Skip to content

Commit

Permalink
Merge tag 'linux-kselftest-kunit-next-6.2-rc1' of git://git.kernel.or…
Browse files Browse the repository at this point in the history
…g/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull KUnit updates from Shuah Khan:
 "Several enhancements, fixes, clean-ups, documentation updates,
  improvements to logging and KTAP compliance of KUnit test output:

   - log numbers in decimal and hex

   - parse KTAP compliant test output

   - allow conditionally exposing static symbols to tests when KUNIT is
     enabled

   - make static symbols visible during kunit testing

   - clean-ups to remove unused structure definition"

* tag 'linux-kselftest-kunit-next-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (29 commits)
  Documentation: dev-tools: Clarify requirements for result description
  apparmor: test: make static symbols visible during kunit testing
  kunit: add macro to allow conditionally exposing static symbols to tests
  kunit: tool: make parser preserve whitespace when printing test log
  Documentation: kunit: Fix "How Do I Use This" / "Next Steps" sections
  kunit: tool: don't include KTAP headers and the like in the test log
  kunit: improve KTAP compliance of KUnit test output
  kunit: tool: parse KTAP compliant test output
  mm: slub: test: Use the kunit_get_current_test() function
  kunit: Use the static key when retrieving the current test
  kunit: Provide a static key to check if KUnit is actively running tests
  kunit: tool: make --json do nothing if --raw_ouput is set
  kunit: tool: tweak error message when no KTAP found
  kunit: remove KUNIT_INIT_MEM_ASSERTION macro
  Documentation: kunit: Remove redundant 'tips.rst' page
  Documentation: KUnit: reword description of assertions
  Documentation: KUnit: make usage.rst a superset of tips.rst, remove duplication
  kunit: eliminate KUNIT_INIT_*_ASSERT_STRUCT macros
  kunit: tool: remove redundant file.close() call in unit test
  kunit: tool: unit tests all check parser errors, standardize formatting a bit
  ...
  • Loading branch information
torvalds committed Dec 13, 2022
2 parents 23a68d1 + 054be25 commit e2ed78d
Show file tree
Hide file tree
Showing 30 changed files with 901 additions and 700 deletions.
4 changes: 2 additions & 2 deletions Documentation/dev-tools/ktap.rst
Original file line number Diff line number Diff line change
Expand Up @@ -80,8 +80,8 @@ have the number 1 and the number then must increase by 1 for each additional
subtest within the same test at the same nesting level.

The description is a description of the test, generally the name of
the test, and can be any string of words (can't include #). The
description is optional, but recommended.
the test, and can be any string of characters other than # or a
newline. The description is optional, but recommended.

The directive and any diagnostic data is optional. If either are present, they
must follow a hash sign, "#".
Expand Down
115 changes: 58 additions & 57 deletions Documentation/dev-tools/kunit/architecture.rst
Original file line number Diff line number Diff line change
Expand Up @@ -4,16 +4,17 @@
KUnit Architecture
==================

The KUnit architecture can be divided into two parts:
The KUnit architecture is divided into two parts:

- `In-Kernel Testing Framework`_
- `kunit_tool (Command Line Test Harness)`_
- `kunit_tool (Command-line Test Harness)`_

In-Kernel Testing Framework
===========================

The kernel testing library supports KUnit tests written in C using
KUnit. KUnit tests are kernel code. KUnit does several things:
KUnit. These KUnit tests are kernel code. KUnit performs the following
tasks:

- Organizes tests
- Reports test results
Expand All @@ -22,19 +23,17 @@ KUnit. KUnit tests are kernel code. KUnit does several things:
Test Cases
----------

The fundamental unit in KUnit is the test case. The KUnit test cases are
grouped into KUnit suites. A KUnit test case is a function with type
signature ``void (*)(struct kunit *test)``.
These test case functions are wrapped in a struct called
struct kunit_case.
The test case is the fundamental unit in KUnit. KUnit test cases are organised
into suites. A KUnit test case is a function with type signature
``void (*)(struct kunit *test)``. These test case functions are wrapped in a
struct called struct kunit_case.

.. note:
``generate_params`` is optional for non-parameterized tests.
Each KUnit test case gets a ``struct kunit`` context
object passed to it that tracks a running test. The KUnit assertion
macros and other KUnit utilities use the ``struct kunit`` context
object. As an exception, there are two fields:
Each KUnit test case receives a ``struct kunit`` context object that tracks a
running test. The KUnit assertion macros and other KUnit utilities use the
``struct kunit`` context object. As an exception, there are two fields:

- ``->priv``: The setup functions can use it to store arbitrary test
user data.
Expand Down Expand Up @@ -77,30 +76,31 @@ Executor

The KUnit executor can list and run built-in KUnit tests on boot.
The Test suites are stored in a linker section
called ``.kunit_test_suites``. For code, see:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/asm-generic/vmlinux.lds.h?h=v5.15#n945.
called ``.kunit_test_suites``. For the code, see ``KUNIT_TABLE()`` macro
definition in
`include/asm-generic/vmlinux.lds.h <https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/asm-generic/vmlinux.lds.h?h=v6.0#n950>`_.
The linker section consists of an array of pointers to
``struct kunit_suite``, and is populated by the ``kunit_test_suites()``
macro. To run all tests compiled into the kernel, the KUnit executor
iterates over the linker section array.
macro. The KUnit executor iterates over the linker section array in order to
run all the tests that are compiled into the kernel.

.. kernel-figure:: kunit_suitememorydiagram.svg
:alt: KUnit Suite Memory

KUnit Suite Memory Diagram

On the kernel boot, the KUnit executor uses the start and end addresses
of this section to iterate over and run all tests. For code, see:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/lib/kunit/executor.c

of this section to iterate over and run all tests. For the implementation of the
executor, see
`lib/kunit/executor.c <https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/lib/kunit/executor.c>`_.
When built as a module, the ``kunit_test_suites()`` macro defines a
``module_init()`` function, which runs all the tests in the compilation
unit instead of utilizing the executor.

In KUnit tests, some error classes do not affect other tests
or parts of the kernel, each KUnit case executes in a separate thread
context. For code, see:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/lib/kunit/try-catch.c?h=v5.15#n58
context. See the ``kunit_try_catch_run()`` function in
`lib/kunit/try-catch.c <https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/lib/kunit/try-catch.c?h=v5.15#n58>`_.

Assertion Macros
----------------
Expand All @@ -111,37 +111,36 @@ All expectations/assertions are formatted as:

- ``{EXPECT|ASSERT}`` determines whether the check is an assertion or an
expectation.
In the event of a failure, the testing flow differs as follows:

- For an expectation, if the check fails, marks the test as failed
and logs the failure.
- For expectations, the test is marked as failed and the failure is logged.

- An assertion, on failure, causes the test case to terminate
immediately.
- Failing assertions, on the other hand, result in the test case being
terminated immediately.

- Assertions call function:
- Assertions call the function:
``void __noreturn kunit_abort(struct kunit *)``.

- ``kunit_abort`` calls function:
- ``kunit_abort`` calls the function:
``void __noreturn kunit_try_catch_throw(struct kunit_try_catch *try_catch)``.

- ``kunit_try_catch_throw`` calls function:
- ``kunit_try_catch_throw`` calls the function:
``void kthread_complete_and_exit(struct completion *, long) __noreturn;``
and terminates the special thread context.

- ``<op>`` denotes a check with options: ``TRUE`` (supplied property
has the boolean value true), ``EQ`` (two supplied properties are
has the boolean value "true"), ``EQ`` (two supplied properties are
equal), ``NOT_ERR_OR_NULL`` (supplied pointer is not null and does not
contain an err value).
contain an "err" value).

- ``[_MSG]`` prints a custom message on failure.

Test Result Reporting
---------------------
KUnit prints test results in KTAP format. KTAP is based on TAP14, see:
https://github.com/isaacs/testanything.github.io/blob/tap14/tap-version-14-specification.md.
KTAP (yet to be standardized format) works with KUnit and Kselftest.
The KUnit executor prints KTAP results to dmesg, and debugfs
(if configured).
KUnit prints the test results in KTAP format. KTAP is based on TAP14, see
Documentation/dev-tools/ktap.rst.
KTAP works with KUnit and Kselftest. The KUnit executor prints KTAP results to
dmesg, and debugfs (if configured).

Parameterized Tests
-------------------
Expand All @@ -150,42 +149,44 @@ Each KUnit parameterized test is associated with a collection of
parameters. The test is invoked multiple times, once for each parameter
value and the parameter is stored in the ``param_value`` field.
The test case includes a KUNIT_CASE_PARAM() macro that accepts a
generator function.
The generator function is passed the previous parameter and returns the next
parameter. It also provides a macro to generate common-case generators based on
arrays.
generator function. The generator function is passed the previous parameter
and returns the next parameter. It also includes a macro for generating
array-based common-case generators.

kunit_tool (Command Line Test Harness)
kunit_tool (Command-line Test Harness)
======================================

kunit_tool is a Python script ``(tools/testing/kunit/kunit.py)``
that can be used to configure, build, exec, parse and run (runs other
commands in order) test results. You can either run KUnit tests using
kunit_tool or can include KUnit in kernel and parse manually.
``kunit_tool`` is a Python script, found in ``tools/testing/kunit/kunit.py``. It
is used to configure, build, execute, parse test results and run all of the
previous commands in correct order (i.e., configure, build, execute and parse).
You have two options for running KUnit tests: either build the kernel with KUnit
enabled and manually parse the results (see
Documentation/dev-tools/kunit/run_manual.rst) or use ``kunit_tool``
(see Documentation/dev-tools/kunit/run_wrapper.rst).

- ``configure`` command generates the kernel ``.config`` from a
``.kunitconfig`` file (and any architecture-specific options).
For some architectures, additional config options are specified in the
``qemu_config`` Python script
(For example: ``tools/testing/kunit/qemu_configs/powerpc.py``).
The Python scripts available in ``qemu_configs`` folder
(for example, ``tools/testing/kunit/qemu configs/powerpc.py``) contains
additional configuration options for specific architectures.
It parses both the existing ``.config`` and the ``.kunitconfig`` files
and ensures that ``.config`` is a superset of ``.kunitconfig``.
If this is not the case, it will combine the two and run
``make olddefconfig`` to regenerate the ``.config`` file. It then
verifies that ``.config`` is now a superset. This checks if all
Kconfig dependencies are correctly specified in ``.kunitconfig``.
``kunit_config.py`` includes the parsing Kconfigs code. The code which
runs ``make olddefconfig`` is a part of ``kunit_kernel.py``. You can
invoke this command via: ``./tools/testing/kunit/kunit.py config`` and
to ensure that ``.config`` is a superset of ``.kunitconfig``.
If not, it will combine the two and run ``make olddefconfig`` to regenerate
the ``.config`` file. It then checks to see if ``.config`` has become a superset.
This verifies that all the Kconfig dependencies are correctly specified in the
file ``.kunitconfig``. The ``kunit_config.py`` script contains the code for parsing
Kconfigs. The code which runs ``make olddefconfig`` is part of the
``kunit_kernel.py`` script. You can invoke this command through:
``./tools/testing/kunit/kunit.py config`` and
generate a ``.config`` file.
- ``build`` runs ``make`` on the kernel tree with required options
(depends on the architecture and some options, for example: build_dir)
and reports any errors.
To build a KUnit kernel from the current ``.config``, you can use the
``build`` argument: ``./tools/testing/kunit/kunit.py build``.
- ``exec`` command executes kernel results either directly (using
User-mode Linux configuration), or via an emulator such
as QEMU. It reads results from the log via standard
User-mode Linux configuration), or through an emulator such
as QEMU. It reads results from the log using standard
output (stdout), and passes them to ``parse`` to be parsed.
If you already have built a kernel with built-in KUnit tests,
you can run the kernel and display the test results with the ``exec``
Expand Down
20 changes: 8 additions & 12 deletions Documentation/dev-tools/kunit/index.rst
Original file line number Diff line number Diff line change
Expand Up @@ -16,7 +16,6 @@ KUnit - Linux Kernel Unit Testing
api/index
style
faq
tips
running_tips

This section details the kernel unit testing framework.
Expand Down Expand Up @@ -100,14 +99,11 @@ Read also :ref:`kinds-of-tests`.
How do I use it?
================

* Documentation/dev-tools/kunit/start.rst - for KUnit new users.
* Documentation/dev-tools/kunit/architecture.rst - KUnit architecture.
* Documentation/dev-tools/kunit/run_wrapper.rst - run kunit_tool.
* Documentation/dev-tools/kunit/run_manual.rst - run tests without kunit_tool.
* Documentation/dev-tools/kunit/usage.rst - write tests.
* Documentation/dev-tools/kunit/tips.rst - best practices with
examples.
* Documentation/dev-tools/kunit/api/index.rst - KUnit APIs
used for testing.
* Documentation/dev-tools/kunit/faq.rst - KUnit common questions and
answers.
You can find a step-by-step guide to writing and running KUnit tests in
Documentation/dev-tools/kunit/start.rst

Alternatively, feel free to look through the rest of the KUnit documentation,
or to experiment with tools/testing/kunit/kunit.py and the example test under
lib/kunit/kunit-example-test.c

Happy testing!
18 changes: 8 additions & 10 deletions Documentation/dev-tools/kunit/start.rst
Original file line number Diff line number Diff line change
Expand Up @@ -294,13 +294,11 @@ Congrats! You just wrote your first KUnit test.
Next Steps
==========

* Documentation/dev-tools/kunit/architecture.rst - KUnit architecture.
* Documentation/dev-tools/kunit/run_wrapper.rst - run kunit_tool.
* Documentation/dev-tools/kunit/run_manual.rst - run tests without kunit_tool.
* Documentation/dev-tools/kunit/usage.rst - write tests.
* Documentation/dev-tools/kunit/tips.rst - best practices with
examples.
* Documentation/dev-tools/kunit/api/index.rst - KUnit APIs
used for testing.
* Documentation/dev-tools/kunit/faq.rst - KUnit common questions and
answers.
If you're interested in using some of the more advanced features of kunit.py,
take a look at Documentation/dev-tools/kunit/run_wrapper.rst

If you'd like to run tests without using kunit.py, check out
Documentation/dev-tools/kunit/run_manual.rst

For more information on writing KUnit tests (including some common techniques
for testing different things), see Documentation/dev-tools/kunit/usage.rst
Loading

0 comments on commit e2ed78d

Please sign in to comment.