[DominatorTree] Add support for mixed pre/post CFG views.
[llvm-project.git] / compiler-rt / lib / asan / asan_allocator.cpp
blob58b496a3ca4b1c5d836821cd970d9bc9cdbb03c7
1 //===-- asan_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 AddressSanitizer, an address sanity checker.
11 // Implementation of ASan's memory allocator, 2-nd version.
12 // This variant uses the allocator from sanitizer_common, i.e. the one shared
13 // with ThreadSanitizer and MemorySanitizer.
15 //===----------------------------------------------------------------------===//
17 #include "asan_allocator.h"
19 #include "asan_mapping.h"
20 #include "asan_poisoning.h"
21 #include "asan_report.h"
22 #include "asan_stack.h"
23 #include "asan_thread.h"
24 #include "lsan/lsan_common.h"
25 #include "sanitizer_common/sanitizer_allocator_checks.h"
26 #include "sanitizer_common/sanitizer_allocator_interface.h"
27 #include "sanitizer_common/sanitizer_errno.h"
28 #include "sanitizer_common/sanitizer_flags.h"
29 #include "sanitizer_common/sanitizer_internal_defs.h"
30 #include "sanitizer_common/sanitizer_list.h"
31 #include "sanitizer_common/sanitizer_quarantine.h"
32 #include "sanitizer_common/sanitizer_stackdepot.h"
34 namespace __asan {
36 // Valid redzone sizes are 16, 32, 64, ... 2048, so we encode them in 3 bits.
37 // We use adaptive redzones: for larger allocation larger redzones are used.
38 static u32 RZLog2Size(u32 rz_log) {
39 CHECK_LT(rz_log, 8);
40 return 16 << rz_log;
43 static u32 RZSize2Log(u32 rz_size) {
44 CHECK_GE(rz_size, 16);
45 CHECK_LE(rz_size, 2048);
46 CHECK(IsPowerOfTwo(rz_size));
47 u32 res = Log2(rz_size) - 4;
48 CHECK_EQ(rz_size, RZLog2Size(res));
49 return res;
52 static AsanAllocator &get_allocator();
54 static void AtomicContextStore(volatile atomic_uint64_t *atomic_context,
55 u32 tid, u32 stack) {
56 u64 context = tid;
57 context <<= 32;
58 context += stack;
59 atomic_store(atomic_context, context, memory_order_relaxed);
62 static void AtomicContextLoad(const volatile atomic_uint64_t *atomic_context,
63 u32 &tid, u32 &stack) {
64 u64 context = atomic_load(atomic_context, memory_order_relaxed);
65 stack = context;
66 context >>= 32;
67 tid = context;
70 // The memory chunk allocated from the underlying allocator looks like this:
71 // L L L L L L H H U U U U U U R R
72 // L -- left redzone words (0 or more bytes)
73 // H -- ChunkHeader (16 bytes), which is also a part of the left redzone.
74 // U -- user memory.
75 // R -- right redzone (0 or more bytes)
76 // ChunkBase consists of ChunkHeader and other bytes that overlap with user
77 // memory.
79 // If the left redzone is greater than the ChunkHeader size we store a magic
80 // value in the first uptr word of the memory block and store the address of
81 // ChunkBase in the next uptr.
82 // M B L L L L L L L L L H H U U U U U U
83 // | ^
84 // ---------------------|
85 // M -- magic value kAllocBegMagic
86 // B -- address of ChunkHeader pointing to the first 'H'
88 class ChunkHeader {
89 public:
90 atomic_uint8_t chunk_state;
91 u8 alloc_type : 2;
92 u8 lsan_tag : 2;
94 // align < 8 -> 0
95 // else -> log2(min(align, 512)) - 2
96 u8 user_requested_alignment_log : 3;
98 private:
99 u16 user_requested_size_hi;
100 u32 user_requested_size_lo;
101 atomic_uint64_t alloc_context_id;
103 public:
104 uptr UsedSize() const {
105 uptr R = user_requested_size_lo;
106 if (sizeof(uptr) > sizeof(user_requested_size_lo))
107 R += (uptr)user_requested_size_hi << (8 * sizeof(user_requested_size_lo));
108 return R;
111 void SetUsedSize(uptr size) {
112 user_requested_size_lo = size;
113 if (sizeof(uptr) > sizeof(user_requested_size_lo)) {
114 size >>= (8 * sizeof(user_requested_size_lo));
115 user_requested_size_hi = size;
116 CHECK_EQ(user_requested_size_hi, size);
120 void SetAllocContext(u32 tid, u32 stack) {
121 AtomicContextStore(&alloc_context_id, tid, stack);
124 void GetAllocContext(u32 &tid, u32 &stack) const {
125 AtomicContextLoad(&alloc_context_id, tid, stack);
129 class ChunkBase : public ChunkHeader {
130 atomic_uint64_t free_context_id;
132 public:
133 void SetFreeContext(u32 tid, u32 stack) {
134 AtomicContextStore(&free_context_id, tid, stack);
137 void GetFreeContext(u32 &tid, u32 &stack) const {
138 AtomicContextLoad(&free_context_id, tid, stack);
142 static const uptr kChunkHeaderSize = sizeof(ChunkHeader);
143 static const uptr kChunkHeader2Size = sizeof(ChunkBase) - kChunkHeaderSize;
144 COMPILER_CHECK(kChunkHeaderSize == 16);
145 COMPILER_CHECK(kChunkHeader2Size <= 16);
147 enum {
148 // Either just allocated by underlying allocator, but AsanChunk is not yet
149 // ready, or almost returned to undelying allocator and AsanChunk is already
150 // meaningless.
151 CHUNK_INVALID = 0,
152 // The chunk is allocated and not yet freed.
153 CHUNK_ALLOCATED = 2,
154 // The chunk was freed and put into quarantine zone.
155 CHUNK_QUARANTINE = 3,
158 class AsanChunk : public ChunkBase {
159 public:
160 uptr Beg() { return reinterpret_cast<uptr>(this) + kChunkHeaderSize; }
161 bool AddrIsInside(uptr addr) {
162 return (addr >= Beg()) && (addr < Beg() + UsedSize());
166 class LargeChunkHeader {
167 static constexpr uptr kAllocBegMagic =
168 FIRST_32_SECOND_64(0xCC6E96B9, 0xCC6E96B9CC6E96B9ULL);
169 atomic_uintptr_t magic;
170 AsanChunk *chunk_header;
172 public:
173 AsanChunk *Get() const {
174 return atomic_load(&magic, memory_order_acquire) == kAllocBegMagic
175 ? chunk_header
176 : nullptr;
179 void Set(AsanChunk *p) {
180 if (p) {
181 chunk_header = p;
182 atomic_store(&magic, kAllocBegMagic, memory_order_release);
183 return;
186 uptr old = kAllocBegMagic;
187 if (!atomic_compare_exchange_strong(&magic, &old, 0,
188 memory_order_release)) {
189 CHECK_EQ(old, kAllocBegMagic);
194 struct QuarantineCallback {
195 QuarantineCallback(AllocatorCache *cache, BufferedStackTrace *stack)
196 : cache_(cache),
197 stack_(stack) {
200 void Recycle(AsanChunk *m) {
201 void *p = get_allocator().GetBlockBegin(m);
202 if (p != m) {
203 // Clear the magic value, as allocator internals may overwrite the
204 // contents of deallocated chunk, confusing GetAsanChunk lookup.
205 reinterpret_cast<LargeChunkHeader *>(p)->Set(nullptr);
208 u8 old_chunk_state = CHUNK_QUARANTINE;
209 if (!atomic_compare_exchange_strong(&m->chunk_state, &old_chunk_state,
210 CHUNK_INVALID, memory_order_acquire)) {
211 CHECK_EQ(old_chunk_state, CHUNK_QUARANTINE);
214 PoisonShadow(m->Beg(),
215 RoundUpTo(m->UsedSize(), SHADOW_GRANULARITY),
216 kAsanHeapLeftRedzoneMagic);
218 // Statistics.
219 AsanStats &thread_stats = GetCurrentThreadStats();
220 thread_stats.real_frees++;
221 thread_stats.really_freed += m->UsedSize();
223 get_allocator().Deallocate(cache_, p);
226 void *Allocate(uptr size) {
227 void *res = get_allocator().Allocate(cache_, size, 1);
228 // TODO(alekseys): Consider making quarantine OOM-friendly.
229 if (UNLIKELY(!res))
230 ReportOutOfMemory(size, stack_);
231 return res;
234 void Deallocate(void *p) {
235 get_allocator().Deallocate(cache_, p);
238 private:
239 AllocatorCache* const cache_;
240 BufferedStackTrace* const stack_;
243 typedef Quarantine<QuarantineCallback, AsanChunk> AsanQuarantine;
244 typedef AsanQuarantine::Cache QuarantineCache;
246 void AsanMapUnmapCallback::OnMap(uptr p, uptr size) const {
247 PoisonShadow(p, size, kAsanHeapLeftRedzoneMagic);
248 // Statistics.
249 AsanStats &thread_stats = GetCurrentThreadStats();
250 thread_stats.mmaps++;
251 thread_stats.mmaped += size;
253 void AsanMapUnmapCallback::OnUnmap(uptr p, uptr size) const {
254 PoisonShadow(p, size, 0);
255 // We are about to unmap a chunk of user memory.
256 // Mark the corresponding shadow memory as not needed.
257 FlushUnneededASanShadowMemory(p, size);
258 // Statistics.
259 AsanStats &thread_stats = GetCurrentThreadStats();
260 thread_stats.munmaps++;
261 thread_stats.munmaped += size;
264 // We can not use THREADLOCAL because it is not supported on some of the
265 // platforms we care about (OSX 10.6, Android).
266 // static THREADLOCAL AllocatorCache cache;
267 AllocatorCache *GetAllocatorCache(AsanThreadLocalMallocStorage *ms) {
268 CHECK(ms);
269 return &ms->allocator_cache;
272 QuarantineCache *GetQuarantineCache(AsanThreadLocalMallocStorage *ms) {
273 CHECK(ms);
274 CHECK_LE(sizeof(QuarantineCache), sizeof(ms->quarantine_cache));
275 return reinterpret_cast<QuarantineCache *>(ms->quarantine_cache);
278 void AllocatorOptions::SetFrom(const Flags *f, const CommonFlags *cf) {
279 quarantine_size_mb = f->quarantine_size_mb;
280 thread_local_quarantine_size_kb = f->thread_local_quarantine_size_kb;
281 min_redzone = f->redzone;
282 max_redzone = f->max_redzone;
283 may_return_null = cf->allocator_may_return_null;
284 alloc_dealloc_mismatch = f->alloc_dealloc_mismatch;
285 release_to_os_interval_ms = cf->allocator_release_to_os_interval_ms;
288 void AllocatorOptions::CopyTo(Flags *f, CommonFlags *cf) {
289 f->quarantine_size_mb = quarantine_size_mb;
290 f->thread_local_quarantine_size_kb = thread_local_quarantine_size_kb;
291 f->redzone = min_redzone;
292 f->max_redzone = max_redzone;
293 cf->allocator_may_return_null = may_return_null;
294 f->alloc_dealloc_mismatch = alloc_dealloc_mismatch;
295 cf->allocator_release_to_os_interval_ms = release_to_os_interval_ms;
298 struct Allocator {
299 static const uptr kMaxAllowedMallocSize =
300 FIRST_32_SECOND_64(3UL << 30, 1ULL << 40);
302 AsanAllocator allocator;
303 AsanQuarantine quarantine;
304 StaticSpinMutex fallback_mutex;
305 AllocatorCache fallback_allocator_cache;
306 QuarantineCache fallback_quarantine_cache;
308 uptr max_user_defined_malloc_size;
309 atomic_uint8_t rss_limit_exceeded;
311 // ------------------- Options --------------------------
312 atomic_uint16_t min_redzone;
313 atomic_uint16_t max_redzone;
314 atomic_uint8_t alloc_dealloc_mismatch;
316 // ------------------- Initialization ------------------------
317 explicit Allocator(LinkerInitialized)
318 : quarantine(LINKER_INITIALIZED),
319 fallback_quarantine_cache(LINKER_INITIALIZED) {}
321 void CheckOptions(const AllocatorOptions &options) const {
322 CHECK_GE(options.min_redzone, 16);
323 CHECK_GE(options.max_redzone, options.min_redzone);
324 CHECK_LE(options.max_redzone, 2048);
325 CHECK(IsPowerOfTwo(options.min_redzone));
326 CHECK(IsPowerOfTwo(options.max_redzone));
329 void SharedInitCode(const AllocatorOptions &options) {
330 CheckOptions(options);
331 quarantine.Init((uptr)options.quarantine_size_mb << 20,
332 (uptr)options.thread_local_quarantine_size_kb << 10);
333 atomic_store(&alloc_dealloc_mismatch, options.alloc_dealloc_mismatch,
334 memory_order_release);
335 atomic_store(&min_redzone, options.min_redzone, memory_order_release);
336 atomic_store(&max_redzone, options.max_redzone, memory_order_release);
339 void InitLinkerInitialized(const AllocatorOptions &options) {
340 SetAllocatorMayReturnNull(options.may_return_null);
341 allocator.InitLinkerInitialized(options.release_to_os_interval_ms);
342 SharedInitCode(options);
343 max_user_defined_malloc_size = common_flags()->max_allocation_size_mb
344 ? common_flags()->max_allocation_size_mb
345 << 20
346 : kMaxAllowedMallocSize;
349 bool RssLimitExceeded() {
350 return atomic_load(&rss_limit_exceeded, memory_order_relaxed);
353 void SetRssLimitExceeded(bool limit_exceeded) {
354 atomic_store(&rss_limit_exceeded, limit_exceeded, memory_order_relaxed);
357 void RePoisonChunk(uptr chunk) {
358 // This could be a user-facing chunk (with redzones), or some internal
359 // housekeeping chunk, like TransferBatch. Start by assuming the former.
360 AsanChunk *ac = GetAsanChunk((void *)chunk);
361 uptr allocated_size = allocator.GetActuallyAllocatedSize((void *)chunk);
362 if (ac && atomic_load(&ac->chunk_state, memory_order_acquire) ==
363 CHUNK_ALLOCATED) {
364 uptr beg = ac->Beg();
365 uptr end = ac->Beg() + ac->UsedSize();
366 uptr chunk_end = chunk + allocated_size;
367 if (chunk < beg && beg < end && end <= chunk_end) {
368 // Looks like a valid AsanChunk in use, poison redzones only.
369 PoisonShadow(chunk, beg - chunk, kAsanHeapLeftRedzoneMagic);
370 uptr end_aligned_down = RoundDownTo(end, SHADOW_GRANULARITY);
371 FastPoisonShadowPartialRightRedzone(
372 end_aligned_down, end - end_aligned_down,
373 chunk_end - end_aligned_down, kAsanHeapLeftRedzoneMagic);
374 return;
378 // This is either not an AsanChunk or freed or quarantined AsanChunk.
379 // In either case, poison everything.
380 PoisonShadow(chunk, allocated_size, kAsanHeapLeftRedzoneMagic);
383 void ReInitialize(const AllocatorOptions &options) {
384 SetAllocatorMayReturnNull(options.may_return_null);
385 allocator.SetReleaseToOSIntervalMs(options.release_to_os_interval_ms);
386 SharedInitCode(options);
388 // Poison all existing allocation's redzones.
389 if (CanPoisonMemory()) {
390 allocator.ForceLock();
391 allocator.ForEachChunk(
392 [](uptr chunk, void *alloc) {
393 ((Allocator *)alloc)->RePoisonChunk(chunk);
395 this);
396 allocator.ForceUnlock();
400 void GetOptions(AllocatorOptions *options) const {
401 options->quarantine_size_mb = quarantine.GetSize() >> 20;
402 options->thread_local_quarantine_size_kb = quarantine.GetCacheSize() >> 10;
403 options->min_redzone = atomic_load(&min_redzone, memory_order_acquire);
404 options->max_redzone = atomic_load(&max_redzone, memory_order_acquire);
405 options->may_return_null = AllocatorMayReturnNull();
406 options->alloc_dealloc_mismatch =
407 atomic_load(&alloc_dealloc_mismatch, memory_order_acquire);
408 options->release_to_os_interval_ms = allocator.ReleaseToOSIntervalMs();
411 // -------------------- Helper methods. -------------------------
412 uptr ComputeRZLog(uptr user_requested_size) {
413 u32 rz_log = user_requested_size <= 64 - 16 ? 0
414 : user_requested_size <= 128 - 32 ? 1
415 : user_requested_size <= 512 - 64 ? 2
416 : user_requested_size <= 4096 - 128 ? 3
417 : user_requested_size <= (1 << 14) - 256 ? 4
418 : user_requested_size <= (1 << 15) - 512 ? 5
419 : user_requested_size <= (1 << 16) - 1024 ? 6
420 : 7;
421 u32 hdr_log = RZSize2Log(RoundUpToPowerOfTwo(sizeof(ChunkHeader)));
422 u32 min_log = RZSize2Log(atomic_load(&min_redzone, memory_order_acquire));
423 u32 max_log = RZSize2Log(atomic_load(&max_redzone, memory_order_acquire));
424 return Min(Max(rz_log, Max(min_log, hdr_log)), Max(max_log, hdr_log));
427 static uptr ComputeUserRequestedAlignmentLog(uptr user_requested_alignment) {
428 if (user_requested_alignment < 8)
429 return 0;
430 if (user_requested_alignment > 512)
431 user_requested_alignment = 512;
432 return Log2(user_requested_alignment) - 2;
435 static uptr ComputeUserAlignment(uptr user_requested_alignment_log) {
436 if (user_requested_alignment_log == 0)
437 return 0;
438 return 1LL << (user_requested_alignment_log + 2);
441 // We have an address between two chunks, and we want to report just one.
442 AsanChunk *ChooseChunk(uptr addr, AsanChunk *left_chunk,
443 AsanChunk *right_chunk) {
444 if (!left_chunk)
445 return right_chunk;
446 if (!right_chunk)
447 return left_chunk;
448 // Prefer an allocated chunk over freed chunk and freed chunk
449 // over available chunk.
450 u8 left_state = atomic_load(&left_chunk->chunk_state, memory_order_relaxed);
451 u8 right_state =
452 atomic_load(&right_chunk->chunk_state, memory_order_relaxed);
453 if (left_state != right_state) {
454 if (left_state == CHUNK_ALLOCATED)
455 return left_chunk;
456 if (right_state == CHUNK_ALLOCATED)
457 return right_chunk;
458 if (left_state == CHUNK_QUARANTINE)
459 return left_chunk;
460 if (right_state == CHUNK_QUARANTINE)
461 return right_chunk;
463 // Same chunk_state: choose based on offset.
464 sptr l_offset = 0, r_offset = 0;
465 CHECK(AsanChunkView(left_chunk).AddrIsAtRight(addr, 1, &l_offset));
466 CHECK(AsanChunkView(right_chunk).AddrIsAtLeft(addr, 1, &r_offset));
467 if (l_offset < r_offset)
468 return left_chunk;
469 return right_chunk;
472 bool UpdateAllocationStack(uptr addr, BufferedStackTrace *stack) {
473 AsanChunk *m = GetAsanChunkByAddr(addr);
474 if (!m) return false;
475 if (atomic_load(&m->chunk_state, memory_order_acquire) != CHUNK_ALLOCATED)
476 return false;
477 if (m->Beg() != addr) return false;
478 AsanThread *t = GetCurrentThread();
479 m->SetAllocContext(t ? t->tid() : 0, StackDepotPut(*stack));
480 return true;
483 // -------------------- Allocation/Deallocation routines ---------------
484 void *Allocate(uptr size, uptr alignment, BufferedStackTrace *stack,
485 AllocType alloc_type, bool can_fill) {
486 if (UNLIKELY(!asan_inited))
487 AsanInitFromRtl();
488 if (RssLimitExceeded()) {
489 if (AllocatorMayReturnNull())
490 return nullptr;
491 ReportRssLimitExceeded(stack);
493 Flags &fl = *flags();
494 CHECK(stack);
495 const uptr min_alignment = SHADOW_GRANULARITY;
496 const uptr user_requested_alignment_log =
497 ComputeUserRequestedAlignmentLog(alignment);
498 if (alignment < min_alignment)
499 alignment = min_alignment;
500 if (size == 0) {
501 // We'd be happy to avoid allocating memory for zero-size requests, but
502 // some programs/tests depend on this behavior and assume that malloc
503 // would not return NULL even for zero-size allocations. Moreover, it
504 // looks like operator new should never return NULL, and results of
505 // consecutive "new" calls must be different even if the allocated size
506 // is zero.
507 size = 1;
509 CHECK(IsPowerOfTwo(alignment));
510 uptr rz_log = ComputeRZLog(size);
511 uptr rz_size = RZLog2Size(rz_log);
512 uptr rounded_size = RoundUpTo(Max(size, kChunkHeader2Size), alignment);
513 uptr needed_size = rounded_size + rz_size;
514 if (alignment > min_alignment)
515 needed_size += alignment;
516 // If we are allocating from the secondary allocator, there will be no
517 // automatic right redzone, so add the right redzone manually.
518 if (!PrimaryAllocator::CanAllocate(needed_size, alignment))
519 needed_size += rz_size;
520 CHECK(IsAligned(needed_size, min_alignment));
521 if (size > kMaxAllowedMallocSize || needed_size > kMaxAllowedMallocSize ||
522 size > max_user_defined_malloc_size) {
523 if (AllocatorMayReturnNull()) {
524 Report("WARNING: AddressSanitizer failed to allocate 0x%zx bytes\n",
525 (void*)size);
526 return nullptr;
528 uptr malloc_limit =
529 Min(kMaxAllowedMallocSize, max_user_defined_malloc_size);
530 ReportAllocationSizeTooBig(size, needed_size, malloc_limit, stack);
533 AsanThread *t = GetCurrentThread();
534 void *allocated;
535 if (t) {
536 AllocatorCache *cache = GetAllocatorCache(&t->malloc_storage());
537 allocated = allocator.Allocate(cache, needed_size, 8);
538 } else {
539 SpinMutexLock l(&fallback_mutex);
540 AllocatorCache *cache = &fallback_allocator_cache;
541 allocated = allocator.Allocate(cache, needed_size, 8);
543 if (UNLIKELY(!allocated)) {
544 SetAllocatorOutOfMemory();
545 if (AllocatorMayReturnNull())
546 return nullptr;
547 ReportOutOfMemory(size, stack);
550 if (*(u8 *)MEM_TO_SHADOW((uptr)allocated) == 0 && CanPoisonMemory()) {
551 // Heap poisoning is enabled, but the allocator provides an unpoisoned
552 // chunk. This is possible if CanPoisonMemory() was false for some
553 // time, for example, due to flags()->start_disabled.
554 // Anyway, poison the block before using it for anything else.
555 uptr allocated_size = allocator.GetActuallyAllocatedSize(allocated);
556 PoisonShadow((uptr)allocated, allocated_size, kAsanHeapLeftRedzoneMagic);
559 uptr alloc_beg = reinterpret_cast<uptr>(allocated);
560 uptr alloc_end = alloc_beg + needed_size;
561 uptr user_beg = alloc_beg + rz_size;
562 if (!IsAligned(user_beg, alignment))
563 user_beg = RoundUpTo(user_beg, alignment);
564 uptr user_end = user_beg + size;
565 CHECK_LE(user_end, alloc_end);
566 uptr chunk_beg = user_beg - kChunkHeaderSize;
567 AsanChunk *m = reinterpret_cast<AsanChunk *>(chunk_beg);
568 m->alloc_type = alloc_type;
569 CHECK(size);
570 m->SetUsedSize(size);
571 m->user_requested_alignment_log = user_requested_alignment_log;
573 m->SetAllocContext(t ? t->tid() : 0, StackDepotPut(*stack));
575 uptr size_rounded_down_to_granularity =
576 RoundDownTo(size, SHADOW_GRANULARITY);
577 // Unpoison the bulk of the memory region.
578 if (size_rounded_down_to_granularity)
579 PoisonShadow(user_beg, size_rounded_down_to_granularity, 0);
580 // Deal with the end of the region if size is not aligned to granularity.
581 if (size != size_rounded_down_to_granularity && CanPoisonMemory()) {
582 u8 *shadow =
583 (u8 *)MemToShadow(user_beg + size_rounded_down_to_granularity);
584 *shadow = fl.poison_partial ? (size & (SHADOW_GRANULARITY - 1)) : 0;
587 AsanStats &thread_stats = GetCurrentThreadStats();
588 thread_stats.mallocs++;
589 thread_stats.malloced += size;
590 thread_stats.malloced_redzones += needed_size - size;
591 if (needed_size > SizeClassMap::kMaxSize)
592 thread_stats.malloc_large++;
593 else
594 thread_stats.malloced_by_size[SizeClassMap::ClassID(needed_size)]++;
596 void *res = reinterpret_cast<void *>(user_beg);
597 if (can_fill && fl.max_malloc_fill_size) {
598 uptr fill_size = Min(size, (uptr)fl.max_malloc_fill_size);
599 REAL(memset)(res, fl.malloc_fill_byte, fill_size);
601 #if CAN_SANITIZE_LEAKS
602 m->lsan_tag = __lsan::DisabledInThisThread() ? __lsan::kIgnored
603 : __lsan::kDirectlyLeaked;
604 #endif
605 // Must be the last mutation of metadata in this function.
606 atomic_store(&m->chunk_state, CHUNK_ALLOCATED, memory_order_release);
607 if (alloc_beg != chunk_beg) {
608 CHECK_LE(alloc_beg + sizeof(LargeChunkHeader), chunk_beg);
609 reinterpret_cast<LargeChunkHeader *>(alloc_beg)->Set(m);
611 ASAN_MALLOC_HOOK(res, size);
612 return res;
615 // Set quarantine flag if chunk is allocated, issue ASan error report on
616 // available and quarantined chunks. Return true on success, false otherwise.
617 bool AtomicallySetQuarantineFlagIfAllocated(AsanChunk *m, void *ptr,
618 BufferedStackTrace *stack) {
619 u8 old_chunk_state = CHUNK_ALLOCATED;
620 // Flip the chunk_state atomically to avoid race on double-free.
621 if (!atomic_compare_exchange_strong(&m->chunk_state, &old_chunk_state,
622 CHUNK_QUARANTINE,
623 memory_order_acquire)) {
624 ReportInvalidFree(ptr, old_chunk_state, stack);
625 // It's not safe to push a chunk in quarantine on invalid free.
626 return false;
628 CHECK_EQ(CHUNK_ALLOCATED, old_chunk_state);
629 // It was a user data.
630 m->SetFreeContext(kInvalidTid, 0);
631 return true;
634 // Expects the chunk to already be marked as quarantined by using
635 // AtomicallySetQuarantineFlagIfAllocated.
636 void QuarantineChunk(AsanChunk *m, void *ptr, BufferedStackTrace *stack) {
637 CHECK_EQ(atomic_load(&m->chunk_state, memory_order_relaxed),
638 CHUNK_QUARANTINE);
639 AsanThread *t = GetCurrentThread();
640 m->SetFreeContext(t ? t->tid() : 0, StackDepotPut(*stack));
642 Flags &fl = *flags();
643 if (fl.max_free_fill_size > 0) {
644 // We have to skip the chunk header, it contains free_context_id.
645 uptr scribble_start = (uptr)m + kChunkHeaderSize + kChunkHeader2Size;
646 if (m->UsedSize() >= kChunkHeader2Size) { // Skip Header2 in user area.
647 uptr size_to_fill = m->UsedSize() - kChunkHeader2Size;
648 size_to_fill = Min(size_to_fill, (uptr)fl.max_free_fill_size);
649 REAL(memset)((void *)scribble_start, fl.free_fill_byte, size_to_fill);
653 // Poison the region.
654 PoisonShadow(m->Beg(),
655 RoundUpTo(m->UsedSize(), SHADOW_GRANULARITY),
656 kAsanHeapFreeMagic);
658 AsanStats &thread_stats = GetCurrentThreadStats();
659 thread_stats.frees++;
660 thread_stats.freed += m->UsedSize();
662 // Push into quarantine.
663 if (t) {
664 AsanThreadLocalMallocStorage *ms = &t->malloc_storage();
665 AllocatorCache *ac = GetAllocatorCache(ms);
666 quarantine.Put(GetQuarantineCache(ms), QuarantineCallback(ac, stack), m,
667 m->UsedSize());
668 } else {
669 SpinMutexLock l(&fallback_mutex);
670 AllocatorCache *ac = &fallback_allocator_cache;
671 quarantine.Put(&fallback_quarantine_cache, QuarantineCallback(ac, stack),
672 m, m->UsedSize());
676 void Deallocate(void *ptr, uptr delete_size, uptr delete_alignment,
677 BufferedStackTrace *stack, AllocType alloc_type) {
678 uptr p = reinterpret_cast<uptr>(ptr);
679 if (p == 0) return;
681 uptr chunk_beg = p - kChunkHeaderSize;
682 AsanChunk *m = reinterpret_cast<AsanChunk *>(chunk_beg);
684 // On Windows, uninstrumented DLLs may allocate memory before ASan hooks
685 // malloc. Don't report an invalid free in this case.
686 if (SANITIZER_WINDOWS &&
687 !get_allocator().PointerIsMine(ptr)) {
688 if (!IsSystemHeapAddress(p))
689 ReportFreeNotMalloced(p, stack);
690 return;
693 ASAN_FREE_HOOK(ptr);
695 // Must mark the chunk as quarantined before any changes to its metadata.
696 // Do not quarantine given chunk if we failed to set CHUNK_QUARANTINE flag.
697 if (!AtomicallySetQuarantineFlagIfAllocated(m, ptr, stack)) return;
699 if (m->alloc_type != alloc_type) {
700 if (atomic_load(&alloc_dealloc_mismatch, memory_order_acquire)) {
701 ReportAllocTypeMismatch((uptr)ptr, stack, (AllocType)m->alloc_type,
702 (AllocType)alloc_type);
704 } else {
705 if (flags()->new_delete_type_mismatch &&
706 (alloc_type == FROM_NEW || alloc_type == FROM_NEW_BR) &&
707 ((delete_size && delete_size != m->UsedSize()) ||
708 ComputeUserRequestedAlignmentLog(delete_alignment) !=
709 m->user_requested_alignment_log)) {
710 ReportNewDeleteTypeMismatch(p, delete_size, delete_alignment, stack);
714 QuarantineChunk(m, ptr, stack);
717 void *Reallocate(void *old_ptr, uptr new_size, BufferedStackTrace *stack) {
718 CHECK(old_ptr && new_size);
719 uptr p = reinterpret_cast<uptr>(old_ptr);
720 uptr chunk_beg = p - kChunkHeaderSize;
721 AsanChunk *m = reinterpret_cast<AsanChunk *>(chunk_beg);
723 AsanStats &thread_stats = GetCurrentThreadStats();
724 thread_stats.reallocs++;
725 thread_stats.realloced += new_size;
727 void *new_ptr = Allocate(new_size, 8, stack, FROM_MALLOC, true);
728 if (new_ptr) {
729 u8 chunk_state = atomic_load(&m->chunk_state, memory_order_acquire);
730 if (chunk_state != CHUNK_ALLOCATED)
731 ReportInvalidFree(old_ptr, chunk_state, stack);
732 CHECK_NE(REAL(memcpy), nullptr);
733 uptr memcpy_size = Min(new_size, m->UsedSize());
734 // If realloc() races with free(), we may start copying freed memory.
735 // However, we will report racy double-free later anyway.
736 REAL(memcpy)(new_ptr, old_ptr, memcpy_size);
737 Deallocate(old_ptr, 0, 0, stack, FROM_MALLOC);
739 return new_ptr;
742 void *Calloc(uptr nmemb, uptr size, BufferedStackTrace *stack) {
743 if (UNLIKELY(CheckForCallocOverflow(size, nmemb))) {
744 if (AllocatorMayReturnNull())
745 return nullptr;
746 ReportCallocOverflow(nmemb, size, stack);
748 void *ptr = Allocate(nmemb * size, 8, stack, FROM_MALLOC, false);
749 // If the memory comes from the secondary allocator no need to clear it
750 // as it comes directly from mmap.
751 if (ptr && allocator.FromPrimary(ptr))
752 REAL(memset)(ptr, 0, nmemb * size);
753 return ptr;
756 void ReportInvalidFree(void *ptr, u8 chunk_state, BufferedStackTrace *stack) {
757 if (chunk_state == CHUNK_QUARANTINE)
758 ReportDoubleFree((uptr)ptr, stack);
759 else
760 ReportFreeNotMalloced((uptr)ptr, stack);
763 void CommitBack(AsanThreadLocalMallocStorage *ms, BufferedStackTrace *stack) {
764 AllocatorCache *ac = GetAllocatorCache(ms);
765 quarantine.Drain(GetQuarantineCache(ms), QuarantineCallback(ac, stack));
766 allocator.SwallowCache(ac);
769 // -------------------------- Chunk lookup ----------------------
771 // Assumes alloc_beg == allocator.GetBlockBegin(alloc_beg).
772 // Returns nullptr if AsanChunk is not yet initialized just after
773 // get_allocator().Allocate(), or is being destroyed just before
774 // get_allocator().Deallocate().
775 AsanChunk *GetAsanChunk(void *alloc_beg) {
776 if (!alloc_beg)
777 return nullptr;
778 AsanChunk *p = reinterpret_cast<LargeChunkHeader *>(alloc_beg)->Get();
779 if (!p) {
780 if (!allocator.FromPrimary(alloc_beg))
781 return nullptr;
782 p = reinterpret_cast<AsanChunk *>(alloc_beg);
784 u8 state = atomic_load(&p->chunk_state, memory_order_relaxed);
785 // It does not guaranty that Chunk is initialized, but it's
786 // definitely not for any other value.
787 if (state == CHUNK_ALLOCATED || state == CHUNK_QUARANTINE)
788 return p;
789 return nullptr;
792 AsanChunk *GetAsanChunkByAddr(uptr p) {
793 void *alloc_beg = allocator.GetBlockBegin(reinterpret_cast<void *>(p));
794 return GetAsanChunk(alloc_beg);
797 // Allocator must be locked when this function is called.
798 AsanChunk *GetAsanChunkByAddrFastLocked(uptr p) {
799 void *alloc_beg =
800 allocator.GetBlockBeginFastLocked(reinterpret_cast<void *>(p));
801 return GetAsanChunk(alloc_beg);
804 uptr AllocationSize(uptr p) {
805 AsanChunk *m = GetAsanChunkByAddr(p);
806 if (!m) return 0;
807 if (atomic_load(&m->chunk_state, memory_order_acquire) != CHUNK_ALLOCATED)
808 return 0;
809 if (m->Beg() != p) return 0;
810 return m->UsedSize();
813 AsanChunkView FindHeapChunkByAddress(uptr addr) {
814 AsanChunk *m1 = GetAsanChunkByAddr(addr);
815 sptr offset = 0;
816 if (!m1 || AsanChunkView(m1).AddrIsAtLeft(addr, 1, &offset)) {
817 // The address is in the chunk's left redzone, so maybe it is actually
818 // a right buffer overflow from the other chunk to the left.
819 // Search a bit to the left to see if there is another chunk.
820 AsanChunk *m2 = nullptr;
821 for (uptr l = 1; l < GetPageSizeCached(); l++) {
822 m2 = GetAsanChunkByAddr(addr - l);
823 if (m2 == m1) continue; // Still the same chunk.
824 break;
826 if (m2 && AsanChunkView(m2).AddrIsAtRight(addr, 1, &offset))
827 m1 = ChooseChunk(addr, m2, m1);
829 return AsanChunkView(m1);
832 void Purge(BufferedStackTrace *stack) {
833 AsanThread *t = GetCurrentThread();
834 if (t) {
835 AsanThreadLocalMallocStorage *ms = &t->malloc_storage();
836 quarantine.DrainAndRecycle(GetQuarantineCache(ms),
837 QuarantineCallback(GetAllocatorCache(ms),
838 stack));
841 SpinMutexLock l(&fallback_mutex);
842 quarantine.DrainAndRecycle(&fallback_quarantine_cache,
843 QuarantineCallback(&fallback_allocator_cache,
844 stack));
847 allocator.ForceReleaseToOS();
850 void PrintStats() {
851 allocator.PrintStats();
852 quarantine.PrintStats();
855 void ForceLock() {
856 allocator.ForceLock();
857 fallback_mutex.Lock();
860 void ForceUnlock() {
861 fallback_mutex.Unlock();
862 allocator.ForceUnlock();
866 static Allocator instance(LINKER_INITIALIZED);
868 static AsanAllocator &get_allocator() {
869 return instance.allocator;
872 bool AsanChunkView::IsValid() const {
873 return chunk_ && atomic_load(&chunk_->chunk_state, memory_order_relaxed) !=
874 CHUNK_INVALID;
876 bool AsanChunkView::IsAllocated() const {
877 return chunk_ && atomic_load(&chunk_->chunk_state, memory_order_relaxed) ==
878 CHUNK_ALLOCATED;
880 bool AsanChunkView::IsQuarantined() const {
881 return chunk_ && atomic_load(&chunk_->chunk_state, memory_order_relaxed) ==
882 CHUNK_QUARANTINE;
884 uptr AsanChunkView::Beg() const { return chunk_->Beg(); }
885 uptr AsanChunkView::End() const { return Beg() + UsedSize(); }
886 uptr AsanChunkView::UsedSize() const { return chunk_->UsedSize(); }
887 u32 AsanChunkView::UserRequestedAlignment() const {
888 return Allocator::ComputeUserAlignment(chunk_->user_requested_alignment_log);
891 uptr AsanChunkView::AllocTid() const {
892 u32 tid = 0;
893 u32 stack = 0;
894 chunk_->GetAllocContext(tid, stack);
895 return tid;
898 uptr AsanChunkView::FreeTid() const {
899 if (!IsQuarantined())
900 return kInvalidTid;
901 u32 tid = 0;
902 u32 stack = 0;
903 chunk_->GetFreeContext(tid, stack);
904 return tid;
907 AllocType AsanChunkView::GetAllocType() const {
908 return (AllocType)chunk_->alloc_type;
911 static StackTrace GetStackTraceFromId(u32 id) {
912 CHECK(id);
913 StackTrace res = StackDepotGet(id);
914 CHECK(res.trace);
915 return res;
918 u32 AsanChunkView::GetAllocStackId() const {
919 u32 tid = 0;
920 u32 stack = 0;
921 chunk_->GetAllocContext(tid, stack);
922 return stack;
925 u32 AsanChunkView::GetFreeStackId() const {
926 if (!IsQuarantined())
927 return 0;
928 u32 tid = 0;
929 u32 stack = 0;
930 chunk_->GetFreeContext(tid, stack);
931 return stack;
934 StackTrace AsanChunkView::GetAllocStack() const {
935 return GetStackTraceFromId(GetAllocStackId());
938 StackTrace AsanChunkView::GetFreeStack() const {
939 return GetStackTraceFromId(GetFreeStackId());
942 void InitializeAllocator(const AllocatorOptions &options) {
943 instance.InitLinkerInitialized(options);
946 void ReInitializeAllocator(const AllocatorOptions &options) {
947 instance.ReInitialize(options);
950 void GetAllocatorOptions(AllocatorOptions *options) {
951 instance.GetOptions(options);
954 AsanChunkView FindHeapChunkByAddress(uptr addr) {
955 return instance.FindHeapChunkByAddress(addr);
957 AsanChunkView FindHeapChunkByAllocBeg(uptr addr) {
958 return AsanChunkView(instance.GetAsanChunk(reinterpret_cast<void*>(addr)));
961 void AsanThreadLocalMallocStorage::CommitBack() {
962 GET_STACK_TRACE_MALLOC;
963 instance.CommitBack(this, &stack);
966 void PrintInternalAllocatorStats() {
967 instance.PrintStats();
970 void asan_free(void *ptr, BufferedStackTrace *stack, AllocType alloc_type) {
971 instance.Deallocate(ptr, 0, 0, stack, alloc_type);
974 void asan_delete(void *ptr, uptr size, uptr alignment,
975 BufferedStackTrace *stack, AllocType alloc_type) {
976 instance.Deallocate(ptr, size, alignment, stack, alloc_type);
979 void *asan_malloc(uptr size, BufferedStackTrace *stack) {
980 return SetErrnoOnNull(instance.Allocate(size, 8, stack, FROM_MALLOC, true));
983 void *asan_calloc(uptr nmemb, uptr size, BufferedStackTrace *stack) {
984 return SetErrnoOnNull(instance.Calloc(nmemb, size, stack));
987 void *asan_reallocarray(void *p, uptr nmemb, uptr size,
988 BufferedStackTrace *stack) {
989 if (UNLIKELY(CheckForCallocOverflow(size, nmemb))) {
990 errno = errno_ENOMEM;
991 if (AllocatorMayReturnNull())
992 return nullptr;
993 ReportReallocArrayOverflow(nmemb, size, stack);
995 return asan_realloc(p, nmemb * size, stack);
998 void *asan_realloc(void *p, uptr size, BufferedStackTrace *stack) {
999 if (!p)
1000 return SetErrnoOnNull(instance.Allocate(size, 8, stack, FROM_MALLOC, true));
1001 if (size == 0) {
1002 if (flags()->allocator_frees_and_returns_null_on_realloc_zero) {
1003 instance.Deallocate(p, 0, 0, stack, FROM_MALLOC);
1004 return nullptr;
1006 // Allocate a size of 1 if we shouldn't free() on Realloc to 0
1007 size = 1;
1009 return SetErrnoOnNull(instance.Reallocate(p, size, stack));
1012 void *asan_valloc(uptr size, BufferedStackTrace *stack) {
1013 return SetErrnoOnNull(
1014 instance.Allocate(size, GetPageSizeCached(), stack, FROM_MALLOC, true));
1017 void *asan_pvalloc(uptr size, BufferedStackTrace *stack) {
1018 uptr PageSize = GetPageSizeCached();
1019 if (UNLIKELY(CheckForPvallocOverflow(size, PageSize))) {
1020 errno = errno_ENOMEM;
1021 if (AllocatorMayReturnNull())
1022 return nullptr;
1023 ReportPvallocOverflow(size, stack);
1025 // pvalloc(0) should allocate one page.
1026 size = size ? RoundUpTo(size, PageSize) : PageSize;
1027 return SetErrnoOnNull(
1028 instance.Allocate(size, PageSize, stack, FROM_MALLOC, true));
1031 void *asan_memalign(uptr alignment, uptr size, BufferedStackTrace *stack,
1032 AllocType alloc_type) {
1033 if (UNLIKELY(!IsPowerOfTwo(alignment))) {
1034 errno = errno_EINVAL;
1035 if (AllocatorMayReturnNull())
1036 return nullptr;
1037 ReportInvalidAllocationAlignment(alignment, stack);
1039 return SetErrnoOnNull(
1040 instance.Allocate(size, alignment, stack, alloc_type, true));
1043 void *asan_aligned_alloc(uptr alignment, uptr size, BufferedStackTrace *stack) {
1044 if (UNLIKELY(!CheckAlignedAllocAlignmentAndSize(alignment, size))) {
1045 errno = errno_EINVAL;
1046 if (AllocatorMayReturnNull())
1047 return nullptr;
1048 ReportInvalidAlignedAllocAlignment(size, alignment, stack);
1050 return SetErrnoOnNull(
1051 instance.Allocate(size, alignment, stack, FROM_MALLOC, true));
1054 int asan_posix_memalign(void **memptr, uptr alignment, uptr size,
1055 BufferedStackTrace *stack) {
1056 if (UNLIKELY(!CheckPosixMemalignAlignment(alignment))) {
1057 if (AllocatorMayReturnNull())
1058 return errno_EINVAL;
1059 ReportInvalidPosixMemalignAlignment(alignment, stack);
1061 void *ptr = instance.Allocate(size, alignment, stack, FROM_MALLOC, true);
1062 if (UNLIKELY(!ptr))
1063 // OOM error is already taken care of by Allocate.
1064 return errno_ENOMEM;
1065 CHECK(IsAligned((uptr)ptr, alignment));
1066 *memptr = ptr;
1067 return 0;
1070 uptr asan_malloc_usable_size(const void *ptr, uptr pc, uptr bp) {
1071 if (!ptr) return 0;
1072 uptr usable_size = instance.AllocationSize(reinterpret_cast<uptr>(ptr));
1073 if (flags()->check_malloc_usable_size && (usable_size == 0)) {
1074 GET_STACK_TRACE_FATAL(pc, bp);
1075 ReportMallocUsableSizeNotOwned((uptr)ptr, &stack);
1077 return usable_size;
1080 uptr asan_mz_size(const void *ptr) {
1081 return instance.AllocationSize(reinterpret_cast<uptr>(ptr));
1084 void asan_mz_force_lock() {
1085 instance.ForceLock();
1088 void asan_mz_force_unlock() {
1089 instance.ForceUnlock();
1092 void AsanSoftRssLimitExceededCallback(bool limit_exceeded) {
1093 instance.SetRssLimitExceeded(limit_exceeded);
1096 } // namespace __asan
1098 // --- Implementation of LSan-specific functions --- {{{1
1099 namespace __lsan {
1100 void LockAllocator() {
1101 __asan::get_allocator().ForceLock();
1104 void UnlockAllocator() {
1105 __asan::get_allocator().ForceUnlock();
1108 void GetAllocatorGlobalRange(uptr *begin, uptr *end) {
1109 *begin = (uptr)&__asan::get_allocator();
1110 *end = *begin + sizeof(__asan::get_allocator());
1113 uptr PointsIntoChunk(void *p) {
1114 uptr addr = reinterpret_cast<uptr>(p);
1115 __asan::AsanChunk *m = __asan::instance.GetAsanChunkByAddrFastLocked(addr);
1116 if (!m || atomic_load(&m->chunk_state, memory_order_acquire) !=
1117 __asan::CHUNK_ALLOCATED)
1118 return 0;
1119 uptr chunk = m->Beg();
1120 if (m->AddrIsInside(addr))
1121 return chunk;
1122 if (IsSpecialCaseOfOperatorNew0(chunk, m->UsedSize(), addr))
1123 return chunk;
1124 return 0;
1127 uptr GetUserBegin(uptr chunk) {
1128 __asan::AsanChunk *m = __asan::instance.GetAsanChunkByAddrFastLocked(chunk);
1129 return m ? m->Beg() : 0;
1132 LsanMetadata::LsanMetadata(uptr chunk) {
1133 metadata_ = chunk ? reinterpret_cast<void *>(chunk - __asan::kChunkHeaderSize)
1134 : nullptr;
1137 bool LsanMetadata::allocated() const {
1138 if (!metadata_)
1139 return false;
1140 __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
1141 return atomic_load(&m->chunk_state, memory_order_relaxed) ==
1142 __asan::CHUNK_ALLOCATED;
1145 ChunkTag LsanMetadata::tag() const {
1146 __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
1147 return static_cast<ChunkTag>(m->lsan_tag);
1150 void LsanMetadata::set_tag(ChunkTag value) {
1151 __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
1152 m->lsan_tag = value;
1155 uptr LsanMetadata::requested_size() const {
1156 __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
1157 return m->UsedSize();
1160 u32 LsanMetadata::stack_trace_id() const {
1161 __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
1162 u32 tid = 0;
1163 u32 stack = 0;
1164 m->GetAllocContext(tid, stack);
1165 return stack;
1168 void ForEachChunk(ForEachChunkCallback callback, void *arg) {
1169 __asan::get_allocator().ForEachChunk(callback, arg);
1172 IgnoreObjectResult IgnoreObjectLocked(const void *p) {
1173 uptr addr = reinterpret_cast<uptr>(p);
1174 __asan::AsanChunk *m = __asan::instance.GetAsanChunkByAddr(addr);
1175 if (!m ||
1176 (atomic_load(&m->chunk_state, memory_order_acquire) !=
1177 __asan::CHUNK_ALLOCATED) ||
1178 !m->AddrIsInside(addr)) {
1179 return kIgnoreObjectInvalid;
1181 if (m->lsan_tag == kIgnored)
1182 return kIgnoreObjectAlreadyIgnored;
1183 m->lsan_tag = __lsan::kIgnored;
1184 return kIgnoreObjectSuccess;
1186 } // namespace __lsan
1188 // ---------------------- Interface ---------------- {{{1
1189 using namespace __asan;
1191 // ASan allocator doesn't reserve extra bytes, so normally we would
1192 // just return "size". We don't want to expose our redzone sizes, etc here.
1193 uptr __sanitizer_get_estimated_allocated_size(uptr size) {
1194 return size;
1197 int __sanitizer_get_ownership(const void *p) {
1198 uptr ptr = reinterpret_cast<uptr>(p);
1199 return instance.AllocationSize(ptr) > 0;
1202 uptr __sanitizer_get_allocated_size(const void *p) {
1203 if (!p) return 0;
1204 uptr ptr = reinterpret_cast<uptr>(p);
1205 uptr allocated_size = instance.AllocationSize(ptr);
1206 // Die if p is not malloced or if it is already freed.
1207 if (allocated_size == 0) {
1208 GET_STACK_TRACE_FATAL_HERE;
1209 ReportSanitizerGetAllocatedSizeNotOwned(ptr, &stack);
1211 return allocated_size;
1214 void __sanitizer_purge_allocator() {
1215 GET_STACK_TRACE_MALLOC;
1216 instance.Purge(&stack);
1219 int __asan_update_allocation_context(void* addr) {
1220 GET_STACK_TRACE_MALLOC;
1221 return instance.UpdateAllocationStack((uptr)addr, &stack);
1224 #if !SANITIZER_SUPPORTS_WEAK_HOOKS
1225 // Provide default (no-op) implementation of malloc hooks.
1226 SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_malloc_hook,
1227 void *ptr, uptr size) {
1228 (void)ptr;
1229 (void)size;
1232 SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_free_hook, void *ptr) {
1233 (void)ptr;
1235 #endif