From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933399AbbDITlw (ORCPT ); Thu, 9 Apr 2015 15:41:52 -0400 Received: from mail-ig0-f175.google.com ([209.85.213.175]:38882 "EHLO mail-ig0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933300AbbDITlu (ORCPT ); Thu, 9 Apr 2015 15:41:50 -0400 Date: Thu, 9 Apr 2015 12:41:47 -0700 (PDT) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Gerald Schaefer cc: Naoya Horiguchi , Andrew Morton , Hugh Dickins , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Michal Hocko , Andrea Arcangeli , Martin Schwidefsky Subject: Re: [PATCH] mm/hugetlb: use pmd_page() in follow_huge_pmd() In-Reply-To: <1428595895-24140-1-git-send-email-gerald.schaefer@de.ibm.com> Message-ID: References: <1428595895-24140-1-git-send-email-gerald.schaefer@de.ibm.com> User-Agent: Alpine 2.10 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 9 Apr 2015, Gerald Schaefer wrote: > commit 61f77eda "mm/hugetlb: reduce arch dependent code around follow_huge_*" > broke follow_huge_pmd() on s390, where pmd and pte layout differ and using > pte_page() on a huge pmd will return wrong results. Using pmd_page() instead > fixes this. > > All architectures that were touched by commit 61f77eda have pmd_page() > defined, so this should not break anything on other architectures. > > Signed-off-by: Gerald Schaefer > Cc: stable@vger.kernel.org # v3.12 Acked-by: David Rientjes I'm not sure where the stable cc came from, though: commit 61f77eda makes s390 use a generic version of follow_huge_pmd() and that generic version is buggy for s930 because of commit e66f17ff7177 ("mm/hugetlb: take page table lock in follow_huge_pmd()"). Both of those are 4.0 material, though, so why is this needed for stable 3.12?