ping: fix breakage from -I fix

passwd: SELinux support by KaiGai Kohei <kaigai@ak.jp.nec.com>

libbb/selinux_common.c

@@ -38,3 +38,17 @@ void setfscreatecon_or_die(security_context_t scontext)
 				"file creation context to %s", scontext);
 	}
 }
+
+void selinux_preserve_fcontext(int fdesc)
+{
+	security_context_t context;
+
+	if (fgetfilecon(fdesc, &context) < 0) {
+		if (errno == ENODATA || errno == ENOTSUP)
+			return;
+		bb_perror_msg_and_die("fgetfilecon failed");
+	}
+	setfscreatecon_or_die(context);
+	freecon(context);
+}
+