ALSA: fireface: fix locking bug in ff400_copy_msg_to_user()

[linux-2.6-microblaze.git] / sound / firewire / fireface / ff-protocol-former.c

diff --git a/sound/firewire/fireface/ff-protocol-former.c b/sound/firewire/fireface/ff-protocol-former.c
index f580087..fa41de9 100644 (file)
--- a/sound/firewire/fireface/ff-protocol-former.c
+++ b/sound/firewire/fireface/ff-protocol-former.c
@@ -680,28 +680,30 @@ static long ff400_copy_msg_to_user(struct snd_ff *ff, char __user *buf, long cou
        struct ff400_msg_parser *parser = ff->msg_parser;
        u32 type = SNDRV_FIREWIRE_EVENT_FF400_MESSAGE;
        long consumed = 0;
+       int ret = 0;
 
        if (count < 8)
                return 0;
 
        spin_unlock_irq(&ff->lock);
-
        if (copy_to_user(buf, &type, sizeof(type)))
-               return -EFAULT;
-
+               ret = -EFAULT;
        spin_lock_irq(&ff->lock);
+       if (ret)
+               return ret;
 
        count -= sizeof(type);
        consumed += sizeof(type);
 
        while (count >= sizeof(*parser->msgs) && parser->pull_pos != parser->push_pos) {
                spin_unlock_irq(&ff->lock);
-
                if (copy_to_user(buf + consumed, parser->msgs + parser->pull_pos,
                                 sizeof(*parser->msgs)))
-                       return -EFAULT;
-
+                       ret = -EFAULT;
                spin_lock_irq(&ff->lock);
+               if (ret)
+                       return ret;
+
                ++parser->pull_pos;
                if (parser->pull_pos >= FF400_QUEUE_SIZE)
                        parser->pull_pos = 0;