/dev/snd/* permissions always like to change on their own

vtowel

I've had this problem with both systems I've installed Gentoo on.

I've installed KDE 3 and ALSA and these systems (different hardware, though) and generally it works fine. I am part of the 'audio' group and the permissions of /dev/snd are usually as follows:

Naan Yaar · Bodhisattva Joined: 27 Jun 2002 Posts: 1549

I *think* that when I enabled the option that lets the kernel initialize devfs devices upon booting (don't remember exact option), something like this happened to my permissions. I turned it off and there have been no issues since.

mksoft · l33t Joined: 28 May 2002 Posts: 844

vtowel

Yes, I did make a couple changes to devfsd.conf, but none related to my sound devices. I've included a copy from the system that exhibits this problem the most (my laptop).

mksoft · l33t Joined: 28 May 2002 Posts: 844

Do you have the same issues with vanilla devfsd.conf :?:

_________________
There's someone in my head but it's not me - Pink Floyd

vtowel · Posted: Thu Jul 25, 2002 3:50 pm Post subject: I don't know

I don't know if this happens with vanilla devfsd.conf. I guess I can try that then, but it could take up to a week for me to confirm that it works then (this behaviour is pretty erratic).
_________________
cool book

mksoft · l33t Joined: 28 May 2002 Posts: 844

vtowel · Posted: Fri Jul 26, 2002 2:52 am Post subject:

Well, I'd go ahead and try it but vanilla devfsd.conf doesn't include any dri device entries, and I need proper permissions on those if I want to run X with dri enabled (and I do want that).

Anything else I can try?
_________________
cool book

vtowel · Posted: Fri Jul 26, 2002 5:28 am Post subject:

This seems to happen in between restarting X. I often have to turn off DRI in X because DRI support for the Radeon on laptops isn't quite ready yet (but it's being improved quickly). So I was using sound just fine in X for a while. Then I logged out of KDE and switched so a virtual console to comment out DRI support in XF86Config. Then I saved it, restarted xdm (kdm), and logged back into KDE.

Upon logging in KDE informed me that arts couldn't grab a hold of the audio device due to permission being denied. It turned out that all my /dev/snd/* and /dev/sound/* devices had changed their ownership to paul.audio and permissions to 0600 (and for some reason I still couldn't access the device, even though I somehow owned it now).

I wonder if this has to do with DRI?

But the strange thing is, I have the exact same behaviour on my Gentoo desktop, which has an nVidia card and uses the proprietary nVidia drivers. It doesn't use DRI (there's nothing in devfsd.conf about DRI on that computer). On my laptop the only difference between my devfsd.conf and the vanilla devfsd.conf is the presence of dri entries to set their permissions appropriately.

I'm using KDE 3.0.1 on my desktop and KDE 3.0.2 on my laptop.

Anything else I should try?
_________________
cool book

vtowel · Posted: Tue Jul 30, 2002 1:28 am Post subject: Tip from a DRI guy

mksoft,

I don't have time to look into this right now, but after describing my problem to a developer of the DRI drivers (Charl P. Botha), here is what he said:

vtowel · Posted: Tue Jul 30, 2002 1:37 am Post subject:

Maybe the culprit he's talking about is /etc/security/console.perms? What is that for?
_________________
cool book

HalfFlat · n00b Joined: 30 Jul 2002 Posts: 3

As far as I know, it's an interaction between the PAM console permissions support and devfs.

When you login through xdm for the first time, you're given access to all the console devices currently present under /dev, as specified in the console.perms file.

However, something run in your xsession, e.g. a mixer applet, tries to access a sound device which in turn causes some sound module to be loaded which in turn via devfs creates a new device entry under /dev. PAM doesn't get a look in, and that's why there are mixed up permissions.

One solution is to load all the sound modules before xdm starts. Another is to log in through xdm, log out, and then log back in. The ideal solution though would involve running some program that updated console device permissions appropriately as they were created. There are hooks in devfs for this sort of thing, but I haven't looked into it. I also don't know how hard or easy it will be to get PAM to do the hard work.

This last solution would be 'right' though. Not much free time at the moment, so I probably won't do anything about it anytime soon. Anyone feel motivated? :wink:

pjp · Administrator Joined: 16 Apr 2002 Posts: 20067

Has any more information been discovered? Maybe a longshot, but is 'File Systems -> '/dev/pts for Unix98 PTYs' enabled in your kernel config? If it is, try disabling it.
_________________
Quis separabit? Quo animo?

vtowel · Posted: Fri Aug 09, 2002 5:43 am Post subject:

It doesn't seem to be causing a problem much for me anymore. I might be able to reproduce it, but in my dad-to-day tasks I'm not noticing it anymore. I'll let you know if it starts bugging me again.

_________________
cool book

thehyperintelligentslug · n00b Joined: 30 Jun 2002 Posts: 49 Location: Edinburgh

Hi everybody,

Sorry to 'revive' an old thread but the symptoms described here are exactly like those being experienced by my system and I wonder if anyone has had any :idea:

's over the last three or so months?!

I can confirm that:

the_bard · n00b Joined: 03 Dec 2002 Posts: 60 Location: Albany, NY

Talk about reviving an ancient thread...

First off... I'm using Gentoo 1.4rc1, with a Diamond MX300 (aureal 8830 based). I had the sound card modules set up to load on demand.

The problem I was having: The very first time I started X, I could receive no sound due to permission problems. Exit out, and restart X, and it'd work fine. Confused me a bit...

Solution: Simply added the module to /etc/modules.autoload. Now it gets loaded at boot, and the permission problem goes away. Why? I have no clue. I'd like to know why, so I don't have to continuously have the module loaded, but I'll settle for having it work. Besides... what else am I going to use all this memory for? :roll:

turbofish · n00b Joined: 05 Dec 2002 Posts: 8 Location: Sweden

Heh, I posted this yesterday. I didn't find this thread while searching the
forums. Silly me.

thehyperintelligentslug · n00b Joined: 30 Jun 2002 Posts: 49 Location: Edinburgh

Hi,

The problem I am having is that when someone else has been logged in before me and I go to log in it seems they have 'ownership' of the /dev sound entries (and nvidia stuff for that matter);

sekh · n00b Joined: 20 Dec 2002 Posts: 55

Hey there..

I just installed gentoo today.. LOVE it so far

great job on making it.

as u've guessed i have the same problem. It doesn't appear to be linked particularily to X for me though. I login in a terminal, and it seems that whomever i login with on the system gets ownership of the files in /dev/sound too on my comp. (I'm using the vanilla sources as suggested above btw).

here's an example:

sekh · n00b Joined: 20 Dec 2002 Posts: 55

i found out that it was the pam_console module doing this. Apparently it sets "speciel" permissions on things for users who log in locally. I've commented a few lines out in the /etc/security/console.perms file, and apparently this did the trick.

pjp · Administrator Joined: 16 Apr 2002 Posts: 20067

Moved from OTG.
_________________
Quis separabit? Quo animo?