Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965596AbXHGVSQ (ORCPT ); Tue, 7 Aug 2007 17:18:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964897AbXHGUzY (ORCPT ); Tue, 7 Aug 2007 16:55:24 -0400 Received: from pentafluge.infradead.org ([213.146.154.40]:59739 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964941AbXHGUzU (ORCPT ); Tue, 7 Aug 2007 16:55:20 -0400 Date: Tue, 7 Aug 2007 13:48:05 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org, torvalds@linux-foundation.org Cc: Justin Forbes , Zwane Mwaikambo , "Theodore Ts'o" , Randy Dunlap , Dave Jones , Chuck Wolber , Chris Wedgwood , Michael Krufky , Chuck Ebbert , Domenico Andreoli , akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, joe.jin@oracle.com, gurudas.pai@oracle.com Subject: [2.6.22.2 review 60/84] hugetlb: fix race in alloc_fresh_huge_page() Message-ID: <20070807204805.GJ23028@kroah.com> References: <20070807204034.882009319@mini.kroah.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline; filename="hugetlb-fix-race-in-alloc_fresh_huge_page.patch" In-Reply-To: <20070807204157.GA23028@kroah.com> User-Agent: Mutt/1.5.15 (2007-04-06) X-Bad-Reply: References and In-Reply-To but no 'Re:' in Subject. Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1442 Lines: 48 From: Joe Jin That static `nid' index needs locking. Without it we can end up calling alloc_pages_node() with an illegal node ID and the kernel crashes. Acked-by: Gurudas Pai Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- mm/hugetlb.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -101,13 +101,20 @@ static void free_huge_page(struct page * static int alloc_fresh_huge_page(void) { - static int nid = 0; + static int prev_nid; struct page *page; - page = alloc_pages_node(nid, GFP_HIGHUSER|__GFP_COMP|__GFP_NOWARN, - HUGETLB_PAGE_ORDER); - nid = next_node(nid, node_online_map); + static DEFINE_SPINLOCK(nid_lock); + int nid; + + spin_lock(&nid_lock); + nid = next_node(prev_nid, node_online_map); if (nid == MAX_NUMNODES) nid = first_node(node_online_map); + prev_nid = nid; + spin_unlock(&nid_lock); + + page = alloc_pages_node(nid, GFP_HIGHUSER|__GFP_COMP|__GFP_NOWARN, + HUGETLB_PAGE_ORDER); if (page) { set_compound_page_dtor(page, free_huge_page); spin_lock(&hugetlb_lock); -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/