[PATCH] coresight: fix missing error code when trace ID is invalid

[Jie Gan]

When coresight_path_assign_trace_id() fails to allocate a valid trace
ID, the code jumps to err_path without setting ret to an error value.
This causes coresight_enable_sysfs() to return 0 (success) to the
caller even though no trace session was started.

Set ret = -EINVAL before the goto so that callers receive a proper
error code.

Fixes: d87d76d823d1 ("Coresight: Allocate trace ID after building the path")
Signed-off-by: Jie Gan <jie.gan at oss.qualcomm.com>
---
 drivers/hwtracing/coresight/coresight-sysfs.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/hwtracing/coresight/coresight-sysfs.c b/drivers/hwtracing/coresight/coresight-sysfs.c
index d2a6ed8bcc74..c9338c783540 100644
--- a/drivers/hwtracing/coresight/coresight-sysfs.c
+++ b/drivers/hwtracing/coresight/coresight-sysfs.c
@@ -195,42 +195,44 @@ int coresight_enable_sysfs(struct coresight_device *csdev)
 		 */
 		if (subtype == CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE)
 			csdev->refcnt++;
 		goto out;
 	}
 
 	sink = coresight_find_activated_sysfs_sink(csdev);
 	if (!sink) {
 		ret = -EINVAL;
 		goto out;
 	}
 
 	path = coresight_build_path(csdev, sink);
 	if (IS_ERR(path)) {
 		pr_err("building path(s) failed\n");
 		ret = PTR_ERR(path);
 		goto out;
 	}
 
 	coresight_path_assign_trace_id(path, CS_MODE_SYSFS);
-	if (!IS_VALID_CS_TRACE_ID(path->trace_id))
+	if (!IS_VALID_CS_TRACE_ID(path->trace_id)) {
+		ret = -EINVAL;
 		goto err_path;
+	}
 
 	ret = coresight_enable_path(path, CS_MODE_SYSFS);
 	if (ret)
 		goto err_path;
 
 	ret = coresight_enable_source_sysfs(csdev, CS_MODE_SYSFS, path);
 	if (ret)
 		goto err_source;
 
 	switch (subtype) {
 	case CORESIGHT_DEV_SUBTYPE_SOURCE_PROC:
 		/*
 		 * When working from sysFS it is important to keep track
 		 * of the paths that were created so that they can be
 		 * undone in 'coresight_disable()'.  Since there can only
 		 * be a single session per tracer (when working from sysFS)
 		 * a per-cpu variable will do just fine.
 		 */
 		cpu = source_ops(csdev)->cpu_id(csdev);
 		per_cpu(tracer_path, cpu) = path;

---
base-commit: 17c7841d09ee7d33557fd075562d9289b6018c90
change-id: 20260508-fix-trace-id-error-dbfdd4d8f2d1

Best regards,
-- 
Jie Gan <jie.gan at oss.qualcomm.com>