[PATCH] ww_mutex: convert self-test to KUnit

Convert this unit test to a KUnit test.

Signed-off-by: Tamir Duberstein tamird@gmail.com --- I tested this using: $ tools/testing/kunit/kunit.py run --arch arm64 --make_options LLVM=1 ww_mutex

On success: ; [12:48:16] ================== ww_mutex (5 subtests) =================== ; [12:48:16] ======================= test_mutex ======================== ; [12:48:16] [PASSED] flags=0 ; [12:48:16] [PASSED] flags=1 ; [12:48:16] [PASSED] flags=2 ; [12:48:16] [PASSED] flags=3 ; [12:48:16] [PASSED] flags=4 ; [12:48:17] [PASSED] flags=5 ; [12:48:17] [PASSED] flags=6 ; [12:48:17] [PASSED] flags=7 ; [12:48:17] =================== [PASSED] test_mutex ==================== ; [12:48:17] ========================= test_aa ========================= ; [12:48:17] [PASSED] lock ; [12:48:17] [PASSED] trylock ; [12:48:17] ===================== [PASSED] test_aa ===================== ; [12:48:17] ======================== test_abba ======================== ; [12:48:17] [PASSED] trylock=0,resolve=0 ; [12:48:17] [PASSED] trylock=1,resolve=1 ; [12:48:17] [PASSED] trylock=0,resolve=0 ; [12:48:17] [PASSED] trylock=1,resolve=1 ; [12:48:17] ==================== [PASSED] test_abba ==================== ; [12:48:17] ======================= test_cycle ======================== ; [12:48:17] [PASSED] nthreads=2 ; [12:48:17] =================== [PASSED] test_cycle ==================== ; [12:48:21] ========================= stress ========================== ; [12:48:21] [PASSED] nlocks=16,nthreads_per_cpu=2,flags=1 ; [12:48:23] [PASSED] nlocks=16,nthreads_per_cpu=2,flags=2 ; [12:48:23] [PASSED] nlocks=2046,nthreads_per_cpu=3,flags=7 ; [12:48:23] ===================== [PASSED] stress ====================== ; [12:48:23] ==================== [PASSED] ww_mutex ===================== ; [12:48:23] ============================================================ ; [12:48:23] Testing complete. Ran 18 tests: passed: 18

On failure: --- kernel/locking/Makefile | 3 +- .../locking/{test-ww_mutex.c => ww_mutex_kunit.c} | 311 ++++++++++----------- lib/Kconfig.debug | 12 +- tools/testing/selftests/locking/ww_mutex.sh | 19 -- 4 files changed, 163 insertions(+), 182 deletions(-)

diff --git a/kernel/locking/Makefile b/kernel/locking/Makefile index 0db4093d17b8..26af3e88fffa 100644 --- a/kernel/locking/Makefile +++ b/kernel/locking/Makefile @@ -30,5 +30,6 @@ obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock.o obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock_debug.o obj-$(CONFIG_QUEUED_RWLOCKS) += qrwlock.o obj-$(CONFIG_LOCK_TORTURE_TEST) += locktorture.o -obj-$(CONFIG_WW_MUTEX_SELFTEST) += test-ww_mutex.o obj-$(CONFIG_LOCK_EVENT_COUNTS) += lock_events.o + +obj-$(CONFIG_WW_MUTEX_KUNIT_TEST) += ww_mutex_kunit.o diff --git a/kernel/locking/test-ww_mutex.c b/kernel/locking/ww_mutex_kunit.c similarity index 67% rename from kernel/locking/test-ww_mutex.c rename to kernel/locking/ww_mutex_kunit.c index bcb1b9fea588..ba89a4a702f9 100644 --- a/kernel/locking/test-ww_mutex.c +++ b/kernel/locking/ww_mutex_kunit.c @@ -3,10 +3,10 @@ * Module-based API test facility for ww_mutexes */

-#include <linux/kernel.h> - +#include <kunit/test.h> #include <linux/completion.h> #include <linux/delay.h> +#include <linux/kernel.h> #include <linux/kthread.h> #include <linux/module.h> #include <linux/prandom.h> @@ -54,12 +54,39 @@ static void test_mutex_work(struct work_struct *work) ww_mutex_unlock(&mtx->mutex); }

-static int __test_mutex(unsigned int flags) +static const unsigned int *gen_range( + unsigned int *storage, + const unsigned int min, + const unsigned int max, + const int *prev) +{ + if (prev != NULL) { + if (*prev >= max) + return NULL; + *storage = *prev + 1; + } else { + *storage = min; + } + return storage; +} + +static const void *test_mutex_gen_params(const void *prev, char *desc) +{ + static unsigned int storage; + const unsigned int *next = gen_range(&storage, 0, __TEST_MTX_LAST - 1, prev); + + if (next != NULL) + snprintf(desc, KUNIT_PARAM_DESC_SIZE, "flags=%x", *next); + return next; +} + +static void test_mutex(struct kunit *test) { #define TIMEOUT (HZ / 16) + const unsigned int *param = test->param_value; + const unsigned int flags = *param; struct test_mutex mtx; struct ww_acquire_ctx ctx; - int ret;

ww_mutex_init(&mtx.mutex, &ww_class); if (flags & TEST_MTX_CTX) @@ -79,53 +106,42 @@ static int __test_mutex(unsigned int flags) if (flags & TEST_MTX_SPIN) { unsigned long timeout = jiffies + TIMEOUT;

- ret = 0; do { if (completion_done(&mtx.done)) { - ret = -EINVAL; + KUNIT_FAIL(test, "mutual exclusion failure"); break; } cond_resched(); } while (time_before(jiffies, timeout)); } else { - ret = wait_for_completion_timeout(&mtx.done, TIMEOUT); + KUNIT_EXPECT_EQ(test, wait_for_completion_timeout(&mtx.done, TIMEOUT), 0); } ww_mutex_unlock(&mtx.mutex); if (flags & TEST_MTX_CTX) ww_acquire_fini(&ctx);

- if (ret) { - pr_err("%s(flags=%x): mutual exclusion failure\n", - __func__, flags); - ret = -EINVAL; - } - flush_work(&mtx.work); destroy_work_on_stack(&mtx.work); - return ret; #undef TIMEOUT }

-static int test_mutex(void) +static const void *test_aa_gen_params(const void *prev, char *desc) { - int ret; - int i; + static unsigned int storage; + const unsigned int *next = gen_range(&storage, 0, 1, prev);

- for (i = 0; i < __TEST_MTX_LAST; i++) { - ret = __test_mutex(i); - if (ret) - return ret; - } - - return 0; + if (next != NULL) + snprintf(desc, KUNIT_PARAM_DESC_SIZE, *next ? "trylock" : "lock"); + return next; }

-static int test_aa(bool trylock) +static void test_aa(struct kunit *test) { + const unsigned int *param = test->param_value; + const bool trylock = *param; struct ww_mutex mutex; struct ww_acquire_ctx ctx; int ret; - const char *from = trylock ? "trylock" : "lock";

ww_mutex_init(&mutex, &ww_class); ww_acquire_init(&ctx, &ww_class); @@ -133,46 +149,42 @@ static int test_aa(bool trylock) if (!trylock) { ret = ww_mutex_lock(&mutex, &ctx); if (ret) { - pr_err("%s: initial lock failed!\n", __func__); + KUNIT_FAIL(test, "initial lock failed, ret=%d", ret); goto out; } } else { ret = !ww_mutex_trylock(&mutex, &ctx); if (ret) { - pr_err("%s: initial trylock failed!\n", __func__); + KUNIT_FAIL(test, "initial trylock failed, ret=%d", ret); goto out; } }

- if (ww_mutex_trylock(&mutex, NULL)) { - pr_err("%s: trylocked itself without context from %s!\n", __func__, from); + ret = ww_mutex_trylock(&mutex, NULL); + if (ret) { + KUNIT_FAIL(test, "trylocked itself without context, ret=%d", ret); ww_mutex_unlock(&mutex); - ret = -EINVAL; goto out; }

- if (ww_mutex_trylock(&mutex, &ctx)) { - pr_err("%s: trylocked itself with context from %s!\n", __func__, from); + ret = ww_mutex_trylock(&mutex, &ctx); + if (ret) { + KUNIT_FAIL(test, "trylocked itself with context, ret=%d", ret); ww_mutex_unlock(&mutex); - ret = -EINVAL; goto out; }

ret = ww_mutex_lock(&mutex, &ctx); if (ret != -EALREADY) { - pr_err("%s: missed deadlock for recursing, ret=%d from %s\n", - __func__, ret, from); + KUNIT_FAIL(test, "missed deadlock for recursing, ret=%d", ret); if (!ret) ww_mutex_unlock(&mutex); - ret = -EINVAL; goto out; }

ww_mutex_unlock(&mutex); - ret = 0; out: ww_acquire_fini(&ctx); - return ret; }

struct test_abba { @@ -217,11 +229,28 @@ static void test_abba_work(struct work_struct *work) abba->result = err; }

-static int test_abba(bool trylock, bool resolve) +static const void *test_abba_gen_params(const void *prev, char *desc) { + static unsigned int storage; + const unsigned int *next = gen_range(&storage, 0b00, 0b11, prev); + + if (next != NULL) { + const bool trylock = *next & 0b01 >> 0; + const bool resolve = *next & 0b10 >> 1; + + snprintf(desc, KUNIT_PARAM_DESC_SIZE, "trylock=%d,resolve=%d", trylock, resolve); + } + return next; +} + +static void test_abba(struct kunit *test) +{ + const unsigned int *param = test->param_value; + const bool trylock = *param & 0b01 >> 0; + const bool resolve = *param & 0b10 >> 1; struct test_abba abba; struct ww_acquire_ctx ctx; - int err, ret; + int err;

ww_mutex_init(&abba.a_mutex, &ww_class); ww_mutex_init(&abba.b_mutex, &ww_class); @@ -259,21 +288,17 @@ static int test_abba(bool trylock, bool resolve) flush_work(&abba.work); destroy_work_on_stack(&abba.work);

- ret = 0; if (resolve) { if (err || abba.result) { - pr_err("%s: failed to resolve ABBA deadlock, A err=%d, B err=%d\n", - __func__, err, abba.result); - ret = -EINVAL; + KUNIT_FAIL(test, "failed to resolve ABBA deadlock, A err=%d, B err=%d", + err, abba.result); } } else { if (err != -EDEADLK && abba.result != -EDEADLK) { - pr_err("%s: missed ABBA deadlock, A err=%d, B err=%d\n", - __func__, err, abba.result); - ret = -EINVAL; + KUNIT_FAIL(test, "missed ABBA deadlock, A err=%d, B err=%d", + err, abba.result); } } - return ret; }

struct test_cycle { @@ -314,15 +339,25 @@ static void test_cycle_work(struct work_struct *work) cycle->result = err ?: erra; }

-static int __test_cycle(unsigned int nthreads) +static const void *test_cycle_gen_params(const void *prev, char *desc) { + static unsigned int storage; + const unsigned int *next = gen_range(&storage, 2, num_online_cpus(), prev); + + if (next != NULL) + snprintf(desc, KUNIT_PARAM_DESC_SIZE, "nthreads=%d", *next); + return next; +} + +static void test_cycle(struct kunit *test) +{ + const unsigned int *param = test->param_value; + const unsigned int nthreads = *param; struct test_cycle *cycles; unsigned int n, last = nthreads - 1; - int ret;

- cycles = kmalloc_array(nthreads, sizeof(*cycles), GFP_KERNEL); - if (!cycles) - return -ENOMEM; + cycles = kunit_kmalloc_array(test, nthreads, sizeof(*cycles), GFP_KERNEL); + KUNIT_ASSERT_NOT_NULL(test, cycles);

for (n = 0; n < nthreads; n++) { struct test_cycle *cycle = &cycles[n]; @@ -348,41 +383,24 @@ static int __test_cycle(unsigned int nthreads)

flush_workqueue(wq);

- ret = 0; for (n = 0; n < nthreads; n++) { struct test_cycle *cycle = &cycles[n];

if (!cycle->result) continue;

- pr_err("cyclic deadlock not resolved, ret[%d/%d] = %d\n", - n, nthreads, cycle->result); - ret = -EINVAL; + KUNIT_FAIL(test, "cyclic deadlock not resolved, ret[%d/%d] = %d", + n, nthreads, cycle->result); break; }

for (n = 0; n < nthreads; n++) ww_mutex_destroy(&cycles[n].a_mutex); - kfree(cycles); - return ret; -} - -static int test_cycle(unsigned int ncpus) -{ - unsigned int n; - int ret; - - for (n = 2; n <= ncpus + 1; n++) { - ret = __test_cycle(n); - if (ret) - return ret; - } - - return 0; }

struct stress { struct work_struct work; + struct kunit *test; struct ww_mutex *locks; unsigned long timeout; int nlocks; @@ -401,12 +419,12 @@ static inline u32 prandom_u32_below(u32 ceil) return ret; }

-static int *get_random_order(int count) +static int *get_random_order(struct kunit *test, int count) { int *order; int n, r;

- order = kmalloc_array(count, sizeof(*order), GFP_KERNEL); + order = kunit_kmalloc_array(test, count, sizeof(*order), GFP_KERNEL); if (!order) return order;

@@ -435,7 +453,7 @@ static void stress_inorder_work(struct work_struct *work) struct ww_acquire_ctx ctx; int *order;

- order = get_random_order(nlocks); + order = get_random_order(stress->test, nlocks); if (!order) return;

@@ -472,13 +490,10 @@ static void stress_inorder_work(struct work_struct *work)

ww_acquire_fini(&ctx); if (err) { - pr_err_once("stress (%s) failed with %d\n", - __func__, err); + KUNIT_FAIL(stress->test, "lock[%d] failed, err=%d", n, err); break; } } while (!time_after(jiffies, stress->timeout)); - - kfree(order); }

struct reorder_lock { @@ -495,19 +510,16 @@ static void stress_reorder_work(struct work_struct *work) int *order; int n, err;

- order = get_random_order(stress->nlocks); - if (!order) - return; + order = get_random_order(stress->test, stress->nlocks); + KUNIT_ASSERT_NOT_NULL(stress->test, order);

for (n = 0; n < stress->nlocks; n++) { - ll = kmalloc(sizeof(*ll), GFP_KERNEL); - if (!ll) - goto out; + ll = kunit_kmalloc(stress->test, sizeof(*ll), GFP_KERNEL); + KUNIT_ASSERT_NOT_NULL(stress->test, ll);

ll->lock = &stress->locks[order[n]]; list_add(&ll->link, &locks); } - kfree(order); order = NULL;

do { @@ -523,8 +535,7 @@ static void stress_reorder_work(struct work_struct *work) ww_mutex_unlock(ln->lock);

if (err != -EDEADLK) { - pr_err_once("stress (%s) failed with %d\n", - __func__, err); + KUNIT_FAIL(stress->test, "lock failed, err=%d", err); break; }

@@ -538,11 +549,6 @@ static void stress_reorder_work(struct work_struct *work)

ww_acquire_fini(&ctx); } while (!time_after(jiffies, stress->timeout)); - -out: - list_for_each_entry_safe(ll, ln, &locks, link) - kfree(ll); - kfree(order); }

static void stress_one_work(struct work_struct *work) @@ -558,8 +564,7 @@ static void stress_one_work(struct work_struct *work) dummy_load(stress); ww_mutex_unlock(lock); } else { - pr_err_once("stress (%s) failed with %d\n", - __func__, err); + KUNIT_FAIL(stress->test, "lock failed, err=%d", err); break; } } while (!time_after(jiffies, stress->timeout)); @@ -570,22 +575,41 @@ static void stress_one_work(struct work_struct *work) #define STRESS_ONE BIT(2) #define STRESS_ALL (STRESS_INORDER | STRESS_REORDER | STRESS_ONE)

-static int stress(int nlocks, int nthreads, unsigned int flags) +struct stress_case { + int nlocks; + int nthreads_per_cpu; + unsigned int flags; +}; + +static const struct stress_case stress_cases[] = { + { 16, 2, STRESS_INORDER }, + { 16, 2, STRESS_REORDER }, + { 2046, hweight32(STRESS_ALL), STRESS_ALL }, +}; + +static void stress_case_to_desc(const struct stress_case *param, char *desc) { + snprintf(desc, KUNIT_PARAM_DESC_SIZE, "nlocks=%d,nthreads_per_cpu=%d,flags=%x", + param->nlocks, param->nthreads_per_cpu, param->flags); +} + +KUNIT_ARRAY_PARAM(stress_cases, stress_cases, stress_case_to_desc); + +static void stress(struct kunit *test) +{ + const struct stress_case *param = test->param_value; + const int nlocks = param->nlocks; + int nthreads = param->nthreads_per_cpu * num_online_cpus(); + const unsigned int flags = param->flags; struct ww_mutex *locks; struct stress *stress_array; int n, count;

- locks = kmalloc_array(nlocks, sizeof(*locks), GFP_KERNEL); - if (!locks) - return -ENOMEM; + locks = kunit_kmalloc_array(test, nlocks, sizeof(*locks), GFP_KERNEL); + KUNIT_ASSERT_NOT_NULL(test, locks);

- stress_array = kmalloc_array(nthreads, sizeof(*stress_array), - GFP_KERNEL); - if (!stress_array) { - kfree(locks); - return -ENOMEM; - } + stress_array = kunit_kmalloc_array(test, nthreads, sizeof(*stress_array), GFP_KERNEL); + KUNIT_ASSERT_NOT_NULL(test, stress_array);

for (n = 0; n < nlocks; n++) ww_mutex_init(&locks[n], &ww_class); @@ -617,6 +641,7 @@ static int stress(int nlocks, int nthreads, unsigned int flags) stress = &stress_array[count++];

INIT_WORK(&stress->work, fn); + stress->test = test; stress->locks = locks; stress->nlocks = nlocks; stress->timeout = jiffies + 2*HZ; @@ -629,70 +654,42 @@ static int stress(int nlocks, int nthreads, unsigned int flags)

for (n = 0; n < nlocks; n++) ww_mutex_destroy(&locks[n]); - kfree(stress_array); - kfree(locks); - - return 0; }

-static int __init test_ww_mutex_init(void) +static int ww_mutex_suite_init(struct kunit_suite *suite) { - int ncpus = num_online_cpus(); - int ret, i; - - printk(KERN_INFO "Beginning ww mutex selftests\n"); - - prandom_seed_state(&rng, get_random_u64()); - wq = alloc_workqueue("test-ww_mutex", WQ_UNBOUND, 0); if (!wq) return -ENOMEM;

- ret = test_mutex(); - if (ret) - return ret; - - ret = test_aa(false); - if (ret) - return ret; - - ret = test_aa(true); - if (ret) - return ret; - - for (i = 0; i < 4; i++) { - ret = test_abba(i & 1, i & 2); - if (ret) - return ret; - } - - ret = test_cycle(ncpus); - if (ret) - return ret; - - ret = stress(16, 2*ncpus, STRESS_INORDER); - if (ret) - return ret; - - ret = stress(16, 2*ncpus, STRESS_REORDER); - if (ret) - return ret; - - ret = stress(2046, hweight32(STRESS_ALL)*ncpus, STRESS_ALL); - if (ret) - return ret; + prandom_seed_state(&rng, get_random_u64());

- printk(KERN_INFO "All ww mutex selftests passed\n"); return 0; }

-static void __exit test_ww_mutex_exit(void) +static void ww_mutex_suite_exit(struct kunit_suite *suite) { - destroy_workqueue(wq); + if (wq) + destroy_workqueue(wq); }

-module_init(test_ww_mutex_init); -module_exit(test_ww_mutex_exit); +static struct kunit_case ww_mutex_cases[] = { + KUNIT_CASE_PARAM(test_mutex, test_mutex_gen_params), + KUNIT_CASE_PARAM(test_aa, test_aa_gen_params), + KUNIT_CASE_PARAM(test_abba, test_abba_gen_params), + KUNIT_CASE_PARAM(test_cycle, test_cycle_gen_params), + KUNIT_CASE_PARAM_ATTR(stress, stress_cases_gen_params, {.speed = KUNIT_SPEED_SLOW}), + {}, +}; + +static struct kunit_suite ww_mutex_suite = { + .name = "ww_mutex", + .suite_init = ww_mutex_suite_init, + .suite_exit = ww_mutex_suite_exit, + .test_cases = ww_mutex_cases, +}; + +kunit_test_suite(ww_mutex_suite);

MODULE_LICENSE("GPL"); MODULE_AUTHOR("Intel Corporation"); diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 1af972a92d06..a7edcbdc1428 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1586,16 +1586,18 @@ config LOCK_TORTURE_TEST Say M if you want these torture tests to build as a module. Say N if you are unsure.

-config WW_MUTEX_SELFTEST - tristate "Wait/wound mutex selftests" +config WW_MUTEX_KUNIT_TEST + tristate "KUnit test for wait/wound mutex" if !KUNIT_ALL_TESTS + depends on KUNIT + default KUNIT_ALL_TESTS help - This option provides a kernel module that runs tests on the - on the struct ww_mutex locking API. + This option provides a KUnit test that exercises the struct + ww_mutex locking API.

It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction with this test harness.

- Say M if you want these self tests to build as a module. + Say M if you want these tests to build as a module. Say N if you are unsure.

config SCF_TORTURE_TEST diff --git a/tools/testing/selftests/locking/ww_mutex.sh b/tools/testing/selftests/locking/ww_mutex.sh deleted file mode 100755 index 91e4ac7566af..000000000000 --- a/tools/testing/selftests/locking/ww_mutex.sh +++ /dev/null @@ -1,19 +0,0 @@ -#!/bin/sh -# SPDX-License-Identifier: GPL-2.0 - -# Kselftest framework requirement - SKIP code is 4. -ksft_skip=4 - -# Runs API tests for struct ww_mutex (Wait/Wound mutexes) -if ! /sbin/modprobe -q -n test-ww_mutex; then - echo "ww_mutex: module test-ww_mutex is not found [SKIP]" - exit $ksft_skip -fi - -if /sbin/modprobe -q test-ww_mutex; then - /sbin/modprobe -q -r test-ww_mutex - echo "locking/ww_mutex: ok" -else - echo "locking/ww_mutex: [FAIL]" - exit 1 -fi

--- base-commit: a64dcfb451e254085a7daee5fe51bf22959d52d3 change-id: 20250208-ww_mutex-kunit-convert-71842a7a6be2

Best regards,