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Date: Tue, 21 Feb 2006 23:00:47 -0000
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Subject: recover from a segfault
From: nlopess@php.net ("Nuno Lopes")

Hi,

In the last days I've exchanged some e-mails with PCRE's author because of 
one more bug that appeared in our database about segfaults in PCRE (related 
to stack overflows).
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)  :)

But I was thinking why we can't fail more silently from segfaults. A 
recursive PHP function can easily segfault PHP. Why can't we catch the 
signal and recover from the error? (and print a "stack overflow" message, 
like java does).

I've done a little program for fun to show myself how to catch the SIGSEGV 
signals and print a nice message. 
(http://mega.ist.utl.pt/~ncpl/break-stack.html)

So, catching the signal is easy. What about recovery? Doesn't anyone has 
experience in this area? Can this be done? (and in most 
SAPIs/architectures?)


Nuno

P.S.: sorry if my "bright" idea is dumb and/or undoable :)