From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi0-f50.google.com (mail-oi0-f50.google.com [209.85.218.50]) by kanga.kvack.org (Postfix) with ESMTP id 7A31E6B0254 for ; Mon, 10 Aug 2015 07:56:13 -0400 (EDT) Received: by oip136 with SMTP id 136so84282499oip.1 for ; Mon, 10 Aug 2015 04:56:13 -0700 (PDT) Received: from BLU004-OMC1S14.hotmail.com (blu004-omc1s14.hotmail.com. [65.55.116.25]) by mx.google.com with ESMTPS id mw13si14209619obb.86.2015.08.10.04.56.12 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 10 Aug 2015 04:56:12 -0700 (PDT) Message-ID: From: Wanpeng Li Subject: [PATCH v2 2/5] mm/hwpoison: fix PageHWPoison test/set race Date: Mon, 10 Aug 2015 19:28:20 +0800 In-Reply-To: <1439206103-86829-1-git-send-email-wanpeng.li@hotmail.com> References: <1439206103-86829-1-git-send-email-wanpeng.li@hotmail.com> MIME-Version: 1.0 Content-Type: text/plain Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Naoya Horiguchi , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Wanpeng Li There is a race between madvise_hwpoison path and memory_failure: CPU0 CPU1 madvise_hwpoison get_user_pages_fast PageHWPoison check (false) memory_failure TestSetPageHWPoison soft_offline_page PageHWPoison check (true) return -EBUSY (without put_page) Suggested-by: Naoya Horiguchi Signed-off-by: Wanpeng Li --- mm/memory-failure.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 56b8a71..e0eb7ab 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1704,6 +1704,8 @@ int soft_offline_page(struct page *page, int flags) if (PageHWPoison(page)) { pr_info("soft offline: %#lx page already poisoned\n", pfn); + if (flags & MF_COUNT_INCREASED) + put_page(page); return -EBUSY; } if (!PageHuge(page) && PageTransHuge(hpage)) { -- 1.7.1 -- 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