locking/lockdep: Add a test for lockdep_set_subclass()

Add a test case to ensure that no new name string literal will be
created in lockdep_set_subclass(), otherwise a warning will be triggered
in look_up_lock_class(). Add this to catch the problem in the future.

[boqun: Reword the title, replace #if with #ifdef and rename functions
and variables]

Signed-off-by: Ahmed Ehab <bottaawesome633@gmail.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/lkml/20240905011220.356973-1-bottaawesome633@gmail.com/
This commit is contained in:
Ahmed Ehab 2024-09-05 04:12:20 +03:00 committed by Boqun Feng
parent d7fe143cb1
commit 5eadeb7b3b

View File

@ -2710,6 +2710,43 @@ static void local_lock_3B(void)
} }
#ifdef CONFIG_DEBUG_LOCK_ALLOC
static inline const char *rw_semaphore_lockdep_name(struct rw_semaphore *rwsem)
{
return rwsem->dep_map.name;
}
#else
static inline const char *rw_semaphore_lockdep_name(struct rw_semaphore *rwsem)
{
return NULL;
}
#endif
static void test_lockdep_set_subclass_name(void)
{
const char *name_before = rw_semaphore_lockdep_name(&rwsem_X1);
const char *name_after;
lockdep_set_subclass(&rwsem_X1, 1);
name_after = rw_semaphore_lockdep_name(&rwsem_X1);
DEBUG_LOCKS_WARN_ON(name_before != name_after);
}
/*
* lockdep_set_subclass() should reuse the existing lock class name instead
* of creating a new one.
*/
static void lockdep_set_subclass_name_test(void)
{
printk(" --------------------------------------------------------------------------\n");
printk(" | lockdep_set_subclass() name test|\n");
printk(" -----------------------------------\n");
print_testname("compare name before and after");
dotest(test_lockdep_set_subclass_name, SUCCESS, LOCKTYPE_RWSEM);
pr_cont("\n");
}
static void local_lock_tests(void) static void local_lock_tests(void)
{ {
printk(" --------------------------------------------------------------------------\n"); printk(" --------------------------------------------------------------------------\n");
@ -2920,6 +2957,8 @@ void locking_selftest(void)
dotest(hardirq_deadlock_softirq_not_deadlock, FAILURE, LOCKTYPE_SPECIAL); dotest(hardirq_deadlock_softirq_not_deadlock, FAILURE, LOCKTYPE_SPECIAL);
pr_cont("\n"); pr_cont("\n");
lockdep_set_subclass_name_test();
if (unexpected_testcase_failures) { if (unexpected_testcase_failures) {
printk("-----------------------------------------------------------------\n"); printk("-----------------------------------------------------------------\n");
debug_locks = 0; debug_locks = 0;