Add core facilities for defining unit tests; this provides a common way to define test cases, functions that execute code which is under test and determine whether the code under test behaves as expected; this also provides a way to group together related test cases in test suites (here we call them test_modules).
Just define test cases and how to execute them for now; setting expectations on code will be defined later.
Signed-off-by: Brendan Higgins brendanhiggins@google.com Reviewed-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Reviewed-by: Logan Gunthorpe logang@deltatee.com --- Changes Since Last Revision: - Removed spinlock. - Suggested by Luis and Stephen - Renamed `struct kunit_module` to `struct kunit_suite`. - Inspired by Luis. - Made a number of minor cleanups. - Suggested by Luis and Stephen. --- include/kunit/test.h | 182 +++++++++++++++++++++++++++++++++++++++++ kunit/Kconfig | 17 ++++ kunit/Makefile | 1 + kunit/test.c | 190 +++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 390 insertions(+) create mode 100644 include/kunit/test.h create mode 100644 kunit/Kconfig create mode 100644 kunit/Makefile create mode 100644 kunit/test.c
diff --git a/include/kunit/test.h b/include/kunit/test.h new file mode 100644 index 0000000000000..b34d9f2ac6f9c --- /dev/null +++ b/include/kunit/test.h @@ -0,0 +1,182 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Base unit test (KUnit) API. + * + * Copyright (C) 2019, Google LLC. + * Author: Brendan Higgins brendanhiggins@google.com + */ + +#ifndef _KUNIT_TEST_H +#define _KUNIT_TEST_H + +#include <linux/types.h> + +struct kunit; + +/** + * struct kunit_case - represents an individual test case. + * @run_case: the function representing the actual test case. + * @name: the name of the test case. + * + * A test case is a function with the signature, ``void (*)(struct kunit *)`` + * that makes expectations (see KUNIT_EXPECT_TRUE()) about code under test. Each + * test case is associated with a &struct kunit_suite and will be run after the + * suite's init function and followed by the suite's exit function. + * + * A test case should be static and should only be created with the KUNIT_CASE() + * macro; additionally, every array of test cases should be terminated with an + * empty test case. + * + * Example: + * + * .. code-block:: c + * + * void add_test_basic(struct kunit *test) + * { + * KUNIT_EXPECT_EQ(test, 1, add(1, 0)); + * KUNIT_EXPECT_EQ(test, 2, add(1, 1)); + * KUNIT_EXPECT_EQ(test, 0, add(-1, 1)); + * KUNIT_EXPECT_EQ(test, INT_MAX, add(0, INT_MAX)); + * KUNIT_EXPECT_EQ(test, -1, add(INT_MAX, INT_MIN)); + * } + * + * static struct kunit_case example_test_cases[] = { + * KUNIT_CASE(add_test_basic), + * {} + * }; + * + */ +struct kunit_case { + void (*run_case)(struct kunit *test); + const char *name; + + /* private: internal use only. */ + bool success; +}; + +/** + * KUNIT_CASE - A helper for creating a &struct kunit_case + * @test_name: a reference to a test case function. + * + * Takes a symbol for a function representing a test case and creates a + * &struct kunit_case object from it. See the documentation for + * &struct kunit_case for an example on how to use it. + */ +#define KUNIT_CASE(test_name) { .run_case = test_name, .name = #test_name } + +/** + * struct kunit_suite - describes a related collection of &struct kunit_case s. + * @name: the name of the test. Purely informational. + * @init: called before every test case. + * @exit: called after every test case. + * @test_cases: a null terminated array of test cases. + * + * A kunit_suite is a collection of related &struct kunit_case s, such that + * @init is called before every test case and @exit is called after every test + * case, similar to the notion of a *test fixture* or a *test class* in other + * unit testing frameworks like JUnit or Googletest. + * + * Every &struct kunit_case must be associated with a kunit_suite for KUnit to + * run it. + */ +struct kunit_suite { + const char name[256]; + int (*init)(struct kunit *test); + void (*exit)(struct kunit *test); + struct kunit_case *test_cases; +}; + +/** + * struct kunit - represents a running instance of a test. + * @priv: for user to store arbitrary data. Commonly used to pass data created + * in the init function (see &struct kunit_suite). + * + * Used to store information about the current context under which the test is + * running. Most of this data is private and should only be accessed indirectly + * via public functions; the one exception is @priv which can be used by the + * test writer to store arbitrary data. + * + * A brief note on locking: + * + * First off, we need to lock because in certain cases a user may want to use an + * expectation in a thread other than the thread that the test case is running + * in. + * + * The next point is that the locking should be safe in an irq context. + * Technically speaking a user should use a mock/fake irqchip or some other fake + * method to trigger an irq handler under test; however, the irq handler should + * think that it is in a real irq context. Given that the code being run expects + * to be in an irq context, we should act as though it is. + */ +struct kunit { + void *priv; + + /* private: internal use only. */ + const char *name; /* Read only after initialization! */ + bool success; /* Read only after test_case finishes! */ +}; + +void kunit_init_test(struct kunit *test, const char *name); + +int kunit_run_tests(struct kunit_suite *suite); + +/** + * suite_test() - used to register a &struct kunit_suite with KUnit. + * @suite: a statically allocated &struct kunit_suite. + * + * Registers @suite with the test framework. See &struct kunit_suite for more + * information. + * + * NOTE: Currently KUnit tests are all run as late_initcalls; this means that + * they cannot test anything where tests must run at a different init phase. One + * significant restriction resulting from this is that KUnit cannot reliably + * test anything that is initialize in the late_init phase. + * + * TODO(brendanhiggins@google.com): Don't run all KUnit tests as late_initcalls. + * I have some future work planned to dispatch all KUnit tests from the same + * place, and at the very least to do so after everything else is definitely + * initialized. + */ +#define kunit_test_suite(suite) \ + static int kunit_suite_init##suite(void) \ + { \ + return kunit_run_tests(&suite); \ + } \ + late_initcall(kunit_suite_init##suite) + +void __printf(3, 4) kunit_printk(const char *level, + const struct kunit *test, + const char *fmt, ...); + +/** + * kunit_info() - Prints an INFO level message associated with the current test. + * @test: The test context object. + * @fmt: A printk() style format string. + * + * Prints an info level message associated with the test suite being run. Takes + * a variable number of format parameters just like printk(). + */ +#define kunit_info(test, fmt, ...) \ + kunit_printk(KERN_INFO, test, fmt, ##__VA_ARGS__) + +/** + * kunit_warn() - Prints a WARN level message associated with the current test. + * @test: The test context object. + * @fmt: A printk() style format string. + * + * Prints a warning level message. + */ +#define kunit_warn(test, fmt, ...) \ + kunit_printk(KERN_WARNING, test, fmt, ##__VA_ARGS__) + +/** + * kunit_err() - Prints an ERROR level message associated with the current test. + * @test: The test context object. + * @fmt: A printk() style format string. + * + * Prints an error level message. + */ +#define kunit_err(test, fmt, ...) \ + kunit_printk(KERN_ERR, test, fmt, ##__VA_ARGS__) + +#endif /* _KUNIT_TEST_H */ diff --git a/kunit/Kconfig b/kunit/Kconfig new file mode 100644 index 0000000000000..330ae83527c23 --- /dev/null +++ b/kunit/Kconfig @@ -0,0 +1,17 @@ +# +# KUnit base configuration +# + +menu "KUnit support" + +config KUNIT + bool "Enable support for unit tests (KUnit)" + help + Enables support for kernel unit tests (KUnit), a lightweight unit + testing and mocking framework for the Linux kernel. These tests are + able to be run locally on a developer's workstation without a VM or + special hardware when using UML. Can also be used on most other + architectures. For more information, please see + Documentation/dev-tools/kunit/. + +endmenu diff --git a/kunit/Makefile b/kunit/Makefile new file mode 100644 index 0000000000000..5efdc4dea2c08 --- /dev/null +++ b/kunit/Makefile @@ -0,0 +1 @@ +obj-$(CONFIG_KUNIT) += test.o diff --git a/kunit/test.c b/kunit/test.c new file mode 100644 index 0000000000000..c030ba5a43e40 --- /dev/null +++ b/kunit/test.c @@ -0,0 +1,190 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Base unit test (KUnit) API. + * + * Copyright (C) 2019, Google LLC. + * Author: Brendan Higgins brendanhiggins@google.com + */ + +#include <linux/sched/debug.h> +#include <kunit/test.h> + +static void kunit_set_failure(struct kunit *test) +{ + WRITE_ONCE(test->success, false); +} + +static int kunit_vprintk_emit(int level, const char *fmt, va_list args) +{ + return vprintk_emit(0, level, NULL, 0, fmt, args); +} + +static int kunit_printk_emit(int level, const char *fmt, ...) +{ + va_list args; + int ret; + + va_start(args, fmt); + ret = kunit_vprintk_emit(level, fmt, args); + va_end(args); + + return ret; +} + +static void kunit_vprintk(const struct kunit *test, + const char *level, + struct va_format *vaf) +{ + kunit_printk_emit(level[1] - '0', "\t# %s: %pV", test->name, vaf); +} + +static void kunit_print_tap_version(void) +{ + static bool kunit_has_printed_tap_version; + + if (!kunit_has_printed_tap_version) { + kunit_printk_emit(LOGLEVEL_INFO, "TAP version 14\n"); + kunit_has_printed_tap_version = true; + } +} + +static size_t kunit_test_cases_len(struct kunit_case *test_cases) +{ + struct kunit_case *test_case; + size_t len = 0; + + for (test_case = test_cases; test_case->run_case; test_case++) + len++; + + return len; +} + +static void kunit_print_subtest_start(struct kunit_suite *suite) +{ + kunit_print_tap_version(); + kunit_printk_emit(LOGLEVEL_INFO, "\t# Subtest: %s\n", suite->name); + kunit_printk_emit(LOGLEVEL_INFO, + "\t1..%zd\n", + kunit_test_cases_len(suite->test_cases)); +} + +static void kunit_print_ok_not_ok(bool should_indent, + bool is_ok, + size_t test_number, + const char *description) +{ + const char *indent, *ok_not_ok; + + if (should_indent) + indent = "\t"; + else + indent = ""; + + if (is_ok) + ok_not_ok = "ok"; + else + ok_not_ok = "not ok"; + + kunit_printk_emit(LOGLEVEL_INFO, + "%s%s %zd - %s\n", + indent, ok_not_ok, test_number, description); +} + +static bool kunit_suite_has_succeeded(struct kunit_suite *suite) +{ + const struct kunit_case *test_case; + + for (test_case = suite->test_cases; test_case->run_case; test_case++) + if (!test_case->success) + return false; + + return true; +} + +static void kunit_print_subtest_end(struct kunit_suite *suite) +{ + static size_t kunit_suite_counter = 1; + + kunit_print_ok_not_ok(false, + kunit_suite_has_succeeded(suite), + kunit_suite_counter++, + suite->name); +} + +static void kunit_print_test_case_ok_not_ok(struct kunit_case *test_case, + size_t test_number) +{ + kunit_print_ok_not_ok(true, + test_case->success, + test_number, + test_case->name); +} + +void kunit_init_test(struct kunit *test, const char *name) +{ + spin_lock_init(&test->lock); + test->name = name; + test->success = true; +} + +/* + * Performs all logic to run a test case. + */ +static void kunit_run_case(struct kunit_suite *suite, + struct kunit_case *test_case) +{ + struct kunit test; + int ret = 0; + + kunit_init_test(&test, test_case->name); + + if (suite->init) { + ret = suite->init(&test); + if (ret) { + kunit_err(&test, "failed to initialize: %d\n", ret); + kunit_set_failure(&test); + return; + } + } + + test_case->run_case(&test); + + if (suite->exit) + suite->exit(&test); + + test_case->success = test.success; +} + +int kunit_run_tests(struct kunit_suite *suite) +{ + struct kunit_case *test_case; + size_t test_case_count = 1; + + kunit_print_subtest_start(suite); + + for (test_case = suite->test_cases; test_case->run_case; test_case++) { + kunit_run_case(suite, test_case); + kunit_print_test_case_ok_not_ok(test_case, test_case_count++); + } + + kunit_print_subtest_end(suite); + + return 0; +} + +void kunit_printk(const char *level, + const struct kunit *test, + const char *fmt, ...) +{ + struct va_format vaf; + va_list args; + + va_start(args, fmt); + + vaf.fmt = fmt; + vaf.va = &args; + + kunit_vprintk(test, level, &vaf); + + va_end(args); +}