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Wed, 14 Jul 2021 04:56:31 -0700 (PDT) MIME-Version: 1.0 References: <20210714113140.2949995-1-o451686892@gmail.com> In-Reply-To: <20210714113140.2949995-1-o451686892@gmail.com> From: Marco Elver Date: Wed, 14 Jul 2021 13:56:20 +0200 Message-ID: Subject: Re: [PATCH] kfence: defer kfence_test_init to ensure that kunit debugfs is created To: Weizhao Ouyang Cc: glider@google.com, dvyukov@google.com, akpm@linux-foundation.org, kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Authentication-Results: imf10.hostedemail.com; dkim=pass header.d=google.com header.s=20161025 header.b=VkTKir8E; spf=pass (imf10.hostedemail.com: domain of elver@google.com designates 209.85.210.43 as permitted sender) smtp.mailfrom=elver@google.com; dmarc=pass (policy=reject) header.from=google.com X-Rspamd-Server: rspam02 X-Stat-Signature: dk3nczpq3bswsdgngyd6jpbumxe68ztx X-Rspamd-Queue-Id: A603F6001985 X-HE-Tag: 1626263792-621095 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000003, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, 14 Jul 2021 at 13:31, Weizhao Ouyang wrote: > 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 Tested-by: Marco Elver Thank you. > --- > 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