[pgpool-general: 9144] Re: Another segmentation fault

[Tatsuo Ishii]

> Hi,
> 
> Thanks for the very detailed analysis. These kinds of concurrency issues
> are very hard to get right. The tests we run are very good at triggering
> these kinds of race conditions, because many steps are executed after each
> other in very rapid succession. I've added the patch to our build.

Thanks for the testing. Yeah, your tests reveal long standing corner
case bugs.

> You are right that in 14136 several processes segfaulted. I'm not sure if
> the coredump was for pid 15 (you might be able to find the correct pid
> using the timestamp from the coredump), but I've noticed in the cases where
> several processes segfault in just a few seconds, the crashes are almost
> always the same. Therefore I didn't include the other coredumps, as they
> will give you the same backtrace and variables.

On my Linux (Ubuntu 20) there's a file which controls the core dump
file name.

cat /proc/sys/kernel/core_pattern
|/usr/share/apport/apport -p%p -s%s -c%c -d%d -P%P -u%u -g%g -- %E

Is it possible for you to include pid in core file name?

BTW, I have pushed fix_segfault2.patch and fix_main_node_id.patch.

Best reagards,
--
Tatsuo Ishii
SRA OSS LLC
English: http://www.sraoss.co.jp/index_en/
Japanese:http://www.sraoss.co.jp