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>

1 files changed, 1 insertions, 1 deletions

diff --git a/sound/core/rawmidi.c b/sound/core/rawmidi.c
index c0adc14c91f..8a81bdafce6 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;