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 X-Spam-Level: X-Spam-Status: No, score=-13.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5D43CC433E0 for ; Tue, 28 Jul 2020 09:46:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 37EF620775 for ; Tue, 28 Jul 2020 09:46:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728604AbgG1Jq0 (ORCPT ); Tue, 28 Jul 2020 05:46:26 -0400 Received: from mail5.windriver.com ([192.103.53.11]:58298 "EHLO mail5.wrs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728441AbgG1JqZ (ORCPT ); Tue, 28 Jul 2020 05:46:25 -0400 Received: from ALA-HCA.corp.ad.wrs.com (ala-hca.corp.ad.wrs.com [147.11.189.40]) by mail5.wrs.com (8.15.2/8.15.2) with ESMTPS id 06S9iHF0005340 (version=TLSv1 cipher=DHE-RSA-AES256-SHA bits=256 verify=FAIL); Tue, 28 Jul 2020 02:44:28 -0700 Received: from pek-lpg-core1-vm1.wrs.com (128.224.156.106) by ALA-HCA.corp.ad.wrs.com (147.11.189.40) with Microsoft SMTP Server id 14.3.487.0; Tue, 28 Jul 2020 02:44:07 -0700 From: To: , , , , CC: , Subject: [PATCH] mm/slab.c: add node spinlock protect in __cache_free_alien Date: Tue, 28 Jul 2020 17:55:51 +0800 Message-ID: <20200728095551.30634-1-qiang.zhang@windriver.com> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Zhang Qiang We should add node spinlock protect "n->alien" which may be assigned to NULL in cpuup_canceled func. cause address access exception. Fixes: 18bf854117c6 ("slab: use get_node() and kmem_cache_node() functions") Signed-off-by: Zhang Qiang --- mm/slab.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/mm/slab.c b/mm/slab.c index a89633603b2d..290523c90b4e 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -759,8 +759,10 @@ static int __cache_free_alien(struct kmem_cache *cachep, void *objp, n = get_node(cachep, node); STATS_INC_NODEFREES(cachep); + spin_lock(&n->list_lock); if (n->alien && n->alien[page_node]) { alien = n->alien[page_node]; + spin_unlock(&n->list_lock); ac = &alien->ac; spin_lock(&alien->lock); if (unlikely(ac->avail == ac->limit)) { @@ -769,14 +771,15 @@ static int __cache_free_alien(struct kmem_cache *cachep, void *objp, } ac->entry[ac->avail++] = objp; spin_unlock(&alien->lock); - slabs_destroy(cachep, &list); } else { + spin_unlock(&n->list_lock); n = get_node(cachep, page_node); spin_lock(&n->list_lock); free_block(cachep, &objp, 1, page_node, &list); spin_unlock(&n->list_lock); - slabs_destroy(cachep, &list); } + + slabs_destroy(cachep, &list); return 1; } -- 2.26.2