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 #include "asan_allocator.h"
18
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, 64UL << 30);
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 %p 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 uptr class_id =
441 Min(kNumberOfSizeClasses, SizeClassMap::ClassID(needed_size));
442 thread_stats.malloced_by_size[class_id]++;
443 if (needed_size > SizeClassMap::kMaxSize)
444 thread_stats.malloc_large++;
445
446 void *res = reinterpret_cast<void *>(user_beg);
447 if (can_fill && fl.max_malloc_fill_size) {
448 uptr fill_size = Min(size, (uptr)fl.max_malloc_fill_size);
449 REAL(memset)(res, fl.malloc_fill_byte, fill_size);
450 }
451 #if CAN_SANITIZE_LEAKS
452 m->lsan_tag = __lsan::DisabledInThisThread() ? __lsan::kIgnored
453 : __lsan::kDirectlyLeaked;
454 #endif
455 // Must be the last mutation of metadata in this function.
456 atomic_store((atomic_uint8_t *)m, CHUNK_ALLOCATED, memory_order_release);
457 ASAN_MALLOC_HOOK(res, size);
458 return res;
459 }
460
AtomicallySetQuarantineFlag__asan::Allocator461 void AtomicallySetQuarantineFlag(AsanChunk *m, void *ptr,
462 BufferedStackTrace *stack) {
463 u8 old_chunk_state = CHUNK_ALLOCATED;
464 // Flip the chunk_state atomically to avoid race on double-free.
465 if (!atomic_compare_exchange_strong((atomic_uint8_t*)m, &old_chunk_state,
466 CHUNK_QUARANTINE, memory_order_acquire))
467 ReportInvalidFree(ptr, old_chunk_state, stack);
468 CHECK_EQ(CHUNK_ALLOCATED, old_chunk_state);
469 }
470
471 // Expects the chunk to already be marked as quarantined by using
472 // AtomicallySetQuarantineFlag.
QuarantineChunk__asan::Allocator473 void QuarantineChunk(AsanChunk *m, void *ptr, BufferedStackTrace *stack,
474 AllocType alloc_type) {
475 CHECK_EQ(m->chunk_state, CHUNK_QUARANTINE);
476
477 if (m->alloc_type != alloc_type) {
478 if (atomic_load(&alloc_dealloc_mismatch, memory_order_acquire)) {
479 ReportAllocTypeMismatch((uptr)ptr, stack, (AllocType)m->alloc_type,
480 (AllocType)alloc_type);
481 }
482 }
483
484 CHECK_GE(m->alloc_tid, 0);
485 if (SANITIZER_WORDSIZE == 64) // On 32-bits this resides in user area.
486 CHECK_EQ(m->free_tid, kInvalidTid);
487 AsanThread *t = GetCurrentThread();
488 m->free_tid = t ? t->tid() : 0;
489 m->free_context_id = StackDepotPut(*stack);
490 // Poison the region.
491 PoisonShadow(m->Beg(),
492 RoundUpTo(m->UsedSize(), SHADOW_GRANULARITY),
493 kAsanHeapFreeMagic);
494
495 AsanStats &thread_stats = GetCurrentThreadStats();
496 thread_stats.frees++;
497 thread_stats.freed += m->UsedSize();
498
499 // Push into quarantine.
500 if (t) {
501 AsanThreadLocalMallocStorage *ms = &t->malloc_storage();
502 AllocatorCache *ac = GetAllocatorCache(ms);
503 quarantine.Put(GetQuarantineCache(ms), QuarantineCallback(ac), m,
504 m->UsedSize());
505 } else {
506 SpinMutexLock l(&fallback_mutex);
507 AllocatorCache *ac = &fallback_allocator_cache;
508 quarantine.Put(&fallback_quarantine_cache, QuarantineCallback(ac), m,
509 m->UsedSize());
510 }
511 }
512
Deallocate__asan::Allocator513 void Deallocate(void *ptr, uptr delete_size, BufferedStackTrace *stack,
514 AllocType alloc_type) {
515 uptr p = reinterpret_cast<uptr>(ptr);
516 if (p == 0) return;
517
518 uptr chunk_beg = p - kChunkHeaderSize;
519 AsanChunk *m = reinterpret_cast<AsanChunk *>(chunk_beg);
520 if (delete_size && flags()->new_delete_type_mismatch &&
521 delete_size != m->UsedSize()) {
522 ReportNewDeleteSizeMismatch(p, delete_size, stack);
523 }
524 ASAN_FREE_HOOK(ptr);
525 // Must mark the chunk as quarantined before any changes to its metadata.
526 AtomicallySetQuarantineFlag(m, ptr, stack);
527 QuarantineChunk(m, ptr, stack, alloc_type);
528 }
529
Reallocate__asan::Allocator530 void *Reallocate(void *old_ptr, uptr new_size, BufferedStackTrace *stack) {
531 CHECK(old_ptr && new_size);
532 uptr p = reinterpret_cast<uptr>(old_ptr);
533 uptr chunk_beg = p - kChunkHeaderSize;
534 AsanChunk *m = reinterpret_cast<AsanChunk *>(chunk_beg);
535
536 AsanStats &thread_stats = GetCurrentThreadStats();
537 thread_stats.reallocs++;
538 thread_stats.realloced += new_size;
539
540 void *new_ptr = Allocate(new_size, 8, stack, FROM_MALLOC, true);
541 if (new_ptr) {
542 u8 chunk_state = m->chunk_state;
543 if (chunk_state != CHUNK_ALLOCATED)
544 ReportInvalidFree(old_ptr, chunk_state, stack);
545 CHECK_NE(REAL(memcpy), (void*)0);
546 uptr memcpy_size = Min(new_size, m->UsedSize());
547 // If realloc() races with free(), we may start copying freed memory.
548 // However, we will report racy double-free later anyway.
549 REAL(memcpy)(new_ptr, old_ptr, memcpy_size);
550 Deallocate(old_ptr, 0, stack, FROM_MALLOC);
551 }
552 return new_ptr;
553 }
554
Calloc__asan::Allocator555 void *Calloc(uptr nmemb, uptr size, BufferedStackTrace *stack) {
556 if (CallocShouldReturnNullDueToOverflow(size, nmemb))
557 return allocator.ReturnNullOrDie();
558 void *ptr = Allocate(nmemb * size, 8, stack, FROM_MALLOC, false);
559 // If the memory comes from the secondary allocator no need to clear it
560 // as it comes directly from mmap.
561 if (ptr && allocator.FromPrimary(ptr))
562 REAL(memset)(ptr, 0, nmemb * size);
563 return ptr;
564 }
565
ReportInvalidFree__asan::Allocator566 void ReportInvalidFree(void *ptr, u8 chunk_state, BufferedStackTrace *stack) {
567 if (chunk_state == CHUNK_QUARANTINE)
568 ReportDoubleFree((uptr)ptr, stack);
569 else
570 ReportFreeNotMalloced((uptr)ptr, stack);
571 }
572
CommitBack__asan::Allocator573 void CommitBack(AsanThreadLocalMallocStorage *ms) {
574 AllocatorCache *ac = GetAllocatorCache(ms);
575 quarantine.Drain(GetQuarantineCache(ms), QuarantineCallback(ac));
576 allocator.SwallowCache(ac);
577 }
578
579 // -------------------------- Chunk lookup ----------------------
580
581 // Assumes alloc_beg == allocator.GetBlockBegin(alloc_beg).
GetAsanChunk__asan::Allocator582 AsanChunk *GetAsanChunk(void *alloc_beg) {
583 if (!alloc_beg) return 0;
584 if (!allocator.FromPrimary(alloc_beg)) {
585 uptr *meta = reinterpret_cast<uptr *>(allocator.GetMetaData(alloc_beg));
586 AsanChunk *m = reinterpret_cast<AsanChunk *>(meta[1]);
587 return m;
588 }
589 uptr *alloc_magic = reinterpret_cast<uptr *>(alloc_beg);
590 if (alloc_magic[0] == kAllocBegMagic)
591 return reinterpret_cast<AsanChunk *>(alloc_magic[1]);
592 return reinterpret_cast<AsanChunk *>(alloc_beg);
593 }
594
GetAsanChunkByAddr__asan::Allocator595 AsanChunk *GetAsanChunkByAddr(uptr p) {
596 void *alloc_beg = allocator.GetBlockBegin(reinterpret_cast<void *>(p));
597 return GetAsanChunk(alloc_beg);
598 }
599
600 // Allocator must be locked when this function is called.
GetAsanChunkByAddrFastLocked__asan::Allocator601 AsanChunk *GetAsanChunkByAddrFastLocked(uptr p) {
602 void *alloc_beg =
603 allocator.GetBlockBeginFastLocked(reinterpret_cast<void *>(p));
604 return GetAsanChunk(alloc_beg);
605 }
606
AllocationSize__asan::Allocator607 uptr AllocationSize(uptr p) {
608 AsanChunk *m = GetAsanChunkByAddr(p);
609 if (!m) return 0;
610 if (m->chunk_state != CHUNK_ALLOCATED) return 0;
611 if (m->Beg() != p) return 0;
612 return m->UsedSize();
613 }
614
FindHeapChunkByAddress__asan::Allocator615 AsanChunkView FindHeapChunkByAddress(uptr addr) {
616 AsanChunk *m1 = GetAsanChunkByAddr(addr);
617 if (!m1) return AsanChunkView(m1);
618 sptr offset = 0;
619 if (AsanChunkView(m1).AddrIsAtLeft(addr, 1, &offset)) {
620 // The address is in the chunk's left redzone, so maybe it is actually
621 // a right buffer overflow from the other chunk to the left.
622 // Search a bit to the left to see if there is another chunk.
623 AsanChunk *m2 = 0;
624 for (uptr l = 1; l < GetPageSizeCached(); l++) {
625 m2 = GetAsanChunkByAddr(addr - l);
626 if (m2 == m1) continue; // Still the same chunk.
627 break;
628 }
629 if (m2 && AsanChunkView(m2).AddrIsAtRight(addr, 1, &offset))
630 m1 = ChooseChunk(addr, m2, m1);
631 }
632 return AsanChunkView(m1);
633 }
634
PrintStats__asan::Allocator635 void PrintStats() {
636 allocator.PrintStats();
637 }
638
ForceLock__asan::Allocator639 void ForceLock() {
640 allocator.ForceLock();
641 fallback_mutex.Lock();
642 }
643
ForceUnlock__asan::Allocator644 void ForceUnlock() {
645 fallback_mutex.Unlock();
646 allocator.ForceUnlock();
647 }
648 };
649
650 static Allocator instance(LINKER_INITIALIZED);
651
get_allocator()652 static AsanAllocator &get_allocator() {
653 return instance.allocator;
654 }
655
IsValid()656 bool AsanChunkView::IsValid() {
657 return chunk_ != 0 && chunk_->chunk_state != CHUNK_AVAILABLE;
658 }
Beg()659 uptr AsanChunkView::Beg() { return chunk_->Beg(); }
End()660 uptr AsanChunkView::End() { return Beg() + UsedSize(); }
UsedSize()661 uptr AsanChunkView::UsedSize() { return chunk_->UsedSize(); }
AllocTid()662 uptr AsanChunkView::AllocTid() { return chunk_->alloc_tid; }
FreeTid()663 uptr AsanChunkView::FreeTid() { return chunk_->free_tid; }
664
GetStackTraceFromId(u32 id)665 static StackTrace GetStackTraceFromId(u32 id) {
666 CHECK(id);
667 StackTrace res = StackDepotGet(id);
668 CHECK(res.trace);
669 return res;
670 }
671
GetAllocStack()672 StackTrace AsanChunkView::GetAllocStack() {
673 return GetStackTraceFromId(chunk_->alloc_context_id);
674 }
675
GetFreeStack()676 StackTrace AsanChunkView::GetFreeStack() {
677 return GetStackTraceFromId(chunk_->free_context_id);
678 }
679
InitializeAllocator(const AllocatorOptions & options)680 void InitializeAllocator(const AllocatorOptions &options) {
681 instance.Initialize(options);
682 }
683
ReInitializeAllocator(const AllocatorOptions & options)684 void ReInitializeAllocator(const AllocatorOptions &options) {
685 instance.ReInitialize(options);
686 }
687
GetAllocatorOptions(AllocatorOptions * options)688 void GetAllocatorOptions(AllocatorOptions *options) {
689 instance.GetOptions(options);
690 }
691
FindHeapChunkByAddress(uptr addr)692 AsanChunkView FindHeapChunkByAddress(uptr addr) {
693 return instance.FindHeapChunkByAddress(addr);
694 }
695
CommitBack()696 void AsanThreadLocalMallocStorage::CommitBack() {
697 instance.CommitBack(this);
698 }
699
PrintInternalAllocatorStats()700 void PrintInternalAllocatorStats() {
701 instance.PrintStats();
702 }
703
asan_memalign(uptr alignment,uptr size,BufferedStackTrace * stack,AllocType alloc_type)704 void *asan_memalign(uptr alignment, uptr size, BufferedStackTrace *stack,
705 AllocType alloc_type) {
706 return instance.Allocate(size, alignment, stack, alloc_type, true);
707 }
708
asan_free(void * ptr,BufferedStackTrace * stack,AllocType alloc_type)709 void asan_free(void *ptr, BufferedStackTrace *stack, AllocType alloc_type) {
710 instance.Deallocate(ptr, 0, stack, alloc_type);
711 }
712
asan_sized_free(void * ptr,uptr size,BufferedStackTrace * stack,AllocType alloc_type)713 void asan_sized_free(void *ptr, uptr size, BufferedStackTrace *stack,
714 AllocType alloc_type) {
715 instance.Deallocate(ptr, size, stack, alloc_type);
716 }
717
asan_malloc(uptr size,BufferedStackTrace * stack)718 void *asan_malloc(uptr size, BufferedStackTrace *stack) {
719 return instance.Allocate(size, 8, stack, FROM_MALLOC, true);
720 }
721
asan_calloc(uptr nmemb,uptr size,BufferedStackTrace * stack)722 void *asan_calloc(uptr nmemb, uptr size, BufferedStackTrace *stack) {
723 return instance.Calloc(nmemb, size, stack);
724 }
725
asan_realloc(void * p,uptr size,BufferedStackTrace * stack)726 void *asan_realloc(void *p, uptr size, BufferedStackTrace *stack) {
727 if (p == 0)
728 return instance.Allocate(size, 8, stack, FROM_MALLOC, true);
729 if (size == 0) {
730 instance.Deallocate(p, 0, stack, FROM_MALLOC);
731 return 0;
732 }
733 return instance.Reallocate(p, size, stack);
734 }
735
asan_valloc(uptr size,BufferedStackTrace * stack)736 void *asan_valloc(uptr size, BufferedStackTrace *stack) {
737 return instance.Allocate(size, GetPageSizeCached(), stack, FROM_MALLOC, true);
738 }
739
asan_pvalloc(uptr size,BufferedStackTrace * stack)740 void *asan_pvalloc(uptr size, BufferedStackTrace *stack) {
741 uptr PageSize = GetPageSizeCached();
742 size = RoundUpTo(size, PageSize);
743 if (size == 0) {
744 // pvalloc(0) should allocate one page.
745 size = PageSize;
746 }
747 return instance.Allocate(size, PageSize, stack, FROM_MALLOC, true);
748 }
749
asan_posix_memalign(void ** memptr,uptr alignment,uptr size,BufferedStackTrace * stack)750 int asan_posix_memalign(void **memptr, uptr alignment, uptr size,
751 BufferedStackTrace *stack) {
752 void *ptr = instance.Allocate(size, alignment, stack, FROM_MALLOC, true);
753 CHECK(IsAligned((uptr)ptr, alignment));
754 *memptr = ptr;
755 return 0;
756 }
757
asan_malloc_usable_size(void * ptr,uptr pc,uptr bp)758 uptr asan_malloc_usable_size(void *ptr, uptr pc, uptr bp) {
759 if (ptr == 0) return 0;
760 uptr usable_size = instance.AllocationSize(reinterpret_cast<uptr>(ptr));
761 if (flags()->check_malloc_usable_size && (usable_size == 0)) {
762 GET_STACK_TRACE_FATAL(pc, bp);
763 ReportMallocUsableSizeNotOwned((uptr)ptr, &stack);
764 }
765 return usable_size;
766 }
767
asan_mz_size(const void * ptr)768 uptr asan_mz_size(const void *ptr) {
769 return instance.AllocationSize(reinterpret_cast<uptr>(ptr));
770 }
771
asan_mz_force_lock()772 void asan_mz_force_lock() {
773 instance.ForceLock();
774 }
775
asan_mz_force_unlock()776 void asan_mz_force_unlock() {
777 instance.ForceUnlock();
778 }
779
AsanSoftRssLimitExceededCallback(bool exceeded)780 void AsanSoftRssLimitExceededCallback(bool exceeded) {
781 instance.allocator.SetRssLimitIsExceeded(exceeded);
782 }
783
784 } // namespace __asan
785
786 // --- Implementation of LSan-specific functions --- {{{1
787 namespace __lsan {
LockAllocator()788 void LockAllocator() {
789 __asan::get_allocator().ForceLock();
790 }
791
UnlockAllocator()792 void UnlockAllocator() {
793 __asan::get_allocator().ForceUnlock();
794 }
795
GetAllocatorGlobalRange(uptr * begin,uptr * end)796 void GetAllocatorGlobalRange(uptr *begin, uptr *end) {
797 *begin = (uptr)&__asan::get_allocator();
798 *end = *begin + sizeof(__asan::get_allocator());
799 }
800
PointsIntoChunk(void * p)801 uptr PointsIntoChunk(void* p) {
802 uptr addr = reinterpret_cast<uptr>(p);
803 __asan::AsanChunk *m = __asan::instance.GetAsanChunkByAddrFastLocked(addr);
804 if (!m) return 0;
805 uptr chunk = m->Beg();
806 if (m->chunk_state != __asan::CHUNK_ALLOCATED)
807 return 0;
808 if (m->AddrIsInside(addr, /*locked_version=*/true))
809 return chunk;
810 if (IsSpecialCaseOfOperatorNew0(chunk, m->UsedSize(/*locked_version*/ true),
811 addr))
812 return chunk;
813 return 0;
814 }
815
GetUserBegin(uptr chunk)816 uptr GetUserBegin(uptr chunk) {
817 __asan::AsanChunk *m = __asan::instance.GetAsanChunkByAddrFastLocked(chunk);
818 CHECK(m);
819 return m->Beg();
820 }
821
LsanMetadata(uptr chunk)822 LsanMetadata::LsanMetadata(uptr chunk) {
823 metadata_ = reinterpret_cast<void *>(chunk - __asan::kChunkHeaderSize);
824 }
825
allocated() const826 bool LsanMetadata::allocated() const {
827 __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
828 return m->chunk_state == __asan::CHUNK_ALLOCATED;
829 }
830
tag() const831 ChunkTag LsanMetadata::tag() const {
832 __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
833 return static_cast<ChunkTag>(m->lsan_tag);
834 }
835
set_tag(ChunkTag value)836 void LsanMetadata::set_tag(ChunkTag value) {
837 __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
838 m->lsan_tag = value;
839 }
840
requested_size() const841 uptr LsanMetadata::requested_size() const {
842 __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
843 return m->UsedSize(/*locked_version=*/true);
844 }
845
stack_trace_id() const846 u32 LsanMetadata::stack_trace_id() const {
847 __asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
848 return m->alloc_context_id;
849 }
850
ForEachChunk(ForEachChunkCallback callback,void * arg)851 void ForEachChunk(ForEachChunkCallback callback, void *arg) {
852 __asan::get_allocator().ForEachChunk(callback, arg);
853 }
854
IgnoreObjectLocked(const void * p)855 IgnoreObjectResult IgnoreObjectLocked(const void *p) {
856 uptr addr = reinterpret_cast<uptr>(p);
857 __asan::AsanChunk *m = __asan::instance.GetAsanChunkByAddr(addr);
858 if (!m) return kIgnoreObjectInvalid;
859 if ((m->chunk_state == __asan::CHUNK_ALLOCATED) && m->AddrIsInside(addr)) {
860 if (m->lsan_tag == kIgnored)
861 return kIgnoreObjectAlreadyIgnored;
862 m->lsan_tag = __lsan::kIgnored;
863 return kIgnoreObjectSuccess;
864 } else {
865 return kIgnoreObjectInvalid;
866 }
867 }
868 } // namespace __lsan
869
870 // ---------------------- Interface ---------------- {{{1
871 using namespace __asan; // NOLINT
872
873 // ASan allocator doesn't reserve extra bytes, so normally we would
874 // just return "size". We don't want to expose our redzone sizes, etc here.
__sanitizer_get_estimated_allocated_size(uptr size)875 uptr __sanitizer_get_estimated_allocated_size(uptr size) {
876 return size;
877 }
878
__sanitizer_get_ownership(const void * p)879 int __sanitizer_get_ownership(const void *p) {
880 uptr ptr = reinterpret_cast<uptr>(p);
881 return instance.AllocationSize(ptr) > 0;
882 }
883
__sanitizer_get_allocated_size(const void * p)884 uptr __sanitizer_get_allocated_size(const void *p) {
885 if (p == 0) return 0;
886 uptr ptr = reinterpret_cast<uptr>(p);
887 uptr allocated_size = instance.AllocationSize(ptr);
888 // Die if p is not malloced or if it is already freed.
889 if (allocated_size == 0) {
890 GET_STACK_TRACE_FATAL_HERE;
891 ReportSanitizerGetAllocatedSizeNotOwned(ptr, &stack);
892 }
893 return allocated_size;
894 }
895
896 #if !SANITIZER_SUPPORTS_WEAK_HOOKS
897 // Provide default (no-op) implementation of malloc hooks.
898 extern "C" {
899 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
__sanitizer_malloc_hook(void * ptr,uptr size)900 void __sanitizer_malloc_hook(void *ptr, uptr size) {
901 (void)ptr;
902 (void)size;
903 }
904 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
__sanitizer_free_hook(void * ptr)905 void __sanitizer_free_hook(void *ptr) {
906 (void)ptr;
907 }
908 } // extern "C"
909 #endif
910