====================== Linux Kernel Selftests ====================== The kernel contains a set of "self tests" under the tools/testing/selftests/ 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. On some systems, hot-plug tests could hang forever waiting for cpu and memory to be ready to be offlined. A special hot-plug target is created to run full range of hot-plug tests. In default mode, hot-plug tests run in safe mode with a limited scope. In limited mode, cpu-hotplug test is run on a single cpu as opposed to all hotplug capable cpus, and memory hotplug test is run on 2% of hotplug capable memory instead of 10%. Running the selftests (hotplug tests are run in limited mode) ============================================================= To build the tests:: $ make -C tools/testing/selftests To run the tests:: $ make -C tools/testing/selftests run_tests To build and run the tests with a single command, use:: $ make kselftest Note that some tests will require root privileges. Running a subset of selftests ============================= You can use the "TARGETS" variable on the make command line to specify single test to run, or a list of tests to run. To run only tests targeted for a single subsystem:: $ make -C tools/testing/selftests TARGETS=ptrace run_tests You can specify multiple tests to build and run:: $ make TARGETS="size timers" kselftest See the top-level tools/testing/selftests/Makefile for the list of all possible targets. Running the full range hotplug selftests ======================================== To build the hotplug tests:: $ make -C tools/testing/selftests hotplug To run the hotplug tests:: $ make -C tools/testing/selftests run_hotplug Note that some tests will require root privileges. Install selftests ================= You can use kselftest_install.sh tool installs selftests in default location which is tools/testing/selftests/kselftest or a user specified location. To install selftests in default location:: $ cd tools/testing/selftests $ ./kselftest_install.sh To install selftests in a user specified location:: $ cd tools/testing/selftests $ ./kselftest_install.sh install_dir Running installed selftests =========================== Kselftest install as well as the Kselftest tarball provide 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 $ ./run_kselftest.sh Contributing new tests ====================== In general, the rules for selftests are * Do as much as you can if you're not root; * Don't take too long; * Don't break the build on any architecture, and * Don't cause the top-level "make run_tests" to fail if your feature is unconfigured. Contributing new tests (details) ================================ * Use TEST_GEN_XXX if such binaries or files are generated during compiling. TEST_PROGS, TEST_GEN_PROGS mean it is the excutable tested by default. TEST_PROGS_EXTENDED, TEST_GEN_PROGS_EXTENDED mean it is the executable which is not tested by default. TEST_FILES, TEST_GEN_FILES mean it is the file which is used by test. Test Harness ============ The kselftest_harness.h file contains useful helpers to build tests. The tests from tools/testing/selftests/seccomp/seccomp_bpf.c can be used as example. Example ------- .. kernel-doc:: tools/testing/selftests/kselftest_harness.h :doc: example 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 Operators --------- .. kernel-doc:: tools/testing/selftests/kselftest_harness.h :doc: operators .. kernel-doc:: tools/testing/selftests/kselftest_harness.h :functions: ASSERT_EQ ASSERT_NE ASSERT_LT ASSERT_LE ASSERT_GT ASSERT_GE ASSERT_NULL ASSERT_TRUE ASSERT_NULL ASSERT_TRUE ASSERT_FALSE ASSERT_STREQ ASSERT_STRNE EXPECT_EQ EXPECT_NE EXPECT_LT EXPECT_LE EXPECT_GT EXPECT_GE EXPECT_NULL EXPECT_TRUE EXPECT_FALSE EXPECT_STREQ EXPECT_STRNE