Messages in this thread | | | Subject | Re: [PATCH v14 09/18] kunit: test: add support for test abort | From | shuah <> | Date | Fri, 23 Aug 2019 11:07:50 -0600 |
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On 8/23/19 10:56 AM, Brendan Higgins wrote: > On Fri, Aug 23, 2019 at 8:36 AM shuah <shuah@kernel.org> wrote: >> >> Hi Brendan, >> >> On 8/20/19 5:20 PM, Brendan Higgins wrote: >>> Add support for aborting/bailing out of test cases, which is needed for >>> implementing assertions. >>> >>> An assertion is like an expectation, but bails out of the test case >>> early if the assertion is not met. The idea with assertions is that you >>> use them to state all the preconditions for your test. Logically >>> speaking, these are the premises of the test case, so if a premise isn't >>> true, there is no point in continuing the test case because there are no >>> conclusions that can be drawn without the premises. Whereas, the >>> expectation is the thing you are trying to prove. >>> >>> Signed-off-by: Brendan Higgins <brendanhiggins@google.com> >>> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> >>> Reviewed-by: Logan Gunthorpe <logang@deltatee.com> >>> Reviewed-by: Stephen Boyd <sboyd@kernel.org> >>> --- >>> include/kunit/test.h | 2 + >>> include/kunit/try-catch.h | 75 +++++++++++++++++++++ >>> kunit/Makefile | 3 +- >>> kunit/test.c | 137 +++++++++++++++++++++++++++++++++----- >>> kunit/try-catch.c | 118 ++++++++++++++++++++++++++++++++ >>> 5 files changed, 319 insertions(+), 16 deletions(-) >>> create mode 100644 include/kunit/try-catch.h >>> create mode 100644 kunit/try-catch.c >>> >>> diff --git a/include/kunit/test.h b/include/kunit/test.h >>> index 6917b186b737a..390ce02f717b6 100644 >>> --- a/include/kunit/test.h >>> +++ b/include/kunit/test.h >>> @@ -10,6 +10,7 @@ >>> #define _KUNIT_TEST_H >>> >>> #include <kunit/assert.h> >>> +#include <kunit/try-catch.h> >>> #include <linux/kernel.h> >>> #include <linux/slab.h> >>> #include <linux/types.h> >>> @@ -167,6 +168,7 @@ 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 threads using >>> diff --git a/include/kunit/try-catch.h b/include/kunit/try-catch.h >>> new file mode 100644 >>> index 0000000000000..404f336cbdc85 >>> --- /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 <brendanhiggins@google.com> >>> + */ >>> + >>> +#ifndef _KUNIT_TRY_CATCH_H >>> +#define _KUNIT_TRY_CATCH_H >>> + >>> +#include <linux/types.h> >>> + >>> +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/kunit/Makefile b/kunit/Makefile >>> index 4e46450bcb3a8..c9176c9c578c6 100644 >>> --- a/kunit/Makefile >>> +++ b/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/kunit/test.c b/kunit/test.c >>> index 3cbceb34b3b36..ded9895143209 100644 >>> --- a/kunit/test.c >>> +++ b/kunit/test.c >>> @@ -7,7 +7,9 @@ >>> */ >>> >>> #include <kunit/test.h> >>> +#include <kunit/try-catch.h> >>> #include <linux/kernel.h> >>> +#include <linux/sched/debug.h> >>> >>> 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. >>> + */ >>> + BUG(); >> >> >> I recall discussion on this. What's the point in keeping thie >> BUG() around when it doesn't even reach? It can even be a >> WARN_ON() in that case right? > > Originally I had BUG() here, and Frank (I think it was Frank, sorry it > was a while ago) told me it should be WARN_ON(). In v12 Stephen told > me it should be BUG(), and nobody objected so I went back to making it > a BUG() (note I also mentioned this change on the cover letter of v13 > and still no one objected). >
Yeah. Sorry for the confusing advice. WARN_ON() or nothing is the right thing here. I have been cleaning BUG() and WARN_ON() that aren't needed.
I would just delete BUG all together.
thanks, -- Shuah
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