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

From: Michael Ellerman <mpe@ellerman.id.au>
To: Cristian Marussi <cristian.marussi@arm.com>,
	Tim.Bird@sony.com, "shuah\@kernel.org" <shuah@kernel.org>,
	"linux-kselftest\@vger.kernel.org"
	<linux-kselftest@vger.kernel.org>
Subject: Re: kselftest: failed to build with -C tool/testing/selftests when KBUILD_OUTPUT is set
Date: Wed, 27 Nov 2019 14:54:49 +1100	[thread overview]
Message-ID: <8736ea2cty.fsf@mpe.ellerman.id.au> (raw)
In-Reply-To: <8d34a9b9-f8f3-0e37-00bf-c342cf3d4074@arm.com>

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.

> (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?

cheers