compiler-rt/lib/memprof/memprof_allocator.cpp

   1 //===-- memprof_allocator.cpp --------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file is a part of MemProfiler, a memory profiler.
  10 //
  11 // Implementation of MemProf's memory allocator, which uses the allocator
  12 // from sanitizer_common.
  13 //
  14 //===----------------------------------------------------------------------===//
  15
  16 #include "memprof_allocator.h"
  17 #include "memprof_mapping.h"
  18 #include "memprof_mibmap.h"
  19 #include "memprof_rawprofile.h"
  20 #include "memprof_stack.h"
  21 #include "memprof_thread.h"
  22 #include "profile/MemProfData.inc"
  23 #include "sanitizer_common/sanitizer_allocator_checks.h"
  24 #include "sanitizer_common/sanitizer_allocator_interface.h"
  25 #include "sanitizer_common/sanitizer_allocator_report.h"
  26 #include "sanitizer_common/sanitizer_array_ref.h"
  27 #include "sanitizer_common/sanitizer_common.h"
  28 #include "sanitizer_common/sanitizer_errno.h"
  29 #include "sanitizer_common/sanitizer_file.h"
  30 #include "sanitizer_common/sanitizer_flags.h"
  31 #include "sanitizer_common/sanitizer_internal_defs.h"
  32 #include "sanitizer_common/sanitizer_stackdepot.h"
  33
  34 #include <sched.h>
  35 #include <time.h>
  36
  37 #define MAX_HISTOGRAM_PRINT_SIZE 32U
  38
  39 extern bool __memprof_histogram;
  40
  41 namespace __memprof {
  42 namespace {
  43 using ::llvm::memprof::MemInfoBlock;
  44
  45 void Print(const MemInfoBlock &M, const u64 id, bool print_terse) {
  46   u64 p;
  47
  48   if (print_terse) {
  49     p = M.TotalSize * 100 / M.AllocCount;
  50     Printf("MIB:%llu/%u/%llu.%02llu/%u/%u/", id, M.AllocCount, p / 100, p % 100,
  51            M.MinSize, M.MaxSize);
  52     p = M.TotalAccessCount * 100 / M.AllocCount;
  53     Printf("%llu.%02llu/%llu/%llu/", p / 100, p % 100, M.MinAccessCount,
  54            M.MaxAccessCount);
  55     p = M.TotalLifetime * 100 / M.AllocCount;
  56     Printf("%llu.%02llu/%u/%u/", p / 100, p % 100, M.MinLifetime,
  57            M.MaxLifetime);
  58     Printf("%u/%u/%u/%u\n", M.NumMigratedCpu, M.NumLifetimeOverlaps,
  59            M.NumSameAllocCpu, M.NumSameDeallocCpu);
  60   } else {
  61     p = M.TotalSize * 100 / M.AllocCount;
  62     Printf("Memory allocation stack id = %llu\n", id);
  63     Printf("\talloc_count %u, size (ave/min/max) %llu.%02llu / %u / %u\n",
  64            M.AllocCount, p / 100, p % 100, M.MinSize, M.MaxSize);
  65     p = M.TotalAccessCount * 100 / M.AllocCount;
  66     Printf("\taccess_count (ave/min/max): %llu.%02llu / %llu / %llu\n", p / 100,
  67            p % 100, M.MinAccessCount, M.MaxAccessCount);
  68     p = M.TotalLifetime * 100 / M.AllocCount;
  69     Printf("\tlifetime (ave/min/max): %llu.%02llu / %u / %u\n", p / 100,
  70            p % 100, M.MinLifetime, M.MaxLifetime);
  71     Printf("\tnum migrated: %u, num lifetime overlaps: %u, num same alloc "
  72            "cpu: %u, num same dealloc_cpu: %u\n",
  73            M.NumMigratedCpu, M.NumLifetimeOverlaps, M.NumSameAllocCpu,
  74            M.NumSameDeallocCpu);
  75     Printf("AccessCountHistogram[%u]: ", M.AccessHistogramSize);
  76     uint32_t PrintSize = M.AccessHistogramSize > MAX_HISTOGRAM_PRINT_SIZE
  77                              ? MAX_HISTOGRAM_PRINT_SIZE
  78                              : M.AccessHistogramSize;
  79     for (size_t i = 0; i < PrintSize; ++i) {
  80       Printf("%llu ", ((uint64_t *)M.AccessHistogram)[i]);
  81     }
  82     Printf("\n");
  83   }
  84 }
  85 } // namespace
  86
  87 static int GetCpuId(void) {
  88   // _memprof_preinit is called via the preinit_array, which subsequently calls
  89   // malloc. Since this is before _dl_init calls VDSO_SETUP, sched_getcpu
  90   // will seg fault as the address of __vdso_getcpu will be null.
  91   if (!memprof_inited)
  92     return -1;
  93   return sched_getcpu();
  94 }
  95
  96 // Compute the timestamp in ms.
  97 static int GetTimestamp(void) {
  98   // timespec_get will segfault if called from dl_init
  99   if (!memprof_timestamp_inited) {
 100     // By returning 0, this will be effectively treated as being
 101     // timestamped at memprof init time (when memprof_init_timestamp_s
 102     // is initialized).
 103     return 0;
 104   }
 105   timespec ts;
 106   clock_gettime(CLOCK_REALTIME, &ts);
 107   return (ts.tv_sec - memprof_init_timestamp_s) * 1000 + ts.tv_nsec / 1000000;
 108 }
 109
 110 static MemprofAllocator &get_allocator();
 111
 112 // The memory chunk allocated from the underlying allocator looks like this:
 113 // H H U U U U U U
 114 //   H -- ChunkHeader (32 bytes)
 115 //   U -- user memory.
 116
 117 // If there is left padding before the ChunkHeader (due to use of memalign),
 118 // we store a magic value in the first uptr word of the memory block and
 119 // store the address of ChunkHeader in the next uptr.
 120 // M B L L L L L L L L L  H H U U U U U U
 121 //   |                    ^
 122 //   ---------------------|
 123 //   M -- magic value kAllocBegMagic
 124 //   B -- address of ChunkHeader pointing to the first 'H'
 125
 126 constexpr uptr kMaxAllowedMallocBits = 40;
 127
 128 // Should be no more than 32-bytes
 129 struct ChunkHeader {
 130   // 1-st 4 bytes.
 131   u32 alloc_context_id;
 132   // 2-nd 4 bytes
 133   u32 cpu_id;
 134   // 3-rd 4 bytes
 135   u32 timestamp_ms;
 136   // 4-th 4 bytes
 137   // Note only 1 bit is needed for this flag if we need space in the future for
 138   // more fields.
 139   u32 from_memalign;
 140   // 5-th and 6-th 4 bytes
 141   // The max size of an allocation is 2^40 (kMaxAllowedMallocSize), so this
 142   // could be shrunk to kMaxAllowedMallocBits if we need space in the future for
 143   // more fields.
 144   atomic_uint64_t user_requested_size;
 145   // 23 bits available
 146   // 7-th and 8-th 4 bytes
 147   u64 data_type_id; // TODO: hash of type name
 148 };
 149
 150 static const uptr kChunkHeaderSize = sizeof(ChunkHeader);
 151 COMPILER_CHECK(kChunkHeaderSize == 32);
 152
 153 struct MemprofChunk : ChunkHeader {
 154   uptr Beg() { return reinterpret_cast<uptr>(this) + kChunkHeaderSize; }
 155   uptr UsedSize() {
 156     return atomic_load(&user_requested_size, memory_order_relaxed);
 157   }
 158   void *AllocBeg() {
 159     if (from_memalign)
 160       return get_allocator().GetBlockBegin(reinterpret_cast<void *>(this));
 161     return reinterpret_cast<void *>(this);
 162   }
 163 };
 164
 165 class LargeChunkHeader {
 166   static constexpr uptr kAllocBegMagic =
 167       FIRST_32_SECOND_64(0xCC6E96B9, 0xCC6E96B9CC6E96B9ULL);
 168   atomic_uintptr_t magic;
 169   MemprofChunk *chunk_header;
 170
 171 public:
 172   MemprofChunk *Get() const {
 173     return atomic_load(&magic, memory_order_acquire) == kAllocBegMagic
 174                ? chunk_header
 175                : nullptr;
 176   }
 177
 178   void Set(MemprofChunk *p) {
 179     if (p) {
 180       chunk_header = p;
 181       atomic_store(&magic, kAllocBegMagic, memory_order_release);
 182       return;
 183     }
 184
 185     uptr old = kAllocBegMagic;
 186     if (!atomic_compare_exchange_strong(&magic, &old, 0,
 187                                         memory_order_release)) {
 188       CHECK_EQ(old, kAllocBegMagic);
 189     }
 190   }
 191 };
 192
 193 void FlushUnneededMemProfShadowMemory(uptr p, uptr size) {
 194   // Since memprof's mapping is compacting, the shadow chunk may be
 195   // not page-aligned, so we only flush the page-aligned portion.
 196   ReleaseMemoryPagesToOS(MemToShadow(p), MemToShadow(p + size));
 197 }
 198
 199 void MemprofMapUnmapCallback::OnMap(uptr p, uptr size) const {
 200   // Statistics.
 201   MemprofStats &thread_stats = GetCurrentThreadStats();
 202   thread_stats.mmaps++;
 203   thread_stats.mmaped += size;
 204 }
 205
 206 void MemprofMapUnmapCallback::OnUnmap(uptr p, uptr size) const {
 207   // We are about to unmap a chunk of user memory.
 208   // Mark the corresponding shadow memory as not needed.
 209   FlushUnneededMemProfShadowMemory(p, size);
 210   // Statistics.
 211   MemprofStats &thread_stats = GetCurrentThreadStats();
 212   thread_stats.munmaps++;
 213   thread_stats.munmaped += size;
 214 }
 215
 216 AllocatorCache *GetAllocatorCache(MemprofThreadLocalMallocStorage *ms) {
 217   CHECK(ms);
 218   return &ms->allocator_cache;
 219 }
 220
 221 // Accumulates the access count from the shadow for the given pointer and size.
 222 u64 GetShadowCount(uptr p, u32 size) {
 223   u64 *shadow = (u64 *)MEM_TO_SHADOW(p);
 224   u64 *shadow_end = (u64 *)MEM_TO_SHADOW(p + size);
 225   u64 count = 0;
 226   for (; shadow <= shadow_end; shadow++)
 227     count += *shadow;
 228   return count;
 229 }
 230
 231 // Accumulates the access count from the shadow for the given pointer and size.
 232 // See memprof_mapping.h for an overview on histogram counters.
 233 u64 GetShadowCountHistogram(uptr p, u32 size) {
 234   u8 *shadow = (u8 *)HISTOGRAM_MEM_TO_SHADOW(p);
 235   u8 *shadow_end = (u8 *)HISTOGRAM_MEM_TO_SHADOW(p + size);
 236   u64 count = 0;
 237   for (; shadow <= shadow_end; shadow++)
 238     count += *shadow;
 239   return count;
 240 }
 241
 242 // Clears the shadow counters (when memory is allocated).
 243 void ClearShadow(uptr addr, uptr size) {
 244   CHECK(AddrIsAlignedByGranularity(addr));
 245   CHECK(AddrIsInMem(addr));
 246   CHECK(AddrIsAlignedByGranularity(addr + size));
 247   CHECK(AddrIsInMem(addr + size - SHADOW_GRANULARITY));
 248   CHECK(REAL(memset));
 249   uptr shadow_beg;
 250   uptr shadow_end;
 251   if (__memprof_histogram) {
 252     shadow_beg = HISTOGRAM_MEM_TO_SHADOW(addr);
 253     shadow_end = HISTOGRAM_MEM_TO_SHADOW(addr + size);
 254   } else {
 255     shadow_beg = MEM_TO_SHADOW(addr);
 256     shadow_end = MEM_TO_SHADOW(addr + size - SHADOW_GRANULARITY) + 1;
 257   }
 258
 259   if (shadow_end - shadow_beg < common_flags()->clear_shadow_mmap_threshold) {
 260     REAL(memset)((void *)shadow_beg, 0, shadow_end - shadow_beg);
 261   } else {
 262     uptr page_size = GetPageSizeCached();
 263     uptr page_beg = RoundUpTo(shadow_beg, page_size);
 264     uptr page_end = RoundDownTo(shadow_end, page_size);
 265
 266     if (page_beg >= page_end) {
 267       REAL(memset)((void *)shadow_beg, 0, shadow_end - shadow_beg);
 268     } else {
 269       if (page_beg != shadow_beg) {
 270         REAL(memset)((void *)shadow_beg, 0, page_beg - shadow_beg);
 271       }
 272       if (page_end != shadow_end) {
 273         REAL(memset)((void *)page_end, 0, shadow_end - page_end);
 274       }
 275       ReserveShadowMemoryRange(page_beg, page_end - 1, nullptr);
 276     }
 277   }
 278 }
 279
 280 struct Allocator {
 281   static const uptr kMaxAllowedMallocSize = 1ULL << kMaxAllowedMallocBits;
 282
 283   MemprofAllocator allocator;
 284   StaticSpinMutex fallback_mutex;
 285   AllocatorCache fallback_allocator_cache;
 286
 287   uptr max_user_defined_malloc_size;
 288
 289   // Holds the mapping of stack ids to MemInfoBlocks.
 290   MIBMapTy MIBMap;
 291
 292   atomic_uint8_t destructing;
 293   atomic_uint8_t constructed;
 294   bool print_text;
 295
 296   // ------------------- Initialization ------------------------
 297   explicit Allocator(LinkerInitialized) : print_text(flags()->print_text) {
 298     atomic_store_relaxed(&destructing, 0);
 299     atomic_store_relaxed(&constructed, 1);
 300   }
 301
 302   ~Allocator() {
 303     atomic_store_relaxed(&destructing, 1);
 304     FinishAndWrite();
 305   }
 306
 307   static void PrintCallback(const uptr Key, LockedMemInfoBlock *const &Value,
 308                             void *Arg) {
 309     SpinMutexLock l(&Value->mutex);
 310     Print(Value->mib, Key, bool(Arg));
 311   }
 312
 313   // See memprof_mapping.h for an overview on histogram counters.
 314   static MemInfoBlock CreateNewMIB(uptr p, MemprofChunk *m, u64 user_size) {
 315     if (__memprof_histogram) {
 316       return CreateNewMIBWithHistogram(p, m, user_size);
 317     } else {
 318       return CreateNewMIBWithoutHistogram(p, m, user_size);
 319     }
 320   }
 321
 322   static MemInfoBlock CreateNewMIBWithHistogram(uptr p, MemprofChunk *m,
 323                                                 u64 user_size) {
 324
 325     u64 c = GetShadowCountHistogram(p, user_size);
 326     long curtime = GetTimestamp();
 327     uint32_t HistogramSize =
 328         RoundUpTo(user_size, HISTOGRAM_GRANULARITY) / HISTOGRAM_GRANULARITY;
 329     uintptr_t Histogram =
 330         (uintptr_t)InternalAlloc(HistogramSize * sizeof(uint64_t));
 331     memset((void *)Histogram, 0, HistogramSize * sizeof(uint64_t));
 332     for (size_t i = 0; i < HistogramSize; ++i) {
 333       u8 Counter =
 334           *((u8 *)HISTOGRAM_MEM_TO_SHADOW(p + HISTOGRAM_GRANULARITY * i));
 335       ((uint64_t *)Histogram)[i] = (uint64_t)Counter;
 336     }
 337     MemInfoBlock newMIB(user_size, c, m->timestamp_ms, curtime, m->cpu_id,
 338                         GetCpuId(), Histogram, HistogramSize);
 339     return newMIB;
 340   }
 341
 342   static MemInfoBlock CreateNewMIBWithoutHistogram(uptr p, MemprofChunk *m,
 343                                                    u64 user_size) {
 344     u64 c = GetShadowCount(p, user_size);
 345     long curtime = GetTimestamp();
 346     MemInfoBlock newMIB(user_size, c, m->timestamp_ms, curtime, m->cpu_id,
 347                         GetCpuId(), 0, 0);
 348     return newMIB;
 349   }
 350
 351   void FinishAndWrite() {
 352     if (print_text && common_flags()->print_module_map)
 353       DumpProcessMap();
 354
 355     allocator.ForceLock();
 356
 357     InsertLiveBlocks();
 358     if (print_text) {
 359       if (!flags()->print_terse)
 360         Printf("Recorded MIBs (incl. live on exit):\n");
 361       MIBMap.ForEach(PrintCallback,
 362                      reinterpret_cast<void *>(flags()->print_terse));
 363       StackDepotPrintAll();
 364     } else {
 365       // Serialize the contents to a raw profile. Format documented in
 366       // memprof_rawprofile.h.
 367       char *Buffer = nullptr;
 368
 369       __sanitizer::ListOfModules List;
 370       List.init();
 371       ArrayRef<LoadedModule> Modules(List.begin(), List.end());
 372       u64 BytesSerialized = SerializeToRawProfile(MIBMap, Modules, Buffer);
 373       CHECK(Buffer && BytesSerialized && "could not serialize to buffer");
 374       report_file.Write(Buffer, BytesSerialized);
 375     }
 376
 377     allocator.ForceUnlock();
 378   }
 379
 380   // Inserts any blocks which have been allocated but not yet deallocated.
 381   void InsertLiveBlocks() {
 382     allocator.ForEachChunk(
 383         [](uptr chunk, void *alloc) {
 384           u64 user_requested_size;
 385           Allocator *A = (Allocator *)alloc;
 386           MemprofChunk *m =
 387               A->GetMemprofChunk((void *)chunk, user_requested_size);
 388           if (!m)
 389             return;
 390           uptr user_beg = ((uptr)m) + kChunkHeaderSize;
 391           MemInfoBlock newMIB = CreateNewMIB(user_beg, m, user_requested_size);
 392           InsertOrMerge(m->alloc_context_id, newMIB, A->MIBMap);
 393         },
 394         this);
 395   }
 396
 397   void InitLinkerInitialized() {
 398     SetAllocatorMayReturnNull(common_flags()->allocator_may_return_null);
 399     allocator.InitLinkerInitialized(
 400         common_flags()->allocator_release_to_os_interval_ms);
 401     max_user_defined_malloc_size = common_flags()->max_allocation_size_mb
 402                                        ? common_flags()->max_allocation_size_mb
 403                                              << 20
 404                                        : kMaxAllowedMallocSize;
 405   }
 406
 407   // -------------------- Allocation/Deallocation routines ---------------
 408   void *Allocate(uptr size, uptr alignment, BufferedStackTrace *stack,
 409                  AllocType alloc_type) {
 410     if (UNLIKELY(!memprof_inited))
 411       MemprofInitFromRtl();
 412     if (UNLIKELY(IsRssLimitExceeded())) {
 413       if (AllocatorMayReturnNull())
 414         return nullptr;
 415       ReportRssLimitExceeded(stack);
 416     }
 417     CHECK(stack);
 418     const uptr min_alignment = MEMPROF_ALIGNMENT;
 419     if (alignment < min_alignment)
 420       alignment = min_alignment;
 421     if (size == 0) {
 422       // We'd be happy to avoid allocating memory for zero-size requests, but
 423       // some programs/tests depend on this behavior and assume that malloc
 424       // would not return NULL even for zero-size allocations. Moreover, it
 425       // looks like operator new should never return NULL, and results of
 426       // consecutive "new" calls must be different even if the allocated size
 427       // is zero.
 428       size = 1;
 429     }
 430     CHECK(IsPowerOfTwo(alignment));
 431     uptr rounded_size = RoundUpTo(size, alignment);
 432     uptr needed_size = rounded_size + kChunkHeaderSize;
 433     if (alignment > min_alignment)
 434       needed_size += alignment;
 435     CHECK(IsAligned(needed_size, min_alignment));
 436     if (size > kMaxAllowedMallocSize || needed_size > kMaxAllowedMallocSize ||
 437         size > max_user_defined_malloc_size) {
 438       if (AllocatorMayReturnNull()) {
 439         Report("WARNING: MemProfiler failed to allocate 0x%zx bytes\n", size);
 440         return nullptr;
 441       }
 442       uptr malloc_limit =
 443           Min(kMaxAllowedMallocSize, max_user_defined_malloc_size);
 444       ReportAllocationSizeTooBig(size, malloc_limit, stack);
 445     }
 446
 447     MemprofThread *t = GetCurrentThread();
 448     void *allocated;
 449     if (t) {
 450       AllocatorCache *cache = GetAllocatorCache(&t->malloc_storage());
 451       allocated = allocator.Allocate(cache, needed_size, 8);
 452     } else {
 453       SpinMutexLock l(&fallback_mutex);
 454       AllocatorCache *cache = &fallback_allocator_cache;
 455       allocated = allocator.Allocate(cache, needed_size, 8);
 456     }
 457     if (UNLIKELY(!allocated)) {
 458       SetAllocatorOutOfMemory();
 459       if (AllocatorMayReturnNull())
 460         return nullptr;
 461       ReportOutOfMemory(size, stack);
 462     }
 463
 464     uptr alloc_beg = reinterpret_cast<uptr>(allocated);
 465     uptr alloc_end = alloc_beg + needed_size;
 466     uptr beg_plus_header = alloc_beg + kChunkHeaderSize;
 467     uptr user_beg = beg_plus_header;
 468     if (!IsAligned(user_beg, alignment))
 469       user_beg = RoundUpTo(user_beg, alignment);
 470     uptr user_end = user_beg + size;
 471     CHECK_LE(user_end, alloc_end);
 472     uptr chunk_beg = user_beg - kChunkHeaderSize;
 473     MemprofChunk *m = reinterpret_cast<MemprofChunk *>(chunk_beg);
 474     m->from_memalign = alloc_beg != chunk_beg;
 475     CHECK(size);
 476
 477     m->cpu_id = GetCpuId();
 478     m->timestamp_ms = GetTimestamp();
 479     m->alloc_context_id = StackDepotPut(*stack);
 480
 481     uptr size_rounded_down_to_granularity =
 482         RoundDownTo(size, SHADOW_GRANULARITY);
 483     if (size_rounded_down_to_granularity)
 484       ClearShadow(user_beg, size_rounded_down_to_granularity);
 485
 486     MemprofStats &thread_stats = GetCurrentThreadStats();
 487     thread_stats.mallocs++;
 488     thread_stats.malloced += size;
 489     thread_stats.malloced_overhead += needed_size - size;
 490     if (needed_size > SizeClassMap::kMaxSize)
 491       thread_stats.malloc_large++;
 492     else
 493       thread_stats.malloced_by_size[SizeClassMap::ClassID(needed_size)]++;
 494
 495     void *res = reinterpret_cast<void *>(user_beg);
 496     atomic_store(&m->user_requested_size, size, memory_order_release);
 497     if (alloc_beg != chunk_beg) {
 498       CHECK_LE(alloc_beg + sizeof(LargeChunkHeader), chunk_beg);
 499       reinterpret_cast<LargeChunkHeader *>(alloc_beg)->Set(m);
 500     }
 501     RunMallocHooks(res, size);
 502     return res;
 503   }
 504
 505   void Deallocate(void *ptr, uptr delete_size, uptr delete_alignment,
 506                   BufferedStackTrace *stack, AllocType alloc_type) {
 507     uptr p = reinterpret_cast<uptr>(ptr);
 508     if (p == 0)
 509       return;
 510
 511     RunFreeHooks(ptr);
 512
 513     uptr chunk_beg = p - kChunkHeaderSize;
 514     MemprofChunk *m = reinterpret_cast<MemprofChunk *>(chunk_beg);
 515
 516     u64 user_requested_size =
 517         atomic_exchange(&m->user_requested_size, 0, memory_order_acquire);
 518     if (memprof_inited && atomic_load_relaxed(&constructed) &&
 519         !atomic_load_relaxed(&destructing)) {
 520       MemInfoBlock newMIB = this->CreateNewMIB(p, m, user_requested_size);
 521       InsertOrMerge(m->alloc_context_id, newMIB, MIBMap);
 522     }
 523
 524     MemprofStats &thread_stats = GetCurrentThreadStats();
 525     thread_stats.frees++;
 526     thread_stats.freed += user_requested_size;
 527
 528     void *alloc_beg = m->AllocBeg();
 529     if (alloc_beg != m) {
 530       // Clear the magic value, as allocator internals may overwrite the
 531       // contents of deallocated chunk, confusing GetMemprofChunk lookup.
 532       reinterpret_cast<LargeChunkHeader *>(alloc_beg)->Set(nullptr);
 533     }
 534
 535     MemprofThread *t = GetCurrentThread();
 536     if (t) {
 537       AllocatorCache *cache = GetAllocatorCache(&t->malloc_storage());
 538       allocator.Deallocate(cache, alloc_beg);
 539     } else {
 540       SpinMutexLock l(&fallback_mutex);
 541       AllocatorCache *cache = &fallback_allocator_cache;
 542       allocator.Deallocate(cache, alloc_beg);
 543     }
 544   }
 545
 546   void *Reallocate(void *old_ptr, uptr new_size, BufferedStackTrace *stack) {
 547     CHECK(old_ptr && new_size);
 548     uptr p = reinterpret_cast<uptr>(old_ptr);
 549     uptr chunk_beg = p - kChunkHeaderSize;
 550     MemprofChunk *m = reinterpret_cast<MemprofChunk *>(chunk_beg);
 551
 552     MemprofStats &thread_stats = GetCurrentThreadStats();
 553     thread_stats.reallocs++;
 554     thread_stats.realloced += new_size;
 555
 556     void *new_ptr = Allocate(new_size, 8, stack, FROM_MALLOC);
 557     if (new_ptr) {
 558       CHECK_NE(REAL(memcpy), nullptr);
 559       uptr memcpy_size = Min(new_size, m->UsedSize());
 560       REAL(memcpy)(new_ptr, old_ptr, memcpy_size);
 561       Deallocate(old_ptr, 0, 0, stack, FROM_MALLOC);
 562     }
 563     return new_ptr;
 564   }
 565
 566   void *Calloc(uptr nmemb, uptr size, BufferedStackTrace *stack) {
 567     if (UNLIKELY(CheckForCallocOverflow(size, nmemb))) {
 568       if (AllocatorMayReturnNull())
 569         return nullptr;
 570       ReportCallocOverflow(nmemb, size, stack);
 571     }
 572     void *ptr = Allocate(nmemb * size, 8, stack, FROM_MALLOC);
 573     // If the memory comes from the secondary allocator no need to clear it
 574     // as it comes directly from mmap.
 575     if (ptr && allocator.FromPrimary(ptr))
 576       REAL(memset)(ptr, 0, nmemb * size);
 577     return ptr;
 578   }
 579
 580   void CommitBack(MemprofThreadLocalMallocStorage *ms) {
 581     AllocatorCache *ac = GetAllocatorCache(ms);
 582     allocator.SwallowCache(ac);
 583   }
 584
 585   // -------------------------- Chunk lookup ----------------------
 586
 587   // Assumes alloc_beg == allocator.GetBlockBegin(alloc_beg).
 588   MemprofChunk *GetMemprofChunk(void *alloc_beg, u64 &user_requested_size) {
 589     if (!alloc_beg)
 590       return nullptr;
 591     MemprofChunk *p = reinterpret_cast<LargeChunkHeader *>(alloc_beg)->Get();
 592     if (!p) {
 593       if (!allocator.FromPrimary(alloc_beg))
 594         return nullptr;
 595       p = reinterpret_cast<MemprofChunk *>(alloc_beg);
 596     }
 597     // The size is reset to 0 on deallocation (and a min of 1 on
 598     // allocation).
 599     user_requested_size =
 600         atomic_load(&p->user_requested_size, memory_order_acquire);
 601     if (user_requested_size)
 602       return p;
 603     return nullptr;
 604   }
 605
 606   MemprofChunk *GetMemprofChunkByAddr(uptr p, u64 &user_requested_size) {
 607     void *alloc_beg = allocator.GetBlockBegin(reinterpret_cast<void *>(p));
 608     return GetMemprofChunk(alloc_beg, user_requested_size);
 609   }
 610
 611   uptr AllocationSize(uptr p) {
 612     u64 user_requested_size;
 613     MemprofChunk *m = GetMemprofChunkByAddr(p, user_requested_size);
 614     if (!m)
 615       return 0;
 616     if (m->Beg() != p)
 617       return 0;
 618     return user_requested_size;
 619   }
 620
 621   uptr AllocationSizeFast(uptr p) {
 622     return reinterpret_cast<MemprofChunk *>(p - kChunkHeaderSize)->UsedSize();
 623   }
 624
 625   void Purge() { allocator.ForceReleaseToOS(); }
 626
 627   void PrintStats() { allocator.PrintStats(); }
 628
 629   void ForceLock() SANITIZER_NO_THREAD_SAFETY_ANALYSIS {
 630     allocator.ForceLock();
 631     fallback_mutex.Lock();
 632   }
 633
 634   void ForceUnlock() SANITIZER_NO_THREAD_SAFETY_ANALYSIS {
 635     fallback_mutex.Unlock();
 636     allocator.ForceUnlock();
 637   }
 638 };
 639
 640 static Allocator instance(LINKER_INITIALIZED);
 641
 642 static MemprofAllocator &get_allocator() { return instance.allocator; }
 643
 644 void InitializeAllocator() { instance.InitLinkerInitialized(); }
 645
 646 void MemprofThreadLocalMallocStorage::CommitBack() {
 647   instance.CommitBack(this);
 648 }
 649
 650 void PrintInternalAllocatorStats() { instance.PrintStats(); }
 651
 652 void memprof_free(void *ptr, BufferedStackTrace *stack, AllocType alloc_type) {
 653   instance.Deallocate(ptr, 0, 0, stack, alloc_type);
 654 }
 655
 656 void memprof_delete(void *ptr, uptr size, uptr alignment,
 657                     BufferedStackTrace *stack, AllocType alloc_type) {
 658   instance.Deallocate(ptr, size, alignment, stack, alloc_type);
 659 }
 660
 661 void *memprof_malloc(uptr size, BufferedStackTrace *stack) {
 662   return SetErrnoOnNull(instance.Allocate(size, 8, stack, FROM_MALLOC));
 663 }
 664
 665 void *memprof_calloc(uptr nmemb, uptr size, BufferedStackTrace *stack) {
 666   return SetErrnoOnNull(instance.Calloc(nmemb, size, stack));
 667 }
 668
 669 void *memprof_reallocarray(void *p, uptr nmemb, uptr size,
 670                            BufferedStackTrace *stack) {
 671   if (UNLIKELY(CheckForCallocOverflow(size, nmemb))) {
 672     errno = errno_ENOMEM;
 673     if (AllocatorMayReturnNull())
 674       return nullptr;
 675     ReportReallocArrayOverflow(nmemb, size, stack);
 676   }
 677   return memprof_realloc(p, nmemb * size, stack);
 678 }
 679
 680 void *memprof_realloc(void *p, uptr size, BufferedStackTrace *stack) {
 681   if (!p)
 682     return SetErrnoOnNull(instance.Allocate(size, 8, stack, FROM_MALLOC));
 683   if (size == 0) {
 684     if (flags()->allocator_frees_and_returns_null_on_realloc_zero) {
 685       instance.Deallocate(p, 0, 0, stack, FROM_MALLOC);
 686       return nullptr;
 687     }
 688     // Allocate a size of 1 if we shouldn't free() on Realloc to 0
 689     size = 1;
 690   }
 691   return SetErrnoOnNull(instance.Reallocate(p, size, stack));
 692 }
 693
 694 void *memprof_valloc(uptr size, BufferedStackTrace *stack) {
 695   return SetErrnoOnNull(
 696       instance.Allocate(size, GetPageSizeCached(), stack, FROM_MALLOC));
 697 }
 698
 699 void *memprof_pvalloc(uptr size, BufferedStackTrace *stack) {
 700   uptr PageSize = GetPageSizeCached();
 701   if (UNLIKELY(CheckForPvallocOverflow(size, PageSize))) {
 702     errno = errno_ENOMEM;
 703     if (AllocatorMayReturnNull())
 704       return nullptr;
 705     ReportPvallocOverflow(size, stack);
 706   }
 707   // pvalloc(0) should allocate one page.
 708   size = size ? RoundUpTo(size, PageSize) : PageSize;
 709   return SetErrnoOnNull(instance.Allocate(size, PageSize, stack, FROM_MALLOC));
 710 }
 711
 712 void *memprof_memalign(uptr alignment, uptr size, BufferedStackTrace *stack,
 713                        AllocType alloc_type) {
 714   if (UNLIKELY(!IsPowerOfTwo(alignment))) {
 715     errno = errno_EINVAL;
 716     if (AllocatorMayReturnNull())
 717       return nullptr;
 718     ReportInvalidAllocationAlignment(alignment, stack);
 719   }
 720   return SetErrnoOnNull(instance.Allocate(size, alignment, stack, alloc_type));
 721 }
 722
 723 void *memprof_aligned_alloc(uptr alignment, uptr size,
 724                             BufferedStackTrace *stack) {
 725   if (UNLIKELY(!CheckAlignedAllocAlignmentAndSize(alignment, size))) {
 726     errno = errno_EINVAL;
 727     if (AllocatorMayReturnNull())
 728       return nullptr;
 729     ReportInvalidAlignedAllocAlignment(size, alignment, stack);
 730   }
 731   return SetErrnoOnNull(instance.Allocate(size, alignment, stack, FROM_MALLOC));
 732 }
 733
 734 int memprof_posix_memalign(void **memptr, uptr alignment, uptr size,
 735                            BufferedStackTrace *stack) {
 736   if (UNLIKELY(!CheckPosixMemalignAlignment(alignment))) {
 737     if (AllocatorMayReturnNull())
 738       return errno_EINVAL;
 739     ReportInvalidPosixMemalignAlignment(alignment, stack);
 740   }
 741   void *ptr = instance.Allocate(size, alignment, stack, FROM_MALLOC);
 742   if (UNLIKELY(!ptr))
 743     // OOM error is already taken care of by Allocate.
 744     return errno_ENOMEM;
 745   CHECK(IsAligned((uptr)ptr, alignment));
 746   *memptr = ptr;
 747   return 0;
 748 }
 749
 750 static const void *memprof_malloc_begin(const void *p) {
 751   u64 user_requested_size;
 752   MemprofChunk *m =
 753       instance.GetMemprofChunkByAddr((uptr)p, user_requested_size);
 754   if (!m)
 755     return nullptr;
 756   if (user_requested_size == 0)
 757     return nullptr;
 758
 759   return (const void *)m->Beg();
 760 }
 761
 762 uptr memprof_malloc_usable_size(const void *ptr) {
 763   if (!ptr)
 764     return 0;
 765   uptr usable_size = instance.AllocationSize(reinterpret_cast<uptr>(ptr));
 766   return usable_size;
 767 }
 768
 769 } // namespace __memprof
 770
 771 // ---------------------- Interface ---------------- {{{1
 772 using namespace __memprof;
 773
 774 uptr __sanitizer_get_estimated_allocated_size(uptr size) { return size; }
 775
 776 int __sanitizer_get_ownership(const void *p) {
 777   return memprof_malloc_usable_size(p) != 0;
 778 }
 779
 780 const void *__sanitizer_get_allocated_begin(const void *p) {
 781   return memprof_malloc_begin(p);
 782 }
 783
 784 uptr __sanitizer_get_allocated_size(const void *p) {
 785   return memprof_malloc_usable_size(p);
 786 }
 787
 788 uptr __sanitizer_get_allocated_size_fast(const void *p) {
 789   DCHECK_EQ(p, __sanitizer_get_allocated_begin(p));
 790   uptr ret = instance.AllocationSizeFast(reinterpret_cast<uptr>(p));
 791   DCHECK_EQ(ret, __sanitizer_get_allocated_size(p));
 792   return ret;
 793 }
 794
 795 void __sanitizer_purge_allocator() { instance.Purge(); }
 796
 797 int __memprof_profile_dump() {
 798   instance.FinishAndWrite();
 799   // In the future we may want to return non-zero if there are any errors
 800   // detected during the dumping process.
 801   return 0;
 802 }
 803
 804 void __memprof_profile_reset() {
 805   if (report_file.fd != kInvalidFd && report_file.fd != kStdoutFd &&
 806       report_file.fd != kStderrFd) {
 807     CloseFile(report_file.fd);
 808     // Setting the file descriptor to kInvalidFd ensures that we will reopen the
 809     // file when invoking Write again.
 810     report_file.fd = kInvalidFd;
 811   }
 812 }