sysctl: Remove the now superfluous sentinel elements from ctl_table array

This commit comes at the tail end of a greater effort to remove the
empty elements at the end of the ctl_table arrays (sentinels) which
will reduce the overall build time size of the kernel and run time
memory bloat by ~64 bytes per sentinel (further information Link :
https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/)

Remove empty sentinel element from test_table and test_table_unregister.

Signed-off-by: Joel Granados <j.granados@samsung.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

sysctl: Add a selftest for handling empty dirs

Basic test to ensure that empty directories can be registered and that
they in turn can serve as a base dir for other registrations.

Add one test to the sysctl selftest module. It first registers an empty
directory under "empty_add" and then uses that as a base to register
another empty dir.
The sysctl bash script then checks that "empty_add" is present and that
there an empty directory within it.

Signed-off-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

test_sysclt: Test for registering a mount point

Test that target gets created by register_sysctl_mount_point and that no
additional target can be created "on top" of a permanently empty sysctl
table.

Create a mount point target (mnt) in the sysctl test driver; try to
create another on top of that (mnt_error). Output an error if
"mnt_error" is present when we run the sysctl selftests.

Signed-off-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

test_sysctl: Add an unregister sysctl test

Add a test that checks that the unregistered directory is removed from
/proc/sys/debug

Signed-off-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

test_sysctl: Group node sysctl test under one func

Preparation commit to add a new type of test to test_sysctl.c. We
want to differentiate between node and (sub)directory tests.

Signed-off-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

testing: use the copyleft-next-0.3.1 SPDX tag

Two selftests drivers exist under the copyleft-next license.
These drivers were added prior to SPDX practice taking full swing
in the kernel. Now that we have an SPDX tag for copyleft-next-0.3.1
documented, embrace it and remove the boiler plate.

Cc: Goldwyn Rodrigues <rgoldwyn@suse.com>
Cc: Kuno Woudt <kuno@frob.nl>
Cc: Richard Fontana <fontana@sharpeleven.org>
Cc: copyleft-next@lists.fedorahosted.org
Cc: Ciaran Farrell <Ciaran.Farrell@suse.com>
Cc: Christopher De Nicolo <Christopher.DeNicolo@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Thorsten Leemhuis <linux@leemhuis.info>
Cc: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Tim Bird <tim.bird@sony.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

selftests/sysctl: add sysctl macro test

Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: David Ahern <dsahern@kernel.org>
Cc: Simon Horman <horms@verge.net.au>
Cc: Julian Anastasov <ja@ssi.bg>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Jozsef Kadlecsik <kadlec@netfilter.org>
Cc: Florian Westphal <fw@strlen.de>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Lorenz Bauer <lmb@cloudflare.com>
Cc: Akhmat Karakotov <hmukos@yandex-team.ru>
Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

test_sysctl: simplify subdirectory registration with register_sysctl()

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 lib/test_sysctl.c

@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/20211123202422.819032-6-mcgrof@kernel.org
Signed-off-by: Luis 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: 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib: test_sysctl: delete duplicated words

Drop the repeated word "the".

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/20200823040520.1999-1-rdunlap@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/test_sysctl: support testing of sysctl. boot parameter

Testing is done by a new parameter debug.test_sysctl.boot_int which
defaults to 0 and it's expected that the tester passes a boot parameter
that sets it to 1. The test checks if it's set to 1.

To distinguish true failure from parameter not being set, the test
checks /proc/cmdline for the expected parameter, and whether test_sysctl
is built-in and not a module.

[vbabka@suse.cz: skip the new test if boot_int sysctl is not present]
Link: http://lkml.kernel.org/r/305af605-1e60-cf84-fada-6ce1ca37c102@suse.cz

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Guilherme G . Piccoli" <gpiccoli@canonical.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Ivan Teterevkov <ivan.teterevkov@nutanix.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200427180433.7029-6-vbabka@suse.cz
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib: Make test_sysctl initialized as module

test_sysctl.c is expected to be used as a module, but since
it does not use module_init(), it never be registered as
a module and not appeared under /sys/module/.
In the result, the selftests/sysctl/sysctl.sh always fails
to find the test module and is skipped.

This makes test_sysctl.c initialized as a module by module_init()
and allow sysctl.sh to find the test module is loaded.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

tools/testing/selftests/sysctl/sysctl.sh: add proc_do_large_bitmap() test case

The kernel has only two users of proc_do_large_bitmap(), the kernel CPU
watchdog, and the ip_local_reserved_ports. Refer to watchdog_cpumask
and ip_local_reserved_ports in Documentation for further details on
these. When you input a large buffer into these, when it is larger than
PAGE_SIZE- 1, the input data gets misparsed, and the user get
incorrectly informed that the desired input value was set. This commit
implements a test which mimics and exploits that use case, it uses a
bitmap size, as in the watchdog case. The bitmap is used to test the
bitmap proc handler, proc_do_large_bitmap().

The next commit fixes this issue.

[akpm@linux-foundation.org: move proc_do_large_bitmap() export to EOF]
[mcgrof@kernel.org: use new target description for backward compatibility]
[mcgrof@kernel.org: augment test number to 50, ran into issues with bash string comparisons when testing up to 50 cases.]
[mcgrof@kernel.org: introduce and use verify_diff_proc_file() to use diff]
[mcgrof@kernel.org: use mktemp for tmp file]
[mcgrof@kernel.org: merge shell test and C code]
[mcgrof@kernel.org: commit log love]
[mcgrof@kernel.org: export proc_do_large_bitmap() to allow for the test
[mcgrof@kernel.org: check for the return value when writing to the proc file]
Link: http://lkml.kernel.org/r/20190320222831.8243-6-mcgrof@kernel.org
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

test_sysctl: test against int proc_dointvec() array support

Add a few initial respective tests for an array:

o Echoing values separated by spaces works
o Echoing only first elements will set first elements
o Confirm PAGE_SIZE limit still applies even if an array is used

Link: http://lkml.kernel.org/r/20170630224431.17374-7-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

test_sysctl: add simple proc_douintvec() case

Test against a simple proc_douintvec() case. While at it, add a test
against UINT_MAX. Make sure UINT_MAX works, and UINT_MAX+1 will fail
and that negative values are not accepted.

Link: http://lkml.kernel.org/r/20170630224431.17374-6-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

test_sysctl: add simple proc_dointvec() case

Test against a simple proc_dointvec() case. While at it, add a test
against INT_MAX. Make sure INT_MAX works, and INT_MAX+1 will fail.
Also test negative values work.

Link: http://lkml.kernel.org/r/20170630224431.17374-5-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

test_sysctl: add dedicated proc sysctl test driver

The existing tools/testing/selftests/sysctl/ tests include two test
cases, but these use existing production kernel sysctl interfaces. We
want to expand test coverage but we can't just be looking for random
safe production values to poke at, that's just insane!

Instead just dedicate a test driver for debugging purposes and port the
existing scripts to use it. This will make it easier for further tests
to be added.

Subsequent patches will extend our test coverage for sysctl.

The stress test driver uses a new license (GPL on Linux, copyleft-next
outside of Linux). Linus was fine with this [0] and later due to Ted's
and Alans's request ironed out an "or" language clause to use [1] which
is already present upstream.

[0] https://lkml.kernel.org/r/CA+55aFyhxcvD+q7tp+-yrSFDKfR0mOHgyEAe=f_94aKLsOu0Og@mail.gmail.com
[1] https://lkml.kernel.org/r/1495234558.7848.122.camel@linux.intel.com

Link: http://lkml.kernel.org/r/20170630224431.17374-2-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>