preemptirq_delay_test accepts cpu_affinity as a module parameter and, when it is non-negative, writes that CPU directly into a temporary cpumask from the worker thread. Values outside nr_cpu_ids can set a bit outside the allocated cpumask before the test reports a normal affinity error.
Validate the requested CPU before starting the worker thread, and return -EINVAL for invalid affinity requests. Assisted-by: Codex:gpt-5.5-cyber-preview Signed-off-by: Samuel Moelius <[email protected]> --- kernel/trace/preemptirq_delay_test.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/kernel/trace/preemptirq_delay_test.c b/kernel/trace/preemptirq_delay_test.c index acb0c971a408..0f017799754a 100644 --- a/kernel/trace/preemptirq_delay_test.c +++ b/kernel/trace/preemptirq_delay_test.c @@ -14,6 +14,7 @@ #include <linux/kthread.h> #include <linux/module.h> #include <linux/printk.h> +#include <linux/cpumask.h> #include <linux/string.h> #include <linux/sysfs.h> #include <linux/completion.h> @@ -152,6 +153,15 @@ static int preemptirq_run_test(void) struct task_struct *task; char task_name[50]; + if (cpu_affinity > -1) { + unsigned int cpu = cpu_affinity; + + if (cpu >= nr_cpu_ids || !cpu_possible(cpu)) { + pr_err("cpu_affinity:%d, invalid CPU\n", cpu_affinity); + return -EINVAL; + } + } + init_completion(&done); snprintf(task_name, sizeof(task_name), "%s_test", test_mode); -- 2.43.0
