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1 //=-- lsan_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 LeakSanitizer.
11 // See lsan_allocator.h for details.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "lsan_allocator.h"
16 
17 #include "sanitizer_common/sanitizer_allocator.h"
18 #include "sanitizer_common/sanitizer_allocator_interface.h"
19 #include "sanitizer_common/sanitizer_internal_defs.h"
20 #include "sanitizer_common/sanitizer_stackdepot.h"
21 #include "sanitizer_common/sanitizer_stacktrace.h"
22 #include "lsan_common.h"
23 
24 extern "C" void *memset(void *ptr, int value, uptr num);
25 
26 namespace __lsan {
27 
28 struct ChunkMetadata {
29   u8 allocated : 8;  // Must be first.
30   ChunkTag tag : 2;
31   uptr requested_size : 54;
32   u32 stack_trace_id;
33 };
34 
35 #if defined(__mips64) || defined(__aarch64__)
36 static const uptr kMaxAllowedMallocSize = 4UL << 30;
37 static const uptr kRegionSizeLog = 20;
38 static const uptr kNumRegions = SANITIZER_MMAP_RANGE_SIZE >> kRegionSizeLog;
39 typedef TwoLevelByteMap<(kNumRegions >> 12), 1 << 12> ByteMap;
40 typedef CompactSizeClassMap SizeClassMap;
41 typedef SizeClassAllocator32<0, SANITIZER_MMAP_RANGE_SIZE,
42     sizeof(ChunkMetadata), SizeClassMap, kRegionSizeLog, ByteMap>
43     PrimaryAllocator;
44 #else
45 static const uptr kMaxAllowedMallocSize = 8UL << 30;
46 static const uptr kAllocatorSpace = 0x600000000000ULL;
47 static const uptr kAllocatorSize = 0x40000000000ULL; // 4T.
48 typedef SizeClassAllocator64<kAllocatorSpace, kAllocatorSize,
49         sizeof(ChunkMetadata), DefaultSizeClassMap> PrimaryAllocator;
50 #endif
51 typedef SizeClassAllocatorLocalCache<PrimaryAllocator> AllocatorCache;
52 typedef LargeMmapAllocator<> SecondaryAllocator;
53 typedef CombinedAllocator<PrimaryAllocator, AllocatorCache,
54           SecondaryAllocator> Allocator;
55 
56 static Allocator allocator;
57 static THREADLOCAL AllocatorCache cache;
58 
InitializeAllocator()59 void InitializeAllocator() {
60   allocator.InitLinkerInitialized(common_flags()->allocator_may_return_null);
61 }
62 
AllocatorThreadFinish()63 void AllocatorThreadFinish() {
64   allocator.SwallowCache(&cache);
65 }
66 
Metadata(const void * p)67 static ChunkMetadata *Metadata(const void *p) {
68   return reinterpret_cast<ChunkMetadata *>(allocator.GetMetaData(p));
69 }
70 
RegisterAllocation(const StackTrace & stack,void * p,uptr size)71 static void RegisterAllocation(const StackTrace &stack, void *p, uptr size) {
72   if (!p) return;
73   ChunkMetadata *m = Metadata(p);
74   CHECK(m);
75   m->tag = DisabledInThisThread() ? kIgnored : kDirectlyLeaked;
76   m->stack_trace_id = StackDepotPut(stack);
77   m->requested_size = size;
78   atomic_store(reinterpret_cast<atomic_uint8_t *>(m), 1, memory_order_relaxed);
79 }
80 
RegisterDeallocation(void * p)81 static void RegisterDeallocation(void *p) {
82   if (!p) return;
83   ChunkMetadata *m = Metadata(p);
84   CHECK(m);
85   atomic_store(reinterpret_cast<atomic_uint8_t *>(m), 0, memory_order_relaxed);
86 }
87 
Allocate(const StackTrace & stack,uptr size,uptr alignment,bool cleared)88 void *Allocate(const StackTrace &stack, uptr size, uptr alignment,
89                bool cleared) {
90   if (size == 0)
91     size = 1;
92   if (size > kMaxAllowedMallocSize) {
93     Report("WARNING: LeakSanitizer failed to allocate %zu bytes\n", size);
94     return nullptr;
95   }
96   void *p = allocator.Allocate(&cache, size, alignment, false);
97   // Do not rely on the allocator to clear the memory (it's slow).
98   if (cleared && allocator.FromPrimary(p))
99     memset(p, 0, size);
100   RegisterAllocation(stack, p, size);
101   if (&__sanitizer_malloc_hook) __sanitizer_malloc_hook(p, size);
102   RunMallocHooks(p, size);
103   return p;
104 }
105 
Deallocate(void * p)106 void Deallocate(void *p) {
107   if (&__sanitizer_free_hook) __sanitizer_free_hook(p);
108   RunFreeHooks(p);
109   RegisterDeallocation(p);
110   allocator.Deallocate(&cache, p);
111 }
112 
Reallocate(const StackTrace & stack,void * p,uptr new_size,uptr alignment)113 void *Reallocate(const StackTrace &stack, void *p, uptr new_size,
114                  uptr alignment) {
115   RegisterDeallocation(p);
116   if (new_size > kMaxAllowedMallocSize) {
117     Report("WARNING: LeakSanitizer failed to allocate %zu bytes\n", new_size);
118     allocator.Deallocate(&cache, p);
119     return nullptr;
120   }
121   p = allocator.Reallocate(&cache, p, new_size, alignment);
122   RegisterAllocation(stack, p, new_size);
123   return p;
124 }
125 
GetAllocatorCacheRange(uptr * begin,uptr * end)126 void GetAllocatorCacheRange(uptr *begin, uptr *end) {
127   *begin = (uptr)&cache;
128   *end = *begin + sizeof(cache);
129 }
130 
GetMallocUsableSize(const void * p)131 uptr GetMallocUsableSize(const void *p) {
132   ChunkMetadata *m = Metadata(p);
133   if (!m) return 0;
134   return m->requested_size;
135 }
136 
137 ///// Interface to the common LSan module. /////
138 
LockAllocator()139 void LockAllocator() {
140   allocator.ForceLock();
141 }
142 
UnlockAllocator()143 void UnlockAllocator() {
144   allocator.ForceUnlock();
145 }
146 
GetAllocatorGlobalRange(uptr * begin,uptr * end)147 void GetAllocatorGlobalRange(uptr *begin, uptr *end) {
148   *begin = (uptr)&allocator;
149   *end = *begin + sizeof(allocator);
150 }
151 
PointsIntoChunk(void * p)152 uptr PointsIntoChunk(void* p) {
153   uptr addr = reinterpret_cast<uptr>(p);
154   uptr chunk = reinterpret_cast<uptr>(allocator.GetBlockBeginFastLocked(p));
155   if (!chunk) return 0;
156   // LargeMmapAllocator considers pointers to the meta-region of a chunk to be
157   // valid, but we don't want that.
158   if (addr < chunk) return 0;
159   ChunkMetadata *m = Metadata(reinterpret_cast<void *>(chunk));
160   CHECK(m);
161   if (!m->allocated)
162     return 0;
163   if (addr < chunk + m->requested_size)
164     return chunk;
165   if (IsSpecialCaseOfOperatorNew0(chunk, m->requested_size, addr))
166     return chunk;
167   return 0;
168 }
169 
GetUserBegin(uptr chunk)170 uptr GetUserBegin(uptr chunk) {
171   return chunk;
172 }
173 
LsanMetadata(uptr chunk)174 LsanMetadata::LsanMetadata(uptr chunk) {
175   metadata_ = Metadata(reinterpret_cast<void *>(chunk));
176   CHECK(metadata_);
177 }
178 
allocated() const179 bool LsanMetadata::allocated() const {
180   return reinterpret_cast<ChunkMetadata *>(metadata_)->allocated;
181 }
182 
tag() const183 ChunkTag LsanMetadata::tag() const {
184   return reinterpret_cast<ChunkMetadata *>(metadata_)->tag;
185 }
186 
set_tag(ChunkTag value)187 void LsanMetadata::set_tag(ChunkTag value) {
188   reinterpret_cast<ChunkMetadata *>(metadata_)->tag = value;
189 }
190 
requested_size() const191 uptr LsanMetadata::requested_size() const {
192   return reinterpret_cast<ChunkMetadata *>(metadata_)->requested_size;
193 }
194 
stack_trace_id() const195 u32 LsanMetadata::stack_trace_id() const {
196   return reinterpret_cast<ChunkMetadata *>(metadata_)->stack_trace_id;
197 }
198 
ForEachChunk(ForEachChunkCallback callback,void * arg)199 void ForEachChunk(ForEachChunkCallback callback, void *arg) {
200   allocator.ForEachChunk(callback, arg);
201 }
202 
IgnoreObjectLocked(const void * p)203 IgnoreObjectResult IgnoreObjectLocked(const void *p) {
204   void *chunk = allocator.GetBlockBegin(p);
205   if (!chunk || p < chunk) return kIgnoreObjectInvalid;
206   ChunkMetadata *m = Metadata(chunk);
207   CHECK(m);
208   if (m->allocated && (uptr)p < (uptr)chunk + m->requested_size) {
209     if (m->tag == kIgnored)
210       return kIgnoreObjectAlreadyIgnored;
211     m->tag = kIgnored;
212     return kIgnoreObjectSuccess;
213   } else {
214     return kIgnoreObjectInvalid;
215   }
216 }
217 } // namespace __lsan
218 
219 using namespace __lsan;
220 
221 extern "C" {
222 SANITIZER_INTERFACE_ATTRIBUTE
__sanitizer_get_current_allocated_bytes()223 uptr __sanitizer_get_current_allocated_bytes() {
224   uptr stats[AllocatorStatCount];
225   allocator.GetStats(stats);
226   return stats[AllocatorStatAllocated];
227 }
228 
229 SANITIZER_INTERFACE_ATTRIBUTE
__sanitizer_get_heap_size()230 uptr __sanitizer_get_heap_size() {
231   uptr stats[AllocatorStatCount];
232   allocator.GetStats(stats);
233   return stats[AllocatorStatMapped];
234 }
235 
236 SANITIZER_INTERFACE_ATTRIBUTE
__sanitizer_get_free_bytes()237 uptr __sanitizer_get_free_bytes() { return 0; }
238 
239 SANITIZER_INTERFACE_ATTRIBUTE
__sanitizer_get_unmapped_bytes()240 uptr __sanitizer_get_unmapped_bytes() { return 0; }
241 
242 SANITIZER_INTERFACE_ATTRIBUTE
__sanitizer_get_estimated_allocated_size(uptr size)243 uptr __sanitizer_get_estimated_allocated_size(uptr size) { return size; }
244 
245 SANITIZER_INTERFACE_ATTRIBUTE
__sanitizer_get_ownership(const void * p)246 int __sanitizer_get_ownership(const void *p) { return Metadata(p) != nullptr; }
247 
248 SANITIZER_INTERFACE_ATTRIBUTE
__sanitizer_get_allocated_size(const void * p)249 uptr __sanitizer_get_allocated_size(const void *p) {
250   return GetMallocUsableSize(p);
251 }
252 } // extern "C"
253