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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