libsanitizer/asan/asan_allocator.cc

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