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Diffstat (limited to 'Documentation/dev-tools/kselftest.rst')
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1 files changed, 113 insertions, 15 deletions
diff --git a/Documentation/dev-tools/kselftest.rst b/Documentation/dev-tools/kselftest.rst index 61ae13c44f91..deede972f254 100644 --- a/Documentation/dev-tools/kselftest.rst +++ b/Documentation/dev-tools/kselftest.rst @@ -7,6 +7,14 @@ directory. These are intended to be small tests to exercise individual code paths in the kernel. Tests are intended to be run after building, installing and booting a kernel. +Kselftest from mainline can be run on older stable kernels. Running tests +from mainline offers the best coverage. Several test rings run mainline +kselftest suite on stable releases. The reason is that when a new test +gets added to test existing code to regression test a bug, we should be +able to run that test on an older kernel. Hence, it is important to keep +code that can still test an older kernel and make sure it skips the test +gracefully on newer releases. + You can find additional information on Kselftest framework, how to write new tests using the framework on Kselftest wiki: @@ -28,6 +36,7 @@ Running the selftests (hotplug tests are run in limited mode) To build the tests:: + $ make headers $ make -C tools/testing/selftests To run the tests:: @@ -125,32 +134,86 @@ Note that some tests will require root privileges. Install selftests ================= -You can use the kselftest_install.sh tool to install selftests in the -default location, which is tools/testing/selftests/kselftest, or in a -user specified location. +You can use the "install" target of "make" (which calls the `kselftest_install.sh` +tool) to install selftests in the default location (`tools/testing/selftests/kselftest_install`), +or in a user specified location via the `INSTALL_PATH` "make" variable. To install selftests in default location:: - $ cd tools/testing/selftests - $ ./kselftest_install.sh + $ make -C tools/testing/selftests install To install selftests in a user specified location:: - $ cd tools/testing/selftests - $ ./kselftest_install.sh install_dir + $ make -C tools/testing/selftests install INSTALL_PATH=/some/other/path Running installed selftests =========================== -Kselftest install as well as the Kselftest tarball provide a script -named "run_kselftest.sh" to run the tests. +Found in the install directory, as well as in the Kselftest tarball, +is a script named `run_kselftest.sh` to run the tests. You can simply do the following to run the installed Kselftests. Please note some tests will require root privileges:: - $ cd kselftest + $ cd kselftest_install $ ./run_kselftest.sh +To see the list of available tests, the `-l` option can be used:: + + $ ./run_kselftest.sh -l + +The `-c` option can be used to run all the tests from a test collection, or +the `-t` option for specific single tests. Either can be used multiple times:: + + $ ./run_kselftest.sh -c bpf -c seccomp -t timers:posix_timers -t timer:nanosleep + +For other features see the script usage output, seen with the `-h` option. + +Timeout for selftests +===================== + +Selftests are designed to be quick and so a default timeout is used of 45 +seconds for each test. Tests can override the default timeout by adding +a settings file in their directory and set a timeout variable there to the +configured a desired upper timeout for the test. Only a few tests override +the timeout with a value higher than 45 seconds, selftests strives to keep +it that way. Timeouts in selftests are not considered fatal because the +system under which a test runs may change and this can also modify the +expected time it takes to run a test. If you have control over the systems +which will run the tests you can configure a test runner on those systems to +use a greater or lower timeout on the command line as with the `-o` or +the `--override-timeout` argument. For example to use 165 seconds instead +one would use: + + $ ./run_kselftest.sh --override-timeout 165 + +You can look at the TAP output to see if you ran into the timeout. Test +runners which know a test must run under a specific time can then optionally +treat these timeouts then as fatal. + +Packaging selftests +=================== + +In some cases packaging is desired, such as when tests need to run on a +different system. To package selftests, run:: + + $ make -C tools/testing/selftests gen_tar + +This generates a tarball in the `INSTALL_PATH/kselftest-packages` directory. By +default, `.gz` format is used. The tar compression format can be overridden by +specifying a `FORMAT` make variable. Any value recognized by `tar's auto-compress`_ +option is supported, such as:: + + $ make -C tools/testing/selftests gen_tar FORMAT=.xz + +`make gen_tar` invokes `make install` so you can use it to package a subset of +tests by using variables specified in `Running a subset of selftests`_ +section:: + + $ make -C tools/testing/selftests gen_tar TARGETS="bpf" FORMAT=.xz + +.. _tar's auto-compress: https://www.gnu.org/software/tar/manual/html_node/gzip.html#auto_002dcompress + Contributing new tests ====================== @@ -168,6 +231,14 @@ In general, the rules for selftests are Contributing new tests (details) ================================ + * In your Makefile, use facilities from lib.mk by including it instead of + reinventing the wheel. Specify flags and binaries generation flags on + need basis before including lib.mk. :: + + CFLAGS = $(KHDR_INCLUDES) + TEST_GEN_PROGS := close_range_test + include ../lib.mk + * Use TEST_GEN_XXX if such binaries or files are generated during compiling. @@ -190,13 +261,30 @@ Contributing new tests (details) * First use the headers inside the kernel source and/or git repo, and then the system headers. Headers for the kernel release as opposed to headers installed by the distro on the system should be the primary focus to be able - to find regressions. + to find regressions. Use KHDR_INCLUDES in Makefile to include headers from + the kernel source. * If a test needs specific kernel config options enabled, add a config file in the test directory to enable them. e.g: tools/testing/selftests/android/config + * Create a .gitignore file inside test directory and add all generated objects + in it. + + * Add new test name in TARGETS in selftests/Makefile:: + + TARGETS += android + + * All changes should pass:: + + kselftest-{all,install,clean,gen_tar} + kselftest-{all,install,clean,gen_tar} O=abo_path + kselftest-{all,install,clean,gen_tar} O=rel_path + make -C tools/testing/selftests {all,install,clean,gen_tar} + make -C tools/testing/selftests {all,install,clean,gen_tar} O=abs_path + make -C tools/testing/selftests {all,install,clean,gen_tar} O=rel_path + Test Module =========== @@ -207,8 +295,16 @@ using a shell script test runner. ``kselftest/module.sh`` is designed to facilitate this process. There is also a header file provided to assist writing kernel modules that are for use with kselftest: -- ``tools/testing/kselftest/kselftest_module.h`` -- ``tools/testing/kselftest/kselftest/module.sh`` +- ``tools/testing/selftests/kselftest_module.h`` +- ``tools/testing/selftests/kselftest/module.sh`` + +Note that test modules should taint the kernel with TAINT_TEST. This will +happen automatically for modules which are in the ``tools/testing/`` +directory, or for modules which use the ``kselftest_module.h`` header above. +Otherwise, you'll need to add ``MODULE_INFO(test, "Y")`` to your module +source. selftests which do not load modules typically should not taint the +kernel, but in cases where a non-test module is loaded, TEST_TAINT can be +applied from userspace by writing to ``/proc/sys/kernel/tainted``. How to use ---------- @@ -247,7 +343,7 @@ A bare bones test module might look like this: #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt - #include "../tools/testing/selftests/kselftest/module.h" + #include "../tools/testing/selftests/kselftest_module.h" KSTM_MODULE_GLOBALS(); @@ -268,6 +364,7 @@ A bare bones test module might look like this: KSTM_MODULE_LOADERS(test_foo); MODULE_AUTHOR("John Developer <jd@fooman.org>"); MODULE_LICENSE("GPL"); + MODULE_INFO(test, "Y"); Example test script ------------------- @@ -301,7 +398,8 @@ Helpers .. kernel-doc:: tools/testing/selftests/kselftest_harness.h :functions: TH_LOG TEST TEST_SIGNAL FIXTURE FIXTURE_DATA FIXTURE_SETUP - FIXTURE_TEARDOWN TEST_F TEST_HARNESS_MAIN + FIXTURE_TEARDOWN TEST_F TEST_HARNESS_MAIN FIXTURE_VARIANT + FIXTURE_VARIANT_ADD Operators --------- |