1 //===-- sanitizer_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 shared between AddressSanitizer and ThreadSanitizer
10 // run-time libraries.
11 // This allocator is used inside run-times.
12 //===----------------------------------------------------------------------===//
13
14 #include "sanitizer_allocator.h"
15
16 #include "sanitizer_allocator_checks.h"
17 #include "sanitizer_allocator_internal.h"
18 #include "sanitizer_atomic.h"
19 #include "sanitizer_common.h"
20
21 namespace __sanitizer {
22
23 // Default allocator names.
24 const char *PrimaryAllocatorName = "SizeClassAllocator";
25 const char *SecondaryAllocatorName = "LargeMmapAllocator";
26
27 // ThreadSanitizer for Go uses libc malloc/free.
28 #if defined(SANITIZER_USE_MALLOC)
29 # if SANITIZER_LINUX && !SANITIZER_ANDROID
30 extern "C" void *__libc_malloc(uptr size);
31 # if !SANITIZER_GO
32 extern "C" void *__libc_memalign(uptr alignment, uptr size);
33 # endif
34 extern "C" void *__libc_realloc(void *ptr, uptr size);
35 extern "C" void __libc_free(void *ptr);
36 # else
37 # include <stdlib.h>
38 # define __libc_malloc malloc
39 # if !SANITIZER_GO
__libc_memalign(uptr alignment,uptr size)40 static void *__libc_memalign(uptr alignment, uptr size) {
41 void *p;
42 uptr error = posix_memalign(&p, alignment, size);
43 if (error) return nullptr;
44 return p;
45 }
46 # endif
47 # define __libc_realloc realloc
48 # define __libc_free free
49 # endif
50
RawInternalAlloc(uptr size,InternalAllocatorCache * cache,uptr alignment)51 static void *RawInternalAlloc(uptr size, InternalAllocatorCache *cache,
52 uptr alignment) {
53 (void)cache;
54 #if !SANITIZER_GO
55 if (alignment == 0)
56 return __libc_malloc(size);
57 else
58 return __libc_memalign(alignment, size);
59 #else
60 // Windows does not provide __libc_memalign/posix_memalign. It provides
61 // __aligned_malloc, but the allocated blocks can't be passed to free,
62 // they need to be passed to __aligned_free. InternalAlloc interface does
63 // not account for such requirement. Alignemnt does not seem to be used
64 // anywhere in runtime, so just call __libc_malloc for now.
65 DCHECK_EQ(alignment, 0);
66 return __libc_malloc(size);
67 #endif
68 }
69
RawInternalRealloc(void * ptr,uptr size,InternalAllocatorCache * cache)70 static void *RawInternalRealloc(void *ptr, uptr size,
71 InternalAllocatorCache *cache) {
72 (void)cache;
73 return __libc_realloc(ptr, size);
74 }
75
RawInternalFree(void * ptr,InternalAllocatorCache * cache)76 static void RawInternalFree(void *ptr, InternalAllocatorCache *cache) {
77 (void)cache;
78 __libc_free(ptr);
79 }
80
internal_allocator()81 InternalAllocator *internal_allocator() {
82 return 0;
83 }
84
85 #else // SANITIZER_GO || defined(SANITIZER_USE_MALLOC)
86
87 static ALIGNED(64) char internal_alloc_placeholder[sizeof(InternalAllocator)];
88 static atomic_uint8_t internal_allocator_initialized;
89 static StaticSpinMutex internal_alloc_init_mu;
90
91 static InternalAllocatorCache internal_allocator_cache;
92 static StaticSpinMutex internal_allocator_cache_mu;
93
internal_allocator()94 InternalAllocator *internal_allocator() {
95 InternalAllocator *internal_allocator_instance =
96 reinterpret_cast<InternalAllocator *>(&internal_alloc_placeholder);
97 if (atomic_load(&internal_allocator_initialized, memory_order_acquire) == 0) {
98 SpinMutexLock l(&internal_alloc_init_mu);
99 if (atomic_load(&internal_allocator_initialized, memory_order_relaxed) ==
100 0) {
101 internal_allocator_instance->Init(kReleaseToOSIntervalNever);
102 atomic_store(&internal_allocator_initialized, 1, memory_order_release);
103 }
104 }
105 return internal_allocator_instance;
106 }
107
RawInternalAlloc(uptr size,InternalAllocatorCache * cache,uptr alignment)108 static void *RawInternalAlloc(uptr size, InternalAllocatorCache *cache,
109 uptr alignment) {
110 if (alignment == 0) alignment = 8;
111 if (cache == 0) {
112 SpinMutexLock l(&internal_allocator_cache_mu);
113 return internal_allocator()->Allocate(&internal_allocator_cache, size,
114 alignment);
115 }
116 return internal_allocator()->Allocate(cache, size, alignment);
117 }
118
RawInternalRealloc(void * ptr,uptr size,InternalAllocatorCache * cache)119 static void *RawInternalRealloc(void *ptr, uptr size,
120 InternalAllocatorCache *cache) {
121 uptr alignment = 8;
122 if (cache == 0) {
123 SpinMutexLock l(&internal_allocator_cache_mu);
124 return internal_allocator()->Reallocate(&internal_allocator_cache, ptr,
125 size, alignment);
126 }
127 return internal_allocator()->Reallocate(cache, ptr, size, alignment);
128 }
129
RawInternalFree(void * ptr,InternalAllocatorCache * cache)130 static void RawInternalFree(void *ptr, InternalAllocatorCache *cache) {
131 if (!cache) {
132 SpinMutexLock l(&internal_allocator_cache_mu);
133 return internal_allocator()->Deallocate(&internal_allocator_cache, ptr);
134 }
135 internal_allocator()->Deallocate(cache, ptr);
136 }
137
138 #endif // SANITIZER_GO || defined(SANITIZER_USE_MALLOC)
139
ReportInternalAllocatorOutOfMemory(uptr requested_size)140 static void NORETURN ReportInternalAllocatorOutOfMemory(uptr requested_size) {
141 SetAllocatorOutOfMemory();
142 Report("FATAL: %s: internal allocator is out of memory trying to allocate "
143 "0x%zx bytes\n", SanitizerToolName, requested_size);
144 Die();
145 }
146
InternalAlloc(uptr size,InternalAllocatorCache * cache,uptr alignment)147 void *InternalAlloc(uptr size, InternalAllocatorCache *cache, uptr alignment) {
148 void *p = RawInternalAlloc(size, cache, alignment);
149 if (UNLIKELY(!p))
150 ReportInternalAllocatorOutOfMemory(size);
151 return p;
152 }
153
InternalRealloc(void * addr,uptr size,InternalAllocatorCache * cache)154 void *InternalRealloc(void *addr, uptr size, InternalAllocatorCache *cache) {
155 void *p = RawInternalRealloc(addr, size, cache);
156 if (UNLIKELY(!p))
157 ReportInternalAllocatorOutOfMemory(size);
158 return p;
159 }
160
InternalReallocArray(void * addr,uptr count,uptr size,InternalAllocatorCache * cache)161 void *InternalReallocArray(void *addr, uptr count, uptr size,
162 InternalAllocatorCache *cache) {
163 if (UNLIKELY(CheckForCallocOverflow(count, size))) {
164 Report(
165 "FATAL: %s: reallocarray parameters overflow: count * size (%zd * %zd) "
166 "cannot be represented in type size_t\n",
167 SanitizerToolName, count, size);
168 Die();
169 }
170 return InternalRealloc(addr, count * size, cache);
171 }
172
InternalCalloc(uptr count,uptr size,InternalAllocatorCache * cache)173 void *InternalCalloc(uptr count, uptr size, InternalAllocatorCache *cache) {
174 if (UNLIKELY(CheckForCallocOverflow(count, size))) {
175 Report("FATAL: %s: calloc parameters overflow: count * size (%zd * %zd) "
176 "cannot be represented in type size_t\n", SanitizerToolName, count,
177 size);
178 Die();
179 }
180 void *p = InternalAlloc(count * size, cache);
181 if (LIKELY(p))
182 internal_memset(p, 0, count * size);
183 return p;
184 }
185
InternalFree(void * addr,InternalAllocatorCache * cache)186 void InternalFree(void *addr, InternalAllocatorCache *cache) {
187 RawInternalFree(addr, cache);
188 }
189
190 // LowLevelAllocator
191 constexpr uptr kLowLevelAllocatorDefaultAlignment = 8;
192 static uptr low_level_alloc_min_alignment = kLowLevelAllocatorDefaultAlignment;
193 static LowLevelAllocateCallback low_level_alloc_callback;
194
Allocate(uptr size)195 void *LowLevelAllocator::Allocate(uptr size) {
196 // Align allocation size.
197 size = RoundUpTo(size, low_level_alloc_min_alignment);
198 if (allocated_end_ - allocated_current_ < (sptr)size) {
199 uptr size_to_allocate = RoundUpTo(size, GetPageSizeCached());
200 allocated_current_ =
201 (char*)MmapOrDie(size_to_allocate, __func__);
202 allocated_end_ = allocated_current_ + size_to_allocate;
203 if (low_level_alloc_callback) {
204 low_level_alloc_callback((uptr)allocated_current_,
205 size_to_allocate);
206 }
207 }
208 CHECK(allocated_end_ - allocated_current_ >= (sptr)size);
209 void *res = allocated_current_;
210 allocated_current_ += size;
211 return res;
212 }
213
SetLowLevelAllocateMinAlignment(uptr alignment)214 void SetLowLevelAllocateMinAlignment(uptr alignment) {
215 CHECK(IsPowerOfTwo(alignment));
216 low_level_alloc_min_alignment = Max(alignment, low_level_alloc_min_alignment);
217 }
218
SetLowLevelAllocateCallback(LowLevelAllocateCallback callback)219 void SetLowLevelAllocateCallback(LowLevelAllocateCallback callback) {
220 low_level_alloc_callback = callback;
221 }
222
223 // Allocator's OOM and other errors handling support.
224
225 static atomic_uint8_t allocator_out_of_memory = {0};
226 static atomic_uint8_t allocator_may_return_null = {0};
227
IsAllocatorOutOfMemory()228 bool IsAllocatorOutOfMemory() {
229 return atomic_load_relaxed(&allocator_out_of_memory);
230 }
231
SetAllocatorOutOfMemory()232 void SetAllocatorOutOfMemory() {
233 atomic_store_relaxed(&allocator_out_of_memory, 1);
234 }
235
AllocatorMayReturnNull()236 bool AllocatorMayReturnNull() {
237 return atomic_load(&allocator_may_return_null, memory_order_relaxed);
238 }
239
SetAllocatorMayReturnNull(bool may_return_null)240 void SetAllocatorMayReturnNull(bool may_return_null) {
241 atomic_store(&allocator_may_return_null, may_return_null,
242 memory_order_relaxed);
243 }
244
PrintHintAllocatorCannotReturnNull()245 void PrintHintAllocatorCannotReturnNull() {
246 Report("HINT: if you don't care about these errors you may set "
247 "allocator_may_return_null=1\n");
248 }
249
250 } // namespace __sanitizer
251