From: Weizhao Ouyang <o451686892@xxxxxxxxx> Subject: kfence: defer kfence_test_init to ensure that kunit debugfs is created 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. Link: https://lkml.kernel.org/r/20210714113140.2949995-1-o451686892@xxxxxxxxx Signed-off-by: Weizhao Ouyang <o451686892@xxxxxxxxx> Tested-by: Marco Elver <elver@xxxxxxxxxx> Cc: Alexander Potapenko <glider@xxxxxxxxxx> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/kfence/kfence_test.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/kfence/kfence_test.c~kfence-defer-kfence_test_init-to-ensure-that-kunit-debugfs-is-created +++ a/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"); _
