asan_allocator.h revision c3390df6670cb166119b961eb27a033fb9073496
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 21namespace __asan { 22 23static const uptr kNumberOfSizeClasses = 255; 24struct AsanChunk; 25 26class AsanChunkFifoList { 27 public: 28 explicit AsanChunkFifoList(LinkerInitialized) { } 29 AsanChunkFifoList() { clear(); } 30 void Push(AsanChunk *n); 31 void PushList(AsanChunkFifoList *q); 32 AsanChunk *Pop(); 33 uptr size() { return size_; } 34 void clear() { 35 first_ = last_ = 0; 36 size_ = 0; 37 } 38 private: 39 AsanChunk *first_; 40 AsanChunk *last_; 41 uptr size_; 42}; 43 44struct AsanThreadLocalMallocStorage { 45 explicit AsanThreadLocalMallocStorage(LinkerInitialized x) 46 : quarantine_(x) { } 47 AsanThreadLocalMallocStorage() { 48 CHECK(REAL(memset)); 49 REAL(memset)(this, 0, sizeof(AsanThreadLocalMallocStorage)); 50 } 51 52 AsanChunkFifoList quarantine_; 53 AsanChunk *free_lists_[kNumberOfSizeClasses]; 54 void CommitBack(); 55}; 56 57// Fake stack frame contains local variables of one function. 58// This struct should fit into a stack redzone (32 bytes). 59struct FakeFrame { 60 uptr magic; // Modified by the instrumented code. 61 uptr descr; // Modified by the instrumented code. 62 FakeFrame *next; 63 u64 real_stack : 48; 64 u64 size_minus_one : 16; 65}; 66 67struct FakeFrameFifo { 68 public: 69 void FifoPush(FakeFrame *node); 70 FakeFrame *FifoPop(); 71 private: 72 FakeFrame *first_, *last_; 73}; 74 75class FakeFrameLifo { 76 public: 77 void LifoPush(FakeFrame *node) { 78 node->next = top_; 79 top_ = node; 80 } 81 void LifoPop() { 82 CHECK(top_); 83 top_ = top_->next; 84 } 85 FakeFrame *top() { return top_; } 86 private: 87 FakeFrame *top_; 88}; 89 90// For each thread we create a fake stack and place stack objects on this fake 91// stack instead of the real stack. The fake stack is not really a stack but 92// a fast malloc-like allocator so that when a function exits the fake stack 93// is not poped but remains there for quite some time until gets used again. 94// So, we poison the objects on the fake stack when function returns. 95// It helps us find use-after-return bugs. 96// We can not rely on __asan_stack_free being called on every function exit, 97// so we maintain a lifo list of all current fake frames and update it on every 98// call to __asan_stack_malloc. 99class FakeStack { 100 public: 101 FakeStack(); 102 explicit FakeStack(LinkerInitialized) {} 103 void Init(uptr stack_size); 104 void StopUsingFakeStack() { alive_ = false; } 105 void Cleanup(); 106 uptr AllocateStack(uptr size, uptr real_stack); 107 static void OnFree(uptr ptr, uptr size, uptr real_stack); 108 // Return the bottom of the maped region. 109 uptr AddrIsInFakeStack(uptr addr); 110 bool StackSize() { return stack_size_; } 111 private: 112 static const uptr kMinStackFrameSizeLog = 9; // Min frame is 512B. 113 static const uptr kMaxStackFrameSizeLog = 16; // Max stack frame is 64K. 114 static const uptr kMaxStackMallocSize = 1 << kMaxStackFrameSizeLog; 115 static const uptr kNumberOfSizeClasses = 116 kMaxStackFrameSizeLog - kMinStackFrameSizeLog + 1; 117 118 bool AddrIsInSizeClass(uptr addr, uptr size_class); 119 120 // Each size class should be large enough to hold all frames. 121 uptr ClassMmapSize(uptr size_class); 122 123 uptr ClassSize(uptr size_class) { 124 return 1UL << (size_class + kMinStackFrameSizeLog); 125 } 126 127 void DeallocateFrame(FakeFrame *fake_frame); 128 129 uptr ComputeSizeClass(uptr alloc_size); 130 void AllocateOneSizeClass(uptr size_class); 131 132 uptr stack_size_; 133 bool alive_; 134 135 uptr allocated_size_classes_[kNumberOfSizeClasses]; 136 FakeFrameFifo size_classes_[kNumberOfSizeClasses]; 137 FakeFrameLifo call_stack_; 138}; 139 140void *asan_memalign(uptr alignment, uptr size, StackTrace *stack); 141void asan_free(void *ptr, StackTrace *stack); 142 143void *asan_malloc(uptr size, StackTrace *stack); 144void *asan_calloc(uptr nmemb, uptr size, StackTrace *stack); 145void *asan_realloc(void *p, uptr size, StackTrace *stack); 146void *asan_valloc(uptr size, StackTrace *stack); 147void *asan_pvalloc(uptr size, StackTrace *stack); 148 149int asan_posix_memalign(void **memptr, uptr alignment, uptr size, 150 StackTrace *stack); 151uptr asan_malloc_usable_size(void *ptr, StackTrace *stack); 152 153uptr asan_mz_size(const void *ptr); 154void asan_mz_force_lock(); 155void asan_mz_force_unlock(); 156 157} // namespace __asan 158#endif // ASAN_ALLOCATOR_H 159