msan_allocator.cc revision 5d71de26cedae3dafc17449fe0182045c0bd20e8 
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 "sanitizer_common/sanitizer_stackdepot.h"
18#include "msan.h"
19#include "msan_allocator.h"
20#include "msan_chained_origin_depot.h"
21#include "msan_origin.h"
22#include "msan_thread.h"
23
24namespace __msan {
25
26struct Metadata {
27  uptr requested_size;
28};
29
30struct MsanMapUnmapCallback {
31  void OnMap(uptr p, uptr size) const {}
32  void OnUnmap(uptr p, uptr size) const {
33    __msan_unpoison((void *)p, size);
34
35    // We are about to unmap a chunk of user memory.
36    // Mark the corresponding shadow memory as not needed.
37    FlushUnneededShadowMemory(MEM_TO_SHADOW(p), size);
38    if (__msan_get_track_origins())
39      FlushUnneededShadowMemory(MEM_TO_ORIGIN(p), size);
40  }
41};
42
43static const uptr kAllocatorSpace = 0x600000000000ULL;
44static const uptr kAllocatorSize   = 0x80000000000;  // 8T.
45static const uptr kMetadataSize  = sizeof(Metadata);
46static const uptr kMaxAllowedMallocSize = 8UL << 30;
47
48typedef SizeClassAllocator64<kAllocatorSpace, kAllocatorSize, kMetadataSize,
49                             DefaultSizeClassMap,
50                             MsanMapUnmapCallback> PrimaryAllocator;
51typedef SizeClassAllocatorLocalCache<PrimaryAllocator> AllocatorCache;
52typedef LargeMmapAllocator<MsanMapUnmapCallback> SecondaryAllocator;
53typedef CombinedAllocator<PrimaryAllocator, AllocatorCache,
54                          SecondaryAllocator> Allocator;
55
56static Allocator allocator;
57static AllocatorCache fallback_allocator_cache;
58static SpinMutex fallback_mutex;
59
60static int inited = 0;
61
62static inline void Init() {
63  if (inited) return;
64  __msan_init();
65  inited = true;  // this must happen before any threads are created.
66  allocator.Init();
67}
68
69AllocatorCache *GetAllocatorCache(MsanThreadLocalMallocStorage *ms) {
70  CHECK(ms);
71  CHECK_LE(sizeof(AllocatorCache), sizeof(ms->allocator_cache));
72  return reinterpret_cast<AllocatorCache *>(ms->allocator_cache);
73}
74
75void MsanThreadLocalMallocStorage::CommitBack() {
76  allocator.SwallowCache(GetAllocatorCache(this));
77}
78
79static void *MsanAllocate(StackTrace *stack, uptr size, uptr alignment,
80                          bool zeroise) {
81  Init();
82  if (size > kMaxAllowedMallocSize) {
83    Report("WARNING: MemorySanitizer failed to allocate %p bytes\n",
84           (void *)size);
85    return AllocatorReturnNull();
86  }
87  MsanThread *t = GetCurrentThread();
88  void *allocated;
89  if (t) {
90    AllocatorCache *cache = GetAllocatorCache(&t->malloc_storage());
91    allocated = allocator.Allocate(cache, size, alignment, false);
92  } else {
93    SpinMutexLock l(&fallback_mutex);
94    AllocatorCache *cache = &fallback_allocator_cache;
95    allocated = allocator.Allocate(cache, size, alignment, false);
96  }
97  Metadata *meta =
98      reinterpret_cast<Metadata *>(allocator.GetMetaData(allocated));
99  meta->requested_size = size;
100  if (zeroise) {
101    __msan_clear_and_unpoison(allocated, size);
102  } else if (flags()->poison_in_malloc) {
103    __msan_poison(allocated, size);
104    if (__msan_get_track_origins()) {
105      u32 stack_id = StackDepotPut(stack->trace, stack->size);
106      CHECK(stack_id);
107      u32 id;
108      ChainedOriginDepotPut(stack_id, Origin::kHeapRoot, &id);
109      __msan_set_origin(allocated, size, Origin(id, 1).raw_id());
110    }
111  }
112  MSAN_MALLOC_HOOK(allocated, size);
113  return allocated;
114}
115
116void MsanDeallocate(StackTrace *stack, void *p) {
117  CHECK(p);
118  Init();
119  MSAN_FREE_HOOK(p);
120  Metadata *meta = reinterpret_cast<Metadata *>(allocator.GetMetaData(p));
121  uptr size = meta->requested_size;
122  meta->requested_size = 0;
123  // This memory will not be reused by anyone else, so we are free to keep it
124  // poisoned.
125  if (flags()->poison_in_free) {
126    __msan_poison(p, size);
127    if (__msan_get_track_origins()) {
128      u32 stack_id = StackDepotPut(stack->trace, stack->size);
129      CHECK(stack_id);
130      u32 id;
131      ChainedOriginDepotPut(stack_id, Origin::kHeapRoot, &id);
132      __msan_set_origin(p, size, Origin(id, 1).raw_id());
133    }
134  }
135  MsanThread *t = GetCurrentThread();
136  if (t) {
137    AllocatorCache *cache = GetAllocatorCache(&t->malloc_storage());
138    allocator.Deallocate(cache, p);
139  } else {
140    SpinMutexLock l(&fallback_mutex);
141    AllocatorCache *cache = &fallback_allocator_cache;
142    allocator.Deallocate(cache, p);
143  }
144}
145
146void *MsanReallocate(StackTrace *stack, void *old_p, uptr new_size,
147                     uptr alignment, bool zeroise) {
148  if (!old_p)
149    return MsanAllocate(stack, new_size, alignment, zeroise);
150  if (!new_size) {
151    MsanDeallocate(stack, old_p);
152    return 0;
153  }
154  Metadata *meta = reinterpret_cast<Metadata*>(allocator.GetMetaData(old_p));
155  uptr old_size = meta->requested_size;
156  uptr actually_allocated_size = allocator.GetActuallyAllocatedSize(old_p);
157  if (new_size <= actually_allocated_size) {
158    // We are not reallocating here.
159    meta->requested_size = new_size;
160    if (new_size > old_size)
161      __msan_poison((char*)old_p + old_size, new_size - old_size);
162    return old_p;
163  }
164  uptr memcpy_size = Min(new_size, old_size);
165  void *new_p = MsanAllocate(stack, new_size, alignment, zeroise);
166  // Printf("realloc: old_size %zd new_size %zd\n", old_size, new_size);
167  if (new_p) {
168    __msan_memcpy(new_p, old_p, memcpy_size);
169    MsanDeallocate(stack, old_p);
170  }
171  return new_p;
172}
173
174static uptr AllocationSize(const void *p) {
175  if (p == 0) return 0;
176  const void *beg = allocator.GetBlockBegin(p);
177  if (beg != p) return 0;
178  Metadata *b = (Metadata *)allocator.GetMetaData(p);
179  return b->requested_size;
180}
181
182}  // namespace __msan
183
184using namespace __msan;
185
186uptr __sanitizer_get_current_allocated_bytes() {
187  uptr stats[AllocatorStatCount];
188  allocator.GetStats(stats);
189  return stats[AllocatorStatAllocated];
190}
191uptr __msan_get_current_allocated_bytes() {
192  return __sanitizer_get_current_allocated_bytes();
193}
194
195uptr __sanitizer_get_heap_size() {
196  uptr stats[AllocatorStatCount];
197  allocator.GetStats(stats);
198  return stats[AllocatorStatMapped];
199}
200uptr __msan_get_heap_size() {
201  return __sanitizer_get_heap_size();
202}
203
204uptr __sanitizer_get_free_bytes() { return 1; }
205uptr __msan_get_free_bytes() {
206  return __sanitizer_get_free_bytes();
207}
208
209uptr __sanitizer_get_unmapped_bytes() { return 1; }
210uptr __msan_get_unmapped_bytes() {
211  return __sanitizer_get_unmapped_bytes();
212}
213
214uptr __sanitizer_get_estimated_allocated_size(uptr size) { return size; }
215uptr __msan_get_estimated_allocated_size(uptr size) {
216  return __sanitizer_get_estimated_allocated_size(size);
217}
218
219int __sanitizer_get_ownership(const void *p) { return AllocationSize(p) != 0; }
220int __msan_get_ownership(const void *p) {
221  return __sanitizer_get_ownership(p);
222}
223
224uptr __sanitizer_get_allocated_size(const void *p) { return AllocationSize(p); }
225uptr __msan_get_allocated_size(const void *p) {
226  return __sanitizer_get_allocated_size(p);
227}
228