From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.11] helo=sc8-sf-mx1.sourceforge.net) by sc8-sf-list1.sourceforge.net with esmtp (Exim 4.30) id 1DYDHl-0001Ml-0f for user-mode-linux-devel@lists.sourceforge.net; Tue, 17 May 2005 18:23:45 -0700 Received: from lakshmi.addtoit.com ([198.99.130.6] helo=lakshmi.solana.com) by sc8-sf-mx1.sourceforge.net with esmtp (Exim 4.41) id 1DYDHj-0002Rm-D1 for user-mode-linux-devel@lists.sourceforge.net; Tue, 17 May 2005 18:23:44 -0700 From: Jeff Dike Subject: Re: [uml-devel] copy_from_user in SKAS mode Message-ID: <20050518011827.GA13287@ccure.user-mode-linux.org> References: <3524bf1f0505171633edddc7@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3524bf1f0505171633edddc7@mail.gmail.com> Sender: user-mode-linux-devel-admin@lists.sourceforge.net Errors-To: user-mode-linux-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Id: The user-mode Linux development list List-Post: List-Help: List-Subscribe: , List-Archive: Date: Tue, 17 May 2005 21:18:27 -0400 To: Young Koh Cc: user-mode-linux-devel@lists.sourceforge.net On Tue, May 17, 2005 at 07:33:26PM -0400, Young Koh wrote: > i'm trying to understand how copy_from_user (and copy_to_user) is > working in SKAS mode. i started from copy_from_user_skas, and followed > the functions. but i kinda got lost and couldn't get the intuition how > data are transferred to the UML kernel, which is a different process. > Could anyone explain how copy_from_user works in SKAS mode? i'd really > appreciate it. Thank you! Since UML has no direct access to the process userspace (i.e. process virtual addresses are meaningless in the kernel), it has to translate them to physical addresses. So, each page containing a piece of the incoming buffer is translated into a physical page, and the data copied from there. Jeff ------------------------------------------------------- This SF.Net email is sponsored by Oracle Space Sweepstakes Want to be the first software developer in space? Enter now for the Oracle Space Sweepstakes! http://ads.osdn.com/?ad_id=7412&alloc_id=16344&op=click _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel