Re: [alsa-devel] [PATCH] sound: convert snd_seq_subscribers.ref_count from atomic_t to refcount_t

21 Feb 2017

On Tue, Feb 21, 2017 at 05:27:10PM +0200, Elena Reshetova wrote:
...

diff --git a/sound/core/seq/seq_ports.c b/sound/core/seq/seq_ports.c
index fe686ee..1ca896b 100644
--- a/sound/core/seq/seq_ports.c
+++ b/sound/core/seq/seq_ports.c
...
@@ -520,7 +520,6 @@ static int check_and_subscribe_port(struct snd_seq_client *client,
   else
   	list_add_tail(&subs->dest_list, &grp->list_head);
   grp->exclusive = exclusive;

atomic_inc(&subs->ref_count);
write_unlock_irq(&grp->list_lock);
err = 0;

@@ -570,7 +569,6 @@ int snd_seq_port_connect(struct snd_seq_client *connector,
   	return -ENOMEM;
subs->info = *info;

atomic_set(&subs->ref_count, 0);
INIT_LIST_HEAD(&subs->src_list);
INIT_LIST_HEAD(&subs->dest_list);

@@ -587,6 +585,7 @@ int snd_seq_port_connect(struct snd_seq_client *connector,
   if (err < 0)
   	goto error_dest;

refcount_set(&subs->ref_count, 2);
return 0;
error_dest:


@@ -613,7 +612,7 @@ int snd_seq_port_disconnect(struct snd_seq_client *connector,
   /* look for the connection */
   list_for_each_entry(subs, &src->list_head, src_list) {
   	if (match_subs_info(info, &subs->info)) {

	atomic_dec(&subs->ref_count); /* mark as not ready */




	refcount_dec(&subs->ref_count); /* mark as not ready */
err = 0;
break;

}

This looks dodgy... someone should look hard at this.

    

Peter Zijlstra