Date: Mon, 5 Feb 2007 23:12:31 -0600 From: Terry Todd <tlt@badger.tltodd.com> To: Garrett Cooper <youshi10@u.washington.edu> Subject: Re: phpMyAdmin httpd segmentation fault Message-ID: <20070205231230.A9862@badger.tltodd.com> Resent-Message-ID: <200702060513.XAA10731@tltodd.com> In-Reply-To: <45C7482D.2060103@u.washington.edu>; from youshi10@u.washington.edu on Mon, Feb 05, 2007 at 07:07:25AM -0800 References: <20070203204156.A4743@badger.tltodd.com> <45C5A93A.8010501@infracaninophile.co.uk> <20070205055425.A68136@badger.tltodd.com> <45C7482D.2060103@u.washington.edu>
next in thread | previous in thread | raw e-mail | index | archive | help
On Mon, Feb 05, 2007 at 07:07:25AM -0800, Garrett Cooper wrote:
> Terry Todd wrote:
> > On Sun, Feb 04, 2007 at 09:36:58AM +0000, Matthew Seaman wrote:
> >> Terry Todd wrote:
> >>> I installed FreeBSD 6.2-RELEASE, php-5.1.6_3, php5-extensions-1.0,
> >>> mysql-5.0.27 and apache_1.3.37_1.
> >>>
> >>> php -i now works Ok after I moved recode.so to the top of the list
> >>> of extensions in extensions.ini. It took a while to figure that
> >>> one out. Before that php -i would seg fault and core dump. It
> >>> took some google searching and using gdb on the core file to fix
> >>> it.
> >>>
> >>> A test web page for phpinfo works fine too. Mysql works OK from
> >>> the command line.
> >>>
> >>> However I can't get phpMyAdmin to work. It seg faults in reading
> >>> /usr/local/www/phpMyAdmin/libraries/url_generating.lib.php
> >>> There is no core dump produced.
> >> Hmmm... very strange. We have just built a RELENG_6_2 server with
> >> apache13-ssl, php5 and phpMyAdmin and no such problems are apparent.
> >>
> >> Did you modify the CFLAGS or otherwise change the level of
> >> optimization used by the compiler?
> >
> > No CFLAGS were changed or anything else. It's a very standard install.
> >
> >>> I ran ktrace httpd -X
> >>>
> >>> Then when I try to open the phpMyAdmin/index.php page in a browser
> >>> httpd seg faults.
> >>>
> >>> Here is the tail of kdump from the ktrace.out from the above ktrace.
> >>>
> >>> ....
> >>> 1372 httpd CALL gettimeofday(0xbfbf7158,0)
> >>> 1372 httpd RET gettimeofday 0
> >>> 1372 httpd CALL lstat(0xbfbf75b0,0xbfbf70f0)
> >>> 1372 httpd NAMI "/usr"
> >>> 1372 httpd RET lstat 0
> >>> 1372 httpd CALL lstat(0xbfbf75b0,0xbfbf70f0)
> >>> 1372 httpd NAMI "/usr/local"
> >>> 1372 httpd RET lstat 0
> >>> 1372 httpd CALL lstat(0xbfbf75b0,0xbfbf70f0)
> >>> 1372 httpd NAMI "/usr/local/www"
> >>> 1372 httpd RET lstat 0
> >>> 1372 httpd CALL lstat(0xbfbf75b0,0xbfbf70f0)
> >>> 1372 httpd NAMI "/usr/local/www/phpMyAdmin"
> >>> 1372 httpd RET lstat 0
> >>> 1372 httpd CALL lstat(0xbfbf75b0,0xbfbf70f0)
> >>> 1372 httpd NAMI "/usr/local/www/phpMyAdmin/libraries"
> >>> 1372 httpd RET lstat 0
> >>> 1372 httpd CALL lstat(0xbfbf75b0,0xbfbf70f0)
> >>> 1372 httpd NAMI "/usr/local/www/phpMyAdmin/libraries/url_generating.lib.php"
> >>> 1372 httpd RET lstat 0
> >>> 1372 httpd CALL open(0x845eda8,0,0x1b6)
> >>> 1372 httpd NAMI "/usr/local/www/phpMyAdmin/libraries/url_generating.lib.php"
> >>> 1372 httpd RET open 4
> >>> 1372 httpd CALL fstat(0x4,0x8102748)
> >>> 1372 httpd RET fstat 0
> >>> 1372 httpd CALL lseek(0x4,0,0,0,0x1)
> >>> 1372 httpd RET lseek 0
> >>> 1372 httpd CALL read(0x4,0x82e3028,0x2000)
> >>> 1372 httpd GIO fd 4 read 4096 bytes
> >>> "<?php
> >>> /* $Id: url_generating.lib.php,v 2.12.2.1 2006/09/26 19:23:24 lem9 Exp $ */
> >>> // vim: expandtab sw=4 ts=4 sts=4:
> >>>
> >>>
> >>> /**
> >>> * URL/hidden inputs generating.
> >>> */
> >>>
> >>>
> >>> /**
> >>> * Generates text with hidden inputs.
> >>> *
> >>> * @see PMA_generate_common_url()
> >>> * @param string optional database name
> >>> * @param string optional table name
> >>> * @param int indenting level
> >>> *
> >>> * @return string string with input fields
> >>> *
> >>> * @global string the current language
> >>> * @global string the current conversion charset
> >>> * @global string the current connection collation
> >>> * @global string the current server
> >>> * @global array the configuration array
> >>> * @global boolean whether recoding is allowed or not
> >>> *
> >>> *
> >>> * @access public
> >>> *
> >>> * @author nijel
> >>> */
> >>> function PMA_generate_common_hidden_inputs($db = '', $table = '', $indent = 0, $skip = array())
> >>> {
> >>> if (is_array($db)) {
> >>> $params =& $db;
> >>> $_indent = empty($table) ? $indent : $table;
> >>> $_skip = empty($indent) ? $skip : $indent;
> >>> $indent =& $_indent;
> >>> $skip =& $_skip;
> >>> } else {
> >>> $params = array();
> >>> if (isset($db) && strlen($db)) {
> >>> $params['db'] = $db;
> >>> }
> >>> if (isset($table) && strlen($table)) {
> >>> $params['table'] = $table;
> >>> }
> >>> }
> >>>
> >>> if (! empty($GLOBALS['server'])
> >>> && $GLOBALS['server'] != $GLOBALS['cfg']['ServerDefault']) {
> >>> $params['server'] = $GLOBALS['server'];
> >>> }
> >>> if (empty($_COOKIE['pma_lang'])
> >>> && ! empty($GLOBALS['lang'])) {
> >>> $params['lang'] = $GLOBALS['lang'];
> >>> }
> >>> if (empty($_COOKIE['pma_charset'])
> >>> && ! empty($GLOBALS['convcharset'])) {
> >>> $params['convcharset'] = $GLOBALS['convcharset'];
> >>> }
> >>> if (empty($_COOKIE['pma_collation_connection'])
> >>> && ! empty($GLOBALS['collation_connection'])) {
> >>> $params['collation_connection'] = $GLOBALS['collation_connection'];
> >>> }
> >>>
> >>> $params['token'] = $_SESSION[' PMA_token '];
> >>>
> >>> if (! is_array($skip)) {
> >>> if (isset($params[$skip])) {
> >>> unset($params[$skip]);
> >>> }
> >>> } else {
> >>> foreach ($skip as $skipping) {
> >>> if (isset($params[$skipping])) {
> >>> unset($params[$skipping]);
> >>> }
> >>> }
> >>> }
> >>>
> >>> $spaces = str_repeat(' ', $indent);
> >>>
> >>> $return = '';
> >>> foreach ($params as $key => $val) {
> >>> $return .= $spaces . '<input type="hidden" name="' . htmlspecialchars($key) . '" value="' . htmlspecialchars(\
> >>> $val) . '" />' . "\\n";
> >>> }
> >>>
> >>> return $return;
> >>> }
> >>>
> >>> /**
> >>> * Generates text with URL parameters.
> >>> *
> >>> * <code>
> >>> * // note the ?
> >>> * echo 'script.php?' . PMA_generate_common_url('mysql', 'rights');
> >>> * // produces with cookies enabled:
> >>> * // script.php?db=mysql&table=rights
> >>> * // with cookies disabled:
> >>> * // script.php?server=1&lang=en-utf-8&db=mysql&table=rights
> >>> *
> >>> * $params['myparam'] = 'myvalue';
> >>> * $params['db'] = 'mysql';
> >>> * $params['table'] = 'rights';
> >>> * // note the missing ?
> >>> * echo 'script.php' . PMA_generate_common_url($params);
> >>> * // produces with cookies enabled:
> >>> * // script.php?myparam=myvalue&db=mysql&table=rights
> >>> * // with cookies disabled:
> >>> * // script.php?server=1&lang=en-utf-8&myparam=myvalue&db=mysql&table=rights
> >>> *
> >>> * // note the missing ?
> >>> * echo 'script.php' . PMA_generate_common_url();
> >>> * // produces with cookies enabled:
> >>> * // script.php
> >>> * // with cookies disabled:
> >>> * // script.php?server=1&lang=en-utf-8
> >>> * </code>
> >>> *
> >>> * @param mixed assoc. array with url params or optional string with database name
> >>> * if first param is an array there is also an ? prefixed to the url
> >>> * @param string optional table name only if first param is array
> >>> * @param string character to use instead of '&' for deviding
> >>> * multiple URL parameters from each other
> >>> *
> >>> * @return string string with URL parameters
> >>> *
> >>> * @global string the current language
> >>> * @global string the current conversion charset
> >>> * @global string the current connection collation
> >>> * @global string the current server
> >>> * @global arra"
> >>> 1372 httpd RET read 6467/0x1943
> >>> 1372 httpd CALL read(0x4,0x82e3028,0x2000)
> >>> 1372 httpd GIO fd 4 read 0 bytes
> >>> ""
> >>> 1372 httpd RET read 0
> >>> 1372 httpd CALL read(0x4,0x82e3028,0x2000)
> >>> 1372 httpd GIO fd 4 read 0 bytes
> >>> ""
> >>> 1372 httpd RET read 0
> >>> 1372 httpd CALL close(0x4)
> >>> 1372 httpd RET close 0
> >>> 1372 httpd PSIG SIGSEGV SIG_DFL
> >>>
> >>>
> >>> I moved url_generating.lib.php to url_generating.lib.php.sav and
> >>> copied url_generating.lib.php.sav to a new url_generating.lib.php.
> >>> Same thing happens.
> >>>
> >>> I tried the latest phpMyAdmin-2.9.2 and it does the exact same thing.
> >>>
> >>> It always seg faults in the exact same place in the exact same way.
> >>>
> >>> /var/log/messages file gets:
> >>> Feb 3 16:07:38 testbox kernel: pid 8512 (httpd), uid 80: exited on signal 11
> >> Hmmm... a SEGV in apache or one of it's loaded modules should result
> >> in a core file in the cwd of the apache process. The general way to
> >> switch that behaviour off is by using the limits(1) command to set
> >> coredumpsize=0 -- and you can use /etc/login.conf to set limits for
> >> a whole class of users. If the apache startup scripts
> >> are running eg:
> >>
> >> eval `limits -e -C daemon`
> >>
> >> or similar that might be the cause. However, the default settings
> >> are 'coredumpsize=unlimited' for all, and I guess you'ld know if you'ld
> >> changed any of that sort of thing.
> >>
> >> Hmmm... cwd for the Apache process is set to the root directory, like
> >> all good daemons should. You can see that by:
> >>
> >> fstat -p `cat /var/run/httpd.pid`
> >>
> >> For very obvious security reasons, the root directory should not
> >> be writable by daemon processes with network listeners (and conversely,
> >> daemons should never be run as root or any other UID with write access,
> >> well, anywhere much). In this case, however, and strictly for testing
> >> purposes, so long as it's on a machine not accessible from the Internet,
> >> temporarily making the root dir writable by the apache process could help
> >> get you a core file to analyse.
> >
> > I changed / to mode 777 and reran the test. Same seg fault and still no core file.
> > When I say there is no core file I have checked with find / -name "*.core"
> > and there are no core files anywhere on the system.
> >
> >
> >>> /var/log/httpd-errors gets:
> >>> [Sat Feb 3 16:07:39 2007] [notice] child pid 8512 exit signal Segmentation fault (11)
> >>>
> >>> I am out of ideas on what to try next. Anyone else have any suggestions?
> >> Can you try unmounting and fsck'ing the partition (fsck -f /dev/adXsYz)
> >> where url_generating.lib.php lives?
> >
> > I thought by creating a new url_generating.lib.php file that would test the problem
> > of there being a bad spot on the disk. fsck runs clean.
> >
> >> Given that the error you are seeing is so repeatable, it is unlikely
> >> to be a hardware fault, but it may be worth running a cycle or two
> >> of memtest86 to see if it picks up anything.
> >>
> >> Otherwise the only thing I can think to try is the rather blunt approach
> >> of recompiling/reinstalling the phpMyAdmin port and everything it depends
> >> on:
> >>
> >> portupgrade -Rfi phpMyAdmin
> >
> >
> > I ran portupgrade -Rfv phpMyAdmin. It has a lot of dependencies
> > so it took a long time to finish and I didn't want to sit in front
> > of it and answer yes to all the questions.
> >
> >
> > It still does the exact same thing.
> >
> > I'm stumped. I guess I'll try a new install on a different system.
> >
> > Thanks,
> > Terry Todd
>
> It's a memory access issue most likely (signal 11), so making sure that
> all of its dependencies are current would be the first order of
> business. Don't forget to restart the http daemon that's using php so it
> can reload the libraries / dependencies.
>
> Next I'd check for memory errors on your machine; memtest86+ can solve that.
>
> Finally, (if possible) I'd see if you could trace down the exact line of
> code where it segfaulted (if it's a consistent location where it fails)
> in the phpMyAdmin program and then send it upstream to the maintainer
> via a bug report.
>
> -Garrett
I took the hard drive out of the computer that was having the
problem and installed in a completely different computer.
It still has the same exact problem in the same exact place.
The only reference to url_generating.lib.php is on line 2682 of
phpMyAdmin/libraries/common.lib.php
httpd is what actually segfaults when reading the file url_generating.lib.php.
Terry Todd
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20070205231230.A9862>