From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi0-f51.google.com (mail-oi0-f51.google.com [209.85.218.51]) by kanga.kvack.org (Postfix) with ESMTP id 3DA3B6B006C for ; Tue, 14 Oct 2014 16:16:55 -0400 (EDT) Received: by mail-oi0-f51.google.com with SMTP id h136so17754300oig.24 for ; Tue, 14 Oct 2014 13:16:55 -0700 (PDT) Received: from mail-oi0-x249.google.com (mail-oi0-x249.google.com [2607:f8b0:4003:c06::249]) by mx.google.com with ESMTPS id oz16si19965110oeb.36.2014.10.14.13.16.54 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 14 Oct 2014 13:16:54 -0700 (PDT) Received: by mail-oi0-f73.google.com with SMTP id u20so3306494oif.4 for ; Tue, 14 Oct 2014 13:16:54 -0700 (PDT) From: Yu Zhao Subject: [PATCH 2/2] mm: verify compound order when freeing a page Date: Tue, 14 Oct 2014 13:16:40 -0700 Message-Id: <1413317800-25450-2-git-send-email-yuzhao@google.com> In-Reply-To: <1413317800-25450-1-git-send-email-yuzhao@google.com> References: <1413317800-25450-1-git-send-email-yuzhao@google.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton , "Kirill A. Shutemov" , Mel Gorman , Rik van Riel , Ingo Molnar , Hugh Dickins , Sasha Levin , Bob Liu , Johannes Weiner , David Rientjes , Vlastimil Babka Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Yu Zhao 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); + trace_mm_page_free(page, order); kmemcheck_free_shadow(page, order); -- 2.1.0.rc2.206.gedb03e5 -- 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