libsanitizer/lsan/lsan_allocator.cpp

   1 //=-- lsan_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 LeakSanitizer.
  10 // See lsan_allocator.h for details.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "lsan_allocator.h"
  15
  16 #include "sanitizer_common/sanitizer_allocator.h"
  17 #include "sanitizer_common/sanitizer_allocator_checks.h"
  18 #include "sanitizer_common/sanitizer_allocator_interface.h"
  19 #include "sanitizer_common/sanitizer_allocator_report.h"
  20 #include "sanitizer_common/sanitizer_errno.h"
  21 #include "sanitizer_common/sanitizer_internal_defs.h"
  22 #include "sanitizer_common/sanitizer_stackdepot.h"
  23 #include "sanitizer_common/sanitizer_stacktrace.h"
  24 #include "lsan_common.h"
  25
  26 extern "C" void *memset(void *ptr, int value, uptr num);
  27
  28 namespace __lsan {
  29 #if defined(__i386__) || defined(__arm__)
  30 static const uptr kMaxAllowedMallocSize = 1ULL << 30;
  31 #elif defined(__mips64) || defined(__aarch64__)
  32 static const uptr kMaxAllowedMallocSize = 4ULL << 30;
  33 #else
  34 static const uptr kMaxAllowedMallocSize = 8ULL << 30;
  35 #endif
  36
  37 static Allocator allocator;
  38
  39 static uptr max_malloc_size;
  40
  41 void InitializeAllocator() {
  42   SetAllocatorMayReturnNull(common_flags()->allocator_may_return_null);
  43   allocator.InitLinkerInitialized(
  44       common_flags()->allocator_release_to_os_interval_ms);
  45   if (common_flags()->max_allocation_size_mb)
  46     max_malloc_size = Min(common_flags()->max_allocation_size_mb << 20,
  47                           kMaxAllowedMallocSize);
  48   else
  49     max_malloc_size = kMaxAllowedMallocSize;
  50 }
  51
  52 void AllocatorThreadFinish() {
  53   allocator.SwallowCache(GetAllocatorCache());
  54 }
  55
  56 static ChunkMetadata *Metadata(const void *p) {
  57   return reinterpret_cast<ChunkMetadata *>(allocator.GetMetaData(p));
  58 }
  59
  60 static void RegisterAllocation(const StackTrace &stack, void *p, uptr size) {
  61   if (!p) return;
  62   ChunkMetadata *m = Metadata(p);
  63   CHECK(m);
  64   m->tag = DisabledInThisThread() ? kIgnored : kDirectlyLeaked;
  65   m->stack_trace_id = StackDepotPut(stack);
  66   m->requested_size = size;
  67   atomic_store(reinterpret_cast<atomic_uint8_t *>(m), 1, memory_order_relaxed);
  68 }
  69
  70 static void RegisterDeallocation(void *p) {
  71   if (!p) return;
  72   ChunkMetadata *m = Metadata(p);
  73   CHECK(m);
  74   atomic_store(reinterpret_cast<atomic_uint8_t *>(m), 0, memory_order_relaxed);
  75 }
  76
  77 static void *ReportAllocationSizeTooBig(uptr size, const StackTrace &stack) {
  78   if (AllocatorMayReturnNull()) {
  79     Report("WARNING: LeakSanitizer failed to allocate 0x%zx bytes\n", size);
  80     return nullptr;
  81   }
  82   ReportAllocationSizeTooBig(size, max_malloc_size, &stack);
  83 }
  84
  85 void *Allocate(const StackTrace &stack, uptr size, uptr alignment,
  86                bool cleared) {
  87   if (size == 0)
  88     size = 1;
  89   if (size > max_malloc_size)
  90     return ReportAllocationSizeTooBig(size, stack);
  91   if (UNLIKELY(IsRssLimitExceeded())) {
  92     if (AllocatorMayReturnNull())
  93       return nullptr;
  94     ReportRssLimitExceeded(&stack);
  95   }
  96   void *p = allocator.Allocate(GetAllocatorCache(), size, alignment);
  97   if (UNLIKELY(!p)) {
  98     SetAllocatorOutOfMemory();
  99     if (AllocatorMayReturnNull())
 100       return nullptr;
 101     ReportOutOfMemory(size, &stack);
 102   }
 103   // Do not rely on the allocator to clear the memory (it's slow).
 104   if (cleared && allocator.FromPrimary(p))
 105     memset(p, 0, size);
 106   RegisterAllocation(stack, p, size);
 107   RunMallocHooks(p, size);
 108   return p;
 109 }
 110
 111 static void *Calloc(uptr nmemb, uptr size, const StackTrace &stack) {
 112   if (UNLIKELY(CheckForCallocOverflow(size, nmemb))) {
 113     if (AllocatorMayReturnNull())
 114       return nullptr;
 115     ReportCallocOverflow(nmemb, size, &stack);
 116   }
 117   size *= nmemb;
 118   return Allocate(stack, size, 1, true);
 119 }
 120
 121 void Deallocate(void *p) {
 122   RunFreeHooks(p);
 123   RegisterDeallocation(p);
 124   allocator.Deallocate(GetAllocatorCache(), p);
 125 }
 126
 127 void *Reallocate(const StackTrace &stack, void *p, uptr new_size,
 128                  uptr alignment) {
 129   if (new_size > max_malloc_size) {
 130     ReportAllocationSizeTooBig(new_size, stack);
 131     return nullptr;
 132   }
 133   RegisterDeallocation(p);
 134   void *new_p =
 135       allocator.Reallocate(GetAllocatorCache(), p, new_size, alignment);
 136   if (new_p)
 137     RegisterAllocation(stack, new_p, new_size);
 138   else if (new_size != 0)
 139     RegisterAllocation(stack, p, new_size);
 140   return new_p;
 141 }
 142
 143 void GetAllocatorCacheRange(uptr *begin, uptr *end) {
 144   *begin = (uptr)GetAllocatorCache();
 145   *end = *begin + sizeof(AllocatorCache);
 146 }
 147
 148 uptr GetMallocUsableSize(const void *p) {
 149   if (!p)
 150     return 0;
 151   ChunkMetadata *m = Metadata(p);
 152   if (!m) return 0;
 153   return m->requested_size;
 154 }
 155
 156 int lsan_posix_memalign(void **memptr, uptr alignment, uptr size,
 157                         const StackTrace &stack) {
 158   if (UNLIKELY(!CheckPosixMemalignAlignment(alignment))) {
 159     if (AllocatorMayReturnNull())
 160       return errno_EINVAL;
 161     ReportInvalidPosixMemalignAlignment(alignment, &stack);
 162   }
 163   void *ptr = Allocate(stack, size, alignment, kAlwaysClearMemory);
 164   if (UNLIKELY(!ptr))
 165     // OOM error is already taken care of by Allocate.
 166     return errno_ENOMEM;
 167   CHECK(IsAligned((uptr)ptr, alignment));
 168   *memptr = ptr;
 169   return 0;
 170 }
 171
 172 void *lsan_aligned_alloc(uptr alignment, uptr size, const StackTrace &stack) {
 173   if (UNLIKELY(!CheckAlignedAllocAlignmentAndSize(alignment, size))) {
 174     errno = errno_EINVAL;
 175     if (AllocatorMayReturnNull())
 176       return nullptr;
 177     ReportInvalidAlignedAllocAlignment(size, alignment, &stack);
 178   }
 179   return SetErrnoOnNull(Allocate(stack, size, alignment, kAlwaysClearMemory));
 180 }
 181
 182 void *lsan_memalign(uptr alignment, uptr size, const StackTrace &stack) {
 183   if (UNLIKELY(!IsPowerOfTwo(alignment))) {
 184     errno = errno_EINVAL;
 185     if (AllocatorMayReturnNull())
 186       return nullptr;
 187     ReportInvalidAllocationAlignment(alignment, &stack);
 188   }
 189   return SetErrnoOnNull(Allocate(stack, size, alignment, kAlwaysClearMemory));
 190 }
 191
 192 void *lsan_malloc(uptr size, const StackTrace &stack) {
 193   return SetErrnoOnNull(Allocate(stack, size, 1, kAlwaysClearMemory));
 194 }
 195
 196 void lsan_free(void *p) {
 197   Deallocate(p);
 198 }
 199
 200 void *lsan_realloc(void *p, uptr size, const StackTrace &stack) {
 201   return SetErrnoOnNull(Reallocate(stack, p, size, 1));
 202 }
 203
 204 void *lsan_reallocarray(void *ptr, uptr nmemb, uptr size,
 205                         const StackTrace &stack) {
 206   if (UNLIKELY(CheckForCallocOverflow(size, nmemb))) {
 207     errno = errno_ENOMEM;
 208     if (AllocatorMayReturnNull())
 209       return nullptr;
 210     ReportReallocArrayOverflow(nmemb, size, &stack);
 211   }
 212   return lsan_realloc(ptr, nmemb * size, stack);
 213 }
 214
 215 void *lsan_calloc(uptr nmemb, uptr size, const StackTrace &stack) {
 216   return SetErrnoOnNull(Calloc(nmemb, size, stack));
 217 }
 218
 219 void *lsan_valloc(uptr size, const StackTrace &stack) {
 220   return SetErrnoOnNull(
 221       Allocate(stack, size, GetPageSizeCached(), kAlwaysClearMemory));
 222 }
 223
 224 void *lsan_pvalloc(uptr size, const StackTrace &stack) {
 225   uptr PageSize = GetPageSizeCached();
 226   if (UNLIKELY(CheckForPvallocOverflow(size, PageSize))) {
 227     errno = errno_ENOMEM;
 228     if (AllocatorMayReturnNull())
 229       return nullptr;
 230     ReportPvallocOverflow(size, &stack);
 231   }
 232   // pvalloc(0) should allocate one page.
 233   size = size ? RoundUpTo(size, PageSize) : PageSize;
 234   return SetErrnoOnNull(Allocate(stack, size, PageSize, kAlwaysClearMemory));
 235 }
 236
 237 uptr lsan_mz_size(const void *p) {
 238   return GetMallocUsableSize(p);
 239 }
 240
 241 ///// Interface to the common LSan module. /////
 242
 243 void LockAllocator() {
 244   allocator.ForceLock();
 245 }
 246
 247 void UnlockAllocator() {
 248   allocator.ForceUnlock();
 249 }
 250
 251 void GetAllocatorGlobalRange(uptr *begin, uptr *end) {
 252   *begin = (uptr)&allocator;
 253   *end = *begin + sizeof(allocator);
 254 }
 255
 256 uptr PointsIntoChunk(void* p) {
 257   uptr addr = reinterpret_cast<uptr>(p);
 258   uptr chunk = reinterpret_cast<uptr>(allocator.GetBlockBeginFastLocked(p));
 259   if (!chunk) return 0;
 260   // LargeMmapAllocator considers pointers to the meta-region of a chunk to be
 261   // valid, but we don't want that.
 262   if (addr < chunk) return 0;
 263   ChunkMetadata *m = Metadata(reinterpret_cast<void *>(chunk));
 264   CHECK(m);
 265   if (!m->allocated)
 266     return 0;
 267   if (addr < chunk + m->requested_size)
 268     return chunk;
 269   if (IsSpecialCaseOfOperatorNew0(chunk, m->requested_size, addr))
 270     return chunk;
 271   return 0;
 272 }
 273
 274 uptr GetUserBegin(uptr chunk) {
 275   return chunk;
 276 }
 277
 278 LsanMetadata::LsanMetadata(uptr chunk) {
 279   metadata_ = Metadata(reinterpret_cast<void *>(chunk));
 280   CHECK(metadata_);
 281 }
 282
 283 bool LsanMetadata::allocated() const {
 284   return reinterpret_cast<ChunkMetadata *>(metadata_)->allocated;
 285 }
 286
 287 ChunkTag LsanMetadata::tag() const {
 288   return reinterpret_cast<ChunkMetadata *>(metadata_)->tag;
 289 }
 290
 291 void LsanMetadata::set_tag(ChunkTag value) {
 292   reinterpret_cast<ChunkMetadata *>(metadata_)->tag = value;
 293 }
 294
 295 uptr LsanMetadata::requested_size() const {
 296   return reinterpret_cast<ChunkMetadata *>(metadata_)->requested_size;
 297 }
 298
 299 u32 LsanMetadata::stack_trace_id() const {
 300   return reinterpret_cast<ChunkMetadata *>(metadata_)->stack_trace_id;
 301 }
 302
 303 void ForEachChunk(ForEachChunkCallback callback, void *arg) {
 304   allocator.ForEachChunk(callback, arg);
 305 }
 306
 307 IgnoreObjectResult IgnoreObjectLocked(const void *p) {
 308   void *chunk = allocator.GetBlockBegin(p);
 309   if (!chunk || p < chunk) return kIgnoreObjectInvalid;
 310   ChunkMetadata *m = Metadata(chunk);
 311   CHECK(m);
 312   if (m->allocated && (uptr)p < (uptr)chunk + m->requested_size) {
 313     if (m->tag == kIgnored)
 314       return kIgnoreObjectAlreadyIgnored;
 315     m->tag = kIgnored;
 316     return kIgnoreObjectSuccess;
 317   } else {
 318     return kIgnoreObjectInvalid;
 319   }
 320 }
 321
 322 void GetAdditionalThreadContextPtrs(ThreadContextBase *tctx, void *ptrs) {
 323   // This function can be used to treat memory reachable from `tctx` as live.
 324   // This is useful for threads that have been created but not yet started.
 325
 326   // This is currently a no-op because the LSan `pthread_create()` interceptor
 327   // blocks until the child thread starts which keeps the thread's `arg` pointer
 328   // live.
 329 }
 330
 331 } // namespace __lsan
 332
 333 using namespace __lsan;
 334
 335 extern "C" {
 336 SANITIZER_INTERFACE_ATTRIBUTE
 337 uptr __sanitizer_get_current_allocated_bytes() {
 338   uptr stats[AllocatorStatCount];
 339   allocator.GetStats(stats);
 340   return stats[AllocatorStatAllocated];
 341 }
 342
 343 SANITIZER_INTERFACE_ATTRIBUTE
 344 uptr __sanitizer_get_heap_size() {
 345   uptr stats[AllocatorStatCount];
 346   allocator.GetStats(stats);
 347   return stats[AllocatorStatMapped];
 348 }
 349
 350 SANITIZER_INTERFACE_ATTRIBUTE
 351 uptr __sanitizer_get_free_bytes() { return 0; }
 352
 353 SANITIZER_INTERFACE_ATTRIBUTE
 354 uptr __sanitizer_get_unmapped_bytes() { return 0; }
 355
 356 SANITIZER_INTERFACE_ATTRIBUTE
 357 uptr __sanitizer_get_estimated_allocated_size(uptr size) { return size; }
 358
 359 SANITIZER_INTERFACE_ATTRIBUTE
 360 int __sanitizer_get_ownership(const void *p) { return Metadata(p) != nullptr; }
 361
 362 SANITIZER_INTERFACE_ATTRIBUTE
 363 uptr __sanitizer_get_allocated_size(const void *p) {
 364   return GetMallocUsableSize(p);
 365 }
 366
 367 } // extern "C"