[PATCH v2 12/28] coresight: sysfs: Validate CPU online status for per-CPU sources

[Yeoreum Yun]

Reviewed-by: Yeoreum Yun <yeoreum.yun at arm.com>

> 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.
>
> Signed-off-by: Leo Yan <leo.yan at 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 feadaf065b5318c8426aa53420b8e5f67a258683..14ee15297b98115122068cbe932f0b2ce004b77e 100644
> --- a/drivers/hwtracing/coresight/coresight-sysfs.c
> +++ b/drivers/hwtracing/coresight/coresight-sysfs.c
> @@ -161,6 +161,9 @@ 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
>

--
Sincerely,
Yeoreum Yun