From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753943AbbAVUIj (ORCPT ); Thu, 22 Jan 2015 15:08:39 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:51530 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752954AbbAVUIh (ORCPT ); Thu, 22 Jan 2015 15:08:37 -0500 Date: Thu, 22 Jan 2015 12:08:20 -0800 From: Andrew Morton To: Shiraz Hashim Cc: linux-mm@kvack.org, oleg@redhat.com, gorcunov@openvz.org, linux-kernel@vger.kernel.org, n-horiguchi@ah.jp.nec.com Subject: Re: [PATCH] mm: pagewalk: call pte_hole() for VM_PFNMAP during walk_page_range Message-Id: <20150122120820.8c279cf8.akpm@linux-foundation.org> In-Reply-To: <1421820793-28883-1-git-send-email-shashim@codeaurora.org> References: <1421820793-28883-1-git-send-email-shashim@codeaurora.org> X-Mailer: Sylpheed 2.7.1 (GTK+ 2.18.9; x86_64-redhat-linux-gnu) 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 On Wed, 21 Jan 2015 11:43:13 +0530 Shiraz Hashim wrote: > walk_page_range silently skips vma having VM_PFNMAP set, > which leads to undesirable behaviour at client end (who > called walk_page_range). For example for pagemap_read, > when no callbacks are called against VM_PFNMAP vma, > pagemap_read may prepare pagemap data for next virtual > address range at wrong index. This changelog doesn't have enough information for me to be able to work out whether a -stable backport is needed. Please always describe the user-visible effects of a bug.