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 27BD8C6FA82 for ; Tue, 13 Sep 2022 09:06:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231233AbiIMJGZ (ORCPT ); Tue, 13 Sep 2022 05:06:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54204 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230521AbiIMJGT (ORCPT ); Tue, 13 Sep 2022 05:06:19 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 0C9451093 for ; Tue, 13 Sep 2022 02:06:19 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 1E1D01063; Tue, 13 Sep 2022 02:06:25 -0700 (PDT) Received: from [10.162.42.9] (unknown [10.162.42.9]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 57AFB3F73B; Tue, 13 Sep 2022 02:06:16 -0700 (PDT) Message-ID: <976e07e6-cfef-da8b-1a08-bab4601fa433@arm.com> Date: Tue, 13 Sep 2022 14:36:13 +0530 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Subject: Re: [PATCH 13/16] mm/page_alloc: init local variable buddy_pfn Content-Language: en-US To: Miaohe Lin , akpm@linux-foundation.org Cc: david@redhat.com, osalvador@suse.de, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20220909092451.24883-1-linmiaohe@huawei.com> <20220909092451.24883-14-linmiaohe@huawei.com> From: Anshuman Khandual In-Reply-To: <20220909092451.24883-14-linmiaohe@huawei.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 9/9/22 14:54, Miaohe Lin wrote: > The local variable buddy_pfn could be passed to buddy_merge_likely() > without initialization if the passed in order is MAX_ORDER - 1. This > looks buggy but buddy_pfn won't be used in this case as there's a > order >= MAX_ORDER - 2 check. Init buddy_pfn to 0 anyway to avoid > possible future misuse. > > Signed-off-by: Miaohe Lin Reviewed-by: Anshuman Khandual > --- > mm/page_alloc.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index e1c7f98cff96..63ad25e86010 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -1113,7 +1113,7 @@ static inline void __free_one_page(struct page *page, > int migratetype, fpi_t fpi_flags) > { > struct capture_control *capc = task_capc(zone); > - unsigned long buddy_pfn; > + unsigned long buddy_pfn = 0; > unsigned long combined_pfn; > struct page *buddy; > bool to_tail;