asan_allocator2.cc revision 9fc0df892cab8735e7de0e86e995a3202c42cf82
1//===-- asan_allocator2.cc ------------------------------------------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file is a part of AddressSanitizer, an address sanity checker. 11// 12// Implementation of ASan's memory allocator, 2-nd version. 13// This variant uses the allocator from sanitizer_common, i.e. the one shared 14// with ThreadSanitizer and MemorySanitizer. 15// 16// Status: under development, not enabled by default yet. 17//===----------------------------------------------------------------------===// 18#include "asan_allocator.h" 19#if ASAN_ALLOCATOR_VERSION == 2 20 21#include "asan_mapping.h" 22#include "asan_report.h" 23#include "asan_thread.h" 24#include "asan_thread_registry.h" 25#include "sanitizer/asan_interface.h" 26#include "sanitizer_common/sanitizer_allocator.h" 27#include "sanitizer_common/sanitizer_internal_defs.h" 28#include "sanitizer_common/sanitizer_list.h" 29#include "sanitizer_common/sanitizer_stackdepot.h" 30#include "sanitizer_common/sanitizer_quarantine.h" 31 32namespace __asan { 33 34struct AsanMapUnmapCallback { 35 void OnMap(uptr p, uptr size) const { 36 PoisonShadow(p, size, kAsanHeapLeftRedzoneMagic); 37 // Statistics. 38 AsanStats &thread_stats = asanThreadRegistry().GetCurrentThreadStats(); 39 thread_stats.mmaps++; 40 thread_stats.mmaped += size; 41 } 42 void OnUnmap(uptr p, uptr size) const { 43 PoisonShadow(p, size, 0); 44 // We are about to unmap a chunk of user memory. 45 // Mark the corresponding shadow memory as not needed. 46 // Since asan's mapping is compacting, the shadow chunk may be 47 // not page-aligned, so we only flush the page-aligned portion. 48 uptr page_size = GetPageSizeCached(); 49 uptr shadow_beg = RoundUpTo(MemToShadow(p), page_size); 50 uptr shadow_end = RoundDownTo(MemToShadow(p + size), page_size); 51 FlushUnneededShadowMemory(shadow_beg, shadow_end - shadow_beg); 52 // Statistics. 53 AsanStats &thread_stats = asanThreadRegistry().GetCurrentThreadStats(); 54 thread_stats.munmaps++; 55 thread_stats.munmaped += size; 56 } 57}; 58 59#if SANITIZER_WORDSIZE == 64 60const uptr kAllocatorSpace = 0x600000000000ULL; 61const uptr kAllocatorSize = 0x10000000000ULL; // 1T. 62typedef DefaultSizeClassMap SizeClassMap; 63typedef SizeClassAllocator64<kAllocatorSpace, kAllocatorSize, 0 /*metadata*/, 64 SizeClassMap, AsanMapUnmapCallback> PrimaryAllocator; 65#elif SANITIZER_WORDSIZE == 32 66static const u64 kAddressSpaceSize = 1ULL << 32; 67typedef CompactSizeClassMap SizeClassMap; 68typedef SizeClassAllocator32<0, kAddressSpaceSize, 16, 69 SizeClassMap, AsanMapUnmapCallback> PrimaryAllocator; 70#endif 71 72typedef SizeClassAllocatorLocalCache<PrimaryAllocator> AllocatorCache; 73typedef LargeMmapAllocator<AsanMapUnmapCallback> SecondaryAllocator; 74typedef CombinedAllocator<PrimaryAllocator, AllocatorCache, 75 SecondaryAllocator> Allocator; 76 77// We can not use THREADLOCAL because it is not supported on some of the 78// platforms we care about (OSX 10.6, Android). 79// static THREADLOCAL AllocatorCache cache; 80AllocatorCache *GetAllocatorCache(AsanThreadLocalMallocStorage *ms) { 81 CHECK(ms); 82 CHECK_LE(sizeof(AllocatorCache), sizeof(ms->allocator2_cache)); 83 return reinterpret_cast<AllocatorCache *>(ms->allocator2_cache); 84} 85 86static Allocator allocator; 87 88static const uptr kMaxAllowedMallocSize = 89 FIRST_32_SECOND_64(3UL << 30, 8UL << 30); 90 91static const uptr kMaxThreadLocalQuarantine = 92 FIRST_32_SECOND_64(1 << 18, 1 << 20); 93 94static const uptr kReturnOnZeroMalloc = 2048; // Zero page is protected. 95 96// Every chunk of memory allocated by this allocator can be in one of 3 states: 97// CHUNK_AVAILABLE: the chunk is in the free list and ready to be allocated. 98// CHUNK_ALLOCATED: the chunk is allocated and not yet freed. 99// CHUNK_QUARANTINE: the chunk was freed and put into quarantine zone. 100enum { 101 CHUNK_AVAILABLE = 0, // 0 is the default value even if we didn't set it. 102 CHUNK_ALLOCATED = 2, 103 CHUNK_QUARANTINE = 3 104}; 105 106// Valid redzone sizes are 16, 32, 64, ... 2048, so we encode them in 3 bits. 107// We use adaptive redzones: for larger allocation larger redzones are used. 108static u32 RZLog2Size(u32 rz_log) { 109 CHECK_LT(rz_log, 8); 110 return 16 << rz_log; 111} 112 113static u32 RZSize2Log(u32 rz_size) { 114 CHECK_GE(rz_size, 16); 115 CHECK_LE(rz_size, 2048); 116 CHECK(IsPowerOfTwo(rz_size)); 117 u32 res = __builtin_ctz(rz_size) - 4; 118 CHECK_EQ(rz_size, RZLog2Size(res)); 119 return res; 120} 121 122static uptr ComputeRZLog(uptr user_requested_size) { 123 u32 rz_log = 124 user_requested_size <= 64 - 16 ? 0 : 125 user_requested_size <= 128 - 32 ? 1 : 126 user_requested_size <= 512 - 64 ? 2 : 127 user_requested_size <= 4096 - 128 ? 3 : 128 user_requested_size <= (1 << 14) - 256 ? 4 : 129 user_requested_size <= (1 << 15) - 512 ? 5 : 130 user_requested_size <= (1 << 16) - 1024 ? 6 : 7; 131 return Max(rz_log, RZSize2Log(flags()->redzone)); 132} 133 134// The memory chunk allocated from the underlying allocator looks like this: 135// L L L L L L H H U U U U U U R R 136// L -- left redzone words (0 or more bytes) 137// H -- ChunkHeader (16 bytes), which is also a part of the left redzone. 138// U -- user memory. 139// R -- right redzone (0 or more bytes) 140// ChunkBase consists of ChunkHeader and other bytes that overlap with user 141// memory. 142 143// If a memory chunk is allocated by memalign and we had to increase the 144// allocation size to achieve the proper alignment, then we store this magic 145// value in the first uptr word of the memory block and store the address of 146// ChunkBase in the next uptr. 147// M B ? ? ? L L L L L L H H U U U U U U 148// M -- magic value kMemalignMagic 149// B -- address of ChunkHeader pointing to the first 'H' 150static const uptr kMemalignMagic = 0xCC6E96B9; 151 152struct ChunkHeader { 153 // 1-st 8 bytes. 154 u32 chunk_state : 8; // Must be first. 155 u32 alloc_tid : 24; 156 157 u32 free_tid : 24; 158 u32 from_memalign : 1; 159 u32 alloc_type : 2; 160 u32 rz_log : 3; 161 // 2-nd 8 bytes 162 // This field is used for small sizes. For large sizes it is equal to 163 // SizeClassMap::kMaxSize and the actual size is stored in the 164 // SecondaryAllocator's metadata. 165 u32 user_requested_size; 166 u32 alloc_context_id; 167}; 168 169struct ChunkBase : ChunkHeader { 170 // Header2, intersects with user memory. 171 AsanChunk *next; 172 u32 free_context_id; 173}; 174 175static const uptr kChunkHeaderSize = sizeof(ChunkHeader); 176static const uptr kChunkHeader2Size = sizeof(ChunkBase) - kChunkHeaderSize; 177COMPILER_CHECK(kChunkHeaderSize == 16); 178COMPILER_CHECK(kChunkHeader2Size <= 16); 179 180struct AsanChunk: ChunkBase { 181 uptr Beg() { return reinterpret_cast<uptr>(this) + kChunkHeaderSize; } 182 uptr UsedSize() { 183 if (user_requested_size != SizeClassMap::kMaxSize) 184 return user_requested_size; 185 return *reinterpret_cast<uptr *>(allocator.GetMetaData(AllocBeg())); 186 } 187 void *AllocBeg() { 188 if (from_memalign) 189 return allocator.GetBlockBegin(reinterpret_cast<void *>(this)); 190 return reinterpret_cast<void*>(Beg() - RZLog2Size(rz_log)); 191 } 192 // We store the alloc/free stack traces in the chunk itself. 193 u32 *AllocStackBeg() { 194 return (u32*)(Beg() - RZLog2Size(rz_log)); 195 } 196 uptr AllocStackSize() { 197 CHECK_LE(RZLog2Size(rz_log), kChunkHeaderSize); 198 return (RZLog2Size(rz_log) - kChunkHeaderSize) / sizeof(u32); 199 } 200 u32 *FreeStackBeg() { 201 return (u32*)(Beg() + kChunkHeader2Size); 202 } 203 uptr FreeStackSize() { 204 if (user_requested_size < kChunkHeader2Size) return 0; 205 uptr available = RoundUpTo(user_requested_size, SHADOW_GRANULARITY); 206 return (available - kChunkHeader2Size) / sizeof(u32); 207 } 208}; 209 210uptr AsanChunkView::Beg() { return chunk_->Beg(); } 211uptr AsanChunkView::End() { return Beg() + UsedSize(); } 212uptr AsanChunkView::UsedSize() { return chunk_->UsedSize(); } 213uptr AsanChunkView::AllocTid() { return chunk_->alloc_tid; } 214uptr AsanChunkView::FreeTid() { return chunk_->free_tid; } 215 216static void GetStackTraceFromId(u32 id, StackTrace *stack) { 217 CHECK(id); 218 uptr size = 0; 219 const uptr *trace = StackDepotGet(id, &size); 220 CHECK_LT(size, kStackTraceMax); 221 internal_memcpy(stack->trace, trace, sizeof(uptr) * size); 222 stack->size = size; 223} 224 225void AsanChunkView::GetAllocStack(StackTrace *stack) { 226 if (flags()->use_stack_depot) 227 GetStackTraceFromId(chunk_->alloc_context_id, stack); 228 else 229 StackTrace::UncompressStack(stack, chunk_->AllocStackBeg(), 230 chunk_->AllocStackSize()); 231} 232 233void AsanChunkView::GetFreeStack(StackTrace *stack) { 234 if (flags()->use_stack_depot) 235 GetStackTraceFromId(chunk_->free_context_id, stack); 236 else 237 StackTrace::UncompressStack(stack, chunk_->FreeStackBeg(), 238 chunk_->FreeStackSize()); 239} 240 241struct QuarantineCallback; 242typedef Quarantine<QuarantineCallback, AsanChunk> AsanQuarantine; 243typedef AsanQuarantine::Cache QuarantineCache; 244static AsanQuarantine quarantine(LINKER_INITIALIZED); 245static QuarantineCache fallback_quarantine_cache(LINKER_INITIALIZED); 246static AllocatorCache fallback_allocator_cache; 247static SpinMutex fallback_mutex; 248 249QuarantineCache *GetQuarantineCache(AsanThreadLocalMallocStorage *ms) { 250 DCHECK(ms); 251 DCHECK_LE(sizeof(QuarantineCache), sizeof(ms->quarantine_cache)); 252 return reinterpret_cast<QuarantineCache *>(ms->quarantine_cache); 253} 254 255struct QuarantineCallback { 256 explicit QuarantineCallback(AllocatorCache *cache) 257 : cache_(cache) { 258 } 259 260 void Recycle(AsanChunk *m) { 261 CHECK(m->chunk_state == CHUNK_QUARANTINE); 262 m->chunk_state = CHUNK_AVAILABLE; 263 CHECK_NE(m->alloc_tid, kInvalidTid); 264 CHECK_NE(m->free_tid, kInvalidTid); 265 PoisonShadow(m->Beg(), 266 RoundUpTo(m->UsedSize(), SHADOW_GRANULARITY), 267 kAsanHeapLeftRedzoneMagic); 268 void *p = reinterpret_cast<void *>(m->AllocBeg()); 269 if (m->from_memalign) { 270 uptr *memalign_magic = reinterpret_cast<uptr *>(p); 271 CHECK_EQ(memalign_magic[0], kMemalignMagic); 272 CHECK_EQ(memalign_magic[1], reinterpret_cast<uptr>(m)); 273 } 274 275 // Statistics. 276 AsanStats &thread_stats = asanThreadRegistry().GetCurrentThreadStats(); 277 thread_stats.real_frees++; 278 thread_stats.really_freed += m->UsedSize(); 279 280 allocator.Deallocate(cache_, p); 281 } 282 283 void *Allocate(uptr size) { 284 return allocator.Allocate(cache_, size, 0, false); 285 } 286 287 void Deallocate(void *p) { 288 allocator.Deallocate(cache_, p); 289 } 290 291 AllocatorCache *cache_; 292}; 293 294static void Init() { 295 static int inited = 0; 296 if (inited) return; 297 __asan_init(); 298 inited = true; // this must happen before any threads are created. 299 allocator.Init(); 300 quarantine.Init((uptr)flags()->quarantine_size, kMaxThreadLocalQuarantine); 301} 302 303static void *Allocate(uptr size, uptr alignment, StackTrace *stack, 304 AllocType alloc_type) { 305 Init(); 306 CHECK(stack); 307 const uptr min_alignment = SHADOW_GRANULARITY; 308 if (alignment < min_alignment) 309 alignment = min_alignment; 310 if (size == 0) { 311 if (alignment <= kReturnOnZeroMalloc) 312 return reinterpret_cast<void *>(kReturnOnZeroMalloc); 313 else 314 return 0; // 0 bytes with large alignment requested. Just return 0. 315 } 316 CHECK(IsPowerOfTwo(alignment)); 317 uptr rz_log = ComputeRZLog(size); 318 uptr rz_size = RZLog2Size(rz_log); 319 uptr rounded_size = RoundUpTo(size, alignment); 320 if (rounded_size < kChunkHeader2Size) 321 rounded_size = kChunkHeader2Size; 322 uptr needed_size = rounded_size + rz_size; 323 if (alignment > min_alignment) 324 needed_size += alignment; 325 bool using_primary_allocator = true; 326 // If we are allocating from the secondary allocator, there will be no 327 // automatic right redzone, so add the right redzone manually. 328 if (!PrimaryAllocator::CanAllocate(needed_size, alignment)) { 329 needed_size += rz_size; 330 using_primary_allocator = false; 331 } 332 CHECK(IsAligned(needed_size, min_alignment)); 333 if (size > kMaxAllowedMallocSize || needed_size > kMaxAllowedMallocSize) { 334 Report("WARNING: AddressSanitizer failed to allocate %p bytes\n", 335 (void*)size); 336 return 0; 337 } 338 339 AsanThread *t = asanThreadRegistry().GetCurrent(); 340 AllocatorCache *cache = t ? GetAllocatorCache(&t->malloc_storage()) : 0; 341 void *allocated = allocator.Allocate(cache, needed_size, 8, false); 342 uptr alloc_beg = reinterpret_cast<uptr>(allocated); 343 uptr alloc_end = alloc_beg + needed_size; 344 uptr beg_plus_redzone = alloc_beg + rz_size; 345 uptr user_beg = beg_plus_redzone; 346 if (!IsAligned(user_beg, alignment)) 347 user_beg = RoundUpTo(user_beg, alignment); 348 uptr user_end = user_beg + size; 349 CHECK_LE(user_end, alloc_end); 350 uptr chunk_beg = user_beg - kChunkHeaderSize; 351 AsanChunk *m = reinterpret_cast<AsanChunk *>(chunk_beg); 352 m->chunk_state = CHUNK_ALLOCATED; 353 m->alloc_type = alloc_type; 354 m->rz_log = rz_log; 355 u32 alloc_tid = t ? t->tid() : 0; 356 m->alloc_tid = alloc_tid; 357 CHECK_EQ(alloc_tid, m->alloc_tid); // Does alloc_tid fit into the bitfield? 358 m->free_tid = kInvalidTid; 359 m->from_memalign = user_beg != beg_plus_redzone; 360 if (m->from_memalign) { 361 CHECK_LE(beg_plus_redzone + 2 * sizeof(uptr), user_beg); 362 uptr *memalign_magic = reinterpret_cast<uptr *>(alloc_beg); 363 memalign_magic[0] = kMemalignMagic; 364 memalign_magic[1] = chunk_beg; 365 } 366 if (using_primary_allocator) { 367 CHECK(size); 368 m->user_requested_size = size; 369 CHECK(allocator.FromPrimary(allocated)); 370 } else { 371 CHECK(!allocator.FromPrimary(allocated)); 372 m->user_requested_size = SizeClassMap::kMaxSize; 373 uptr *meta = reinterpret_cast<uptr *>(allocator.GetMetaData(allocated)); 374 meta[0] = size; 375 meta[1] = chunk_beg; 376 } 377 378 if (flags()->use_stack_depot) { 379 m->alloc_context_id = StackDepotPut(stack->trace, stack->size); 380 } else { 381 m->alloc_context_id = 0; 382 StackTrace::CompressStack(stack, m->AllocStackBeg(), m->AllocStackSize()); 383 } 384 385 uptr size_rounded_down_to_granularity = RoundDownTo(size, SHADOW_GRANULARITY); 386 // Unpoison the bulk of the memory region. 387 if (size_rounded_down_to_granularity) 388 PoisonShadow(user_beg, size_rounded_down_to_granularity, 0); 389 // Deal with the end of the region if size is not aligned to granularity. 390 if (size != size_rounded_down_to_granularity && flags()->poison_heap) { 391 u8 *shadow = (u8*)MemToShadow(user_beg + size_rounded_down_to_granularity); 392 *shadow = size & (SHADOW_GRANULARITY - 1); 393 } 394 395 AsanStats &thread_stats = asanThreadRegistry().GetCurrentThreadStats(); 396 thread_stats.mallocs++; 397 thread_stats.malloced += size; 398 thread_stats.malloced_redzones += needed_size - size; 399 uptr class_id = Min(kNumberOfSizeClasses, SizeClassMap::ClassID(needed_size)); 400 thread_stats.malloced_by_size[class_id]++; 401 if (needed_size > SizeClassMap::kMaxSize) 402 thread_stats.malloc_large++; 403 404 void *res = reinterpret_cast<void *>(user_beg); 405 ASAN_MALLOC_HOOK(res, size); 406 return res; 407} 408 409static void Deallocate(void *ptr, StackTrace *stack, AllocType alloc_type) { 410 uptr p = reinterpret_cast<uptr>(ptr); 411 if (p == 0 || p == kReturnOnZeroMalloc) return; 412 uptr chunk_beg = p - kChunkHeaderSize; 413 AsanChunk *m = reinterpret_cast<AsanChunk *>(chunk_beg); 414 415 // Flip the chunk_state atomically to avoid race on double-free. 416 u8 old_chunk_state = atomic_exchange((atomic_uint8_t*)m, CHUNK_QUARANTINE, 417 memory_order_acq_rel); 418 419 if (old_chunk_state == CHUNK_QUARANTINE) 420 ReportDoubleFree((uptr)ptr, stack); 421 else if (old_chunk_state != CHUNK_ALLOCATED) 422 ReportFreeNotMalloced((uptr)ptr, stack); 423 CHECK(old_chunk_state == CHUNK_ALLOCATED); 424 if (m->alloc_type != alloc_type && flags()->alloc_dealloc_mismatch) 425 ReportAllocTypeMismatch((uptr)ptr, stack, 426 (AllocType)m->alloc_type, (AllocType)alloc_type); 427 428 CHECK_GE(m->alloc_tid, 0); 429 if (SANITIZER_WORDSIZE == 64) // On 32-bits this resides in user area. 430 CHECK_EQ(m->free_tid, kInvalidTid); 431 AsanThread *t = asanThreadRegistry().GetCurrent(); 432 m->free_tid = t ? t->tid() : 0; 433 if (flags()->use_stack_depot) { 434 m->free_context_id = StackDepotPut(stack->trace, stack->size); 435 } else { 436 m->free_context_id = 0; 437 StackTrace::CompressStack(stack, m->FreeStackBeg(), m->FreeStackSize()); 438 } 439 CHECK(m->chunk_state == CHUNK_QUARANTINE); 440 // Poison the region. 441 PoisonShadow(m->Beg(), 442 RoundUpTo(m->UsedSize(), SHADOW_GRANULARITY), 443 kAsanHeapFreeMagic); 444 445 AsanStats &thread_stats = asanThreadRegistry().GetCurrentThreadStats(); 446 thread_stats.frees++; 447 thread_stats.freed += m->UsedSize(); 448 449 // Push into quarantine. 450 if (t) { 451 AsanThreadLocalMallocStorage *ms = &t->malloc_storage(); 452 AllocatorCache *ac = GetAllocatorCache(ms); 453 quarantine.Put(GetQuarantineCache(ms), QuarantineCallback(ac), m); 454 } else { 455 SpinMutexLock l(&fallback_mutex); 456 AllocatorCache *ac = &fallback_allocator_cache; 457 quarantine.Put(&fallback_quarantine_cache, QuarantineCallback(ac), m); 458 } 459 460 ASAN_FREE_HOOK(ptr); 461} 462 463static void *Reallocate(void *old_ptr, uptr new_size, StackTrace *stack) { 464 CHECK(old_ptr && new_size); 465 uptr p = reinterpret_cast<uptr>(old_ptr); 466 uptr chunk_beg = p - kChunkHeaderSize; 467 AsanChunk *m = reinterpret_cast<AsanChunk *>(chunk_beg); 468 469 AsanStats &thread_stats = asanThreadRegistry().GetCurrentThreadStats(); 470 thread_stats.reallocs++; 471 thread_stats.realloced += new_size; 472 473 CHECK(m->chunk_state == CHUNK_ALLOCATED); 474 uptr old_size = m->UsedSize(); 475 uptr memcpy_size = Min(new_size, old_size); 476 void *new_ptr = Allocate(new_size, 8, stack, FROM_MALLOC); 477 if (new_ptr) { 478 CHECK(REAL(memcpy) != 0); 479 REAL(memcpy)(new_ptr, old_ptr, memcpy_size); 480 Deallocate(old_ptr, stack, FROM_MALLOC); 481 } 482 return new_ptr; 483} 484 485static AsanChunk *GetAsanChunkByAddr(uptr p) { 486 void *ptr = reinterpret_cast<void *>(p); 487 uptr alloc_beg = reinterpret_cast<uptr>(allocator.GetBlockBegin(ptr)); 488 if (!alloc_beg) return 0; 489 uptr *memalign_magic = reinterpret_cast<uptr *>(alloc_beg); 490 if (memalign_magic[0] == kMemalignMagic) { 491 AsanChunk *m = reinterpret_cast<AsanChunk *>(memalign_magic[1]); 492 CHECK(m->from_memalign); 493 return m; 494 } 495 if (!allocator.FromPrimary(ptr)) { 496 uptr *meta = reinterpret_cast<uptr *>( 497 allocator.GetMetaData(reinterpret_cast<void *>(alloc_beg))); 498 AsanChunk *m = reinterpret_cast<AsanChunk *>(meta[1]); 499 return m; 500 } 501 uptr actual_size = allocator.GetActuallyAllocatedSize(ptr); 502 CHECK_LE(actual_size, SizeClassMap::kMaxSize); 503 // We know the actually allocted size, but we don't know the redzone size. 504 // Just try all possible redzone sizes. 505 for (u32 rz_log = 0; rz_log < 8; rz_log++) { 506 u32 rz_size = RZLog2Size(rz_log); 507 uptr max_possible_size = actual_size - rz_size; 508 if (ComputeRZLog(max_possible_size) != rz_log) 509 continue; 510 return reinterpret_cast<AsanChunk *>( 511 alloc_beg + rz_size - kChunkHeaderSize); 512 } 513 return 0; 514} 515 516static uptr AllocationSize(uptr p) { 517 AsanChunk *m = GetAsanChunkByAddr(p); 518 if (!m) return 0; 519 if (m->chunk_state != CHUNK_ALLOCATED) return 0; 520 if (m->Beg() != p) return 0; 521 return m->UsedSize(); 522} 523 524// We have an address between two chunks, and we want to report just one. 525AsanChunk *ChooseChunk(uptr addr, 526 AsanChunk *left_chunk, AsanChunk *right_chunk) { 527 // Prefer an allocated chunk over freed chunk and freed chunk 528 // over available chunk. 529 if (left_chunk->chunk_state != right_chunk->chunk_state) { 530 if (left_chunk->chunk_state == CHUNK_ALLOCATED) 531 return left_chunk; 532 if (right_chunk->chunk_state == CHUNK_ALLOCATED) 533 return right_chunk; 534 if (left_chunk->chunk_state == CHUNK_QUARANTINE) 535 return left_chunk; 536 if (right_chunk->chunk_state == CHUNK_QUARANTINE) 537 return right_chunk; 538 } 539 // Same chunk_state: choose based on offset. 540 uptr l_offset = 0, r_offset = 0; 541 CHECK(AsanChunkView(left_chunk).AddrIsAtRight(addr, 1, &l_offset)); 542 CHECK(AsanChunkView(right_chunk).AddrIsAtLeft(addr, 1, &r_offset)); 543 if (l_offset < r_offset) 544 return left_chunk; 545 return right_chunk; 546} 547 548AsanChunkView FindHeapChunkByAddress(uptr addr) { 549 AsanChunk *m1 = GetAsanChunkByAddr(addr); 550 if (!m1) return AsanChunkView(m1); 551 uptr offset = 0; 552 if (AsanChunkView(m1).AddrIsAtLeft(addr, 1, &offset)) { 553 // The address is in the chunk's left redzone, so maybe it is actually 554 // a right buffer overflow from the other chunk to the left. 555 // Search a bit to the left to see if there is another chunk. 556 AsanChunk *m2 = 0; 557 for (uptr l = 1; l < GetPageSizeCached(); l++) { 558 m2 = GetAsanChunkByAddr(addr - l); 559 if (m2 == m1) continue; // Still the same chunk. 560 break; 561 } 562 if (m2 && AsanChunkView(m2).AddrIsAtRight(addr, 1, &offset)) 563 m1 = ChooseChunk(addr, m2, m1); 564 } 565 return AsanChunkView(m1); 566} 567 568void AsanThreadLocalMallocStorage::CommitBack() { 569 AllocatorCache *ac = GetAllocatorCache(this); 570 quarantine.Drain(GetQuarantineCache(this), QuarantineCallback(ac)); 571 allocator.SwallowCache(GetAllocatorCache(this)); 572} 573 574void PrintInternalAllocatorStats() { 575 allocator.PrintStats(); 576} 577 578SANITIZER_INTERFACE_ATTRIBUTE 579void *asan_memalign(uptr alignment, uptr size, StackTrace *stack, 580 AllocType alloc_type) { 581 return Allocate(size, alignment, stack, alloc_type); 582} 583 584SANITIZER_INTERFACE_ATTRIBUTE 585void asan_free(void *ptr, StackTrace *stack, AllocType alloc_type) { 586 Deallocate(ptr, stack, alloc_type); 587} 588 589SANITIZER_INTERFACE_ATTRIBUTE 590void *asan_malloc(uptr size, StackTrace *stack) { 591 return Allocate(size, 8, stack, FROM_MALLOC); 592} 593 594void *asan_calloc(uptr nmemb, uptr size, StackTrace *stack) { 595 void *ptr = Allocate(nmemb * size, 8, stack, FROM_MALLOC); 596 if (ptr) 597 REAL(memset)(ptr, 0, nmemb * size); 598 return ptr; 599} 600 601void *asan_realloc(void *p, uptr size, StackTrace *stack) { 602 if (p == 0) 603 return Allocate(size, 8, stack, FROM_MALLOC); 604 if (size == 0) { 605 Deallocate(p, stack, FROM_MALLOC); 606 return 0; 607 } 608 return Reallocate(p, size, stack); 609} 610 611void *asan_valloc(uptr size, StackTrace *stack) { 612 return Allocate(size, GetPageSizeCached(), stack, FROM_MALLOC); 613} 614 615void *asan_pvalloc(uptr size, StackTrace *stack) { 616 uptr PageSize = GetPageSizeCached(); 617 size = RoundUpTo(size, PageSize); 618 if (size == 0) { 619 // pvalloc(0) should allocate one page. 620 size = PageSize; 621 } 622 return Allocate(size, PageSize, stack, FROM_MALLOC); 623} 624 625int asan_posix_memalign(void **memptr, uptr alignment, uptr size, 626 StackTrace *stack) { 627 void *ptr = Allocate(size, alignment, stack, FROM_MALLOC); 628 CHECK(IsAligned((uptr)ptr, alignment)); 629 *memptr = ptr; 630 return 0; 631} 632 633uptr asan_malloc_usable_size(void *ptr, StackTrace *stack) { 634 CHECK(stack); 635 if (ptr == 0) return 0; 636 uptr usable_size = AllocationSize(reinterpret_cast<uptr>(ptr)); 637 if (flags()->check_malloc_usable_size && (usable_size == 0)) 638 ReportMallocUsableSizeNotOwned((uptr)ptr, stack); 639 return usable_size; 640} 641 642uptr asan_mz_size(const void *ptr) { 643 UNIMPLEMENTED(); 644 return 0; 645} 646 647void asan_mz_force_lock() { 648 UNIMPLEMENTED(); 649} 650 651void asan_mz_force_unlock() { 652 UNIMPLEMENTED(); 653} 654 655} // namespace __asan 656 657// ---------------------- Interface ---------------- {{{1 658using namespace __asan; // NOLINT 659 660// ASan allocator doesn't reserve extra bytes, so normally we would 661// just return "size". We don't want to expose our redzone sizes, etc here. 662uptr __asan_get_estimated_allocated_size(uptr size) { 663 return size; 664} 665 666bool __asan_get_ownership(const void *p) { 667 return AllocationSize(reinterpret_cast<uptr>(p)) > 0; 668} 669 670uptr __asan_get_allocated_size(const void *p) { 671 if (p == 0) return 0; 672 uptr allocated_size = AllocationSize(reinterpret_cast<uptr>(p)); 673 // Die if p is not malloced or if it is already freed. 674 if (allocated_size == 0) { 675 GET_STACK_TRACE_FATAL_HERE; 676 ReportAsanGetAllocatedSizeNotOwned(reinterpret_cast<uptr>(p), &stack); 677 } 678 return allocated_size; 679} 680 681#if !SANITIZER_SUPPORTS_WEAK_HOOKS 682// Provide default (no-op) implementation of malloc hooks. 683extern "C" { 684SANITIZER_WEAK_ATTRIBUTE SANITIZER_INTERFACE_ATTRIBUTE 685void __asan_malloc_hook(void *ptr, uptr size) { 686 (void)ptr; 687 (void)size; 688} 689SANITIZER_WEAK_ATTRIBUTE SANITIZER_INTERFACE_ATTRIBUTE 690void __asan_free_hook(void *ptr) { 691 (void)ptr; 692} 693} // extern "C" 694#endif 695 696 697#endif // ASAN_ALLOCATOR_VERSION 698