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Subject: Re: [PATCH v1] kunit: add support for kunit_suites that reference
 init code
To:     Brendan Higgins <brendanhiggins@google.com>, shuah@kernel.org,
        davidgow@google.com, dlatypov@google.com,
        martin.fernandez@eclypsium.com, daniel.gutson@eclypsium.com
Cc:     linux-kselftest@vger.kernel.org, kunit-dev@googlegroups.com,
        linux-kernel@vger.kernel.org, keescook@chromium.org,
        jk@codeconstruct.com.au, Shuah Khan <skhan@linuxfoundation.org>
References: <20220311072859.2174624-1-brendanhiggins@google.com>
From:   Shuah Khan <skhan@linuxfoundation.org>
Message-ID: <1e1472e8-1813-3903-f934-cb0ae7f09864@linuxfoundation.org>
Date:   Mon, 4 Apr 2022 16:37:15 -0600
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Hi Brendan,

On 3/11/22 12:28 AM, Brendan Higgins wrote:
> Add support for a new kind of kunit_suite registration macro called
> kunit_test_init_suite(); this new registration macro allows the
> registration of kunit_suites that reference functions marked __init and
> data marked __initdata.
> 
> Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
> Tested-by: Martin Fernandez <martin.fernandez@eclypsium.com>
> Reviewed-by: Kees Cook <keescook@chromium.org>
> Reviewed-by: David Gow <davidgow@google.com>
> ---
> 

I almost applied it ...

> This is a follow-up to the RFC here[1].
> 
> This patch is in response to a KUnit user issue[2] in which the user was
> attempting to test some init functions; although this is a functional
> solution as long as KUnit tests only run during the init phase, we will
> need to do more work if we ever allow tests to run after the init phase
> is over; it is for this reason that this patch adds a new registration
> macro rather than simply modifying the existing macros.
> 
> Changes since last version:
>   - I added more to the kunit_test_init_suites() kernel-doc comment
>     detailing "how" the modpost warnings are suppressed in addition to
>     the existing information regarding "why" it is OK for the modpost
>     warnings to be suppressed.
> 
> [1] https://lore.kernel.org/linux-kselftest/20220310210210.2124637-1-brendanhiggins@google.com/
> [2] https://groups.google.com/g/kunit-dev/c/XDjieRHEneg/m/D0rFCwVABgAJ
> 
> ---
>   include/kunit/test.h | 26 ++++++++++++++++++++++++++
>   1 file changed, 26 insertions(+)
> 
> diff --git a/include/kunit/test.h b/include/kunit/test.h
> index b26400731c02..7f303a06bc97 100644
> --- a/include/kunit/test.h
> +++ b/include/kunit/test.h
> @@ -379,6 +379,32 @@ static inline int kunit_run_all_tests(void)
>   
>   #define kunit_test_suite(suite)	kunit_test_suites(&suite)
>   
> +/**
> + * kunit_test_init_suites() - used to register one or more &struct kunit_suite
> + *			      containing init functions or init data.
> + *
> + * @__suites: a statically allocated list of &struct kunit_suite.
> + *
> + * This functions identically as &kunit_test_suites() except that it suppresses
> + * modpost warnings for referencing functions marked __init or data marked
> + * __initdata; this is OK because currently KUnit only runs tests upon boot
> + * during the init phase or upon loading a module during the init phase.
> + *
> + * NOTE TO KUNIT DEVS: If we ever allow KUnit tests to be run after boot, these
> + * tests must be excluded.
> + *
> + * The only thing this macro does that's different from kunit_test_suites is
> + * that it suffixes the array and suite declarations it makes with _probe;
> + * modpost suppresses warnings about referencing init data for symbols named in
> + * this manner.
> + */
> +#define kunit_test_init_suites(__suites...)				\
> +	__kunit_test_suites(CONCATENATE(__UNIQUE_ID(array), _probe),	\
> +			    CONCATENATE(__UNIQUE_ID(suites), _probe),	\
> +			    ##__suites)
> +
> +#define kunit_test_init_suite(suite)	kunit_test_init_suites(&suite)
> +
>   #define kunit_suite_for_each_test_case(suite, test_case)		\
>   	for (test_case = suite->test_cases; test_case->run_case; test_case++)
>   
> 

The naming of the function and macro are rather confusing and can become
error prone. Let's find better naming scheme.

> base-commit: 330f4c53d3c2d8b11d86ec03a964b86dc81452f5
> 

thanks,
-- Shuah