alsa update breaks kernel ABI

Bug #192559 reported by Fabio Massimo Di Nitto
62
Affects Status Importance Assigned to Milestone
linux-ubuntu-modules-2.6.24 (Ubuntu)
Fix Released
Critical
Tim Gardner

Bug Description

Hi guys,

so there is a major issue introduced by upgrading alsa via lum as it changes the kernel ABI breaking subsystems that depends on alsa like v4l
or the load of any external built module that depends on alsa.

Booting a perfecly clean 2.6.24-8:

[ 45.403831] cx88_alsa: disagrees about version of symbol snd_pcm_new
[ 45.403839] cx88_alsa: Unknown symbol snd_pcm_new
[ 45.404362] cx88_alsa: disagrees about version of symbol snd_pcm_lib_ioctl
[ 45.404364] cx88_alsa: Unknown symbol snd_pcm_lib_ioctl
[ 45.404440] cx88_alsa: disagrees about version of symbol snd_pcm_hw_constraint_pow2
[ 45.404443] cx88_alsa: Unknown symbol snd_pcm_hw_constraint_pow2
[ 45.404483] cx88_alsa: disagrees about version of symbol snd_pcm_set_ops
[ 45.404485] cx88_alsa: Unknown symbol snd_pcm_set_ops
[ 45.404787] cx88_alsa: disagrees about version of symbol snd_pcm_period_elapsed
[ 45.404790] cx88_alsa: Unknown symbol snd_pcm_period_elapsed

the cx88_alsa module is provided by linux-image-2.6.24-8-generic and built against alsa shipped in the same package.
0x1add4b71 snd_pcm_new sound/core/snd-pcm EXPORT_SYMBOL <- from /usr/src/linux-headers-2.6.24-8-generic/Module.symvers

that value is hardencoded into any module built against alsa.

The version provided by linux-ubuntu-module changes that BUT:

1) all modules in the kernel are built against the old version and fail to load
2) all external modules will suffer the same problem as 1) since the shipped headers are against the main kernel tree and not lum.

This is a serious issue that needs to be addressed because it breaks badly in several ways.

Fabio

Revision history for this message
Fabio Massimo Di Nitto (fabbione) wrote :

Setting to Critical. The general approach of upgrading subsystems in lum is elegant (to keep the code clean) but it breaks subsystems.

Changed in linux-ubuntu-modules-2.6.24:
importance: Undecided → Critical
Changed in linux-ubuntu-modules-2.6.24:
assignee: nobody → ubuntu-kernel-team
status: New → Triaged
Revision history for this message
Ben Collins (ben-collins) wrote :

We'll be discussing this bug at the Kernel Team Spring next week.

Changed in linux-ubuntu-modules-2.6.24:
status: Triaged → In Progress
Tim Gardner (timg-tpi)
Changed in linux-ubuntu-modules-2.6.24:
assignee: ubuntu-kernel-team → timg-tpi
Revision history for this message
Nathaniel McCallum (nmccallum) wrote :

Any update on this?

Revision history for this message
Felix Kuehling (fxkuehl) wrote :

Not sure if I'm seeing the same issue, but after upgrading from 2.6.24-11 to 2.6.24-12 I have no sound and lots of these messages in my kernel log, affecting virtually every single snd_* module that is loaded at boot time:

[ 49.921905] snd: Unknown symbol unregister_sound_special
[ 49.922033] snd: Unknown symbol register_sound_special_device
[ 49.922378] snd: Unknown symbol sound_class
[ 50.191061] snd_hwdep: Unknown symbol snd_info_register
[ 50.191112] snd_hwdep: Unknown symbol snd_info_create_module_entry
[ 50.191152] snd_hwdep: Unknown symbol snd_info_free_entry
....

Wanted to check first before adding yet another duplicate.

Revision history for this message
Jesse Burt (avsa242) wrote :

Confirmed; not sure how related this is but it happened to me as well

Revision history for this message
Mikael Gerdin (mgerdin) wrote :

I don't think that this is the same issue that we're seeing with 2.6.24-12

Revision history for this message
Shirish Agarwal (shirishag75) wrote :

Hi all,
     I filed Bug #203419 can somebody see & tell is that part of this bug or something new?

Revision history for this message
Tim Gardner (timg-tpi) wrote :
Changed in linux-ubuntu-modules-2.6.24:
milestone: none → ubuntu-8.04
status: In Progress → Fix Released
Revision history for this message
Dave L (wizkey1) wrote :

This issue is still present, even in the Hardy Heron RC.

Revision history for this message
mosestruong (mosestruong) wrote :

I was able to get my sound working by creating symbolic links in /lib/modules/2.6.24-15-generic/kernel/sound/ to /lib/modules/2.6.24-15-generic/ubuntu/sound/alsa-driver

(I wan't able to get 2.6.24-16 to boot - but i guess that's another bug)

Revision history for this message
Colin Brace (cbrace) wrote :

Works again here under 2.6.24-16 (HH RC)

My only audio-related issue at the moment is that sound doesn't work in Flash, but I suppose that is a different bug too.

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