Hello, kselftest can be built using the kernel's top most Makefile without using kselftest's Makefile directly. But there is bug in the top most Makefile. The build fails if the specified output directory is first level sub-directory. Here is a example to reproduce this bug: make kselftest-all O=build "The Make is working in a wrong directory, that is why the relative path does not work." Masahiro Yamada. Feel free to fix it if someone pin the bug. It should be noted that the build works in some other combinations: make kselftest-all (works) make kselftest-all O=/tmp (works) make kselftest-all O=build/build2 (works) My unsuccessful attempt to fix this bug can be found here: https://lore.kernel.org/lkml/20220223191016.1658728-1-usama.anjum@xxxxxxxxxxxxx/ Thanks, Muhammad Usama Anjum
