PhpMyAdmin + PHP-FPM = SEGFAULT?

Question

PHP

A very strange situation in my opinion, it happens on a server running Debian 6. nginx/1.1.19, php5-fpm 5.4.2, MySQL 5.1.49, phpMyAdmin 3.5.1 are installed (but version 4 from GitHub was also tested) . There were attempts to use the php-mysql and php-mysqli extensions - there is no difference.

Any access to phpMyAdmin results in a 502 error. There are no errors in the PHP logs, in the nginx logs something like this:

2012/05/19 21:22:10 [error] 28509#0: *8917 recv() failed (104: Connection reset by peer) while reading response header from upstream, client: xxx.xxx.xxx.xxx, server: example.com, request: "GET /folder/phpmyadmin/ HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "example.com"

And when we look at it, /var/log/syslogwe see:

May 19 21:22:10 Debian-60-squeeze-64-minimal kernel: [477859.209978] php5-fpm[28475]: segfault at 7fff6c7abff8 ip 0000000000641d5e sp 00007fff6c7ac000 error 6 in php5-fpm[400000+6ff000]

What can phpMyAdmin do that causes the php-fpm process to crash with a segfault? More such a situation, fortunately, did not occur anywhere - only in phpMyAdmin'e.

Answer 1

You can build/install the debug version and, after crashing, use the gdb debugger to see where (in which function) the error occurred.

Answer 2

Why not install xdebug and meticulously go through all the steps to the crash site?