asan_allocator.h revision d4de2a1a7b15d0ed1a303b1604894ae82d5e8748
1//===-- asan_allocator.h ----------------------------------------*- C++ -*-===// 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 AddressSanitizer, an address sanity checker. 11// 12// ASan-private header for asan_allocator.cc. 13//===----------------------------------------------------------------------===// 14 15#ifndef ASAN_ALLOCATOR_H 16#define ASAN_ALLOCATOR_H 17 18#include "asan_internal.h" 19#include "asan_interceptors.h" 20#include "sanitizer_common/sanitizer_list.h" 21 22// We are in the process of transitioning from the old allocator (version 1) 23// to a new one (version 2). The change is quite intrusive so both allocators 24// will co-exist in the source base for a while. The actual allocator is chosen 25// at build time by redefining this macro. 26#ifndef ASAN_ALLOCATOR_VERSION 27# if (ASAN_LINUX && !ASAN_ANDROID) || ASAN_MAC || ASAN_WINDOWS 28# define ASAN_ALLOCATOR_VERSION 2 29# else 30# define ASAN_ALLOCATOR_VERSION 1 31# endif 32#endif // ASAN_ALLOCATOR_VERSION 33 34namespace __asan { 35 36enum AllocType { 37 FROM_MALLOC = 1, // Memory block came from malloc, calloc, realloc, etc. 38 FROM_NEW = 2, // Memory block came from operator new. 39 FROM_NEW_BR = 3 // Memory block came from operator new [ ] 40}; 41 42static const uptr kNumberOfSizeClasses = 255; 43struct AsanChunk; 44 45void InitializeAllocator(); 46 47class AsanChunkView { 48 public: 49 explicit AsanChunkView(AsanChunk *chunk) : chunk_(chunk) {} 50 bool IsValid() { return chunk_ != 0; } 51 uptr Beg(); // first byte of user memory. 52 uptr End(); // last byte of user memory. 53 uptr UsedSize(); // size requested by the user. 54 uptr AllocTid(); 55 uptr FreeTid(); 56 void GetAllocStack(StackTrace *stack); 57 void GetFreeStack(StackTrace *stack); 58 bool AddrIsInside(uptr addr, uptr access_size, sptr *offset) { 59 if (addr >= Beg() && (addr + access_size) <= End()) { 60 *offset = addr - Beg(); 61 return true; 62 } 63 return false; 64 } 65 bool AddrIsAtLeft(uptr addr, uptr access_size, sptr *offset) { 66 (void)access_size; 67 if (addr < Beg()) { 68 *offset = Beg() - addr; 69 return true; 70 } 71 return false; 72 } 73 bool AddrIsAtRight(uptr addr, uptr access_size, sptr *offset) { 74 if (addr + access_size > End()) { 75 *offset = addr - End(); 76 return true; 77 } 78 return false; 79 } 80 81 private: 82 AsanChunk *const chunk_; 83}; 84 85AsanChunkView FindHeapChunkByAddress(uptr address); 86 87// List of AsanChunks with total size. 88class AsanChunkFifoList: public IntrusiveList<AsanChunk> { 89 public: 90 explicit AsanChunkFifoList(LinkerInitialized) { } 91 AsanChunkFifoList() { clear(); } 92 void Push(AsanChunk *n); 93 void PushList(AsanChunkFifoList *q); 94 AsanChunk *Pop(); 95 uptr size() { return size_; } 96 void clear() { 97 IntrusiveList<AsanChunk>::clear(); 98 size_ = 0; 99 } 100 private: 101 uptr size_; 102}; 103 104struct AsanThreadLocalMallocStorage { 105 explicit AsanThreadLocalMallocStorage(LinkerInitialized x) 106#if ASAN_ALLOCATOR_VERSION == 1 107 : quarantine_(x) 108#endif 109 { } 110 AsanThreadLocalMallocStorage() { 111 CHECK(REAL(memset)); 112 REAL(memset)(this, 0, sizeof(AsanThreadLocalMallocStorage)); 113 } 114 115#if ASAN_ALLOCATOR_VERSION == 1 116 AsanChunkFifoList quarantine_; 117 AsanChunk *free_lists_[kNumberOfSizeClasses]; 118#else 119 uptr quarantine_cache[16]; 120 uptr allocator2_cache[96 * (512 * 8 + 16)]; // Opaque. 121#endif 122 void CommitBack(); 123}; 124 125// Fake stack frame contains local variables of one function. 126// This struct should fit into a stack redzone (32 bytes). 127struct FakeFrame { 128 uptr magic; // Modified by the instrumented code. 129 uptr descr; // Modified by the instrumented code. 130 FakeFrame *next; 131 u64 real_stack : 48; 132 u64 size_minus_one : 16; 133}; 134 135struct FakeFrameFifo { 136 public: 137 void FifoPush(FakeFrame *node); 138 FakeFrame *FifoPop(); 139 private: 140 FakeFrame *first_, *last_; 141}; 142 143class FakeFrameLifo { 144 public: 145 void LifoPush(FakeFrame *node) { 146 node->next = top_; 147 top_ = node; 148 } 149 void LifoPop() { 150 CHECK(top_); 151 top_ = top_->next; 152 } 153 FakeFrame *top() { return top_; } 154 private: 155 FakeFrame *top_; 156}; 157 158// For each thread we create a fake stack and place stack objects on this fake 159// stack instead of the real stack. The fake stack is not really a stack but 160// a fast malloc-like allocator so that when a function exits the fake stack 161// is not poped but remains there for quite some time until gets used again. 162// So, we poison the objects on the fake stack when function returns. 163// It helps us find use-after-return bugs. 164// We can not rely on __asan_stack_free being called on every function exit, 165// so we maintain a lifo list of all current fake frames and update it on every 166// call to __asan_stack_malloc. 167class FakeStack { 168 public: 169 FakeStack(); 170 explicit FakeStack(LinkerInitialized) {} 171 void Init(uptr stack_size); 172 void StopUsingFakeStack() { alive_ = false; } 173 void Cleanup(); 174 uptr AllocateStack(uptr size, uptr real_stack); 175 static void OnFree(uptr ptr, uptr size, uptr real_stack); 176 // Return the bottom of the maped region. 177 uptr AddrIsInFakeStack(uptr addr); 178 bool StackSize() { return stack_size_; } 179 180 private: 181 static const uptr kMinStackFrameSizeLog = 9; // Min frame is 512B. 182 static const uptr kMaxStackFrameSizeLog = 16; // Max stack frame is 64K. 183 static const uptr kMaxStackMallocSize = 1 << kMaxStackFrameSizeLog; 184 static const uptr kNumberOfSizeClasses = 185 kMaxStackFrameSizeLog - kMinStackFrameSizeLog + 1; 186 187 bool AddrIsInSizeClass(uptr addr, uptr size_class); 188 189 // Each size class should be large enough to hold all frames. 190 uptr ClassMmapSize(uptr size_class); 191 192 uptr ClassSize(uptr size_class) { 193 return 1UL << (size_class + kMinStackFrameSizeLog); 194 } 195 196 void DeallocateFrame(FakeFrame *fake_frame); 197 198 uptr ComputeSizeClass(uptr alloc_size); 199 void AllocateOneSizeClass(uptr size_class); 200 201 uptr stack_size_; 202 bool alive_; 203 204 uptr allocated_size_classes_[kNumberOfSizeClasses]; 205 FakeFrameFifo size_classes_[kNumberOfSizeClasses]; 206 FakeFrameLifo call_stack_; 207}; 208 209void *asan_memalign(uptr alignment, uptr size, StackTrace *stack, 210 AllocType alloc_type); 211void asan_free(void *ptr, StackTrace *stack, AllocType alloc_type); 212 213void *asan_malloc(uptr size, StackTrace *stack); 214void *asan_calloc(uptr nmemb, uptr size, StackTrace *stack); 215void *asan_realloc(void *p, uptr size, StackTrace *stack); 216void *asan_valloc(uptr size, StackTrace *stack); 217void *asan_pvalloc(uptr size, StackTrace *stack); 218 219int asan_posix_memalign(void **memptr, uptr alignment, uptr size, 220 StackTrace *stack); 221uptr asan_malloc_usable_size(void *ptr, StackTrace *stack); 222 223uptr asan_mz_size(const void *ptr); 224void asan_mz_force_lock(); 225void asan_mz_force_unlock(); 226 227void PrintInternalAllocatorStats(); 228 229} // namespace __asan 230#endif // ASAN_ALLOCATOR_H 231