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Diffstat (limited to 'kernel/locking/test-ww_mutex.c')
-rw-r--r--kernel/locking/test-ww_mutex.c155
1 files changed, 110 insertions, 45 deletions
diff --git a/kernel/locking/test-ww_mutex.c b/kernel/locking/test-ww_mutex.c
index 3e82f449b4ff..bcb1b9fea588 100644
--- a/kernel/locking/test-ww_mutex.c
+++ b/kernel/locking/test-ww_mutex.c
@@ -9,13 +9,22 @@
#include <linux/delay.h>
#include <linux/kthread.h>
#include <linux/module.h>
-#include <linux/random.h>
+#include <linux/prandom.h>
#include <linux/slab.h>
#include <linux/ww_mutex.h>
static DEFINE_WD_CLASS(ww_class);
struct workqueue_struct *wq;
+#ifdef CONFIG_DEBUG_WW_MUTEX_SLOWPATH
+#define ww_acquire_init_noinject(a, b) do { \
+ ww_acquire_init((a), (b)); \
+ (a)->deadlock_inject_countdown = ~0U; \
+ } while (0)
+#else
+#define ww_acquire_init_noinject(a, b) ww_acquire_init((a), (b))
+#endif
+
struct test_mutex {
struct work_struct work;
struct ww_mutex mutex;
@@ -36,7 +45,7 @@ static void test_mutex_work(struct work_struct *work)
wait_for_completion(&mtx->go);
if (mtx->flags & TEST_MTX_TRY) {
- while (!ww_mutex_trylock(&mtx->mutex))
+ while (!ww_mutex_trylock(&mtx->mutex, NULL))
cond_resched();
} else {
ww_mutex_lock(&mtx->mutex, NULL);
@@ -53,7 +62,8 @@ static int __test_mutex(unsigned int flags)
int ret;
ww_mutex_init(&mtx.mutex, &ww_class);
- ww_acquire_init(&ctx, &ww_class);
+ if (flags & TEST_MTX_CTX)
+ ww_acquire_init(&ctx, &ww_class);
INIT_WORK_ONSTACK(&mtx.work, test_mutex_work);
init_completion(&mtx.ready);
@@ -81,7 +91,8 @@ static int __test_mutex(unsigned int flags)
ret = wait_for_completion_timeout(&mtx.done, TIMEOUT);
}
ww_mutex_unlock(&mtx.mutex);
- ww_acquire_fini(&ctx);
+ if (flags & TEST_MTX_CTX)
+ ww_acquire_fini(&ctx);
if (ret) {
pr_err("%s(flags=%x): mutual exclusion failure\n",
@@ -109,19 +120,39 @@ static int test_mutex(void)
return 0;
}
-static int test_aa(void)
+static int test_aa(bool trylock)
{
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);
- ww_mutex_lock(&mutex, &ctx);
+ if (!trylock) {
+ ret = ww_mutex_lock(&mutex, &ctx);
+ if (ret) {
+ pr_err("%s: initial lock failed!\n", __func__);
+ goto out;
+ }
+ } else {
+ ret = !ww_mutex_trylock(&mutex, &ctx);
+ if (ret) {
+ pr_err("%s: initial trylock failed!\n", __func__);
+ goto out;
+ }
+ }
+
+ if (ww_mutex_trylock(&mutex, NULL)) {
+ pr_err("%s: trylocked itself without context from %s!\n", __func__, from);
+ ww_mutex_unlock(&mutex);
+ ret = -EINVAL;
+ goto out;
+ }
- if (ww_mutex_trylock(&mutex)) {
- pr_err("%s: trylocked itself!\n", __func__);
+ if (ww_mutex_trylock(&mutex, &ctx)) {
+ pr_err("%s: trylocked itself with context from %s!\n", __func__, from);
ww_mutex_unlock(&mutex);
ret = -EINVAL;
goto out;
@@ -129,17 +160,17 @@ static int test_aa(void)
ret = ww_mutex_lock(&mutex, &ctx);
if (ret != -EALREADY) {
- pr_err("%s: missed deadlock for recursing, ret=%d\n",
- __func__, ret);
+ pr_err("%s: missed deadlock for recursing, ret=%d from %s\n",
+ __func__, ret, from);
if (!ret)
ww_mutex_unlock(&mutex);
ret = -EINVAL;
goto out;
}
+ ww_mutex_unlock(&mutex);
ret = 0;
out:
- ww_mutex_unlock(&mutex);
ww_acquire_fini(&ctx);
return ret;
}
@@ -150,7 +181,7 @@ struct test_abba {
struct ww_mutex b_mutex;
struct completion a_ready;
struct completion b_ready;
- bool resolve;
+ bool resolve, trylock;
int result;
};
@@ -160,8 +191,13 @@ static void test_abba_work(struct work_struct *work)
struct ww_acquire_ctx ctx;
int err;
- ww_acquire_init(&ctx, &ww_class);
- ww_mutex_lock(&abba->b_mutex, &ctx);
+ ww_acquire_init_noinject(&ctx, &ww_class);
+ if (!abba->trylock)
+ ww_mutex_lock(&abba->b_mutex, &ctx);
+ else
+ WARN_ON(!ww_mutex_trylock(&abba->b_mutex, &ctx));
+
+ WARN_ON(READ_ONCE(abba->b_mutex.ctx) != &ctx);
complete(&abba->b_ready);
wait_for_completion(&abba->a_ready);
@@ -181,7 +217,7 @@ static void test_abba_work(struct work_struct *work)
abba->result = err;
}
-static int test_abba(bool resolve)
+static int test_abba(bool trylock, bool resolve)
{
struct test_abba abba;
struct ww_acquire_ctx ctx;
@@ -192,12 +228,18 @@ static int test_abba(bool resolve)
INIT_WORK_ONSTACK(&abba.work, test_abba_work);
init_completion(&abba.a_ready);
init_completion(&abba.b_ready);
+ abba.trylock = trylock;
abba.resolve = resolve;
schedule_work(&abba.work);
- ww_acquire_init(&ctx, &ww_class);
- ww_mutex_lock(&abba.a_mutex, &ctx);
+ ww_acquire_init_noinject(&ctx, &ww_class);
+ if (!trylock)
+ ww_mutex_lock(&abba.a_mutex, &ctx);
+ else
+ WARN_ON(!ww_mutex_trylock(&abba.a_mutex, &ctx));
+
+ WARN_ON(READ_ONCE(abba.a_mutex.ctx) != &ctx);
complete(&abba.a_ready);
wait_for_completion(&abba.b_ready);
@@ -249,7 +291,7 @@ static void test_cycle_work(struct work_struct *work)
struct ww_acquire_ctx ctx;
int err, erra = 0;
- ww_acquire_init(&ctx, &ww_class);
+ ww_acquire_init_noinject(&ctx, &ww_class);
ww_mutex_lock(&cycle->a_mutex, &ctx);
complete(cycle->a_signal);
@@ -346,10 +388,23 @@ struct stress {
int nlocks;
};
+struct rnd_state rng;
+DEFINE_SPINLOCK(rng_lock);
+
+static inline u32 prandom_u32_below(u32 ceil)
+{
+ u32 ret;
+
+ spin_lock(&rng_lock);
+ ret = prandom_u32_state(&rng) % ceil;
+ spin_unlock(&rng_lock);
+ return ret;
+}
+
static int *get_random_order(int count)
{
int *order;
- int n, r, tmp;
+ int n, r;
order = kmalloc_array(count, sizeof(*order), GFP_KERNEL);
if (!order)
@@ -359,12 +414,9 @@ static int *get_random_order(int count)
order[n] = n;
for (n = count - 1; n > 1; n--) {
- r = get_random_int() % (n + 1);
- if (r != n) {
- tmp = order[n];
- order[n] = order[r];
- order[r] = tmp;
- }
+ r = prandom_u32_below(n + 1);
+ if (r != n)
+ swap(order[n], order[r]);
}
return order;
@@ -412,21 +464,21 @@ retry:
ww_mutex_unlock(&locks[order[n]]);
if (err == -EDEADLK) {
- ww_mutex_lock_slow(&locks[order[contended]], &ctx);
- goto retry;
+ if (!time_after(jiffies, stress->timeout)) {
+ ww_mutex_lock_slow(&locks[order[contended]], &ctx);
+ goto retry;
+ }
}
+ ww_acquire_fini(&ctx);
if (err) {
pr_err_once("stress (%s) failed with %d\n",
__func__, err);
break;
}
-
- ww_acquire_fini(&ctx);
} while (!time_after(jiffies, stress->timeout));
kfree(order);
- kfree(stress);
}
struct reorder_lock {
@@ -491,14 +543,13 @@ out:
list_for_each_entry_safe(ll, ln, &locks, link)
kfree(ll);
kfree(order);
- kfree(stress);
}
static void stress_one_work(struct work_struct *work)
{
struct stress *stress = container_of(work, typeof(*stress), work);
const int nlocks = stress->nlocks;
- struct ww_mutex *lock = stress->locks + (get_random_int() % nlocks);
+ struct ww_mutex *lock = stress->locks + get_random_u32_below(nlocks);
int err;
do {
@@ -512,8 +563,6 @@ static void stress_one_work(struct work_struct *work)
break;
}
} while (!time_after(jiffies, stress->timeout));
-
- kfree(stress);
}
#define STRESS_INORDER BIT(0)
@@ -524,15 +573,24 @@ static void stress_one_work(struct work_struct *work)
static int stress(int nlocks, int nthreads, unsigned int flags)
{
struct ww_mutex *locks;
- int n;
+ struct stress *stress_array;
+ int n, count;
locks = kmalloc_array(nlocks, sizeof(*locks), GFP_KERNEL);
if (!locks)
return -ENOMEM;
+ stress_array = kmalloc_array(nthreads, sizeof(*stress_array),
+ GFP_KERNEL);
+ if (!stress_array) {
+ kfree(locks);
+ return -ENOMEM;
+ }
+
for (n = 0; n < nlocks; n++)
ww_mutex_init(&locks[n], &ww_class);
+ count = 0;
for (n = 0; nthreads; n++) {
struct stress *stress;
void (*fn)(struct work_struct *work);
@@ -556,9 +614,7 @@ static int stress(int nlocks, int nthreads, unsigned int flags)
if (!fn)
continue;
- stress = kmalloc(sizeof(*stress), GFP_KERNEL);
- if (!stress)
- break;
+ stress = &stress_array[count++];
INIT_WORK(&stress->work, fn);
stress->locks = locks;
@@ -573,6 +629,7 @@ 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;
@@ -581,7 +638,11 @@ static int stress(int nlocks, int nthreads, unsigned int flags)
static int __init test_ww_mutex_init(void)
{
int ncpus = num_online_cpus();
- int ret;
+ 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)
@@ -591,17 +652,19 @@ static int __init test_ww_mutex_init(void)
if (ret)
return ret;
- ret = test_aa();
+ ret = test_aa(false);
if (ret)
return ret;
- ret = test_abba(false);
+ ret = test_aa(true);
if (ret)
return ret;
- ret = test_abba(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)
@@ -615,10 +678,11 @@ static int __init test_ww_mutex_init(void)
if (ret)
return ret;
- ret = stress(4095, hweight32(STRESS_ALL)*ncpus, STRESS_ALL);
+ ret = stress(2046, hweight32(STRESS_ALL)*ncpus, STRESS_ALL);
if (ret)
return ret;
+ printk(KERN_INFO "All ww mutex selftests passed\n");
return 0;
}
@@ -632,3 +696,4 @@ module_exit(test_ww_mutex_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Intel Corporation");
+MODULE_DESCRIPTION("API test facility for ww_mutexes");
generated by cgit (git 2.34.1) at 2025-07-24 06:53:47 +0000