From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wg0-f43.google.com (mail-wg0-f43.google.com [74.125.82.43]) by kanga.kvack.org (Postfix) with ESMTP id F19006B0070 for ; Wed, 15 Oct 2014 05:14:44 -0400 (EDT) Received: by mail-wg0-f43.google.com with SMTP id m15so844334wgh.2 for ; Wed, 15 Oct 2014 02:14:44 -0700 (PDT) Received: from kirsi1.inet.fi (mta-out1.inet.fi. [62.71.2.197]) by mx.google.com with ESMTP id mv10si5399289wib.37.2014.10.15.02.14.43 for ; Wed, 15 Oct 2014 02:14:43 -0700 (PDT) Date: Wed, 15 Oct 2014 12:14:39 +0300 From: "Kirill A. Shutemov" 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> Sender: owner-linux-mm@kvack.org List-ID: 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 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, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org