[syslog-ng] Critical hang while opening tty

[Jean-Baptiste Quenot]

Hi there,

I'm using syslog-ng 2.0.9-4.1 on Ubuntu 9.04.  In the configuration
file, emergency messages are configured to be logged to all ttys.
Sometimes syslog-ng blocks the whole system while opening /dev/ttyS0:

# pgrep -f syslog-ng
# strace -f -p 3172
Process 3172 attached - interrupt to quit
open("/dev/ttyS0", O_WRONLY|O_NOCTTY|O_APPEND

I'm surprised because I saw the same bug report, and this was supposed
to be fixed in Ubuntu's 2.0.9-1 version as stated in the changelog at
See http://changelogs.ubuntu.com/changelogs/pool/universe/s/syslog-ng/syslog-ng_2.0.9-4.1/changelog

The changelog says:

syslog-ng (2.0.9-1) unstable; urgency=low

  * New upstream version. (Closes: #397650, #447105)

This corresponds to this bug:

syslog-ng hangs writing to /dev/ttyN
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=397650

I notice the bug is fixed in syslog-ng:
http://git.balabit.hu/?p=bazsi/syslog-ng-2.0.git;a=commit;h=c5cc92d54d2e33b9b55d01af0104d536e6d8b797

Is there maybe another call to tty open() that was not covered by alarm()?

The issue happens on several machines, but I don't know what triggers
this.  Reloading syslog-ng fixes the problem.

Thanks in advance,
-- 
Jean-Baptiste Quenot
http://jbq.caraldi.com/