[PATCH 03/11] compat_ioctl: remove translation for sound ioctls

[PATCH 03/11] compat_ioctl: remove translation for sound ioctls

[Arnd Bergmann]

The SNDCTL_* and SOUND_* commands are the old OSS user interface.

I checked all the sound ioctl commands listed in fs/compat_ioctl.c
to see if we still need the translation handlers. Here is what I
found:

- sound/oss/ is (almost) gone from the kernel, this is what actually
  needed all the translations
- The ALSA emulation for OSS correctly handles all compat_ioctl
  commands already.
- sound/oss/dmasound/ is the last holdout of the original OSS code,
  this is only used on arch/m68k, which has no 64-bit mode and
  hence needs no compat handlers
- arch/um/drivers/hostaudio_kern.c may run in 64-bit mode with
  32-bit x86 user space underneath it. This rare corner case is
  the only one that still needs the compat handlers.

By adding a simple redirect of .compat_ioctl to .unlocked_ioctl in the
UML driver, we can remove all the COMPATIBLE_IOCTL() annotations without
a change in functionality. For completeness, I'm adding the same thing
to the dmasound file, knowing that it makes no difference.

The compat_ioctl list contains one comment about SNDCTL_DSP_MAPINBUF and
SNDCTL_DSP_MAPOUTBUF, which actually would need a translation handler
if implemented. However, the native implementation just returns -EINVAL,
so we don't care.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/um/drivers/hostaudio_kern.c   |   1 +
 fs/compat_ioctl.c                  | 157 -----------------------------
 sound/core/oss/pcm_oss.c           |   4 +
 sound/oss/dmasound/dmasound_core.c |   2 +
 4 files changed, 7 insertions(+), 157 deletions(-)

diff --git a/arch/um/drivers/hostaudio_kern.c b/arch/um/drivers/hostaudio_kern.c
index 7f9dbdbc4eb7..0278a642a622 100644
--- a/arch/um/drivers/hostaudio_kern.c
+++ b/arch/um/drivers/hostaudio_kern.c
@@ -298,6 +298,7 @@ static const struct file_operations hostaudio_fops = {
 	.write          = hostaudio_write,
 	.poll           = hostaudio_poll,
 	.unlocked_ioctl	= hostaudio_ioctl,
+	.compat_ioctl	= hostaudio_ioctl,
 	.mmap           = NULL,
 	.open           = hostaudio_open,
 	.release        = hostaudio_release,
diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c
index c2c73b802fb3..875516658c39 100644
--- a/fs/compat_ioctl.c
+++ b/fs/compat_ioctl.c
@@ -78,7 +78,6 @@
 #include <linux/if_bonding.h>
 #include <linux/watchdog.h>
 
-#include <linux/soundcard.h>
 #include <linux/lp.h>
 #include <linux/ppdev.h>
 
@@ -605,162 +604,6 @@ COMPATIBLE_IOCTL(SG_GET_KEEP_ORPHAN)
 /* PPP stuff */
 COMPATIBLE_IOCTL(PPPIOCGUNIT)
 COMPATIBLE_IOCTL(PPPIOCGCHAN)
-/* Big A */
-/* sparc only */
-/* Big Q for sound/OSS */
-COMPATIBLE_IOCTL(SNDCTL_SEQ_RESET)
-COMPATIBLE_IOCTL(SNDCTL_SEQ_SYNC)
-COMPATIBLE_IOCTL(SNDCTL_SYNTH_INFO)
-COMPATIBLE_IOCTL(SNDCTL_SEQ_CTRLRATE)
-COMPATIBLE_IOCTL(SNDCTL_SEQ_GETOUTCOUNT)
-COMPATIBLE_IOCTL(SNDCTL_SEQ_GETINCOUNT)
-COMPATIBLE_IOCTL(SNDCTL_SEQ_PERCMODE)
-COMPATIBLE_IOCTL(SNDCTL_FM_LOAD_INSTR)
-COMPATIBLE_IOCTL(SNDCTL_SEQ_TESTMIDI)
-COMPATIBLE_IOCTL(SNDCTL_SEQ_RESETSAMPLES)
-COMPATIBLE_IOCTL(SNDCTL_SEQ_NRSYNTHS)
-COMPATIBLE_IOCTL(SNDCTL_SEQ_NRMIDIS)
-COMPATIBLE_IOCTL(SNDCTL_MIDI_INFO)
-COMPATIBLE_IOCTL(SNDCTL_SEQ_THRESHOLD)
-COMPATIBLE_IOCTL(SNDCTL_SYNTH_MEMAVL)
-COMPATIBLE_IOCTL(SNDCTL_FM_4OP_ENABLE)
-COMPATIBLE_IOCTL(SNDCTL_SEQ_PANIC)
-COMPATIBLE_IOCTL(SNDCTL_SEQ_OUTOFBAND)
-COMPATIBLE_IOCTL(SNDCTL_SEQ_GETTIME)
-COMPATIBLE_IOCTL(SNDCTL_SYNTH_ID)
-COMPATIBLE_IOCTL(SNDCTL_SYNTH_CONTROL)
-COMPATIBLE_IOCTL(SNDCTL_SYNTH_REMOVESAMPLE)
-/* Big T for sound/OSS */
-COMPATIBLE_IOCTL(SNDCTL_TMR_TIMEBASE)
-COMPATIBLE_IOCTL(SNDCTL_TMR_START)
-COMPATIBLE_IOCTL(SNDCTL_TMR_STOP)
-COMPATIBLE_IOCTL(SNDCTL_TMR_CONTINUE)
-COMPATIBLE_IOCTL(SNDCTL_TMR_TEMPO)
-COMPATIBLE_IOCTL(SNDCTL_TMR_SOURCE)
-COMPATIBLE_IOCTL(SNDCTL_TMR_METRONOME)
-COMPATIBLE_IOCTL(SNDCTL_TMR_SELECT)
-/* Little m for sound/OSS */
-COMPATIBLE_IOCTL(SNDCTL_MIDI_PRETIME)
-COMPATIBLE_IOCTL(SNDCTL_MIDI_MPUMODE)
-COMPATIBLE_IOCTL(SNDCTL_MIDI_MPUCMD)
-/* Big P for sound/OSS */
-COMPATIBLE_IOCTL(SNDCTL_DSP_RESET)
-COMPATIBLE_IOCTL(SNDCTL_DSP_SYNC)
-COMPATIBLE_IOCTL(SNDCTL_DSP_SPEED)
-COMPATIBLE_IOCTL(SNDCTL_DSP_STEREO)
-COMPATIBLE_IOCTL(SNDCTL_DSP_GETBLKSIZE)
-COMPATIBLE_IOCTL(SNDCTL_DSP_CHANNELS)
-COMPATIBLE_IOCTL(SOUND_PCM_WRITE_FILTER)
-COMPATIBLE_IOCTL(SNDCTL_DSP_POST)
-COMPATIBLE_IOCTL(SNDCTL_DSP_SUBDIVIDE)
-COMPATIBLE_IOCTL(SNDCTL_DSP_SETFRAGMENT)
-COMPATIBLE_IOCTL(SNDCTL_DSP_GETFMTS)
-COMPATIBLE_IOCTL(SNDCTL_DSP_SETFMT)
-COMPATIBLE_IOCTL(SNDCTL_DSP_GETOSPACE)
-COMPATIBLE_IOCTL(SNDCTL_DSP_GETISPACE)
-COMPATIBLE_IOCTL(SNDCTL_DSP_NONBLOCK)
-COMPATIBLE_IOCTL(SNDCTL_DSP_GETCAPS)
-COMPATIBLE_IOCTL(SNDCTL_DSP_GETTRIGGER)
-COMPATIBLE_IOCTL(SNDCTL_DSP_SETTRIGGER)
-COMPATIBLE_IOCTL(SNDCTL_DSP_GETIPTR)
-COMPATIBLE_IOCTL(SNDCTL_DSP_GETOPTR)
-/* SNDCTL_DSP_MAPINBUF,  XXX needs translation */
-/* SNDCTL_DSP_MAPOUTBUF,  XXX needs translation */
-COMPATIBLE_IOCTL(SNDCTL_DSP_SETSYNCRO)
-COMPATIBLE_IOCTL(SNDCTL_DSP_SETDUPLEX)
-COMPATIBLE_IOCTL(SNDCTL_DSP_GETODELAY)
-COMPATIBLE_IOCTL(SNDCTL_DSP_PROFILE)
-COMPATIBLE_IOCTL(SOUND_PCM_READ_RATE)
-COMPATIBLE_IOCTL(SOUND_PCM_READ_CHANNELS)
-COMPATIBLE_IOCTL(SOUND_PCM_READ_BITS)
-COMPATIBLE_IOCTL(SOUND_PCM_READ_FILTER)
-/* Big C for sound/OSS */
-COMPATIBLE_IOCTL(SNDCTL_COPR_RESET)
-COMPATIBLE_IOCTL(SNDCTL_COPR_LOAD)
-COMPATIBLE_IOCTL(SNDCTL_COPR_RDATA)
-COMPATIBLE_IOCTL(SNDCTL_COPR_RCODE)
-COMPATIBLE_IOCTL(SNDCTL_COPR_WDATA)
-COMPATIBLE_IOCTL(SNDCTL_COPR_WCODE)
-COMPATIBLE_IOCTL(SNDCTL_COPR_RUN)
-COMPATIBLE_IOCTL(SNDCTL_COPR_HALT)
-COMPATIBLE_IOCTL(SNDCTL_COPR_SENDMSG)
-COMPATIBLE_IOCTL(SNDCTL_COPR_RCVMSG)
-/* Big M for sound/OSS */
-COMPATIBLE_IOCTL(SOUND_MIXER_READ_VOLUME)
-COMPATIBLE_IOCTL(SOUND_MIXER_READ_BASS)
-COMPATIBLE_IOCTL(SOUND_MIXER_READ_TREBLE)
-COMPATIBLE_IOCTL(SOUND_MIXER_READ_SYNTH)
-COMPATIBLE_IOCTL(SOUND_MIXER_READ_PCM)
-COMPATIBLE_IOCTL(SOUND_MIXER_READ_SPEAKER)
-COMPATIBLE_IOCTL(SOUND_MIXER_READ_LINE)
-COMPATIBLE_IOCTL(SOUND_MIXER_READ_MIC)
-COMPATIBLE_IOCTL(SOUND_MIXER_READ_CD)
-COMPATIBLE_IOCTL(SOUND_MIXER_READ_IMIX)
-COMPATIBLE_IOCTL(SOUND_MIXER_READ_ALTPCM)
-COMPATIBLE_IOCTL(SOUND_MIXER_READ_RECLEV)
-COMPATIBLE_IOCTL(SOUND_MIXER_READ_IGAIN)
-COMPATIBLE_IOCTL(SOUND_MIXER_READ_OGAIN)
-COMPATIBLE_IOCTL(SOUND_MIXER_READ_LINE1)
-COMPATIBLE_IOCTL(SOUND_MIXER_READ_LINE2)
-COMPATIBLE_IOCTL(SOUND_MIXER_READ_LINE3)
-COMPATIBLE_IOCTL(MIXER_READ(SOUND_MIXER_DIGITAL1))
-COMPATIBLE_IOCTL(MIXER_READ(SOUND_MIXER_DIGITAL2))
-COMPATIBLE_IOCTL(MIXER_READ(SOUND_MIXER_DIGITAL3))
-COMPATIBLE_IOCTL(MIXER_READ(SOUND_MIXER_PHONEIN))
-COMPATIBLE_IOCTL(MIXER_READ(SOUND_MIXER_PHONEOUT))
-COMPATIBLE_IOCTL(MIXER_READ(SOUND_MIXER_VIDEO))
-COMPATIBLE_IOCTL(MIXER_READ(SOUND_MIXER_RADIO))
-COMPATIBLE_IOCTL(MIXER_READ(SOUND_MIXER_MONITOR))
-COMPATIBLE_IOCTL(SOUND_MIXER_READ_MUTE)
-/* SOUND_MIXER_READ_ENHANCE,  same value as READ_MUTE */
-/* SOUND_MIXER_READ_LOUD,  same value as READ_MUTE */
-COMPATIBLE_IOCTL(SOUND_MIXER_READ_RECSRC)
-COMPATIBLE_IOCTL(SOUND_MIXER_READ_DEVMASK)
-COMPATIBLE_IOCTL(SOUND_MIXER_READ_RECMASK)
-COMPATIBLE_IOCTL(SOUND_MIXER_READ_STEREODEVS)
-COMPATIBLE_IOCTL(SOUND_MIXER_READ_CAPS)
-COMPATIBLE_IOCTL(SOUND_MIXER_WRITE_VOLUME)
-COMPATIBLE_IOCTL(SOUND_MIXER_WRITE_BASS)
-COMPATIBLE_IOCTL(SOUND_MIXER_WRITE_TREBLE)
-COMPATIBLE_IOCTL(SOUND_MIXER_WRITE_SYNTH)
-COMPATIBLE_IOCTL(SOUND_MIXER_WRITE_PCM)
-COMPATIBLE_IOCTL(SOUND_MIXER_WRITE_SPEAKER)
-COMPATIBLE_IOCTL(SOUND_MIXER_WRITE_LINE)
-COMPATIBLE_IOCTL(SOUND_MIXER_WRITE_MIC)
-COMPATIBLE_IOCTL(SOUND_MIXER_WRITE_CD)
-COMPATIBLE_IOCTL(SOUND_MIXER_WRITE_IMIX)
-COMPATIBLE_IOCTL(SOUND_MIXER_WRITE_ALTPCM)
-COMPATIBLE_IOCTL(SOUND_MIXER_WRITE_RECLEV)
-COMPATIBLE_IOCTL(SOUND_MIXER_WRITE_IGAIN)
-COMPATIBLE_IOCTL(SOUND_MIXER_WRITE_OGAIN)
-COMPATIBLE_IOCTL(SOUND_MIXER_WRITE_LINE1)
-COMPATIBLE_IOCTL(SOUND_MIXER_WRITE_LINE2)
-COMPATIBLE_IOCTL(SOUND_MIXER_WRITE_LINE3)
-COMPATIBLE_IOCTL(MIXER_WRITE(SOUND_MIXER_DIGITAL1))
-COMPATIBLE_IOCTL(MIXER_WRITE(SOUND_MIXER_DIGITAL2))
-COMPATIBLE_IOCTL(MIXER_WRITE(SOUND_MIXER_DIGITAL3))
-COMPATIBLE_IOCTL(MIXER_WRITE(SOUND_MIXER_PHONEIN))
-COMPATIBLE_IOCTL(MIXER_WRITE(SOUND_MIXER_PHONEOUT))
-COMPATIBLE_IOCTL(MIXER_WRITE(SOUND_MIXER_VIDEO))
-COMPATIBLE_IOCTL(MIXER_WRITE(SOUND_MIXER_RADIO))
-COMPATIBLE_IOCTL(MIXER_WRITE(SOUND_MIXER_MONITOR))
-COMPATIBLE_IOCTL(SOUND_MIXER_WRITE_MUTE)
-/* SOUND_MIXER_WRITE_ENHANCE,  same value as WRITE_MUTE */
-/* SOUND_MIXER_WRITE_LOUD,  same value as WRITE_MUTE */
-COMPATIBLE_IOCTL(SOUND_MIXER_WRITE_RECSRC)
-COMPATIBLE_IOCTL(SOUND_MIXER_INFO)
-COMPATIBLE_IOCTL(SOUND_OLD_MIXER_INFO)
-COMPATIBLE_IOCTL(SOUND_MIXER_ACCESS)
-COMPATIBLE_IOCTL(SOUND_MIXER_AGC)
-COMPATIBLE_IOCTL(SOUND_MIXER_3DSE)
-COMPATIBLE_IOCTL(SOUND_MIXER_PRIVATE1)
-COMPATIBLE_IOCTL(SOUND_MIXER_PRIVATE2)
-COMPATIBLE_IOCTL(SOUND_MIXER_PRIVATE3)
-COMPATIBLE_IOCTL(SOUND_MIXER_PRIVATE4)
-COMPATIBLE_IOCTL(SOUND_MIXER_PRIVATE5)
-COMPATIBLE_IOCTL(SOUND_MIXER_GETLEVELS)
-COMPATIBLE_IOCTL(SOUND_MIXER_SETLEVELS)
-COMPATIBLE_IOCTL(OSS_GETVERSION)
 /* Raw devices */
 COMPATIBLE_IOCTL(RAW_SETBIND)
 COMPATIBLE_IOCTL(RAW_GETBIND)
diff --git a/sound/core/oss/pcm_oss.c b/sound/core/oss/pcm_oss.c
index f8d4a419f3af..3f25c9d7b7df 100644
--- a/sound/core/oss/pcm_oss.c
+++ b/sound/core/oss/pcm_oss.c
@@ -2732,6 +2732,10 @@ static long snd_pcm_oss_ioctl(struct file *file, unsigned int cmd, unsigned long
 static long snd_pcm_oss_ioctl_compat(struct file *file, unsigned int cmd,
 				     unsigned long arg)
 {
+	/*
+	 * Everything is compatbile except SNDCTL_DSP_MAPINBUF/SNDCTL_DSP_MAPOUTBUF,
+	 * which are not implemented for the native case either
+	 */
 	return snd_pcm_oss_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
 }
 #else
diff --git a/sound/oss/dmasound/dmasound_core.c b/sound/oss/dmasound/dmasound_core.c
index fc9bcd47d6a4..b6b5f5a5df9c 100644
--- a/sound/oss/dmasound/dmasound_core.c
+++ b/sound/oss/dmasound/dmasound_core.c
@@ -384,6 +384,7 @@ static const struct file_operations mixer_fops =
 	.owner		= THIS_MODULE,
 	.llseek		= no_llseek,
 	.unlocked_ioctl	= mixer_unlocked_ioctl,
+	.compat_ioctl	= mixer_unlocked_ioctl,
 	.open		= mixer_open,
 	.release	= mixer_release,
 };
@@ -1167,6 +1168,7 @@ static const struct file_operations sq_fops =
 	.write		= sq_write,
 	.poll		= sq_poll,
 	.unlocked_ioctl	= sq_unlocked_ioctl,
+	.compat_ioctl	= sq_unlocked_ioctl,
 	.open		= sq_open,
 	.release	= sq_release,
 };
-- 
2.18.0

Re: [PATCH 03/11] compat_ioctl: remove translation for sound ioctls

[Al Viro]

On Sat, Sep 08, 2018 at 04:28:09PM +0200, Arnd Bergmann wrote:
> The SNDCTL_* and SOUND_* commands are the old OSS user interface.
> 
> I checked all the sound ioctl commands listed in fs/compat_ioctl.c
> to see if we still need the translation handlers. Here is what I
> found:
> 
> - sound/oss/ is (almost) gone from the kernel, this is what actually
>   needed all the translations
> - The ALSA emulation for OSS correctly handles all compat_ioctl
>   commands already.
> - sound/oss/dmasound/ is the last holdout of the original OSS code,
>   this is only used on arch/m68k, which has no 64-bit mode and
>   hence needs no compat handlers
> - arch/um/drivers/hostaudio_kern.c may run in 64-bit mode with
>   32-bit x86 user space underneath it. This rare corner case is
>   the only one that still needs the compat handlers.
> 
> By adding a simple redirect of .compat_ioctl to .unlocked_ioctl in the
> UML driver, we can remove all the COMPATIBLE_IOCTL() annotations without
> a change in functionality. For completeness, I'm adding the same thing
> to the dmasound file, knowing that it makes no difference.

> diff --git a/arch/um/drivers/hostaudio_kern.c b/arch/um/drivers/hostaudio_kern.c
> index 7f9dbdbc4eb7..0278a642a622 100644
> --- a/arch/um/drivers/hostaudio_kern.c
> +++ b/arch/um/drivers/hostaudio_kern.c
> @@ -298,6 +298,7 @@ static const struct file_operations hostaudio_fops = {
>  	.write          = hostaudio_write,
>  	.poll           = hostaudio_poll,
>  	.unlocked_ioctl	= hostaudio_ioctl,
> +	.compat_ioctl	= hostaudio_ioctl,

Umm...  OK, seeing that it's not going to be used on s390...  It's still
not quite right, though, and I'm afraid that places where we have the
same ->unlocked_ioctl and ->compat_ioctl need an audit - there probably
had been other folks who'd stepped into the same.

Re: [PATCH 03/11] compat_ioctl: remove translation for sound ioctls

[Arnd Bergmann]

On Sun, Sep 9, 2018 at 6:17 AM Al Viro <viro@zeniv.linux.org.uk> wrote:
>
> On Sat, Sep 08, 2018 at 04:28:09PM +0200, Arnd Bergmann wrote:
> > The SNDCTL_* and SOUND_* commands are the old OSS user interface.
> >
> > I checked all the sound ioctl commands listed in fs/compat_ioctl.c
> > to see if we still need the translation handlers. Here is what I
> > found:
> >
> > - sound/oss/ is (almost) gone from the kernel, this is what actually
> >   needed all the translations
> > - The ALSA emulation for OSS correctly handles all compat_ioctl
> >   commands already.
> > - sound/oss/dmasound/ is the last holdout of the original OSS code,
> >   this is only used on arch/m68k, which has no 64-bit mode and
> >   hence needs no compat handlers
> > - arch/um/drivers/hostaudio_kern.c may run in 64-bit mode with
> >   32-bit x86 user space underneath it. This rare corner case is
> >   the only one that still needs the compat handlers.
> >
> > By adding a simple redirect of .compat_ioctl to .unlocked_ioctl in the
> > UML driver, we can remove all the COMPATIBLE_IOCTL() annotations without
> > a change in functionality. For completeness, I'm adding the same thing
> > to the dmasound file, knowing that it makes no difference.
>
> > diff --git a/arch/um/drivers/hostaudio_kern.c b/arch/um/drivers/hostaudio_kern.c
> > index 7f9dbdbc4eb7..0278a642a622 100644
> > --- a/arch/um/drivers/hostaudio_kern.c
> > +++ b/arch/um/drivers/hostaudio_kern.c
> > @@ -298,6 +298,7 @@ static const struct file_operations hostaudio_fops = {
> >       .write          = hostaudio_write,
> >       .poll           = hostaudio_poll,
> >       .unlocked_ioctl = hostaudio_ioctl,
> > +     .compat_ioctl   = hostaudio_ioctl,
>
> Umm...  OK, seeing that it's not going to be used on s390...  It's still
> not quite right, though, and I'm afraid that places where we have the
> same ->unlocked_ioctl and ->compat_ioctl need an audit - there probably
> had been other folks who'd stepped into the same.

It turns out that it's actually much more common to have the same
pointer for ioctl handlers that thake pointer arguments than to have
the wrapper. I found 16 instances of trivial wrappers to do compat_ptr()
for file_operations, 4 instances that have a wrapper but skip the
compat_ptr() and around 40 (depending on how you count) that use
the same pointer for both when they only use pointers and should
go through compat_ptr(). This includes a couple that don't use
the argument at all, so they are fine either way.

I've created patches to change all of the above to a new
generic_compat_ioctl_ptrarg() helper I added.

loop_control_ioctl(), kcov_ioctl(), proc_bus_pci_ioctl(), and nbd_ioctl() seem
to be ones that are correct because,  the argument is always an integer.
fs3270_ioctl() has a is_compat_task() check to deal with the problem.

inotify_ioctl(),  vsoc_ioctl(), and usblp_ioctl() are somethat uses both integer
and pointer arguments and may need special handling for s390.

I did not touch those so far.

       Arnd