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 #elif defined(__powerpc64__)
62 static const uptr kAllocatorSpace = 0x300000000000;
63 static const uptr kAllocatorSize = 0x020000000000; // 2T
64 static const uptr kMetadataSize = sizeof(Metadata);
65 static const uptr kMaxAllowedMallocSize = 2UL << 30; // 2G
66
67 typedef SizeClassAllocator64<kAllocatorSpace, kAllocatorSize, kMetadataSize,
68 DefaultSizeClassMap,
69 MsanMapUnmapCallback> PrimaryAllocator;
70 #endif
71 typedef SizeClassAllocatorLocalCache<PrimaryAllocator> AllocatorCache;
72 typedef LargeMmapAllocator<MsanMapUnmapCallback> SecondaryAllocator;
73 typedef CombinedAllocator<PrimaryAllocator, AllocatorCache,
74 SecondaryAllocator> Allocator;
75
76 static Allocator allocator;
77 static AllocatorCache fallback_allocator_cache;
78 static SpinMutex fallback_mutex;
79
80 static int inited = 0;
81
Init()82 static inline void Init() {
83 if (inited) return;
84 __msan_init();
85 inited = true; // this must happen before any threads are created.
86 allocator.Init(common_flags()->allocator_may_return_null);
87 }
88
GetAllocatorCache(MsanThreadLocalMallocStorage * ms)89 AllocatorCache *GetAllocatorCache(MsanThreadLocalMallocStorage *ms) {
90 CHECK(ms);
91 CHECK_LE(sizeof(AllocatorCache), sizeof(ms->allocator_cache));
92 return reinterpret_cast<AllocatorCache *>(ms->allocator_cache);
93 }
94
CommitBack()95 void MsanThreadLocalMallocStorage::CommitBack() {
96 allocator.SwallowCache(GetAllocatorCache(this));
97 }
98
MsanAllocate(StackTrace * stack,uptr size,uptr alignment,bool zeroise)99 static void *MsanAllocate(StackTrace *stack, uptr size, uptr alignment,
100 bool zeroise) {
101 Init();
102 if (size > kMaxAllowedMallocSize) {
103 Report("WARNING: MemorySanitizer failed to allocate %p bytes\n",
104 (void *)size);
105 return allocator.ReturnNullOrDie();
106 }
107 MsanThread *t = GetCurrentThread();
108 void *allocated;
109 if (t) {
110 AllocatorCache *cache = GetAllocatorCache(&t->malloc_storage());
111 allocated = allocator.Allocate(cache, size, alignment, false);
112 } else {
113 SpinMutexLock l(&fallback_mutex);
114 AllocatorCache *cache = &fallback_allocator_cache;
115 allocated = allocator.Allocate(cache, size, alignment, false);
116 }
117 Metadata *meta =
118 reinterpret_cast<Metadata *>(allocator.GetMetaData(allocated));
119 meta->requested_size = size;
120 if (zeroise) {
121 __msan_clear_and_unpoison(allocated, size);
122 } else if (flags()->poison_in_malloc) {
123 __msan_poison(allocated, size);
124 if (__msan_get_track_origins()) {
125 stack->tag = StackTrace::TAG_ALLOC;
126 Origin o = Origin::CreateHeapOrigin(stack);
127 __msan_set_origin(allocated, size, o.raw_id());
128 }
129 }
130 MSAN_MALLOC_HOOK(allocated, size);
131 return allocated;
132 }
133
MsanDeallocate(StackTrace * stack,void * p)134 void MsanDeallocate(StackTrace *stack, void *p) {
135 CHECK(p);
136 Init();
137 MSAN_FREE_HOOK(p);
138 Metadata *meta = reinterpret_cast<Metadata *>(allocator.GetMetaData(p));
139 uptr size = meta->requested_size;
140 meta->requested_size = 0;
141 // This memory will not be reused by anyone else, so we are free to keep it
142 // poisoned.
143 if (flags()->poison_in_free) {
144 __msan_poison(p, size);
145 if (__msan_get_track_origins()) {
146 stack->tag = StackTrace::TAG_DEALLOC;
147 Origin o = Origin::CreateHeapOrigin(stack);
148 __msan_set_origin(p, size, o.raw_id());
149 }
150 }
151 MsanThread *t = GetCurrentThread();
152 if (t) {
153 AllocatorCache *cache = GetAllocatorCache(&t->malloc_storage());
154 allocator.Deallocate(cache, p);
155 } else {
156 SpinMutexLock l(&fallback_mutex);
157 AllocatorCache *cache = &fallback_allocator_cache;
158 allocator.Deallocate(cache, p);
159 }
160 }
161
MsanCalloc(StackTrace * stack,uptr nmemb,uptr size)162 void *MsanCalloc(StackTrace *stack, uptr nmemb, uptr size) {
163 Init();
164 if (CallocShouldReturnNullDueToOverflow(size, nmemb))
165 return allocator.ReturnNullOrDie();
166 return MsanReallocate(stack, 0, nmemb * size, sizeof(u64), true);
167 }
168
MsanReallocate(StackTrace * stack,void * old_p,uptr new_size,uptr alignment,bool zeroise)169 void *MsanReallocate(StackTrace *stack, void *old_p, uptr new_size,
170 uptr alignment, bool zeroise) {
171 if (!old_p)
172 return MsanAllocate(stack, new_size, alignment, zeroise);
173 if (!new_size) {
174 MsanDeallocate(stack, old_p);
175 return 0;
176 }
177 Metadata *meta = reinterpret_cast<Metadata*>(allocator.GetMetaData(old_p));
178 uptr old_size = meta->requested_size;
179 uptr actually_allocated_size = allocator.GetActuallyAllocatedSize(old_p);
180 if (new_size <= actually_allocated_size) {
181 // We are not reallocating here.
182 meta->requested_size = new_size;
183 if (new_size > old_size) {
184 if (zeroise) {
185 __msan_clear_and_unpoison((char *)old_p + old_size,
186 new_size - old_size);
187 } else if (flags()->poison_in_malloc) {
188 stack->tag = StackTrace::TAG_ALLOC;
189 PoisonMemory((char *)old_p + old_size, new_size - old_size, stack);
190 }
191 }
192 return old_p;
193 }
194 uptr memcpy_size = Min(new_size, old_size);
195 void *new_p = MsanAllocate(stack, new_size, alignment, zeroise);
196 // Printf("realloc: old_size %zd new_size %zd\n", old_size, new_size);
197 if (new_p) {
198 CopyMemory(new_p, old_p, memcpy_size, stack);
199 MsanDeallocate(stack, old_p);
200 }
201 return new_p;
202 }
203
AllocationSize(const void * p)204 static uptr AllocationSize(const void *p) {
205 if (p == 0) return 0;
206 const void *beg = allocator.GetBlockBegin(p);
207 if (beg != p) return 0;
208 Metadata *b = (Metadata *)allocator.GetMetaData(p);
209 return b->requested_size;
210 }
211
212 } // namespace __msan
213
214 using namespace __msan;
215
__sanitizer_get_current_allocated_bytes()216 uptr __sanitizer_get_current_allocated_bytes() {
217 uptr stats[AllocatorStatCount];
218 allocator.GetStats(stats);
219 return stats[AllocatorStatAllocated];
220 }
221
__sanitizer_get_heap_size()222 uptr __sanitizer_get_heap_size() {
223 uptr stats[AllocatorStatCount];
224 allocator.GetStats(stats);
225 return stats[AllocatorStatMapped];
226 }
227
__sanitizer_get_free_bytes()228 uptr __sanitizer_get_free_bytes() { return 1; }
229
__sanitizer_get_unmapped_bytes()230 uptr __sanitizer_get_unmapped_bytes() { return 1; }
231
__sanitizer_get_estimated_allocated_size(uptr size)232 uptr __sanitizer_get_estimated_allocated_size(uptr size) { return size; }
233
__sanitizer_get_ownership(const void * p)234 int __sanitizer_get_ownership(const void *p) { return AllocationSize(p) != 0; }
235
__sanitizer_get_allocated_size(const void * p)236 uptr __sanitizer_get_allocated_size(const void *p) { return AllocationSize(p); }
237