From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262417AbVDGKPJ (ORCPT ); Thu, 7 Apr 2005 06:15:09 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262419AbVDGKPJ (ORCPT ); Thu, 7 Apr 2005 06:15:09 -0400 Received: from mx1.redhat.com ([66.187.233.31]:31386 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S262417AbVDGKOv (ORCPT ); Thu, 7 Apr 2005 06:14:51 -0400 From: David Howells In-Reply-To: References: To: Hugh Dickins Cc: Andrew Morton , Nick Piggin , Russell King , linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/6] freepgt2: sys_mincore ignore FIRST_USER_PGD_NR X-Mailer: MH-E 7.82; nmh 1.0.4; GNU Emacs 21.3.50.1 Date: Thu, 07 Apr 2005 11:14:24 +0100 Message-ID: <19283.1112868864@redhat.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hugh Dickins wrote: > > Remove use of FIRST_USER_PGD_NR from sys_mincore: it's inconsistent (no > other syscall refers to it), unnecessary (sys_mincore loops over vmas > further down) and incorrect (misses user addresses in ARM's first pgd). You should make it use FIRST_USER_ADDRESS instead. This check allows NULL pointers and suchlike to be weeded out before having to take the semaphore. Also, just because no other syscall refers to such a value doesn't mean that this one shouldn't and that others shouldn't. David