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 = 1ULL << 30;
31 #elif defined(__mips64) || defined(__aarch64__)
32 static const uptr kMaxAllowedMallocSize = 4ULL << 30;
33 #else
34 static const uptr kMaxAllowedMallocSize = 8ULL << 30;
35 #endif
36 
37 static Allocator allocator;
38 
39 static uptr max_malloc_size;
40 
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 
52 void AllocatorThreadFinish() {
53   allocator.SwallowCache(GetAllocatorCache());
54 }
55 
56 static ChunkMetadata *Metadata(const void *p) {
57   return reinterpret_cast<ChunkMetadata *>(allocator.GetMetaData(p));
58 }
59 
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 
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 
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 
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   if (UNLIKELY(IsRssLimitExceeded())) {
92     if (AllocatorMayReturnNull())
93       return nullptr;
94     ReportRssLimitExceeded(&stack);
95   }
96   void *p = allocator.Allocate(GetAllocatorCache(), size, alignment);
97   if (UNLIKELY(!p)) {
98     SetAllocatorOutOfMemory();
99     if (AllocatorMayReturnNull())
100       return nullptr;
101     ReportOutOfMemory(size, &stack);
102   }
103   // Do not rely on the allocator to clear the memory (it's slow).
104   if (cleared && allocator.FromPrimary(p))
105     memset(p, 0, size);
106   RegisterAllocation(stack, p, size);
107   RunMallocHooks(p, size);
108   return p;
109 }
110 
111 static void *Calloc(uptr nmemb, uptr size, const StackTrace &stack) {
112   if (UNLIKELY(CheckForCallocOverflow(size, nmemb))) {
113     if (AllocatorMayReturnNull())
114       return nullptr;
115     ReportCallocOverflow(nmemb, size, &stack);
116   }
117   size *= nmemb;
118   return Allocate(stack, size, 1, true);
119 }
120 
121 void Deallocate(void *p) {
122   RunFreeHooks(p);
123   RegisterDeallocation(p);
124   allocator.Deallocate(GetAllocatorCache(), p);
125 }
126 
127 void *Reallocate(const StackTrace &stack, void *p, uptr new_size,
128                  uptr alignment) {
129   if (new_size > max_malloc_size) {
130     ReportAllocationSizeTooBig(new_size, stack);
131     return nullptr;
132   }
133   RegisterDeallocation(p);
134   void *new_p =
135       allocator.Reallocate(GetAllocatorCache(), p, new_size, alignment);
136   if (new_p)
137     RegisterAllocation(stack, new_p, new_size);
138   else if (new_size != 0)
139     RegisterAllocation(stack, p, new_size);
140   return new_p;
141 }
142 
143 void GetAllocatorCacheRange(uptr *begin, uptr *end) {
144   *begin = (uptr)GetAllocatorCache();
145   *end = *begin + sizeof(AllocatorCache);
146 }
147 
148 uptr GetMallocUsableSize(const void *p) {
149   if (!p)
150     return 0;
151   ChunkMetadata *m = Metadata(p);
152   if (!m) return 0;
153   return m->requested_size;
154 }
155 
156 int lsan_posix_memalign(void **memptr, uptr alignment, uptr size,
157                         const StackTrace &stack) {
158   if (UNLIKELY(!CheckPosixMemalignAlignment(alignment))) {
159     if (AllocatorMayReturnNull())
160       return errno_EINVAL;
161     ReportInvalidPosixMemalignAlignment(alignment, &stack);
162   }
163   void *ptr = Allocate(stack, size, alignment, kAlwaysClearMemory);
164   if (UNLIKELY(!ptr))
165     // OOM error is already taken care of by Allocate.
166     return errno_ENOMEM;
167   CHECK(IsAligned((uptr)ptr, alignment));
168   *memptr = ptr;
169   return 0;
170 }
171 
172 void *lsan_aligned_alloc(uptr alignment, uptr size, const StackTrace &stack) {
173   if (UNLIKELY(!CheckAlignedAllocAlignmentAndSize(alignment, size))) {
174     errno = errno_EINVAL;
175     if (AllocatorMayReturnNull())
176       return nullptr;
177     ReportInvalidAlignedAllocAlignment(size, alignment, &stack);
178   }
179   return SetErrnoOnNull(Allocate(stack, size, alignment, kAlwaysClearMemory));
180 }
181 
182 void *lsan_memalign(uptr alignment, uptr size, const StackTrace &stack) {
183   if (UNLIKELY(!IsPowerOfTwo(alignment))) {
184     errno = errno_EINVAL;
185     if (AllocatorMayReturnNull())
186       return nullptr;
187     ReportInvalidAllocationAlignment(alignment, &stack);
188   }
189   return SetErrnoOnNull(Allocate(stack, size, alignment, kAlwaysClearMemory));
190 }
191 
192 void *lsan_malloc(uptr size, const StackTrace &stack) {
193   return SetErrnoOnNull(Allocate(stack, size, 1, kAlwaysClearMemory));
194 }
195 
196 void lsan_free(void *p) {
197   Deallocate(p);
198 }
199 
200 void *lsan_realloc(void *p, uptr size, const StackTrace &stack) {
201   return SetErrnoOnNull(Reallocate(stack, p, size, 1));
202 }
203 
204 void *lsan_reallocarray(void *ptr, uptr nmemb, uptr size,
205                         const StackTrace &stack) {
206   if (UNLIKELY(CheckForCallocOverflow(size, nmemb))) {
207     errno = errno_ENOMEM;
208     if (AllocatorMayReturnNull())
209       return nullptr;
210     ReportReallocArrayOverflow(nmemb, size, &stack);
211   }
212   return lsan_realloc(ptr, nmemb * size, stack);
213 }
214 
215 void *lsan_calloc(uptr nmemb, uptr size, const StackTrace &stack) {
216   return SetErrnoOnNull(Calloc(nmemb, size, stack));
217 }
218 
219 void *lsan_valloc(uptr size, const StackTrace &stack) {
220   return SetErrnoOnNull(
221       Allocate(stack, size, GetPageSizeCached(), kAlwaysClearMemory));
222 }
223 
224 void *lsan_pvalloc(uptr size, const StackTrace &stack) {
225   uptr PageSize = GetPageSizeCached();
226   if (UNLIKELY(CheckForPvallocOverflow(size, PageSize))) {
227     errno = errno_ENOMEM;
228     if (AllocatorMayReturnNull())
229       return nullptr;
230     ReportPvallocOverflow(size, &stack);
231   }
232   // pvalloc(0) should allocate one page.
233   size = size ? RoundUpTo(size, PageSize) : PageSize;
234   return SetErrnoOnNull(Allocate(stack, size, PageSize, kAlwaysClearMemory));
235 }
236 
237 uptr lsan_mz_size(const void *p) {
238   return GetMallocUsableSize(p);
239 }
240 
241 ///// Interface to the common LSan module. /////
242 
243 void LockAllocator() {
244   allocator.ForceLock();
245 }
246 
247 void UnlockAllocator() {
248   allocator.ForceUnlock();
249 }
250 
251 void GetAllocatorGlobalRange(uptr *begin, uptr *end) {
252   *begin = (uptr)&allocator;
253   *end = *begin + sizeof(allocator);
254 }
255 
256 uptr PointsIntoChunk(void* p) {
257   uptr addr = reinterpret_cast<uptr>(p);
258   uptr chunk = reinterpret_cast<uptr>(allocator.GetBlockBeginFastLocked(p));
259   if (!chunk) return 0;
260   // LargeMmapAllocator considers pointers to the meta-region of a chunk to be
261   // valid, but we don't want that.
262   if (addr < chunk) return 0;
263   ChunkMetadata *m = Metadata(reinterpret_cast<void *>(chunk));
264   CHECK(m);
265   if (!m->allocated)
266     return 0;
267   if (addr < chunk + m->requested_size)
268     return chunk;
269   if (IsSpecialCaseOfOperatorNew0(chunk, m->requested_size, addr))
270     return chunk;
271   return 0;
272 }
273 
274 uptr GetUserBegin(uptr chunk) {
275   return chunk;
276 }
277 
278 LsanMetadata::LsanMetadata(uptr chunk) {
279   metadata_ = Metadata(reinterpret_cast<void *>(chunk));
280   CHECK(metadata_);
281 }
282 
283 bool LsanMetadata::allocated() const {
284   return reinterpret_cast<ChunkMetadata *>(metadata_)->allocated;
285 }
286 
287 ChunkTag LsanMetadata::tag() const {
288   return reinterpret_cast<ChunkMetadata *>(metadata_)->tag;
289 }
290 
291 void LsanMetadata::set_tag(ChunkTag value) {
292   reinterpret_cast<ChunkMetadata *>(metadata_)->tag = value;
293 }
294 
295 uptr LsanMetadata::requested_size() const {
296   return reinterpret_cast<ChunkMetadata *>(metadata_)->requested_size;
297 }
298 
299 u32 LsanMetadata::stack_trace_id() const {
300   return reinterpret_cast<ChunkMetadata *>(metadata_)->stack_trace_id;
301 }
302 
303 void ForEachChunk(ForEachChunkCallback callback, void *arg) {
304   allocator.ForEachChunk(callback, arg);
305 }
306 
307 IgnoreObjectResult IgnoreObjectLocked(const void *p) {
308   void *chunk = allocator.GetBlockBegin(p);
309   if (!chunk || p < chunk) return kIgnoreObjectInvalid;
310   ChunkMetadata *m = Metadata(chunk);
311   CHECK(m);
312   if (m->allocated && (uptr)p < (uptr)chunk + m->requested_size) {
313     if (m->tag == kIgnored)
314       return kIgnoreObjectAlreadyIgnored;
315     m->tag = kIgnored;
316     return kIgnoreObjectSuccess;
317   } else {
318     return kIgnoreObjectInvalid;
319   }
320 }
321 
322 void GetAdditionalThreadContextPtrsLocked(InternalMmapVector<uptr> *ptrs) {
323   // This function can be used to treat memory reachable from `tctx` as live.
324   // This is useful for threads that have been created but not yet started.
325 
326   // This is currently a no-op because the LSan `pthread_create()` interceptor
327   // blocks until the child thread starts which keeps the thread's `arg` pointer
328   // live.
329 }
330 
331 } // namespace __lsan
332 
333 using namespace __lsan;
334 
335 extern "C" {
336 SANITIZER_INTERFACE_ATTRIBUTE
337 uptr __sanitizer_get_current_allocated_bytes() {
338   uptr stats[AllocatorStatCount];
339   allocator.GetStats(stats);
340   return stats[AllocatorStatAllocated];
341 }
342 
343 SANITIZER_INTERFACE_ATTRIBUTE
344 uptr __sanitizer_get_heap_size() {
345   uptr stats[AllocatorStatCount];
346   allocator.GetStats(stats);
347   return stats[AllocatorStatMapped];
348 }
349 
350 SANITIZER_INTERFACE_ATTRIBUTE
351 uptr __sanitizer_get_free_bytes() { return 0; }
352 
353 SANITIZER_INTERFACE_ATTRIBUTE
354 uptr __sanitizer_get_unmapped_bytes() { return 0; }
355 
356 SANITIZER_INTERFACE_ATTRIBUTE
357 uptr __sanitizer_get_estimated_allocated_size(uptr size) { return size; }
358 
359 SANITIZER_INTERFACE_ATTRIBUTE
360 int __sanitizer_get_ownership(const void *p) { return Metadata(p) != nullptr; }
361 
362 SANITIZER_INTERFACE_ATTRIBUTE
363 uptr __sanitizer_get_allocated_size(const void *p) {
364   return GetMallocUsableSize(p);
365 }
366 
367 } // extern "C"
368