/usr/src/kernel-patches/ is in rtai-source 3.9.1-4.
This file is owned by root:root, with mode 0o755.
..
/usr/src/kernel-patches/diffs/
/usr/src/kernel-patches/diffs/rtai/
/usr/src/kernel-patches/diffs/rtai/hal-linux-2.4.36-i386-1.3-04.patch
/usr/src/kernel-patches/diffs/rtai/hal-linux-2.6.14-ppc-1.5-01.patch
/usr/src/kernel-patches/diffs/rtai/hal-linux-2.6.20-powerpc-1.8-06.patch
/usr/src/kernel-patches/diffs/rtai/hal-linux-2.6.29.4-powerpc-2.6-02.patch
/usr/src/kernel-patches/diffs/rtai/hal-linux-2.6.32.20-x86-2.7-03.patch
/usr/src/kernel-patches/diffs/rtai/hal-linux-2.6.34.5-x86-2.7-04.patch
/usr/src/kernel-patches/diffs/rtai/hal-linux-2.6.35.9-x86-2.8-04.patch
/usr/src/kernel-patches/diffs/rtai/hal-linux-2.6.37.6-x86-2.9-02.patch
/usr/src/kernel-patches/diffs/rtai/hal-linux-2.6.38.8-x86-2.11-02.patch