Lighttpd php segfault at 0000000000000040 rip 0000003e30228278 rsp 0000007fbffff708 error 4

I have recently noticed this error. Although server continues to work w/o problem at some point your server will crash. It is better to fix this error. The main problem was chrooted lighttpd installation. Few libraries were not copied. You need to use ldd command to locate name of libraries. In my case it was curl library used my DOMXML php module. Use following procedure to trace required libraries:

# mkdir /webroot/bin # cp /bin/bash /webroot/bin # cp /usr/bin/strace /webroot/bin # l2chroot /usr/bin/strace # l2chroot /bin/bash # chroot /webroot # strace php /path/to/script.php 2> /tmp/debug.txt # exit # vi /webroot/tmp/debug.txt
Now find out which shared libraries not found. Next you need to copy all missing libraries to /lib or /usr/lib location. You need to repeat above procedure till all shared libraries not copied to chroot jail.

Following is recommended solution if you run Apache or lighttpd in chroot jail.
Copy all shared libs from /lib and /usr/lib to /chroot directory. But don't copy any executable from /bin/ /usr/bin or /usr/sbin directory.
# cp -avr /lib/ /chroot/lib/ # cp -avr /usr/lib/ /chroot/usr/lib/

Above solution is quite secure and I have successfully implemented it for high performance Apache shared load balancing business hosting. More than 800+ sites are hosted using 6 Apache web server and 2 node MySQL cluster.

Don't forget to remove /chroot/bin directory and all files after troubleshooting.