Return-Path: <linux-kernel-owner+willy=40w.ods.org@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id <S267084AbTBTWCL>; Thu, 20 Feb 2003 17:02:11 -0500
Received: (majordomo@vger.kernel.org) by vger.kernel.org
	id <S267104AbTBTWCL>; Thu, 20 Feb 2003 17:02:11 -0500
Received: from [195.223.140.107] ([195.223.140.107]:18050 "EHLO athlon.random")
	by vger.kernel.org with ESMTP id <S267084AbTBTWCJ>;
	Thu, 20 Feb 2003 17:02:09 -0500
Date: Thu, 20 Feb 2003 23:10:27 +0100
From: Andrea Arcangeli <andrea@suse.de>
To: Jeff Garzik <jgarzik@pobox.com>
Cc: Prasad <prasad_s@students.iiit.net>, lkml <linux-kernel@vger.kernel.org>
Subject: Re: Syscall from Kernel Space
Message-ID: <20030220221027.GA31480@x30.school.suse.de>
References: <Pine.LNX.4.44.0302202301350.12696-100000@students.iiit.net> <20030220174043.GI9800@gtf.org>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20030220174043.GI9800@gtf.org>
User-Agent: Mutt/1.4i
X-GPG-Key: 1024D/68B9CB43
X-PGP-Key: 1024R/CB4660B9
Sender: linux-kernel-owner@vger.kernel.org
X-Mailing-List: linux-kernel@vger.kernel.org
Content-Length: 1071
Lines: 23

On Thu, Feb 20, 2003 at 12:40:43PM -0500, Jeff Garzik wrote:
> On Thu, Feb 20, 2003 at 11:04:37PM +0530, Prasad wrote:
> > 	Is there a way using which i could invoke a syscall in the kernel 
> > space?  The syscall is to be run disguised as another process.  The actual 
> 
> Call sys_<syscall>.  Look at the kernel code for examples.
> 
> Note that typically you don't want to do this... and you _really_ don't
> want to do this if the syscall is not one of the common file I/O
> syscalls (read/write/open/close, etc.)

you never want to do this, the only point of a syscall is to enter
kernel, if you're just in kernel you're wasting time in calling the
syscall (not to tell about the new non soft interrupt based syscall
instructions, btw this is also why I rejected the int 0x81 thing on
x86-64 for 64bit syscalls)

Andrea
-
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/