On Fri, 17 Dec 2021 at 05:49, Harinder Singh sharinder@google.com wrote:
Describe the components of KUnit and how the kernel mode parts interact with kunit_tool.
Signed-off-by: Harinder Singh sharinder@google.com
Acked-by: Marco Elver elver@google.com
For the .svg file, I think per https://www.kernel.org/doc/html/latest/process/submitting-patches.html#sign-... at least my Signed-off-by is required, but probably also my Co-developed-by? In any case my SOB for kunit_suitememorydiagram.svg is hereby given:
Signed-off-by: Marco Elver elver@google.com
Thanks, -- Marco
.../dev-tools/kunit/architecture.rst | 204 ++++++++++++++++++ Documentation/dev-tools/kunit/index.rst | 2 + .../kunit/kunit_suitememorydiagram.svg | 81 +++++++ Documentation/dev-tools/kunit/start.rst | 1 + 4 files changed, 288 insertions(+) create mode 100644 Documentation/dev-tools/kunit/architecture.rst create mode 100644 Documentation/dev-tools/kunit/kunit_suitememorydiagram.svg
diff --git a/Documentation/dev-tools/kunit/architecture.rst b/Documentation/dev-tools/kunit/architecture.rst new file mode 100644 index 000000000000..aa2cea821e25 --- /dev/null +++ b/Documentation/dev-tools/kunit/architecture.rst @@ -0,0 +1,204 @@ +.. SPDX-License-Identifier: GPL-2.0
+================== +KUnit Architecture +==================
+The KUnit architecture can be divided into two parts:
+- Kernel testing library +- 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:
+- Organizes tests +- Reports test results +- Provides test utilities
+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``. For code, see:
+.. kernel-doc:: include/kunit/test.h
:identifiers: 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:
+- ``->priv``: The setup functions can use it to store arbitrary test
- user data.
+- ``->param_value``: It contains the parameter value which can be
- retrieved in the parameterized tests.
+Test Suites +-----------
+A KUnit suite includes a collection of test cases. The KUnit suites +are represented by the ``struct kunit_suite``. For example:
+.. code-block:: c
static struct kunit_case example_test_cases[] = {KUNIT_CASE(example_test_foo),KUNIT_CASE(example_test_bar),KUNIT_CASE(example_test_baz),{}};static struct kunit_suite example_test_suite = {.name = "example",.init = example_test_init,.exit = example_test_exit,.test_cases = example_test_cases,};kunit_test_suite(example_test_suite);+In the above example, the test suite ``example_test_suite``, runs the +test cases ``example_test_foo``, ``example_test_bar``, and +``example_test_baz``. Before running the test, the ``example_test_init`` +is called and after running the test, ``example_test_exit`` is called. +The ``kunit_test_suite(example_test_suite)`` registers the test suite +with the KUnit test framework.
+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/incl.... +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.
+.. kernel-figure:: kunit_suitememorydiagram.svg
:alt: KUnit Suite MemoryKUnit 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/...
+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/...
+Assertion Macros +----------------
+KUnit tests verify state using expectations/assertions. +All expectations/assertions are formatted as: +``KUNIT_{EXPECT|ASSERT}_<op>[_MSG](kunit, property[, message])``
+- ``{EXPECT|ASSERT}`` determines whether the check is an assertion or an
- expectation.
- For an expectation, if the check fails, marks the test as failedand logs the failure.- An assertion, on failure, causes the test case to terminateimmediately.- Assertions call function:``void __noreturn kunit_abort(struct kunit *)``.- ``kunit_abort`` calls function:``void __noreturn kunit_try_catch_throw(struct kunit_try_catch *try_catch)``.- ``kunit_try_catch_throw`` calls function:``void 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
- equal), ``NOT_ERR_OR_NULL`` (supplied pointer is not null and does not
- 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-s.... +KTAP (yet to be standardized format) works with KUnit and Kselftest. +The KUnit executor prints KTAP results to dmesg, and debugfs +(if configured).
+Parameterized Tests +-------------------
+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.
+For code, see:
+.. kernel-doc:: include/kunit/test.h
:identifiers: KUNIT_ARRAY_PARAM+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.
+- ``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``).
- 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
- 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
- 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``
- argument: ``./tools/testing/kunit/kunit.py exec``.
+- ``parse`` extracts the KTAP output from a kernel log, parses
- the test results, and prints a summary. For failed tests, any
- diagnostic output will be included.
diff --git a/Documentation/dev-tools/kunit/index.rst b/Documentation/dev-tools/kunit/index.rst index 55d2444b0745..50d3ef9359dd 100644 --- a/Documentation/dev-tools/kunit/index.rst +++ b/Documentation/dev-tools/kunit/index.rst @@ -9,6 +9,7 @@ KUnit - Linux Kernel Unit Testing :caption: Contents:
start
architecture usage kunit-tool api/index@@ -96,6 +97,7 @@ 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/usage.rst - KUnit features.
- Documentation/dev-tools/kunit/tips.rst - best practices with examples.
diff --git a/Documentation/dev-tools/kunit/kunit_suitememorydiagram.svg b/Documentation/dev-tools/kunit/kunit_suitememorydiagram.svg new file mode 100644 index 000000000000..cf8fddc27500 --- /dev/null +++ b/Documentation/dev-tools/kunit/kunit_suitememorydiagram.svg @@ -0,0 +1,81 @@ +<?xml version="1.0" encoding="UTF-8"?> +<svg width="796.93" height="555.73" version="1.1" viewBox="0 0 796.93 555.73" xmlns="http://www.w3.org/2000/svg">
<g transform="translate(-13.724 -17.943)"><g fill="#dad4d4" fill-opacity=".91765" stroke="#1a1a1a"><rect x="323.56" y="18.443" width="115.75" height="41.331"/><rect x="323.56" y="463.09" width="115.75" height="41.331"/><rect x="323.56" y="531.84" width="115.75" height="41.331"/><rect x="323.56" y="88.931" width="115.75" height="74.231"/></g><g><rect x="323.56" y="421.76" width="115.75" height="41.331" fill="#b9dbc6" stroke="#1a1a1a"/><text x="328.00888" y="446.61826" fill="#000000" font-family="sans-serif" font-size="16px" style="line-height:1.25" xml:space="preserve"><tspan x="328.00888" y="446.61826" font-family="monospace" font-size="16px">kunit_suite</tspan></text></g><g transform="translate(0 -258.6)"><rect x="323.56" y="421.76" width="115.75" height="41.331" fill="#b9dbc6" stroke="#1a1a1a"/><text x="328.00888" y="446.61826" fill="#000000" font-family="sans-serif" font-size="16px" style="line-height:1.25" xml:space="preserve"><tspan x="328.00888" y="446.61826" font-family="monospace" font-size="16px">kunit_suite</tspan></text></g><g transform="translate(0 -217.27)"><rect x="323.56" y="421.76" width="115.75" height="41.331" fill="#b9dbc6" stroke="#1a1a1a"/><text x="328.00888" y="446.61826" fill="#000000" font-family="sans-serif" font-size="16px" style="line-height:1.25" xml:space="preserve"><tspan x="328.00888" y="446.61826" font-family="monospace" font-size="16px">kunit_suite</tspan></text></g><g transform="translate(0 -175.94)"><rect x="323.56" y="421.76" width="115.75" height="41.331" fill="#b9dbc6" stroke="#1a1a1a"/><text x="328.00888" y="446.61826" fill="#000000" font-family="sans-serif" font-size="16px" style="line-height:1.25" xml:space="preserve"><tspan x="328.00888" y="446.61826" font-family="monospace" font-size="16px">kunit_suite</tspan></text></g><g transform="translate(0 -134.61)"><rect x="323.56" y="421.76" width="115.75" height="41.331" fill="#b9dbc6" stroke="#1a1a1a"/><text x="328.00888" y="446.61826" fill="#000000" font-family="sans-serif" font-size="16px" style="line-height:1.25" xml:space="preserve"><tspan x="328.00888" y="446.61826" font-family="monospace" font-size="16px">kunit_suite</tspan></text></g><g transform="translate(0 -41.331)"><rect x="323.56" y="421.76" width="115.75" height="41.331" fill="#b9dbc6" stroke="#1a1a1a"/><text x="328.00888" y="446.61826" fill="#000000" font-family="sans-serif" font-size="16px" style="line-height:1.25" xml:space="preserve"><tspan x="328.00888" y="446.61826" font-family="monospace" font-size="16px">kunit_suite</tspan></text></g><g transform="translate(3.4459e-5 -.71088)"><rect x="502.19" y="143.16" width="201.13" height="41.331" fill="#dad4d4" fill-opacity=".91765" stroke="#1a1a1a"/><text x="512.02319" y="168.02026" font-family="sans-serif" font-size="16px" style="line-height:1.25" xml:space="preserve"><tspan x="512.02319" y="168.02026" font-family="monospace">_kunit_suites_start</tspan></text></g><g transform="translate(3.0518e-5 -3.1753)"><rect x="502.19" y="445.69" width="201.13" height="41.331" fill="#dad4d4" fill-opacity=".91765" stroke="#1a1a1a"/><text x="521.61694" y="470.54846" font-family="sans-serif" font-size="16px" style="line-height:1.25" xml:space="preserve"><tspan x="521.61694" y="470.54846" font-family="monospace">_kunit_suites_end</tspan></text></g><rect x="14.224" y="277.78" width="134.47" height="41.331" fill="#dad4d4" fill-opacity=".91765" stroke="#1a1a1a"/><text x="32.062176" y="304.41287" font-family="sans-serif" font-size="16px" style="line-height:1.25" xml:space="preserve"><tspan x="32.062176" y="304.41287" font-family="monospace">.init.data</tspan></text><g transform="translate(217.98 145.12)" stroke="#1a1a1a"><circle cx="149.97" cy="373.01" r="3.4012"/><circle cx="163.46" cy="373.01" r="3.4012"/><circle cx="176.95" cy="373.01" r="3.4012"/></g><g transform="translate(217.98 -298.66)" stroke="#1a1a1a"><circle cx="149.97" cy="373.01" r="3.4012"/><circle cx="163.46" cy="373.01" r="3.4012"/><circle cx="176.95" cy="373.01" r="3.4012"/></g><g stroke="#1a1a1a"><rect x="323.56" y="328.49" width="115.75" height="51.549" fill="#b9dbc6"/><g transform="translate(217.98 -18.75)"><circle cx="149.97" cy="373.01" r="3.4012"/><circle cx="163.46" cy="373.01" r="3.4012"/><circle cx="176.95" cy="373.01" r="3.4012"/></g></g><g transform="scale(1.0933 .9147)" stroke-width="32.937" aria-label="{"><path d="m275.49 545.57c-35.836-8.432-47.43-24.769-47.957-64.821v-88.536c-0.527-44.795-10.54-57.97-49.538-67.456 38.998-10.013 49.011-23.715 49.538-67.983v-88.536c0.527-40.052 12.121-56.389 47.957-64.821v-5.797c-65.348 0-85.901 17.391-86.955 73.253v93.806c-0.527 36.89-10.013 50.065-44.795 59.551 34.782 10.013 44.268 23.188 44.795 60.078v93.279c1.581 56.389 21.607 73.78 86.955 73.78z"/></g><g transform="scale(1.1071 .90325)" stroke-width="14.44" aria-label="{"><path d="m461.46 443.55c-15.711-3.6967-20.794-10.859-21.025-28.418v-38.815c-0.23104-19.639-4.6209-25.415-21.718-29.574 17.097-4.3898 21.487-10.397 21.718-29.805v-38.815c0.23105-17.559 5.314-24.722 21.025-28.418v-2.5415c-28.649 0-37.66 7.6244-38.122 32.115v41.126c-0.23105 16.173-4.3898 21.949-19.639 26.108 15.249 4.3898 19.408 10.166 19.639 26.339v40.895c0.69313 24.722 9.4728 32.346 38.122 32.346z"/></g><path d="m449.55 161.84v2.5h49.504v-2.5z" color="#000000" style="-inkscape-stroke:none"/><g fill-rule="evenodd"><path d="m443.78 163.09 8.65-5v10z" color="#000000" stroke-width="1pt" style="-inkscape-stroke:none"/><path d="m453.1 156.94-10.648 6.1543 0.99804 0.57812 9.6504 5.5781zm-1.334 2.3125v7.6856l-6.6504-3.8438z" color="#000000" style="-inkscape-stroke:none"/></g><path d="m449.55 461.91v2.5h49.504v-2.5z" color="#000000" style="-inkscape-stroke:none"/><g fill-rule="evenodd"><path d="m443.78 463.16 8.65-5v10z" color="#000000" stroke-width="1pt" style="-inkscape-stroke:none"/><path d="m453.1 457-10.648 6.1562 0.99804 0.57617 9.6504 5.5781zm-1.334 2.3125v7.6856l-6.6504-3.8438z" color="#000000" style="-inkscape-stroke:none"/></g><rect x="515.64" y="223.9" width="294.52" height="178.49" fill="#dad4d4" fill-opacity=".91765" stroke="#1a1a1a"/><text x="523.33319" y="262.52542" font-family="monospace" font-size="14.667px" style="line-height:1.25" xml:space="preserve"><tspan x="523.33319" y="262.52542"><tspan fill="#008000" font-family="monospace" font-size="14.667px" font-weight="bold">struct</tspan> kunit_suite {</tspan><tspan x="523.33319" y="280.8588"><tspan fill="#008000" font-family="monospace" font-size="14.667px" font-weight="bold"> const char</tspan> name[<tspan fill="#ff00ff" font-size="14.667px">256</tspan>];</tspan><tspan x="523.33319" y="299.19217"> <tspan fill="#008000" font-family="monospace" font-size="14.667px" font-weight="bold">int</tspan> (*init)(<tspan fill="#008000" font-family="monospace" font-size="14.667px" font-weight="bold">struct</tspan> kunit *);</tspan><tspan x="523.33319" y="317.52554"> <tspan fill="#008000" font-family="monospace" font-size="14.667px" font-weight="bold">void</tspan> (*exit)(<tspan fill="#008000" font-family="monospace" font-size="14.667px" font-weight="bold">struct</tspan> kunit *);</tspan><tspan x="523.33319" y="335.85892"> <tspan fill="#008000" font-family="monospace" font-size="14.667px" font-weight="bold">struct</tspan> kunit_case *test_cases;</tspan><tspan x="523.33319" y="354.19229"> ...</tspan><tspan x="523.33319" y="372.52567">};</tspan></text></g>+</svg> diff --git a/Documentation/dev-tools/kunit/start.rst b/Documentation/dev-tools/kunit/start.rst index 55f8df1abd40..5dd2c88fa2bd 100644 --- a/Documentation/dev-tools/kunit/start.rst +++ b/Documentation/dev-tools/kunit/start.rst @@ -240,6 +240,7 @@ Congrats! You just wrote your first KUnit test. Next Steps ==========
+* Documentation/dev-tools/kunit/architecture.rst - KUnit architecture.
- Documentation/dev-tools/kunit/usage.rst - KUnit features.
- Documentation/dev-tools/kunit/tips.rst - best practices with examples.
-- 2.34.1.173.g76aa8bc2d0-goog