[PATCH] coresight: perf: Fix pointer check with IS_ERR_OR_NULL()

[Leo Yan]

The returned pointer from .alloc_buffer() callback can be an error, if
only checking NULL pointer the driver cannot capture errors. The driver
will proceed even after failure and cause kernel panic.

Change to use IS_ERR_OR_NULL() check for capture error cases.

Fixes: 0bcbf2e30ff2 ("coresight: etm-perf: new PMU driver for ETM tracers")
Reported-by: Tamas Zsoldos <tamas.zsoldos at arm.com>
Signed-off-by: Leo Yan <leo.yan at arm.com>
---
 drivers/hwtracing/coresight/coresight-etm-perf.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
index f677c08233ba1a28b277674662c6e6db904873dd..440d967f5d0962df187a81b0dd69a7d82a8b62ba 100644
--- a/drivers/hwtracing/coresight/coresight-etm-perf.c
+++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
@@ -198,7 +198,7 @@ static void free_sink_buffer(struct etm_event_data *event_data)
 	cpumask_t *mask = &event_data->mask;
 	struct coresight_device *sink;
 
-	if (!event_data->snk_config)
+	if (IS_ERR_OR_NULL(event_data->snk_config))
 		return;
 
 	if (WARN_ON(cpumask_empty(mask)))
@@ -450,7 +450,7 @@ static void *etm_setup_aux(struct perf_event *event, void **pages,
 	event_data->snk_config =
 			sink_ops(sink)->alloc_buffer(sink, event, pages,
 						     nr_pages, overwrite);
-	if (!event_data->snk_config)
+	if (IS_ERR_OR_NULL(event_data->snk_config))
 		goto err;
 
 out:

---
base-commit: fa71e9cb4cfa59abb196229667ec84929bdc18fe
change-id: 20250904-cs_etm_auxsetup_fix_error_handling-cb7e07ed9adf

Best regards,
-- 
Leo Yan <leo.yan at arm.com>