Re: [PATCH v3 2/2] usercopy: Convert test_user_copy to KUnit test

[Shuah Khan <skhan@linuxfoundation.org>]

On 6/17/24 13:00, Kees Cook wrote:
> On Fri, Jun 14, 2024 at 09:50:05AM -0600, Shuah Khan wrote:
>> On 6/12/24 13:59, Kees Cook wrote:
>>> Convert the runtime tests of hardened usercopy to standard KUnit tests.
>>>
>>> Additionally disable usercopy_test_invalid() for systems with separate
>>> address spaces (or no MMU) since it's not sensible to test for address
>>> confusion there (e.g. m68k).
>>>
>>> Co-developed-by: Vitor Massaru Iha <vitor@massaru.org>
>>> Signed-off-by: Vitor Massaru Iha <vitor@massaru.org>
>>> Link: https://lore.kernel.org/r/20200721174654.72132-1-vitor@massaru.org
>>> Tested-by: Ivan Orlov <ivan.orlov0322@gmail.com>
>>> Reviewed-by: David Gow <davidgow@google.com>
>>> Signed-off-by: Kees Cook <kees@kernel.org>
>>> ---
>>>    MAINTAINERS                                |   1 +
>>>    lib/Kconfig.debug                          |  21 +-
>>>    lib/Makefile                               |   2 +-
>>>    lib/{test_user_copy.c => usercopy_kunit.c} | 282 ++++++++++-----------
>>>    4 files changed, 151 insertions(+), 155 deletions(-)
>>>    rename lib/{test_user_copy.c => usercopy_kunit.c} (46%)
>>>
>>> diff --git a/MAINTAINERS b/MAINTAINERS
>>> index 8754ac2c259d..0cd171ec6010 100644
>>> --- a/MAINTAINERS
>>> +++ b/MAINTAINERS
>>> @@ -11962,6 +11962,7 @@ F:	arch/*/configs/hardening.config
>>>    F:	include/linux/overflow.h
>>>    F:	include/linux/randomize_kstack.h
>>>    F:	kernel/configs/hardening.config
>>> +F:	lib/usercopy_kunit.c
>>>    F:	mm/usercopy.c
>>>    K:	\b(add|choose)_random_kstack_offset\b
>>>    K:	\b__check_(object_size|heap_object)\b
>>> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
>>> index 59b6765d86b8..561e346f5cb0 100644
>>> --- a/lib/Kconfig.debug
>>> +++ b/lib/Kconfig.debug
>>> @@ -2505,18 +2505,6 @@ config TEST_VMALLOC
>>>    	  If unsure, say N.
>>> -config TEST_USER_COPY
>>> -	tristate "Test user/kernel boundary protections"
>>> -	depends on m
>>> -	help
>>> -	  This builds the "test_user_copy" module that runs sanity checks
>>> -	  on the copy_to/from_user infrastructure, making sure basic
>>> -	  user/kernel boundary testing is working. If it fails to load,
>>> -	  a regression has been detected in the user/kernel memory boundary
>>> -	  protections.
>>> -
>>> -	  If unsure, say N.
>>> -
>>>    config TEST_BPF
>>>    	tristate "Test BPF filter functionality"
>>>    	depends on m && NET
>>> @@ -2814,6 +2802,15 @@ config SIPHASH_KUNIT_TEST
>>>    	  This is intended to help people writing architecture-specific
>>>    	  optimized versions.  If unsure, say N.
>>> +config USERCOPY_KUNIT_TEST
>>> +	tristate "KUnit Test for user/kernel boundary protections"
>>> +	depends on KUNIT
>>> +	default KUNIT_ALL_TESTS
>>> +	help
>>> +	  This builds the "usercopy_kunit" module that runs sanity checks
>>> +	  on the copy_to/from_user infrastructure, making sure basic
>>> +	  user/kernel boundary testing is working.
>>> +
>>
>> Please carry the following line forward as well to be complete assuming
>> it is relevant.
>>
>> If unsure, say N.
> 
> I've explicitly removed that because it would be repetitive if it were
> included for all KUnit tests.
> 

Thanks for the explanation.

thanks,
-- Shuah