Question

问了一个问题Call CloseHandle on handle that is a function parameter?

在有人编辑了代码之后，我对其进行了更新，以发现代码不再按预期工作。

intptr_t readMem(HANDLE processHandle, intptr_t address, int sizeToReadBytes)
{
  intptr_t memValue = 0;

  bool success = ReadProcessMemory(processHandle, (LPVOID)address, memValue, sizeToReadBytes, NULL);
  if (!success)
      std::wcout << "Memory read failed on address: " << std::hex << address << "\n";

  return memValue;
}

在第

行

ReadProcessMemory(processHandle, (LPVOID)address, memValue, sizeToReadBytes, NULL);

memValue不会在没有(LPVOID)或(LPCVOID)强制转换的情况下进行编译，但是对于它们，代码不再读取内存（或者使用{在函数的情况下写入） {1}}

最初（现在我已经在我的小程序中将其更改回来）它使用引用WriteProcessMemory并且工作正常。

我的问题是：

这应该有用吗？或者编辑是否正确，我的程序的其余部分可能是错误的？

如果需要，我可以提供更多代码，只是不确定哪些比特并且不想比我更多地阻塞屏幕...还应该回滚编辑吗？

Answer 1

ReadProcessMemory()的第三个参数是调用进程中的内存地址，函数将读取的数据写入。但是，您没有传递内存地址。在原始问题的第三个修订版中显示的代码中，您将未初始化的整数变量的值输入到内存指针中。所以函数会尝试写入随机存储器。现在你已经删除了类型转换，所以代码甚至不应该再编译了。

您的readMem()功能设计不正确。您需要更改它以便：

调用者分配所需大小的内存，然后该函数只是填充内存：

bool readMem(HANDLE processHandle, intptr_t address, void *memValue, int sizeToReadBytes)
{
  bool success = ReadProcessMemory(processHandle, (LPVOID)address, memValue, sizeToReadBytes, NULL);
  if (!success)
    std::wcout << "Memory read failed on address: " << std::hex << address << "\n";
  return success;
}

intptr_t memValue = 0;
readMem(processHandle, address, &memValue, sizeof(memValue));

该函数分配内存并将其返回给调用者：

void* readMem(HANDLE processHandle, intptr_t address, int sizeToReadBytes)
{
  uint8_t memValue = new uint8_t[sizeToReadBytes];
  bool success = ReadProcessMemory(processHandle, (LPVOID)address, memValue, sizeToReadBytes, NULL);
  if (!success) {
    std::wcout << "Memory read failed on address: " << std::hex << address << "\n";
    delete [] memValue;
    memValue = NULL;
  }
  return memValue;
}

intptr_t *memValue = (intptr_t*) readMem(processHandle, address, sizeof(intptr_t));
...
delete [] memValue;

或者：

bool readMem(HANDLE processHandle, intptr_t address, int sizeToReadBytes, std:vector<uint8_t> &memValue)
{
  memValue.resize(sizeToReadBytes);
  bool success = ReadProcessMemory(processHandle, (LPVOID)address, &memValue[0], sizeToReadBytes, NULL);
  if (!success)
    std::wcout << "Memory read failed on address: " << std::hex << address << "\n";
  return success;
}

std::vector<uint8_t> buffer;
readMem(processHandle, address, sizeof(intptr_t), buffer);
intptr_t memValue = (intptr_t*) &buffer[0];

使用ReadProcessMemory编辑的代码存在问题

1 个答案: