[PATCH] kfence: defer kfence_test_init to ensure that kunit debugfs is created

From: Weizhao Ouyang
Date: Wed Jul 14 2021 - 07:31:50 EST


kfence_test_init and kunit_init both use the same level late_initcall,
which means if kfence_test_init linked ahead of kunit_init,
kfence_test_init will get a NULL debugfs_rootdir as parent dentry,
then kfence_test_init and kfence_debugfs_init both create a debugfs
node named "kfence" under debugfs_mount->mnt_root, and it will throw
out "debugfs: Directory 'kfence' with parent '/' already present!" with
EEXIST. So kfence_test_init should be deferred.

Signed-off-by: Weizhao Ouyang <o451686892@xxxxxxxxx>
---
mm/kfence/kfence_test.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/kfence/kfence_test.c b/mm/kfence/kfence_test.c
index 7f24b9bcb2ec..942cbc16ad26 100644
--- a/mm/kfence/kfence_test.c
+++ b/mm/kfence/kfence_test.c
@@ -852,7 +852,7 @@ static void kfence_test_exit(void)
tracepoint_synchronize_unregister();
}

-late_initcall(kfence_test_init);
+late_initcall_sync(kfence_test_init);
module_exit(kfence_test_exit);

MODULE_LICENSE("GPL v2");
--
2.30.2