Re: [alsa-devel] Segfault in pulseaudio since Alsa 1.1.7

23 Oct 2018

      Dne 23.10.2018 v 09:06 Hyperion napsal(a):
...
Sorry, I have no more time to spend debugging :(

Thus I guess that the true alsa maintainers will be much more efficient
than me (I'm just doing quick and dirty hacking here).

My XMOS USB soundcard now works with this workaround, please could you
take a look at traces I posted in the discussion on LQ.org ?
Here is the better fix:
http://git.alsa-project.org/?p=alsa-plugins.git;a=commitdiff;h=a4e7e1282c57a...
There was really a double pcm free, because:
snd_pcm_ioplug_delete ->
    snd_pcm_close ->
      snd_pcm_ioplug_close ->
        a52_close() ->
          snd_pcm_close(rec->slave)
Jaroslav
...
All the best
JP

23.10.2018, 08:53, "Jaroslav Kysela" perex@perex.cz:
...
Dne 23.10.2018 v 08:43 Hyperion napsal(a):
    I have narrowed to the simpler patch below :
    Â
    Quote:
    diff -rNaud alsa-plugins-1.1.7/a52/pcm_a52.c
    alsa-plugins-1.1.7-new/a52/pcm_a52.c
    --- alsa-plugins-1.1.7/a52/pcm_a52.c 2018-10-16 14:00:22.000000000
    +0200
    +++ alsa-plugins-1.1.7-new/a52/pcm_a52.c 2018-10-23
08:35:15.699830909
    +0200
    @@ -978,7 +978,8 @@
    if ((err = a52_set_hw_constraint(rec)) < 0) {
    snd_pcm_ioplug_delete(&rec->io);
    - goto error;
    + free(rec);
    + return err;
    }
    *pcmp = rec->io.pcm;
    Â

It does not appear like a correct change, because rec->slave is
initialized in previous lines (snd_pcm_open calls). Could you inspect
rec->slave in gdb ?
Jaroslav
    Â

    22.10.2018, 23:30, "Hyperion" <h1p8r10n@yandex.com
<mailto:h1p8r10n@yandex.com>>:

      Â Â Â Hi,
      Â Â Â Ã‚
      Â Â Â Since the upgrade to Alsa 1.1.7, I get a segfault at
      pulseaudio
      Â Â Â startup. This have been discussed and documented here :
      Â Â Â
[1][1]https://www.linuxquestions.org/questions/slackware-14/cu
      rrent-fri-oc
      Â Â Â t-19-puseaudio-segfauts-4175640773/
      Â Â Â Ã‚
      Â Â Â It seems that I found the origin of the bug :
reverting these
      2 commits
      Â Â Â fixes the problem :
      Â Â Â
[2][2]http://git.alsa-project.org/?p=alsa-...792dc809c908cc
      Â Â Â
[3][3]http://git.alsa-project.org/?p=alsa-...5dc6e1594291e7
      Â Â Â Then no more segfault in pulseaudio when accessing the USB
      soundcard.
      Â Â Â Ã‚
      Â Â Â Please could you fix it ?
      Â Â Â Ã‚
      Â Â Â Regards
      Â Â Â jp
      References
      Â Â Â Visible links
      Â Â Â 1.
      [4]https://www.linuxquestions.org/questions/slackware-14/current-fri
      -oct-19-puseaudio-segfauts-4175640773/
      Â Â Â 2.
      [5]http://git.alsa-project.org/?p=alsa-plugins.git;a=commitdiff;h=fc
      3f5d51062ff438780e568995792dc809c908cc
      Â Â Â 3.
      [6]http://git.alsa-project.org/?p=alsa-plugins.git;a=commitdiff;h=6b
      996865126dd559ef186002e45dc6e1594291e7
      Â Â Â Hidden links:
      Â Â Â 4.
      [7]https://www.linuxquestions.org/questions/slackware-14/current-fri
      -oct-19-puseaudio-segfauts-4175640773/
      _______________________________________________
      Alsa-devel mailing list
      [8]Alsa-devel@alsa-project.org
<mailto:Alsa-devel@alsa-project.org>
      [9]http://mailman.alsa-project.org/mailman/listinfo/alsa-devel

 References

    1.
https://www.linuxquestions.org/questions/slackware-14/current-fri-oc
    2. http://git.alsa-project.org/?p=alsa-...792dc809c908cc
    3. http://git.alsa-project.org/?p=alsa-...5dc6e1594291e7
    4.
https://www.linuxquestions.org/questions/slackware-14/current-fri-oct-19-puseaudio-segfauts-4175640773/
    5.
http://git.alsa-project.org/?p=alsa-plugins.git;a=commitdiff;h=fc3f5d51062ff438780e568995792dc809c908cc
    6.
http://git.alsa-project.org/?p=alsa-plugins.git;a=commitdiff;h=6b996865126dd559ef186002e45dc6e1594291e7
    7.
https://www.linuxquestions.org/questions/slackware-14/current-fri-oct-19-puseaudio-segfauts-4175640773/
    8. mailto:Alsa-devel@alsa-project.org
<mailto:Alsa-devel@alsa-project.org>
    9. http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
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--
Jaroslav Kysela <perex@perex.cz mailto:perex@perex.cz>
Linux Sound Maintainer; ALSA Project; Red Hat, Inc.
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-- 
Jaroslav Kysela perex@perex.cz
Linux Sound Maintainer; ALSA Project; Red Hat, Inc.