From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brendan Higgins Subject: Re: [PATCH v14 09/18] kunit: test: add support for test abort Date: Fri, 23 Aug 2019 10:29:41 -0700 Message-ID: References: <20190820232046.50175-1-brendanhiggins@google.com> <20190820232046.50175-10-brendanhiggins@google.com> <93cad898-78c8-2bd4-f1c7-5d34fdfbb7cb@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Return-path: In-Reply-To: <93cad898-78c8-2bd4-f1c7-5d34fdfbb7cb@kernel.org> Sender: linux-kernel-owner@vger.kernel.org To: shuah Cc: Frank Rowand , Greg KH , Josh Poimboeuf , Kees Cook , Kieran Bingham , Luis Chamberlain , Peter Zijlstra , Rob Herring , Stephen Boyd , Theodore Ts'o , Masahiro Yamada , devicetree , dri-devel , kunit-dev@googlegroups.com, "open list:DOCUMENTATION" , linux-fsdevel@vger.kernel.org, linux-kbuild , Linux Kernel Mailing List , open list:KERNEL SELFTEST FRAMEWORK List-Id: linux-nvdimm@lists.01.org On Fri, Aug 23, 2019 at 10:07 AM shuah wrote: > > On 8/23/19 10:56 AM, Brendan Higgins wrote: > > On Fri, Aug 23, 2019 at 8:36 AM shuah 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 > >>> Reviewed-by: Greg Kroah-Hartman > >>> Reviewed-by: Logan Gunthorpe > >>> Reviewed-by: Stephen Boyd > >>> --- > >>> 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 > >>> +#include > >>> #include > >>> #include > >>> #include > >>> @@ -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 > >>> + */ > >>> + > >>> +#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/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 > >>> +#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. > >>> + */ > >>> + 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. Alright, that's fine. I will send out a new patch set that removes this once we get the discussion on 01/18 resolved.