1 //===-- msan_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 MemorySanitizer.
11 //
12 // MemorySanitizer allocator.
13 //===----------------------------------------------------------------------===//
14
15 #include "sanitizer_common/sanitizer_allocator.h"
16 #include "sanitizer_common/sanitizer_allocator_interface.h"
17 #include "msan.h"
18 #include "msan_allocator.h"
19 #include "msan_origin.h"
20 #include "msan_thread.h"
21 #include "msan_poisoning.h"
22
23 namespace __msan {
24
25 struct Metadata {
26 uptr requested_size;
27 };
28
29 struct MsanMapUnmapCallback {
OnMap__msan::MsanMapUnmapCallback30 void OnMap(uptr p, uptr size) const {}
OnUnmap__msan::MsanMapUnmapCallback31 void OnUnmap(uptr p, uptr size) const {
32 __msan_unpoison((void *)p, size);
33
34 // We are about to unmap a chunk of user memory.
35 // Mark the corresponding shadow memory as not needed.
36 FlushUnneededShadowMemory(MEM_TO_SHADOW(p), size);
37 if (__msan_get_track_origins())
38 FlushUnneededShadowMemory(MEM_TO_ORIGIN(p), size);
39 }
40 };
41
42 #if defined(__mips64)
43 static const uptr kMaxAllowedMallocSize = 2UL << 30;
44 static const uptr kRegionSizeLog = 20;
45 static const uptr kNumRegions = SANITIZER_MMAP_RANGE_SIZE >> kRegionSizeLog;
46 typedef TwoLevelByteMap<(kNumRegions >> 12), 1 << 12> ByteMap;
47 typedef CompactSizeClassMap SizeClassMap;
48
49 typedef SizeClassAllocator32<0, SANITIZER_MMAP_RANGE_SIZE, sizeof(Metadata),
50 SizeClassMap, kRegionSizeLog, ByteMap,
51 MsanMapUnmapCallback> PrimaryAllocator;
52
53 #elif defined(__x86_64__)
54 #if SANITIZER_LINUX && !defined(MSAN_LINUX_X86_64_OLD_MAPPING)
55 static const uptr kAllocatorSpace = 0x700000000000ULL;
56 #else
57 static const uptr kAllocatorSpace = 0x600000000000ULL;
58 #endif
59 static const uptr kAllocatorSize = 0x80000000000; // 8T.
60 static const uptr kMetadataSize = sizeof(Metadata);
61 static const uptr kMaxAllowedMallocSize = 8UL << 30;
62
63 typedef SizeClassAllocator64<kAllocatorSpace, kAllocatorSize, kMetadataSize,
64 DefaultSizeClassMap,
65 MsanMapUnmapCallback> PrimaryAllocator;
66
67 #elif defined(__powerpc64__)
68 static const uptr kAllocatorSpace = 0x300000000000;
69 static const uptr kAllocatorSize = 0x020000000000; // 2T
70 static const uptr kMetadataSize = sizeof(Metadata);
71 static const uptr kMaxAllowedMallocSize = 2UL << 30; // 2G
72
73 typedef SizeClassAllocator64<kAllocatorSpace, kAllocatorSize, kMetadataSize,
74 DefaultSizeClassMap,
75 MsanMapUnmapCallback> PrimaryAllocator;
76 #elif defined(__aarch64__)
77 static const uptr kMaxAllowedMallocSize = 2UL << 30; // 2G
78 static const uptr kRegionSizeLog = 20;
79 static const uptr kNumRegions = SANITIZER_MMAP_RANGE_SIZE >> kRegionSizeLog;
80 typedef TwoLevelByteMap<(kNumRegions >> 12), 1 << 12> ByteMap;
81 typedef CompactSizeClassMap SizeClassMap;
82
83 typedef SizeClassAllocator32<0, SANITIZER_MMAP_RANGE_SIZE, sizeof(Metadata),
84 SizeClassMap, kRegionSizeLog, ByteMap,
85 MsanMapUnmapCallback> PrimaryAllocator;
86 #endif
87 typedef SizeClassAllocatorLocalCache<PrimaryAllocator> AllocatorCache;
88 typedef LargeMmapAllocator<MsanMapUnmapCallback> SecondaryAllocator;
89 typedef CombinedAllocator<PrimaryAllocator, AllocatorCache,
90 SecondaryAllocator> Allocator;
91
92 static Allocator allocator;
93 static AllocatorCache fallback_allocator_cache;
94 static SpinMutex fallback_mutex;
95
MsanAllocatorInit()96 void MsanAllocatorInit() {
97 allocator.Init(common_flags()->allocator_may_return_null);
98 }
99
GetAllocatorCache(MsanThreadLocalMallocStorage * ms)100 AllocatorCache *GetAllocatorCache(MsanThreadLocalMallocStorage *ms) {
101 CHECK(ms);
102 CHECK_LE(sizeof(AllocatorCache), sizeof(ms->allocator_cache));
103 return reinterpret_cast<AllocatorCache *>(ms->allocator_cache);
104 }
105
CommitBack()106 void MsanThreadLocalMallocStorage::CommitBack() {
107 allocator.SwallowCache(GetAllocatorCache(this));
108 }
109
MsanAllocate(StackTrace * stack,uptr size,uptr alignment,bool zeroise)110 static void *MsanAllocate(StackTrace *stack, uptr size, uptr alignment,
111 bool zeroise) {
112 if (size > kMaxAllowedMallocSize) {
113 Report("WARNING: MemorySanitizer failed to allocate %p bytes\n",
114 (void *)size);
115 return allocator.ReturnNullOrDie();
116 }
117 MsanThread *t = GetCurrentThread();
118 void *allocated;
119 if (t) {
120 AllocatorCache *cache = GetAllocatorCache(&t->malloc_storage());
121 allocated = allocator.Allocate(cache, size, alignment, false);
122 } else {
123 SpinMutexLock l(&fallback_mutex);
124 AllocatorCache *cache = &fallback_allocator_cache;
125 allocated = allocator.Allocate(cache, size, alignment, false);
126 }
127 Metadata *meta =
128 reinterpret_cast<Metadata *>(allocator.GetMetaData(allocated));
129 meta->requested_size = size;
130 if (zeroise) {
131 __msan_clear_and_unpoison(allocated, size);
132 } else if (flags()->poison_in_malloc) {
133 __msan_poison(allocated, size);
134 if (__msan_get_track_origins()) {
135 stack->tag = StackTrace::TAG_ALLOC;
136 Origin o = Origin::CreateHeapOrigin(stack);
137 __msan_set_origin(allocated, size, o.raw_id());
138 }
139 }
140 MSAN_MALLOC_HOOK(allocated, size);
141 return allocated;
142 }
143
MsanDeallocate(StackTrace * stack,void * p)144 void MsanDeallocate(StackTrace *stack, void *p) {
145 CHECK(p);
146 MSAN_FREE_HOOK(p);
147 Metadata *meta = reinterpret_cast<Metadata *>(allocator.GetMetaData(p));
148 uptr size = meta->requested_size;
149 meta->requested_size = 0;
150 // This memory will not be reused by anyone else, so we are free to keep it
151 // poisoned.
152 if (flags()->poison_in_free) {
153 __msan_poison(p, size);
154 if (__msan_get_track_origins()) {
155 stack->tag = StackTrace::TAG_DEALLOC;
156 Origin o = Origin::CreateHeapOrigin(stack);
157 __msan_set_origin(p, size, o.raw_id());
158 }
159 }
160 MsanThread *t = GetCurrentThread();
161 if (t) {
162 AllocatorCache *cache = GetAllocatorCache(&t->malloc_storage());
163 allocator.Deallocate(cache, p);
164 } else {
165 SpinMutexLock l(&fallback_mutex);
166 AllocatorCache *cache = &fallback_allocator_cache;
167 allocator.Deallocate(cache, p);
168 }
169 }
170
MsanCalloc(StackTrace * stack,uptr nmemb,uptr size)171 void *MsanCalloc(StackTrace *stack, uptr nmemb, uptr size) {
172 if (CallocShouldReturnNullDueToOverflow(size, nmemb))
173 return allocator.ReturnNullOrDie();
174 return MsanReallocate(stack, nullptr, nmemb * size, sizeof(u64), true);
175 }
176
MsanReallocate(StackTrace * stack,void * old_p,uptr new_size,uptr alignment,bool zeroise)177 void *MsanReallocate(StackTrace *stack, void *old_p, uptr new_size,
178 uptr alignment, bool zeroise) {
179 if (!old_p)
180 return MsanAllocate(stack, new_size, alignment, zeroise);
181 if (!new_size) {
182 MsanDeallocate(stack, old_p);
183 return nullptr;
184 }
185 Metadata *meta = reinterpret_cast<Metadata*>(allocator.GetMetaData(old_p));
186 uptr old_size = meta->requested_size;
187 uptr actually_allocated_size = allocator.GetActuallyAllocatedSize(old_p);
188 if (new_size <= actually_allocated_size) {
189 // We are not reallocating here.
190 meta->requested_size = new_size;
191 if (new_size > old_size) {
192 if (zeroise) {
193 __msan_clear_and_unpoison((char *)old_p + old_size,
194 new_size - old_size);
195 } else if (flags()->poison_in_malloc) {
196 stack->tag = StackTrace::TAG_ALLOC;
197 PoisonMemory((char *)old_p + old_size, new_size - old_size, stack);
198 }
199 }
200 return old_p;
201 }
202 uptr memcpy_size = Min(new_size, old_size);
203 void *new_p = MsanAllocate(stack, new_size, alignment, zeroise);
204 // Printf("realloc: old_size %zd new_size %zd\n", old_size, new_size);
205 if (new_p) {
206 CopyMemory(new_p, old_p, memcpy_size, stack);
207 MsanDeallocate(stack, old_p);
208 }
209 return new_p;
210 }
211
AllocationSize(const void * p)212 static uptr AllocationSize(const void *p) {
213 if (!p) return 0;
214 const void *beg = allocator.GetBlockBegin(p);
215 if (beg != p) return 0;
216 Metadata *b = (Metadata *)allocator.GetMetaData(p);
217 return b->requested_size;
218 }
219
220 } // namespace __msan
221
222 using namespace __msan;
223
__sanitizer_get_current_allocated_bytes()224 uptr __sanitizer_get_current_allocated_bytes() {
225 uptr stats[AllocatorStatCount];
226 allocator.GetStats(stats);
227 return stats[AllocatorStatAllocated];
228 }
229
__sanitizer_get_heap_size()230 uptr __sanitizer_get_heap_size() {
231 uptr stats[AllocatorStatCount];
232 allocator.GetStats(stats);
233 return stats[AllocatorStatMapped];
234 }
235
__sanitizer_get_free_bytes()236 uptr __sanitizer_get_free_bytes() { return 1; }
237
__sanitizer_get_unmapped_bytes()238 uptr __sanitizer_get_unmapped_bytes() { return 1; }
239
__sanitizer_get_estimated_allocated_size(uptr size)240 uptr __sanitizer_get_estimated_allocated_size(uptr size) { return size; }
241
__sanitizer_get_ownership(const void * p)242 int __sanitizer_get_ownership(const void *p) { return AllocationSize(p) != 0; }
243
__sanitizer_get_allocated_size(const void * p)244 uptr __sanitizer_get_allocated_size(const void *p) { return AllocationSize(p); }
245