Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755660AbbBDOEq (ORCPT ); Wed, 4 Feb 2015 09:04:46 -0500 Received: from mail-ig0-f177.google.com ([209.85.213.177]:65138 "EHLO mail-ig0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754262AbbBDOEp (ORCPT ); Wed, 4 Feb 2015 09:04:45 -0500 MIME-Version: 1.0 In-Reply-To: <1423058265-23032-1-git-send-email-ivan.khoronzhuk@linaro.org> References: <1423058265-23032-1-git-send-email-ivan.khoronzhuk@linaro.org> Date: Wed, 4 Feb 2015 14:04:44 +0000 Message-ID: Subject: Re: [Patch] firmware: dmi_scan: fix dmi scan to handle "End of Table" structure From: Ard Biesheuvel To: Ivan Khoronzhuk Cc: "linux-kernel@vger.kernel.org" , Matt Fleming , Leif Lindholm Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2143 Lines: 50 On 4 February 2015 at 13:57, Ivan Khoronzhuk wrote: > The dmi-sysfs should create "End of Table" entry, that is type 127. > But after adding initial SMBIOS v3 support the 127-0 entry is not > handled any more, as result it's not created in sysfs. > This is important because the size of whole DMI table must correspond > to sum of all DMI entry sizes. > > Of-course, it can be handled in newly introduced libdmifs by adding > end entry virtually, but it's brake backward compatibility and don't > correspond to SMBIOS DMI table size read from SMBIOS entry point > structure. > > Signed-off-by: Ivan Khoronzhuk > --- > drivers/firmware/dmi_scan.c | 6 ------ > 1 file changed, 6 deletions(-) > > diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c > index c5f7b4e..c63e5e5 100644 > --- a/drivers/firmware/dmi_scan.c > +++ b/drivers/firmware/dmi_scan.c > @@ -93,12 +93,6 @@ static void dmi_table(u8 *buf, int len, int num, > const struct dmi_header *dm = (const struct dmi_header *)data; > > /* > - * 7.45 End-of-Table (Type 127) [SMBIOS reference spec v3.0.0] > - */ > - if (dm->type == DMI_ENTRY_END_OF_TABLE) > - break; > - > - /* > * We want to know the total length (formatted area and > * strings) before decoding to make sure we won't run off the > * table in dmi_decode or dmi_string This is not the right way to fix this: the end-of-table check needs to be done, because the v3 entry point does not contain the actual length of the data, but only an upper bound, and there may be trailing garbage. So apparently, I put this check and break in the wrong place, and we should place it after the decode() call instead, but not remove it. -- Ard. -- 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/