linux/arch/um/drivers/hostaudio_kern.c
Arnd Bergmann 2022ca0a94 compat_ioctl: remove translation for sound ioctls
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.

Reviewed-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-10-23 17:23:45 +02:00

356 lines
7.6 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2002 Steve Schmidtke
*/
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/sound.h>
#include <linux/soundcard.h>
#include <linux/mutex.h>
#include <linux/uaccess.h>
#include <init.h>
#include <os.h>
struct hostaudio_state {
int fd;
};
struct hostmixer_state {
int fd;
};
#define HOSTAUDIO_DEV_DSP "/dev/sound/dsp"
#define HOSTAUDIO_DEV_MIXER "/dev/sound/mixer"
/*
* Changed either at boot time or module load time. At boot, this is
* single-threaded; at module load, multiple modules would each have
* their own copy of these variables.
*/
static char *dsp = HOSTAUDIO_DEV_DSP;
static char *mixer = HOSTAUDIO_DEV_MIXER;
#define DSP_HELP \
" This is used to specify the host dsp device to the hostaudio driver.\n" \
" The default is \"" HOSTAUDIO_DEV_DSP "\".\n\n"
#define MIXER_HELP \
" This is used to specify the host mixer device to the hostaudio driver.\n"\
" The default is \"" HOSTAUDIO_DEV_MIXER "\".\n\n"
module_param(dsp, charp, 0644);
MODULE_PARM_DESC(dsp, DSP_HELP);
module_param(mixer, charp, 0644);
MODULE_PARM_DESC(mixer, MIXER_HELP);
#ifndef MODULE
static int set_dsp(char *name, int *add)
{
dsp = name;
return 0;
}
__uml_setup("dsp=", set_dsp, "dsp=<dsp device>\n" DSP_HELP);
static int set_mixer(char *name, int *add)
{
mixer = name;
return 0;
}
__uml_setup("mixer=", set_mixer, "mixer=<mixer device>\n" MIXER_HELP);
#endif
static DEFINE_MUTEX(hostaudio_mutex);
/* /dev/dsp file operations */
static ssize_t hostaudio_read(struct file *file, char __user *buffer,
size_t count, loff_t *ppos)
{
struct hostaudio_state *state = file->private_data;
void *kbuf;
int err;
#ifdef DEBUG
printk(KERN_DEBUG "hostaudio: read called, count = %d\n", count);
#endif
kbuf = kmalloc(count, GFP_KERNEL);
if (kbuf == NULL)
return -ENOMEM;
err = os_read_file(state->fd, kbuf, count);
if (err < 0)
goto out;
if (copy_to_user(buffer, kbuf, err))
err = -EFAULT;
out:
kfree(kbuf);
return err;
}
static ssize_t hostaudio_write(struct file *file, const char __user *buffer,
size_t count, loff_t *ppos)
{
struct hostaudio_state *state = file->private_data;
void *kbuf;
int err;
#ifdef DEBUG
printk(KERN_DEBUG "hostaudio: write called, count = %d\n", count);
#endif
kbuf = memdup_user(buffer, count);
if (IS_ERR(kbuf))
return PTR_ERR(kbuf);
err = os_write_file(state->fd, kbuf, count);
if (err < 0)
goto out;
*ppos += err;
out:
kfree(kbuf);
return err;
}
static __poll_t hostaudio_poll(struct file *file,
struct poll_table_struct *wait)
{
__poll_t mask = 0;
#ifdef DEBUG
printk(KERN_DEBUG "hostaudio: poll called (unimplemented)\n");
#endif
return mask;
}
static long hostaudio_ioctl(struct file *file,
unsigned int cmd, unsigned long arg)
{
struct hostaudio_state *state = file->private_data;
unsigned long data = 0;
int err;
#ifdef DEBUG
printk(KERN_DEBUG "hostaudio: ioctl called, cmd = %u\n", cmd);
#endif
switch(cmd){
case SNDCTL_DSP_SPEED:
case SNDCTL_DSP_STEREO:
case SNDCTL_DSP_GETBLKSIZE:
case SNDCTL_DSP_CHANNELS:
case SNDCTL_DSP_SUBDIVIDE:
case SNDCTL_DSP_SETFRAGMENT:
if (get_user(data, (int __user *) arg))
return -EFAULT;
break;
default:
break;
}
err = os_ioctl_generic(state->fd, cmd, (unsigned long) &data);
switch(cmd){
case SNDCTL_DSP_SPEED:
case SNDCTL_DSP_STEREO:
case SNDCTL_DSP_GETBLKSIZE:
case SNDCTL_DSP_CHANNELS:
case SNDCTL_DSP_SUBDIVIDE:
case SNDCTL_DSP_SETFRAGMENT:
if (put_user(data, (int __user *) arg))
return -EFAULT;
break;
default:
break;
}
return err;
}
static int hostaudio_open(struct inode *inode, struct file *file)
{
struct hostaudio_state *state;
int r = 0, w = 0;
int ret;
#ifdef DEBUG
kernel_param_lock(THIS_MODULE);
printk(KERN_DEBUG "hostaudio: open called (host: %s)\n", dsp);
kernel_param_unlock(THIS_MODULE);
#endif
state = kmalloc(sizeof(struct hostaudio_state), GFP_KERNEL);
if (state == NULL)
return -ENOMEM;
if (file->f_mode & FMODE_READ)
r = 1;
if (file->f_mode & FMODE_WRITE)
w = 1;
kernel_param_lock(THIS_MODULE);
mutex_lock(&hostaudio_mutex);
ret = os_open_file(dsp, of_set_rw(OPENFLAGS(), r, w), 0);
mutex_unlock(&hostaudio_mutex);
kernel_param_unlock(THIS_MODULE);
if (ret < 0) {
kfree(state);
return ret;
}
state->fd = ret;
file->private_data = state;
return 0;
}
static int hostaudio_release(struct inode *inode, struct file *file)
{
struct hostaudio_state *state = file->private_data;
#ifdef DEBUG
printk(KERN_DEBUG "hostaudio: release called\n");
#endif
os_close_file(state->fd);
kfree(state);
return 0;
}
/* /dev/mixer file operations */
static long hostmixer_ioctl_mixdev(struct file *file,
unsigned int cmd, unsigned long arg)
{
struct hostmixer_state *state = file->private_data;
#ifdef DEBUG
printk(KERN_DEBUG "hostmixer: ioctl called\n");
#endif
return os_ioctl_generic(state->fd, cmd, arg);
}
static int hostmixer_open_mixdev(struct inode *inode, struct file *file)
{
struct hostmixer_state *state;
int r = 0, w = 0;
int ret;
#ifdef DEBUG
printk(KERN_DEBUG "hostmixer: open called (host: %s)\n", mixer);
#endif
state = kmalloc(sizeof(struct hostmixer_state), GFP_KERNEL);
if (state == NULL)
return -ENOMEM;
if (file->f_mode & FMODE_READ)
r = 1;
if (file->f_mode & FMODE_WRITE)
w = 1;
kernel_param_lock(THIS_MODULE);
mutex_lock(&hostaudio_mutex);
ret = os_open_file(mixer, of_set_rw(OPENFLAGS(), r, w), 0);
mutex_unlock(&hostaudio_mutex);
kernel_param_unlock(THIS_MODULE);
if (ret < 0) {
kernel_param_lock(THIS_MODULE);
printk(KERN_ERR "hostaudio_open_mixdev failed to open '%s', "
"err = %d\n", dsp, -ret);
kernel_param_unlock(THIS_MODULE);
kfree(state);
return ret;
}
file->private_data = state;
return 0;
}
static int hostmixer_release(struct inode *inode, struct file *file)
{
struct hostmixer_state *state = file->private_data;
#ifdef DEBUG
printk(KERN_DEBUG "hostmixer: release called\n");
#endif
os_close_file(state->fd);
kfree(state);
return 0;
}
/* kernel module operations */
static const struct file_operations hostaudio_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.read = hostaudio_read,
.write = hostaudio_write,
.poll = hostaudio_poll,
.unlocked_ioctl = hostaudio_ioctl,
.compat_ioctl = compat_ptr_ioctl,
.mmap = NULL,
.open = hostaudio_open,
.release = hostaudio_release,
};
static const struct file_operations hostmixer_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.unlocked_ioctl = hostmixer_ioctl_mixdev,
.open = hostmixer_open_mixdev,
.release = hostmixer_release,
};
struct {
int dev_audio;
int dev_mixer;
} module_data;
MODULE_AUTHOR("Steve Schmidtke");
MODULE_DESCRIPTION("UML Audio Relay");
MODULE_LICENSE("GPL");
static int __init hostaudio_init_module(void)
{
kernel_param_lock(THIS_MODULE);
printk(KERN_INFO "UML Audio Relay (host dsp = %s, host mixer = %s)\n",
dsp, mixer);
kernel_param_unlock(THIS_MODULE);
module_data.dev_audio = register_sound_dsp(&hostaudio_fops, -1);
if (module_data.dev_audio < 0) {
printk(KERN_ERR "hostaudio: couldn't register DSP device!\n");
return -ENODEV;
}
module_data.dev_mixer = register_sound_mixer(&hostmixer_fops, -1);
if (module_data.dev_mixer < 0) {
printk(KERN_ERR "hostmixer: couldn't register mixer "
"device!\n");
unregister_sound_dsp(module_data.dev_audio);
return -ENODEV;
}
return 0;
}
static void __exit hostaudio_cleanup_module (void)
{
unregister_sound_mixer(module_data.dev_mixer);
unregister_sound_dsp(module_data.dev_audio);
}
module_init(hostaudio_init_module);
module_exit(hostaudio_cleanup_module);