Re: [PATCH v5 1/7] tracing/events: Fix to check the simple_tsk_fn creation

[Masami Hiramatsu (Google) <mhiramat@kernel.org>]

Let me pick this fix to probes/core.

Thanks,

On Wed, 17 Jun 2026 10:02:53 +0900
"Masami Hiramatsu (Google)" <mhiramat@kernel.org> wrote:

> From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
> 
> Sashiko pointed that this sample code does not correctly handle the
> failure of thread creation because kthread_run() can return -errno.
> 
> Check the simple_tsk_fn is correctly initialized (created) or not.
> 
> Link: https://sashiko.dev/#/patchset/178092865666.163648.10457567771536160909.stgit%40devnote2
> 
> Fixes: 9cfe06f8cd5c ("tracing/events: add trace-events-sample")
> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
> ---
>  Changes in v4:
>    - Fix to remove decrementing counter in error path, since foo_bar_reg() always returns 0.
>    - Add a newline to error message.
>  Changes in v3:
>    - Recover the usage counter.
> ---
>  samples/trace_events/trace-events-sample.c |    4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/samples/trace_events/trace-events-sample.c b/samples/trace_events/trace-events-sample.c
> index ecc7db237f2e..0b7a6efdb247 100644
> --- a/samples/trace_events/trace-events-sample.c
> +++ b/samples/trace_events/trace-events-sample.c
> @@ -107,6 +107,10 @@ int foo_bar_reg(void)
>  	 * for consistency sake, we still take the thread_mutex.
>  	 */
>  	simple_tsk_fn = kthread_run(simple_thread_fn, NULL, "event-sample-fn");
> +	if (IS_ERR_OR_NULL(simple_tsk_fn)) {
> +		pr_err("Failed to create simple_thread_fn\n");
> +		simple_tsk_fn = NULL;
> +	}
>   out:
>  	mutex_unlock(&thread_mutex);
>  	return 0;
> 


-- 
Masami Hiramatsu (Google) <mhiramat@kernel.org>