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, 1UL << 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 ReInitialize(const AllocatorOptions &options) {
 268     allocator.SetMayReturnNull(options.may_return_null);
 269     SharedInitCode(options);
 270   }
 271
 272   void GetOptions(AllocatorOptions *options) const {
 273     options->quarantine_size_mb = quarantine.GetSize() >> 20;
 274     options->min_redzone = atomic_load(&min_redzone, memory_order_acquire);
 275     options->max_redzone = atomic_load(&max_redzone, memory_order_acquire);
 276     options->may_return_null = allocator.MayReturnNull();
 277     options->alloc_dealloc_mismatch =
 278         atomic_load(&alloc_dealloc_mismatch, memory_order_acquire);
 279   }
 280
 281   // -------------------- Helper methods. -------------------------
 282   uptr ComputeRZLog(uptr user_requested_size) {
 283     u32 rz_log =
 284       user_requested_size <= 64        - 16   ? 0 :
 285       user_requested_size <= 128       - 32   ? 1 :
 286       user_requested_size <= 512       - 64   ? 2 :
 287       user_requested_size <= 4096      - 128  ? 3 :
 288       user_requested_size <= (1 << 14) - 256  ? 4 :
 289       user_requested_size <= (1 << 15) - 512  ? 5 :
 290       user_requested_size <= (1 << 16) - 1024 ? 6 : 7;
 291     u32 min_rz = atomic_load(&min_redzone, memory_order_acquire);
 292     u32 max_rz = atomic_load(&max_redzone, memory_order_acquire);
 293     return Min(Max(rz_log, RZSize2Log(min_rz)), RZSize2Log(max_rz));
 294   }
 295
 296   // We have an address between two chunks, and we want to report just one.
 297   AsanChunk *ChooseChunk(uptr addr, AsanChunk *left_chunk,
 298                          AsanChunk *right_chunk) {
 299     // Prefer an allocated chunk over freed chunk and freed chunk
 300     // over available chunk.
 301     if (left_chunk->chunk_state != right_chunk->chunk_state) {
 302       if (left_chunk->chunk_state == CHUNK_ALLOCATED)
 303         return left_chunk;
 304       if (right_chunk->chunk_state == CHUNK_ALLOCATED)
 305         return right_chunk;
 306       if (left_chunk->chunk_state == CHUNK_QUARANTINE)
 307         return left_chunk;
 308       if (right_chunk->chunk_state == CHUNK_QUARANTINE)
 309         return right_chunk;
 310     }
 311     // Same chunk_state: choose based on offset.
 312     sptr l_offset = 0, r_offset = 0;
 313     CHECK(AsanChunkView(left_chunk).AddrIsAtRight(addr, 1, &l_offset));
 314     CHECK(AsanChunkView(right_chunk).AddrIsAtLeft(addr, 1, &r_offset));
 315     if (l_offset < r_offset)
 316       return left_chunk;
 317     return right_chunk;
 318   }
 319
 320   // -------------------- Allocation/Deallocation routines ---------------
 321   void *Allocate(uptr size, uptr alignment, BufferedStackTrace *stack,
 322                  AllocType alloc_type, bool can_fill) {
 323     if (UNLIKELY(!asan_inited))
 324       AsanInitFromRtl();
 325     Flags &fl = *flags();
 326     CHECK(stack);
 327     const uptr min_alignment = SHADOW_GRANULARITY;
 328     if (alignment < min_alignment)
 329       alignment = min_alignment;
 330     if (size == 0) {
 331       // We'd be happy to avoid allocating memory for zero-size requests, but
 332       // some programs/tests depend on this behavior and assume that malloc
 333       // would not return NULL even for zero-size allocations. Moreover, it
 334       // looks like operator new should never return NULL, and results of
 335       // consecutive "new" calls must be different even if the allocated size
 336       // is zero.
 337       size = 1;
 338     }
 339     CHECK(IsPowerOfTwo(alignment));
 340     uptr rz_log = ComputeRZLog(size);
 341     uptr rz_size = RZLog2Size(rz_log);
 342     uptr rounded_size = RoundUpTo(Max(size, kChunkHeader2Size), alignment);
 343     uptr needed_size = rounded_size + rz_size;
 344     if (alignment > min_alignment)
 345       needed_size += alignment;
 346     bool using_primary_allocator = true;
 347     // If we are allocating from the secondary allocator, there will be no
 348     // automatic right redzone, so add the right redzone manually.
 349     if (!PrimaryAllocator::CanAllocate(needed_size, alignment)) {
 350       needed_size += rz_size;
 351       using_primary_allocator = false;
 352     }
 353     CHECK(IsAligned(needed_size, min_alignment));
 354     if (size > kMaxAllowedMallocSize || needed_size > kMaxAllowedMallocSize) {
 355       Report("WARNING: AddressSanitizer failed to allocate 0x%zx bytes\n",
 356              (void*)size);
 357       return allocator.ReturnNullOrDie();
 358     }
 359
 360     AsanThread *t = GetCurrentThread();
 361     void *allocated;
 362     bool check_rss_limit = true;
 363     if (t) {
 364       AllocatorCache *cache = GetAllocatorCache(&t->malloc_storage());
 365       allocated =
 366           allocator.Allocate(cache, needed_size, 8, false, check_rss_limit);
 367     } else {
 368       SpinMutexLock l(&fallback_mutex);
 369       AllocatorCache *cache = &fallback_allocator_cache;
 370       allocated =
 371           allocator.Allocate(cache, needed_size, 8, false, check_rss_limit);
 372     }
 373
 374     if (!allocated)
 375       return allocator.ReturnNullOrDie();
 376
 377     if (*(u8 *)MEM_TO_SHADOW((uptr)allocated) == 0 && CanPoisonMemory()) {
 378       // Heap poisoning is enabled, but the allocator provides an unpoisoned
 379       // chunk. This is possible if CanPoisonMemory() was false for some
 380       // time, for example, due to flags()->start_disabled.
 381       // Anyway, poison the block before using it for anything else.
 382       uptr allocated_size = allocator.GetActuallyAllocatedSize(allocated);
 383       PoisonShadow((uptr)allocated, allocated_size, kAsanHeapLeftRedzoneMagic);
 384     }
 385
 386     uptr alloc_beg = reinterpret_cast<uptr>(allocated);
 387     uptr alloc_end = alloc_beg + needed_size;
 388     uptr beg_plus_redzone = alloc_beg + rz_size;
 389     uptr user_beg = beg_plus_redzone;
 390     if (!IsAligned(user_beg, alignment))
 391       user_beg = RoundUpTo(user_beg, alignment);
 392     uptr user_end = user_beg + size;
 393     CHECK_LE(user_end, alloc_end);
 394     uptr chunk_beg = user_beg - kChunkHeaderSize;
 395     AsanChunk *m = reinterpret_cast<AsanChunk *>(chunk_beg);
 396     m->alloc_type = alloc_type;
 397     m->rz_log = rz_log;
 398     u32 alloc_tid = t ? t->tid() : 0;
 399     m->alloc_tid = alloc_tid;
 400     CHECK_EQ(alloc_tid, m->alloc_tid);  // Does alloc_tid fit into the bitfield?
 401     m->free_tid = kInvalidTid;
 402     m->from_memalign = user_beg != beg_plus_redzone;
 403     if (alloc_beg != chunk_beg) {
 404       CHECK_LE(alloc_beg+ 2 * sizeof(uptr), chunk_beg);
 405       reinterpret_cast<uptr *>(alloc_beg)[0] = kAllocBegMagic;
 406       reinterpret_cast<uptr *>(alloc_beg)[1] = chunk_beg;
 407     }
 408     if (using_primary_allocator) {
 409       CHECK(size);
 410       m->user_requested_size = size;
 411       CHECK(allocator.FromPrimary(allocated));
 412     } else {
 413       CHECK(!allocator.FromPrimary(allocated));
 414       m->user_requested_size = SizeClassMap::kMaxSize;
 415       uptr *meta = reinterpret_cast<uptr *>(allocator.GetMetaData(allocated));
 416       meta[0] = size;
 417       meta[1] = chunk_beg;
 418     }
 419
 420     m->alloc_context_id = StackDepotPut(*stack);
 421
 422     uptr size_rounded_down_to_granularity =
 423         RoundDownTo(size, SHADOW_GRANULARITY);
 424     // Unpoison the bulk of the memory region.
 425     if (size_rounded_down_to_granularity)
 426       PoisonShadow(user_beg, size_rounded_down_to_granularity, 0);
 427     // Deal with the end of the region if size is not aligned to granularity.
 428     if (size != size_rounded_down_to_granularity && CanPoisonMemory()) {
 429       u8 *shadow =
 430           (u8 *)MemToShadow(user_beg + size_rounded_down_to_granularity);
 431       *shadow = fl.poison_partial ? (size & (SHADOW_GRANULARITY - 1)) : 0;
 432     }
 433
 434     AsanStats &thread_stats = GetCurrentThreadStats();
 435     thread_stats.mallocs++;
 436     thread_stats.malloced += size;
 437     thread_stats.malloced_redzones += needed_size - size;
 438     if (needed_size > SizeClassMap::kMaxSize)
 439       thread_stats.malloc_large++;
 440     else
 441       thread_stats.malloced_by_size[SizeClassMap::ClassID(needed_size)]++;
 442
 443     void *res = reinterpret_cast<void *>(user_beg);
 444     if (can_fill && fl.max_malloc_fill_size) {
 445       uptr fill_size = Min(size, (uptr)fl.max_malloc_fill_size);
 446       REAL(memset)(res, fl.malloc_fill_byte, fill_size);
 447     }
 448 #if CAN_SANITIZE_LEAKS
 449     m->lsan_tag = __lsan::DisabledInThisThread() ? __lsan::kIgnored
 450                                                  : __lsan::kDirectlyLeaked;
 451 #endif
 452     // Must be the last mutation of metadata in this function.
 453     atomic_store((atomic_uint8_t *)m, CHUNK_ALLOCATED, memory_order_release);
 454     ASAN_MALLOC_HOOK(res, size);
 455     return res;
 456   }
 457
 458   void AtomicallySetQuarantineFlag(AsanChunk *m, void *ptr,
 459                                    BufferedStackTrace *stack) {
 460     u8 old_chunk_state = CHUNK_ALLOCATED;
 461     // Flip the chunk_state atomically to avoid race on double-free.
 462     if (!atomic_compare_exchange_strong((atomic_uint8_t*)m, &old_chunk_state,
 463                                         CHUNK_QUARANTINE, memory_order_acquire))
 464       ReportInvalidFree(ptr, old_chunk_state, stack);
 465     CHECK_EQ(CHUNK_ALLOCATED, old_chunk_state);
 466   }
 467
 468   // Expects the chunk to already be marked as quarantined by using
 469   // AtomicallySetQuarantineFlag.
 470   void QuarantineChunk(AsanChunk *m, void *ptr, BufferedStackTrace *stack,
 471                        AllocType alloc_type) {
 472     CHECK_EQ(m->chunk_state, CHUNK_QUARANTINE);
 473
 474     if (m->alloc_type != alloc_type) {
 475       if (atomic_load(&alloc_dealloc_mismatch, memory_order_acquire)) {
 476         ReportAllocTypeMismatch((uptr)ptr, stack, (AllocType)m->alloc_type,
 477                                 (AllocType)alloc_type);
 478       }
 479     }
 480
 481     CHECK_GE(m->alloc_tid, 0);
 482     if (SANITIZER_WORDSIZE == 64)  // On 32-bits this resides in user area.
 483       CHECK_EQ(m->free_tid, kInvalidTid);
 484     AsanThread *t = GetCurrentThread();
 485     m->free_tid = t ? t->tid() : 0;
 486     m->free_context_id = StackDepotPut(*stack);
 487     // Poison the region.
 488     PoisonShadow(m->Beg(),
 489                  RoundUpTo(m->UsedSize(), SHADOW_GRANULARITY),
 490                  kAsanHeapFreeMagic);
 491
 492     AsanStats &thread_stats = GetCurrentThreadStats();
 493     thread_stats.frees++;
 494     thread_stats.freed += m->UsedSize();
 495
 496     // Push into quarantine.
 497     if (t) {
 498       AsanThreadLocalMallocStorage *ms = &t->malloc_storage();
 499       AllocatorCache *ac = GetAllocatorCache(ms);
 500       quarantine.Put(GetQuarantineCache(ms), QuarantineCallback(ac), m,
 501                            m->UsedSize());
 502     } else {
 503       SpinMutexLock l(&fallback_mutex);
 504       AllocatorCache *ac = &fallback_allocator_cache;
 505       quarantine.Put(&fallback_quarantine_cache, QuarantineCallback(ac), m,
 506                            m->UsedSize());
 507     }
 508   }
 509
 510   void Deallocate(void *ptr, uptr delete_size, BufferedStackTrace *stack,
 511                   AllocType alloc_type) {
 512     uptr p = reinterpret_cast<uptr>(ptr);
 513     if (p == 0) return;
 514
 515     uptr chunk_beg = p - kChunkHeaderSize;
 516     AsanChunk *m = reinterpret_cast<AsanChunk *>(chunk_beg);
 517     if (delete_size && flags()->new_delete_type_mismatch &&
 518         delete_size != m->UsedSize()) {
 519       ReportNewDeleteSizeMismatch(p, delete_size, stack);
 520     }
 521     ASAN_FREE_HOOK(ptr);
 522     // Must mark the chunk as quarantined before any changes to its metadata.
 523     AtomicallySetQuarantineFlag(m, ptr, stack);
 524     QuarantineChunk(m, ptr, stack, alloc_type);
 525   }
 526
 527   void *Reallocate(void *old_ptr, uptr new_size, BufferedStackTrace *stack) {
 528     CHECK(old_ptr && new_size);
 529     uptr p = reinterpret_cast<uptr>(old_ptr);
 530     uptr chunk_beg = p - kChunkHeaderSize;
 531     AsanChunk *m = reinterpret_cast<AsanChunk *>(chunk_beg);
 532
 533     AsanStats &thread_stats = GetCurrentThreadStats();
 534     thread_stats.reallocs++;
 535     thread_stats.realloced += new_size;
 536
 537     void *new_ptr = Allocate(new_size, 8, stack, FROM_MALLOC, true);
 538     if (new_ptr) {
 539       u8 chunk_state = m->chunk_state;
 540       if (chunk_state != CHUNK_ALLOCATED)
 541         ReportInvalidFree(old_ptr, chunk_state, stack);
 542       CHECK_NE(REAL(memcpy), nullptr);
 543       uptr memcpy_size = Min(new_size, m->UsedSize());
 544       // If realloc() races with free(), we may start copying freed memory.
 545       // However, we will report racy double-free later anyway.
 546       REAL(memcpy)(new_ptr, old_ptr, memcpy_size);
 547       Deallocate(old_ptr, 0, stack, FROM_MALLOC);
 548     }
 549     return new_ptr;
 550   }
 551
 552   void *Calloc(uptr nmemb, uptr size, BufferedStackTrace *stack) {
 553     if (CallocShouldReturnNullDueToOverflow(size, nmemb))
 554       return allocator.ReturnNullOrDie();
 555     void *ptr = Allocate(nmemb * size, 8, stack, FROM_MALLOC, false);
 556     // If the memory comes from the secondary allocator no need to clear it
 557     // as it comes directly from mmap.
 558     if (ptr && allocator.FromPrimary(ptr))
 559       REAL(memset)(ptr, 0, nmemb * size);
 560     return ptr;
 561   }
 562
 563   void ReportInvalidFree(void *ptr, u8 chunk_state, BufferedStackTrace *stack) {
 564     if (chunk_state == CHUNK_QUARANTINE)
 565       ReportDoubleFree((uptr)ptr, stack);
 566     else
 567       ReportFreeNotMalloced((uptr)ptr, stack);
 568   }
 569
 570   void CommitBack(AsanThreadLocalMallocStorage *ms) {
 571     AllocatorCache *ac = GetAllocatorCache(ms);
 572     quarantine.Drain(GetQuarantineCache(ms), QuarantineCallback(ac));
 573     allocator.SwallowCache(ac);
 574   }
 575
 576   // -------------------------- Chunk lookup ----------------------
 577
 578   // Assumes alloc_beg == allocator.GetBlockBegin(alloc_beg).
 579   AsanChunk *GetAsanChunk(void *alloc_beg) {
 580     if (!alloc_beg) return nullptr;
 581     if (!allocator.FromPrimary(alloc_beg)) {
 582       uptr *meta = reinterpret_cast<uptr *>(allocator.GetMetaData(alloc_beg));
 583       AsanChunk *m = reinterpret_cast<AsanChunk *>(meta[1]);
 584       return m;
 585     }
 586     uptr *alloc_magic = reinterpret_cast<uptr *>(alloc_beg);
 587     if (alloc_magic[0] == kAllocBegMagic)
 588       return reinterpret_cast<AsanChunk *>(alloc_magic[1]);
 589     return reinterpret_cast<AsanChunk *>(alloc_beg);
 590   }
 591
 592   AsanChunk *GetAsanChunkByAddr(uptr p) {
 593     void *alloc_beg = allocator.GetBlockBegin(reinterpret_cast<void *>(p));
 594     return GetAsanChunk(alloc_beg);
 595   }
 596
 597   // Allocator must be locked when this function is called.
 598   AsanChunk *GetAsanChunkByAddrFastLocked(uptr p) {
 599     void *alloc_beg =
 600         allocator.GetBlockBeginFastLocked(reinterpret_cast<void *>(p));
 601     return GetAsanChunk(alloc_beg);
 602   }
 603
 604   uptr AllocationSize(uptr p) {
 605     AsanChunk *m = GetAsanChunkByAddr(p);
 606     if (!m) return 0;
 607     if (m->chunk_state != CHUNK_ALLOCATED) return 0;
 608     if (m->Beg() != p) return 0;
 609     return m->UsedSize();
 610   }
 611
 612   AsanChunkView FindHeapChunkByAddress(uptr addr) {
 613     AsanChunk *m1 = GetAsanChunkByAddr(addr);
 614     if (!m1) return AsanChunkView(m1);
 615     sptr offset = 0;
 616     if (AsanChunkView(m1).AddrIsAtLeft(addr, 1, &offset)) {
 617       // The address is in the chunk's left redzone, so maybe it is actually
 618       // a right buffer overflow from the other chunk to the left.
 619       // Search a bit to the left to see if there is another chunk.
 620       AsanChunk *m2 = nullptr;
 621       for (uptr l = 1; l < GetPageSizeCached(); l++) {
 622         m2 = GetAsanChunkByAddr(addr - l);
 623         if (m2 == m1) continue;  // Still the same chunk.
 624         break;
 625       }
 626       if (m2 && AsanChunkView(m2).AddrIsAtRight(addr, 1, &offset))
 627         m1 = ChooseChunk(addr, m2, m1);
 628     }
 629     return AsanChunkView(m1);
 630   }
 631
 632   void PrintStats() {
 633     allocator.PrintStats();
 634   }
 635
 636   void ForceLock() {
 637     allocator.ForceLock();
 638     fallback_mutex.Lock();
 639   }
 640
 641   void ForceUnlock() {
 642     fallback_mutex.Unlock();
 643     allocator.ForceUnlock();
 644   }
 645 };
 646
 647 static Allocator instance(LINKER_INITIALIZED);
 648
 649 static AsanAllocator &get_allocator() {
 650   return instance.allocator;
 651 }
 652
 653 bool AsanChunkView::IsValid() {
 654   return chunk_ && chunk_->chunk_state != CHUNK_AVAILABLE;
 655 }
 656 uptr AsanChunkView::Beg() { return chunk_->Beg(); }
 657 uptr AsanChunkView::End() { return Beg() + UsedSize(); }
 658 uptr AsanChunkView::UsedSize() { return chunk_->UsedSize(); }
 659 uptr AsanChunkView::AllocTid() { return chunk_->alloc_tid; }
 660 uptr AsanChunkView::FreeTid() { return chunk_->free_tid; }
 661
 662 static StackTrace GetStackTraceFromId(u32 id) {
 663   CHECK(id);
 664   StackTrace res = StackDepotGet(id);
 665   CHECK(res.trace);
 666   return res;
 667 }
 668
 669 StackTrace AsanChunkView::GetAllocStack() {
 670   return GetStackTraceFromId(chunk_->alloc_context_id);
 671 }
 672
 673 StackTrace AsanChunkView::GetFreeStack() {
 674   return GetStackTraceFromId(chunk_->free_context_id);
 675 }
 676
 677 void InitializeAllocator(const AllocatorOptions &options) {
 678   instance.Initialize(options);
 679 }
 680
 681 void ReInitializeAllocator(const AllocatorOptions &options) {
 682   instance.ReInitialize(options);
 683 }
 684
 685 void GetAllocatorOptions(AllocatorOptions *options) {
 686   instance.GetOptions(options);
 687 }
 688
 689 AsanChunkView FindHeapChunkByAddress(uptr addr) {
 690   return instance.FindHeapChunkByAddress(addr);
 691 }
 692
 693 void AsanThreadLocalMallocStorage::CommitBack() {
 694   instance.CommitBack(this);
 695 }
 696
 697 void PrintInternalAllocatorStats() {
 698   instance.PrintStats();
 699 }
 700
 701 void *asan_memalign(uptr alignment, uptr size, BufferedStackTrace *stack,
 702                     AllocType alloc_type) {
 703   return instance.Allocate(size, alignment, stack, alloc_type, true);
 704 }
 705
 706 void asan_free(void *ptr, BufferedStackTrace *stack, AllocType alloc_type) {
 707   instance.Deallocate(ptr, 0, stack, alloc_type);
 708 }
 709
 710 void asan_sized_free(void *ptr, uptr size, BufferedStackTrace *stack,
 711                      AllocType alloc_type) {
 712   instance.Deallocate(ptr, size, stack, alloc_type);
 713 }
 714
 715 void *asan_malloc(uptr size, BufferedStackTrace *stack) {
 716   return instance.Allocate(size, 8, stack, FROM_MALLOC, true);
 717 }
 718
 719 void *asan_calloc(uptr nmemb, uptr size, BufferedStackTrace *stack) {
 720   return instance.Calloc(nmemb, size, stack);
 721 }
 722
 723 void *asan_realloc(void *p, uptr size, BufferedStackTrace *stack) {
 724   if (!p)
 725     return instance.Allocate(size, 8, stack, FROM_MALLOC, true);
 726   if (size == 0) {
 727     instance.Deallocate(p, 0, stack, FROM_MALLOC);
 728     return nullptr;
 729   }
 730   return instance.Reallocate(p, size, stack);
 731 }
 732
 733 void *asan_valloc(uptr size, BufferedStackTrace *stack) {
 734   return instance.Allocate(size, GetPageSizeCached(), stack, FROM_MALLOC, true);
 735 }
 736
 737 void *asan_pvalloc(uptr size, BufferedStackTrace *stack) {
 738   uptr PageSize = GetPageSizeCached();
 739   size = RoundUpTo(size, PageSize);
 740   if (size == 0) {
 741     // pvalloc(0) should allocate one page.
 742     size = PageSize;
 743   }
 744   return instance.Allocate(size, PageSize, stack, FROM_MALLOC, true);
 745 }
 746
 747 int asan_posix_memalign(void **memptr, uptr alignment, uptr size,
 748                         BufferedStackTrace *stack) {
 749   void *ptr = instance.Allocate(size, alignment, stack, FROM_MALLOC, true);
 750   CHECK(IsAligned((uptr)ptr, alignment));
 751   *memptr = ptr;
 752   return 0;
 753 }
 754
 755 uptr asan_malloc_usable_size(void *ptr, uptr pc, uptr bp) {
 756   if (!ptr) return 0;
 757   uptr usable_size = instance.AllocationSize(reinterpret_cast<uptr>(ptr));
 758   if (flags()->check_malloc_usable_size && (usable_size == 0)) {
 759     GET_STACK_TRACE_FATAL(pc, bp);
 760     ReportMallocUsableSizeNotOwned((uptr)ptr, &stack);
 761   }
 762   return usable_size;
 763 }
 764
 765 uptr asan_mz_size(const void *ptr) {
 766   return instance.AllocationSize(reinterpret_cast<uptr>(ptr));
 767 }
 768
 769 void asan_mz_force_lock() {
 770   instance.ForceLock();
 771 }
 772
 773 void asan_mz_force_unlock() {
 774   instance.ForceUnlock();
 775 }
 776
 777 void AsanSoftRssLimitExceededCallback(bool exceeded) {
 778   instance.allocator.SetRssLimitIsExceeded(exceeded);
 779 }
 780
 781 } // namespace __asan
 782
 783 // --- Implementation of LSan-specific functions --- {{{1
 784 namespace __lsan {
 785 void LockAllocator() {
 786   __asan::get_allocator().ForceLock();
 787 }
 788
 789 void UnlockAllocator() {
 790   __asan::get_allocator().ForceUnlock();
 791 }
 792
 793 void GetAllocatorGlobalRange(uptr *begin, uptr *end) {
 794   *begin = (uptr)&__asan::get_allocator();
 795   *end = *begin + sizeof(__asan::get_allocator());
 796 }
 797
 798 uptr PointsIntoChunk(void* p) {
 799   uptr addr = reinterpret_cast<uptr>(p);
 800   __asan::AsanChunk *m = __asan::instance.GetAsanChunkByAddrFastLocked(addr);
 801   if (!m) return 0;
 802   uptr chunk = m->Beg();
 803   if (m->chunk_state != __asan::CHUNK_ALLOCATED)
 804     return 0;
 805   if (m->AddrIsInside(addr, /*locked_version=*/true))
 806     return chunk;
 807   if (IsSpecialCaseOfOperatorNew0(chunk, m->UsedSize(/*locked_version*/ true),
 808                                   addr))
 809     return chunk;
 810   return 0;
 811 }
 812
 813 uptr GetUserBegin(uptr chunk) {
 814   __asan::AsanChunk *m = __asan::instance.GetAsanChunkByAddrFastLocked(chunk);
 815   CHECK(m);
 816   return m->Beg();
 817 }
 818
 819 LsanMetadata::LsanMetadata(uptr chunk) {
 820   metadata_ = reinterpret_cast<void *>(chunk - __asan::kChunkHeaderSize);
 821 }
 822
 823 bool LsanMetadata::allocated() const {
 824   __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
 825   return m->chunk_state == __asan::CHUNK_ALLOCATED;
 826 }
 827
 828 ChunkTag LsanMetadata::tag() const {
 829   __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
 830   return static_cast<ChunkTag>(m->lsan_tag);
 831 }
 832
 833 void LsanMetadata::set_tag(ChunkTag value) {
 834   __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
 835   m->lsan_tag = value;
 836 }
 837
 838 uptr LsanMetadata::requested_size() const {
 839   __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
 840   return m->UsedSize(/*locked_version=*/true);
 841 }
 842
 843 u32 LsanMetadata::stack_trace_id() const {
 844   __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
 845   return m->alloc_context_id;
 846 }
 847
 848 void ForEachChunk(ForEachChunkCallback callback, void *arg) {
 849   __asan::get_allocator().ForEachChunk(callback, arg);
 850 }
 851
 852 IgnoreObjectResult IgnoreObjectLocked(const void *p) {
 853   uptr addr = reinterpret_cast<uptr>(p);
 854   __asan::AsanChunk *m = __asan::instance.GetAsanChunkByAddr(addr);
 855   if (!m) return kIgnoreObjectInvalid;
 856   if ((m->chunk_state == __asan::CHUNK_ALLOCATED) && m->AddrIsInside(addr)) {
 857     if (m->lsan_tag == kIgnored)
 858       return kIgnoreObjectAlreadyIgnored;
 859     m->lsan_tag = __lsan::kIgnored;
 860     return kIgnoreObjectSuccess;
 861   } else {
 862     return kIgnoreObjectInvalid;
 863   }
 864 }
 865 }  // namespace __lsan
 866
 867 // ---------------------- Interface ---------------- {{{1
 868 using namespace __asan;  // NOLINT
 869
 870 // ASan allocator doesn't reserve extra bytes, so normally we would
 871 // just return "size". We don't want to expose our redzone sizes, etc here.
 872 uptr __sanitizer_get_estimated_allocated_size(uptr size) {
 873   return size;
 874 }
 875
 876 int __sanitizer_get_ownership(const void *p) {
 877   uptr ptr = reinterpret_cast<uptr>(p);
 878   return instance.AllocationSize(ptr) > 0;
 879 }
 880
 881 uptr __sanitizer_get_allocated_size(const void *p) {
 882   if (!p) return 0;
 883   uptr ptr = reinterpret_cast<uptr>(p);
 884   uptr allocated_size = instance.AllocationSize(ptr);
 885   // Die if p is not malloced or if it is already freed.
 886   if (allocated_size == 0) {
 887     GET_STACK_TRACE_FATAL_HERE;
 888     ReportSanitizerGetAllocatedSizeNotOwned(ptr, &stack);
 889   }
 890   return allocated_size;
 891 }
 892
 893 #if !SANITIZER_SUPPORTS_WEAK_HOOKS
 894 // Provide default (no-op) implementation of malloc hooks.
 895 extern "C" {
 896 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
 897 void __sanitizer_malloc_hook(void *ptr, uptr size) {
 898   (void)ptr;
 899   (void)size;
 900 }
 901 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
 902 void __sanitizer_free_hook(void *ptr) {
 903   (void)ptr;
 904 }
 905 } // extern "C"
 906 #endif