Merge tag 'linux-kselftest-5.5-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull kselftest fixes from Shuah Khan:

 - ftrace and safesetid test fixes from Masami Hiramatsu

 - Kunit fixes from Brendan Higgins, Iurii Zaikin, and Heidi Fahim

 - Kselftest framework fixes from SeongJae Park and Michael Ellerman

* tag 'linux-kselftest-5.5-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  kselftest: Support old perl versions
  kselftest/runner: Print new line in print of timeout log
  selftests: Fix dangling documentation references to kselftest_module.sh
  Documentation: kunit: add documentation for kunit_tool
  Documentation: kunit: fix typos and gramatical errors
  kunit: testing kunit: Bug fix in test_run_timeout function
  fs/ext4/inode-test: Fix inode test on 32 bit platforms.
  selftests: safesetid: Fix Makefile to set correct test program
  selftests: safesetid: Check the return value of setuid/setgid
  selftests: safesetid: Move link library to LDLIBS
  selftests/ftrace: Fix multiple kprobe testcase
  selftests/ftrace: Do not to use absolute debugfs path
  selftests/ftrace: Fix ftrace test cases to check unsupported
  selftests/ftrace: Fix to check the existence of set_ftrace_filter

1 files changed, 57 insertions, 0 deletions

diff --git a/Documentation/dev-tools/kunit/kunit-tool.rst b/Documentation/dev-tools/kunit/kunit-tool.rst
new file mode 100644
index 000000000000..50d46394e97e
--- /dev/null
+++ b/Documentation/dev-tools/kunit/kunit-tool.rst
@@ -0,0 +1,57 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=================
+kunit_tool How-To
+=================
+
+What is kunit_tool?
+===================
+
+kunit_tool is a script (``tools/testing/kunit/kunit.py``) that aids in building
+the Linux kernel as UML (`User Mode Linux
+<http://user-mode-linux.sourceforge.net/>`_), running KUnit tests, parsing
+the test results and displaying them in a user friendly manner.
+
+What is a kunitconfig?
+======================
+
+It's just a defconfig that kunit_tool looks for in the base directory.
+kunit_tool uses it to generate a .config as you might expect. In addition, it
+verifies that the generated .config contains the CONFIG options in the
+kunitconfig; the reason it does this is so that it is easy to be sure that a
+CONFIG that enables a test actually ends up in the .config.
+
+How do I use kunit_tool?
+========================
+
+If a kunitconfig is present at the root directory, all you have to do is:
+
+.. code-block:: bash
+
+	./tools/testing/kunit/kunit.py run
+
+However, you most likely want to use it with the following options:
+
+.. code-block:: bash
+
+	./tools/testing/kunit/kunit.py run --timeout=30 --jobs=`nproc --all`
+
+- ``--timeout`` sets a maximum amount of time to allow tests to run.
+- ``--jobs`` sets the number of threads to use to build the kernel.
+
+If you just want to use the defconfig that ships with the kernel, you can
+append the ``--defconfig`` flag as well:
+
+.. code-block:: bash
+
+	./tools/testing/kunit/kunit.py run --timeout=30 --jobs=`nproc --all` --defconfig
+
+.. note::
+	This command is particularly helpful for getting started because it
+	just works. No kunitconfig needs to be present.
+
+For a list of all the flags supported by kunit_tool, you can run:
+
+.. code-block:: bash
+
+	./tools/testing/kunit/kunit.py run --help