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 #elif defined(__x86_64__)
53 static const uptr kAllocatorSpace = 0x600000000000ULL;
54 static const uptr kAllocatorSize = 0x80000000000; // 8T.
55 static const uptr kMetadataSize = sizeof(Metadata);
56 static const uptr kMaxAllowedMallocSize = 8UL << 30;
57
58 typedef SizeClassAllocator64<kAllocatorSpace, kAllocatorSize, kMetadataSize,
59 DefaultSizeClassMap,
60 MsanMapUnmapCallback> PrimaryAllocator;
61 #endif
62 typedef SizeClassAllocatorLocalCache<PrimaryAllocator> AllocatorCache;
63 typedef LargeMmapAllocator<MsanMapUnmapCallback> SecondaryAllocator;
64 typedef CombinedAllocator<PrimaryAllocator, AllocatorCache,
65 SecondaryAllocator> Allocator;
66
67 static Allocator allocator;
68 static AllocatorCache fallback_allocator_cache;
69 static SpinMutex fallback_mutex;
70
71 static int inited = 0;
72
Init()73 static inline void Init() {
74 if (inited) return;
75 __msan_init();
76 inited = true; // this must happen before any threads are created.
77 allocator.Init(common_flags()->allocator_may_return_null);
78 }
79
GetAllocatorCache(MsanThreadLocalMallocStorage * ms)80 AllocatorCache *GetAllocatorCache(MsanThreadLocalMallocStorage *ms) {
81 CHECK(ms);
82 CHECK_LE(sizeof(AllocatorCache), sizeof(ms->allocator_cache));
83 return reinterpret_cast<AllocatorCache *>(ms->allocator_cache);
84 }
85
CommitBack()86 void MsanThreadLocalMallocStorage::CommitBack() {
87 allocator.SwallowCache(GetAllocatorCache(this));
88 }
89
MsanAllocate(StackTrace * stack,uptr size,uptr alignment,bool zeroise)90 static void *MsanAllocate(StackTrace *stack, uptr size, uptr alignment,
91 bool zeroise) {
92 Init();
93 if (size > kMaxAllowedMallocSize) {
94 Report("WARNING: MemorySanitizer failed to allocate %p bytes\n",
95 (void *)size);
96 return allocator.ReturnNullOrDie();
97 }
98 MsanThread *t = GetCurrentThread();
99 void *allocated;
100 if (t) {
101 AllocatorCache *cache = GetAllocatorCache(&t->malloc_storage());
102 allocated = allocator.Allocate(cache, size, alignment, false);
103 } else {
104 SpinMutexLock l(&fallback_mutex);
105 AllocatorCache *cache = &fallback_allocator_cache;
106 allocated = allocator.Allocate(cache, size, alignment, false);
107 }
108 Metadata *meta =
109 reinterpret_cast<Metadata *>(allocator.GetMetaData(allocated));
110 meta->requested_size = size;
111 if (zeroise) {
112 __msan_clear_and_unpoison(allocated, size);
113 } else if (flags()->poison_in_malloc) {
114 __msan_poison(allocated, size);
115 if (__msan_get_track_origins()) {
116 stack->tag = StackTrace::TAG_ALLOC;
117 Origin o = Origin::CreateHeapOrigin(stack);
118 __msan_set_origin(allocated, size, o.raw_id());
119 }
120 }
121 MSAN_MALLOC_HOOK(allocated, size);
122 return allocated;
123 }
124
MsanDeallocate(StackTrace * stack,void * p)125 void MsanDeallocate(StackTrace *stack, void *p) {
126 CHECK(p);
127 Init();
128 MSAN_FREE_HOOK(p);
129 Metadata *meta = reinterpret_cast<Metadata *>(allocator.GetMetaData(p));
130 uptr size = meta->requested_size;
131 meta->requested_size = 0;
132 // This memory will not be reused by anyone else, so we are free to keep it
133 // poisoned.
134 if (flags()->poison_in_free) {
135 __msan_poison(p, size);
136 if (__msan_get_track_origins()) {
137 stack->tag = StackTrace::TAG_DEALLOC;
138 Origin o = Origin::CreateHeapOrigin(stack);
139 __msan_set_origin(p, size, o.raw_id());
140 }
141 }
142 MsanThread *t = GetCurrentThread();
143 if (t) {
144 AllocatorCache *cache = GetAllocatorCache(&t->malloc_storage());
145 allocator.Deallocate(cache, p);
146 } else {
147 SpinMutexLock l(&fallback_mutex);
148 AllocatorCache *cache = &fallback_allocator_cache;
149 allocator.Deallocate(cache, p);
150 }
151 }
152
MsanCalloc(StackTrace * stack,uptr nmemb,uptr size)153 void *MsanCalloc(StackTrace *stack, uptr nmemb, uptr size) {
154 Init();
155 if (CallocShouldReturnNullDueToOverflow(size, nmemb))
156 return allocator.ReturnNullOrDie();
157 return MsanReallocate(stack, 0, nmemb * size, sizeof(u64), true);
158 }
159
MsanReallocate(StackTrace * stack,void * old_p,uptr new_size,uptr alignment,bool zeroise)160 void *MsanReallocate(StackTrace *stack, void *old_p, uptr new_size,
161 uptr alignment, bool zeroise) {
162 if (!old_p)
163 return MsanAllocate(stack, new_size, alignment, zeroise);
164 if (!new_size) {
165 MsanDeallocate(stack, old_p);
166 return 0;
167 }
168 Metadata *meta = reinterpret_cast<Metadata*>(allocator.GetMetaData(old_p));
169 uptr old_size = meta->requested_size;
170 uptr actually_allocated_size = allocator.GetActuallyAllocatedSize(old_p);
171 if (new_size <= actually_allocated_size) {
172 // We are not reallocating here.
173 meta->requested_size = new_size;
174 if (new_size > old_size) {
175 if (zeroise) {
176 __msan_clear_and_unpoison((char *)old_p + old_size,
177 new_size - old_size);
178 } else if (flags()->poison_in_malloc) {
179 stack->tag = StackTrace::TAG_ALLOC;
180 PoisonMemory((char *)old_p + old_size, new_size - old_size, stack);
181 }
182 }
183 return old_p;
184 }
185 uptr memcpy_size = Min(new_size, old_size);
186 void *new_p = MsanAllocate(stack, new_size, alignment, zeroise);
187 // Printf("realloc: old_size %zd new_size %zd\n", old_size, new_size);
188 if (new_p) {
189 CopyMemory(new_p, old_p, memcpy_size, stack);
190 MsanDeallocate(stack, old_p);
191 }
192 return new_p;
193 }
194
AllocationSize(const void * p)195 static uptr AllocationSize(const void *p) {
196 if (p == 0) return 0;
197 const void *beg = allocator.GetBlockBegin(p);
198 if (beg != p) return 0;
199 Metadata *b = (Metadata *)allocator.GetMetaData(p);
200 return b->requested_size;
201 }
202
203 } // namespace __msan
204
205 using namespace __msan;
206
__sanitizer_get_current_allocated_bytes()207 uptr __sanitizer_get_current_allocated_bytes() {
208 uptr stats[AllocatorStatCount];
209 allocator.GetStats(stats);
210 return stats[AllocatorStatAllocated];
211 }
212
__sanitizer_get_heap_size()213 uptr __sanitizer_get_heap_size() {
214 uptr stats[AllocatorStatCount];
215 allocator.GetStats(stats);
216 return stats[AllocatorStatMapped];
217 }
218
__sanitizer_get_free_bytes()219 uptr __sanitizer_get_free_bytes() { return 1; }
220
__sanitizer_get_unmapped_bytes()221 uptr __sanitizer_get_unmapped_bytes() { return 1; }
222
__sanitizer_get_estimated_allocated_size(uptr size)223 uptr __sanitizer_get_estimated_allocated_size(uptr size) { return size; }
224
__sanitizer_get_ownership(const void * p)225 int __sanitizer_get_ownership(const void *p) { return AllocationSize(p) != 0; }
226
__sanitizer_get_allocated_size(const void * p)227 uptr __sanitizer_get_allocated_size(const void *p) { return AllocationSize(p); }
228