linux/include/sound/core.h
Takashi Iwai ef34a0ae7a ALSA: core: Add async signal helpers
Currently the call of kill_fasync() from an interrupt handler might
lead to potential spin deadlocks, as spotted by syzkaller.
Unfortunately, it's not so trivial to fix this lock chain as it's
involved with the tasklist_lock that is touched in allover places.

As a temporary workaround, this patch provides the way to defer the
async signal notification in a work.  The new helper functions,
snd_fasync_helper() and snd_kill_faync() are replacements for
fasync_helper() and kill_fasync(), respectively.  In addition,
snd_fasync_free() needs to be called at the destructor of the relevant
file object.

Link: https://lore.kernel.org/r/20220728125945.29533-2-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2022-07-29 12:57:10 +02:00

519 lines
16 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
#ifndef __SOUND_CORE_H
#define __SOUND_CORE_H
/*
* Main header file for the ALSA driver
* Copyright (c) 1994-2001 by Jaroslav Kysela <perex@perex.cz>
*/
#include <linux/device.h>
#include <linux/sched.h> /* wake_up() */
#include <linux/mutex.h> /* struct mutex */
#include <linux/rwsem.h> /* struct rw_semaphore */
#include <linux/pm.h> /* pm_message_t */
#include <linux/stringify.h>
#include <linux/printk.h>
#include <linux/xarray.h>
/* number of supported soundcards */
#ifdef CONFIG_SND_DYNAMIC_MINORS
#define SNDRV_CARDS CONFIG_SND_MAX_CARDS
#else
#define SNDRV_CARDS 8 /* don't change - minor numbers */
#endif
#define CONFIG_SND_MAJOR 116 /* standard configuration */
/* forward declarations */
struct pci_dev;
struct module;
struct completion;
/* device allocation stuff */
/* type of the object used in snd_device_*()
* this also defines the calling order
*/
enum snd_device_type {
SNDRV_DEV_LOWLEVEL,
SNDRV_DEV_INFO,
SNDRV_DEV_BUS,
SNDRV_DEV_CODEC,
SNDRV_DEV_PCM,
SNDRV_DEV_COMPRESS,
SNDRV_DEV_RAWMIDI,
SNDRV_DEV_TIMER,
SNDRV_DEV_SEQUENCER,
SNDRV_DEV_HWDEP,
SNDRV_DEV_JACK,
SNDRV_DEV_CONTROL, /* NOTE: this must be the last one */
};
enum snd_device_state {
SNDRV_DEV_BUILD,
SNDRV_DEV_REGISTERED,
SNDRV_DEV_DISCONNECTED,
};
struct snd_device;
struct snd_device_ops {
int (*dev_free)(struct snd_device *dev);
int (*dev_register)(struct snd_device *dev);
int (*dev_disconnect)(struct snd_device *dev);
};
struct snd_device {
struct list_head list; /* list of registered devices */
struct snd_card *card; /* card which holds this device */
enum snd_device_state state; /* state of the device */
enum snd_device_type type; /* device type */
void *device_data; /* device structure */
const struct snd_device_ops *ops; /* operations */
};
#define snd_device(n) list_entry(n, struct snd_device, list)
/* main structure for soundcard */
struct snd_card {
int number; /* number of soundcard (index to
snd_cards) */
char id[16]; /* id string of this card */
char driver[16]; /* driver name */
char shortname[32]; /* short name of this soundcard */
char longname[80]; /* name of this soundcard */
char irq_descr[32]; /* Interrupt description */
char mixername[80]; /* mixer name */
char components[128]; /* card components delimited with
space */
struct module *module; /* top-level module */
void *private_data; /* private data for soundcard */
void (*private_free) (struct snd_card *card); /* callback for freeing of
private data */
struct list_head devices; /* devices */
struct device ctl_dev; /* control device */
unsigned int last_numid; /* last used numeric ID */
struct rw_semaphore controls_rwsem; /* controls list lock */
rwlock_t ctl_files_rwlock; /* ctl_files list lock */
int controls_count; /* count of all controls */
size_t user_ctl_alloc_size; // current memory allocation by user controls.
struct list_head controls; /* all controls for this card */
struct list_head ctl_files; /* active control files */
#ifdef CONFIG_SND_CTL_FAST_LOOKUP
struct xarray ctl_numids; /* hash table for numids */
struct xarray ctl_hash; /* hash table for ctl id matching */
bool ctl_hash_collision; /* ctl_hash collision seen? */
#endif
struct snd_info_entry *proc_root; /* root for soundcard specific files */
struct proc_dir_entry *proc_root_link; /* number link to real id */
struct list_head files_list; /* all files associated to this card */
struct snd_shutdown_f_ops *s_f_ops; /* file operations in the shutdown
state */
spinlock_t files_lock; /* lock the files for this card */
int shutdown; /* this card is going down */
struct completion *release_completion;
struct device *dev; /* device assigned to this card */
struct device card_dev; /* cardX object for sysfs */
const struct attribute_group *dev_groups[4]; /* assigned sysfs attr */
bool registered; /* card_dev is registered? */
bool managed; /* managed via devres */
bool releasing; /* during card free process */
int sync_irq; /* assigned irq, used for PCM sync */
wait_queue_head_t remove_sleep;
size_t total_pcm_alloc_bytes; /* total amount of allocated buffers */
struct mutex memory_mutex; /* protection for the above */
#ifdef CONFIG_SND_DEBUG
struct dentry *debugfs_root; /* debugfs root for card */
#endif
#ifdef CONFIG_PM
unsigned int power_state; /* power state */
atomic_t power_ref;
wait_queue_head_t power_sleep;
wait_queue_head_t power_ref_sleep;
#endif
#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
struct snd_mixer_oss *mixer_oss;
int mixer_oss_change_count;
#endif
};
#define dev_to_snd_card(p) container_of(p, struct snd_card, card_dev)
#ifdef CONFIG_PM
static inline unsigned int snd_power_get_state(struct snd_card *card)
{
return READ_ONCE(card->power_state);
}
static inline void snd_power_change_state(struct snd_card *card, unsigned int state)
{
WRITE_ONCE(card->power_state, state);
wake_up(&card->power_sleep);
}
/**
* snd_power_ref - Take the reference count for power control
* @card: sound card object
*
* The power_ref reference of the card is used for managing to block
* the snd_power_sync_ref() operation. This function increments the reference.
* The counterpart snd_power_unref() has to be called appropriately later.
*/
static inline void snd_power_ref(struct snd_card *card)
{
atomic_inc(&card->power_ref);
}
/**
* snd_power_unref - Release the reference count for power control
* @card: sound card object
*/
static inline void snd_power_unref(struct snd_card *card)
{
if (atomic_dec_and_test(&card->power_ref))
wake_up(&card->power_ref_sleep);
}
/**
* snd_power_sync_ref - wait until the card power_ref is freed
* @card: sound card object
*
* This function is used to synchronize with the pending power_ref being
* released.
*/
static inline void snd_power_sync_ref(struct snd_card *card)
{
wait_event(card->power_ref_sleep, !atomic_read(&card->power_ref));
}
/* init.c */
int snd_power_wait(struct snd_card *card);
int snd_power_ref_and_wait(struct snd_card *card);
#else /* ! CONFIG_PM */
static inline int snd_power_wait(struct snd_card *card) { return 0; }
static inline void snd_power_ref(struct snd_card *card) {}
static inline void snd_power_unref(struct snd_card *card) {}
static inline int snd_power_ref_and_wait(struct snd_card *card) { return 0; }
static inline void snd_power_sync_ref(struct snd_card *card) {}
#define snd_power_get_state(card) ({ (void)(card); SNDRV_CTL_POWER_D0; })
#define snd_power_change_state(card, state) do { (void)(card); } while (0)
#endif /* CONFIG_PM */
struct snd_minor {
int type; /* SNDRV_DEVICE_TYPE_XXX */
int card; /* card number */
int device; /* device number */
const struct file_operations *f_ops; /* file operations */
void *private_data; /* private data for f_ops->open */
struct device *dev; /* device for sysfs */
struct snd_card *card_ptr; /* assigned card instance */
};
/* return a device pointer linked to each sound device as a parent */
static inline struct device *snd_card_get_device_link(struct snd_card *card)
{
return card ? &card->card_dev : NULL;
}
/* sound.c */
extern int snd_major;
extern int snd_ecards_limit;
extern struct class *sound_class;
#ifdef CONFIG_SND_DEBUG
extern struct dentry *sound_debugfs_root;
#endif
void snd_request_card(int card);
void snd_device_initialize(struct device *dev, struct snd_card *card);
int snd_register_device(int type, struct snd_card *card, int dev,
const struct file_operations *f_ops,
void *private_data, struct device *device);
int snd_unregister_device(struct device *dev);
void *snd_lookup_minor_data(unsigned int minor, int type);
#ifdef CONFIG_SND_OSSEMUL
int snd_register_oss_device(int type, struct snd_card *card, int dev,
const struct file_operations *f_ops, void *private_data);
int snd_unregister_oss_device(int type, struct snd_card *card, int dev);
void *snd_lookup_oss_minor_data(unsigned int minor, int type);
#endif
int snd_minor_info_init(void);
/* sound_oss.c */
#ifdef CONFIG_SND_OSSEMUL
int snd_minor_info_oss_init(void);
#else
static inline int snd_minor_info_oss_init(void) { return 0; }
#endif
/* memory.c */
int copy_to_user_fromio(void __user *dst, const volatile void __iomem *src, size_t count);
int copy_from_user_toio(volatile void __iomem *dst, const void __user *src, size_t count);
/* init.c */
int snd_card_locked(int card);
#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
#define SND_MIXER_OSS_NOTIFY_REGISTER 0
#define SND_MIXER_OSS_NOTIFY_DISCONNECT 1
#define SND_MIXER_OSS_NOTIFY_FREE 2
extern int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int cmd);
#endif
int snd_card_new(struct device *parent, int idx, const char *xid,
struct module *module, int extra_size,
struct snd_card **card_ret);
int snd_devm_card_new(struct device *parent, int idx, const char *xid,
struct module *module, size_t extra_size,
struct snd_card **card_ret);
int snd_card_disconnect(struct snd_card *card);
void snd_card_disconnect_sync(struct snd_card *card);
int snd_card_free(struct snd_card *card);
int snd_card_free_when_closed(struct snd_card *card);
int snd_card_free_on_error(struct device *dev, int ret);
void snd_card_set_id(struct snd_card *card, const char *id);
int snd_card_register(struct snd_card *card);
int snd_card_info_init(void);
int snd_card_add_dev_attr(struct snd_card *card,
const struct attribute_group *group);
int snd_component_add(struct snd_card *card, const char *component);
int snd_card_file_add(struct snd_card *card, struct file *file);
int snd_card_file_remove(struct snd_card *card, struct file *file);
struct snd_card *snd_card_ref(int card);
/**
* snd_card_unref - Unreference the card object
* @card: the card object to unreference
*
* Call this function for the card object that was obtained via snd_card_ref()
* or snd_lookup_minor_data().
*/
static inline void snd_card_unref(struct snd_card *card)
{
put_device(&card->card_dev);
}
#define snd_card_set_dev(card, devptr) ((card)->dev = (devptr))
/* device.c */
int snd_device_new(struct snd_card *card, enum snd_device_type type,
void *device_data, const struct snd_device_ops *ops);
int snd_device_register(struct snd_card *card, void *device_data);
int snd_device_register_all(struct snd_card *card);
void snd_device_disconnect(struct snd_card *card, void *device_data);
void snd_device_disconnect_all(struct snd_card *card);
void snd_device_free(struct snd_card *card, void *device_data);
void snd_device_free_all(struct snd_card *card);
int snd_device_get_state(struct snd_card *card, void *device_data);
/* isadma.c */
#ifdef CONFIG_ISA_DMA_API
#define DMA_MODE_NO_ENABLE 0x0100
void snd_dma_program(unsigned long dma, unsigned long addr, unsigned int size, unsigned short mode);
void snd_dma_disable(unsigned long dma);
unsigned int snd_dma_pointer(unsigned long dma, unsigned int size);
int snd_devm_request_dma(struct device *dev, int dma, const char *name);
#endif
/* misc.c */
struct resource;
void release_and_free_resource(struct resource *res);
/* --- */
/* sound printk debug levels */
enum {
SND_PR_ALWAYS,
SND_PR_DEBUG,
SND_PR_VERBOSE,
};
#if defined(CONFIG_SND_DEBUG) || defined(CONFIG_SND_VERBOSE_PRINTK)
__printf(4, 5)
void __snd_printk(unsigned int level, const char *file, int line,
const char *format, ...);
#else
#define __snd_printk(level, file, line, format, ...) \
printk(format, ##__VA_ARGS__)
#endif
/**
* snd_printk - printk wrapper
* @fmt: format string
*
* Works like printk() but prints the file and the line of the caller
* when configured with CONFIG_SND_VERBOSE_PRINTK.
*/
#define snd_printk(fmt, ...) \
__snd_printk(0, __FILE__, __LINE__, fmt, ##__VA_ARGS__)
#ifdef CONFIG_SND_DEBUG
/**
* snd_printd - debug printk
* @fmt: format string
*
* Works like snd_printk() for debugging purposes.
* Ignored when CONFIG_SND_DEBUG is not set.
*/
#define snd_printd(fmt, ...) \
__snd_printk(1, __FILE__, __LINE__, fmt, ##__VA_ARGS__)
#define _snd_printd(level, fmt, ...) \
__snd_printk(level, __FILE__, __LINE__, fmt, ##__VA_ARGS__)
/**
* snd_BUG - give a BUG warning message and stack trace
*
* Calls WARN() if CONFIG_SND_DEBUG is set.
* Ignored when CONFIG_SND_DEBUG is not set.
*/
#define snd_BUG() WARN(1, "BUG?\n")
/**
* snd_printd_ratelimit - Suppress high rates of output when
* CONFIG_SND_DEBUG is enabled.
*/
#define snd_printd_ratelimit() printk_ratelimit()
/**
* snd_BUG_ON - debugging check macro
* @cond: condition to evaluate
*
* Has the same behavior as WARN_ON when CONFIG_SND_DEBUG is set,
* otherwise just evaluates the conditional and returns the value.
*/
#define snd_BUG_ON(cond) WARN_ON((cond))
#else /* !CONFIG_SND_DEBUG */
__printf(1, 2)
static inline void snd_printd(const char *format, ...) {}
__printf(2, 3)
static inline void _snd_printd(int level, const char *format, ...) {}
#define snd_BUG() do { } while (0)
#define snd_BUG_ON(condition) ({ \
int __ret_warn_on = !!(condition); \
unlikely(__ret_warn_on); \
})
static inline bool snd_printd_ratelimit(void) { return false; }
#endif /* CONFIG_SND_DEBUG */
#ifdef CONFIG_SND_DEBUG_VERBOSE
/**
* snd_printdd - debug printk
* @format: format string
*
* Works like snd_printk() for debugging purposes.
* Ignored when CONFIG_SND_DEBUG_VERBOSE is not set.
*/
#define snd_printdd(format, ...) \
__snd_printk(2, __FILE__, __LINE__, format, ##__VA_ARGS__)
#else
__printf(1, 2)
static inline void snd_printdd(const char *format, ...) {}
#endif
#define SNDRV_OSS_VERSION ((3<<16)|(8<<8)|(1<<4)|(0)) /* 3.8.1a */
/* for easier backward-porting */
#if IS_ENABLED(CONFIG_GAMEPORT)
#define gameport_set_dev_parent(gp,xdev) ((gp)->dev.parent = (xdev))
#define gameport_set_port_data(gp,r) ((gp)->port_data = (r))
#define gameport_get_port_data(gp) (gp)->port_data
#endif
/* PCI quirk list helper */
struct snd_pci_quirk {
unsigned short subvendor; /* PCI subvendor ID */
unsigned short subdevice; /* PCI subdevice ID */
unsigned short subdevice_mask; /* bitmask to match */
int value; /* value */
#ifdef CONFIG_SND_DEBUG_VERBOSE
const char *name; /* name of the device (optional) */
#endif
};
#define _SND_PCI_QUIRK_ID_MASK(vend, mask, dev) \
.subvendor = (vend), .subdevice = (dev), .subdevice_mask = (mask)
#define _SND_PCI_QUIRK_ID(vend, dev) \
_SND_PCI_QUIRK_ID_MASK(vend, 0xffff, dev)
#define SND_PCI_QUIRK_ID(vend,dev) {_SND_PCI_QUIRK_ID(vend, dev)}
#ifdef CONFIG_SND_DEBUG_VERBOSE
#define SND_PCI_QUIRK(vend,dev,xname,val) \
{_SND_PCI_QUIRK_ID(vend, dev), .value = (val), .name = (xname)}
#define SND_PCI_QUIRK_VENDOR(vend, xname, val) \
{_SND_PCI_QUIRK_ID_MASK(vend, 0, 0), .value = (val), .name = (xname)}
#define SND_PCI_QUIRK_MASK(vend, mask, dev, xname, val) \
{_SND_PCI_QUIRK_ID_MASK(vend, mask, dev), \
.value = (val), .name = (xname)}
#define snd_pci_quirk_name(q) ((q)->name)
#else
#define SND_PCI_QUIRK(vend,dev,xname,val) \
{_SND_PCI_QUIRK_ID(vend, dev), .value = (val)}
#define SND_PCI_QUIRK_MASK(vend, mask, dev, xname, val) \
{_SND_PCI_QUIRK_ID_MASK(vend, mask, dev), .value = (val)}
#define SND_PCI_QUIRK_VENDOR(vend, xname, val) \
{_SND_PCI_QUIRK_ID_MASK(vend, 0, 0), .value = (val)}
#define snd_pci_quirk_name(q) ""
#endif
#ifdef CONFIG_PCI
const struct snd_pci_quirk *
snd_pci_quirk_lookup(struct pci_dev *pci, const struct snd_pci_quirk *list);
const struct snd_pci_quirk *
snd_pci_quirk_lookup_id(u16 vendor, u16 device,
const struct snd_pci_quirk *list);
#else
static inline const struct snd_pci_quirk *
snd_pci_quirk_lookup(struct pci_dev *pci, const struct snd_pci_quirk *list)
{
return NULL;
}
static inline const struct snd_pci_quirk *
snd_pci_quirk_lookup_id(u16 vendor, u16 device,
const struct snd_pci_quirk *list)
{
return NULL;
}
#endif
/* async signal helpers */
struct snd_fasync;
int snd_fasync_helper(int fd, struct file *file, int on,
struct snd_fasync **fasyncp);
void snd_kill_fasync(struct snd_fasync *fasync, int signal, int poll);
void snd_fasync_free(struct snd_fasync *fasync);
#endif /* __SOUND_CORE_H */