Hi while testing on linux-next I see that, when KBUILD_OUTPUT is set in the env, running something like (using TARGETS=exec as a random subsystem here...) $ make TARGETS=exec INSTALL_PATH=/nfs/LTP-official-debian-aarch64-rootfs/opt/KSFT_next kselftest-install works fine as usual, WHILE the alternative invocation (still documented in Documentation/dev-tools/kselftest.rst) make -C tools/testing/selftests/ TARGETS=exec INSTALL_PATH=/nfs/LTP-official-debian-aarch64-rootfs/opt/KSFT_next install fails miserably with: ... ... REMOVE usr/include/rdma/cxgb3-abi.h usr/include/rdma/nes-abi.h HDRINST usr/include/asm/kvm.h INSTALL /kselftest/usr/include mkdir: cannot create directory ‘/kselftest’: Permission denied /home/crimar01/ARM/dev/src/pdsw/linux/Makefile:1187: recipe for target 'headers_install' failed make[2]: *** [headers_install] Error 1 This is fixed by unsetting KBUILD_OUTPUT OR reverting: 303e6218ecec (ksft/fixes) selftests: Fix O= and KBUILD_OUTPUT handling for relative paths since bypassing top makefile with -C, the definition of abs-objtree used by the above patch is no more available. As a side effect when KBUILD_OUTPUT is set, this breaks also the usage kselftest_install.sh. $ ./kselftest_install.sh /home/crimar01/ARM/dev/nfs/LTP-official-debian-aarch64-rootfs/opt/KSFT_full_next ./kselftest_install.sh: Installing in specified location - /home/crimar01/ARM/dev/nfs/LTP-official-debian-aarch64-rootfs/opt/KSFT_full_next ... make --no-builtin-rules INSTALL_HDR_PATH=$BUILD/usr \ ARCH=arm64 -C ../../.. headers_install make[1]: Entering directory '/home/crimar01/ARM/dev/src/pdsw/linux' make[2]: Entering directory '/home/crimar01/ARM/dev/src/pdsw/out_linux' INSTALL /kselftest/usr/include mkdir: cannot create directory ‘/kselftest’: Permission denied /home/crimar01/ARM/dev/src/pdsw/linux/Makefile:1187: recipe for target 'headers_install' failed make[2]: *** [headers_install] Error 1 make[2]: Leaving directory '/home/crimar01/ARM/dev/src/pdsw/out_linux' Makefile:179: recipe for target 'sub-make' failed make[1]: *** [sub-make] Error 2 make[1]: Leaving directory '/home/crimar01/ARM/dev/src/pdsw/linux' Makefile:142: recipe for target 'khdr' failed make: *** [khdr] Error 2 A possible fix would be (but duplicates in fact the main Makefile logic) diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile index 319e094c3212..491d8b3ef1c7 100644 --- a/tools/testing/selftests/Makefile +++ b/tools/testing/selftests/Makefile @@ -88,6 +88,15 @@ ifdef building_out_of_srctree override LDFLAGS = endif +ifeq ($(abs_objtree),) +ifneq ($(KBUILD_OUTPUT),) +abs_objtree := $(shell cd $(KBUILD_OUTPUT) && pwd) +abs_objtree := $(realpath $(abs_objtree)) +else +abs_objtree := $(shell pwd) +endif +endif #ifeq ($(abs_objtree),) + ifneq ($(O),) BUILD := $(abs_objtree) else Any thoughts ? ... or am I missing something ? (I think I'm starting to see this in latest CI linaro kselftest while they cross-compile for arm64) Thanks Cristian