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 88F77C67790 for ; Fri, 27 Jul 2018 10:36:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3ED9A208A1 for ; Fri, 27 Jul 2018 10:36:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3ED9A208A1 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=perches.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 S1730971AbeG0L6C (ORCPT ); Fri, 27 Jul 2018 07:58:02 -0400 Received: from smtprelay0066.hostedemail.com ([216.40.44.66]:53274 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730026AbeG0L6C (ORCPT ); Fri, 27 Jul 2018 07:58:02 -0400 Received: from filter.hostedemail.com (clb03-v110.bra.tucows.net [216.40.38.60]) by smtprelay02.hostedemail.com (Postfix) with ESMTP id 4C83014D37; Fri, 27 Jul 2018 10:36:42 +0000 (UTC) X-Session-Marker: 6A6F6540706572636865732E636F6D X-HE-Tag: color66_749997c5a6d5c X-Filterd-Recvd-Size: 2639 Received: from XPS-9350.home (unknown [47.151.153.53]) (Authenticated sender: joe@perches.com) by omf06.hostedemail.com (Postfix) with ESMTPA; Fri, 27 Jul 2018 10:36:41 +0000 (UTC) Message-ID: <1a75fda0861a0b2bce208fbf9b53785bf0e76fa2.camel@perches.com> Subject: Re: [RFC PATCH] checkpatch: check for function calls with struct or union on stack From: Joe Perches To: David Laight , 'Andrew Morton' , Andy Whitcroft , LKML Cc: Julia Lawall Date: Fri, 27 Jul 2018 03:36:39 -0700 In-Reply-To: <9f0377fa74bd4964912ba5a4fc76526d@AcuMS.aculab.com> References: <1236369d28b2f1f5389ff652c4eb89e699e6481e.camel@perches.com> <20180726122533.104f6eea950853ef50ebc680@linux-foundation.org> <20180726122807.fad0566951e36d930edb6874@linux-foundation.org> <9d7441a14897426f8ed5befe8da0cad3@AcuMS.aculab.com> <0a6d2ecfacf3786228de664c8e01f6de10314c1b.camel@perches.com> <9f0377fa74bd4964912ba5a4fc76526d@AcuMS.aculab.com> Content-Type: text/plain; charset="ISO-8859-1" X-Mailer: Evolution 3.28.1-2 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2018-07-27 at 10:21 +0000, David Laight wrote: > From: Joe Perches Sent: 27 July 2018 11:09 > > On Fri, 2018-07-27 at 10:04 +0000, David Laight wrote: > > > 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. > > > > checkpatch is stupid and basically can't do that > > as it has no context other than the current line. > > > > It would need a list of specific struct types to > > ignore. Care to create and send that list to me? > > Does it even have the type? Yes, kinda. But only on the line being matched. i.e.: [struct or union] [type] [name] > If it has the prototype it could ignore aggregates that > are marked 'const'. checkpatch has no visibility of any prototype. It might make sense for this sort of check to be added to coccinelle or maybe as a compiler warning when the struct is larger than some size. Original thread for Julia: https://lore.kernel.org/patchwork/patch/967890/