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//===-- 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 <sys/mman.h>
using namespace klee;
namespace {
llvm::cl::opt<bool> DeterministicAllocation(
"allocate-determ",
llvm::cl::desc("Allocate memory deterministically(default=off)"),
llvm::cl::init(false));
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::opt<bool>
NullOnZeroMalloc("return-null-on-zero-malloc",
llvm::cl::desc("Returns NULL in case malloc(size) was "
"called with size 0 (default=off)."),
llvm::cl::init(false));
llvm::cl::opt<unsigned> RedZoneSpace(
"red-zone-space",
llvm::cl::desc("Set the amount of free space between allocations. This is "
"important to detect out-of-bound accesses (default=10)."),
llvm::cl::init(10));
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));
}
/***/
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: %lu 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) {
address = llvm::RoundUpToAlignment((uint64_t)nextFreeSlot + alignment - 1,
alignment);
// 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 + RedZoneSpace;
} else {
klee_warning_once(
0,
"Couldn't allocate %lu 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;
}
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