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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_GIT autolearn=ham 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 56CA0C4743D for ; Fri, 11 Jun 2021 04:23:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3BAB4613B4 for ; Fri, 11 Jun 2021 04:23:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230392AbhFKEY5 (ORCPT ); Fri, 11 Jun 2021 00:24:57 -0400 Received: from out30-130.freemail.mail.aliyun.com ([115.124.30.130]:56426 "EHLO out30-130.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230353AbhFKEY4 (ORCPT ); Fri, 11 Jun 2021 00:24:56 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R851e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04400;MF=yaohuiwang@linux.alibaba.com;NM=1;PH=DS;RN=10;SR=0;TI=SMTPD_---0Uc0K0DG_1623385376; Received: from localhost(mailfrom:yaohuiwang@linux.alibaba.com fp:SMTPD_---0Uc0K0DG_1623385376) by smtp.aliyun-inc.com(127.0.0.1); Fri, 11 Jun 2021 12:22:57 +0800 From: Yaohui Wang To: dave.hansen@linux.intel.com Cc: luto@kernel.org, peterz@infradead.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, linux-kernel@vger.kernel.org, Ben Luo , Yahui Wang Subject: [PATCH v2 2/2] mm: fix boundary judgment issues in kernel/resource.c Date: Fri, 11 Jun 2021 12:21:47 +0800 Message-Id: <20210611042147.80744-3-yaohuiwang@linux.alibaba.com> X-Mailer: git-send-email 2.24.3 (Apple Git-128) In-Reply-To: <20210611042147.80744-1-yaohuiwang@linux.alibaba.com> References: <20210611042147.80744-1-yaohuiwang@linux.alibaba.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The original boundary judgment may ignore @end if @end equals @start. For example, if we call ioremap(phys, 1), then @end == @start, and the memory check will not be applied on the page where @end lives, which is unexpected. In kernel/resource.c:find_next_iomem_res, the mem region is a closed interval (i.e. [@start..@end]). So @start == @end should be allowed. In kernel/resource.c:__walk_iomem_res_desc, the mem region is a closed interval (i.e. [@start..@end]). So @start == @end should be allowed. Signed-off-by: Ben Luo Signed-off-by: Yahui Wang --- kernel/resource.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/resource.c b/kernel/resource.c index 16e0c7e8e..b29c8c720 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -353,7 +353,7 @@ static int find_next_iomem_res(resource_size_t start, resource_size_t end, if (!res) return -EINVAL; - if (start >= end) + if (start > end) return -EINVAL; read_lock(&resource_lock); @@ -408,7 +408,7 @@ static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end, struct resource res; int ret = -EINVAL; - while (start < end && + while (start <= end && !find_next_iomem_res(start, end, flags, desc, first_lvl, &res)) { ret = (*func)(&res, arg); if (ret) -- 2.25.1