addr)) {
1179     return kIgnoreObjectInvalid;
1180   }
1181   if (m->lsan_tag == kIgnored)
1182     return kIgnoreObjectAlreadyIgnored;
1183   m->lsan_tag = __lsan::kIgnored;
1184   return kIgnoreObjectSuccess;
1185 }
1186
1187 void GetAdditionalThreadContextPtrs(ThreadContextBase *tctx, void *ptrs) {
1188   // Look for the arg pointer of threads that have been created or are running.
1189   // This is necessary to prevent false positive leaks due to the AsanThread
1190   // holding the only live reference to a heap object.  This can happen because
1191   // the `pthread_create()` interceptor doesn't wait for the child thread to
1192   // start before returning and thus loosing the the only live reference to the
1193   // heap object on the stack.
1194
1195   __asan::AsanThreadContext *atctx =
1196       reinterpret_cast<__asan::AsanThreadContext *>(tctx);
1197   __asan::AsanThread *asan_thread = atctx->thread;
1198
1199   // Note ThreadStatusRunning is required because there is a small window where
1200   // the thread status switches to `ThreadStatusRunning` but the `arg` pointer
1201   // still isn't on the stack yet.
1202   if (atctx->status != ThreadStatusCreated &&
1203       atctx->status != ThreadStatusRunning)
1204     return;
1205
1206   uptr thread_arg = reinterpret_cast<uptr>(asan_thread->get_arg());
1207   if (!thread_arg)
1208     return;
1209
1210   auto ptrsVec = reinterpret_cast<InternalMmapVector<uptr> *>(ptrs);
1211   ptrsVec->push_back(thread_arg);
1212 }
1213
1214 }  // namespace __lsan
1215
1216 // ---------------------- Interface ---------------- {{{1
1217 using namespace __asan;
1218
1219 // ASan allocator doesn't reserve extra bytes, so normally we would
1220 // just return "size". We don't want to expose our redzone sizes, etc here.
1221 uptr __sanitizer_get_estimated_allocated_size(uptr size) {
1222   return size;
1223 }
1224
1225 int __sanitizer_get_ownership(const void *p) {
1226   uptr ptr = reinterpret_cast<uptr>(p);
1227   return instance.AllocationSize(ptr) > 0;
1228 }
1229
1230 uptr __sanitizer_get_allocated_size(const void *p) {
1231   if (!p) return 0;
1232   uptr ptr = reinterpret_cast<uptr>(p);
1233   uptr allocated_size = instance.AllocationSize(ptr);
1234   // Die if p is not malloced or if it is already freed.
1235   if (allocated_size == 0) {
1236     GET_STACK_TRACE_FATAL_HERE;
1237     ReportSanitizerGetAllocatedSizeNotOwned(ptr, &stack);
1238   }
1239   return allocated_size;
1240 }
1241
1242 void __sanitizer_purge_allocator() {
1243   GET_STACK_TRACE_MALLOC;
1244   instance.Purge(&stack);
1245 }
1246
1247 int __asan_update_allocation_context(void* addr) {
1248   GET_STACK_TRACE_MALLOC;
1249   return instance.UpdateAllocationStack((uptr)addr, &stack);
1250 }
1251
1252 #if !SANITIZER_SUPPORTS_WEAK_HOOKS
1253 // Provide default (no-op) implementation of malloc hooks.
1254 SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_malloc_hook,
1255                              void *ptr, uptr size) {
1256   (void)ptr;
1257   (void)size;
1258 }
1259
1260 SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_free_hook, void *ptr) {
1261   (void)ptr;
1262 }
1263 #endif