From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754388Ab0DFFnt (ORCPT ); Tue, 6 Apr 2010 01:43:49 -0400 Received: from gate.crashing.org ([63.228.1.57]:51721 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751152Ab0DFFnp (ORCPT ); Tue, 6 Apr 2010 01:43:45 -0400 Subject: Re: mprotect pgprot handling weirdness From: Benjamin Herrenschmidt To: linux-mm@kvack.org Cc: "linux-kernel@vger.kernel.org" In-Reply-To: <1270530566.13812.28.camel@pasglop> References: <1270530566.13812.28.camel@pasglop> Content-Type: text/plain; charset="UTF-8" Date: Tue, 06 Apr 2010 15:43:42 +1000 Message-ID: <1270532622.13812.30.camel@pasglop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2010-04-06 at 15:09 +1000, Benjamin Herrenschmidt wrote: > (*) Right now it's near impossible to add arch specific PROT_* bits to > mmap/mprotect for fancy things like cachability attributes, or other > nifty things like reverse-endian mappings that we have on some embedded > platforms, I'm investigating ways to better separate vm_page_prot from > vm_flags so some PROT_* bits can go straight to the former without > having to be mirrored in some way in the later. The other (easier) option is to make the vm flags always 64-bit and reserve a range of bits here for the arch to use but I suppose there's going to be unhappiness about that one :-) Cheers, Ben.