From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758383Ab0FUUjs (ORCPT ); Mon, 21 Jun 2010 16:39:48 -0400 Received: from mx1.redhat.com ([209.132.183.28]:27767 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758275Ab0FUUjr (ORCPT ); Mon, 21 Jun 2010 16:39:47 -0400 Date: Mon, 21 Jun 2010 16:33:49 -0400 From: Rik van Riel To: linux-kernel@vger.kernel.org Cc: akpm@linux-foundation.org, aarcange@redhat.com, linux-mm@kvack.org Subject: [PATCH -mm 2/6] rmap: always add new vmas at the end Message-ID: <20100621163349.7dbd1ef6@annuminas.surriel.com> In-Reply-To: <20100621163146.4e4e30cb@annuminas.surriel.com> References: <20100621163146.4e4e30cb@annuminas.surriel.com> Organization: Red Hat, Inc. Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Andrea Arcangeli Subject: always add new vmas at the end Make sure to always add new VMAs at the end of the list. This is important so rmap_walk does not miss a VMA that was created during the rmap_walk. The old code got this right most of the time due to luck, but was buggy when anon_vma_prepare reused a mergeable anon_vma. Signed-off-by: Andrea Arcangeli Signed-off-by: Rik van Riel --- diff --git a/mm/rmap.c b/mm/rmap.c --- a/mm/rmap.c +++ b/mm/rmap.c @@ -149,7 +149,7 @@ int anon_vma_prepare(struct vm_area_stru avc->anon_vma = anon_vma; avc->vma = vma; list_add(&avc->same_vma, &vma->anon_vma_chain); - list_add(&avc->same_anon_vma, &anon_vma->head); + list_add_tail(&avc->same_anon_vma, &anon_vma->head); allocated = NULL; avc = NULL; }