[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Crash noticed multiple times using libssh 0.3.4


Thanks Aris for investigating the issue and providing the fix. I'll test using this patch and let you know.

Thanks,
Uday.

Aris Adamantiadis wrote:
I was too quick, I found the issue. I'll commit it in the 0.3 branch ASAP.

Aris

Aris Adamantiadis a écrit :
Hello Uday,

I think I found the source of the problem. Somewhere in the
enter_function() or leave_function(), a counter is underflowed (the
current indentation level). Could you test the attached patch ? It
doesn't resolve the indentation problem but stop it from crashing the
process. Seeing your log, it seem the problem is in ssh_connect_host.

Thanks for your feedback, if the patch is helping, we'll commit it.

Regards,

Aris

Uday Tennety a écrit :
Hello Aris,
I made changes to our code and added mutex for the read and write blocks
for a particular session. During my testing, I still see the libssh
crashing at times. Also, I found that it always crashes at the following
location:
A call to the function ssh_log() is made from function ssh_connect in
client.c  Could it be that the session is getting corrupted at some
point? Can you give me some pointers looking at this Log.

Thanks for your help.
Uday.

t@133 (l@133) terminated by signal ABRT (Abort)
0xff2c16e8: __lwp_kill+0x0008:  bcc,a,pt  %icc,__lwp_kill+0x18  !
0xff2c16f8
Current function is ssh_log
  67         memset(indent, ' ', min);
--------------------------------------------------

current thread: t@133
 [1] __lwp_kill(0x0, 0x6, 0x0, 0x6, 0xfc00, 0x0), at 0xff2c16e8
 [2] raise(0x6, 0x0, 0xff2a4d28, 0xffffffff, 0xff2e8298, 0x6), at
0xff25ff38
 [3] abort(0x2d740, 0x1, 0xfeb00ab0, 0xa8244, 0xff2eb298, 0x0), at
0xff240158
 [4] os::abort(0x1, 0xfedca58c, 0x1, 0xfedb2000, 0x1858c, 0x18400), at
0xfeaf67b4
 [5] VMError::report_and_die(0xfeded4a8, 0x0, 0x1, 0xfed6095b,
0xfed67006, 0xfedf2ce8), at 0xfec088d8
 [6] JVM_handle_solaris_signal(0xb, 0xdec7d670, 0xdec7d3b8, 0xafc00,
0x0, 0x0), at 0xfe5b91e8
 [7] __sighndlr(0xb, 0xdec7d670, 0xdec7d3b8, 0xfe5b8724, 0x0, 0x1), at
0xff2c0620
 ---- called from signal handler with signal 11 (SIGSEGV) ------
 [8] _memset(0xdec7d758, 0x20202020, 0xffffffd7, 0x17, 0xffffd740,
0xdec80000), at 0xff351040
=>[9] ssh_log(session = 0x20202020, verbosity = 538976288, format =
0x20202020 "<bad address 0x20202020>", ...), line 67 in "log.c"
 [10] ssh_connect(session = 0x20202020), line 510 in "client.c"





Uday Tennety wrote:
Hello Aris,
Thanks for your inputs. I'll make the changes to my code adding mutex
and let you know if I see any issues.

Thanks,
Uday.

Aris Adamantiadis wrote:
ouch that reply-to catches me every time...
------------------------------------------------------------------------

Subject:
Re: [Fwd: Re: Crash noticed multiple times using libssh 0.3.4]
From:
Aris Adamantiadis <aris@xxxxxxxxxxxx>
Date:
Tue, 19 Jan 2010 09:56:01 +0100
To:
uday.tennety@xxxxxxxxxxxxxx

To:
uday.tennety@xxxxxxxxxxxxxx


Uday Tennety a écrit :
Hello Aris,
I tried initialization using ssh_init() before calling any of the ssh
functions but I still notice the crash. I've attached the relevant log
statements. We're actually using one thread to read from the channel
and
another thread to write. Do you think this might be the reason for the
crash? If so, what kind of workarounds do you recommend?

Hi Uday,

I still have to analyze the log you provided, but by what you describe,
the problem is that you're using two libssh function at same time on
functions that are not threadsafe on the same channel.

I would recommend the use of a mutex in your own code, in order to
access only one libssh function at a time (at least on a single session,
there is normally no problem on different sessions).

Do not hesitate to ask if you need any help.

Regards,

Aris



References:
[Fwd: Re: [Fwd: Re: Crash noticed multiple times using libssh 0.3.4]]Aris Adamantiadis <aris@xxxxxxxxxxxx>
Re: [Fwd: Re: [Fwd: Re: Crash noticed multiple times using libssh 0.3.4]]Uday Tennety <uday.tennety@xxxxxxxxxxxxxx>
Re: Crash noticed multiple times using libssh 0.3.4Uday Tennety <uday.tennety@xxxxxxxxxxxxxx>
Re: Crash noticed multiple times using libssh 0.3.4Aris Adamantiadis <aris@xxxxxxxxxxxx>
Re: Crash noticed multiple times using libssh 0.3.4Aris Adamantiadis <aris@xxxxxxxxxxxx>
Archive administrator: postmaster@lists.cynapses.org