linux-stable/sound/core/hwdep.c
Arnd Bergmann 18d122c028 ALSA: compat_ioctl: avoid compat_alloc_user_space
Using compat_alloc_user_space() tends to add complexity
to the ioctl handling, so I am trying to remove it everywhere.

The two callers in sound/core can rewritten to just call
the same code that operates on a kernel pointer as the
native handler.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20200918095642.1446243-1-arnd@arndb.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-09-21 10:37:07 +02:00

543 lines
13 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Hardware dependent layer
* Copyright (c) by Jaroslav Kysela <perex@perex.cz>
*/
#include <linux/major.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/mutex.h>
#include <linux/module.h>
#include <linux/sched/signal.h>
#include <sound/core.h>
#include <sound/control.h>
#include <sound/minors.h>
#include <sound/hwdep.h>
#include <sound/info.h>
MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
MODULE_DESCRIPTION("Hardware dependent layer");
MODULE_LICENSE("GPL");
static LIST_HEAD(snd_hwdep_devices);
static DEFINE_MUTEX(register_mutex);
static int snd_hwdep_dev_free(struct snd_device *device);
static int snd_hwdep_dev_register(struct snd_device *device);
static int snd_hwdep_dev_disconnect(struct snd_device *device);
static struct snd_hwdep *snd_hwdep_search(struct snd_card *card, int device)
{
struct snd_hwdep *hwdep;
list_for_each_entry(hwdep, &snd_hwdep_devices, list)
if (hwdep->card == card && hwdep->device == device)
return hwdep;
return NULL;
}
static loff_t snd_hwdep_llseek(struct file * file, loff_t offset, int orig)
{
struct snd_hwdep *hw = file->private_data;
if (hw->ops.llseek)
return hw->ops.llseek(hw, file, offset, orig);
return -ENXIO;
}
static ssize_t snd_hwdep_read(struct file * file, char __user *buf,
size_t count, loff_t *offset)
{
struct snd_hwdep *hw = file->private_data;
if (hw->ops.read)
return hw->ops.read(hw, buf, count, offset);
return -ENXIO;
}
static ssize_t snd_hwdep_write(struct file * file, const char __user *buf,
size_t count, loff_t *offset)
{
struct snd_hwdep *hw = file->private_data;
if (hw->ops.write)
return hw->ops.write(hw, buf, count, offset);
return -ENXIO;
}
static int snd_hwdep_open(struct inode *inode, struct file * file)
{
int major = imajor(inode);
struct snd_hwdep *hw;
int err;
wait_queue_entry_t wait;
if (major == snd_major) {
hw = snd_lookup_minor_data(iminor(inode),
SNDRV_DEVICE_TYPE_HWDEP);
#ifdef CONFIG_SND_OSSEMUL
} else if (major == SOUND_MAJOR) {
hw = snd_lookup_oss_minor_data(iminor(inode),
SNDRV_OSS_DEVICE_TYPE_DMFM);
#endif
} else
return -ENXIO;
if (hw == NULL)
return -ENODEV;
if (!try_module_get(hw->card->module)) {
snd_card_unref(hw->card);
return -EFAULT;
}
init_waitqueue_entry(&wait, current);
add_wait_queue(&hw->open_wait, &wait);
mutex_lock(&hw->open_mutex);
while (1) {
if (hw->exclusive && hw->used > 0) {
err = -EBUSY;
break;
}
if (!hw->ops.open) {
err = 0;
break;
}
err = hw->ops.open(hw, file);
if (err >= 0)
break;
if (err == -EAGAIN) {
if (file->f_flags & O_NONBLOCK) {
err = -EBUSY;
break;
}
} else
break;
set_current_state(TASK_INTERRUPTIBLE);
mutex_unlock(&hw->open_mutex);
schedule();
mutex_lock(&hw->open_mutex);
if (hw->card->shutdown) {
err = -ENODEV;
break;
}
if (signal_pending(current)) {
err = -ERESTARTSYS;
break;
}
}
remove_wait_queue(&hw->open_wait, &wait);
if (err >= 0) {
err = snd_card_file_add(hw->card, file);
if (err >= 0) {
file->private_data = hw;
hw->used++;
} else {
if (hw->ops.release)
hw->ops.release(hw, file);
}
}
mutex_unlock(&hw->open_mutex);
if (err < 0)
module_put(hw->card->module);
snd_card_unref(hw->card);
return err;
}
static int snd_hwdep_release(struct inode *inode, struct file * file)
{
int err = 0;
struct snd_hwdep *hw = file->private_data;
struct module *mod = hw->card->module;
mutex_lock(&hw->open_mutex);
if (hw->ops.release)
err = hw->ops.release(hw, file);
if (hw->used > 0)
hw->used--;
mutex_unlock(&hw->open_mutex);
wake_up(&hw->open_wait);
snd_card_file_remove(hw->card, file);
module_put(mod);
return err;
}
static __poll_t snd_hwdep_poll(struct file * file, poll_table * wait)
{
struct snd_hwdep *hw = file->private_data;
if (hw->ops.poll)
return hw->ops.poll(hw, file, wait);
return 0;
}
static int snd_hwdep_info(struct snd_hwdep *hw,
struct snd_hwdep_info __user *_info)
{
struct snd_hwdep_info info;
memset(&info, 0, sizeof(info));
info.card = hw->card->number;
strlcpy(info.id, hw->id, sizeof(info.id));
strlcpy(info.name, hw->name, sizeof(info.name));
info.iface = hw->iface;
if (copy_to_user(_info, &info, sizeof(info)))
return -EFAULT;
return 0;
}
static int snd_hwdep_dsp_status(struct snd_hwdep *hw,
struct snd_hwdep_dsp_status __user *_info)
{
struct snd_hwdep_dsp_status info;
int err;
if (! hw->ops.dsp_status)
return -ENXIO;
memset(&info, 0, sizeof(info));
info.dsp_loaded = hw->dsp_loaded;
if ((err = hw->ops.dsp_status(hw, &info)) < 0)
return err;
if (copy_to_user(_info, &info, sizeof(info)))
return -EFAULT;
return 0;
}
static int snd_hwdep_dsp_load(struct snd_hwdep *hw,
struct snd_hwdep_dsp_image *info)
{
int err;
if (! hw->ops.dsp_load)
return -ENXIO;
if (info->index >= 32)
return -EINVAL;
/* check whether the dsp was already loaded */
if (hw->dsp_loaded & (1u << info->index))
return -EBUSY;
err = hw->ops.dsp_load(hw, info);
if (err < 0)
return err;
hw->dsp_loaded |= (1u << info->index);
return 0;
}
static int snd_hwdep_dsp_load_user(struct snd_hwdep *hw,
struct snd_hwdep_dsp_image __user *_info)
{
struct snd_hwdep_dsp_image info = {};
if (copy_from_user(&info, _info, sizeof(info)))
return -EFAULT;
return snd_hwdep_dsp_load(hw, &info);
}
static long snd_hwdep_ioctl(struct file * file, unsigned int cmd,
unsigned long arg)
{
struct snd_hwdep *hw = file->private_data;
void __user *argp = (void __user *)arg;
switch (cmd) {
case SNDRV_HWDEP_IOCTL_PVERSION:
return put_user(SNDRV_HWDEP_VERSION, (int __user *)argp);
case SNDRV_HWDEP_IOCTL_INFO:
return snd_hwdep_info(hw, argp);
case SNDRV_HWDEP_IOCTL_DSP_STATUS:
return snd_hwdep_dsp_status(hw, argp);
case SNDRV_HWDEP_IOCTL_DSP_LOAD:
return snd_hwdep_dsp_load_user(hw, argp);
}
if (hw->ops.ioctl)
return hw->ops.ioctl(hw, file, cmd, arg);
return -ENOTTY;
}
static int snd_hwdep_mmap(struct file * file, struct vm_area_struct * vma)
{
struct snd_hwdep *hw = file->private_data;
if (hw->ops.mmap)
return hw->ops.mmap(hw, file, vma);
return -ENXIO;
}
static int snd_hwdep_control_ioctl(struct snd_card *card,
struct snd_ctl_file * control,
unsigned int cmd, unsigned long arg)
{
switch (cmd) {
case SNDRV_CTL_IOCTL_HWDEP_NEXT_DEVICE:
{
int device;
if (get_user(device, (int __user *)arg))
return -EFAULT;
mutex_lock(&register_mutex);
if (device < 0)
device = 0;
else if (device < SNDRV_MINOR_HWDEPS)
device++;
else
device = SNDRV_MINOR_HWDEPS;
while (device < SNDRV_MINOR_HWDEPS) {
if (snd_hwdep_search(card, device))
break;
device++;
}
if (device >= SNDRV_MINOR_HWDEPS)
device = -1;
mutex_unlock(&register_mutex);
if (put_user(device, (int __user *)arg))
return -EFAULT;
return 0;
}
case SNDRV_CTL_IOCTL_HWDEP_INFO:
{
struct snd_hwdep_info __user *info = (struct snd_hwdep_info __user *)arg;
int device, err;
struct snd_hwdep *hwdep;
if (get_user(device, &info->device))
return -EFAULT;
mutex_lock(&register_mutex);
hwdep = snd_hwdep_search(card, device);
if (hwdep)
err = snd_hwdep_info(hwdep, info);
else
err = -ENXIO;
mutex_unlock(&register_mutex);
return err;
}
}
return -ENOIOCTLCMD;
}
#ifdef CONFIG_COMPAT
#include "hwdep_compat.c"
#else
#define snd_hwdep_ioctl_compat NULL
#endif
/*
*/
static const struct file_operations snd_hwdep_f_ops =
{
.owner = THIS_MODULE,
.llseek = snd_hwdep_llseek,
.read = snd_hwdep_read,
.write = snd_hwdep_write,
.open = snd_hwdep_open,
.release = snd_hwdep_release,
.poll = snd_hwdep_poll,
.unlocked_ioctl = snd_hwdep_ioctl,
.compat_ioctl = snd_hwdep_ioctl_compat,
.mmap = snd_hwdep_mmap,
};
static void release_hwdep_device(struct device *dev)
{
kfree(container_of(dev, struct snd_hwdep, dev));
}
/**
* snd_hwdep_new - create a new hwdep instance
* @card: the card instance
* @id: the id string
* @device: the device index (zero-based)
* @rhwdep: the pointer to store the new hwdep instance
*
* Creates a new hwdep instance with the given index on the card.
* The callbacks (hwdep->ops) must be set on the returned instance
* after this call manually by the caller.
*
* Return: Zero if successful, or a negative error code on failure.
*/
int snd_hwdep_new(struct snd_card *card, char *id, int device,
struct snd_hwdep **rhwdep)
{
struct snd_hwdep *hwdep;
int err;
static const struct snd_device_ops ops = {
.dev_free = snd_hwdep_dev_free,
.dev_register = snd_hwdep_dev_register,
.dev_disconnect = snd_hwdep_dev_disconnect,
};
if (snd_BUG_ON(!card))
return -ENXIO;
if (rhwdep)
*rhwdep = NULL;
hwdep = kzalloc(sizeof(*hwdep), GFP_KERNEL);
if (!hwdep)
return -ENOMEM;
init_waitqueue_head(&hwdep->open_wait);
mutex_init(&hwdep->open_mutex);
hwdep->card = card;
hwdep->device = device;
if (id)
strlcpy(hwdep->id, id, sizeof(hwdep->id));
snd_device_initialize(&hwdep->dev, card);
hwdep->dev.release = release_hwdep_device;
dev_set_name(&hwdep->dev, "hwC%iD%i", card->number, device);
#ifdef CONFIG_SND_OSSEMUL
hwdep->oss_type = -1;
#endif
err = snd_device_new(card, SNDRV_DEV_HWDEP, hwdep, &ops);
if (err < 0) {
put_device(&hwdep->dev);
return err;
}
if (rhwdep)
*rhwdep = hwdep;
return 0;
}
EXPORT_SYMBOL(snd_hwdep_new);
static int snd_hwdep_dev_free(struct snd_device *device)
{
struct snd_hwdep *hwdep = device->device_data;
if (!hwdep)
return 0;
if (hwdep->private_free)
hwdep->private_free(hwdep);
put_device(&hwdep->dev);
return 0;
}
static int snd_hwdep_dev_register(struct snd_device *device)
{
struct snd_hwdep *hwdep = device->device_data;
struct snd_card *card = hwdep->card;
int err;
mutex_lock(&register_mutex);
if (snd_hwdep_search(card, hwdep->device)) {
mutex_unlock(&register_mutex);
return -EBUSY;
}
list_add_tail(&hwdep->list, &snd_hwdep_devices);
err = snd_register_device(SNDRV_DEVICE_TYPE_HWDEP,
hwdep->card, hwdep->device,
&snd_hwdep_f_ops, hwdep, &hwdep->dev);
if (err < 0) {
dev_err(&hwdep->dev, "unable to register\n");
list_del(&hwdep->list);
mutex_unlock(&register_mutex);
return err;
}
#ifdef CONFIG_SND_OSSEMUL
hwdep->ossreg = 0;
if (hwdep->oss_type >= 0) {
if (hwdep->oss_type == SNDRV_OSS_DEVICE_TYPE_DMFM &&
hwdep->device)
dev_warn(&hwdep->dev,
"only hwdep device 0 can be registered as OSS direct FM device!\n");
else if (snd_register_oss_device(hwdep->oss_type,
card, hwdep->device,
&snd_hwdep_f_ops, hwdep) < 0)
dev_warn(&hwdep->dev,
"unable to register OSS compatibility device\n");
else
hwdep->ossreg = 1;
}
#endif
mutex_unlock(&register_mutex);
return 0;
}
static int snd_hwdep_dev_disconnect(struct snd_device *device)
{
struct snd_hwdep *hwdep = device->device_data;
if (snd_BUG_ON(!hwdep))
return -ENXIO;
mutex_lock(&register_mutex);
if (snd_hwdep_search(hwdep->card, hwdep->device) != hwdep) {
mutex_unlock(&register_mutex);
return -EINVAL;
}
mutex_lock(&hwdep->open_mutex);
wake_up(&hwdep->open_wait);
#ifdef CONFIG_SND_OSSEMUL
if (hwdep->ossreg)
snd_unregister_oss_device(hwdep->oss_type, hwdep->card, hwdep->device);
#endif
snd_unregister_device(&hwdep->dev);
list_del_init(&hwdep->list);
mutex_unlock(&hwdep->open_mutex);
mutex_unlock(&register_mutex);
return 0;
}
#ifdef CONFIG_SND_PROC_FS
/*
* Info interface
*/
static void snd_hwdep_proc_read(struct snd_info_entry *entry,
struct snd_info_buffer *buffer)
{
struct snd_hwdep *hwdep;
mutex_lock(&register_mutex);
list_for_each_entry(hwdep, &snd_hwdep_devices, list)
snd_iprintf(buffer, "%02i-%02i: %s\n",
hwdep->card->number, hwdep->device, hwdep->name);
mutex_unlock(&register_mutex);
}
static struct snd_info_entry *snd_hwdep_proc_entry;
static void __init snd_hwdep_proc_init(void)
{
struct snd_info_entry *entry;
if ((entry = snd_info_create_module_entry(THIS_MODULE, "hwdep", NULL)) != NULL) {
entry->c.text.read = snd_hwdep_proc_read;
if (snd_info_register(entry) < 0) {
snd_info_free_entry(entry);
entry = NULL;
}
}
snd_hwdep_proc_entry = entry;
}
static void __exit snd_hwdep_proc_done(void)
{
snd_info_free_entry(snd_hwdep_proc_entry);
}
#else /* !CONFIG_SND_PROC_FS */
#define snd_hwdep_proc_init()
#define snd_hwdep_proc_done()
#endif /* CONFIG_SND_PROC_FS */
/*
* ENTRY functions
*/
static int __init alsa_hwdep_init(void)
{
snd_hwdep_proc_init();
snd_ctl_register_ioctl(snd_hwdep_control_ioctl);
snd_ctl_register_ioctl_compat(snd_hwdep_control_ioctl);
return 0;
}
static void __exit alsa_hwdep_exit(void)
{
snd_ctl_unregister_ioctl(snd_hwdep_control_ioctl);
snd_ctl_unregister_ioctl_compat(snd_hwdep_control_ioctl);
snd_hwdep_proc_done();
}
module_init(alsa_hwdep_init)
module_exit(alsa_hwdep_exit)