# assistance with segfaults in debug_backtrace()

- Thread: https://externals.io/message/15287
- Original archive: https://news-web.php.net/php.internals/15287
- Started by Greg Beaver on 2005-03-06T15:38:30+00:00
- Messages: 2
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## #15287 — Greg Beaver — 2005-03-06T15:38:30+00:00

URL: https://externals.io/message/15287#15287

Hi,

We're getting quite a few reports of PEAR segfaulting on a 
 `debug_backtrace()` call found in the constructor of PEAR_Error.  Jan 
Schneider reported that it seemed to occur when one of the methods in 
the trace happened in a file that the uid did not have write access to 
(i.e. a PEAR file installed by root), but Davey Shafik posted a report 
that it happened to him while running "pear upgrade PEAR" as root.  He 
also posted a backtrace that might be useful at:

http://pear.php.net/bugs/bug.php?id=3683

Any tips on how to proceed in isolating this?  I can't reproduce the 
problem on any of my systems (windows xp, gentoo).

Greg

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## #15288 — Derick Rethans — 2005-03-06T15:49:57+00:00

URL: https://externals.io/message/15287#15288 · In reply to: #15287

> We're getting quite a few reports of PEAR segfaulting on a
> `debug_backtrace()` call found in the constructor of PEAR_Error.  Jan
> Schneider reported that it seemed to occur when one of the methods in
> the trace happened in a file that the uid did not have write access to
> (i.e. a PEAR file installed by root), but Davey Shafik posted a report
> that it happened to him while running "pear upgrade PEAR" as root.  He
> also posted a backtrace that might be useful at:
>
> http://pear.php.net/bugs/bug.php?id=3683
>
> Any tips on how to proceed in isolating this?  I can't reproduce the
> problem on any of my systems (windows xp, gentoo).

Disable the memory manager in zend_alloc.h (it's a define "ZEND_ALLOC"
afaik). Then use valgrind to run PHP and see whether it shows errors...

regards,
Derick

-- 
Derick Rethans
http://derickrethans.nl | http://ez.no | http://xdebug.org