Hi Sakari, On Wednesday 24 September 2014 12:17:45 Sakari Ailus wrote: > Hi Laurent, > > Oops. this got buried in my inbox... > > Laurent Pinchart wrote: > > On Thursday 17 July 2014 14:53:49 Sakari Ailus wrote: > >> On Thu, Jul 17, 2014 at 01:43:09PM +0200, Laurent Pinchart wrote: > >>> On Tuesday 27 May 2014 16:27:49 Sakari Ailus wrote: > >>>> Calling media_entity_cleanup() on a cleaned-up entity would result into > >>>> double free of the entity->links pointer and likely memory corruption > >>>> as well. > >>> > >>> My first question is, why would anyone do that ? :-) > >> > >> Because it makes error handling easier. Many cleanup functions work this > >> way, but not media_entity_cleanup(). > > > > Do the cleanup functions support being called multiple times, or do they > > just support being called on memory that has been zeroed and not further > > initialized ? The media_entity_cleanup() function supports the latter. > > I'd hope they wouldn't be called multiple times, or on memory that's not > been zeroed, but in that case it's better to behave rather than corrupt > system memory. That could be an indication of other problems, too, so > one could consider adding WARN_ON() to this as well. What do you think? I agree that calling the cleanup function on uninitialized memory simplifies error paths, that's a good feature. Regarding double calls, I have no strong opinion. I don't think they should happen in the first place though. -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
