Build of several selftests fail if separate output directory is specified by the following methods: 1) make -C tools/testing/selftests O=<build_dir> 2) export KBUILD_OUTPUT="build_dir"; make -C tools/testing/selftests
Build fails because of several reasons: 1) The kernel headers aren't found. 2) The path of output objects is wrong and hence unaccessible.
These problems can be solved by: 1) Including the correct path of uapi header files 2) By setting the BUILD variable correctly inside Makefile
Following different build scenarios have been tested after making these changes to verify that nothing gets broken with these changes: make -C tools/testing/selftests make -C tools/testing/selftests/futex make -C tools/testing/selftests/kvm make -C tools/testing/selftests/landlock make -C tools/testing/selftests/net make -C tools/testing/selftests/net/mptcp make -C tools/testing/selftests/vm make -C tools/testing/selftests O=build make -C tools/testing/selftests o=/opt/build export KBUILD_OUTPUT="/opt/build"; make -C tools/testing/selftests export KBUILD_OUTPUT="build"; make -C tools/testing/selftests cd <any_dir>; make -C <src_path>/tools/testing/selftests cd <any_dir>; make -C <src_path>/tools/testing/selftests O=build
--- Changes in V2: Revert the excessive cleanup which was breaking the individual test build.
Muhammad Usama Anjum (10): selftests: set the BUILD variable to absolute path selftests: Add and export a kernel uapi headers path selftests: Correct the headers install path selftests: futex: Add the uapi headers include variable selftests: kvm: Add the uapi headers include variable selftests: landlock: Add the uapi headers include variable selftests: net: Add the uapi headers include variable selftests: mptcp: Add the uapi headers include variable selftests: vm: Add the uapi headers include variable selftests: vm: remove dependecy from internal kernel macros
tools/testing/selftests/Makefile | 32 +++++++++++++------ .../selftests/futex/functional/Makefile | 5 ++- tools/testing/selftests/kvm/Makefile | 2 +- tools/testing/selftests/landlock/Makefile | 2 +- tools/testing/selftests/net/Makefile | 2 +- tools/testing/selftests/net/mptcp/Makefile | 2 +- tools/testing/selftests/vm/Makefile | 2 +- tools/testing/selftests/vm/userfaultfd.c | 3 ++ 8 files changed, 32 insertions(+), 18 deletions(-)