Segmentation fault in Apache after installing XDebug

[Todd Chaffee]

After installing php5-xdebug, I get segmentation faults in the apache error log. Using gdb, I was able to get the following backtrace.

Program received signal SIGSEGV, Segmentation fault.
0xb75f2785 in ?? () from /lib/tls/i686/cmov/libc.so.6
(gdb) backtrace
#0 0xb75f2785 in ?? () from /lib/tls/i686/cmov/libc.so.6
#1 0xb6fa1d6c in php_addcslashes () from /usr/lib/apache2/modules/libphp5.so
#2 0xb6575b0a in xdebug_var_export (struc=0xbfd12d20, str=0xbfd12d00, level=1, debug_zval=0, options=0xba0e5a98)
    at /build/buildd/xdebug-2.0.5/build-php5/xdebug_var.c:283
#3 0xb6575fc6 in xdebug_get_zval_value (val=0xb9924ffc, debug_zval=0, options=0xba0e5a98) at /build/buildd/xdebug-2.0.5/build-php5/xdebug_var.c:365
#4 0xb655c985 in add_stack_frame (zdata=0xb96dff44, op_array=0xb999bbcc, type=2) at /build/buildd/xdebug-2.0.5/build-php5/xdebug.c:1081
#5 0xb655de3f in xdebug_execute (op_array=0xb999bbcc) at /build/buildd/xdebug-2.0.5/build-php5/xdebug.c:1512
#6 0xb708d8c0 in ?? () from /usr/lib/apache2/modules/libphp5.so
#7 0xb707894e in execute () from /usr/lib/apache2/modules/libphp5.so
#8 0xb655e015 in xdebug_execute (op_array=0xb9c9f3e4) at /build/buildd/xdebug-2.0.5/build-php5/xdebug.c:1562
#9 0xb70a1a86 in ?? () from /usr/lib/apache2/modules/libphp5.so
#10 0xb707894e in execute () from /usr/lib/apache2/modules/libphp5.so
#11 0xb655e015 in xdebug_execute (op_array=0xb9c9ec50) at /build/buildd/xdebug-2.0.5/build-php5/xdebug.c:1562
#12 0xb70a1a86 in ?? () from /usr/lib/apache2/modules/libphp5.so
#13 0xb707894e in execute () from /usr/lib/apache2/modules/libphp5.so
#14 0xb655e015 in xdebug_execute (op_array=0xb9c9ff1c) at /build/buildd/xdebug-2.0.5/build-php5/xdebug.c:1562
#15 0xb70a1a86 in ?? () from /usr/lib/apache2/modules/libphp5.so
#16 0xb707894e in execute () from /usr/lib/apache2/modules/libphp5.so
#17 0xb655e015 in xdebug_execute (op_array=0xb9cf44e8) at /build/buildd/xdebug-2.0.5/build-php5/xdebug.c:1562
#18 0xb704e836 in zend_execute_scripts () from /usr/lib/apache2/modules/libphp5.so
#19 0xb6ff2be4 in php_execute_script () from /usr/lib/apache2/modules/libphp5.so
#20 0xb70e0f8b in ?? () from /usr/lib/apache2/modules/libphp5.so
#21 0xb77d4291 in ap_run_handler (r=0xb95af8d0) at /build/buildd/apache2-2.2.14/server/config.c:159
#22 0xb77d8077 in ap_invoke_handler (r=0xb95af8d0) at /build/buildd/apache2-2.2.14/server/config.c:373
#23 0xb77e79a8 in ap_process_request (r=0xb95af8d0) at /build/buildd/apache2-2.2.14/modules/http/http_request.c:282
#24 0xb77e44d8 in ap_process_http_connection (c=0xb9588ae0) at /build/buildd/apache2-2.2.14/modules/http/http_core.c:190
#25 0xb77dcb01 in ap_run_process_connection (c=0xb9588ae0) at /build/buildd/apache2-2.2.14/server/connection.c:43
#26 0xb77ed63a in child_main (child_num_arg=<value optimised out>) at /build/buildd/apache2-2.2.14/server/mpm/prefork/prefork.c:662
#27 0xb77ed9be in make_child (s=<value optimised out>, slot=0) at /build/buildd/apache2-2.2.14/server/mpm/prefork/prefork.c:758
#28 0xb77ee96b in perform_idle_server_maintenance (_pconf=0xb91c10a8, plog=0xb91f3170, s=0xb91c58e8)
    at /build/buildd/apache2-2.2.14/server/mpm/prefork/prefork.c:893
#29 ap_mpm_run (_pconf=0xb91c10a8, plog=0xb91f3170, s=0xb91c58e8) at /build/buildd/apache2-2.2.14/server/mpm/prefork/prefork.c:1097
#30 0xb77bea92 in main (argc=3, argv=0xbfd15e84) at /build/buildd/apache2-2.2.14/server/main.c:742

[Todd Chaffee (tc-toddbiz)]

This is on Ubuntu 10.04.4.

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

To change the source package that this bug is filed about visit https://bugs.launchpad.net/ubuntu/+bug/949923/+editstatus and add the package name in the text box next to the word Package.

[This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.]

[Fabio Marconi (fabiomarconi)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. This bug did not have a package associated with it, which is important for ensuring that it gets looked at by the proper developers. You can learn more about finding the right package at https://wiki.ubuntu.com/Bugs/FindRightPackage . I have classified this bug as a bug in xdebug.

When reporting bugs in the future please use apport by using 'ubuntu-bug' and the name of the package affected. You can learn more about this functionality at https://help.ubuntu.com/community/ReportingBugs.

[Martin Meredith (mez)]

Can you please provide the output of

apt-cache policy php5-xdebug

[Launchpad Janitor (janitor)]

[Expired for xdebug (Ubuntu) because there has been no activity for 60 days.]