On 21/12/2024 11:41, Masahiro Yamada wrote:
On Tue, Dec 17, 2024 at 12:10 PM Li Zhijian lizhijian@fujitsu.com 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, the srctree is exported as an absolute path (abs_srctree) 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.
NACK. This negates 9da0763bdd82572be243fcf5161734f11568960f
This is a recurring topic [1] because kselftest adopts a completely different build system. If kselftest cannot do this correctly, please do not hook it to the top-Makefile.
Hi Masahiro,
Thank you for your feedback I understand and agree with your points, thanks again for these information.
[1] https://lore.kernel.org/linux-kbuild/cover.1657614127.git.guillaume.tucker@c...
Signed-off-by: Li Zhijian lizhijian@fujitsu.com
Request for Additional Testing
We welcome all contributors and CI systems to test this change thoroughly.
This is NACKed. I recommend not wasting CI system resources.
It sounds reasonable. It makes sense to avoid using CI resources on this patch given the current circumstances.
Thanks Zhijian
In theory, this change should not affect in-tree builds. However, to ensure stability and compatibility, we encourage testing across different configurations.
What has been tested?
- out-of-tree kernel build
- out-of-tree kselftest-all
Makefile | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/Makefile b/Makefile index e5b8a8832c0c..36e65806bb5e 100644 --- a/Makefile +++ b/Makefile @@ -275,7 +275,8 @@ else ifeq ($(srcroot)/,$(dir $(CURDIR))) srcroot := .. endif
-export srctree := $(if $(KBUILD_EXTMOD),$(abs_srctree),$(srcroot)) +srctree := $(if $(KBUILD_EXTMOD),$(abs_srctree),$(srcroot)) +export srctree := $(if $(building_out_of_srctree),$(abs_srctree),$(srctree))
ifdef building_out_of_srctree export VPATH := $(srcroot) -- 2.44.0