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1 //=-- lsan_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 LeakSanitizer.
10 // See lsan_allocator.h for details.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "lsan_allocator.h"
15 
16 #include "sanitizer_common/sanitizer_allocator.h"
17 #include "sanitizer_common/sanitizer_allocator_checks.h"
18 #include "sanitizer_common/sanitizer_allocator_interface.h"
19 #include "sanitizer_common/sanitizer_allocator_report.h"
20 #include "sanitizer_common/sanitizer_errno.h"
21 #include "sanitizer_common/sanitizer_internal_defs.h"
22 #include "sanitizer_common/sanitizer_stackdepot.h"
23 #include "sanitizer_common/sanitizer_stacktrace.h"
24 #include "lsan_common.h"
25 
26 extern "C" void *memset(void *ptr, int value, uptr num);
27 
28 namespace __lsan {
29 #if defined(__i386__) || defined(__arm__)
30 static const uptr kMaxAllowedMallocSize = 1UL << 30;
31 #elif defined(__mips64) || defined(__aarch64__)
32 static const uptr kMaxAllowedMallocSize = 4UL << 30;
33 #else
34 static const uptr kMaxAllowedMallocSize = 8UL << 30;
35 #endif
36 
37 static Allocator allocator;
38 
39 static uptr max_malloc_size;
40 
InitializeAllocator()41 void InitializeAllocator() {
42   SetAllocatorMayReturnNull(common_flags()->allocator_may_return_null);
43   allocator.InitLinkerInitialized(
44       common_flags()->allocator_release_to_os_interval_ms);
45   if (common_flags()->max_allocation_size_mb)
46     max_malloc_size = Min(common_flags()->max_allocation_size_mb << 20,
47                           kMaxAllowedMallocSize);
48   else
49     max_malloc_size = kMaxAllowedMallocSize;
50 }
51 
AllocatorThreadFinish()52 void AllocatorThreadFinish() {
53   allocator.SwallowCache(GetAllocatorCache());
54 }
55 
Metadata(const void * p)56 static ChunkMetadata *Metadata(const void *p) {
57   return reinterpret_cast<ChunkMetadata *>(allocator.GetMetaData(p));
58 }
59 
RegisterAllocation(const StackTrace & stack,void * p,uptr size)60 static void RegisterAllocation(const StackTrace &stack, void *p, uptr size) {
61   if (!p) return;
62   ChunkMetadata *m = Metadata(p);
63   CHECK(m);
64   m->tag = DisabledInThisThread() ? kIgnored : kDirectlyLeaked;
65   m->stack_trace_id = StackDepotPut(stack);
66   m->requested_size = size;
67   atomic_store(reinterpret_cast<atomic_uint8_t *>(m), 1, memory_order_relaxed);
68 }
69 
RegisterDeallocation(void * p)70 static void RegisterDeallocation(void *p) {
71   if (!p) return;
72   ChunkMetadata *m = Metadata(p);
73   CHECK(m);
74   atomic_store(reinterpret_cast<atomic_uint8_t *>(m), 0, memory_order_relaxed);
75 }
76 
ReportAllocationSizeTooBig(uptr size,const StackTrace & stack)77 static void *ReportAllocationSizeTooBig(uptr size, const StackTrace &stack) {
78   if (AllocatorMayReturnNull()) {
79     Report("WARNING: LeakSanitizer failed to allocate 0x%zx bytes\n", size);
80     return nullptr;
81   }
82   ReportAllocationSizeTooBig(size, max_malloc_size, &stack);
83 }
84 
Allocate(const StackTrace & stack,uptr size,uptr alignment,bool cleared)85 void *Allocate(const StackTrace &stack, uptr size, uptr alignment,
86                bool cleared) {
87   if (size == 0)
88     size = 1;
89   if (size > max_malloc_size)
90     return ReportAllocationSizeTooBig(size, stack);
91   void *p = allocator.Allocate(GetAllocatorCache(), size, alignment);
92   if (UNLIKELY(!p)) {
93     SetAllocatorOutOfMemory();
94     if (AllocatorMayReturnNull())
95       return nullptr;
96     ReportOutOfMemory(size, &stack);
97   }
98   // Do not rely on the allocator to clear the memory (it's slow).
99   if (cleared && allocator.FromPrimary(p))
100     memset(p, 0, size);
101   RegisterAllocation(stack, p, size);
102   if (&__sanitizer_malloc_hook) __sanitizer_malloc_hook(p, size);
103   RunMallocHooks(p, size);
104   return p;
105 }
106 
Calloc(uptr nmemb,uptr size,const StackTrace & stack)107 static void *Calloc(uptr nmemb, uptr size, const StackTrace &stack) {
108   if (UNLIKELY(CheckForCallocOverflow(size, nmemb))) {
109     if (AllocatorMayReturnNull())
110       return nullptr;
111     ReportCallocOverflow(nmemb, size, &stack);
112   }
113   size *= nmemb;
114   return Allocate(stack, size, 1, true);
115 }
116 
Deallocate(void * p)117 void Deallocate(void *p) {
118   if (&__sanitizer_free_hook) __sanitizer_free_hook(p);
119   RunFreeHooks(p);
120   RegisterDeallocation(p);
121   allocator.Deallocate(GetAllocatorCache(), p);
122 }
123 
Reallocate(const StackTrace & stack,void * p,uptr new_size,uptr alignment)124 void *Reallocate(const StackTrace &stack, void *p, uptr new_size,
125                  uptr alignment) {
126   RegisterDeallocation(p);
127   if (new_size > max_malloc_size) {
128     allocator.Deallocate(GetAllocatorCache(), p);
129     return ReportAllocationSizeTooBig(new_size, stack);
130   }
131   p = allocator.Reallocate(GetAllocatorCache(), p, new_size, alignment);
132   RegisterAllocation(stack, p, new_size);
133   return p;
134 }
135 
GetAllocatorCacheRange(uptr * begin,uptr * end)136 void GetAllocatorCacheRange(uptr *begin, uptr *end) {
137   *begin = (uptr)GetAllocatorCache();
138   *end = *begin + sizeof(AllocatorCache);
139 }
140 
GetMallocUsableSize(const void * p)141 uptr GetMallocUsableSize(const void *p) {
142   ChunkMetadata *m = Metadata(p);
143   if (!m) return 0;
144   return m->requested_size;
145 }
146 
lsan_posix_memalign(void ** memptr,uptr alignment,uptr size,const StackTrace & stack)147 int lsan_posix_memalign(void **memptr, uptr alignment, uptr size,
148                         const StackTrace &stack) {
149   if (UNLIKELY(!CheckPosixMemalignAlignment(alignment))) {
150     if (AllocatorMayReturnNull())
151       return errno_EINVAL;
152     ReportInvalidPosixMemalignAlignment(alignment, &stack);
153   }
154   void *ptr = Allocate(stack, size, alignment, kAlwaysClearMemory);
155   if (UNLIKELY(!ptr))
156     // OOM error is already taken care of by Allocate.
157     return errno_ENOMEM;
158   CHECK(IsAligned((uptr)ptr, alignment));
159   *memptr = ptr;
160   return 0;
161 }
162 
lsan_aligned_alloc(uptr alignment,uptr size,const StackTrace & stack)163 void *lsan_aligned_alloc(uptr alignment, uptr size, const StackTrace &stack) {
164   if (UNLIKELY(!CheckAlignedAllocAlignmentAndSize(alignment, size))) {
165     errno = errno_EINVAL;
166     if (AllocatorMayReturnNull())
167       return nullptr;
168     ReportInvalidAlignedAllocAlignment(size, alignment, &stack);
169   }
170   return SetErrnoOnNull(Allocate(stack, size, alignment, kAlwaysClearMemory));
171 }
172 
lsan_memalign(uptr alignment,uptr size,const StackTrace & stack)173 void *lsan_memalign(uptr alignment, uptr size, const StackTrace &stack) {
174   if (UNLIKELY(!IsPowerOfTwo(alignment))) {
175     errno = errno_EINVAL;
176     if (AllocatorMayReturnNull())
177       return nullptr;
178     ReportInvalidAllocationAlignment(alignment, &stack);
179   }
180   return SetErrnoOnNull(Allocate(stack, size, alignment, kAlwaysClearMemory));
181 }
182 
lsan_malloc(uptr size,const StackTrace & stack)183 void *lsan_malloc(uptr size, const StackTrace &stack) {
184   return SetErrnoOnNull(Allocate(stack, size, 1, kAlwaysClearMemory));
185 }
186 
lsan_free(void * p)187 void lsan_free(void *p) {
188   Deallocate(p);
189 }
190 
lsan_realloc(void * p,uptr size,const StackTrace & stack)191 void *lsan_realloc(void *p, uptr size, const StackTrace &stack) {
192   return SetErrnoOnNull(Reallocate(stack, p, size, 1));
193 }
194 
lsan_reallocarray(void * ptr,uptr nmemb,uptr size,const StackTrace & stack)195 void *lsan_reallocarray(void *ptr, uptr nmemb, uptr size,
196                         const StackTrace &stack) {
197   if (UNLIKELY(CheckForCallocOverflow(size, nmemb))) {
198     errno = errno_ENOMEM;
199     if (AllocatorMayReturnNull())
200       return nullptr;
201     ReportReallocArrayOverflow(nmemb, size, &stack);
202   }
203   return lsan_realloc(ptr, nmemb * size, stack);
204 }
205 
lsan_calloc(uptr nmemb,uptr size,const StackTrace & stack)206 void *lsan_calloc(uptr nmemb, uptr size, const StackTrace &stack) {
207   return SetErrnoOnNull(Calloc(nmemb, size, stack));
208 }
209 
lsan_valloc(uptr size,const StackTrace & stack)210 void *lsan_valloc(uptr size, const StackTrace &stack) {
211   return SetErrnoOnNull(
212       Allocate(stack, size, GetPageSizeCached(), kAlwaysClearMemory));
213 }
214 
lsan_pvalloc(uptr size,const StackTrace & stack)215 void *lsan_pvalloc(uptr size, const StackTrace &stack) {
216   uptr PageSize = GetPageSizeCached();
217   if (UNLIKELY(CheckForPvallocOverflow(size, PageSize))) {
218     errno = errno_ENOMEM;
219     if (AllocatorMayReturnNull())
220       return nullptr;
221     ReportPvallocOverflow(size, &stack);
222   }
223   // pvalloc(0) should allocate one page.
224   size = size ? RoundUpTo(size, PageSize) : PageSize;
225   return SetErrnoOnNull(Allocate(stack, size, PageSize, kAlwaysClearMemory));
226 }
227 
lsan_mz_size(const void * p)228 uptr lsan_mz_size(const void *p) {
229   return GetMallocUsableSize(p);
230 }
231 
232 ///// Interface to the common LSan module. /////
233 
LockAllocator()234 void LockAllocator() {
235   allocator.ForceLock();
236 }
237 
UnlockAllocator()238 void UnlockAllocator() {
239   allocator.ForceUnlock();
240 }
241 
GetAllocatorGlobalRange(uptr * begin,uptr * end)242 void GetAllocatorGlobalRange(uptr *begin, uptr *end) {
243   *begin = (uptr)&allocator;
244   *end = *begin + sizeof(allocator);
245 }
246 
PointsIntoChunk(void * p)247 uptr PointsIntoChunk(void* p) {
248   uptr addr = reinterpret_cast<uptr>(p);
249   uptr chunk = reinterpret_cast<uptr>(allocator.GetBlockBeginFastLocked(p));
250   if (!chunk) return 0;
251   // LargeMmapAllocator considers pointers to the meta-region of a chunk to be
252   // valid, but we don't want that.
253   if (addr < chunk) return 0;
254   ChunkMetadata *m = Metadata(reinterpret_cast<void *>(chunk));
255   CHECK(m);
256   if (!m->allocated)
257     return 0;
258   if (addr < chunk + m->requested_size)
259     return chunk;
260   if (IsSpecialCaseOfOperatorNew0(chunk, m->requested_size, addr))
261     return chunk;
262   return 0;
263 }
264 
GetUserBegin(uptr chunk)265 uptr GetUserBegin(uptr chunk) {
266   return chunk;
267 }
268 
LsanMetadata(uptr chunk)269 LsanMetadata::LsanMetadata(uptr chunk) {
270   metadata_ = Metadata(reinterpret_cast<void *>(chunk));
271   CHECK(metadata_);
272 }
273 
allocated() const274 bool LsanMetadata::allocated() const {
275   return reinterpret_cast<ChunkMetadata *>(metadata_)->allocated;
276 }
277 
tag() const278 ChunkTag LsanMetadata::tag() const {
279   return reinterpret_cast<ChunkMetadata *>(metadata_)->tag;
280 }
281 
set_tag(ChunkTag value)282 void LsanMetadata::set_tag(ChunkTag value) {
283   reinterpret_cast<ChunkMetadata *>(metadata_)->tag = value;
284 }
285 
requested_size() const286 uptr LsanMetadata::requested_size() const {
287   return reinterpret_cast<ChunkMetadata *>(metadata_)->requested_size;
288 }
289 
stack_trace_id() const290 u32 LsanMetadata::stack_trace_id() const {
291   return reinterpret_cast<ChunkMetadata *>(metadata_)->stack_trace_id;
292 }
293 
ForEachChunk(ForEachChunkCallback callback,void * arg)294 void ForEachChunk(ForEachChunkCallback callback, void *arg) {
295   allocator.ForEachChunk(callback, arg);
296 }
297 
IgnoreObjectLocked(const void * p)298 IgnoreObjectResult IgnoreObjectLocked(const void *p) {
299   void *chunk = allocator.GetBlockBegin(p);
300   if (!chunk || p < chunk) return kIgnoreObjectInvalid;
301   ChunkMetadata *m = Metadata(chunk);
302   CHECK(m);
303   if (m->allocated && (uptr)p < (uptr)chunk + m->requested_size) {
304     if (m->tag == kIgnored)
305       return kIgnoreObjectAlreadyIgnored;
306     m->tag = kIgnored;
307     return kIgnoreObjectSuccess;
308   } else {
309     return kIgnoreObjectInvalid;
310   }
311 }
312 } // namespace __lsan
313 
314 using namespace __lsan;
315 
316 extern "C" {
317 SANITIZER_INTERFACE_ATTRIBUTE
__sanitizer_get_current_allocated_bytes()318 uptr __sanitizer_get_current_allocated_bytes() {
319   uptr stats[AllocatorStatCount];
320   allocator.GetStats(stats);
321   return stats[AllocatorStatAllocated];
322 }
323 
324 SANITIZER_INTERFACE_ATTRIBUTE
__sanitizer_get_heap_size()325 uptr __sanitizer_get_heap_size() {
326   uptr stats[AllocatorStatCount];
327   allocator.GetStats(stats);
328   return stats[AllocatorStatMapped];
329 }
330 
331 SANITIZER_INTERFACE_ATTRIBUTE
__sanitizer_get_free_bytes()332 uptr __sanitizer_get_free_bytes() { return 0; }
333 
334 SANITIZER_INTERFACE_ATTRIBUTE
__sanitizer_get_unmapped_bytes()335 uptr __sanitizer_get_unmapped_bytes() { return 0; }
336 
337 SANITIZER_INTERFACE_ATTRIBUTE
__sanitizer_get_estimated_allocated_size(uptr size)338 uptr __sanitizer_get_estimated_allocated_size(uptr size) { return size; }
339 
340 SANITIZER_INTERFACE_ATTRIBUTE
__sanitizer_get_ownership(const void * p)341 int __sanitizer_get_ownership(const void *p) { return Metadata(p) != nullptr; }
342 
343 SANITIZER_INTERFACE_ATTRIBUTE
__sanitizer_get_allocated_size(const void * p)344 uptr __sanitizer_get_allocated_size(const void *p) {
345   return GetMallocUsableSize(p);
346 }
347 
348 #if !SANITIZER_SUPPORTS_WEAK_HOOKS
349 // Provide default (no-op) implementation of malloc hooks.
350 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
__sanitizer_malloc_hook(void * ptr,uptr size)351 void __sanitizer_malloc_hook(void *ptr, uptr size) {
352   (void)ptr;
353   (void)size;
354 }
355 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
__sanitizer_free_hook(void * ptr)356 void __sanitizer_free_hook(void *ptr) {
357   (void)ptr;
358 }
359 #endif
360 } // extern "C"
361