diff options
author | Luis Chamberlain <mcgrof@kernel.org> | 2021-12-14 01:36:29 +0000 |
---|---|---|
committer | Mark Brown <broonie@kernel.org> | 2021-12-14 02:23:18 +0000 |
commit | 2ea3f7104d4a801d279ae1a9e896e56397f27319 (patch) | |
tree | 36ae0052737759b20488507617d4b1493c92c797 | |
parent | 3626f9da9e5cf7a99a858a8145bb13eeb929ec77 (diff) | |
download | linux-2ea3f7104d4a801d279ae1a9e896e56397f27319.tar.gz linux-2ea3f7104d4a801d279ae1a9e896e56397f27319.tar.xz |
sysctl: add helper to register a sysctl mount point
The way to create a subdirectory on top of sysctl_mount_point is a bit
obscure, and *why* we do that even so more. Provide a helper which makes
it clear why we do this.
Link: https://lkml.kernel.org/r/20211124231435.1445213-4-mcgrof@kernel.org
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Suggested-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Amir Goldstein <amir73il@gmail.com>
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: James E.J. Bottomley <jejb@linux.ibm.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Jan Kara <jack@suse.cz>
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: Mauro Carvalho Chehab <mchehab@kernel.org>
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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
-rw-r--r-- | fs/proc/proc_sysctl.c | 13 | ||||
-rw-r--r-- | include/linux/sysctl.h | 7 |
2 files changed, 20 insertions, 0 deletions
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c index 0b7a00ed6c49..a670b4bb4234 100644 --- a/fs/proc/proc_sysctl.c +++ b/fs/proc/proc_sysctl.c @@ -35,6 +35,19 @@ struct ctl_table sysctl_mount_point[] = { { } }; +/** + * register_sysctl_mount_point() - registers a sysctl mount point + * @path: path for the mount point + * + * Used to create a permanently empty directory to serve as mount point. + * There are some subtle but important permission checks this allows in the + * case of unprivileged mounts. + */ +struct ctl_table_header *register_sysctl_mount_point(const char *path) +{ + return register_sysctl(path, sysctl_mount_point); +} + static bool is_empty_dir(struct ctl_table_header *head) { return head->ctl_table[0].child == sysctl_mount_point; diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h index fce05a060bc5..746c098a6ff5 100644 --- a/include/linux/sysctl.h +++ b/include/linux/sysctl.h @@ -209,6 +209,8 @@ extern int sysctl_init(void); extern void __register_sysctl_init(const char *path, struct ctl_table *table, const char *table_name); #define register_sysctl_init(path, table) __register_sysctl_init(path, table, #table) +extern struct ctl_table_header *register_sysctl_mount_point(const char *path); + void do_sysctl_args(void); extern int pwrsw_enabled; @@ -224,6 +226,11 @@ static inline struct ctl_table_header *register_sysctl_table(struct ctl_table * return NULL; } +static inline struct sysctl_header *register_sysctl_mount_point(const char *path) +{ + return NULL; +} + static inline struct ctl_table_header *register_sysctl_paths( const struct ctl_path *path, struct ctl_table *table) { |