On Fri, Apr 1, 2022 at 5:52 AM Jakob Koschel jakobkoschel@gmail.com 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=EHreAsk5SqXPwr9Y7k9sA6cWX... [1] Signed-off-by: Jakob Koschel jakobkoschel@gmail.com
LGTM. Thanks. Reviewed-by: Baolin Wang baolin.wang@linux.alibaba.com
sound/soc/sprd/sprd-mcdt.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-)
diff --git a/sound/soc/sprd/sprd-mcdt.c b/sound/soc/sprd/sprd-mcdt.c index f6a55fa60c1b..6e27789a0df5 100644 --- a/sound/soc/sprd/sprd-mcdt.c +++ b/sound/soc/sprd/sprd-mcdt.c @@ -866,20 +866,19 @@ EXPORT_SYMBOL_GPL(sprd_mcdt_chan_dma_disable); struct sprd_mcdt_chan *sprd_mcdt_request_chan(u8 channel, enum sprd_mcdt_channel_type type) {
struct sprd_mcdt_chan *temp;
struct sprd_mcdt_chan *temp = NULL;struct sprd_mcdt_chan *iter; mutex_lock(&sprd_mcdt_list_mutex);
list_for_each_entry(temp, &sprd_mcdt_chan_list, list) {if (temp->type == type && temp->id == channel) {list_del_init(&temp->list);
list_for_each_entry(iter, &sprd_mcdt_chan_list, list) {if (iter->type == type && iter->id == channel) {list_del_init(&iter->list);temp = iter; break; } }
if (list_entry_is_head(temp, &sprd_mcdt_chan_list, list))temp = NULL;mutex_unlock(&sprd_mcdt_list_mutex); return temp;-- 2.25.1