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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 771A0C6778F for ; Fri, 27 Jul 2018 10:03:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 34FB720894 for ; Fri, 27 Jul 2018 10:03:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 34FB720894 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ACULAB.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 S2389365AbeG0LY2 convert rfc822-to-8bit (ORCPT ); Fri, 27 Jul 2018 07:24:28 -0400 Received: from eu-smtp-delivery-211.mimecast.com ([146.101.78.211]:28204 "EHLO eu-smtp-delivery-211.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388562AbeG0LY2 (ORCPT ); Fri, 27 Jul 2018 07:24:28 -0400 Received: from AcuMS.aculab.com (156.67.243.126 [156.67.243.126]) (Using TLS) by eu-smtp-1.mimecast.com with ESMTP id uk-mta-89-ojS13K8VPQCLTutgFW1spg-1; Fri, 27 Jul 2018 11:03:15 +0100 Received: from AcuMS.Aculab.com (fd9f:af1c:a25b::d117) by AcuMS.aculab.com (fd9f:af1c:a25b::d117) with Microsoft SMTP Server (TLS) id 15.0.1347.2; Fri, 27 Jul 2018 11:04:54 +0100 Received: from AcuMS.Aculab.com ([fe80::43c:695e:880f:8750]) by AcuMS.aculab.com ([fe80::43c:695e:880f:8750%12]) with mapi id 15.00.1347.000; Fri, 27 Jul 2018 11:04:54 +0100 From: David Laight To: 'Andrew Morton' , Joe Perches , Andy Whitcroft , LKML Subject: RE: [RFC PATCH] checkpatch: check for function calls with struct or union on stack Thread-Topic: [RFC PATCH] checkpatch: check for function calls with struct or union on stack Thread-Index: AQHUJRcFUx4+BuOgSky66zuZVVqB+6Si1nhw Date: Fri, 27 Jul 2018 10:04:54 +0000 Message-ID: <9d7441a14897426f8ed5befe8da0cad3@AcuMS.aculab.com> References: <1236369d28b2f1f5389ff652c4eb89e699e6481e.camel@perches.com> <20180726122533.104f6eea950853ef50ebc680@linux-foundation.org> <20180726122807.fad0566951e36d930edb6874@linux-foundation.org> In-Reply-To: <20180726122807.fad0566951e36d930edb6874@linux-foundation.org> Accept-Language: en-GB, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.33] MIME-Version: 1.0 X-MC-Unique: ojS13K8VPQCLTutgFW1spg-1 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Andrew Morton > Sent: 26 July 2018 20:28 > On Thu, 26 Jul 2018 12:25:33 -0700 Andrew Morton wrote: > > > I'll give it a spin, see how noisy it is. > > Actually, I would prefer if the message, changelog and title > used the term "passed by value". It's a more familiar term > and it is possible for a passed-by-value aggregate to in fact > be passed in registers. You need to detect (and ignore) 'small' structures. Quite a few ABI pass small structures by value in register(s) or directly on the stack. So it can make sense to encapsulate an integer value in a structure in order to get strong typing. It would, for instance, make sense to do that for user addresses. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)