asterisk users - Jun 2017 - CentOS7: How to debug SEGV when asterisk starts with autoload=yes ?

Hello,

I was tasked to install Asterisk 13.16.0. from source on a CentOS7 platform.

For that purpose, I used an unmaintened script of mine, written 10 monthes
ago, and I was surprised to get segmentation violations whenever I ran
"asterisk -cvvvvvvv -U asterisk".

Usually, my /etc/asterisk/modules.conf file includes "autoload=yes"
setting.

Basically, I see two alternative methods:

1. leave "autoload=yes and remove modules one by one in modules.conf.
When segmentation violations stops, then focus on latest disabled module.

2.set  "autoload=no and add modules one by one in modules.conf.
When segmentation violations starts, then focus on latest enabled module.


I've not decided yet which method I should use but I must add here that
I'm
very suprised to observe things like bellow:

*CLI> module show
Module                         Description                              Use
Count  Status      Support Level
res_pjsip.so                   Basic SIP resource
0          Not Running          core
1 modules loaded
*CLI> module unload res_pjsip.so
Unable to unload resource res_pjsip.so
Command 'module unload res_pjsip.so' failed.
*CLI> module
load    reload  show    unload
*CLI> module show
Module                         Description                              Use
Count  Status      Support Level
res_pjsip.so                   Basic SIP resource
0          Not Running          core
1 modules loaded
*CLI> module unload res_pjsip.so
Unable to unload resource res_pjsip.so
Command 'module unload res_pjsip.so ' failed.
*CLI> module reload res_pjsip.so
The module 'res_pjsip.so' was not properly initialized. Before reloading
the module, you must run "module load res_pjsip.so" and fix whatever
is
preventing the module from being initialized.
*CLI> module load res_pjsip.so
Unable to load module res_pjsip.so
Command 'module load res_pjsip.so' failed.
*CLI> module show
Module                         Description                              Use
Count  Status      Support Level
res_pjsip.so                   Basic SIP resource
0          Not Running          core
1 modules loaded


Form full file:
...
2017-06-12 10:15:05] WARNING[1649] loader.c: Unload failed,
'res_pjsip.so'
is not loaded.


My questions are:
1. When autoload=yes, if module foo.so depens on bar.so, does loading of
foo.so also loads bar.so ?

2. How shall I understand the above load/unload/reload sequence ?

3. I'm inclined to load modules one by one and set autoload=no, but I would
like to be 100% sure to avoid runtime errors due to missing module/config
file/dependency/whatever. What would you suggest ?

Regards
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On Mon, Jun 12, 2017 at 10:36:21AM +0200, Olivier wrote:
> Hello,
> 
> I was tasked to install Asterisk 13.16.0. from source on a CentOS7
platform.
> 
> For that purpose, I used an unmaintened script of mine, written 10 monthes
> ago, and I was surprised to get segmentation violations whenever I ran
> "asterisk -cvvvvvvv -U asterisk".
> 
> Usually, my /etc/asterisk/modules.conf file includes
"autoload=yes" setting.
> 
> Basically, I see two alternative methods:
> 
> 1. leave "autoload=yes and remove modules one by one in modules.conf.
> When segmentation violations stops, then focus on latest disabled module.
Never a good idea. Disable half for starters. Then disable/enable half
of the remaining, etc.
> 
> 2.set  "autoload=no and add modules one by one in modules.conf.
> When segmentation violations starts, then focus on latest enabled module.
3. strace -eopen asterisk -U asterisk -c

IIRC the message that Asterisk prints for loading a module is only
printed after the module is loaded, and hence you need strace.

-- 
               Tzafrir Cohen
+972-50-7952406           mailto:tzafrir.cohen at xorcom.com
http://www.xorcom.com

Hi,

I think I was (once more) tricked by SELinux's enforce mode.
Changing it to permissive improved things.

Anyway, as I would like to learn more about strace, SELinux and Asterisk
module loading, I'll leave this thread "open"
and append my findings, in couple of days, when I'll be back from a
business trip.



2017-06-12 15:29 GMT+02:00 Tzafrir Cohen <tzafrir.cohen at xorcom.com>:
> On Mon, Jun 12, 2017 at 10:36:21AM +0200, Olivier wrote:
> > Hello,
> >
> > I was tasked to install Asterisk 13.16.0. from source on a CentOS7
> platform.
> >
> > For that purpose, I used an unmaintened script of mine, written 10
> monthes
> > ago, and I was surprised to get segmentation violations whenever I ran
> > "asterisk -cvvvvvvv -U asterisk".
> >
> > Usually, my /etc/asterisk/modules.conf file includes
"autoload=yes"
> setting.
> >
> > Basically, I see two alternative methods:
> >
> > 1. leave "autoload=yes and remove modules one by one in
modules.conf.
> > When segmentation violations stops, then focus on latest disabled
module.
>
> Never a good idea. Disable half for starters. Then disable/enable half
> of the remaining, etc.
>
> >
> > 2.set  "autoload=no and add modules one by one in modules.conf.
> > When segmentation violations starts, then focus on latest enabled
module.
>
> 3. strace -eopen asterisk -U asterisk -c
>
> IIRC the message that Asterisk prints for loading a module is only
> printed after the module is loaded, and hence you need strace.
>
> --
>                Tzafrir Cohen
> +972-50-7952406           mailto:tzafrir.cohen at xorcom.com
> http://www.xorcom.com
>
> --
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