asan_allocator2.cc revision 7f80655d8283dbdf77bfee4a849eed4d59e95c7a
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, 64UL << 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(bool locked_version = false) { 190 if (user_requested_size != SizeClassMap::kMaxSize) 191 return user_requested_size; 192 return *reinterpret_cast<uptr *>( 193 allocator.GetMetaData(AllocBeg(locked_version))); 194 } 195 void *AllocBeg(bool locked_version = false) { 196 if (from_memalign) { 197 if (locked_version) 198 return allocator.GetBlockBeginFastLocked( 199 reinterpret_cast<void *>(this)); 200 return allocator.GetBlockBegin(reinterpret_cast<void *>(this)); 201 } 202 return reinterpret_cast<void*>(Beg() - RZLog2Size(rz_log)); 203 } 204 // If we don't use stack depot, we store the alloc/free stack traces 205 // in the chunk itself. 206 u32 *AllocStackBeg() { 207 return (u32*)(Beg() - RZLog2Size(rz_log)); 208 } 209 uptr AllocStackSize() { 210 CHECK_LE(RZLog2Size(rz_log), kChunkHeaderSize); 211 return (RZLog2Size(rz_log) - kChunkHeaderSize) / sizeof(u32); 212 } 213 u32 *FreeStackBeg() { 214 return (u32*)(Beg() + kChunkHeader2Size); 215 } 216 uptr FreeStackSize() { 217 if (user_requested_size < kChunkHeader2Size) return 0; 218 uptr available = RoundUpTo(user_requested_size, SHADOW_GRANULARITY); 219 return (available - kChunkHeader2Size) / sizeof(u32); 220 } 221 bool AddrIsInside(uptr addr, bool locked_version = false) { 222 return (addr >= Beg()) && (addr < Beg() + UsedSize(locked_version)); 223 } 224}; 225 226bool AsanChunkView::IsValid() { 227 return chunk_ != 0 && chunk_->chunk_state != CHUNK_AVAILABLE; 228} 229uptr AsanChunkView::Beg() { return chunk_->Beg(); } 230uptr AsanChunkView::End() { return Beg() + UsedSize(); } 231uptr AsanChunkView::UsedSize() { return chunk_->UsedSize(); } 232uptr AsanChunkView::AllocTid() { return chunk_->alloc_tid; } 233uptr AsanChunkView::FreeTid() { return chunk_->free_tid; } 234 235static void GetStackTraceFromId(u32 id, StackTrace *stack) { 236 CHECK(id); 237 uptr size = 0; 238 const uptr *trace = StackDepotGet(id, &size); 239 CHECK(trace); 240 stack->CopyFrom(trace, size); 241} 242 243void AsanChunkView::GetAllocStack(StackTrace *stack) { 244 GetStackTraceFromId(chunk_->alloc_context_id, stack); 245} 246 247void AsanChunkView::GetFreeStack(StackTrace *stack) { 248 GetStackTraceFromId(chunk_->free_context_id, stack); 249} 250 251struct QuarantineCallback; 252typedef Quarantine<QuarantineCallback, AsanChunk> AsanQuarantine; 253typedef AsanQuarantine::Cache QuarantineCache; 254static AsanQuarantine quarantine(LINKER_INITIALIZED); 255static QuarantineCache fallback_quarantine_cache(LINKER_INITIALIZED); 256static AllocatorCache fallback_allocator_cache; 257static SpinMutex fallback_mutex; 258 259QuarantineCache *GetQuarantineCache(AsanThreadLocalMallocStorage *ms) { 260 CHECK(ms); 261 CHECK_LE(sizeof(QuarantineCache), sizeof(ms->quarantine_cache)); 262 return reinterpret_cast<QuarantineCache *>(ms->quarantine_cache); 263} 264 265struct QuarantineCallback { 266 explicit QuarantineCallback(AllocatorCache *cache) 267 : cache_(cache) { 268 } 269 270 void Recycle(AsanChunk *m) { 271 CHECK_EQ(m->chunk_state, CHUNK_QUARANTINE); 272 atomic_store((atomic_uint8_t*)m, CHUNK_AVAILABLE, memory_order_relaxed); 273 CHECK_NE(m->alloc_tid, kInvalidTid); 274 CHECK_NE(m->free_tid, kInvalidTid); 275 PoisonShadow(m->Beg(), 276 RoundUpTo(m->UsedSize(), SHADOW_GRANULARITY), 277 kAsanHeapLeftRedzoneMagic); 278 void *p = reinterpret_cast<void *>(m->AllocBeg()); 279 if (p != m) { 280 uptr *alloc_magic = reinterpret_cast<uptr *>(p); 281 CHECK_EQ(alloc_magic[0], kAllocBegMagic); 282 // Clear the magic value, as allocator internals may overwrite the 283 // contents of deallocated chunk, confusing GetAsanChunk lookup. 284 alloc_magic[0] = 0; 285 CHECK_EQ(alloc_magic[1], reinterpret_cast<uptr>(m)); 286 } 287 288 // Statistics. 289 AsanStats &thread_stats = GetCurrentThreadStats(); 290 thread_stats.real_frees++; 291 thread_stats.really_freed += m->UsedSize(); 292 293 allocator.Deallocate(cache_, p); 294 } 295 296 void *Allocate(uptr size) { 297 return allocator.Allocate(cache_, size, 1, false); 298 } 299 300 void Deallocate(void *p) { 301 allocator.Deallocate(cache_, p); 302 } 303 304 AllocatorCache *cache_; 305}; 306 307void InitializeAllocator() { 308 allocator.Init(); 309 quarantine.Init((uptr)flags()->quarantine_size, kMaxThreadLocalQuarantine); 310} 311 312static void *Allocate(uptr size, uptr alignment, StackTrace *stack, 313 AllocType alloc_type, bool can_fill) { 314 if (!asan_inited) 315 __asan_init(); 316 Flags &fl = *flags(); 317 CHECK(stack); 318 const uptr min_alignment = SHADOW_GRANULARITY; 319 if (alignment < min_alignment) 320 alignment = min_alignment; 321 if (size == 0) { 322 // We'd be happy to avoid allocating memory for zero-size requests, but 323 // some programs/tests depend on this behavior and assume that malloc would 324 // not return NULL even for zero-size allocations. Moreover, it looks like 325 // operator new should never return NULL, and results of consecutive "new" 326 // calls must be different even if the allocated size is zero. 327 size = 1; 328 } 329 CHECK(IsPowerOfTwo(alignment)); 330 uptr rz_log = ComputeRZLog(size); 331 uptr rz_size = RZLog2Size(rz_log); 332 uptr rounded_size = RoundUpTo(Max(size, kChunkHeader2Size), alignment); 333 uptr needed_size = rounded_size + rz_size; 334 if (alignment > min_alignment) 335 needed_size += alignment; 336 bool using_primary_allocator = true; 337 // If we are allocating from the secondary allocator, there will be no 338 // automatic right redzone, so add the right redzone manually. 339 if (!PrimaryAllocator::CanAllocate(needed_size, alignment)) { 340 needed_size += rz_size; 341 using_primary_allocator = false; 342 } 343 CHECK(IsAligned(needed_size, min_alignment)); 344 if (size > kMaxAllowedMallocSize || needed_size > kMaxAllowedMallocSize) { 345 Report("WARNING: AddressSanitizer failed to allocate %p bytes\n", 346 (void*)size); 347 return AllocatorReturnNull(); 348 } 349 350 AsanThread *t = GetCurrentThread(); 351 void *allocated; 352 if (t) { 353 AllocatorCache *cache = GetAllocatorCache(&t->malloc_storage()); 354 allocated = allocator.Allocate(cache, needed_size, 8, false); 355 } else { 356 SpinMutexLock l(&fallback_mutex); 357 AllocatorCache *cache = &fallback_allocator_cache; 358 allocated = allocator.Allocate(cache, needed_size, 8, false); 359 } 360 uptr alloc_beg = reinterpret_cast<uptr>(allocated); 361 uptr alloc_end = alloc_beg + needed_size; 362 uptr beg_plus_redzone = alloc_beg + rz_size; 363 uptr user_beg = beg_plus_redzone; 364 if (!IsAligned(user_beg, alignment)) 365 user_beg = RoundUpTo(user_beg, alignment); 366 uptr user_end = user_beg + size; 367 CHECK_LE(user_end, alloc_end); 368 uptr chunk_beg = user_beg - kChunkHeaderSize; 369 AsanChunk *m = reinterpret_cast<AsanChunk *>(chunk_beg); 370 m->alloc_type = alloc_type; 371 m->rz_log = rz_log; 372 u32 alloc_tid = t ? t->tid() : 0; 373 m->alloc_tid = alloc_tid; 374 CHECK_EQ(alloc_tid, m->alloc_tid); // Does alloc_tid fit into the bitfield? 375 m->free_tid = kInvalidTid; 376 m->from_memalign = user_beg != beg_plus_redzone; 377 if (alloc_beg != chunk_beg) { 378 CHECK_LE(alloc_beg+ 2 * sizeof(uptr), chunk_beg); 379 reinterpret_cast<uptr *>(alloc_beg)[0] = kAllocBegMagic; 380 reinterpret_cast<uptr *>(alloc_beg)[1] = chunk_beg; 381 } 382 if (using_primary_allocator) { 383 CHECK(size); 384 m->user_requested_size = size; 385 CHECK(allocator.FromPrimary(allocated)); 386 } else { 387 CHECK(!allocator.FromPrimary(allocated)); 388 m->user_requested_size = SizeClassMap::kMaxSize; 389 uptr *meta = reinterpret_cast<uptr *>(allocator.GetMetaData(allocated)); 390 meta[0] = size; 391 meta[1] = chunk_beg; 392 } 393 394 m->alloc_context_id = StackDepotPut(stack->trace, stack->size); 395 396 uptr size_rounded_down_to_granularity = RoundDownTo(size, SHADOW_GRANULARITY); 397 // Unpoison the bulk of the memory region. 398 if (size_rounded_down_to_granularity) 399 PoisonShadow(user_beg, size_rounded_down_to_granularity, 0); 400 // Deal with the end of the region if size is not aligned to granularity. 401 if (size != size_rounded_down_to_granularity && fl.poison_heap) { 402 u8 *shadow = (u8*)MemToShadow(user_beg + size_rounded_down_to_granularity); 403 *shadow = fl.poison_partial ? (size & (SHADOW_GRANULARITY - 1)) : 0; 404 } 405 406 AsanStats &thread_stats = GetCurrentThreadStats(); 407 thread_stats.mallocs++; 408 thread_stats.malloced += size; 409 thread_stats.malloced_redzones += needed_size - size; 410 uptr class_id = Min(kNumberOfSizeClasses, SizeClassMap::ClassID(needed_size)); 411 thread_stats.malloced_by_size[class_id]++; 412 if (needed_size > SizeClassMap::kMaxSize) 413 thread_stats.malloc_large++; 414 415 void *res = reinterpret_cast<void *>(user_beg); 416 if (can_fill && fl.max_malloc_fill_size) { 417 uptr fill_size = Min(size, (uptr)fl.max_malloc_fill_size); 418 REAL(memset)(res, fl.malloc_fill_byte, fill_size); 419 } 420#if CAN_SANITIZE_LEAKS 421 m->lsan_tag = __lsan::DisabledInThisThread() ? __lsan::kIgnored 422 : __lsan::kDirectlyLeaked; 423#endif 424 // Must be the last mutation of metadata in this function. 425 atomic_store((atomic_uint8_t *)m, CHUNK_ALLOCATED, memory_order_release); 426 ASAN_MALLOC_HOOK(res, size); 427 return res; 428} 429 430static void ReportInvalidFree(void *ptr, u8 chunk_state, StackTrace *stack) { 431 if (chunk_state == CHUNK_QUARANTINE) 432 ReportDoubleFree((uptr)ptr, stack); 433 else 434 ReportFreeNotMalloced((uptr)ptr, stack); 435} 436 437static void AtomicallySetQuarantineFlag(AsanChunk *m, 438 void *ptr, StackTrace *stack) { 439 u8 old_chunk_state = CHUNK_ALLOCATED; 440 // Flip the chunk_state atomically to avoid race on double-free. 441 if (!atomic_compare_exchange_strong((atomic_uint8_t*)m, &old_chunk_state, 442 CHUNK_QUARANTINE, memory_order_acquire)) 443 ReportInvalidFree(ptr, old_chunk_state, stack); 444 CHECK_EQ(CHUNK_ALLOCATED, old_chunk_state); 445} 446 447// Expects the chunk to already be marked as quarantined by using 448// AtomicallySetQuarantineFlag. 449static void QuarantineChunk(AsanChunk *m, void *ptr, 450 StackTrace *stack, AllocType alloc_type) { 451 CHECK_EQ(m->chunk_state, CHUNK_QUARANTINE); 452 453 if (m->alloc_type != alloc_type && flags()->alloc_dealloc_mismatch) 454 ReportAllocTypeMismatch((uptr)ptr, stack, 455 (AllocType)m->alloc_type, (AllocType)alloc_type); 456 457 CHECK_GE(m->alloc_tid, 0); 458 if (SANITIZER_WORDSIZE == 64) // On 32-bits this resides in user area. 459 CHECK_EQ(m->free_tid, kInvalidTid); 460 AsanThread *t = GetCurrentThread(); 461 m->free_tid = t ? t->tid() : 0; 462 m->free_context_id = StackDepotPut(stack->trace, stack->size); 463 // Poison the region. 464 PoisonShadow(m->Beg(), 465 RoundUpTo(m->UsedSize(), SHADOW_GRANULARITY), 466 kAsanHeapFreeMagic); 467 468 AsanStats &thread_stats = GetCurrentThreadStats(); 469 thread_stats.frees++; 470 thread_stats.freed += m->UsedSize(); 471 472 // Push into quarantine. 473 if (t) { 474 AsanThreadLocalMallocStorage *ms = &t->malloc_storage(); 475 AllocatorCache *ac = GetAllocatorCache(ms); 476 quarantine.Put(GetQuarantineCache(ms), QuarantineCallback(ac), 477 m, m->UsedSize()); 478 } else { 479 SpinMutexLock l(&fallback_mutex); 480 AllocatorCache *ac = &fallback_allocator_cache; 481 quarantine.Put(&fallback_quarantine_cache, QuarantineCallback(ac), 482 m, m->UsedSize()); 483 } 484} 485 486static void Deallocate(void *ptr, StackTrace *stack, AllocType alloc_type) { 487 uptr p = reinterpret_cast<uptr>(ptr); 488 if (p == 0) return; 489 490 uptr chunk_beg = p - kChunkHeaderSize; 491 AsanChunk *m = reinterpret_cast<AsanChunk *>(chunk_beg); 492 ASAN_FREE_HOOK(ptr); 493 // Must mark the chunk as quarantined before any changes to its metadata. 494 AtomicallySetQuarantineFlag(m, ptr, stack); 495 QuarantineChunk(m, ptr, stack, alloc_type); 496} 497 498static void *Reallocate(void *old_ptr, uptr new_size, StackTrace *stack) { 499 CHECK(old_ptr && new_size); 500 uptr p = reinterpret_cast<uptr>(old_ptr); 501 uptr chunk_beg = p - kChunkHeaderSize; 502 AsanChunk *m = reinterpret_cast<AsanChunk *>(chunk_beg); 503 504 AsanStats &thread_stats = GetCurrentThreadStats(); 505 thread_stats.reallocs++; 506 thread_stats.realloced += new_size; 507 508 void *new_ptr = Allocate(new_size, 8, stack, FROM_MALLOC, true); 509 if (new_ptr) { 510 u8 chunk_state = m->chunk_state; 511 if (chunk_state != CHUNK_ALLOCATED) 512 ReportInvalidFree(old_ptr, chunk_state, stack); 513 CHECK_NE(REAL(memcpy), (void*)0); 514 uptr memcpy_size = Min(new_size, m->UsedSize()); 515 // If realloc() races with free(), we may start copying freed memory. 516 // However, we will report racy double-free later anyway. 517 REAL(memcpy)(new_ptr, old_ptr, memcpy_size); 518 Deallocate(old_ptr, stack, FROM_MALLOC); 519 } 520 return new_ptr; 521} 522 523// Assumes alloc_beg == allocator.GetBlockBegin(alloc_beg). 524static AsanChunk *GetAsanChunk(void *alloc_beg) { 525 if (!alloc_beg) return 0; 526 if (!allocator.FromPrimary(alloc_beg)) { 527 uptr *meta = reinterpret_cast<uptr *>(allocator.GetMetaData(alloc_beg)); 528 AsanChunk *m = reinterpret_cast<AsanChunk *>(meta[1]); 529 return m; 530 } 531 uptr *alloc_magic = reinterpret_cast<uptr *>(alloc_beg); 532 if (alloc_magic[0] == kAllocBegMagic) 533 return reinterpret_cast<AsanChunk *>(alloc_magic[1]); 534 return reinterpret_cast<AsanChunk *>(alloc_beg); 535} 536 537static AsanChunk *GetAsanChunkByAddr(uptr p) { 538 void *alloc_beg = allocator.GetBlockBegin(reinterpret_cast<void *>(p)); 539 return GetAsanChunk(alloc_beg); 540} 541 542// Allocator must be locked when this function is called. 543static AsanChunk *GetAsanChunkByAddrFastLocked(uptr p) { 544 void *alloc_beg = 545 allocator.GetBlockBeginFastLocked(reinterpret_cast<void *>(p)); 546 return GetAsanChunk(alloc_beg); 547} 548 549static uptr AllocationSize(uptr p) { 550 AsanChunk *m = GetAsanChunkByAddr(p); 551 if (!m) return 0; 552 if (m->chunk_state != CHUNK_ALLOCATED) return 0; 553 if (m->Beg() != p) return 0; 554 return m->UsedSize(); 555} 556 557// We have an address between two chunks, and we want to report just one. 558AsanChunk *ChooseChunk(uptr addr, 559 AsanChunk *left_chunk, AsanChunk *right_chunk) { 560 // Prefer an allocated chunk over freed chunk and freed chunk 561 // over available chunk. 562 if (left_chunk->chunk_state != right_chunk->chunk_state) { 563 if (left_chunk->chunk_state == CHUNK_ALLOCATED) 564 return left_chunk; 565 if (right_chunk->chunk_state == CHUNK_ALLOCATED) 566 return right_chunk; 567 if (left_chunk->chunk_state == CHUNK_QUARANTINE) 568 return left_chunk; 569 if (right_chunk->chunk_state == CHUNK_QUARANTINE) 570 return right_chunk; 571 } 572 // Same chunk_state: choose based on offset. 573 sptr l_offset = 0, r_offset = 0; 574 CHECK(AsanChunkView(left_chunk).AddrIsAtRight(addr, 1, &l_offset)); 575 CHECK(AsanChunkView(right_chunk).AddrIsAtLeft(addr, 1, &r_offset)); 576 if (l_offset < r_offset) 577 return left_chunk; 578 return right_chunk; 579} 580 581AsanChunkView FindHeapChunkByAddress(uptr addr) { 582 AsanChunk *m1 = GetAsanChunkByAddr(addr); 583 if (!m1) return AsanChunkView(m1); 584 sptr offset = 0; 585 if (AsanChunkView(m1).AddrIsAtLeft(addr, 1, &offset)) { 586 // The address is in the chunk's left redzone, so maybe it is actually 587 // a right buffer overflow from the other chunk to the left. 588 // Search a bit to the left to see if there is another chunk. 589 AsanChunk *m2 = 0; 590 for (uptr l = 1; l < GetPageSizeCached(); l++) { 591 m2 = GetAsanChunkByAddr(addr - l); 592 if (m2 == m1) continue; // Still the same chunk. 593 break; 594 } 595 if (m2 && AsanChunkView(m2).AddrIsAtRight(addr, 1, &offset)) 596 m1 = ChooseChunk(addr, m2, m1); 597 } 598 return AsanChunkView(m1); 599} 600 601void AsanThreadLocalMallocStorage::CommitBack() { 602 AllocatorCache *ac = GetAllocatorCache(this); 603 quarantine.Drain(GetQuarantineCache(this), QuarantineCallback(ac)); 604 allocator.SwallowCache(GetAllocatorCache(this)); 605} 606 607void PrintInternalAllocatorStats() { 608 allocator.PrintStats(); 609} 610 611void *asan_memalign(uptr alignment, uptr size, StackTrace *stack, 612 AllocType alloc_type) { 613 return Allocate(size, alignment, stack, alloc_type, true); 614} 615 616void asan_free(void *ptr, StackTrace *stack, AllocType alloc_type) { 617 Deallocate(ptr, stack, alloc_type); 618} 619 620void *asan_malloc(uptr size, StackTrace *stack) { 621 return Allocate(size, 8, stack, FROM_MALLOC, true); 622} 623 624void *asan_calloc(uptr nmemb, uptr size, StackTrace *stack) { 625 if (CallocShouldReturnNullDueToOverflow(size, nmemb)) 626 return AllocatorReturnNull(); 627 void *ptr = Allocate(nmemb * size, 8, stack, FROM_MALLOC, false); 628 // If the memory comes from the secondary allocator no need to clear it 629 // as it comes directly from mmap. 630 if (ptr && allocator.FromPrimary(ptr)) 631 REAL(memset)(ptr, 0, nmemb * size); 632 return ptr; 633} 634 635void *asan_realloc(void *p, uptr size, StackTrace *stack) { 636 if (p == 0) 637 return Allocate(size, 8, stack, FROM_MALLOC, true); 638 if (size == 0) { 639 Deallocate(p, stack, FROM_MALLOC); 640 return 0; 641 } 642 return Reallocate(p, size, stack); 643} 644 645void *asan_valloc(uptr size, StackTrace *stack) { 646 return Allocate(size, GetPageSizeCached(), stack, FROM_MALLOC, true); 647} 648 649void *asan_pvalloc(uptr size, StackTrace *stack) { 650 uptr PageSize = GetPageSizeCached(); 651 size = RoundUpTo(size, PageSize); 652 if (size == 0) { 653 // pvalloc(0) should allocate one page. 654 size = PageSize; 655 } 656 return Allocate(size, PageSize, stack, FROM_MALLOC, true); 657} 658 659int asan_posix_memalign(void **memptr, uptr alignment, uptr size, 660 StackTrace *stack) { 661 void *ptr = Allocate(size, alignment, stack, FROM_MALLOC, true); 662 CHECK(IsAligned((uptr)ptr, alignment)); 663 *memptr = ptr; 664 return 0; 665} 666 667uptr asan_malloc_usable_size(void *ptr, StackTrace *stack) { 668 CHECK(stack); 669 if (ptr == 0) return 0; 670 uptr usable_size = AllocationSize(reinterpret_cast<uptr>(ptr)); 671 if (flags()->check_malloc_usable_size && (usable_size == 0)) 672 ReportMallocUsableSizeNotOwned((uptr)ptr, stack); 673 return usable_size; 674} 675 676uptr asan_mz_size(const void *ptr) { 677 return AllocationSize(reinterpret_cast<uptr>(ptr)); 678} 679 680void asan_mz_force_lock() { 681 allocator.ForceLock(); 682 fallback_mutex.Lock(); 683} 684 685void asan_mz_force_unlock() { 686 fallback_mutex.Unlock(); 687 allocator.ForceUnlock(); 688} 689 690} // namespace __asan 691 692// --- Implementation of LSan-specific functions --- {{{1 693namespace __lsan { 694void LockAllocator() { 695 __asan::allocator.ForceLock(); 696} 697 698void UnlockAllocator() { 699 __asan::allocator.ForceUnlock(); 700} 701 702void GetAllocatorGlobalRange(uptr *begin, uptr *end) { 703 *begin = (uptr)&__asan::allocator; 704 *end = *begin + sizeof(__asan::allocator); 705} 706 707uptr PointsIntoChunk(void* p) { 708 uptr addr = reinterpret_cast<uptr>(p); 709 __asan::AsanChunk *m = __asan::GetAsanChunkByAddrFastLocked(addr); 710 if (!m) return 0; 711 uptr chunk = m->Beg(); 712 if ((m->chunk_state == __asan::CHUNK_ALLOCATED) && 713 m->AddrIsInside(addr, /*locked_version=*/true)) 714 return chunk; 715 return 0; 716} 717 718uptr GetUserBegin(uptr chunk) { 719 __asan::AsanChunk *m = 720 __asan::GetAsanChunkByAddrFastLocked(chunk); 721 CHECK(m); 722 return m->Beg(); 723} 724 725LsanMetadata::LsanMetadata(uptr chunk) { 726 metadata_ = reinterpret_cast<void *>(chunk - __asan::kChunkHeaderSize); 727} 728 729bool LsanMetadata::allocated() const { 730 __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_); 731 return m->chunk_state == __asan::CHUNK_ALLOCATED; 732} 733 734ChunkTag LsanMetadata::tag() const { 735 __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_); 736 return static_cast<ChunkTag>(m->lsan_tag); 737} 738 739void LsanMetadata::set_tag(ChunkTag value) { 740 __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_); 741 m->lsan_tag = value; 742} 743 744uptr LsanMetadata::requested_size() const { 745 __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_); 746 return m->UsedSize(/*locked_version=*/true); 747} 748 749u32 LsanMetadata::stack_trace_id() const { 750 __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_); 751 return m->alloc_context_id; 752} 753 754void ForEachChunk(ForEachChunkCallback callback, void *arg) { 755 __asan::allocator.ForEachChunk(callback, arg); 756} 757 758IgnoreObjectResult IgnoreObjectLocked(const void *p) { 759 uptr addr = reinterpret_cast<uptr>(p); 760 __asan::AsanChunk *m = __asan::GetAsanChunkByAddr(addr); 761 if (!m) return kIgnoreObjectInvalid; 762 if ((m->chunk_state == __asan::CHUNK_ALLOCATED) && m->AddrIsInside(addr)) { 763 if (m->lsan_tag == kIgnored) 764 return kIgnoreObjectAlreadyIgnored; 765 m->lsan_tag = __lsan::kIgnored; 766 return kIgnoreObjectSuccess; 767 } else { 768 return kIgnoreObjectInvalid; 769 } 770} 771} // namespace __lsan 772 773// ---------------------- Interface ---------------- {{{1 774using namespace __asan; // NOLINT 775 776// ASan allocator doesn't reserve extra bytes, so normally we would 777// just return "size". We don't want to expose our redzone sizes, etc here. 778uptr __asan_get_estimated_allocated_size(uptr size) { 779 return size; 780} 781 782bool __asan_get_ownership(const void *p) { 783 uptr ptr = reinterpret_cast<uptr>(p); 784 return (AllocationSize(ptr) > 0); 785} 786 787uptr __asan_get_allocated_size(const void *p) { 788 if (p == 0) return 0; 789 uptr ptr = reinterpret_cast<uptr>(p); 790 uptr allocated_size = AllocationSize(ptr); 791 // Die if p is not malloced or if it is already freed. 792 if (allocated_size == 0) { 793 GET_STACK_TRACE_FATAL_HERE; 794 ReportAsanGetAllocatedSizeNotOwned(ptr, &stack); 795 } 796 return allocated_size; 797} 798 799#if !SANITIZER_SUPPORTS_WEAK_HOOKS 800// Provide default (no-op) implementation of malloc hooks. 801extern "C" { 802SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE 803void __asan_malloc_hook(void *ptr, uptr size) { 804 (void)ptr; 805 (void)size; 806} 807SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE 808void __asan_free_hook(void *ptr) { 809 (void)ptr; 810} 811} // extern "C" 812#endif 813