From: Ahmed Ehab <bottaawesome633@xxxxxxxxx>
Checking if the lockdep_map->name will change when setting the subclass.
It shouldn't change so that the lock class and subclass will have the same name
Reported-by: <syzbot+7f4a6f7f7051474e40ad@xxxxxxxxxxxxxxxxxxxxxxxxx>
Fixes: fd5e3f5fe27
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: botta633 <bottaawesome633@xxxxxxxxx>
---
lib/locking-selftest.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/lib/locking-selftest.c b/lib/locking-selftest.c
index 6f6a5fc85b42..1d7885205f36 100644
--- a/lib/locking-selftest.c
+++ b/lib/locking-selftest.c
@@ -2710,12 +2710,24 @@ static void local_lock_3B(void)
}
+static void class_subclass_X1_name(void)
+{
+ const char *name_before_subclass = rwsem_X1.dep_map.name;
+ const char *name_after_subclass;
+
+ WARN_ON(!rwsem_X1.dep_map.name);
+ lockdep_set_subclass(&rwsem_X1, 1);
+ WARN_ON(name_before_subclass != name_after_subclass);
+}
+
static void local_lock_tests(void)
{
printk(" --------------------------------------------------------------------------\n");
printk(" | local_lock tests |\n");
printk(" ---------------------\n");
+ init_class_X(&lock_X1, &rwlock_X1, &mutex_X1, &rwsem_X1);
+
print_testname("local_lock inversion 2");
dotest(local_lock_2, SUCCESS, LOCKTYPE_LL);
pr_cont("\n");
@@ -2727,6 +2739,10 @@ static void local_lock_tests(void)
print_testname("local_lock inversion 3B");
dotest(local_lock_3B, FAILURE, LOCKTYPE_LL);
pr_cont("\n");
+
+ print_testname("Class and subclass");
+ dotest(class_subclass_X1_name, SUCCESS, LOCKTYPE_RWSEM);
+ pr_cont("\n");
}
static void hardirq_deadlock_softirq_not_deadlock(void)
--
2.45.2
