aboutsummaryrefslogtreecommitdiff
path: root/libsanitizer/sanitizer_common/sanitizer_allocator.cc
blob: b5e0bab91f15d08bda730af0b6548c6a7f98d217 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
//===-- sanitizer_allocator.cc --------------------------------------------===//
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file is shared between AddressSanitizer and ThreadSanitizer
// run-time libraries.
// This allocator is used inside run-times.
//===----------------------------------------------------------------------===//

#include "sanitizer_allocator.h"
#include "sanitizer_allocator_internal.h"
#include "sanitizer_common.h"

namespace __sanitizer {

// ThreadSanitizer for Go uses libc malloc/free.
#if defined(SANITIZER_GO) || defined(SANITIZER_USE_MALLOC)
# if SANITIZER_LINUX && !SANITIZER_ANDROID
extern "C" void *__libc_malloc(uptr size);
extern "C" void __libc_free(void *ptr);
#  define LIBC_MALLOC __libc_malloc
#  define LIBC_FREE __libc_free
# else
#  include <stdlib.h>
#  define LIBC_MALLOC malloc
#  define LIBC_FREE free
# endif

static void *RawInternalAlloc(uptr size, InternalAllocatorCache *cache) {
  (void)cache;
  return LIBC_MALLOC(size);
}

static void RawInternalFree(void *ptr, InternalAllocatorCache *cache) {
  (void)cache;
  LIBC_FREE(ptr);
}

InternalAllocator *internal_allocator() {
  return 0;
}

#else // SANITIZER_GO

static ALIGNED(64) char internal_alloc_placeholder[sizeof(InternalAllocator)];
static atomic_uint8_t internal_allocator_initialized;
static StaticSpinMutex internal_alloc_init_mu;

static InternalAllocatorCache internal_allocator_cache;
static StaticSpinMutex internal_allocator_cache_mu;

InternalAllocator *internal_allocator() {
  InternalAllocator *internal_allocator_instance =
      reinterpret_cast<InternalAllocator *>(&internal_alloc_placeholder);
  if (atomic_load(&internal_allocator_initialized, memory_order_acquire) == 0) {
    SpinMutexLock l(&internal_alloc_init_mu);
    if (atomic_load(&internal_allocator_initialized, memory_order_relaxed) ==
        0) {
      internal_allocator_instance->Init(/* may_return_null*/ false);
      atomic_store(&internal_allocator_initialized, 1, memory_order_release);
    }
  }
  return internal_allocator_instance;
}

static void *RawInternalAlloc(uptr size, InternalAllocatorCache *cache) {
  if (cache == 0) {
    SpinMutexLock l(&internal_allocator_cache_mu);
    return internal_allocator()->Allocate(&internal_allocator_cache, size, 8,
                                          false);
  }
  return internal_allocator()->Allocate(cache, size, 8, false);
}

static void RawInternalFree(void *ptr, InternalAllocatorCache *cache) {
  if (!cache) {
    SpinMutexLock l(&internal_allocator_cache_mu);
    return internal_allocator()->Deallocate(&internal_allocator_cache, ptr);
  }
  internal_allocator()->Deallocate(cache, ptr);
}

#endif // SANITIZER_GO

const u64 kBlockMagic = 0x6A6CB03ABCEBC041ull;

void *InternalAlloc(uptr size, InternalAllocatorCache *cache) {
  if (size + sizeof(u64) < size)
    return nullptr;
  void *p = RawInternalAlloc(size + sizeof(u64), cache);
  if (!p)
    return nullptr;
  ((u64*)p)[0] = kBlockMagic;
  return (char*)p + sizeof(u64);
}

void InternalFree(void *addr, InternalAllocatorCache *cache) {
  if (!addr)
    return;
  addr = (char*)addr - sizeof(u64);
  CHECK_EQ(kBlockMagic, ((u64*)addr)[0]);
  ((u64*)addr)[0] = 0;
  RawInternalFree(addr, cache);
}

// LowLevelAllocator
static LowLevelAllocateCallback low_level_alloc_callback;

void *LowLevelAllocator::Allocate(uptr size) {
  // Align allocation size.
  size = RoundUpTo(size, 8);
  if (allocated_end_ - allocated_current_ < (sptr)size) {
    uptr size_to_allocate = Max(size, GetPageSizeCached());
    allocated_current_ =
        (char*)MmapOrDie(size_to_allocate, __func__);
    allocated_end_ = allocated_current_ + size_to_allocate;
    if (low_level_alloc_callback) {
      low_level_alloc_callback((uptr)allocated_current_,
                               size_to_allocate);
    }
  }
  CHECK(allocated_end_ - allocated_current_ >= (sptr)size);
  void *res = allocated_current_;
  allocated_current_ += size;
  return res;
}

void SetLowLevelAllocateCallback(LowLevelAllocateCallback callback) {
  low_level_alloc_callback = callback;
}

bool CallocShouldReturnNullDueToOverflow(uptr size, uptr n) {
  if (!size) return false;
  uptr max = (uptr)-1L;
  return (max / size) < n;
}

void NORETURN ReportAllocatorCannotReturnNull() {
  Report("%s's allocator is terminating the process instead of returning 0\n",
         SanitizerToolName);
  Report("If you don't like this behavior set allocator_may_return_null=1\n");
  CHECK(0);
  Die();
}

} // namespace __sanitizer