Apache children occasionally killed with SIGSEGV

[Jukka Salmi <j+nbsd%2009.salmi.ch@localhost>]

Hello,

some weeks ago I noticed that child processes of an Apache 1.3 with SSL,
Perl and PHP modules loaded (everything built from pkgsrc-2008Q3)
running on a NetBSD/i386 5.0_BETA system were occasionally killed with
SIGSEGV:

$ zcat /var/log/httpd/error_log.1.gz
[...]
[Sun Feb  1 20:00:01 2009] [notice] Apache/1.3.41 (Unix) mod_ssl/2.8.31 
OpenSSL/0.9.9-dev PHP/5.2.6 mod_perl/1.29 configured -- resuming normal 
operations
[Sun Feb  1 20:00:01 2009] [notice] Accept mutex: flock (Default: flock)
[Mon Feb  2 07:59:44 2009] [notice] child pid 26424 exit signal Segmentation 
fault (11)
[...]

According to the logs this happened every few hours, probably when under
load caused by a PHP application.

After upgrading the system to NetBSD 5.0_RC2 and the packages to
pkgsrc-2008Q4 (note: Perl 5.8 -> 5.10), Apache immediately dumped core
on startup:

$ /usr/pkg/sbin/httpd -X
Memory fault (core dumped)
$ gdb /usr/pkg/sbin/httpd httpd.core
GNU gdb 6.5
[...]
Core was generated by `httpd'.
Program terminated with signal 11, Segmentation fault.
#0  0xbb44a6f4 in Perl_av_undef (my_perl=0xbb936000, av=0x0) at av.c:479
479     av.c: No such file or directory.
        in av.c
(gdb) bt
#0  0xbb44a6f4 in Perl_av_undef (my_perl=0xbb936000, av=0x0) at av.c:479
#1  0xbb5bc389 in perl_shutdown (s=0x0, p=0x0) at mod_perl.c:284
#2  0xbb5bc868 in mp_dso_unload (data=0xbb904010) at mod_perl.c:489
#3  0x080714f0 in ap_clear_pool (a=0xbb904010) at alloc.c:1937
#4  0x0807c173 in standalone_main (argc=<value optimized out>, argv=<value 
optimized out>)
    at http_main.c:5480
#5  0x0807dae1 in main (argc=2, argv=0xbfbfed58) at http_main.c:5883
(gdb) 

Because I wanted to upgrade Apache to 2.2 anyway I didn't debug this
further and built and installed www/apache22 and the needed modules;
Apache 2.2 starts up and seems to run fine, but I still see those
occasional segmentation faults:

$ tail /var/log/httpd/error_log
[...]
[Wed Feb 18 14:48:25 2009] [notice] Apache/2.2.11 (Unix) mod_ssl/2.2.11 
OpenSSL/0.9.9-dev DAV/2 mod_auth_kerb/5.3 PHP/5.2.8 mod_perl/2.0.4 Perl/v5.10.0 
configured -- resuming normal operations
[Wed Feb 18 16:40:06 2009] [notice] child pid 23811 exit signal Segmentation 
fault (11)

Is anybody seeing this as well?  Any hints?


TIA, Jukka

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