Re: [PATCH] Makefile: Fix separate output directory build of kselftests

[Shuah Khan <skhan@linuxfoundation.org>]

On 3/8/22 1:11 AM, Muhammad Usama Anjum wrote:
> On 3/4/22 2:32 AM, Shuah Khan wrote:
>> On 2/23/22 12:10 PM, Muhammad Usama Anjum wrote:
>>> Build of kselftests fail if kernel's top most Makefile is used for
>>> running or building kselftests with separate output directory. The
>>> absolute path is needed to reference other files during this kind of
>>> build. Set KBUILD_ABS_SRCTREE to use absolute path during the build. It
>>> fixes the following different types of errors:
>>>
>>> make kselftest-all O=/linux_mainline/build
>>> Makefile:1080: ../scripts/Makefile.extrawarn: No such file or directory
>>>
>>> make kselftest-all O=build
>>> Makefile:1080: ../scripts/Makefile.extrawarn: No such file or directory
>>>
>>> Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
>>> ---
>>> I've tested this patch on top of next-20220217. The latest next-20220222
>>> have missing patches.
>>
>> Can you give more details on the use-cases you tested? Did you test all
>> the ways kselftest are built?
>>
> Yeah, I've tried to test all the ways. Here are the different ways I've
> used to test it:
> 1) Same directory build of kselftest (this is already working)
> make kselftest
> make kselftest-all
> make kselftest-install
> make kselftest-clean
> make kselftest-gen_tar
> 
> 2) These were failing when separate output directory is specified either
> as relative or absolute path. After adding this patch, these are also
> working. kselfetst.rst mentions separate output directory build in this way.
> make kselftest O=build
> make kselftest-all O=build
> make kselftest-install O=build
> make kselftest-clean O=build
> make kselftest-gen_tar O=build
> 
> make kselftest O=/build
> make kselftest-all O=/build
> make kselftest-install O=/build
> make kselftest-clean O=/build
> make kselftest-gen_tar O=/build
> 
> Tested on top of next-20220307 after applying this patch.
> 

Thank you for testing all these use-cases. This is a good comprehensive
list. Do you mind sending a doc patch for

Documentation/dev-tools/kselftest.rst

The text here could almost as is as a new section after

Contributing new tests (details) with a new section that outlines
the tests to run when adding a new test to selftests/Makefile
and making changes to kselftest common frameowork: selftests/Makefile,
selftests/lib.mk

Let me know if you are unable to, I will send a patch in.

thanks,
-- Shuah