diff options
| author | Clemens Ladisch <clemens@ladisch.de> | 2009-11-02 08:35:44 (GMT) |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2009-11-06 13:32:06 (GMT) |
| commit | 25d27eded1f4fc728e64f443adc339b5229be5d7 (patch) | |
| tree | b738266467fc0f85d9f7f29e439dfff8e33da4c0 | |
| parent | 31cef7076ed9409a33f19ea372d6dc5fdefe27ae (diff) | |
| download | linux-25d27eded1f4fc728e64f443adc339b5229be5d7.tar.xz | |
control: use reference-counted pid
Instead of storing the PID number, take a reference to the task's pid
structure. This protects against duplicates due to PID overflows, and
using pid_vnr() ensures that the PID returned by snd_ctl_elem_info() is
correct as seen from the current namespace.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
| -rw-r--r-- | include/sound/control.h | 4 | ||||
| -rw-r--r-- | sound/core/control.c | 5 | ||||
| -rw-r--r-- | sound/core/pcm.c | 2 | ||||
| -rw-r--r-- | sound/core/rawmidi.c | 2 |
4 files changed, 8 insertions, 5 deletions
diff --git a/include/sound/control.h b/include/sound/control.h index 3517745..112374d 100644 --- a/include/sound/control.h +++ b/include/sound/control.h @@ -86,10 +86,12 @@ struct snd_kctl_event { #define snd_kctl_event(n) list_entry(n, struct snd_kctl_event, list) +struct pid; + struct snd_ctl_file { struct list_head list; /* list of all control files */ struct snd_card *card; - pid_t pid; + struct pid *pid; int prefer_pcm_subdevice; int prefer_rawmidi_subdevice; wait_queue_head_t change_sleep; diff --git a/sound/core/control.c b/sound/core/control.c index 814d2cf..73dc10a 100644 --- a/sound/core/control.c +++ b/sound/core/control.c @@ -75,7 +75,7 @@ static int snd_ctl_open(struct inode *inode, struct file *file) ctl->card = card; ctl->prefer_pcm_subdevice = -1; ctl->prefer_rawmidi_subdevice = -1; - ctl->pid = current->pid; + ctl->pid = get_pid(task_pid(current)); file->private_data = ctl; write_lock_irqsave(&card->ctl_files_rwlock, flags); list_add_tail(&ctl->list, &card->ctl_files); @@ -125,6 +125,7 @@ static int snd_ctl_release(struct inode *inode, struct file *file) control->vd[idx].owner = NULL; up_write(&card->controls_rwsem); snd_ctl_empty_read_queue(ctl); + put_pid(ctl->pid); kfree(ctl); module_put(card->module); snd_card_file_remove(card, file); @@ -672,7 +673,7 @@ static int snd_ctl_elem_info(struct snd_ctl_file *ctl, info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK; if (vd->owner == ctl) info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER; - info->owner = vd->owner->pid; + info->owner = pid_vnr(vd->owner->pid); } else { info->owner = -1; } diff --git a/sound/core/pcm.c b/sound/core/pcm.c index c69c60b..8e2c783 100644 --- a/sound/core/pcm.c +++ b/sound/core/pcm.c @@ -809,7 +809,7 @@ int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream, card = pcm->card; read_lock(&card->ctl_files_rwlock); list_for_each_entry(kctl, &card->ctl_files, list) { - if (kctl->pid == current->pid) { + if (kctl->pid == task_pid(current)) { prefer_subdevice = kctl->prefer_pcm_subdevice; if (prefer_subdevice != -1) break; diff --git a/sound/core/rawmidi.c b/sound/core/rawmidi.c index c0adc14..8a81bda 100644 --- a/sound/core/rawmidi.c +++ b/sound/core/rawmidi.c @@ -415,7 +415,7 @@ static int snd_rawmidi_open(struct inode *inode, struct file *file) subdevice = -1; read_lock(&card->ctl_files_rwlock); list_for_each_entry(kctl, &card->ctl_files, list) { - if (kctl->pid == current->pid) { + if (kctl->pid == task_pid(current)) { subdevice = kctl->prefer_rawmidi_subdevice; if (subdevice != -1) break; |