Re: Disabling the GC during shutdown

Hi! > Honestly, I am not sure. Every report that I've seen has it happening at > shutdown. Could very well be a coincidence. Well, if we don't know why or if it's shutdown only, disabling on shutdown wouldn't do much good. > I have a patch which prevents the > segfault: > https://github.com/ircmaxell/php-src/compare/invalidate_object_on_dtor > > However, that's not really fixing the situation either, as the zval is > still getting nuked (but only partially). If there's a memory overwrite or use-after-free is going on, this patch is not a complete solution - it relies on the fact that "bad" data will be always out of range of "good" data. I see no way to ensure that - so if there's an overwrite that writes garbage inside the object there will be situations where the garbage looks exactly like a valid object ID and it will still crash, but it would be significantly harder to reproduce. So I think before patching it we need to get to the root cause and figure out why it happens and what causes it, instead of partially fixing the symptoms. > And no, I'm withdrawing the original concept of disabling the GC during > shutdown. The current patch I have works, but it's still just a bandaid > on a gunshot wound, and I'm going to try to figure out what's actually > overwriting the zval.. That'd be great, if you have any script that reproduces - always or at least frequently - the problem, please post it. -- Stanislav Malyshev, Software Architect SugarCRM: http://www.sugarcrm.com/ (408)454-6900 ext. 227