可能是 boost ssl 握手功能有一些内存泄漏

Posted 2023-02-22

【中文标题】可能是 boost ssl 握手功能有一些内存泄漏

【英文标题】：may be boost ssl handshake function have some memory leak

【发布时间】：2013-08-09 01:46:52

【问题描述】：

我的代码中有内存泄漏问题。 当我调用 socket.handshake() 函数时， 然后退出主线程，我得到了内存泄漏。 但是，删除“socket.handshake”，然后 运行&退出主线程，内存泄漏问题消失。

1.示例代码：内存泄漏

#include <boost/asio.hpp>
#include <boost/asio/ssl.hpp>
#include <boost/thread.hpp>

using namespace boost;

void ThSslEchoClient()

    try
    
        asio::io_service ios;
        asio::ssl::context context(boost::asio::ssl::context::sslv23);

        context.set_options(
            asio::ssl::context::default_workarounds  
            | asio::ssl::context::no_sslv2  
            | asio::ssl::context::single_dh_use);

        asio::ssl::stream<boost::asio::ip::tcp::socket> socket(ios, context);
        boost::system::error_code ec;
        boost::asio::ip::tcp::endpoint host(boost::asio::ip::address::from_string("127.0.0.1"), 13);

        socket.lowest_layer().connect(host, ec);
        // REMOVE THE FOLLOWING LINE FOR COMPARISON
        socket.handshake(asio::ssl::stream_base::client, ec);

        if (ec)
            throw boost::system::system_error(ec);
    
    catch (std::exception& _e)
    
        std::cerr << _e.what() << std::endl;
    


void TestBoostAsioSslEchoClient()

    boost::thread_group tg;

    tg.create_thread(ThSslEchoClient);
    tg.join_all();

2。示例代码：没有内存泄漏。 （只需删除“socket.handshake”）

        // REMOVE THE FOLLOWING LINE FOR COMPARISON
        //socket.handshake(asio::ssl::stream_base::client, ec);

我不知道哪里错了。 请帮我。

【问题讨论】：

您是如何确定存在内存泄漏的？

【参考方案1】：

我在我的电脑上看不出有什么不同。

我在端口 13 上伪造了一个小服务器：

while true; do date | sudo netcat -l -p 13; done

我运行程序：

make && valgrind ./test

没有握手的输出：

sehe@desktop:/tmp$ valgrind ./test
==15878== Memcheck, a memory error detector
==15878== Copyright (C) 2002-2011, and GNU GPL'd, by Julian Seward et al.
==15878== Using Valgrind-3.7.0 and LibVEX; rerun with -h for copyright info
==15878== Command: ./test
==15878== 
==15878== 
==15878== HEAP SUMMARY:
==15878==     in use at exit: 64 bytes in 2 blocks
==15878==   total heap usage: 3,348 allocs, 3,346 frees, 207,156 bytes allocated
==15878== 
==15878== LEAK SUMMARY:
==15878==    definitely lost: 0 bytes in 0 blocks
==15878==    indirectly lost: 0 bytes in 0 blocks
==15878==      possibly lost: 0 bytes in 0 blocks
==15878==    still reachable: 64 bytes in 2 blocks
==15878==         suppressed: 0 bytes in 0 blocks
==15878== Rerun with --leak-check=full to see details of leaked memory
==15878== 
==15878== For counts of detected and suppressed errors, rerun with: -v
==15878== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 2 from 2)

通过握手，它会打印：

unkn protocol

泄漏报告握手：

140 ==16017== 24 bytes in 1 blocks are still reachable in loss record 1 of 6
141 ==16017==    at 0x4C2B3F8: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
142 ==16017==    by 0x60031FF: CRYPTO_malloc (in /lib/x86_64-linux-gnu/libcrypto.so.1.0.0)
154 ==16017== 32 bytes in 1 blocks are still reachable in loss record 2 of 6
155 ==16017==    at 0x4C2B3F8: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
156 ==16017==    by 0x60031FF: CRYPTO_malloc (in /lib/x86_64-linux-gnu/libcrypto.so.1.0.0)
168 ==16017== 32 bytes in 1 blocks are still reachable in loss record 3 of 6
169 ==16017==    at 0x4C2B3F8: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
170 ==16017==    by 0x60031FF: CRYPTO_malloc (in /lib/x86_64-linux-gnu/libcrypto.so.1.0.0)
182 ==16017== 128 bytes in 1 blocks are still reachable in loss record 4 of 6
183 ==16017==    at 0x4C2B3F8: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
184 ==16017==    by 0x60031FF: CRYPTO_malloc (in /lib/x86_64-linux-gnu/libcrypto.so.1.0.0)
196 ==16017== 176 bytes in 1 blocks are still reachable in loss record 5 of 6
197 ==16017==    at 0x4C2B3F8: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
198 ==16017==    by 0x60031FF: CRYPTO_malloc (in /lib/x86_64-linux-gnu/libcrypto.so.1.0.0)
210 ==16017== 600 bytes in 1 blocks are still reachable in loss record 6 of 6
211 ==16017==    at 0x4C2B3F8: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
212 ==16017==    by 0x60031FF: CRYPTO_malloc (in /lib/x86_64-linux-gnu/libcrypto.so.1.0.0)
228 ==16017==    still reachable: 992 bytes in 6 blocks
229 ==16017==         suppressed: 0 bytes in 0 blocks
230 ==16017== 

如您所见，“泄漏”位于加密库（openssl 的一部分）内部，可能是错误警报。

【讨论】：

谢谢，但我的工作环境是 windows。并在 Visual Studio 2012 下运行示例代码，然后提醒一些内存泄漏。好吧，忽略它？

请像这样测试 =============================== boost::thread_group tg; tg.create_thread(ThSslEchoClient); tg.join_all(); ================================

@user2666399 是什么让你认为我改变了测试？！另外，我建议您找到一个类似的工具来报告您的平台泄漏了哪些内存。我的预期是 99% 它将具有相同的源（可能是一些加密 RNG 状态，它获得线程本地初始化并且没有被释放）

我认为 libcrypto 内置了内存泄漏报告。尝试CRYPTO_memcheck_ctrl(CRYPTO_MEM_CHECK_ON);，然后（退出时）CRYPTO_mem_leaks(stderr);

@user2666399 也许我正在使用thread_group。 是什么让你认为我改变了测试？！。当然平台不一样。我正在努力提供帮助。