about summary refs log tree commit diff homepage
path: root/lib/Core/MemoryManager.cpp
blob: dba90f8da09dfd467aa385191ecceac9c5c9df86 (plain) (blame)
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
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
//===-- MemoryManager.cpp -------------------------------------------------===//
//
//                     The KLEE Symbolic Virtual Machine
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "CoreStats.h"
#include "Memory.h"
#include "MemoryManager.h"

#include "klee/Expr.h"
#include "klee/Internal/Support/ErrorHandling.h"

#include "llvm/Support/CommandLine.h"
#include "llvm/Support/MathExtras.h"

#include <inttypes.h>
#include <sys/mman.h>

using namespace klee;

namespace {

llvm::cl::OptionCategory MemoryCat("Memory management options",
                                   "These options control memory management.");

llvm::cl::opt<bool> DeterministicAllocation(
    "allocate-determ",
    llvm::cl::desc("Allocate memory deterministically (default=false)"),
    llvm::cl::init(false), llvm::cl::cat(MemoryCat));

llvm::cl::opt<unsigned> DeterministicAllocationSize(
    "allocate-determ-size",
    llvm::cl::desc(
        "Preallocated memory for deterministic allocation in MB (default=100)"),
    llvm::cl::init(100), llvm::cl::cat(MemoryCat));

llvm::cl::opt<bool> NullOnZeroMalloc(
    "return-null-on-zero-malloc",
    llvm::cl::desc("Returns NULL if malloc(0) is called (default=false)"),
    llvm::cl::init(false), llvm::cl::cat(MemoryCat));

llvm::cl::opt<unsigned> RedzoneSize(
    "redzone-size",
    llvm::cl::desc("Set the size of the redzones to be added after each "
                   "allocation (in bytes). This is important to detect "
                   "out-of-bounds accesses (default=10)"),
    llvm::cl::init(10), llvm::cl::cat(MemoryCat));

llvm::cl::opt<unsigned long long> DeterministicStartAddress(
    "allocate-determ-start-address",
    llvm::cl::desc("Start address for deterministic allocation. Has to be page "
                   "aligned (default=0x7ff30000000)"),
    llvm::cl::init(0x7ff30000000), llvm::cl::cat(MemoryCat));
} // namespace

/***/
MemoryManager::MemoryManager(ArrayCache *_arrayCache)
    : arrayCache(_arrayCache), deterministicSpace(0), nextFreeSlot(0),
      spaceSize(DeterministicAllocationSize.getValue() * 1024 * 1024) {
  if (DeterministicAllocation) {
    // Page boundary
    void *expectedAddress = (void *)DeterministicStartAddress.getValue();

    char *newSpace =
        (char *)mmap(expectedAddress, spaceSize, PROT_READ | PROT_WRITE,
                     MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);

    if (newSpace == MAP_FAILED) {
      klee_error("Couldn't mmap() memory for deterministic allocations");
    }
    if (expectedAddress != newSpace && expectedAddress != 0) {
      klee_error("Could not allocate memory deterministically");
    }

    klee_message("Deterministic memory allocation starting from %p", newSpace);
    deterministicSpace = newSpace;
    nextFreeSlot = newSpace;
  }
}

MemoryManager::~MemoryManager() {
  while (!objects.empty()) {
    MemoryObject *mo = *objects.begin();
    if (!mo->isFixed && !DeterministicAllocation)
      free((void *)mo->address);
    objects.erase(mo);
    delete mo;
  }

  if (DeterministicAllocation)
    munmap(deterministicSpace, spaceSize);
}

MemoryObject *MemoryManager::allocate(uint64_t size, bool isLocal,
                                      bool isGlobal,
                                      const llvm::Value *allocSite,
                                      size_t alignment) {
  if (size > 10 * 1024 * 1024)
    klee_warning_once(0, "Large alloc: %" PRIu64
                         " bytes.  KLEE may run out of memory.",
                      size);

  // Return NULL if size is zero, this is equal to error during allocation
  if (NullOnZeroMalloc && size == 0)
    return 0;

  if (!llvm::isPowerOf2_64(alignment)) {
    klee_warning("Only alignment of power of two is supported");
    return 0;
  }

  uint64_t address = 0;
  if (DeterministicAllocation) {
#if LLVM_VERSION_CODE >= LLVM_VERSION(3, 9)
    address = llvm::alignTo((uint64_t)nextFreeSlot + alignment - 1, alignment);
#else
    address = llvm::RoundUpToAlignment((uint64_t)nextFreeSlot + alignment - 1,
                                       alignment);
#endif

    // Handle the case of 0-sized allocations as 1-byte allocations.
    // This way, we make sure we have this allocation between its own red zones
    size_t alloc_size = std::max(size, (uint64_t)1);
    if ((char *)address + alloc_size < deterministicSpace + spaceSize) {
      nextFreeSlot = (char *)address + alloc_size + RedzoneSize;
    } else {
      klee_warning_once(0, "Couldn't allocate %" PRIu64
                           " bytes. Not enough deterministic space left.",
                        size);
      address = 0;
    }
  } else {
    // Use malloc for the standard case
    if (alignment <= 8)
      address = (uint64_t)malloc(size);
    else {
      int res = posix_memalign((void **)&address, alignment, size);
      if (res < 0) {
        klee_warning("Allocating aligned memory failed.");
        address = 0;
      }
    }
  }

  if (!address)
    return 0;

  ++stats::allocations;
  MemoryObject *res = new MemoryObject(address, size, isLocal, isGlobal, false,
                                       allocSite, this);
  objects.insert(res);
  return res;
}

MemoryObject *MemoryManager::allocateFixed(uint64_t address, uint64_t size,
                                           const llvm::Value *allocSite) {
#ifndef NDEBUG
  for (objects_ty::iterator it = objects.begin(), ie = objects.end(); it != ie;
       ++it) {
    MemoryObject *mo = *it;
    if (address + size > mo->address && address < mo->address + mo->size)
      klee_error("Trying to allocate an overlapping object");
  }
#endif

  ++stats::allocations;
  MemoryObject *res =
      new MemoryObject(address, size, false, true, true, allocSite, this);
  objects.insert(res);
  return res;
}

void MemoryManager::deallocate(const MemoryObject *mo) { assert(0); }

void MemoryManager::markFreed(MemoryObject *mo) {
  if (objects.find(mo) != objects.end()) {
    if (!mo->isFixed && !DeterministicAllocation)
      free((void *)mo->address);
    objects.erase(mo);
  }
}

size_t MemoryManager::getUsedDeterministicSize() {
  return nextFreeSlot - deterministicSpace;
}