libsanitizer/sanitizer_common/sanitizer_allocator.cpp

   1 //===-- sanitizer_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 shared between AddressSanitizer and ThreadSanitizer
  10 // run-time libraries.
  11 // This allocator is used inside run-times.
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "sanitizer_allocator.h"
  15
  16 #include "sanitizer_allocator_checks.h"
  17 #include "sanitizer_allocator_internal.h"
  18 #include "sanitizer_atomic.h"
  19 #include "sanitizer_common.h"
  20 #include "sanitizer_platform.h"
  21
  22 namespace __sanitizer {
  23
  24 // Default allocator names.
  25 const char *PrimaryAllocatorName = "SizeClassAllocator";
  26 const char *SecondaryAllocatorName = "LargeMmapAllocator";
  27
  28 static ALIGNED(64) char internal_alloc_placeholder[sizeof(InternalAllocator)];
  29 static atomic_uint8_t internal_allocator_initialized;
  30 static StaticSpinMutex internal_alloc_init_mu;
  31
  32 static InternalAllocatorCache internal_allocator_cache;
  33 static StaticSpinMutex internal_allocator_cache_mu;
  34
  35 InternalAllocator *internal_allocator() {
  36   InternalAllocator *internal_allocator_instance =
  37       reinterpret_cast<InternalAllocator *>(&internal_alloc_placeholder);
  38   if (atomic_load(&internal_allocator_initialized, memory_order_acquire) == 0) {
  39     SpinMutexLock l(&internal_alloc_init_mu);
  40     if (atomic_load(&internal_allocator_initialized, memory_order_relaxed) ==
  41         0) {
  42       internal_allocator_instance->Init(kReleaseToOSIntervalNever);
  43       atomic_store(&internal_allocator_initialized, 1, memory_order_release);
  44     }
  45   }
  46   return internal_allocator_instance;
  47 }
  48
  49 static void *RawInternalAlloc(uptr size, InternalAllocatorCache *cache,
  50                               uptr alignment) {
  51   if (alignment == 0) alignment = 8;
  52   if (cache == 0) {
  53     SpinMutexLock l(&internal_allocator_cache_mu);
  54     return internal_allocator()->Allocate(&internal_allocator_cache, size,
  55                                           alignment);
  56   }
  57   return internal_allocator()->Allocate(cache, size, alignment);
  58 }
  59
  60 static void *RawInternalRealloc(void *ptr, uptr size,
  61                                 InternalAllocatorCache *cache) {
  62   uptr alignment = 8;
  63   if (cache == 0) {
  64     SpinMutexLock l(&internal_allocator_cache_mu);
  65     return internal_allocator()->Reallocate(&internal_allocator_cache, ptr,
  66                                             size, alignment);
  67   }
  68   return internal_allocator()->Reallocate(cache, ptr, size, alignment);
  69 }
  70
  71 static void RawInternalFree(void *ptr, InternalAllocatorCache *cache) {
  72   if (!cache) {
  73     SpinMutexLock l(&internal_allocator_cache_mu);
  74     return internal_allocator()->Deallocate(&internal_allocator_cache, ptr);
  75   }
  76   internal_allocator()->Deallocate(cache, ptr);
  77 }
  78
  79 static void NORETURN ReportInternalAllocatorOutOfMemory(uptr requested_size) {
  80   SetAllocatorOutOfMemory();
  81   Report("FATAL: %s: internal allocator is out of memory trying to allocate "
  82          "0x%zx bytes\n", SanitizerToolName, requested_size);
  83   Die();
  84 }
  85
  86 void *InternalAlloc(uptr size, InternalAllocatorCache *cache, uptr alignment) {
  87   void *p = RawInternalAlloc(size, cache, alignment);
  88   if (UNLIKELY(!p))
  89     ReportInternalAllocatorOutOfMemory(size);
  90   return p;
  91 }
  92
  93 void *InternalRealloc(void *addr, uptr size, InternalAllocatorCache *cache) {
  94   void *p = RawInternalRealloc(addr, size, cache);
  95   if (UNLIKELY(!p))
  96     ReportInternalAllocatorOutOfMemory(size);
  97   return p;
  98 }
  99
 100 void *InternalReallocArray(void *addr, uptr count, uptr size,
 101                            InternalAllocatorCache *cache) {
 102   if (UNLIKELY(CheckForCallocOverflow(count, size))) {
 103     Report(
 104         "FATAL: %s: reallocarray parameters overflow: count * size (%zd * %zd) "
 105         "cannot be represented in type size_t\n",
 106         SanitizerToolName, count, size);
 107     Die();
 108   }
 109   return InternalRealloc(addr, count * size, cache);
 110 }
 111
 112 void *InternalCalloc(uptr count, uptr size, InternalAllocatorCache *cache) {
 113   if (UNLIKELY(CheckForCallocOverflow(count, size))) {
 114     Report("FATAL: %s: calloc parameters overflow: count * size (%zd * %zd) "
 115            "cannot be represented in type size_t\n", SanitizerToolName, count,
 116            size);
 117     Die();
 118   }
 119   void *p = InternalAlloc(count * size, cache);
 120   if (LIKELY(p))
 121     internal_memset(p, 0, count * size);
 122   return p;
 123 }
 124
 125 void InternalFree(void *addr, InternalAllocatorCache *cache) {
 126   RawInternalFree(addr, cache);
 127 }
 128
 129 void InternalAllocatorLock() SANITIZER_NO_THREAD_SAFETY_ANALYSIS {
 130   internal_allocator_cache_mu.Lock();
 131   internal_allocator()->ForceLock();
 132 }
 133
 134 void InternalAllocatorUnlock() SANITIZER_NO_THREAD_SAFETY_ANALYSIS {
 135   internal_allocator()->ForceUnlock();
 136   internal_allocator_cache_mu.Unlock();
 137 }
 138
 139 // LowLevelAllocator
 140 constexpr uptr kLowLevelAllocatorDefaultAlignment = 8;
 141 constexpr uptr kMinNumPagesRounded = 16;
 142 constexpr uptr kMinRoundedSize = 65536;
 143 static uptr low_level_alloc_min_alignment = kLowLevelAllocatorDefaultAlignment;
 144 static LowLevelAllocateCallback low_level_alloc_callback;
 145
 146 static LowLevelAllocator Alloc;
 147 LowLevelAllocator &GetGlobalLowLevelAllocator() { return Alloc; }
 148
 149 void *LowLevelAllocator::Allocate(uptr size) {
 150   // Align allocation size.
 151   size = RoundUpTo(size, low_level_alloc_min_alignment);
 152   if (allocated_end_ - allocated_current_ < (sptr)size) {
 153     uptr size_to_allocate = RoundUpTo(
 154         size, Min(GetPageSizeCached() * kMinNumPagesRounded, kMinRoundedSize));
 155     allocated_current_ = (char *)MmapOrDie(size_to_allocate, __func__);
 156     allocated_end_ = allocated_current_ + size_to_allocate;
 157     if (low_level_alloc_callback) {
 158       low_level_alloc_callback((uptr)allocated_current_, size_to_allocate);
 159     }
 160   }
 161   CHECK(allocated_end_ - allocated_current_ >= (sptr)size);
 162   void *res = allocated_current_;
 163   allocated_current_ += size;
 164   return res;
 165 }
 166
 167 void SetLowLevelAllocateMinAlignment(uptr alignment) {
 168   CHECK(IsPowerOfTwo(alignment));
 169   low_level_alloc_min_alignment = Max(alignment, low_level_alloc_min_alignment);
 170 }
 171
 172 void SetLowLevelAllocateCallback(LowLevelAllocateCallback callback) {
 173   low_level_alloc_callback = callback;
 174 }
 175
 176 // Allocator's OOM and other errors handling support.
 177
 178 static atomic_uint8_t allocator_out_of_memory = {0};
 179 static atomic_uint8_t allocator_may_return_null = {0};
 180
 181 bool IsAllocatorOutOfMemory() {
 182   return atomic_load_relaxed(&allocator_out_of_memory);
 183 }
 184
 185 void SetAllocatorOutOfMemory() {
 186   atomic_store_relaxed(&allocator_out_of_memory, 1);
 187 }
 188
 189 bool AllocatorMayReturnNull() {
 190   return atomic_load(&allocator_may_return_null, memory_order_relaxed);
 191 }
 192
 193 void SetAllocatorMayReturnNull(bool may_return_null) {
 194   atomic_store(&allocator_may_return_null, may_return_null,
 195                memory_order_relaxed);
 196 }
 197
 198 void PrintHintAllocatorCannotReturnNull() {
 199   Report("HINT: if you don't care about these errors you may set "
 200          "allocator_may_return_null=1\n");
 201 }
 202
 203 static atomic_uint8_t rss_limit_exceeded;
 204
 205 bool IsRssLimitExceeded() {
 206   return atomic_load(&rss_limit_exceeded, memory_order_relaxed);
 207 }
 208
 209 void SetRssLimitExceeded(bool limit_exceeded) {
 210   atomic_store(&rss_limit_exceeded, limit_exceeded, memory_order_relaxed);
 211 }
 212
 213 } // namespace __sanitizer