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; }