From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 984A4C32772 for ; Thu, 18 Aug 2022 13:01:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244407AbiHRNBM (ORCPT ); Thu, 18 Aug 2022 09:01:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51194 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244860AbiHRNAt (ORCPT ); Thu, 18 Aug 2022 09:00:49 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2F17F6B16B for ; Thu, 18 Aug 2022 06:00:48 -0700 (PDT) Received: from canpemm500002.china.huawei.com (unknown [172.30.72.56]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4M7lLZ5N68znTYd; Thu, 18 Aug 2022 20:58:30 +0800 (CST) Received: from huawei.com (10.175.124.27) by canpemm500002.china.huawei.com (7.192.104.244) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Thu, 18 Aug 2022 21:00:43 +0800 From: Miaohe Lin To: , CC: , , Subject: [PATCH 6/6] mm, hwpoison: avoid trying to unpoison reserved page Date: Thu, 18 Aug 2022 21:00:16 +0800 Message-ID: <20220818130016.45313-7-linmiaohe@huawei.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20220818130016.45313-1-linmiaohe@huawei.com> References: <20220818130016.45313-1-linmiaohe@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.175.124.27] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To canpemm500002.china.huawei.com (7.192.104.244) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org For reserved pages, HWPoison flag will be set without increasing the page refcnt. So we shouldn't even try to unpoison these pages and thus decrease the page refcnt unexpectly. Add a PageReserved() check to filter this case out and remove the below unneeded zero page (zero page is reserved) check. Signed-off-by: Miaohe Lin --- mm/memory-failure.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 5f9615a86296..c831c41bb092 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -2355,7 +2355,7 @@ int unpoison_memory(unsigned long pfn) goto unlock_mutex; } - if (PageSlab(page) || PageTable(page)) + if (PageSlab(page) || PageTable(page) || PageReserved(page)) goto unlock_mutex; ret = get_hwpoison_page(p, MF_UNPOISON); @@ -2386,7 +2386,7 @@ int unpoison_memory(unsigned long pfn) freeit = !!TestClearPageHWPoison(p); put_page(page); - if (freeit && !(pfn == my_zero_pfn(0) && page_count(p) == 1)) { + if (freeit) { put_page(page); ret = 0; } -- 2.23.0