diff options
| author | Takashi Iwai <tiwai@suse.de> | 2012-10-16 13:05:59 +0200 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2012-11-16 16:46:50 +0000 |
| commit | 3b4a36722e5e518e4bdd3a215d8a1c5adc18e911 (patch) | |
| tree | 3db0ebb96a886ce6ff3c91e60510a03b561a20bc /include | |
| parent | f6415ce55f2430e38f674d8421511e489b2c71b0 (diff) | |
ALSA: Add a reference counter to card instance
commit a0830dbd4e42b38aefdf3fb61ba5019a1a99ea85 upstream.
For more strict protection for wild disconnections, a refcount is
introduced to the card instance, and let it up/down when an object is
referred via snd_lookup_*() in the open ops.
The free-after-last-close check is also changed to check this refcount
instead of the empty list, too.
Reported-by: Matthieu CASTET <matthieu.castet@parrot.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'include')
| -rw-r--r-- | include/sound/core.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/sound/core.h b/include/sound/core.h index 3be5ab782b9..222f11eb191 100644 --- a/include/sound/core.h +++ b/include/sound/core.h @@ -132,6 +132,7 @@ struct snd_card { int shutdown; /* this card is going down */ int free_on_last_close; /* free in context of file_release */ wait_queue_head_t shutdown_sleep; + atomic_t refcount; /* refcount for disconnection */ struct device *dev; /* device assigned to this card */ struct device *card_dev; /* cardX object for sysfs */ @@ -189,6 +190,7 @@ struct snd_minor { 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 */ @@ -295,6 +297,7 @@ int snd_card_info_done(void); 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); +void snd_card_unref(struct snd_card *card); #define snd_card_set_dev(card, devptr) ((card)->dev = (devptr)) |