| Message ID | YgNyAC8VMeuOD/uQ@dumbo (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] Fix regression due to "fs: move binfmt_misc sysctl to its own file" | expand |
On Tue, Feb 8, 2022 at 11:49 PM Domenico Andreoli <domenico.andreoli@linux.com> wrote: > > Commit 3ba442d5331f did not go unnoticed, binfmt-support stopped to > work on my Debian system since v5.17-rc2 (did not check with -rc1). > > The existance of the /proc/sys/fs/binfmt_misc is a precondition for > attempting to mount the binfmt_misc fs, which in turn triggers the > autoload of the binfmt_misc module. Without it, no module is loaded > and no binfmt is available at boot. > > Building as built-in or manually loading the module and mounting the fs > works fine, it's therefore only a matter of interaction with user-space. > I could try to improve the Debian systemd configuration but I can't > say anything about the other distributions. > > This patch restores a working system right after boot. > > v2: > - move creation of fs/binfmt_misc to fs/file_table.c > - use IS_ENABLED() to conditionally create it > > Fixes: 3ba442d5331f ("fs: move binfmt_misc sysctl to its own file") > Signed-off-by: Domenico Andreoli <domenico.andreoli@linux.com> > Cc: Al Viro <viro@zeniv.linux.org.uk> > Cc: Amir Goldstein <amir73il@gmail.com> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > Cc: Antti Palosaari <crope@iki.fi> > Cc: Arnd Bergmann <arnd@arndb.de> > Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> > Cc: Benjamin LaHaise <bcrl@kvack.org> > Cc: Clemens Ladisch <clemens@ladisch.de> > Cc: David Airlie <airlied@linux.ie> > Cc: Douglas Gilbert <dgilbert@interlog.com> > Cc: Eric Biederman <ebiederm@xmission.com> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Cc: Iurii Zaikin <yzaikin@google.com> > Cc: James E.J. Bottomley <jejb@linux.ibm.com> > Cc: Jan Kara <jack@suse.cz> > Cc: Jani Nikula <jani.nikula@intel.com> > Cc: Jani Nikula <jani.nikula@linux.intel.com> > Cc: Joel Becker <jlbec@evilplan.org> > Cc: John Ogness <john.ogness@linutronix.de> > Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> > Cc: Joseph Qi <joseph.qi@linux.alibaba.com> > Cc: Julia Lawall <julia.lawall@inria.fr> > Cc: Kees Cook <keescook@chromium.org> > Cc: Lukas Middendorf <kernel@tuxforce.de> > Cc: Mark Fasheh <mark@fasheh.com> > Cc: Martin K. Petersen <martin.petersen@oracle.com> > Cc: Paul Turner <pjt@google.com> > Cc: Peter Zijlstra <peterz@infradead.org> > Cc: Petr Mladek <pmladek@suse.com> > Cc: Phillip Potter <phil@philpotter.co.uk> > Cc: Qing Wang <wangqing@vivo.com> > Cc: "Rafael J. Wysocki" <rafael@kernel.org> > Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> > Cc: Sebastian Reichel <sre@kernel.org> > Cc: Sergey Senozhatsky <senozhatsky@chromium.org> > Cc: Stephen Kitt <steve@sk2.org> > Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> > Cc: Suren Baghdasaryan <surenb@google.com> > Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> > Cc: "Theodore Ts'o" <tytso@mit.edu> > Cc: Xiaoming Ni <nixiaoming@huawei.com> > > --- > 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"); > return 0; > } > fs_initcall(init_fs_stat_sysctls); Looks good Thanks! Reviewed-by: Tong Zhang <ztong0001@gmail.com>
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: [<ffffffff81d11637>] __register_sysctl_table+0x117/0x1150 [<ffffffff86c3600f>] init_fs_stat_sysctls+0x30/0x33 [<ffffffff81002558>] do_one_initcall+0x108/0x690 [<ffffffff86bca8bd>] kernel_init_freeable+0x45a/0x4de [<ffffffff83e0757f>] kernel_init+0x1f/0x220 [<ffffffff810048cf>] ret_from_fork+0x1f/0x30 > return 0; > } > fs_initcall(init_fs_stat_sysctls); >
> On Feb 13, 2022, at 7:34 AM, Ido Schimmel <idosch@idosch.org> 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: > [<ffffffff81d11637>] __register_sysctl_table+0x117/0x1150 > [<ffffffff86c3600f>] init_fs_stat_sysctls+0x30/0x33 > [<ffffffff81002558>] do_one_initcall+0x108/0x690 > [<ffffffff86bca8bd>] kernel_init_freeable+0x45a/0x4de > [<ffffffff83e0757f>] kernel_init+0x1f/0x220 > [<ffffffff810048cf>] 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/ <https://lore.kernel.org/all/YgRbEG21AUrLSFKX@bombadil.infradead.org/> Thanks, - Tong
On Sun, Feb 13, 2022 at 7:34 AM Ido Schimmel <idosch@idosch.org> 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: > [<ffffffff81d11637>] __register_sysctl_table+0x117/0x1150 > [<ffffffff86c3600f>] init_fs_stat_sysctls+0x30/0x33 > [<ffffffff81002558>] do_one_initcall+0x108/0x690 > [<ffffffff86bca8bd>] kernel_init_freeable+0x45a/0x4de > [<ffffffff83e0757f>] kernel_init+0x1f/0x220 > [<ffffffff810048cf>] 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
On Sun, Feb 13, 2022 at 01:10:42PM -0800, Tong Zhang wrote: > 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/ Great, thanks for letting me know
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"); return 0; } fs_initcall(init_fs_stat_sysctls);
Commit 3ba442d5331f did not go unnoticed, binfmt-support stopped to work on my Debian system since v5.17-rc2 (did not check with -rc1). The existance of the /proc/sys/fs/binfmt_misc is a precondition for attempting to mount the binfmt_misc fs, which in turn triggers the autoload of the binfmt_misc module. Without it, no module is loaded and no binfmt is available at boot. Building as built-in or manually loading the module and mounting the fs works fine, it's therefore only a matter of interaction with user-space. I could try to improve the Debian systemd configuration but I can't say anything about the other distributions. This patch restores a working system right after boot. v2: - move creation of fs/binfmt_misc to fs/file_table.c - use IS_ENABLED() to conditionally create it Fixes: 3ba442d5331f ("fs: move binfmt_misc sysctl to its own file") Signed-off-by: Domenico Andreoli <domenico.andreoli@linux.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Amir Goldstein <amir73il@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Antti Palosaari <crope@iki.fi> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Clemens Ladisch <clemens@ladisch.de> Cc: David Airlie <airlied@linux.ie> Cc: Douglas Gilbert <dgilbert@interlog.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Iurii Zaikin <yzaikin@google.com> Cc: James E.J. Bottomley <jejb@linux.ibm.com> Cc: Jan Kara <jack@suse.cz> Cc: Jani Nikula <jani.nikula@intel.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: John Ogness <john.ogness@linutronix.de> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Julia Lawall <julia.lawall@inria.fr> Cc: Kees Cook <keescook@chromium.org> Cc: Lukas Middendorf <kernel@tuxforce.de> Cc: Mark Fasheh <mark@fasheh.com> Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: Paul Turner <pjt@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Phillip Potter <phil@philpotter.co.uk> Cc: Qing Wang <wangqing@vivo.com> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Sebastian Reichel <sre@kernel.org> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Stephen Kitt <steve@sk2.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Xiaoming Ni <nixiaoming@huawei.com> --- fs/binfmt_misc.c | 6 +----- fs/file_table.c | 2 ++ 2 files changed, 3 insertions(+), 5 deletions(-)