From: Masami Hiramatsu (Google) <[email protected]> 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) <[email protected]> --- 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;
