每个进程是否都可以拒绝访问PROCESS_VM_READ？

不是所有进程都可以拒绝访问PROCESS_VM_READ，只有在具有必要权限的进程中才能执行此操作。以下是使用Windows API检查并获取进程权限的示例代码：

HANDLE hProcess = OpenProcess(PROCESS_QUERY_INFORMATION, FALSE, dwProcessId);
if(hProcess != NULL)
{
    BOOL bHasAccess = FALSE;
    HANDLE hToken = NULL;
    if(OpenProcessToken(hProcess, TOKEN_QUERY, &hToken))
    {
        DWORD dwSize = 0;
        if(GetTokenInformation(hToken, TokenPrivileges, NULL, 0, &dwSize))
        {
            PTOKEN_PRIVILEGES pPrivileges = (PTOKEN_PRIVILEGES)malloc(dwSize);
            if(pPrivileges != NULL)
            {
                if(GetTokenInformation(hToken, TokenPrivileges, pPrivileges, dwSize, &dwSize))
                {
                    for(DWORD i = 0; i < pPrivileges->PrivilegeCount; i++)
                    {
                        if(pPrivileges->Privileges[i].Attributes & SE_PRIVILEGE_ENABLED &&
                            pPrivileges->Privileges[i].Luid.LowPart == SE_DEBUG_NAME &&
                            pPrivileges->Privileges[i].Luid.HighPart == 0)
                        {
                            bHasAccess = TRUE;
                            break;
                        }
                    }
                }
                free(pPrivileges);
            }
        }
        CloseHandle(hToken);
    }
    CloseHandle(hProcess);
}

上述代码可以检查当前进程的“SE_DEBUG_NAME”权限。如果进程拥有此权限，则可以拒绝访问PROCESS_VM_READ。如果要重新分配此权限，请使用以下代码：

HANDLE hToken = NULL;
if(OpenProcessToken(GetCurrentProcess(), TOKEN_ADJUST_PRIVILEGES, &hToken))
{
    LUID luidDebugName = {0};
    if(LookupPrivilegeValue(NULL, SE_DEBUG_NAME, &luidDebugName))
    {
        TOKEN_PRIVILEGES tp = {0};
        tp.PrivilegeCount = 1;
        tp.Privileges[0].Luid = luidDebugName;
        tp