diff options
| author | Takashi Iwai <tiwai@suse.de> | 2023-07-18 16:13:03 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2023-07-20 10:03:00 +0200 |
| commit | 9c2cc5652e4390bd4492433d96ad4caa785b09de (patch) | |
| tree | e59325e3de7ece5af318864cb74358043e961ff1 /sound/core | |
| parent | b1e055f67611daf098e27e8731386eeb5257bde3 (diff) | |
ALSA: control: Take lock in snd_ctl_find_id() and snd_ctl_find_numid()
Now all needed callers have been replaced with *_locked() versions,
let's turn on the locking in snd_ctl_find_id() and
snd_ctl_find_numid().
This patch also adds the lockdep assertions for debugging, too.
Link: https://lore.kernel.org/r/20230718141304.1032-11-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core')
| -rw-r--r-- | sound/core/control.c | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/sound/core/control.c b/sound/core/control.c index 30741293708d..e13e9d6b3b89 100644 --- a/sound/core/control.c +++ b/sound/core/control.c @@ -836,6 +836,7 @@ snd_ctl_find_numid_locked(struct snd_card *card, unsigned int numid) { if (snd_BUG_ON(!card || !numid)) return NULL; + lockdep_assert_held(&card->controls_rwsem); #ifdef CONFIG_SND_CTL_FAST_LOOKUP return xa_load(&card->ctl_numids, numid); #else @@ -852,11 +853,18 @@ EXPORT_SYMBOL(snd_ctl_find_numid_locked); * Finds the control instance with the given number-id from the card. * * Return: The pointer of the instance if found, or %NULL if not. + * + * Note that this function takes card->controls_rwsem lock internally. */ struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid) { - return snd_ctl_find_numid_locked(card, numid); + struct snd_kcontrol *kctl; + + down_read(&card->controls_rwsem); + kctl = snd_ctl_find_numid_locked(card, numid); + up_read(&card->controls_rwsem); + return kctl; } EXPORT_SYMBOL(snd_ctl_find_numid); @@ -879,6 +887,7 @@ struct snd_kcontrol *snd_ctl_find_id_locked(struct snd_card *card, if (snd_BUG_ON(!card || !id)) return NULL; + lockdep_assert_held(&card->controls_rwsem); if (id->numid != 0) return snd_ctl_find_numid_locked(card, id->numid); #ifdef CONFIG_SND_CTL_FAST_LOOKUP @@ -905,11 +914,18 @@ EXPORT_SYMBOL(snd_ctl_find_id_locked); * Finds the control instance with the given id from the card. * * Return: The pointer of the instance if found, or %NULL if not. + * + * Note that this function takes card->controls_rwsem lock internally. */ struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card, const struct snd_ctl_elem_id *id) { - return snd_ctl_find_id_locked(card, id); + struct snd_kcontrol *kctl; + + down_read(&card->controls_rwsem); + kctl = snd_ctl_find_id_locked(card, id); + up_read(&card->controls_rwsem); + return kctl; } EXPORT_SYMBOL(snd_ctl_find_id); |