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authorLars-Peter Clausen <lars@metafoo.de>2015-07-06 17:01:24 +0200
committerMark Brown <broonie@kernel.org>2015-07-06 20:27:06 +0100
commite50b1e06b79e9d51efbff9627b4dd407184ef43f (patch)
tree522717f8b80cd98f5b03b5a900129bf411aaef4a /sound
parentffacb48e5a4665d3d7286babb38a5af855a36bc0 (diff)
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ASoC: dapm: Lock during userspace access
The DAPM lock must be held when accessing the DAPM graph status through sysfs or debugfs, otherwise concurrent changes to the graph can result in undefined behaviour. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Mark Brown <broonie@kernel.org> Cc: stable@vger.kernel.org
Diffstat (limited to 'sound')
-rw-r--r--sound/soc/soc-dapm.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/sound/soc/soc-dapm.c b/sound/soc/soc-dapm.c
index a47a8ce7a5ea..1779430013ea 100644
--- a/sound/soc/soc-dapm.c
+++ b/sound/soc/soc-dapm.c
@@ -1952,6 +1952,7 @@ static ssize_t dapm_widget_power_read_file(struct file *file,
size_t count, loff_t *ppos)
{
struct snd_soc_dapm_widget *w = file->private_data;
+ struct snd_soc_card *card = w->dapm->card;
char *buf;
int in, out;
ssize_t ret;
@@ -1961,6 +1962,8 @@ static ssize_t dapm_widget_power_read_file(struct file *file,
if (!buf)
return -ENOMEM;
+ mutex_lock(&card->dapm_mutex);
+
/* Supply widgets are not handled by is_connected_{input,output}_ep() */
if (w->is_supply) {
in = 0;
@@ -2007,6 +2010,8 @@ static ssize_t dapm_widget_power_read_file(struct file *file,
p->sink->name);
}
+ mutex_unlock(&card->dapm_mutex);
+
ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);
kfree(buf);
@@ -2281,11 +2286,15 @@ static ssize_t dapm_widget_show(struct device *dev,
struct snd_soc_pcm_runtime *rtd = dev_get_drvdata(dev);
int i, count = 0;
+ mutex_lock(&rtd->card->dapm_mutex);
+
for (i = 0; i < rtd->num_codecs; i++) {
struct snd_soc_codec *codec = rtd->codec_dais[i]->codec;
count += dapm_widget_show_codec(codec, buf + count);
}
+ mutex_unlock(&rtd->card->dapm_mutex);
+
return count;
}