From: Arnd Bergmann Date: Tue, 2 Sep 2025 14:03:26 +0000 (+0200) Subject: printk: kunit: support offstack cpumask X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=bf42df09b6aa4ebb596ecba66cf35b75362b55c7;p=thirdparty%2Fkernel%2Fstable.git printk: kunit: support offstack cpumask For large values of CONFIG_NR_CPUS, the newly added kunit test fails to build: kernel/printk/printk_ringbuffer_kunit_test.c: In function 'test_readerwriter': kernel/printk/printk_ringbuffer_kunit_test.c:279:1: error: the frame size of 1432 bytes is larger than 1280 bytes [-Werror=frame-larger-than=] Change this to use cpumask_var_t and allocate it dynamically when CONFIG_CPUMASK_OFFSTACK is set. The variable has to be released via a KUnit action wrapper so that it is freed when the test fails and gets aborted. The parameter type is hardcoded to "struct cpumask *" because the macro KUNIT_DEFINE_ACTION_WRAPPER() does not accept an array. But the function does nothing when CONFIG_CPUMASK_OFFSTACK is not set anyway. Fixes: 5ea2bcdfbf46 ("printk: ringbuffer: Add KUnit test") Signed-off-by: Arnd Bergmann Link: https://lore.kernel.org/all/20250620192554.2234184-1-arnd@kernel.org # v1 [pmladek@suse.com: Correctly handle allocation failures and freeing using KUnit test API.] Link: https://lore.kernel.org/all/20250702095157.110916-3-pmladek@suse.com # v2 Signed-off-by: Petr Mladek --- diff --git a/kernel/printk/printk_ringbuffer_kunit_test.c b/kernel/printk/printk_ringbuffer_kunit_test.c index e67e1815f4c8f..2282348e869a6 100644 --- a/kernel/printk/printk_ringbuffer_kunit_test.c +++ b/kernel/printk/printk_ringbuffer_kunit_test.c @@ -223,8 +223,17 @@ static int prbtest_reader(struct prbtest_data *test_data, unsigned long timeout_ return 0; } +KUNIT_DEFINE_ACTION_WRAPPER(prbtest_cpumask_cleanup, free_cpumask_var, struct cpumask *); KUNIT_DEFINE_ACTION_WRAPPER(prbtest_kthread_cleanup, kthread_stop, struct task_struct *); +static void prbtest_add_cpumask_cleanup(struct kunit *test, cpumask_var_t mask) +{ + int err; + + err = kunit_add_action_or_reset(test, prbtest_cpumask_cleanup, mask); + KUNIT_ASSERT_EQ(test, err, 0); +} + static void prbtest_add_kthread_cleanup(struct kunit *test, struct task_struct *kthread) { int err; @@ -247,9 +256,12 @@ static void test_readerwriter(struct kunit *test) struct prbtest_thread_data *thread_data; struct prbtest_data *test_data; struct task_struct *thread; - cpumask_t test_cpus; + cpumask_var_t test_cpus; int cpu, reader_cpu; + KUNIT_ASSERT_TRUE(test, alloc_cpumask_var(&test_cpus, GFP_KERNEL)); + prbtest_add_cpumask_cleanup(test, test_cpus); + cpus_read_lock(); /* * Failure of KUNIT_ASSERT() kills the current task @@ -257,15 +269,15 @@ static void test_readerwriter(struct kunit *test) * Instead use a snapshot of the online CPUs. * If they change during test execution it is unfortunate but not a grave error. */ - cpumask_copy(&test_cpus, cpu_online_mask); + cpumask_copy(test_cpus, cpu_online_mask); cpus_read_unlock(); /* One CPU is for the reader, all others are writers */ - reader_cpu = cpumask_first(&test_cpus); - if (cpumask_weight(&test_cpus) == 1) + reader_cpu = cpumask_first(test_cpus); + if (cpumask_weight(test_cpus) == 1) kunit_warn(test, "more than one CPU is recommended"); else - cpumask_clear_cpu(reader_cpu, &test_cpus); + cpumask_clear_cpu(reader_cpu, test_cpus); /* KUnit test can get restarted more times. */ prbtest_prb_reinit(&test_rb); @@ -278,7 +290,7 @@ static void test_readerwriter(struct kunit *test) kunit_info(test, "running for %lu ms\n", runtime_ms); - for_each_cpu(cpu, &test_cpus) { + for_each_cpu(cpu, test_cpus) { thread_data = kunit_kmalloc(test, sizeof(*thread_data), GFP_KERNEL); KUNIT_ASSERT_NOT_NULL(test, thread_data); thread_data->test_data = test_data;