2024-12-23 16:33 UTC+0800 ~ Li Zhijian <lizhijian@xxxxxxxxxxx> > 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. > > Signed-off-by: Li Zhijian <lizhijian@xxxxxxxxxxx> I simply tested with "make V=1 O=build/ TARGETS=hid kselftest-all", this approach fixes the build just as well as v1. Thanks! Tested-by: Quentin Monnet <qmo@xxxxxxxxxx>