kernel/sysctl.c is a kitchen sink where everyone leaves their dirty
dishes, this makes it very difficult to maintain.

To help with this maintenance let's start by moving sysctls to places
where they actually belong.  The proc sysctl maintainers do not want to
know what sysctl knobs you wish to add for your own piece of code, we
just care about the core logic.

So move the dcache sysctl clutter out of kernel/sysctl.c.  This is a
small one-off entry, perhaps later we can simplify this representation,
but for now we use the helpers we have.  We won't know how we can
simplify this further untl we're fully done with the cleanup.

[arnd@arndb.de: avoid unused-function warning]
  Link: https://lkml.kernel.org/r/20211203190123.874239-2-arnd@kernel.org

Link: https://lkml.kernel.org/r/20211129205548.605569-4-mcgrof@kernel.orgSigned-off-by: NLuis Chamberlain <mcgrof@kernel.org>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Antti Palosaari <crope@iki.fi>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Lukas Middendorf <kernel@tuxforce.de>
Cc: Stephen Kitt <steve@sk2.org>
Cc: Xiaoming Ni <nixiaoming@huawei.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

kernel/sysctl.c is a kitchen sink where everyone leaves their dirty
dishes, this makes it very difficult to maintain.

To help with this maintenance let's start by moving sysctls to places
where they actually belong.  The proc sysctl maintainers do not want to
know what sysctl knobs you wish to add for your own piece of code, we
just care about the core logic.

We can create the sysctl dynamically on early init for fs stat to help
with this clutter.  This dusts off the fs stat syctls knobs and puts
them into where they are declared.

Link: https://lkml.kernel.org/r/20211129205548.605569-3-mcgrof@kernel.orgSigned-off-by: NLuis Chamberlain <mcgrof@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Antti Palosaari <crope@iki.fi>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Lukas Middendorf <kernel@tuxforce.de>
Cc: Stephen Kitt <steve@sk2.org>
Cc: Xiaoming Ni <nixiaoming@huawei.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "sysctl: 4th set of kernel/sysctl cleanups".

This is slimming down the fs uses of kernel/sysctl.c to the point that
the next step is to just get rid of the fs base directory for it and
move that elsehwere, so that next patch series starts dealing with that
to demo how we can end up cleaning up a full base directory from
kernel/sysctl.c, one at a time.

This patch (of 9):

kernel/sysctl.c is a kitchen sink where everyone leaves their dirty
dishes, this makes it very difficult to maintain.

To help with this maintenance let's start by moving sysctls to places
where they actually belong.  The proc sysctl maintainers do not want to
know what sysctl knobs you wish to add for your own piece of code, we
just care about the core logic.

So move the inode sysctls to its own file.  Since we are no longer using
this outside of fs/ remove the extern declaration of its respective proc
helper.

We use early_initcall() as it is the earliest we can use.

[arnd@arndb.de: avoid unused-variable warning]
  Link: https://lkml.kernel.org/r/20211203190123.874239-1-arnd@kernel.org

Link: https://lkml.kernel.org/r/20211129205548.605569-1-mcgrof@kernel.org
Link: https://lkml.kernel.org/r/20211129205548.605569-2-mcgrof@kernel.orgSigned-off-by: NLuis Chamberlain <mcgrof@kernel.org>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Xiaoming Ni <nixiaoming@huawei.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Stephen Kitt <steve@sk2.org>
Cc: Lukas Middendorf <kernel@tuxforce.de>
Cc: Antti Palosaari <crope@iki.fi>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Provide a way to share unsigned long values.  This will allow others to
not have to re-invent these values.

Link: https://lkml.kernel.org/r/20211124231435.1445213-9-mcgrof@kernel.orgSigned-off-by: NLuis Chamberlain <mcgrof@kernel.org>
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: 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: 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: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

kernel/sysctl.c is a kitchen sink where everyone leaves their dirty
dishes, this makes it very difficult to maintain.

To help with this maintenance let's start by moving sysctls to places
where they actually belong.  The proc sysctl maintainers do not want to
know what sysctl knobs you wish to add for your own piece of code, we
just care about the core logic.

This moves the binfmt_misc sysctl to its own file to help remove clutter
from kernel/sysctl.c.

Link: https://lkml.kernel.org/r/20211124231435.1445213-5-mcgrof@kernel.orgSigned-off-by: NLuis Chamberlain <mcgrof@kernel.org>
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: 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: 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: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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: NLuis Chamberlain <mcgrof@kernel.org>
Suggested-by: N"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: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The kernel/sysctl.c is a kitchen sink where everyone leaves their dirty
dishes, this makes it very difficult to maintain.

To help with this maintenance let's start by moving sysctls to places
where they actually belong.  The proc sysctl maintainers do not want to
know what sysctl knobs you wish to add for your own piece of code, we
just care about the core logic.

So move the epoll_table sysctl to fs/eventpoll.c and use
register_sysctl().

Link: https://lkml.kernel.org/r/20211123202422.819032-9-mcgrof@kernel.orgSigned-off-by: NXiaoming Ni <nixiaoming@huawei.com>
Signed-off-by: NLuis Chamberlain <mcgrof@kernel.org>
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: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Joel Becker <jlbec@evilplan.org>
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: 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: 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: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Cc: James E.J. Bottomley <jejb@linux.ibm.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There is no need to user boiler plate code to specify a set of base
directories we're going to stuff sysctls under.  Simplify this by using
register_sysctl() and specifying the directory path directly.

Move inotify_user sysctl to inotify_user.c while at it to remove clutter
from kernel/sysctl.c.

[mcgrof@kernel.org: remember to register fanotify_table]
  Link: https://lkml.kernel.org/r/YZ5A6iWLb0h3N3RC@bombadil.infradead.org
[mcgrof@kernel.org: update commit log to reflect new path we decided to take]

Link: https://lkml.kernel.org/r/20211123202422.819032-7-mcgrof@kernel.orgSigned-off-by: NXiaoming Ni <nixiaoming@huawei.com>
Signed-off-by: NLuis Chamberlain <mcgrof@kernel.org>
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: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Joel Becker <jlbec@evilplan.org>
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: 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: 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: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Cc: James E.J. Bottomley <jejb@linux.ibm.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There is no need to user boiler plate code to specify a set of base
directories we're going to stuff sysctls under.  Simplify this by using
register_sysctl() and specifying the directory path directly.

// pycocci sysctl-subdir-register-sysctl-simplify.cocci PATH

@c1@
expression E1;
identifier subdir, sysctls;
@@

static struct ctl_table subdir[] = {
	{
		.procname = E1,
		.maxlen = 0,
		.mode = 0555,
		.child = sysctls,
	},
	{ }
};

@c2@
identifier c1.subdir;

expression E2;
identifier base;
@@

static struct ctl_table base[] = {
	{
		.procname = E2,
		.maxlen = 0,
		.mode = 0555,
		.child = subdir,
	},
	{ }
};

@c3@
identifier c2.base;
identifier header;
@@

header = register_sysctl_table(base);

@r1 depends on c1 && c2 && c3@
expression c1.E1;
identifier c1.subdir, c1.sysctls;
@@

-static struct ctl_table subdir[] = {
-	{
-		.procname = E1,
-		.maxlen = 0,
-		.mode = 0555,
-		.child = sysctls,
-	},
-	{ }
-};

@r2 depends on c1 && c2 && c3@
identifier c1.subdir;

expression c2.E2;
identifier c2.base;
@@
-static struct ctl_table base[] = {
-	{
-		.procname = E2,
-		.maxlen = 0,
-		.mode = 0555,
-		.child = subdir,
-	},
-	{ }
-};

@initialize:python@
@@

def make_my_fresh_expression(s1, s2):
  return '"' + s1.strip('"') + "/" + s2.strip('"') + '"'

@r3 depends on c1 && c2 && c3@
expression c1.E1;
identifier c1.sysctls;
expression c2.E2;
identifier c2.base;
identifier c3.header;
fresh identifier E3 = script:python(E2, E1) { make_my_fresh_expression(E2, E1) };
@@

header =
-register_sysctl_table(base);
+register_sysctl(E3, sysctls);

Generated-by: Coccinelle SmPL
Link: https://lkml.kernel.org/r/20211123202422.819032-5-mcgrof@kernel.orgSigned-off-by: NLuis Chamberlain <mcgrof@kernel.org>
Reviewed-by: NJan Kara <jack@suse.cz>
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: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joel Becker <jlbec@evilplan.org>
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: 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: 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: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Xiaoming Ni <nixiaoming@huawei.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Cc: James E.J. Bottomley <jejb@linux.ibm.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The kernel/sysctl.c is a kitchen sink where everyone leaves their dirty
dishes, this makes it very difficult to maintain.

To help with this maintenance let's start by moving sysctls to places
where they actually belong.  The proc sysctl maintainers do not want to
know what sysctl knobs you wish to add for your own piece of code, we
just care about the core logic.

So move dnotify sysctls to dnotify.c and use the new
register_sysctl_init() to register the sysctl interface.

[mcgrof@kernel.org: adjust the commit log to justify the move]

Link: https://lkml.kernel.org/r/20211123202347.818157-10-mcgrof@kernel.orgSigned-off-by: NXiaoming Ni <nixiaoming@huawei.com>
Signed-off-by: NLuis Chamberlain <mcgrof@kernel.org>
Acked-by: NJan Kara <jack@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Qing Wang <wangqing@vivo.com>
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Stephen Kitt <steve@sk2.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Antti Palosaari <crope@iki.fi>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Clemens Ladisch <clemens@ladisch.de>
Cc: David Airlie <airlied@linux.ie>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Julia Lawall <julia.lawall@inria.fr>
Cc: Lukas Middendorf <kernel@tuxforce.de>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Phillip Potter <phil@philpotter.co.uk>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Cc: James E.J. Bottomley <jejb@linux.ibm.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The kernel/sysctl.c is a kitchen sink where everyone leaves their dirty
dishes, this makes it very difficult to maintain.

To help with this maintenance let's start by moving sysctls to places
where they actually belong.  The proc sysctl maintainers do not want to
know what sysctl knobs you wish to add for your own piece of code, we
just care about the core logic.

Move aio sysctl to aio.c and use the new register_sysctl_init() to
register the sysctl interface for aio.

[mcgrof@kernel.org: adjust commit log to justify the move]

Link: https://lkml.kernel.org/r/20211123202347.818157-9-mcgrof@kernel.orgSigned-off-by: NXiaoming Ni <nixiaoming@huawei.com>
Signed-off-by: NLuis Chamberlain <mcgrof@kernel.org>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Qing Wang <wangqing@vivo.com>
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Stephen Kitt <steve@sk2.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Antti Palosaari <crope@iki.fi>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Clemens Ladisch <clemens@ladisch.de>
Cc: David Airlie <airlied@linux.ie>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Julia Lawall <julia.lawall@inria.fr>
Cc: Lukas Middendorf <kernel@tuxforce.de>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Phillip Potter <phil@philpotter.co.uk>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Cc: James E.J. Bottomley <jejb@linux.ibm.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

sysctl has helpers which let us specify boundary values for a min or max
int value.  Since these are used for a boundary check only they don't
change, so move these variables to sysctl_vals to avoid adding duplicate
variables.  This will help with our cleanup of kernel/sysctl.c.

[akpm@linux-foundation.org: update it for "mm/pagealloc: sysctl: change watermark_scale_factor max limit to 30%"]
[mcgrof@kernel.org: major rebase]

Link: https://lkml.kernel.org/r/20211123202347.818157-3-mcgrof@kernel.orgSigned-off-by: NXiaoming Ni <nixiaoming@huawei.com>
Signed-off-by: NLuis Chamberlain <mcgrof@kernel.org>
Reviewed-by: NKees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Qing Wang <wangqing@vivo.com>
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Stephen Kitt <steve@sk2.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Antti Palosaari <crope@iki.fi>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Clemens Ladisch <clemens@ladisch.de>
Cc: David Airlie <airlied@linux.ie>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Julia Lawall <julia.lawall@inria.fr>
Cc: Lukas Middendorf <kernel@tuxforce.de>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Phillip Potter <phil@philpotter.co.uk>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Cc: James E.J. Bottomley <jejb@linux.ibm.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "sysctl: first set of kernel/sysctl cleanups", v2.

Finally had time to respin the series of the work we had started last
year on cleaning up the kernel/sysct.c kitchen sink.  People keeps
stuffing their sysctls in that file and this creates a maintenance
burden.  So this effort is aimed at placing sysctls where they actually
belong.

I'm going to split patches up into series as there is quite a bit of
work.

This first set adds register_sysctl_init() for uses of registerting a
sysctl on the init path, adds const where missing to a few places,
generalizes common values so to be more easy to share, and starts the
move of a few kernel/sysctl.c out where they belong.

The majority of rework on v2 in this first patch set is 0-day fixes.
Eric Biederman's feedback is later addressed in subsequent patch sets.

I'll only post the first two patch sets for now.  We can address the
rest once the first two patch sets get completely reviewed / Acked.

This patch (of 9):

The kernel/sysctl.c is a kitchen sink where everyone leaves their dirty
dishes, this makes it very difficult to maintain.

To help with this maintenance let's start by moving sysctls to places
where they actually belong.  The proc sysctl maintainers do not want to
know what sysctl knobs you wish to add for your own piece of code, we
just care about the core logic.

Today though folks heavily rely on tables on kernel/sysctl.c so they can
easily just extend this table with their needed sysctls.  In order to
help users move their sysctls out we need to provide a helper which can
be used during code initialization.

We special-case the initialization use of register_sysctl() since it
*is* safe to fail, given all that sysctls do is provide a dynamic
interface to query or modify at runtime an existing variable.  So the
use case of register_sysctl() on init should *not* stop if the sysctls
don't end up getting registered.  It would be counter productive to stop
boot if a simple sysctl registration failed.

Provide a helper for init then, and document the recommended init levels
to use for callers of this routine.  We will later use this in
subsequent patches to start slimming down kernel/sysctl.c tables and
moving sysctl registration to the code which actually needs these
sysctls.

[mcgrof@kernel.org: major commit log and documentation rephrasing also moved to fs/proc/proc_sysctl.c                  ]

Link: https://lkml.kernel.org/r/20211123202347.818157-1-mcgrof@kernel.org
Link: https://lkml.kernel.org/r/20211123202347.818157-2-mcgrof@kernel.orgSigned-off-by: NXiaoming Ni <nixiaoming@huawei.com>
Signed-off-by: NLuis Chamberlain <mcgrof@kernel.org>
Reviewed-by: NKees Cook <keescook@chromium.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Paul Turner <pjt@google.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Qing Wang <wangqing@vivo.com>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Jan Kara <jack@suse.cz>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: Stephen Kitt <steve@sk2.org>
Cc: Antti Palosaari <crope@iki.fi>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Clemens Ladisch <clemens@ladisch.de>
Cc: David Airlie <airlied@linux.ie>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Julia Lawall <julia.lawall@inria.fr>
Cc: Lukas Middendorf <kernel@tuxforce.de>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Phillip Potter <phil@philpotter.co.uk>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Cc: James E.J. Bottomley <jejb@linux.ibm.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use the newly introduced CONFIG_PAGE_SIZE_LESS_THAN_256KB to describe
the dependency introduced by commit b05fbcc3 ("btrfs: disable build
on platforms having page size 256K").

Link: https://lkml.kernel.org/r/20211129230141.228085-3-nathan@kernel.orgSigned-off-by: NNathan Chancellor <nathan@kernel.org>
Acked-by: NDavid Sterba <dsterba@suse.com>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: kernel test robot <lkp@intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Return value directly instead of taking this in a variable.

Link: https://lkml.kernel.org/r/20211210023211.424609-1-chi.minghao@zte.com.cnSigned-off-by: NMinghao Chi <chi.minghao@zte.com.cn>
Reported-by: NZeal Robot <zealci@zte.com.cm>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

congestion_wait() in this context is just a sleep - block devices do not
support congestion signalling any more.

The goal for this wait, which was introduced in commit ae78bf9c
("[PATCH] add -o flush for fat") is to wait for any recently written
data to get to storage.  We currently have no direct mechanism to do
this, so a simple wait that behaves identically to the current
congestion_wait() is the best we can do.

This is a step towards removing congestion_wait()

Link: https://lkml.kernel.org/r/163936544519.22433.13400436295732112065@noble.neil.brown.nameSigned-off-by: NNeilBrown <neilb@suse.de>
Acked-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Add struct_group() to mark the "info" region (containing struct DInfo
and struct DXInfo structs) in struct hfsplus_cat_folder and struct
hfsplus_cat_file that are written into directly, so the compiler can
correctly reason about the expected size of the writes.

"pahole" shows no size nor member offset changes to struct
hfsplus_cat_folder nor struct hfsplus_cat_file.  "objdump -d" shows no
object code changes.

Link: https://lkml.kernel.org/r/20211119192851.1046717-1-keescook@chromium.orgSigned-off-by: NKees Cook <keescook@chromium.org>
Acked-by: NChristian Brauner <christian.brauner@ubuntu.com>
Cc: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pointer sbufs is being assigned a value but it's not being used later
on.  The pointer is redundant and can be removed.  Cleans up scan-build
static analysis warning:

  fs/nilfs2/page.c:203:8: warning: Although the value stored to 'sbufs'
    is used in the enclosing expression, the value is never actually read
    from 'sbufs' [deadcode.DeadStores]
        sbh = sbufs = page_buffers(src);

Link: https://lkml.kernel.org/r/20211211180955.550380-1-colin.i.king@gmail.com
Link: https://lkml.kernel.org/r/1640712476-15136-1-git-send-email-konishi.ryusuke@gmail.comSigned-off-by: NColin Ian King <colin.i.king@gmail.com>
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Extend commit ce81bb25 ("fs/binfmt_elf: use PT_LOAD p_align values
for suitable start address") which fixed PIE binaries built with
-Wl,-z,max-page-size=0x200000, to cover static PIE binaries.  This
fixes:

    https://bugzilla.kernel.org/show_bug.cgi?id=215275

Tested by verifying static PIE binaries with -Wl,-z,max-page-size=0x200000 loading.

Link: https://lkml.kernel.org/r/20211209174052.370537-1-hjl.tools@gmail.comSigned-off-by: NH.J. Lu <hjl.tools@gmail.com>
Cc: Chris Kennelly <ckennelly@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sandeep Patil <sspatil@google.com>
Cc: Fangrui Song <maskray@google.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When I was implementing a new per-cpu kthread cfs_migration, I found the
comm of it "cfs_migration/%u" is truncated due to the limitation of
TASK_COMM_LEN.  For example, the comm of the percpu thread on CPU10~19
all have the same name "cfs_migration/1", which will confuse the user.
This issue is not critical, because we can get the corresponding CPU
from the task's Cpus_allowed.  But for kthreads corresponding to other
hardware devices, it is not easy to get the detailed device info from
task comm, for example,

    jbd2/nvme0n1p2-
    xfs-reclaim/sdf

Currently there are so many truncated kthreads:

    rcu_tasks_kthre
    rcu_tasks_rude_
    rcu_tasks_trace
    poll_mpt3sas0_s
    ext4-rsv-conver
    xfs-reclaim/sd{a, b, c, ...}
    xfs-blockgc/sd{a, b, c, ...}
    xfs-inodegc/sd{a, b, c, ...}
    audit_send_repl
    ecryptfs-kthrea
    vfio-irqfd-clea
    jbd2/nvme0n1p2-
    ...

We can shorten these names to work around this problem, but it may be
not applied to all of the truncated kthreads.  Take 'jbd2/nvme0n1p2-'
for example, it is a nice name, and it is not a good idea to shorten it.

One possible way to fix this issue is extending the task comm size, but
as task->comm is used in lots of places, that may cause some potential
buffer overflows.  Another more conservative approach is introducing a
new pointer to store kthread's full name if it is truncated, which won't
introduce too much overhead as it is in the non-critical path.  Finally
we make a dicision to use the second approach.  See also the discussions
in this thread:
https://lore.kernel.org/lkml/20211101060419.4682-1-laoar.shao@gmail.com/

After this change, the full name of these truncated kthreads will be
displayed via /proc/[pid]/comm:

    rcu_tasks_kthread
    rcu_tasks_rude_kthread
    rcu_tasks_trace_kthread
    poll_mpt3sas0_statu
    ext4-rsv-conversion
    xfs-reclaim/sdf1
    xfs-blockgc/sdf1
    xfs-inodegc/sdf1
    audit_send_reply
    ecryptfs-kthread
    vfio-irqfd-cleanup
    jbd2/nvme0n1p2-8

Link: https://lkml.kernel.org/r/20211120112850.46047-1-laoar.shao@gmail.comSigned-off-by: NYafang Shao <laoar.shao@gmail.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Reviewed-by: NPetr Mladek <pmladek@suse.com>
Suggested-by: NPetr Mladek <pmladek@suse.com>
Suggested-by: NSteven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Michal Miroslaw <mirq-linux@rere.qmqm.pl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It is better to use get_task_comm() instead of the open coded string
copy as we do in other places.

struct elf_prpsinfo is used to dump the task information in userspace
coredump or kernel vmcore.  Below is the verification of vmcore,

  crash> ps
     PID    PPID  CPU       TASK        ST  %MEM     VSZ    RSS  COMM
        0      0   0  ffffffff9d21a940  RU   0.0       0      0  [swapper/0]
  >     0      0   1  ffffa09e40f85e80  RU   0.0       0      0  [swapper/1]
  >     0      0   2  ffffa09e40f81f80  RU   0.0       0      0  [swapper/2]
  >     0      0   3  ffffa09e40f83f00  RU   0.0       0      0  [swapper/3]
  >     0      0   4  ffffa09e40f80000  RU   0.0       0      0  [swapper/4]
  >     0      0   5  ffffa09e40f89f80  RU   0.0       0      0  [swapper/5]
        0      0   6  ffffa09e40f8bf00  RU   0.0       0      0  [swapper/6]
  >     0      0   7  ffffa09e40f88000  RU   0.0       0      0  [swapper/7]
  >     0      0   8  ffffa09e40f8de80  RU   0.0       0      0  [swapper/8]
  >     0      0   9  ffffa09e40f95e80  RU   0.0       0      0  [swapper/9]
  >     0      0  10  ffffa09e40f91f80  RU   0.0       0      0  [swapper/10]
  >     0      0  11  ffffa09e40f93f00  RU   0.0       0      0  [swapper/11]
  >     0      0  12  ffffa09e40f90000  RU   0.0       0      0  [swapper/12]
  >     0      0  13  ffffa09e40f9bf00  RU   0.0       0      0  [swapper/13]
  >     0      0  14  ffffa09e40f98000  RU   0.0       0      0  [swapper/14]
  >     0      0  15  ffffa09e40f9de80  RU   0.0       0      0  [swapper/15]

It works well as expected.

Some comments are added to explain why we use the hard-coded 16.

Link: https://lkml.kernel.org/r/20211120112738.45980-5-laoar.shao@gmail.comSuggested-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NYafang Shao <laoar.shao@gmail.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Michal Miroslaw <mirq-linux@rere.qmqm.pl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If the dest buffer size is smaller than sizeof(tsk->comm), the buffer
will be without null ternimator, that may cause problem.  Using
strscpy_pad() instead of strncpy() in __get_task_comm() can make the
string always nul ternimated and zero padded.

Link: https://lkml.kernel.org/r/20211120112738.45980-3-laoar.shao@gmail.comSuggested-by: NKees Cook <keescook@chromium.org>
Suggested-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NYafang Shao <laoar.shao@gmail.com>
Reviewed-by: NKees Cook <keescook@chromium.org>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Michal Miroslaw <mirq-linux@rere.qmqm.pl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "task comm cleanups", v2.

This patchset is part of the patchset "extend task comm from 16 to
24"[1].  Now we have different opinion that dynamically allocates memory
to store kthread's long name into a separate pointer, so I decide to
take the useful cleanups apart from the original patchset and send it
separately[2].

These useful cleanups can make the usage around task comm less
error-prone.  Furthermore, it will be useful if we want to extend task
comm in the future.

[1]. https://lore.kernel.org/lkml/20211101060419.4682-1-laoar.shao@gmail.com/
[2]. https://lore.kernel.org/lkml/CALOAHbAx55AUo3bm8ZepZSZnw7A08cvKPdPyNTf=E_tPqmw5hw@mail.gmail.com/

This patch (of 7):

strlcpy() can trigger out-of-bound reads on the source string[1], we'd
better use strscpy() instead.  To make it be robust against full tsk->comm
copies that got noticed in other places, we should make sure it's zero
padded.

[1] https://github.com/KSPP/linux/issues/89

Link: https://lkml.kernel.org/r/20211120112738.45980-1-laoar.shao@gmail.com
Link: https://lkml.kernel.org/r/20211120112738.45980-2-laoar.shao@gmail.comSigned-off-by: NYafang Shao <laoar.shao@gmail.com>
Reviewed-by: NKees Cook <keescook@chromium.org>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Michal Miroslaw <mirq-linux@rere.qmqm.pl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Subsequent if judgments will assign new values to ret, so the statement
here should be deleted

The clang_analyzer complains as follows:

  fs/proc/proc_sysctl.c:
  Value stored to 'ret' is never read

Link: https://lkml.kernel.org/r/20211230063622.586360-1-luo.penghao@zte.com.cnSigned-off-by: Nluo penghao <luo.penghao@zte.com.cn>
Reported-by: NZeal Robot <zealci@zte.com.cn>
Acked-by: NLuis Chamberlain <mcgrof@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

sysctl_print_dir() always terminates the printed path name with a slash,
so printing a slash before the file part causes a duplicate like in

    sysctl duplicate entry: /kernel//perf_user_access

Fix this by dropping the extra slash.

Link: https://lkml.kernel.org/r/e3054d605dc56f83971e4b6d2f5fa63a978720ad.1641551872.git.geert+renesas@glider.beSigned-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Acked-by: NChristian Brauner <christian.brauner@ubuntu.com>
Acked-by: NLuis Chamberlain <mcgrof@kernel.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Convert return type of proc_fd_access_allowed() and the 'allowed' in it
to be boolean since the return type of ptrace_may_access() is boolean.

Link: https://lkml.kernel.org/r/20211219024404.29779-1-zhengqi.arch@bytedance.comSigned-off-by: NQi Zheng <zhengqi.arch@bytedance.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In commit cc5f2704 ("proc/vmcore: convert oldmem_pfn_is_ram callback
to more generic vmcore callbacks"), we added detection of surprise
vmcore_cb unregistration after the vmcore was already opened.  Once
detected, we warn the user and simulate reading zeroes from that point
on when accessing the vmcore.

The basic reason was that unexpected unregistration, for example, by
manually unbinding a driver from a device after opening the vmcore, is
not supported and could result in reading oldmem the vmcore_cb would
have actually prohibited while registered.  However, something like that
can similarly be trigger by a user that's really looking for trouble
simply by unbinding the relevant driver before opening the vmcore -- or
by disallowing loading the driver in the first place.  So it's actually
of limited help.

Currently, unregistration can only be triggered via virtio-mem when
manually unbinding the driver from the device inside the VM; there is no
way to trigger it from the hypervisor, as hypervisors don't allow for
unplugging virtio-mem devices -- ripping out system RAM from a VM
without coordination with the guest is usually not a good idea.

The important part is that unbinding the driver and unregistering the
vmcore_cb while concurrently reading the vmcore won't crash the system,
and that is handled by the rwsem.

To make the mechanism more future proof, let's remove the "read zero"
part, but leave the warning in place.  For example, we could have a
future driver (like virtio-balloon) that will contact the hypervisor to
figure out if we already populated a page for a given PFN.
Hotunplugging such a device and consequently unregistering the vmcore_cb
could be triggered from the hypervisor without harming the system even
while kdump is running.  In that case, we don't want to silently end up
with a vmcore that contains wrong data, because the user inside the VM
might be unaware of the hypervisor action and might easily miss the
warning in the log.

Link: https://lkml.kernel.org/r/20211111192243.22002-1-david@redhat.comSigned-off-by: NDavid Hildenbrand <david@redhat.com>
Acked-by: NBaoquan He <bhe@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Philipp Rudo <prudo@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We used to have more code around the work loop, but now the goto and
lock juggling just makes it less readable than it should. Get rid of it.
Signed-off-by: NJens Axboe <axboe@kernel.dk>

An active work can have poll armed, hence it's not enough to just do
the async work removal and return the value if it's different from "not
found". Rather than make poll removal special, just fall through to do
the remaining type lookups and removals.
Reported-by: NFlorian Fischer <florian.fl.fischer@fau.de>
Link: https://lore.kernel.org/io-uring/20220118151337.fac6cthvbnu7icoc@pasture/Signed-off-by: NJens Axboe <axboe@kernel.dk>

We have a gap where a worker removes an item from the work list and to
when it gets added as the workers active work. In this state, the work
item cannot be found by cancelations. This is a small window, but it does
exist.

Add a temporary pointer to a work item that isn't on the pending work
list anymore, but also not the active work. This is needed as we need
to drop the wqe lock in between grabbing the work item and marking it
as active, to ensure that signal based cancelations are properly
ordered.
Reported-by: NFlorian Fischer <florian.fl.fischer@fau.de>
Link: https://lore.kernel.org/io-uring/20220118151337.fac6cthvbnu7icoc@pasture/Signed-off-by: NJens Axboe <axboe@kernel.dk>

Rather than split these into two separate lookups and matches, combine
them into one loop. This will become important when we can guarantee
that we don't have a window where a pending work item isn't discoverable
in either state.
Signed-off-by: NJens Axboe <axboe@kernel.dk>

io_wqe_cancel_pending_work() grabs it internally, grab it upfront
instead. For the running work cancelation, grab the lock around it as
well.
Signed-off-by: NJens Axboe <axboe@kernel.dk>

In preparation to nesting it under the wqe lock (which is raw due to
being acquired from the scheduler side), change the io_worker lock from
a normal spinlock to a raw spinlock.
Signed-off-by: NJens Axboe <axboe@kernel.dk>

We don't use 'work' anymore in the busy logic, remove the dead argument.
Signed-off-by: NJens Axboe <axboe@kernel.dk>

MS-SMB2 describe session sign like the following.
Session.SigningRequired MUST be set to TRUE under the following conditions:
 - If the SMB2_NEGOTIATE_SIGNING_REQUIRED bit is set in the SecurityMode
   field of the client request.
 - If the SMB2_SESSION_FLAG_IS_GUEST bit is not set in the SessionFlags
   field and Session.IsAnonymous is FALSE and either Connection.ShouldSign
   or global RequireMessageSigning is TRUE.

When trying guest account connection using nautilus, The login failure
happened on session setup. ksmbd does not allow this connection
when the user is a guest and the connection sign is set. Just do not set
session sign instead of error response as described in the specification.
And this change improves the guest connection in Nautilus.

Fixes: e2f34481 ("cifsd: add server-side procedures for SMB3")
Cc: stable@vger.kernel.org # v5.15+
Signed-off-by: NNamjae Jeon <linkinjeon@kernel.org>
Signed-off-by: NSteve French <stfrench@microsoft.com>

The "ksmbd_socket" variable is not initialized on this error path.

Cc: stable@vger.kernel.org
Fixes: 0626e664 ("cifsd: add server handler for central processing and tranport layers")
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Acked-by: NNamjae Jeon <linkinjeon@kernel.org>
Signed-off-by: NSteve French <stfrench@microsoft.com>

if the Channel of a SMB2 WRITE request is
SMB2_CHANNEL_RDMA_V1_INVALIDTE, a client
does not invalidate its memory regions but
ksmbd must do it by sending a SMB2 WRITE response
with IB_WR_SEND_WITH_INV.

But if errors occur while processing a SMB2
READ/WRITE request, ksmbd sends a response
with IB_WR_SEND. So a client could use memory
regions already in use.
Acked-by: NNamjae Jeon <linkinjeon@kernel.org>
Signed-off-by: NHyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

The "PAGE_SIZE - 2 - size" calculation in legacy_parse_param() is an
unsigned type so a large value of "size" results in a high positive
value instead of a negative value as expected.  Fix this by getting rid
of the subtraction.
Signed-off-by: NJamie Hill-Daniel <jamie@hill-daniel.co.uk>
Signed-off-by: NWilliam Liu <willsroot@protonmail.com>
Tested-by: NSalvatore Bonaccorso <carnil@debian.org>
Tested-by: NThadeu Lima de Souza Cascardo <cascardo@canonical.com>
Acked-by: NDan Carpenter <dan.carpenter@oracle.com>
Acked-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Now that we've made these ioctls defunct, move them from xfs_fs.h to
xfs_ioctl.c, which effectively removes them from the publicly supported
ioctl interfaces for XFS.
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NEric Sandeen <sandeen@redhat.com>

According to the glibc compat header for Irix 4, these ioctls originated
in April 1991 as a (somewhat clunky) way to preallocate space at the end
of a file on an EFS filesystem.  XFS, which was released in Irix 5.3 in
December 1993, picked up these ioctls to maintain compatibility and they
were ported to Linux in the early 2000s.

Recently it was pointed out to me they still lurk in the kernel, even
though the Linux fallocate syscall supplanted the functionality a long
time ago.  fstests doesn't seem to include any real functional or stress
tests for these ioctls, which means that the code quality is ... very
questionable.  Most notably, it was a stale disk block exposure vector
for 21 years and nobody noticed or complained.  As mature programmers
say, "If you're not testing it, it's broken."

Given all that, let's withdraw these ioctls from the XFS userspace API.
Normally we'd set a long deprecation process, but I estimate that there
aren't any real users, so let's trigger a warning in dmesg and return
-ENOTTY.

See: CVE-2021-4155

Augments: 983d8e60 ("xfs: map unwritten blocks in XFS_IOC_{ALLOC,FREE}SP just like fallocate")
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>
Reviewed-by: NEric Sandeen <sandeen@redhat.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>