RE: [PHP-DEV] Disabling the GC during shutdown
| From: | Andi Gutmans | Date: | Sat, 22 Jun 2013 02:41:22 +0000 |
| Subject: | RE: [PHP-DEV] Disabling the GC during shutdown | ||
| References: | 1 2 3 4 5 6 | Groups: | php.internals |
| Request: | Send a blank email to internals+get-67774@lists.php.net to get a copy of this message | ||
>-----Original Message-----
>From: Stas Malyshev [mailto:smalyshev@sugarcrm.com]
>Sent: Thursday, June 20, 2013 8:20 PM
>To: Anthony Ferrara
>Cc: Laruence; internals@lists.php.net
>Subject: Re: [PHP-DEV] Disabling the GC during shutdown
>
>> 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
symptom
I agree with that. I think it'd be a mistake to submit any patch without
us understanding root cause.
We may cover up a bug which will resurface elsewhere...
Hopefully you can find a way to pin it down.
Thanks for putting this much effort into it!
Andi