[PATCH v11 27/27] coresight: sysfs: Validate CPU online status for per-CPU sources

Leo Yan
2026-05-01T16:49:37Z

The current SysFS flow first enables the links and sink, then rolls back
to disable them if the source fails to enable. This failure can occur if
the associated CPU is offline, which causes the SMP call to fail.

Validate whether the associated CPU is online for a per-CPU tracer.
If the CPU is offline, return -ENODEV and bail out.

Tested-by: James Clark <james.clark@linaro.org>
Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
Reviewed-by: James Clark <james.clark@linaro.org>
Tested-by: Jie Gan <jie.gan@oss.qualcomm.com>
Signed-off-by: Leo Yan <leo.yan@arm.com>
---
drivers/hwtracing/coresight/coresight-sysfs.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/hwtracing/coresight/coresight-sysfs.c b/drivers/hwtracing/coresight/coresight-sysfs.c
index 42cf07b8d15a420e963650000dc32bbb38f0aa62..762d1ef91ccb49071720263c9b2a8438df7fa4a3 100644
--- a/drivers/hwtracing/coresight/coresight-sysfs.c
+++ b/drivers/hwtracing/coresight/coresight-sysfs.c
@@ -170,6 +170,9 @@ static int coresight_validate_source_sysfs(struct coresight_device *csdev,
return -EINVAL;
}

+ if (coresight_is_percpu_source(csdev) && !cpu_online(csdev->cpu))
+ return -ENODEV;
+
return 0;
}

--
2.34.1