Documentation/dev-tools/kselftest.rst

   1 ======================
   2 Linux Kernel Selftests
   3 ======================
   4
   5 The kernel contains a set of "self tests" under the tools/testing/selftests/
   6 directory. These are intended to be small tests to exercise individual code
   7 paths in the kernel. Tests are intended to be run after building, installing
   8 and booting a kernel.
   9
  10 On some systems, hot-plug tests could hang forever waiting for cpu and
  11 memory to be ready to be offlined. A special hot-plug target is created
  12 to run full range of hot-plug tests. In default mode, hot-plug tests run
  13 in safe mode with a limited scope. In limited mode, cpu-hotplug test is
  14 run on a single cpu as opposed to all hotplug capable cpus, and memory
  15 hotplug test is run on 2% of hotplug capable memory instead of 10%.
  16
  17 Running the selftests (hotplug tests are run in limited mode)
  18 =============================================================
  19
  20 To build the tests::
  21
  22   $ make -C tools/testing/selftests
  23
  24 To run the tests::
  25
  26   $ make -C tools/testing/selftests run_tests
  27
  28 To build and run the tests with a single command, use::
  29
  30   $ make kselftest
  31
  32 Note that some tests will require root privileges.
  33
  34
  35 Running a subset of selftests
  36 =============================
  37
  38 You can use the "TARGETS" variable on the make command line to specify
  39 single test to run, or a list of tests to run.
  40
  41 To run only tests targeted for a single subsystem::
  42
  43   $ make -C tools/testing/selftests TARGETS=ptrace run_tests
  44
  45 You can specify multiple tests to build and run::
  46
  47   $  make TARGETS="size timers" kselftest
  48
  49 See the top-level tools/testing/selftests/Makefile for the list of all
  50 possible targets.
  51
  52
  53 Running the full range hotplug selftests
  54 ========================================
  55
  56 To build the hotplug tests::
  57
  58   $ make -C tools/testing/selftests hotplug
  59
  60 To run the hotplug tests::
  61
  62   $ make -C tools/testing/selftests run_hotplug
  63
  64 Note that some tests will require root privileges.
  65
  66
  67 Install selftests
  68 =================
  69
  70 You can use kselftest_install.sh tool installs selftests in default
  71 location which is tools/testing/selftests/kselftest or a user specified
  72 location.
  73
  74 To install selftests in default location::
  75
  76    $ cd tools/testing/selftests
  77    $ ./kselftest_install.sh
  78
  79 To install selftests in a user specified location::
  80
  81    $ cd tools/testing/selftests
  82    $ ./kselftest_install.sh install_dir
  83
  84 Running installed selftests
  85 ===========================
  86
  87 Kselftest install as well as the Kselftest tarball provide a script
  88 named "run_kselftest.sh" to run the tests.
  89
  90 You can simply do the following to run the installed Kselftests. Please
  91 note some tests will require root privileges::
  92
  93    $ cd kselftest
  94    $ ./run_kselftest.sh
  95
  96 Contributing new tests
  97 ======================
  98
  99 In general, the rules for selftests are
 100
 101  * Do as much as you can if you're not root;
 102
 103  * Don't take too long;
 104
 105  * Don't break the build on any architecture, and
 106
 107  * Don't cause the top-level "make run_tests" to fail if your feature is
 108    unconfigured.
 109
 110 Contributing new tests (details)
 111 ================================
 112
 113  * Use TEST_GEN_XXX if such binaries or files are generated during
 114    compiling.
 115
 116    TEST_PROGS, TEST_GEN_PROGS mean it is the excutable tested by
 117    default.
 118
 119    TEST_PROGS_EXTENDED, TEST_GEN_PROGS_EXTENDED mean it is the
 120    executable which is not tested by default.
 121    TEST_FILES, TEST_GEN_FILES mean it is the file which is used by
 122    test.
 123
 124 Test Harness
 125 ============
 126
 127 The kselftest_harness.h file contains useful helpers to build tests.  The tests
 128 from tools/testing/selftests/seccomp/seccomp_bpf.c can be used as example.
 129
 130 Example
 131 -------
 132
 133 .. kernel-doc:: tools/testing/selftests/kselftest_harness.h
 134     :doc: example
 135
 136
 137 Helpers
 138 -------
 139
 140 .. kernel-doc:: tools/testing/selftests/kselftest_harness.h
 141     :functions: TH_LOG TEST TEST_SIGNAL FIXTURE FIXTURE_DATA FIXTURE_SETUP
 142                 FIXTURE_TEARDOWN TEST_F TEST_HARNESS_MAIN
 143
 144 Operators
 145 ---------
 146
 147 .. kernel-doc:: tools/testing/selftests/kselftest_harness.h
 148     :doc: operators
 149
 150 .. kernel-doc:: tools/testing/selftests/kselftest_harness.h
 151     :functions: ASSERT_EQ ASSERT_NE ASSERT_LT ASSERT_LE ASSERT_GT ASSERT_GE
 152                 ASSERT_NULL ASSERT_TRUE ASSERT_NULL ASSERT_TRUE ASSERT_FALSE
 153                 ASSERT_STREQ ASSERT_STRNE EXPECT_EQ EXPECT_NE EXPECT_LT
 154                 EXPECT_LE EXPECT_GT EXPECT_GE EXPECT_NULL EXPECT_TRUE
 155                 EXPECT_FALSE EXPECT_STREQ EXPECT_STRNE