Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756122AbaLHR4w (ORCPT ); Mon, 8 Dec 2014 12:56:52 -0500 Received: from mail-ie0-f182.google.com ([209.85.223.182]:47736 "EHLO mail-ie0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756056AbaLHR4t (ORCPT ); Mon, 8 Dec 2014 12:56:49 -0500 MIME-Version: 1.0 In-Reply-To: <20141208175050.92EDAC40D73@trevor.secretlab.ca> References: <1414007405-32186-1-git-send-email-atull@opensource.altera.com> <1414007405-32186-3-git-send-email-atull@opensource.altera.com> <20141024105200.GA20775@amd> <20141206135533.GA19672@amd> <20141208175050.92EDAC40D73@trevor.secretlab.ca> From: Grant Likely Date: Mon, 8 Dec 2014 17:56:19 +0000 X-Google-Sender-Auth: I2VEkM-babbhjiIoDAo8jQ6xHiY Message-ID: Subject: Re: [PATCH v2 2/3] fpga manager: framework core To: Pavel Machek Cc: atull , Pantelis Antoniou , Greg Kroah-Hartman , Jason Gunthorpe , "H. Peter Anvin" , Michal Simek , Michal Simek , Randy Dunlap , linux-kernel , "devicetree@vger.kernel.org" , Rob Herring , Ira Snyder , "linux-doc@vger.kernel.org" , Mark Brown , philip@balister.org, rubini , Steffen Trumtrar , Jason , kyle.teske@ni.com, Nicolas Pitre , Felipe Balbi , Mauro Carvalho Chehab , David Brown , Rob Landley , David Miller , cesarb@cesarb.net, "sameo@linux.intel.com" , Andrew Morton , Linus Walleij , Alan Tull , dinguyen@opensource.altera.com, Yves Vandervennet Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 8, 2014 at 5:50 PM, Grant Likely wrote: > On Sat, 6 Dec 2014 14:55:33 +0100 > , Pavel Machek > wrote: >> Hi! >> >> > > I am accustomed to doing 'echo -n' for most of sysfs anyway. Once in a >> > > while I am a bonehead and forget the '-n' and spend a few minutes >> > > wondering why this thing that worked last week suddenly rejects all >> > > commands. I'm just trying to make my user interface a bit user-friendly. >> > > >> > > I will take out the '\n' stripping and update the documentation. I didn't >> > > realize this would be controversial. >> > >> > Don't. You're doing the right thing by scrubbing your input. Requiring >> > 'echo -n' is just stupid when it is so easy to make work easily. >> >> 'foo\nbar\n' is unusual but valid filename in linux. It is bad idea to >> echo filenames into files in the first place... and arbitrarily >> disallowing certain filenames is not helping. > > Meh. Just because it is a valid linux filename doesn't mean this > interface is forced to accept it. There should be tighter rules about > how the filename can be constructed. Allowing any arbitrary path for any > arbitrary valid linux filename makes for a large attack surface. > > I would like to know, what is the purpose of the interface? Why is it > important to provide the firmware filename in this manor? Are there > going to be a lot of different FPGA bitstreams that may need to be > loaded? How does userspace choose between them, and is there a better > way to do the selection without passing the firmware filename through > the kernel? Is this merely intended to get udev to behave in a certain > way? If so, then maybe there is a better way to go about it. > > We could for example use a UDEV 'PROGRAM=' rule to execute a userspace > app and have that program figure out which firmware file to provide to > the kernel. Correction, a 'RUN+=' rule is actually what I mean here. The PROGRAM= tag is for executing a program to determine if a device matches. g. -- 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/