1 //===-- sanitizer_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 shared between AddressSanitizer and ThreadSanitizer
11 // run-time libraries.
12 // This allocator is used inside run-times.
13 //===----------------------------------------------------------------------===//
14
15 #include "sanitizer_allocator.h"
16
17 #include "sanitizer_allocator_checks.h"
18 #include "sanitizer_allocator_internal.h"
19 #include "sanitizer_atomic.h"
20 #include "sanitizer_common.h"
21
22 namespace __sanitizer {
23
24 // Default allocator names.
25 const char *PrimaryAllocatorName = "SizeClassAllocator";
26 const char *SecondaryAllocatorName = "LargeMmapAllocator";
27
28 // ThreadSanitizer for Go uses libc malloc/free.
29 #if SANITIZER_GO || defined(SANITIZER_USE_MALLOC)
30 # if SANITIZER_LINUX && !SANITIZER_ANDROID
31 extern "C" void *__libc_malloc(uptr size);
32 # if !SANITIZER_GO
33 extern "C" void *__libc_memalign(uptr alignment, uptr size);
34 # endif
35 extern "C" void *__libc_realloc(void *ptr, uptr size);
36 extern "C" void __libc_free(void *ptr);
37 # else
38 # include <stdlib.h>
39 # define __libc_malloc malloc
40 # if !SANITIZER_GO
__libc_memalign(uptr alignment,uptr size)41 static void *__libc_memalign(uptr alignment, uptr size) {
42 void *p;
43 uptr error = posix_memalign(&p, alignment, size);
44 if (error) return nullptr;
45 return p;
46 }
47 # endif
48 # define __libc_realloc realloc
49 # define __libc_free free
50 # endif
51
RawInternalAlloc(uptr size,InternalAllocatorCache * cache,uptr alignment)52 static void *RawInternalAlloc(uptr size, InternalAllocatorCache *cache,
53 uptr alignment) {
54 (void)cache;
55 #if !SANITIZER_GO
56 if (alignment == 0)
57 return __libc_malloc(size);
58 else
59 return __libc_memalign(alignment, size);
60 #else
61 // Windows does not provide __libc_memalign/posix_memalign. It provides
62 // __aligned_malloc, but the allocated blocks can't be passed to free,
63 // they need to be passed to __aligned_free. InternalAlloc interface does
64 // not account for such requirement. Alignemnt does not seem to be used
65 // anywhere in runtime, so just call __libc_malloc for now.
66 DCHECK_EQ(alignment, 0);
67 return __libc_malloc(size);
68 #endif
69 }
70
RawInternalRealloc(void * ptr,uptr size,InternalAllocatorCache * cache)71 static void *RawInternalRealloc(void *ptr, uptr size,
72 InternalAllocatorCache *cache) {
73 (void)cache;
74 return __libc_realloc(ptr, size);
75 }
76
RawInternalFree(void * ptr,InternalAllocatorCache * cache)77 static void RawInternalFree(void *ptr, InternalAllocatorCache *cache) {
78 (void)cache;
79 __libc_free(ptr);
80 }
81
internal_allocator()82 InternalAllocator *internal_allocator() {
83 return 0;
84 }
85
86 #else // SANITIZER_GO || defined(SANITIZER_USE_MALLOC)
87
88 static ALIGNED(64) char internal_alloc_placeholder[sizeof(InternalAllocator)];
89 static atomic_uint8_t internal_allocator_initialized;
90 static StaticSpinMutex internal_alloc_init_mu;
91
92 static InternalAllocatorCache internal_allocator_cache;
93 static StaticSpinMutex internal_allocator_cache_mu;
94
internal_allocator()95 InternalAllocator *internal_allocator() {
96 InternalAllocator *internal_allocator_instance =
97 reinterpret_cast<InternalAllocator *>(&internal_alloc_placeholder);
98 if (atomic_load(&internal_allocator_initialized, memory_order_acquire) == 0) {
99 SpinMutexLock l(&internal_alloc_init_mu);
100 if (atomic_load(&internal_allocator_initialized, memory_order_relaxed) ==
101 0) {
102 internal_allocator_instance->Init(kReleaseToOSIntervalNever);
103 atomic_store(&internal_allocator_initialized, 1, memory_order_release);
104 }
105 }
106 return internal_allocator_instance;
107 }
108
RawInternalAlloc(uptr size,InternalAllocatorCache * cache,uptr alignment)109 static void *RawInternalAlloc(uptr size, InternalAllocatorCache *cache,
110 uptr alignment) {
111 if (alignment == 0) alignment = 8;
112 if (cache == 0) {
113 SpinMutexLock l(&internal_allocator_cache_mu);
114 return internal_allocator()->Allocate(&internal_allocator_cache, size,
115 alignment);
116 }
117 return internal_allocator()->Allocate(cache, size, alignment);
118 }
119
RawInternalRealloc(void * ptr,uptr size,InternalAllocatorCache * cache)120 static void *RawInternalRealloc(void *ptr, uptr size,
121 InternalAllocatorCache *cache) {
122 uptr alignment = 8;
123 if (cache == 0) {
124 SpinMutexLock l(&internal_allocator_cache_mu);
125 return internal_allocator()->Reallocate(&internal_allocator_cache, ptr,
126 size, alignment);
127 }
128 return internal_allocator()->Reallocate(cache, ptr, size, alignment);
129 }
130
RawInternalFree(void * ptr,InternalAllocatorCache * cache)131 static void RawInternalFree(void *ptr, InternalAllocatorCache *cache) {
132 if (!cache) {
133 SpinMutexLock l(&internal_allocator_cache_mu);
134 return internal_allocator()->Deallocate(&internal_allocator_cache, ptr);
135 }
136 internal_allocator()->Deallocate(cache, ptr);
137 }
138
139 #endif // SANITIZER_GO || defined(SANITIZER_USE_MALLOC)
140
141 const u64 kBlockMagic = 0x6A6CB03ABCEBC041ull;
142
ReportInternalAllocatorOutOfMemory(uptr requested_size)143 static void NORETURN ReportInternalAllocatorOutOfMemory(uptr requested_size) {
144 SetAllocatorOutOfMemory();
145 Report("FATAL: %s: internal allocator is out of memory trying to allocate "
146 "0x%zx bytes\n", SanitizerToolName, requested_size);
147 Die();
148 }
149
InternalAlloc(uptr size,InternalAllocatorCache * cache,uptr alignment)150 void *InternalAlloc(uptr size, InternalAllocatorCache *cache, uptr alignment) {
151 if (size + sizeof(u64) < size)
152 return nullptr;
153 void *p = RawInternalAlloc(size + sizeof(u64), cache, alignment);
154 if (UNLIKELY(!p))
155 ReportInternalAllocatorOutOfMemory(size + sizeof(u64));
156 ((u64*)p)[0] = kBlockMagic;
157 return (char*)p + sizeof(u64);
158 }
159
InternalRealloc(void * addr,uptr size,InternalAllocatorCache * cache)160 void *InternalRealloc(void *addr, uptr size, InternalAllocatorCache *cache) {
161 if (!addr)
162 return InternalAlloc(size, cache);
163 if (size + sizeof(u64) < size)
164 return nullptr;
165 addr = (char*)addr - sizeof(u64);
166 size = size + sizeof(u64);
167 CHECK_EQ(kBlockMagic, ((u64*)addr)[0]);
168 void *p = RawInternalRealloc(addr, size, cache);
169 if (UNLIKELY(!p))
170 ReportInternalAllocatorOutOfMemory(size);
171 return (char*)p + sizeof(u64);
172 }
173
InternalCalloc(uptr count,uptr size,InternalAllocatorCache * cache)174 void *InternalCalloc(uptr count, uptr size, InternalAllocatorCache *cache) {
175 if (UNLIKELY(CheckForCallocOverflow(count, size))) {
176 Report("FATAL: %s: calloc parameters overflow: count * size (%zd * %zd) "
177 "cannot be represented in type size_t\n", SanitizerToolName, count,
178 size);
179 Die();
180 }
181 void *p = InternalAlloc(count * size, cache);
182 if (LIKELY(p))
183 internal_memset(p, 0, count * size);
184 return p;
185 }
186
InternalFree(void * addr,InternalAllocatorCache * cache)187 void InternalFree(void *addr, InternalAllocatorCache *cache) {
188 if (!addr)
189 return;
190 addr = (char*)addr - sizeof(u64);
191 CHECK_EQ(kBlockMagic, ((u64*)addr)[0]);
192 ((u64*)addr)[0] = 0;
193 RawInternalFree(addr, cache);
194 }
195
196 // LowLevelAllocator
197 constexpr uptr kLowLevelAllocatorDefaultAlignment = 8;
198 static uptr low_level_alloc_min_alignment = kLowLevelAllocatorDefaultAlignment;
199 static LowLevelAllocateCallback low_level_alloc_callback;
200
Allocate(uptr size)201 void *LowLevelAllocator::Allocate(uptr size) {
202 // Align allocation size.
203 size = RoundUpTo(size, low_level_alloc_min_alignment);
204 if (allocated_end_ - allocated_current_ < (sptr)size) {
205 uptr size_to_allocate = Max(size, GetPageSizeCached());
206 allocated_current_ =
207 (char*)MmapOrDie(size_to_allocate, __func__);
208 allocated_end_ = allocated_current_ + size_to_allocate;
209 if (low_level_alloc_callback) {
210 low_level_alloc_callback((uptr)allocated_current_,
211 size_to_allocate);
212 }
213 }
214 CHECK(allocated_end_ - allocated_current_ >= (sptr)size);
215 void *res = allocated_current_;
216 allocated_current_ += size;
217 return res;
218 }
219
SetLowLevelAllocateMinAlignment(uptr alignment)220 void SetLowLevelAllocateMinAlignment(uptr alignment) {
221 CHECK(IsPowerOfTwo(alignment));
222 low_level_alloc_min_alignment = Max(alignment, low_level_alloc_min_alignment);
223 }
224
SetLowLevelAllocateCallback(LowLevelAllocateCallback callback)225 void SetLowLevelAllocateCallback(LowLevelAllocateCallback callback) {
226 low_level_alloc_callback = callback;
227 }
228
229 // Allocator's OOM and other errors handling support.
230
231 static atomic_uint8_t allocator_out_of_memory = {0};
232 static atomic_uint8_t allocator_may_return_null = {0};
233
IsAllocatorOutOfMemory()234 bool IsAllocatorOutOfMemory() {
235 return atomic_load_relaxed(&allocator_out_of_memory);
236 }
237
SetAllocatorOutOfMemory()238 void SetAllocatorOutOfMemory() {
239 atomic_store_relaxed(&allocator_out_of_memory, 1);
240 }
241
AllocatorMayReturnNull()242 bool AllocatorMayReturnNull() {
243 return atomic_load(&allocator_may_return_null, memory_order_relaxed);
244 }
245
SetAllocatorMayReturnNull(bool may_return_null)246 void SetAllocatorMayReturnNull(bool may_return_null) {
247 atomic_store(&allocator_may_return_null, may_return_null,
248 memory_order_relaxed);
249 }
250
PrintHintAllocatorCannotReturnNull()251 void PrintHintAllocatorCannotReturnNull() {
252 Report("HINT: if you don't care about these errors you may set "
253 "allocator_may_return_null=1\n");
254 }
255
256 } // namespace __sanitizer
257