Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753917AbaFEFM0 (ORCPT ); Thu, 5 Jun 2014 01:12:26 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:43691 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752154AbaFEEUL (ORCPT ); Thu, 5 Jun 2014 00:20:11 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Chen Yucong , Naoya Horiguchi , Andi Kleen , Andrew Morton , Linus Torvalds Subject: [PATCH 3.4 043/214] hwpoison, hugetlb: lock_page/unlock_page does not match for handling a free hugepage Date: Wed, 4 Jun 2014 21:16:46 -0700 Message-Id: <20140605041645.385769087@linuxfoundation.org> X-Mailer: git-send-email 2.0.0 In-Reply-To: <20140605041639.638675216@linuxfoundation.org> References: <20140605041639.638675216@linuxfoundation.org> User-Agent: quilt/0.60-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chen Yucong commit b985194c8c0a130ed155b71662e39f7eaea4876f upstream. For handling a free hugepage in memory failure, the race will happen if another thread hwpoisoned this hugepage concurrently. So we need to check PageHWPoison instead of !PageHWPoison. If hwpoison_filter(p) returns true or a race happens, then we need to unlock_page(hpage). Signed-off-by: Chen Yucong Reviewed-by: Naoya Horiguchi Tested-by: Naoya Horiguchi Reviewed-by: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/memory-failure.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1061,15 +1061,16 @@ int memory_failure(unsigned long pfn, in return 0; } else if (PageHuge(hpage)) { /* - * Check "just unpoisoned", "filter hit", and - * "race with other subpage." + * Check "filter hit" and "race with other subpage." */ lock_page(hpage); - if (!PageHWPoison(hpage) - || (hwpoison_filter(p) && TestClearPageHWPoison(p)) - || (p != hpage && TestSetPageHWPoison(hpage))) { - atomic_long_sub(nr_pages, &mce_bad_pages); - return 0; + if (PageHWPoison(hpage)) { + if ((hwpoison_filter(p) && TestClearPageHWPoison(p)) + || (p != hpage && TestSetPageHWPoison(hpage))) { + atomic_long_sub(nr_pages, &mce_bad_pages); + unlock_page(hpage); + return 0; + } } set_page_hwpoison_huge_page(hpage); res = dequeue_hwpoisoned_huge_page(hpage); -- 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/