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>

selftests: add default rules for c source file

There are difference rules for compiling c source file in different
testcases. In order to enable KBUILD_OUTPUT support in later patch,
this patch introduce the default rules in
"tools/testing/selftest/lib.mk" and remove the existing rules in each
testcase.

Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Bamvor Jian Zhang <bamvor.zhangjian@linaro.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>

selftests: remove duplicated all and clean target

Currently, kselftest use TEST_PROGS, TEST_PROGS_EXTENDED, TEST_FILES to
indicate the test program, extended test program and test files. It is
easy to understand the purpose of these files. But mix of compiled and
uncompiled files lead to duplicated "all" and "clean" targets.

In order to remove the duplicated targets, introduce TEST_GEN_PROGS,
TEST_GEN_PROGS_EXTENDED, TEST_GEN_FILES to indicate the compiled
objects.

Also, the later patch will make use of TEST_GEN_XXX to redirect these
files to output directory indicated by KBUILD_OUTPUT or O.

And add this changes to "Contributing new tests(details)" of
Documentation/kselftest.txt.

Signed-off-by: Bamvor Jian Zhang <bamvor.zhangjian@linaro.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>

selftests: Set CC using CROSS_COMPILE once in lib.mk

This avoids repeating the logic in every Makefile. We mimic the
top-level Makefile and use $(CROSS_COMPILE)gcc.

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>

selftest: size: Add size test for Linux kernel

This test shows the amount of memory used by the system.
Note that this is dependent on the user-space that is loaded
when this program runs. Optimally, this program would be
run as the init program itself.

The program is optimized for size itself, to avoid conflating
its own execution with that of the system software.
The code is compiled statically, with no stdlibs. On my x86_64 system,
this results in a statically linked binary of less than 5K.

Signed-off-by: Tim Bird <tim.bird@sonymobile.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>