Re: Crash noticed multiple times using libssh 0.3.4

[Uday Tennety <uday.tennety@xxxxxxxxxxxxxx>]

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
> >
> >