Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753333Ab2JJJSp (ORCPT ); Wed, 10 Oct 2012 05:18:45 -0400 Received: from mail-lb0-f174.google.com ([209.85.217.174]:37053 "EHLO mail-lb0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753058Ab2JJJSn (ORCPT ); Wed, 10 Oct 2012 05:18:43 -0400 Date: Wed, 10 Oct 2012 10:18:29 +0100 From: Dave Martin To: Jason Gunthorpe Cc: Russell King - ARM Linux , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH] [ARM] Use AT() in the linker script to create correct program headers Message-ID: <20121010091829.GA2131@linaro.org> References: <20120930232116.GC30637@obsidianresearch.com> <20121001153952.GB2100@linaro.org> <20121001160639.GA31620@obsidianresearch.com> <20121005084500.GI4625@n2100.arm.linux.org.uk> <20121008102413.GC2302@linaro.org> <20121009173706.GE4124@obsidianresearch.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20121009173706.GE4124@obsidianresearch.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1136 Lines: 26 On Tue, Oct 09, 2012 at 11:37:06AM -0600, Jason Gunthorpe wrote: > On Mon, Oct 08, 2012 at 11:24:13AM +0100, Dave Martin wrote: > > > Partly this came from some side speculation about whether we could do > > things like privileged read-only permissions on newer CPUs, for preventing > > unintended or undesired writes to the kernel's code or read-only data. > > Some other arches page protect the kernel, but that tends to be at > odds with the desire to use huge pages for the kernel mapping, and > independent of the load headers.. This wasn't so much about that headers themselves as about fragmentation of the page permissions which makes it difficult to map everything using huge pages / sections. But as you say, there are conflicting concerns here, and it seems not to be a priority. Privileged write-protect is nice to have if non-disruptive, but not essential. Cheers ---Dave -- 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/