From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp.polymtl.ca (smtp.polymtl.ca [132.207.4.11]) by sourceware.org (Postfix) with ESMTPS id 10A083857816 for ; Thu, 29 Jul 2021 02:27:09 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 10A083857816 Received: from simark.ca (simark.ca [158.69.221.121]) (authenticated bits=0) by smtp.polymtl.ca (8.14.7/8.14.7) with ESMTP id 16T2QwwA019781 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 28 Jul 2021 22:27:03 -0400 DKIM-Filter: OpenDKIM Filter v2.11.0 smtp.polymtl.ca 16T2QwwA019781 Received: from [10.0.0.11] (192-222-157-6.qc.cable.ebox.net [192.222.157.6]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by simark.ca (Postfix) with ESMTPSA id 789D41E4A3; Wed, 28 Jul 2021 22:26:58 -0400 (EDT) Subject: Re: [PING][PATCH,v5][AArch64] MTE corefile support To: Catalin Marinas , Joel Brobecker Cc: Luis Machado via Gdb-patches , david.spickett@linaro.org References: <20210518202047.3492211-1-luis.machado@linaro.org> <20210601174519.4157316-1-luis.machado@linaro.org> <20210711142200.GA637634@adacore.com> <20210714130702.GA9376@arm.com> From: Simon Marchi Message-ID: Date: Wed, 28 Jul 2021 22:26:58 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.12.0 MIME-Version: 1.0 In-Reply-To: <20210714130702.GA9376@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Poly-FromMTA: (simark.ca [158.69.221.121]) at Thu, 29 Jul 2021 02:26:58 +0000 X-Spam-Status: No, score=-4.1 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, NICE_REPLY_A, RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL, SPF_HELO_PASS, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 29 Jul 2021 02:27:10 -0000 On 2021-07-14 9:07 a.m., Catalin Marinas wrote: > On Sun, Jul 11, 2021 at 07:22:00AM -0700, Joel Brobecker wrote: >> Luis is trying to have this new feature ready for the GDB 11.1 >> release. As I understand it, the AArch64-specific part has already >> been approved, so he's waiting for someone to review the rest of >> the changes. Is there a Global Maintainer who would feel comfortable >> doing so and who would have the time? > > I'm a Linux kernel maintainer, so not much for me to review on the gdb > front. But feedback from the gdb maintainers would be appreciated. > > W.r.t. upstreaming the feature in gdb, I'd wait until the Linux > counterpart is merged. We agreed in principle on the ABI but I wouldn't > consider it stable until the feature hits a kernel release. I reviewed a few of the previous iterations, and there were only really some nits remaining, so I am confident that this version is OK, from a GDB point of view. ABI-wise, I tend to agree with Catalin: as long as it's not in a released kernel, the format *could* change. But is it a problem in practice? Let's say this happens: - We merge support for MTE core files in GDB 11 - The format gets changed, merged and released in a kernel - We fix GDB 12 based on the new format Then GDB 11 users end up with a GDB that can't read MTE notes. But had we not merged the support for it, they would also end up with a GDB that can't read MTE notes. In both cases, we'll tell them "upgrade to GDB 12" (once it's released). If we merge support for MTE in core files now and if the format doesn't change, everybody is happy. I guess it depends on how likely it is that the format is going to change. Simon