/usr/include/xenomai/asm-sh/ is in libxenomai-dev 2.6.4+dfsg-0.2.
This file is owned by root:root, with mode 0o755.
..
/usr/include/xenomai/asm-sh/arith.h
/usr/include/xenomai/asm-sh/atomic.h
/usr/include/xenomai/asm-sh/bits/
/usr/include/xenomai/asm-sh/bits/bind.h
/usr/include/xenomai/asm-sh/bits/heap.h
/usr/include/xenomai/asm-sh/bits/init.h
/usr/include/xenomai/asm-sh/bits/intr.h
/usr/include/xenomai/asm-sh/bits/pod.h
/usr/include/xenomai/asm-sh/bits/sched.h
/usr/include/xenomai/asm-sh/bits/shadow.h
/usr/include/xenomai/asm-sh/bits/thread.h
/usr/include/xenomai/asm-sh/bits/timer.h
/usr/include/xenomai/asm-sh/calibration.h
/usr/include/xenomai/asm-sh/features.h
/usr/include/xenomai/asm-sh/fptest.h
/usr/include/xenomai/asm-sh/hal.h
/usr/include/xenomai/asm-sh/switch.h
/usr/include/xenomai/asm-sh/syscall.h
/usr/include/xenomai/asm-sh/system.h
/usr/include/xenomai/asm-sh/tsc.h
/usr/include/xenomai/asm-sh/wrappers.h