From b81dce77cedcea6f00292f02d4b1ebbfc2c5988d Mon Sep 17 00:00:00 2001 From: Sander Vanheule Date: Sat, 2 Jul 2022 18:08:25 +0200 Subject: cpumask: Fix invalid uniprocessor mask assumption On uniprocessor builds, any CPU mask is assumed to contain exactly one CPU (cpu0). This assumption ignores the existence of empty masks, resulting in incorrect behaviour. cpumask_first_zero(), cpumask_next_zero(), and for_each_cpu_not() don't provide behaviour matching the assumption that a UP mask is always "1", and instead provide behaviour matching the empty mask. Drop the incorrectly optimised code and use the generic implementations in all cases. Link: https://lkml.kernel.org/r/86bf3f005abba2d92120ddd0809235cab4f759a6.1656777646.git.sander@svanheule.net Signed-off-by: Sander Vanheule Suggested-by: Yury Norov Cc: Andy Shevchenko Cc: Borislav Petkov Cc: Dave Hansen Cc: Greg Kroah-Hartman Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Marco Elver Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Valentin Schneider Signed-off-by: Andrew Morton --- lib/Makefile | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'lib/Makefile') diff --git a/lib/Makefile b/lib/Makefile index f99bf61f8bbc..bcc7e8ea0cde 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -34,10 +34,9 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \ is_single_threaded.o plist.o decompress.o kobject_uevent.o \ earlycpio.o seq_buf.o siphash.o dec_and_lock.o \ nmi_backtrace.o nodemask.o win_minmax.o memcat_p.o \ - buildid.o + buildid.o cpumask.o lib-$(CONFIG_PRINTK) += dump_stack.o -lib-$(CONFIG_SMP) += cpumask.o lib-y += kobject.o klist.o obj-y += lockref.o -- cgit v1.2.3 From c41e8866c28c4d1a88a085fc3c3d6ba403510804 Mon Sep 17 00:00:00 2001 From: Sander Vanheule Date: Sat, 2 Jul 2022 18:08:26 +0200 Subject: lib/test: introduce cpumask KUnit test suite Add a basic suite of tests for cpumask, providing some tests for empty and completely filled cpumasks. Link: https://lkml.kernel.org/r/c96980ec35c3bd23f17c3374bf42c22971545e85.1656777646.git.sander@svanheule.net Signed-off-by: Sander Vanheule Reviewed-by: Andy Shevchenko Suggested-by: Yury Norov Cc: Borislav Petkov Cc: Dave Hansen Cc: Greg Kroah-Hartman Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Marco Elver Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Valentin Schneider Signed-off-by: Andrew Morton --- lib/Kconfig.debug | 9 ++++ lib/Makefile | 1 + lib/test_cpumask.c | 138 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 148 insertions(+) create mode 100644 lib/test_cpumask.c (limited to 'lib/Makefile') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 2e24db4bff19..04aaa20d50f9 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2021,6 +2021,15 @@ config LKDTM Documentation on how to use the module can be found in Documentation/fault-injection/provoke-crashes.rst +config TEST_CPUMASK + tristate "cpumask tests" if !KUNIT_ALL_TESTS + depends on KUNIT + default KUNIT_ALL_TESTS + help + Enable to turn on cpumask tests, running at boot or module load time. + + If unsure, say N. + config TEST_LIST_SORT tristate "Linked list sorting test" if !KUNIT_ALL_TESTS depends on KUNIT diff --git a/lib/Makefile b/lib/Makefile index bcc7e8ea0cde..de3e47453fe8 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -99,6 +99,7 @@ obj-$(CONFIG_TEST_HMM) += test_hmm.o obj-$(CONFIG_TEST_FREE_PAGES) += test_free_pages.o obj-$(CONFIG_KPROBES_SANITY_TEST) += test_kprobes.o obj-$(CONFIG_TEST_REF_TRACKER) += test_ref_tracker.o +obj-$(CONFIG_TEST_CPUMASK) += test_cpumask.o CFLAGS_test_fprobe.o += $(CC_FLAGS_FTRACE) obj-$(CONFIG_FPROBE_SANITY_TEST) += test_fprobe.o # diff --git a/lib/test_cpumask.c b/lib/test_cpumask.c new file mode 100644 index 000000000000..a31a1622f1f6 --- /dev/null +++ b/lib/test_cpumask.c @@ -0,0 +1,138 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * KUnit tests for cpumask. + * + * Author: Sander Vanheule + */ + +#include +#include +#include + +#define EXPECT_FOR_EACH_CPU_EQ(test, mask) \ + do { \ + const cpumask_t *m = (mask); \ + int mask_weight = cpumask_weight(m); \ + int cpu, iter = 0; \ + for_each_cpu(cpu, m) \ + iter++; \ + KUNIT_EXPECT_EQ((test), mask_weight, iter); \ + } while (0) + +#define EXPECT_FOR_EACH_CPU_NOT_EQ(test, mask) \ + do { \ + const cpumask_t *m = (mask); \ + int mask_weight = cpumask_weight(m); \ + int cpu, iter = 0; \ + for_each_cpu_not(cpu, m) \ + iter++; \ + KUNIT_EXPECT_EQ((test), nr_cpu_ids - mask_weight, iter); \ + } while (0) + +#define EXPECT_FOR_EACH_CPU_WRAP_EQ(test, mask) \ + do { \ + const cpumask_t *m = (mask); \ + int mask_weight = cpumask_weight(m); \ + int cpu, iter = 0; \ + for_each_cpu_wrap(cpu, m, nr_cpu_ids / 2) \ + iter++; \ + KUNIT_EXPECT_EQ((test), mask_weight, iter); \ + } while (0) + +#define EXPECT_FOR_EACH_CPU_BUILTIN_EQ(test, name) \ + do { \ + int mask_weight = num_##name##_cpus(); \ + int cpu, iter = 0; \ + for_each_##name##_cpu(cpu) \ + iter++; \ + KUNIT_EXPECT_EQ((test), mask_weight, iter); \ + } while (0) + +static cpumask_t mask_empty; +static cpumask_t mask_all; + +static void test_cpumask_weight(struct kunit *test) +{ + KUNIT_EXPECT_TRUE(test, cpumask_empty(&mask_empty)); + KUNIT_EXPECT_TRUE(test, cpumask_full(cpu_possible_mask)); + KUNIT_EXPECT_TRUE(test, cpumask_full(&mask_all)); + + KUNIT_EXPECT_EQ(test, 0, cpumask_weight(&mask_empty)); + KUNIT_EXPECT_EQ(test, nr_cpu_ids, cpumask_weight(cpu_possible_mask)); + KUNIT_EXPECT_EQ(test, nr_cpumask_bits, cpumask_weight(&mask_all)); +} + +static void test_cpumask_first(struct kunit *test) +{ + KUNIT_EXPECT_LE(test, nr_cpu_ids, cpumask_first(&mask_empty)); + KUNIT_EXPECT_EQ(test, 0, cpumask_first(cpu_possible_mask)); + + KUNIT_EXPECT_EQ(test, 0, cpumask_first_zero(&mask_empty)); + KUNIT_EXPECT_LE(test, nr_cpu_ids, cpumask_first_zero(cpu_possible_mask)); +} + +static void test_cpumask_last(struct kunit *test) +{ + KUNIT_EXPECT_LE(test, nr_cpumask_bits, cpumask_last(&mask_empty)); + KUNIT_EXPECT_EQ(test, nr_cpumask_bits - 1, cpumask_last(cpu_possible_mask)); +} + +static void test_cpumask_next(struct kunit *test) +{ + KUNIT_EXPECT_EQ(test, 0, cpumask_next_zero(-1, &mask_empty)); + KUNIT_EXPECT_LE(test, nr_cpu_ids, cpumask_next_zero(-1, cpu_possible_mask)); + + KUNIT_EXPECT_LE(test, nr_cpu_ids, cpumask_next(-1, &mask_empty)); + KUNIT_EXPECT_EQ(test, 0, cpumask_next(-1, cpu_possible_mask)); +} + +static void test_cpumask_iterators(struct kunit *test) +{ + EXPECT_FOR_EACH_CPU_EQ(test, &mask_empty); + EXPECT_FOR_EACH_CPU_NOT_EQ(test, &mask_empty); + EXPECT_FOR_EACH_CPU_WRAP_EQ(test, &mask_empty); + + EXPECT_FOR_EACH_CPU_EQ(test, cpu_possible_mask); + EXPECT_FOR_EACH_CPU_NOT_EQ(test, cpu_possible_mask); + EXPECT_FOR_EACH_CPU_WRAP_EQ(test, cpu_possible_mask); +} + +static void test_cpumask_iterators_builtin(struct kunit *test) +{ + EXPECT_FOR_EACH_CPU_BUILTIN_EQ(test, possible); + + /* Ensure the dynamic masks are stable while running the tests */ + cpu_hotplug_disable(); + + EXPECT_FOR_EACH_CPU_BUILTIN_EQ(test, online); + EXPECT_FOR_EACH_CPU_BUILTIN_EQ(test, present); + + cpu_hotplug_enable(); +} + +static int test_cpumask_init(struct kunit *test) +{ + cpumask_clear(&mask_empty); + cpumask_setall(&mask_all); + + return 0; +} + +static struct kunit_case test_cpumask_cases[] = { + KUNIT_CASE(test_cpumask_weight), + KUNIT_CASE(test_cpumask_first), + KUNIT_CASE(test_cpumask_last), + KUNIT_CASE(test_cpumask_next), + KUNIT_CASE(test_cpumask_iterators), + KUNIT_CASE(test_cpumask_iterators_builtin), + {} +}; + +static struct kunit_suite test_cpumask_suite = { + .name = "cpumask", + .init = test_cpumask_init, + .test_cases = test_cpumask_cases, +}; +kunit_test_suite(test_cpumask_suite); + +MODULE_LICENSE("GPL"); -- cgit v1.2.3