Commit b5fd12d6 authored by Takashi Iwai's avatar Takashi Iwai

ALSA: seq: Correct unlock sequence at snd_seq_client_ioctl_unlock()

The doubly unlock sequence at snd_seq_client_ioctl_unlock() is tricky.
I took a direct unref call since I thought it would avoid
misunderstanding, but rather this seems more confusing.  Let's use
snd_seq_client_unlock() consistently even if they look strange to be
called twice, and add more comments for avoiding reader's confusion.

Fixes: 6b580f52 ("ALSA: seq: Protect racy pool manipulation from OSS sequencer")
Reviewed-by: default avatarKai Vehmanen <kai.vehmanen@linux.intel.com>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 46f5710f
...@@ -191,6 +191,7 @@ bool snd_seq_client_ioctl_lock(int clientid) ...@@ -191,6 +191,7 @@ bool snd_seq_client_ioctl_lock(int clientid)
if (!client) if (!client)
return false; return false;
mutex_lock(&client->ioctl_mutex); mutex_lock(&client->ioctl_mutex);
/* The client isn't unrefed here; see snd_seq_client_ioctl_unlock() */
return true; return true;
} }
EXPORT_SYMBOL_GPL(snd_seq_client_ioctl_lock); EXPORT_SYMBOL_GPL(snd_seq_client_ioctl_lock);
...@@ -204,7 +205,11 @@ void snd_seq_client_ioctl_unlock(int clientid) ...@@ -204,7 +205,11 @@ void snd_seq_client_ioctl_unlock(int clientid)
if (WARN_ON(!client)) if (WARN_ON(!client))
return; return;
mutex_unlock(&client->ioctl_mutex); mutex_unlock(&client->ioctl_mutex);
snd_use_lock_free(&client->use_lock); /* The doubly unrefs below are intentional; the first one releases the
* leftover from snd_seq_client_ioctl_lock() above, and the second one
* is for releasing snd_seq_client_use_ptr() in this function
*/
snd_seq_client_unlock(client);
snd_seq_client_unlock(client); snd_seq_client_unlock(client);
} }
EXPORT_SYMBOL_GPL(snd_seq_client_ioctl_unlock); EXPORT_SYMBOL_GPL(snd_seq_client_ioctl_unlock);
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment