From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 2 Apr 2003 18:31:10 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 2 Apr 2003 18:31:09 -0500 Received: from pixpat.austin.ibm.com ([192.35.232.241]:19730 "EHLO baldur.austin.ibm.com") by vger.kernel.org with ESMTP id ; Wed, 2 Apr 2003 18:31:07 -0500 Date: Wed, 02 Apr 2003 17:42:25 -0600 From: Dave McCracken To: Andrew Morton cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2.5.66-mm2] Fix page_convert_anon locking issues Message-ID: <110950000.1049326945@baldur.austin.ibm.com> In-Reply-To: <20030402153845.0770ef54.akpm@digeo.com> References: <8910000.1049303582@baldur.austin.ibm.com> <20030402132939.647c74a6.akpm@digeo.com> <80300000.1049320593@baldur.austin.ibm.com> <20030402150903.21765844.akpm@digeo.com> <102170000.1049325787@baldur.austin.ibm.com> <20030402153845.0770ef54.akpm@digeo.com> X-Mailer: Mulberry/2.2.1 (Linux/x86) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --On Wednesday, April 02, 2003 15:38:45 -0800 Andrew Morton wrote: > But: > > + /* Double check to make sure the pte page hasn't been freed */ > + if (!pmd_present(*pmd)) > + goto out_unmap; > + > ==> munmap, pte page is freed, reallocated for pagecache, someone > happens to write the correct value into it. > > + if (page_to_pfn(page) != pte_pfn(*pte)) > + goto out_unmap; > + > + if (addr) > + *addr = address; > + Oops. The pmd_present() check should be after the page_to_pfn() != pte_pfn() check. Dave ====================================================================== Dave McCracken IBM Linux Base Kernel Team 1-512-838-3059 dmccr@us.ibm.com T/L 678-3059