From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752540AbcAFNBl (ORCPT ); Wed, 6 Jan 2016 08:01:41 -0500 Received: from mx2.suse.de ([195.135.220.15]:43515 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751930AbcAFNBh (ORCPT ); Wed, 6 Jan 2016 08:01:37 -0500 Date: Wed, 6 Jan 2016 14:01:33 +0100 From: Jean Delvare To: Matt Fleming Cc: Andrea Arcangeli , Ivan Khoronzhuk , Paolo Bonzini , Federico Simoncelli , linux-kernel@vger.kernel.org, Andrew Morton Subject: Re: [PATCH 1/1] dmi_scan: uuid: fix endianess for smbios >= 0x206 Message-ID: <20160106140133.7376ec04@endymion.delvare> In-Reply-To: <20151222151751.GA2279@codeblueprint.co.uk> References: <1450792390-27853-1-git-send-email-aarcange@redhat.com> <1450792390-27853-2-git-send-email-aarcange@redhat.com> <20151222151751.GA2279@codeblueprint.co.uk> Organization: SUSE Linux X-Mailer: Claws Mail 3.10.1 (GTK+ 2.24.23; x86_64-suse-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Matt, Andrea, On Tue, 22 Dec 2015 15:17:51 +0000, Matt Fleming wrote: > (Cc'ing Jean since he's the maintainer) > > On Tue, 22 Dec, at 02:53:10PM, Andrea Arcangeli wrote: > > The dmi_ver wasn't updated correctly before the dmi_decode method run > > to save the uuid. > > > > That resulted in "dmidecode -s system-uuid" and > > /sys/class/dmi/id/product_uuid disagreeing. The latter was buggy and > > this fixes it. > > > > Reported-by: Federico Simoncelli > > Signed-off-by: Andrea Arcangeli > > --- > > drivers/firmware/dmi_scan.c | 6 +++--- > > 1 file changed, 3 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c > > index ac1ce4a..0e08e66 100644 > > --- a/drivers/firmware/dmi_scan.c > > +++ b/drivers/firmware/dmi_scan.c > > @@ -521,6 +521,7 @@ static int __init dmi_present(const u8 *buf) > > dmi_ver = smbios_ver; > > else > > dmi_ver = (buf[14] & 0xF0) << 4 | (buf[14] & 0x0F); > > + dmi_ver <<= 8; > > dmi_num = get_unaligned_le16(buf + 12); > > dmi_len = get_unaligned_le16(buf + 6); > > dmi_base = get_unaligned_le32(buf + 8); > > @@ -528,15 +529,14 @@ static int __init dmi_present(const u8 *buf) > > if (dmi_walk_early(dmi_decode) == 0) { > > if (smbios_ver) { > > pr_info("SMBIOS %d.%d present.\n", > > - dmi_ver >> 8, dmi_ver & 0xFF); > > + dmi_ver >> 16, (dmi_ver >> 8) & 0xFF); > > } else { > > smbios_entry_point_size = 15; > > memcpy(smbios_entry_point, buf, > > smbios_entry_point_size); > > pr_info("Legacy DMI %d.%d present.\n", > > - dmi_ver >> 8, dmi_ver & 0xFF); > > + dmi_ver >> 16, (dmi_ver >> 8) & 0xFF); > > } > > - dmi_ver <<= 8; > > dmi_format_ids(dmi_ids_string, sizeof(dmi_ids_string)); > > printk(KERN_DEBUG "DMI: %s\n", dmi_ids_string); > > return 0; Baaah. This was supposed to be fixed by my commit 5c1ac56b51b9d222ab202dec1ac2f4215346129d ("firmware: dmi_scan: Fix ordering of product_uuid") but clearly I missed half of the required changes. Should have tested... The irony is that I clearly remember when reviewing Ivan's patches that I did not like this part of the code. Quoting myself: "I understand this was the easiest way to implement the change, but I'm not really comfortable with dmi_ver having different formats for different parts of the code. This is rather error prone for future changes, even if the code is currently correct." Even though I was wrong when claiming that the code was "currently correct", I should have listened to my gut feeling back then and asked for a different implementation. Anyway... Thanks Andrea, applied with the missing "Fixes:" markers added. I'll send to Linus soon. -- Jean Delvare SUSE L3 Support