diff options
Diffstat (limited to 'Documentation/dev-tools/kunit')
| -rw-r--r-- | Documentation/dev-tools/kunit/api/resource.rst | 9 | ||||
| -rw-r--r-- | Documentation/dev-tools/kunit/run_manual.rst | 51 | ||||
| -rw-r--r-- | Documentation/dev-tools/kunit/running_tips.rst | 18 | ||||
| -rw-r--r-- | Documentation/dev-tools/kunit/usage.rst | 81 |
4 files changed, 145 insertions, 14 deletions
diff --git a/Documentation/dev-tools/kunit/api/resource.rst b/Documentation/dev-tools/kunit/api/resource.rst index 0a94f83125..ec6002a6b0 100644 --- a/Documentation/dev-tools/kunit/api/resource.rst +++ b/Documentation/dev-tools/kunit/api/resource.rst @@ -11,3 +11,12 @@ state on a per-test basis, register custom cleanup actions, and more. .. kernel-doc:: include/kunit/resource.h :internal: + +Managed Devices +--------------- + +Functions for using KUnit-managed struct device and struct device_driver. +Include ``kunit/device.h`` to use these. + +.. kernel-doc:: include/kunit/device.h + :internal: diff --git a/Documentation/dev-tools/kunit/run_manual.rst b/Documentation/dev-tools/kunit/run_manual.rst index e7b46421f2..699d928850 100644 --- a/Documentation/dev-tools/kunit/run_manual.rst +++ b/Documentation/dev-tools/kunit/run_manual.rst @@ -49,9 +49,52 @@ loaded. The results will appear in TAP format in ``dmesg``. +debugfs +======= + +KUnit can be accessed from userspace via the debugfs filesystem (See more +information about debugfs at Documentation/filesystems/debugfs.rst). + +If ``CONFIG_KUNIT_DEBUGFS`` is enabled, the KUnit debugfs filesystem is +mounted at /sys/kernel/debug/kunit. You can use this filesystem to perform +the following actions. + +Retrieve Test Results +===================== + +You can use debugfs to retrieve KUnit test results. The test results are +accessible from the debugfs filesystem in the following read-only file: + +.. code-block :: bash + + /sys/kernel/debug/kunit/<test_suite>/results + +The test results are printed in a KTAP document. Note this document is separate +to the kernel log and thus, may have different test suite numbering. + +Run Tests After Kernel Has Booted +================================= + +You can use the debugfs filesystem to trigger built-in tests to run after +boot. To run the test suite, you can use the following command to write to +the ``/sys/kernel/debug/kunit/<test_suite>/run`` file: + +.. code-block :: bash + + echo "any string" > /sys/kernel/debugfs/kunit/<test_suite>/run + +As a result, the test suite runs and the results are printed to the kernel +log. + +However, this feature is not available with KUnit suites that use init data, +because init data may have been discarded after the kernel boots. KUnit +suites that use init data should be defined using the +kunit_test_init_section_suites() macro. + +Also, you cannot use this feature to run tests concurrently. Instead a test +will wait to run until other tests have completed or failed. + .. note :: - If ``CONFIG_KUNIT_DEBUGFS`` is enabled, KUnit test results will - be accessible from the ``debugfs`` filesystem (if mounted). - They will be in ``/sys/kernel/debug/kunit/<test_suite>/results``, in - TAP format. + For test authors, to use this feature, tests will need to correctly initialise + and/or clean up any data, so the test runs correctly a second time. diff --git a/Documentation/dev-tools/kunit/running_tips.rst b/Documentation/dev-tools/kunit/running_tips.rst index 766f9cdea0..bd689db6fd 100644 --- a/Documentation/dev-tools/kunit/running_tips.rst +++ b/Documentation/dev-tools/kunit/running_tips.rst @@ -139,6 +139,17 @@ If your installed version of gcc doesn't work, you can tweak the steps: $ ./tools/testing/kunit/kunit.py run --make_options=CC=/usr/bin/gcc-6 $ lcov -t "my_kunit_tests" -o coverage.info -c -d .kunit/ --gcov-tool=/usr/bin/gcov-6 +Alternatively, LLVM-based toolchains can also be used: + +.. code-block:: bash + + # Build with LLVM and append coverage options to the current config + $ ./tools/testing/kunit/kunit.py run --make_options LLVM=1 --kunitconfig=.kunit/ --kunitconfig=tools/testing/kunit/configs/coverage_uml.config + $ llvm-profdata merge -sparse default.profraw -o default.profdata + $ llvm-cov export --format=lcov .kunit/vmlinux -instr-profile default.profdata > coverage.info + # The coverage.info file is in lcov-compatible format and it can be used to e.g. generate HTML report + $ genhtml -o /tmp/coverage_html coverage.info + Running tests manually ====================== @@ -428,3 +439,10 @@ This attribute indicates the name of the module associated with the test. This attribute is automatically saved as a string and is printed for each suite. Tests can also be filtered using this attribute. + +``is_init`` + +This attribute indicates whether the test uses init data or functions. + +This attribute is automatically saved as a boolean and tests can also be +filtered using this attribute. diff --git a/Documentation/dev-tools/kunit/usage.rst b/Documentation/dev-tools/kunit/usage.rst index 9db12e9166..22955d56b3 100644 --- a/Documentation/dev-tools/kunit/usage.rst +++ b/Documentation/dev-tools/kunit/usage.rst @@ -566,13 +566,9 @@ By reusing the same ``cases`` array from above, we can write the test as a }, }; - // Need a helper function to generate a name for each test case. - static void case_to_desc(const struct sha1_test_case *t, char *desc) - { - strcpy(desc, t->str); - } - // Creates `sha1_gen_params()` to iterate over `cases`. - KUNIT_ARRAY_PARAM(sha1, cases, case_to_desc); + // Creates `sha1_gen_params()` to iterate over `cases` while using + // the struct member `str` for the case description. + KUNIT_ARRAY_PARAM_DESC(sha1, cases, str); // Looks no different from a normal test. static void sha1_test(struct kunit *test) @@ -588,7 +584,7 @@ By reusing the same ``cases`` array from above, we can write the test as a } // Instead of KUNIT_CASE, we use KUNIT_CASE_PARAM and pass in the - // function declared by KUNIT_ARRAY_PARAM. + // function declared by KUNIT_ARRAY_PARAM or KUNIT_ARRAY_PARAM_DESC. static struct kunit_case sha1_test_cases[] = { KUNIT_CASE_PARAM(sha1_test, sha1_gen_params), {} @@ -675,8 +671,23 @@ Testing Static Functions ------------------------ If we do not want to expose functions or variables for testing, one option is to -conditionally ``#include`` the test file at the end of your .c file. For -example: +conditionally export the used symbol. For example: + +.. code-block:: c + + /* In my_file.c */ + + VISIBLE_IF_KUNIT int do_interesting_thing(); + EXPORT_SYMBOL_IF_KUNIT(do_interesting_thing); + + /* In my_file.h */ + + #if IS_ENABLED(CONFIG_KUNIT) + int do_interesting_thing(void); + #endif + +Alternatively, you could conditionally ``#include`` the test file at the end of +your .c file. For example: .. code-block:: c @@ -797,3 +808,53 @@ structures as shown below: KUnit is not enabled, or if no test is running in the current task, it will do nothing. This compiles down to either a no-op or a static key check, so will have a negligible performance impact when no test is running. + +Managing Fake Devices and Drivers +--------------------------------- + +When testing drivers or code which interacts with drivers, many functions will +require a ``struct device`` or ``struct device_driver``. In many cases, setting +up a real device is not required to test any given function, so a fake device +can be used instead. + +KUnit provides helper functions to create and manage these fake devices, which +are internally of type ``struct kunit_device``, and are attached to a special +``kunit_bus``. These devices support managed device resources (devres), as +described in Documentation/driver-api/driver-model/devres.rst + +To create a KUnit-managed ``struct device_driver``, use ``kunit_driver_create()``, +which will create a driver with the given name, on the ``kunit_bus``. This driver +will automatically be destroyed when the corresponding test finishes, but can also +be manually destroyed with ``driver_unregister()``. + +To create a fake device, use the ``kunit_device_register()``, which will create +and register a device, using a new KUnit-managed driver created with ``kunit_driver_create()``. +To provide a specific, non-KUnit-managed driver, use ``kunit_device_register_with_driver()`` +instead. Like with managed drivers, KUnit-managed fake devices are automatically +cleaned up when the test finishes, but can be manually cleaned up early with +``kunit_device_unregister()``. + +The KUnit devices should be used in preference to ``root_device_register()``, and +instead of ``platform_device_register()`` in cases where the device is not otherwise +a platform device. + +For example: + +.. code-block:: c + + #include <kunit/device.h> + + static void test_my_device(struct kunit *test) + { + struct device *fake_device; + const char *dev_managed_string; + + // Create a fake device. + fake_device = kunit_device_register(test, "my_device"); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, fake_device) + + // Pass it to functions which need a device. + dev_managed_string = devm_kstrdup(fake_device, "Hello, World!"); + + // Everything is cleaned up automatically when the test ends. + }
\ No newline at end of file |