Audio Still Not Right On Werewolf

[Chuck Ebbert]

On 10/24/2007 02:19 PM, Janina Sajka wrote:
> 2.)	Logging in that same user on a console instead does not get
> audio

pulseaudio takes over all audio output but doesn't get started
for console logins. Removing pulseaudio and alsa-plugins-pulseaudio
fixes this.

A much more amusing one (after removing pulseaudio):

1. Login as root and run speaker-test

2. Press ctrl-c to terminate the test early.

3. Run ipcs and look at the SysV shared memory
   and semaphores that still exist, especially:
------ Semaphore Arrays --------
key        semid      owner      perms      nsems
0x0056a4d5 0          root      600        1

4. Log out, then login as a normal user; try to run speaker-test:
ALSA lib pcm_dmix.c:833:(snd_pcm_dmix_open) unable to create IPC semaphore

strace shows it is trying to create/access semaphore key 0x56a4d5


That semaphore set exists until manually removed with ipcrm or the
system is rebooted, preventing anyone but root from using audio
on the console. (Fortunately X startup knows how to deal with this.)