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

[Cristian Marussi <cristian.marussi@arm.com>]

On 27/11/2019 18:16, shuah wrote:
> On 11/27/19 10:57 AM, Tim.Bird@sony.com wrote:
>>
>>
>>> -----Original Message-----
>>> From: linux-kselftest-owner@vger.kernel.org [mailto:linux-kselftest-
>>> owner@vger.kernel.org] On Behalf Of shuah
>>> Sent: Wednesday, November 27, 2019 5:33 PM
>>> To: Cristian Marussi <cristian.marussi@arm.com>; Michael Ellerman
>>> <mpe@ellerman.id.au>; Bird, Tim <Tim.Bird@sony.com>; 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
>>>
>>> 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:17a7b03f2049
>>>>>>>>>>
>>>>>>>>>> 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.
>>
>> There may not be many people using relative paths for KBUILD_OUTPUT.
>> I was affected by it, and it's quite handy given some of the mechanisms in
>> my CI system, but it's not that hard to work around.  (That is, I can just
>> convert relative paths to absolute paths in a few key places in my
>> CI, before calling the kernel make.)
>>
>> Given that I'm the only person (seemingly) who reported this, and I'm ok
>> working around it, I think a revert is OK for now.
>>
> 
> Sorry Cristian! You reported this a couple of weeks ago and I missed
> your email. I was away on family emergency and this email got buried
> in my Inbox. No excuses though. My bad.

No worries :D 

> 
> Cristian suggested this fix. There is another issue here.
> 
> INSTALL_PATH conflicts with main Makefile variable. The recent
> kbuild changes impacted kselftest use-cases and I had to drop
> support for INSTALL_PATH in kselftest_install.sh and move
> to KSFT_INSTALL_PATH - sorry the document is outdated.
> 
I saw that because I saw your change merged, but it did not seem to make
any difference using the proper KSFT_INSTALL_PATH ... (but...I cannot remember
why now :D ... tomorrow I'll double check about this)

> I should update it. I would like to see CIs migrate to using
> KSFT_INSTALL_PATH
> 
> If we go with the below fix, does it fix for both O and KBUILD_OUTPUT
> cases, does it cover all cases?
> 

I'll have a look, I tested that tentative fix only with the KBUILD_OUTPUT interaction
which is in my setup and local CI, so it immediately broke all.
Not sure what Linaro CI is running though, I saw those logs and I can see same errors
but then they carry on partially, so I don't have a clear view of all the possible
scenarios here...I'll try to test more extensively next days.

Regards

Cristian
> A possible fix would be (but duplicates in fact the main Makefile logic)
> 
> 
> diff --git a/tools/testing/selftests/Makefile 
> b/tools/testing/selftests/Makefile
> index 319e094c3212..491d8b3ef1c7 100644
> --- a/tools/testing/selftests/Makefile
> +++ b/tools/testing/selftests/Makefile
> @@ -88,6 +88,15 @@ ifdef building_out_of_srctree
>   override LDFLAGS =
>   endif
> 
> +ifeq ($(abs_objtree),)
> +ifneq ($(KBUILD_OUTPUT),)
> +abs_objtree := $(shell cd $(KBUILD_OUTPUT) && pwd)
> +abs_objtree := $(realpath $(abs_objtree))
> +else
> +abs_objtree := $(shell pwd)
> +endif
> +endif #ifeq ($(abs_objtree),)
> +
>   ifneq ($(O),)
>          BUILD := $(abs_objtree)
>   else
> 
> thanks,
> -- Shuah
>