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=-5.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_2 autolearn=no 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 5CB04C433DF for ; Tue, 28 Jul 2020 09:08:21 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3250920786 for ; Tue, 28 Jul 2020 09:08:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3250920786 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kaod.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:46214 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1k0Lau-0005Wi-Gj for qemu-devel@archiver.kernel.org; Tue, 28 Jul 2020 05:08:20 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:58792) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1k0LaH-00056F-Ut for qemu-devel@nongnu.org; Tue, 28 Jul 2020 05:07:41 -0400 Received: from 15.mo4.mail-out.ovh.net ([91.121.62.11]:47589) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1k0LaF-0006OY-PI for qemu-devel@nongnu.org; Tue, 28 Jul 2020 05:07:41 -0400 Received: from player699.ha.ovh.net (unknown [10.110.208.124]) by mo4.mail-out.ovh.net (Postfix) with ESMTP id B8BCC246887 for ; Tue, 28 Jul 2020 11:07:36 +0200 (CEST) Received: from kaod.org (lns-bzn-46-82-253-208-248.adsl.proxad.net [82.253.208.248]) (Authenticated sender: groug@kaod.org) by player699.ha.ovh.net (Postfix) with ESMTPSA id 10AF814BA7817; Tue, 28 Jul 2020 09:07:28 +0000 (UTC) Authentication-Results: garm.ovh; auth=pass (GARM-103G00511f049d4-4040-4a9d-9273-ab7c05060d9e,96196EA346850768E7E70500A314E772A5EF2CEB) smtp.auth=groug@kaod.org Date: Tue, 28 Jul 2020 11:07:26 +0200 From: Greg Kurz To: Markus Armbruster Subject: Re: [PATCH v4 for-5.2 1/2] spapr: Use error_append_hint() in spapr_caps.c Message-ID: <20200728110726.5882b046@bahia.lan> In-Reply-To: <87h7tsf6cv.fsf@dusky.pond.sub.org> References: <159491945918.188975.4358645698778061430.stgit@bahia.lan> <159491947184.188975.5055299566400098290.stgit@bahia.lan> <87mu3uciq4.fsf@dusky.pond.sub.org> <20200727150425.2c7562ed@bahia.lan> <87h7tsf6cv.fsf@dusky.pond.sub.org> X-Mailer: Claws Mail 3.17.5 (GTK+ 2.24.32; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Ovh-Tracer-Id: 16922275603143563662 X-VR-SPAMSTATE: OK X-VR-SPAMSCORE: -100 X-VR-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgeduiedriedvgddtlecutefuodetggdotefrodftvfcurfhrohhfihhlvgemucfqggfjpdevjffgvefmvefgnecuuegrihhlohhuthemucehtddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjughrpeffhffvuffkjghfofggtgfgsehtjeertdertddvnecuhfhrohhmpefirhgvghcumfhurhiiuceoghhrohhugheskhgrohgurdhorhhgqeenucggtffrrghtthgvrhhnpeehkefhtdehgeehheejledufeekhfdvleefvdeihefhkefhudffhfeuuedvffdthfenucfkpheptddrtddrtddrtddpkedvrddvheefrddvtdekrddvgeeknecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmohguvgepshhmthhpqdhouhhtpdhhvghlohepphhlrgihvghrieelledrhhgrrdhovhhhrdhnvghtpdhinhgvtheptddrtddrtddrtddpmhgrihhlfhhrohhmpehgrhhouhhgsehkrghougdrohhrghdprhgtphhtthhopehqvghmuhdquggvvhgvlhesnhhonhhgnhhurdhorhhg Received-SPF: pass client-ip=91.121.62.11; envelope-from=groug@kaod.org; helo=15.mo4.mail-out.ovh.net X-detected-operating-system: by eggs.gnu.org: First seen = 2020/07/28 05:07:37 X-ACL-Warn: Detected OS = Linux 3.11 and newer X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Vladimir Sementsov-Ogievskiy , qemu-ppc@nongnu.org, qemu-devel@nongnu.org, David Gibson , Laurent Vivier Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Tue, 28 Jul 2020 09:26:08 +0200 Markus Armbruster wrote: > Greg Kurz writes: > > > On Mon, 20 Jul 2020 17:24:35 +0200 > > Markus Armbruster wrote: > > > >> Greg Kurz writes: > >> > >> > We have a dedicated error API for hints. Use it instead of embedding > >> > the hint in the error message, as recommanded in the "qapi/error.h" > >> > header file. > >> > > >> > Since spapr_caps_apply() passes &error_fatal, all functions must > >> > also call the ERRP_GUARD() macro for error_append_hint() to be > >> > functional. > >> > >> This isn't a request for change in this patch, just an attempt to squash > >> possible misunderstandings. > >> > >> It's true that error_append_hint() without ERRP_GUARD() works as long as > >> the caller doesn't pass certain errp arguments. But the callee should > >> work for all possible @errp arguments, not just the ones that get passed > >> today. That's why error.h wants you to guard *all* uses of > >> error_append_hint(errp): > >> > >> * = Why, when and how to use ERRP_GUARD() = > >> * > >> * Without ERRP_GUARD(), use of the @errp parameter is restricted: > >> * - It must not be dereferenced, because it may be null. > >> * - It should not be passed to error_prepend() or > >> * error_append_hint(), because that doesn't work with &error_fatal. > >> * ERRP_GUARD() lifts these restrictions. > >> > > > > Yeah, I just wanted to emphasize that we were precisely in the case > > where we _really_ need to lift the restriction, but I'm perfectly fine > > with dropping this sentence if you consider it useless. > > I lean towards dropping it. > David, Do you want me to send an updated version of this patch or can you fix this in your tree ? > > BTW, should we have a way for CI to ensure that a patch that adds > > error_prepend(errp, ...) or error_append_hint(errp, ...) also adds > > ERRP_GUARD() ? Not sure that people read error.h that often... > > I don't know. Wait and see whether it's worth automating? We didn't > automate checking other Error API rules, like "no newlines in error > messages". That one can't crash, though. > > The check would have to look beyond the patch, which checkpatch.pl > doesn't do. > Maybe checkpatch.pl could be fed with an extended version of the patch that has enough context, eg. git show -U$(wc -l ${file}) ${file} ? > >> No need to make an argument involving the possible arguments (pardon the > >> pun). > >> > > > > :) > > > >> [...] > >> >