asan_allocator.h revision 3f4c3875c42078e22c7e5356c5746fd18756d958 
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  uint64_t real_stack     : 48;
64  uint64_t 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, AsanStackTrace *stack);
141void asan_free(void *ptr, AsanStackTrace *stack);
142
143void *asan_malloc(uptr size, AsanStackTrace *stack);
144void *asan_calloc(uptr nmemb, uptr size, AsanStackTrace *stack);
145void *asan_realloc(void *p, uptr size, AsanStackTrace *stack);
146void *asan_valloc(uptr size, AsanStackTrace *stack);
147void *asan_pvalloc(uptr size, AsanStackTrace *stack);
148
149int asan_posix_memalign(void **memptr, uptr alignment, uptr size,
150                          AsanStackTrace *stack);
151uptr asan_malloc_usable_size(void *ptr, AsanStackTrace *stack);
152
153uptr asan_mz_size(const void *ptr);
154void asan_mz_force_lock();
155void asan_mz_force_unlock();
156void DescribeHeapAddress(uptr addr, uptr access_size);
157
158}  // namespace __asan
159#endif  // ASAN_ALLOCATOR_H
160