Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751947AbaJOJOz (ORCPT ); Wed, 15 Oct 2014 05:14:55 -0400 Received: from mta-out1.inet.fi ([62.71.2.197]:46741 "EHLO kirsi1.inet.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751916AbaJOJOy (ORCPT ); Wed, 15 Oct 2014 05:14:54 -0400 Date: Wed, 15 Oct 2014 12:14:39 +0300 From: "Kirill A. Shutemov" To: Yu Zhao Cc: Andrew Morton , "Kirill A. Shutemov" , Mel Gorman , Rik van Riel , Ingo Molnar , Hugh Dickins , Sasha Levin , Bob Liu , Johannes Weiner , David Rientjes , Vlastimil Babka , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] mm: verify compound order when freeing a page Message-ID: <20141015091439.GC12538@node.dhcp.inet.fi> References: <1413317800-25450-1-git-send-email-yuzhao@google.com> <1413317800-25450-2-git-send-email-yuzhao@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1413317800-25450-2-git-send-email-yuzhao@google.com> User-Agent: Mutt/1.5.22.1 (2013-10-16) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 14, 2014 at 01:16:40PM -0700, Yu Zhao wrote: > This allows us to easily catch the bug fixed in previous patch. > > Here we also verify whether a page is tail page or not -- tail > pages are supposed to be freed along with their head, not by > themselves. > > Signed-off-by: Yu Zhao > --- > mm/page_alloc.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 736d8e1..2bcc770 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -750,6 +750,9 @@ static bool free_pages_prepare(struct page *page, unsigned int order) > int i; > int bad = 0; > > + VM_BUG_ON(PageTail(page)); > + VM_BUG_ON(PageHead(page) && compound_order(page) != order); > + Use VM_BUG_ON_PAGE(), please. > trace_mm_page_free(page, order); > kmemcheck_free_shadow(page, order); > > -- > 2.1.0.rc2.206.gedb03e5 > > -- > 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/ -- Kirill A. Shutemov -- 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/