@@ -154,15 +154,19 @@ override LDFLAGS =
override MAKEFLAGS =
endif
+top_srcdir ?= ../../..
+
# Append kselftest to KBUILD_OUTPUT and O to avoid cluttering
# KBUILD_OUTPUT with selftest objects and headers installed
# by selftests Makefile or lib.mk.
+# Override the `srctree` variable to ensure it is correctly resolved in
+# sub-Makefiles, such as those within `bpf`, when managing targets like
+# `net` and `hid`.
ifdef building_out_of_srctree
override LDFLAGS =
+override srctree := $(top_srcdir)
endif
-top_srcdir ?= ../../..
-
ifeq ("$(origin O)", "command line")
KBUILD_OUTPUT := $(O)
endif
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> --- Cc: Masahiro Yamada <masahiroy@kernel.org> V3: collected Tested-by and rebased on bpf-next V2: - handle srctree in selftests itself rather than the linux' top Makefile # Masahiro Yamada <masahiroy@kernel.org> V1: https://lore.kernel.org/lkml/20241217031052.69744-1-lizhijian@fujitsu.com/ --- tools/testing/selftests/Makefile | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)