1 //===-- msan_allocator.cpp -------------------------- ---------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file is a part of MemorySanitizer.
10 //
11 // MemorySanitizer allocator.
12 //===----------------------------------------------------------------------===//
13 
14 #include "sanitizer_common/sanitizer_allocator.h"
15 #include "sanitizer_common/sanitizer_allocator_checks.h"
16 #include "sanitizer_common/sanitizer_allocator_interface.h"
17 #include "sanitizer_common/sanitizer_allocator_report.h"
18 #include "sanitizer_common/sanitizer_errno.h"
19 #include "msan.h"
20 #include "msan_allocator.h"
21 #include "msan_origin.h"
22 #include "msan_thread.h"
23 #include "msan_poisoning.h"
24 
25 namespace __msan {
26 
27 struct Metadata {
28   uptr requested_size;
29 };
30 
31 struct MsanMapUnmapCallback {
32   void OnMap(uptr p, uptr size) const {}
33   void OnUnmap(uptr p, uptr size) const {
34     __msan_unpoison((void *)p, size);
35 
36     // We are about to unmap a chunk of user memory.
37     // Mark the corresponding shadow memory as not needed.
38     uptr shadow_p = MEM_TO_SHADOW(p);
39     ReleaseMemoryPagesToOS(shadow_p, shadow_p + size);
40     if (__msan_get_track_origins()) {
41       uptr origin_p = MEM_TO_ORIGIN(p);
42       ReleaseMemoryPagesToOS(origin_p, origin_p + size);
43     }
44   }
45 };
46 
47 #if defined(__mips64)
48 static const uptr kMaxAllowedMallocSize = 2UL << 30;
49 
50 struct AP32 {
51   static const uptr kSpaceBeg = 0;
52   static const u64 kSpaceSize = SANITIZER_MMAP_RANGE_SIZE;
53   static const uptr kMetadataSize = sizeof(Metadata);
54   typedef __sanitizer::CompactSizeClassMap SizeClassMap;
55   static const uptr kRegionSizeLog = 20;
56   using AddressSpaceView = LocalAddressSpaceView;
57   typedef MsanMapUnmapCallback MapUnmapCallback;
58   static const uptr kFlags = 0;
59 };
60 typedef SizeClassAllocator32<AP32> PrimaryAllocator;
61 #elif defined(__x86_64__)
62 #if SANITIZER_NETBSD || \
63     (SANITIZER_LINUX && !defined(MSAN_LINUX_X86_64_OLD_MAPPING))
64 static const uptr kAllocatorSpace = 0x700000000000ULL;
65 #else
66 static const uptr kAllocatorSpace = 0x600000000000ULL;
67 #endif
68 static const uptr kMaxAllowedMallocSize = 8UL << 30;
69 
70 struct AP64 {  // Allocator64 parameters. Deliberately using a short name.
71   static const uptr kSpaceBeg = kAllocatorSpace;
72   static const uptr kSpaceSize = 0x40000000000;  // 4T.
73   static const uptr kMetadataSize = sizeof(Metadata);
74   typedef DefaultSizeClassMap SizeClassMap;
75   typedef MsanMapUnmapCallback MapUnmapCallback;
76   static const uptr kFlags = 0;
77   using AddressSpaceView = LocalAddressSpaceView;
78 };
79 
80 typedef SizeClassAllocator64<AP64> PrimaryAllocator;
81 
82 #elif defined(__powerpc64__)
83 static const uptr kMaxAllowedMallocSize = 2UL << 30;  // 2G
84 
85 struct AP64 {  // Allocator64 parameters. Deliberately using a short name.
86   static const uptr kSpaceBeg = 0x300000000000;
87   static const uptr kSpaceSize = 0x020000000000;  // 2T.
88   static const uptr kMetadataSize = sizeof(Metadata);
89   typedef DefaultSizeClassMap SizeClassMap;
90   typedef MsanMapUnmapCallback MapUnmapCallback;
91   static const uptr kFlags = 0;
92   using AddressSpaceView = LocalAddressSpaceView;
93 };
94 
95 typedef SizeClassAllocator64<AP64> PrimaryAllocator;
96 #elif defined(__aarch64__)
97 static const uptr kMaxAllowedMallocSize = 2UL << 30;  // 2G
98 
99 struct AP32 {
100   static const uptr kSpaceBeg = 0;
101   static const u64 kSpaceSize = SANITIZER_MMAP_RANGE_SIZE;
102   static const uptr kMetadataSize = sizeof(Metadata);
103   typedef __sanitizer::CompactSizeClassMap SizeClassMap;
104   static const uptr kRegionSizeLog = 20;
105   using AddressSpaceView = LocalAddressSpaceView;
106   typedef MsanMapUnmapCallback MapUnmapCallback;
107   static const uptr kFlags = 0;
108 };
109 typedef SizeClassAllocator32<AP32> PrimaryAllocator;
110 #endif
111 typedef CombinedAllocator<PrimaryAllocator> Allocator;
112 typedef Allocator::AllocatorCache AllocatorCache;
113 
114 static Allocator allocator;
115 static AllocatorCache fallback_allocator_cache;
116 static StaticSpinMutex fallback_mutex;
117 
118 static uptr max_malloc_size;
119 
120 void MsanAllocatorInit() {
121   SetAllocatorMayReturnNull(common_flags()->allocator_may_return_null);
122   allocator.Init(common_flags()->allocator_release_to_os_interval_ms);
123   if (common_flags()->max_allocation_size_mb)
124     max_malloc_size = Min(common_flags()->max_allocation_size_mb << 20,
125                           kMaxAllowedMallocSize);
126   else
127     max_malloc_size = kMaxAllowedMallocSize;
128 }
129 
130 AllocatorCache *GetAllocatorCache(MsanThreadLocalMallocStorage *ms) {
131   CHECK(ms);
132   CHECK_LE(sizeof(AllocatorCache), sizeof(ms->allocator_cache));
133   return reinterpret_cast<AllocatorCache *>(ms->allocator_cache);
134 }
135 
136 void MsanThreadLocalMallocStorage::CommitBack() {
137   allocator.SwallowCache(GetAllocatorCache(this));
138 }
139 
140 static void *MsanAllocate(StackTrace *stack, uptr size, uptr alignment,
141                           bool zeroise) {
142   if (size > max_malloc_size) {
143     if (AllocatorMayReturnNull()) {
144       Report("WARNING: MemorySanitizer failed to allocate 0x%zx bytes\n", size);
145       return nullptr;
146     }
147     ReportAllocationSizeTooBig(size, max_malloc_size, stack);
148   }
149   MsanThread *t = GetCurrentThread();
150   void *allocated;
151   if (t) {
152     AllocatorCache *cache = GetAllocatorCache(&t->malloc_storage());
153     allocated = allocator.Allocate(cache, size, alignment);
154   } else {
155     SpinMutexLock l(&fallback_mutex);
156     AllocatorCache *cache = &fallback_allocator_cache;
157     allocated = allocator.Allocate(cache, size, alignment);
158   }
159   if (UNLIKELY(!allocated)) {
160     SetAllocatorOutOfMemory();
161     if (AllocatorMayReturnNull())
162       return nullptr;
163     ReportOutOfMemory(size, stack);
164   }
165   Metadata *meta =
166       reinterpret_cast<Metadata *>(allocator.GetMetaData(allocated));
167   meta->requested_size = size;
168   if (zeroise) {
169     __msan_clear_and_unpoison(allocated, size);
170   } else if (flags()->poison_in_malloc) {
171     __msan_poison(allocated, size);
172     if (__msan_get_track_origins()) {
173       stack->tag = StackTrace::TAG_ALLOC;
174       Origin o = Origin::CreateHeapOrigin(stack);
175       __msan_set_origin(allocated, size, o.raw_id());
176     }
177   }
178   MSAN_MALLOC_HOOK(allocated, size);
179   return allocated;
180 }
181 
182 void MsanDeallocate(StackTrace *stack, void *p) {
183   CHECK(p);
184   MSAN_FREE_HOOK(p);
185   Metadata *meta = reinterpret_cast<Metadata *>(allocator.GetMetaData(p));
186   uptr size = meta->requested_size;
187   meta->requested_size = 0;
188   // This memory will not be reused by anyone else, so we are free to keep it
189   // poisoned.
190   if (flags()->poison_in_free) {
191     __msan_poison(p, size);
192     if (__msan_get_track_origins()) {
193       stack->tag = StackTrace::TAG_DEALLOC;
194       Origin o = Origin::CreateHeapOrigin(stack);
195       __msan_set_origin(p, size, o.raw_id());
196     }
197   }
198   MsanThread *t = GetCurrentThread();
199   if (t) {
200     AllocatorCache *cache = GetAllocatorCache(&t->malloc_storage());
201     allocator.Deallocate(cache, p);
202   } else {
203     SpinMutexLock l(&fallback_mutex);
204     AllocatorCache *cache = &fallback_allocator_cache;
205     allocator.Deallocate(cache, p);
206   }
207 }
208 
209 void *MsanReallocate(StackTrace *stack, void *old_p, uptr new_size,
210                      uptr alignment) {
211   Metadata *meta = reinterpret_cast<Metadata*>(allocator.GetMetaData(old_p));
212   uptr old_size = meta->requested_size;
213   uptr actually_allocated_size = allocator.GetActuallyAllocatedSize(old_p);
214   if (new_size <= actually_allocated_size) {
215     // We are not reallocating here.
216     meta->requested_size = new_size;
217     if (new_size > old_size) {
218       if (flags()->poison_in_malloc) {
219         stack->tag = StackTrace::TAG_ALLOC;
220         PoisonMemory((char *)old_p + old_size, new_size - old_size, stack);
221       }
222     }
223     return old_p;
224   }
225   uptr memcpy_size = Min(new_size, old_size);
226   void *new_p = MsanAllocate(stack, new_size, alignment, false /*zeroise*/);
227   if (new_p) {
228     CopyMemory(new_p, old_p, memcpy_size, stack);
229     MsanDeallocate(stack, old_p);
230   }
231   return new_p;
232 }
233 
234 void *MsanCalloc(StackTrace *stack, uptr nmemb, uptr size) {
235   if (UNLIKELY(CheckForCallocOverflow(size, nmemb))) {
236     if (AllocatorMayReturnNull())
237       return nullptr;
238     ReportCallocOverflow(nmemb, size, stack);
239   }
240   return MsanAllocate(stack, nmemb * size, sizeof(u64), true);
241 }
242 
243 static uptr AllocationSize(const void *p) {
244   if (!p) return 0;
245   const void *beg = allocator.GetBlockBegin(p);
246   if (beg != p) return 0;
247   Metadata *b = (Metadata *)allocator.GetMetaData(p);
248   return b->requested_size;
249 }
250 
251 void *msan_malloc(uptr size, StackTrace *stack) {
252   return SetErrnoOnNull(MsanAllocate(stack, size, sizeof(u64), false));
253 }
254 
255 void *msan_calloc(uptr nmemb, uptr size, StackTrace *stack) {
256   return SetErrnoOnNull(MsanCalloc(stack, nmemb, size));
257 }
258 
259 void *msan_realloc(void *ptr, uptr size, StackTrace *stack) {
260   if (!ptr)
261     return SetErrnoOnNull(MsanAllocate(stack, size, sizeof(u64), false));
262   if (size == 0) {
263     MsanDeallocate(stack, ptr);
264     return nullptr;
265   }
266   return SetErrnoOnNull(MsanReallocate(stack, ptr, size, sizeof(u64)));
267 }
268 
269 void *msan_reallocarray(void *ptr, uptr nmemb, uptr size, StackTrace *stack) {
270   if (UNLIKELY(CheckForCallocOverflow(size, nmemb))) {
271     errno = errno_ENOMEM;
272     if (AllocatorMayReturnNull())
273       return nullptr;
274     ReportReallocArrayOverflow(nmemb, size, stack);
275   }
276   return msan_realloc(ptr, nmemb * size, stack);
277 }
278 
279 void *msan_valloc(uptr size, StackTrace *stack) {
280   return SetErrnoOnNull(MsanAllocate(stack, size, GetPageSizeCached(), false));
281 }
282 
283 void *msan_pvalloc(uptr size, StackTrace *stack) {
284   uptr PageSize = GetPageSizeCached();
285   if (UNLIKELY(CheckForPvallocOverflow(size, PageSize))) {
286     errno = errno_ENOMEM;
287     if (AllocatorMayReturnNull())
288       return nullptr;
289     ReportPvallocOverflow(size, stack);
290   }
291   // pvalloc(0) should allocate one page.
292   size = size ? RoundUpTo(size, PageSize) : PageSize;
293   return SetErrnoOnNull(MsanAllocate(stack, size, PageSize, false));
294 }
295 
296 void *msan_aligned_alloc(uptr alignment, uptr size, StackTrace *stack) {
297   if (UNLIKELY(!CheckAlignedAllocAlignmentAndSize(alignment, size))) {
298     errno = errno_EINVAL;
299     if (AllocatorMayReturnNull())
300       return nullptr;
301     ReportInvalidAlignedAllocAlignment(size, alignment, stack);
302   }
303   return SetErrnoOnNull(MsanAllocate(stack, size, alignment, false));
304 }
305 
306 void *msan_memalign(uptr alignment, uptr size, StackTrace *stack) {
307   if (UNLIKELY(!IsPowerOfTwo(alignment))) {
308     errno = errno_EINVAL;
309     if (AllocatorMayReturnNull())
310       return nullptr;
311     ReportInvalidAllocationAlignment(alignment, stack);
312   }
313   return SetErrnoOnNull(MsanAllocate(stack, size, alignment, false));
314 }
315 
316 int msan_posix_memalign(void **memptr, uptr alignment, uptr size,
317                         StackTrace *stack) {
318   if (UNLIKELY(!CheckPosixMemalignAlignment(alignment))) {
319     if (AllocatorMayReturnNull())
320       return errno_EINVAL;
321     ReportInvalidPosixMemalignAlignment(alignment, stack);
322   }
323   void *ptr = MsanAllocate(stack, size, alignment, false);
324   if (UNLIKELY(!ptr))
325     // OOM error is already taken care of by MsanAllocate.
326     return errno_ENOMEM;
327   CHECK(IsAligned((uptr)ptr, alignment));
328   *memptr = ptr;
329   return 0;
330 }
331 
332 } // namespace __msan
333 
334 using namespace __msan;
335 
336 uptr __sanitizer_get_current_allocated_bytes() {
337   uptr stats[AllocatorStatCount];
338   allocator.GetStats(stats);
339   return stats[AllocatorStatAllocated];
340 }
341 
342 uptr __sanitizer_get_heap_size() {
343   uptr stats[AllocatorStatCount];
344   allocator.GetStats(stats);
345   return stats[AllocatorStatMapped];
346 }
347 
348 uptr __sanitizer_get_free_bytes() { return 1; }
349 
350 uptr __sanitizer_get_unmapped_bytes() { return 1; }
351 
352 uptr __sanitizer_get_estimated_allocated_size(uptr size) { return size; }
353 
354 int __sanitizer_get_ownership(const void *p) { return AllocationSize(p) != 0; }
355 
356 uptr __sanitizer_get_allocated_size(const void *p) { return AllocationSize(p); }
357