From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Date: Wed, 24 Jun 2026 23:34:46 +0000 (+0900)
Subject: tracing/events: Fix to check the simple_tsk_fn creation
X-Git-Tag: v7.2-rc2~26^2~4
X-Git-Url: http://git.ipfire.org/index.cgi?a=commitdiff_plain;h=cda1fbfc5313bb90daa271d45eea4a8d317a8544;p=thirdparty%2Flinux.git

tracing/events: Fix to check the simple_tsk_fn creation

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://lore.kernel.org/all/178165817322.269421.3992299509400184196.stgit@devnote2/

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>
---

diff --git a/samples/trace_events/trace-events-sample.c b/samples/trace_events/trace-events-sample.c
index ecc7db237f2ef..0b7a6efdb247a 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;