From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753474AbYKQH2K (ORCPT ); Mon, 17 Nov 2008 02:28:10 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755142AbYKQHVT (ORCPT ); Mon, 17 Nov 2008 02:21:19 -0500 Received: from kroah.org ([198.145.64.141]:38421 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752992AbYKQHVK (ORCPT ); Mon, 17 Nov 2008 02:21:10 -0500 Date: Sun, 16 Nov 2008 23:15:28 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: Justin Forbes , Zwane Mwaikambo , "Theodore Ts'o" , Randy Dunlap , Dave Jones , Chuck Wolber , Chris Wedgwood , Michael Krufky , Chuck Ebbert , Domenico Andreoli , Willy Tarreau , Rodrigo Rubira Branco , Jake Edge , Eugene Teo , torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Gerald Schaefer , Nathan Fontenot , Greg Kroah-Hartman Subject: [patch 20/46] memory hotplug: fix page_zone() calculation in test_pages_isolated() Message-ID: <20081117071528.GU29522@kroah.com> References: <20081117070621.430169021@blue.kroah.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline; filename="memory-hotplug-fix-page_zone-calculation-in-test_pages_isolated.patch" In-Reply-To: <20081117071333.GA29522@kroah.com> User-Agent: Mutt/1.5.16 (2007-06-09) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.27-stable review patch. If anyone has any objections, please let us know. ------------------ From: Gerald Schaefer commit a70dcb969f64e2fa98c24f47854f20bf02ff0092 upstream. My last bugfix here (adding zone->lock) introduced a new problem: Using page_zone(pfn_to_page(pfn)) to get the zone after the for() loop is wrong. pfn will then be >= end_pfn, which may be in a different zone or not present at all. This may lead to an addressing exception in page_zone() or spin_lock_irqsave(). Now I use __first_valid_page() again after the loop to find a valid page for page_zone(). Signed-off-by: Gerald Schaefer Acked-by: Nathan Fontenot Reviewed-by: KAMEZAWA Hiroyuki Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/page_isolation.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/mm/page_isolation.c +++ b/mm/page_isolation.c @@ -130,10 +130,11 @@ int test_pages_isolated(unsigned long st if (page && get_pageblock_migratetype(page) != MIGRATE_ISOLATE) break; } - if (pfn < end_pfn) + page = __first_valid_page(start_pfn, end_pfn - start_pfn); + if ((pfn < end_pfn) || !page) return -EBUSY; /* Check all pages are free or Marked as ISOLATED */ - zone = page_zone(pfn_to_page(pfn)); + zone = page_zone(page); spin_lock_irqsave(&zone->lock, flags); ret = __test_page_isolated_in_pageblock(start_pfn, end_pfn); spin_unlock_irqrestore(&zone->lock, flags); --