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 --- Changes in v2: - modified the patch as suggestions. --- 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..8a5a59434cc9 100644 --- a/drivers/hwtracing/coresight/coresight-etm-perf.c +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c @@ -454,6 +454,11 @@ static void *etm_setup_aux(struct perf_event *event, void **pages, goto err;
out: + if (user_sink) { + put_device(&user_sink->dev); + user_sink = NULL; + } + return event_data;
err:
On 11/12/25 01:24, Ma Ke wrote:
@@ -454,6 +454,11 @@ static void *etm_setup_aux(struct perf_event *event, void **pages, goto err; out:
- if (user_sink) {
put_device(&user_sink->dev);user_sink = NULL;- }
After searched kernel, I prefer to put device in coresight_get_sink_by_id(). Please refer acpi_dev_present() how to do that.
I would like Suzuki's confirmation in case I introduce noise.
Thanks, Leo
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