At Wed, 11 Feb 2015 19:40:11 +0900, Takashi Sakamoto wrote:
It's assumed that the number of userspace controls is just 1 in several parts, while this assumptions is not always true because the value of 'owner' member can be assigned to.
This commit fixes this issue.
Well, the current code isn't incorrect, it deals with the number of grouped elements, not the total number of elements. So, this is rather a change of the semantics of card->user_ctl_count field than a fix, and it's the question: whether we should limit for the whole number of elements.
There is a very slight chance of user-space breakage by counting the whole numbers, but pragmatically seen, I think it's acceptable from the safety POV.
However, changing the error code is no-go.
thanks,
Takashi
Signed-off-by: Takashi Sakamoto o-takashi@sakamocchi.jp
sound/core/control.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-)
diff --git a/sound/core/control.c b/sound/core/control.c index 1edd6c5..bce4730 100644 --- a/sound/core/control.c +++ b/sound/core/control.c @@ -514,6 +514,7 @@ static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file, { struct snd_card *card = file->card; struct snd_kcontrol *kctl;
unsigned int count; int i, ret;
down_write(&card->controls_rwsem);
@@ -531,10 +532,11 @@ static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file, ret = -EBUSY; goto error; }
- count = kctl->count; ret = snd_ctl_remove(card, kctl); if (ret < 0) goto error;
- card->user_ctl_count--;
- card->user_ctl_count -= count;
error: up_write(&card->controls_rwsem); return ret; @@ -1202,10 +1204,15 @@ static int snd_ctl_elem_add(struct snd_ctl_file *file, return err; }
- if (card->user_ctl_count >= MAX_USER_CONTROLS)
return -ENOMEM;
- /*
* The number of controls with the same feature, distinguished by index.*/- kctl.count = info->owner;
- if (kctl.count == 0)
kctl.count = 1;- if (card->user_ctl_count + kctl.count > MAX_USER_CONTROLS)
return -ENOSPC;
- kctl.count = info->owner ? info->owner : 1; if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) kctl.info = snd_ctl_elem_user_enum_info; else
@@ -1259,7 +1266,7 @@ static int snd_ctl_elem_add(struct snd_ctl_file *file, return err;
down_write(&card->controls_rwsem);
- card->user_ctl_count++;
card->user_ctl_count += _kctl->count; up_write(&card->controls_rwsem);
return 0;
-- 2.1.0