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 5259BC433F5 for ; Mon, 18 Apr 2022 12:39:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235110AbiDRMmC (ORCPT ); Mon, 18 Apr 2022 08:42:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50952 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239780AbiDRMd2 (ORCPT ); Mon, 18 Apr 2022 08:33:28 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 43AE41B791; Mon, 18 Apr 2022 05:26:04 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id F3A02B80EC4; Mon, 18 Apr 2022 12:26:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4CCC8C385AC; Mon, 18 Apr 2022 12:26:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1650284761; bh=k6ThlEZYjczdMB9/EZpDeNWEqo0mO1axpTlVDPr7w40=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YomlO909fTkxBsXEGFURv73+xDGVTFoBI/zenJMOuveQPiDVKXKV3tLM7Qa4fnwWL +K7YNFpD4utCMeIDFrFyyAyVqCS4j+hyswu1hNsV1SLekUCP+7qNQebid68S/FZwdP pr0y5Vc4GTQD2aqDgI2bOwR4tp+g3ssyz+Tm3r3w= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mike Kravetz , Naoya Horiguchi , Andrew Morton , Linus Torvalds Subject: [PATCH 5.17 179/219] hugetlb: do not demote poisoned hugetlb pages Date: Mon, 18 Apr 2022 14:12:28 +0200 Message-Id: <20220418121211.887283123@linuxfoundation.org> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20220418121203.462784814@linuxfoundation.org> References: <20220418121203.462784814@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mike Kravetz commit 5a317412ef884763fdf7aa17f9f3636959d11d8f upstream. It is possible for poisoned hugetlb pages to reside on the free lists. The huge page allocation routines which dequeue entries from the free lists make a point of avoiding poisoned pages. There is no such check and avoidance in the demote code path. If a hugetlb page on the is on a free list, poison will only be set in the head page rather then the page with the actual error. If such a page is demoted, then the poison flag may follow the wrong page. A page without error could have poison set, and a page with poison could not have the flag set. Check for poison before attempting to demote a hugetlb page. Also, return -EBUSY to the caller if only poisoned pages are on the free list. Link: https://lkml.kernel.org/r/20220307215707.50916-1-mike.kravetz@oracle.com Fixes: 8531fc6f52f5 ("hugetlb: add hugetlb demote page support") Signed-off-by: Mike Kravetz Reviewed-by: Naoya Horiguchi Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/hugetlb.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -3469,7 +3469,6 @@ static int demote_pool_huge_page(struct { int nr_nodes, node; struct page *page; - int rc = 0; lockdep_assert_held(&hugetlb_lock); @@ -3480,15 +3479,19 @@ static int demote_pool_huge_page(struct } for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { - if (!list_empty(&h->hugepage_freelists[node])) { - page = list_entry(h->hugepage_freelists[node].next, - struct page, lru); - rc = demote_free_huge_page(h, page); - break; + list_for_each_entry(page, &h->hugepage_freelists[node], lru) { + if (PageHWPoison(page)) + continue; + + return demote_free_huge_page(h, page); } } - return rc; + /* + * Only way to get here is if all pages on free lists are poisoned. + * Return -EBUSY so that caller will not retry. + */ + return -EBUSY; } #define HSTATE_ATTR_RO(_name) \