overlay profiles: Set up SELinux policy directory

sdk_container/src/third_party/coreos-overlay/profiles/coreos/base/profile.bashrc

@@ -104,6 +104,26 @@ cros_pre_pkg_postinst_no_modifications_of_users() {
     export ACCT_USER_NO_MODIFY=x
 }
 
+# sys-apps/policycoreutils creates /var/lib/selinux directory in
+# src_install and then needs it to be available when running
+# pkg_postinst, because it does a policy module rebuild there. We
+# initially have put /var/lib/selinux into INSTALL_MASK and told
+# coreos-base/misc-files to install the directory at
+# /usr/lib/selinux/policy together with a symlink at /var/lib/selinux
+# pointing to the directory. But this is done too late - at
+# sys-apps/policycoreutils' pkg_postinst time, /var/lib/selinux does
+# not exist, because coreos-base/misc-files was not yet emerged. So we
+# need to fall back to this hack, where we set up /var/lib/selinux and
+# /usr/lib/selinux/policy the way we want.
+cros_post_src_install_set_up_var_lib_selinux() {
+    if [[ ${CATEGORY} != 'sys-apps' ]] || [[ ${PN} != 'policycoreutils' ]]; then
+        return 0;
+    fi
+    dodir /usr/lib/selinux
+    mv "${ED}/var/lib/selinux" "${ED}/usr/lib/selinux/policy"
+    dosym ../../usr/lib/selinux/policy /var/lib/selinux
+}
+
 # Source hooks for SLSA build provenance report generation
 source "${BASH_SOURCE[0]}.slsa-provenance"