Re: snd-ioctl32 is failing on x86_64 (no crashes, just errors)

[Takashi Iwai <tiwai@suse.de>]

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At Mon, 10 Jan 2005 21:33:42 +0900,
Georgi Georgiev wrote:
> 
> maillog: 10/01/2005-12:26:28(+0100): Takashi Iwai types
> > At Sat, 8 Jan 2005 16:40:27 +0900, Georgi Georgiev wrote:
> > 
> > It's SNDRV_CTL_IOCTL_ELEM_READ.  Could you check which place returns
> > -EINVAL in _snd_ioctl32_ctl_elem_value in
> > alsa-kernel/core/ioctl32/ioctl32.c?
> 
> It says:
> 
>         /* FIXME: indirect access is not supported */
>         if (data->indirect) {
>                 err = -EINVAL;
>                 goto __end;
>         }
> 
> There is another one shortly after this:
> 
>         switch (type) {
> 	...
>         default:
>                 printk(KERN_ERR "snd_ioctl32_ctl_elem_value: unknown type %d\n", type);
>                 err = -EINVAL;
>                 goto __end;
>         }

I know :)  Also, the return value from snd_ctl_elem_read() can be
-EINVAL.  My question was which of them returns indeed in your case...

> Seeing the printk I checked my logs:
> 
> Jan 10 21:08:24 lion ioctl32(amixer:243138): Unknown cmd fd(3) cmd(c2c45512){02} arg(ffffc610) on /dev/snd/controlC0
> Jan 10 21:08:27 lion ioctl32(amixer:243139): Unknown cmd fd(3) cmd(c2c45512){02} arg(ffffc600) on /dev/snd/controlC0
> Jan 10 21:21:06 lion ioctl32(amixer:243280): Unknown cmd fd(3) cmd(c2c45512){02} arg(ffffc670) on /dev/snd/controlC0
> Jan 10 21:21:09 lion ioctl32(amixer:243281): Unknown cmd fd(3) cmd(c2c45512){02} arg(ffffc670) on /dev/snd/controlC0
> 
> though the error message is quite different than the printk above, it
> could still be helpful.

... or, this can be the real problem.  It looks the struct size
doesn't match.  Could you try the attached patch?


> I also don't see any differences between ioctl32.c from CVS and
> 1.0.8rc2. CVS version is at rev.1.26 and tagged as v1-0-8rc1.

Yes.  No change since then.

> > > > ALSA ioctl32 in 2.6.10 or older is buggy.  Try to avoid it.
> > > 
> > > Avoid using ioctl32? I don't have much of a choice since it doesn't work
> > > anyway. It would be nice to get some sound on flash pages and wine,
> > > though.
> > 
> > Yes, but the code in 2.6.10 may crash your system.
> > (On x86-64, this might work, though...)
> > 
> > > 2.6.10 or older pretty much covers every kernel out there. What kernel
> > > version is it OK to test this with?
> > 
> > The one in latest alsa-driver (alsa-kernel) tree.
> > I think Linus's bk and mm trees have included already fixes.
> 
> The most important point that I did not get -- your advice about
> avoiding ioctl32 is a different point of concern, that is completely
> unrelated to the current problem, is it?

I wrote to avoid the one on 2.6.10 (or older) since it's broken.
I did NOT mean to avoid the one on the latest ALSA tree.  This should
get fixed ASAP, of course.


Takashi

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Index: alsa-kernel/core/ioctl32/ioctl32.c
===================================================================
RCS file: /suse/tiwai/cvs/alsa/alsa-kernel/core/ioctl32/ioctl32.c,v
retrieving revision 1.30
diff -u -r1.30 ioctl32.c
--- alsa-kernel/core/ioctl32/ioctl32.c	15 Dec 2004 15:26:24 -0000	1.30
+++ alsa-kernel/core/ioctl32/ioctl32.c	10 Jan 2005 13:36:49 -0000
@@ -238,7 +238,7 @@
 		struct sndrv_aes_iec958 iec958;
         } value;
         unsigned char reserved[128];
-};
+}_ _attribute__((packed));
 
 
 /* hmm, it's so hard to retrieve the value type from the control id.. */