On 2022-03-31 11:50 PM, Jakob Koschel wrote:
When list_for_each_entry() completes the iteration over the whole list
without breaking the loop, the iterator value will be a bogus pointer
computed based on the head element.
While it is safe to use the pointer to determine if it was computed
based on the head element, either with list_entry_is_head() or
&pos->member == head, using the iterator variable after the loop should
be avoided.
In preparation to limiting the scope of a list iterator to the list
traversal loop, use a dedicated pointer to point to the found element [1].
Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@xxxxxxxxxxxxxx/ [1]
Signed-off-by: Jakob Koschel <jakobkoschel@xxxxxxxxx>
Thank you for taking time and updating catpt-driver along the way.
Acked-by: Cezary Rojewski <cezary.rojewski@xxxxxxxxx>
---
sound/soc/intel/catpt/pcm.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/sound/soc/intel/catpt/pcm.c b/sound/soc/intel/catpt/pcm.c
index a26000cd5ceb..b103b2d4026e 100644
--- a/sound/soc/intel/catpt/pcm.c
+++ b/sound/soc/intel/catpt/pcm.c
@@ -330,7 +330,8 @@ static int catpt_dai_apply_usettings(struct snd_soc_dai *dai,
struct catpt_stream_runtime *stream)
{
struct snd_soc_component *component = dai->component;
- struct snd_kcontrol *pos;
+ struct snd_kcontrol *pos = NULL;
+ struct snd_kcontrol *iter;
struct catpt_dev *cdev = dev_get_drvdata(dai->dev);
const char *name;
int ret;
@@ -354,12 +355,14 @@ static int catpt_dai_apply_usettings(struct snd_soc_dai *dai,
return 0;
}
- list_for_each_entry(pos, &component->card->snd_card->controls, list) {
- if (pos->private_data == component &&
- !strncmp(name, pos->id.name, sizeof(pos->id.name)))
+ list_for_each_entry(iter, &component->card->snd_card->controls, list) {
+ if (iter->private_data == component &&
+ !strncmp(name, iter->id.name, sizeof(iter->id.name))) {
+ pos = iter;
break;
+ }
}
- if (list_entry_is_head(pos, &component->card->snd_card->controls, list))
+ if (!pos)
return -ENOENT;
if (stream->template->type != CATPT_STRM_TYPE_LOOPBACK)
base-commit: f82da161ea75dc4db21b2499e4b1facd36dab275
