linux - SIGSEGV，段错误。仅在 linux 上，它适用于 windows

Question

我已经坚持了几个小时，出于某种原因，我只在 Linux 上收到段错误。它只发生在长度为 17 个或更多字符的数据包中。我正在使用 Enet 库发送数据包。任何人都可以帮助我，我不知道我在这里错过了什么......

这是gdb输出的截图 这是服务器端示例:

void GameServer::start()
{
if (!m_isRunning)
    m_isRunning = true;

ENetEvent  event;
//ENetPacket *packet;

while (m_isRunning)
{
    while (enet_host_service(server, &event, 1000) > 0)
    {
        switch (event.type)
        {
        case ENET_EVENT_TYPE_CONNECT:
            std::cout << "A new client connected from ";
            std::cout << event.peer->address.host << " ";
            std::cout << event.peer->address.port << std::endl;

            break;
        case ENET_EVENT_TYPE_DISCONNECT:
            printf("%s disconnected.\n", event.peer->data);
            delete (char*)event.peer->data;
            break;
        case ENET_EVENT_TYPE_RECEIVE:
        {
            std::cout << "A packet of length ";
            std::cout << event.packet->dataLength;
            std::cout << " containing ";
            std::cout << event.packet->data;
            std::cout << " was received from ";
            printf("%s", event.peer->data);
            std::cout << " on channel ";
            std::cout << event.channelID << std::endl;

            // Split the packet data, ex:   packettype:data:data
            std::vector<std::string> tokens;
            std::string data;
            std::istringstream split((const char *)event.packet->data);

            // Process the packet data
            while (std::getline(split, data, ':')) Line 89: Crash here
                tokens.push_back(data);

            if (tokens.size() > 1)
            {

                //pc = player connected so we will broadcast the name to all peers
                if (tokens[0] == "pc")
                {
                    if (tokens.size() == 2)
                    {
                        char* data = new char[tokens[1].length() + 1];
                        strcpy(data, tokens[1].c_str());
                        event.peer->data = (void*)data;
                        for (size_t i = 0; i < server->connectedPeers; i++)
                        {
                            enet_host_broadcast(server, 0, event.packet);
                        }
                    }
                }

                //ma = message all so we are going to broadcast the message to all peers
                else if (tokens[0] == "ma") 
                {
                    if (tokens.size() == 2)
                    {
                        enet_host_broadcast(server, 0, event.packet);
                    }
                }


                /* One could just use enet_host_service() instead. */
                enet_host_flush(server);
            }
            /* Clean up the packet now that we're done using it. */
            enet_packet_destroy(event.packet);
            break;
        }
        case ENET_EVENT_TYPE_NONE:
            break;
        default:
            break;
        }

    }
}

}

这是客户端如何创建数据包，然后将其发送到服务器的过程。

if (connected) {
        std::cout << "Input: ";
        std::string str = "";
        std::getline(std::cin, str);

        if (str.length() == 0) { continue; }

        packet = enet_packet_create(str.c_str(), str.length() + 1, ENET_PACKET_FLAG_RELIABLE);
        enet_peer_send(peer, 0, packet);

    }

如果代码示例不够，我可以提供更多。

Answer 1

malloc() 中的崩溃通常意味着有人在较早的某个时间写入了已分配缓冲区的末尾。缓冲区溢出破坏了存储在空闲内存中以将空闲 block 链接在一起的指针。直到 malloc() 尝试使用这些指针时才出现问题。然后砰!

贴出event.packet类型的声明。您确定 data[] 足以容纳您放入其中的数据吗？