treewide: Add SPDX license identifier - Makefile/Kconfig

Add SPDX license identifiers to all Make/Kconfig files which:

- Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

test_sysctl: add generic script to expand on tests

This adds a generic script to let us more easily add more tests cases.
Since we really have only two types of tests cases just fold them into
the one file. Each test unit is now identified into its separate
function:

# ./sysctl.sh -l
Test ID list:

TEST_ID x NUM_TEST
TEST_ID: Test ID
NUM_TESTS: Number of recommended times to run the test

0001 x 1 - tests proc_dointvec_minmax()
0002 x 1 - tests proc_dostring()

For now we start off with what we had before, and run only each test
once. We can now watch a test case until it fails:

./sysctl.sh -w 0002

We can also run a test case x number of times, say we want to run a test
case 100 times:

./sysctl.sh -c 0001 100

To run a test case only once, for example:

./sysctl.sh -s 0002

The default settings are specified at the top of sysctl.sh.

Link: http://lkml.kernel.org/r/20170630224431.17374-3-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>

selftests: Add install target

This adds make install support to selftests. The basic usage is:

$ cd tools/testing/selftests
$ make install

That installs into tools/testing/selftests/install, which can then be
copied where ever necessary.

The install destination is also configurable using eg:

$ INSTALL_PATH=/mnt/selftests make install

The implementation uses two targets in the child makefiles. The first
"install" is expected to install all files into $(INSTALL_PATH).

The second, "emit_tests", is expected to emit the test instructions (ie.
bash script) on stdout. Separating this from install means the child
makefiles need no knowledge of the location of the test script.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>

selftests: Introduce minimal shared logic for running tests

This adds a Make include file which most selftests can then include to
get the run_tests logic.

On its own this has the advantage of some reduction in repetition, and
also means the pass/fail message is defined in fewer places.

However the key advantage is it will allow us to implement install very
simply in a subsequent patch.

The default implementation just executes each program in $(TEST_PROGS).

We use a variable to hold the default implementation of $(RUN_TESTS)
because that gives us a clean way to override it if necessary, ie. using
override. The mount, memory-hotplug and mqueue tests use that to provide
a different implementation.

Tests are not run via /bin/bash, so if they are scripts they must be
executable, we add a+x to several.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>

tools/testing/selftests/sysctl: validate sysctl_writes_strict

This adds several behavioral tests to sysctl string and number writing
to detect unexpected cases that behaved differently when the sysctl
kernel.sysctl_writes_strict != 1.

[ original ]
root@localhost:~# make test_num
== Testing sysctl behavior against /proc/sys/kernel/domainname ==
Writing test file ... ok
Checking sysctl is not set to test value ... ok
Writing sysctl from shell ... ok
Resetting sysctl to original value ... ok
Writing entire sysctl in single write ... ok
Writing middle of sysctl after synchronized seek ... FAIL
Writing beyond end of sysctl ... FAIL
Writing sysctl with multiple long writes ... FAIL
Writing entire sysctl in short writes ... FAIL
Writing middle of sysctl after unsynchronized seek ... ok
Checking sysctl maxlen is at least 65 ... ok
Checking sysctl keeps original string on overflow append ... FAIL
Checking sysctl stays NULL terminated on write ... ok
Checking sysctl stays NULL terminated on overwrite ... ok
make: *** [test_num] Error 1
root@localhost:~# make test_string
== Testing sysctl behavior against /proc/sys/vm/swappiness ==
Writing test file ... ok
Checking sysctl is not set to test value ... ok
Writing sysctl from shell ... ok
Resetting sysctl to original value ... ok
Writing entire sysctl in single write ... ok
Writing middle of sysctl after synchronized seek ... FAIL
Writing beyond end of sysctl ... FAIL
Writing sysctl with multiple long writes ... ok
make: *** [test_string] Error 1

[ with CONFIG_PROC_SYSCTL_STRICT_WRITES ]
root@localhost:~# make run_tests
== Testing sysctl behavior against /proc/sys/kernel/domainname ==
Writing test file ... ok
Checking sysctl is not set to test value ... ok
Writing sysctl from shell ... ok
Resetting sysctl to original value ... ok
Writing entire sysctl in single write ... ok
Writing middle of sysctl after synchronized seek ... ok
Writing beyond end of sysctl ... ok
Writing sysctl with multiple long writes ... ok
Writing entire sysctl in short writes ... ok
Writing middle of sysctl after unsynchronized seek ... ok
Checking sysctl maxlen is at least 65 ... ok
Checking sysctl keeps original string on overflow append ... ok
Checking sysctl stays NULL terminated on write ... ok
Checking sysctl stays NULL terminated on overwrite ... ok
== Testing sysctl behavior against /proc/sys/vm/swappiness ==
Writing test file ... ok
Checking sysctl is not set to test value ... ok
Writing sysctl from shell ... ok
Resetting sysctl to original value ... ok
Writing entire sysctl in single write ... ok
Writing middle of sysctl after synchronized seek ... ok
Writing beyond end of sysctl ... ok
Writing sysctl with multiple long writes ... ok

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>