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 X-Spam-Level: X-Spam-Status: No, score=-13.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A8FAFC43441 for ; Tue, 27 Nov 2018 15:02:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 72FFF21104 for ; Tue, 27 Nov 2018 15:02:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 72FFF21104 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728903AbeK1CAS (ORCPT ); Tue, 27 Nov 2018 21:00:18 -0500 Received: from foss.arm.com ([217.140.101.70]:39532 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726834AbeK1CAR (ORCPT ); Tue, 27 Nov 2018 21:00:17 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 4D504364A; Tue, 27 Nov 2018 07:02:06 -0800 (PST) Received: from e107981-ln.cambridge.arm.com (e107981-ln.cambridge.arm.com [10.1.197.40]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 387C03F5A0; Tue, 27 Nov 2018 07:02:04 -0800 (PST) Date: Tue, 27 Nov 2018 15:01:50 +0000 From: Lorenzo Pieralisi To: Jeremy Linton Cc: linux-arm-kernel@lists.infradead.org, catalin.marinas@arm.com, will.deacon@arm.com, ard.biesheuvel@linaro.org, james.morse@arm.com, rafael.j.wysocki@intel.com, takahiro.akashi@linaro.org, sudeep.holla@arm.com, ahs3@redhat.com, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] arm64: acpi: Prepare for longer MADTs Message-ID: <20181127150150.GA25270@e107981-ln.cambridge.arm.com> References: <20181012192937.3819951-1-jeremy.linton@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181012192937.3819951-1-jeremy.linton@arm.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Oct 12, 2018 at 02:29:37PM -0500, Jeremy Linton wrote: > The BAD_MADT_GICC_ENTRY check is a little too strict because > it rejects MADT entries that don't match the currently known > lengths. We should remove this restriction to avoid problems > if the table length changes. Future code which might depend on > additional fields should be written to validate those fields > before using them, rather than trying to globally check > known MADT version lengths. > > Signed-off-by: Jeremy Linton > --- > arch/arm64/include/asm/acpi.h | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) Hi Jeremy, as mentioned, I added a comment to the macro so that in the future we will be able to remember the logic behind it. I pushed the commit out: git://git.kernel.org/pub/scm/linux/kernel/git/lpieralisi/linux.git acpi/madt Please have a look, if I hear no objections I shall be sending it to Will and Catalin to queue it for v4.21. Thanks, Lorenzo > diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h > index 709208dfdc8b..4d0946bd485a 100644 > --- a/arch/arm64/include/asm/acpi.h > +++ b/arch/arm64/include/asm/acpi.h > @@ -22,12 +22,12 @@ > #include > > /* Macros for consistency checks of the GICC subtable of MADT */ > -#define ACPI_MADT_GICC_LENGTH \ > - (acpi_gbl_FADT.header.revision < 6 ? 76 : 80) > +#define ACPI_MADT_GICC_MIN_LENGTH ACPI_OFFSET( \ > + struct acpi_madt_generic_interrupt, efficiency_class) > > #define BAD_MADT_GICC_ENTRY(entry, end) \ > - (!(entry) || (entry)->header.length != ACPI_MADT_GICC_LENGTH || \ > - (unsigned long)(entry) + ACPI_MADT_GICC_LENGTH > (end)) > + (!(entry) || (entry)->header.length < ACPI_MADT_GICC_MIN_LENGTH || \ > + (unsigned long)(entry) + (entry)->header.length > (end)) > > /* Basic configuration for ACPI */ > #ifdef CONFIG_ACPI > -- > 2.14.3 >