From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yb1-f180.google.com (mail-yb1-f180.google.com [209.85.219.180]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0448C7C for ; Sun, 13 Feb 2022 21:10:53 +0000 (UTC) Received: by mail-yb1-f180.google.com with SMTP id j2so40818663ybu.0 for ; Sun, 13 Feb 2022 13:10:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=KnKCC7oMagFCvCCjM7qG97XmzNcP6hM32qMyVum/dto=; b=MBIsTxnulA1MrNZ+IsfyQOaRrtwl2q4GUdFP2YSW/j/CQ7Uo5Oyds++JXr0KB6K9x+ VvreKfnZ4OI7eVME/n17ninBX9E56yUSQQ2R5qj1lIXf8yPQQYP0ERc5X1WpaRPHcP6q QBrvTrlTGLyZ33s8yg3ouAySmVx67aNQvEXNDL9nOKXi0E+hnuwldGSabx914lYBnHX/ z3iO9qpTjoXA7zxlL3mje/Z58DspXjcEz6W1Er/cCM6QtpZm7+Fqnit3iBgWOcMGkzpT 3G/s1CZFbveKF+K2Tz9XNltXXoekdReLddn9QZCT9+yQ8vWU3HTdGuaU+22FP9LRB0Wd ZMIQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=KnKCC7oMagFCvCCjM7qG97XmzNcP6hM32qMyVum/dto=; b=5RMWL1aICPbRtF4ZTj5NjOOVKk9Gk1gzrfjC2p8+lAJY9M6oDjqi4oZmdGl4QJ90Wk YFhoi3p6oiPwv4AhilArCLH0J0U0W2uWRcfa8hv5quas4p0sqp6Ob+GCHG677wH7n5aw l88QrqEVqzxjyFCNxokzWiqkkBpS7G182ISxQROAbCkqWxpoVz8qTlUk6LL0R21bnuGa 9boOMCsl0mQx8XngrhwQu7LcBsguJFN1weMUQ+/udrG8eOEVNQqtwZuPzEnJiz11Mtba 4RkDedJqQLW+GEISQosDzj6v7U2rdRN66/630wagHX7kZwMWIMsRf87XjfV4qfwmukKC l0GA== X-Gm-Message-State: AOAM530KR4eDRI2PvfjP7XCJzzFZddoZ/XipYxxgsL3sUhtazh05r6q2 eaKYQMVcx3lPmDWwMFs5e34yu0d4AY1cZFQSf24= X-Google-Smtp-Source: ABdhPJxsBiwJdcvDK4XS9bg3KFwCrZ2nWejzoPKdiLINBF5sJzAhBkiYNgJAgG2bJBMKOIu1ap5H/J3qK03vAQhcyqc= X-Received: by 2002:a05:6902:124f:: with SMTP id t15mr11084809ybu.640.1644786652734; Sun, 13 Feb 2022 13:10:52 -0800 (PST) Precedence: bulk X-Mailing-List: regressions@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20220121221021.60533b009c357d660791476e@linux-foundation.org> <20220122061228.nmuo75sDn%akpm@linux-foundation.org> In-Reply-To: From: Tong Zhang Date: Sun, 13 Feb 2022 13:10:42 -0800 Message-ID: Subject: Re: [PATCH v2] Fix regression due to "fs: move binfmt_misc sysctl to its own file" To: Ido Schimmel Cc: Domenico Andreoli , Luis Chamberlain , "Eric W. Biederman" , David Airlie , Andrew Morton , amir73il@gmail.com, Andy Shevchenko , Arnd Bergmann , bcrl@kvack.org, benh@kernel.crashing.org, clemens@ladisch.de, crope@iki.fi, dgilbert@interlog.com, Greg KH , jack@suse.cz, jani.nikula@intel.com, Jani Nikula , "James E.J. Bottomley" , jlbec@evilplan.org, john.ogness@linutronix.de, Joonas Lahtinen , Joseph Qi , julia.lawall@inria.fr, Kees Cook , kernel@tuxforce.de, Linux Memory Management List , Mark Fasheh , "Martin K. Petersen" , mm-commits@vger.kernel.org, nixiaoming@huawei.com, penguin-kernel@i-love.sakura.ne.jp, peterz@infradead.org, Phillip Potter , Paul Turner , pmladek@suse.com, rafael@kernel.org, Rodrigo Vivi , rostedt@goodmis.org, senozhatsky@chromium.org, sre@kernel.org, steve@sk2.org, Suren Baghdasaryan , Linus Torvalds , tytso@mit.edu, Al Viro , wangqing@vivo.com, Iurii Zaikin , open list , regressions@lists.linux.dev Content-Type: text/plain; charset="UTF-8" On Sun, Feb 13, 2022 at 7:34 AM Ido Schimmel wrote: > > On Wed, Feb 09, 2022 at 08:49:20AM +0100, Domenico Andreoli wrote: > > fs/binfmt_misc.c | 6 +----- > > fs/file_table.c | 2 ++ > > 2 files changed, 3 insertions(+), 5 deletions(-) > > > > Index: b/fs/binfmt_misc.c > > =================================================================== > > --- a/fs/binfmt_misc.c > > +++ b/fs/binfmt_misc.c > > @@ -817,20 +817,16 @@ static struct file_system_type bm_fs_typ > > }; > > MODULE_ALIAS_FS("binfmt_misc"); > > > > -static struct ctl_table_header *binfmt_misc_header; > > - > > static int __init init_misc_binfmt(void) > > { > > int err = register_filesystem(&bm_fs_type); > > if (!err) > > insert_binfmt(&misc_format); > > - binfmt_misc_header = register_sysctl_mount_point("fs/binfmt_misc"); > > - return 0; > > + return err; > > } > > > > static void __exit exit_misc_binfmt(void) > > { > > - unregister_sysctl_table(binfmt_misc_header); > > unregister_binfmt(&misc_format); > > unregister_filesystem(&bm_fs_type); > > } > > Index: b/fs/file_table.c > > =================================================================== > > --- a/fs/file_table.c > > +++ b/fs/file_table.c > > @@ -119,6 +119,8 @@ static struct ctl_table fs_stat_sysctls[ > > static int __init init_fs_stat_sysctls(void) > > { > > register_sysctl_init("fs", fs_stat_sysctls); > > + if (IS_ENABLED(CONFIG_BINFMT_MISC)) > > + register_sysctl_mount_point("fs/binfmt_misc"); > > Hi, > > kmemleak complains about this: > > # cat /sys/kernel/debug/kmemleak > unreferenced object 0xffff8881045fea88 (size 96): > comm "swapper/0", pid 1, jiffies 4294669355 (age 167.804s) > hex dump (first 32 bytes): > e0 c8 07 88 ff ff ff ff 00 00 00 00 01 00 00 00 ................ > 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > backtrace: > [] __register_sysctl_table+0x117/0x1150 > [] init_fs_stat_sysctls+0x30/0x33 > [] do_one_initcall+0x108/0x690 > [] kernel_init_freeable+0x45a/0x4de > [] kernel_init+0x1f/0x220 > [] ret_from_fork+0x1f/0x30 > > > return 0; > > } > > fs_initcall(init_fs_stat_sysctls); > > Hi Ido, Thanks for the report. This is a known issue. The fix is proposed here. https://lore.kernel.org/all/YgRbEG21AUrLSFKX@bombadil.infradead.org/ Thanks, - Tong