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_internal.h"
  20 #include "asan_mapping.h"
  21 #include "asan_poisoning.h"
  22 #include "asan_report.h"
  23 #include "asan_stack.h"
  24 #include "asan_thread.h"
  25 #include "lsan/lsan_common.h"
  26 #include "sanitizer_common/sanitizer_allocator_checks.h"
  27 #include "sanitizer_common/sanitizer_allocator_interface.h"
  28 #include "sanitizer_common/sanitizer_common.h"
  29 #include "sanitizer_common/sanitizer_errno.h"
  30 #include "sanitizer_common/sanitizer_flags.h"
  31 #include "sanitizer_common/sanitizer_internal_defs.h"
  32 #include "sanitizer_common/sanitizer_list.h"
  33 #include "sanitizer_common/sanitizer_quarantine.h"
  34 #include "sanitizer_common/sanitizer_stackdepot.h"
  35
  36 namespace __asan {
  37
  38 // Valid redzone sizes are 16, 32, 64, ... 2048, so we encode them in 3 bits.
  39 // We use adaptive redzones: for larger allocation larger redzones are used.
  40 static u32 RZLog2Size(u32 rz_log) {
  41   CHECK_LT(rz_log, 8);
  42   return 16 << rz_log;
  43 }
  44
  45 static u32 RZSize2Log(u32 rz_size) {
  46   CHECK_GE(rz_size, 16);
  47   CHECK_LE(rz_size, 2048);
  48   CHECK(IsPowerOfTwo(rz_size));
  49   u32 res = Log2(rz_size) - 4;
  50   CHECK_EQ(rz_size, RZLog2Size(res));
  51   return res;
  52 }
  53
  54 static AsanAllocator &get_allocator();
  55
  56 static void AtomicContextStore(volatile atomic_uint64_t *atomic_context,
  57                                u32 tid, u32 stack) {
  58   u64 context = tid;
  59   context <<= 32;
  60   context += stack;
  61   atomic_store(atomic_context, context, memory_order_relaxed);
  62 }
  63
  64 static void AtomicContextLoad(const volatile atomic_uint64_t *atomic_context,
  65                               u32 &tid, u32 &stack) {
  66   u64 context = atomic_load(atomic_context, memory_order_relaxed);
  67   stack = context;
  68   context >>= 32;
  69   tid = context;
  70 }
  71
  72 // The memory chunk allocated from the underlying allocator looks like this:
  73 // L L L L L L H H U U U U U U R R
  74 //   L -- left redzone words (0 or more bytes)
  75 //   H -- ChunkHeader (16 bytes), which is also a part of the left redzone.
  76 //   U -- user memory.
  77 //   R -- right redzone (0 or more bytes)
  78 // ChunkBase consists of ChunkHeader and other bytes that overlap with user
  79 // memory.
  80
  81 // If the left redzone is greater than the ChunkHeader size we store a magic
  82 // value in the first uptr word of the memory block and store the address of
  83 // ChunkBase in the next uptr.
  84 // M B L L L L L L L L L  H H U U U U U U
  85 //   |                    ^
  86 //   ---------------------|
  87 //   M -- magic value kAllocBegMagic
  88 //   B -- address of ChunkHeader pointing to the first 'H'
  89
  90 class ChunkHeader {
  91  public:
  92   atomic_uint8_t chunk_state;
  93   u8 alloc_type : 2;
  94   u8 lsan_tag : 2;
  95
  96   // align < 8 -> 0
  97   // else      -> log2(min(align, 512)) - 2
  98   u8 user_requested_alignment_log : 3;
  99
 100  private:
 101   u16 user_requested_size_hi;
 102   u32 user_requested_size_lo;
 103   atomic_uint64_t alloc_context_id;
 104
 105  public:
 106   uptr UsedSize() const {
 107     static_assert(sizeof(user_requested_size_lo) == 4,
 108                   "Expression below requires this");
 109     return FIRST_32_SECOND_64(0, ((uptr)user_requested_size_hi << 32)) +
 110            user_requested_size_lo;
 111   }
 112
 113   void SetUsedSize(uptr size) {
 114     user_requested_size_lo = size;
 115     static_assert(sizeof(user_requested_size_lo) == 4,
 116                   "Expression below requires this");
 117     user_requested_size_hi = FIRST_32_SECOND_64(0, size >> 32);
 118     CHECK_EQ(UsedSize(), size);
 119   }
 120
 121   void SetAllocContext(u32 tid, u32 stack) {
 122     AtomicContextStore(&alloc_context_id, tid, stack);
 123   }
 124
 125   void GetAllocContext(u32 &tid, u32 &stack) const {
 126     AtomicContextLoad(&alloc_context_id, tid, stack);
 127   }
 128 };
 129
 130 class ChunkBase : public ChunkHeader {
 131   atomic_uint64_t free_context_id;
 132
 133  public:
 134   void SetFreeContext(u32 tid, u32 stack) {
 135     AtomicContextStore(&free_context_id, tid, stack);
 136   }
 137
 138   void GetFreeContext(u32 &tid, u32 &stack) const {
 139     AtomicContextLoad(&free_context_id, tid, stack);
 140   }
 141 };
 142
 143 static const uptr kChunkHeaderSize = sizeof(ChunkHeader);
 144 static const uptr kChunkHeader2Size = sizeof(ChunkBase) - kChunkHeaderSize;
 145 COMPILER_CHECK(kChunkHeaderSize == 16);
 146 COMPILER_CHECK(kChunkHeader2Size <= 16);
 147
 148 enum {
 149   // Either just allocated by underlying allocator, but AsanChunk is not yet
 150   // ready, or almost returned to undelying allocator and AsanChunk is already
 151   // meaningless.
 152   CHUNK_INVALID = 0,
 153   // The chunk is allocated and not yet freed.
 154   CHUNK_ALLOCATED = 2,
 155   // The chunk was freed and put into quarantine zone.
 156   CHUNK_QUARANTINE = 3,
 157 };
 158
 159 class AsanChunk : public ChunkBase {
 160  public:
 161   uptr Beg() { return reinterpret_cast<uptr>(this) + kChunkHeaderSize; }
 162   bool AddrIsInside(uptr addr) {
 163     return (addr >= Beg()) && (addr < Beg() + UsedSize());
 164   }
 165 };
 166
 167 class LargeChunkHeader {
 168   static constexpr uptr kAllocBegMagic =
 169       FIRST_32_SECOND_64(0xCC6E96B9, 0xCC6E96B9CC6E96B9ULL);
 170   atomic_uintptr_t magic;
 171   AsanChunk *chunk_header;
 172
 173  public:
 174   AsanChunk *Get() const {
 175     return atomic_load(&magic, memory_order_acquire) == kAllocBegMagic
 176                ? chunk_header
 177                : nullptr;
 178   }
 179
 180   void Set(AsanChunk *p) {
 181     if (p) {
 182       chunk_header = p;
 183       atomic_store(&magic, kAllocBegMagic, memory_order_release);
 184       return;
 185     }
 186
 187     uptr old = kAllocBegMagic;
 188     if (!atomic_compare_exchange_strong(&magic, &old, 0,
 189                                         memory_order_release)) {
 190       CHECK_EQ(old, kAllocBegMagic);
 191     }
 192   }
 193 };
 194
 195 static void FillChunk(AsanChunk *m) {
 196   // FIXME: Use ReleaseMemoryPagesToOS.
 197   Flags &fl = *flags();
 198
 199   if (fl.max_free_fill_size > 0) {
 200     // We have to skip the chunk header, it contains free_context_id.
 201     uptr scribble_start = (uptr)m + kChunkHeaderSize + kChunkHeader2Size;
 202     if (m->UsedSize() >= kChunkHeader2Size) {  // Skip Header2 in user area.
 203       uptr size_to_fill = m->UsedSize() - kChunkHeader2Size;
 204       size_to_fill = Min(size_to_fill, (uptr)fl.max_free_fill_size);
 205       REAL(memset)((void *)scribble_start, fl.free_fill_byte, size_to_fill);
 206     }
 207   }
 208 }
 209
 210 struct QuarantineCallback {
 211   QuarantineCallback(AllocatorCache *cache, BufferedStackTrace *stack)
 212       : cache_(cache),
 213         stack_(stack) {
 214   }
 215
 216   void PreQuarantine(AsanChunk *m) const {
 217     FillChunk(m);
 218     // Poison the region.
 219     PoisonShadow(m->Beg(), RoundUpTo(m->UsedSize(), ASAN_SHADOW_GRANULARITY),
 220                  kAsanHeapFreeMagic);
 221   }
 222
 223   void Recycle(AsanChunk *m) const {
 224     void *p = get_allocator().GetBlockBegin(m);
 225
 226     // The secondary will immediately unpoison and unmap the memory, so this
 227     // branch is unnecessary.
 228     if (get_allocator().FromPrimary(p)) {
 229       if (p != m) {
 230         // Clear the magic value, as allocator internals may overwrite the
 231         // contents of deallocated chunk, confusing GetAsanChunk lookup.
 232         reinterpret_cast<LargeChunkHeader *>(p)->Set(nullptr);
 233       }
 234
 235       u8 old_chunk_state = CHUNK_QUARANTINE;
 236       if (!atomic_compare_exchange_strong(&m->chunk_state, &old_chunk_state,
 237                                           CHUNK_INVALID,
 238                                           memory_order_acquire)) {
 239         CHECK_EQ(old_chunk_state, CHUNK_QUARANTINE);
 240       }
 241
 242       PoisonShadow(m->Beg(), RoundUpTo(m->UsedSize(), ASAN_SHADOW_GRANULARITY),
 243                    kAsanHeapLeftRedzoneMagic);
 244     }
 245
 246     // Statistics.
 247     AsanStats &thread_stats = GetCurrentThreadStats();
 248     thread_stats.real_frees++;
 249     thread_stats.really_freed += m->UsedSize();
 250
 251     get_allocator().Deallocate(cache_, p);
 252   }
 253
 254   void RecyclePassThrough(AsanChunk *m) const {
 255     // Recycle for the secondary will immediately unpoison and unmap the
 256     // memory, so quarantine preparation is unnecessary.
 257     if (get_allocator().FromPrimary(m)) {
 258       // The primary allocation may need pattern fill if enabled.
 259       FillChunk(m);
 260     }
 261     Recycle(m);
 262   }
 263
 264   void *Allocate(uptr size) const {
 265     void *res = get_allocator().Allocate(cache_, size, 1);
 266     // TODO(alekseys): Consider making quarantine OOM-friendly.
 267     if (UNLIKELY(!res))
 268       ReportOutOfMemory(size, stack_);
 269     return res;
 270   }
 271
 272   void Deallocate(void *p) const { get_allocator().Deallocate(cache_, p); }
 273
 274  private:
 275   AllocatorCache* const cache_;
 276   BufferedStackTrace* const stack_;
 277 };
 278
 279 typedef Quarantine<QuarantineCallback, AsanChunk> AsanQuarantine;
 280 typedef AsanQuarantine::Cache QuarantineCache;
 281
 282 void AsanMapUnmapCallback::OnMap(uptr p, uptr size) const {
 283   PoisonShadow(p, size, kAsanHeapLeftRedzoneMagic);
 284   // Statistics.
 285   AsanStats &thread_stats = GetCurrentThreadStats();
 286   thread_stats.mmaps++;
 287   thread_stats.mmaped += size;
 288 }
 289
 290 void AsanMapUnmapCallback::OnMapSecondary(uptr p, uptr size, uptr user_begin,
 291                                           uptr user_size) const {
 292   uptr user_end = RoundDownTo(user_begin + user_size, ASAN_SHADOW_GRANULARITY);
 293   user_begin = RoundUpTo(user_begin, ASAN_SHADOW_GRANULARITY);
 294   // The secondary mapping will be immediately returned to user, no value
 295   // poisoning that with non-zero just before unpoisoning by Allocate(). So just
 296   // poison head/tail invisible to Allocate().
 297   PoisonShadow(p, user_begin - p, kAsanHeapLeftRedzoneMagic);
 298   PoisonShadow(user_end, size - (user_end - p), kAsanHeapLeftRedzoneMagic);
 299   // Statistics.
 300   AsanStats &thread_stats = GetCurrentThreadStats();
 301   thread_stats.mmaps++;
 302   thread_stats.mmaped += size;
 303 }
 304
 305 void AsanMapUnmapCallback::OnUnmap(uptr p, uptr size) const {
 306   PoisonShadow(p, size, 0);
 307   // We are about to unmap a chunk of user memory.
 308   // Mark the corresponding shadow memory as not needed.
 309   FlushUnneededASanShadowMemory(p, size);
 310   // Statistics.
 311   AsanStats &thread_stats = GetCurrentThreadStats();
 312   thread_stats.munmaps++;
 313   thread_stats.munmaped += size;
 314 }
 315
 316 // We can not use THREADLOCAL because it is not supported on some of the
 317 // platforms we care about (OSX 10.6, Android).
 318 // static THREADLOCAL AllocatorCache cache;
 319 AllocatorCache *GetAllocatorCache(AsanThreadLocalMallocStorage *ms) {
 320   CHECK(ms);
 321   return &ms->allocator_cache;
 322 }
 323
 324 QuarantineCache *GetQuarantineCache(AsanThreadLocalMallocStorage *ms) {
 325   CHECK(ms);
 326   CHECK_LE(sizeof(QuarantineCache), sizeof(ms->quarantine_cache));
 327   return reinterpret_cast<QuarantineCache *>(ms->quarantine_cache);
 328 }
 329
 330 void AllocatorOptions::SetFrom(const Flags *f, const CommonFlags *cf) {
 331   quarantine_size_mb = f->quarantine_size_mb;
 332   thread_local_quarantine_size_kb = f->thread_local_quarantine_size_kb;
 333   min_redzone = f->redzone;
 334   max_redzone = f->max_redzone;
 335   may_return_null = cf->allocator_may_return_null;
 336   alloc_dealloc_mismatch = f->alloc_dealloc_mismatch;
 337   release_to_os_interval_ms = cf->allocator_release_to_os_interval_ms;
 338 }
 339
 340 void AllocatorOptions::CopyTo(Flags *f, CommonFlags *cf) {
 341   f->quarantine_size_mb = quarantine_size_mb;
 342   f->thread_local_quarantine_size_kb = thread_local_quarantine_size_kb;
 343   f->redzone = min_redzone;
 344   f->max_redzone = max_redzone;
 345   cf->allocator_may_return_null = may_return_null;
 346   f->alloc_dealloc_mismatch = alloc_dealloc_mismatch;
 347   cf->allocator_release_to_os_interval_ms = release_to_os_interval_ms;
 348 }
 349
 350 struct Allocator {
 351   static const uptr kMaxAllowedMallocSize =
 352       FIRST_32_SECOND_64(3UL << 30, 1ULL << 40);
 353
 354   AsanAllocator allocator;
 355   AsanQuarantine quarantine;
 356   StaticSpinMutex fallback_mutex;
 357   AllocatorCache fallback_allocator_cache;
 358   QuarantineCache fallback_quarantine_cache;
 359
 360   uptr max_user_defined_malloc_size;
 361
 362   // ------------------- Options --------------------------
 363   atomic_uint16_t min_redzone;
 364   atomic_uint16_t max_redzone;
 365   atomic_uint8_t alloc_dealloc_mismatch;
 366
 367   // ------------------- Initialization ------------------------
 368   explicit Allocator(LinkerInitialized)
 369       : quarantine(LINKER_INITIALIZED),
 370         fallback_quarantine_cache(LINKER_INITIALIZED) {}
 371
 372   void CheckOptions(const AllocatorOptions &options) const {
 373     CHECK_GE(options.min_redzone, 16);
 374     CHECK_GE(options.max_redzone, options.min_redzone);
 375     CHECK_LE(options.max_redzone, 2048);
 376     CHECK(IsPowerOfTwo(options.min_redzone));
 377     CHECK(IsPowerOfTwo(options.max_redzone));
 378   }
 379
 380   void SharedInitCode(const AllocatorOptions &options) {
 381     CheckOptions(options);
 382     quarantine.Init((uptr)options.quarantine_size_mb << 20,
 383                     (uptr)options.thread_local_quarantine_size_kb << 10);
 384     atomic_store(&alloc_dealloc_mismatch, options.alloc_dealloc_mismatch,
 385                  memory_order_release);
 386     atomic_store(&min_redzone, options.min_redzone, memory_order_release);
 387     atomic_store(&max_redzone, options.max_redzone, memory_order_release);
 388   }
 389
 390   void InitLinkerInitialized(const AllocatorOptions &options) {
 391     SetAllocatorMayReturnNull(options.may_return_null);
 392     allocator.InitLinkerInitialized(options.release_to_os_interval_ms);
 393     SharedInitCode(options);
 394     max_user_defined_malloc_size = common_flags()->max_allocation_size_mb
 395                                        ? common_flags()->max_allocation_size_mb
 396                                              << 20
 397                                        : kMaxAllowedMallocSize;
 398   }
 399
 400   void RePoisonChunk(uptr chunk) {
 401     // This could be a user-facing chunk (with redzones), or some internal
 402     // housekeeping chunk, like TransferBatch. Start by assuming the former.
 403     AsanChunk *ac = GetAsanChunk((void *)chunk);
 404     uptr allocated_size = allocator.GetActuallyAllocatedSize((void *)chunk);
 405     if (ac && atomic_load(&ac->chunk_state, memory_order_acquire) ==
 406                   CHUNK_ALLOCATED) {
 407       uptr beg = ac->Beg();
 408       uptr end = ac->Beg() + ac->UsedSize();
 409       uptr chunk_end = chunk + allocated_size;
 410       if (chunk < beg && beg < end && end <= chunk_end) {
 411         // Looks like a valid AsanChunk in use, poison redzones only.
 412         PoisonShadow(chunk, beg - chunk, kAsanHeapLeftRedzoneMagic);
 413         uptr end_aligned_down = RoundDownTo(end, ASAN_SHADOW_GRANULARITY);
 414         FastPoisonShadowPartialRightRedzone(
 415             end_aligned_down, end - end_aligned_down,
 416             chunk_end - end_aligned_down, kAsanHeapLeftRedzoneMagic);
 417         return;
 418       }
 419     }
 420
 421     // This is either not an AsanChunk or freed or quarantined AsanChunk.
 422     // In either case, poison everything.
 423     PoisonShadow(chunk, allocated_size, kAsanHeapLeftRedzoneMagic);
 424   }
 425
 426   void ReInitialize(const AllocatorOptions &options) {
 427     SetAllocatorMayReturnNull(options.may_return_null);
 428     allocator.SetReleaseToOSIntervalMs(options.release_to_os_interval_ms);
 429     SharedInitCode(options);
 430
 431     // Poison all existing allocation's redzones.
 432     if (CanPoisonMemory()) {
 433       allocator.ForceLock();
 434       allocator.ForEachChunk(
 435           [](uptr chunk, void *alloc) {
 436             ((Allocator *)alloc)->RePoisonChunk(chunk);
 437           },
 438           this);
 439       allocator.ForceUnlock();
 440     }
 441   }
 442
 443   void GetOptions(AllocatorOptions *options) const {
 444     options->quarantine_size_mb = quarantine.GetMaxSize() >> 20;
 445     options->thread_local_quarantine_size_kb =
 446         quarantine.GetMaxCacheSize() >> 10;
 447     options->min_redzone = atomic_load(&min_redzone, memory_order_acquire);
 448     options->max_redzone = atomic_load(&max_redzone, memory_order_acquire);
 449     options->may_return_null = AllocatorMayReturnNull();
 450     options->alloc_dealloc_mismatch =
 451         atomic_load(&alloc_dealloc_mismatch, memory_order_acquire);
 452     options->release_to_os_interval_ms = allocator.ReleaseToOSIntervalMs();
 453   }
 454
 455   // -------------------- Helper methods. -------------------------
 456   uptr ComputeRZLog(uptr user_requested_size) {
 457     u32 rz_log = user_requested_size <= 64 - 16            ? 0
 458                  : user_requested_size <= 128 - 32         ? 1
 459                  : user_requested_size <= 512 - 64         ? 2
 460                  : user_requested_size <= 4096 - 128       ? 3
 461                  : user_requested_size <= (1 << 14) - 256  ? 4
 462                  : user_requested_size <= (1 << 15) - 512  ? 5
 463                  : user_requested_size <= (1 << 16) - 1024 ? 6
 464                                                            : 7;
 465     u32 hdr_log = RZSize2Log(RoundUpToPowerOfTwo(sizeof(ChunkHeader)));
 466     u32 min_log = RZSize2Log(atomic_load(&min_redzone, memory_order_acquire));
 467     u32 max_log = RZSize2Log(atomic_load(&max_redzone, memory_order_acquire));
 468     return Min(Max(rz_log, Max(min_log, hdr_log)), Max(max_log, hdr_log));
 469   }
 470
 471   static uptr ComputeUserRequestedAlignmentLog(uptr user_requested_alignment) {
 472     if (user_requested_alignment < 8)
 473       return 0;
 474     if (user_requested_alignment > 512)
 475       user_requested_alignment = 512;
 476     return Log2(user_requested_alignment) - 2;
 477   }
 478
 479   static uptr ComputeUserAlignment(uptr user_requested_alignment_log) {
 480     if (user_requested_alignment_log == 0)
 481       return 0;
 482     return 1LL << (user_requested_alignment_log + 2);
 483   }
 484
 485   // We have an address between two chunks, and we want to report just one.
 486   AsanChunk *ChooseChunk(uptr addr, AsanChunk *left_chunk,
 487                          AsanChunk *right_chunk) {
 488     if (!left_chunk)
 489       return right_chunk;
 490     if (!right_chunk)
 491       return left_chunk;
 492     // Prefer an allocated chunk over freed chunk and freed chunk
 493     // over available chunk.
 494     u8 left_state = atomic_load(&left_chunk->chunk_state, memory_order_relaxed);
 495     u8 right_state =
 496         atomic_load(&right_chunk->chunk_state, memory_order_relaxed);
 497     if (left_state != right_state) {
 498       if (left_state == CHUNK_ALLOCATED)
 499         return left_chunk;
 500       if (right_state == CHUNK_ALLOCATED)
 501         return right_chunk;
 502       if (left_state == CHUNK_QUARANTINE)
 503         return left_chunk;
 504       if (right_state == CHUNK_QUARANTINE)
 505         return right_chunk;
 506     }
 507     // Same chunk_state: choose based on offset.
 508     sptr l_offset = 0, r_offset = 0;
 509     CHECK(AsanChunkView(left_chunk).AddrIsAtRight(addr, 1, &l_offset));
 510     CHECK(AsanChunkView(right_chunk).AddrIsAtLeft(addr, 1, &r_offset));
 511     if (l_offset < r_offset)
 512       return left_chunk;
 513     return right_chunk;
 514   }
 515
 516   bool UpdateAllocationStack(uptr addr, BufferedStackTrace *stack) {
 517     AsanChunk *m = GetAsanChunkByAddr(addr);
 518     if (!m) return false;
 519     if (atomic_load(&m->chunk_state, memory_order_acquire) != CHUNK_ALLOCATED)
 520       return false;
 521     if (m->Beg() != addr) return false;
 522     AsanThread *t = GetCurrentThread();
 523     m->SetAllocContext(t ? t->tid() : kMainTid, StackDepotPut(*stack));
 524     return true;
 525   }
 526
 527   // -------------------- Allocation/Deallocation routines ---------------
 528   void *Allocate(uptr size, uptr alignment, BufferedStackTrace *stack,
 529                  AllocType alloc_type, bool can_fill) {
 530     if (UNLIKELY(!AsanInited()))
 531       AsanInitFromRtl();
 532     if (UNLIKELY(IsRssLimitExceeded())) {
 533       if (AllocatorMayReturnNull())
 534         return nullptr;
 535       ReportRssLimitExceeded(stack);
 536     }
 537     Flags &fl = *flags();
 538     CHECK(stack);
 539     const uptr min_alignment = ASAN_SHADOW_GRANULARITY;
 540     const uptr user_requested_alignment_log =
 541         ComputeUserRequestedAlignmentLog(alignment);
 542     if (alignment < min_alignment)
 543       alignment = min_alignment;
 544     if (size == 0) {
 545       // We'd be happy to avoid allocating memory for zero-size requests, but
 546       // some programs/tests depend on this behavior and assume that malloc
 547       // would not return NULL even for zero-size allocations. Moreover, it
 548       // looks like operator new should never return NULL, and results of
 549       // consecutive "new" calls must be different even if the allocated size
 550       // is zero.
 551       size = 1;
 552     }
 553     CHECK(IsPowerOfTwo(alignment));
 554     uptr rz_log = ComputeRZLog(size);
 555     uptr rz_size = RZLog2Size(rz_log);
 556     uptr rounded_size = RoundUpTo(Max(size, kChunkHeader2Size), alignment);
 557     uptr needed_size = rounded_size + rz_size;
 558     if (alignment > min_alignment)
 559       needed_size += alignment;
 560     bool from_primary = PrimaryAllocator::CanAllocate(needed_size, alignment);
 561     // If we are allocating from the secondary allocator, there will be no
 562     // automatic right redzone, so add the right redzone manually.
 563     if (!from_primary)
 564       needed_size += rz_size;
 565     CHECK(IsAligned(needed_size, min_alignment));
 566     if (size > kMaxAllowedMallocSize || needed_size > kMaxAllowedMallocSize ||
 567         size > max_user_defined_malloc_size) {
 568       if (AllocatorMayReturnNull()) {
 569         Report("WARNING: AddressSanitizer failed to allocate 0x%zx bytes\n",
 570                size);
 571         return nullptr;
 572       }
 573       uptr malloc_limit =
 574           Min(kMaxAllowedMallocSize, max_user_defined_malloc_size);
 575       ReportAllocationSizeTooBig(size, needed_size, malloc_limit, stack);
 576     }
 577
 578     AsanThread *t = GetCurrentThread();
 579     void *allocated;
 580     if (t) {
 581       AllocatorCache *cache = GetAllocatorCache(&t->malloc_storage());
 582       allocated = allocator.Allocate(cache, needed_size, 8);
 583     } else {
 584       SpinMutexLock l(&fallback_mutex);
 585       AllocatorCache *cache = &fallback_allocator_cache;
 586       allocated = allocator.Allocate(cache, needed_size, 8);
 587     }
 588     if (UNLIKELY(!allocated)) {
 589       SetAllocatorOutOfMemory();
 590       if (AllocatorMayReturnNull())
 591         return nullptr;
 592       ReportOutOfMemory(size, stack);
 593     }
 594
 595     uptr alloc_beg = reinterpret_cast<uptr>(allocated);
 596     uptr alloc_end = alloc_beg + needed_size;
 597     uptr user_beg = alloc_beg + rz_size;
 598     if (!IsAligned(user_beg, alignment))
 599       user_beg = RoundUpTo(user_beg, alignment);
 600     uptr user_end = user_beg + size;
 601     CHECK_LE(user_end, alloc_end);
 602     uptr chunk_beg = user_beg - kChunkHeaderSize;
 603     AsanChunk *m = reinterpret_cast<AsanChunk *>(chunk_beg);
 604     m->alloc_type = alloc_type;
 605     CHECK(size);
 606     m->SetUsedSize(size);
 607     m->user_requested_alignment_log = user_requested_alignment_log;
 608
 609     m->SetAllocContext(t ? t->tid() : kMainTid, StackDepotPut(*stack));
 610
 611     if (!from_primary || *(u8 *)MEM_TO_SHADOW((uptr)allocated) == 0) {
 612       // The allocator provides an unpoisoned chunk. This is possible for the
 613       // secondary allocator, or if CanPoisonMemory() was false for some time,
 614       // for example, due to flags()->start_disabled. Anyway, poison left and
 615       // right of the block before using it for anything else.
 616       uptr tail_beg = RoundUpTo(user_end, ASAN_SHADOW_GRANULARITY);
 617       uptr tail_end = alloc_beg + allocator.GetActuallyAllocatedSize(allocated);
 618       PoisonShadow(alloc_beg, user_beg - alloc_beg, kAsanHeapLeftRedzoneMagic);
 619       PoisonShadow(tail_beg, tail_end - tail_beg, kAsanHeapLeftRedzoneMagic);
 620     }
 621
 622     uptr size_rounded_down_to_granularity =
 623         RoundDownTo(size, ASAN_SHADOW_GRANULARITY);
 624     // Unpoison the bulk of the memory region.
 625     if (size_rounded_down_to_granularity)
 626       PoisonShadow(user_beg, size_rounded_down_to_granularity, 0);
 627     // Deal with the end of the region if size is not aligned to granularity.
 628     if (size != size_rounded_down_to_granularity && CanPoisonMemory()) {
 629       u8 *shadow =
 630           (u8 *)MemToShadow(user_beg + size_rounded_down_to_granularity);
 631       *shadow = fl.poison_partial ? (size & (ASAN_SHADOW_GRANULARITY - 1)) : 0;
 632     }
 633
 634     AsanStats &thread_stats = GetCurrentThreadStats();
 635     thread_stats.mallocs++;
 636     thread_stats.malloced += size;
 637     thread_stats.malloced_redzones += needed_size - size;
 638     if (needed_size > SizeClassMap::kMaxSize)
 639       thread_stats.malloc_large++;
 640     else
 641       thread_stats.malloced_by_size[SizeClassMap::ClassID(needed_size)]++;
 642
 643     void *res = reinterpret_cast<void *>(user_beg);
 644     if (can_fill && fl.max_malloc_fill_size) {
 645       uptr fill_size = Min(size, (uptr)fl.max_malloc_fill_size);
 646       REAL(memset)(res, fl.malloc_fill_byte, fill_size);
 647     }
 648 #if CAN_SANITIZE_LEAKS
 649     m->lsan_tag = __lsan::DisabledInThisThread() ? __lsan::kIgnored
 650                                                  : __lsan::kDirectlyLeaked;
 651 #endif
 652     // Must be the last mutation of metadata in this function.
 653     atomic_store(&m->chunk_state, CHUNK_ALLOCATED, memory_order_release);
 654     if (alloc_beg != chunk_beg) {
 655       CHECK_LE(alloc_beg + sizeof(LargeChunkHeader), chunk_beg);
 656       reinterpret_cast<LargeChunkHeader *>(alloc_beg)->Set(m);
 657     }
 658     RunMallocHooks(res, size);
 659     return res;
 660   }
 661
 662   // Set quarantine flag if chunk is allocated, issue ASan error report on
 663   // available and quarantined chunks. Return true on success, false otherwise.
 664   bool AtomicallySetQuarantineFlagIfAllocated(AsanChunk *m, void *ptr,
 665                                               BufferedStackTrace *stack) {
 666     u8 old_chunk_state = CHUNK_ALLOCATED;
 667     // Flip the chunk_state atomically to avoid race on double-free.
 668     if (!atomic_compare_exchange_strong(&m->chunk_state, &old_chunk_state,
 669                                         CHUNK_QUARANTINE,
 670                                         memory_order_acquire)) {
 671       ReportInvalidFree(ptr, old_chunk_state, stack);
 672       // It's not safe to push a chunk in quarantine on invalid free.
 673       return false;
 674     }
 675     CHECK_EQ(CHUNK_ALLOCATED, old_chunk_state);
 676     // It was a user data.
 677     m->SetFreeContext(kInvalidTid, 0);
 678     return true;
 679   }
 680
 681   // Expects the chunk to already be marked as quarantined by using
 682   // AtomicallySetQuarantineFlagIfAllocated.
 683   void QuarantineChunk(AsanChunk *m, void *ptr, BufferedStackTrace *stack) {
 684     CHECK_EQ(atomic_load(&m->chunk_state, memory_order_relaxed),
 685              CHUNK_QUARANTINE);
 686     AsanThread *t = GetCurrentThread();
 687     m->SetFreeContext(t ? t->tid() : 0, StackDepotPut(*stack));
 688
 689     // Push into quarantine.
 690     if (t) {
 691       AsanThreadLocalMallocStorage *ms = &t->malloc_storage();
 692       AllocatorCache *ac = GetAllocatorCache(ms);
 693       quarantine.Put(GetQuarantineCache(ms), QuarantineCallback(ac, stack), m,
 694                      m->UsedSize());
 695     } else {
 696       SpinMutexLock l(&fallback_mutex);
 697       AllocatorCache *ac = &fallback_allocator_cache;
 698       quarantine.Put(&fallback_quarantine_cache, QuarantineCallback(ac, stack),
 699                      m, m->UsedSize());
 700     }
 701   }
 702
 703   void Deallocate(void *ptr, uptr delete_size, uptr delete_alignment,
 704                   BufferedStackTrace *stack, AllocType alloc_type) {
 705     uptr p = reinterpret_cast<uptr>(ptr);
 706     if (p == 0) return;
 707
 708     uptr chunk_beg = p - kChunkHeaderSize;
 709     AsanChunk *m = reinterpret_cast<AsanChunk *>(chunk_beg);
 710
 711     // On Windows, uninstrumented DLLs may allocate memory before ASan hooks
 712     // malloc. Don't report an invalid free in this case.
 713     if (SANITIZER_WINDOWS &&
 714         !get_allocator().PointerIsMine(ptr)) {
 715       if (!IsSystemHeapAddress(p))
 716         ReportFreeNotMalloced(p, stack);
 717       return;
 718     }
 719
 720     if (RunFreeHooks(ptr)) {
 721       // Someone used __sanitizer_ignore_free_hook() and decided that they
 722       // didn't want the memory to __sanitizer_ignore_free_hook freed right now.
 723       // When they call free() on this pointer again at a later time, we should
 724       // ignore the alloc-type mismatch and allow them to deallocate the pointer
 725       // through free(), rather than the initial alloc type.
 726       m->alloc_type = FROM_MALLOC;
 727       return;
 728     }
 729
 730     // Must mark the chunk as quarantined before any changes to its metadata.
 731     // Do not quarantine given chunk if we failed to set CHUNK_QUARANTINE flag.
 732     if (!AtomicallySetQuarantineFlagIfAllocated(m, ptr, stack)) return;
 733
 734     if (m->alloc_type != alloc_type) {
 735       if (atomic_load(&alloc_dealloc_mismatch, memory_order_acquire)) {
 736         ReportAllocTypeMismatch((uptr)ptr, stack, (AllocType)m->alloc_type,
 737                                 (AllocType)alloc_type);
 738       }
 739     } else {
 740       if (flags()->new_delete_type_mismatch &&
 741           (alloc_type == FROM_NEW || alloc_type == FROM_NEW_BR) &&
 742           ((delete_size && delete_size != m->UsedSize()) ||
 743            ComputeUserRequestedAlignmentLog(delete_alignment) !=
 744                m->user_requested_alignment_log)) {
 745         ReportNewDeleteTypeMismatch(p, delete_size, delete_alignment, stack);
 746       }
 747     }
 748
 749     AsanStats &thread_stats = GetCurrentThreadStats();
 750     thread_stats.frees++;
 751     thread_stats.freed += m->UsedSize();
 752
 753     QuarantineChunk(m, ptr, stack);
 754   }
 755
 756   void *Reallocate(void *old_ptr, uptr new_size, BufferedStackTrace *stack) {
 757     CHECK(old_ptr && new_size);
 758     uptr p = reinterpret_cast<uptr>(old_ptr);
 759     uptr chunk_beg = p - kChunkHeaderSize;
 760     AsanChunk *m = reinterpret_cast<AsanChunk *>(chunk_beg);
 761
 762     AsanStats &thread_stats = GetCurrentThreadStats();
 763     thread_stats.reallocs++;
 764     thread_stats.realloced += new_size;
 765
 766     void *new_ptr = Allocate(new_size, 8, stack, FROM_MALLOC, true);
 767     if (new_ptr) {
 768       u8 chunk_state = atomic_load(&m->chunk_state, memory_order_acquire);
 769       if (chunk_state != CHUNK_ALLOCATED)
 770         ReportInvalidFree(old_ptr, chunk_state, stack);
 771       CHECK_NE(REAL(memcpy), nullptr);
 772       uptr memcpy_size = Min(new_size, m->UsedSize());
 773       // If realloc() races with free(), we may start copying freed memory.
 774       // However, we will report racy double-free later anyway.
 775       REAL(memcpy)(new_ptr, old_ptr, memcpy_size);
 776       Deallocate(old_ptr, 0, 0, stack, FROM_MALLOC);
 777     }
 778     return new_ptr;
 779   }
 780
 781   void *Calloc(uptr nmemb, uptr size, BufferedStackTrace *stack) {
 782     if (UNLIKELY(CheckForCallocOverflow(size, nmemb))) {
 783       if (AllocatorMayReturnNull())
 784         return nullptr;
 785       ReportCallocOverflow(nmemb, size, stack);
 786     }
 787     void *ptr = Allocate(nmemb * size, 8, stack, FROM_MALLOC, false);
 788     // If the memory comes from the secondary allocator no need to clear it
 789     // as it comes directly from mmap.
 790     if (ptr && allocator.FromPrimary(ptr))
 791       REAL(memset)(ptr, 0, nmemb * size);
 792     return ptr;
 793   }
 794
 795   void ReportInvalidFree(void *ptr, u8 chunk_state, BufferedStackTrace *stack) {
 796     if (chunk_state == CHUNK_QUARANTINE)
 797       ReportDoubleFree((uptr)ptr, stack);
 798     else
 799       ReportFreeNotMalloced((uptr)ptr, stack);
 800   }
 801
 802   void CommitBack(AsanThreadLocalMallocStorage *ms, BufferedStackTrace *stack) {
 803     AllocatorCache *ac = GetAllocatorCache(ms);
 804     quarantine.Drain(GetQuarantineCache(ms), QuarantineCallback(ac, stack));
 805     allocator.SwallowCache(ac);
 806   }
 807
 808   // -------------------------- Chunk lookup ----------------------
 809
 810   // Assumes alloc_beg == allocator.GetBlockBegin(alloc_beg).
 811   // Returns nullptr if AsanChunk is not yet initialized just after
 812   // get_allocator().Allocate(), or is being destroyed just before
 813   // get_allocator().Deallocate().
 814   AsanChunk *GetAsanChunk(void *alloc_beg) {
 815     if (!alloc_beg)
 816       return nullptr;
 817     AsanChunk *p = reinterpret_cast<LargeChunkHeader *>(alloc_beg)->Get();
 818     if (!p) {
 819       if (!allocator.FromPrimary(alloc_beg))
 820         return nullptr;
 821       p = reinterpret_cast<AsanChunk *>(alloc_beg);
 822     }
 823     u8 state = atomic_load(&p->chunk_state, memory_order_relaxed);
 824     // It does not guaranty that Chunk is initialized, but it's
 825     // definitely not for any other value.
 826     if (state == CHUNK_ALLOCATED || state == CHUNK_QUARANTINE)
 827       return p;
 828     return nullptr;
 829   }
 830
 831   AsanChunk *GetAsanChunkByAddr(uptr p) {
 832     void *alloc_beg = allocator.GetBlockBegin(reinterpret_cast<void *>(p));
 833     return GetAsanChunk(alloc_beg);
 834   }
 835
 836   // Allocator must be locked when this function is called.
 837   AsanChunk *GetAsanChunkByAddrFastLocked(uptr p) {
 838     void *alloc_beg =
 839         allocator.GetBlockBeginFastLocked(reinterpret_cast<void *>(p));
 840     return GetAsanChunk(alloc_beg);
 841   }
 842
 843   uptr AllocationSize(uptr p) {
 844     AsanChunk *m = GetAsanChunkByAddr(p);
 845     if (!m) return 0;
 846     if (atomic_load(&m->chunk_state, memory_order_acquire) != CHUNK_ALLOCATED)
 847       return 0;
 848     if (m->Beg() != p) return 0;
 849     return m->UsedSize();
 850   }
 851
 852   uptr AllocationSizeFast(uptr p) {
 853     return reinterpret_cast<AsanChunk *>(p - kChunkHeaderSize)->UsedSize();
 854   }
 855
 856   AsanChunkView FindHeapChunkByAddress(uptr addr) {
 857     AsanChunk *m1 = GetAsanChunkByAddr(addr);
 858     sptr offset = 0;
 859     if (!m1 || AsanChunkView(m1).AddrIsAtLeft(addr, 1, &offset)) {
 860       // The address is in the chunk's left redzone, so maybe it is actually
 861       // a right buffer overflow from the other chunk before.
 862       // Search a bit before to see if there is another chunk.
 863       AsanChunk *m2 = nullptr;
 864       for (uptr l = 1; l < GetPageSizeCached(); l++) {
 865         m2 = GetAsanChunkByAddr(addr - l);
 866         if (m2 == m1) continue;  // Still the same chunk.
 867         break;
 868       }
 869       if (m2 && AsanChunkView(m2).AddrIsAtRight(addr, 1, &offset))
 870         m1 = ChooseChunk(addr, m2, m1);
 871     }
 872     return AsanChunkView(m1);
 873   }
 874
 875   void Purge(BufferedStackTrace *stack) {
 876     AsanThread *t = GetCurrentThread();
 877     if (t) {
 878       AsanThreadLocalMallocStorage *ms = &t->malloc_storage();
 879       quarantine.DrainAndRecycle(GetQuarantineCache(ms),
 880                                  QuarantineCallback(GetAllocatorCache(ms),
 881                                                     stack));
 882     }
 883     {
 884       SpinMutexLock l(&fallback_mutex);
 885       quarantine.DrainAndRecycle(&fallback_quarantine_cache,
 886                                  QuarantineCallback(&fallback_allocator_cache,
 887                                                     stack));
 888     }
 889
 890     allocator.ForceReleaseToOS();
 891   }
 892
 893   void PrintStats() {
 894     allocator.PrintStats();
 895     quarantine.PrintStats();
 896   }
 897
 898   void ForceLock() SANITIZER_ACQUIRE(fallback_mutex) {
 899     allocator.ForceLock();
 900     fallback_mutex.Lock();
 901   }
 902
 903   void ForceUnlock() SANITIZER_RELEASE(fallback_mutex) {
 904     fallback_mutex.Unlock();
 905     allocator.ForceUnlock();
 906   }
 907 };
 908
 909 static Allocator instance(LINKER_INITIALIZED);
 910
 911 static AsanAllocator &get_allocator() {
 912   return instance.allocator;
 913 }
 914
 915 bool AsanChunkView::IsValid() const {
 916   return chunk_ && atomic_load(&chunk_->chunk_state, memory_order_relaxed) !=
 917                        CHUNK_INVALID;
 918 }
 919 bool AsanChunkView::IsAllocated() const {
 920   return chunk_ && atomic_load(&chunk_->chunk_state, memory_order_relaxed) ==
 921                        CHUNK_ALLOCATED;
 922 }
 923 bool AsanChunkView::IsQuarantined() const {
 924   return chunk_ && atomic_load(&chunk_->chunk_state, memory_order_relaxed) ==
 925                        CHUNK_QUARANTINE;
 926 }
 927 uptr AsanChunkView::Beg() const { return chunk_->Beg(); }
 928 uptr AsanChunkView::End() const { return Beg() + UsedSize(); }
 929 uptr AsanChunkView::UsedSize() const { return chunk_->UsedSize(); }
 930 u32 AsanChunkView::UserRequestedAlignment() const {
 931   return Allocator::ComputeUserAlignment(chunk_->user_requested_alignment_log);
 932 }
 933
 934 uptr AsanChunkView::AllocTid() const {
 935   u32 tid = 0;
 936   u32 stack = 0;
 937   chunk_->GetAllocContext(tid, stack);
 938   return tid;
 939 }
 940
 941 uptr AsanChunkView::FreeTid() const {
 942   if (!IsQuarantined())
 943     return kInvalidTid;
 944   u32 tid = 0;
 945   u32 stack = 0;
 946   chunk_->GetFreeContext(tid, stack);
 947   return tid;
 948 }
 949
 950 AllocType AsanChunkView::GetAllocType() const {
 951   return (AllocType)chunk_->alloc_type;
 952 }
 953
 954 u32 AsanChunkView::GetAllocStackId() const {
 955   u32 tid = 0;
 956   u32 stack = 0;
 957   chunk_->GetAllocContext(tid, stack);
 958   return stack;
 959 }
 960
 961 u32 AsanChunkView::GetFreeStackId() const {
 962   if (!IsQuarantined())
 963     return 0;
 964   u32 tid = 0;
 965   u32 stack = 0;
 966   chunk_->GetFreeContext(tid, stack);
 967   return stack;
 968 }
 969
 970 void InitializeAllocator(const AllocatorOptions &options) {
 971   instance.InitLinkerInitialized(options);
 972 }
 973
 974 void ReInitializeAllocator(const AllocatorOptions &options) {
 975   instance.ReInitialize(options);
 976 }
 977
 978 void GetAllocatorOptions(AllocatorOptions *options) {
 979   instance.GetOptions(options);
 980 }
 981
 982 AsanChunkView FindHeapChunkByAddress(uptr addr) {
 983   return instance.FindHeapChunkByAddress(addr);
 984 }
 985 AsanChunkView FindHeapChunkByAllocBeg(uptr addr) {
 986   return AsanChunkView(instance.GetAsanChunk(reinterpret_cast<void*>(addr)));
 987 }
 988
 989 void AsanThreadLocalMallocStorage::CommitBack() {
 990   GET_STACK_TRACE_MALLOC;
 991   instance.CommitBack(this, &stack);
 992 }
 993
 994 void PrintInternalAllocatorStats() {
 995   instance.PrintStats();
 996 }
 997
 998 void asan_free(void *ptr, BufferedStackTrace *stack, AllocType alloc_type) {
 999   instance.Deallocate(ptr, 0, 0, stack, alloc_type);
1000 }
1001
1002 void asan_delete(void *ptr, uptr size, uptr alignment,
1003                  BufferedStackTrace *stack, AllocType alloc_type) {
1004   instance.Deallocate(ptr, size, alignment, stack, alloc_type);
1005 }
1006
1007 void *asan_malloc(uptr size, BufferedStackTrace *stack) {
1008   return SetErrnoOnNull(instance.Allocate(size, 8, stack, FROM_MALLOC, true));
1009 }
1010
1011 void *asan_calloc(uptr nmemb, uptr size, BufferedStackTrace *stack) {
1012   return SetErrnoOnNull(instance.Calloc(nmemb, size, stack));
1013 }
1014
1015 void *asan_reallocarray(void *p, uptr nmemb, uptr size,
1016                         BufferedStackTrace *stack) {
1017   if (UNLIKELY(CheckForCallocOverflow(size, nmemb))) {
1018     errno = errno_ENOMEM;
1019     if (AllocatorMayReturnNull())
1020       return nullptr;
1021     ReportReallocArrayOverflow(nmemb, size, stack);
1022   }
1023   return asan_realloc(p, nmemb * size, stack);
1024 }
1025
1026 void *asan_realloc(void *p, uptr size, BufferedStackTrace *stack) {
1027   if (!p)
1028     return SetErrnoOnNull(instance.Allocate(size, 8, stack, FROM_MALLOC, true));
1029   if (size == 0) {
1030     if (flags()->allocator_frees_and_returns_null_on_realloc_zero) {
1031       instance.Deallocate(p, 0, 0, stack, FROM_MALLOC);
1032       return nullptr;
1033     }
1034     // Allocate a size of 1 if we shouldn't free() on Realloc to 0
1035     size = 1;
1036   }
1037   return SetErrnoOnNull(instance.Reallocate(p, size, stack));
1038 }
1039
1040 void *asan_valloc(uptr size, BufferedStackTrace *stack) {
1041   return SetErrnoOnNull(
1042       instance.Allocate(size, GetPageSizeCached(), stack, FROM_MALLOC, true));
1043 }
1044
1045 void *asan_pvalloc(uptr size, BufferedStackTrace *stack) {
1046   uptr PageSize = GetPageSizeCached();
1047   if (UNLIKELY(CheckForPvallocOverflow(size, PageSize))) {
1048     errno = errno_ENOMEM;
1049     if (AllocatorMayReturnNull())
1050       return nullptr;
1051     ReportPvallocOverflow(size, stack);
1052   }
1053   // pvalloc(0) should allocate one page.
1054   size = size ? RoundUpTo(size, PageSize) : PageSize;
1055   return SetErrnoOnNull(
1056       instance.Allocate(size, PageSize, stack, FROM_MALLOC, true));
1057 }
1058
1059 void *asan_memalign(uptr alignment, uptr size, BufferedStackTrace *stack,
1060                     AllocType alloc_type) {
1061   if (UNLIKELY(!IsPowerOfTwo(alignment))) {
1062     errno = errno_EINVAL;
1063     if (AllocatorMayReturnNull())
1064       return nullptr;
1065     ReportInvalidAllocationAlignment(alignment, stack);
1066   }
1067   return SetErrnoOnNull(
1068       instance.Allocate(size, alignment, stack, alloc_type, true));
1069 }
1070
1071 void *asan_aligned_alloc(uptr alignment, uptr size, BufferedStackTrace *stack) {
1072   if (UNLIKELY(!CheckAlignedAllocAlignmentAndSize(alignment, size))) {
1073     errno = errno_EINVAL;
1074     if (AllocatorMayReturnNull())
1075       return nullptr;
1076     ReportInvalidAlignedAllocAlignment(size, alignment, stack);
1077   }
1078   return SetErrnoOnNull(
1079       instance.Allocate(size, alignment, stack, FROM_MALLOC, true));
1080 }
1081
1082 int asan_posix_memalign(void **memptr, uptr alignment, uptr size,
1083                         BufferedStackTrace *stack) {
1084   if (UNLIKELY(!CheckPosixMemalignAlignment(alignment))) {
1085     if (AllocatorMayReturnNull())
1086       return errno_EINVAL;
1087     ReportInvalidPosixMemalignAlignment(alignment, stack);
1088   }
1089   void *ptr = instance.Allocate(size, alignment, stack, FROM_MALLOC, true);
1090   if (UNLIKELY(!ptr))
1091     // OOM error is already taken care of by Allocate.
1092     return errno_ENOMEM;
1093   CHECK(IsAligned((uptr)ptr, alignment));
1094   *memptr = ptr;
1095   return 0;
1096 }
1097
1098 uptr asan_malloc_usable_size(const void *ptr, uptr pc, uptr bp) {
1099   if (!ptr) return 0;
1100   uptr usable_size = instance.AllocationSize(reinterpret_cast<uptr>(ptr));
1101   if (flags()->check_malloc_usable_size && (usable_size == 0)) {
1102     GET_STACK_TRACE_FATAL(pc, bp);
1103     ReportMallocUsableSizeNotOwned((uptr)ptr, &stack);
1104   }
1105   return usable_size;
1106 }
1107
1108 uptr asan_mz_size(const void *ptr) {
1109   return instance.AllocationSize(reinterpret_cast<uptr>(ptr));
1110 }
1111
1112 void asan_mz_force_lock() SANITIZER_NO_THREAD_SAFETY_ANALYSIS {
1113   instance.ForceLock();
1114 }
1115
1116 void asan_mz_force_unlock() SANITIZER_NO_THREAD_SAFETY_ANALYSIS {
1117   instance.ForceUnlock();
1118 }
1119
1120 }  // namespace __asan
1121
1122 // --- Implementation of LSan-specific functions --- {{{1
1123 namespace __lsan {
1124 void LockAllocator() {
1125   __asan::get_allocator().ForceLock();
1126 }
1127
1128 void UnlockAllocator() {
1129   __asan::get_allocator().ForceUnlock();
1130 }
1131
1132 void GetAllocatorGlobalRange(uptr *begin, uptr *end) {
1133   *begin = (uptr)&__asan::get_allocator();
1134   *end = *begin + sizeof(__asan::get_allocator());
1135 }
1136
1137 uptr PointsIntoChunk(void *p) {
1138   uptr addr = reinterpret_cast<uptr>(p);
1139   __asan::AsanChunk *m = __asan::instance.GetAsanChunkByAddrFastLocked(addr);
1140   if (!m || atomic_load(&m->chunk_state, memory_order_acquire) !=
1141                 __asan::CHUNK_ALLOCATED)
1142     return 0;
1143   uptr chunk = m->Beg();
1144   if (m->AddrIsInside(addr))
1145     return chunk;
1146   if (IsSpecialCaseOfOperatorNew0(chunk, m->UsedSize(), addr))
1147     return chunk;
1148   return 0;
1149 }
1150
1151 uptr GetUserBegin(uptr chunk) {
1152   // FIXME: All usecases provide chunk address, GetAsanChunkByAddrFastLocked is
1153   // not needed.
1154   __asan::AsanChunk *m = __asan::instance.GetAsanChunkByAddrFastLocked(chunk);
1155   return m ? m->Beg() : 0;
1156 }
1157
1158 uptr GetUserAddr(uptr chunk) {
1159   return chunk;
1160 }
1161
1162 LsanMetadata::LsanMetadata(uptr chunk) {
1163   metadata_ = chunk ? reinterpret_cast<void *>(chunk - __asan::kChunkHeaderSize)
1164                     : nullptr;
1165 }
1166
1167 bool LsanMetadata::allocated() const {
1168   if (!metadata_)
1169     return false;
1170   __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
1171   return atomic_load(&m->chunk_state, memory_order_relaxed) ==
1172          __asan::CHUNK_ALLOCATED;
1173 }
1174
1175 ChunkTag LsanMetadata::tag() const {
1176   __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
1177   return static_cast<ChunkTag>(m->lsan_tag);
1178 }
1179
1180 void LsanMetadata::set_tag(ChunkTag value) {
1181   __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
1182   m->lsan_tag = value;
1183 }
1184
1185 uptr LsanMetadata::requested_size() const {
1186   __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
1187   return m->UsedSize();
1188 }
1189
1190 u32 LsanMetadata::stack_trace_id() const {
1191   __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
1192   u32 tid = 0;
1193   u32 stack = 0;
1194   m->GetAllocContext(tid, stack);
1195   return stack;
1196 }
1197
1198 void ForEachChunk(ForEachChunkCallback callback, void *arg) {
1199   __asan::get_allocator().ForEachChunk(callback, arg);
1200 }
1201
1202 IgnoreObjectResult IgnoreObject(const void *p) {
1203   uptr addr = reinterpret_cast<uptr>(p);
1204   __asan::AsanChunk *m = __asan::instance.GetAsanChunkByAddr(addr);
1205   if (!m ||
1206       (atomic_load(&m->chunk_state, memory_order_acquire) !=
1207        __asan::CHUNK_ALLOCATED) ||
1208       !m->AddrIsInside(addr)) {
1209     return kIgnoreObjectInvalid;
1210   }
1211   if (m->lsan_tag == kIgnored)
1212     return kIgnoreObjectAlreadyIgnored;
1213   m->lsan_tag = __lsan::kIgnored;
1214   return kIgnoreObjectSuccess;
1215 }
1216
1217 }  // namespace __lsan
1218
1219 // ---------------------- Interface ---------------- {{{1
1220 using namespace __asan;
1221
1222 static const void *AllocationBegin(const void *p) {
1223   AsanChunk *m = __asan::instance.GetAsanChunkByAddr((uptr)p);
1224   if (!m)
1225     return nullptr;
1226   if (atomic_load(&m->chunk_state, memory_order_acquire) != CHUNK_ALLOCATED)
1227     return nullptr;
1228   if (m->UsedSize() == 0)
1229     return nullptr;
1230   return (const void *)(m->Beg());
1231 }
1232
1233 // ASan allocator doesn't reserve extra bytes, so normally we would
1234 // just return "size". We don't want to expose our redzone sizes, etc here.
1235 uptr __sanitizer_get_estimated_allocated_size(uptr size) {
1236   return size;
1237 }
1238
1239 int __sanitizer_get_ownership(const void *p) {
1240   uptr ptr = reinterpret_cast<uptr>(p);
1241   return instance.AllocationSize(ptr) > 0;
1242 }
1243
1244 uptr __sanitizer_get_allocated_size(const void *p) {
1245   if (!p) return 0;
1246   uptr ptr = reinterpret_cast<uptr>(p);
1247   uptr allocated_size = instance.AllocationSize(ptr);
1248   // Die if p is not malloced or if it is already freed.
1249   if (allocated_size == 0) {
1250     GET_STACK_TRACE_FATAL_HERE;
1251     ReportSanitizerGetAllocatedSizeNotOwned(ptr, &stack);
1252   }
1253   return allocated_size;
1254 }
1255
1256 uptr __sanitizer_get_allocated_size_fast(const void *p) {
1257   DCHECK_EQ(p, __sanitizer_get_allocated_begin(p));
1258   uptr ret = instance.AllocationSizeFast(reinterpret_cast<uptr>(p));
1259   DCHECK_EQ(ret, __sanitizer_get_allocated_size(p));
1260   return ret;
1261 }
1262
1263 const void *__sanitizer_get_allocated_begin(const void *p) {
1264   return AllocationBegin(p);
1265 }
1266
1267 void __sanitizer_purge_allocator() {
1268   GET_STACK_TRACE_MALLOC;
1269   instance.Purge(&stack);
1270 }
1271
1272 int __asan_update_allocation_context(void* addr) {
1273   GET_STACK_TRACE_MALLOC;
1274   return instance.UpdateAllocationStack((uptr)addr, &stack);
1275 }