From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932196AbbDQINf (ORCPT ); Fri, 17 Apr 2015 04:13:35 -0400 Received: from cantor2.suse.de ([195.135.220.15]:34175 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932147AbbDQIN3 (ORCPT ); Fri, 17 Apr 2015 04:13:29 -0400 Date: Fri, 17 Apr 2015 10:13:25 +0200 From: Jean Delvare To: LKML Cc: Zhenzhong Duan , Ben Hutchings , Artem Savkov , Ivan Khoronzhuk , Matt Fleming Subject: [PATCH v2] firmware: dmi_scan: Fix ordering of product_uuid Message-ID: <20150417101325.296fc081@endymion.delvare> 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 In function dmi_present(), dmi_walk_early() calls dmi_table(), which calls dmi_decode(), which ultimately calls dmi_save_uuid(). This last function makes a decision based on the value of global variable dmi_ver. The problem is that this variable is set right _after_ dmi_walk_early() returns. So dmi_save_uuid() always sees dmi_ver == 0 regardless of the actual version implemented. This causes /sys/class/dmi/id/product_uuid to always use the old ordering even on systems implementing DMI/SMBIOS 2.6 or later, which should use the new ordering. This is broken since kernel v3.8 for legacy DMI implementations and since kernel v3.10 for SMBIOS 2 implementations. SMBIOS 3 implementations with the 64-bit entry point are not affected. The first breakage does not matter much as in practice legacy DMI implementations are always for versions older than 2.6, which is when the UUID ordering changed. The second breakage is more problematic as it affects the vast majority of x86 systems manufactured since 2009. Signed-off-by: Jean Delvare Fixes: 9f9c9cbb6057 ("drivers/firmware/dmi_scan.c: fetch dmi version from SMBIOS if it exists") Fixes: 79bae42d51a5 ("dmi_scan: refactor dmi_scan_machine(), {smbios,dmi}_present()") Acked-by: Zhenzhong Duan Cc: Ben Hutchings Cc: Artem Savkov Cc: Ivan Khoronzhuk Cc: Matt Fleming Cc: stable@vger.kernel.org [v3.10+] --- Changes since v1: * Rebased on torvalds/linux/master. drivers/firmware/dmi_scan.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) --- linux-4.0.orig/drivers/firmware/dmi_scan.c 2015-04-13 00:12:50.000000000 +0200 +++ linux-4.0/drivers/firmware/dmi_scan.c 2015-04-15 10:24:37.556994240 +0200 @@ -499,19 +499,20 @@ static int __init dmi_present(const u8 * buf += 16; if (memcmp(buf, "_DMI_", 5) == 0 && dmi_checksum(buf, 15)) { + if (smbios_ver) + dmi_ver = smbios_ver; + else + dmi_ver = (buf[14] & 0xF0) << 4 | (buf[14] & 0x0F); dmi_num = get_unaligned_le16(buf + 12); dmi_len = get_unaligned_le16(buf + 6); dmi_base = get_unaligned_le32(buf + 8); if (dmi_walk_early(dmi_decode) == 0) { if (smbios_ver) { - dmi_ver = smbios_ver; pr_info("SMBIOS %d.%d%s present.\n", dmi_ver >> 8, dmi_ver & 0xFF, (dmi_ver < 0x0300) ? "" : ".x"); } else { - dmi_ver = (buf[14] & 0xF0) << 4 | - (buf[14] & 0x0F); pr_info("Legacy DMI %d.%d present.\n", dmi_ver >> 8, dmi_ver & 0xFF); } -- Jean Delvare SUSE L3 Support