Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756235Ab2JRO10 (ORCPT ); Thu, 18 Oct 2012 10:27:26 -0400 Received: from terminus.zytor.com ([198.137.202.10]:45324 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755810Ab2JRO1Y (ORCPT ); Thu, 18 Oct 2012 10:27:24 -0400 Message-ID: <508011AD.5080307@zytor.com> Date: Thu, 18 Oct 2012 07:26:53 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:16.0) Gecko/20121009 Thunderbird/16.0 MIME-Version: 1.0 To: mtk.manpages@gmail.com CC: Rusty Russell , Kees Cook , linux-kernel@vger.kernel.org, Andrew Morton , Mimi Zohar , Serge Hallyn , Arnd Bergmann , James Morris , Al Viro , Eric Paris , Jiri Kosina , linux-security-module@vger.kernel.org Subject: Re: [PATCH 1/4] module: add syscall to load module from fd References: <1348179300-11653-1-git-send-email-keescook@chromium.org> <50749DE8.7010703@zytor.com> <5074A0AB.8040207@zytor.com> <87d30o7iy6.fsf@rustcorp.com.au> <507F848F.50707@zytor.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1359 Lines: 34 On 10/18/2012 01:05 AM, Michael Kerrisk (man-pages) wrote: >> >> So perhaps what we *should* have is something that points to the module >> to a (buffer, length) in userspace, and the equivalent of the current >> init_module() would be open() + mmap() + minit_module() + close()? > > So, I don't get it. What are the args you propose for of minit_module()? > Nevermind, this is what the current init_module() already takes. So it sounds like Rusty is objecting to the very notion of tying a module to a file descriptor the way the proposed finit_module() system call does -- I was confused about the functioning of the *current* init_module() system call. Given that, I have to say I now seriously question the value of finit_module(). The kernel can trivially discover if the pointed-to memory area is a MAP_SHARED mmap() of a file descriptor and if so which file descriptor... why can't we handle this behind the scenes? -hpa P.S. the man page for init_module(2) is seriously out of date... -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf. -- 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/