libsanitizer/sanitizer_common/sanitizer_allocator.cc

   1 //===-- sanitizer_allocator.cc --------------------------------------------===//
   2 //
   3 // This file is distributed under the University of Illinois Open Source
   4 // License. See LICENSE.TXT for details.
   5 //
   6 //===----------------------------------------------------------------------===//
   7 //
   8 // This file is shared between AddressSanitizer and ThreadSanitizer
   9 // run-time libraries.
  10 // This allocator is used inside run-times.
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "sanitizer_allocator.h"
  14
  15 #include "sanitizer_allocator_checks.h"
  16 #include "sanitizer_allocator_internal.h"
  17 #include "sanitizer_atomic.h"
  18 #include "sanitizer_common.h"
  19
  20 namespace __sanitizer {
  21
  22 // Default allocator names.
  23 const char *PrimaryAllocatorName = "SizeClassAllocator";
  24 const char *SecondaryAllocatorName = "LargeMmapAllocator";
  25
  26 // ThreadSanitizer for Go uses libc malloc/free.
  27 #if SANITIZER_GO || defined(SANITIZER_USE_MALLOC)
  28 # if SANITIZER_LINUX && !SANITIZER_ANDROID
  29 extern "C" void *__libc_malloc(uptr size);
  30 #  if !SANITIZER_GO
  31 extern "C" void *__libc_memalign(uptr alignment, uptr size);
  32 #  endif
  33 extern "C" void *__libc_realloc(void *ptr, uptr size);
  34 extern "C" void __libc_free(void *ptr);
  35 # else
  36 #  include <stdlib.h>
  37 #  define __libc_malloc malloc
  38 #  if !SANITIZER_GO
  39 static void *__libc_memalign(uptr alignment, uptr size) {
  40   void *p;
  41   uptr error = posix_memalign(&p, alignment, size);
  42   if (error) return nullptr;
  43   return p;
  44 }
  45 #  endif
  46 #  define __libc_realloc realloc
  47 #  define __libc_free free
  48 # endif
  49
  50 static void *RawInternalAlloc(uptr size, InternalAllocatorCache *cache,
  51                               uptr alignment) {
  52   (void)cache;
  53 #if !SANITIZER_GO
  54   if (alignment == 0)
  55     return __libc_malloc(size);
  56   else
  57     return __libc_memalign(alignment, size);
  58 #else
  59   // Windows does not provide __libc_memalign/posix_memalign. It provides
  60   // __aligned_malloc, but the allocated blocks can't be passed to free,
  61   // they need to be passed to __aligned_free. InternalAlloc interface does
  62   // not account for such requirement. Alignemnt does not seem to be used
  63   // anywhere in runtime, so just call __libc_malloc for now.
  64   DCHECK_EQ(alignment, 0);
  65   return __libc_malloc(size);
  66 #endif
  67 }
  68
  69 static void *RawInternalRealloc(void *ptr, uptr size,
  70                                 InternalAllocatorCache *cache) {
  71   (void)cache;
  72   return __libc_realloc(ptr, size);
  73 }
  74
  75 static void RawInternalFree(void *ptr, InternalAllocatorCache *cache) {
  76   (void)cache;
  77   __libc_free(ptr);
  78 }
  79
  80 InternalAllocator *internal_allocator() {
  81   return 0;
  82 }
  83
  84 #else  // SANITIZER_GO || defined(SANITIZER_USE_MALLOC)
  85
  86 static ALIGNED(64) char internal_alloc_placeholder[sizeof(InternalAllocator)];
  87 static atomic_uint8_t internal_allocator_initialized;
  88 static StaticSpinMutex internal_alloc_init_mu;
  89
  90 static InternalAllocatorCache internal_allocator_cache;
  91 static StaticSpinMutex internal_allocator_cache_mu;
  92
  93 InternalAllocator *internal_allocator() {
  94   InternalAllocator *internal_allocator_instance =
  95       reinterpret_cast<InternalAllocator *>(&internal_alloc_placeholder);
  96   if (atomic_load(&internal_allocator_initialized, memory_order_acquire) == 0) {
  97     SpinMutexLock l(&internal_alloc_init_mu);
  98     if (atomic_load(&internal_allocator_initialized, memory_order_relaxed) ==
  99         0) {
 100       internal_allocator_instance->Init(kReleaseToOSIntervalNever);
 101       atomic_store(&internal_allocator_initialized, 1, memory_order_release);
 102     }
 103   }
 104   return internal_allocator_instance;
 105 }
 106
 107 static void *RawInternalAlloc(uptr size, InternalAllocatorCache *cache,
 108                               uptr alignment) {
 109   if (alignment == 0) alignment = 8;
 110   if (cache == 0) {
 111     SpinMutexLock l(&internal_allocator_cache_mu);
 112     return internal_allocator()->Allocate(&internal_allocator_cache, size,
 113                                           alignment);
 114   }
 115   return internal_allocator()->Allocate(cache, size, alignment);
 116 }
 117
 118 static void *RawInternalRealloc(void *ptr, uptr size,
 119                                 InternalAllocatorCache *cache) {
 120   uptr alignment = 8;
 121   if (cache == 0) {
 122     SpinMutexLock l(&internal_allocator_cache_mu);
 123     return internal_allocator()->Reallocate(&internal_allocator_cache, ptr,
 124                                             size, alignment);
 125   }
 126   return internal_allocator()->Reallocate(cache, ptr, size, alignment);
 127 }
 128
 129 static void RawInternalFree(void *ptr, InternalAllocatorCache *cache) {
 130   if (!cache) {
 131     SpinMutexLock l(&internal_allocator_cache_mu);
 132     return internal_allocator()->Deallocate(&internal_allocator_cache, ptr);
 133   }
 134   internal_allocator()->Deallocate(cache, ptr);
 135 }
 136
 137 #endif  // SANITIZER_GO || defined(SANITIZER_USE_MALLOC)
 138
 139 const u64 kBlockMagic = 0x6A6CB03ABCEBC041ull;
 140
 141 static void NORETURN ReportInternalAllocatorOutOfMemory(uptr requested_size) {
 142   SetAllocatorOutOfMemory();
 143   Report("FATAL: %s: internal allocator is out of memory trying to allocate "
 144          "0x%zx bytes\n", SanitizerToolName, requested_size);
 145   Die();
 146 }
 147
 148 void *InternalAlloc(uptr size, InternalAllocatorCache *cache, uptr alignment) {
 149   if (size + sizeof(u64) < size)
 150     return nullptr;
 151   void *p = RawInternalAlloc(size + sizeof(u64), cache, alignment);
 152   if (UNLIKELY(!p))
 153     ReportInternalAllocatorOutOfMemory(size + sizeof(u64));
 154   ((u64*)p)[0] = kBlockMagic;
 155   return (char*)p + sizeof(u64);
 156 }
 157
 158 void *InternalRealloc(void *addr, uptr size, InternalAllocatorCache *cache) {
 159   if (!addr)
 160     return InternalAlloc(size, cache);
 161   if (size + sizeof(u64) < size)
 162     return nullptr;
 163   addr = (char*)addr - sizeof(u64);
 164   size = size + sizeof(u64);
 165   CHECK_EQ(kBlockMagic, ((u64*)addr)[0]);
 166   void *p = RawInternalRealloc(addr, size, cache);
 167   if (UNLIKELY(!p))
 168     ReportInternalAllocatorOutOfMemory(size);
 169   return (char*)p + sizeof(u64);
 170 }
 171
 172 void *InternalCalloc(uptr count, uptr size, InternalAllocatorCache *cache) {
 173   if (UNLIKELY(CheckForCallocOverflow(count, size))) {
 174     Report("FATAL: %s: calloc parameters overflow: count * size (%zd * %zd) "
 175            "cannot be represented in type size_t\n", SanitizerToolName, count,
 176            size);
 177     Die();
 178   }
 179   void *p = InternalAlloc(count * size, cache);
 180   if (LIKELY(p))
 181     internal_memset(p, 0, count * size);
 182   return p;
 183 }
 184
 185 void InternalFree(void *addr, InternalAllocatorCache *cache) {
 186   if (!addr)
 187     return;
 188   addr = (char*)addr - sizeof(u64);
 189   CHECK_EQ(kBlockMagic, ((u64*)addr)[0]);
 190   ((u64*)addr)[0] = 0;
 191   RawInternalFree(addr, cache);
 192 }
 193
 194 // LowLevelAllocator
 195 constexpr uptr kLowLevelAllocatorDefaultAlignment = 8;
 196 static uptr low_level_alloc_min_alignment = kLowLevelAllocatorDefaultAlignment;
 197 static LowLevelAllocateCallback low_level_alloc_callback;
 198
 199 void *LowLevelAllocator::Allocate(uptr size) {
 200   // Align allocation size.
 201   size = RoundUpTo(size, low_level_alloc_min_alignment);
 202   if (allocated_end_ - allocated_current_ < (sptr)size) {
 203     uptr size_to_allocate = Max(size, GetPageSizeCached());
 204     allocated_current_ =
 205         (char*)MmapOrDie(size_to_allocate, __func__);
 206     allocated_end_ = allocated_current_ + size_to_allocate;
 207     if (low_level_alloc_callback) {
 208       low_level_alloc_callback((uptr)allocated_current_,
 209                                size_to_allocate);
 210     }
 211   }
 212   CHECK(allocated_end_ - allocated_current_ >= (sptr)size);
 213   void *res = allocated_current_;
 214   allocated_current_ += size;
 215   return res;
 216 }
 217
 218 void SetLowLevelAllocateMinAlignment(uptr alignment) {
 219   CHECK(IsPowerOfTwo(alignment));
 220   low_level_alloc_min_alignment = Max(alignment, low_level_alloc_min_alignment);
 221 }
 222
 223 void SetLowLevelAllocateCallback(LowLevelAllocateCallback callback) {
 224   low_level_alloc_callback = callback;
 225 }
 226
 227 // Allocator's OOM and other errors handling support.
 228
 229 static atomic_uint8_t allocator_out_of_memory = {0};
 230 static atomic_uint8_t allocator_may_return_null = {0};
 231
 232 bool IsAllocatorOutOfMemory() {
 233   return atomic_load_relaxed(&allocator_out_of_memory);
 234 }
 235
 236 void SetAllocatorOutOfMemory() {
 237   atomic_store_relaxed(&allocator_out_of_memory, 1);
 238 }
 239
 240 bool AllocatorMayReturnNull() {
 241   return atomic_load(&allocator_may_return_null, memory_order_relaxed);
 242 }
 243
 244 void SetAllocatorMayReturnNull(bool may_return_null) {
 245   atomic_store(&allocator_may_return_null, may_return_null,
 246                memory_order_relaxed);
 247 }
 248
 249 void PrintHintAllocatorCannotReturnNull() {
 250   Report("HINT: if you don't care about these errors you may set "
 251          "allocator_may_return_null=1\n");
 252 }
 253
 254 } // namespace __sanitizer