[PATCH v2] coresight: add verification process for coresight_etm_get_trace_id

[Jie Gan]

The coresight_etm_get_trace_id function is a global function. The
verification process for 'csdev' is required prior to its usage.

Fixes: c367a89dec26 ("Coresight: Add trace_id function to retrieving the trace ID")
Signed-off-by: Jie Gan <quic_jiegan@xxxxxxxxxxx>
---
Changes in V2:
1. fix the logic error.
Link to V1 - https://lore.kernel.org/all/20250310022348.1654501-1-quic_jiegan@xxxxxxxxxxx/
---
 drivers/hwtracing/coresight/coresight-core.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
index bd0a7edd38c9..c915a055534e 100644
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -1616,9 +1616,12 @@ EXPORT_SYMBOL_GPL(coresight_remove_driver);
 int coresight_etm_get_trace_id(struct coresight_device *csdev, enum cs_mode mode,
 			       struct coresight_device *sink)
 {
-	int trace_id;
-	int cpu = source_ops(csdev)->cpu_id(csdev);
+	int cpu, trace_id;
+
+	if (csdev->type != CORESIGHT_DEV_TYPE_SOURCE || !source_ops(csdev)->cpu_id)
+		return -EINVAL;
 
+	cpu = source_ops(csdev)->cpu_id(csdev);
 	switch (mode) {
 	case CS_MODE_SYSFS:
 		trace_id = coresight_trace_id_get_cpu_id(cpu);
-- 
2.34.1