1 //===-- asan_allocator.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
18 #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 "sanitizer_common/sanitizer_allocator_interface.h"
25 #include "sanitizer_common/sanitizer_flags.h"
26 #include "sanitizer_common/sanitizer_internal_defs.h"
27 #include "sanitizer_common/sanitizer_list.h"
28 #include "sanitizer_common/sanitizer_stackdepot.h"
29 #include "sanitizer_common/sanitizer_quarantine.h"
30 #include "lsan/lsan_common.h"
31
32 namespace __asan {
33
34 // Valid redzone sizes are 16, 32, 64, ... 2048, so we encode them in 3 bits.
35 // We use adaptive redzones: for larger allocation larger redzones are used.
RZLog2Size(u32 rz_log)36 static u32 RZLog2Size(u32 rz_log) {
37 CHECK_LT(rz_log, 8);
38 return 16 << rz_log;
39 }
40
RZSize2Log(u32 rz_size)41 static u32 RZSize2Log(u32 rz_size) {
42 CHECK_GE(rz_size, 16);
43 CHECK_LE(rz_size, 2048);
44 CHECK(IsPowerOfTwo(rz_size));
45 u32 res = Log2(rz_size) - 4;
46 CHECK_EQ(rz_size, RZLog2Size(res));
47 return res;
48 }
49
50 static AsanAllocator &get_allocator();
51
52 // The memory chunk allocated from the underlying allocator looks like this:
53 // L L L L L L H H U U U U U U R R
54 // L -- left redzone words (0 or more bytes)
55 // H -- ChunkHeader (16 bytes), which is also a part of the left redzone.
56 // U -- user memory.
57 // R -- right redzone (0 or more bytes)
58 // ChunkBase consists of ChunkHeader and other bytes that overlap with user
59 // memory.
60
61 // If the left redzone is greater than the ChunkHeader size we store a magic
62 // value in the first uptr word of the memory block and store the address of
63 // ChunkBase in the next uptr.
64 // M B L L L L L L L L L H H U U U U U U
65 // | ^
66 // ---------------------|
67 // M -- magic value kAllocBegMagic
68 // B -- address of ChunkHeader pointing to the first 'H'
69 static const uptr kAllocBegMagic = 0xCC6E96B9;
70
71 struct ChunkHeader {
72 // 1-st 8 bytes.
73 u32 chunk_state : 8; // Must be first.
74 u32 alloc_tid : 24;
75
76 u32 free_tid : 24;
77 u32 from_memalign : 1;
78 u32 alloc_type : 2;
79 u32 rz_log : 3;
80 u32 lsan_tag : 2;
81 // 2-nd 8 bytes
82 // This field is used for small sizes. For large sizes it is equal to
83 // SizeClassMap::kMaxSize and the actual size is stored in the
84 // SecondaryAllocator's metadata.
85 u32 user_requested_size;
86 u32 alloc_context_id;
87 };
88
89 struct ChunkBase : ChunkHeader {
90 // Header2, intersects with user memory.
91 u32 free_context_id;
92 };
93
94 static const uptr kChunkHeaderSize = sizeof(ChunkHeader);
95 static const uptr kChunkHeader2Size = sizeof(ChunkBase) - kChunkHeaderSize;
96 COMPILER_CHECK(kChunkHeaderSize == 16);
97 COMPILER_CHECK(kChunkHeader2Size <= 16);
98
99 // Every chunk of memory allocated by this allocator can be in one of 3 states:
100 // CHUNK_AVAILABLE: the chunk is in the free list and ready to be allocated.
101 // CHUNK_ALLOCATED: the chunk is allocated and not yet freed.
102 // CHUNK_QUARANTINE: the chunk was freed and put into quarantine zone.
103 enum {
104 CHUNK_AVAILABLE = 0, // 0 is the default value even if we didn't set it.
105 CHUNK_ALLOCATED = 2,
106 CHUNK_QUARANTINE = 3
107 };
108
109 struct AsanChunk: ChunkBase {
Beg__asan::AsanChunk110 uptr Beg() { return reinterpret_cast<uptr>(this) + kChunkHeaderSize; }
UsedSize__asan::AsanChunk111 uptr UsedSize(bool locked_version = false) {
112 if (user_requested_size != SizeClassMap::kMaxSize)
113 return user_requested_size;
114 return *reinterpret_cast<uptr *>(
115 get_allocator().GetMetaData(AllocBeg(locked_version)));
116 }
AllocBeg__asan::AsanChunk117 void *AllocBeg(bool locked_version = false) {
118 if (from_memalign) {
119 if (locked_version)
120 return get_allocator().GetBlockBeginFastLocked(
121 reinterpret_cast<void *>(this));
122 return get_allocator().GetBlockBegin(reinterpret_cast<void *>(this));
123 }
124 return reinterpret_cast<void*>(Beg() - RZLog2Size(rz_log));
125 }
AddrIsInside__asan::AsanChunk126 bool AddrIsInside(uptr addr, bool locked_version = false) {
127 return (addr >= Beg()) && (addr < Beg() + UsedSize(locked_version));
128 }
129 };
130
131 struct QuarantineCallback {
QuarantineCallback__asan::QuarantineCallback132 explicit QuarantineCallback(AllocatorCache *cache)
133 : cache_(cache) {
134 }
135
Recycle__asan::QuarantineCallback136 void Recycle(AsanChunk *m) {
137 CHECK_EQ(m->chunk_state, CHUNK_QUARANTINE);
138 atomic_store((atomic_uint8_t*)m, CHUNK_AVAILABLE, memory_order_relaxed);
139 CHECK_NE(m->alloc_tid, kInvalidTid);
140 CHECK_NE(m->free_tid, kInvalidTid);
141 PoisonShadow(m->Beg(),
142 RoundUpTo(m->UsedSize(), SHADOW_GRANULARITY),
143 kAsanHeapLeftRedzoneMagic);
144 void *p = reinterpret_cast<void *>(m->AllocBeg());
145 if (p != m) {
146 uptr *alloc_magic = reinterpret_cast<uptr *>(p);
147 CHECK_EQ(alloc_magic[0], kAllocBegMagic);
148 // Clear the magic value, as allocator internals may overwrite the
149 // contents of deallocated chunk, confusing GetAsanChunk lookup.
150 alloc_magic[0] = 0;
151 CHECK_EQ(alloc_magic[1], reinterpret_cast<uptr>(m));
152 }
153
154 // Statistics.
155 AsanStats &thread_stats = GetCurrentThreadStats();
156 thread_stats.real_frees++;
157 thread_stats.really_freed += m->UsedSize();
158
159 get_allocator().Deallocate(cache_, p);
160 }
161
Allocate__asan::QuarantineCallback162 void *Allocate(uptr size) {
163 return get_allocator().Allocate(cache_, size, 1, false);
164 }
165
Deallocate__asan::QuarantineCallback166 void Deallocate(void *p) {
167 get_allocator().Deallocate(cache_, p);
168 }
169
170 AllocatorCache *cache_;
171 };
172
173 typedef Quarantine<QuarantineCallback, AsanChunk> AsanQuarantine;
174 typedef AsanQuarantine::Cache QuarantineCache;
175
OnMap(uptr p,uptr size) const176 void AsanMapUnmapCallback::OnMap(uptr p, uptr size) const {
177 PoisonShadow(p, size, kAsanHeapLeftRedzoneMagic);
178 // Statistics.
179 AsanStats &thread_stats = GetCurrentThreadStats();
180 thread_stats.mmaps++;
181 thread_stats.mmaped += size;
182 }
OnUnmap(uptr p,uptr size) const183 void AsanMapUnmapCallback::OnUnmap(uptr p, uptr size) const {
184 PoisonShadow(p, size, 0);
185 // We are about to unmap a chunk of user memory.
186 // Mark the corresponding shadow memory as not needed.
187 FlushUnneededASanShadowMemory(p, size);
188 // Statistics.
189 AsanStats &thread_stats = GetCurrentThreadStats();
190 thread_stats.munmaps++;
191 thread_stats.munmaped += size;
192 }
193
194 // We can not use THREADLOCAL because it is not supported on some of the
195 // platforms we care about (OSX 10.6, Android).
196 // static THREADLOCAL AllocatorCache cache;
GetAllocatorCache(AsanThreadLocalMallocStorage * ms)197 AllocatorCache *GetAllocatorCache(AsanThreadLocalMallocStorage *ms) {
198 CHECK(ms);
199 return &ms->allocator_cache;
200 }
201
GetQuarantineCache(AsanThreadLocalMallocStorage * ms)202 QuarantineCache *GetQuarantineCache(AsanThreadLocalMallocStorage *ms) {
203 CHECK(ms);
204 CHECK_LE(sizeof(QuarantineCache), sizeof(ms->quarantine_cache));
205 return reinterpret_cast<QuarantineCache *>(ms->quarantine_cache);
206 }
207
SetFrom(const Flags * f,const CommonFlags * cf)208 void AllocatorOptions::SetFrom(const Flags *f, const CommonFlags *cf) {
209 quarantine_size_mb = f->quarantine_size_mb;
210 min_redzone = f->redzone;
211 max_redzone = f->max_redzone;
212 may_return_null = cf->allocator_may_return_null;
213 alloc_dealloc_mismatch = f->alloc_dealloc_mismatch;
214 }
215
CopyTo(Flags * f,CommonFlags * cf)216 void AllocatorOptions::CopyTo(Flags *f, CommonFlags *cf) {
217 f->quarantine_size_mb = quarantine_size_mb;
218 f->redzone = min_redzone;
219 f->max_redzone = max_redzone;
220 cf->allocator_may_return_null = may_return_null;
221 f->alloc_dealloc_mismatch = alloc_dealloc_mismatch;
222 }
223
224 struct Allocator {
225 static const uptr kMaxAllowedMallocSize =
226 FIRST_32_SECOND_64(3UL << 30, 1UL << 40);
227 static const uptr kMaxThreadLocalQuarantine =
228 FIRST_32_SECOND_64(1 << 18, 1 << 20);
229
230 AsanAllocator allocator;
231 AsanQuarantine quarantine;
232 StaticSpinMutex fallback_mutex;
233 AllocatorCache fallback_allocator_cache;
234 QuarantineCache fallback_quarantine_cache;
235
236 // ------------------- Options --------------------------
237 atomic_uint16_t min_redzone;
238 atomic_uint16_t max_redzone;
239 atomic_uint8_t alloc_dealloc_mismatch;
240
241 // ------------------- Initialization ------------------------
Allocator__asan::Allocator242 explicit Allocator(LinkerInitialized)
243 : quarantine(LINKER_INITIALIZED),
244 fallback_quarantine_cache(LINKER_INITIALIZED) {}
245
CheckOptions__asan::Allocator246 void CheckOptions(const AllocatorOptions &options) const {
247 CHECK_GE(options.min_redzone, 16);
248 CHECK_GE(options.max_redzone, options.min_redzone);
249 CHECK_LE(options.max_redzone, 2048);
250 CHECK(IsPowerOfTwo(options.min_redzone));
251 CHECK(IsPowerOfTwo(options.max_redzone));
252 }
253
SharedInitCode__asan::Allocator254 void SharedInitCode(const AllocatorOptions &options) {
255 CheckOptions(options);
256 quarantine.Init((uptr)options.quarantine_size_mb << 20,
257 kMaxThreadLocalQuarantine);
258 atomic_store(&alloc_dealloc_mismatch, options.alloc_dealloc_mismatch,
259 memory_order_release);
260 atomic_store(&min_redzone, options.min_redzone, memory_order_release);
261 atomic_store(&max_redzone, options.max_redzone, memory_order_release);
262 }
263
Initialize__asan::Allocator264 void Initialize(const AllocatorOptions &options) {
265 allocator.Init(options.may_return_null);
266 SharedInitCode(options);
267 }
268
ReInitialize__asan::Allocator269 void ReInitialize(const AllocatorOptions &options) {
270 allocator.SetMayReturnNull(options.may_return_null);
271 SharedInitCode(options);
272 }
273
GetOptions__asan::Allocator274 void GetOptions(AllocatorOptions *options) const {
275 options->quarantine_size_mb = quarantine.GetSize() >> 20;
276 options->min_redzone = atomic_load(&min_redzone, memory_order_acquire);
277 options->max_redzone = atomic_load(&max_redzone, memory_order_acquire);
278 options->may_return_null = allocator.MayReturnNull();
279 options->alloc_dealloc_mismatch =
280 atomic_load(&alloc_dealloc_mismatch, memory_order_acquire);
281 }
282
283 // -------------------- Helper methods. -------------------------
ComputeRZLog__asan::Allocator284 uptr ComputeRZLog(uptr user_requested_size) {
285 u32 rz_log =
286 user_requested_size <= 64 - 16 ? 0 :
287 user_requested_size <= 128 - 32 ? 1 :
288 user_requested_size <= 512 - 64 ? 2 :
289 user_requested_size <= 4096 - 128 ? 3 :
290 user_requested_size <= (1 << 14) - 256 ? 4 :
291 user_requested_size <= (1 << 15) - 512 ? 5 :
292 user_requested_size <= (1 << 16) - 1024 ? 6 : 7;
293 u32 min_rz = atomic_load(&min_redzone, memory_order_acquire);
294 u32 max_rz = atomic_load(&max_redzone, memory_order_acquire);
295 return Min(Max(rz_log, RZSize2Log(min_rz)), RZSize2Log(max_rz));
296 }
297
298 // We have an address between two chunks, and we want to report just one.
ChooseChunk__asan::Allocator299 AsanChunk *ChooseChunk(uptr addr, AsanChunk *left_chunk,
300 AsanChunk *right_chunk) {
301 // Prefer an allocated chunk over freed chunk and freed chunk
302 // over available chunk.
303 if (left_chunk->chunk_state != right_chunk->chunk_state) {
304 if (left_chunk->chunk_state == CHUNK_ALLOCATED)
305 return left_chunk;
306 if (right_chunk->chunk_state == CHUNK_ALLOCATED)
307 return right_chunk;
308 if (left_chunk->chunk_state == CHUNK_QUARANTINE)
309 return left_chunk;
310 if (right_chunk->chunk_state == CHUNK_QUARANTINE)
311 return right_chunk;
312 }
313 // Same chunk_state: choose based on offset.
314 sptr l_offset = 0, r_offset = 0;
315 CHECK(AsanChunkView(left_chunk).AddrIsAtRight(addr, 1, &l_offset));
316 CHECK(AsanChunkView(right_chunk).AddrIsAtLeft(addr, 1, &r_offset));
317 if (l_offset < r_offset)
318 return left_chunk;
319 return right_chunk;
320 }
321
322 // -------------------- Allocation/Deallocation routines ---------------
Allocate__asan::Allocator323 void *Allocate(uptr size, uptr alignment, BufferedStackTrace *stack,
324 AllocType alloc_type, bool can_fill) {
325 if (UNLIKELY(!asan_inited))
326 AsanInitFromRtl();
327 Flags &fl = *flags();
328 CHECK(stack);
329 const uptr min_alignment = SHADOW_GRANULARITY;
330 if (alignment < min_alignment)
331 alignment = min_alignment;
332 if (size == 0) {
333 // We'd be happy to avoid allocating memory for zero-size requests, but
334 // some programs/tests depend on this behavior and assume that malloc
335 // would not return NULL even for zero-size allocations. Moreover, it
336 // looks like operator new should never return NULL, and results of
337 // consecutive "new" calls must be different even if the allocated size
338 // is zero.
339 size = 1;
340 }
341 CHECK(IsPowerOfTwo(alignment));
342 uptr rz_log = ComputeRZLog(size);
343 uptr rz_size = RZLog2Size(rz_log);
344 uptr rounded_size = RoundUpTo(Max(size, kChunkHeader2Size), alignment);
345 uptr needed_size = rounded_size + rz_size;
346 if (alignment > min_alignment)
347 needed_size += alignment;
348 bool using_primary_allocator = true;
349 // If we are allocating from the secondary allocator, there will be no
350 // automatic right redzone, so add the right redzone manually.
351 if (!PrimaryAllocator::CanAllocate(needed_size, alignment)) {
352 needed_size += rz_size;
353 using_primary_allocator = false;
354 }
355 CHECK(IsAligned(needed_size, min_alignment));
356 if (size > kMaxAllowedMallocSize || needed_size > kMaxAllowedMallocSize) {
357 Report("WARNING: AddressSanitizer failed to allocate 0x%zx bytes\n",
358 (void*)size);
359 return allocator.ReturnNullOrDie();
360 }
361
362 AsanThread *t = GetCurrentThread();
363 void *allocated;
364 bool check_rss_limit = true;
365 if (t) {
366 AllocatorCache *cache = GetAllocatorCache(&t->malloc_storage());
367 allocated =
368 allocator.Allocate(cache, needed_size, 8, false, check_rss_limit);
369 } else {
370 SpinMutexLock l(&fallback_mutex);
371 AllocatorCache *cache = &fallback_allocator_cache;
372 allocated =
373 allocator.Allocate(cache, needed_size, 8, false, check_rss_limit);
374 }
375
376 if (!allocated)
377 return allocator.ReturnNullOrDie();
378
379 if (*(u8 *)MEM_TO_SHADOW((uptr)allocated) == 0 && CanPoisonMemory()) {
380 // Heap poisoning is enabled, but the allocator provides an unpoisoned
381 // chunk. This is possible if CanPoisonMemory() was false for some
382 // time, for example, due to flags()->start_disabled.
383 // Anyway, poison the block before using it for anything else.
384 uptr allocated_size = allocator.GetActuallyAllocatedSize(allocated);
385 PoisonShadow((uptr)allocated, allocated_size, kAsanHeapLeftRedzoneMagic);
386 }
387
388 uptr alloc_beg = reinterpret_cast<uptr>(allocated);
389 uptr alloc_end = alloc_beg + needed_size;
390 uptr beg_plus_redzone = alloc_beg + rz_size;
391 uptr user_beg = beg_plus_redzone;
392 if (!IsAligned(user_beg, alignment))
393 user_beg = RoundUpTo(user_beg, alignment);
394 uptr user_end = user_beg + size;
395 CHECK_LE(user_end, alloc_end);
396 uptr chunk_beg = user_beg - kChunkHeaderSize;
397 AsanChunk *m = reinterpret_cast<AsanChunk *>(chunk_beg);
398 m->alloc_type = alloc_type;
399 m->rz_log = rz_log;
400 u32 alloc_tid = t ? t->tid() : 0;
401 m->alloc_tid = alloc_tid;
402 CHECK_EQ(alloc_tid, m->alloc_tid); // Does alloc_tid fit into the bitfield?
403 m->free_tid = kInvalidTid;
404 m->from_memalign = user_beg != beg_plus_redzone;
405 if (alloc_beg != chunk_beg) {
406 CHECK_LE(alloc_beg+ 2 * sizeof(uptr), chunk_beg);
407 reinterpret_cast<uptr *>(alloc_beg)[0] = kAllocBegMagic;
408 reinterpret_cast<uptr *>(alloc_beg)[1] = chunk_beg;
409 }
410 if (using_primary_allocator) {
411 CHECK(size);
412 m->user_requested_size = size;
413 CHECK(allocator.FromPrimary(allocated));
414 } else {
415 CHECK(!allocator.FromPrimary(allocated));
416 m->user_requested_size = SizeClassMap::kMaxSize;
417 uptr *meta = reinterpret_cast<uptr *>(allocator.GetMetaData(allocated));
418 meta[0] = size;
419 meta[1] = chunk_beg;
420 }
421
422 m->alloc_context_id = StackDepotPut(*stack);
423
424 uptr size_rounded_down_to_granularity =
425 RoundDownTo(size, SHADOW_GRANULARITY);
426 // Unpoison the bulk of the memory region.
427 if (size_rounded_down_to_granularity)
428 PoisonShadow(user_beg, size_rounded_down_to_granularity, 0);
429 // Deal with the end of the region if size is not aligned to granularity.
430 if (size != size_rounded_down_to_granularity && CanPoisonMemory()) {
431 u8 *shadow =
432 (u8 *)MemToShadow(user_beg + size_rounded_down_to_granularity);
433 *shadow = fl.poison_partial ? (size & (SHADOW_GRANULARITY - 1)) : 0;
434 }
435
436 AsanStats &thread_stats = GetCurrentThreadStats();
437 thread_stats.mallocs++;
438 thread_stats.malloced += size;
439 thread_stats.malloced_redzones += needed_size - size;
440 if (needed_size > SizeClassMap::kMaxSize)
441 thread_stats.malloc_large++;
442 else
443 thread_stats.malloced_by_size[SizeClassMap::ClassID(needed_size)]++;
444
445 void *res = reinterpret_cast<void *>(user_beg);
446 if (can_fill && fl.max_malloc_fill_size) {
447 uptr fill_size = Min(size, (uptr)fl.max_malloc_fill_size);
448 REAL(memset)(res, fl.malloc_fill_byte, fill_size);
449 }
450 #if CAN_SANITIZE_LEAKS
451 m->lsan_tag = __lsan::DisabledInThisThread() ? __lsan::kIgnored
452 : __lsan::kDirectlyLeaked;
453 #endif
454 // Must be the last mutation of metadata in this function.
455 atomic_store((atomic_uint8_t *)m, CHUNK_ALLOCATED, memory_order_release);
456 ASAN_MALLOC_HOOK(res, size);
457 return res;
458 }
459
AtomicallySetQuarantineFlag__asan::Allocator460 void AtomicallySetQuarantineFlag(AsanChunk *m, void *ptr,
461 BufferedStackTrace *stack) {
462 u8 old_chunk_state = CHUNK_ALLOCATED;
463 // Flip the chunk_state atomically to avoid race on double-free.
464 if (!atomic_compare_exchange_strong((atomic_uint8_t*)m, &old_chunk_state,
465 CHUNK_QUARANTINE, memory_order_acquire))
466 ReportInvalidFree(ptr, old_chunk_state, stack);
467 CHECK_EQ(CHUNK_ALLOCATED, old_chunk_state);
468 }
469
470 // Expects the chunk to already be marked as quarantined by using
471 // AtomicallySetQuarantineFlag.
QuarantineChunk__asan::Allocator472 void QuarantineChunk(AsanChunk *m, void *ptr, BufferedStackTrace *stack,
473 AllocType alloc_type) {
474 CHECK_EQ(m->chunk_state, CHUNK_QUARANTINE);
475
476 if (m->alloc_type != alloc_type) {
477 if (atomic_load(&alloc_dealloc_mismatch, memory_order_acquire)) {
478 ReportAllocTypeMismatch((uptr)ptr, stack, (AllocType)m->alloc_type,
479 (AllocType)alloc_type);
480 }
481 }
482
483 CHECK_GE(m->alloc_tid, 0);
484 if (SANITIZER_WORDSIZE == 64) // On 32-bits this resides in user area.
485 CHECK_EQ(m->free_tid, kInvalidTid);
486 AsanThread *t = GetCurrentThread();
487 m->free_tid = t ? t->tid() : 0;
488 m->free_context_id = StackDepotPut(*stack);
489 // Poison the region.
490 PoisonShadow(m->Beg(),
491 RoundUpTo(m->UsedSize(), SHADOW_GRANULARITY),
492 kAsanHeapFreeMagic);
493
494 AsanStats &thread_stats = GetCurrentThreadStats();
495 thread_stats.frees++;
496 thread_stats.freed += m->UsedSize();
497
498 // Push into quarantine.
499 if (t) {
500 AsanThreadLocalMallocStorage *ms = &t->malloc_storage();
501 AllocatorCache *ac = GetAllocatorCache(ms);
502 quarantine.Put(GetQuarantineCache(ms), QuarantineCallback(ac), m,
503 m->UsedSize());
504 } else {
505 SpinMutexLock l(&fallback_mutex);
506 AllocatorCache *ac = &fallback_allocator_cache;
507 quarantine.Put(&fallback_quarantine_cache, QuarantineCallback(ac), m,
508 m->UsedSize());
509 }
510 }
511
Deallocate__asan::Allocator512 void Deallocate(void *ptr, uptr delete_size, BufferedStackTrace *stack,
513 AllocType alloc_type) {
514 uptr p = reinterpret_cast<uptr>(ptr);
515 if (p == 0) return;
516
517 uptr chunk_beg = p - kChunkHeaderSize;
518 AsanChunk *m = reinterpret_cast<AsanChunk *>(chunk_beg);
519 if (delete_size && flags()->new_delete_type_mismatch &&
520 delete_size != m->UsedSize()) {
521 ReportNewDeleteSizeMismatch(p, delete_size, stack);
522 }
523 ASAN_FREE_HOOK(ptr);
524 // Must mark the chunk as quarantined before any changes to its metadata.
525 AtomicallySetQuarantineFlag(m, ptr, stack);
526 QuarantineChunk(m, ptr, stack, alloc_type);
527 }
528
Reallocate__asan::Allocator529 void *Reallocate(void *old_ptr, uptr new_size, BufferedStackTrace *stack) {
530 CHECK(old_ptr && new_size);
531 uptr p = reinterpret_cast<uptr>(old_ptr);
532 uptr chunk_beg = p - kChunkHeaderSize;
533 AsanChunk *m = reinterpret_cast<AsanChunk *>(chunk_beg);
534
535 AsanStats &thread_stats = GetCurrentThreadStats();
536 thread_stats.reallocs++;
537 thread_stats.realloced += new_size;
538
539 void *new_ptr = Allocate(new_size, 8, stack, FROM_MALLOC, true);
540 if (new_ptr) {
541 u8 chunk_state = m->chunk_state;
542 if (chunk_state != CHUNK_ALLOCATED)
543 ReportInvalidFree(old_ptr, chunk_state, stack);
544 CHECK_NE(REAL(memcpy), nullptr);
545 uptr memcpy_size = Min(new_size, m->UsedSize());
546 // If realloc() races with free(), we may start copying freed memory.
547 // However, we will report racy double-free later anyway.
548 REAL(memcpy)(new_ptr, old_ptr, memcpy_size);
549 Deallocate(old_ptr, 0, stack, FROM_MALLOC);
550 }
551 return new_ptr;
552 }
553
Calloc__asan::Allocator554 void *Calloc(uptr nmemb, uptr size, BufferedStackTrace *stack) {
555 if (CallocShouldReturnNullDueToOverflow(size, nmemb))
556 return allocator.ReturnNullOrDie();
557 void *ptr = Allocate(nmemb * size, 8, stack, FROM_MALLOC, false);
558 // If the memory comes from the secondary allocator no need to clear it
559 // as it comes directly from mmap.
560 if (ptr && allocator.FromPrimary(ptr))
561 REAL(memset)(ptr, 0, nmemb * size);
562 return ptr;
563 }
564
ReportInvalidFree__asan::Allocator565 void ReportInvalidFree(void *ptr, u8 chunk_state, BufferedStackTrace *stack) {
566 if (chunk_state == CHUNK_QUARANTINE)
567 ReportDoubleFree((uptr)ptr, stack);
568 else
569 ReportFreeNotMalloced((uptr)ptr, stack);
570 }
571
CommitBack__asan::Allocator572 void CommitBack(AsanThreadLocalMallocStorage *ms) {
573 AllocatorCache *ac = GetAllocatorCache(ms);
574 quarantine.Drain(GetQuarantineCache(ms), QuarantineCallback(ac));
575 allocator.SwallowCache(ac);
576 }
577
578 // -------------------------- Chunk lookup ----------------------
579
580 // Assumes alloc_beg == allocator.GetBlockBegin(alloc_beg).
GetAsanChunk__asan::Allocator581 AsanChunk *GetAsanChunk(void *alloc_beg) {
582 if (!alloc_beg) return nullptr;
583 if (!allocator.FromPrimary(alloc_beg)) {
584 uptr *meta = reinterpret_cast<uptr *>(allocator.GetMetaData(alloc_beg));
585 AsanChunk *m = reinterpret_cast<AsanChunk *>(meta[1]);
586 return m;
587 }
588 uptr *alloc_magic = reinterpret_cast<uptr *>(alloc_beg);
589 if (alloc_magic[0] == kAllocBegMagic)
590 return reinterpret_cast<AsanChunk *>(alloc_magic[1]);
591 return reinterpret_cast<AsanChunk *>(alloc_beg);
592 }
593
GetAsanChunkByAddr__asan::Allocator594 AsanChunk *GetAsanChunkByAddr(uptr p) {
595 void *alloc_beg = allocator.GetBlockBegin(reinterpret_cast<void *>(p));
596 return GetAsanChunk(alloc_beg);
597 }
598
599 // Allocator must be locked when this function is called.
GetAsanChunkByAddrFastLocked__asan::Allocator600 AsanChunk *GetAsanChunkByAddrFastLocked(uptr p) {
601 void *alloc_beg =
602 allocator.GetBlockBeginFastLocked(reinterpret_cast<void *>(p));
603 return GetAsanChunk(alloc_beg);
604 }
605
AllocationSize__asan::Allocator606 uptr AllocationSize(uptr p) {
607 AsanChunk *m = GetAsanChunkByAddr(p);
608 if (!m) return 0;
609 if (m->chunk_state != CHUNK_ALLOCATED) return 0;
610 if (m->Beg() != p) return 0;
611 return m->UsedSize();
612 }
613
FindHeapChunkByAddress__asan::Allocator614 AsanChunkView FindHeapChunkByAddress(uptr addr) {
615 AsanChunk *m1 = GetAsanChunkByAddr(addr);
616 if (!m1) return AsanChunkView(m1);
617 sptr offset = 0;
618 if (AsanChunkView(m1).AddrIsAtLeft(addr, 1, &offset)) {
619 // The address is in the chunk's left redzone, so maybe it is actually
620 // a right buffer overflow from the other chunk to the left.
621 // Search a bit to the left to see if there is another chunk.
622 AsanChunk *m2 = nullptr;
623 for (uptr l = 1; l < GetPageSizeCached(); l++) {
624 m2 = GetAsanChunkByAddr(addr - l);
625 if (m2 == m1) continue; // Still the same chunk.
626 break;
627 }
628 if (m2 && AsanChunkView(m2).AddrIsAtRight(addr, 1, &offset))
629 m1 = ChooseChunk(addr, m2, m1);
630 }
631 return AsanChunkView(m1);
632 }
633
PrintStats__asan::Allocator634 void PrintStats() {
635 allocator.PrintStats();
636 }
637
ForceLock__asan::Allocator638 void ForceLock() {
639 allocator.ForceLock();
640 fallback_mutex.Lock();
641 }
642
ForceUnlock__asan::Allocator643 void ForceUnlock() {
644 fallback_mutex.Unlock();
645 allocator.ForceUnlock();
646 }
647 };
648
649 static Allocator instance(LINKER_INITIALIZED);
650
get_allocator()651 static AsanAllocator &get_allocator() {
652 return instance.allocator;
653 }
654
IsValid()655 bool AsanChunkView::IsValid() {
656 return chunk_ && chunk_->chunk_state != CHUNK_AVAILABLE;
657 }
Beg()658 uptr AsanChunkView::Beg() { return chunk_->Beg(); }
End()659 uptr AsanChunkView::End() { return Beg() + UsedSize(); }
UsedSize()660 uptr AsanChunkView::UsedSize() { return chunk_->UsedSize(); }
AllocTid()661 uptr AsanChunkView::AllocTid() { return chunk_->alloc_tid; }
FreeTid()662 uptr AsanChunkView::FreeTid() { return chunk_->free_tid; }
663
GetStackTraceFromId(u32 id)664 static StackTrace GetStackTraceFromId(u32 id) {
665 CHECK(id);
666 StackTrace res = StackDepotGet(id);
667 CHECK(res.trace);
668 return res;
669 }
670
GetAllocStack()671 StackTrace AsanChunkView::GetAllocStack() {
672 return GetStackTraceFromId(chunk_->alloc_context_id);
673 }
674
GetFreeStack()675 StackTrace AsanChunkView::GetFreeStack() {
676 return GetStackTraceFromId(chunk_->free_context_id);
677 }
678
InitializeAllocator(const AllocatorOptions & options)679 void InitializeAllocator(const AllocatorOptions &options) {
680 instance.Initialize(options);
681 }
682
ReInitializeAllocator(const AllocatorOptions & options)683 void ReInitializeAllocator(const AllocatorOptions &options) {
684 instance.ReInitialize(options);
685 }
686
GetAllocatorOptions(AllocatorOptions * options)687 void GetAllocatorOptions(AllocatorOptions *options) {
688 instance.GetOptions(options);
689 }
690
FindHeapChunkByAddress(uptr addr)691 AsanChunkView FindHeapChunkByAddress(uptr addr) {
692 return instance.FindHeapChunkByAddress(addr);
693 }
694
CommitBack()695 void AsanThreadLocalMallocStorage::CommitBack() {
696 instance.CommitBack(this);
697 }
698
PrintInternalAllocatorStats()699 void PrintInternalAllocatorStats() {
700 instance.PrintStats();
701 }
702
asan_memalign(uptr alignment,uptr size,BufferedStackTrace * stack,AllocType alloc_type)703 void *asan_memalign(uptr alignment, uptr size, BufferedStackTrace *stack,
704 AllocType alloc_type) {
705 return instance.Allocate(size, alignment, stack, alloc_type, true);
706 }
707
asan_free(void * ptr,BufferedStackTrace * stack,AllocType alloc_type)708 void asan_free(void *ptr, BufferedStackTrace *stack, AllocType alloc_type) {
709 instance.Deallocate(ptr, 0, stack, alloc_type);
710 }
711
asan_sized_free(void * ptr,uptr size,BufferedStackTrace * stack,AllocType alloc_type)712 void asan_sized_free(void *ptr, uptr size, BufferedStackTrace *stack,
713 AllocType alloc_type) {
714 instance.Deallocate(ptr, size, stack, alloc_type);
715 }
716
asan_malloc(uptr size,BufferedStackTrace * stack)717 void *asan_malloc(uptr size, BufferedStackTrace *stack) {
718 return instance.Allocate(size, 8, stack, FROM_MALLOC, true);
719 }
720
asan_calloc(uptr nmemb,uptr size,BufferedStackTrace * stack)721 void *asan_calloc(uptr nmemb, uptr size, BufferedStackTrace *stack) {
722 return instance.Calloc(nmemb, size, stack);
723 }
724
asan_realloc(void * p,uptr size,BufferedStackTrace * stack)725 void *asan_realloc(void *p, uptr size, BufferedStackTrace *stack) {
726 if (!p)
727 return instance.Allocate(size, 8, stack, FROM_MALLOC, true);
728 if (size == 0) {
729 instance.Deallocate(p, 0, stack, FROM_MALLOC);
730 return nullptr;
731 }
732 return instance.Reallocate(p, size, stack);
733 }
734
asan_valloc(uptr size,BufferedStackTrace * stack)735 void *asan_valloc(uptr size, BufferedStackTrace *stack) {
736 return instance.Allocate(size, GetPageSizeCached(), stack, FROM_MALLOC, true);
737 }
738
asan_pvalloc(uptr size,BufferedStackTrace * stack)739 void *asan_pvalloc(uptr size, BufferedStackTrace *stack) {
740 uptr PageSize = GetPageSizeCached();
741 size = RoundUpTo(size, PageSize);
742 if (size == 0) {
743 // pvalloc(0) should allocate one page.
744 size = PageSize;
745 }
746 return instance.Allocate(size, PageSize, stack, FROM_MALLOC, true);
747 }
748
asan_posix_memalign(void ** memptr,uptr alignment,uptr size,BufferedStackTrace * stack)749 int asan_posix_memalign(void **memptr, uptr alignment, uptr size,
750 BufferedStackTrace *stack) {
751 void *ptr = instance.Allocate(size, alignment, stack, FROM_MALLOC, true);
752 CHECK(IsAligned((uptr)ptr, alignment));
753 *memptr = ptr;
754 return 0;
755 }
756
asan_malloc_usable_size(void * ptr,uptr pc,uptr bp)757 uptr asan_malloc_usable_size(void *ptr, uptr pc, uptr bp) {
758 if (!ptr) return 0;
759 uptr usable_size = instance.AllocationSize(reinterpret_cast<uptr>(ptr));
760 if (flags()->check_malloc_usable_size && (usable_size == 0)) {
761 GET_STACK_TRACE_FATAL(pc, bp);
762 ReportMallocUsableSizeNotOwned((uptr)ptr, &stack);
763 }
764 return usable_size;
765 }
766
asan_mz_size(const void * ptr)767 uptr asan_mz_size(const void *ptr) {
768 return instance.AllocationSize(reinterpret_cast<uptr>(ptr));
769 }
770
asan_mz_force_lock()771 void asan_mz_force_lock() {
772 instance.ForceLock();
773 }
774
asan_mz_force_unlock()775 void asan_mz_force_unlock() {
776 instance.ForceUnlock();
777 }
778
AsanSoftRssLimitExceededCallback(bool exceeded)779 void AsanSoftRssLimitExceededCallback(bool exceeded) {
780 instance.allocator.SetRssLimitIsExceeded(exceeded);
781 }
782
783 } // namespace __asan
784
785 // --- Implementation of LSan-specific functions --- {{{1
786 namespace __lsan {
LockAllocator()787 void LockAllocator() {
788 __asan::get_allocator().ForceLock();
789 }
790
UnlockAllocator()791 void UnlockAllocator() {
792 __asan::get_allocator().ForceUnlock();
793 }
794
GetAllocatorGlobalRange(uptr * begin,uptr * end)795 void GetAllocatorGlobalRange(uptr *begin, uptr *end) {
796 *begin = (uptr)&__asan::get_allocator();
797 *end = *begin + sizeof(__asan::get_allocator());
798 }
799
PointsIntoChunk(void * p)800 uptr PointsIntoChunk(void* p) {
801 uptr addr = reinterpret_cast<uptr>(p);
802 __asan::AsanChunk *m = __asan::instance.GetAsanChunkByAddrFastLocked(addr);
803 if (!m) return 0;
804 uptr chunk = m->Beg();
805 if (m->chunk_state != __asan::CHUNK_ALLOCATED)
806 return 0;
807 if (m->AddrIsInside(addr, /*locked_version=*/true))
808 return chunk;
809 if (IsSpecialCaseOfOperatorNew0(chunk, m->UsedSize(/*locked_version*/ true),
810 addr))
811 return chunk;
812 return 0;
813 }
814
GetUserBegin(uptr chunk)815 uptr GetUserBegin(uptr chunk) {
816 __asan::AsanChunk *m = __asan::instance.GetAsanChunkByAddrFastLocked(chunk);
817 CHECK(m);
818 return m->Beg();
819 }
820
LsanMetadata(uptr chunk)821 LsanMetadata::LsanMetadata(uptr chunk) {
822 metadata_ = reinterpret_cast<void *>(chunk - __asan::kChunkHeaderSize);
823 }
824
allocated() const825 bool LsanMetadata::allocated() const {
826 __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
827 return m->chunk_state == __asan::CHUNK_ALLOCATED;
828 }
829
tag() const830 ChunkTag LsanMetadata::tag() const {
831 __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
832 return static_cast<ChunkTag>(m->lsan_tag);
833 }
834
set_tag(ChunkTag value)835 void LsanMetadata::set_tag(ChunkTag value) {
836 __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
837 m->lsan_tag = value;
838 }
839
requested_size() const840 uptr LsanMetadata::requested_size() const {
841 __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
842 return m->UsedSize(/*locked_version=*/true);
843 }
844
stack_trace_id() const845 u32 LsanMetadata::stack_trace_id() const {
846 __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
847 return m->alloc_context_id;
848 }
849
ForEachChunk(ForEachChunkCallback callback,void * arg)850 void ForEachChunk(ForEachChunkCallback callback, void *arg) {
851 __asan::get_allocator().ForEachChunk(callback, arg);
852 }
853
IgnoreObjectLocked(const void * p)854 IgnoreObjectResult IgnoreObjectLocked(const void *p) {
855 uptr addr = reinterpret_cast<uptr>(p);
856 __asan::AsanChunk *m = __asan::instance.GetAsanChunkByAddr(addr);
857 if (!m) return kIgnoreObjectInvalid;
858 if ((m->chunk_state == __asan::CHUNK_ALLOCATED) && m->AddrIsInside(addr)) {
859 if (m->lsan_tag == kIgnored)
860 return kIgnoreObjectAlreadyIgnored;
861 m->lsan_tag = __lsan::kIgnored;
862 return kIgnoreObjectSuccess;
863 } else {
864 return kIgnoreObjectInvalid;
865 }
866 }
867 } // namespace __lsan
868
869 // ---------------------- Interface ---------------- {{{1
870 using namespace __asan; // NOLINT
871
872 // ASan allocator doesn't reserve extra bytes, so normally we would
873 // just return "size". We don't want to expose our redzone sizes, etc here.
__sanitizer_get_estimated_allocated_size(uptr size)874 uptr __sanitizer_get_estimated_allocated_size(uptr size) {
875 return size;
876 }
877
__sanitizer_get_ownership(const void * p)878 int __sanitizer_get_ownership(const void *p) {
879 uptr ptr = reinterpret_cast<uptr>(p);
880 return instance.AllocationSize(ptr) > 0;
881 }
882
__sanitizer_get_allocated_size(const void * p)883 uptr __sanitizer_get_allocated_size(const void *p) {
884 if (!p) return 0;
885 uptr ptr = reinterpret_cast<uptr>(p);
886 uptr allocated_size = instance.AllocationSize(ptr);
887 // Die if p is not malloced or if it is already freed.
888 if (allocated_size == 0) {
889 GET_STACK_TRACE_FATAL_HERE;
890 ReportSanitizerGetAllocatedSizeNotOwned(ptr, &stack);
891 }
892 return allocated_size;
893 }
894
895 #if !SANITIZER_SUPPORTS_WEAK_HOOKS
896 // Provide default (no-op) implementation of malloc hooks.
897 extern "C" {
898 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
__sanitizer_malloc_hook(void * ptr,uptr size)899 void __sanitizer_malloc_hook(void *ptr, uptr size) {
900 (void)ptr;
901 (void)size;
902 }
903 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
__sanitizer_free_hook(void * ptr)904 void __sanitizer_free_hook(void *ptr) {
905 (void)ptr;
906 }
907 } // extern "C"
908 #endif
909