Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261182AbVA0VWY (ORCPT ); Thu, 27 Jan 2005 16:22:24 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261191AbVA0VT7 (ORCPT ); Thu, 27 Jan 2005 16:19:59 -0500 Received: from holomorphy.com ([66.93.40.71]:63419 "EHLO holomorphy.com") by vger.kernel.org with ESMTP id S261182AbVA0VN3 (ORCPT ); Thu, 27 Jan 2005 16:13:29 -0500 Date: Thu, 27 Jan 2005 13:13:19 -0800 From: William Lee Irwin III To: Rik van Riel Cc: Russell King , Mikael Pettersson , Andrew Morton , linux-kernel@vger.kernel.org, James Antill , Bryn Reeves Subject: Re: don't let mmap allocate down to zero Message-ID: <20050127211319.GN10843@holomorphy.com> References: <20050126172538.GN10843@holomorphy.com> <20050127050927.GR10843@holomorphy.com> <16888.46184.52179.812873@alkaid.it.uu.se> <20050127125254.GZ10843@holomorphy.com> <20050127142500.A775@flint.arm.linux.org.uk> <20050127151211.GB10843@holomorphy.com> <20050127204455.GM10843@holomorphy.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: The Domain of Holomorphy User-Agent: Mutt/1.5.6+20040907i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1191 Lines: 32 On Thu, 27 Jan 2005, William Lee Irwin III wrote: >> (b) sys_mremap() isn't covered. On Thu, Jan 27, 2005 at 03:58:12PM -0500, Rik van Riel wrote: > AFAICS it is covered. > >--- mm1-2.6.11-rc2.orig/mm/mremap.c 2005-01-26 00:26:43.000000000 -0800 > >+++ mm1-2.6.11-rc2/mm/mremap.c 2005-01-27 12:34:34.000000000 -0800 > >@@ -297,6 +297,8 @@ > > if (flags & MREMAP_FIXED) { > > if (new_addr & ~PAGE_MASK) > > goto out; > >+ if (!new_addr) > >+ goto out; > > This looks broken, look at the MREMAP_FIXED part... The only way I can make sense of this is if you're trying to say that because the user is trying to pass in a fixed address, that 0 should then be permitted. The intention was to disallow vmas starting at 0 categorically. i.e. it is very intentional to deny the MREMAP_FIXED to 0 case of mremap(). It was also the intention to deny the MAP_FIXED to 0 case of mmap(), though I didn't actually sweep that much (if at all). -- wli - 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/