Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756906AbbDPJau (ORCPT ); Thu, 16 Apr 2015 05:30:50 -0400 Received: from cantor2.suse.de ([195.135.220.15]:46605 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752948AbbDPJal (ORCPT ); Thu, 16 Apr 2015 05:30:41 -0400 Subject: Re: [PATCH] firmware: dmi_scan: Fix ordering of product_uuid From: Jean Delvare To: zhenzhong.duan@oracle.com Cc: LKML , Ben Hutchings , Artem Savkov , Ivan Khoronzhuk , Matt Fleming In-Reply-To: <552F76E6.8030104@oracle.com> References: <20150415110222.194867c1@endymion.delvare> <552F5535.9010302@oracle.com> <1429168164.4386.12.camel@chaos.site> <552F76E6.8030104@oracle.com> Content-Type: text/plain; charset="UTF-8" Organization: Suse Linux Date: Thu, 16 Apr 2015 11:30:38 +0200 Message-ID: <1429176638.4386.19.camel@chaos.site> Mime-Version: 1.0 X-Mailer: Evolution 2.28.2 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1511 Lines: 41 Le Thursday 16 April 2015 à 16:46 +0800, Zhenzhong Duan a écrit : > On 2015/4/16 15:09, Jean Delvare wrote: > > Le Thursday 16 April 2015 à 14:22 +0800, Zhenzhong Duan a écrit : > >> The basic idea is right, but you ignore the case dmi_walk_early may > >> fail, though looks impossible when bootup. > >> > >> Better to add below for robust. > >> > >> @@ -521,6 +521,6 @@ static int __init dmi_present(const u8 * > >> > >> return 0; > >> } > >> } > >> + dmi_ver = 0; > >> return 1; > >> } > >> > > What is the value of this? dmi_ver will never be accessed after this > > point anyway, as far as I can see. > Same as above, future commit may not realize you bring this faulty when > they want to use dmi_ver. Why do you think this is "faulty"? The value in dmi_ver is correct whether dmi_walk_early() succeeded or not. There's no rationale for resetting dmi_ver on error and not dmi_num, dmi_len and dmi_base. Note that dmi_smbios3_present() doesn't reset any of these either. These values are all correct. If other modules need to check whether DMI was successfully initialized, they must check dmi_available rather than any of the variables above (which are all static anyway.) -- Jean Delvare SUSE L3 Support -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/