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 in preemptirq_delay_run() before setting it in the temporary cpumask. Invalid affinity requests are reported by the test thread and skipped before cpumask_set_cpu() can touch an out-of-range bit. Assisted-by: Codex:gpt-5.5-cyber-preview Signed-off-by: Samuel Moelius <[email protected]> --- Changes in v2: - Move check to preemptirq_delay_run kernel/trace/preemptirq_delay_test.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/kernel/trace/preemptirq_delay_test.c b/kernel/trace/preemptirq_delay_test.c index acb0c971a408..69e5238737ed 100644 --- a/kernel/trace/preemptirq_delay_test.c +++ b/kernel/trace/preemptirq_delay_test.c @@ -6,6 +6,7 @@ */ #include <linux/trace_clock.h> +#include <linux/cpumask.h> #include <linux/delay.h> #include <linux/interrupt.h> #include <linux/irq.h> @@ -123,6 +124,13 @@ static int preemptirq_delay_run(void *data) return -ENOMEM; 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); + goto out; + } + cpumask_clear(cpu_mask); cpumask_set_cpu(cpu_affinity, cpu_mask); if (set_cpus_allowed_ptr(current, cpu_mask)) @@ -132,6 +140,7 @@ static int preemptirq_delay_run(void *data) for (i = 0; i < s; i++) (testfuncs[i])(i); +out: complete(&done); set_current_state(TASK_INTERRUPTIBLE); -- 2.43.0
