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To: "Wez Furlong" <kingwez@gmail.com>,
	"Ilia Alshanetsky" <ilia@prohost.org>
Cc: "Nuno Lopes" <nlopess@php.net>,
	"PHPdev" <internals@lists.php.net>
References: <005101c6373a$a6ef0170$0100a8c0@pc07653><43FB9D99.5070302@prohost.org> <4e89b4260602222029s454a0075jbdeadd1ec4b8372b@mail.gmail.com>
Date: Fri, 24 Feb 2006 16:43:02 +0100
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Subject: Re: [PHP-DEV] recover from a segfault
From: mv-php@binarysec.com ("Michael Vergoz")

Hi,

The problem is that setrlimit() need privilege to expand the process stack.
I don't think it's a good idea to use this system call to fix the 
too-high-function-stack bug.
There is no really way to fix correctly this bug.
However I think we should re-examined the execution flow of PECL functions.
It is not normal PECL can eat all the stack.

-michael

----- Original Message ----- 
From: "Wez Furlong" <kingwez@gmail.com>
To: "Ilia Alshanetsky" <ilia@prohost.org>
Cc: "Nuno Lopes" <nlopess@php.net>; "PHPdev" <internals@lists.php.net>
Sent: Thursday, February 23, 2006 5:29 AM
Subject: Re: [PHP-DEV] recover from a segfault


If we do do this, please make it optional; it's bad form when a module
or a library unilaterally changes a process-wide option or setting and
impacts a system that has already been tuned; the sysadmin may already
have set up appropriate limits.

--Wez.

On 2/21/06, Ilia Alshanetsky <ilia@prohost.org> wrote:
> Nuno Lopes wrote:
> > PCRE can consume a lot of stack, because of backtracking (thus
> > segfaulting PHP). Yesterday I've discovered that when using the
> > setrlimit() function, most segfaults can be avoided
> > (http://mega.ist.utl.pt/~ncpl/php_pcre_stack_limits.txt)  :)
>
> This sounds like an interesting idea, I think we need to consider it
> doing for PHP in general rather then jut when PCRE is being used. The
> only thing is that rather then setting the stack to infinity, perhaps a
> small value can be used ;-)

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