diff --git a/include/kunit/test.h b/include/kunit/test.h index 30a62de16bc9..3d554d7c1c79 100644 --- a/include/kunit/test.h +++ b/include/kunit/test.h @@ -10,6 +10,7 @@ #define _KUNIT_TEST_H #include +#include #include #include #include @@ -172,6 +173,7 @@ struct kunit { /* private: internal use only. */ const char *name; /* Read only after initialization! */ + struct kunit_try_catch try_catch; /* * success starts as true, and may only be set to false during a * test case; thus, it is safe to update this across multiple diff --git a/include/kunit/try-catch.h b/include/kunit/try-catch.h new file mode 100644 index 000000000000..404f336cbdc8 --- /dev/null +++ b/include/kunit/try-catch.h @@ -0,0 +1,75 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * An API to allow a function, that may fail, to be executed, and recover in a + * controlled manner. + * + * Copyright (C) 2019, Google LLC. + * Author: Brendan Higgins + */ + +#ifndef _KUNIT_TRY_CATCH_H +#define _KUNIT_TRY_CATCH_H + +#include + +typedef void (*kunit_try_catch_func_t)(void *); + +struct completion; +struct kunit; + +/** + * struct kunit_try_catch - provides a generic way to run code which might fail. + * @test: The test case that is currently being executed. + * @try_completion: Completion that the control thread waits on while test runs. + * @try_result: Contains any errno obtained while running test case. + * @try: The function, the test case, to attempt to run. + * @catch: The function called if @try bails out. + * @context: used to pass user data to the try and catch functions. + * + * kunit_try_catch provides a generic, architecture independent way to execute + * an arbitrary function of type kunit_try_catch_func_t which may bail out by + * calling kunit_try_catch_throw(). If kunit_try_catch_throw() is called, @try + * is stopped at the site of invocation and @catch is called. + * + * struct kunit_try_catch provides a generic interface for the functionality + * needed to implement kunit->abort() which in turn is needed for implementing + * assertions. Assertions allow stating a precondition for a test simplifying + * how test cases are written and presented. + * + * Assertions are like expectations, except they abort (call + * kunit_try_catch_throw()) when the specified condition is not met. This is + * useful when you look at a test case as a logical statement about some piece + * of code, where assertions are the premises for the test case, and the + * conclusion is a set of predicates, rather expectations, that must all be + * true. If your premises are violated, it does not makes sense to continue. + */ +struct kunit_try_catch { + /* private: internal use only. */ + struct kunit *test; + struct completion *try_completion; + int try_result; + kunit_try_catch_func_t try; + kunit_try_catch_func_t catch; + void *context; +}; + +void kunit_try_catch_init(struct kunit_try_catch *try_catch, + struct kunit *test, + kunit_try_catch_func_t try, + kunit_try_catch_func_t catch); + +void kunit_try_catch_run(struct kunit_try_catch *try_catch, void *context); + +void __noreturn kunit_try_catch_throw(struct kunit_try_catch *try_catch); + +static inline int kunit_try_catch_get_result(struct kunit_try_catch *try_catch) +{ + return try_catch->try_result; +} + +/* + * Exposed for testing only. + */ +void kunit_generic_try_catch_init(struct kunit_try_catch *try_catch); + +#endif /* _KUNIT_TRY_CATCH_H */ diff --git a/lib/kunit/Makefile b/lib/kunit/Makefile index 4e46450bcb3a..c9176c9c578c 100644 --- a/lib/kunit/Makefile +++ b/lib/kunit/Makefile @@ -1,6 +1,7 @@ obj-$(CONFIG_KUNIT) += test.o \ string-stream.o \ - assert.o + assert.o \ + try-catch.o obj-$(CONFIG_KUNIT_TEST) += string-stream-test.o diff --git a/lib/kunit/test.c b/lib/kunit/test.c index 3cbceb34b3b3..b2ca9b94c353 100644 --- a/lib/kunit/test.c +++ b/lib/kunit/test.c @@ -7,7 +7,9 @@ */ #include +#include #include +#include static void kunit_set_failure(struct kunit *test) { @@ -162,6 +164,19 @@ static void kunit_fail(struct kunit *test, struct kunit_assert *assert) WARN_ON(string_stream_destroy(stream)); } +static void __noreturn kunit_abort(struct kunit *test) +{ + kunit_try_catch_throw(&test->try_catch); /* Does not return. */ + + /* + * Throw could not abort from test. + * + * XXX: we should never reach this line! As kunit_try_catch_throw is + * marked __noreturn. + */ + WARN_ONCE(true, "Throw could not abort from test!\n"); +} + void kunit_do_assertion(struct kunit *test, struct kunit_assert *assert, bool pass, @@ -180,6 +195,9 @@ void kunit_do_assertion(struct kunit *test, kunit_fail(test, assert); va_end(args); + + if (assert->type == KUNIT_ASSERTION) + kunit_abort(test); } void kunit_init_test(struct kunit *test, const char *name) @@ -191,33 +209,122 @@ void kunit_init_test(struct kunit *test, const char *name) } /* - * Performs all logic to run a test case. + * Initializes and runs test case. Does not clean up or do post validations. */ -static void kunit_run_case(struct kunit_suite *suite, - struct kunit_case *test_case) +static void kunit_run_case_internal(struct kunit *test, + struct kunit_suite *suite, + struct kunit_case *test_case) { - struct kunit test; - - kunit_init_test(&test, test_case->name); - if (suite->init) { int ret; - ret = suite->init(&test); + ret = suite->init(test); if (ret) { - kunit_err(&test, "failed to initialize: %d\n", ret); - kunit_set_failure(&test); - test_case->success = test.success; + kunit_err(test, "failed to initialize: %d\n", ret); + kunit_set_failure(test); return; } } - test_case->run_case(&test); + test_case->run_case(test); +} +static void kunit_case_internal_cleanup(struct kunit *test) +{ + kunit_cleanup(test); +} + +/* + * Performs post validations and cleanup after a test case was run. + * XXX: Should ONLY BE CALLED AFTER kunit_run_case_internal! + */ +static void kunit_run_case_cleanup(struct kunit *test, + struct kunit_suite *suite) +{ if (suite->exit) - suite->exit(&test); + suite->exit(test); - kunit_cleanup(&test); + kunit_case_internal_cleanup(test); +} + +struct kunit_try_catch_context { + struct kunit *test; + struct kunit_suite *suite; + struct kunit_case *test_case; +}; + +static void kunit_try_run_case(void *data) +{ + struct kunit_try_catch_context *ctx = data; + struct kunit *test = ctx->test; + struct kunit_suite *suite = ctx->suite; + struct kunit_case *test_case = ctx->test_case; + + /* + * kunit_run_case_internal may encounter a fatal error; if it does, + * abort will be called, this thread will exit, and finally the parent + * thread will resume control and handle any necessary clean up. + */ + kunit_run_case_internal(test, suite, test_case); + /* This line may never be reached. */ + kunit_run_case_cleanup(test, suite); +} + +static void kunit_catch_run_case(void *data) +{ + struct kunit_try_catch_context *ctx = data; + struct kunit *test = ctx->test; + struct kunit_suite *suite = ctx->suite; + int try_exit_code = kunit_try_catch_get_result(&test->try_catch); + + if (try_exit_code) { + kunit_set_failure(test); + /* + * Test case could not finish, we have no idea what state it is + * in, so don't do clean up. + */ + if (try_exit_code == -ETIMEDOUT) { + kunit_err(test, "test case timed out\n"); + /* + * Unknown internal error occurred preventing test case from + * running, so there is nothing to clean up. + */ + } else { + kunit_err(test, "internal error occurred preventing test case from running: %d\n", + try_exit_code); + } + return; + } + + /* + * Test case was run, but aborted. It is the test case's business as to + * whether it failed or not, we just need to clean up. + */ + kunit_run_case_cleanup(test, suite); +} + +/* + * Performs all logic to run a test case. It also catches most errors that + * occur in a test case and reports them as failures. + */ +static void kunit_run_case_catch_errors(struct kunit_suite *suite, + struct kunit_case *test_case) +{ + struct kunit_try_catch_context context; + struct kunit_try_catch *try_catch; + struct kunit test; + + kunit_init_test(&test, test_case->name); + try_catch = &test.try_catch; + + kunit_try_catch_init(try_catch, + &test, + kunit_try_run_case, + kunit_catch_run_case); + context.test = &test; + context.suite = suite; + context.test_case = test_case; + kunit_try_catch_run(try_catch, &context); test_case->success = test.success; } @@ -230,7 +337,7 @@ int kunit_run_tests(struct kunit_suite *suite) kunit_print_subtest_start(suite); for (test_case = suite->test_cases; test_case->run_case; test_case++) { - kunit_run_case(suite, test_case); + kunit_run_case_catch_errors(suite, test_case); kunit_print_test_case_ok_not_ok(test_case, test_case_count++); } diff --git a/lib/kunit/try-catch.c b/lib/kunit/try-catch.c new file mode 100644 index 000000000000..55686839eb61 --- /dev/null +++ b/lib/kunit/try-catch.c @@ -0,0 +1,118 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * An API to allow a function, that may fail, to be executed, and recover in a + * controlled manner. + * + * Copyright (C) 2019, Google LLC. + * Author: Brendan Higgins + */ + +#include +#include +#include +#include +#include +#include + +void __noreturn kunit_try_catch_throw(struct kunit_try_catch *try_catch) +{ + try_catch->try_result = -EFAULT; + complete_and_exit(try_catch->try_completion, -EFAULT); +} + +static int kunit_generic_run_threadfn_adapter(void *data) +{ + struct kunit_try_catch *try_catch = data; + + try_catch->try(try_catch->context); + + complete_and_exit(try_catch->try_completion, 0); +} + +static unsigned long kunit_test_timeout(void) +{ + unsigned long timeout_msecs; + + /* + * TODO(brendanhiggins@google.com): We should probably have some type of + * variable timeout here. The only question is what that timeout value + * should be. + * + * The intention has always been, at some point, to be able to label + * tests with some type of size bucket (unit/small, integration/medium, + * large/system/end-to-end, etc), where each size bucket would get a + * default timeout value kind of like what Bazel does: + * https://docs.bazel.build/versions/master/be/common-definitions.html#test.size + * There is still some debate to be had on exactly how we do this. (For + * one, we probably want to have some sort of test runner level + * timeout.) + * + * For more background on this topic, see: + * https://mike-bland.com/2011/11/01/small-medium-large.html + */ + if (sysctl_hung_task_timeout_secs) { + /* + * If sysctl_hung_task is active, just set the timeout to some + * value less than that. + * + * In regards to the above TODO, if we decide on variable + * timeouts, this logic will likely need to change. + */ + timeout_msecs = (sysctl_hung_task_timeout_secs - 1) * + MSEC_PER_SEC; + } else { + timeout_msecs = 300 * MSEC_PER_SEC; /* 5 min */ + } + + return timeout_msecs; +} + +void kunit_try_catch_run(struct kunit_try_catch *try_catch, void *context) +{ + DECLARE_COMPLETION_ONSTACK(try_completion); + struct kunit *test = try_catch->test; + struct task_struct *task_struct; + int exit_code, time_remaining; + + try_catch->context = context; + try_catch->try_completion = &try_completion; + try_catch->try_result = 0; + task_struct = kthread_run(kunit_generic_run_threadfn_adapter, + try_catch, + "kunit_try_catch_thread"); + if (IS_ERR(task_struct)) { + try_catch->catch(try_catch->context); + return; + } + + time_remaining = wait_for_completion_timeout(&try_completion, + kunit_test_timeout()); + if (time_remaining == 0) { + kunit_err(test, "try timed out\n"); + try_catch->try_result = -ETIMEDOUT; + } + + exit_code = try_catch->try_result; + + if (!exit_code) + return; + + if (exit_code == -EFAULT) + try_catch->try_result = 0; + else if (exit_code == -EINTR) + kunit_err(test, "wake_up_process() was never called\n"); + else if (exit_code) + kunit_err(test, "Unknown error: %d\n", exit_code); + + try_catch->catch(try_catch->context); +} + +void kunit_try_catch_init(struct kunit_try_catch *try_catch, + struct kunit *test, + kunit_try_catch_func_t try, + kunit_try_catch_func_t catch) +{ + try_catch->test = test; + try_catch->try = try; + try_catch->catch = catch; +}