[PATCH v2] tracing: reject invalid preemptirq_delay_test CPU affinity
From: Samuel Moelius <hidden>
Date: 2026-06-28 13:12:57
Also in:
lkml
Subsystem:
the rest, tracing · Maintainers:
Linus Torvalds, Steven Rostedt, Masami Hiramatsu
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 <redacted> --- 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);
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2.43.0