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.
10//
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.
14//
15//===----------------------------------------------------------------------===//
16
17#include "asan_allocator.h"
18
19#include "asan_internal.h"
20#include "asan_mapping.h"
21#include "asan_poisoning.h"
22#include "asan_report.h"
23#include "asan_stack.h"
24#include "asan_suppressions.h"
25#include "asan_thread.h"
26#include "lsan/lsan_common.h"
27#include "sanitizer_common/sanitizer_allocator_checks.h"
28#include "sanitizer_common/sanitizer_allocator_interface.h"
29#include "sanitizer_common/sanitizer_common.h"
30#include "sanitizer_common/sanitizer_errno.h"
31#include "sanitizer_common/sanitizer_flags.h"
32#include "sanitizer_common/sanitizer_internal_defs.h"
33#include "sanitizer_common/sanitizer_list.h"
34#include "sanitizer_common/sanitizer_quarantine.h"
35#include "sanitizer_common/sanitizer_stackdepot.h"
36
37namespace __asan {
38
39// Valid redzone sizes are 16, 32, 64, ... 2048, so we encode them in 3 bits.
40// We use adaptive redzones: for larger allocation larger redzones are used.
41static u32 RZLog2Size(u32 rz_log) {
42 CHECK_LT(rz_log, 8);
43 return 16 << rz_log;
44}
45
46static u32 RZSize2Log(u32 rz_size) {
47 CHECK_GE(rz_size, 16);
48 CHECK_LE(rz_size, 2048);
49 CHECK(IsPowerOfTwo(rz_size));
50 u32 res = Log2(x: rz_size) - 4;
51 CHECK_EQ(rz_size, RZLog2Size(res));
52 return res;
53}
54
55static AsanAllocator &get_allocator();
56
57static void AtomicContextStore(volatile atomic_uint64_t *atomic_context,
58 u32 tid, u32 stack) {
59 u64 context = tid;
60 context <<= 32;
61 context += stack;
62 atomic_store(a: atomic_context, v: context, mo: memory_order_relaxed);
63}
64
65static void AtomicContextLoad(const volatile atomic_uint64_t *atomic_context,
66 u32 &tid, u32 &stack) {
67 u64 context = atomic_load(a: atomic_context, mo: memory_order_relaxed);
68 stack = context;
69 context >>= 32;
70 tid = context;
71}
72
73// The memory chunk allocated from the underlying allocator looks like this:
74// L L L L L L H H U U U U U U R R
75// L -- left redzone words (0 or more bytes)
76// H -- ChunkHeader (16 bytes), which is also a part of the left redzone.
77// U -- user memory.
78// R -- right redzone (0 or more bytes)
79// ChunkBase consists of ChunkHeader and other bytes that overlap with user
80// memory.
81
82// If the left redzone is greater than the ChunkHeader size we store a magic
83// value in the first uptr word of the memory block and store the address of
84// ChunkBase in the next uptr.
85// M B L L L L L L L L L H H U U U U U U
86// | ^
87// ---------------------|
88// M -- magic value kAllocBegMagic
89// B -- address of ChunkHeader pointing to the first 'H'
90
91class ChunkHeader {
92 public:
93 atomic_uint8_t chunk_state;
94 u8 alloc_type : 2;
95 u8 lsan_tag : 2;
96
97 // align < 8 -> 0
98 // else -> log2(min(align, 512)) - 2
99 u8 user_requested_alignment_log : 3;
100
101 private:
102 u16 user_requested_size_hi;
103 u32 user_requested_size_lo;
104 atomic_uint64_t alloc_context_id;
105
106 public:
107 uptr UsedSize() const {
108 static_assert(sizeof(user_requested_size_lo) == 4,
109 "Expression below requires this");
110 return FIRST_32_SECOND_64(0, ((uptr)user_requested_size_hi << 32)) +
111 user_requested_size_lo;
112 }
113
114 void SetUsedSize(uptr size) {
115 user_requested_size_lo = size;
116 static_assert(sizeof(user_requested_size_lo) == 4,
117 "Expression below requires this");
118 user_requested_size_hi = FIRST_32_SECOND_64(0, size >> 32);
119 CHECK_EQ(UsedSize(), size);
120 }
121
122 void SetAllocContext(u32 tid, u32 stack) {
123 AtomicContextStore(atomic_context: &alloc_context_id, tid, stack);
124 }
125
126 void GetAllocContext(u32 &tid, u32 &stack) const {
127 AtomicContextLoad(atomic_context: &alloc_context_id, tid, stack);
128 }
129};
130
131class ChunkBase : public ChunkHeader {
132 atomic_uint64_t free_context_id;
133
134 public:
135 void SetFreeContext(u32 tid, u32 stack) {
136 AtomicContextStore(atomic_context: &free_context_id, tid, stack);
137 }
138
139 void GetFreeContext(u32 &tid, u32 &stack) const {
140 AtomicContextLoad(atomic_context: &free_context_id, tid, stack);
141 }
142};
143
144static const uptr kChunkHeaderSize = sizeof(ChunkHeader);
145static const uptr kChunkHeader2Size = sizeof(ChunkBase) - kChunkHeaderSize;
146COMPILER_CHECK(kChunkHeaderSize == 16);
147COMPILER_CHECK(kChunkHeader2Size <= 16);
148
149enum {
150 // Either just allocated by underlying allocator, but AsanChunk is not yet
151 // ready, or almost returned to undelying allocator and AsanChunk is already
152 // meaningless.
153 CHUNK_INVALID = 0,
154 // The chunk is allocated and not yet freed.
155 CHUNK_ALLOCATED = 2,
156 // The chunk was freed and put into quarantine zone.
157 CHUNK_QUARANTINE = 3,
158};
159
160class AsanChunk : public ChunkBase {
161 public:
162 uptr Beg() { return reinterpret_cast<uptr>(this) + kChunkHeaderSize; }
163 bool AddrIsInside(uptr addr) {
164 return (addr >= Beg()) && (addr < Beg() + UsedSize());
165 }
166};
167
168class LargeChunkHeader {
169 static constexpr uptr kAllocBegMagic =
170 FIRST_32_SECOND_64(0xCC6E96B9, 0xCC6E96B9CC6E96B9ULL);
171 atomic_uintptr_t magic;
172 AsanChunk *chunk_header;
173
174 public:
175 AsanChunk *Get() const {
176 return atomic_load(a: &magic, mo: memory_order_acquire) == kAllocBegMagic
177 ? chunk_header
178 : nullptr;
179 }
180
181 void Set(AsanChunk *p) {
182 if (p) {
183 chunk_header = p;
184 atomic_store(a: &magic, v: kAllocBegMagic, mo: memory_order_release);
185 return;
186 }
187
188 uptr old = kAllocBegMagic;
189 if (!atomic_compare_exchange_strong(a: &magic, cmp: &old, xchg: 0,
190 mo: memory_order_release)) {
191 CHECK_EQ(old, kAllocBegMagic);
192 }
193 }
194};
195
196static void FillChunk(AsanChunk *m) {
197 // FIXME: Use ReleaseMemoryPagesToOS.
198 Flags &fl = *flags();
199
200 if (fl.max_free_fill_size > 0) {
201 // We have to skip the chunk header, it contains free_context_id.
202 uptr scribble_start = (uptr)m + kChunkHeaderSize + kChunkHeader2Size;
203 if (m->UsedSize() >= kChunkHeader2Size) { // Skip Header2 in user area.
204 uptr size_to_fill = m->UsedSize() - kChunkHeader2Size;
205 size_to_fill = Min(a: size_to_fill, b: (uptr)fl.max_free_fill_size);
206 REAL(memset)((void *)scribble_start, fl.free_fill_byte, size_to_fill);
207 }
208 }
209}
210
211struct QuarantineCallback {
212 QuarantineCallback(AllocatorCache *cache, BufferedStackTrace *stack)
213 : cache_(cache),
214 stack_(stack) {
215 }
216
217 void PreQuarantine(AsanChunk *m) const {
218 FillChunk(m);
219 // Poison the region.
220 PoisonShadow(addr: m->Beg(), size: RoundUpTo(size: m->UsedSize(), ASAN_SHADOW_GRANULARITY),
221 value: kAsanHeapFreeMagic);
222 }
223
224 void Recycle(AsanChunk *m) const {
225 void *p = get_allocator().GetBlockBegin(p: m);
226
227 // The secondary will immediately unpoison and unmap the memory, so this
228 // branch is unnecessary.
229 if (get_allocator().FromPrimary(p)) {
230 if (p != m) {
231 // Clear the magic value, as allocator internals may overwrite the
232 // contents of deallocated chunk, confusing GetAsanChunk lookup.
233 reinterpret_cast<LargeChunkHeader *>(p)->Set(nullptr);
234 }
235
236 u8 old_chunk_state = CHUNK_QUARANTINE;
237 if (!atomic_compare_exchange_strong(a: &m->chunk_state, cmp: &old_chunk_state,
238 xchg: CHUNK_INVALID,
239 mo: memory_order_acquire)) {
240 CHECK_EQ(old_chunk_state, CHUNK_QUARANTINE);
241 }
242
243 PoisonShadow(addr: m->Beg(), size: RoundUpTo(size: m->UsedSize(), ASAN_SHADOW_GRANULARITY),
244 value: kAsanHeapLeftRedzoneMagic);
245 }
246
247 // Statistics.
248 AsanStats &thread_stats = GetCurrentThreadStats();
249 thread_stats.real_frees++;
250 thread_stats.really_freed += m->UsedSize();
251
252 get_allocator().Deallocate(cache: cache_, p);
253 }
254
255 void RecyclePassThrough(AsanChunk *m) const {
256 // Recycle for the secondary will immediately unpoison and unmap the
257 // memory, so quarantine preparation is unnecessary.
258 if (get_allocator().FromPrimary(p: m)) {
259 // The primary allocation may need pattern fill if enabled.
260 FillChunk(m);
261 }
262 Recycle(m);
263 }
264
265 void *Allocate(uptr size) const {
266 void *res = get_allocator().Allocate(cache: cache_, size, alignment: 1);
267 // TODO(alekseys): Consider making quarantine OOM-friendly.
268 if (UNLIKELY(!res))
269 ReportOutOfMemory(requested_size: size, stack: stack_);
270 return res;
271 }
272
273 void Deallocate(void *p) const { get_allocator().Deallocate(cache: cache_, p); }
274
275 private:
276 AllocatorCache* const cache_;
277 BufferedStackTrace* const stack_;
278};
279
280typedef Quarantine<QuarantineCallback, AsanChunk> AsanQuarantine;
281typedef AsanQuarantine::Cache QuarantineCache;
282
283void AsanMapUnmapCallback::OnMap(uptr p, uptr size) const {
284 PoisonShadow(addr: p, size, value: kAsanHeapLeftRedzoneMagic);
285 // Statistics.
286 AsanStats &thread_stats = GetCurrentThreadStats();
287 thread_stats.mmaps++;
288 thread_stats.mmaped += size;
289}
290
291void AsanMapUnmapCallback::OnMapSecondary(uptr p, uptr size, uptr user_begin,
292 uptr user_size) const {
293 uptr user_end = RoundDownTo(x: user_begin + user_size, ASAN_SHADOW_GRANULARITY);
294 user_begin = RoundUpTo(size: user_begin, ASAN_SHADOW_GRANULARITY);
295 // The secondary mapping will be immediately returned to user, no value
296 // poisoning that with non-zero just before unpoisoning by Allocate(). So just
297 // poison head/tail invisible to Allocate().
298 PoisonShadow(addr: p, size: user_begin - p, value: kAsanHeapLeftRedzoneMagic);
299 PoisonShadow(addr: user_end, size: size - (user_end - p), value: kAsanHeapLeftRedzoneMagic);
300 // Statistics.
301 AsanStats &thread_stats = GetCurrentThreadStats();
302 thread_stats.mmaps++;
303 thread_stats.mmaped += size;
304}
305
306void AsanMapUnmapCallback::OnUnmap(uptr p, uptr size) const {
307 PoisonShadow(addr: p, size, value: 0);
308 // We are about to unmap a chunk of user memory.
309 // Mark the corresponding shadow memory as not needed.
310 FlushUnneededASanShadowMemory(p, size);
311 // Statistics.
312 AsanStats &thread_stats = GetCurrentThreadStats();
313 thread_stats.munmaps++;
314 thread_stats.munmaped += size;
315}
316
317// We can not use THREADLOCAL because it is not supported on some of the
318// platforms we care about (OSX 10.6, Android).
319// static THREADLOCAL AllocatorCache cache;
320AllocatorCache *GetAllocatorCache(AsanThreadLocalMallocStorage *ms) {
321 CHECK(ms);
322 return &ms->allocator_cache;
323}
324
325QuarantineCache *GetQuarantineCache(AsanThreadLocalMallocStorage *ms) {
326 CHECK(ms);
327 CHECK_LE(sizeof(QuarantineCache), sizeof(ms->quarantine_cache));
328 return reinterpret_cast<QuarantineCache *>(ms->quarantine_cache);
329}
330
331void AllocatorOptions::SetFrom(const Flags *f, const CommonFlags *cf) {
332 quarantine_size_mb = f->quarantine_size_mb;
333 thread_local_quarantine_size_kb = f->thread_local_quarantine_size_kb;
334 min_redzone = f->redzone;
335 max_redzone = f->max_redzone;
336 may_return_null = cf->allocator_may_return_null;
337 alloc_dealloc_mismatch = f->alloc_dealloc_mismatch;
338 release_to_os_interval_ms = cf->allocator_release_to_os_interval_ms;
339}
340
341void AllocatorOptions::CopyTo(Flags *f, CommonFlags *cf) {
342 f->quarantine_size_mb = quarantine_size_mb;
343 f->thread_local_quarantine_size_kb = thread_local_quarantine_size_kb;
344 f->redzone = min_redzone;
345 f->max_redzone = max_redzone;
346 cf->allocator_may_return_null = may_return_null;
347 f->alloc_dealloc_mismatch = alloc_dealloc_mismatch;
348 cf->allocator_release_to_os_interval_ms = release_to_os_interval_ms;
349}
350
351struct Allocator {
352 static const uptr kMaxAllowedMallocSize =
353 FIRST_32_SECOND_64(3UL << 30, 1ULL << 40);
354
355 AsanAllocator allocator;
356 AsanQuarantine quarantine;
357 StaticSpinMutex fallback_mutex;
358 AllocatorCache fallback_allocator_cache;
359 QuarantineCache fallback_quarantine_cache;
360
361 uptr max_user_defined_malloc_size;
362
363 // ------------------- Options --------------------------
364 atomic_uint16_t min_redzone;
365 atomic_uint16_t max_redzone;
366 atomic_uint8_t alloc_dealloc_mismatch;
367
368 // ------------------- Initialization ------------------------
369 explicit Allocator(LinkerInitialized)
370 : quarantine(LINKER_INITIALIZED),
371 fallback_quarantine_cache(LINKER_INITIALIZED) {}
372
373 void CheckOptions(const AllocatorOptions &options) const {
374 CHECK_GE(options.min_redzone, 16);
375 CHECK_GE(options.max_redzone, options.min_redzone);
376 CHECK_LE(options.max_redzone, 2048);
377 CHECK(IsPowerOfTwo(options.min_redzone));
378 CHECK(IsPowerOfTwo(options.max_redzone));
379 }
380
381 void SharedInitCode(const AllocatorOptions &options) {
382 CheckOptions(options);
383 quarantine.Init(size: (uptr)options.quarantine_size_mb << 20,
384 cache_size: (uptr)options.thread_local_quarantine_size_kb << 10);
385 atomic_store(a: &alloc_dealloc_mismatch, v: options.alloc_dealloc_mismatch,
386 mo: memory_order_release);
387 atomic_store(a: &min_redzone, v: options.min_redzone, mo: memory_order_release);
388 atomic_store(a: &max_redzone, v: options.max_redzone, mo: memory_order_release);
389 }
390
391 void InitLinkerInitialized(const AllocatorOptions &options) {
392 SetAllocatorMayReturnNull(options.may_return_null);
393 allocator.InitLinkerInitialized(release_to_os_interval_ms: options.release_to_os_interval_ms);
394 SharedInitCode(options);
395 max_user_defined_malloc_size = common_flags()->max_allocation_size_mb
396 ? common_flags()->max_allocation_size_mb
397 << 20
398 : kMaxAllowedMallocSize;
399 }
400
401 void RePoisonChunk(uptr chunk) {
402 // This could be a user-facing chunk (with redzones), or some internal
403 // housekeeping chunk, like TransferBatch. Start by assuming the former.
404 AsanChunk *ac = GetAsanChunk(alloc_beg: (void *)chunk);
405 uptr allocated_size = allocator.GetActuallyAllocatedSize(p: (void *)chunk);
406 if (ac && atomic_load(a: &ac->chunk_state, mo: memory_order_acquire) ==
407 CHUNK_ALLOCATED) {
408 uptr beg = ac->Beg();
409 uptr end = ac->Beg() + ac->UsedSize();
410 uptr chunk_end = chunk + allocated_size;
411 if (chunk < beg && beg < end && end <= chunk_end) {
412 // Looks like a valid AsanChunk in use, poison redzones only.
413 PoisonShadow(addr: chunk, size: beg - chunk, value: kAsanHeapLeftRedzoneMagic);
414 uptr end_aligned_down = RoundDownTo(x: end, ASAN_SHADOW_GRANULARITY);
415 FastPoisonShadowPartialRightRedzone(
416 aligned_addr: end_aligned_down, size: end - end_aligned_down,
417 redzone_size: chunk_end - end_aligned_down, value: kAsanHeapLeftRedzoneMagic);
418 return;
419 }
420 }
421
422 // This is either not an AsanChunk or freed or quarantined AsanChunk.
423 // In either case, poison everything.
424 PoisonShadow(addr: chunk, size: allocated_size, value: kAsanHeapLeftRedzoneMagic);
425 }
426
427 void ReInitialize(const AllocatorOptions &options) {
428 SetAllocatorMayReturnNull(options.may_return_null);
429 allocator.SetReleaseToOSIntervalMs(options.release_to_os_interval_ms);
430 SharedInitCode(options);
431
432 // Poison all existing allocation's redzones.
433 if (CanPoisonMemory()) {
434 allocator.ForceLock();
435 allocator.ForEachChunk(
436 callback: [](uptr chunk, void *alloc) {
437 ((Allocator *)alloc)->RePoisonChunk(chunk);
438 },
439 arg: this);
440 allocator.ForceUnlock();
441 }
442 }
443
444 void GetOptions(AllocatorOptions *options) const {
445 options->quarantine_size_mb = quarantine.GetMaxSize() >> 20;
446 options->thread_local_quarantine_size_kb =
447 quarantine.GetMaxCacheSize() >> 10;
448 options->min_redzone = atomic_load(a: &min_redzone, mo: memory_order_acquire);
449 options->max_redzone = atomic_load(a: &max_redzone, mo: memory_order_acquire);
450 options->may_return_null = AllocatorMayReturnNull();
451 options->alloc_dealloc_mismatch =
452 atomic_load(a: &alloc_dealloc_mismatch, mo: memory_order_acquire);
453 options->release_to_os_interval_ms = allocator.ReleaseToOSIntervalMs();
454 }
455
456 // -------------------- Helper methods. -------------------------
457 uptr ComputeRZLog(uptr user_requested_size) {
458 u32 rz_log = user_requested_size <= 64 - 16 ? 0
459 : user_requested_size <= 128 - 32 ? 1
460 : user_requested_size <= 512 - 64 ? 2
461 : user_requested_size <= 4096 - 128 ? 3
462 : user_requested_size <= (1 << 14) - 256 ? 4
463 : user_requested_size <= (1 << 15) - 512 ? 5
464 : user_requested_size <= (1 << 16) - 1024 ? 6
465 : 7;
466 u32 hdr_log = RZSize2Log(rz_size: RoundUpToPowerOfTwo(size: sizeof(ChunkHeader)));
467 u32 min_log = RZSize2Log(rz_size: atomic_load(a: &min_redzone, mo: memory_order_acquire));
468 u32 max_log = RZSize2Log(rz_size: atomic_load(a: &max_redzone, mo: memory_order_acquire));
469 return Min(a: Max(a: rz_log, b: Max(a: min_log, b: hdr_log)), b: Max(a: max_log, b: hdr_log));
470 }
471
472 static uptr ComputeUserRequestedAlignmentLog(uptr user_requested_alignment) {
473 if (user_requested_alignment < 8)
474 return 0;
475 if (user_requested_alignment > 512)
476 user_requested_alignment = 512;
477 return Log2(x: user_requested_alignment) - 2;
478 }
479
480 static uptr ComputeUserAlignment(uptr user_requested_alignment_log) {
481 if (user_requested_alignment_log == 0)
482 return 0;
483 return 1LL << (user_requested_alignment_log + 2);
484 }
485
486 // We have an address between two chunks, and we want to report just one.
487 AsanChunk *ChooseChunk(uptr addr, AsanChunk *left_chunk,
488 AsanChunk *right_chunk) {
489 if (!left_chunk)
490 return right_chunk;
491 if (!right_chunk)
492 return left_chunk;
493 // Prefer an allocated chunk over freed chunk and freed chunk
494 // over available chunk.
495 u8 left_state = atomic_load(a: &left_chunk->chunk_state, mo: memory_order_relaxed);
496 u8 right_state =
497 atomic_load(a: &right_chunk->chunk_state, mo: memory_order_relaxed);
498 if (left_state != right_state) {
499 if (left_state == CHUNK_ALLOCATED)
500 return left_chunk;
501 if (right_state == CHUNK_ALLOCATED)
502 return right_chunk;
503 if (left_state == CHUNK_QUARANTINE)
504 return left_chunk;
505 if (right_state == CHUNK_QUARANTINE)
506 return right_chunk;
507 }
508 // Same chunk_state: choose based on offset.
509 sptr l_offset = 0, r_offset = 0;
510 CHECK(AsanChunkView(left_chunk).AddrIsAtRight(addr, 1, &l_offset));
511 CHECK(AsanChunkView(right_chunk).AddrIsAtLeft(addr, 1, &r_offset));
512 if (l_offset < r_offset)
513 return left_chunk;
514 return right_chunk;
515 }
516
517 bool UpdateAllocationStack(uptr addr, BufferedStackTrace *stack) {
518 AsanChunk *m = GetAsanChunkByAddr(p: addr);
519 if (!m) return false;
520 if (atomic_load(a: &m->chunk_state, mo: memory_order_acquire) != CHUNK_ALLOCATED)
521 return false;
522 if (m->Beg() != addr) return false;
523 AsanThread *t = GetCurrentThread();
524 m->SetAllocContext(tid: t ? t->tid() : kMainTid, stack: StackDepotPut(stack: *stack));
525 return true;
526 }
527
528 // -------------------- Allocation/Deallocation routines ---------------
529 void *Allocate(uptr size, uptr alignment, BufferedStackTrace *stack,
530 AllocType alloc_type, bool can_fill) {
531 if (UNLIKELY(!AsanInited()))
532 AsanInitFromRtl();
533 if (UNLIKELY(IsRssLimitExceeded())) {
534 if (AllocatorMayReturnNull())
535 return nullptr;
536 ReportRssLimitExceeded(stack);
537 }
538 Flags &fl = *flags();
539 CHECK(stack);
540 const uptr min_alignment = ASAN_SHADOW_GRANULARITY;
541 const uptr user_requested_alignment_log =
542 ComputeUserRequestedAlignmentLog(user_requested_alignment: alignment);
543 if (alignment < min_alignment)
544 alignment = min_alignment;
545 if (size == 0) {
546 // We'd be happy to avoid allocating memory for zero-size requests, but
547 // some programs/tests depend on this behavior and assume that malloc
548 // would not return NULL even for zero-size allocations. Moreover, it
549 // looks like operator new should never return NULL, and results of
550 // consecutive "new" calls must be different even if the allocated size
551 // is zero.
552 size = 1;
553 }
554 CHECK(IsPowerOfTwo(alignment));
555 uptr rz_log = ComputeRZLog(user_requested_size: size);
556 uptr rz_size = RZLog2Size(rz_log);
557 uptr rounded_size = RoundUpTo(size: Max(a: size, b: kChunkHeader2Size), boundary: alignment);
558 uptr needed_size = rounded_size + rz_size;
559 if (alignment > min_alignment)
560 needed_size += alignment;
561 bool from_primary = PrimaryAllocator::CanAllocate(size: needed_size, alignment);
562 // If we are allocating from the secondary allocator, there will be no
563 // automatic right redzone, so add the right redzone manually.
564 if (!from_primary)
565 needed_size += rz_size;
566 CHECK(IsAligned(needed_size, min_alignment));
567 if (size > kMaxAllowedMallocSize || needed_size > kMaxAllowedMallocSize ||
568 size > max_user_defined_malloc_size) {
569 if (AllocatorMayReturnNull()) {
570 Report(format: "WARNING: AddressSanitizer failed to allocate 0x%zx bytes\n",
571 size);
572 return nullptr;
573 }
574 uptr malloc_limit =
575 Min(a: kMaxAllowedMallocSize, b: max_user_defined_malloc_size);
576 ReportAllocationSizeTooBig(user_size: size, total_size: needed_size, max_size: malloc_limit, stack);
577 }
578
579 AsanThread *t = GetCurrentThread();
580 void *allocated;
581 if (t) {
582 AllocatorCache *cache = GetAllocatorCache(ms: &t->malloc_storage());
583 allocated = allocator.Allocate(cache, size: needed_size, alignment: 8);
584 } else {
585 SpinMutexLock l(&fallback_mutex);
586 AllocatorCache *cache = &fallback_allocator_cache;
587 allocated = allocator.Allocate(cache, size: needed_size, alignment: 8);
588 }
589 if (UNLIKELY(!allocated)) {
590 SetAllocatorOutOfMemory();
591 if (AllocatorMayReturnNull())
592 return nullptr;
593 ReportOutOfMemory(requested_size: size, stack);
594 }
595
596 uptr alloc_beg = reinterpret_cast<uptr>(allocated);
597 uptr alloc_end = alloc_beg + needed_size;
598 uptr user_beg = alloc_beg + rz_size;
599 if (!IsAligned(a: user_beg, alignment))
600 user_beg = RoundUpTo(size: user_beg, boundary: alignment);
601 uptr user_end = user_beg + size;
602 CHECK_LE(user_end, alloc_end);
603 uptr chunk_beg = user_beg - kChunkHeaderSize;
604 AsanChunk *m = reinterpret_cast<AsanChunk *>(chunk_beg);
605 m->alloc_type = alloc_type;
606 CHECK(size);
607 m->SetUsedSize(size);
608 m->user_requested_alignment_log = user_requested_alignment_log;
609
610 m->SetAllocContext(tid: t ? t->tid() : kMainTid, stack: StackDepotPut(stack: *stack));
611
612 if (!from_primary || *(u8 *)MEM_TO_SHADOW((uptr)allocated) == 0) {
613 // The allocator provides an unpoisoned chunk. This is possible for the
614 // secondary allocator, or if CanPoisonMemory() was false for some time,
615 // for example, due to flags()->start_disabled. Anyway, poison left and
616 // right of the block before using it for anything else.
617 uptr tail_beg = RoundUpTo(size: user_end, ASAN_SHADOW_GRANULARITY);
618 uptr tail_end = alloc_beg + allocator.GetActuallyAllocatedSize(p: allocated);
619 PoisonShadow(addr: alloc_beg, size: user_beg - alloc_beg, value: kAsanHeapLeftRedzoneMagic);
620 PoisonShadow(addr: tail_beg, size: tail_end - tail_beg, value: kAsanHeapLeftRedzoneMagic);
621 }
622
623 uptr size_rounded_down_to_granularity =
624 RoundDownTo(x: size, ASAN_SHADOW_GRANULARITY);
625 // Unpoison the bulk of the memory region.
626 if (size_rounded_down_to_granularity)
627 PoisonShadow(addr: user_beg, size: size_rounded_down_to_granularity, value: 0);
628 // Deal with the end of the region if size is not aligned to granularity.
629 if (size != size_rounded_down_to_granularity && CanPoisonMemory()) {
630 u8 *shadow =
631 (u8 *)MemToShadow(p: user_beg + size_rounded_down_to_granularity);
632 *shadow = fl.poison_partial ? (size & (ASAN_SHADOW_GRANULARITY - 1)) : 0;
633 }
634
635 AsanStats &thread_stats = GetCurrentThreadStats();
636 thread_stats.mallocs++;
637 thread_stats.malloced += size;
638 thread_stats.malloced_redzones += needed_size - size;
639 if (needed_size > SizeClassMap::kMaxSize)
640 thread_stats.malloc_large++;
641 else
642 thread_stats.malloced_by_size[SizeClassMap::ClassID(size: needed_size)]++;
643
644 void *res = reinterpret_cast<void *>(user_beg);
645 if (can_fill && fl.max_malloc_fill_size) {
646 uptr fill_size = Min(a: size, b: (uptr)fl.max_malloc_fill_size);
647 REAL(memset)(res, fl.malloc_fill_byte, fill_size);
648 }
649#if CAN_SANITIZE_LEAKS
650 m->lsan_tag = __lsan::DisabledInThisThread() ? __lsan::kIgnored
651 : __lsan::kDirectlyLeaked;
652#endif
653 // Must be the last mutation of metadata in this function.
654 atomic_store(a: &m->chunk_state, v: CHUNK_ALLOCATED, mo: memory_order_release);
655 if (alloc_beg != chunk_beg) {
656 CHECK_LE(alloc_beg + sizeof(LargeChunkHeader), chunk_beg);
657 reinterpret_cast<LargeChunkHeader *>(alloc_beg)->Set(m);
658 }
659 RunMallocHooks(ptr: res, size);
660 return res;
661 }
662
663 // Set quarantine flag if chunk is allocated, issue ASan error report on
664 // available and quarantined chunks. Return true on success, false otherwise.
665 bool AtomicallySetQuarantineFlagIfAllocated(AsanChunk *m, void *ptr,
666 BufferedStackTrace *stack) {
667 u8 old_chunk_state = CHUNK_ALLOCATED;
668 // Flip the chunk_state atomically to avoid race on double-free.
669 if (!atomic_compare_exchange_strong(a: &m->chunk_state, cmp: &old_chunk_state,
670 xchg: CHUNK_QUARANTINE,
671 mo: memory_order_acquire)) {
672 ReportInvalidFree(ptr, chunk_state: old_chunk_state, stack);
673 // It's not safe to push a chunk in quarantine on invalid free.
674 return false;
675 }
676 CHECK_EQ(CHUNK_ALLOCATED, old_chunk_state);
677 // It was a user data.
678 m->SetFreeContext(tid: kInvalidTid, stack: 0);
679 return true;
680 }
681
682 // Expects the chunk to already be marked as quarantined by using
683 // AtomicallySetQuarantineFlagIfAllocated.
684 void QuarantineChunk(AsanChunk *m, void *ptr, BufferedStackTrace *stack) {
685 CHECK_EQ(atomic_load(&m->chunk_state, memory_order_relaxed),
686 CHUNK_QUARANTINE);
687 AsanThread *t = GetCurrentThread();
688 m->SetFreeContext(tid: t ? t->tid() : 0, stack: StackDepotPut(stack: *stack));
689
690 // Push into quarantine.
691 if (t) {
692 AsanThreadLocalMallocStorage *ms = &t->malloc_storage();
693 AllocatorCache *ac = GetAllocatorCache(ms);
694 quarantine.Put(c: GetQuarantineCache(ms), cb: QuarantineCallback(ac, stack), ptr: m,
695 size: m->UsedSize());
696 } else {
697 SpinMutexLock l(&fallback_mutex);
698 AllocatorCache *ac = &fallback_allocator_cache;
699 quarantine.Put(c: &fallback_quarantine_cache, cb: QuarantineCallback(ac, stack),
700 ptr: m, size: m->UsedSize());
701 }
702 }
703
704 void Deallocate(void *ptr, uptr delete_size, uptr delete_alignment,
705 BufferedStackTrace *stack, AllocType alloc_type) {
706 uptr p = reinterpret_cast<uptr>(ptr);
707 if (p == 0) return;
708
709 uptr chunk_beg = p - kChunkHeaderSize;
710 AsanChunk *m = reinterpret_cast<AsanChunk *>(chunk_beg);
711
712 // On Windows, uninstrumented DLLs may allocate memory before ASan hooks
713 // malloc. Don't report an invalid free in this case.
714 if (SANITIZER_WINDOWS &&
715 !get_allocator().PointerIsMine(p: ptr)) {
716 if (!IsSystemHeapAddress(addr: p))
717 ReportFreeNotMalloced(addr: p, free_stack: stack);
718 return;
719 }
720
721 if (RunFreeHooks(ptr)) {
722 // Someone used __sanitizer_ignore_free_hook() and decided that they
723 // didn't want the memory to __sanitizer_ignore_free_hook freed right now.
724 // When they call free() on this pointer again at a later time, we should
725 // ignore the alloc-type mismatch and allow them to deallocate the pointer
726 // through free(), rather than the initial alloc type.
727 m->alloc_type = FROM_MALLOC;
728 return;
729 }
730
731 // Must mark the chunk as quarantined before any changes to its metadata.
732 // Do not quarantine given chunk if we failed to set CHUNK_QUARANTINE flag.
733 if (!AtomicallySetQuarantineFlagIfAllocated(m, ptr, stack)) return;
734
735 if (m->alloc_type != alloc_type) {
736 if (atomic_load(a: &alloc_dealloc_mismatch, mo: memory_order_acquire) &&
737 !IsAllocDeallocMismatchSuppressed(stack)) {
738 ReportAllocTypeMismatch(addr: (uptr)ptr, free_stack: stack, alloc_type: (AllocType)m->alloc_type,
739 dealloc_type: (AllocType)alloc_type);
740 }
741 } else {
742 if (flags()->new_delete_type_mismatch &&
743 (alloc_type == FROM_NEW || alloc_type == FROM_NEW_BR) &&
744 ((delete_size && delete_size != m->UsedSize()) ||
745 ComputeUserRequestedAlignmentLog(user_requested_alignment: delete_alignment) !=
746 m->user_requested_alignment_log)) {
747 ReportNewDeleteTypeMismatch(addr: p, delete_size, delete_alignment, free_stack: stack);
748 }
749 }
750
751 AsanStats &thread_stats = GetCurrentThreadStats();
752 thread_stats.frees++;
753 thread_stats.freed += m->UsedSize();
754
755 QuarantineChunk(m, ptr, stack);
756 }
757
758 void *Reallocate(void *old_ptr, uptr new_size, BufferedStackTrace *stack) {
759 CHECK(old_ptr && new_size);
760 uptr p = reinterpret_cast<uptr>(old_ptr);
761 uptr chunk_beg = p - kChunkHeaderSize;
762 AsanChunk *m = reinterpret_cast<AsanChunk *>(chunk_beg);
763
764 AsanStats &thread_stats = GetCurrentThreadStats();
765 thread_stats.reallocs++;
766 thread_stats.realloced += new_size;
767
768 void *new_ptr = Allocate(size: new_size, alignment: 8, stack, alloc_type: FROM_MALLOC, can_fill: true);
769 if (new_ptr) {
770 u8 chunk_state = atomic_load(a: &m->chunk_state, mo: memory_order_acquire);
771 if (chunk_state != CHUNK_ALLOCATED)
772 ReportInvalidFree(ptr: old_ptr, chunk_state, stack);
773 CHECK_NE(REAL(memcpy), nullptr);
774 uptr memcpy_size = Min(a: new_size, b: m->UsedSize());
775 // If realloc() races with free(), we may start copying freed memory.
776 // However, we will report racy double-free later anyway.
777 REAL(memcpy)(new_ptr, old_ptr, memcpy_size);
778 Deallocate(ptr: old_ptr, delete_size: 0, delete_alignment: 0, stack, alloc_type: FROM_MALLOC);
779 }
780 return new_ptr;
781 }
782
783 void *Calloc(uptr nmemb, uptr size, BufferedStackTrace *stack) {
784 if (UNLIKELY(CheckForCallocOverflow(size, nmemb))) {
785 if (AllocatorMayReturnNull())
786 return nullptr;
787 ReportCallocOverflow(count: nmemb, size, stack);
788 }
789 void *ptr = Allocate(size: nmemb * size, alignment: 8, stack, alloc_type: FROM_MALLOC, can_fill: false);
790 // If the memory comes from the secondary allocator no need to clear it
791 // as it comes directly from mmap.
792 if (ptr && allocator.FromPrimary(p: ptr))
793 REAL(memset)(ptr, 0, nmemb * size);
794 return ptr;
795 }
796
797 void ReportInvalidFree(void *ptr, u8 chunk_state, BufferedStackTrace *stack) {
798 if (chunk_state == CHUNK_QUARANTINE)
799 ReportDoubleFree(addr: (uptr)ptr, free_stack: stack);
800 else
801 ReportFreeNotMalloced(addr: (uptr)ptr, free_stack: stack);
802 }
803
804 void CommitBack(AsanThreadLocalMallocStorage *ms, BufferedStackTrace *stack) {
805 AllocatorCache *ac = GetAllocatorCache(ms);
806 quarantine.Drain(c: GetQuarantineCache(ms), cb: QuarantineCallback(ac, stack));
807 allocator.SwallowCache(cache: ac);
808 }
809
810 // -------------------------- Chunk lookup ----------------------
811
812 // Assumes alloc_beg == allocator.GetBlockBegin(alloc_beg).
813 // Returns nullptr if AsanChunk is not yet initialized just after
814 // get_allocator().Allocate(), or is being destroyed just before
815 // get_allocator().Deallocate().
816 AsanChunk *GetAsanChunk(void *alloc_beg) {
817 if (!alloc_beg)
818 return nullptr;
819 AsanChunk *p = reinterpret_cast<LargeChunkHeader *>(alloc_beg)->Get();
820 if (!p) {
821 if (!allocator.FromPrimary(p: alloc_beg))
822 return nullptr;
823 p = reinterpret_cast<AsanChunk *>(alloc_beg);
824 }
825 u8 state = atomic_load(a: &p->chunk_state, mo: memory_order_relaxed);
826 // It does not guaranty that Chunk is initialized, but it's
827 // definitely not for any other value.
828 if (state == CHUNK_ALLOCATED || state == CHUNK_QUARANTINE)
829 return p;
830 return nullptr;
831 }
832
833 AsanChunk *GetAsanChunkByAddr(uptr p) {
834 void *alloc_beg = allocator.GetBlockBegin(p: reinterpret_cast<void *>(p));
835 return GetAsanChunk(alloc_beg);
836 }
837
838 // Allocator must be locked when this function is called.
839 AsanChunk *GetAsanChunkByAddrFastLocked(uptr p) {
840 void *alloc_beg =
841 allocator.GetBlockBeginFastLocked(p: reinterpret_cast<void *>(p));
842 return GetAsanChunk(alloc_beg);
843 }
844
845 uptr AllocationSize(uptr p) {
846 AsanChunk *m = GetAsanChunkByAddr(p);
847 if (!m) return 0;
848 if (atomic_load(a: &m->chunk_state, mo: memory_order_acquire) != CHUNK_ALLOCATED)
849 return 0;
850 if (m->Beg() != p) return 0;
851 return m->UsedSize();
852 }
853
854 uptr AllocationSizeFast(uptr p) {
855 return reinterpret_cast<AsanChunk *>(p - kChunkHeaderSize)->UsedSize();
856 }
857
858 AsanChunkView FindHeapChunkByAddress(uptr addr) {
859 AsanChunk *m1 = GetAsanChunkByAddr(p: addr);
860 sptr offset = 0;
861 if (!m1 || AsanChunkView(m1).AddrIsAtLeft(addr, access_size: 1, offset: &offset)) {
862 // The address is in the chunk's left redzone, so maybe it is actually
863 // a right buffer overflow from the other chunk before.
864 // Search a bit before to see if there is another chunk.
865 AsanChunk *m2 = nullptr;
866 for (uptr l = 1; l < GetPageSizeCached(); l++) {
867 m2 = GetAsanChunkByAddr(p: addr - l);
868 if (m2 == m1) continue; // Still the same chunk.
869 break;
870 }
871 if (m2 && AsanChunkView(m2).AddrIsAtRight(addr, access_size: 1, offset: &offset))
872 m1 = ChooseChunk(addr, left_chunk: m2, right_chunk: m1);
873 }
874 return AsanChunkView(m1);
875 }
876
877 void Purge(BufferedStackTrace *stack) {
878 AsanThread *t = GetCurrentThread();
879 if (t) {
880 AsanThreadLocalMallocStorage *ms = &t->malloc_storage();
881 quarantine.DrainAndRecycle(c: GetQuarantineCache(ms),
882 cb: QuarantineCallback(GetAllocatorCache(ms),
883 stack));
884 }
885 {
886 SpinMutexLock l(&fallback_mutex);
887 quarantine.DrainAndRecycle(c: &fallback_quarantine_cache,
888 cb: QuarantineCallback(&fallback_allocator_cache,
889 stack));
890 }
891
892 allocator.ForceReleaseToOS();
893 }
894
895 void PrintStats() {
896 allocator.PrintStats();
897 quarantine.PrintStats();
898 }
899
900 void ForceLock() SANITIZER_ACQUIRE(fallback_mutex) {
901 allocator.ForceLock();
902 fallback_mutex.Lock();
903 }
904
905 void ForceUnlock() SANITIZER_RELEASE(fallback_mutex) {
906 fallback_mutex.Unlock();
907 allocator.ForceUnlock();
908 }
909};
910
911static Allocator instance(LINKER_INITIALIZED);
912
913static AsanAllocator &get_allocator() {
914 return instance.allocator;
915}
916
917bool AsanChunkView::IsValid() const {
918 return chunk_ && atomic_load(a: &chunk_->chunk_state, mo: memory_order_relaxed) !=
919 CHUNK_INVALID;
920}
921bool AsanChunkView::IsAllocated() const {
922 return chunk_ && atomic_load(a: &chunk_->chunk_state, mo: memory_order_relaxed) ==
923 CHUNK_ALLOCATED;
924}
925bool AsanChunkView::IsQuarantined() const {
926 return chunk_ && atomic_load(a: &chunk_->chunk_state, mo: memory_order_relaxed) ==
927 CHUNK_QUARANTINE;
928}
929uptr AsanChunkView::Beg() const { return chunk_->Beg(); }
930uptr AsanChunkView::End() const { return Beg() + UsedSize(); }
931uptr AsanChunkView::UsedSize() const { return chunk_->UsedSize(); }
932u32 AsanChunkView::UserRequestedAlignment() const {
933 return Allocator::ComputeUserAlignment(user_requested_alignment_log: chunk_->user_requested_alignment_log);
934}
935
936uptr AsanChunkView::AllocTid() const {
937 u32 tid = 0;
938 u32 stack = 0;
939 chunk_->GetAllocContext(tid, stack);
940 return tid;
941}
942
943uptr AsanChunkView::FreeTid() const {
944 if (!IsQuarantined())
945 return kInvalidTid;
946 u32 tid = 0;
947 u32 stack = 0;
948 chunk_->GetFreeContext(tid, stack);
949 return tid;
950}
951
952AllocType AsanChunkView::GetAllocType() const {
953 return (AllocType)chunk_->alloc_type;
954}
955
956u32 AsanChunkView::GetAllocStackId() const {
957 u32 tid = 0;
958 u32 stack = 0;
959 chunk_->GetAllocContext(tid, stack);
960 return stack;
961}
962
963u32 AsanChunkView::GetFreeStackId() const {
964 if (!IsQuarantined())
965 return 0;
966 u32 tid = 0;
967 u32 stack = 0;
968 chunk_->GetFreeContext(tid, stack);
969 return stack;
970}
971
972void InitializeAllocator(const AllocatorOptions &options) {
973 instance.InitLinkerInitialized(options);
974}
975
976void ReInitializeAllocator(const AllocatorOptions &options) {
977 instance.ReInitialize(options);
978}
979
980void GetAllocatorOptions(AllocatorOptions *options) {
981 instance.GetOptions(options);
982}
983
984AsanChunkView FindHeapChunkByAddress(uptr addr) {
985 return instance.FindHeapChunkByAddress(addr);
986}
987AsanChunkView FindHeapChunkByAllocBeg(uptr addr) {
988 return AsanChunkView(instance.GetAsanChunk(alloc_beg: reinterpret_cast<void*>(addr)));
989}
990
991void AsanThreadLocalMallocStorage::CommitBack() {
992 GET_STACK_TRACE_MALLOC;
993 instance.CommitBack(ms: this, stack: &stack);
994}
995
996void PrintInternalAllocatorStats() {
997 instance.PrintStats();
998}
999
1000void asan_free(void *ptr, BufferedStackTrace *stack, AllocType alloc_type) {
1001 instance.Deallocate(ptr, delete_size: 0, delete_alignment: 0, stack, alloc_type);
1002}
1003
1004void asan_delete(void *ptr, uptr size, uptr alignment,
1005 BufferedStackTrace *stack, AllocType alloc_type) {
1006 instance.Deallocate(ptr, delete_size: size, delete_alignment: alignment, stack, alloc_type);
1007}
1008
1009void *asan_malloc(uptr size, BufferedStackTrace *stack) {
1010 return SetErrnoOnNull(instance.Allocate(size, alignment: 8, stack, alloc_type: FROM_MALLOC, can_fill: true));
1011}
1012
1013void *asan_calloc(uptr nmemb, uptr size, BufferedStackTrace *stack) {
1014 return SetErrnoOnNull(instance.Calloc(nmemb, size, stack));
1015}
1016
1017void *asan_reallocarray(void *p, uptr nmemb, uptr size,
1018 BufferedStackTrace *stack) {
1019 if (UNLIKELY(CheckForCallocOverflow(size, nmemb))) {
1020 errno = errno_ENOMEM;
1021 if (AllocatorMayReturnNull())
1022 return nullptr;
1023 ReportReallocArrayOverflow(count: nmemb, size, stack);
1024 }
1025 return asan_realloc(p, size: nmemb * size, stack);
1026}
1027
1028void *asan_realloc(void *p, uptr size, BufferedStackTrace *stack) {
1029 if (!p)
1030 return SetErrnoOnNull(instance.Allocate(size, alignment: 8, stack, alloc_type: FROM_MALLOC, can_fill: true));
1031 if (size == 0) {
1032 if (flags()->allocator_frees_and_returns_null_on_realloc_zero) {
1033 instance.Deallocate(ptr: p, delete_size: 0, delete_alignment: 0, stack, alloc_type: FROM_MALLOC);
1034 return nullptr;
1035 }
1036 // Allocate a size of 1 if we shouldn't free() on Realloc to 0
1037 size = 1;
1038 }
1039 return SetErrnoOnNull(instance.Reallocate(old_ptr: p, new_size: size, stack));
1040}
1041
1042void *asan_valloc(uptr size, BufferedStackTrace *stack) {
1043 return SetErrnoOnNull(
1044 instance.Allocate(size, alignment: GetPageSizeCached(), stack, alloc_type: FROM_MALLOC, can_fill: true));
1045}
1046
1047void *asan_pvalloc(uptr size, BufferedStackTrace *stack) {
1048 uptr PageSize = GetPageSizeCached();
1049 if (UNLIKELY(CheckForPvallocOverflow(size, PageSize))) {
1050 errno = errno_ENOMEM;
1051 if (AllocatorMayReturnNull())
1052 return nullptr;
1053 ReportPvallocOverflow(size, stack);
1054 }
1055 // pvalloc(0) should allocate one page.
1056 size = size ? RoundUpTo(size, boundary: PageSize) : PageSize;
1057 return SetErrnoOnNull(
1058 instance.Allocate(size, alignment: PageSize, stack, alloc_type: FROM_MALLOC, can_fill: true));
1059}
1060
1061void *asan_memalign(uptr alignment, uptr size, BufferedStackTrace *stack,
1062 AllocType alloc_type) {
1063 if (UNLIKELY(!IsPowerOfTwo(alignment))) {
1064 errno = errno_EINVAL;
1065 if (AllocatorMayReturnNull())
1066 return nullptr;
1067 ReportInvalidAllocationAlignment(alignment, stack);
1068 }
1069 return SetErrnoOnNull(
1070 instance.Allocate(size, alignment, stack, alloc_type, can_fill: true));
1071}
1072
1073void *asan_aligned_alloc(uptr alignment, uptr size, BufferedStackTrace *stack) {
1074 if (UNLIKELY(!CheckAlignedAllocAlignmentAndSize(alignment, size))) {
1075 errno = errno_EINVAL;
1076 if (AllocatorMayReturnNull())
1077 return nullptr;
1078 ReportInvalidAlignedAllocAlignment(size, alignment, stack);
1079 }
1080 return SetErrnoOnNull(
1081 instance.Allocate(size, alignment, stack, alloc_type: FROM_MALLOC, can_fill: true));
1082}
1083
1084int asan_posix_memalign(void **memptr, uptr alignment, uptr size,
1085 BufferedStackTrace *stack) {
1086 if (UNLIKELY(!CheckPosixMemalignAlignment(alignment))) {
1087 if (AllocatorMayReturnNull())
1088 return errno_EINVAL;
1089 ReportInvalidPosixMemalignAlignment(alignment, stack);
1090 }
1091 void *ptr = instance.Allocate(size, alignment, stack, alloc_type: FROM_MALLOC, can_fill: true);
1092 if (UNLIKELY(!ptr))
1093 // OOM error is already taken care of by Allocate.
1094 return errno_ENOMEM;
1095 CHECK(IsAligned((uptr)ptr, alignment));
1096 *memptr = ptr;
1097 return 0;
1098}
1099
1100uptr asan_malloc_usable_size(const void *ptr, uptr pc, uptr bp) {
1101 if (!ptr) return 0;
1102 uptr usable_size = instance.AllocationSize(p: reinterpret_cast<uptr>(ptr));
1103 if (flags()->check_malloc_usable_size && (usable_size == 0)) {
1104 GET_STACK_TRACE_FATAL(pc, bp);
1105 ReportMallocUsableSizeNotOwned(addr: (uptr)ptr, stack: &stack);
1106 }
1107 return usable_size;
1108}
1109
1110uptr asan_mz_size(const void *ptr) {
1111 return instance.AllocationSize(p: reinterpret_cast<uptr>(ptr));
1112}
1113
1114void asan_mz_force_lock() SANITIZER_NO_THREAD_SAFETY_ANALYSIS {
1115 instance.ForceLock();
1116}
1117
1118void asan_mz_force_unlock() SANITIZER_NO_THREAD_SAFETY_ANALYSIS {
1119 instance.ForceUnlock();
1120}
1121
1122} // namespace __asan
1123
1124// --- Implementation of LSan-specific functions --- {{{1
1125namespace __lsan {
1126void LockAllocator() {
1127 __asan::get_allocator().ForceLock();
1128}
1129
1130void UnlockAllocator() {
1131 __asan::get_allocator().ForceUnlock();
1132}
1133
1134void GetAllocatorGlobalRange(uptr *begin, uptr *end) {
1135 *begin = (uptr)&__asan::get_allocator();
1136 *end = *begin + sizeof(__asan::get_allocator());
1137}
1138
1139uptr PointsIntoChunk(void *p) {
1140 uptr addr = reinterpret_cast<uptr>(p);
1141 __asan::AsanChunk *m = __asan::instance.GetAsanChunkByAddrFastLocked(p: addr);
1142 if (!m || atomic_load(a: &m->chunk_state, mo: memory_order_acquire) !=
1143 __asan::CHUNK_ALLOCATED)
1144 return 0;
1145 uptr chunk = m->Beg();
1146 if (m->AddrIsInside(addr))
1147 return chunk;
1148 if (IsSpecialCaseOfOperatorNew0(chunk_beg: chunk, chunk_size: m->UsedSize(), addr))
1149 return chunk;
1150 return 0;
1151}
1152
1153uptr GetUserBegin(uptr chunk) {
1154 // FIXME: All usecases provide chunk address, GetAsanChunkByAddrFastLocked is
1155 // not needed.
1156 __asan::AsanChunk *m = __asan::instance.GetAsanChunkByAddrFastLocked(p: chunk);
1157 return m ? m->Beg() : 0;
1158}
1159
1160uptr GetUserAddr(uptr chunk) {
1161 return chunk;
1162}
1163
1164LsanMetadata::LsanMetadata(uptr chunk) {
1165 metadata_ = chunk ? reinterpret_cast<void *>(chunk - __asan::kChunkHeaderSize)
1166 : nullptr;
1167}
1168
1169bool LsanMetadata::allocated() const {
1170 if (!metadata_)
1171 return false;
1172 __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
1173 return atomic_load(a: &m->chunk_state, mo: memory_order_relaxed) ==
1174 __asan::CHUNK_ALLOCATED;
1175}
1176
1177ChunkTag LsanMetadata::tag() const {
1178 __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
1179 return static_cast<ChunkTag>(m->lsan_tag);
1180}
1181
1182void LsanMetadata::set_tag(ChunkTag value) {
1183 __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
1184 m->lsan_tag = value;
1185}
1186
1187uptr LsanMetadata::requested_size() const {
1188 __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
1189 return m->UsedSize();
1190}
1191
1192u32 LsanMetadata::stack_trace_id() const {
1193 __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
1194 u32 tid = 0;
1195 u32 stack = 0;
1196 m->GetAllocContext(tid, stack);
1197 return stack;
1198}
1199
1200void ForEachChunk(ForEachChunkCallback callback, void *arg) {
1201 __asan::get_allocator().ForEachChunk(callback, arg);
1202}
1203
1204IgnoreObjectResult IgnoreObject(const void *p) {
1205 uptr addr = reinterpret_cast<uptr>(p);
1206 __asan::AsanChunk *m = __asan::instance.GetAsanChunkByAddr(p: addr);
1207 if (!m ||
1208 (atomic_load(a: &m->chunk_state, mo: memory_order_acquire) !=
1209 __asan::CHUNK_ALLOCATED) ||
1210 !m->AddrIsInside(addr)) {
1211 return kIgnoreObjectInvalid;
1212 }
1213 if (m->lsan_tag == kIgnored)
1214 return kIgnoreObjectAlreadyIgnored;
1215 m->lsan_tag = __lsan::kIgnored;
1216 return kIgnoreObjectSuccess;
1217}
1218
1219} // namespace __lsan
1220
1221// ---------------------- Interface ---------------- {{{1
1222using namespace __asan;
1223
1224static const void *AllocationBegin(const void *p) {
1225 AsanChunk *m = __asan::instance.GetAsanChunkByAddr(p: (uptr)p);
1226 if (!m)
1227 return nullptr;
1228 if (atomic_load(a: &m->chunk_state, mo: memory_order_acquire) != CHUNK_ALLOCATED)
1229 return nullptr;
1230 if (m->UsedSize() == 0)
1231 return nullptr;
1232 return (const void *)(m->Beg());
1233}
1234
1235// ASan allocator doesn't reserve extra bytes, so normally we would
1236// just return "size". We don't want to expose our redzone sizes, etc here.
1237uptr __sanitizer_get_estimated_allocated_size(uptr size) {
1238 return size;
1239}
1240
1241int __sanitizer_get_ownership(const void *p) {
1242 uptr ptr = reinterpret_cast<uptr>(p);
1243 return instance.AllocationSize(p: ptr) > 0;
1244}
1245
1246uptr __sanitizer_get_allocated_size(const void *p) {
1247 if (!p) return 0;
1248 uptr ptr = reinterpret_cast<uptr>(p);
1249 uptr allocated_size = instance.AllocationSize(p: ptr);
1250 // Die if p is not malloced or if it is already freed.
1251 if (allocated_size == 0) {
1252 GET_STACK_TRACE_FATAL_HERE;
1253 ReportSanitizerGetAllocatedSizeNotOwned(addr: ptr, stack: &stack);
1254 }
1255 return allocated_size;
1256}
1257
1258uptr __sanitizer_get_allocated_size_fast(const void *p) {
1259 DCHECK_EQ(p, __sanitizer_get_allocated_begin(p));
1260 uptr ret = instance.AllocationSizeFast(p: reinterpret_cast<uptr>(p));
1261 DCHECK_EQ(ret, __sanitizer_get_allocated_size(p));
1262 return ret;
1263}
1264
1265const void *__sanitizer_get_allocated_begin(const void *p) {
1266 return AllocationBegin(p);
1267}
1268
1269void __sanitizer_purge_allocator() {
1270 GET_STACK_TRACE_MALLOC;
1271 instance.Purge(stack: &stack);
1272}
1273
1274int __asan_update_allocation_context(void* addr) {
1275 GET_STACK_TRACE_MALLOC;
1276 return instance.UpdateAllocationStack(addr: (uptr)addr, stack: &stack);
1277}
1278

source code of compiler-rt/lib/asan/asan_allocator.cpp