Re: kselftest: failed to build with -C tool/testing/selftests when KBUILD_OUTPUT is set

From: shuah <shuah@kernel.org>
To: Cristian Marussi <cristian.marussi@arm.com>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Tim.Bird@sony.com,
	"linux-kselftest@vger.kernel.org"
	<linux-kselftest@vger.kernel.org>, shuah <shuah@kernel.org>
Subject: Re: kselftest: failed to build with -C tool/testing/selftests when KBUILD_OUTPUT is set
Date: Wed, 27 Nov 2019 10:32:45 -0700	[thread overview]
Message-ID: <2fa5f914-e5d6-9ddd-03f0-abe95569a6f2@kernel.org> (raw)
In-Reply-To: <3f436c1b-1921-78f7-c021-9c8472e24733@arm.com>

On 11/27/19 9:53 AM, Cristian Marussi wrote:
> On 27/11/2019 16:42, shuah wrote:
>> On 11/27/19 9:23 AM, Cristian Marussi wrote:
>>> On 27/11/2019 16:04, shuah wrote:
>>>> On 11/27/19 3:54 AM, Cristian Marussi wrote:
>>>>> Hi
>>>>>
>>>>> On 27/11/2019 03:54, Michael Ellerman wrote:
>>>>>> Cristian Marussi <cristian.marussi@arm.com> writes:
>>>>>>> Hi
>>>>>>>
>>>>>>> while testing on linux-next
>>>>>>>
>>>>>>> I see that, when KBUILD_OUTPUT is set in the env, running something like (using TARGETS=exec as a random subsystem here...)
>>>>>>>
>>>>>>> $ make TARGETS=exec INSTALL_PATH=/nfs/LTP-official-debian-aarch64-rootfs/opt/KSFT_next kselftest-install
>>>>>>>
>>>>>>> works fine as usual, WHILE the alternative invocation (still documented in Documentation/dev-tools/kselftest.rst)
>>>>>>>
>>>>>>> make -C tools/testing/selftests/ TARGETS=exec INSTALL_PATH=/nfs/LTP-official-debian-aarch64-rootfs/opt/KSFT_next install
>>>>>>>
>>>>>>> fails miserably with:
>>>>>>> ...
>>>>>>> ...
>>>>>>>     REMOVE  usr/include/rdma/cxgb3-abi.h usr/include/rdma/nes-abi.h
>>>>>>>      HDRINST usr/include/asm/kvm.h
>>>>>>>      INSTALL /kselftest/usr/include
>>>>>>> mkdir: cannot create directory ‘/kselftest’: Permission denied
>>>>>>> /home/crimar01/ARM/dev/src/pdsw/linux/Makefile:1187: recipe for target 'headers_install' failed
>>>>>>> make[2]: *** [headers_install] Error 1
>>>>>>>
>>>>>>>
>>>>>>> This is fixed by unsetting KBUILD_OUTPUT OR reverting:
>>>>>>>
>>>>>>> 303e6218ecec (ksft/fixes) selftests: Fix O= and KBUILD_OUTPUT handling for relative paths
>>>>>>>
>>>>>>> since bypassing top makefile with -C, the definition of abs-objtree used by the above patch
>>>>>>> is no more available.
>>>>>>>
>>>>>>> As a side effect when KBUILD_OUTPUT is set, this breaks also the usage kselftest_install.sh.
>>>>>>>
>>>>>>>     $ ./kselftest_install.sh /home/crimar01/ARM/dev/nfs/LTP-official-debian-aarch64-rootfs/opt/KSFT_full_next
>>>>>>> ./kselftest_install.sh: Installing in specified location - /home/crimar01/ARM/dev/nfs/LTP-official-debian-aarch64-rootfs/opt/KSFT_full_next ...
>>>>>>> make --no-builtin-rules INSTALL_HDR_PATH=$BUILD/usr \
>>>>>>> 	ARCH=arm64 -C ../../.. headers_install
>>>>>>> make[1]: Entering directory '/home/crimar01/ARM/dev/src/pdsw/linux'
>>>>>>> make[2]: Entering directory '/home/crimar01/ARM/dev/src/pdsw/out_linux'
>>>>>>>      INSTALL /kselftest/usr/include
>>>>>>> mkdir: cannot create directory ‘/kselftest’: Permission denied
>>>>>>> /home/crimar01/ARM/dev/src/pdsw/linux/Makefile:1187: recipe for target 'headers_install' failed
>>>>>>> make[2]: *** [headers_install] Error 1
>>>>>>> make[2]: Leaving directory '/home/crimar01/ARM/dev/src/pdsw/out_linux'
>>>>>>> Makefile:179: recipe for target 'sub-make' failed
>>>>>>> make[1]: *** [sub-make] Error 2
>>>>>>> make[1]: Leaving directory '/home/crimar01/ARM/dev/src/pdsw/linux'
>>>>>>> Makefile:142: recipe for target 'khdr' failed
>>>>>>> make: *** [khdr] Error 2
>>>>>>>
>>>>>>>
>>>>>> ...
>>>>>>> Any thoughts ? ... or am I missing something ?
>>>>>>
>>>>>> You're not missing anything, this is broken.
>>>>> Thanks for the feedback !
>>>>>
>>>>> Cristian
>>>>>
>>>>>>
>>>>>>> (I think I'm starting to see this in latest CI linaro kselftest while they cross-compile for arm64)
>>>>>>
>>>>>> It just hit my travis jobs when I merged up to master:
>>>>>>
>>>>>>      https://travis-ci.org/linuxppc/linux/jobs/617482001
>>>>>>
>>>>>> Shuah can we please get this reverted?
>>>>>>
>>>>
>>>> I will take care of this. Supporting all these use-cases has been
>>>> maintenance problem. Fixing one use-case breaks another. :(
>>>>
>>>> I will look into fixing this once for all.
>>>
>>> Thanks.
>>>
>>> In fact all of the above works fine with the new kselftest-install target you added recently
>>> but I think a lot of CI is still using the old -C method.
>>>
>>> Regards
>>
>> If all of the above works with kselftest-install target, I would rather
>> ask for CI's to change, so we can get rid of make -C usage for install.
>>
>> In which case, I would rather not revert this and request CIs to start
>> using kselftest-install target.
>>
>>
>> I would like to see CI's use kselftest-* targets from the main makefile
>> for build/run/install.
>>
>> It has been very difficult to support "make -C" use-cases in general
>> and especially for install and relocatable builds.
>>
> 
> Well I'm not sure if it covers all the build cases/scenario for CIs and I have
> only verified that this specific failure seems to work using the toplevel Makefile
> targets (since the offending commit uses abs-objtree).
> Anyway $ ./kselftest_install.sh is broken too as of now.
> 

With the revert, it will go back to not having support for relative
paths :(

I will look into reverting the offending commit or fixing it.

thanks,
-- Shuah