Re: instability

[Paulo Panhoto <paulo.panhoto@xxxxxxxxx>]

There are several threads running but each session is only accessed by one
thread.

Sure, it does help. thanks.

On Mon, May 23, 2011 at 6:22 PM, Aris Adamantiadis <aris@xxxxxxxxxxxx>wrote:

> Hi Paulo,
>
> Are you using libssh in several threads ? Libssh is threadsafe under two
> conditions : call ssh_init() outside of threads and initialize threading in
> the crypto library (http://www.openssl.org/support/faq.html#PROG1).
> With libssh 0.5, it's a little different, you have to initialize libssh
> threads and call ssh_init(). (libssh does the dirty work of initilalizing
> libcrypto or libgcrypt).
>
> Hope this helps,
>
> Aris
>
> Le 23/05/11 21:41, Paulo Panhoto a écrit :
>
>  Hello,
>>
>> I'm writing a Qt app with libssh. The best approach I've got was this:
>> wrap ssh in a QThread that emits signals to other components.
>>
>>
>>         session = ssh_new();
>>
>>         if (session == NULL)
>>         {
>>             throw SSHException(tr("ssh_new failed"));
>>         }
>>         const std::string & stdHost = host.toStdString();
>>         ssh_options_set(session, SSH_OPTIONS_HOST, stdHost.c_str());
>>         ssh_options_set(session, SSH_OPTIONS_PORT, &port);
>>         ssh_options_set(session, SSH_OPTIONS_SSH1, &disabled);
>>         ssh_options_set(session, SSH_OPTIONS_SSH2, &enabled);
>>
>>         emit stateChanged(CONNECTING);
>>         emit debugInfo(tr("Conecting to %0:%1").arg(host).arg(port));
>>         if (ssh_connect(session) != SSH_OK)
>>         {
>>             throw SSHException(QString("ssh_connect:
>> %1").arg(ssh_get_error(session)));
>>         }
>>
>> This piece of code is causing me trouble: I'm running it on a opensuse
>> 11.3 and tested it with libssh 0.4.2 (the "branding" release) and 0.4.8.
>>
>> When I compile it against OpenSSL, I get aborts due to double free
>> inside libcrypto: works most of the time when I run it natively.
>> Nevertheless, when the program is run via xming server, the error rate
>> is almost 100%
>> libopenssl 1.0.0-6.7.1 - x86_64
>>
>> #0  0x00007ffff5aca9e5 in raise () from /lib64/libc.so.6
>> #1  0x00007ffff5acbee6 in abort () from /lib64/libc.so.6
>> #2  0x00007ffff5b05c53 in __libc_message () from /lib64/libc.so.6
>> #3  0x00007ffff5b0b226 in malloc_printerr () from /lib64/libc.so.6
>> #4  0x00007ffff5b0e8e3 in _int_realloc () from /lib64/libc.so.6
>> #5  0x00007ffff5b10142 in realloc () from /lib64/libc.so.6
>> #6  0x00007ffff4ca6d4f in CRYPTO_realloc () from /lib64/libcrypto.so.1.0.0
>> #7  0x00007ffff4d0d2a8 in lh_insert () from /lib64/libcrypto.so.1.0.0
>> #8  0x00007ffff4ca980c in OBJ_NAME_add () from /lib64/libcrypto.so.1.0.0
>> #9  0x00007ffff4d1a66b in OpenSSL_add_all_digests () from
>> /lib64/libcrypto.so.1.0.0
>> #10 0x00007ffff7bac3cc in ssh_crypto_init () at
>> /home/paulo/Downloads/oss-src/libssh-0.4.8/libssh/dh.c:144
>> #11 0x00007ffff7bae8f1 in ssh_init () at
>> /home/paulo/Downloads/oss-src/libssh-0.4.8/libssh/init.c:47
>> #12 0x00007ffff7ba929c in ssh_connect (session=0xc3b8e0)
>>
>> If I compile it against libgcrypt, it fails all the time due to an
>> assertion failure --  ath.c:193: _gcry_ath_mutex_lock: Assertion `*lock
>> == ((ath_mutex_t) 0)' failed.
>> libgcrypt  1.4.4-6.1 - x86-64
>>
>> #0  0x00007ffff5ac79e5 in raise () from /lib64/libc.so.6
>> #1  0x00007ffff5ac8ee6 in abort () from /lib64/libc.so.6
>> #2  0x00007ffff4fdcaa8 in ?? () from /lib64/libgcrypt.so.11
>> #3  0x00007ffff4fdd1c7 in ?? () from /lib64/libgcrypt.so.11
>> #4  0x00007ffff4fd75f6 in ?? () from /lib64/libgcrypt.so.11
>> #5  0x00007ffff4fd7792 in ?? () from /lib64/libgcrypt.so.11
>> #6  0x00007ffff7ba8f7b in ssh_crypto_init ()
>>     at /home/paulo/Downloads/oss-src/libssh-0.4.8/libssh/dh.c:115
>> #7  0x00007ffff7bab961 in ssh_init ()
>>     at /home/paulo/Downloads/oss-src/libssh-0.4.8/libssh/init.c:47
>> #8  0x00007ffff7ba5ebc in ssh_connect (session=0xccf260)
>>     at /home/paulo/Downloads/oss-src/libssh-0.4.8/libssh/client.c:516
>>
>> Am I missing any steps?? Is openSSL the best library to compile with??
>>
>> Any idea is appreciated.
>>
>> Regards,
>>
>> Paulo.
>>
>>
>