snd/PCM: fasync BKL pushdown

Chances are this is unneeded, but the code is twisty enough that it is hard
to tell.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>

1 files changed, 6 insertions, 2 deletions

diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index 61f5d425b630..c49b9d9e303c 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -22,6 +22,7 @@
 #include <linux/mm.h>
 #include <linux/file.h>
 #include <linux/slab.h>
+#include <linux/smp_lock.h>
 #include <linux/time.h>
 #include <linux/pm_qos_params.h>
 #include <linux/uio.h>
@@ -3249,14 +3250,17 @@ static int snd_pcm_fasync(int fd, struct file * file, int on)
         struct snd_pcm_file * pcm_file;
         struct snd_pcm_substream *substream;
         struct snd_pcm_runtime *runtime;
-        int err;
+        int err = -ENXIO;
 
+        lock_kernel();
         pcm_file = file->private_data;
         substream = pcm_file->substream;
-        snd_assert(substream != NULL, return -ENXIO);
+        snd_assert(substream != NULL, goto out);
         runtime = substream->runtime;
 
         err = fasync_helper(fd, file, on, &runtime->fasync);
+out:
+        unlock_kernel();
         if (err < 0)
                 return err;
         return 0;