Commit ee9efac4 authored by Luis Chamberlain's avatar Luis Chamberlain Committed by Linus Torvalds

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.

[akpm@linux-foundation.org: export register_sysctl_mount_point() to
modules]

Link: https://lkml.kernel.org/r/20211124231435.1445213-4-mcgrof@kernel.orgSigned-off-by: default avatarLuis Chamberlain <mcgrof@kernel.org>
Suggested-by: default avatar"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: 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 5475e8f0
......@@ -35,6 +35,20 @@ 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);
}
EXPORT_SYMBOL(register_sysctl_mount_point);
static bool is_empty_dir(struct ctl_table_header *head)
{
return head->ctl_table[0].child == sysctl_mount_point;
......
......@@ -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)
{
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment