Re: [PATCH bpf-next v3] selftests/Makefile: override the srctree for out-of-tree builds

["Zhijian Li (Fujitsu)" <lizhijian@fujitsu.com>]

ping...


On 15/01/2025 23:06, Daniel Borkmann wrote:
> On 1/15/25 2:47 AM, Li Zhijian wrote:
>> Fixes an issue where out-of-tree kselftest builds fail when building
>> the BPF and bpftools components. The failure occurs because the top-level
>> Makefile passes a relative srctree path to its sub-Makefiles, which
>> leads to errors in locating necessary files.
>>
>> For example, the following error is encountered:
>>
>> ```
>> $ make V=1 O=$build/ TARGETS=hid kselftest-all
>> ...
>> make -C ../tools/testing/selftests all
>> make[4]: Entering directory '/path/to/linux/tools/testing/selftests/hid'
>> make  -C /path/to/linux/tools/testing/selftests/../../../tools/lib/bpf OUTPUT=/path/to/linux/O/kselftest/hid/tools/build/libbpf/ \
>>              EXTRA_CFLAGS='-g -O0'                                      \
>>              DESTDIR=/path/to/linux/O/kselftest/hid/tools prefix= all install_headers
>> make[5]: Entering directory '/path/to/linux/tools/lib/bpf'
>> ...
>> make[5]: Entering directory '/path/to/linux/tools/bpf/bpftool'
>> Makefile:127: ../tools/build/Makefile.feature: No such file or directory
>> make[5]: *** No rule to make target '../tools/build/Makefile.feature'.  Stop.
>> ```
>>
>> To resolve this, override the srctree in the kselftests's top Makefile
>> when performing an out-of-tree build. This ensures that all sub-Makefiles
>> have the correct path to the source tree, preventing directory resolution
>> errors.
>>
>> Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
>> Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
>> Tested-by: Quentin Monnet <qmo@kernel.org>
> 
> [...]
>>   tools/testing/selftests/Makefile | 8 ++++++--
>>   1 file changed, 6 insertions(+), 2 deletions(-)
> 
> Shuah, want to pick this up given its the top-level Makefile or want us to
> route it via bpf-next with your Ack? Fwiw, BPF CI went through fine.