Hi

On 11/11/2025 14:42, Ma Ke wrote:

In etm_setup_aux(), when a user sink is obtained via coresight_get_sink_by_id(), it increments the reference count of the sink device. However, if the sink is used in path building, the path holds a reference, but the initial reference from coresight_get_sink_by_id() is not released, causing a reference count leak. We should release the initial reference after the path is built.

Found by code review.

Cc: stable@vger.kernel.org Fixes: 0e6c20517596 ("coresight: etm-perf: Allow an event to use different sinks") Signed-off-by: Ma Ke make24@iscas.ac.cn

---

drivers/hwtracing/coresight/coresight-etm-perf.c | 5 +++++ 1 file changed, 5 insertions(+)

diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c index f677c08233ba..6584f6aa87bf 100644 --- a/drivers/hwtracing/coresight/coresight-etm-perf.c +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c @@ -453,6 +453,11 @@ static void *etm_setup_aux(struct perf_event *event, void **pages, if (!event_data->snk_config) goto err;

• if (user_sink) {

• put_device(&user_sink->dev);
  

• user_sink = NULL;
  

• }

I would recommend moving this to the out: label below, to make sure we drop the refcount even in the error path.

Otherwise looks good to me.

Suzuki

out: return event_data;