post_install() {
  echo "/usr/lib/libarmmem.so" >> /etc/ld.so.preload
}

post_upgrade() {
  touch /etc/ld.so.preload
  grep -q "/usr/lib/libarmmem.so" /etc/ld.so.preload
  if [[ $? -ne 0 ]]; then
    post_install
  fi
}

pre_remove() {
  sed '|/usr/lib/libarmmem.so|d' -i /etc/ld.so.preload
}