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>
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 @@
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 @@
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 @@
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;
}