esc_textarea()

function esc_textarea( $text ) {
	$safe_text = htmlspecialchars( $text, ENT_QUOTES, get_option( 'blog_charset' ) );
	/**
	 * Filters a string cleaned and escaped for output in a textarea element.
	 *
	 * @since 3.1.0
	 *
	 * @param string $safe_text The text after it has been escaped.
	 * @param string $text      The text prior to being escaped.
	 */
	return apply_filters( 'esc_textarea', $safe_text, $text );
}