Hi Masahiro, I saw these warnings in my build-log: if ! command -v sha1sum >/dev/null; then echo "warning: cannot check the header due to sha1sum missing"; exit 0; fi; if [ "$(sed -n '$s:// ::p' include/linux/atomic/ atomic-arch-fallback.h)" != "$(sed '$d' include/linux/atomic/atomic-arch-fallback.h | sha1sum | sed 's/ .*//')" ]; then echo "error: include/linux/atomic/atomic-arch-f allback.h has been modified." >&2; exit 1; fi; touch .checked-atomic-arch-fallback.h if ! command -v sha1sum >/dev/null; then echo "warning: cannot check the header due to sha1sum missing"; exit 0; fi; if [ "$(sed -n '$s:// ::p' include/linux/atomic/ atomic-instrumented.h)" != "$(sed '$d' include/linux/atomic/atomic-instrumented.h | sha1sum | sed 's/ .*//')" ]; then echo "error: include/linux/atomic/atomic-instrume nted.h has been modified." >&2; exit 1; fi; touch .checked-atomic-instrumented.h if ! command -v sha1sum >/dev/null; then echo "warning: cannot check the header due to sha1sum missing"; exit 0; fi; if [ "$(sed -n '$s:// ::p' include/linux/atomic/ atomic-long.h)" != "$(sed '$d' include/linux/atomic/atomic-long.h | sha1sum | sed 's/ .*//')" ]; then echo "error: include/linux/atomic/atomic-long.h has been modified ." >&2; exit 1; fi; touch .checked-atomic-long.h NOTE: I did a `make distclean` before I started my build. Can you please comment on this? Thanks. Best regards, -Sedat-