Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932295AbcDDJ6L (ORCPT ); Mon, 4 Apr 2016 05:58:11 -0400 Received: from pandora.arm.linux.org.uk ([78.32.30.218]:53822 "EHLO pandora.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754807AbcDDJ6J (ORCPT ); Mon, 4 Apr 2016 05:58:09 -0400 Date: Mon, 4 Apr 2016 10:57:57 +0100 From: Russell King - ARM Linux To: Alexandre Belloni Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Ard Biesheuvel , Dave Martin , Olof Johansson , Doug Anderson , Heiko Stuebner , Russ Dill Subject: Re: [PATCH 0/2] Embedding Position Independent Executables Message-ID: <20160404095757.GR19428@n2100.arm.linux.org.uk> References: <1459668234-16033-1-git-send-email-alexandre.belloni@free-electrons.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1459668234-16033-1-git-send-email-alexandre.belloni@free-electrons.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1990 Lines: 43 [Manually reformatted your email so I can reply to it sensibly - please don't make me have to do this again, next time I'll ignore your message as it's too much effort, thanks] On Sun, Apr 03, 2016 at 09:23:52AM +0200, Alexandre Belloni wrote: > Hi, > > This series tries to revive the many series trying to achieve the same > thing. > > I've tried numerous approaches and while using the kernel module loader > is actually quite convenient from a relocation point of view it is quite > overkill and also it is quite often too late as a lot of the arch > specific PM code assume that it is running at boot time, befor having > access to any filesystem. > > I've chosen to be less generic than what Russ did and only handle ARM. > I reused the API he defined but I actually went closer to his first > implementation by compiling and embedding a real PIE that doesn't > actually need relocations (gcc seems to be better at it thanks to ASLR). > > In this series, I'm also converting the AT91 suspend code to use that > infrastructure as it is quite simple but I also toyed with more complex > functions. > > The current limitation is that is doesn't actually tries to handle big > endian and I didn't test thumb (and this will probably require more work > to get that working reliably). > > Also, to be more useful prppoer handling of a stack has to be added > (this is not too difficult and is planned) and will be enough to get > rk3288 suspend/resume and DDR timing changes working. Provided there is no linking back to the kernel image (which is enforced by the --no-undefined flag), this at first glance looks okay, but what is the motivation behind this change? Just because there's "many series trying to do this" isn't really a justification or a reason why we should include this in the mainline kernel. -- RMK's Patch system: http://www.arm.linux.org.uk/developer/patches/ FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up according to speedtest.net.