Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753997Ab0GKCPg (ORCPT ); Sat, 10 Jul 2010 22:15:36 -0400 Received: from govinda.solana.com ([198.99.130.30]:54745 "EHLO govinda.addtoit.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753414Ab0GKCPe (ORCPT ); Sat, 10 Jul 2010 22:15:34 -0400 Date: Sat, 10 Jul 2010 22:15:26 -0400 From: Jeff Dike To: Philip Wernersbach Cc: linux-kernel@vger.kernel.org Subject: Re: Calling system call from User-mode Linux? Message-ID: <20100711021526.GA30049@c-98-229-117-200.hsd1.ma.comcast.net> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 849 Lines: 18 On Sat, Jul 10, 2010 at 05:55:48PM -0400, Philip Wernersbach wrote: > I'm trying to add some functionality to User-mode Linux that requires > the UML kernel to call a custom syscall I've added to the host kernel. > This should be technically possible since UML runs in the userspace, > but I can't figure out how to call the syscall, as the syscall() > function isn't defined in UML. Are there other ways I can accomplish > this? Add a function in the userspace side of UML (arch/um/os-Linux) which invokes your new system call through syscall(), and then call that from wherever you need to. Jeff -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/