From: Guenter Roeck <[email protected]> Document API functions for suppressing warning backtraces.
Tested-by: Linux Kernel Functional Testing <[email protected]> Acked-by: Dan Carpenter <[email protected]> Reviewed-by: Kees Cook <[email protected]> Signed-off-by: Guenter Roeck <[email protected]> Reviewed-by: David Gow <[email protected]> Signed-off-by: Alessandro Carminati <[email protected]> Signed-off-by: Albert Esteve <[email protected]> --- Documentation/dev-tools/kunit/usage.rst | 30 +++++++++++++++++++++++++++++- 1 file changed, 29 insertions(+), 1 deletion(-) diff --git a/Documentation/dev-tools/kunit/usage.rst b/Documentation/dev-tools/kunit/usage.rst index ebd06f5ea4550..76e85412f240e 100644 --- a/Documentation/dev-tools/kunit/usage.rst +++ b/Documentation/dev-tools/kunit/usage.rst @@ -157,6 +157,34 @@ Alternatively, one can take full control over the error message by using if (some_setup_function()) KUNIT_FAIL(test, "Failed to setup thing for testing"); +Suppressing warning backtraces +------------------------------ + +Some unit tests trigger warning backtraces either intentionally or as side +effect. Such backtraces are normally undesirable since they distract from +the actual test and may result in the impression that there is a problem. + +Such backtraces can be suppressed with **task scope suppression**: while +``START`` / ``END`` is active on the current task, the backtrace and stack +dump from warnings on that task are suppressed. Wrap the call from your test +in that window, like shown in the following code. + +.. code-block:: c + + static void some_test(struct kunit *test) + { + KUNIT_START_SUPPRESSED_WARNING(test); + trigger_backtrace(); + KUNIT_END_SUPPRESSED_WARNING(test); + } + +``KUNIT_SUPPRESSED_WARNING_COUNT()`` returns the number of suppressed backtraces. +If the suppressed backtrace was triggered on purpose, this can be used to check +if the backtrace was actually triggered. + +.. code-block:: c + + KUNIT_EXPECT_EQ(test, KUNIT_SUPPRESSED_WARNING_COUNT(), 1); Test Suites ~~~~~~~~~~~ @@ -1211,4 +1239,4 @@ For example: dev_managed_string = devm_kstrdup(fake_device, "Hello, World!"); // Everything is cleaned up automatically when the test ends. - } \ No newline at end of file + } -- 2.52.0
