asan_allocator2.cc revision d9def29fe0dc8fc70ef270dcc1a266ad9257ec1f
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//===----------------------------------------------------------------------===// 17#include "asan_allocator.h" 18 19#include "asan_mapping.h" 20#include "asan_poisoning.h" 21#include "asan_report.h" 22#include "asan_thread.h" 23#include "sanitizer_common/sanitizer_allocator.h" 24#include "sanitizer_common/sanitizer_flags.h" 25#include "sanitizer_common/sanitizer_internal_defs.h" 26#include "sanitizer_common/sanitizer_list.h" 27#include "sanitizer_common/sanitizer_stackdepot.h" 28#include "sanitizer_common/sanitizer_quarantine.h" 29#include "lsan/lsan_common.h" 30 31namespace __asan { 32 33struct AsanMapUnmapCallback { 34 void OnMap(uptr p, uptr size) const { 35 PoisonShadow(p, size, kAsanHeapLeftRedzoneMagic); 36 // Statistics. 37 AsanStats &thread_stats = GetCurrentThreadStats(); 38 thread_stats.mmaps++; 39 thread_stats.mmaped += size; 40 } 41 void OnUnmap(uptr p, uptr size) const { 42 PoisonShadow(p, size, 0); 43 // We are about to unmap a chunk of user memory. 44 // Mark the corresponding shadow memory as not needed. 45 // Since asan's mapping is compacting, the shadow chunk may be 46 // not page-aligned, so we only flush the page-aligned portion. 47 uptr page_size = GetPageSizeCached(); 48 uptr shadow_beg = RoundUpTo(MemToShadow(p), page_size); 49 uptr shadow_end = RoundDownTo(MemToShadow(p + size), page_size); 50 FlushUnneededShadowMemory(shadow_beg, shadow_end - shadow_beg); 51 // Statistics. 52 AsanStats &thread_stats = GetCurrentThreadStats(); 53 thread_stats.munmaps++; 54 thread_stats.munmaped += size; 55 } 56}; 57 58#if SANITIZER_WORDSIZE == 64 59#if defined(__powerpc64__) 60const uptr kAllocatorSpace = 0xa0000000000ULL; 61const uptr kAllocatorSize = 0x20000000000ULL; // 2T. 62#else 63const uptr kAllocatorSpace = 0x600000000000ULL; 64const uptr kAllocatorSize = 0x40000000000ULL; // 4T. 65#endif 66typedef DefaultSizeClassMap SizeClassMap; 67typedef SizeClassAllocator64<kAllocatorSpace, kAllocatorSize, 0 /*metadata*/, 68 SizeClassMap, AsanMapUnmapCallback> PrimaryAllocator; 69#elif SANITIZER_WORDSIZE == 32 70static const u64 kAddressSpaceSize = 1ULL << 32; 71typedef CompactSizeClassMap SizeClassMap; 72static const uptr kRegionSizeLog = 20; 73static const uptr kFlatByteMapSize = kAddressSpaceSize >> kRegionSizeLog; 74typedef SizeClassAllocator32<0, kAddressSpaceSize, 16, 75 SizeClassMap, kRegionSizeLog, 76 FlatByteMap<kFlatByteMapSize>, 77 AsanMapUnmapCallback> PrimaryAllocator; 78#endif 79 80typedef SizeClassAllocatorLocalCache<PrimaryAllocator> AllocatorCache; 81typedef LargeMmapAllocator<AsanMapUnmapCallback> SecondaryAllocator; 82typedef CombinedAllocator<PrimaryAllocator, AllocatorCache, 83 SecondaryAllocator> Allocator; 84 85// We can not use THREADLOCAL because it is not supported on some of the 86// platforms we care about (OSX 10.6, Android). 87// static THREADLOCAL AllocatorCache cache; 88AllocatorCache *GetAllocatorCache(AsanThreadLocalMallocStorage *ms) { 89 CHECK(ms); 90 CHECK_LE(sizeof(AllocatorCache), sizeof(ms->allocator2_cache)); 91 return reinterpret_cast<AllocatorCache *>(ms->allocator2_cache); 92} 93 94static Allocator allocator; 95 96static const uptr kMaxAllowedMallocSize = 97 FIRST_32_SECOND_64(3UL << 30, 8UL << 30); 98 99static const uptr kMaxThreadLocalQuarantine = 100 FIRST_32_SECOND_64(1 << 18, 1 << 20); 101 102// Every chunk of memory allocated by this allocator can be in one of 3 states: 103// CHUNK_AVAILABLE: the chunk is in the free list and ready to be allocated. 104// CHUNK_ALLOCATED: the chunk is allocated and not yet freed. 105// CHUNK_QUARANTINE: the chunk was freed and put into quarantine zone. 106enum { 107 CHUNK_AVAILABLE = 0, // 0 is the default value even if we didn't set it. 108 CHUNK_ALLOCATED = 2, 109 CHUNK_QUARANTINE = 3 110}; 111 112// Valid redzone sizes are 16, 32, 64, ... 2048, so we encode them in 3 bits. 113// We use adaptive redzones: for larger allocation larger redzones are used. 114static u32 RZLog2Size(u32 rz_log) { 115 CHECK_LT(rz_log, 8); 116 return 16 << rz_log; 117} 118 119static u32 RZSize2Log(u32 rz_size) { 120 CHECK_GE(rz_size, 16); 121 CHECK_LE(rz_size, 2048); 122 CHECK(IsPowerOfTwo(rz_size)); 123 u32 res = Log2(rz_size) - 4; 124 CHECK_EQ(rz_size, RZLog2Size(res)); 125 return res; 126} 127 128static uptr ComputeRZLog(uptr user_requested_size) { 129 u32 rz_log = 130 user_requested_size <= 64 - 16 ? 0 : 131 user_requested_size <= 128 - 32 ? 1 : 132 user_requested_size <= 512 - 64 ? 2 : 133 user_requested_size <= 4096 - 128 ? 3 : 134 user_requested_size <= (1 << 14) - 256 ? 4 : 135 user_requested_size <= (1 << 15) - 512 ? 5 : 136 user_requested_size <= (1 << 16) - 1024 ? 6 : 7; 137 return Max(rz_log, RZSize2Log(flags()->redzone)); 138} 139 140// The memory chunk allocated from the underlying allocator looks like this: 141// L L L L L L H H U U U U U U R R 142// L -- left redzone words (0 or more bytes) 143// H -- ChunkHeader (16 bytes), which is also a part of the left redzone. 144// U -- user memory. 145// R -- right redzone (0 or more bytes) 146// ChunkBase consists of ChunkHeader and other bytes that overlap with user 147// memory. 148 149// If the left redzone is greater than the ChunkHeader size we store a magic 150// value in the first uptr word of the memory block and store the address of 151// ChunkBase in the next uptr. 152// M B L L L L L L L L L H H U U U U U U 153// | ^ 154// ---------------------| 155// M -- magic value kAllocBegMagic 156// B -- address of ChunkHeader pointing to the first 'H' 157static const uptr kAllocBegMagic = 0xCC6E96B9; 158 159struct ChunkHeader { 160 // 1-st 8 bytes. 161 u32 chunk_state : 8; // Must be first. 162 u32 alloc_tid : 24; 163 164 u32 free_tid : 24; 165 u32 from_memalign : 1; 166 u32 alloc_type : 2; 167 u32 rz_log : 3; 168 u32 lsan_tag : 2; 169 // 2-nd 8 bytes 170 // This field is used for small sizes. For large sizes it is equal to 171 // SizeClassMap::kMaxSize and the actual size is stored in the 172 // SecondaryAllocator's metadata. 173 u32 user_requested_size; 174 u32 alloc_context_id; 175}; 176 177struct ChunkBase : ChunkHeader { 178 // Header2, intersects with user memory. 179 u32 free_context_id; 180}; 181 182static const uptr kChunkHeaderSize = sizeof(ChunkHeader); 183static const uptr kChunkHeader2Size = sizeof(ChunkBase) - kChunkHeaderSize; 184COMPILER_CHECK(kChunkHeaderSize == 16); 185COMPILER_CHECK(kChunkHeader2Size <= 16); 186 187struct AsanChunk: ChunkBase { 188 uptr Beg() { return reinterpret_cast<uptr>(this) + kChunkHeaderSize; } 189 uptr UsedSize() { 190 if (user_requested_size != SizeClassMap::kMaxSize) 191 return user_requested_size; 192 return *reinterpret_cast<uptr *>(allocator.GetMetaData(AllocBeg())); 193 } 194 void *AllocBeg() { 195 if (from_memalign) 196 return allocator.GetBlockBegin(reinterpret_cast<void *>(this)); 197 return reinterpret_cast<void*>(Beg() - RZLog2Size(rz_log)); 198 } 199 // If we don't use stack depot, we store the alloc/free stack traces 200 // in the chunk itself. 201 u32 *AllocStackBeg() { 202 return (u32*)(Beg() - RZLog2Size(rz_log)); 203 } 204 uptr AllocStackSize() { 205 CHECK_LE(RZLog2Size(rz_log), kChunkHeaderSize); 206 return (RZLog2Size(rz_log) - kChunkHeaderSize) / sizeof(u32); 207 } 208 u32 *FreeStackBeg() { 209 return (u32*)(Beg() + kChunkHeader2Size); 210 } 211 uptr FreeStackSize() { 212 if (user_requested_size < kChunkHeader2Size) return 0; 213 uptr available = RoundUpTo(user_requested_size, SHADOW_GRANULARITY); 214 return (available - kChunkHeader2Size) / sizeof(u32); 215 } 216 bool AddrIsInside(uptr addr) { 217 return (addr >= Beg()) && (addr < Beg() + UsedSize()); 218 } 219}; 220 221bool AsanChunkView::IsValid() { 222 return chunk_ != 0 && chunk_->chunk_state != CHUNK_AVAILABLE; 223} 224uptr AsanChunkView::Beg() { return chunk_->Beg(); } 225uptr AsanChunkView::End() { return Beg() + UsedSize(); } 226uptr AsanChunkView::UsedSize() { return chunk_->UsedSize(); } 227uptr AsanChunkView::AllocTid() { return chunk_->alloc_tid; } 228uptr AsanChunkView::FreeTid() { return chunk_->free_tid; } 229 230static void GetStackTraceFromId(u32 id, StackTrace *stack) { 231 CHECK(id); 232 uptr size = 0; 233 const uptr *trace = StackDepotGet(id, &size); 234 CHECK(trace); 235 stack->CopyFrom(trace, size); 236} 237 238void AsanChunkView::GetAllocStack(StackTrace *stack) { 239 if (flags()->use_stack_depot) 240 GetStackTraceFromId(chunk_->alloc_context_id, stack); 241 else 242 StackTrace::UncompressStack(stack, chunk_->AllocStackBeg(), 243 chunk_->AllocStackSize()); 244} 245 246void AsanChunkView::GetFreeStack(StackTrace *stack) { 247 if (flags()->use_stack_depot) 248 GetStackTraceFromId(chunk_->free_context_id, stack); 249 else 250 StackTrace::UncompressStack(stack, chunk_->FreeStackBeg(), 251 chunk_->FreeStackSize()); 252} 253 254struct QuarantineCallback; 255typedef Quarantine<QuarantineCallback, AsanChunk> AsanQuarantine; 256typedef AsanQuarantine::Cache QuarantineCache; 257static AsanQuarantine quarantine(LINKER_INITIALIZED); 258static QuarantineCache fallback_quarantine_cache(LINKER_INITIALIZED); 259static AllocatorCache fallback_allocator_cache; 260static SpinMutex fallback_mutex; 261 262QuarantineCache *GetQuarantineCache(AsanThreadLocalMallocStorage *ms) { 263 CHECK(ms); 264 CHECK_LE(sizeof(QuarantineCache), sizeof(ms->quarantine_cache)); 265 return reinterpret_cast<QuarantineCache *>(ms->quarantine_cache); 266} 267 268struct QuarantineCallback { 269 explicit QuarantineCallback(AllocatorCache *cache) 270 : cache_(cache) { 271 } 272 273 void Recycle(AsanChunk *m) { 274 CHECK_EQ(m->chunk_state, CHUNK_QUARANTINE); 275 atomic_store((atomic_uint8_t*)m, CHUNK_AVAILABLE, memory_order_relaxed); 276 CHECK_NE(m->alloc_tid, kInvalidTid); 277 CHECK_NE(m->free_tid, kInvalidTid); 278 PoisonShadow(m->Beg(), 279 RoundUpTo(m->UsedSize(), SHADOW_GRANULARITY), 280 kAsanHeapLeftRedzoneMagic); 281 void *p = reinterpret_cast<void *>(m->AllocBeg()); 282 if (p != m) { 283 uptr *alloc_magic = reinterpret_cast<uptr *>(p); 284 CHECK_EQ(alloc_magic[0], kAllocBegMagic); 285 // Clear the magic value, as allocator internals may overwrite the 286 // contents of deallocated chunk, confusing GetAsanChunk lookup. 287 alloc_magic[0] = 0; 288 CHECK_EQ(alloc_magic[1], reinterpret_cast<uptr>(m)); 289 } 290 291 // Statistics. 292 AsanStats &thread_stats = GetCurrentThreadStats(); 293 thread_stats.real_frees++; 294 thread_stats.really_freed += m->UsedSize(); 295 296 allocator.Deallocate(cache_, p); 297 } 298 299 void *Allocate(uptr size) { 300 return allocator.Allocate(cache_, size, 1, false); 301 } 302 303 void Deallocate(void *p) { 304 allocator.Deallocate(cache_, p); 305 } 306 307 AllocatorCache *cache_; 308}; 309 310void InitializeAllocator() { 311 allocator.Init(); 312 quarantine.Init((uptr)flags()->quarantine_size, kMaxThreadLocalQuarantine); 313} 314 315static void *Allocate(uptr size, uptr alignment, StackTrace *stack, 316 AllocType alloc_type, bool can_fill) { 317 if (!asan_inited) 318 __asan_init(); 319 Flags &fl = *flags(); 320 CHECK(stack); 321 const uptr min_alignment = SHADOW_GRANULARITY; 322 if (alignment < min_alignment) 323 alignment = min_alignment; 324 if (size == 0) { 325 // We'd be happy to avoid allocating memory for zero-size requests, but 326 // some programs/tests depend on this behavior and assume that malloc would 327 // not return NULL even for zero-size allocations. Moreover, it looks like 328 // operator new should never return NULL, and results of consecutive "new" 329 // calls must be different even if the allocated size is zero. 330 size = 1; 331 } 332 CHECK(IsPowerOfTwo(alignment)); 333 uptr rz_log = ComputeRZLog(size); 334 uptr rz_size = RZLog2Size(rz_log); 335 uptr rounded_size = RoundUpTo(Max(size, kChunkHeader2Size), alignment); 336 uptr needed_size = rounded_size + rz_size; 337 if (alignment > min_alignment) 338 needed_size += alignment; 339 bool using_primary_allocator = true; 340 // If we are allocating from the secondary allocator, there will be no 341 // automatic right redzone, so add the right redzone manually. 342 if (!PrimaryAllocator::CanAllocate(needed_size, alignment)) { 343 needed_size += rz_size; 344 using_primary_allocator = false; 345 } 346 CHECK(IsAligned(needed_size, min_alignment)); 347 if (size > kMaxAllowedMallocSize || needed_size > kMaxAllowedMallocSize) { 348 Report("WARNING: AddressSanitizer failed to allocate %p bytes\n", 349 (void*)size); 350 return AllocatorReturnNull(); 351 } 352 353 AsanThread *t = GetCurrentThread(); 354 void *allocated; 355 if (t) { 356 AllocatorCache *cache = GetAllocatorCache(&t->malloc_storage()); 357 allocated = allocator.Allocate(cache, needed_size, 8, false); 358 } else { 359 SpinMutexLock l(&fallback_mutex); 360 AllocatorCache *cache = &fallback_allocator_cache; 361 allocated = allocator.Allocate(cache, needed_size, 8, false); 362 } 363 uptr alloc_beg = reinterpret_cast<uptr>(allocated); 364 uptr alloc_end = alloc_beg + needed_size; 365 uptr beg_plus_redzone = alloc_beg + rz_size; 366 uptr user_beg = beg_plus_redzone; 367 if (!IsAligned(user_beg, alignment)) 368 user_beg = RoundUpTo(user_beg, alignment); 369 uptr user_end = user_beg + size; 370 CHECK_LE(user_end, alloc_end); 371 uptr chunk_beg = user_beg - kChunkHeaderSize; 372 AsanChunk *m = reinterpret_cast<AsanChunk *>(chunk_beg); 373 m->alloc_type = alloc_type; 374 m->rz_log = rz_log; 375 u32 alloc_tid = t ? t->tid() : 0; 376 m->alloc_tid = alloc_tid; 377 CHECK_EQ(alloc_tid, m->alloc_tid); // Does alloc_tid fit into the bitfield? 378 m->free_tid = kInvalidTid; 379 m->from_memalign = user_beg != beg_plus_redzone; 380 if (alloc_beg != chunk_beg) { 381 CHECK_LE(alloc_beg+ 2 * sizeof(uptr), chunk_beg); 382 reinterpret_cast<uptr *>(alloc_beg)[0] = kAllocBegMagic; 383 reinterpret_cast<uptr *>(alloc_beg)[1] = chunk_beg; 384 } 385 if (using_primary_allocator) { 386 CHECK(size); 387 m->user_requested_size = size; 388 CHECK(allocator.FromPrimary(allocated)); 389 } else { 390 CHECK(!allocator.FromPrimary(allocated)); 391 m->user_requested_size = SizeClassMap::kMaxSize; 392 uptr *meta = reinterpret_cast<uptr *>(allocator.GetMetaData(allocated)); 393 meta[0] = size; 394 meta[1] = chunk_beg; 395 } 396 397 if (fl.use_stack_depot) { 398 m->alloc_context_id = StackDepotPut(stack->trace, stack->size); 399 } else { 400 m->alloc_context_id = 0; 401 StackTrace::CompressStack(stack, m->AllocStackBeg(), m->AllocStackSize()); 402 } 403 404 uptr size_rounded_down_to_granularity = RoundDownTo(size, SHADOW_GRANULARITY); 405 // Unpoison the bulk of the memory region. 406 if (size_rounded_down_to_granularity) 407 PoisonShadow(user_beg, size_rounded_down_to_granularity, 0); 408 // Deal with the end of the region if size is not aligned to granularity. 409 if (size != size_rounded_down_to_granularity && fl.poison_heap) { 410 u8 *shadow = (u8*)MemToShadow(user_beg + size_rounded_down_to_granularity); 411 *shadow = size & (SHADOW_GRANULARITY - 1); 412 } 413 414 AsanStats &thread_stats = GetCurrentThreadStats(); 415 thread_stats.mallocs++; 416 thread_stats.malloced += size; 417 thread_stats.malloced_redzones += needed_size - size; 418 uptr class_id = Min(kNumberOfSizeClasses, SizeClassMap::ClassID(needed_size)); 419 thread_stats.malloced_by_size[class_id]++; 420 if (needed_size > SizeClassMap::kMaxSize) 421 thread_stats.malloc_large++; 422 423 void *res = reinterpret_cast<void *>(user_beg); 424 if (can_fill && fl.max_malloc_fill_size) { 425 uptr fill_size = Min(size, (uptr)fl.max_malloc_fill_size); 426 REAL(memset)(res, fl.malloc_fill_byte, fill_size); 427 } 428#if CAN_SANITIZE_LEAKS 429 m->lsan_tag = __lsan::DisabledInThisThread() ? __lsan::kIgnored 430 : __lsan::kDirectlyLeaked; 431#endif 432 // Must be the last mutation of metadata in this function. 433 atomic_store((atomic_uint8_t *)m, CHUNK_ALLOCATED, memory_order_release); 434 ASAN_MALLOC_HOOK(res, size); 435 return res; 436} 437 438static void ReportInvalidFree(void *ptr, u8 chunk_state, StackTrace *stack) { 439 if (chunk_state == CHUNK_QUARANTINE) 440 ReportDoubleFree((uptr)ptr, stack); 441 else 442 ReportFreeNotMalloced((uptr)ptr, stack); 443} 444 445static void AtomicallySetQuarantineFlag(AsanChunk *m, 446 void *ptr, StackTrace *stack) { 447 u8 old_chunk_state = CHUNK_ALLOCATED; 448 // Flip the chunk_state atomically to avoid race on double-free. 449 if (!atomic_compare_exchange_strong((atomic_uint8_t*)m, &old_chunk_state, 450 CHUNK_QUARANTINE, memory_order_acquire)) 451 ReportInvalidFree(ptr, old_chunk_state, stack); 452 CHECK_EQ(CHUNK_ALLOCATED, old_chunk_state); 453} 454 455// Expects the chunk to already be marked as quarantined by using 456// AtomicallySetQuarantineFlag. 457static void QuarantineChunk(AsanChunk *m, void *ptr, 458 StackTrace *stack, AllocType alloc_type) { 459 CHECK_EQ(m->chunk_state, CHUNK_QUARANTINE); 460 461 if (m->alloc_type != alloc_type && flags()->alloc_dealloc_mismatch) 462 ReportAllocTypeMismatch((uptr)ptr, stack, 463 (AllocType)m->alloc_type, (AllocType)alloc_type); 464 465 CHECK_GE(m->alloc_tid, 0); 466 if (SANITIZER_WORDSIZE == 64) // On 32-bits this resides in user area. 467 CHECK_EQ(m->free_tid, kInvalidTid); 468 AsanThread *t = GetCurrentThread(); 469 m->free_tid = t ? t->tid() : 0; 470 if (flags()->use_stack_depot) { 471 m->free_context_id = StackDepotPut(stack->trace, stack->size); 472 } else { 473 m->free_context_id = 0; 474 StackTrace::CompressStack(stack, m->FreeStackBeg(), m->FreeStackSize()); 475 } 476 // Poison the region. 477 PoisonShadow(m->Beg(), 478 RoundUpTo(m->UsedSize(), SHADOW_GRANULARITY), 479 kAsanHeapFreeMagic); 480 481 AsanStats &thread_stats = GetCurrentThreadStats(); 482 thread_stats.frees++; 483 thread_stats.freed += m->UsedSize(); 484 485 // Push into quarantine. 486 if (t) { 487 AsanThreadLocalMallocStorage *ms = &t->malloc_storage(); 488 AllocatorCache *ac = GetAllocatorCache(ms); 489 quarantine.Put(GetQuarantineCache(ms), QuarantineCallback(ac), 490 m, m->UsedSize()); 491 } else { 492 SpinMutexLock l(&fallback_mutex); 493 AllocatorCache *ac = &fallback_allocator_cache; 494 quarantine.Put(&fallback_quarantine_cache, QuarantineCallback(ac), 495 m, m->UsedSize()); 496 } 497} 498 499static void Deallocate(void *ptr, StackTrace *stack, AllocType alloc_type) { 500 uptr p = reinterpret_cast<uptr>(ptr); 501 if (p == 0) return; 502 503 uptr chunk_beg = p - kChunkHeaderSize; 504 AsanChunk *m = reinterpret_cast<AsanChunk *>(chunk_beg); 505 ASAN_FREE_HOOK(ptr); 506 // Must mark the chunk as quarantined before any changes to its metadata. 507 AtomicallySetQuarantineFlag(m, ptr, stack); 508 QuarantineChunk(m, ptr, stack, alloc_type); 509} 510 511static void *Reallocate(void *old_ptr, uptr new_size, StackTrace *stack) { 512 CHECK(old_ptr && new_size); 513 uptr p = reinterpret_cast<uptr>(old_ptr); 514 uptr chunk_beg = p - kChunkHeaderSize; 515 AsanChunk *m = reinterpret_cast<AsanChunk *>(chunk_beg); 516 517 AsanStats &thread_stats = GetCurrentThreadStats(); 518 thread_stats.reallocs++; 519 thread_stats.realloced += new_size; 520 521 void *new_ptr = Allocate(new_size, 8, stack, FROM_MALLOC, true); 522 if (new_ptr) { 523 u8 chunk_state = m->chunk_state; 524 if (chunk_state != CHUNK_ALLOCATED) 525 ReportInvalidFree(old_ptr, chunk_state, stack); 526 CHECK_NE(REAL(memcpy), (void*)0); 527 uptr memcpy_size = Min(new_size, m->UsedSize()); 528 // If realloc() races with free(), we may start copying freed memory. 529 // However, we will report racy double-free later anyway. 530 REAL(memcpy)(new_ptr, old_ptr, memcpy_size); 531 Deallocate(old_ptr, stack, FROM_MALLOC); 532 } 533 return new_ptr; 534} 535 536// Assumes alloc_beg == allocator.GetBlockBegin(alloc_beg). 537static AsanChunk *GetAsanChunk(void *alloc_beg) { 538 if (!alloc_beg) return 0; 539 if (!allocator.FromPrimary(alloc_beg)) { 540 uptr *meta = reinterpret_cast<uptr *>(allocator.GetMetaData(alloc_beg)); 541 AsanChunk *m = reinterpret_cast<AsanChunk *>(meta[1]); 542 return m; 543 } 544 uptr *alloc_magic = reinterpret_cast<uptr *>(alloc_beg); 545 if (alloc_magic[0] == kAllocBegMagic) 546 return reinterpret_cast<AsanChunk *>(alloc_magic[1]); 547 return reinterpret_cast<AsanChunk *>(alloc_beg); 548} 549 550static AsanChunk *GetAsanChunkByAddr(uptr p) { 551 void *alloc_beg = allocator.GetBlockBegin(reinterpret_cast<void *>(p)); 552 return GetAsanChunk(alloc_beg); 553} 554 555// Allocator must be locked when this function is called. 556static AsanChunk *GetAsanChunkByAddrFastLocked(uptr p) { 557 void *alloc_beg = 558 allocator.GetBlockBeginFastLocked(reinterpret_cast<void *>(p)); 559 return GetAsanChunk(alloc_beg); 560} 561 562static uptr AllocationSize(uptr p) { 563 AsanChunk *m = GetAsanChunkByAddr(p); 564 if (!m) return 0; 565 if (m->chunk_state != CHUNK_ALLOCATED) return 0; 566 if (m->Beg() != p) return 0; 567 return m->UsedSize(); 568} 569 570// We have an address between two chunks, and we want to report just one. 571AsanChunk *ChooseChunk(uptr addr, 572 AsanChunk *left_chunk, AsanChunk *right_chunk) { 573 // Prefer an allocated chunk over freed chunk and freed chunk 574 // over available chunk. 575 if (left_chunk->chunk_state != right_chunk->chunk_state) { 576 if (left_chunk->chunk_state == CHUNK_ALLOCATED) 577 return left_chunk; 578 if (right_chunk->chunk_state == CHUNK_ALLOCATED) 579 return right_chunk; 580 if (left_chunk->chunk_state == CHUNK_QUARANTINE) 581 return left_chunk; 582 if (right_chunk->chunk_state == CHUNK_QUARANTINE) 583 return right_chunk; 584 } 585 // Same chunk_state: choose based on offset. 586 sptr l_offset = 0, r_offset = 0; 587 CHECK(AsanChunkView(left_chunk).AddrIsAtRight(addr, 1, &l_offset)); 588 CHECK(AsanChunkView(right_chunk).AddrIsAtLeft(addr, 1, &r_offset)); 589 if (l_offset < r_offset) 590 return left_chunk; 591 return right_chunk; 592} 593 594AsanChunkView FindHeapChunkByAddress(uptr addr) { 595 AsanChunk *m1 = GetAsanChunkByAddr(addr); 596 if (!m1) return AsanChunkView(m1); 597 sptr offset = 0; 598 if (AsanChunkView(m1).AddrIsAtLeft(addr, 1, &offset)) { 599 // The address is in the chunk's left redzone, so maybe it is actually 600 // a right buffer overflow from the other chunk to the left. 601 // Search a bit to the left to see if there is another chunk. 602 AsanChunk *m2 = 0; 603 for (uptr l = 1; l < GetPageSizeCached(); l++) { 604 m2 = GetAsanChunkByAddr(addr - l); 605 if (m2 == m1) continue; // Still the same chunk. 606 break; 607 } 608 if (m2 && AsanChunkView(m2).AddrIsAtRight(addr, 1, &offset)) 609 m1 = ChooseChunk(addr, m2, m1); 610 } 611 return AsanChunkView(m1); 612} 613 614void AsanThreadLocalMallocStorage::CommitBack() { 615 AllocatorCache *ac = GetAllocatorCache(this); 616 quarantine.Drain(GetQuarantineCache(this), QuarantineCallback(ac)); 617 allocator.SwallowCache(GetAllocatorCache(this)); 618} 619 620void PrintInternalAllocatorStats() { 621 allocator.PrintStats(); 622} 623 624void *asan_memalign(uptr alignment, uptr size, StackTrace *stack, 625 AllocType alloc_type) { 626 return Allocate(size, alignment, stack, alloc_type, true); 627} 628 629void asan_free(void *ptr, StackTrace *stack, AllocType alloc_type) { 630 Deallocate(ptr, stack, alloc_type); 631} 632 633void *asan_malloc(uptr size, StackTrace *stack) { 634 return Allocate(size, 8, stack, FROM_MALLOC, true); 635} 636 637void *asan_calloc(uptr nmemb, uptr size, StackTrace *stack) { 638 if (CallocShouldReturnNullDueToOverflow(size, nmemb)) 639 return AllocatorReturnNull(); 640 void *ptr = Allocate(nmemb * size, 8, stack, FROM_MALLOC, false); 641 // If the memory comes from the secondary allocator no need to clear it 642 // as it comes directly from mmap. 643 if (ptr && allocator.FromPrimary(ptr)) 644 REAL(memset)(ptr, 0, nmemb * size); 645 return ptr; 646} 647 648void *asan_realloc(void *p, uptr size, StackTrace *stack) { 649 if (p == 0) 650 return Allocate(size, 8, stack, FROM_MALLOC, true); 651 if (size == 0) { 652 Deallocate(p, stack, FROM_MALLOC); 653 return 0; 654 } 655 return Reallocate(p, size, stack); 656} 657 658void *asan_valloc(uptr size, StackTrace *stack) { 659 return Allocate(size, GetPageSizeCached(), stack, FROM_MALLOC, true); 660} 661 662void *asan_pvalloc(uptr size, StackTrace *stack) { 663 uptr PageSize = GetPageSizeCached(); 664 size = RoundUpTo(size, PageSize); 665 if (size == 0) { 666 // pvalloc(0) should allocate one page. 667 size = PageSize; 668 } 669 return Allocate(size, PageSize, stack, FROM_MALLOC, true); 670} 671 672int asan_posix_memalign(void **memptr, uptr alignment, uptr size, 673 StackTrace *stack) { 674 void *ptr = Allocate(size, alignment, stack, FROM_MALLOC, true); 675 CHECK(IsAligned((uptr)ptr, alignment)); 676 *memptr = ptr; 677 return 0; 678} 679 680uptr asan_malloc_usable_size(void *ptr, StackTrace *stack) { 681 CHECK(stack); 682 if (ptr == 0) return 0; 683 uptr usable_size = AllocationSize(reinterpret_cast<uptr>(ptr)); 684 if (flags()->check_malloc_usable_size && (usable_size == 0)) 685 ReportMallocUsableSizeNotOwned((uptr)ptr, stack); 686 return usable_size; 687} 688 689uptr asan_mz_size(const void *ptr) { 690 return AllocationSize(reinterpret_cast<uptr>(ptr)); 691} 692 693void asan_mz_force_lock() { 694 allocator.ForceLock(); 695 fallback_mutex.Lock(); 696} 697 698void asan_mz_force_unlock() { 699 fallback_mutex.Unlock(); 700 allocator.ForceUnlock(); 701} 702 703} // namespace __asan 704 705// --- Implementation of LSan-specific functions --- {{{1 706namespace __lsan { 707void LockAllocator() { 708 __asan::allocator.ForceLock(); 709} 710 711void UnlockAllocator() { 712 __asan::allocator.ForceUnlock(); 713} 714 715void GetAllocatorGlobalRange(uptr *begin, uptr *end) { 716 *begin = (uptr)&__asan::allocator; 717 *end = *begin + sizeof(__asan::allocator); 718} 719 720uptr PointsIntoChunk(void* p) { 721 uptr addr = reinterpret_cast<uptr>(p); 722 __asan::AsanChunk *m = __asan::GetAsanChunkByAddrFastLocked(addr); 723 if (!m) return 0; 724 uptr chunk = m->Beg(); 725 if ((m->chunk_state == __asan::CHUNK_ALLOCATED) && m->AddrIsInside(addr)) 726 return chunk; 727 return 0; 728} 729 730uptr GetUserBegin(uptr chunk) { 731 __asan::AsanChunk *m = 732 __asan::GetAsanChunkByAddrFastLocked(chunk); 733 CHECK(m); 734 return m->Beg(); 735} 736 737LsanMetadata::LsanMetadata(uptr chunk) { 738 metadata_ = reinterpret_cast<void *>(chunk - __asan::kChunkHeaderSize); 739} 740 741bool LsanMetadata::allocated() const { 742 __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_); 743 return m->chunk_state == __asan::CHUNK_ALLOCATED; 744} 745 746ChunkTag LsanMetadata::tag() const { 747 __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_); 748 return static_cast<ChunkTag>(m->lsan_tag); 749} 750 751void LsanMetadata::set_tag(ChunkTag value) { 752 __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_); 753 m->lsan_tag = value; 754} 755 756uptr LsanMetadata::requested_size() const { 757 __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_); 758 return m->UsedSize(); 759} 760 761u32 LsanMetadata::stack_trace_id() const { 762 __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_); 763 return m->alloc_context_id; 764} 765 766void ForEachChunk(ForEachChunkCallback callback, void *arg) { 767 __asan::allocator.ForEachChunk(callback, arg); 768} 769 770IgnoreObjectResult IgnoreObjectLocked(const void *p) { 771 uptr addr = reinterpret_cast<uptr>(p); 772 __asan::AsanChunk *m = __asan::GetAsanChunkByAddr(addr); 773 if (!m) return kIgnoreObjectInvalid; 774 if ((m->chunk_state == __asan::CHUNK_ALLOCATED) && m->AddrIsInside(addr)) { 775 if (m->lsan_tag == kIgnored) 776 return kIgnoreObjectAlreadyIgnored; 777 m->lsan_tag = __lsan::kIgnored; 778 return kIgnoreObjectSuccess; 779 } else { 780 return kIgnoreObjectInvalid; 781 } 782} 783} // namespace __lsan 784 785// ---------------------- Interface ---------------- {{{1 786using namespace __asan; // NOLINT 787 788// ASan allocator doesn't reserve extra bytes, so normally we would 789// just return "size". We don't want to expose our redzone sizes, etc here. 790uptr __asan_get_estimated_allocated_size(uptr size) { 791 return size; 792} 793 794bool __asan_get_ownership(const void *p) { 795 uptr ptr = reinterpret_cast<uptr>(p); 796 return (AllocationSize(ptr) > 0); 797} 798 799uptr __asan_get_allocated_size(const void *p) { 800 if (p == 0) return 0; 801 uptr ptr = reinterpret_cast<uptr>(p); 802 uptr allocated_size = AllocationSize(ptr); 803 // Die if p is not malloced or if it is already freed. 804 if (allocated_size == 0) { 805 GET_STACK_TRACE_FATAL_HERE; 806 ReportAsanGetAllocatedSizeNotOwned(ptr, &stack); 807 } 808 return allocated_size; 809} 810 811#if !SANITIZER_SUPPORTS_WEAK_HOOKS 812// Provide default (no-op) implementation of malloc hooks. 813extern "C" { 814SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE 815void __asan_malloc_hook(void *ptr, uptr size) { 816 (void)ptr; 817 (void)size; 818} 819SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE 820void __asan_free_hook(void *ptr) { 821 (void)ptr; 822} 823} // extern "C" 824#endif 825