cannot get core dump of crashing freeradius

[Jakob Hirsch]

Hi,

we have freeradius 2.1.8 running on a couple of servers and are very
happy with it. But every few days FR crashes on one of the servers (a
random one, not always the same). The load is significant (average 150
requests/s per server, 400/s peak) but sureley not too high. So
everything seems to run fine besides the annoying crashes, which alarms
people and make the weekly availibility reports look bad (even though FR
is restarted automatically, of course). The previous 1.1.8 installation
we upgraded 6 months ago from did not have this problem.

Anyways, I really want to find out what's going wrong, so I wanted to
get core dumps of these crashes. Only that I just don't get them.
- radiusd.conf has allow_core_dumps = yes (and FR says "Info: Core dumps
are enabled." at startup)
- /proc/sys/kernel/core_pattern is set to '/tmp/core.%t.%e.%p', so core
dumps can be written to disk (tested with a little programm that forces
a segfault)
- I put "ulimit -c unlimited" in the startup script.
cat /proc/$(pidof freeradius)/limits shows "unlimited" for soft and hard
limit of "Max core file size"

So what's missing? The only indication of the crash is this line in syslog:

> Apr 10 17:57:19 xxxxxxxx kernel: [12268615.000288] freeradius[14846]: segfault at 73818 ip 00007f0cb40e875e sp 00007fff9c6304c0 error 4 in libfreeradius-radius-2.1.8.so[7f0cb40d1000+1f000]

(This is debian lenny x86_64, btw.)

Any hints?
I even thought about running FR as a foreground process or even with
gdb, but I wanted to check here first.


Regards and thanks in advance,
Jakob