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