kernel/linux.git/Documentation/dev-tools/kunit/usage.rst, branch v6.6.131

Documentation: kunit: Add usage notes for kunit_add_action()

2023-05-25T14:53:12+00:00

Add some basic documentation for kunit_add_action() and related deferred action functions. Reviewed-by: Rae Moar Signed-off-by: David Gow Signed-off-by: Shuah Khan

Documentation: kunit: Warn that exit functions run even if init fails

2023-05-12T00:17:35+00:00

KUnit's exit functions will run even if the corresponding init function fails. It's easy, when writing an exit function, to assume the init function succeeded, and (for example) access uninitialised memory or dereference NULL pointers. Note that this case exists and should be handled in the documentation. Suggested-by: Benjamin Berg Link: https://lore.kernel.org/linux-kselftest/a39af0400abedb2e9b31d84c37551cecc3eed0e1.camel@sipsolutions.net/ Reviewed-by: Sadiya Kazi Signed-off-by: David Gow Signed-off-by: Shuah Khan

Documentation: kunit: Note that assertions should not be used in cleanup

2023-05-12T00:17:29+00:00

As assertions abort the test cleanup process, they should be avoided from within a suite's exit function, or from within resource 'free' functions. Unlike with initialisation or main test execution, no further cleanup will be performed after a failed assertion, potentially causing a leak of resources. Reviewed-by: Sadiya Kazi Signed-off-by: David Gow Signed-off-by: Shuah Khan

kunit: Add "hooks" to call into KUnit when it's built as a module

2023-02-08T21:26:25+00:00

KUnit has several macros and functions intended for use from non-test code. These hooks, currently the kunit_get_current_test() and kunit_fail_current_test() macros, didn't work when CONFIG_KUNIT=m. In order to support this case, the required functions and static data need to be available unconditionally, even when KUnit itself is not built-in. The new 'hooks.c' file is therefore always included, and has both the static key required for kunit_get_current_test(), and a table of function pointers in struct kunit_hooks_table. This is filled in with the real implementations by kunit_install_hooks(), which is kept in hooks-impl.h and called when the kunit module is loaded. This can be extended for future features which require similar "hook" behaviour, such as static stubs, by simply adding new entries to the struct, and the appropriate code to set them. Fixed white-space errors during commit: Shuah Khan Resolved merge conflicts with: db105c37a4d6 ("kunit: Export kunit_running()") This patch supersedes the above. Shuah Khan Signed-off-by: David Gow Reviewed-by: Rae Moar Reviewed-by: Brendan Higgins Signed-off-by: Shuah Khan

kunit: Use the static key when retrieving the current test

2022-12-12T21:13:47+00:00

In order to detect if a KUnit test is running, and to access its context, the 'kunit_test' member of the current task_struct is used. Usually, this is accessed directly or via the kunit_fail_current_task() function. In order to speed up the case where no test is running, add a wrapper, kunit_get_current_test(), which uses the static key to fail early. Equally, Speed up kunit_fail_current_test() by using the static key. This should make it convenient for code to call this unconditionally in fakes or error paths, without worrying that this will slow the code down significantly. If CONFIG_KUNIT=n (or m), this compiles away to nothing. If CONFIG_KUNIT=y, it will compile down to a NOP (on most architectures) if no KUnit test is currently running. Note that kunit_get_current_test() does not work if KUnit is built as a module. This mirrors the existing restriction on kunit_fail_current_test(). Note that the definition of kunit_fail_current_test() still wraps an empty, inline function if KUnit is not built-in. This is to ensure that the printf format string __attribute__ will still work. Also update the documentation to suggest users use the new kunit_get_current_test() function, update the example, and to describe the behaviour when KUnit is disabled better. Cc: Jonathan Corbet Cc: Sadiya Kazi Signed-off-by: David Gow Reviewed-by: Daniel Latypov Signed-off-by: Shuah Khan

Documentation: KUnit: reword description of assertions

2022-12-12T21:13:47+00:00

The existing wording implies that kunit_kmalloc_array() is "the method under test". We're actually testing the sort() function in that example. This is because the example was changed in commit 953574390634 ("Documentation: KUnit: Rework writing page to focus on writing tests"), but the wording was not. Also add a `note` telling people they can use the KUNIT_ASSERT_EQ() macros from any function. Some users might be coming from a framework like gUnit where that'll compile but silently do the wrong thing. Signed-off-by: Daniel Latypov Reviewed-by: Sadiya Kazi Reviewed-by: David Gow Signed-off-by: Shuah Khan

Documentation: KUnit: make usage.rst a superset of tips.rst, remove duplication

2022-12-12T21:13:47+00:00

usage.rst had most of the content of the tips.rst page copied over. But it's missing https://www.kernel.org/doc/html/v6.0/dev-tools/kunit/tips.html#customizing-error-messages Copy it over so we can retire tips.rst w/o losing content. And in that process, it also gained a duplicate section about how KUNIT_ASSERT_*() exit the test case early. Remove that. Signed-off-by: Daniel Latypov Reviewed-by: Sadiya Kazi Reviewed-by: David Gow Signed-off-by: Shuah Khan

Documentation: KUnit: Fix non-uml anchor

2022-09-30T19:19:03+00:00

The section was rewritten but its anchor got left behind. Fix the anchor and add some references to running on QEMU. Signed-off-by: Tales Aparecida Reviewed-by: David Gow Signed-off-by: Shuah Khan

Documentation: KUnit: Fix example with compilation error

2022-07-28T19:06:35+00:00

The Parameterized Testing example contains a compilation error, as the signature for the description helper function is void(*)(const struct sha1_test_case *, char *), and the struct is non-const. This is warned by Clang: error: initialization of ‘void (*)(struct sha1_test_case *, char *)’ from incompatible pointer type ‘void (*)(const struct sha1_test_case *, char *)’ [-Werror=incompatible-pointer-types] 33 | KUNIT_ARRAY_PARAM(sha1, cases, case_to_desc); | ^~~~~~~~~~~~ ../include/kunit/test.h:1339:70: note: in definition of macro ‘KUNIT_ARRAY_PARAM’ 1339 | void (*__get_desc)(typeof(__next), char *) = get_desc; \ Signed-off-by: Maíra Canal Reviewed-by: Daniel Latypov Reviewed-by: Brendan Higgins Signed-off-by: Shuah Khan

kunit: add ability to specify suite-level init and exit functions

2022-05-02T18:35:51+00:00

KUnit has support for setup/cleanup logic for each test case in a suite. But it lacks the ability to specify setup/cleanup for the entire suite itself. This can be used to do setup that is too expensive or cumbersome to do for each test. Or it can be used to do simpler things like log debug information after the suite completes. It's a fairly common feature, so the lack of it is noticeable. Some examples in other frameworks and languages: * https://docs.python.org/3/library/unittest.html#setupclass-and-teardownclass * https://google.github.io/googletest/reference/testing.html#Test::SetUpTestSuite Meta: This is very similar to this patch here: https://lore.kernel.org/linux-kselftest/20210805043503.20252-3-bvanassche@acm.org/ The changes from that patch: * pass in `struct kunit *` so users can do stuff like `kunit_info(suite, "debug message")` * makes sure the init failure is bubbled up as a failure * updates kunit-example-test.c to use a suite init * Updates kunit/usage.rst to mention the new support * some minor cosmetic things * use `suite_{init,exit}` instead of `{init/exit}_suite` * make suite init error message more consistent w/ test init * etc. Signed-off-by: Daniel Latypov Reviewed-by: David Gow Reviewed-by: Brendan Higgins Signed-off-by: Shuah Khan