[asterisk-dev] [Code Review] Make ast_unload_resource actually remove the module from the module list when it is unloaded

[Tilghman Lesher]

-----------------------------------------------------------
This is an automatically generated e-mail. To reply, visit:
https://reviewboard.asterisk.org/r/1752/#review5592
-----------------------------------------------------------

Ship it!


I like this solution much better.  There are some other modules for which this same treatment might be given, such as cdr_odbc, cdr_adaptive_odbc, and res_config_odbc's dependencies on res_odbc.

- Tilghman


On Feb. 22, 2012, 12:12 p.m., Terry Wilson wrote:
> 
> -----------------------------------------------------------
> This is an automatically generated e-mail. To reply, visit:
> https://reviewboard.asterisk.org/r/1752/
> -----------------------------------------------------------
> 
> (Updated Feb. 22, 2012, 12:12 p.m.)
> 
> 
> Review request for Asterisk Developers.
> 
> 
> Summary
> -------
> 
> res_calendar calls ast_unload_resource for the related tech modules when it is unloaded. If this happens through a 'core stop gracefully', then it will be unloading the tech modules that are already in the list that is being traversed (supposedly safely) for unloading, eventually causing a double free. The problem seems to be that ast_unload_resource, while it calls the unload() callback function for the module, does not actually unlink the module from the list of modules. So the AST_LIST_TRAVERSE_SAFE_BEGIN {} still iterates over the unloaded module.
> 
> This patch causes ast_unload_resource to call AST_LIST_REMOVE on successfully unloaded modules.
> 
> 
> Diffs
> -----
> 
>   /trunk/include/asterisk/calendar.h 356213 
>   /trunk/main/loader.c 356213 
>   /trunk/res/res_calendar.c 356213 
> 
> Diff: https://reviewboard.asterisk.org/r/1752/diff
> 
> 
> Testing
> -------
> 
> Scenario: Start Asterisk with res_calendar and assorted calendar tech modules loaded. Run 'core stop gracefully'.
> Before patch: Crash.
> After patch: No crash.
> 
> 
> Thanks,
> 
> Terry
> 
>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.digium.com/pipermail/asterisk-dev/attachments/20120222/8ef10bd4/attachment.htm>