From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754676AbcEQHnB (ORCPT ); Tue, 17 May 2016 03:43:01 -0400 Received: from mail-pf0-f196.google.com ([209.85.192.196]:36785 "EHLO mail-pf0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752233AbcEQHm7 (ORCPT ); Tue, 17 May 2016 03:42:59 -0400 From: Naoya Horiguchi To: Andrew Morton Cc: Vlastimil Babka , Mel Gorman , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Naoya Horiguchi , Naoya Horiguchi Subject: [PATCH v1] mm: bad_page() checks bad_flags instead of page->flags for hwpoison page Date: Tue, 17 May 2016 16:42:55 +0900 Message-Id: <1463470975-29972-1-git-send-email-n-horiguchi@ah.jp.nec.com> X-Mailer: git-send-email 2.7.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There's a race window between checking page->flags and unpoisoning, which taints kernel with "BUG: Bad page state". That's overkill. It's safer to use bad_flags to detect hwpoisoned page. Signed-off-by: Naoya Horiguchi --- mm/page_alloc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git tmp/mm/page_alloc.c tmp_patched/mm/page_alloc.c index 5b269bc..4e0fa37 100644 --- tmp/mm/page_alloc.c +++ tmp_patched/mm/page_alloc.c @@ -522,8 +522,8 @@ static void bad_page(struct page *page, const char *reason, static unsigned long nr_shown; static unsigned long nr_unshown; - /* Don't complain about poisoned pages */ - if (PageHWPoison(page)) { + /* Don't complain about hwpoisoned pages */ + if (bad_flags == __PG_HWPOISON) { page_mapcount_reset(page); /* remove PageBuddy */ return; } -- 2.7.0