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=-5.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, 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 03B32C10F00 for ; Fri, 5 Apr 2019 08:24:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C309E217D7 for ; Fri, 5 Apr 2019 08:24:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alien8.de header.i=@alien8.de header.b="heErWUCv" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730385AbfDEIY5 (ORCPT ); Fri, 5 Apr 2019 04:24:57 -0400 Received: from mail.skyhub.de ([5.9.137.197]:37996 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725955AbfDEIY4 (ORCPT ); Fri, 5 Apr 2019 04:24:56 -0400 Received: from zn.tnic (p200300EC2F148A00329C23FFFEA6A903.dip0.t-ipconnect.de [IPv6:2003:ec:2f14:8a00:329c:23ff:fea6:a903]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 4DF7E1EC0A6C; Fri, 5 Apr 2019 10:24:54 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1554452694; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=vxMltuRWQ2c/2Wp7yTv8Di56B8om9ePsax7Ud9l7tzA=; b=heErWUCv2djwFtSBDYib03xVxX00bt1gIBFbUKIGOXSbeFvYFnswJagqrNonmu80kgkzWK YPJyup7W6NuG34jO8tththTWtSKoB0Z2ny0AFAnWEzSSiQy8tFlfUdrPq74fg7aFXOBcvZ 5CyuG/8U/1/C1zKMQdCJl6YcqlIZzWw= Date: Fri, 5 Apr 2019 10:24:47 +0200 From: Borislav Petkov To: Rasmus Villemoes Cc: LKML , Kees Cook , Matthew Wilcox Subject: Re: [PATCH] overflow.h: Rename __ab_c_size() to __calc_size() Message-ID: <20190405082447.GD23348@zn.tnic> References: <20190405045711.30339-1-bp@alien8.de> <20190405075251.GC23348@zn.tnic> <3fefb03d-3ea0-5a08-f00c-09a47b17f2a8@rasmusvillemoes.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <3fefb03d-3ea0-5a08-f00c-09a47b17f2a8@rasmusvillemoes.dk> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 05, 2019 at 10:09:31AM +0200, Rasmus Villemoes wrote: > On 05/04/2019 09.52, Borislav Petkov wrote: > > On Fri, Apr 05, 2019 at 08:26:45AM +0200, Rasmus Villemoes wrote: > > >> It computes a*b+c with overflow checking at each step. calc_size > >> is way too generic and doesn't say anything at all about how the > >> calc(ulation) is done. > > > > Ok, whatever. > > > > Then it would need at least a comment above it to state what it does. I > > don't want to go and parse the macros each time. > > It's an internal helper, and struct_size is fully kernel-doc'ed. But > yeah, a comment wouldn't hurt, and let's rename the parameters so they > match the abc naming. > > diff --git a/include/linux/overflow.h b/include/linux/overflow.h > index 40b48e2133cb..6534a727cadb 100644 > --- a/include/linux/overflow.h > +++ b/include/linux/overflow.h > @@ -278,11 +278,15 @@ static inline __must_check size_t > array3_size(size_t a, size_t b, size_t c) > return bytes; > } > > -static inline __must_check size_t __ab_c_size(size_t n, size_t size, > size_t c) > +/* > + * Compute a*b+c, returning SIZE_MAX on overflow. Internal helper for > + * struct_size() below. > + */ > +static inline __must_check size_t __ab_c_size(size_t a, size_t b, size_t c) > { > size_t bytes; > > - if (check_mul_overflow(n, size, &bytes)) > + if (check_mul_overflow(a, b, &bytes)) > return SIZE_MAX; > if (check_add_overflow(bytes, c, &bytes)) > return SIZE_MAX; > > Reported-by: Borislav Petkov Acked-by: Borislav Petkov Thx. -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.