PHP 5 Segmentation Fault

Recently, I used portupgrade to upgrade the PHP5 on my FreeBSD box, and it seems working smoothly. But few days ago, I found that php sometimes got Signal 11 (Segmentation Fault) unexpectedly.

Even type php --version in command line, I also get the segmentation fault!!
It took me lots of time to trace/solve the problem. Re-install the ports didn’t work.

Finally, it occur to me…the problem might seat on the extensions.
After try-and-error testing by disable/enable extensions in the extension.ini file.
The faulty extension is
Simplexml related extensions are also impact, including: