From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758010AbXFLNzM (ORCPT ); Tue, 12 Jun 2007 09:55:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756578AbXFLNy7 (ORCPT ); Tue, 12 Jun 2007 09:54:59 -0400 Received: from py-out-1112.google.com ([64.233.166.177]:24932 "EHLO py-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755737AbXFLNy6 (ORCPT ); Tue, 12 Jun 2007 09:54:58 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:mime-version:content-type:content-transfer-encoding:content-disposition; b=HFvaOA1yBzEmSXKXhH5XTM/VVmb/+Staxhj0STren6Dt1CCCNcHG2BhFR0pdWzdl6oKMA7PFWtsJzEGKm102svSc9c7PdrFHsT1iXrS5VHFMlqM0uVoi5Hl/0F8uKsEtEOfpdhQJaZWZp5qYT5zjGBGo39d0HSKi8g1yGuqhGj8= Message-ID: <7f7732360706120654i34f34da8q6428e41bc5a76728@mail.gmail.com> Date: Tue, 12 Jun 2007 15:54:57 +0200 From: "Federico Paparoni" To: linux-kernel@vger.kernel.org Subject: Linux kernel 2.4 programming problem MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi all, i'm trying to create a simple system call in a kernel 2.4 distribution. I read guide/articles like this http://irfanhabib.wordpress.com/2006/10/01/adding-a-system-call-linux-24x/ All the articles say the same things, but the implementation of my new system call doesn't work. I create a new entry in arch/i386/kernel/entry.S I create a new entry in include/asm/unistd.h I create a new function with the asmlinkage prefix in a source file already defined (in ipc/sem.c for example) When i create my user program, it doesn't work. Firstly when i try to compile i receive a problem like this : undefined reference to 'errno' Then I include errno.h (also if i don't understand this step) and the compilation works, but the syscall neverworks, because the call always return -1. Any help? Any tutorial FOR DUMMY MAN that someone already used? Cheers Federico