From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753889AbYCIS6x (ORCPT ); Sun, 9 Mar 2008 14:58:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752575AbYCIS6p (ORCPT ); Sun, 9 Mar 2008 14:58:45 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:34000 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752501AbYCIS6p (ORCPT ); Sun, 9 Mar 2008 14:58:45 -0400 Date: Sun, 9 Mar 2008 19:57:52 +0100 From: Ingo Molnar To: Linus Torvalds Cc: Arjan van de Ven , hans.rosenfeld@amd.com, linux-kernel@vger.kernel.org, Thomas Gleixner , "H. Peter Anvin" Subject: Re: bisected boot regression post 2.6.25-rc3.. please revert Message-ID: <20080309185752.GA9548@elte.hu> References: <20080301105646.2c8620d9@laptopd505.fenrus.org> <20080303074620.GC5934@elte.hu> <20080303091304.GA17911@elte.hu> <47CC2A3D.1000307@linux.intel.com> <20080303174009.GA19131@elte.hu> <47CC451A.2060501@linux.intel.com> <20080309115603.GA951@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Linus Torvalds wrote: > So I would *very* strongly instead argue: > > - "unsigned long" is the native kernel type for all address manipulation, > and thus "PAGE_SIZE" and "PAGE_MASK" should continue to have that type. > > - anything that uses any other type without explicitly making sure it's > safe is mis-using those macros. IOW, PAGE_MASk was *never* a type that > had anything what-so-ever to do with page table entry bits, and this is > purely a page table entry issue! > > So my suggested patch would: > > - make the page table code use a specific mask that it builds up itself, > and makes sure it's of the right type and has the rigth value in > whatever type "struct pte_entry" is. The fact that "pte_val()" is > larger than "unsigned long" on x86-32 is very clearly a PTE issue, > *not* an issue for PAGE_SIZE or PAGE_MASK. yeah, indeed my patch was sloppy, i didnt think it through - i fell for the lure of the easy-looking 'PAGE_SIZE is small, sign-extend it' hack. Will do it cleanly and will also clean up all the pte/address/pgprot type mixing that currently goes on in this maze of macros. Ingo